Revue de presse de la revue Hepatology

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Les derniers abstracts de la revue Hepatology :

Date de mise en ligne : Lundi 06 f�vrier 2012
Ivan Rusyn
Inter‐strain differences in liver injury and one‐carbon metabolism in alcohol‐fed mice
Alcoholic liver injury is a major public health issue worldwide. Even though the major mechanisms of this disease have been established over the past decades, little is known about genetic susceptibility factors that may predispose individuals who abuse alcoholic beverages to liver damage and subsequent pathological conditions. We hypothesized that a panel of genetically diverse mouse strains may be used to examine the role of ER stress and one‐carbon metabolism in the mechanism of inter‐individual variability in alcoholic liver injury. We administered alcohol (up to 27 mg/kg/d) in high fat diet using intragastric intubation model for 28 days to male mice from 14 inbred strains (129S1/SvImJ, AKR/J, BALB/cJ, BALB/cByJ, BTBR T+tf/J, C3H/HeJ, C57BL/10J, DBA/2J, FVB/NJ, KK/HIJ, MOLF/EiJ, NZW/LacJ, PWD/PhJ, and WSB/EiJ). Profound inter‐strain differences (more than 3‐fold) in alcohol‐induced steatohepatitis were observed among the strains in spite of consistently high levels of urine alcohol that was monitored throughout the study. We found that endoplasmic reticulum stress genes were induced only in strains with the highest liver injury. Liver glutathione and methyl donor levels were affected in all strains, albeit to a different degree. Most pronounced effects that were closely associated with the degree of liver injury were hyperhomocysteinemia and strain‐dependent differences in expression patterns of one‐carbon metabolism‐related genes.Conclusion:Our data demonstrate that strain differences in alcohol‐induced liver injury and steatosis are striking and independent of alcohol exposure and the most severely affected strains exhibit major differences in the expression of ER stress markers and genes of one‐carbon metabolism. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 06 f�vrier 2012
Daiming Fan
Drug‐related adverse events may predict efficacy in sorafenib therapy for hepatocellular carcinoma
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Date de mise en ligne : Lundi 06 f�vrier 2012
Antonio Craxì
Assessment by fibroscan of fibrosis in NAFLD: XL vs. M probe?
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Date de mise en ligne : Lundi 06 f�vrier 2012
Hans Christian Spangenberg
Diarrhea predicts a positive response to sorafenib in patients with advanced hepatocellular carcinoma
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Date de mise en ligne : Lundi 06 f�vrier 2012
Harry L.A. Janssen
Presence of precore and core promoter mutants limits the probability of response to peginterferon in HBeAg‐positive chronic hepatitis B
Peginterferon (PEG‐IFN) treatment of HBeAg‐positive chronic hepatitis B (CHB) results in HBeAg loss in 30% of patients, but clearance of HBV DNA and HBsAg from serum is less often achieved. We investigated whether the presence of precore (PC) and basal core promoter (BCP) mutants before PEG‐IFN treatment affects serological and virological response. A total of 214 HBeAg‐positive CHB patients treated with PEG‐IFN±lamivudine for 52 weeks in a global randomized trial were classified at baseline as wildtype (WT) or non‐WT (detectable mutants at PC/BCP) by line‐probe assay. Response was assessed at 6 months post‐treatment and through long‐term follow‐up(LTFU). Mutants were detected in 64% of patients, in varying frequencies across HBV genotypes A through D. Patients with WT had higher baseline HBV DNA, HBeAg and HBsAg levels than patients with non‐WT. Patients with WT were more likely to achieve HBeAg loss with HBV DNA<10,000 copies/mL (response, 34 versus 11%,p<0.001) and HBsAg clearance (18 versus 2%,p<0.001) at week 78 than non‐WT patients. Among WT patients who achieved HBeAg clearance at week 78, 78% had undetectable HBV DNA and 61% achieved HBsAg clearance at LTFU (versus 26% and 15% in non‐WT patients,p<0.001 for both). Presence of WT virus at baseline was an independent predictor of response (OR 2.90, 95%CI:1.15–7.31,p=0.023) and HBsAg clearance (OR 5.58, 95%CI:1.26–24.63,p=0.013) and patients with non‐A genotypes with detectable mutants had a low probability of response.Conclusion:Presence of only WT virus at baseline is a strong predictor of response (HBeAg loss with HBV DNA <10,000 copies/mL) to PEG‐IFN for HBeAg‐positive CHB. Patients with detectable PC and/or BCP mutants have a lower probability of response and are less optimal candidates for PEG‐IFN therapy. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 06 f�vrier 2012
Valerio Nobili
I148M PNPLA3 variant and progressive liver disease: A new paradigm in hepatology
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Date de mise en ligne : Lundi 06 f�vrier 2012
Morris Sherman
Response to letter to the editor by Caturelli and Ghittoni
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Date de mise en ligne : Lundi 30 janvier 2012
Frank J. Gonzalez
Disruption of phospholipid and bile acid homeostasis in mice with nonalcoholic steatohepatitis
Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease. , can develop into cirrhosis, hepatic failure, and hepatocellular carcinoma. While several metabolic pathways are disrupted, the mechanism of NASH development remains unclear. While several metabolic pathways are disrupted and endogenous metabolites may change in NASH, alterations in serum metabolites during NASH development remain unclear. To gain insight into disease mechanism, Serum metabolite changes were assessed using metabolomics with ultra‐performance liquid chromatography‐electrospray ionization‐quadrupole time‐of‐flight mass spectrometry and a conventional mouse NASH model induced by a methionine‐ and choline‐deficient (MCD) diet. Significant decreases in serum palmitoyl‐, stearoyl‐, and oleoyl‐lysophosphatidylcholine (LPC) and marked increases in tauro‐β‐muricholate, taurocholate, and 12‐hydroxyeicosatetraenoic acid (12‐HETE) were detected in mice with NASH. In agreement with these metabolite changes, hepatic mRNAs encoding enzymes and proteins involved in LPC degradation [lysophosphatidylcholine acyltransferase (Lpcat) 1‐4], basolateral bile acid excretion [ATP‐binding cassette sub‐family C member (Abcc) 1/4/5 and organic solute transporter β], and 12‐HETE synthesis (arachidonate 12‐lipoxygenase) were significantly up‐regulated. In contrast, the expression of sodium/taurocholate transport protein (Slc10a1) and solute carrier organic anion transporter family member (Slco) 1a1 and 1b2, responsible for transporting bile acids into hepatocytes, were markedly suppressed. Supplementation of methionine to the MCD diet revealed that the changes in serum metabolites and the related gene expression were derived from steatohepatitis, but not dietary choline deficiency or steatosis. Furthermore, Tumor necrosis factor‐α and transforming growth factor‐β1 induced the expression of Lpcat2/4 and Abcc1/4 and down‐regulated Slc10a1 and Slco1a1 in primary hepatocytes, suggesting an association between the changes in serum LPC and bile acids and pro‐inflammatory cytokines. Finally, induction of hepatitis to ob/ob mice by D‐galactosamine injection led to similar changes in serum metabolites and the related gene expression. Conclusion: Phospholipid and bile acid metabolism is disrupted in NASH, likely due to enhanced hepatic inflammatory signaling. Serum LPC and bile acids may be biomarkers of NASH. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Julie K. Heimbach
Predictors of pre‐transplant dropout and post‐transplant recurrence in patients with perihilar cholangiocarcinoma
We have previously reported excellent outcomes with liver transplantation for selected patients with early‐stage perihilar cholangiocarcinoma (CCA) following neoadjuvant chemoradiotherapy. Our aim was to identify predictors of dropout before transplantation and predictors of cancer recurrence after transplantation.We reviewed all patients with unresectable perihilar CCA treated with neoadjuvant chemoradiation in anticipation for transplantation between 1993 and 2010. Predictors were identified by uni‐ and multivariable Cox regression analysis of clinical variables.In total 199 patients were enrolled, of whom 62 dropped out and 131 underwent transplantation at our institution, with 6 undergoing transplantation elsewhere. Predictors of dropout were CA 19‐9 ≥ 500 U/ml (HR 2.3; P=.04), mass ≥ 3 cm (HR 2.1; P=.05), malignant brushing or biopsy (HR 3.6; P=.001) and MELD score ≥ 20 (HR 3.5; P=.02). Post‐transplant, recurrence‐free 5‐year survival was 68%. Predictors of recurrence were elevated CA 19‐9 (HR 1.8; P=.01), portal vein encasement (HR 3.3; P=.007) and residual tumor on explant (HR 9.8; P<.001). PSC, age, history of cholecystectomy and waiting time were not independent predictors.Conclusion: Outcome following neoadjuvant chemoradiation and liver transplantation for perihilar CCA is excellent. Risk of dropout is related to patient and tumor characteristics and this can be used to guide patient counseling prior to enrolment. Recurrence risk is mostly associated with presence of residual cancer on explant. PSC patients do not have an independent survival advantage over de‐novo patients, but present with more favorable tumor characteristics. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Olivier Diaz
High plasma level of nucleocapsid‐free envelope glycoprotein‐positive lipoproteins in hepatitis C patients
Hepatitis C virus (HCV) particles associate viral and lipoprotein moieties to form hybrid lipo‐viral‐particles (LVP). Cell culture produced HCV (HCVcc) and ex vivo characterized LVP primarily differ by their apolipoprotein B (apoB) content, which is low for HCVcc, but high for LVP. Recombinant nucleocapsid‐free subviral LVP are assembled and secreted by apoB producing cell lines. To determine whether such subviral particles circulate in HCV‐infected individuals. LVP complexed with immunoglobulin were precipitated with protein A from low density plasma fractions of 36 hepatitis C patients and their lipid content, apolipoprotein profile and viral composition was determined. HCV RNA in LVP was quantified and molar ratios of apoB and HCV genome copy number were calculated. LVP lipidome from four patients was determined by electrospray ionization tandem mass spectrometry. Protein A purified LVP contained at least the envelope glycoprotein E2 and E2‐specific antibodies. LVP were present in every patient and were characterized by high lipid content, presence of apolipoproteins characteristic for triglyceride rich lipoproteins (TRL), HCV RNA and viral glycoprotein. Importantly, save for four patient, LVP fractions contained large amount of apoB, with on average more than 1x106 apoB molecules per HCV RNA genome. As there is one apoB molecule per TRL, this ratio suggested that most LVP are nucleocapsid‐free, envelope glycoprotein‐containing subviral particles. LVP and TRL had similar composition of triacylglycerol and phospholipid classes. Conclusion: LVP are a mixed population of particles, comprising predominantly subviral particles that represent a distinct class of modified lipoproteins within the TRL family. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Yasuni Nakanuma
Significance of IgG4‐positive cells in extrahepatic cholangiocarcinoma: Molecular mechanism of IgG4 reaction in cancer tissue
IgG4 reactions consisting of marked infiltration by IgG4‐positive plasma cells in affected organs is found in cancer patients as well as patients with IgG4‐related diseases. Notably, extrahepatic cholangiocarcinomas accompanying marked IgG4 reactions clinicopathologically mimic IgG4‐related sclerosing cholangitis. A regulatory cytokine, IL‐10, is thought to induce the differentiation of IgG4‐positive cells. In this study, to clarify the mechanism of the IgG4 reaction in extrahepatic cholangiocarcinoma, we investigated non‐professional antigen‐presenting cells (APCs) generating IL‐10‐producing regulatory T cells (anergy T cells) and Foxp3‐positive regulatory cells producing IL‐10. Immunohistochemistry targeting IgG4, HLA‐DR, CD80, CD86, and Foxp3 was performed using 54 cholangiocarcinoma specimens from 24 patients with gallbladder cancer, 22 with common bile duct cancer, and 8 with cancer of the Papilla of Vater. Moreover, a molecular analysis of Foxp3 and IL‐10 was performed using a cultured human cholangiocarcinoma cell line. Consequently, 43% of the cholangiocarcinomas were found to be abundant in IgG4. Those expressing HLA‐DR, but lacking costimulatory molecules (CD80 and CD86), and those expressing Foxp3 detected by an antibody recognizing the N terminus, accounted for 54% and 39% of cases, respectively. Moreover, the number of IgG4‐positive cells was larger in these cases than in other groups. In cultured cells, the presence of a splicing variant of Foxp3 mRNA and the expression of IL‐10 were demonstrated. In conclusion, extrahepatic cholangiocarcinoma is often accompanied by the significant infiltration of IgG4‐positive cells. Cholangiocarcinoma cells could play the role of non‐professional APCs and Foxp3‐positive regulatory cells, inducing IgG4 reactions via the production of IL‐10 indirectly and directly, respectively. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Pierre‐Alain Clavien
Serotonin protects mouse liver from cholestatic injury by decreasing bile salt pool after bile duct ligation
Obstructive cholestasis induces liver injury, postoperative complications and mortality after surgery. Adaptive control of cholestasis including bile salt homeostasis is necessary for recovery and survival. Peripheral serotonin is a cytoprotective neurotransmitter also associated with liver regeneration. The effect of serotonin on cholestatic liver injury is not known. Therefore, we tested whether serotonin affects the severity of cholestatic liver injury.We induced cholestasis by ligation of the bile duct (BDL) in either wild type (wt) mice or mice lacking peripheral serotonin (Tph1‐/‐ and immune thrombocytopenic (ITP) mice). Liver injury was assessed by the levels of plasma AST/ALT and tissue necrosis. Bile salt regulating genes were measured by quantitative PCR and confirmed by western blotting and immunohistochemistry.Tph1‐/‐ mice displayed higher levels of plasma AST, ALT, bile salts, and hepatic necrosis after three days of BDL than wt mice. Likewise, liver injury was disproportional in ITP mice. Moreover, severe cholestatic complications and mortality after prolonged BDL were increased in Tph1‐/‐ mice. Despite the elevation in toxic bile salts, expression of genes involved in bile salt homeostasis and detoxification were not affected in Tph1‐/‐ livers. In contrast, the bile salt re‐absorption transporters Ostα and Ostβ were up‐regulated in the kidneys of Tph1‐/‐ mice, along with a decrease in urinary bile salt excretion. Serotonin reloading of Tph1‐/‐ mice reversed this phenotype, resulting in a reduction of circulating bile salts and liver injury.Conclusion: We propose a physiological function of serotonin is to ameliorate liver injury and stabilize the bile salt pool through adaptation of renal transporters in cholestatis. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Shou‐Dong Lee
Cannabinoid receptor 2 agonist ameliorates mesenteric angiogenesis and portosystemic collaterals in cirrhotic rats
Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow and portosystemic collaterals formation, which may induce lethal complications such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids inhibit angiogenesis but the relevant influences in cirrhosis are unknown. In this study, Spraque‐Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, ACEA (cannabinoid receptor type 1 (CB1) agonist), JWH‐015 (CB2 agonist), AM630 (CB2 antagonist) since the 35th to 42nd days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, VEGF, VEGFR‐1, VEGFR‐2, phospho‐VEGFR‐2, cyclooxygenase‐1 (COX‐1), COX‐2, endothelial nitric oxide synthase (eNOS) expressions and plasma VEGF levels were evaluated. The results showed that CB1 and CB2 receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intra‐abdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB2 receptor was up‐regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH‐015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH‐015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH‐015 and AM630 abolished JWH‐015 effects. JWH‐133, another CB2 agonist, mimicked the JWH‐015 effects. JWH‐015 decreased mesenteric COX‐1, COX‐2 mRNA expressions and COX‐1, COX‐2, eNOS protein expressions. Furthermore, JWH‐015 decreased intrahepatic angiogenesis and fibrosis. Conclusions: CB2 agonist alleviates portal hypertension, severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down‐regulation. Cannabinoids may be targeted in the control of portal hypertension and portosystemic collaterals. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 30 janvier 2012
Marian Major
CD4+ immune escape and subsequent T‐cell failure following chimpanzee immunization against hepatitis C virus
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Date de mise en ligne : Lundi 30 janvier 2012
Kristy Boyd
Living and dying well with end‐stage liver disease: Time for palliative care?
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Date de mise en ligne : Lundi 30 janvier 2012
Gin‐Ho Lo
The role of imaging techniques in clinical decision making for the management of hepatocellular carcinoma
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Date de mise en ligne : Vendredi 27 janvier 2012
Valerio Nobili
Unraveling the genetics of fatty liver in obese children: Additive effect of P446L GCKR and I148M PNPLA3 polymorphisms
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Date de mise en ligne : Mercredi 25 janvier 2012
Tomas Ganz
Inhibition of hepcidin transcription by growth factors
The hepatic peptide hormone hepcidin controls the duodenal absorption of iron, its storage and its systemic distribution. Hepcidin production is often insufficient in chronic hepatitis C and alcoholic liver disease, leading to hyperabsorption of iron and its accumulation in the liver. Hepatocyte growth factor (HGF) and epidermal growth factor (EGF) mediate the hepatic regeneration after liver injury. We examined the effect of the growth factors on hepcidin synthesis by hepatocytes. Results: HGF and EGF treatment of primary mouse hepatocytes, as well as EGF administration in mice, suppressed hepcidin mRNA synthesis. The suppression of hepcidin by these growth factors was transcriptional, and was mediated by a direct effect of HGF and EGF on the BMP pathway regulating hepcidin synthesis. We further showed that growth factors interfered with nuclear localization of activated Smads and increased the nuclear pool of the BMP transcriptional co‐repressor TG‐interacting factor (TGIF). In a kinase screen with small‐molecule kinase inhibitors, inhibitors in the PI3 kinase pathway and in the MEK/ERK pathway prevented HGF suppression of hepcidin in primary mouse hepatocytes.Conclusion:HGF and EGF suppress hepatic hepcidin synthesis, in part through PI3 kinase MEK/ERK kinase pathways which may be modulating the nuclear localization of BMP pathway transcriptional regulators including activated Smads1/5/8 and the co‐repressor TGIF. EGF, HGF and possibly other growth factors that activate similar pathways may contribute to hepcidin suppression in chronic liver diseases, promote iron accumulation in the liver and exacerbate the destructive disease processes. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Ramon Bataller
Liver progenitor cell markers correlate with liver damage and predict short‐term mortality in patients with alcoholic hepatitis
Alcoholic Hepatitis (AH) is a severe condition developed in patients with underlying alcoholic liver disease. Ductular reaction has been associated with chronic alcohol consumption but there is no information regarding the extent of liver progenitor cell (LPC) proliferation in AH. The aim of this study was to investigate LPC markers in AH, and its correlation with disease severity. Fifty‐nine patients with clinical and histological diagnosis of AH were included in the study. LPC markers were assessed by real time PCR and immunohistochemistry. Standard logistic regression analysis and classification and regression trees (CART) analysis were used for statistical analysis. A microarray analysis showed an up‐regulation of LPC markers in patients with AH. Real time PCR demonstrated that epithelial cell adhesion molecule (EpCAM), Prominin‐1, and Keratin7 were significantly increased in patients with AH compared to normal livers (p≤0,01), chronic hepatitis C (p≤0,01), and HCV‐induced cirrhosis (p≤0,01). Immunohistochemistry scores generated for Keratin7 and EpCAM demonstrated a good correlation with gene expression. Keratin7 gene expression correlated with liver failure as assessed by MELD score (r=0.41, p =0.006) and Maddrey's discriminant function (r=0.43, p=0.004). Moreover, Keratin7 (HR1.14, p=0.004) and Prominin‐1 (HR1.14, p=0.002), but not EpCAM (HR1.16, p=0.06), were identified as independent predictors of 90‐days mortality. CART analysis generated an algorithm based‐on the combination of Keratin7 and EpCAM gene expression that stratified three groups of patients with high, intermediate and low short‐term mortality (89%, 33% and 6% respectively; AUROC 0.73, CI 95%: 0.60‐0.87). Keratin7 expression provided additional discrimination potential to ABIC score.Conclusion:LPC markers correlate positively with severity of liver disease and short‐term mortality in AH patients. This study suggests that LPC proliferation may be an important feature of AH pathophysiology. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Laura W. Schrum
Inhibitory effects of microRNA 19b in hepatic stellate cell‐mediated fibrogenesis
Hepatic stellate cell (HSC) activation is a pivotal event in initiation and progression of hepatic fibrosis and a major contributor to collagen deposition driven by transforming growth factor beta (TGFβ). microRNAs (miRs), small non‐coding RNAs modulating mRNA and protein expression, have emerged as key regulatory molecules in chronic liver disease. We investigated differentially expressed miRs in quiescent and activated HSCs to identify novel regulators of profibrotic TGFβ signaling. miR microarray analysis was performed on quiescent and activated rat HSCs. Members of the miR‐17‐92 cluster (19a, 19b, 92a) were significantly down‐regulated in activated HSCs. Since miR 19b showed the highest fold‐change of the cluster members, activated HSCs were transfected with miR 19b mimic or negative control and TGFβ signaling and HSC activation assessed. miR 19b expression was determined in fibrotic rat and human liver specimens. miR 19b mimic negatively regulated TGFβ signaling components demonstrated by decreased TGFβ receptor II (TGFβRII) and SMAD3 expression. Computational prediction of miR 19b binding to the 3′UTR of TGFβRII was validated by luciferase reporter assay. Inhibition of TGFβ signaling by miR 19b was confirmed by decreased expression of type I collagen and by blocking TGFβ‐induced expression of α1(I) and α2(I) procollagen mRNAs. miR 19b blunted the activated HSC phenotype by morphological assessment and decreased αSMA expression. Additionally, miR 19b expression was markedly diminished in fibrotic rat liver compared to normal liver; similarly, miR 19b expression was markedly down‐regulated in fibrotic compared to normal human livers.Conclusions:miR 19b is a novel regulator of TGFβ signaling in HSCs suggesting a potential therapeutic approach for hepatic fibrosis. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Michael G. Katze
Early transcriptional programming links progression to hepatitis C virus‐induced severe liver disease in transplant patients
Liver failure due to chronic hepatitis C virus infection is a major cause for liver transplantation worldwide. Recurrent infection of the graft is universal in HCV patients following transplant and results in rapid progression to severe fibrosis and end‐stage liver disease in one‐third of all patients. No single clinical variable, or combination thereof, has so far proven accurate in identifying patients at risk of hepatic decompensation in the transplant setting. A combination of longitudinal, dimensionality reduction, and categorical analysis of the transcriptome from 111 liver biopsy specimens taken from 57 HCV‐infected patients over time identified a molecular signature of gene expression of patients at risk of developing severe fibrosis. Significantly, alterations in gene expression occur prior to histologic evidence of liver disease progression, suggesting that events which occur during the acute phase of infection influence patient outcome. Additionally, a common precursor state for different severe clinical outcomes was identified. Hence, based on this patient cohort, incidence of severe liver disease is a process initiated early during HCV infection of the donor organ. The probable cellular network at the basis of the initial transition to severe liver disease was identified and characterized. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Peng Li
Cidea promotes hepatic steatosis by sensing dietary fatty acids
High levels of dietary saturated fat have been closely associated with the development of hepatic steatosis, but the factors that mediate this process remain elusive. Here, we observed that the level of Cidea expression was highly correlated with the severity of hepatic steatosis in humans. Overexpression of Cidea in mouse liver resulted in increased hepatic lipid accumulation and the formation of large lipid droplets (LDs). In contrast, mice with a Cidea deficiency had decreased lipid accumulation and alleviated hepatic steatosis when they received an HFD feeding or in ob/ob mice. Furthermore, the knockdown of Cidea in the livers of ob/ob mice resulted in significantly reduced hepatic lipid accumulation and smaller LDs. Importantly, we observed that Cidea expression in hepatocytes was specifically induced by saturated fatty acids, and such induction was reduced when SREBP1c was knocked down. In contrast, the overexpression of SREBP1c restored the saturated fatty acid‐induced expression of Cidea. In addition, we observed that the stability of Cidea protein in hepatocytes increased significantly in response to treatment with fatty acids.Conclusion:Cidea plays critical roles in promoting hepatic lipid accumulation and in the development of hepatic steatosis by acting as a sensor that responds to diets that contain fatty acids. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Bei Zhang
Performance of magnetic resonance elastography and diffusion‐weighted imaging for the staging of hepatic fibrosis: A meta‐analysis
A meta‐analysis was performed to assess and compare the accuracies of magnetic resonance elastography (MRE) and diffusion‐weighted imaging (DWI) for the staging of hepatic fibrosis. Online journal databases and a manual search from January 2000 to May 2011 were used. We identified 41 studies, but only 14 met the criteria to perform a meta‐analysis assessing MRE (five trials) or DWI (10 trials). Fibrosis was categorized by redistribution into five stages according to histopathological description. A bivariate binomial model was used to combine the sensitivity and specificity and their 95% confidence intervals (CIs), from which diagnostic odds ratio (DOR), positive likelihood ratios (PLR), negative likelihood ratio (NLR), and summary receiver operating characteristic (sROC) were derived to indicate the diagnostic accuracy of imaging modalities. With MRE, the sensitivity, specificity, DOR, PLR, NLR and area under sROC curve (with 95% CIs) for staging F0∼F1 vs. F2∼F4 and F0∼F2 vs. F3∼F4 were 0.94 (0.81–0.98), 0.95 (0.87–0.98), 20 (7–57), 0.06 (0.02–0.22), 317 (55–1796), 0.98 (0.97–0.99) and 0.92 (0.85–0.96), 0.96 (0.91–0.98), 21 (10–45), 0.08 (0.04–0.16), 251 (103–609), 0.98 (0.96–0.99) respectively; and with DWI, these values were 0.77 (0.71 –0.82), 0.78 (0.69–0.85), 3 (2–5), 0.30 (0.22–0.40), 12 (6–21), 0.83 (0.79–0.86) and 0.72 (0.60–0.81), 0.84 (0.77–0.89), 5 (3–7), 0.34 (0.23–0.50), 13 (6–29), 0.86 (0.83–0.89) respectively. A z‐test demonstrated MRE had a significantly higher accuracy than DWI in those indicators (P < 0.05).Conclusion:MRE is more reliable for staging hepatic fibrosis compared with DWI with a high combination of sensitivity, specificity, likelihood ratios, DOR, and area under sROC curve. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Jongsook Kim Kemper
Genomic analysis of hepatic farnesoid X receptor (FXR) binding sites reveals altered binding in obesity and direct gene repression by FXR
The nuclear bile acid receptor, Farnesoid X Receptor (FXR), is an important transcriptional regulator of liver metabolism. Despite recent advances in understanding its functions, how FXR regulates genomic targets and whether the transcriptional regulation by FXR is altered in obesity remain largely unknown. Here, we analyzed hepatic genome‐wide binding sites of FXR in normal and dietary obese mice by chromatin immunoprecipitation‐sequencing (ChIP‐seq) analysis. A total of 15,263 and 5,272 FXR binding sites were identified in livers of normal and obese mice, respectively, after a short one hour treatment with the synthetic FXR agonist, GW4064. Of these sites, 7,440 and 2,344 were detected uniquely in normal and obese mice. FXR binding sites were localized mostly in intergenic and intron regions at an IR1 motif in both groups, but also clustered within 1 kb of transcription start sites. FXR binding sites were detected near previously unknown target genes with novel functions, including diverse cellular signaling pathways, apoptosis, autophagy, hypoxia, inflammation, RNA processing, metabolism of amino acids, and transcriptional regulators. Further analyses of randomly selected genes from both normal and obese mice suggested more FXR binding sites are likely functionally inactive in obesity. Surprisingly, occupancies of FXR, RXRα, RNA polymerase II, and epigenetic gene activation and repression histone marks, and mRNA levels of genes examined, suggested that direct gene repression by agonist‐activated FXR is common. Comparison of genomic FXR binding sites in normal and obese mice further suggested that FXR transcriptional signaling is altered in dietary obese mice, which may underlie aberrant metabolism and liver function in obesity. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 25 janvier 2012
Juan Antonio Pineda
Liver stiffness predicts clinical outcome in HIV/HCV‐coinfected patients with compensated liver cirrhosis
Our aim was to assess the predictive value of liver stiffness (LS), measured by transient elastography (TE), for clinical outcome in HIV/HCV‐coinfected patients with compensated liver cirrhosis. This was a prospective cohort study of 239 consecutive HIV/HCV‐coinfected patients with a new diagnosis of cirrhosis, done by TE, and no previous decompensation of liver disease. The time from diagnosis to the first liver decompensation and death from liver disease, as well as the predictors of these outcomes, were evaluated. After a median (Q1‐Q3) follow‐up of 20 (9‐34) months, 31 (13%, 95% confidence interval [CI]: 9%‐17%) patients developed a decompensation. The incidence of decompensation was 6.7 cases per 100 person‐years (95% CI, 4.7‐9‐6). Fourteen (8%) out of 181 patients with a baseline LS < 40 kPa developed a decompensation versus 17 (29%) out of 58 with a LS = 40 kPa (p=0.001). Factors independently associated with decompensation were Child‐Turcotte‐Pugh (CTP) class B versus A (hazard ratio [HR] 7.7; 95% CI 3.3‐18.5; p<0.0001), log‐plasma HCV RNA load (HR 2.1; 95% CI 1.2‐3.6; p=0.01), hepatitis B virus coinfection (HR, 10.3; 95% CI, 2.1‐50.4; p=0.004) and baseline LS (HR 1.03; 95% CI 1.01‐1.05; p=0.02). Fifteen (6%, 95% CI: 3.5%‐9.9%) patients died, 10 of them due to liver disease, and one underwent liver transplantation. CTP class B (HR 16.5; 95% CI 3.4‐68.2; p<0.0001) and previous exposure to HCV therapy (HR 7.4; 95% CI 1.7‐32.4, p=0.007) were independently associated with liver‐related death; baseline LS (HR 1.03; 95% CI 0.98‐1.07; p=0.08) was of borderline significance.Conclusion:LS predicts the development of hepatic decompensations and liver‐related mortality in HIV/HCV‐coinfected with compensated cirrhosis and provides additional prognostic information to that provided by CTP score. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Wei Liu
MxA inhibits hepatitis B virus replication by interaction with core protein HBcAg
Human MxA, an interferon‐inducible cytoplasmic dynamin‐like GTPase, possesses antiviral activity against multiple RNA viruses. Recently, MxA has also been demonstrated to have activity against the hepatitis B virus (HBV), a well‐known DNA virus responsible for acute and chronic liver disease in humans. Here, we investigated the molecular mechanism for the anti‐HBV activity of MxA. Our results demonstrated that in HepG2.2.15 cells, MxA GTPase‐independently suppressed the production of hepatitis B surface antigen (HBsAg) and HBV DNA without changing the level of hepatitis B core antigen (HBcAg) and the distribution of HBV mRNA. MxA significantly reduced the level of the encapsidated pregenomic RNA (pgRNA). Through its central interactive domain, MxA interacted with HBcAg causing accumulation of the proteins in perinuclear compartments. MxA‐HBcAg interaction significantly affected the dynamics of HBcAg by immobilizing HBcAg in the perinuclear structures.Conclusion:MxA displays antiviral activity against HBV involving a mechanism of MxA‐HBcAg interaction which may interfere with core particle formation. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Mitsuru Hashida
Efficient suppression of murine ICAM‐1 using ultrasound‐responsive and mannose‐modified lipoplexes inhibits acute hepatic inflammation
Hepatitis is often associated with the over‐expression of various adhesion molecules. In particular, intracellular adhesion molecule‐1 (ICAM‐1), which is expressed on hepatic endothelial cells (HECs) in the early stage of inflammation, is involved in serious illnesses. Therefore, ICAM‐1 suppression in HECs enables the suppression of inflammatory responses. Here, we developed an ICAM‐1 siRNA transfer method using ultrasound (US)‐responsive and mannose‐modified liposome/ICAM‐1 siRNA complexes (Man‐PEG2000 bubble lipoplexes; Man‐PEG2000 BLs), and achieved efficient HEC‐selective ICAM‐1 siRNA delivery in combination with US exposure. Moreover, the sufficient ICAM‐1 suppression effects were obtained by this ICAM‐1 siRNA transfer in vitro and in vivo, and potent anti‐inflammatory effects were observed in various types of inflammation, such as lipopolysaccharide (LPS), dimethylnitrosamine (DMN), carbon tetrachloride (CCl4), and ischemia‐reperfusion (IR)‐induced inflammatory mouse models.Conclusion:In the present study, we demonstrated that HEC‐selective and efficient ICAM‐1 siRNA delivery using Man‐PEG2000 BLs and US exposure enables to suppress various types of acute hepatic inflammation. This novel siRNA delivery method may offer a valuable system for medical treatment where the targeted cells are HECs. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Pierre Bedossa
A morphometric and immunohistochemical study to assess the benefit of an svr in hcv cirrhotic patients
Background:Although annular fibrosis is the hallmark of cirrhosis, other microscopic changes impacting on liver function such as sinusoid capillarization or loss of metabolic zonation are common. A sustained virological response (SVR) may halt fibrosis deposition in hepatitis C virus (HCV) infected patients, but its impact on the other cirrhosis‐associated lesions is unknown.Aims:To assess the impact of an SVR on cirrhosis‐related histopathological features.Material and Methods:Paired pre‐ and post‐treatment liver biopsies from 38 HCV cirrhotics with an SVR were analysed. Fibrosis was staged by METAVIR and the area of fibrosis by morphometry. Ductular proliferation, metabolic zonation, sinusoid capillarization and hepatic stellate cells activation were assessed by anti‐cytokeratin7 (CK7), ‐glutamine synthetase (GS), ‐cytochrome P4502E1 (CYP2E1), ‐CD34 and alpha‐smooth muscle actine (αSMA).Results:After 61 months from an SVR, cirrhosis regression was observed in 61%, and the collagen content decreased in 89%. Although periportal and lobular necroinflammation vanished, portal inflammation persisted in 66%. Ductular proliferation decreased in 92%. Before treatment, metabolic zonation was lost, as shown by GS and CYP2E1, in 71% and 88%, respectively, with normalization in 79% and 73%, after an SVR. Conversely, no changes in sinusoidal capillarization were observed after treatment, as assessed by CD34 (p=0.41) and αSMA (p=0.95). Finally, no differences in all the immunohistochemical scores emerged whether or not cirrhosis persisted.Conclusion:Cirrhosis regression and fibrosis amount decrease are frequently observed among HCV cirrhotic patients with an SVR. Despite ductular proliferation vanishing and lobular zonation restoration, portal inflammation and sinusoidal capillarization may not regress after viral eradication. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
David Q‐H Wang
Intestinal absorption, hepatic synthesis, and biliary secretion of cholesterol: Where are we for cholesterol gallstone formation?
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Date de mise en ligne : Lundi 23 janvier 2012
Giovanni Raimondo
Impact of hepatitis B virus (HBV) preS/S genomic variability on HBV surface antigen and HBV DNA serum levels
To evaluate whether hepatitis B virus (HBV) preS/S gene variability has any impact on serum HBsAg levels and to analyze the replication capacity of naturally occurring preS/S variants, sera from 40 untreated patients with HBV‐related chronic liver disease [hepatitis B e antigen (HBeAg)‐positive, n=11; HBeAg‐negative, n=29] were virologically characterized. Additionally, phenotypic analysis of three different preS/S variant isolates (carrying a 183 nucleotide deletion within the preS1 region, the deletion of preS2 start codon, and a stop signal at codon 182 within the S gene, respectively) was performed. HBV infecting 14/40 patients (35%) had single or multiple preS/S genomic mutations (i.e. preS1 and/or preS2 deletions, preS2 start codon mutations, C‐terminally truncated and/or “a” determinant mutated S protein). Presence of preS/S variants negatively correlated with HBsAg titers (r = ‐ 0.431; P= 0.005) and its prevalence did not significantly differ between HBeAg‐positive and HBeAg‐negative patients. No correlation was found between HBsAg and HBV DNA levels in patients infected with preS/S mutants, whereas a significant correlation was found between HBsAg and viremia levels (r = 0.607; P= 0.001) in patients infected with wild type‐HBV strains. HepG2 cells replicating the above‐mentioned three preS/S variants showed significant reduction of HBsAg secretion, retention of envelope proteins in the endoplasmic reticulum, less efficient virion secretion and nuclear accumulation of significantly higher amounts of covalently‐closed‐circular‐DNA compared to wild type‐HBV replicating cells.Conclusions.In patients infected with preS/S variants, HBV DNA replication and HBsAg synthesis/secretion appear to be dissociated. Therefore, the use of HBsAg titer as diagnostic/prognostic tool has to take into account the frequent emergence of preS/S variants in chronic HBV infection. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Felix Hoppe‐Seyler
The inhibitors of nucleotide biosynthesis leflunomide, FK778, and mycophenolic acid activate hepatitis b virus replication In Vitro
The inhibitors of pyrimidine synthesis leflunomide and FK778 have been reported to exert broad antiviral effects, in addition to their immunosuppressive activities. Their possible therapeutic benefit for transplantation medicine is currently discussed, since they also block replication of human cytomegalovirus (CMV) and human polyomavirus BK (BKV) which both cause important complications in transplant recipients. Here, we show that leflunomide and FK778 strongly enhance hepatitis B virus (HBV) replication in vitro. This activity is shared by mycophenolic acid (MPA), an inhibitor of purine biosynthesis. Stimulation of HBV replication by these agents was linked to their inhibitory effects on de novo nucleotide biosynthesis since it could be efficiently counteracted by external nucleoside supply. Mechanistically, we found that MAP kinase (MAPK) p38 played a key role for the enhancement of HBV replication by leflunomide, FK778, and MPA. All three HBV‐activating compounds increased p38 phosphorylation, in contrast to the HBV inhibitors telbivudine and cyclosporine A (CsA). Moreover, silencing of p38 expression via RNA interference (RNAi) efficiently counteracted the stimulatory effect of leflunomide, FK778, and MPA on HBV replication. In conclusion, our data indicate that ‐ in contrast to their reported inhibitory effects on other viruses ‐ both leflunomide and FK778 can augment HBV replication. Treatment with leflunomide, FK778, or MPA may bear the risk to enhance HBV replication in infected patients. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
W. Ray Kim
Nonalcoholic fatty liver disease is associated with coronary artery calcification
Nonalcoholic fatty liver disease (NAFLD) is related to risk factors of coronary artery disease, such as dyslipidemia, diabetes, and metabolic syndrome, which are closely linked with visceral adiposity. The aim of this study was to investigate whether NAFLD was associated with coronary artery calcification (CAC), which is used as a surrogate marker for coronary atherosclerosis independent of computed tomography (CT)‐measured visceral adiposity. Out of 5,648 subjects who visited one of health screening centers between 2003 and 2008, we enrolled 4,023 (mean age 56.9 ± 9.4 years, 60.7% males) subjects without known liver disease or a history of ischemic heart disease. CAC score was evaluated by the Agatston method. In univariate analyses, the presence of CAC (score >0) was significantly associated with age, sex, body mass index, aspartate aminotransferase, alanine aminotransferase, high‐density lipoprotein cholesterol, triglycerides and increased odds of diabetes, hypertension, smoking, and NAFLD. Increasing CAC scores (0, <10, 10‐100, ≥100) were associated with higher prevalence of NAFLD (OR 1.84, 95% CI 1.61‐2.10, P<0.001). Multivariate ordinal regression analysis adjusted for traditional risk factors, and CT‐measured visceral adipose tissue area in a subgroup of subjects showed that the increased CAC scores were significantly associated with the presence of NAFLD (OR 1.28, 95% CI 1.04‐1.59, P=0.023) independent of visceral adiposity.CONCLUSIONS:Patients with NAFLD are at increased risk for coronary atherosclerosis independent of classical coronary risk factors, including visceral adiposity. These data suggest that NAFLD per se might be an independent risk factor for coronary artery disease. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Tania Roskams
Histological diversity in cholangiocellular carcinoma reflects the different cholangiocyte phenotypes
Cholangiocellular carcinoma (CC) originates from topographically heterogeneous cholangiocytes. The cylindrical mucin‐producing cholangiocytes are located in large bile ducts and the cuboidal non‐mucin producing cholangiocytes are located in ductules containing bipotential hepatic progenitor cells (HPCs). We investigated the clinicopathological and molecular features of 85 resected CCs [14 hilar CCs (so‐called Klatskin tumor), 71 intrahepatic CCs (ICCs) including 20 cholangiolocellular carcinomas (CLCs)(thought to be originated from HPCs)], and compared these with the different cholangiocyte phenotypes, including HPCs. Immunohistochemistry was performed with biliary/HPC and hepatocytic markers. Gene expression profiling was performed in different tumors, and compared with non‐neoplastic different cholangiocyte phenotypes obtained by laser microdissection. Invasion and cell proliferation assay were assessed using different types of CC cell lines: KMC‐1, KMCH‐1, and KMCH‐2. Among 51 ICCs, 31 (60.8 %) contained only mucin‐producing CC features (muc‐ICCs), while 39.2 % displayed histological diversity; focal hepatocytic differentiation and ductular areas (mixed‐ICCs). Clinicopathologically, muc‐ICCs and hilar CCs showed a predominantly (peri‐) hilar location, smaller tumor size, and more lymphatic and perineural invasion compared with mixed‐ICCs and CLCs (predominantly peripheral location, larger tumor size, and less lymphatic and perineural invasion). Immunoreactivity was similar in muc‐ICCs and hilar CCs, and in mixed‐ICCs and CLCs. S100P and MUC1 were significantly up‐regulated in hilar CCs and muc‐ICCs compared with mixed‐ICC and CLC, while NCAM1 and ALB tended to be up‐regulated in mixed‐ICCs and CLCs compared with other tumors. KMC‐1 showed significantly higher invasiveness than KMCH‐1 and KMCH‐2.Conclusion:Muc‐ICCs had a similar clinicopathological, immunohistochemical, and molecular profile to hilar CCs (from mucin‐producing cholangiocytes), while mixed‐ICCs had a similar profile to CLCs (thought to be of HPC origin), possibly reflecting their respective cells of origin. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Hongyang Wang
Cyclin G1‐mediated epithelial‐mesenchymal transition via PI3‐K/Akt signaling facilitates liver cancer progression
Cyclin G1 deficiency is associated with reduced incidence of carcinogen‐induced hepatocellular carcinoma (HCC), but its function in HCC progression remains obscure. Herein we reported a critical role of cyclin G1 in HCC metastasis. Elevated expression of cyclin G1 was detected in HCCs (60.6%) and its expression levels were even higher in portal vein tumor thrombus. Clinicopathological analysis revealed a close correlation of cyclin G1 expression with distant metastasis and poor prognosis of HCC. Forced expression of cyclin G1 promoted epithelial‐mesenchymal transition (EMT) and metastasis of HCC cells in vitro and in vivo. Cyclin G1 overexpression enhanced Akt activation through interaction with p85 (regulatory subunit of PI3‐K), which led to subsequent phosphorylation of GSK‐3β and stabilization of snail, a critical EMT mediator. These results suggest that elevated cyclin G1 facilitates HCC metastasis by promoting EMT via PI3‐K/Akt/GSK‐3β/Snail‐dependent pathway. Consistently, we have observed a significant correlation between cyclin G1 expression and p‐Akt levels in a cohort of HCC patients, and found that combination of these two parameters is a more powerful predictor of poor prognosis. (HEPATOLOGY 2012.)Conclusions:Cyclin G1 plays a pivotal role in HCC metastasis and may serve as a novel prognostic biomarker and therapeutic target. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Frank Dombrowski
AKT/mTOR activation induces a module of metabolic changes contributing to growth in insulin‐induced hepatocarcinogenesis
Mounting epidemiological evidence supports a role of insulin signaling deregulation and diabetes mellitus in human hepatocarcinogenesis. However, the underlying molecular mechanisms remain unknown. To study the oncogenic effect of chronically elevated insulin on hepatocytes in the presence of mild hyperglycemia, we developed a model of pancreatic islet transplantation into the liver. In this model, islets of a donor rat are transplanted into the liver of a recipient diabetic rat, with resulting local hyperinsulinism that leads to the development of preneoplastic lesions and hepatocellular carcinoma (HCC). Here, we investigated the metabolic and growth properties of the AKT/mTOR pathway, a major downstream effector of the insulin signaling, in this model of insulin‐induced hepatocarcinogenesis. We found that activation of insulin signaling triggers a strong induction of the AKT/mTOR cascade that is paralleled by increased synthesis of fatty acids, cholesterol, and triglycerides, induction of glycolysis and decrease of fatty acid oxidation and gluconeogenesis in rat preneoplastic and neoplastic liver lesions when compared with normal liver. AKT/mTOR metabolic effects on hepatocytes, following insulin stimulation, were found to be mTORC1‐dependent and –independent in human HCC cell lines. In these cells, suppression of lipogenesis, glycolysis, and the pentose phosphate pathway triggered a strong growth restraint despite insulin administration. Noticeably, metabolic abnormalities and proliferation driven by insulin were effectively reverted using the dual PI3K/mTOR inhibitor, NVP‐BEZ235, both in vitro and in vivo. Conclusions: The present results indicate that activation of the AKT/mTOR cascade by unconstrained insulin signaling induces a defined module of metabolic alterations in hepatocytes contributing to aberrant cell growth. Thus, inhibition of AKT/mTOR and related metabolic changes might represent a novel preventive and therapeutic approach to effectively inhibit insulin‐induced hepatocarcinogenesis. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Michael Trauner
Absence of adipose triglyceride lipase protects from hepatic ER stress
Non‐alcoholic fatty liver disease (NAFLD) is characterized by triglyceride (TG) accumulation and ER stress. Since fatty acids (FAs) may trigger ER stress, we hypothesized that absence of adipose triglyceride lipase (ATGL/PNPLA2) – the main enzyme for intracellular lipolysis, releasing FAs and closest homologue to adiponutrin (PNPLA3) recently implicated in the pathogenesis of NAFLD – protects against hepatic ER stress. Wildtype (WT) and ATGL knockout (KO) mice were challenged with tunicamycin (TM) to induce ER stress. Serum biochemistry, hepatic TG and FA profiles, liver histology and gene expression for markers of hepatic lipid metabolism, ER stress and inflammation were explored. Moreover, cell culture experiments were performed in Hepa1.6 cells after knock‐down of ATGL prior to FA and TM treatment. TM increased hepatic TG accumulation in ATGL KO but not in WT mice. Lipogenesis and β‐oxidation were repressed at the gene expression level (Srebp1c, FasN, Acc2, Cpt1α) in both WT and ATGL KO mice. Genes for VLDL synthesis (Mttp, ApoB) were down‐regulated by TM in WT and even more in ATGL KO mice which displayed strongly reduced serum VLDL‐cholesterol levels. Notably, ER stress markers Grp78, Chop, spliced Xbp1, ERdJ4 and inflammatory markers Tnfα and iNos were induced exclusively in TM treated WT but not ATGL KO mice. Total hepatic FA profiling revealed a higher palmitic acid (PA)/oleic acid (OA) ratio in WT mice compared to ATGL KO mice at baseline. Phosphoinositide‐3‐kinase inhibitor (Pik3ip1) – known to be involved in FA‐derived ER stress and blocked by OA – was increased in TM‐treated WT mice only. In line, in vitro OA protected hepatocytes from TM‐induced ER stress.Conclusions:Lack of ATGL may protect from hepatic ER stress via alterations in FA composition. ATGL could constitute a new therapeutic strategy to target ER stress in NAFLD. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Christophe Combescure
A model for dropout assessment of candidates with or without hepatocellular carcinoma on a common liver transplant waiting list
In many countries, the allocation of liver grafts is based on the Model of End‐stage Liver Disease (MELD) score and the use of exception points for patients with hepatocellular carcinoma (HCC). With this strategy, HCC patients have easier access to transplantation than non‐HCC ones. In addition, this system does not allow for a dynamic assessment, which would be required to picture the current use of local tumor treatment. This study was based on the Scientific Registry of Transplant Recipients and included 5'498 adult candidates of a liver transplantation for HCC and 43'528 for non‐HCC diagnoses. A proportional hazard competitive risk model was used. The risk of drop‐out of HCC patients was independently predicted by MELD score, HCC size, HCC number and alpha fetoprotein (AFP). When combined in a model with age and diagnosis, these factors allowed for the extrapolation of the risk of drop‐out. While this model and MELD did not share compatible scales, a correlation between both models was computed according to the predicted risk of drop‐out, and drop‐out equivalent MELD (deMELD) points were calculated.Conclusion:The proposed model, with the allocation of deMELD, has the potential to allow for a dynamic and combined comparison of opportunities to receive a graft for HCC and non‐HCC patients on a common waiting list. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Raoul Poupon
Noninvasive elastography‐based assessment of liver fibrosis progression and prognosis in primary biliary cirrhosis
The development of liver fibrosis markers in primary biliary cirrhosis (PBC) is needed to facilitate the assessment of its progression and the effectiveness of new therapies. Here we investigated the potential usefulness of transient elastography (TE) in the non‐invasive evaluation of liver fibrosis stage and disease progression in PBC. We performed first a prospective performance analysis of TE for the diagnosis of METAVIR fibrosis stages in a diagnostic cohort of 103 patients, and second a retrospective longitudinal analysis of repeated examinations in a monitoring cohort of 150 patients followed‐up for up to 5 years. All patients were treated with ursodeoxycholic acid. Diagnostic thresholds of liver stiffness in discriminating fibrosis stages ≥ F1, ≥ F2, ≥ F3 and = F4 were 7.1 kPa, 8.8 kPa, 10.7 kPa, and 16.9 kPa, respectively. TE showed high performance and was significantly superior to biochemical markers (APRI, FIB‐4, hyaluronic acid, AST/ALT ratio, Mayo score) in diagnosing significant fibrosis, severe fibrosis or cirrhosis. Analysis of the monitoring cohort data set using generalized linear models showed: 1) an overall progression rate of 0.48 ± 0.21 kPa/year (p=0.02); 2) no significant progression in patients with F0F1, F2 or F3 stages, but a significant increase (4.06 ± 0.72 kPa/year; p<0.0001) in cirrhotic patients. A cutoff value of 2.1 kPa/year was associated with a 8.4‐fold increased risk of liver decompensations, liver transplantations or deaths (p<0.0001, Cox regression analysis).Conclusion:TE is one of the best current surrogate markers of liver fibrosis in PBC. Over a 5‐year period, on‐treatment liver stiffness appears stable in most non‐cirrhotic PBC patients, while it significantly increases in patients with cirrhosis. Progression of LSM in PBC is predictive of poor outcome. (HEPATOLOGY 2012.)

Date de mise en ligne : Lundi 23 janvier 2012
Martin Lagging
Association between IL28B‐related genetic variants and liver histopathology differs between hcv genotypes
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Date de mise en ligne : Lundi 23 janvier 2012
Osamu Yokosuka
Frequent detection of IgM anti‐herpes simplex viral antibody in patients with primary biliary cirrhosis
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Date de mise en ligne : Lundi 23 janvier 2012
Maria Lauda Tomasi
Transcriptional regulation of methionine adenosyltransferase 2A by peroxisome proliferator‐activated receptors in rat hepatic stellate cells
Background and rationale:Methionine adenosyltransferases (MAT) are critical enzymes that catalyze the formation of the methyl donor, S‐adenosylmethionine (SAMe). The MAT2A gene, which encodes the catalytic subunit α2, is induced in de‐differentiated liver. We previously demonstrated that MAT2A expression is enhanced in activated hepatic stellate cells (HSCs) and silencing this gene reduces HSC activation. In this study we examined the molecular mechanisms responsible for the transcriptional regulation of the MAT2A gene in HSCs.Results:We identified peroxisome proliferator‐activated receptor (PPAR) response elements (PPREs) in the rat MAT2A promoter. The PPARγ agonist, rosiglitazone (RSG) promoted quiescence in the activated rat HSC cell line (BSC) or culture‐activated primary rat HSCs, decreased MAT2A expression and promoter activity and enhanced PPARγ binding to MAT2A PPREs. In vivo HSC activation in bile duct ligated (BDL) rats lowered PPARγ interaction with MAT2A PPREs. Silencing PPARγ increased MAT2A transcription whereas over‐expressing it had the opposite effect demonstrating that PPARγ negatively controls this gene. Site‐directed mutagenesis of PPREs abolished PPARγ recruitment to the MAT2A promoter and its inhibitory effect on MAT2A transcription in quiescent HSCs. PPRE mutations decreased the basal promoter activity of MAT2A in activated HSCs independent of PPARγ, indicating that other factors might be involved in PPRE interaction. We identified PPARβ binding to wild type but not to mutated PPREs, in activated cells. Furthermore, silencing PPARβ inhibited MAT2A expression and promoter activity. Forced expression of MAT2A in RSG‐treated HSCs lowered PPARγ and enhanced PPARβ expression, thereby promoting an activated phenotype.Conclusion:We have identified PPARγ as a negative regulator of MAT2A in quiescent HSCs. A switch from quiescence to activation state abolishes this control and allows PPARβ to up‐regulate MAT2A transcription. (HEPATOLOGY 2012.)

Date de mise en ligne : Jeudi 19 janvier 2012
Yasunori Sato
Cystic and papillary neoplasm involving peribiliary glands: A biliary counterpart of branch‐type IPMN?
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Date de mise en ligne : Jeudi 19 janvier 2012
Yuichi Sugiyama
AP2 mediates BSEP internalization and modulates its hepatocanalicular expression and transport function
The bile salt export pump (BSEP) mediates biliary excretion of bile salts and its dysfunction induces intrahepatic cholestasis. Reduced canalicular expression of BSEP due to promotion of its internalization is one of the causes of this disease state. However, the molecular mechanism underlying BSEP internalization from the canalicular membrane (CM) remains unknown. We have shown previously that 4‐phenylbutyrate (4PBA), a drug used for ornithine transcarbamylase deficiency (OTCD), inhibited internalization and subsequent degradation of cell surface‐resident BSEP. The current study found that 4PBA treatment decreased significantly the expression of α‐ and μ2‐adaptin, both of which are subunits of the AP2 adaptor complex (AP2) that mediates clathrin‐dependent endocytosis, in liver specimens from rats and patients with OTCD, and that BSEP has potential AP2 recognition motifs in its cytosolic region. Based on these backgrounds, the implication of the AP2 in BSEP internalization was explored further. In vitro analysis with 3×FLAG‐human BSEP‐expressing HeLa cells and human sandwich‐culture hepatocytes indicates that the impairment of AP2 function by RNAi targeting α‐adaptin inhibits the BSEP internalization from the plasma membrane and increases its cell surface expression and transport function. Studies using immunostaining, co‐immunoprecipitation, GST pulldown assay, and time‐lapse imaging show that AP2 interacts with BSEP at the CM through a tyrosine motif at the carboxyl terminus of BSEP and mediates BSEP internalization from the CM of hepatocytes. Conclusion: AP2 mediates the internalization and subsequent degradation of CM‐resident BSEP through direct interaction with BSEP, and thereby modulates the canalicular expression and transport function of BSEP. This information should be useful for understanding the pathogenesis of severe liver diseases associated with intrahepatic cholestasis. (HEPATOLOGY 2012.)

Date de mise en ligne : Jeudi 19 janvier 2012
Ansgar W. Lohse
Gall bladder polyps in primary sclerosing cholangitis – indication for early intervention
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Date de mise en ligne : Jeudi 19 janvier 2012
DD Houlihan
Informed consent in surveillance for hepatocellular carcinoma in patients with cirrhosis
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Date de mise en ligne : Jeudi 19 janvier 2012
Domenico Alvaro
Mucin‐producing cholangiocarcinoma might derive from biliary tree stem/progenitor cells located in peribiliary glands
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Date de mise en ligne : Jeudi 19 janvier 2012
Jacob George
To screen or not to screen
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Date de mise en ligne : Jeudi 19 janvier 2012
Nataliya Razumilava
RE: Gall bladder polyps in primary sclerosing cholangitis‐ adhere to the guidelines HEP‐11‐2164
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Date de mise en ligne : Jeudi 19 janvier 2012
Xin‐Yuan Guan
Serum and glucocorticoid kinase 3 at 8q13.1 promotes cell proliferation and survival in hepatocellular carcinoma
Amplification of broad regions of 8q is one of the most frequent genetic alterations in hepatocellular carcinoma (HCC), suggesting the existence of oncogenes in addition to MYC at 8q24.21. In this report, we examined the potential role of the candidate amplified oncogene SGK3 at 8q13.1 in HCC pathogenesis. We found amplification and overexpression of SGK3 was frequently detected in clinical HCC specimens and that SGK3 genomic activation was significantly associated with poor outcome of patients (P=0.028). Functionally, we found that overexpression of SGK3 in HCC cells increased cell cycle progression through G1, cell survival, clonogenicity, anchorage‐independent growth, and tumor formation in nude mice. In contrast, RNAi silencing of SGK3 inhibited its oncogenic effects. We provide evidences that SGK3 promotes HCC growth and survival through inactivating GSK3‐β and BAD respectively. We also find that expression of SGK3, which like AKT is activated by PI3K/PDK1 signaling, has more significance than overexpression of AKT in predicting poor outcome in HCC patients. Taken together, our finding in the present study suggests that SGK3 pathway may function in parallel with AKT pathway and undergoes an AKT‐independent signaling pathway in the pathogenesis of HCC. Further characterization of SGK3 may provide a prognostic biomarker for HCC outcome prediction and a novel therapeutic target in HCC treatment. (HEPATOLOGY 2012.)

Date de mise en ligne : Jeudi 12 janvier 2012
Hermann E. Wasmuth
The chemokine Cxcl9 attenuates liver fibrosis‐associated angiogenesis in mice
Recent data suggest that the chemokine receptor CXCR3 is functionally involved in fibroproliferative disorders, including liver fibrosis. Neoangiogenesis is an important pathophysiological feature of liver scarring, but a functional role of angiostatic CXCR3 chemokines in this process is unclear. We therefore investigated neoangiogenesis in CCl4 induced liver fibrosis in Cxcr3‐/‐ and wild‐type mice by histological, molecular and functional imaging methods. Furthermore, we assessed the direct role of VEGF overexpression on liver aniogenesis and the fibroproliferative response using a Tetinducible bitransgenic mouse model. The feasibility of attenuation of angiogenesis and associated liver fibrosis by therapeutic treatment with the angiostatic chemokine Cxcl9 was systematically analyzed in vitro and in vivo. The results demonstrate that fibrosis progression in Cxcr3‐/‐ mice was strongly linked to enhanced neoangiogenesis and VEGF/VEGFR2 expression compared to wild‐type littermates. Systemic VEGF overexpression led to a fibrogenic response within the liver and was associated with a significantly increased Cxcl9 expression. In vitro, Cxcl9 displayed strong antiproliferative and anti‐migratory effects on VEGF stimulated endothelial cells and stellate cells via reduced VEGFR2 (KDR), PLCγ and ERK phosphorylation, identifying this chemokine as a direct counter‐regulatory molecule of VEGF signalling within the liver. Accordingly, systemic administration of Cxcl9 led to a strong attenuation of neoangiogenesis and experimental liver fibrosis in vivo. In conclusion, the results identify direct angiostatic and anti‐fibrotic effects of the Cxcr3 ligand Cxcl9 in a model of experimental liver fibrosis. The amelioration of liver damage by systemic application of Cxcl9 might offer a novel therapeutic approach for chronic liver diseases associated with increased neoangiogenesis. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 11 janvier 2012
Stanislas Pol
Severe skin rash in case of re‐administration of telaprevir in a patient who previously experienced a non severe rash
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Date de mise en ligne : Mercredi 11 janvier 2012
Ling Tian
miR‐7 inhibits tumor growth and metastasis by targeting the PI3K/AKT pathway in hepatocellular carcinoma
microRNAs are known to be involved in carcinogenesis and tumor progression in hepatocellular carcinoma (HCC). Recently, microRNA‐7 (miR‐7) has been proved to play a substantial role in glioblastoma and breast cancer, but its functions in the context of HCC remain unknown. Here we demonstrate that miR‐7 inhibits HCC cell growth and metastasis invitro and in vivo. We first screened and identified a novel miR‐7 target, phosphoinositide 3‐kinase catalytic subunit delta (PIK3CD). Overexpression of miR‐7 would specifically and markedly down‐regulate its expression. miR‐7‐overexpressing subclones showed significant cell growth inhibition by G0/G1‐phase cell cycle arrest and significant impairment of cell migration in vitro. To identify the mechanisms, we investigated the PI3K/Akt pathway and found that Akt, mTOR and p70S6K were down‐regulated, while 4EBP1 was up‐regulated in miR‐7‐overexpressing subclones. We also identified two novel, putative miR‐7 target genes, mTOR and p70S6K, which further suggests miR‐7 may be a key regulator of the PI3K/Akt pathway. In xenograft animal experiments, we found overexpressed miR‐7 effectively repressed tumor growth (3.5‐fold decrease in mean tumor volume, n =5) and abolished extrahepatic migration from liver to lung in nude mouse model of metastasis (n =5). The number of visible nodules on the lung surface was reduced 32 fold. A correlation between miR‐7 and PIK3CD expression was also confirmed in clinical samples of HCC. Conclusion: These findings indicate that miR‐7 functions as a tumor suppressor and plays a substantial role in inhibiting the tumorigenesis and reversing the metastasis of HCC through the PI3K/Akt/mTOR signaling pathway in vitro and in vivo. By targeting PIK3CD, mTOR and p70S6K, miR‐7 efficiently regulates the PI3K/Akt pathway. Given these, miR‐7 may be a potential therapeutic or diagnostic/prognostic‐target for treating HCC. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
K.J. Williams
Inhibition of hepatic Sulf2 in vivo: A novel strategy to correct diabetic dyslipidemia
BACKGROUNDType 2 diabetes mellitus (T2DM) impairs hepatic clearance of atherogenic postprandial triglyceride‐rich lipoproteins (TRL). We recently reported that livers from T2DM db /db mice markedly overexpress glucosamine‐6‐O‐endosulfatase‐2 (SULF2), an enzyme that removes 6‐O sulfate groups from heparan sulfate proteoglycans (HSPGs) and suppresses uptake of TRLs by cultured hepatocytes. In the present study, we evaluated whether Sulf2 inhibition in T2DM mice in vivo could correct their postprandial dyslipidemia.METHODS AND RESULTSSelective second‐generation antisense oligonucleotides (ASOs) targeting Sulf2 were identified. Db /db mice were treated for 5 weeks with Sulf2 ASO (20 or 50 mg /kg per week), non‐target ASO, or phosphate buffered saline (PBS). Administration of Sulf2 ASO to db /db mice suppressed hepatic Sulf2 mRNA expression by 70‐80%, i.e., down to levels in non‐diabetic db /m mice, and increased the ratio of tri‐ to di‐sulfated disaccharides in hepatic HSPGs (p<0.05). Hepatocytes isolated from db /db mice on non‐target ASO exhibited a significant impairment in VLDL binding that was entirely corrected in db /db mice on Sulf2 ASO. Sulf2 ASO lowered the random, non‐fasting plasma triglyceride (TG) levels by 50%, achieving non‐diabetic values. Most importantly, Sulf2 ASO treatment flattened the plasma TG excursions in db /db mice after corn‐oil gavage (iAUC 1500±470 (mg /dL)·h for non‐target ASO versus 160±40 (mg /dL)·h for Sulf2 ASO (p<0.01).CONCLUSIONSDespite extensive metabolic derangements in T2DM mice, inhibition of a single dysregulated molecule, SULF2, normalizes the VLDL‐binding capacity of their hepatocytes and abolishes postprandial hypertriglyceridemia. These findings provide a key proof‐of‐concept in vivo to support Sulf2 inhibition as an attractive strategy to improve metabolic dyslipidemia. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Min Gao
Impact of a baseline polymorphism on the emergence of resistance to the HCV NS5A replication complex inhibitor BMS‐790052
The influence of naturally occurring polymorphisms on the potency of the HCV NS5A replication complex inhibitor BMS‐790052 was investigated by evaluating hybrid replicons in which the entire NS5A coding region of genotype (GT) la and 1b laboratory (lab) strains (H77c and Con1) were replaced with the corresponding regions of specimens collected from ten GT‐1a and six GT‐1b infected subjects. For baseline (BL) specimens, with no previously observed resistance variants indentified by population sequencing, the EC50 values for BMS‐790052 were similar for the clinically‐derived and lab strains. A Q30R variant was observed at viral breakthrough (VBT) in one of the GT‐1a infected subjects. Since the lowest plasma exposure of BMS‐790052 observed in this subject was 117 nM and the EC50 for a GT‐1a H77c replicon containing a Q30R substitution is ∼7 nM, a rigorous investigation was initiated to determine the basis for resistance. Three approaches were used: (i) replacement of the entire H77c NS5A or (ii) replacement of the N‐terminal region of NS5A, with sequence from BL and Day‐14, and (iii) substitution of specific amino acids. A BL polymorphism E62D did not contribute resistance to BMS‐790052; however, the linked variant Q30R‐E62D conferred high level resistance in vitro and is likely responsible for VBT in vivo. Our data show that a BL polymorphism with minimal impact on the anti‐HCV effect of BMS‐790052 can affect the emergence of resistance and significantly impact clinical outcome. This work establishes a clear and systematic approach to monitor resistance to NS5A inhibitors in the clinic. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Thomas Berg
Combined effects of different IL28B gene variants on the outcome of dual combination therapy in chronic HCV type 1 infection
In patients with chronic hepatitis C virus infection (HCV) several variants of the IL28B gene have been shown to correlate significantly with a sustained virologic response (SVR). Recent evidence shows that determination of one single IL28B polymorphism rs12979860 is sufficient for predicting treatment outcome.We examined whether the combined determination of the IL28B single nucleotide polymorphisms (SNP) rs12979860, rs8099917, rs12980275 and rs8103142 might improve prediction of SVR in patients with HCV.In the study cohort, 54% of 942 patients with chronic HCV type 1 infection had SVR. The IL28B SNPs rs12979860CC and rs8099917TT correlated significantly with SVR (68% and 62%). The SNPs rs12980275 and rs8103142 were in strong linkage disequilibrium with rs12979860 and were not included in further analysis.In homozygous carriers of the rs12979860 responder allele C, additional genotyping of the rs8099917 SNP had no impact on response prediction, while in carriers of the rs12979860 non‐responder allele the rs8099917 SNP improved the response prediction. In heterozygous carriers of the rs12979860 non‐responder T allele SVR rates were 55% in the presence of the rs8099917TT genotype and 40% in patients carrying the rs8099917 TG or GG genotype. Analysis of an independent confirmation cohort of 377 HCV type 1‐infected patients verified the significant difference in SVR rates between the combined genotypes rs12979860CT/rs8099917TT and rs12979860CT/rs8099917TG (38% vs. 21%, p=0.018).Conclusion: Treatment outcome prediction could not be improved in homozygous carriers of the IL28B rs12979860 C responder allele by the additional determination of the rs8099917 SNPs. There is evidence that a significant proportion of heterozygous carriers of the rs12979860 T non‐responder allele can profit with respect to SVR prediction by further determination of the rs8099917 SNPs. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Carlo Merkel
Attention: Minimal hepatic encephalopathy and road accidents
No absract.

Date de mise en ligne : Mercredi 11 janvier 2012
Joshua Miller
Systemic immunoregulatory and proteogenomic effects of tacrolimus to sirolimus conversion in liver transplant recipients
Immunosuppression withdrawal from calcineurin inhibitors is only possible in ∼20% of liver transplant recipients. However, mTOR inhibitors (sirolimus) appear to be more immunoregulatory and might promote a tolerant state for withdrawal. Our purpose was to determine if systemic (blood, marrow, allograft) signatures of immunoregulation are promoted by conversion from tacrolimus to sirolimus. We therefore performed the following serial assays before and after sirolimus conversion in liver transplant recipients to test for enhanced markers of immunoregulation: 1) Flow cytometry immunophenotyping of PBMC and bone marrow aspirates for regulatory T cells (Tregs: CD4+CD25+++FOXP3+) and regulatory dendritic cells (DCregs: ILT3+/4+); 2) liver biopsy immunohistochemical staining (FOXP3:CD3, CD4:CD8 ratios) and immunophenotyping of biopsy‐derived Tregs after growth in culture; 3) effects of pre‐ vs. post‐conversion sera on Treg generation in mixed lymphocyte reactions; 4) peripheral blood non‐specific CD4 responses (Cylex® ImmuKnow); 5) peripheral blood gene transcripts and proteomic profiles. We successfully converted 20 non‐immune, non‐viremic recipients (age 57.2±8; 3.5±2.1 years post‐LT) from tacrolimus to sirolimus for renal dysfunction. Our results demonstrated significant increases in Tregs in PBMC and marrow and DCregs in PBMC (p<0.01) following conversion. In biopsy immunohistochemistry, FOXP3:CD3 and CD4:CD8 ratios were significantly higher after conversion and a number of biopsy cultures developed new or higher FOXP3+ cell growth. Non‐specific CD4 responses (Cylex® ImmuKnow) did not change. Both pre‐ and post‐conversion sera inhibited mixed lymphocyte reactions, although only tacrolimus sera suppressed Treg generation. Finally, 289 novel genes and 22 proteins, several important in immunoregulatory pathways, were expressed after conversion.Conclusions:Tacrolimus to sirolimus conversion increases systemic Tregs, DCregs and immunoregulatory proteogenomic signatures in liver transplant recipients and may therefore facilitate immunosuppression minimization or withdrawal. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Jacques Izopet
Hepatitis E virus‐specific T‐cell response after transplantation
No absract.

Date de mise en ligne : Mercredi 11 janvier 2012
Stuart C. Ray*
Spontaneous clearance of primary acute hepatitis C virus infection correlated with high initial viral RNA level and rapid HVR1 evolution
Objective/Aims:To determine whether early viral dynamics and evolution predict outcome of primary acute hepatitis C virus (HCV) infection.Methods:HCV‐ and HIV‐negative injection drug users were enrolled prospectively and followed monthly to identify acute HCV infection using RNA detection. Subjects with more than one month between HCV RNA negative and positive visits were excluded to ensure stringent acute infection. Differences in medians of log‐transformed viral RNA levels and evolutionary rates in each gene of a 5′‐hemigenomic amplicon were assessed using the Mann‐Whitney Rank Sum test. Correlation coefficient was calculated using Spearman Rank Order.Results:Initial viremia level was 50‐fold higher in subjects with spontaneous clearance (compared with persistence) of primary acute HCV infection (median 7.1 versus 5.4 log10 IU/mL, P=0.002). Initial viremia level in subjects with IL‐28B‐C allele and clearance was higher than that in subjects with IL‐28B‐T allele and persistence (P=0.001). Evolutionary rates in the hypervariable region 1 (HVR1) region of E2 gene were significantly higher in self‐resolvers than those in persistence subjects during early infection, whereas other genes/regions had comparable rates. All major substitutions in HVR1 in persistence subjects were convergent changes whereas over the same time interval clearance subjects displayed divergent evolution, indicating different immune responses between the two groups.Conclusions:Spontaneous clearance of acute HCV infection is predicted by high initial viremia as well as favorable IL‐28B genotype, and associated with rapid envelope sequence evolution. This linkage of host genetics, viral dynamics, and evolution provides new directions for mechanistic studies. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
F Purrello
Adrenocortical dysfunction in liver disease: A systematic review
In patients with cirrhosis adrenal insufficiency (AI) is reported during sepsis and septic shock, and is associated with increased mortality. Consequently, the term “hepato‐adrenal syndrome” was proposed. Some studies have shown that AI is frequent in stable cirrhosis, and in cirrhosis associated with decompensation other than sepsis, such as bleeding and ascites. Moreover, other studies showed a high prevalence in liver transplant recipients, immediately after or some time after liver transplantation. The effect of corticosteroid therapy in critically ill patients with liver disease has been evaluated in some studies, but the results remain controversial.The 250 µg ACTH stimulation test to diagnose AI in critically ill adult patients is recommended by an international task force. However in liver disease there is no consensus on the appropriate tests and normal values to assess adrenal function; thus standardization of normal ranges and methodology is needed. Serum total cortisol assays overestimate AI in patients with cirrhosis, so that direct free cortisol measurement or its surrogates may be useful measurements to define AI, but further studies are needed to clarify this.In addition, the mechanisms by which liver disease leads to adrenal dysfunction are not sufficiently documented. The review evaluates published data regarding adrenal function in patients with liver disease, with particular focus on the potential limitations of these studies, and suggestions for future studies. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Allan Tsung
High mobility group box 1 activates caspase‐1 and promotes hepatocellular carcinoma invasiveness and metastases
Hypoxia is often found in solid tumors and is associated with tumor progression and poor clinical outcomes. The exact mechanisms related to hypoxia‐induced invasion and metastasis remain unclear. We elucidated the mechanism by which the nuclear damage associated molecular pattern molecule, high mobility group box 1 (HMGB1), released under hypoxic stress can induce an inflammatory response to promote invasion and metastasis in hepatocellular carcinoma (HCC) cells. Caspase‐1 activation was found to occur in hypoxic HCC cells in a process that was dependent on the extracellular release of HMGB1 and subsequent activation of both TLR4 and RAGE signaling pathways. Downstream from hypoxia induced caspase‐1 activation, cleavage and release of proinflammatory cytokines, IL‐1β and IL‐18 occurred. We further demonstrate that overexpression of HMGB1 or treatment with recombinant HMGB1 enhanced invasiveness of HCC cells while stable knockdown of HMGB1 remarkably reduced HCC invasion. Moreover, in a murine model of HCC pulmonary metastasis, stable knockdown of HMGB1 suppressed HCC invasion and metastasis. Conclusion: These results suggest that in hypoxic HCC cells, HMGB1 activates TLR4 and RAGE signaling pathways to induce caspase‐1 activation with subsequent production of multiple inflammatory mediators which in turn promotes cancer invasion and metastasis. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Gary H. Perdew
Ah receptor regulates the cholesterol biosynthetic pathway in a dioxin response element‐independent manner
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor. Activation of AHR mediates the expression of target genes (e.g. CYP1A1), by binding to dioxin response element (DRE) sequences in their promoter region. To understand the multiple mechanisms of AHR‐mediated gene regulation, a microarray analysis on liver isolated from ligand‐treated transgenic mice expressing a wild‐type Ahr or a DRE‐binding mutant Ahr (A78D) on an ahr‐null background was performed. Results revealed that AHR DRE‐binding is not required for suppression of genes involved in cholesterol synthesis. Quantitative RT‐ PCR performed on both mouse liver and primary human hepatocyte RNA demonstrated a coordinate repression of genes involved in cholesterol biosynthesis, namely HMGCR, FDFT1, SQLE and LSS following receptor activation. An additional transgenic mouse line was established expressing a liver‐specific Ahr‐A78D on a CreAlb/Ahrflox/flox background. These mice displayed a similar repression of cholesterol biosynthetic genes compared to Ahrflox/flox mice, further indicating that the observed modulation is AHR‐specific and occurs in a DRE‐independent manner. Elevated hepatic transcriptional levels of the genes of interest were noted in congenic C57BL/6J‐Ahd allele mice, when compared to the WT C57BL/6J mice, which carry the Ahb allele. Down‐regulation of ARNT levels using siRNA in a human cell line revealed no effect on the expression of cholesterol biosynthetic genes. Finally, cholesterol secretion was shown to be significantly decreased in human cells following AHR activation. Conclusion: These data firmly establish an endogenous role for AHR as a regulator of the cholesterol biosynthesis pathway independent of its DRE‐binding ability and suggest that AHR may be a previously unrecognized therapeutic target. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Young Nyun Park
A fibrous stromal component in hepatocellular carcinoma reveals a cholangiocarcinoma‐like gene expression trait and EMT
Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the major primary liver cancers in adults. The phenotypic overlap between HCC and CC has been shown to comprise a continuous liver cancer spectrum. As a proof of this concept, a recent study demonstrated a genomic subtype of HCC that expressed CC‐like gene expression traits such as CC‐like HCC, which revealed the common genomic trait of stem cell‐like properties and aggressive clinical outcomes. Scirrhous HCC (S‐HCC), a rare variant of HCC, is characterized by abundant fibrous stroma and has been known to express several liver stem/progenitor cell markers. This suggests that S‐HCC may harbor common intermediate traits between HCC and CC including stem cell traits, which are similar to those of CC‐like HCC. However, the molecular and pathological characteristics of S‐HCC have not been fully evaluated. By performing gene expression profiling and immunohistochemical evaluation, we compared the morphological and molecular features of S‐HCC with those of CC and HCC. S‐HCC expresses both CC‐like and stem cell‐like genomic traits. In addition, we observed the expression of core epithelial‐mesenchymal transition (EMT)‐related genes, which may contribute to the aggressive behavior of S‐HCC. Over‐expression of transforming growth factor β (TGF‐β) signaling was also found, implying its regulatory role in the pathobiology of S‐HCC. Conclusion: We suggest that the fibrous stromal component in HCC may contribute to the acquisition of CC‐like gene expression traits in HCC. The expression of stem cell‐like traits and TGF‐β/EMT molecules may play a pivotal role in the aggressive phenotyping of S‐HCC. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Regina M. Santella
Genome‐wide DNA methylation profiles in hepatocellular carcinoma
Alterations in DNA methylation frequently occur in hepatocellular cancer (HCC). We have previously demonstrated that hypermethylation in candidate genes can be detected in plasma DNA prior to HCC diagnosis. To identify with a genome‐wide approach additional genes hypermethylated in HCC that could be used for more accurate analysis of plasma DNA for early diagnosis, we analyzed tumor and adjacent non‐tumor tissues from 62 Taiwanese HCC cases using Illumina methylation arrays that screen 26,486 autosomal CpG sites. After Bonferroni adjustment, a total of 2,324 CpG sites significantly differed in methylation level, with 684 CpG sites significantly hypermethylated and 1,640 hypomethylated in tumor compared to non‐tumor tissues. Array data were validated with pyrosequencing in a subset of 5 of these genes; correlation coefficients ranged from 0.92 to 0.97. Analysis of plasma DNA from 38 cases demonstrated that 37% to 63% of cases had detectable hypermethylated DNA (≥5% methylation) for these 5 genes individually. At least one of these genes was hypermethylated in 87% of cases, suggesting that measurement of DNA methylation in plasma samples is feasible. The panel of methylated genes indentified in the current study will be further tested in large cohort of prospectively collected samples to determine their utility as early biomarkers of hepatocellular carcinoma. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 11 janvier 2012
Violaine Moreau
Rnd3/RhoE is down‐regulated in hepatocellular carcinoma and controls cellular invasion
We performed a review of public microarray data that revealed a significant down‐regulation of Rnd3 expression in hepatocellular carcinoma as compared to non‐tumor liver. Rnd3/RhoE is an atypical RhoGTPase family member, as it is always under its active GTP‐bound conformation and not sensitive to classical regulators. Rnd3 down‐regulation was validated by quantitative real time PCR in a hundred independent tumors. Moreover, Rnd3 down‐expression was confirmed using immunohistochemistry on tumor sections and Western blot on human tumor and cell line extracts. Rnd3 expression was significantly lower in invasive tumors with satellite nodules. Overexpression and silencing of Rnd3 in Hep3B cells led to decreased and increased 3D cell motility, respectively. The siRNA‐mediated down‐regulation of Rnd3 expression induced loss of E‐cadherin at cell‐cell junctions that was linked to epithelial‐mesenchymal transition through the up‐regulation of the zinc finger E‐box binding homeobox protein ZEB2 and the down‐regulation of miR‐200b and miR‐200c. Rnd3 knockdown mediated tumor hepatocyte invasion in a matrix metalloproteinase‐independent, and Rac1‐dependent manner. Conclusion: Rnd3 down‐regulation provides an invasive advantage to tumor hepatocytes suggesting that RND3 might represent a metastasis suppressor gene in hepatocellular carcinoma. (HEPATOLOGY 2012.)

Date de mise en ligne : Mercredi 04 janvier 2012
Heiner Wedemeyer
Hepatitis E virus‐specific T‐cell response after transplantation
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
Qing‐Sheng Mi
Identification of endogenous normalizers for serum miRNAs by microarray profiling: U6 snRNA is not a reliable normalizer
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
Wengang Li
The AIB1 oncogene enhances human cholangiocarcinoma growth and chemoresistance by simultaneous activation of Akt and Nrf2 pathways
Transcriptional coactivator amplified in breast cancer 1 (AIB1) plays important roles in the progression of several cancers such as prostate cancer, breast cancer, and hepatoceullar carcinoma. However, its role in Cholangiocarcinoma (CCA), a chemoresistant bile duct carcinoma with a poor prognosis, remains unclear. In this study, we found that AIB1 protein was frequently overexpressed in human CCA specimens and CCA cell lines. Down‐regulation of AIB1 induced the G2/M arrest and decreased the expression of mitosis‐promoting factors including Cyclin A, Cyclin B and Cdk1 through suppressing the Akt pathway, which resulted in inhibiting CCA cell proliferation. In addition, AIB1 enhanced the chemoresistance of CCA cells at least in part through up‐regulating the expression of anti‐apoptotic protein Bcl‐2. AIB1 regulated the expression of Bcl‐2 in CCA cells through activating the Akt pathway as well as suppressing intracellular reactive oxygen species (ROS). AIB1 suppressed ROS by up‐regulating antioxindants such as glutathione synthetase and glutathione peroxidase, which are targets of the Nrf2, a critical transcription factor that regulates antioxidants, detoxification enzymes and drug efflux proteins. AIB1 also increased the expression of another two Nrf2 targets ABCC2 and ABCG2 to enhance drug efflux. AIB1 served as an essential coactivator for Nrf2 activation by physically interacting with Nrf2 to enhance its transcriptional activity.Conclusion:AIB1 plays an important role in proliferation and chemoresistance of CCA through simultaneous activation of Akt and Nrf2 pathways, suggesting that AIB1 is a potential molecular target for CCA treatment. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Anne Larson
Introduction to the revised AASLD position paper on acute liver failure 2011
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
DD Houlihan
Prioritising treatment experienced patients with hepatitis C infection for treatment with telaprevir: A number needed to treat approach
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
Carole Ehleben
Impact of IL28B on treatment outcome in hepatitis C virus G1/4 patients receiving response‐guided therapy with peginterferon alpha‐2a/ribavirin
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
Carlos Guarner
Cognitive dysfunction in cirrhosis is associated with falls. A prospective study
Falls are frequent among patients with debilitating disorders and can have a serious impact on health‐status. Mild cognitive disturbances associated with cirrhosis may increase the risk for falls. Identifying subjects at risk may allow implementation of preventive measures. Our aim was to assess the predictive value of the Psychometric Hepatic Encephalopathy Score (PHES) in identifying patients likely to sustain falls. One hundred and twenty‐two outpatients with cirrhosis were assessed using the PHES and followed at specified intervals. One‐third of them exhibited cognitive dysfunction (CD) according to the PHES (<‐4). Seventeen of the 42 patients (40.4%) with CD had at least one fall during follow‐up. In comparison, only 5 of 80 (6.2%) without CD had falls (p<0.001). Fractures occurred in four patients (9.5%) with CD but in no patient without CD (p=0.01). Patients with CD needed more healthcare (23.8% vs 2.5%, p<0.001), more emergency room care (14.2% vs 2.5%, p=0.02) and more hospitalization (9.5% vs 0%, p=0.01) due to falls than patients without CD. Patients taking psychoactive treatment (n=21) had a higher frequency of falls, and this was related to an abnormal PHES. In patients without psychoactive treatment (n=101), the incidence of falls was 32.4% in patients with CD vs 7.5% in those without CD (p=0.003). In the multivariate analysis, CD was the only independent predictive factor of falls (OR 10.2, 95% CI 3.4‐30.4, p<0.001). The 1‐year probability of falling was 52.3% in patients with CD and 6.5% in those without (p<0.001). Conclusion: An abnormal PHES identifies patients with cirrhosis at risk for falls. This psychometric test may be useful to promote awareness of falls and identify patients who may benefit from preventive strategies. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Ruth B Jiles
Awareness of infection, knowledge of hepatitis C, and medical follow‐up among individuals testing positive for hepatitis C: NHANES 2001‐08
Many persons infected with hepatitis C virus (HCV) are unknown to the healthcare system because they may be asymptomatic for years, have not been tested for HCV infection, and only seek medical care when they develop liver‐related complications. We analyzed data from persons who tested positive for past or current HCV infection during participation in the National Health and Nutrition Examination Survey (NHANES) from 2001 through 2008. A Follow‐up Survey was conducted six months after examination to determine: 1) how many participants testing positive for HCV infection were aware of their HCV status before being notified by NHANES, 2) what actions participants took after becoming aware of their first positive test, and 3) participants' knowledge about hepatitis C. Of 30,140 participants tested, 393 (1.3%) had evidence of past or current HCV infection; 170 (43%) could be contacted during the follow‐up survey and interviewed. Only 49.7% were aware of their positive HCV infection status before being notified by NHANES, and only 3.7% of these respondents reported that they had first been tested for HCV because they or their doctor thought they were at risk for infection. Overall, 85.4% had heard of hepatitis C; correct responses to questions about hepatitis C were higher among persons aged 40‐59 years, white non‐Hispanics, and respondents who saw a physician after their first positive HCV test. Eighty percent of respondents indicated they had seen a doctor about their first positive HCV test result.Conclusion:These data indicate that fewer than half of those infected with HCV may be aware of their infection. The findings suggest that more intensive efforts are needed to identify and test persons at risk for HCV infection. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
E. Jenny Heathcote
Clinical trials and their translation in hepatology: Past, present and future
n/a

Date de mise en ligne : Mardi 27 d�cembre 2011
Anna Mae Diehl
Hedgehog pathway activation parallels histologic severity of injury and fibrosis in human nonalcoholic fatty liver disease
The Hedgehog (HH) signaling pathway mediates several processes that are deregulated in patients with the metabolic syndrome (e.g., fat mass regulation, vascular/endothelial remodeling, liver injury and repair, and carcinogenesis). The severity of nonalcoholic fatty liver disease (NAFLD) and the metabolic syndrome generally correlate. Therefore, we hypothesized that the level of HH pathway activation would increase in parallel with the severity of liver damage in NAFLD. To assess potential correlations between known histologic and clinical predictors of advanced liver disease and HH pathway activation, immunohistochemistry was performed on liver biopsies from a large well‐characterized cohort of NAFLD patients (n=90) enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) Database 1 study. Increased HH activity (evidenced by accumulation of HH‐ligand producing cells and HH‐responsive target cells) strongly correlated with portal inflammation, ballooning, and fibrosis stage (each p<0.0001), supporting a relationship between HH pathway activation and liver damage. Pathway activity also correlated significantly with markers of liver repair, including numbers of hepatic progenitors and myofibroblastic cells (both p<0.03). In addition, various clinical parameters that have been linked to histologically‐advanced NAFLD, including increased patient age (p<0.005), BMI (p<0.002), waist circumference (p<0.0007), homeostatic model assessment of insulin resistance (HOMA‐IR) (p<0.0001) and hypertension (p<0.02), correlated with hepatic HH activity.Conclusion:In NAFLD patients, the level of hepatic HH pathway activity is highly correlated with the severity of liver damage and with metabolic syndrome parameters that are known to be predictive of advanced liver disease. Hence, deregulation of the HH signaling network may contribute to the pathogenesis and sequelae of liver damage that develops with the metabolic syndrome. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Xiaodong Shu
An anti‐apoptotic role of SNX7 is required for liver development in zebrafish
Sorting nexin (SNX) family proteins are best characterized for their abilities to regulate protein trafficking during processes such as endocytosis of membrane receptors, endosomal sorting and protein degradation, but their in vivo functions remain largely unknown. We started to investigate the biological functions of SNXs using the zebrafish model. In this study, we demonstrated that SNX7 was essential for embryonic liver development. Hepatoblasts were specified normally and the proliferation of these cells was not affected when SNX7 was knocked‐down by gene specific morpholinos, however, they underwent massive apoptosis during the early budding stage. SNX7 mainly regulated the survival of cells in the embryonic liver and it did not affect the viability of cells in other endoderm derived organs. We further demonstrated that down‐regulation of SNX7 by siRNAs induced apoptosis in cell culture. At the molecular level, the c‐FLIP/caspase 8 pathway was activated when SNX7 was down‐regulated. Furthermore, over‐expression of c‐FLIPs was able to rescue the SNX7 knockdown induced liver defect. Conclusion: SNX7 is a liver‐enriched anti‐apoptotic protein which is indispensable for the survival of hepatoblasts during zebrafish early embryogenesis. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Luc J.W. van der Laan
Mycophenolic acid augments interferon‐stimulated gene expression and inhibits hepatitis C virus infection in vitro and in vivo
Mycophenolic acid (MPA) is a highly effective immunosuppressant that has a broad anti‐viral activity against different viruses and can act in synergy with interferon‐α (IFN‐α) on hepatitis C virus (HCV) replication. MPA is a potent IMPDH inhibitor but the anti‐viral mechanisms are less understood. The aim of this study is to investigate the inhibition of HCV infection by MPA and the molecular basis for it's synergy with IFN‐α. The role of IMPDH and interferon‐stimulated genes (ISGs) was investigated in two HCV models using gain or loss‐of‐function approaches. In vivo effect of MPA treatment was studies in NOD/SCID mice engrafted with HCV replicon cells. Potent anti‐viral effects of MPA at clinically relevant concentrations were observed both the subgenomic and JFH1‐derived infectious HCV models. MPA treatment in mice resulted in a specific and robust inhibition of HCV replication. Ectopic expression of a MPA‐resistant IMPDH2 mutant in HCV host cells completely reversed the anti‐proliferative effect of MPA but only partially affected the anti‐viral potency. However, similar to ribavirin, MPA induced expression of multiple anti‐viral ISGs, including IRF1. Co‐treatment of MPA with IFN‐α resulted in additive effects on ISG expression and enhanced IFN‐induced luciferase reporter activity. Knockdown of IRF1, but not IFITM3, significantly attenuated the inhibition of HCV replication by MPA. Conclusion: MPA exerts a potent anti‐HCV effect in vitro and in mice and acts in synergy with IFN‐α. MPA's anti‐viral activity partially depends on IMPDH but also involves stimulation of ISGs, providing a molecular basis for it's synergy with IFN‐α. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Christian P. Strassburg
Gilbert syndrome redefined: A complex genetic haplotype influences the regulation of glucuronidation
Gilbert syndrome (GS) is characterized by intermittent unconjugated hyperbilirubinemia without structural liver damage affecting about 10% of the white population. In GS the UGT1A1*28 variant reduces bilirubin conjugation by 70% and is associated with irinotecan and protease inhibitor side effects. Aim of this study was to characterize potential in vivo consequences of UGT1A gene variability in GS. Three hundred GS patients (UGT1A1*28 homozygous) and 249 healthy blood donors (HBD) were genotyped for UGT1A (UGT1A1*28, UGT1A3‐66 T>C, UGT1A6*3a, UGT1A7*3) and transporter SNPs (SCLO1B1 p.V174A, SCLO1B1 p.N130D, ABCC2 p.I1324I, ABCC2 ‐24 UTR) using TaqMan‐5′‐nuclease‐assays. A humanized transgenic UGT1A‐SNP and corresponding wild‐type mouse model were established carrying the GS‐associated UGT1A variant haplotype. UGT1A transcript and protein expression, and transcriptional activation were studied in vivo. Homozygous UGT1A1*28 GS individuals were simultaneously homozygous for UGT1A3‐66 T>C (91%), UGT1A6*2a (77%), and UGT1A7*3 (77%). Seventy‐six percent of GS and only 9% of HBD were homozygous for the variant haplotype spanning 4 UGT1A genes. SCLO1B1 and ABCC2 single nucleotide polymorphisms (SNPs) showed no differences. In transgenic humanized UGT1A SNP and wild‐type mice this UGT1A haplotype led to lower UGT1A mRNA expression and UGT1A protein synthesis. UGT1A transcriptional activation by dioxin, phenobarbital and endotoxin was significantly reduced in SNP mice.Conclusion:Our data redefine the genetic basis behind GS. In vivo data studying the genotype present in 76% of GS individuals suggest that transcription and transcriptional activation of glucuronidation genes responsible for conjugation and detoxification is directly affected leading to lower responsiveness. This study suggests that GS should be considered as a potential risk factor for drug toxicity. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Juan Francisco Miquel
Phytosterol and cholesterol precursor levels indicate increased cholesterol excretion and biosynthesis in gallstone patients
In hepatocytes and enterocytes sterol uptake and secretion is mediated by NPC1L1 and ABCG5/8 proteins, respectively. Whereas serum levels of phytosterols represent surrogate markers for intestinal cholesterol absorption, cholesterol precursors reflect cholesterol biosynthesis. Here we compare serum and biliary sterol levels in ethnically different populations of patients with gallstone disease (GSD) and stone‐free controls to identify differences in cholesterol transport and synthesis between these groups. In this case‐control study four cohorts were analyzed: 112 German patients with GSD and 152 controls; two distinct Chilean ethnic groups: Hispanics (100 GSD, 100 controls) and Amerindians (20 GSD, 20 controls); additionally an 8‐year follow‐up of 70 Hispanics was performed. Serum sterols were measured by GC‐MS. Gallbladder bile sterol levels were analyzed in cholesterol GSD and controls (n=17 each). Common ABCG5/8 variants were genotyped. Comparison of serum sterols showed lower levels of phytosterols and higher levels of cholesterol precursors in GSD patients than in controls. The ratios of phytosterols to cholesterol precursors were lower in GSD patients, whereas biliary phytosterol and cholesterol concentrations were elevated as compared to controls. In the follow‐up study, serum phytosterol levels were significantly lower even before GSD were detectable by ultrasound. An ethnic gradient in the ratios of phytosterols to cholesterol precursors was apparent (Germans > Hispanics > Amerindians). ABCG5/8 variants did not fully explain the sterol metabolic trait of GSD in any of the cohorts. Conclusions: Individuals predisposed to GSD display increased biliary output of cholesterol in the setting of relatively low intestinal cholesterol absorption, indicating enhanced whole body sterol clearance. This metabolic trait precedes gallstone formation and is a feature of ethnic groups at higher risk of cholesterol GSD. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
Long Yu
Zinc finger transcription factor 191, directly binding to β‐catenin promoter, promotes cell proliferation of hepatocellular carcinoma
Activation of β‐Catenin, the central effector of the canonical Wnt pathway, has been implicated in hepatocellular carcinoma (HCC). However the transcription regulation mechanism of β‐Catenin gene in HCC remains unknown. Here we report that human zinc finger protein 191 (ZNF191) is a potential regulator of β‐Catenin transcription. ZNF191, a Krüppel‐like protein, specifically interacts with the TCAT motif which constitutes the HUMTH01 microsatellite in the tyrosine hydroxylase (TH) gene ex vivo. We demonstrate that ZNF191 was significantly overexpressed in human HCC specimens and was associated with growth of human HCC cells. Global profiling of gene expression in ZNF191 knockdown human hepatic L02 cells revealed that important Wnt signal pathway genes β‐Catenin and Cyclin D1 mRNAs were significantly down regulated. In agreement with transcription level, β‐catenin and cyclin D1 proteins were also down regulated in transient and stable ZNF191 knockdown L02 and hepatoma Hep3B cell lines. Moreover, significant correlation between ZNF191 and β‐Catenin mRNA expression was detected in human HCCs. Promoter luciferase assay indicated that ZNF191 can increase transcription activity of full‐length CTNNB1 promoter, and nt‐1407/‐907 of CTNNB1 promoter exhibited the maximum transcriptional activity. EMSA assay showed that purified ZNF191 protein can directly bind to CTNNB1 promoter, and the binding region is located at nt‐1254/‐1224. Finally, we demonstrated that the key binding sequence of ZNF191 in vivo is ATTAATT. Conclusion: ZNF191 can directly bind to CTNNB1 promoter, and activate the expression of β‐Catenin and its downstream target genes such as Cyclin D1 in hepatoma cell lines. This study uncovers a new molecular mechanism of transcription regulation of β‐Catenin gene in HCC. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
B. Kevin Park
Reply to Qi et al
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Date de mise en ligne : Mardi 27 d�cembre 2011
Rakesh Kumar
Synergistic inhibition of hepatocellular carcinoma growth by cotargeting chromatin modifying enzymes and poly (ADP‐ribose) polymerases
Hepatocellular carcinoma (HCC) is a particularly lethal form of cancer, yet effective therapeutic options for advanced HCC are limited. As poly(ADP‐ribose) polymerases (PARPs) and histone deacetylases (HDACs) are emerging to be among the most promising targets in cancer therapy, and sensitivity to PARP inhibition depends on homologous recombination (HR) deficiency and inhibition of HDAC activity blocks the HR pathway, we tested the hypothesis that co‐targeting both enzymatic activities could synergistically inhibit HCC growth and defined the molecular determinants of sensitivity to both enzyme inhibitors. We discovered that HCC cells have differential sensitivity to HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) and PARP inhibitor Olaparib, and identified one pair of cell lines, termed SNU‐398 and SNU‐449, with sensitive versus resistant phenotype to both enzyme inhibitors, respectively. Co‐administration of SAHA and Olaparib synergistically inhibited the growth of SNU‐398 but not SNU‐449 cells, which was associated with increased apoptosis and accumulated unrepaired DNA damage. Multiple lines of evidence demonstrate that the hepatic fibrosis/hepatic stellate cell activation may be an important genetic determinant of cellular sensitivity to both enzymatic inhibitors, and coordinate activation or inactivation of the aryl hydrocarbon receptor (AhR) and cAMP‐mediated signaling pathways are involved in cell response to SAHA and Olaparib treatment. Conclusion: These findings suggest that combination therapy with both enzyme inhibitors may be a strategy for therapy of sensitive HCC cells, and identification of these novel molecular determinants may eventually guide the optimal use of PARP and HDAC inhibitors in the clinic. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 27 d�cembre 2011
John P. Iredale
Elastin accumulation is regulated at the level of degradation by macrophage metalloelastase (MMP‐12) during experimental liver fibrosis
Elastin has been linked to maturity of liver fibrosis. To date, the regulation of elastin secretion and its degradation in liver fibrosis has not been characterised. The aim of this work was to define elastin accumulation and the role of the paradigm elastase macrophage metalloelastase (MMP‐12) in its turnover during fibrosis.Liver fibrosis was induced by either IP injections of CCl4 for up to 12 weeks (rat and mouse) or oral administration of thioacetamide (TAA) for one year (mouse). Elastin synthesis, deposition and degradation were investigated by immunohistochemistry, qPCR and western blotting and casein zymography. The regulation of MMP‐12 elastin degradation was defined mechanistically using CD11b‐DTR and MMP‐12 knockout mice.In a CCl4 model of fibrosis in rat, elastin deposition was significantly increased only in advanced fibrosis. Tropoelastin expression increased with duration of injury. MMP‐12 protein levels were only modestly changed and in co‐immunoprecipitation experiments MMP‐12 was bound in greater quantities to its inhibitor TIMP‐1 in advanced vs. early fibrosis. Immunohistochemistry and macrophage depletion experiments indicated that macrophages were the sole source of MMP‐12. Exposure of CCl4 in MMP‐12‐/‐ mice lead to similar degree of overall fibrosis compared to wild‐type but increased perisinusoidal elastin. Conversely, oral administration of TAA caused both higher elastin accumulation and higher fibrosis in MMP‐12‐/‐ mice compared to WT.Conclusions:Elastin is regulated at the level of degradation during liver fibrosis. Macrophage derived MMP‐12 regulates elastin degradation even in progressive experimental liver fibrosis. These observations have important implications for the design of antifibrotic therapies. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 24 d�cembre 2011
Samuel Klein
Randomized trial of exercise effect on intrahepatic triglyceride content and lipid kinetics in nonalcoholic fatty liver disease
Nonalcoholic fatty liver disease (NAFLD) and alterations in hepatic lipoprotein kinetics are common metabolic complications associated with obesity. Lifestyle modification involving dietinduced weight loss and regular exercise decreases intrahepatic triglyceride (IHTG) content and very low density lipoprotein (VLDL) triglyceride (TG) secretion rate. The aim of this study was to evaluate the weight loss‐independent effect of following the physical activity guidelines recommended by the Department of Health and Human Services on IHTG content and VLDL kinetics in obese persons with NAFLD. Eighteen obese people (BMI: 38.1 ± 4.6 kg/m2) with NAFLD were randomized to 16 weeks of exercise training (45‐55% V̇O2peak, 30‐60 min × 5 days/week; n = 12) or observation (control; n = 6). Magnetic resonance spectroscopy and stable isotope tracer infusions in conjunction with compartmental modeling were used to evaluate IHTG content and hepatic VLDL‐TG and apolipoprotein B‐100 (apoB‐100) secretion rates. Exercise training resulted in a 10.3 ± 4.6 % decrease in IHTG content (p<0.05), but did not change total body weight (103.1 ± 4.2 kg before and 102.9 ± 4.2 kg after training) or percent body fat (38.9 ± 2.1 % before and 39.2 ± 2.1 % after training). Exercise training did not change the hepatic VLDL‐TG secretion rate (17.7 ± 3.9 μmol/min before and 16.8 ± 5.4 μmol/min after training) or VLDL‐apoB‐100 secretion rate (1.5 ± 0.5 nmol/min before and 1.6 ± 0.6 nmol/min after training).Conclusions:Following the Department of Health and Human Services recommended physical activity guidelines has small but beneficial effects on IHTG content, but does not improve hepatic lipoprotein kinetics, in obese persons with NAFLD. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 24 d�cembre 2011
Massimo Colombo
Reply to: Sorafenib in clinical practice: Evidence‐based use or abuse?
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Date de mise en ligne : Samedi 24 d�cembre 2011
Bruno Sangro
Reply to Dr. Wigg
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Date de mise en ligne : Samedi 24 d�cembre 2011
Yong‐Fang Kuo
Outcomes after liver transplantation for alcoholic hepatitis are similar to alcoholic cirrhosis: Exploratory analysis from UNOS database
Background and aim:Data on liver transplantation for patients with alcoholic hepatitis are limited.Methods:Using the United Network for Organ Sharing database (2004‐2010), adults undergoing liver transplantation for listing diagnosis of alcoholic hepatitis were matched for age, gender, ethnicity, and MELD score, donor risk index, and year of transplantation with 3 patients transplanted for listing diagnosis of alcoholic cirrhosis. Study outcomes of graft and patient survival on follow up were also analyzed for cohorts based on the diagnosis of the explant (46 alcoholic hepatitis and 138 alcoholic cirrhosis) and diagnosis at both listing as well as of the explant (11 alcoholic hepatitis and 33 alcoholic cirrhosis).Results:Five year graft and patient survival of alcoholic hepatitis and alcoholic cirrhosis patients were 75% and 73% (P=0.97) and 80% and 78% (P=0.90) respectively. Five year graft and patient survival rates were also similar for cohorts based on diagnosis of the explant, and diagnosis at listing as well as explant. Cox proportional regression analysis adjusting for other variables showed no impact of the etiology of liver disease (alcoholic hepatitis vs. alcoholic cirrhosis) on the graft and patient survival. The causes of graft loss and patient mortality were similar in the two groups, and were not alcoholrelated in any patient.Conclusions:Compared with alcoholic cirrhosis, patients with alcoholic hepatitis have similar post transplantation graft and patient survival. Based on these preliminary findings, liver transplantation may be considered in a select group of patients with alcoholic hepatitis who fail to improve with medical therapy. Prospective studies are needed to assess the long‐term outcome after liver transplantation in patients with alcoholic hepatitis. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 24 d�cembre 2011
Natalia Nieto
Argininosuccinate synthase conditions the response to acute and chronic ethanol‐induced liver injury in mice
Background and Aim:Argininosuccinate synthase (ASS) is the rate‐limiting enzyme in both the urea and the L‐citrulline/nitric oxide (NO·) cycles regulating protein catabolism, ammonia levels and NO· generation (1‐2). Since a proteomics analysis identified ASS and nitric oxide synthase‐2 (NOS2) as co‐induced in rat hepatocytes by chronic ethanol consumption, which also occurred in alcoholic liver disease (ALD) and in cirrhotic patients, we hypothesized that ASS could play a role in ethanol binge and chronic ethanol‐induced liver damage.Methods:To investigate the contribution of ASS to the pathophysiology of ALD, wild‐type (WT) and Ass+/− mice (Ass−/− are lethal due to hyperammonemia) were exposed to an ethanol binge or to chronic ethanol drinking.Results:Compared with WT, Ass+/− mice given an ethanol binge exhibited decreased steatosis, lower NOS2 induction and less 3‐nitrotyrosine (3‐NT) protein residues, indicating that reducing nitrosative stress via the L‐citrulline/NO· pathway plays a significant role in preventing liver damage. However, chronic ethanol treated Ass+/− mice displayed enhanced liver injury compared with WT mice. This was due to hyperammonemia, lower phosphorylated AMP‐activated protein kinase (pAMPKα) to total AMPKα ratio, decreased sirtuin (Sirt‐1) and peroxisomal proliferator‐activated receptor coactivator‐1α (Pgc1α) mRNAs, lower fatty acid β‐oxidation due to down‐regulation of carnitine palmitoyl transferase‐II (CPT‐II), decreased antioxidant defense and elevated lipid peroxidation end‐products in spite of comparable nitrosative stress but likely reduced NOS3.Conclusion:Partial Ass ablation protects only in acute ethanol‐induced liver injury by decreasing nitrosative stress but not in a more chronic scenario where oxidative stress and impaired fatty acid β‐oxidation are key events. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 24 d�cembre 2011
Miodrag L. Lukic
Galectin‐3 deficiency prevents concanavalin A‐ induced hepatitis in mice
Background:We used Concanavalin A induced liver injury to study the role of Galectin 3 in the induction of inflammatory pathology and hepatocellular damage.Methods:We tested susceptibility to Concanavalin A induced hepatitis in Galectin 3 deficient (Gal‐3‐/‐) mice and analyzed the effects of pre‐treatment with selective inhibitor of Galectin 3 (TD139) in wild type (WT) C57BL/6 mice as evaluated by liver enzyme test, quantitative histology, mononuclear cell (MNC) infiltration, cytokine production, intracellular staining of immune cells and percentage of apoptotic MNCs in the liver.Results:Gal‐3‐/‐ mice were less sensitive to Con A induced hepatitis and had significantly lower number of activated lymphoid and dendritic cells (DCs) in the liver. The level of TNF alpha, IFN gamma, IL‐17 and IL‐4 in the sera and number of TNF alpha, IFN gamma, IL‐17 and IL‐4 producing CD4+ cells, IL‐12 producing CD11c+ DCs were lower while number of IL‐10 producing CD4+ T cells and F4/80+ macrophages were significantly higher in liver of Gal‐3‐/‐ mice. Significantly higher percentage of late apoptotic Annexin V+ PI+ liver infiltrating MNCs and splenocytes were seen in Gal‐3‐/‐ mice compared with WT mice. Pre‐treatment of WT C57BL/6 mice with TD139 led to attenuation of liver injury and milder infiltration of IFN gamma, IL‐17 and IL‐4 producing CD4+ T cells, increase in total number of IL‐10 producing CD4+ T cells and F4/80+ CD206+ alternatively activated macrophages and prevented apoptosis of liver infiltrating MNCs.Conclusions:Gal‐3 plays an important pro‐inflammatory role in Con A induced hepatitis by promoting activation of T lymphocytes, NKT cells and maturation of DCs, secretion of proinflammatory cytokines and down‐regulating M2 macrophage polarization and apoptosis of MNCs in the liver. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 21 d�cembre 2011
Maria Basso
Sorafenib in clinical practice: Evidence‐based use or abuse?
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Date de mise en ligne : Mardi 20 d�cembre 2011
Kenneth Cusi
Effect of adipose tissue insulin resistance on metabolic parameters and liver histology in obese patients with NAFLD
The role of adipose tissue insulin resistance in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) remains unclear. To evaluate this, we measured in 207 patients with NAFLD (age= 51±1, BMI= 34.1±0.3 kg/m2) and 22 controls without NAFLD (no‐NAFLD) adipose tissue insulin resistance by means of a validated index (adipo‐IRi = plasma free fatty acids [FFA] × insulin [FPI] concentration) and as the suppression of plasma FFA during an oral glucose tolerance test (OGTT) and by a low‐dose insulin infusion. We also explored the relationship between adipose tissue insulin resistance with metabolic and histological parameters by dividing them based on quartiles of adipose tissue insulin resistance (adipo‐IRi quartiles: Q1= more sensitive; Q4= more insulin resistant). Hepatic (HIRi = endogenous glucose production [EGP] × FPI) and muscle (Rd) insulin sensitivity were assessed during a euglycemic insulin clamp with 3‐[3H] glucose. Liver fat was measured by magnetic resonance imaging and spectroscopy and a liver biopsy was performed to assess liver histology. Compared to patients without steatosis, patients with NAFLD were insulin resistant at the level of adipose tissue, liver and skeletal muscle and had higher plasma AST/ALT, triglycerides, and lower HDL‐C and adiponectin levels (all p<0.01). Metabolic parameters, hepatic insulin resistance and liver fibrosis (but not necroinflammation) deteriorated as quartiles of adipose tissue insulin resistance worsened (all p<0.01).Conclusion:adipose tissue insulin resistance plays a key role in the development of metabolic and histological abnormalities of obese patients with NAFLD. Treatment strategies targeting adipose tissue insulin resistance (weight loss, thiazolidinediones) may be of value in this population. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
John H. Eckfeldt
Probability of C282Y homozygosity decreases as liver transaminase activities increase in participants with hyperferritinemia in the HEIRS Study
Background:Hemochromatosis is considered by many to be an uncommon disorder, although the prevalence of HFE C282Y homozygosity is relatively high in Caucasians. Liver disease is one of the most consistent findings in advanced iron overload due to hemochromatosis. Liver clinics are often thought to be ideal venues for diagnosis of hemochromatosis, but diagnosis rates are often low.Methods:The Hemochromatosis and Iron Overload Screening (HEIRS) Study screened 99, 711 primary care participants in North America for iron overload using serum ferritin and transferrin saturation measurements and HFE genotyping. In this HEIRS substudy, serum hepatic transaminases activities (ALT, AST) were compared between 162 C282Y homozygotes and 1,367 non‐homozygotes with a serum ferritin > 300 μg/L in men and > 200 Bg/L in women and transferrin saturation > 45% in women and 50 % in men. The probability of being a C282Y homozygote was determined for AST and ALT ranges.Results:Mean ALT and AST activities were significantly lower in C282Y homozygotes than non‐homozygotes. The probability of being a C282Y homozygote increased as the ALT and AST activities decreased.Conclusions:Patients with hyperferritinemia are more likely to be C282Y homozygotes if they have normal liver transaminase activities. This paradox could explain the low yields of hemochromatosis screening reported by some liver clinics. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Sung Hee Um
S6K2 deficiency enhances ketone body production and increases PPARα activity in the liver
Nutrient homeostasis is tightly regulated by the balance between energy production and utilization. During fasting, production of ketone bodies as an alternative energy source is critical to maintain nutrient homeostasis. An important component in the nutrient sensitive signaling pathway is S6K2, a downstream effector of mTOR. Here, we show that mice lacking S6K2 exhibit elevated levels of ketone bodies and enhanced PPARα activity upon nutrient availability. Consistent with this, knockdown of S6K2 increases transcriptional activity of PPARα. S6K2 suppresses PPARα by associating with its corepressor, NCoR1, and by inducing the recruitment of NCoR1 to the nucleus. Moreover, ob/ob mice, a genetic model of obesity, have markedly elevated S6K2 activity, and S6K2 was strongly associated with NCoR1 in the nucleus of liver cells.Conclusion:Our findings suggest that S6K2 regulates hepatic energy homeostasis by repressing PPARa activity, and point to its potential relevance for therapeutic strategies designed to modulate S6K2 activity as a treatment for deregulated ketone body production. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Allan Tsung
Outcomes of curative treatment for hepatocellular cancer in nonalcoholic steatohepatitis versus hepatitis C and alcoholic liver disease
Background and Aims:Concomitant increasing incidences of hepatocellular carcinoma (HCC) and nonalcoholic steatohepatitis (NASH) suggests that a substantial proportion of HCC arises due to hepatocellular injury from NASH. The objective of this study is to determine differences in severity of liver dysfunction at HCC diagnosis and long‐term survival outcomes between patients undergoing curative therapy for HCC in the background of NASH compared to hepatitis C virus (HCV) and/or alcoholic liver disease.Methods:Patient demographics and comorbidities, clinicopathologic data, and long‐term outcomes among patients who underwent liver transplantation, hepatic resection, or radiofrequency ablation for HCC were reviewed.Results:From 2000‐2010, 303 patients underwent curative treatment of HCC; 52 (17.2%) and 162 (53.5%) had NASH and HCV and/or alcoholic liver disease. At HCC diagnosis, NASH patients were older (median 65 vs. 58 years), more often female (48.1% vs. 16.7%), more often had the metabolic syndrome (45.1% vs. 14.8%), and had lower model for end‐stage liver disease scores (median 9 vs. 10), all p<0.05. NASH patients were less likely to have hepatic bridging fibrosis or cirrhosis (73.1% vs. 93.8%, p<0.001). After a median follow‐up of 50 months after curative treatment, the most frequent cause of death was liver failure. While there were no difference in recurrence free survival after curative therapy (median 60 vs. 56 months, p=0.303), NASH patients had longer overall survival (median not reached vs. 52 months, p=0.009) independent of other clinicopathologic factors and type of curative treatment.Conclusions:Patients with HCC in the setting of NASH have less severe liver dysfunction at HCC diagnosis and better overall survival after curative treatment compared to counterparts with HCV and/or alcoholic liver disease. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Alan Wigg
Yttrium 90 therapy for HCC; is it any better than conventional external beam radiotherapy?
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Date de mise en ligne : Mardi 20 d�cembre 2011
Han‐Chieh Lin
Hepatic endothelin‐1 and endocannabinoids‐dependent effects of hyperleptinaemia in nonalcoholic steatohepatitis‐cirrhotic rats
Leptin, the ob gene product, is a protein released from adipocytes and has been detected in fibrotic and cirrhotic livers. Leptin in brain has the an inhibitory effect on food intake. Nonalcoholic steatohepatitis (NASH) is characterized by hyperleptinaemia. This study explores the possible mechanisms of hyperleptinaemia in relation to increased intrahepatic resistance (IHR) and portal hypertension in NASH‐cirrhotic rats. NASH‐cirrhotic rats with hyperleptinaemia were induced in Zucker (fa/fa) and lean rats by feeding the animals a high fat/methionine‐choline‐deficient (HF/MCD) diet with and without exogenous administration of recombinant leptin. Portal venous pressure (PVP), IHR, plasma and hepatic levels of various substance, histopathology of the liver, the hepatic hydroxyproline content, and the expression of various hepatic protein and mRNA were measured. Hepatic microcirculatory dysfunction and the vasoconstrictive response to endothelin‐1 were also observed using a liver perfusion system and intravital microscopy. Finally, the effect of leptin on hepatic stellate cells (HSC) was evaluated. Both in HF/MCD‐Zucker and HF/MCD+leptin lean rats, significant hepatic fibrogenesis and cirrhosis, marked portal hypertension, microcirculatory dysfunction, an enhanced vasoconstrictive response to endothelin‐1 and an increased IHR were found to be associated with higher levels of hepatic endothelin‐1 and endocannabinoids, expression levels of the cannabinoid type 1 receptor, endothelin‐1 type A receptor (ETAR), activator protein‐1, TGF‐β1, osteopontin, TNF α, leptin, and OBRb. Interestingly, acute incubation of leptin directly increases the expression of ETAR, OBRb and activator protein‐1 in HSCs.Conclusion:A HF/MCD diet and hyperleptinaemia increase hepatic endocannabinoids production, promote hepatic fibrogenesis, enhanced the hepatic vasoconstrictive response to endothelin‐1 and aggravate hepatic microcirculatory dysfunction, these events subsequently increased IHR and portal hypertension in NASH‐cirrhotic rats. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Vicente Arroyo
Prevalence and risk factors of infections by multiresistant bacteria in cirrhosis: A prospective study
Epidemiology, risk factors and clinical impact of infections by multiresistant bacteria in cirrhosis are poorly known.Methods:Prospective evaluation in 2 series of cirrhotic patients admitted with infection or developing infection during hospitalization. The first Series was studied between 2005 and 2007 (507 bacterial infections in 223 patients) and the second between 2010 and 2011 (162 bacterial infections in 110 patients).Results:In the first Series, 32% of infections were community‐acquired, 32% health care‐associated and 36% nosocomial. Multiresistant bacteria (92 infections, 18%) were isolated in 4%, 14% and 35% of these infections, respectively (p<0.001). Extended‐spectrum β‐lactamase‐producing Enterobacteriaceae (ESBL‐E; n=43) was the main multiresistant organism identified, followed by Pseudomonas aeruginosa (n=17), methicillin‐esistant Staphylococcus aureus (n=14) and Enterococcus faecium (n=14). The efficacy of currently recommended empirical antibiotic therapy was very low in nosocomial infections (40%) compared to health care‐associated and community‐acquired episodes (73% and 83% respectively; p<0.0001), particularly in SBP, UTI and pneumonia (26%, 29% and 44%, respectively). Septic shock (26% vs. 10% p<0.0001) and mortality rate (25% vs. 12%, p=0.001) were significantly higher in infections caused by multiresistant strains. Nosocomial origin of infection (HR: 4.43), long‐term norfloxacin prophylaxis (HR: 2.69), recent infection by multiresistant bacteria (HR: 2.45) and recent use of β‐lactams (HR: 2.39) were independently associated to the development of multiresistant infections. Results in the second Series were similar to those observed in the first Series.Conclusions:Multiresistant bacteria, especially ESBL‐producing Enterobacteriaceae, are frequently isolated in nosocomial and to a lesser extent health care‐associated infections in cirrhosis, rendering third‐generation cephalosporins clinically ineffective. New antibiotic strategies tailored according to the local epidemiological patterns are needed for the empirical treatment of nosocomial infections in cirrhosis. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Wolfgang Stremmel
Ursodeoxycholyl lysophosphatidylethanolamide improves steatosis and inflammation in murine models of nonalcoholic fatty liver disease
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Date de mise en ligne : Mardi 20 d�cembre 2011
Saleem Kamili
Suppression of alpha interferon signaling by hepatitis E virus
The interferon (IFN) system is integral to the host response against viruses to which many viruses have developed strategies to overcome its antiviral effects. The effects of hepatitis E virus (HEV), the causative agent of hepatitis E, on IFN signaling have not been investigated primarily because of the non‐availability of an efficient in vitro culture system or small animal models of infection. Herein, we report the generation of A549 cell lines persistently infected with genotype 3 HEV, designated as HEV‐A549 cells and the effects HEV has on IFN‐α‐mediated Janus kinase‐signal transducer and activator of transcription (JAK‐STAT) signaling. Treatment of HEV‐A549 cells with 250, 500, and 1000 Units/ml of IFN‐α for 72 hours showed dose‐dependant reduction of HEV RNA levels by 10%, 20%, and 50% respectively. IFN‐α‐stimulated genes coding for the antiviral proteins, dsRNA‐activated protein kinase (PKR) and 2′,5′‐oligoadenylate synthetase(2,5‐OAS), were down‐regulated in IFN‐α‐treated HEV‐A549 cells. HEV infection also prevented IFN‐α‐induced phosphorylation of STAT1. Regulation of STAT1 by HEV was specific, as phosphorylation of STAT2, tyrosine kinase (Tyk) 2, and Jak1 by IFN‐α were unaltered. Additionally, STAT1 levels were markedly increased in HEV‐A549 cells compared to naive A549 cells. Furthermore, binding of HEV ORF3 protein to STAT1 in HEV‐A549 cells was observed. HEV ORF3 protein alone inhibited IFN‐α‐induced phosphorylation of STAT1 and down‐regulated the IFN‐α‐stimulated genes encoding PKR, 2,5‐OAS and myxovirus resistance A (MxA). Conclusions: HEV inhibits IFN‐α signaling through the regulation of STAT1 phosphorylation in A549 cells. These findings have implications for the development of new strategies against hepatitis E. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 20 d�cembre 2011
Mi‐Ock Lee
RORα‐induced activation of AMP‐activated protein kinase results in attenuation of hepatic steatosis
An increasing volume of data indicates that the retinoic acid receptor‐related orphan receptor α (RORα) plays an important role in the regulation of metabolic pathways, particularly of fatty acid and cholesterol metabolism; however, the role of RORα in the regulation of hepatic lipogenesis has not been studied. Here, we report that RORα attenuates hepatic steatosis, probably via activation of the AMP‐activated protein kinase (AMPK) and repression of the liver X receptor α (LXRα). First, RORα and its activator, cholesterol sulfate (CS), induced phosphorylation of AMPK, which was accompanied by the activation of LKB1. Second, the activation of RORα, either by transient transfection or CS treatment, decreased the TO901317‐induced transcriptional expression of LXRα and its downstream target genes, such as the SREBP‐1 and fatty acid synthase. RORα interacted physically with LXRα and inhibited the LXRα response element in the promoter of LXRα, indicating that RORα interrupts the autoregulatory activation loop of LXRα. Third, infection with adenovirus encoding RORα suppressed the lipid accumulation that had been induced by a free‐fatty‐acid mixture in cultured cells. Furthermore, we observed that the level of expression of the RORα protein was decreased in the liver of mice that were fed a high‐fat‐diet. Restoration of RORα via tail‐vein injection of Ad‐RORα decreased the high‐fat‐diet‐induced hepatic steatosis. Finally, we synthesized thiourea derivatives that activated RORα, thereby inducing the activation of AMPK and the repression of LXRα. These compounds decreased the hepatic triglyceride levels and lipid droplets in the high‐fat‐diet‐fed mice. Conclusion: We found that RORα induced the activation of AMPK and the inhibition of the lipogenic function of LXRα, which may be key phenomena that provide beneficial effects of RORα against hepatic steatosis. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 16 d�cembre 2011
Douglas Dieterich
The end of the beginning for hepatitis C treatment
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Date de mise en ligne : Mardi 13 d�cembre 2011
Ning‐Shao Xia
Safety of the hepatitis E vaccine for pregnant women: A preliminary analysis
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Date de mise en ligne : Lundi 12 d�cembre 2011
Spinello Antinori
Rapid virologic response: Is it four or eight weeks?
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Date de mise en ligne : Lundi 12 d�cembre 2011
Leonard B. Seeff
Re: HEP‐11‐1628 ‐ An update on treatment of genotype 1 chronic hepatitis c virus infection: 2011 practice guidelines by the american association for the study of liver diseases
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Date de mise en ligne : Lundi 12 d�cembre 2011
James L. Boyer
A c‐terminal tyrosine‐based motif in the bile salt export pump directs clathrin‐dependent endocytosis
The liver specific bile salt export pump (BSEP) is crucial for bile‐acid dependent bile flow at the apical membrane. BSEP, a member of the family of structurally related ATP‐Binding Cassette (ABC) proteins, is composed of 12 transmembrane segments (TMS) and 2 large cytoplasmic nucleotide binding domains (NBD). The regulation of trafficking of BSEP to and from the cell surface is not well understood, but is believed to play an important role in cholestatic liver diseases such as primary familial intrahepatic cholestasis type 2 (PFIC2). To address this issue, BSEP endocytosis was studied by immunofluorescence and a cell surface ELISA endocytosis reporter system using a chimera of the interleukin 2 receptor α (previously referred to as Tac) and the C‐terminal tail of BSEP (TacCterm). An autonomous endocytosis motif in the carboxyl cytoplasmic terminus of BSEP was identified. We define this endocytic motif by site‐directed mutagenesis as a canonical tyrosine‐based motif 1310YYKLV1314 (YxxØ). When expressed in HEK293T cells TacCterm is constitutively internalized via a dynamin‐ and clathrin‐dependent pathway. Mutation of the Y1310Y1311 amino acids in TacCterm and in full length human BSEP blocks the internalization. Subsequent sequence analysis reveals this motif to be highly conserved between the closely related ABCB subfamily members that mediate ATP‐dependent transport of broad substrate specificity. Conclusion: Our results indicate constitutive internalization of BSEP is clathrin‐mediated and dependent on the tyrosine‐based endocytic motif at the C‐terminal end of BSEP. (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 12 d�cembre 2011
Stuart Roberts
Feasibility and performance of the fibroscan XL probe
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Date de mise en ligne : Lundi 12 d�cembre 2011
Robert A.F.M. Chamuleau
Acute liver failure – what is it?
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Date de mise en ligne : Lundi 12 d�cembre 2011
Christophe Moreno
PNPLA3 (rs738409 C>G) is a common risk variant associated with hepatocellular carcinoma in alcoholic cirrhosi
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Date de mise en ligne : Lundi 12 d�cembre 2011
Regis A. Vilchez
An update on treatment of HCV genotype 1 infection and viral load assessments
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Date de mise en ligne : Vendredi 02 d�cembre 2011
Junqi Niu
Comparative analysis of portal cell infiltrates in AMA positive versus AMA negative PBC
Substantial evidence supports dysregulated B cell immune responses in patients with primary biliary cirrhosis (PBC), including the presence of serum anti‐mitochondrial antibodies (AMAs). However, recent reports from murine models of PBC suggest that B cells may also provide regulatory function and indeed the absence of B cells in such models leads to exacerbation of disease. The vast majority of patients with PBC have readily detectable antimitochondrial antibodies, but a minority (<5%), are AMA negative (AMA−) even with recombinant diagnostic technology. This issue prompted us to examine the nature of B cell infiltrates surrounding the portal areas in AMA positive (AMA+) and AMA− patients since they display indistinguishable clinical features. Of importance was the finding that the degree of bile duct damage around the portal areas was significantly milder in AMA+ PBC than those seen in AMA− PBC patients. The portal areas from AMA− patients had a significant increase of CD5+ cells infiltrating the ductal regions and the levels of B cell infiltrates were worse in the early phase of bile duct damage. The frequency of positive portal areas and the magnitude of CD5+ and CD20+ cellular infiltrates within areas of ductal invasion is associated with the first evidence of damage of biliary duct epithelia, but becomes reduced in the ductopenia stage, with the exception of CD5+ cells which remain sustained and predominate over CD20+ cells. In conclusion, our data suggest a putative role of B cell autoimmunity in regulating the portal destruction characteristic of PBC. The pathognomic destruction of biliary epithelial cells (BEC) in primary biliary cirrhosis (PBC) is primarily attributed to autoreactive T cells (1‐9). In contrast, the contribution of B cells to PBC immunopathology remains in need of further clarification (10), despite the nearly universal presence of anti‐mitochondrial antibodies (AMA). The cellular infiltrates of PBC include foci of B cells within portal areas of the liver (11). Autoantibodies to the E2 subunit of the PDC enzymes inhibit the catalytic activity of PDC‐E2 and such anti‐PDC‐E2 specific antibodies are reasoned to facilitate the transcytosis of IgA‐AMA through BEC in the form of dimeric IgA‐AMA complexes, leading to the induction of apoptosis of these cells (12‐14). Sera from patients with PBC react with apoptotic blebs formed on the epithelial cell surface of human intrahepatic bile ducts not control cells (15), and induce an innate immune response (16). Moreover, autoantibodies to PDC‐E2 markedly enhanced cross presentation as well as generation of PDC‐E2‐specific cytotoxic T cell responses in the presence of PDC‐E2‐pulsed antigen presenting cells (17). However, neither the presence nor the levels of AMA correlate with the recurrence of PBC in patients following orthotopic liver transplantation (18). Thus, although there is evidence for a profound loss of both B‐ and T‐ cell tolerance to the autoantigenic epitope(s) of PDC‐E2, the degree to which B cells or autoantibodies are involved as effector elements in the pathogenesis of BEC damage in PBC remains unclear. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Yury Khudyakov
Variants in ABCB1, TGFB1, and XRCC1 genes and susceptibility to viral hepatitis A infection in mexican americans
Hepatitis A vaccination has dramatically reduced the incidence of hepatitis A virus (HAV) infection, but new infections continue to occur. To identify human genetic variants conferring a risk for HAV infection among the three major racial/ethnic populations in the United States, we assess associations between 67 genetic variants (single nucleotide polymorphisms, ‘SNPs’) among 31 candidate genes and serologic evidence of prior HAV infection using a population‐based, cross‐sectional study of 6779 participants, including 2619 non‐Hispanic whites, 2095 non‐Hispanic blacks, and 2065 Mexican Americans, enrolled in phase 2 (1991‐1994) of the Third National Health and Nutrition Examination Survey. Among the three racial/ethnic groups, the number (weighted frequency) of seropositivity for antibody to HAV (anti‐HAV) was 958 (24.9%), 802 (39.2%), and 1540 (71.5%), respectively. No significant associations with any of the 67 SNPs were observed among non‐Hispanic whites or non‐Hispanic blacks. In contrast, among Mexican Americans, variants in two genes were found to be associated with an increased risk of HAV infection: TGFB1 rs1800469 (adjusted odds ratio [OR] = 1.38; 95% confidence interval [CI], 1.14‐1.68; p‐value adjusted for false discovery rate [FDR‐P] = 0.017) and XRCC1 rs1799782 (OR = 1.57; 95% CI, 1.27‐1.94; FDR‐P = 0.0007). A decreased risk was found with ABCB1 rs1045642 (OR = 0.79; 95% CI, 0.71‐0.89; FDR‐P = 0.0007).Conclusions:Genetic variants in ABCB1, TGFB1, and XRCC1 appear to be associated with susceptibility to HAV infection among Mexican Americans. Replication studies involving larger population samples are warranted. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Claudia Piccoli
The cyclophilin inhibitor alisporivir prevents hepatitis C virus‐ mediated mitochondrial dysfunction
Alisporivir (Debio‐025) is an analogue of cyclosporine A and represents the prototype of a new class of non‐immunosuppressive cyclophilin inhibitors. In vitro and in vivo studies have shown that alisporivir inhibits hepatitis C virus (HCV) replication, and ongoing clinical trials are exploring its therapeutic potential in patients with chronic hepatitis C. Recent data suggest that the antiviral effect is mediated by inhibition of cyclophilin A which is an essential host factor in the HCV life cycle. However, alisporivir also inhibits mitochondrial permeability transition by binding to cyclophilin D. As HCV is known to affect mitochondrial function, we explored the effect of alisporivir on HCV protein‐mediated mitochondrial dysfunction. By the use of inducible cell lines, which allow to investigate the effects of HCV polyprotein expression independent from viral RNA replication and which recapitulate the major alterations of mitochondrial bioenergetics observed in infectious cell systems, we show that alisporivir prevents HCV protein‐mediated decrease of cell respiration, collapse of mitochondrial membrane potential, overproduction of reactive oxygen species and mitochondrial calcium overload. Strikingly, some of the HCV‐mediated mitochondrial dysfunctions could even be rescued by alisporivir. These observations provide new insights into the pathogenesis of HCV‐related liver disease and reveal an additional mechanism of action of alisporivir that is likely beneficial in the treatment of chronic hepatitis C. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Irene Oi‐Lin Ng
Sequential alterations of miRNA expression in hepatocellular carcinoma development and venous metastasis
Hepatocellular carcinoma (HCC) is a prevalent cancer with an extremely high mortality rate, attributed to HCC metastasis which is the major cause of tumor recurrence and organ failure. Presence of tumor thrombi in the portal veins (venous metastases) is a clinicopathological feature of metastatic HCCs. In this study, we analyzed the microRNA (miRNA) expression profiles of non‐tumorous livers, primary HCCs, and venous metastases in the same livers from 20 HCC patients by low density microarray (LDA) and identified the precise alterations of miRNA expression from non‐tumorous livers to primary HCCs and venous metastases globally. By unsupervised clustering analysis, non‐tumorous livers were distinctly segregated from primary HCCs and venous metastases, whereas no discernible difference in the expression pattern could be found between primary HCCs and venous metastases. However, a marked global reduction of miRNA expression levels was detected in venous metastases, as compared with primary HCCs. These data suggest that miRNA deregulation is an early event in liver carcinogenesis and the later global miRNA down‐regulation aggravates the pre‐existing miRNA deregulation to further promote HCC metastasis. Our study has enriched the current understanding of the deregulation of miRNAs in HCC progression and highlighted the sequential and distinctive alterations of miRNA expression in primary HCC and venous metastasis formation. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Milton C. Weinstein
Economic model of a birth cohort screening program for hepatitis C virus
Recent research has identified high hepatitis C virus (HCV) prevalence among older US residents who contracted HCV decades ago and may no longer be recognized as high‐risk. We assessed the cost‐effectiveness of screening 100% of US residents born 1946‐1970 over 5 years (birth‐cohort screening) compared with current risk‐based screening, by projecting costs and outcomes of screening over the remaining lifetime of this birth cohort. A Markov model of the natural history of HCV was developed using data synthesized from surveillance data, published literature, expert opinion, and other secondary sources. We assumed eligible patients were treated with pegylated interferon plus ribavirin, with genotype 1 patients receiving a direct‐acting antiviral in combination. The target population is US residents born 1946‐1970 with no prior HCV diagnosis. Among the estimated 102 million (1.6 million chronically HCV‐infected) eligible for screening, birth‐cohort screening leads to 84,000 fewer cases of decompensated cirrhosis, 46,000 fewer cases of hepatocellular carcinoma, 10,000 fewer liver transplants and 78,000 fewer HCV‐related deaths. Birth‐cohort screening led to higher overall costs than risk‐based screening ($80.4 billion vs. $53.7 billion), but yielded lower costs related to advanced liver disease ($31.2 billion vs. $39.8 billion); birth‐cohort screening produced an incremental cost‐effectiveness ratio (ICER) of $37,700 per quality‐adjusted life‐year gained versus risk‐based screening. Sensitivity analyses showed that reducing the time horizon during which health and economic consequences are evaluated increases the ICER, whereas decreasing the treatment rates and efficacy increases the ICER. Model results were relatively insensitive to other inputs.Conclusion:Birth‐cohort screening for HCV is likely to provide important health benefits by reducing lifetime cases of advanced liver disease and HCV‐related deaths, and is cost‐effective at conventional willingness‐to‐pay thresholds. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
K. Arnold Chan
Association of thiazolidinediones with liver cancer and colorectal cancer in type 2 diabetes mellitus
Background:The objective of this nationwide case‐control study was to evaluate the risk of specific malignancy in diabetic patients who received thiazolidinediones (TZDs).Methods:A total of 606,583 type 2 diabetic patients, aged 30 years and above, without a history of cancer were identified from the Taiwan National Health Insurance claims database during the period between 1 January 2000 and 31 December 2000. As of 31 December 2007, patients with incident cancer of liver, colorectal, lung, and urinary bladder were included as cases and up to four age‐ and sex‐matched controls were selected by risk‐set sampling. Logistic regression models were applied to estimate the odds ratio (OR) and 95% confidence interval (CI) between TZDs and cancer incidence.Results:A total of 10,741 liver cancer cases, 7,200 colorectal cancer cases, and 70,559 diabetic controls were included. A significantly lower risk of liver cancer incidence was found for any use of rosiglitazone (OR: 0.73, 95% CI: 0.65‐0.81) and pioglitazone (OR: 0.83, 95% CI: 0.72‐0.95), respectively. The protective effects were stronger for higher cumulative dosage and longer duration. For colorectal cancer, rosiglitazone, but not pioglitazone, was associated with a significantly reduced risk (OR: 0.86; 95% CI: 0.76‐0.96). TZDs were not associated with lung and bladder cancer incidence although a potential increased risk for bladder cancer with pioglitazone use ≥3 years could not be excluded (OR: 1.56; 95% CI: 0.51‐4.47).Conclusion:The use of pioglitazone and rosiglitazone is associated with a decreased liver cancer incidence in diabetic patients. The effects on occurrence of specific cancer types may be different for pioglitazone and rosiglitazone. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Antonio Craxì
Carotid atherosclerosis and chronic hepatitis C: A prospective study of risk associations
Background and Aims:There are contrasting results in studies of cardiovascular risk in patients with genotype 1 chronic hepatitis C (G1 CHC). We evaluated the prevalence of carotid atherosclerosis compared with a control population in order to assess the potential association between atherosclerosis, host and viral factors, and liver histological features.Materials and Methods:One hundred seventy‐four consecutive biopsy‐proven G1 CHC patients were evaluated by anthropometric and metabolic measurements. One hundred seventy‐four patients attending an outpatient cardiology unit were used as controls. Intima‐media thickness (IMT) and carotid plaques, defined as focal thickening of > 1.3 mm at the level of common carotid, were evaluated using ultrasonography. All G1 CHC biopsies were scored by one pathologist for staging and grading, and graded for steatosis.Results:Carotid plaques were found in 73 (41.9%) G1 CHC patients compared with 40 (22.9%) control patients (p<0.001). Similarly, G1 CHC patients had a greater IMT compared with control patients (1.04±0.21 versus 0.90±0.16; p<0.001). Multivariate logistic regression analysis showed that older age (OR 1.047, 95%CI 1.014–1.082, p= 0.005), and severe hepatic fibrosis (OR 2.177, 95%CI 1.043–4.542, p=0.03), were independently linked to the presence of carotid plaques. In patients aged ≤55 years, 15/67 cases with F0‐F2 fibrosis (22.3%) had carotid plaques, compared with 11/21 (52.3%) with F3‐F4 fibrosis (p=0.008). By contrast, in patients >55 years the prevalence of carotid plaques was similar in those with or without severe fibrosis (25/43, 58.1% versus 22/43, 51.1%; p=0.51).Conclusion:Severe hepatic fibrosis is associated with a high risk of early carotid atherosclerosis in G1 CHC patients. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Valerio Nobili
Retracted: I148M PNPLA3 variant and progressive liver disease: A new paradigm in hepatology
In this issue of the Journal, Sookoian and Pirola present the results of a meta‐analysis evaluating the strength of I148M Patatin‐like phosholipase domain‐containing protein 3 (PNPLA3) variant on nonalcoholic fatty liver disease risk and severity across different populations, together with its potential influence on intermediate associated phenotypes. The power of this study has definitively proved that I148M polymorphism impacts not only on hepatic triglyceride content, but also on the susceptibility towards a more aggressive disease, i.e. higher scores of histological features associated with nonalcoholic steatohepatitis and liver fibrosis. I148M variant also influences alanine aminotransferase activity, without affecting body mass, insulin resistance, and lipid levels. These findings, and recent data indicating that I148M PNPLA3 polymorphism promotes the progression on liver damage in patients with excessive alcohol intake and with chronic hepatitis C, suggest that this genetic variant is a common inducer of liver damage progression associated with histological features of steatohepatitis, in the presence of metabolic, toxic, or viral risk factors.Conclusion:the evaluation of the impact of PNPLA3 into clinical practice may improve the diagnostic protocols and personalize therapeutic strategies in patients with chronic liver diseases. (HEPATOLOGY 2011.)

Date de mise en ligne : Vendredi 02 d�cembre 2011
Douglas M. Heuman
Diagnosis and treatment of minimal hepatic encephalopathy to prevent motor vehicle accidents: A cost‐effectiveness analysis
Minimal hepatic encephalopathy (MHE) in cirrhosis is associated with impaired driving skills and increased risk of motor vehicle accidents (MVAs). Detection and treatment of MHE has the potential to reduce costs and morbidity associated with MVAs.Methods:We conducted a cost‐effectiveness analysis to assess the benefits of different strategies of MHE diagnosis and treatment for reducing MVA‐related societal costs. The analyses compared five MHE management strategies: (1) presumptive treatment of all cirrhotics; (2) diagnosis by neuropsychological exam (NPE) with treatment; (3) diagnosis by standard psychometric tests (SPT) with treatment; (4) diagnosis by rapid screening using inhibitory control test (ICT) with treatment; and (5) no MHE diagnosis or treatment (status quo). Treatments considered were lactulose or rifaximin, which were assumed to reduce the MVA rate to the level of similarly‐aged non‐cirrhotics with benefit adjusted for treatment compliance. A Markov model followed a simulated cohort of 1000 cirrhotics without overt HE(OHE), from entry into treatment, through MHE development, and later, OHE, when they exited the modeled cohort. Follow‐up was for 5 years and included biannual MHE testing. The societal cost of a single MVA was estimated at $42,100.Results:All 4 strategies with lactulose were cost‐saving compared to the status quo. Diagnosis with ICT and lactulose was the most cost‐effective approach (cost/MVA prevented: $24,454 ICT; $25,470 SPT; $30,469 presumptive treatment and $33,742 NPE). Net program savings over 5 years ranged from $1.7 to 3.6 million depending on the strategy. Rifaximin therapy was not cost‐saving at current prices but would become so at a monthly cost <$353.Conclusion:Detection of MHE, especially using the ICT, and subsequent treatment with lactulose could substantially reduce societal costs by preventing MVAs. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 26 novembre 2011
Ronald J. Sokol
Toll like receptor 4 dependent kupffer cell activation and liver injury in a novel mouse model of parenteral nutrition
Infants with intestinal failure who are parenteral nutrition (PN)‐dependent may develop cholestatic liver injury and cirrhosis (PN‐associated liver injury: PNALI). The pathogenesis of PNALI remains incompletely understood. We hypothesized that intestinal injury with increased intestinal permeability combined with administration of PN promotes LPS‐TLR4 signaling dependent Kupffer cell activation as an early event in the pathogenesis of PNALI. We developed a mouse model in which intestinal injury and increased permeability were induced by oral treatment for 4 days with dextran sulphate sodium (DSS) followed by continuous infusion of soy lipid‐based PN solution through a central venous catheter for 7 (PN/DSS7d) and 28 (PN/DSS28d) days. Liver injury and cholestasis were evaluated by serum AST, ALT, bile acids, total bilirubin, and by histology. Purified Kupffer cells were probed for transcription of pro‐inflammatory cytokines. PN/DSS7d mice showed elevated portal vein LPS levels, evidence of hepatocyte injury and cholestasis, and increased Kupffer cell expression of IL6, TNFα, and TGFβ. Serological markers of liver injury remained elevated in PN/DSS28d mice associated with focal inflammation, hepatocyte apoptosis, peliosis, and Kupffer cell hypertrophy and hyperplasia. PN infusion without DSS pre‐treatment or DSS pre‐treatment alone did not result in liver injury or Kupffer cell activation. Suppression of the intestinal microbiota with broad spectrum antibiotics or ablation of TLR4 signaling in TLR4 mutant mice resulted in significantly reduced Kupffer cell activation and markedly attenuated liver injury in PN/DSS7d mice.Conclusion:These data suggest that intestinal‐derived LPS activates Kupffer cells through TLR4 signaling in early stages of PNALI. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 26 novembre 2011
Jean Dubuisson
Role of LDL receptor in the hepatitis c virus life cycle
Hepatitis C virus (HCV) particles are known to be in complex with lipoproteins. As a result of this interaction, the LDL receptor (LDLR) has been proposed as a potential entry factor for HCV, however, its implication in virus entry remains unclear. Here, we re‐investigated the role of the LDLR in the HCV life cycle by comparing virus entry to the mechanism of lipoprotein uptake. A siRNA targeting the LDLR in Huh‐7 cells reduced HCV infectivity, confirming that this receptor plays a role in the life cycle of HCV generated in cell culture. However, kinetics of internalization were much faster for lipoproteins than for infectious HCV particles. Furthermore, a decrease in HCV RNA replication was observed by blocking the LDLR with a specific antibody, and this was associated with an increase in the ratio of phosphatidylethanolamine to phosphatidylcholine in host cells. Nevertheless, a soluble form of the LDLR inhibited both HCV entry into the hepatocytes and its binding to the LDLR expressed on CHO cells, suggesting a direct interaction between the HCV particle and the LDLR. Finally, we showed that modification of HCV particles by lipoprotein lipase (LPL) reduces HCV infectivity and increases HCV binding to LDLR. Importantly, LPL treatment also induced an increase in RNA internalization, suggesting that LDLR, at least in some conditions, leads to non‐productive internalization of HCV.ConclusionThe LDLR is not essential for infectious HCV particle entry, whereas the physiological function of this receptor is important for optimal replication of HCV genome. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 26 novembre 2011
Mi‐Suk Park
Distal common bile duct (CBD) metastasis from hepatocelluar carcinoma (HCC)
n/a

Date de mise en ligne : Samedi 26 novembre 2011
M. Mahmood Hussain
The phospholipid transfer activity of MTP produces apoB‐lipoproteins and reduces hepatosteatosis while maintaining low plasma lipids
Microsomal triglyceride transfer protein (MTP), essential for apoB‐lipoprotein biosynthesis, evolved as a phospholipid transfer protein and acquired triglyceride transfer activity during a transition from invertebrates to vertebrates. But it is unknown whether MTP directly transfers lipids onto apoB in vivo and, if it does, whether both neutral and polar lipid transfer activities of MTP are critical for lipoprotein assembly. The molecular bases for differences in lipid transfer activities with respect to distinct domains in dMTP and hMTP are not obvious because both proteins have very similar primary, secondary and tertiary structures. We used an in vivo approach to delineate physiological significance of these distinct lipid transfer activities by expressing Drosophila (transfers phospholipids) and human MTP (transfers phospholipids and triglycerides) orthologs using adenoviruses in liver‐specific MTP deficient (L‐MTP−/−) mice that have low plasma and high hepatic lipids. Both orthologs improved plasma lipids but plasma triglycerides were lower in dMTP mice due to lower hepatic triglyceride and apoB production. Hepatosteatosis in L‐MTP−/− mice was ameliorated to similar levels by both. Attenuation of hepatosteatosis upon dMTP expression pertained to enhanced β‐oxidation with no changes in lipogenesis. Phospholipid transfer activity of MTP promoted biogenesis of both apoB48 and apoB100‐containing VLDL in addition to a phospholipid‐rich apoB48‐containing HDL‐size particle. Triglyceride transfer activity augmented the biosynthesis of triglyceride‐rich lipoproteins by increasing the formation of these particles in the lumen of the endoplasmic reticulum. Based on these findings, we posit that the selective inhibition of MTP triglyceride transfer activity might reduce hyperlipidemia while protecting liver from excess lipid accumulation. (HEPATOLOGY 2011.)

Date de mise en ligne : Samedi 26 novembre 2011
Steven T. Wiersma
The global burden of hepatitis E virus
We estimated the global burden of hepatitis E virus (HEV) genotypes 1 and 2 in 2005. HEV is an emergent waterborne infection that causes source‐originated epidemics of acute disease with a case fatality rate thought to vary by age and pregnancy status. To create our estimates, we modeled the annual disease burden of HEV genotypes 1 and 2 for 9 of 21 regions defined for the Global Burden of Diseases, Injuries, and Risk Factors Study (the GBD 2010 Study), which represent 71% of the world's population. We estimated the seroprevalence of anti‐HEV anitbody and annual incidence of infection for each region using data from 37 published national studies and the DISMOD 3, a generic disease model designed for the GBD Study. We converted incident infections into three mutually exclusive results of infection: (1) asymptomatic episodes, (2) symptomatic disease, and (3) death from HEV. We also estimated incremental cases of stillbirths among infected pregnant women. For 2005, we estimated 20.1 (95% credible interval [Cr. I.]. 2.8–37.0) million incident HEV infections across the 9 GBD Regions, resulting in 3.3 (95% Cr.I. 0.5–6.5) million symptomatic cases, 70,000 (95% Cr.I. 12,400–132,732) deaths, and 3,000 (95% Cr.I. 1,892–4,424) stillbirths. We estimated a probability of symptomatic illness given infection of 0.198 (95% Cr.I. 0.167–0.229) and a probability of death given symptomatic illness of 0.019 (95% Cr.I. 0.017–0.021) for nonpregnant cases and 0.198 (95% Cr.I. 0.169–0.227) for pregnant cases. The model was most sensitive to estimates of age‐specific incidence of HEV disease. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 23 novembre 2011
Riad Salem
Extrahepatic metastases occur in a minority of hepatocellular carcinoma patients treated by locoregional therapies: Analyzing patterns of progression in 285 patients
While most cancers are considered to be predominantly systemic processes, this may not hold true for hepatocellular carcinoma (HCC). The literature regarding patterns of progression of HCC (local versus systemic) has been relatively sparse. Our objectives were to: 1) analyze patterns of progression in HCC patients presenting with intrahepatic disease from initial treatment until death and, 2) identify clinically‐relevant risk factors for the development of metastases. Over a 9‐year period, 285 patients treated with transarterial locoregional therapies underwent scheduled imaging follow‐up from treatment until death and were categorized by pattern of progression: 1) intrahepatic (increased tumor enhancement/size, development/progression of vascular invasion, new hepatic lesions) progression or 2) extrahepatic (adrenal/bone/lung/lymph node) metastases. Uni/multivariate analyses assessing the risk factors for the development of metastases were performed. The median time from last scan to death was 2.4 months (inter‐quartile range: 1.3‐4.8 months). The time to development of metastases, vascular invasion and/or new lesions was 13.8 months (confidence interval: 11.3‐17.7 months). Of the 209 patients followed until death, only 50 developed extrahepatic metastases (24%). Multivariate analyses identified age <65 years (p=0.038), AFP >200 ng/ml (p=0.04) and vascular invasion (p=0.017) as significant predictors of metastases development. In conclusion, knowledge of the risk factors associated with the development of metastases may help guide assessment of patient prognosis. Since 76% of patients presenting with local disease treated with locoregional therapies die without developing extrahepatic metastases, the notion of HCC as a systemic disease, as detected by imaging, may be reconsidered. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 23 novembre 2011
Guadalupe Garcia‐Tsao
Quantitative histological‐hemodynamic correlations in cirrhosis
Background/Aims.We have previously shown, in a semiquantitative analysis of liver biopsies showing cirrhosis, that thickness of fibrous septa separating cirrhotic nodules and small size of cirrhotic nodules correlated independently with portal pressure (as determined by the hepatic venous pressure gradient, HVPG) and were independent predictors of the presence of clinically significant portal hypertension. This study aimed to confirm these results using quantitative analysis of these biopsies using digital image analysis.Methods.Biopsies of 42 patients with cirrhosis and HVPG measurements within six months of the biopsy were included in the study. The following parameters were scored quantitatively and without knowledge of HVPG results: total fibrosis area, septal thickness, nodule size, and number of nodules/mm length of liver biopsy.Results.Fibrosis area was the only parameter that independently correlated with HVPG (r=0.606; p<0.0001). Correlation was significant even among patients with clinically significant portal hypertension (r=0.636, p<0.005). Fibrosis area and nodule size were both independently predictive of the presence of clinically significant portal hypertension (r=0.57, p=0.003).Conclusions.On quantitative analysis, fibrosis area is the parameter that correlates best with HVPG and the presence of clinically significant portal hypertension. Beyond pathophysiological implications, this also has methodological implications that are discussed in the paper. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 23 novembre 2011
Katja Klugewitz
Connecting liver and gut: Murine liver sinusoidal endothelium induces gut tropism of CD4+ T cells via retinoic acid
Gut‐activated T cells migrating into the liver can cause extraintestinal manifestations of inflammatory bowel disease. T cells acquire a gut‐homing phenotype dependent on retinoic acid (RA) provided by intestinal dendritic cells (DC). We here investigated whether liver antigen‐presenting cells can vice versa induce gut tropism supporting an enterohepatic lymphocyte circulation. Priming of CD4+ T cells by liver sinusoidal endothelial cells (LSEC) supported migration into gut and gut‐associated lymphoid tissue. As observed for T cells primed by intestinal DC, this gut tropism depended on α4β7 integrin and CCR9 expression by LSEC‐primed CD4+ T cells. The induction of gut‐homing molecules was mediated by RA – a derivate of vitamin A that is stored in large amounts within the liver. LSEC expressed functional retinal dehydrogenases and could convert vitamin A to RA. Conversely, the lack of signaling via the RA receptor prevented the expression of α4β7 integrin and CCR9 on LSEC‐primed CD4+ T cells, consequently reducing their in vivo migration to the intestine. Other liver APC failed to support high expression of α4β7 integrin on CD4+ T cells, thus, the potential to induce gut homing is restricted to LSEC. Conclusion: The capacity to promote gut tropism by vitamin A utilization is not unique for intestinal DC but is also a feature of LSEC. Our data support the assumption that CD4+ T cells can migrate from the liver to the gut as one branch of a postulated enterohepatic lymphocyte circulation. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 23 novembre 2011
Ira J. Fox
The microenvironment in hepatocyte regeneration and function in rats with advanced cirrhosis
In advanced cirrhosis, impaired function is caused by intrinsic damage to the native liver cells and from the abnormal microenvironment in which the cells reside. The extent to which each plays a role in liver failure and regeneration is unknown. To examine this issue, hepatocytes from cirrhotic and age‐matched control rats were isolated, characterized, and transplanted into the livers of non‐cirrhotic hosts whose livers permit extensive repopulation with donor cells. Primary hepatocytes derived from livers with advanced cirrhosis and compensated function maintained metabolic activity and the ability to secrete liver‐specific proteins, whereas hepatocytes derived from cirrhotic livers with decompensated function failed to maintain metabolic or secretory activity. Telomere studies and transcriptomic analysis of hepatocytes recovered from progressively worsening cirrhotic livers suggest that hepatocytes from irreversibly failing livers show signs of replicative senescence and express genes that simultaneously drive both proliferation and apoptosis, with a later effect on metabolism, all under the control of a central cluster of regulatory genes including NF‐κB and HNF‐4α. Cells from cirrhotic and control livers engrafted equally well, but those from animals with cirrhosis and failing livers showed little initial evidence of proliferative capacity or function. Both, however, recovered more than two months after transplantation, indicating that either mature hepatocytes or a subpopulation of adult stem cells are capable of full recovery in severe cirrhosis. Thus, transplant studies indicate that the state of the host microenvironment is critical to the regenerative potential of hepatocytes, and that a change in the extracellular matrix can lead to regeneration and restoration of function by cells derived from livers with end‐stage organ failure. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Ju‐Seog Lee
65‐gene–based risk score classifier predicts overall survival in hepatocellular carcinoma
Clinical application of the prognostic gene expression signature has been delayed due to the large number of genes and complexity of prediction algorithms. In current study, we aim to develop an easy‐to‐use risk score with a limited number of genes that can robustly predict prognosis of patients with HCC. The risk score was developed by using Cox coefficient values of 65 genes in the training set (n=139) and its robustness was validated in test sets (n=292). The risk score was a highly significant predictor of overall survival (OS) in the first test cohort (P = 5.6 × 10−5, n = 100) and the second test cohort (P = 5.0 × 10−5, n = 192). In multivariate analysis, the risk score was significant risk factor among clinical variables examined together (hazard ratio [HR], 1.36; 95% confidential interval [CI], 1.13‐1.64; P = 0.001 for OS).Conclusion:The risk score classifier we have developed can identify two clinically distinct HCC subtypes at early and late stage of the disease in a simple and highly reproducible manner across multiple data sets. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Nicholas F LaRusso
Fibrolamellar hepatocellular carcinoma presenting with Budd Chiari syndrome, right atrial thrombus and pulmonary emboli
n/a

Date de mise en ligne : Mardi 22 novembre 2011
Robert G. Parton
Caveolin‐1 orchestrates the balance between glucose and lipid‐dependent energy metabolism: implications for liver regeneration
To better understand the contribution of the role of caveolin‐1 (CAV1) in liver physiology during liver regeneration and hepatic steatosis, we have generated CAV1 null (CAV1‐/‐) mouse with a pure genetic background. Study of these mice in comparison with another two different CAV1‐/‐ mouse strains demonstrates that: i) upon regular physiological conditions expression of CAV1 in mouse tissues is necessary to guarantee an efficient progression of liver regeneration and mice survival after partial hepatectomy. ii) Expression of CAV1 in mice is required for efficient hepatic lipid storage during physiological and pathological conditions of hepatic steatosis and iii) Under these conditions CAV1 accumulates in the lipid droplet (LD) fraction in wild‐type mouse hepatocytes. Interestingly, our comparative analysis also demonstrates that the absence of CAV1 in mouse tissues can be compensated by the development of a carbohydrate‐dependent anabolic adaptation that in the case of the liver determines the ability of hepatocytes to undergo liver regeneration. These results were supported by extracellular flux analysis of cellular glycolytic metabolism in CAV1‐knock‐down AML12 hepatocytes suggesting cell autonomous effects of CAV1 loss in hepatic glycolysis.Conclusion:Here we demonstrate the extreme importance of the expression of CAV1 in mouse tissues for the metabolism and cell biology of hepatocytes under physiological and pathological conditions. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Songdong Meng
Loss of MiR‐122 expression in patients with hepatitis B enhances hepatitis B virus replication through cyclin G1 modulated P53 activity
Hepatitis B virus (HBV) causes chronic infection in about 350 million people worldwide. Given the important role of the most abundant liver‐specific microRNA miR‐122 in hepatic function and liver pathology, here we investigated the potential role and mechanism of miR‐122 in regulating HBV replication. We found that miR‐122 expression in liver was significantly down‐regulated in patients with HBV infection compared with healthy controls, and the miR‐122 levels were negatively correlated with intrahepatic viral load and hepatic necroinflammation. The depletion of endogenous miR‐122 by its antisense inhibitor led to enhanced HBV replication whereas over‐expression of miR‐122 by transfection of mimic or its expression vector inhibited viral production. We next identified cyclin G1 as a miR‐122 target from multiple candidate target genes which is involved in the regulation of HBV replication. Over‐expression and knock‐down studies both showed that cyclin G1 regulated viral replication in HBV transfected cells. We also observed that cyclin G1 expression was up‐regulated in HBV infected patients, and cyclin G1 levels were inversely associated with miR‐122 expression in liver tissues. Using co‐immunoprecipitation, luciferase reporter system and electrophoretic mobility shift assay (EMSA), we further demonstrated that cyclin G1 specifically interacted with p53, and this interaction blocked the specific binding of p53 to HBV enhancer elements and simultaneously abrogated p53‐mediated inhibition of HBV transcription. Finally, we showed miR‐122 suppressed HBV replication in p53 wild‐type cells but not in null isogenic cells. Conclusion: miR‐122 down‐regulates its target cyclin G1, thus interrupts interaction between cyclin G1 and p53, and abrogates p53‐mediated inhibition of HBV replication. Our work showed that miR‐122 down‐regulation induced by HBV infection can impact HBV replication and possibly contribute to viral persistence and carcinogenesis. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Karin Séron
(‐)‐Epigallocatechin‐3‐gallate is a new inhibitor of hepatitis C virus entry
Here, we identify (‐)‐epigallocatechin‐3‐gallate (EGCG) as a new inhibitor of hepatitis C virus (HCV) entry. EGCG is a flavonoid present in green tea extract belonging to the subclass of catechins which has many properties. Particularly, EGCG possesses antiviral activity and impairs cellular lipid metabolism. Due to close links between HCV life cycle and lipid metabolism, we postulated that EGCG may interfere with HCV infection. We demonstrate that a concentration of 50 μM EGCG inhibits HCV infectivity by more than 90% at an early step of the viral life cycle, most likely the entry step. This inhibition was not observed with other members of the Flaviviridae family tested. The antiviral activity of EGCG on HCV entry was confirmed with pseudoparticles expressing HCV envelope glycoproteins E1 and E2 from six different genotypes. In addition, using binding assays at 4°C, we demonstrate that EGCG prevents attachment of the virus to the cell surface, probably by acting directly on the particle. We also show that EGCG has no effect on viral replication and virion secretion. By inhibiting cell‐free virus transmission using agarose or neutralizing antibodies, we show that EGCG inhibits HCV cell‐to‐cell spread. Finally, by successive inoculation of naïve cells with supernatant of HCV‐infected cells in the presence of EGCG, we observed that EGCG leads to undetectable levels of infection after four passages.Conclusion:EGCG is a new interesting anti‐HCV molecule that could be used in combination with other direct acting antivirals. Furthermore, it is a novel tool to further dissect the mechanisms of HCV entry into the hepatocyte. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Markus Peck‐Radosavljevic
Antagonistic effects of selenium and lipid peroxides on growth control in early hepatocellular carcinoma
Background and aims:Activation of the AP‐1 transcription factor as well as increased serum levels of VEGF and IL‐8 predict poor prognosis of patients with hepatocellular carcinomas (HCCs). Moreover, HCC patients display reduced selenium levels which may cause lipid peroxidation and oxidative stress since selenium is an essential component of antioxidative glutathione peroxidases (GPx). We hypothesized that the selenium – lipid peroxide antagonism controls the above prognostic markers and tumour growth.Results:1) In human HCC cell lines (HCC‐1.2, HCC‐3 and SNU398) linoleic acid peroxide (LOOH) and other prooxidants enhanced the expression of VEGF and IL‐8. LOOH up‐regulated AP‐1 activation. Selenium inhibited these effects. This inhibition was mediated by glutathione peroxidase 4 (GPx4), which preferentially degrades lipid peroxides. Selenium enhanced GPx4 expression and total GPx activity, knock‐down of GPx4 by siRNA increased VEGF and IL‐8 expression. 2) These results were confirmed in a rat hepatocarcinogenesis model. Selenium treatment during tumour promotion increased hepatic GPx4 expression and reduced the expression of VEGF and of the AP‐1 component c‐fos as well as nodule growth. 3) In HCC patients, increased levels of LOOH‐related antibodies (LOOH‐Ab) were found suggesting enhanced LOOH formation. LOOH‐Ab correlated with serum VEGF and IL‐8 and with AP‐1 activation in HCC tissue. In contrast, selenium inversely correlated with VEGF, IL‐8 and HCC size (the latter only for tumours smaller than 3 cm).Conclusions:Reduced selenium levels result in accumulation of lipid peroxides. This leads to enhanced AP‐1 activation and consequentially to elevated expression of VEGF and IL‐8 which accelerate growth of HCC. Selenium supplementation could be considered for investigation as a strategy for chemoprevention or additional therapy of early HCC in patients with low selenium level. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Cara L. Mack
Cytomegalovirus‐specific T cell reactivity in biliary atresia at the time of diagnosis is associated with deficits in regulatory T cells
Biliary atresia (BA) is a progressive, inflammatory cholangiopathy that culminates in fibrosis of extrahepatic and intrahepatic bile ducts. A leading theory on the pathogenesis of BA is that the bile duct damage is initiated by a virus infection, followed by a bile duct‐targeted autoimmune response. One mechanism of autoimmunity entails diminished number or function of regulatory T cells (Tregs). The aim of this study was to identify potential virus‐specific liver T cells from infants with BA at the time of diagnosis, implicating the virus involved in early bile duct damage. A subaim was to determine if presence of virus infection was associated with quantitative changes in Tregs. Results: Liver T cells from BA and control patients were cultured with antigen presenting cells in the presence of a variety of viral or control proteins. 56% of BA patients had significant increases in IFN‐γ‐producing liver T cells in response to cytomegalovirus (CMV), compared to minimal BA responses to other viruses or the control group CMV response. In addition, a positive correlation between BA plasma CMV IgM and liver T cell CMV reactivity was identified. Investigation of peripheral blood Tregs revealed significant deficits in Tregs frequencies in BA compared to controls, with marked deficits in those BA patients who were positive for CMV. Conclusions: Liver T cell responses to CMV were identified in the majority of BA patients at diagnosis, suggesting perinatal CMV infection as a plausible initiator of bile duct damage. Deficiency of Tregs in BA implies decreased inhibition of inflammation and autoreactivity, potentially allowing for exaggerated bile duct injury. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Carol L. Brosgart
Prevalence of chronic hepatitis B among foreign‐born persons living in the United States by country of origin
Estimates of the prevalence of chronic hepatitis B (CHB) in the U.S. differ significantly and the contribution of foreign‐born (FB) persons has not been adequately described. The aim of this study was to estimate the number of FB persons in the U.S. living with CHB by their country of origin. We performed a systematic review for reports of HBsAg seroprevalence rates in 102 countries (covering PubMed 1980 to July 2010). Data from 1,373 articles meeting inclusion criteria were extracted into country‐specific databases. We identified 256 seroprevalence surveys in emigrants from 52 countries (including 689,078 persons) and 1,797 surveys in the general populations of 98 countries (including 17,861,035 persons). Surveys including individuals with lower or higher risk of CHB than the general population were excluded. Data were combined using meta‐analytic methods to determine country‐specific pooled CHB prevalence rates. Rates were multiplied by the number of FB living in the U.S. in 2009 by country of birth from the U.S. Census Bureau to yield the number of FB with CHB from each country. We estimate a total of 1.32 million (95% confidence interval, 1.04 million to 1.61 million) FB in the U.S. living with CHB in 2009; 58% migrated from Asia and 11% migrated from Africa, where hepatitis B is highly endemic. About 7% migrated from Central America, a region with lower CHB rates but many more emigrants to the United States. This analysis suggests that the number of FB persons living with CHB in the U.S. may be significantly greater than previously reported. Assuming 300,000–600,000 U.S.‐born persons with CHB, the total prevalence of CHB in the U.S. may be as high as 2.2 million. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Pranoti Mandrekar
Inhibition of hsp90 attenuates pro‐inflammatory cytokines and prevents LPS induced liver injury
Background:Endotoxin mediated pro‐inflammatory cytokines play a significant role in pathogenesis of acute and chronic liver diseases. Hsp90 functions as an important chaperone of LPS signaling and is required for production of pro‐inflammatory cytokines. We hypothesized that inhibition of hsp90 prevents LPS induced liver injury by decreasing pro‐inflammatory cytokines.Methods:C57BL/6 mice were injected i.p. with an hsp90 inhibitor, 17‐DMAG, and LPS. Parameters of liver injury, pro‐inflammatory cytokines, and mechanisms associated were studied by in vivo and in vitro experiments.Results:Inhibition of hsp90 by 17‐DMAG prevented LPS induced serum ALT and significantly reduced serum TNFα and IL‐6 protein as well as mRNA in liver. Enhanced DNA binding activity of heat shock factor 1 (HSF1) and induction of target gene hsp70 confirmed hsp90 inhibition in liver. 17‐DMAG treatment decreased CD14 mRNA and LPS induced NFκB DNA binding without affecting TLR4 mRNA in liver. Mechanistic studies revealed that 17‐DMAG mediated inhibition of TNFα showed no effect on LPS induced NFκB promoter driven reporter activity but significantly decreased TNFα promoter driven reporter activity. Chromatin immunoprecipitation assays showed that 17‐DMAG enhanced HSF1 binding to TNFα promoter, but not IL‐6 promoter, suggesting HSF1 mediated direct inhibition of TNFα but not IL‐6. We show that HSF1 indirectly regulates IL‐6 via induction of another transcription factor, ATF3. Inhibition of HSF1 using siRNA prevented 17‐DMAG mediated down‐regulation of NFκB binding activity, TNFα and IL‐6 induction supporting a repressive role for HSF1 on pro‐inflammatory cytokine genes during hsp90 inhibition.Conclusion:Hsp90 inhibition in vivo reduces pro‐inflammatory cytokines and prevents LPS induced liver injury likely via repressive action of HSF1. Our results suggest a novel application for 17‐DMAG in alleviating LPS induced liver injury. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Takao Sakai
Thrombospondin‐1 is a novel negative regulator of liver regeneration after partial hepatectomy via TGF‐β1 activation in mice
The matricellular protein thrombospondin‐1 (TSP‐1) is prominently expressed during tissue repair. TSP‐1 binds to matrix components, proteases, cytokines, and growth factors and activates intracellular signals via its multiple domains. TSP‐1 converts latent transforming growth factor‐β1 (TGF‐β1) complexes into biologically active form. TGF‐β plays significant roles in cell‐cycle regulation, modulation of differentiation, and induction of apoptosis. Although TGF‐β1 is a major inhibitor of proliferation in cultured hepatocytes, the functional requirement of TGF‐β1 during liver regeneration remains to be defined in vivo. We generated a TSP‐1‐deficient mouse model of a partial hepatectomy and explored TSP‐1 induction, progression of liver regeneration, and TGF‐β‐mediated signaling during repair process following hepatectomy. We show here that TSP‐1‐mediated TGF‐β1 activation plays an important role in suppressing hepatocyte proliferation. TSP‐1 expression was induced in endothelial cells as an immediate early gene in response to partial hepatectomy. TSP‐1 deficiency resulted in significantly reduced TGF‐β/Smad signaling and accelerated hepatocyte proliferation via downregulation of p21 protein expression. TSP‐1 expression in endothelial cells was induced by reactive oxygen species (ROS) and modulated TGF‐β/Smad signaling and proliferation in hepatocytes in vitro, suggesting that the immediately and transiently produced ROS in the regenerating liver were the responsible factor for TSP‐1 induction.Conclusions:We have identified TSP‐1 as an inhibitory element in regulating liver regeneration via TGF‐β1 activation. Our work defines TSP‐1 as a novel immediate early gene that could be a potential therapeutic target to accelerate liver regeneration. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Wensheng Chen
Elevated hepatic MRP3/ABCC3 expression in human obstructive cholestasis is mediated through TNFα and JNK/SAPK signaling pathway
Multidrug resistance‐associated protein 3 (MRP3, ABCC3) plays an important role in protecting hepatocytes and other tissues by excreting an array of toxic organic anion conjugates, including bile salts. MRP3/ABCC3 expression is increased in the liver of some cholestatic patients, but the molecular mechanism of this up‐regulation remains elusive. In this report, we assessed liver MRP3/ABCC3 expression in patients (n=22) with obstructive cholestasis due to gallstones blockage of bile ducts and non‐cholestatic patient controls (n=22). MRP3/ABCC3 mRNA and protein expression were significantly increased 3.4‐ and 4.6‐ fold, respectively in these cholestatic patients where elevated plasma TNFα (4.7‐fold, P<0.01) and hepatic SP1 and LRH‐1 expression (3.1‐ and 2.1‐fold at mRNA level, 3.5‐ and 2.5‐fold at protein level, respectively) were also observed. The induction of hepatic MRP3/ABCC3 mRNA expression is significantly positively correlated with the level of plasma TNFα in these patients. In HepG2 cells, TNFα treatment induced SP1 and MRP3/ABCC3 expression in a dose‐ and time‐dependent manner, where increased phosphorylation of JNK/SAPK was also detected. These inductions were significantly reduced in the presence of the JNK inhibitor SP600125. TNFα treatment enhanced HepG2 cell nuclear extract binding activity to the MRP3/ABCC3 promoter, but was abolished by SP600125 as demonstrated by EMSA. An increase in nuclear protein binding activity to the MRP3/ABCC3 promoter consisting primarily of SP1 was also seen in liver samples from cholestatic patients as assessed by supershift EMSA assays.Conclusions:Our findings indicate that up‐regulation of hepatic MRP3/ABCC3 expression in human obstructive cholestasis is likely triggered by TNFα, mediated by activations of JNK/SAPK and SP1. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Zhibin Hu
Genetic variants in HLA‐DP/DQ influence both hepatitis B virus clearance and hepatocellular carcinoma development
Recent genome‐wide association studies showed that four single‐nucleotide polymorphisms (SNPs) in HLA‐DP (rs3077and rs9277535) and HLA‐DQ (rs2856718 and rs7453920) were associated with chronic hepatitis B virus (HBV) infection in Japanese populations. More than 75% of the hepatocellular carcinoma (HCC) patients are attributable to persistent infection of HBV, especially in China. We genotyped these four SNPs in1300 HBV‐positive HCC patients, 1344 persistent HBV carriers and 1344 persons with HBV natural clearance from Southeast China to further test the associations of HLA‐DP/DQ variants and with risk of both HBV clearance and HCC development. Logistic regression analyses showed that HLA‐DQ rs2856718 significantly decreased host HCC risk, while three SNPs were associated with HBV clearance (HLA‐DP rs9277535, and HLA‐DQ rs7453920 and rs2856718). In addition, HLA‐DP rs3077 showed an approaching significant effect on susceptibility to HBV persistent infection and HCC development when considering multiple testing adjustments. Taken together, we reported for the first time that genetic variants in the HLA‐DP and HLA‐DQ loci may be marker SNPs for risk of both HBV clearance and HCC development. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Chieh Chiang
International cross‐cultural field validation of an EORTC questionnaire module for patients with primary liver cancer, the EORTC QLQ‐HCC18
This international field validation study examined the psychometric properties and clinical validity of the European Organisation for Research and Treatment of Cancer (EORTC) questionnaire module for hepatocellular carcinoma, the EORTC QLQ‐HCC18. The EORTC QLQ‐HCC18 was administered with the core questionnaire, the EORTC QLQ‐C30 to 272 patients from seven centres in six countries. Patient acceptability of the module was examined with a debriefing questionnaire and psychometric and clinical properties were assessed. Multi‐trait scaling analyses confirmed the hypothesised scale structure without any scaling error and the fatigue scale demonstrated satisfactory internal consistency. The test‐retest reliability scores were high for all scales except abdominal swelling and sexual interest. The correlations between of all scales of the QLQ‐HCC18 and the QLQ‐C30 were low or moderate and many scales could distinguish patients with different clinical conditions. The module demonstrated responsiveness to clinical change in pain before and after surgery and some borderline change in patients undergoing systemic treatment.Conclusion:The EORTC QLQ‐HCC18 can be used as a supplementary module for the EORTC QLQ‐C30 in clinical trials for patients with HCC. (HEPATOLOGY 2011.)

Date de mise en ligne : Mardi 22 novembre 2011
Shulin Li
IL30—A novel anti‐inflammatory cytokine candidate for prevention and treatment of inflammatory cytokine‐induced liver injury
The liver is the major metabolic organ and is subjected to constant attacks from chronic viral infection, uptake of therapeutic drugs, life behavior (alcoholic), and environmental contaminants, all of which result in chronic inflammation, fibrosis, and ultimately, cancer. Therefore, there is an urgent need to discover effective therapeutic agents for the prevention and treatment of liver injury; the ideal drug being a naturally occurring biological inhibitor. Here, we establish the role of IL30 as a potent anti‐inflammatory cytokine which can inhibit inflammation‐induced liver injury. In contrast, IL27, which contains IL30 as a subunit, is not hepatoprotective. Interestingly, IL30 is induced by the pro‐inflammatory signal such as IL12 through IFNγ/STAT1 signaling. In animal models, administration of IL30 via a gene therapy approach prevents and treats both IL12‐, IFNγ‐, and Concanavalin A ‐induced liver toxicity. Likewise, immunohistochemistry analysis of human tissue samples revealed that IL30 is highly expressed in hepatocytes yet barely expressed in inflammation‐induced tissue such as fibrous/connective tissue. These novel observations reveal a novel role of IL30 as a therapeutic cytokine that suppresses pro‐inflammatory cytokine‐associated liver toxicity. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Helen H. Hobbs
Homozygosity mapping identifies a bile acid biosynthetic defect in an adult with cirrhosis of unknown etiology
The most common inborn error of bile acid metabolism is 3β‐hydroxy‐Δ5‐C27‐steroid oxidoreductase (3β‐HSD) deficiency, a disorder that usually presents in early childhood with hepatic dysfunction. Timely diagnosis of this disorder is crucial since it can be effectively treated with primary bile acid replacement. Here we describe a 24‐year‐old woman from Iran with cirrhosis of unknown etiology. Her sister and a first cousin died of cirrhosis (ages 19 and 6 years) and another 32‐year old first cousin had a self‐limited liver disorder in childhood that resolved at age 9 years. The family history was consistent with the notion that affected family members were homozygous for a mutant allele inherited identical‐by‐descent. A genome‐wide analysis of 2.5 million single nucleotide polymorphisms (SNP) was performed to identify regions of homozygosity that were present in the proband and the 32‐year old first cousin, but not in a healthy relative. One of these regions contained the gene encoding 3β‐HSD (HSD3B7). Sequence analysis of HSD3B7 revealed that the proband and her 32‐year old cousin were homozygous for a frameshift mutation (c.45_46del AG, p.T15Tfsx27) in exon 1. The diagnosis of 3β‐HSD deficiency was confirmed by documenting high levels of 3β‐hydroxy‐Δ5 bile acids in the serum of the first cousin using mass spectrometry. To our knowledge, the 32‐year old relative in this family represents the oldest asymptomatic patient with this disorder. Conclusion: This study highlights the clinical utility of homozygosity mapping in diagnosing autosomal recessive metabolic disorders. This family illustrates the wide variation in expressivity that occurs in 3β‐HSD deficiency and underscores the need to consider a bile acid synthetic defect as a possible cause of liver disease in adults. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Dennis E. Vance
Hepatic ratio of phosphatidylcholine to phosphatidylethanolamine predicts survival after partial hepatectomy in mice
A major predictor of failed liver resection and transplantation is non‐alcoholic fatty liver disease (NAFLD). NAFLD is linked to a wide spectrum of diseases including obesity and diabetes that are increasingly prevalent in Western populations. Thus, it is important to develop therapies aimed at improving post‐hepatectomy outcomes in patients with NAFLD, as well as to improve the evaluation of patients slated for hepatic surgery. Decreased hepatic phosphatidylcholine (PC) content and decreased ratio of hepatic PC to phosphatidylethanolamine (PE) have previously been linked to NAFLD. To determine if decreased hepatic PC/PE could predict survival after hepatectomy, we used mouse models lacking key enzymes in PC biosynthesis, namely phosphatidylethanolamine N‐methyltransferase and hepatic‐specific CTP:phosphocholine cytidylyltransferase α. These mice were fed a high fat diet to induce NAFLD. We then performed a 70% partial hepatectomy and monitored postoperative survival. We identified hepatic PC/PE to be inversely correlated with the development of steatosis and inflammation in the progression of NAFLD. Decreased hepatic PC/PE before surgery was also strongly associated with decreased rates of survival after partial hepatectomy. Choline supplementation to the diet increased hepatic PC/PE in Pemt‐/‐ mice with NAFLD, decreased inflammation, and increased the survival rate after partial hepatectomy. Conclusion: Decreased hepatic PC/PE is a predictor of NAFLD and survival following partial hepatectomy. Choline supplementation may serve as a potential therapy to prevent the progression of NAFLD and to improve post‐operative outcome after liver surgery. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Kezhong Zhang
ER‐tethered transcription factor crebh regulates hepatic lipogenesis, fatty acid oxidation, and lipolysis upon metabolic stress
CREBH is a liver‐specific transcription factor that is localized in the endoplasmic reticulum (ER) membrane. Our previous work demonstrated that CREBH is activated by ER stress or inflammatory stimuli to induce an acute‐phase hepatic inflammation. Here we demonstrate that CREBH is a key metabolic regulator of hepatic lipogenesis, fatty acid (FA) oxidation, and lipolysis under metabolic stress. Saturated FA, insulin signals, or an atherogenic high‐fat diet can induce CREBH activation in the liver. Under the normal chow diet, CrebH knockout mice display a modest decrease in hepatic lipid contents but an increase in plasma triglycerides (TG). After feeding an atherogenic high‐fat diet, massive accumulation of hepatic lipid metabolites and significant increase in plasma TG levels were observed in the CrebH knockout mice. Along with the hypertriglyceridemia phenotype, the CrebH null mice displayed significantly reduced body weight gain, diminished abdominal fat, and increased non‐alcoholic steatohepatitis (NASH) activities under the atherogenic high‐fat diet. Gene expression analysis and chromatin‐immunoprecipitation (ChIP) assay indicated that CREBH is required to activate expression of the genes encoding functions involved in de novo lipogenesis, TG and cholesterol biosynthesis, FA elongation and oxidation, lipolysis, and lipid transport. Supporting the role of CREBH in lipogenesis and lipolysis, forced expression of an activated form of CREBH protein in the liver significantly increases accumulation of hepatic lipids but reduces plasma TG levels in mice. All together our study shows that CREBH plays a key role in maintaining lipid homeostasis by regulating expression of the genes involved in hepatic lipogenesis, FA oxidation, and lipolysis under metabolic stress. The identification of CREBH as a stress‐inducible metabolic regulator has important implications in the understanding and treatment of metabolic disease. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Pamela L. Tuma
Lysine acetylation induced by chronic ethanol consumption impairs dynamin‐mediated clathrin‐coated vesicle release
The liver is the major site of ethanol metabolism, and thus, sustains the most injury from chronic alcohol consumption. Ethanol metabolism by the hepatocyte leads to the generation of reactive metabolites and oxygen radicals that can readily adduct DNA, lipids and proteins. More recently, it has become apparent that ethanol consumption also leads to increased post‐translational modifications of the natural repertoire including lysine hyperacetylation. Previously, we determined that alcohol consumption selectively impairs clathrin‐mediated internalization in polarized hepatocytes. However, neither the step at which the block occurs nor the mechanism responsible for the defect have been identified. To identify the specific step at which clathrin‐mediated internalization is impaired, we examined the distributions, levels and assembly of selected components of the clathrin machinery in control and ethanol‐treated cells. To determine whether the impairment is due to ethanol‐induced lysine acetylation, we also examined the same coat components in cells treated with trichostatin A (TSA), a deacetylase inhibitor that leads to protein hyperacetylation in the absence of ethanol. Conclusion. We determined that both ethanol and TSA impair internalization at a late stage prior to vesicle fission. We further determined that this defect is likely due to decreased dynamin recruitment to the necks of clathrin‐coated invaginations resulting in impaired vesicle budding. These results also raise the exciting possibility that agents that promote lysine deacetylation may be effective therapeutics for the treatment of alcoholic liver disease. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Mahlon M. Wilkes
Albumin infusion in patients undergoing large‐volume paracentesis: A meta‐analysis of randomized trials
Albumin infusion reduces the incidence of post‐paracentesis circulatory dysfunction among patients with cirrhosis and tense ascites, as compared with no treatment. Treatment alternatives to albumin such as artificial colloids and vasoconstrictors have been widely investigated. The aim of this meta‐analysis was to determine whether morbidity and mortality differ between patients receiving albumin vs. alternative treatments. The meta‐analysis included randomized trials evaluating albumin infusion in patients with tense ascites. Primary endpoints were post‐paracentesis circulatory dysfunction, hyponatremia and mortality. Eligible trials were sought by multiple methods, including computer searches of bibliographic and abstract databases and the Cochrane Library. Results were quantitatively combined under a fixed effects model. Seventeen trials with 1225 total patients were included. There was no evidence of heterogeneity or publication bias. Compared with alternative treatments, albumin reduced the incidence of post‐paracentesis circulatory dysfunction (odds ratio, 0.39; 95% confidence interval, 0.27‐0.55). Significant reductions in that complication by albumin were also shown in subgroup analyses vs. each of the other volume expanders tested (dextran, gelatin, hydroxyethyl starch and hypertonic saline). The occurrence of hyponatremia was also decreased by albumin compared with alternative treatments (odds ratio, 0.58; 95% confidence interval, 0.39‐0.87). In addition, mortality was lower in patients receiving albumin than alternative treatments (odds ratio, 0.64; 95% confidence interval, 0.41‐0.98). Conclusions: This meta‐analysis provides evidence that albumin reduces morbidity and mortality among patients with tense ascites undergoing large‐volume paracentesis, as compared with alternative treatments investigated thus far. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
GP Aithal
To feed or what to feed in cirrhosis?
n/a

Date de mise en ligne : Mercredi 16 novembre 2011
Pierre‐Yves Bochud
Serum ferritin levels are associated with a distinct phenotype of chronic hepatitis C poorly responding to pegylated interferon‐α and ribavirin therapy
Elevated serum ferritin levels may reflect a systemic inflammatory state as well as increased iron storage, both of which may contribute to an unfavorable outcome of chronic hepatitis C. We therefore performed a comprehensive analysis of the role of serum ferritin and their genetic determinants in the pathogenesis and treatment of chronic hepatitis C. To this end, serum ferritin levels at baseline of therapy with pegylated interferon‐α and ribavirin or before biopsy were correlated with clinical and histological features of chronic HCV infection, including necroinflammatory activity (N=970), fibrosis (N=980), steatosis (N=886) and response to treatment (N=876). The association between high serum ferritin levels (>median) and the endpoints was assessed by logistic regression. Moreover, a candidate gene as well as a genome‐wide association study of serum ferritin were performed. We found that serum ferritin ≥ the sex‐specific median was one of the strongest pre‐treatment predictors of treatment failure (univariate P<0.0001, OR=0.45, 95% CI=0.34‐0.60). This association remained highly significant in a multivariate analysis (P=0.0002, OR=0.35, 95% CI=0.20‐0.61), with an odds ratio comparable to that of IL28B genotype. When patients with the unfavorable IL28B genotypes were stratified according to high vs. low ferritin levels, SVR rates differed by >30% in both HCV genotype 1‐ and 3‐infected patients (P<0.001). Serum ferritin levels were also independently associated with severe liver fibrosis (P<0.0001, OR=2.67, 95% CI=1.68‐4.25) and steatosis (P=0.002, OR=2.29, 95% CI=1.35‐3.91) but not with necroinflammatory activity (P=0.3). Genetic variations had only a limited impact on serum ferritin levels.Conclusion:In patients with chronic hepatitis C, elevated serum ferritin levels are independently associated with advanced liver fibrosis, hepatic steatosis, and poor response to interferon‐α‐based therapy. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Alan S. Perelson
Hepatitis C viral kinetics with the nucleoside polymerase inhibitor mericitabine (RG7128)
Mericitabine (RG7128) is a first‐in class nucleoside polymerase inhibitor (NPI), which requires intracellular uptake and phosphorylation to two active triphosphates. Mathematical modeling has provided important insights for characterizing HCV‐RNA decline and estimating in vivo effectiveness of antiviral agents; however it has not been used to characterize viral kinetics with NPIs. HCV RNA was frequently measured in 32 treatment‐experienced patients infected with HCV genotype‐1 during and after mericitabine monotherapy for 14 days with 750‐mg or 1500‐mg administered once (QD) or twice daily (BID). Initial decline of HCV RNA was typically slower than with interferon‐alpha or protease inhibitors and 12 patients presented a novel pattern of HCV RNA kinetics characterized by a monophasic viral decline. Viral kinetics could be well fitted by assuming that the effectiveness in blocking viral production gradually increased over time to reach its final value, ε2, consistent with previous accumulation time estimates of intracellular triphosphates. ε2 was high with BID dosing (mean 750‐mg and 1500‐mg: 98.0% and 99.8%, P=0.018) and significantly higher than in patients treated QD (mean QD vs BID: 90% vs 99%, P<10‐7). Virus rebounded rapidly upon drug discontinuation, which was attributed to the elimination of active drug and the subsequent decline of drug effectiveness with mean t1/2=13.9 h in the BID regimens.Conclusion:The observed slower initial decline likely represents the time needed to accumulate intracellular triphosphates and is consistent with in vitro data. When administered BID, mericitabine reached a high, dose‐dependent, final effectiveness in blocking viral production, that rapidly dropped upon treatment cessation. Understanding HCV RNA kinetics with mericitabine could provide valuable insights for combining it with other direct‐acting antiviral agents. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Jan Wehkamp
Intestinal bacterial translocation in cirrhotic rats is related to compromised paneth cell antimicrobial host defence
Liver cirrhosis is associated with bacterial translocation (BT) and endotoxemia. Most translocating bacteria belong to the common intestinal microbiota suggesting a breakdown of intestinal barrier function. Herein, we hypothesised that diminished mucosal antimicrobial host defence could predispose to BT.Methods:Two rodent models of portal hypertension with increased BT were used, CCl4‐induced ascitic cirrhosis and 2‐day portal‐vein ligated animals (PVL). BT was assessed by standard microbiological techniques on mesenteric lymph nodes. Total RNA was isolated systematically throughout the intestinal tract and expression of Paneth cell α‐cryptdins and ß‐defensins was determined by qRT PCR. To determine functional consequences, mucosal antimicrobial activity was assessed with FACS assay.Results:BT was detectable in 40% of cirrhotic rats. Compared to the group without BT these animals exhibited diminished intestinal Paneth cell α‐cryptdin 5 and 7 expression. In contrast, portal vein ligation was associated with BT in all animals but did not affect antimicrobial peptides. The decrease of Paneth cell antimicrobials was most pronounced in the ileum and the coecum. Other antimicrobials showed no changes or even an induction in case of BT at different sites. Antimicrobial activity towards different commensal strains was reduced especially in the distal ileum and the coecum in experimental cirrhosis with BT (excluding portal vein ligation).Conclusion:Compromised Paneth cell antimicrobial host defence seems to predispose to BT in experimental cirrhosis. Understanding this liver‐ gut axis including the underlying mechanisms could help to find new treatment avenues. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
María L Martínez‐Chantar
Mdm2 regulates HuR stability in human liver and colon cancer through neddylation
Hu antigen R (HuR) is a central RNA‐binding protein regulating cell dedifferentiation, proliferation and survival, well‐established hallmarks of cancer. HuR is frequently overexpressed in tumors correlating with tumor malignancy, in line with a role for HuR in tumorigenesis. However, the precise mechanism leading to changes in HuR expression remains unclear. In the liver, HuR plays a crucial role in hepatocyte proliferation, differentiation, and transformation. Here, we unravel a novel mean of regulation of HuR expression in HCC and colon cancer. HuR levels correlate with the abundance of the oncogene Mdm2 in human HCC and colon cancer metastases. HuR is stabilized by Mdm2‐mediated NEDDylation in at least three lysine residues, ensuring its nuclear localization and protection from degradation.Conclusion:This novel Mdm2/NEDD8/HuR regulatory framework is essential for malignant transformation of tumor cells, which in turn unveils a novel signaling paradigm, pharmacologically amenable for cancer therapy. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Snorri S. Thorgeirsson
Hepatocyte growth factor (HGF) /c‐Met signaling is required for stem cell mediated liver regeneration
HGF/c‐Met supports a pleiotrophic signal transduction pathway that controls stem cell homeostasis. Here, we directly addressed the role of c‐Met in stem cell‐mediated liver regeneration by utilizing mice harboring c‐met floxed alleles and Alb‐Cre or Mx1‐Cre transgenes. To activate oval cells, the hepatic stem cell (HSC) progeny, we used a model of liver injury induced by diet containing the porphyrinogenic agent, 3, 5‐diethocarbonyl‐1,4‐dihydrocollidine (DDC). Deletion of c‐met in oval cells was confirmed in both models by PCR analysis of FACS‐ sorted EpCam‐positive cells. Loss of c‐Met receptor decreased sphere‐forming capacity of oval cells in vitro as well as reduced oval cell pool, impaired migration and decreased hepatocytic differentiation in vivo as demonstrated by double immunofluorescence using oval‐ (A6 and EpCam) and hepatocyte‐specific (HNF‐4α) antibodies. Furthermore, lack of c‐Met had a profound effect on tissue remodeling and overall composition of HSC niche which was associated with greatly reduced MMP9 activity and decreased expression of SDF1. Using a combination of double immunofluorescence of cell type‐specific markers with MMP9 and gelatin zymography on the isolated cell populations, we identified macrophages as a major source of MMP9 in DDC‐treated livers. The Mx1‐Cre‐driven c‐met deletion caused the greatest phenotypic impact on HSCs response as compared to the selective inactivation in the epithelial cell lineages achieved in c‐Metfl/fl; Alb‐Cre+/‐ mice. However, in both models, genetic loss of c‐met triggered a similar cascade of events leading to failure of HSCs mobilization and death of the mice.Conclusion:These results establish a direct contribution of c‐Met in regulation of HSC response, and support a unique role for HGF/c‐Met as an essential growth factor signaling pathway for regeneration of diseased liver. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Adriano Decarli
Family history of liver cancer and hepatocellular carcinoma
Familial clustering of hepatocellular carcinoma (HCC) has been reported frequently among eastern Asiatic countries, where hepatitis B infection is common. Little is known about the relationship between family history of liver cancer and HCC in Western populations. We carried out a case‐control study in Italy, involving 229 HCC cases and 431 hospital controls. Data on family history were summarized through a binary indicator (yes/no) and a family history score (FHscore), considering selected family characteristics. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were obtained from unconditional multiple logistic regression models including terms for age, sex, study center, education, tobacco smoking, alcohol drinking, hepatitis B surface antigen and/or anti‐hepatitis C virus positivity. We also performed a meta‐analysis on family history and liver cancer updated to April 2011 using random‐effects models. After adjustment for chronic infection with hepatitis B/C viruses, family history of liver cancer was associated to HCC risk, when using both the binary indicator (OR=2.38, 95% CI, 1.01‐5.58) and the FHscore, with increasing ORs for successive score categories. Compared to subjects without family history and no chronic infection with hepatitis B/C viruses, the OR for those exposed to both risk factors was 72.48 (95% CI, 21.92‐239.73). In the meta‐analysis, based on 9 case‐control and 4 cohort studies, for a total of about 3600 liver cancer cases, the pooled relative risk for family history of liver cancer was 2.50 (95% CI, 2.06‐3.03).Conclusion:A family history of liver cancer increases HCC risk, independently of hepatitis. The combination of family history of liver cancer and hepatitis B/C serum markers is associated to an over 70‐fold elevated HCC risk. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Helen L Reeves
Glucokinase links krüppel‐like factor 6 to the regulation of hepatic insulin sensitivity in non‐alcoholic fatty liver disease
The polymorphism, KLF6‐IVS1‐27A, in the Krüppel‐like factor 6 (KLF6) transcription factor gene enhances its splicing into antagonistic isoforms and is associated with delayed histological progression of non‐alcoholic fatty liver disease (NAFLD). To explore a potential role for KLF6 in the development of insulin resistance, central to NAFLD pathogenesis, we genotyped KLF6‐IVS1‐27 in healthy subjects and assayed fasting plasma glucose (FPG) and insulin sensitivities. Furthermore, we quantified mRNA expression of KLF6 and glucokinase (GCK), as an important mediator of insulin sensitivity, in human livers and in liver tissues derived from a murine Klf6 knockdown model (DeltaKlf6). Klf6 overexpression studies in a mouse hepatocyte line were utilized to mechanistically link KLF6 with Gck promoter activity. Results: KLF6‐IVS1‐27Gwt (ie., less KLF6 splicing) was associated with stepwise increases in FPG and insulin and reduced hepatic insulin sensitivity. KLF6 binds to the liver‐specific Gck promoter and activates a GCK promoter‐reporter, identifying GCK as a KLF6 direct transcriptional target. Accordingly, in DeltaKlf6 hepatocytes, Gck expression was reduced and stable transfection of Klf6 led to upregulation of Gck. GCK and KLF6 mRNAs correlate directly in human NAFLD tissues and immunohistochemistry studies confirm falling levels of both KLF6 and GCK in fat laden hepatocytes. In contrast to full length KLF6, splice variant KLF6‐SV1 increases in NAFLD hepatocytes and inversely correlates with glucokinase regulatory protein, which negatively regulates GCK activity.Conclusion:KLF6 regulation of GCK contributes to the development of hepatic insulin resistance. The KLF6‐IVS1‐27A polymorphism, which generates more KLF6‐SV1, combats this, lowering hepatic insulin resistance and blood glucose. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Hidekazu Tsukamoto
Rosmarinic acid and baicalin epigenetically de‐repress Pparγ in hepatic stellate cells for their anti‐fibrotic effect
Hepatic stellate cells (HSCs) undergo myofibroblastic trans‐differentiation (activation) to participate in liver fibrosis, and identification of molecular targets for this cell fate regulation is essential for development of efficacious therapeutic modalities for the disease. Peroxisomal proliferator‐activated receptor γ (PPARγ) is required for differentiation of HSCs and its epigenetic repression underlies HSC activation. The herbal prescription Yang‐Gan‐Wan (YGW) prevents liver fibrosis, but its active ingredients and molecular mechanisms are unknown. Here we demonstrate YGW prevents and reverses HSC activation via epigenetic de‐repression of Pparγ involving reductions in MeCP2 expression and its recruitment to Pparγ promoter, suppressed expression of PRC2 methyltrasferase EZH2 and consequent reduction of H2K27di‐methylation at the 3′ exon. HPLC/MS and NMR analyses identify polyphenolic rosmarinic acid (RA) and baicalin (BC) as active phytocompounds. RA and BC suppress the expression and signaling by canonical Wnts, which are implicated in the aforementioned Pparγ epigenetic repression. RA treatment in mice with existing cholestatic liver fibrosis inhibits HSC activation and progression of liver fibrosis. In conclusion, these results demonstrate a therapeutic potential of YGW and its active component RA and BC for liver fibrosis via Pparγ de‐repression mediated by suppression of canonical Wnt signaling in HSCs. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Lisa K. Naeger
Clinical relevance of detectable but not quantifiable hepatitis C virus RNA during boceprevir or telaprevir treatment
Boceprevir‐ and telaprevir‐based treatments for chronic hepatitis C virus (HCV) infection use specific response‐guided therapy (RGT) guidelines. Eligibility for shortened treatment duration is based on achieving Undetectable HCV RNA early during treatment. It is unclear whether a detected HCV RNA level that is below the assay lower limit of quantitation (Detectable/BLOQ) is comparable to an Undetectable HCV RNA level, particularly regarding RGT decision making. We analyzed data from boceprevir and telaprevir clinical trials to obtain a comprehensive understanding of the frequency and clinical relevance of Detectable/BLOQ HCV RNA measurements. In Phase 3 trials P05216 (boceprevir), C216 (telaprevir) and 108 (telaprevir), Detectable/BLOQ levels were reported for approximately 10‐20% of all on‐treatment HCV RNA measurements. In P05216 and C216, subjects with Detectable/BLOQ HCV RNA, on average, had a reduced sustained virologic response (SVR) rate compared to subjects with Undetectable HCV RNA at the same on‐treatment timepoint. At key RGT timepoints (Week 8 for boceprevir, Week 4 for telaprevir), subjects with Detectable/BLOQ HCV RNA had an approximately 20% lower SVR rate compared to subjects with Undetectable HCV RNA, and this difference widened for later on‐treatment timepoints. A similar trend was observed for Study 108, but the differences in SVR rates were more modest, which may be explained by a higher frequency of reported Detectable/BLOQ results. Analyses of Phase 2 boceprevir and telaprevir trials indicated subjects with Detectable/BLOQ HCV RNA at RGT timepoints benefited from extended treatment duration.Conclusions:During boceprevir‐ and telaprevir‐based treatment, subjects with Detectable/BLOQ HCV RNA had a reduced virologic response compared to subjects with Undetectable HCV RNA. Eligibility for shortened treatment duration should be based on patients achieving Undetectable HCV RNA at RGT decision timepoints. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 16 novembre 2011
Oscar K. Lee
Rapid generation of mature hepatocyte‐like cells from human induced pluripotent stem cells by an efficient three‐step protocol
Liver transplantation is the only definitive treatment for end‐stage cirrhosis and fulminant liver failure but the lack of available donor livers is a major obstacle to liver transplantation. Recently, induced pluripotent stem (iPS) cells, derived from the reprogramming of somatic fibroblasts, have been shown to resemble embryonic stem (ES) cells in that they have pluripotent properties and the potential to differentiate into all cell lineages in vitro, including hepatocytes. Thus iPS cells could serve as a favorable cell source for a wide range of applications, including drug toxicity testing, cell transplantation, and patient‐specific disease modeling. Here we describe an efficient and rapid three‐step protocol that is able to rapidly generate hepatocyte‐like cells from human iPS cells. This occurs because the endodermal induction step allows for more efficient and definitive endoderm cell formation. We show that hepatocyte growth factor (HGF), which synergizes with Activin A and Wnt3a, elevates the expression of the endodermal marker Foxa2 (Forkhead box a2) by 39.3% compared to when HGF is absent (14.2%) during the endodermal induction step. In addition, iPSC–derived hepatocytes had a similar gene expression profile to mature hepatocytes. Importantly, the hepatocyte‐like cells exhibited cytochrome P450 3A4 (CYP3A4) enzyme activity, secreted urea, uptake of low‐density lipoprotein (LDL), and possessed the ability to store glycogen. Moreover, the hepatocyte‐like cells rescued lethal fulminant hepatic failure in a nonobese diabetic severe combined immunodeficienct mouse model.Conclusion:We have established a rapid and efficient differentiation protocol that is able to generate functional hepatocyte‐like cells from human iPS cells. This may offer an alternative option for treatment of liver diseases. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
Elizabeth C. Wright
Quantitative liver function tests improve the prediction of clinical outcomes in chronic hepatitis C: Results from the HALT‐C trial
Risk for future clinical outcomes is proportional to the severity of liver disease in patients with chronic hepatitis C. We measured disease severity by quantitative liver function tests (QLFTs) to determine cutoffs for QLFTs that identified patients who were at low and high risk for a clinical outcome. Two hundred twenty seven participants in the Hepatitis C Antiviral Long‐Term Treatment Against Cirrhosis (HALT‐C) Trial underwent baseline QLFTs and were followed for a median of 5.5 years for clinical outcomes. QLFTs were repeated in 196 patients at month 24 and in 165 patients at month 48. Caffeine elimination rate (k), antipyrine (AP) clearance (Cl), MEGX concentration, methionine breath test (MBT), galactose elimination capacity (GEC), dual cholate (CA) clearances and shunt, and perfused hepatic mass (PHM) and liver and spleen volumes (SPECT) were measured. Baseline QLFTs were significantly worse (p=0.0017 to <0.0001) and spleen volumes larger (p<0.0001) in the 54 patients who subsequently experienced clinical outcomes. QLFT cutoffs that characterized patients as “low” and “high risk” for clinical outcome yielded hazard ratios ranging from 2.21 (95%CI 1.29‐3.78) for GEC to 6.52 (95%CI 3.63‐11.71) for CA Cloral. QLFTs independently predicted outcome in models with Ishak fibrosis score, platelet count, and standard laboratory tests. In serial studies, patients with “high risk” results for CA Cloral or PHM had a nearly 15‐fold increase in risk for clinical outcome. Less than 5% of patients with “low risk” QLFTs experienced a clinical outcome.Conclusion:QLFTs independently predict risk for future clinical outcomes. By improving risk assessment, QLFTs could enhance noninvasive monitoring, counseling, and management of patients with chronic hepatitis C. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
Paula Alves
Human liver cell spheroids in extended perfusion bioreactor culture for repeated dose drug testing
Primary cultures of human hepatocyte spheroids are a promising in vitro model for long term studies of hepatic metabolism and cytotoxicity. The lack of robust methodologies to culture cell spheroids, a poor characterization of the human hepatocyte spheroids architecture and liver‐specific functionality have hampered a widespread adoption of this 3D culture format. In this work, an automated perfusion bioreactor was used to obtain and maintain human hepatocyte spheroids. These spheroids were cultured for 3‐4 weeks in serum‐free conditions, sustaining their phase I enzyme expression and permitting repeated induction during long culture times; the rate of albumin and urea synthesis, as well as phase I and II drug metabolizing enzymes' gene expression and activity of the spheroid hepatocyte cultures presented reproducible profiles, despite the basal inter‐donor variability (n=3 donors). Immunofluorescence microscopy of human hepatocyte spheroids after 3‐4 weeks of long term culture confirmed the presence of the liver‐specific markers hepatocyte nuclear factor 4α, albumin, cytokeratin 18 and cytochrome P450 3A. Moreover, immunostaining of the atypical protein kinase C apical marker, as well as the excretion of a fluorescent dye, evidenced that these spheroids spontaneously assemble a functional bile canaliculi network extending from the surface to the interior of the spheroids after 3‐4 weeks of culture. Conclusion: Perfusion bioreactor cultures of primary human hepatocyte spheroids maintain a liver‐specific activity and architecture and are thus suitable for drug testing in a long term, repeated dose format (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
Peter A. White
Hepatitis C virus reinfection and superinfection among treated and untreated participants with recent infection
Background and aims:To evaluate reinfection and superinfection during treatment for recent HCV.Methods:ATAHC was a prospective study of the natural history and treatment of recent HCV. Reinfection and superinfection were defined by detection of infection with an HCV strain distinct from the primary strain (using RT‐PCR and subtype‐specific nested RT‐PCR assays) in the setting of spontaneous or treatment‐induced viral suppression (one HCV RNA <10 IU/ml) or persistence (HCV RNA >10 IU/mL from enrolment to week 12).Results:Among 163, 111 were treated, 79% (88 of 111) had treatment‐induced viral suppression and 60% (67 of 111) achieved SVR. Following treatment‐induced viral suppression, recurrence was observed in 19% (17 of 88), including 12 with relapse and five with reinfection [4.7 cases per 100 person‐years (py), 95% CI; 1.9, 11.2]. Among 52 untreated, 58% (30 of 52) had spontaneous viral suppression and recurrence was observed in 10% (3 of 30), including two with reinfection. Following reinfection, ALT levels >1.5x the upper limit of normal were observed in 71% (5 of 7). Among 37 with persistence, superinfection was observed in 16% (3 of 19) of those treated and 17% (3 of 18) of those untreated. In adjusted analysis, reinfection/superinfection occurred more often in participants with poorer social functioning at enrolment and more often in those with ongoing injecting drug use (IDU).Conclusions:Reinfection and superinfection can occur during treatment of recent HCV and are associated with poor social functioning and ongoing IDU. ALT levels may be a useful clinical marker of re‐exposure. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
M. Eric Gershwin
Plasma cells and the chronic nonsuppurative destructive cholangitis of primary biliary cirrhosis
There has been increased interest in the role of B cells in the pathogenesis of primary biliary cirrhosis. Although the vast majority of patients with primary biliary cirrhosis have antimitochondrial antibodies, there is no correlation of antimitochondrial antibody titer and/or presence with disease severity. Further, in murine models of primary biliary cirrhosis, it has been suggested that depletion of B cells may exacerbate biliary pathology. To address this issue, we have focused on detailed phenotypic characterization of mononuclear cell infiltrates surrounding the intrahepatic bile ducts of patients with PBC, PSC, AIH, CH‐C and GVHD, including CD3, CD4, CD8, CD20, CD38 and immunoglobulin classes, as well as double immunohistochemical staining for CD38 and IgM. Interestingly, CD20 B lymphocytes, which are a precursor of plasma cells, were found in scattered locations or occasionally forming follicle‐like aggregations but were not noted at the proximal location of chronic nonsuppurative destructive cholangitis. In contrast, there was a unique and distinct coronal arrangement of CD38 cells around the intrahepatic ducts in primary biliary cirrhosis but not controls; the majority of such cells were considered plasma cells based on their expression of intracellular immunoglobulins, including IgM and IgG, but not IgA. Patients with primary biliary cirrhosis who manifest this unique coronal arrangement were those with significantly higher titers of antimitochondrial antibodies. These data collectively suggest a role of plasma cells in the specific destruction of intrahepatic bile ducts in primary biliary cirrhosis and highlight the increasing interest in plasma cells and autoimmunity. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
Emmanuel Gonzales
Claudin‐1 involved in neonatal ichthyosis ‐ sclerosing cholangitis syndrome, regulates hepatic paracellular permeability
Neonatal ichthyosis and sclerosing cholangitis (NISCH) syndrome is a liver disease caused by mutations of CLDN1 encoding Claudin‐1, a tight‐junction (TJ) protein. In this syndrome it is speculated that cholestasis is due to Claudin‐1 absence, leading to increased paracellular permeability and to liver injuries secondary to paracellular bile regurgitation. We studied the role of claudin‐1 in hepatic paracellular permeability. A NISCH liver and polarized rat cell lines forming TJs, the hepatocellular Can 10 and the cholangiocellular NRC, were used. In contrast to NRC, Can 10 does not express claudin‐1. Can 10 cells were transfected with a plasmid encoding Claudin‐1 and stable Claudin‐1 expressing clones isolated. Claudin‐1 expression was silenced by transfection with siRNA in Can 10 clones and with shRNA in NRC. Claudin‐1 expression was evaluated by qRT‐PCR, immunoblotting, and immunolocalization. Paracellular permeability was assessed by FITC‐dextran passage in both lines and by transepithelial resistance measurements in NRC. In NISCH liver, Claudin‐1 was not detected in hepatocytes or cholangiocytes. In Claudin‐1 expressing Can 10 clones, Claudin‐1 was localized at the TJ and paracellular permeability was decreased compared to parental Can 10 cells, this decrease correlating with Claudin‐1 levels. Silencing of Claudin‐1 in Can 10 clones increased paracellular permeability to a level similar to that of parental cells. Similarly, we observed an increase of paracellular permeability in NRC cells silenced for claudin‐1 expression. Conclusion: Defect in claudin‐1 expression increases paracellular permeability in polarized hepatic cell lines, supporting the hypothesis that paracellular bile leakage through deficient tight junctions is involved in liver pathology observed in NISCH syndrome. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 26 octobre 2011
Jaideep Behari
β‐catenin is essential for ethanol metabolism and protection against alcohol‐mediated liver steatosis in mice
The liver plays a central role in ethanol metabolism and oxidative stress is implicated in alcohol‐mediated liver injury. β‐Catenin regulates hepatic metabolic zonation and adaptive response to oxidative stress. We hypothesized that β‐catenin regulates the hepatic response to ethanol ingestion. Female liver‐specific β‐catenin knockout (KO) mice and wild type (WT) littermates were fed the Lieber‐Decarli liquid diet (5% ethanol) in a pair‐wise fashion. Liver histology, biochemistry, and gene expression studies were performed. Plasma alcohol and ammonia levels were measured using standard assays. Ethanol‐fed KO mice exhibited systemic toxicity and early mortality. KO mice exhibited severe macrovesicular steatosis and five to six‐fold higher serum ALT and AST levels. KO mice had modest increase in hepatic oxidative stress, lower expression of mitochondrial superoxide dismutase (SOD‐2), and lower citrate synthase activity, the first step in the tricarboxylic acid cycle. N‐Acetyl cysteine (NAC) did not prevent ethanol‐induced mortality in KO mice. In WT livers, β‐catenin was found to co‐precipitate with FoxO3, the upstream regulator of SOD‐2. Hepatic alcohol dehydrogenase and aldehyde dehydrogenase activities and expression were lower in KO mice. Hepatic cytochrome P450 2E1 protein levels were upregulated in ethanol‐fed WT mice but were nearly undetectable in KO mice. These changes in ethanol‐metabolizing enzymes were associated with 30‐fold higher blood alcohol levels in KO mice. Conclusion: β‐catenin is essential for hepatic ethanol metabolism and plays a protective role in alcohol‐mediated liver steatosis. Our results strongly suggest that integration of these functions by β‐catenin is critical for adaptation to ethanol ingestion in vivo. (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 17 octobre 2011
Graham R. Foster
The protease inhibitor GS‐9256 and non‐nucleoside polymerase inhibitor tegobuvir alone, with RBV or peginterferon plus RBV in hepatitis C
Tegobuvir (GS‐9190), a non‐nucleoside NS5B polymerase inhibitor, and GS‐9256, an NS3 serine protease inhibitor, individually have activity against hepatitis C virus (HCV) genotype 1. The antiviral activity of tegobuvir and GS‐9256 as oral combination therapy, or together with ribavirin (RBV) or peginterferon alfa‐2a (PEG‐IFN) and RBV, was assessed in a phase 2, randomized, open‐label trial. Treatment‐naïve patients with genotype 1 HCV were assigned 28 days of tegobuvir 40 mg twice daily and GS‐9256 75 mg twice daily (n=16), tegobuvir and GS‐9256 plus RBV 1000‐1200 mg daily (n=15), or tegobuvir and GS‐9256 plus PEG‐IFN alfa‐2a (180 mcg qw)/RBV (n=15). The primary efficacy endpoint was rapid virologic response (RVR), HCV RNA <25 IU/mL at Day 28. After 28 days, all patients received PEG‐IFN/RBV. All patients with viral rebound or nonresponse, defined as >0.5‐log10 increase in HCV RNA from nadir or <2‐log decrease at Day 5, initiated PEG‐IFN/RBV immediately. Median maximal reductions in HCV RNA were ‐4.1 log10 IU/mL for tegobuvir/GS‐9256, ‐5.1 log10 IU/mL for tegobuvir/GS‐9256/RBV, and ‐5.7 log10 IU/mL for tegobuvir/9256/PEG‐IFN/RBV. RVR was observed in 7% (1/15) of patients receiving tegobuvir/GS‐9256, 38% (5/13) receiving tegobuvir/GS‐9256/RBV, and 100% (14/14) receiving tegobuvir/9256/PEG‐IFN/RBV. The addition of PEG‐IFN/RBV at Day 28 or earlier resulted in HCV RNA <25 IU/mL at Week 24 in 67% (10/15), 100% (13/13) and 94% (13/14) of patients in the 3 treatment groups. Transient elevations in serum bilirubin occurred in all treatment groups. Conclusion: In genotype 1 HCV, adding RBV or RBV with PEG‐IFN provides additive antiviral activity to combination therapy with tegobuvir and GS‐9256. (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 17 octobre 2011
Heiner Wedemeyer
HEV‐specific T‐cell responses are associated with control of HEV infection
Hepatitis E virus (HEV) infection is usually self‐limited limited but may lead to acute hepatitis and rarely to fulminant hepatic failure. Persistent HEV infections have recently been described in organ transplant recipients receiving immunosuppressive medications suggesting that HEV is controlled by adaptive immune responses. However, only few studies did investigate HEV‐specific T‐cell responses and immune correlates for the failure to clear HEV infection have not been established so far. We investigated T‐cell responses against HEV in 38 subjects including anti‐HEV‐positive (exposed, n=9) and anti‐HEV‐negative (n=10) healthy controls, 12 anti‐HEV‐positive but HEV RNA‐negative organ transplant recipients and 7 transplant recipients with chronic hepatitis E. Proliferation as well as cytokine production of CD4+ and CD8+ T‐cells was studied after stimulation with overlapping peptides spanning all proteins encoded by HEV‐ORF2 and HEV‐ORF3. We show that (i) strong and multi‐specific HEV‐specific T‐cell responses are present in exposed healthy controls and to a lesser extent also in recovered patients after transplantation, (ii) that these responses are absent in patients with chronic hepatitis E but become detectable after viral clearance and (iii) that HEV‐specific T‐cell responses can be restored in vitro by blocking the PD‐1 or CTLA‐4 pathways. However, combination of PD‐1 and CTLA‐4 blockade had no synergistic effects.We conclude that chronic hepatitis E is associated with impaired HEV‐specific T‐cell responses and suggest that enhancing adaptive cellular immunity against HEV might prevent persistent HEV infections. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 12 octobre 2011
Sanjeev Gupta
Molecular perturbations restrict potential for liver repopulation of hepatocytes isolated from nonheart‐beating donor rats
Organs from nonheart‐beating donors are attractive for use in cell therapy. Understanding the nature of molecular perturbations following reperfusion/reoxygenation will be highly significant for nonheart‐beating donor cells. We studied nonheart‐beating donor rats for global gene expression with Affymetrix microarrays, hepatic tissue integrity, viability of isolated hepatocytes, and engraftment and proliferation of transplanted cells in dipeptidyl peptidase IV‐deficient rats. In nonheart‐beating donors, liver tissue was morphologically intact for >24 hours with differential expression of 1, 95, or 372 genes, 4, 16 or 34 hours after death, respectively, compared with heart‐beating donors. These differentially‐expressed genes constituted prominent groupings in ontological pathways of oxidative phosphorylation, adherence junctions, glycolysis/gluconeogenesis, as well as other discrete pathways. We successfully isolated viable hepatocytes from nonheart‐beating donors, especially up to 4 hours after death, although the hepatocyte yield and viability were inferior to hepatocytes from heart‐beating donors, p<0.05. Similarly, although hepatocytes from nonheart‐beating donors engrafted and proliferated after transplantation in recipient animals, this was inferior to hepatocytes from heart‐beating donors, p<0.05. Gene expression profiling in hepatocytes isolated from nonheart‐beating donors showed far greater perturbations compared with corresponding liver tissue, including representation of pathways in focal adhesion, actin cytoskeleton, extracellular matrix‐receptor interactions, multiple ligand‐receptor interactions, and signaling in insulin, calcium, wnt, Jak‐Stat, or other cascades. Conclusion: Liver tissue remained intact over prolonged periods after death in nonheart‐beating donors but extensive molecular perturbations following reperfusion/reoxygenation impaired viability of isolated hepatocytes from these donors. Insights into molecular changes in hepatocytes from nonheart‐beating donors offers opportunities for improving donor cell viability, which will advance utility of nonheart‐beating donor organs for cell therapy or other applications. (HEPATOLOGY 2011.)

Date de mise en ligne : Mercredi 12 octobre 2011
Kris V. Kowdley
Vitamin D deficiency in obese rats exacerbates NAFLD and increases hepatic resistin and toll‐like receptor activation
Childhood obesity is associated with type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD). Recent studies have found associations between vitamin D deficiency (VDD), insulin resistance (IR) and NAFLD among overweight children. To further explore mechanisms mediating these effects, we fed young (age 25d) Sprague‐Dawley rats with a low‐fat diet (LFD) alone or with vitamin D depletion (LFD+VDD). A second group of rats was exposed to a Westernized diet (WD: high‐fat/high‐fructose corn syrup) that is more typically consumed by overweight children, and was either replete (WD) or deficient in vitamin D (WD+VDD). Liver histology was assessed using the NASH CRN scoring system and expression of genes involved in inflammatory pathways were measured in liver and visceral adipose tissue after 10 weeks. In VDD groups, 25‐OH‐vitamin D levels were reduced to 29% (95% CI: 23‐36%) compared to controls. WD+VDD animals exhibited significantly greater hepatic steatosis compared to LFD groups. Lobular inflammation as well as NAFLD activity score (NAS) were higher in WD+VDD vs. the WD group (NAS: WD+VDD 3.2±0.47 vs. WD 1.50±0.48, p<0.05). Hepatic mRNA levels of toll‐like receptors TLR2, TLR4 and TLR9, as well as resistin, interleukins IL‐1β, IL‐4 and IL‐6 and oxidative stress marker heme oxygenase (HO)‐1, were higher in WD+VDD vs. WD animals (p<0.05). Logistic regression analyses showed significant associations between NAS score and liver mRNA levels of TLRs 2,4, and 9, endotoxin receptor CD14, as well as peroxisome proliferator activated receptor (PPAR)γ, and HO‐1.Conclusion:Vitamin D deficiency exacerbates NAFLD through TLR‐activation possibly via endotoxin exposure in a WD rat model. In addition it causes IR, higher hepatic resistin gene expression, and up‐regulation of hepatic inflammatory and oxidative stress genes. (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 10 octobre 2011
Mario Strazzabosco
Altered store operated calcium entry increases cAMP production and ERK1/2 phosphorylation in Polycystin‐2 defective cholangiocytes
Mutations in polycystins (PC1 or PC2/TRPP2) cause progressive polycystic liver disease (PLD). In PC2 defective mice, cAMP/PKA‐dependent activation of ERK/mTOR signaling stimulates cyst growth. We investigated the mechanisms connecting PC2 dysfunction to altered Ca2+ and cAMP production and inappropriate ERK signaling in PC2‐defective cholangiocytes. Cystic cholangiocytes were isolated from PC2 conditional‐KO mice (Pkd2flox/‐:pCxCreERTM – hence called Pkd2KO) and compared to cholangiocytes from Wild Type mice (WT). Our results show that, compared to wild type cells, in PC2 ‐defective cholangiocytes (Pkd2KO) cytoplasmic and ER‐Ca2+ (measured with Fura‐2 and Mag‐Fluo4) levels are decreased, store‐operated Ca2+ entry (SOCE) is inhibited, while the expression of Ca2+‐sensor STIM1 and of store‐operated Ca2+ channels (Orai1 channel) are unchanged. In Pkd2KO cells, ER‐Ca2+ depletion increases [cAMP] and PKA‐dependent ERK1/2 activation and both are inhibited by STIM1 inhibitors or by silencing of adenylyl cyclase 6 (AC6).Conclusion:these data suggest that PC2 plays a key role in SOCE activation and inhibits the STIM‐dependent activation of AC6 by ER Ca2+ depletion. In PC2‐defective cells, the interaction of STIM‐1 with Orai channels is uncoupled, while coupling to AC6 is maximized. The resulting overproduction of cAMP, in turn, potently activates the PKA/ERK pathway. PLD due to PC2‐deficiency represents the first example of human disease linked to inappropriate activation of “Store‐operated cAMP production” (SOcAMP). (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 10 octobre 2011
Nathan Bass
Ethnicity and nonalcoholic fatty liver disease
Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in the U.S.; however, few data are available about racial and ethnic variation. We investigated relationships between ethnicity, NAFLD severity, metabolic derangements and socio‐demographic characteristics in a well‐characterized cohort of adults with biopsy‐proven NAFLD. Data were analyzed from 1026 adults (≥18 years) in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) from 2004‐2008 for whom liver histology data were available within 6‐months of enrollment. Associations between ethnicity (Latino versus Non‐Latino White) and NAFLD severity (NASH versus Non‐NASH histology; and mild versus advanced fibrosis) were explored with multiple logistic regression analysis. We also investigated effect modification of ethnicity on metabolic derangements for NAFLD severity. Within the NASH CRN, 77% (N=785) were Non‐Latino White and 12% (N=118) Latino. Sixty‐one percent (N=668) had NASH histology and 29% (N=291) had advanced fibrosis. Latinos with NASH were younger, performed less physical activity and had higher carbohydrate intake compared to Non‐Latino Whites with NASH. Gender, diabetes, hypertension, hypertriglyceridemia, aspartate aminotransferase (AST), platelets, and the homeostasis model assessment of insulin resistance (HOMA‐IR) were significantly associated with NASH. Age, gender, AST, alanine aminotransferase, alkaline phosphatase, platelets, total cholesterol, hypertension and HOMA‐IR, but not ethnicity, were significantly associated with advanced fibrosis. The effect of HOMA‐IR on risk of NASH was modified by ethnicity: HOMA‐IR was not a significant risk factor for NASH among Latinos (Odds Ratio, OR=0.93 [95% Confidence Interval, CI, 0.85‐1.02]), but was significant among Non‐Latino Whites (OR 1.06, [95%CI 1.01‐1.11]).Conclusion:Metabolic risk factors and socio‐demographic characteristics associated with NASH differ by ethnicity. Additional insights into NASH pathogenesis may come from further studies focused on understanding ethnic differences in this disease. (HEPATOLOGY 2011.)

Date de mise en ligne : Lundi 11 juillet 2011
Fernando Herz Wolff
Ethnic differences in viral dominance patterns in patients with hepatitis B virus and hepatitis C virus dual infection
n/a

Date de mise en ligne : Lundi 23 ao�t 2010
Bo‐Jian Zheng
Retracted: HLA‐A2‐/HLA‐DR1‐transgeneic H‐2 class I‐/class II‐knockout mouse is an ideal animal model for study of chronic HBV infection
n/a

Date de mise en ligne : Lundi 10 octobre 2011
William M. Lee
Two distinct subtypes of hepatitis B virus–related acute liver failure are separable by quantitative serum immunoglobulin M anti‐hepatitis B core antibody and hepatitis B virus DNA levels
Hepatitis B virus (HBV)‐related acute liver failure (HBV‐ALF) may occur after acute HBV infection (AHBV‐ALF) or during an exacerbation of chronic HBV infection (CHBV‐ALF). Clinical differentiation of the two is often difficult if a previous history of HBV is not available. Quantitative measurements of immunoglobulin M (IgM) anti–hepatitis B core antibody (anti‐HBc) titers and of HBV viral loads (VLs) might allow the separation of AHBV‐ALF from CHBV‐ALF. Of 1,602 patients with ALF, 60 met clinical criteria for AHBV‐ALF and 27 for CHBV‐ALF. Sera were available on 47 and 23 patients, respectively. A quantitative immunoassay was used to determine IgM anti‐HBc levels, and real‐time polymerase chain reaction (rtPCR) was used to determine HBV VLs. AHBV‐ALFs had much higher IgM anti‐HBc titers than CHBV‐ALFs (signal‐to‐noise [S/N] ratio median: 88.5; range, 0‐1,120 versus 1.3, 0‐750; P < 0.001); a cut point for a S/N ratio of 5.0 correctly identified 44 of 46 (96%) AHBV‐ALFs and 16 of 23 (70%) CHBV‐ALFs; the area under the receiver operator characteristic curve was 0.86 (P < 0.001). AHBV‐ALF median admission VL was 3.9 (0‐8.1) log10 IU/mL versus 5.2 (2.0‐8.7) log10 IU/mL for CHBV‐ALF (P < 0.025). Twenty percent (12 of 60) of the AHBV‐ALF group had no hepatitis B surface antigen (HBsAg) detectable on admission to study, wheras no CHBV‐ALF patients experienced HBsAg clearance. Rates of transplant‐free survival were 33% (20 of 60) for AHBV‐ALF versus 11% (3 of 27) for CHBV‐ALF (P = 0.030). Conclusions: AHBV‐ALF and CHBV‐ALF differ markedly in IgM anti‐HBc titers, in HBV VLs, and in prognosis, suggesting that the two forms are, indeed, different entities that might each have a unique pathogenesis. (HEPATOLOGY 2011)

Date de mise en ligne : Lundi 10 octobre 2011
Hiromitsu Kumada
Dual therapy with the nonstructural Protein 5A Inhibitor, BMS‐790052, and the Nonstructural Protein 3 Protease Inhibitor, BMS‐650032, in Hepatitis C Virus Genotype 1b–Infected Null Responders
Patients with chronic hepatitis C virus (HCV) infection and previous null response to pegylated interferon (Peg‐IFN) and ribavirin (RBV) have limited therapeutic options. HCV genotype 1 is the most common worldwide and the most difficult to treat; genotype 1b is the most common subtype of genotype 1 outside North America. The enhanced antiviral activity achieved by combining two direct‐acting antiviral (DAA) agents may improve clinical outcomes. This open‐label, phase IIa study included 10 patients with chronic HCV genotype 1b infection and previous null response (<2 log10 reduction in HCV RNA after 12 weeks) to Peg‐IFN and RBV. Patients received dual DAA treatment for 24 weeks with the nonstructural protein 5A replication complex inhibitor, BMS‐790052 (60 mg once‐daily), and the nonstructural protein 3 protease inhibitor, BMS‐650032 (initially 600 mg twice‐daily, then subsequently reduced to 200 mg twice‐daily). The primary efficacy endpoint was the proportion of patients with sustained virologic response (SVR) at 12 weeks post‐treatment (SVR12). Nine patients completed 24 weeks of treatment; 1 patient discontinued treatment after 2 weeks. In the 9 patients who completed the full course of treatment, HCV RNA was undetectable at week 8 and remained undetectable through the end of treatment; all 9 patients achieved SVR12 and SVR24. HCV RNA also remained undetectable post‐treatment in the patient who discontinued after 2 weeks. There was no viral breakthrough. Diarrhea and headache, generally mild, were the most common adverse events; transaminase elevations were reported in 3 patients, but did not result in discontinuation. Conclusions: Dual therapy with BMS‐790052 and BMS‐650032, without Peg‐IFN and RBV, can achieve high SVR rates in difficult‐to‐treat patients with HCV genotype 1b infection and previous null response to Peg‐IFN and RBV. (HEPATOLOGY 2011)

Date de mise en ligne : Lundi 10 octobre 2011
Pascal Degrace
Antagonism of peripheral hepatic cannabinoid receptor‐1 improves liver lipid metabolism in mice: Evidence from cultured explants
It is well established that inactivation of the central endocannabinoid system (ECS) through antagonism of cannabinoid receptor 1 (CB1R) reduces food intake and improves several pathological features associated with obesity, such as dyslipidemia and liver steatosis. Nevertheless, recent data indicate that inactivation of peripheral CB1R could also be directly involved in the control of lipid metabolism independently of central CB1R. To further investigate this notion, we tested the direct effect of the specific CB1R antagonist, SR141716, on hepatic carbohydrate and lipid metabolism using cultured liver slices. CB1R messenger RNA expression was strongly decreased by SR141716, whereas it was increased by the CB1R agonist, arachidonic acid N‐hydroxyethylamide (AEA), indicating the effectiveness of treatments in modulating ECS activity in liver explants both from lean or ob/ob mice. The measurement of O2 consumption revealed that SR141716 increased carbohydrate or fatty acid utilization, according to the cellular hormonal environment. In line with this, SR141716 stimulated ß‐oxidation activity, and the role of CB1R in regulating this pathway was particularly emphasized when ECS was hyperactivated by AEA and in ob/ob tissue. SR141716 also improved carbohydrate and lipid metabolism, blunting the AEA‐induced increase in gene expression of proteins related to lipogenesis. In addition, we showed that SR141716 induced cholesterol de novo synthesis and high‐density lipoprotein uptake, revealing a relationship between CB1R and cholesterol metabolism. Conclusion: These data suggest that blocking hepatic CB1R improves both carbohydrate and lipid metabolism and confirm that peripheral CB1R should be considered as a promising target to reduce cardiometabolic risk in obesity. (HEPATOLOGY 2011)

Date de mise en ligne : Mercredi 26 octobre 2011
Maura Dandri
Humanized chimeric uPA mouse model for the study of hepatitis B and D virus interactions and preclinical drug evaluation
No specific drugs are currently available against hepatitis delta virus (HDV), a defective virus leading to the most severe form of chronic viral hepatitis in man. The lack of convenient HDV infection models has hampered the development of effective therapeutics. In this study, naïve and hepatitis B virus (HBV) chronically infected humanized uPA/SCID mice were employed to establish a small animal model of HBV/HDV coinfection and superinfection. For preclinical antiviral drug evaluation, the GMP version of the myristoylated preS‐peptide (Myrcludex‐B), a lipopeptide derived from the pre‐S1 domain of the HBV envelope, was applied to prevent de novo HBV/HDV coinfection in vivo. Virological parameters were determined at serological and intrahepatic level both by real‐time polymerase chain reaction (PCR) and by immunohistochemistry. Establishment of HDV infection was highly efficient in both HBV‐infected and naïve chimeric mice with HDV titers rising up to 1 × 10E9 copies/mL. Notably, HDV superinfection led to a median 0.6log reduction of HBV viremia, which although not statistically significant suggests that HDV may hinder HBV replication. In the setting of HBV/HDV simultaneous infection, a majority of human hepatocytes stained HDAg‐positive long before HBV spreading was completed, confirming that HDV can replicate intrahepatically also in the absence of HBV infection. Furthermore, the increase of HBV viremia and intrahepatic cccDNA loads was significantly slower than in HBV mono‐infected mice. Treatment with the HBV entry inhibitor Myrcludex‐B, efficiently hindered the establishment of HDV infection in vivo. Conclusion: We established an efficient model of HBV/HDV infection to exploit mechanisms of viral interference in human hepatocytes and to test the efficacy of an HDV‐entry inhibitor in vivo. (HEPATOLOGY 2011)

Date de mise en ligne : Lundi 17 octobre 2011
Françoise Degos
Accuracy and disagreement of computed tomography and magnetic resonance imaging for the diagnosis of small hepatocellular carcinoma and dysplastic nodules: Role of biopsy
Liver macronodules, ranging from benign to low‐grade or high‐grade dysplastic nodules (LGDNs/HGDNs) and hepatocellular carcinoma (HCC), may develop during chronic liver diseases (CLDs). Current guidelines were recently updated and the noninvasive criteria for the diagnosis of small HCC are based on a single typical radiological pattern and nonconclusive coincidental findings with two techniques. This study aimed to assess the accuracy and disagreements of noninvasive multiphasic examinations for the diagnosis of HCC and dysplastic nodules (DNs) and the role of biopsy. Seventy‐four consecutive patients with CLD with ultrasound‐detected 1‐2‐cm nodules underwent, within 1 month, multiphasic computed tomography (CT), magnetic resonance imaging (MRI), and biopsy of the nodule. Median age was 60 years; 33 patients (45%) had hepatitis C virus, 20 (27%) had hepatitis B virus, and 13 (18%) patients had no cirrhosis. Biopsy revealed 47 HCCs, 6 HGDNs, 1 LGDNs, 1 cholangiocarcinoma, and 1 epithelioid hemangioendothelioma. There were no tumors in the other 18 patients. All patients (31 of 31; 100%) who had conclusive coincidental findings (i.e., arterial enhancement and washout) on both examinations had HCC or HGDN (sensitivity, 57%; specificity, 100%). All patients (51 of 51; 100%) who had conclusive findings on at least one of the two examinations had HCC or HGDN (sensitivity, 96%; specificity, 100%). There was a disagreement regarding imaging findings between CT and MRI in 21 of 74 (28%) patients and no washout on both examinations in 23 of 74 patients (31%). In these 44 patients, liver biopsy provided an initial accurate diagnosis. Conclusion: The noninvasive diagnosis of HCC or HGDN can be obtained if arterial enhancement and washout are found in a single dynamic imaging examination. These findings are frequently discordant on both CT and MRI, supporting the place of biopsy for the diagnosis of small HCCs. (HEPATOLOGY 2011)

Date de mise en ligne : Mercredi 16 novembre 2011
Hiroshi Suzuki
Novel function of niemann‐pick C1‐like 1 as a negative regulator of Niemann‐Pick C2 protein
The hepatic expression of Niemann‐Pick C1‐like 1 (NPC1L1), which is a key molecule in intestinal cholesterol absorption, is high in humans. In addition to NPC1L1, Niemann‐Pick C2 (NPC2), a secretory cholesterol‐binding protein involved in intracellular cholesterol trafficking and the stimulation of biliary cholesterol secretion, is also expressed in the liver. In this study, we examined the molecular interaction and functional association between NPC1L1 and NPC2. In vitro studies with adenovirus‐based or plasmid‐mediated gene transfer systems revealed that NPC1L1 negatively regulated the protein expression and secretion of NPC2 without affecting the level of NPC2 messenger RNA. Experiments with small interfering RNA against NPC1L1 confirmed the endogenous association of these proteins. In addition, endocytosed NPC2 could compensate for the reduction of NPC2 in NPC1L1‐overexpressing cells, and this demonstrated that the posttranscriptional regulation of NPC2 was dependent on a novel ability of NPC1L1 to inhibit the maturation of NPC2 and accelerate the degradation of NPC2 during its maturation. Furthermore, to confirm the physiological relevance of NPC1L1‐mediated regulation, we analyzed human liver specimens and found a negative correlation between the protein levels of hepatic NPC1L1 and hepatic NPC2. Conclusion: NPC1L1 down‐regulates the expression and secretion of NPC2 by inhibiting its maturation and accelerating its degradation. NPC2 functions as a regulator of intracellular cholesterol trafficking and biliary cholesterol secretion; therefore, in addition to its role in cholesterol re‐uptake from the bile by hepatocytes, hepatic NPC1L1 may control cholesterol homeostasis via the down‐regulation of NPC2. (HEPATOLOGY 2011)

Date de mise en ligne : Mercredi 26 octobre 2011
Lawrence M. Pfeffer
Activation of chemokine and inflammatory cytokine response in hepatitis C virus–infected hepatocytes depends on toll‐like receptor 3 sensing of hepatitis C virus double‐stranded RNA intermediates
Chemokines and inflammatory cytokines are key regulators of immunity and inflammation during viral infections. Hepatitis C virus (HCV) is a hepatotropic RNA virus frequently associated with chronic liver inflammation and hepatocellular carcinoma. Intrahepatic levels of chemokines and cytokines are elevated in chronic HCV infections, but the underlying mechanisms remain unclear. We found that Toll‐like receptor‐3 (TLR3) senses HCV infection in cultured hepatoma cells, leading to nuclear factor kappa B (NF‐κB) activation and the production of numerous chemokines and inflammatory cytokines, such as regulated on activation normal T cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)‐1α, MIP‐1β, IP‐10, and interleukin‐6. The chemokine/cytokine induction occurred late in HCV infection and was abrogated when HCV was ultraviolet‐inactivated before infection, indicating a dependence on the cellular recognition of HCV replication products. Gel‐shift and chromatin immunoprecipitation assays revealed that NF‐κB plays a pivotal role in HCV‐induced chemokine/cytokine transcription. Mutations specifically disrupting the double‐stranded RNA (dsRNA)‐binding activity of TLR3 ablated the chemokine/cytokine response to HCV infection, indicating that HCV dsRNA was the pathogen‐associated molecular pattern triggering TLR3 signaling. In vitro synthesized HCV dsRNAs, with a minimal length of ∼80‐100 base pairs, activated TLR3‐dependent chemokine expression, regardless of the genome position from which they derived. In contrast, HCV single‐stranded RNAs, including those derived from the structured 3'nontranslated region highly potent for RIG‐I activation, failed to do so. Moreover, robust production of chemokines and inflammatory cytokines was also observed in primary human hepatocytes after stimulation with extracellular poly‐I:C, a TLR3 ligand. Conclusion: Our data suggest that TLR3‐mediated chemokine and inflammatory cytokine responses may play an important role in host immune responses to HCV and the pathogenesis of HCV‐associated liver diseases. (HEPATOLOGY 2011)

Date de mise en ligne : Mardi 20 d�cembre 2011
Samuel W. French
A cell‐permeable hairpin peptide inhibits hepatitis C viral nonstructural protein 5A–mediated translation and virus production
NS5A is a key regulator of the hepatitis C virus (HCV) life cycle including RNA replication, assembly, and translation. We and others have shown that NS5A augments HCV internal ribosomal entry site (IRES)‐mediated translation. Furthermore, Quercetin treatment and heat shock protein (HSP) 70 knockdown inhibit the NS5A‐driven augmentation of IRES‐mediated translation and infectious virus production. We have also coimmunoprecipitated HSP70 with NS5A and demonstrated cellular colocalization, leading to the hypothesis that the NS5A/HSP70 complex formation is important for IRES‐mediated translation. Here, we have identified the NS5A region responsible for complex formation through in vitro deletion analyses. Deletion of NS5A domains II and III failed to reduce HSP70 binding, whereas domain I deletion eliminated complex formation. NS5A domain I alone also bound HSP70. Deletion mapping of domain I identified the C‐terminal 34 amino acids (C34) as the interaction site. Furthermore, addition of C34 to domains II and III restored complex formation. C34 expression significantly reduced intracellular viral protein levels, in contrast to same‐size control peptides from other NS5A domains. C34 also competitively inhibited NS5A‐augmented IRES‐mediated translation, whereas controls did not. Triple‐alanine scan mutagenesis determined that an exposed beta‐sheet hairpin in C34 was primarily responsible for NS5A‐augmented IRES‐mediated translation. Moreover, treatment with a 10–amino acid peptide derivative of C34 suppressed NS5A‐augmented IRES‐mediated translation and significantly inhibited intracellular viral protein synthesis, with no associated cytotoxicity. Conclusion: These results support the hypothesis that the NS5A/HSP70 complex augments viral IRES‐mediated translation, identify a sequence‐specific hairpin element in NS5A responsible for complex formation, and demonstrate the functional significance of C34 hairpin–mediated NS5A/HSP70 interaction. Identification of this element may allow for further interrogation of NS5A‐mediated IRES activity, sequence‐specific HSP recognition, and rational drug design. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 12 octobre 2011
Sara Montagnese
Induced hyperammonemia may compromise the ability to generate restful sleep in patients with cirrhosis
In patients with cirrhosis, hyperammonemia and hepatic encephalopathy are common after gastrointestinal bleeding and can be simulated by an amino acid challenge (AAC), or the administration of a mixture of amino acids mimicking the composition of hemoglobin. The aim of this study was to investigate the clinical, psychometric, and wake‐/sleep‐electroencephalogram (EEG) correlates of induced hyperammonemia. Ten patients with cirrhosis and 10 matched healthy volunteers underwent: (1) 8‐day sleep quality/timing monitoring; (2) neuropsychiatric assessment at baseline/after AAC; (3) hourly ammonia/subjective sleepiness assessment for 8 hours after AAC; (4) sleep EEG recordings (nap opportunity: 17:00‐19:00) at baseline/after AAC. Neuropsychiatric performance was scored according to age‐/education‐adjusted Italian norms. Sleep stages were scored visually for 20‐second epochs; power density spectra were calculated for consecutive 20‐second epochs and average spectra determined for consolidated episodes of non‐rapid eye movement (non‐REM) sleep of minimal common length. The AAC resulted in: (i) an increase in ammonia concentrations/subjective sleepiness in both patients and healthy volunteers; (ii) a worsening of neuropsychiatric performance (wake EEG slowing) in two (20%) patients and none of the healthy volunteers; (iii) an increase in the length of non‐REM sleep in healthy volunteers [49.3 (26.6) versus 30.4 (15.6) min; P = 0.08]; (iv) a decrease in the sleep EEG beta power (fast activity) in the healthy volunteers; (v) a decrease in the sleep EEG delta power in patients. Conclusion: AAC led to a significant increase in daytime subjective sleepiness and changes in the EEG architecture of a subsequent sleep episode in patients with cirrhosis, pointing to a reduced ability to produce restorative sleep. (HEPATOLOGY 2012)

Date de mise en ligne : Lundi 19 septembre 2011
David E. Kaplan
Dysfunctional B‐cell activation in cirrhosis resulting from hepatitis C infection associated with disappearance of CD27‐Positive B‐cell population
Chronic hepatitis C virus (HCV) infection is a leading cause of cirrhosis and hepatocellular carcinoma (HCC). Both advanced solid tumors and HCV have previously been associated with memory B‐cell dysfunction. In this study, we sought to dissect the effect of viral infection, cirrhosis, and liver cancer on memory B‐cell frequency and function in the spectrum of HCV disease. Peripheral blood from healthy donors, HCV‐infected patients with F1‐F2 liver fibrosis, HCV‐infected patients with cirrhosis, patients with HCV‐related HCC, and non‐HCV‐infected cirrhotics were assessed for B‐cell phenotype by flow cytometry. Isolated B cells were stimulated with anti–cluster of differentiation (CD)40 antibodies and Toll‐like receptor (TLR)9 agonist for assessment of costimulation marker expression, cytokine production, immunoglobulin (Ig) production, and CD4+ T‐cell allostimulatory capacity. CD27+ memory B cells and, more specifically, CD27+IgM+ B cells were markedly less frequent in cirrhotic patients independent of HCV infection. Circulating B cells in cirrhotics were hyporesponsive to CD40/TLR9 activation, as characterized by CD70 up‐regulation, tumor necrosis factor beta secretion, IgG production, and T‐cell allostimulation. Last, blockade of TLR4 and TLR9 signaling abrogated the activation of healthy donor B cells by cirrhotic plasma, suggesting a role for bacterial translocation in driving B‐cell changes in cirrhosis. Conclusion: Profound abnormalities in B‐cell phenotype and function occur in cirrhosis independent of HCV infection. These B‐cell defects may explain, in part, the vaccine hyporesponsiveness and susceptibility to bacterial infection in this population. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 26 octobre 2011
Richard Moriggl
Growth‐hormone–induced signal transducer and activator of transcription 5 signaling causes gigantism, inflammation, and premature death but protects mice from aggressive liver cancer
Persistently high levels of growth hormone (GH) can cause liver cancer. GH activates multiple signal‐transduction pathways, among them janus kinase (JAK) 2‐signal transducer and activator of transcription (STAT) 5 (signal transducer and activator of transcription 5). Both hyperactivation and deletion of STAT5 in hepatocytes have been implicated in the development of hepatocellular carcinoma (HCC); nevertheless, the role of STAT5 in the development of HCC as a result of high GH levels remains enigmatic. Thus, we crossed a mouse model of gigantism and inflammatory liver cancer caused by hyperactivated GH signaling (GHtg) to mice with hepatic deletion of STAT5 (STAT5Δhep). Unlike GHtg mice, GHtgSTAT5Δhep animals did not display gigantism. Moreover, the premature mortality, which was associated with chronic inflammation, as well as the pathologic alterations of hepatocytes observed in GHtg mice, were not observed in GHtg animals lacking STAT5. Strikingly, loss of hepatic STAT5 proteins led to enhanced HCC development in GHtg mice. Despite reduced chronic inflammation, GHtgSTAT5Δhep mice displayed earlier and more advanced HCC than GHtg animals. This may be attributed to the combination of increased peripheral lipolysis, hepatic lipid synthesis, loss of hepatoprotective mediators accompanied by aberrant activation of tumor‐promoting c‐JUN and STAT3 signaling cascades, and accumulation of DNA damage secondary to loss of cell‐cycle control. Thus, HCC was never observed in STAT5Δhep mice. Conclusion: As a result of their hepatoprotective functions, STAT5 proteins prevent progressive fatty liver disease and the formation of aggressive HCC in the setting of hyperactivated GH signaling. At the same time, they play a key role in controlling systemic inflammation and regulating organ and body size. (Hepatology 2012)

Date de mise en ligne : Lundi 19 septembre 2011
Pavlina Konstantinova
Adenosine triphosphate‐binding cassette transporter genes up‐regulation in untreated hepatocellular carcinoma is mediated by cellular microRNAs
Adenosine triphosphate (ATP)‐binding cassette (ABC) transporters are drug efflux pumps responsible for the multidrug resistance phenotype causing hepatocellular carcinoma (HCC) treatment failure. Here we studied the expression of 15 ABC transporters relevant for multidrug resistance in 19 paired HCC patient samples (16 untreated, 3 treated by chemotherapeutics). Twelve ABC transporters showed up‐regulation in HCC compared with adjacent healthy liver. These include ABCA2, ABCB1, ABCB6, ABCC1, ABCC2, ABCC3, ABCC4, ABCC5, ABCC10, ABCC11, ABCC12, and ABCE1. The expression profile and function of some of these transporters have not been associated with HCC thus far. Because cellular microRNAs (miRNAs) are involved in posttranscriptional gene silencing, we hypothesized that regulation of ABC expression in HCC might be mediated by miRNAs. To study this, miRNAs were profiled and dysregulation of 90 miRNAs was shown in HCC compared with healthy liver, including up‐regulation of 11 and down‐regulation of 79. miRNA target sites in ABC genes were bioinformatically predicted and experimentally verified in vitro using luciferase reporter assays. In total, 13 cellular miRNAs were confirmed that target ABCA1, ABCC1, ABCC5, ABCC10, and ABCE1 genes and mediate changes in gene expression. Correlation analysis between ABC and miRNA expression in individual patients revealed an inverse relationship, providing an indication for miRNA regulation of ABC genes in HCC. Conclusion: Up‐regulation of ABC transporters in HCC occurs prior to chemotherapeutic treatment and is associated with miRNA down‐regulation. Up‐regulation of five ABC genes appears to be mediated by 13 cellular miRNAs in HCC patient samples. miRNA‐based gene therapy may be a novel and promising way to affect the ABC profile and overcome clinical multidrug resistance. (Hepatology 2012)

Date de mise en ligne : Mercredi 12 octobre 2011
Kwok Wah Chan
CD133+ liver tumor‐initiating cells promote tumor angiogenesis, growth, and self‐renewal through neurotensin/interleukin‐8/CXCL1 signaling
A novel theory in the field of tumor biology postulates that cancer growth is driven by a population of stem‐like cells, called tumor‐initiating cells (TICs). We previously identified a TIC population derived from hepatocellular carcinoma (HCC) that is characterized by membrane expression of CD133. Here, we describe a novel mechanism by which these cells mediate tumor growth and angiogenesis by systematic comparison of the gene expression profiles between sorted CD133 liver subpopulations through genome‐wide microarray analysis. A significantly dysregulated interleukin‐8 (IL‐8) signaling network was identified in CD133+ liver TICs obtained from HCC clinical samples and cell lines. IL‐8 was found to be overexpressed at both the genomic and proteomic levels in CD133+ cells isolated from HCC cell lines or clinical samples. Functional studies found enhanced IL‐8 secretion in CD133+ liver TICs to exhibit a greater ability to self‐renew, induce tumor angiogenesis, and initiate tumors. In further support of these observations, IL‐8 repression in CD133+ liver TICs by knockdown or neutralizing antibody abolished these effects. Subsequent studies of the IL‐8 functional network identified neurotensin (NTS) and CXCL1 to be preferentially expressed in CD133+ liver TICs. Addition of exogenous NTS resulted in concomitant up‐regulation of IL‐8 and CXCL1 with simultaneous activation of p‐ERK1/2 and RAF‐1, both key components of the mitogen‐activated protein kinase (MAPK) pathway. Enhanced IL‐8 secretion by CD133+ liver TICs can in turn activate an IL‐8‐dependent feedback loop that signals through the MAPK pathway. Further, in its role as a liver TIC marker CD133 also plays a functional part in regulating tumorigenesis of liver TICs by way of regulating NTS, IL‐8, CXCL1, and MAPK signaling. Conclusion: CD133+ liver TICs promote angiogenesis, tumorigenesis, and self‐renewal through NTS‐induced activation of the IL‐8 signaling cascade. (Hepatology 2012)

Date de mise en ligne : Mercredi 12 octobre 2011
Kwang‐Huei Lin
Dickkopf 4 positively regulated by the thyroid hormone receptor suppresses cell invasion in human hepatoma cells
Thyroid hormone (T3) mediates cellular growth, development, and differentiation by binding to the nuclear thyroid hormone receptor (TR). Recent studies suggest that long‐term hypothyroidism is associated with human hepatocellular carcinoma (HCC) independent from other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein, antagonizes the Wnt signal pathway. In this study, we demonstrate that T3 may play a suppressor role by inducing DKK4 expression in HCC cells at both the messenger RNA (mRNA) and protein levels. DKK4 was down‐regulated in 67.5% of HCC cancerous tissues. The decrease in DKK4 levels was accompanied by a concomitant decrease in TR protein levels in the matched cancerous tissues in 31% of tissues compared by immunoblotting with the adjacent noncancerous tissues. Further, TR and DKK4 expression levels were positively correlated in both normal and cancerous specimens by tissue array analysis. In function assays, stable DKK4 transfected into J7 or HepG2 cells decreased cell invasion in vitro. Conversely, knocking down DKK4 restores cell invasiveness. DKK4‐expressing J7 clones showed increased degradation of β‐catenin, but down‐regulation of CD44, cyclin D1, and c‐Jun. To investigate the effect of DKK4 and TR on tumor growth in vivo, we established a xenograft of J7 cells in nude mice. J7‐DKK4 and J7‐TRα1 overexpressing mice, which displayed growth arrest, lower lung colony formation index, and smaller tumor size than in control mice, supporting an inhibitory role of DKK4 in tumor progression. Conclusion: Taken together, these data suggest that the TR/DKK4/Wnt/β‐catenin cascade influences the proliferation and migration of hepatoma cells during the metastasis process and support a tumor suppressor role of the TR. (Hepatology 2012)

Date de mise en ligne : Mercredi 26 octobre 2011
Jaime Bosch
Addition of simvastatin to cold storage solution prevents endothelial dysfunction in explanted rat livers
Pathophysiological alterations in the endothelial phenotype result in endothelial dysfunction. Flow cessation, occurring during organ procurement for transplantation, triggers the endothelial dysfunction characteristic of ischemia/reperfusion injury, partly due to a reduction in the expression of the vasoprotective transcription factor Kruppel‐like Factor 2 (KLF2). We aimed at (1) characterizing the effects of flow cessation and cold storage on hepatic endothelial phenotype, and (2) ascertaining if the consequences of cold stasis on the hepatic endothelium can be pharmacologically modulated, improving liver graft function. Expression of KLF2 and its vasoprotective programs was determined in (i) hepatic endothelial cells (HEC) incubated under cold storage conditions with or without the KLF2‐inducer simvastatin, and (ii) rat livers not cold stored or preserved in cold University of Wisconsin solution (UWS) supplemented with simvastatin or its vehicle. In addition, upon warm reperfusion hepatic vascular resistance, endothelial function, nitric oxide vasodilator pathway, apoptosis, inflammation, and liver injury were evaluated in not cold stored livers or livers preserved in cold UWS supplemented with simvastatin or vehicle. Expression of KLF2 and its vasoprotective programs decrease in HEC incubated under cold storage conditions. Cold‐stored rat livers exhibit a time‐dependent decrease in KLF2 and its target genes, liver injury, increased hepatic vascular resistance, and endothelial dysfunction. The addition of simvastatin to the storage solution, maintained KLF2‐dependent vasoprotective programs, prevented liver damage, inflammation, and oxidative stress and improved endothelial dysfunction. Conclusion: Our results provide a rationale to evaluate the beneficial effects of a vasoprotective preservation solution on human liver procurement for transplantation. (Hepatology 2012)

Date de mise en ligne : Mercredi 26 octobre 2011
Alex B. Lentsch
Receptor activator of nuclear factor‐κB ligand (RANKL) protects against hepatic ischemia/reperfusion injury in mice
The transcription factor nuclear factor kappaB (NF‐κB) plays diverse roles in the acute injury response to hepatic ischemia/reperfusion (I/R). Activation of NF‐κB in Kupffer cells promotes inflammation through cytokine expression, whereas activation in hepatocytes may be cell protective. The interaction of receptor activator of NF‐κB (RANK) and its ligand (RANKL) promotes NF‐κB activation; however, this ligand‐receptor system has not been studied in acute liver injury. In the current study, we sought to determine if RANK and RANKL were important in the hepatic response to I/R. Mice were subjected to partial hepatic ischemia followed by reperfusion. In some experiments, mice received recombinant RANKL or neutralizing antibodies to RANKL 1 hour prior to surgery or at reperfusion to assess the role of RANK/RANKL signaling during I/R injury. RANK was constitutively expressed in the liver and was not altered by I/R. RANK was strongly expressed in hepatocytes and very weakly expressed in Kupffer cells. Serum RANKL concentrations increased after I/R and peaked 4 hours after reperfusion. Serum levels of osteoprotegerin (OPG), a decoy receptor for RANKL, steadily increased over the 8‐hour period of reperfusion. Treatment with RANKL, before ischemia or at reperfusion, increased hepatocyte NF‐κB activation and significantly reduced liver injury. These beneficial effects occurred without any effect on cytokine expression or liver inflammation. Treatment with anti‐RANKL antibodies had no effect on liver I/R injury. Conclusion: During the course of injury, endogenous OPG appears to suppress the effects of RANKL. However, exogenous administration of RANKL, given either prophylactically or postinjury, reduces liver injury in a manner associated with increased hepatocyte NF‐κB activation. The data suggest that RANK/RANKL may be a viable therapeutic target in acute liver injury. (Hepatology 2012)

Date de mise en ligne : Mercredi 26 octobre 2011
Frank Tacke
Hepatic macrophage migration and differentiation critical for liver fibrosis is mediated by the chemokine receptor C‐C motif chemokine receptor 8 in mice
Chemokines critically control the infiltration of immune cells upon liver injury, thereby promoting hepatic inflammation and fibrosis. The chemokine receptor CCR8 can affect trafficking of monocytes/macrophages, monocyte‐derived dendritic cells (DCs) and T‐helper cell (Th) subsets, but its role in liver diseases is currently unknown. To investigate the functional role of CCR8 in liver diseases, ccr8−/− and wild‐type (WT) mice were subjected to chronic experimental injury models of carbon tetrachloride (CCl4) administration and surgical bile duct ligation (BDL). CCR8 was strongly up‐regulated in the injured liver. Ccr8−/− mice displayed attenuated liver damage (e.g., ALT, histology, and TUNEL) compared to WT mice and were also protected from liver fibrosis in two independent injury models. Flow cytometry revealed reduced infiltrates of liver macrophages, neutrophils and natural killer cells, whereas hepatic CD4+ T cells increased. The main CCR8‐expressing cells in the liver were hepatic macrophages, and CCR8 was functionally necessary for CCL1‐directed migration of inflammatory but not for nonclassical monocytes into the liver. Moreover, the phenotype of liver macrophages from injured ccr8−/− animals was altered with increased expression of DC markers and enhanced expression of T‐cell‐attracting chemokine macrophage inflammatory protein 1‐alpha (MIP‐1α/CCL3). Correspondingly, hepatic CD4+ T cells showed increased Th1 polarization and reduced Th2 cells in CCR8‐deficient animals. Liver fibrosis progression, but also subsequent T‐cell alterations, could be restored by adoptively transferring CCR8‐expressing monocytes/macrophages into ccr8−/− mice during experimental injury. Conclusions: CCR8 critically mediates hepatic macrophage recruitment upon injury, which subsequently shapes the inflammatory response in the injured liver, affecting macrophage/DC and Th differentiation. CCR8 deficiency protects the liver against injury, ameliorating initial inflammatory responses and hepatic fibrogenesis. Inhibition of CCR8 or its ligand, CCL1, might represent a successful therapeutic target to limit liver inflammation and fibrosis progression. (Hepatology 2012)

Date de mise en ligne : Mercredi 16 novembre 2011
William Sievert
Protease‐activated receptor 2 promotes experimental liver fibrosis in mice and activates human hepatic stellate cells
Protease‐activated receptor (PAR) 2 is a G‐protein–coupled receptor that is activated after proteolytic cleavage by serine proteases, including mast cell tryptase and activated coagulation factors. PAR‐2 activation augments inflammatory and profibrotic pathways through the induction of genes encoding proinflammatory cytokines and extracellular matrix proteins. Thus, PAR‐2 represents an important interface linking coagulation and inflammation. PAR‐2 is widely expressed in cells of the gastrointestinal tract, including hepatic stellate cells (HSCs), endothelial cells, and hepatic macrophages; however, its role in liver fibrosis has not been previously examined. We studied the development of CCl4‐induced liver fibrosis in PAR‐2 knockout mice, and showed that PAR‐2 deficiency reduced the progression of liver fibrosis, hepatic collagen gene expression, and hydroxyproline content. Reduced fibrosis was associated with decreased transforming growth factor beta (TGFβ) gene and protein expression and decreased matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinase 1 gene expression. In addition, PAR‐2 stimulated activation, proliferation, collagen production, and TGFβ protein production by human stellate cells, indicating that hepatic PAR‐2 activation increases profibrogenic cytokines and collagen production both in vivo and in vitro. Conclusion: Our findings demonstrate the capacity of PAR‐2 activation to augment TGFβ production and promote hepatic fibrosis in mice and to induce a profibrogenic phenotype in human HSCs. PAR‐2 antagonists have recently been developed and may represent a novel therapeutic approach in preventing fibrosis in patients with chronic liver disease. (HEPATOLOGY 2011)

Date de mise en ligne : Mercredi 12 octobre 2011
Diego F. Calvisi
AKT (v‐akt murine thymoma viral oncogene homolog 1) and N‐Ras (neuroblastoma ras viral oncogene homolog) coactivation in the mouse liver promotes rapid carcinogenesis by way of mTOR (mammalian target of rapamycin complex 1), FOXM1 (forkhead box M1)/SKP2, and c‐Myc pathways
Activation of v‐akt murine thymoma viral oncogene homolog (AKT) and Ras pathways is often implicated in carcinogenesis. However, the oncogenic cooperation between these two cascades in relationship to hepatocellular carcinoma (HCC) development remains undetermined. To investigate this issue, we generated a mouse model characterized by combined overexpression of activated forms of AKT and neuroblastoma Ras viral oncogene homolog (N‐Ras) protooncogenes in the liver by way of hydrodynamic gene transfer. The molecular mechanisms underlying crosstalk between AKT and N‐Ras were assessed in the mouse model and further evaluated in human and murine HCC cell lines. We found that coexpression of AKT and N‐Ras resulted in a dramatic acceleration of liver tumor development when compared with mice overexpressing AKT alone, whereas N‐Ras alone did not lead to tumor formation. At the cellular level, concomitant up‐regulation of AKT and N‐Ras resulted in increased proliferation and microvascularization when compared with AKT‐injected mice. Mechanistic studies suggested that accelerated hepatocarcinogenesis driven by AKT and N‐Ras resulted from a strong activation of mammalian target of rapamycin complex 1 (mTORC1). Furthermore, elevated expression of FOXM1/SKP2 and c‐Myc also contributed to rapid tumor growth in AKT/Ras mice, yet by way of mTORC1‐independent mechanisms. The biological effects of coactivation of AKT and N‐Ras were then recapitulated in vitro using HCC cell lines, which supports the functional significance of mTORC1, FOXM1/SKP2, and c‐Myc signaling cascades in mediating AKT and N‐Ras‐induced liver tumor development. Conclusion: Our data demonstrate the in vivo crosstalk between the AKT and Ras pathways in promoting liver tumor development, and the pivotal role of mTORC1‐dependent and independent pathways in mediating AKT and Ras induced hepatocarcinogenesis. (HEPATOLOGY 2011)

Date de mise en ligne : Mardi 22 novembre 2011
Sonia Caprio
Variant in the glucokinase regulatory protein (GCKR) gene is associated with fatty liver in obese children and adolescents
Recently, the single nucleotide polymorphism (SNP) identified as rs1260326, in the glucokinase regulatory protein (GCKR), was associated with hypertriglyceridemia in adults. Because accumulation of triglycerides in hepatocytes represents the hallmark of steatosis, we aimed to investigate whether this variant might be associated with fatty liver (hepatic fat content, HFF%). Moreover, because recently rs738409 in the PNPLA3 and rs2854116 in the APOC3 were associated with fatty liver, we explored how the GCKR SNP and these two variants jointly influence hepatosteatosis. We studied 455 obese children and adolescents (181 Caucasians, 139 African Americans, and 135 Hispanics). All underwent an oral glucose tolerance test and fasting lipoprotein subclasses measurement by proton nuclear magnetic resonance. A subset of 142 children underwent a fast gradient magnetic resonance imaging to measure the HFF%. The rs1260326 was associated with elevated triglycerides (Caucasians P = 0.00014; African Americans P = 0.00417), large very low‐density lipoprotein (VLDL) (Caucasians P = 0.001; African Americans, P = 0.03), and with fatty liver (Caucasians P = 0.034; African Americans P = 0.00002; and Hispanics P = 0.016). The PNPLA3, but not the APOC3 rs2854116 SNP, was associated with fatty liver but not with triglyceride levels. There was a joint effect between the PNPLA3 and GCKR SNPs, explaining 32% of HFF% variance in Caucasians (P = 0.00161), 39.0% in African Americans (P = 0.00000496), and 15% in Hispanics (P = 0.00342). Conclusion: The rs1260326 in GCKR is associated with hepatic fat accumulation along with large VLDL and triglyceride levels. GCKR and PNPLA3 act together to convey susceptibility to fatty liver in obese youths. (Hepatology 2012)

Date de mise en ligne : Vendredi 19 ao�t 2011
Hashem B. El‐Serag
Higher serum testosterone is associated with increased risk of advanced hepatitis C–related liver disease in males
Males have strikingly increased risk of advanced liver disease. However, the association between testosterone and risk of hepatitis C virus (HCV)‐related advanced liver disease is unknown. We performed a cross‐sectional study in male veterans with chronic HCV. Blood samples were obtained to measure total serum testosterone and perform the FibroSURE‐ActiTest. Other risk‐factor data were obtained through systematic questionnaires (e.g., alcohol), physical measurements (e.g., body mass index), and serological tests (e.g., viral load). The association between total testosterone and risk of advanced hepatic fibrosis (F3 and F3/F4) and inflammatory activity (A3 and A2/3) measured by the FibroSURE‐ActiTest was evaluated with logistic regression. A total of 308 eligible study participants were prospectively recruited (mean age: 57; 52% African‐American). There were 105 cases with advanced fibrosis and 203 mild fibrosis controls as well as 88 cases with advanced inflammatory activity and 220 mild activity controls. Mean total serum testosterone was significantly higher in advanced fibrosis cases as well as advanced inflammatory activity cases, compared to mild disease controls (6.0 versus 5.3 ng/mL and 5.9 versus 5.4 ng/mL, respectively). We observed a significant 25% increase in advanced fibrosis risk and 15% increase in advanced inflammatory activity risk for each 1‐ng/mL increase in total serum testosterone. Total testosterone in the upper tertile was associated with an even greater excess risk of advanced fibrosis than advanced inflammatory activity (odds ratio [OR]adjusted advanced fibrosis = 3.74; 95% CI: 1.86‐6.54 versus ORadjusted advanced inflammatory activity = 2.23; 95% CI: 1.07‐4.93, respectively). Conclusions: Total serum testosterone is associated with an increased risk of both advanced hepatic fibrosis and advanced hepatic inflammatory activity in HCV‐infected men. Testosterone may be important in the pathogenesis of HCV‐related advanced liver disease in males. (Hepatology 2011)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Anna Mae Diehl
After goodbye? Dead hepatocytes as a biomarker for fibrosis and steatohepatitis
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Date de mise en ligne : Mercredi 01 f�vrier 2012
Massimo Colombo
Interleukin 28B polymorphism predicts pegylated interferon plus ribavirin treatment outcome in chronic hepatitis C genotype 4
Single nucleotide polymorphisms (SNPs) near the interleukin 28B (IL28B) region are the strongest baseline predictors of a sustained virologic response (SVR) to peg‐interferon (PegIFN) and ribavirin (Rbv) in patients with hepatitis C virus (HCV) genotype 1 infection. Whether this holds true for HCV‐4 patients too is unknown. The aim was to investigate the predictive power of the rs12979860 IL28B SNP for a response to Peg‐IFN and Rbv in HCV‐4 patients. All HCV‐4 patients consecutively treated between September 2004 and June 2010 with PegIFN and Rbv at two liver centers at the Maggiore Hospital Milan (Italy) underwent TaqMan SNP Genotyping assays for testing rs12979860 genotype. Of 112 treated patients (98 males, 75 of Egyptian descent, 26 with cirrhosis) 103 were included in the final analysis; five discontinued treatment for nonvirologic reasons and four did not consent to genetic testing. Twenty‐four (23%) were genotype CC, 65 (63%) CT, and 14 (14%) TT. Overall, 50 (49%) achieved an SVR: 21 (88%) CC patients versus 29 (37%) CT/TT (P < 0.0001). CC patients more often had a rapid virologic response (RVR) than CT/TT patients (12, 50% versus 23, 29%; P = 0.08), while also showing lower relapse rates (0% [0/21] versus 36% [16/45] P = 0.0013). In non‐RVR patients, SVR rates were higher in CC than CT/TT patients (9 [75%] versus 13 [23%] P = 0.001). By logistic regression, the IL28B rs12979860 CC genotype was an independent predictor of SVR with an odds ratio of 8.0 (95% confidence interval 2.00‐32.01; P = 0.003). Conclusion: The IL28B rs12979860 SNP may have an added value in the treatment algorithm of HCV‐4 patients because it is the strongest predictor of an SVR to PegIFN/Rbv therapy. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Young S. Hahn
Myeloid suppressor cells induced by hepatitis C virus suppress T‐cell responses through the production of reactive oxygen species
Impaired T‐cell responses in chronic hepatitis C virus (HCV) patients have been reported to be associated with the establishment of HCV persistent infection. However, the mechanism for HCV‐mediated T‐cell dysfunction is yet to be defined. Myeloid‐derived suppressor cells (MDSCs) play a pivotal role in suppressing T‐cell responses. In this study we examined the accumulation of MDSCs in human peripheral blood mononuclear cells (PBMCs) following HCV infection. We found that CD33+ mononuclear cells cocultured with HCV‐infected hepatocytes, or with HCV core protein, suppress autologous T‐cell responses. HCV core‐treated CD33+ cells exhibit a CD14+CD11b+/lowHLADR−/low phenotype with up‐regulated expression of p47phox, a component of the NOX2 complex critical for reactive oxygen species (ROS) production. In contrast, immunosuppressive factors, arginase‐1 and inducible nitric oxide synthase (iNOS), were not up‐regulated. Importantly, treatment with an inactivator of ROS reversed the T‐cell suppressive function of HCV‐induced MDSCs. Lastly, PBMCs of chronic HCV patients mirror CD33+ cells following treatment with HCV core where CD33+ cells are CD14+CD11b+HLADR−/low, and up‐regulate the expression of p47phox. Conclusion: These results suggest that HCV promotes the accumulation of CD33+ MDSC, resulting in ROS‐mediated suppression of T‐cell responsiveness. Thus, the accumulation of MDSCs during HCV infection may facilitate and maintain HCV persistent infection. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Qigui Yu
CD59 incorporation protects hepatitis C virus against complement‐mediated destruction
Several enveloped viruses including human immunodeficiency virus type 1 (HIV‐1), cytomegalovirus (CMV), herpes simplex virus 1 (HSV‐1), Ebola virus, vaccinia virus, and influenza virus have been found to incorporate host regulators of complement activation (RCA) into their viral envelopes and, as a result, escape antibody‐dependent complement‐mediated lysis (ADCML). Hepatitis C virus (HCV) is an enveloped virus of the family Flaviviridae and incorporates more than 10 host lipoproteins. Patients chronically infected with HCV develop high‐titer and crossreactive neutralizing antibodies (nAbs), yet fail to clear the virus, raising the possibility that HCV may also use the similar strategy of RCA incorporation to escape ADCML. The current study was therefore undertaken to determine whether HCV virions incorporate biologically functional CD59, a key member of RCA. Our experiments provided several lines of evidence demonstrating that CD59 was associated with the external membrane of HCV particles derived from either Huh7.5.1 cells or plasma samples from HCV‐infected patients. First, HCV particles were captured by CD59‐specific Abs. Second, CD59 was detected in purified HCV particles by immunoblot analysis and in the cell‐free supernatant from HCV‐infected Huh7.5.1 cells, but not from uninfected or adenovirus serotype 5 (Ad5) (a nonenveloped cytolytic virus)‐infected Huh7.5.1 cells by enzyme‐linked immunosorbent assay. Last, abrogation of CD59 function with its blockers increased the sensitivity of HCV virions to ADCML, resulting in a significant reduction of HCV infectivity. Additionally, direct addition of CD59 blockers into plasma samples from HCV‐infected patients increased autologous virolysis. Conclusion: Our study, for the first time, demonstrates that CD59 is incorporated into both cell line‐derived and plasma primary HCV virions at levels that protect against ADCML. This is also the first report to show that direct addition of RCA blockers into plasma from HCV‐infected patients renders endogenous plasma virions sensitive to ADCML. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Alfredo Nicosia
A Human monoclonal antibody targeting scavenger receptor class B type I precludes hepatitis C virus infection and viral spread in vitro and in vivo
Endstage liver disease caused by chronic hepatitis C virus (HCV) infection is the leading indication for liver transplantation in the Western world. However, immediate reinfection of the grafted donor liver by circulating virus is inevitable and liver disease progresses much faster than the original disease. Standard antiviral therapy is not well tolerated and usually ineffective in liver transplant patients, whereas anti‐HCV immunotherapy is hampered by the extreme genetic diversity of the virus and its ability to spread by way of cell‐cell contacts. We generated a human monoclonal antibody against scavenger receptor class B type I (SR‐BI), monoclonal antibody (mAb)16‐71, which can efficiently prevent infection of Huh‐7.5 hepatoma cells and primary hepatocytes by cell‐culture‐derived HCV (HCVcc). Using an Huh7.5 coculture system we demonstrated that mAb16‐71 interferes with direct cell‐to‐cell transmission of HCV. Finally we evaluated the in vivo efficacy of mAb16‐71 in “human liver urokinase‐type plasminogen activator, severe combined immune deficiency (uPA‐SCID) mice” (chimeric mice). A 2‐week anti‐SR‐BI therapy that was initiated 1 day before viral inoculation completely protected all chimeric mice from infection with serum‐derived HCV of different genotypes. Moreover, a 9‐day postexposure therapy that was initiated 3 days after viral inoculation (when viremia was already observed in the animals) suppressed the rapid viral spread observed in untreated control animals. After cessation of anti‐SR‐BI‐specific antibody therapy, a rise of the viral load was observed. Conclusion: Using in vitro cell culture and human liver‐chimeric mouse models, we show that a human mAb targeting the HCV coreceptor SR‐BI completely prevents infection and intrahepatic spread of multiple HCV genotypes. This strategy may be an efficacious way to prevent infection of allografts following liver transplantation in chronic HCV patients, and may even hold promise for the prevention of virus rebound during or following antiviral therapy. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Stephan Urban
Hepatocyte polarization is essential for the productive entry of the hepatitis B virus
Human hepatitis B virus (HBV) is characterized by a high species specificity and a distinct liver tropism. Within the liver, HBV replication occurs in differentiated and polarized hepatocytes. Accordingly, the in vitro HBV infection of primary human hepatocytes (PHHs) and the human hepatoma cell line, HepaRG, is restricted to differentiated, hepatocyte‐like cells. Though preparations of PHH contain up to 100% hepatic cells, cultures of differentiated HepaRG cells are a mixture of hepatocyte‐like and biliary‐like epithelial cells. We used PHH and HepaRG cells and compared the influence of virus inoculation dose, cell differentiation, and polarization on productive HBV infection. At multiplicities of genome equivalents (mge) >8,000, almost 100% of PHHs could be infected. In contrast, only a subset of HepaRG cells stained positive for HBcAg at comparable or even higher mge. Infection predominantly occurred at the edges of islands of hepatocyte‐like HepaRG cells. This indicates a limited accessibility of the HBV receptor, possibly as a result of its polar sorting. Multidrug resistance protein 2 (MRP2), a marker selectively transported to the apical (i.e., canalicular) cell membrane, revealed two polarization phenotypes of HepaRG cells. HBV infection within the islands of hepatocyte‐like HepaRG cells preferentially occurred in cells that resemble PHH, exhibiting canalicular structures. However, disruption of cell‐cell junctions allowed the additional infection of cells that do not display a PHH‐like polarization. Conclusion: HBV enters hepatocytes via the basolateral membrane. This model, at least partially, explains the difference of PHH and HepaRG cells in infection efficacy, provides insights into natural HBV infection, and establishes a basis for optimization of the HepaRG infection system. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Francesco Negro
IL28B alleles associated with poor hepatitis C virus (HCV) clearance protect against inflammation and fibrosis in patients infected with non‐1 HCV genotypes
Genetic polymorphisms near IL28B are associated with spontaneous and treatment‐induced clearance of hepatitis C virus (HCV), two processes that require the appropriate activation of the host immune responses. Intrahepatic inflammation is believed to mirror such activation, but its relationship with IL28B polymorphisms has yet to be fully appreciated. We analyzed the association of IL28B polymorphisms with histological and follow‐up features in 2335 chronically HCV‐infected Caucasian patients. Assessable phenotypes before any antiviral treatment included necroinflammatory activity (n = 1,098), fibrosis (n = 1,527), fibrosis progression rate (n = 1,312), and hepatocellular carcinoma development (n = 1,915). Associations of alleles with the phenotypes were evaluated by univariate analysis and multivariate logistic regression, accounting for all relevant covariates. The rare G allele at IL28B marker rs8099917—previously shown to be at risk of treatment failure—was associated with lower activity (P = 0.04), lower fibrosis (P = 0.02) with a trend toward lower fibrosis progression rate (P = 0.06). When stratified according to HCV genotype, most significant associations were observed in patients infected with non‐1 genotypes (P = 0.003 for activity, P = 0.001 for fibrosis, and P = 0.02 for fibrosis progression rate), where the odds ratio of having necroinflammation or rapid fibrosis progression for patients with IL28B genotypes TG or GG versus TT were 0.48 (95% confidence intervals 0.30‐0.78) and 0.56 (0.35‐0.92), respectively. IL28B polymorphisms were not predictive of the development of hepatocellular carcinoma. Conclusion: In chronic hepatitis C, IL28B variants associated with poor response to interferon therapy may predict slower fibrosis progression, especially in patients infected with non‐1 HCV genotypes. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Laïla Mselli‐Lakhal
Low doses of bisphenol a induce gene expression related to lipid synthesis and trigger triglyceride accumulation in adult mouse liver
Changes in lifestyle are suspected to have strongly influenced the current obesity epidemic. Based on recent experimental, clinical, and epidemiological work, it has been proposed that some food contaminants may exert damaging effects on endocrine and metabolic functions, thereby promoting obesity and associated metabolic diseases such as nonalcoholic fatty liver disease (NAFLD). In this work, we investigated the effect of one suspicious food contaminant, bisphenol A (BPA), in vivo. We used a transcriptomic approach in male CD1 mice exposed for 28 days to different doses of BPA (0, 5, 50, 500, and 5,000 μg/kg/day) through food contamination. Data analysis revealed a specific impact of low doses of BPA on the hepatic transcriptome, more particularly on genes involved in lipid synthesis. Strikingly, the effect of BPA on the expression of de novo lipogenesis followed a nonmonotonic dose‐response curve, with more important effects at lower doses than at the higher dose. In addition to lipogenic enzymes (Acc, Fasn, Scd1), the expression of transcription factors such as liver X Receptor, the sterol regulatory element binding protein‐1c, and the carbohydrate responsive element binding protein that govern the expression of lipogenic genes also followed a nonmonotonic dose‐response curve in response to BPA. Consistent with an increased fatty acid biosynthesis, determination of fat in the liver showed an accumulation of cholesteryl esters and of triglycerides. Conclusion: Our work suggests that exposure to low BPA doses may influence de novo fatty acid synthesis through increased expression of lipogenic genes, thereby contributing to hepatic steatosis. Exposure to such contaminants should be carefully examined in the etiology of metabolic diseases such as NAFLD and nonalcoholic steatohepatitis. (Hepatology 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Peter Hasselblatt
The transcription factor c‐Jun protects against sustained hepatic endoplasmic reticulum stress thereby promoting hepatocyte survival
Endoplasmic reticulum (ER) stress due to accumulation of hepatoviral or misfolded proteins is increasingly recognized as an important step in the pathogenesis of inflammatory, toxic, and metabolic liver diseases. ER stress results in the activation of several intracellular signaling pathways including Jun N‐terminal kinase (JNK). The AP‐1 (activating protein 1) transcription factor c‐Jun is a prototypic JNK target and important regulator of hepatocyte survival, proliferation, and liver tumorigenesis. Because the functions of c‐Jun during the ER stress response are poorly understood, we addressed this issue in primary hepatocytes and livers of hepatocyte‐specific c‐Jun knockout mice. ER stress was induced pharmacologically in vitro and in vivo and resulted in a rapid and robust induction of c‐Jun protein expression. Interestingly, ER‐stressed hepatocytes lacking c‐Jun displayed massive cytoplasmic vacuolization due to ER distension. This phenotype correlated with exacerbated and sustained activation of canonical ER stress signaling pathways. Moreover, sustained ER stress in hepatocytes lacking c‐Jun resulted in increased cell damage and apoptosis. ER stress is also a strong inducer of macroautophagy, a cell‐protective mechanism of self‐degradation of cytoplasmic components and organelles. Interestingly, autophagosome numbers in response to ER stress were reduced in hepatocytes lacking c‐Jun. To further validate these findings, macroautophagy was inhibited chemically in ER‐stressed wildtype hepatocytes, which resulted in cytoplasmic vacuolization and increased cell damage closely resembling the phenotypes observed in c‐Jun‐deficient cells. Conclusion: Our findings indicate that c‐Jun protects hepatocytes against excessive activation of the ER stress response and subsequent cell death and provide evidence that c‐Jun functionally links ER stress responses and macroautophagy. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Mario Chojkier
A phase 2, randomized, double‐blind, placebo‐controlled study of GS‐9450 in subjects with nonalcoholic steatohepatitis
In nonalcoholic steatohepatitis (NASH), the extent of hepatocyte apoptosis correlates with disease severity. Reducing hepatocyte apoptosis with the selective caspase inhibitor GS‐9450 has a potential for altering the course of the liver disease. In this phase 2, double‐blind study, 124 subjects with biopsy‐proven NASH were randomized to once‐daily placebo or 1, 5, 10, or 40 mg GS‐9450 for 4 weeks. Absolute and percent changes from baseline in ALT levels, AST levels, and caspase‐3–cleaved cytokeratin (CK)‐18 fragments at week 4 were assessed by an analysis of covariance model with adjustment for baseline values. In the 40‐mg group, mean (SD) ALT decreased by 47 (43) U/L from baseline to week 4 (P < 0.0001 versus placebo), and the proportion of subjects with normal ALT increased from 0% to 35% at week 4. In the 40‐mg group, mean AST decreased by 13 U/L from baseline (not significant), and the proportion with normal AST increased from 20% at baseline to 48% at week 4. By week 4, mean CK‐18 fragment levels had decreased to 393 (723) U/L in the GS‐9450 10‐mg group and 125 (212) U/L in the 40‐mg group, but these reductions were not statistically significant. No serious adverse events were reported during treatment, and the percentage of subjects with at least one treatment‐emergent grade 3 or 4 laboratory abnormality ranged from 11.5% to 17% across the GS‐9450 treatment groups versus 35% in the placebo group. Conclusion: GS‐9450 treatment induced significant reductions in ALT levels in NASH patients. Reductions in CK‐18 fragment levels also occurred, although they were not statistically significant. At appropriate therapeutic indices, selective caspase inhibitors may be a promising treatment option in patients with NASH. (Hepatology 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Stephen A. Harrison
Association of coffee and caffeine consumption with fatty liver disease, nonalcoholic steatohepatitis, and degree of hepatic fibrosis
Coffee caffeine consumption (CC) is associated with reduced hepatic fibrosis in patients with chronic liver diseases, such as hepatitis C. The association of CC with nonalcoholic fatty liver disease (NAFLD) has not been established. The aim of this study was to correlate CC with the prevalence and severity of NAFLD. Patients involved in a previously published NAFLD prevalence study, as well as additional NASH patients identified in the Brooke Army Medical Center Hepatology clinic, were queried about their caffeine intake. A validated questionnaire for CC was utilized to assess for a relationship between caffeine and four groups: ultrasound negative (controls), bland steatosis/not‐NASH, NASH stage 0‐1, and NASH stage 2‐4. A total of 306 patients responded to the CC questionnaire. Average milligrams of total caffeine/coffee CC per day in controls, bland steatosis/not‐NASH, NASH stage 0‐1, and NASH stage 2‐4 were 307/228, 229/160, 351/255, and 252/152, respectively. When comparing patients with bland steatosis/not‐NASH to those with NASH stage 0‐1, there was a significant difference in CC between the two groups (P = 0.005). Additionally, when comparing patients with NASH stage 0‐1 to those with NASH stage 2‐4, there was a significant difference in coffee CC (P = 0.016). Spearman's rank correlation analysis further supported a negative relationship between coffee CC and hepatic fibrosis (r = −0.215; P = 0.035). Conclusion: Coffee CC is associated with a significant reduction in risk of fibrosis among NASH patients. (Hepatology 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Min You
Regulation of hepatic lipin‐1 by ethanol: Role of AMP‐activated protein kinase/sterol regulatory element‐binding protein 1 signaling in mice
Lipin‐1 is a protein that exhibits dual functions as a phosphatidic acid phosphohydrolase enzyme in the triglyceride synthesis pathways and a transcriptional coregulator. Our previous studies have shown that ethanol causes fatty liver by activation of sterol regulatory element‐binding protein 1 (SREBP‐1) and inhibition of hepatic AMP‐activated protein kinase (AMPK) in mice. Here, we tested the hypothesis that AMPK‐SREBP‐1 signaling may be involved in ethanol‐mediated up‐regulation of lipin‐1 gene expression. The effects of ethanol on lipin‐1 were investigated in cultured hepatic cells and in the livers of chronic ethanol‐fed mice. Ethanol exposure robustly induced activity of a mouse lipin‐1 promoter, promoted cytoplasmic localization of lipin‐1, and caused excess lipid accumulation, both in cultured hepatic cells and in mouse livers. Mechanistic studies showed that ethanol‐mediated induction of lipin‐1 gene expression was inhibited by a known activator of AMPK or overexpression of a constitutively active form of AMPK. Importantly, overexpression of the processed nuclear form of SREBP‐1c abolished the ability of 5‐aminoimidazole‐4‐carboxamide ribonucleoside to suppress ethanol‐mediated induction of lipin‐1 gene‐expression level. Chromatin immunoprecipitation assays further revealed that ethanol exposure significantly increased the association of acetylated histone H3 at lysine 9 with the SRE‐containing region in the promoter of the lipin‐1 gene. Conclusion: In conclusion, ethanol‐induced up‐regulation of lipin‐1 gene expression is mediated through inhibition of AMPK and activation of SREBP‐1. (Hepatology 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
James E. Everhart
Upper limits of normal for alanine aminotransferase activity in the United States population
Alanine aminotransferase (ALT) is an important test for liver disease, yet there is no generally accepted upper limit of normal (ULN) in the United States. Furthermore, the ability of ALT to differentiate persons with and without liver disease is uncertain. We examined cut‐offs for ALT for their ability to discriminate between persons with positive hepatitis C virus (HCV) RNA and those at low risk for liver injury in the U.S. population. Among adult participants in the 1999‐2008 U.S. National Health and Nutrition Examination Survey, 259 were positive for serum HCV RNA and 3,747 were at low risk for liver injury (i.e., negative HCV RNA and hepatitis B surface antigen, low alcohol consumption, no evidence of diabetes, and normal body mass index and waist circumference). Serum ALT activity was measured centrally. Maximum correct classification was achieved at ALT = 29 IU/L for men (88% sensitivity, 83% specificity) and 22 IU/L (89% sensitivity, 82% specificity) for women. The cut‐off for 95% sensitivity was an ALT = 24 IU/L (70% specificity) for men and 18 IU/L (63% specificity) for women. The cut‐off for 95% specificity was ALT = 44 IU/L (64% sensitivity) for men and 32 IU/L (59% sensitivity) for women. The area under the curve was 0.929 for men and 0.915 for women. If the cut‐offs with the best correct classification were applied to the entire population, 36.4% of men and 28.3% of women would have had abnormal ALT. Conclusion: ALT discriminates persons infected with HCV from those at low risk of liver disease, but would be considered elevated in a large proportion of the U.S. population. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Heike Bantel
Prospective biopsy‐controlled evaluation of cell death biomarkers for prediction of liver fibrosis and nonalcoholic steatohepatitis
Fibrosis and steatosis are major histopathological alterations in chronic liver diseases. Despite various shortcomings, disease severity is generally determined by liver biopsy, emphasizing the need for simple noninvasive methods for assessing disease activity. Because hepatocyte cell death is considered a crucial pathogenic factor, we prospectively evaluated the utility of serum biomarkers of cell death to predict different stages of fibrosis and steatosis in 121 patients with chronic liver disease. We compared the M30 enzyme‐linked immunosorbent assay (ELISA), which detects a caspase‐cleaved cytokeratin‐18 (CK‐18) fragment and thereby apoptotic cell death, with the M65 ELISA, which detects both caspase‐cleaved and uncleaved CK‐18 and thereby overall cell death. Both biomarkers significantly discriminated patients with different fibrosis stages from healthy controls. However, whereas both markers differentiated low or moderate from advanced fibrosis, only the M65 antigen could discriminate even lower stages of fibrosis. The M65 assay also performed better in distinguishing low (≤10%) and higher (>10%) grades of steatosis. In a subgroup of patients, we evaluated the biomarkers for their power to predict nonalcoholic steatohepatitis (NASH). Importantly, both markers accurately differentiated healthy controls or simple steatosis from NASH. However, only serum levels of M65 antigen could differentiate simple steatosis from healthy controls. Conclusion: Cell death biomarkers are potentially useful to predict fibrosis, steatosis, or NASH. Compared with the widely used apoptosis marker M30, the M65 assay had a better diagnostic performance and even differentiated between lower fibrosis stages as well as between healthy individuals and patients with simple steatosis. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Justin L. Mott
miR‐25 targets TNF‐related apoptosis inducing ligand (TRAIL) death receptor‐4 and promotes apoptosis resistance in cholangiocarcinoma
It has been established that microRNA expression and function contribute to phenotypic features of malignant cells, including resistance to apoptosis. Although targets and functional roles for a number of microRNAs have been described in cholangiocarcinoma, many additional microRNAs dysregulated in this tumor have not been assigned functional roles. In this study, we identify elevated miR‐25 expression in malignant cholangiocarcinoma cell lines as well as patient samples. In cultured cells, treatment with the Smoothened inhibitor, cyclopamine, reduced miR‐25 expression, suggesting Hedgehog signaling stimulates miR‐25 production. Functionally, miR‐25 was shown to protect cells against TNF‐related apoptosis‐inducing ligand (TRAIL)‐induced apoptosis. Correspondingly, antagonism of miR‐25 in culture sensitized cells to apoptotic death. Computational analysis identified the TRAIL Death Receptor‐4 (DR4) as a potential novel miR‐25 target, and this prediction was confirmed by immunoblot, cell staining, and reporter assays. Conclusion: These data implicate elevated miR‐25 levels in the control of tumor cell apoptosis in cholangiocarcinoma. The identification of the novel miR‐25 target DR4 provides a mechanism by which miR‐25 contributes to evasion of TRAIL‐induced cholangiocarcinoma apoptosis. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
David E. Kleiner
Hepatocellular Carcinoma Confirmation, Treatment, and Survival in Surveillance, Epidemiology, and End Results Registries, 1992‐2008
Approaches to the diagnosis and management of hepatocellular carcinoma (HCC) are improving survival. In the Surveillance, Epidemiology, and End Results‐13 registries, HCC stage, histological confirmation, and first‐course surgery were examined. Among 21,390 HCC cases diagnosed with follow‐up of vital status during 1998‐2008, there were 4,727 (22%) with reported first‐course invasive liver surgery, local tumor destruction, or both. The proportion with reported liver surgery or ablation was 39% among localized stage cases and only 4% among distant/unstaged cases. Though 70% of cases had histologically confirmed diagnoses, the proportion with confirmed diagnoses was higher among cases with reported invasive surgery (99%), compared to cases receiving ablation (81%) or no reported therapy (65%). Incidence rates of histologically unconfirmed HCC increased faster than those of confirmed HCC from 1992 to 2008 (8% versus 3% per year). Two encouraging findings were that incidence rates of localized‐stage HCC increased faster than rates of regional‐ and distant‐stage HCC combined (8% versus 4% per year), and that incidence rates of reported first‐course surgery or tumor destruction increased faster than incidence rates of HCC without such therapy (11% versus 7%). Between 1975‐1977 and 1998‐2007, 5‐year cause‐specific HCC survival increased from just 3% to 18%. Survival was 84% among transplant recipients, 53% among cases receiving radiofrequency ablation at early stage, 47% among cases undergoing resection, and 35% among cases receiving local tumor destruction. Asian or Pacific Islander cases had significantly better 5‐year survival (23%) than white (18%), Hispanic (15%), or black cases (12%). Conclusion: HCC survival is improving, because more cases are diagnosed and treated at early stages. Additional progress may be possible with continued use of clinical surveillance to follow individuals at risk for HCC, enabling early intervention. (HEPATOLOGY 2012;)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Laura Beretta
Identification of osteopontin as a novel marker for early hepatocellular carcinoma
The aim of this study was to identify a biomarker that could improve alpha‐fetoprotein (AFP) performance in hepatocellular carcinoma (HCC) surveillance among patients with cirrhosis. We performed proteomic profiling of plasma from patients with cirrhosis or HCC and validated selected candidate HCC biomarkers in two geographically distinct cohorts to include HCC of different etiologies. Mass spectrometry profiling of highly fractionated plasma from 18 cirrhosis and 17 HCC patients identified osteopontin (OPN) as significantly up‐regulated in HCC cases, compared to cirrhosis controls. OPN levels were subsequently measured in 312 plasma samples collected from 131 HCC patients, 76 cirrhosis patients, 52 chronic hepatitis C (CHC) and B (CHB) patients, and 53 healthy controls in two independent cohorts. OPN plasma levels were significantly elevated in HCC patients, compared to cirrhosis, CHC, CHB, or healthy controls, in both cohorts. OPN alone or in combination with AFP had significantly better area under the receiver operating characteristic curve, compared to AFP, in comparing cirrhosis and HCC in both cohorts. OPN overall performance remained higher than AFP in comparing cirrhosis and the following HCC groups: HCV‐related HCC, HBV‐associated HCC, and early HCC. OPN also had a good sensitivity in AFP‐negative HCC. In a pilot prospective study including 22 patients who developed HCC during follow‐up, OPN was already elevated 1 year before diagnosis. Conclusion: OPN was more sensitive than AFP for the diagnosis of HCC in all studied HCC groups. In addition, OPN performance remained intact in samples collected 1 year before diagnosis. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Xin‐Yuan Guan
Translationally controlled tumor protein induces mitotic defects and chromosome missegregation in hepatocellular carcinoma development
Emerging evidence implicates the chromodomain helicase/ATPase DNA binding protein 1–like gene (CHD1L) as a specific oncogene in human hepatocellular carcinoma (HCC). To better understand the molecular mechanisms underlying HCC cases carrying CHD1L amplification (>50% HCCs), we identified a CHD1L target, translationally controlled tumor protein (TCTP), and investigated its role in HCC progression. Here, we report that CHD1L protein directly binds to the promoter region (nt −733 to −1,027) of TCTP and activates TCTP transcription. Overexpression of TCTP was detected in 40.7% of human HCC samples analyzed and positively correlated with CHD1L overexpression. Clinically, overexpression of TCTP was significantly associated with the advanced tumor stage (P = 0.037) and overall survival time of HCC patients (P = 0.034). In multivariate analyses, TCTP was determined to be an independent marker associated with poor prognostic outcomes. In vitro and in vivo functional studies in mice showed that TCTP has tumorigenic abilities, and overexpression of TCTP induced by CHD1L contributed to the mitotic defects of tumor cells. Further mechanistic studies demonstrated that TCTP promoted the ubiquitin‐proteasome degradation of Cdc25C during mitotic progression, which caused the failure in the dephosphorylation of Cdk1 on Tyr15 and decreased Cdk1 activity. As a consequence, the sudden drop of Cdk1 activity in mitosis induced a faster mitotic exit and chromosome missegregation, which led to chromosomal instability. The depletion experiment proved that the tumorigenicity of TCTP was linked to its role in mitotic defects. Conclusion: Collectively, we reveal a novel molecular pathway (CHD1L/TCTP/Cdc25C/Cdk1), which causes the malignant transformation of hepatocytes with the phenotypes of accelerated mitotic progression and the production of aneuploidy. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Masao Ota
Human leukocyte antigen class II molecules confer both susceptibility and progression in Japanese patients with primary biliary cirrhosis
Along with twin and family studies, recent genome‐wide association studies suggest that genetic factors contribute to the susceptibility and severity of primary biliary cirrhosis (PBC). Although several reports have demonstrated that the human leukocyte antigen (HLA) DRB1*08:03 allele is associated with disease susceptibility in Japan, the precise analysis of HLA haplotypes and the role of amino acid alignment have not been fully clarified. We investigated HLA class I A, B, and C and HLA class II DRB1 and DQB1 alleles and haplotypes in 229 Japanese patients with PBC and compared them with the published data of 523 healthy subjects. Significant associations were found with PBC susceptibility for the DRB1*08:03‐DQB1*06:01 (13% versus 6%; P = 0.000025; odds ratio [OR] = 2.22) and DRB1*04:05‐DQB1*04:01 haplotypes (17% versus 13%; P = 0.044; OR = 1.38). Conversely, there were significant protective associations with the DRB1*13:02‐DQB1*06:04 (2% versus 5%; P = 0.00093; OR = 0.27) and DRB1*11:01‐DQB1*03:01 haplotypes (1% versus 4%; P = 0.03; OR = 0.37). The frequency of the DRB1*09:01‐DQB1*03:03 haplotype was significantly higher in patients who had received orthotopic liver transplantation (33% versus 11%; P = 0.0012; OR = 3.96). Furthermore, the frequency of serine at position 57 (P = 0.0000015; OR = 1.83) of the DRβchain differed the most in patients with PBC, compared with healthy subjects. Conclusion: This study established the role of HLA haplotypes in determining PBC susceptibility and progression in the Japanese population. Further resequencing of the HLA region is required to more precisely identify the genetic components of PBC. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Christopher L. Bowlus
Biochemical and immunologic effects of rituximab in patients with primary biliary cirrhosis and an incomplete response to ursodeoxycholic acid
The aim of this study was to determine the safety and potential efficacy of B‐cell depletion with the anti‐CD20 monoclonal antibody rituximab in patients with primary biliary cirrhosis (PBC) and an incomplete response to ursodeoxycholic acid (UDCA). This open‐label study enrolled six patients with PBC and incomplete responses to UDCA to be treated with 2 doses of 1000 mg rituximab separated by 2 weeks and followed for 52 weeks. The primary endpoints were safety and changes in B‐cell function. Two patients received only 1 dose of rituximab, one due to activation of latent varicella and the other due to a viral upper respiratory infection. Serum levels of total IgG, IgM, and IgA as well as anti‐mitochondrial autoantibodies (AMAs) IgA and IgM decreased significantly from baseline by 16 weeks and returned to baseline levels by 36 weeks. Stimulation of B cells with CpG produced significantly less IgM at 52 weeks after treatment compared with B cells at baseline. In addition, transient decreases in memory B‐cell and T‐cell frequencies and an increase in CD25high CD4+ T cells were observed after treatment. These changes were associated with significant increases in mRNA levels of FoxP3 and transforming growth factor‐β (TGF‐β) and a decrease in tumor necrosis factor‐α (TNF‐α) in CD4+ T cells. Notably, serum alkaline phosphatase levels were significantly reduced up to 36 weeks following rituximab treatment. Conclusion: These data suggest that depletion of B cells influences the induction, maintenance, and activation of both B and T cells and provides a potential mechanism for treatment of patients with PBC with an incomplete response to UDCA. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Catherine Ann Malcolm Stedman
Mortality and the risk of malignancy in autoimmune liver diseases: A population‐based study in Canterbury, New Zealand
Population‐based quantitative data on the mortality and cancer incidence of autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC) are scarce. Our aim was to systematically investigate the survival and risk of malignancy on population‐based cohorts of AIH, PBC, and PSC in Canterbury, New Zealand. Multiple case‐finding methods were employed, including searches of all public and private, adult and pediatric outpatient clinics, hospital notes, laboratory, radiology, and pathology reports. Cases that fulfilled standardized diagnostic criteria were included. Kaplan‐Meier survival estimates, standardized mortality ratios (SMR), and standard incidence ratios (SIR) for malignancy were calculated. A total of 130 AIH, 70 PBC, and 81 PSC patients were included contributing to 1,156, 625, and 613 person‐years at risk, respectively. For AIH, PBC, and PSC cohorts, SMRs for all‐cause mortality were 2.1 (95% confidence interval [CI] 1.4‐3.1), 2.7 (95% CI 1.7‐4.0), and 4.1 (95% CI 2.6‐6.3), SMRs for hepatobiliary mortality were 42.3 (95% CI 20.3‐77.9), 71.2 (95% CI 30.7‐140.3), and 116.9 (95% CI 66.8‐189.8), SIRs for all cancers were 3.0 (95% CI 2.0‐4.3), 1.6 (95% CI 0.8‐2.9), and 5.2 (95% CI 3.3‐7.8), and SIRs for extrahepatic malignancy were 2.7 (95% CI 1.8‐3.9), 1.6 (95% CI 0.8‐2.9), and 3.0 (95% CI 1.6‐5.1), respectively. Conclusion: This is the first population‐based study to examine and compare the survival and cancer incidence in AIH, PBC, and PSC in the same population. The mortality for all three cohorts was significantly increased due to liver‐related death, demonstrating the inadequacy of current management strategies. The risk of hepatic and extrahepatic malignancy was significantly increased in AIH and PSC patients. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Carmina Montoliu
Patients with minimal hepatic encephalopathy show impaired mismatch negativity correlating with reduced performance in attention tests
Attention deficit is an early event in the cognitive impairment of patients with minimal hepatic encephalopathy (MHE). The underlying mechanisms remain unclear. Mismatch negativity (MMN) is an auditory event‐related potential that reflects an attentional trigger. Patients with schizophrenia show impaired attention and cognitive function, which are reflected in altered MMN. We hypothesized that patients with MHE, similarly to those with schizophrenia, should show MMN alterations related with attention deficits. The aims of this work were to assess whether (1) MMN is altered in cirrhotic patients with MHE, compared to those without MHE, (2) MMN changes in parallel with performance in attention tests and/or MHE in a longitudinal study, and (3) MMN predicts performance in attention tests and/or in the Psychometric Hepatic Encephalopathy Score (PHES). We performed MMN analysis as well as attention and coordination tests in 34 control subjects and in 37 patients with liver cirrhosis without MHE and 23 with MHE. Patients with MHE show reduced performance in selective and sustained attention tests and in visuomotor and bimanual coordination tests. The MMN wave area was reduced in patients with MHE, but not in those without MHE. In the longitudinal study, MMN area improved in parallel with performance in attention tests and PHES in 4 patients and worsened in parallel in another 4. Logistic regression analyses showed that MMN area predicts performance in attention tests and in PHES, but not in other tests or critical flicker frequency. Receiver operating characteristic curve analyses showed that MMN area predicts attention deficits in the number connection tests A and B, Stroop tasks, and MHE, with sensitivities of 75%‐90% and specificities of 76%‐83%. Conclusion: MMN area is useful to diagnose attention deficits and MHE in patients with liver cirrhosis. (HEPATOLOGY 2012;)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Leo A. van Grunsven
Successful isolation of liver progenitor cells by aldehyde dehydrogenase activity in naïve mice
The role of progenitor cells in liver repair and fibrosis has been extensively described, but their purification remains a challenge, hampering their characterization and use in regenerative medicine. To address this issue, we developed an easy and reproducible liver progenitor cell (LPC) isolation strategy based on aldehyde dehydrogenase (ALDH) activity, a common feature shared by many progenitor cells. We demonstrate that a subset of nonparenchymal mouse liver cells displays high levels of ALDH activity, allowing the isolation of these cells by fluorescence‐activated cell sorting. Immunocytochemistry and qPCR analyses on freshly isolated ALDH+ cells reveal an enrichment in cells expressing liver stem cell markers such as EpCAM, CK19, CD133, and Sox9. In culture, the ALDH+ population can give rise to functional hepatocyte‐like cells as illustrated by albumin and urea secretion and cytochrome P450 activity. ALDH1A1 expression can be detected in canals of Hering and bile duct epithelial cells and is increased on liver injury. Finally, we showed that the isolation and differentiation toward hepatocyte‐like cells of LPCs with high ALDH activity is also successfully applicable to human liver samples. Conclusion: High ALDH activity is a feature of LPCs that can be taken advantage of to isolate these cells from untreated mouse as well as human liver tissues. This novel protocol is practically relevant, because it provides an easy and nontoxic method to isolate liver stem cells from normal tissue for potential therapeutic purposes. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Gabriele Sass
Induction of heme oxygenase 1 prevents progression of liver fibrosis in Mdr2 knockout mice
Induction or overexpression of the heme‐degrading enzyme, heme oxygenase 1 (HO‐1), has been shown to protect mice from liver damage induced by acute inflammation. We have investigated the effects of HO‐1 induction in a mouse model of chronic liver inflammation and fibrogenesis with progression to hepatocellular carcinoma (HCC) (Mdr2ko; FVB.129P2‐Abcb4tm1Bor). HO‐1 was induced in vivo by treatment with cobalt protoporphyrin IX, starting at week 5 or 12 of mice lifespan, and continued for 7 weeks. Our results showed that HO‐1 induction reduced liver damage and chronic inflammation by regulating immune cell infiltration or proliferation as well as tumor necrosis factor receptor signaling. Fibrosis progression was significantly reduced by HO‐1 induction in mice with mild, as well as established, portal and lobular fibrosis. HO‐1 induction significantly suppressed hepatic stellate cell activation. During established fibrosis, HO‐1 induction was able to revert portal inflammation and fibrosis below levels observed at the start of treatment. Moreover, hepatocellular proliferation and signs of dysplasia were decreased after HO‐1 induction. Conclusion: Induction of HO‐1 interferes with chronic inflammation and fibrogenesis and, in consequence, might delay progression to HCC. (HEPATOLOGY 2012;)

Date de mise en ligne : Mercredi 01 f�vrier 2012
M. Behnan Sahin
Mature hepatocytes exhibit unexpected plasticity by direct dedifferentiation into liver progenitor cells in culture
Although there have been numerous reports describing the isolation of liver progenitor cells from the adult liver, their exact origin has not been clearly defined; and the role played by mature hepatocytes as direct contributors to the hepatic progenitor cell pool has remained largely unknown. Here, we report strong evidence that mature hepatocytes in culture have the capacity to dedifferentiate into a population of adult liver progenitors without genetic or epigenetic manipulations. By using highly purified mature hepatocytes, which were obtained from untreated, healthy rat liver and labeled with fluorescent dye PKH2, we found that hepatocytes in culture gave rise to a population of PKH2‐positive liver progenitor cells. These cells, liver‐derived progenitor cells, which share phenotypic similarities with oval cells, were previously reported to be capable of forming mature hepatocytes, both in culture and in animals. Studies done at various time points during the course of dedifferentiation cultures revealed that hepatocytes rapidly transformed into liver progenitors within 1 week through a transient oval cell‐like stage. This finding was supported by lineage‐tracing studies involving double‐transgenic AlbuminCreXRosa26 mice expressing β‐galactosidase exclusively in hepatocytes. Cultures set up with hepatocytes obtained from these mice resulted in the generation of β‐galactosidase‐positive liver progenitor cells, demonstrating that they were a direct dedifferentiation product of mature hepatocytes. Additionally, these progenitors differentiated into hepatocytes in vivo when transplanted into rats that had undergone retrorsine pretreatment and partial hepatectomy. Conclusion: Our studies provide strong evidence for the unexpected plasticity of mature hepatocytes to dedifferentiate into progenitor cells in culture, and this may potentially have a significant effect on the treatment of liver diseases requiring liver or hepatocyte transplantation. (HEPATOLOGY 2012;)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Frank G. Schaap
The human gallbladder secretes fibroblast growth factor 19 into bile: Towards defining the role of fibroblast growth factor 19 in the enterobiliary tract
Fibroblast growth factor 19 (FGF19) plays a crucial role in the negative feedback regulation of bile salt synthesis. In the postprandial state, activation of ileal farnesoid X receptor (FXR) by bile salts results in transcriptional induction of FGF19 and elevation of circulating FGF19 levels. An intestinal‐liver axis of FGF19 signaling results in down‐regulation of bile salt synthesis. The aim of this study was to explore a broader signaling activity of FGF19 in organs engaged in the enterohepatic circulation of bile salts. For this aim, FGF19 expression and aspects of FGF19 signaling were studied in surgical specimens and in cell lines of hepatobiliary and intestinal origin. FGF19 messenger RNA was found to be abundantly expressed in the human gallbladder and in the common bile duct, with only minor expression observed in the ileum. Interestingly, human gallbladder bile contains high levels of FGF19 (21.9 ± 13.3 versus 0.22 ± 0.14 ng/mL in the systemic circulation). Gallbladder explants secrete 500 times more FGF19 than FXR agonist‐stimulated ileal explants. Factors required for FGF19 signaling (i.e., FGFR4 and βKlotho) are expressed in mucosal epithelial cells of the gallbladder and small intestine. FGF19 was found to activate signaling pathways in cell lines of cholangiocytic, enteroendocrine, and enterocytic origin. Conclusion: The combined findings raise the intriguing possibility that biliary FGF19 has a signaling function in the biliary tract that differs from its established signaling function in the portal circulation. Delineation of the target cells in bile‐exposed tissues and the affected cellular pathways, as well as a possible involvement in biliary tract disorders, require further studies. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Abhijit Chowdhury
“Normal” liver stiffness measure (LSM) values are higher in both lean and obese individuals: A population‐based study from a developing country
The liver stiffness measure (LSM) needs to be explored in ethnically and anthropometrically diverse healthy subjects (to derive an acceptable normal range) and also in patients with liver disease. In view of this objective, LSM was performed by transient elastography (TE) using FibroScan in 437 healthy subjects with normal alanine aminotransferase (ALT) levels, recruited from a free‐living population of the Birbhum Population Project (BIRPOP; www.shds.in), a Health and Demographic Surveillance System (HDSS), and from 274 patients with liver disease attending the Hepatology Clinic of the School of Digestive and Liver Diseases (SDLD; Institute of Post Graduate Medical Education & Research [IPGME&R], Kolkata, India) including 188 with nonalcoholic fatty liver disease (NAFLD) and 86 with chronic hepatitis of viral and other etiologies. Liver biopsy was performed in 125 patients. The range of normal values for LSM, defined by 5th and 95th percentile values in healthy subjects, was 3.2 and 8.5 kPa, respectively. Healthy subjects with a lower body mass index (BMI; < <18.5 kg/m2) had a higher LSM compared with subjects who had a normal BMI; this LSM value was comparable to that of obese subjects (6.05 ± 1.78 versus 5.51 ± 1.59 and 6.60 ± 1.21, P = 0.016 and 0.349, respectively). Liver disease patients without histologic fibrosis had significantly higher LSM values compared with healthy subjects (7.52 ± 5.49 versus 5.63 ± 1.64, P < 0.001). Among the histologic variables, stage of fibrosis was the only predictor for LSM. LSM did not correlate with inflammatory activity and ALT in both NAFLD and chronic hepatitis groups. Conclusion: LSM varies between 3.2 and 8.5 kPa in healthy subjects of South Asian origin. Both lean and obese healthy subjects have higher LSM values compared with subjects with normal BMI. Liver stiffness begins to increase even before fibrosis appears in patients with liver disease. (Hepatology 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Natalia Nieto
Osteopontin, an oxidant stress sensitive cytokine, up‐regulates collagen‐I via integrin αVβ3 engagement and PI3K/pAkt/NFκB signaling
A key feature in the pathogenesis of liver fibrosis is fibrillar Collagen‐I deposition; yet, mediators that could be key therapeutic targets remain elusive. We hypothesized that osteopontin (OPN), an extracellular matrix (ECM) cytokine expressed in hepatic stellate cells (HSCs), could drive fibrogenesis by modulating the HSC pro‐fibrogenic phenotype and Collagen‐I expression. Recombinant OPN (rOPN) up‐regulated Collagen‐I protein in primary HSCs in a transforming growth factor beta (TGFβ)–independent fashion, whereas it down‐regulated matrix metalloprotease‐13 (MMP13), thus favoring scarring. rOPN activated primary HSCs, confirmed by increased α‐smooth muscle actin (αSMA) expression and enhanced their invasive and wound‐healing potential. HSCs isolated from wild‐type (WT) mice were more profibrogenic than those from OPN knockout (Opn−/−) mice and infection of primary HSCs with an Ad‐OPN increased Collagen‐I, indicating correlation between both proteins. OPN induction of Collagen‐I occurred via integrin αvβ3 engagement and activation of the phosphoinositide 3‐kinase/phosphorylated Akt/nuclear factor kappa B (PI3K/pAkt/NFκB)–signaling pathway, whereas cluster of differentiation 44 (CD44) binding and mammalian target of rapamycin/70‐kDa ribosomal protein S6 kinase (mTOR/p70S6K) were not involved. Neutralization of integrin αvβ3 prevented the OPN‐mediated activation of the PI3K/pAkt/NFκB–signaling cascade and Collagen‐I up‐regulation. Likewise, inhibition of PI3K and NFκB blocked the OPN‐mediated Collagen‐I increase. Hepatitis C Virus (HCV) cirrhotic patients showed coinduction of Collagen‐I and cleaved OPN compared to healthy individuals. Acute and chronic liver injury by CCl4 injection or thioacetamide (TAA) treatment elevated OPN expression. Reactive oxygen species up‐regulated OPN in vitro and in vivo and antioxidants prevented this effect. Transgenic mice overexpressing OPN in hepatocytes (OpnHEP Tg) mice developed spontaneous liver fibrosis compared to WT mice. Last, chronic CCl4 injection and TAA treatment caused more liver fibrosis to WT than to Opn−/− mice and the reverse occurred in OpnHEP Tg mice. Conclusion: OPN emerges as a key cytokine within the ECM protein network driving the increase in Collagen‐I protein contributing to scarring and liver fibrosis. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Laura J. Niedernhofer
A mouse model of accelerated liver aging caused by a defect in DNA repair
The liver changes with age, leading to an impaired ability to respond to hepatic insults and increased incidence of liver disease in the elderly. Therefore, there is critical need for rapid model systems to study aging‐related liver changes. One potential opportunity is murine models of human progerias or diseases of accelerated aging. Ercc1−/Δ mice model a rare human progeroid syndrome caused by inherited defects in DNA repair. To determine whether hepatic changes that occur with normal aging occur prematurely in Ercc1−/Δ mice, we systematically compared liver from 5‐month‐old progeroid Ercc1−/Δ mice to old (24‐36‐month‐old) wild‐type (WT) mice. Both displayed areas of necrosis, foci of hepatocellular degeneration, and acute inflammation. Loss of hepatic architecture, fibrosis, steatosis, pseudocapillarization, and anisokaryosis were more dramatic in Ercc1−/Δ mice than in old WT mice. Liver enzymes were significantly elevated in serum of Ercc1−/Δ mice and old WT mice, whereas albumin was reduced, demonstrating liver damage and dysfunction. The regenerative capacity of Ercc1−/Δ liver after partial hepatectomy was significantly reduced. There was evidence of increased oxidative damage in Ercc1−/Δ and old WT liver, including lipofuscin, lipid hydroperoxides and acrolein, as well as increased hepatocellular senescence. There was a highly significant correlation in genome‐wide transcriptional changes between old WT and 16‐week‐old, but not 5‐week‐old, Ercc1−/Δ mice, emphasizing that the Ercc1−/Δ mice acquire an aging profile in early adulthood. Conclusion: There are strong functional, regulatory, and histopathological parallels between accelerated aging driven by a DNA repair defect and normal aging. This supports a role for DNA damage in driving aging and validates a murine model for rapidly testing hypotheses about causes and treatment for aging‐related hepatic changes. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Gyongyi Szabo
Hypoxia and hypoxia inducible factors: Diverse roles in liver diseases
Hypoxia has been shown to have a role in the pathogenesis of several forms of liver disease. The hypoxia inducible factors (HIFs) are a family of evolutionarily conserved transcriptional regulators that affect a homeostatic response to low oxygen tension and have been identified as key mediators of angiogenesis, inflammation, and metabolism. In this review we summarize the evidence for a role of HIFs across a range of hepatic pathophysiology. We describe regulation of the HIFs and review investigations that demonstrate a role for HIFs in the development of liver fibrosis, activation of innate immune pathways, hepatocellular carcinoma, as well as other liver diseases in both human disease as well as murine models. (HEPATOLOGY 2012;)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Carol S. Portlock
Hepatitis C and non‐Hodgkin lymphoma: The clinical perspective
Hepatitis C virus (HCV) is a commonly transmitted infection that has both hepatic and extrahepatic repercussions. These range from the inflammatory to the oncologic with an undisputed link to hepatitis, liver cirrhosis, and hepatocellular carcinoma. Its role in the development of B cell non‐Hodgkin lymphoma (B‐NHL) is becoming better understood, leading to opportunities for research, therapy, and even prevention. Research in the field has progressed significantly over the last decade, with the number of patients diagnosed with HCV and B‐NHL rising incrementally. It is therefore becoming crucial to fully understand the pathobiologic link of HCV in B cell lymphomagenesis and its optimal management in the oncologic setting. (HEPATOLOGY 2012)

Date de mise en ligne : Mercredi 01 f�vrier 2012
Fabio Tine
Long‐term low‐dose maintenance pegylated interferon may prevent decompensation in cirrhotic patients with portal hypertension: Are we there yet?
644

Date de mise en ligne : Mercredi 01 f�vrier 2012
Alexander Ploss
Exiting from uncharted territory: Hepatitis C virus assembles in mouse cell lines
648

Date de mise en ligne : Mercredi 01 f�vrier 2012
Yoshikazu Murawaki
Contrast‐enhanced sonography with perflubutane revealing active bleeding as a complication of radiofrequency ablation
650

Date de mise en ligne : Mercredi 01 f�vrier 2012
Angelo Sangiovanni
Re: Indeterminate 1‐2 cm nodules found on hepatocellular carcinoma surveillance: Biopsy for all, some, or none?
651

Date de mise en ligne : Mercredi 01 f�vrier 2012
Morris Sherman
Reply:
652

Date de mise en ligne : Mercredi 01 f�vrier 2012
Alfredo Alberti
Diagnostic algorithms for liver fibrosis in hepatitis C: Are they ready to avoid liver biopsy?
653

Date de mise en ligne : Mercredi 01 f�vrier 2012
Paul Calès
Reply:
653

Date de mise en ligne : Mercredi 01 f�vrier 2012
Ramazan Kurt
Is M65 really better than M30 as a biomarker of hepatic fibrosis?
654

Date de mise en ligne : Mercredi 01 f�vrier 2012
Klaus Schulze‐Osthoff
Reply:
655

Date de mise en ligne : Mercredi 01 f�vrier 2012
Epameinondas V. Tsianos
Rifaximin reduces endotoxemia and improves liver function and disease severity in patients with decompensated cirrhosis
656

Date de mise en ligne : Mercredi 01 f�vrier 2012
Jia‐Horng Kao
Hepatitis B virus mutants associated with hepatitis b surface antigen loss: Chicken or egg?
657

Date de mise en ligne : Mercredi 01 f�vrier 2012
Osamu Yokosuka
Histological discrimination between autoimmune hepatitis and drug‐induced liver injury
657

Date de mise en ligne : Mercredi 01 f�vrier 2012
Roberto J. Groszmann
In Memoriam: Harold O. Conn, M.D.
658