ASK1/ p38 axis inhibition blocks the release of mitochondrial "danger signals" from hepatocytes and suppresses progression to cirrhosis and liver cancer.

BACKGROUND AND AIMS: Apoptosis Signal-regulating Kinase 1 (ASK1) is activated by various pathological stimuli and induces cell apoptosis through downstream p38 activation. We studied the effect of pharmacological ASK1 inhibition on cirrhosis and its sequelae using comprehensive preclinical in vivo and in vitro systems. APPROACH AND RESULTS: Short-term (4-6 wk) and long-term (24-44 wk) ASK1 inhibition using small molecule GS-444217 was tested in thioacetamide-induced and BALB/c. Mdr2-/- murine models of cirrhosis and HCC, and in vitro using primary hepatocyte cell death assays. Short-term GS-444217 therapy in both models strongly reduced phosphorylated p38, hepatocyte death, and fibrosis by up to 50%. Profibrogenic release of mitochondrial DAMP mitochondrial deoxyribonucleic acid from dying hepatocytes was blocked by ASK1 or p38 inhibition. Long-term (24 wk) therapy in BALBc.Mdr2 - / - model resulted in a moderate 25% reduction in bridging fibrosis, but not in net collagen deposition. Despite this, the development of cirrhosis was effectively prevented, with strongly reduced p21 + hepatocyte staining (by 72%), serum ammonia levels (by 46%), and portal pressure (average 6.07 vs. 8.53 mm Hg in controls). Extended ASK1 inhibition for 44 wk in aged BALB/c. Mdr2-/- mice resulted in markedly reduced tumor number and size by ~50% compared to the control group. CONCLUSIONS: ASK1 inhibition suppresses the profibrogenic release of mitochondrial deoxyribonucleic acid from dying hepatocytes in a p38-dependent manner and protects from liver fibrosis. Long-term ASK1 targeting resulted in diminished net antifibrotic effect, but the progression to liver cirrhosis and cancer in BALBc/ Mdr2- / - mice was effectively inhibited. These data support the clinical evaluation of ASK1 inhibitors in fibrotic liver diseases.

Longitudinal analysis of serum microRNAs as predictors of cirrhosis regression during treatment of hepatitis B virus infection.

BACKGROUND AND AIMS: Most patients with cirrhosis induced by chronic HBV infection experience fibrosis regression after long-term antiviral treatment, while some remain cirrhotic. Fibrosis regression is associated with lower odds of developing hepatic decompensation and hepatocellular carcinoma, but mechanisms impacting differential fibrosis regression between individuals are unclear. We asked whether soluble molecules, including serum microRNAs, could serve as biomarkers of fibrosis regression. METHODS: We analysed cryopreserved sera from clinical trials in which cirrhotic HBV-infected patients (baseline Ishak fibrosis score of 5-6) received 240 weeks of nucleotide analogue treatment. Liver biopsies at week 240 in these trials showed 71/96 patients (74%) had fibrosis regression (Ishak ≤ 4) while 25/96 (26%) remained cirrhotic (Ishak 5-6). We quantified inflammatory markers (CXCL10, soluble CD163) and miRNAs (n = 179) from serum at baseline, week 48 and week 240 of treatment in a sub-cohort of patients with (n = 14) or without (n = 14) fibrosis regression. RESULTS: CXCL10, sCD163 and miRNAs previously associated with HBV replication and inflammation decreased during treatment but did not differ based on fibrosis regression. Two miRNAs (miR-421 and miR-454-3p) had lower baseline expression in patients with subsequent fibrosis regression. In all, 27 miRNAs differed at week 240 and had higher expression in patients with fibrosis regression (eg miR-199a-3p, miR-423-3p, miR-142-3p, miR-let-7d-5p). Several miRNAs (miR-141-3p, let-7d-5p) that correlated with regression have previously been implicated in the pathophysiology of non-alcoholic steatohepatitis. CONCLUSIONS: In cirrhotic patients with chronic HBV infection treated with antiviral therapy, serum miRNAs have differential expression based on fibrosis regression, suggesting potential utility as biomarkers.

The diagnostic performance of a simplified blood test (SteatoTest-2) for the prediction of liver steatosis.

BACKGROUND: Serum biomarkers of steatosis such as the SteatoTest are recommended for large-scale screening studies, because imaging is less accessible and more expensive. AIMS: The primary aim of this retrospective analysis of prospective studies was to construct a new SteatoTest-2 that was not inferior to the reference first-generation SteatoTest, but that did not include BMI or bilirubin, as these two components can increase test variability because of the assessment of weight and height and in case of Gilbert syndrome or hemolysis, respectively. PATIENTS AND METHODS: Five different subsets of 2997 patients with biopsies were evaluated for test construction and validation, and four to assess the prevalence of steatosis in target populations with increasing risks of steatosis. The performance of the SteatoTest-2 was compared with the reference test, using the noninferiority test (0.10 margin) and the Lin concordance coefficient. RESULTS: Areas under the receiver operating characteristic curve of the SteatoTest-2 were noninferior to the reference test (P<0.001). Areas under the receiver operating characteristic curve varied in the SteatoTest-2 and the reference test according to subsets and the prevalence of steatosis, with 0.772 [95% confidence interval (CI): 0.713-0.820] versus 0.786 (95% CI: 0.729-0.832) in the 2997 cases with biopsy and 0.822 (95% CI: 0.810-0.834) versus 0.868 (95% CI: 0.858-0.878) in the 5776 cases including healthy individuals without risk factors of steatosis as controls, respectively. The Lin coefficient was highly concordant (P<0.001), from 0.74 (95% CI: 0.74-0.74) in presumed NAFLD to 0.91 (95% CI: 0.89-0.93) in the construction subset. CONCLUSION: The SteatoTest-2 is simpler and noninferior to the first-generation SteatoTest for the diagnosis of steatosis, without the limitations of BMI and bilirubin.

The Second Canadian Symposium on hepatitis C virus: a call to action.

In Canada, hepatitis C virus (HCV) infection results in considerable morbidity, mortality and health-related costs. Within the next three to 10 years, it is expected that tolerable, short-duration (12 to 24 weeks) therapies capable of curing >90% of those who undergo treatment will be approved. Given that most of those already infected are aging and at risk for progressive liver disease, building research-based interdisciplinary prevention, care and treatment capacity is an urgent priority. In an effort to increase the dissemination of knowledge in Canada in this rapidly advancing field, the National CIHR Research Training Program in Hepatitis C (NCRTP-HepC) established an annual interdisciplinary Canadian Symposium on Hepatitis C Virus. The first symposium was held in Montreal, Quebec, in 2012, and the second symposium was held in Victoria, British Columbia, in 2013. The current article presents highlights from the 2013 meeting. It summarizes recent advances in HCV research in Canada and internationally, and presents the consensus of the meeting participants that Canada would benefit from having its own national HCV strategy to identify critical gaps in policies and programs to more effectively address the challenges of expanding HCV screening and treatment.

Intra-laboratory analytical variability of biochemical markers of fibrosis (Fibrotest) and activity (Actitest) and reference ranges in healthy blood donors.

Combinations of tests comprising alpha2-macroglobulin, haptoglobin, apolipoprotein Al, gamma-glutamyltransferase, total bilirubin (Fibrotest) and alanine aminotransferase (Actitest) are being developed as alternatives to liver biopsy in patients with chronic hepatitis C. The aim of this study was to assess in the same laboratory the impact of parameter assay variations on Fibrotest and Actitest results and intra-patient reproducibility of the two tests. The stability of the samples for each test was studied after storage at -80 degrees C and -20 degrees C. Within-run, between-run and total imprecision for each parameter assay, and for Fibrotest and Actitest results, were determined. Transferability of assay results between different analyzers was studied. Intra-patient reproducibility was assessed in 55 hospitalized patients. Fibrotest and Actitest reference ranges were determined in 300 blood donors (reference group). The stability of the parameters was affected by serum storage at -20 degrees C only. The impact of parameter analytical variability on Fibrotest and Actitest results was less than 10% and intra-patient reproducibility was acceptable (p > 0.05). The transferability between different analyzers of results of assays performed under the same standardized and calibration conditions was excellent. Fibrotest and Actitest reference ranges in blood donors were (mean+/-SE) 0.075+/-0.004 and 0.068+/-0.004, respectively. The low intra-laboratory and intra-patient variability in Fibrotest and Actitest results confirm Fibrotest and Actitest reliability.

Biochemical surrogate markers of liver fibrosis and activity in a randomized trial of peginterferon alfa-2b and ribavirin.

Liver fibrosis and activity indexes were validated in patients infected by hepatitis C virus (HCV) nontreated and treated by interferon. The aim was to validate their usefulness as surrogate markers of histologic features using the data of a randomized trial of combination peginterferon alfa-2b and ribavirin. Three hundred fifty-two patients who had had 2 interpretable liver biopsies and stored serum sample before and after treatment were selected. Two hundred eight patients received peginterferon alfa-2b 1.5 mcg per kg and ribavirin and 144 patients interferon alfa-2b 3 MU three times a week and ribavirin for 48 weeks. A fibrosis and an activity index combining 5 and 6 biochemical markers were assessed at baseline and at end of follow-up (24 weeks after treatment). The biochemical markers have significant predictive values both for the diagnosis of fibrosis and for activity. For the diagnosis of bridging fibrosis and/or moderate necroinflammatory activity, the area under the receiver operating characteristics curve of the activity index was 0.76 +/- 0.03 at baseline and 0.82 +/- 0.02 at end of follow-up. A cutoff of activity index at 0.30 (range, 0.00-1.00) had 90% sensitivity and 88% positive predictive value for the diagnosis of bridging fibrosis or moderate necroinflammatory activity. Sensitivity analyses with biopsy specimens of size greater than 15 mm suggest that a part of discordances between biochemical markers and histology were due to biopsy specimen sampling error. In conclusion, these biochemical markers of fibrosis and activity could be used as surrogate markers for liver biopsy in patients with chronic hepatitis C, both for the initial evaluation and for follow-up.