The interaction of disulfiram and H2S metabolism in inhibition of aldehyde dehydrogenase activity and liver cancer cell growth.

Disulfiram (DSF), a sulfur-containing compound, has been used to treat chronic alcoholism and cancer for decades by inactivating aldehyde dehydrogenase (ALDH). Hydrogen sulfide (H2S) is a new gasotransmitter and regulates various cellular functions by S-sulfhydrating cysteine in the target proteins. H2S exhibits similar properties to DSF in the sensitization of cancer cells. The interaction of DSF and H2S on ALDH activity and liver cancer cell survival are not clear. Here it was demonstrated that DSF facilitated H2S release from thiol-containing compounds, and DSF and H2S were both capable of regulating ALDH through inhibition of gene expression and enzymatic activity. The supplement of H2S sensitized human liver cancer cells (HepG2) to DSF-inhibited cell viability. The expression of cystathionine gamma-lyase (a major H2S-generating enzyme) was lower but ALDH was higher in mouse liver cancer stem cells (Dt81Hepa1-6) in comparison with their parental cells (Hepa1-6), and H2S was able to inhibit liver cancer stem cell adhesion. In conclusion, these data point to the potential of combining DSF and H2S for inhibition of cancer cell growth and tumor development by targeting ALDH.

Non-invasive diagnostic imaging tests largely underdiagnose cardiac cirrhosis in patients undergoing advanced therapy evaluation: How can we identify the high-risk patient?

BACKGROUND: Patients with liver cirrhosis are generally considered ineligible for isolated cardiac transplantation or left ventricular assist device (LVAD) implantation. The aim of this retrospective study is to explore the diagnostic value of abdominal ultrasound, computed tomography scan (CT scan) and liver-spleen scintigraphy to detect the presence of cirrhosis in patients with advanced heart failure. METHODS: Among 567 consecutive patients who underwent pre-transplantation or LVAD evaluation, 54 had a liver biopsy to rule out cardiac cirrhosis; we compared the biopsy results with the imaging investigations. RESULTS: In about 26% (n = 14) of patients undergoing liver biopsy, histopathological evaluation identified cirrhosis. The respective sensitivity of abdominal ultrasound, CT scan and liver-spleen scintigraphy to detect cirrhosis was 57% [29-82], 50% [16-84], and 25% [3-65]. The specificity was 80% [64-91], 89% [72-98], and 44% [20-70], respectively. CONCLUSION: Ultrasonography has the best-combined sensitivity and specificity for the diagnosis of cirrhosis. However, more than a third of patients with cirrhosis will go undiagnosed by conventional imaging. As liver biopsy is associated with a low rate of complication, it should be considered in patients with a high-risk of cirrhosis or with evidence of portal hypertension to assess their eligibility for heart transplantation or LVAD implantation.

Targeted caspofungin prophylaxis for invasive aspergillosis in high-risk liver transplant recipients, a single-center experience.

BACKGROUND: Invasive aspergillosis (IA) is a rare but highly lethal complication after orthotopic liver transplantation (OLT). Targeted antifungal prophylaxis has been proposed as a strategy to prevent IA among orthotopic liver transplant recipient (OLTr), but limited data are available to support its efficacy. METHOD: We conducted a single-center, retrospective, before and after cohort study, comparing IA incidences among OLTr who did not receive antifungal prophylaxis after transplantation (cohort 1) to OLTr who received targeted antifungal prophylaxis after liver transplantation (cohort 2). Patients in cohort 2 received caspofungin prophylaxis if they presented one of the following risk factors: retransplantation, acute liver failure, dialysis, or Aspergillus colonization prior to transplantation. The primary outcome was IA at 90 days after transplantation. RESULTS: A total of 391 OLTr were included in the study; 181 patients in the cohort 1 (no prophylaxis) and 210 patients in the cohort 2 (targeted prophylaxis). Among patients in cohort 2, 19% (40/ 210) were considered at high risk for IA and 85% (34/40) of those received caspofungin prophylaxis. The incidence of IA at 90 days was 3.3% (6/ 181) and 0.5% (1/ 210), in cohort 1 and 2, respectively (OR 0.14; 95%CI 0.01-0.83; P = .03). Ninety-day mortality was similar among the two cohorts (3.9% (7/181) and 2.4% (5/210) in cohort 1 and 2, respectively (OR 0.61; 95% 0.18-1.93; P = .40)). The 90-day mortality among the OLTs with IA was 71% (5/7). CONCLUSION: Targeted caspofungin prophylaxis was associated with lower rate of IA.

Restrictive fluid management strategies and outcomes in liver transplantation: a systematic review.

PURPOSE: Restrictive fluid management strategies have been proposed to reduce complications in liver transplant recipients. We conducted a systematic review to evaluate the effects of restrictive perioperative fluid management strategies, compared with liberal ones, on postoperative outcomes in adult liver transplant recipients. Our primary outcome was acute kidney injury (AKI). Our secondary outcomes were bleeding, mortality, and other postoperative complications. SOURCE: We searched major databases (CINAHL, EMB Reviews, EMBASE, MEDLINE, and the grey literature) from their inception to 10 July 2018 for randomized-controlled trials (RCTs) and observational studies comparing two fluid management strategies (or observational studies reporting two outcomes with available data on fluid volume received) in adult liver transplant recipients. Study selection, data abstraction, and risk of bias assessment were performed by at least two investigators. Data from RCTs were pooled using risk ratios (RR) and mean differences (MD) with random-effect models. PRINCIPAL FINDINGS: We found seven RCTs and 29 observational studies. Based on RCTs, fluid management strategies did not have any effect on AKI, mortality, or any other postoperative complications. Intraoperative RCTs suggested that a restrictive fluid management strategy reduced pulmonary complications (RR, 0.69; 95% confidence interval [CI], 0.47 to 0.99; n = 283; I2 = 27%), duration of mechanical ventilation (MD, -13.04 hr; 95% CI, -22.2 to -3.88; n = 130; I2 = 0%) and blood loss (MD, -1.14 L; 95% CI, -1.72 to -0.57; n = 151; I2 = 0%). CONCLUSION: Based on low or very low levels of evidence, we did not find any association between restrictive fluid management strategies and AKI, but we observed possible protective effects of intraoperative restrictive fluid management strategies on other outcomes. TRIAL REGISTRATION: PROSPERO (CRD42017054970); registered 18 May, 2017.

Oxaloacetate Protects Rat Liver From Experimental Warm Ischemia/Reperfusion Injury by Improving Cellular Energy Metabolism.

Liver ischemia/reperfusion injury (IRI) is an important cause of liver damage especially early after liver transplantation, following liver resection, and in other clinical situations. Using rat experimental models, we identified oxaloacetate (OAA) as a key metabolite able to protect hepatocytes from hypoxia and IRI. In vitro screening of metabolic intermediates beneficial for hepatocyte survival under hypoxia was performed by measures of cell death and injury. In vivo, the effect of OAA was evaluated using the left portal vein ligation (LPVL) model of liver ischemia and a model of warm IRI. Liver injury was evaluated in vivo by serum transaminase levels, liver histology, and liver weight (edema). Levels and activity of caspase 3 were also measured. In vitro, the addition of OAA to hepatocytes kept in a hypoxic environment significantly improved cell viability (P < 0.01), decreased cell injury (P < 0.01), and improved energy metabolism (P < 0.01). Administration of OAA significantly reduced the extent of liver injury in the LPVL model with lower levels of alanine aminotransferase (ALT; P < 0.01), aspartate aminotransferase (AST; P < 0.01), and reduced liver necrosis (P < 0.05). When tested in a warm IRI model, OAA significantly decreased ALT (P < 0.001) and AST levels (P < 0.001), prevented liver edema (P < 0.001), significantly decreased caspase 3 expression (P < 0.01), as well as histological signs of cellular vesiculation and vacuolation (P < 0.05). This was associated with higher adenosine triphosphate (P < 0.05) and energy charge levels (P < 0.01). In conclusion, OAA can significantly improve survival of ischemic hepatocytes. The hepatoprotective effect of OAA was associated with increased levels of liver bioenergetics both in vitro and in vivo. These results suggest that it is possible to support mitochondrial activity despite the presence of ischemia and that OAA can effectively reduce ischemia-induced injury in the liver.

Impact of MELD Score-Based Organ Allocation on Mortality, Bleeding, and Transfusion in Liver Transplantation: A Before-and-After Observational Cohort Study.

OBJECTIVE: The goal of this study was to evaluate the effect of the Model for End-Stage Liver Disease (MELD)-based allocation system on mortality, bleeding, and transfusion requirement in orthotopic liver transplantation (OLT). DESIGN: OLTs were studied for this observational study (before-and-after observational cohort study). SETTING: One community hospital. PARTICIPANTS: The study comprised 686 patients who underwent 750 consecutive OLTs. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Patients who underwent OLT in the MELD era had an adjusted lower 1-year mortality (adjusted odds ratio 0.45 [0.24-0.83]) compared with patients who underwent OLT the pre-MELD era. No significant difference in 1-month mortality was observed. Other variables with a significant effect on 1-year mortality in multivariate analysis were preoperative international normalized ratio, intraoperative use of a phlebotomy, total intraoperative volume of crystalloid infused, and retransplantation. Blood loss was greater in the MELD era (median difference 200 mL; p < 0.001), as were red blood cell, fresh frozen plasma, and cryoprecipitate transfusions. More patients in the MELD era received at least 1 transfusion (27% v 20%; p = 0.024). CONCLUSION: The MELD allocation system did not affect 1-month mortality, but a decrease in 1-year mortality was demonstrated. Blood loss and transfusions increased during OLTs performed in the MELD era. The role of other variables should be explored further to explain postoperative morbidity and mortality.

Sofosbuvir-Based Therapy in the Pre-Liver Transplant Setting: The Canadian National Experience.

INTRODUCTION AND AIM: Sofosbuvir (SOF)-based regimen has been shown to have high efficacy even in patients with decompensated cirrhosis. Treated patients may experience various degrees of hepatic recovery ranging from stabilization of liver function, to removal from liver transplant wait lists. The frequency of these occurrences in larger transplant eligible patient populations is unknown. The aim of this study was to assess the efficacy of SOF-based therapy in HCV infected transplant eligible patients and to evaluate short term changes in liver function and the effect on their liver transplant status. MATERIAL AND METHODS: A retrospective multicenter Canadian study of liver transplant candidates with advanced HCV cirrhosis treated with SOF-based therapy. Outcomes included sustained virologic response (SVR), and liver transplant status. RESULTS: 105 liver transplant candidates with advanced liver disease due to HCV were evaluated. The overall SVR was 83.8%. Hepatocellular carcinoma was diagnosed in 39 (37.1%) prior to transplant evaluation. In short term follow-up, 14 (13.3%) remained active on the list at the time of SVR12, 22 (20.9%) patients underwent liver transplantation, 7 (6.6%) patients were deactivated due to clinical improvement, 3 patients were delisted, and 10 deaths were reported. CONCLUSIONS: SOF-based therapy for patients progressing to liver transplantation leads to high SVR rates, short term stability in liver function, and deactivation from the transplant list .

Proposal of a novel MELD exception point system for hepatocellular carcinoma based on tumor characteristics and dynamics.

BACKGROUND & AIMS: Patients listed with exception points for hepatocellular carcinoma (HCC) have been more likely to be transplanted than those listed for chronic liver failure (LF) based on the model for end-stage liver disease (MELD) score. The aim of this study was to determine outcomes in the 5-year experience of a scoring system designed to reflect heterogeneity of tumor load of patients listed for HCC. METHODS: A novel MELD exception point system based on size and number of HCC was implemented in July 2009. This system allows stratification of patients based on risk of dropping out from the waiting list according to Milan criteria. LF patients were listed according to biological MELD sodium score; HCC patients were reassigned points every three months upon repeat imaging. RESULTS: Among 624 patients listed for liver transplant (LT), 505 were eligible. 94 (18.6%) were assigned MELD HCC points. Only 24.7% required changes in allocated points over time. Transplantation rates (HCC 83% vs. LF 73%, p=0.04) and waiting time in days (HCC 258 vs. LF 325; p=0.07) were similar. The method of competing risk analysis revealed that HCC patients were more likely to be transplanted than LF during the 5-year period preceding implementation, whereas transplant rates became equivalent for HCC and non-HCC in 2009-2014. One- and two-year survivals were similar between the two groups. CONCLUSIONS: Our study demonstrates that a novel MELD point system for HCC, taking into account dynamics in tumor size and number, allows for equitable liver allocation without compromising graft and patient survival. LAY SUMMARY: It has historically been difficult to achieve equitable liver allocation for liver cancer and chronic liver failure with the allocation systems currently in place in many countries worldwide. We designed a new system to help improve access to organs for liver failure patients in Québec, Canada. Our 5-year experience demonstrates that this unique system renders access to transplant similar for both liver cancer and liver failure indications.

Genome-wide RNAi screen reveals a new role of a WNT/CTNNB1 signaling pathway as negative regulator of virus-induced innate immune responses.

To identify new regulators of antiviral innate immunity, we completed the first genome-wide gene silencing screen assessing the transcriptional response at the interferon-ß (IFNB1) promoter following Sendai virus (SeV) infection. We now report a novel link between WNT signaling pathway and the modulation of retinoic acid-inducible gene I (RIG-I)-like receptor (RLR)-dependent innate immune responses. Here we show that secretion of WNT2B and WNT9B and stabilization of ß-catenin (CTNNB1) upon virus infection negatively regulate expression of representative inducible genes IFNB1, IFIT1 and TNF in a CTNNB1-dependent effector mechanism. The antiviral response is drastically reduced by glycogen synthase kinase 3 (GSK3) inhibitors but restored in CTNNB1 knockdown cells. The findings confirm a novel regulation of antiviral innate immunity by a canonical-like WNT/CTNNB1 signaling pathway. The study identifies novel avenues for broad-spectrum antiviral targets and preventing immune-mediated diseases upon viral infection.

Protease inhibitor-based triple therapy is highly effective for hepatitis C recurrence after liver transplant: a multicenter experience.

INTRODUCTION: Hepatitis C (HCV) continues to be the leading indication for liver transplantation (LT). Sustained virological response (SVR) rates to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy for recurrent HCV in Genotype 1 (G1) LT recipients have been disappointing (30-40%). Experience with triple therapy using protease inhibitors (PI) boceprevir (BOC), telaprevir (TVR) in these patients has been limited. MATERIAL AND METHODS: This national multicenter retrospective study included 76 patients (64 male, mean age 57 ± 6 years), treated for G1 HCV recurrence with either BOC (n = 41) or TVR (n = 35), who were non-responders or relapsers (n = 54), treatment naïve (n = 22) or had fibrosing cholestatic HCV (n = 3). 53 patients were on cyclosporine, 22 on tacrolimus and one patient on prednisone alone. RESULTS: On treatment virologic response was observed in 84% (64/76), 83% in BOC and 85% in TVR group. A higher week 4 response after starting triple therapy (RVR) was noted in TVR group 25/35 (81%) as compared to BOC group 26/41 (63%); p value = 0.02. The end of treatment response was 78% and 75% in BOC and TVR group, respectively. SVR 12 weeks after treatment discontinuation was observed in 59.5% (22/37); 58.3% in the BOC group and 61.5% in TVR group. Treatment was discontinued early in 23 patients (serious adverse effects n = 19, treatment failure n = 4). Infections occurred in 5 patients with 2 deaths (all in BOC). Anemia was the most common side effect (n = 55, 72%) requiring erythropoietin and RBV dose reduction. In the BOC group, cyclosporine dose reduction was 2.2 ± 1.0 fold and 8.6 ± 2.4 fold with tacrolimus. In TVR group, dose reduction was 3.0 ± 1.4 with cyclosporine and 12 ± 5.7 fold with tacrolimus. CONCLUSIONS: PI-based triple therapy appears more effective in producing HCV-RNA clearance than dual therapy. Tolerability is a serious issue and drug-drug interactions are manageable with close monitoring.

Impact of the delay in cryopreservation timing during biobanking procedures on human liver tissue metabolomics.

The liver is a highly specialized organ involved in regulating systemic metabolism. Understanding metabolic reprogramming of liver disease is key in discovering clinical biomarkers, which relies on robust tissue biobanks. However, sample collection and storage procedures pose a threat to obtaining reliable results, as metabolic alterations may occur during sample handling. This study aimed to elucidate the impact of pre-analytical delay during liver resection surgery on liver tissue metabolomics. Patients were enrolled for liver resection during which normal tissue was collected and snap-frozen at three timepoints: before transection, after transection, and after analysis in Pathology. Metabolomics analyses were performed using 1H Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-Mass Spectrometry (LC-MS). Time at cryopreservation was the principal variable contributing to differences between liver specimen metabolomes, which superseded even interindividual variability. NMR revealed global changes in the abundance of an array of metabolites, namely a decrease in most metabolites and an increase in ß-glucose and lactate. LC-MS revealed that succinate, alanine, glutamine, arginine, leucine, glycerol-3-phosphate, lactate, AMP, glutathione, and NADP were enhanced during cryopreservation delay (all p<0.05), whereas aspartate, iso(citrate), ADP, and ATP, decreased (all p<0.05). Cryopreservation delays occurring during liver tissue biobanking significantly alter an array of metabolites. Indeed, such alterations compromise the integrity of metabolomic data from liver specimens, underlining the importance of standardized protocols for tissue biobanking in hepatology.

Liver fibrosis protects mice from acute hepatocellular injury.

BACKGROUND & AIMS: Development of fibrosis is part of the pathophysiologic process of chronic liver disease. Although it is considered deleterious, it also represents a form of tissue repair. Deposition of extracellular matrix changes the cellular environment of the liver; we investigated whether it increases resistance to noxious stimuli and the role of changes in intracellular signaling to hepatocytes in mediating this effect. METHODS: Primary cultures of mouse hepatocytes were exposed to type I collagen (COL1); cell injury was assessed by morphologic and biochemical criteria. The expression of Bcl-2 family members was evaluated by immunoblot analyses. Activation of extracellular signal-regulated kinase (ERK) was assessed using phospho-specific antibodies. Liver fibrosis was induced by repeated administration of thioacetamide or carbon tetrachloride to mice; mice were then exposed to Fas antibodies. RESULTS: Hepatocytes exposed to COL1 were more resistant to a variety of hepatotoxins, in a dose-dependent manner, and had lower levels of Bad, Bid, and Bax proapoptotic proteins compared with control hepatocytes. Activation of ERK1/2 was stronger and quicker in hepatocytes exposed to COL1. The MEK1/2 inhibitors U0126 and PD98059 reversed the protective effects of COL1 and the decrease in proapoptotic proteins. Hepatocytes isolated from ERK1(-/-) mice were insensitive to the protective effect of COL1. Fibrotic livers from wild-type mice had high levels of phospho-ERK1 and were resistant to Fas-induced cell death. ERK1(-/-) mice lost this effect. CONCLUSIONS: Production of COL1 during liver fibrosis induces a hepatoprotective response that is mediated by activation of ERK1 signaling.

Canadian national retrospective chart review comparing the long term effect of cyclosporine vs. tacrolimus on clinical outcomes in patients with post-liver transplantation hepatitis C virus infection.

The transition from regular use of cyclosporine to the newer calcineurin-inhibitors, such as tacrolimus, has been suggested as a contributing factor to the "era effect" of worsening outcomes of post-transplant HCV recurrence. This retrospective medical chart review of 458 patients was undertaken to evaluate the role of immunosuppressant choice (cyclosporine vs. tacrolimus) in determining virologic response and clinical outcomes of post-liver transplant HCV infection recurrence. Our results showed that patients undergoing interferon-based treatment taking cyclosporine have significantly better odds (OR: 2.59, P = 0.043) of presenting a sustained viral response (66.7%) compared to tacrolimus (52.8%). This did not result in a significant effect on post-liver transplantation clinical events including HCV-related deaths, graft loss, fibrosing cholestatic hepatitis, hepatocellular carcinoma or graft rejection. Other variables, which showed a significant relationship with the achievement of sustained viral response included donor age (OR 0.96, P = 0.001) and HCV genotype 1 infection (OR 0.05, P < 0.001). The observed significant increase in the odds of acute/hyperacute (OR 6.49, P = 0.001) and chronic rejection (OR 10.45, P < 0.001) in the cyclosporine to tacrolimus switch group, accompanied by an increase in the odds of HCV-related death (OR 2.30, P < 0.047) compared to tacrolimus merits further study. A significant increase (P < 0.044) in new-onset diabetes mellitus with tacrolimus (28.3%) compared to cyclosporine (18.7%) was also observed. Pre-transplant diabetes mellitus was associated with a significantly increased likelihood of graft fibrosis (HR 1.95, P = 0.003).

Metabolomics-Guided Identification of a Distinctive Hepatocellular Carcinoma Signature.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major contributor to cancer-related morbidity and mortality burdens globally. Given the fundamental metabolic activity of hepatocytes within the liver, hepatocarcinogenesis is bound to be characterized by alterations in metabolite profiles as a manifestation of metabolic reprogramming. METHODS: HCC and adjacent non-tumoral liver specimens were obtained from patients after HCC resection. Global patterns in tissue metabolites were identified using non-targeted 1H Nuclear Magnetic Resonance (1H-NMR) spectroscopy whereas specific metabolites were quantified using targeted liquid chromatography-mass spectrometry (LC/MS). RESULTS: Principal component analysis (PCA) within our 1H-NMR dataset identified a principal component (PC) one of 53.3%, along which the two sample groups were distinctively clustered. Univariate analysis of tissue specimens identified more than 150 metabolites significantly altered in HCC compared to non-tumoral liver. For LC/MS, PCA identified a PC1 of 45.2%, along which samples from HCC tissues and non-tumoral tissues were clearly separated. Supervised analysis (PLS-DA) identified decreases in tissue glutathione, succinate, glycerol-3-phosphate, alanine, malate, and AMP as the most important contributors to the metabolomic signature of HCC by LC/MS. CONCLUSIONS: Together, 1H-NMR and LC/MS metabolomics have the capacity to distinguish HCC from non-tumoral liver. The characterization of such distinct profiles of metabolite abundances underscores the major metabolic alterations that result from hepatocarcinogenesis.

IL-6 Trans-Signaling Is Increased in Diabetes, Impacted by Glucolipotoxicity, and Associated With Liver Stiffness and Fibrosis in Fatty Liver Disease.

Many people living with diabetes also have nonalcoholic fatty liver disease (NAFLD). Interleukin-6 (IL-6) is involved in both diseases, interacting with both membrane-bound (classical) and circulating (trans-signaling) soluble receptors. We investigated whether secretion of IL-6 trans-signaling coreceptors are altered in NAFLD by diabetes and whether this might associate with the severity of fatty liver disease. Secretion patterns were investigated with use of human hepatocyte, stellate, and monocyte cell lines. Associations with liver pathology were investigated in two patient cohorts: 1) biopsy-confirmed steatohepatitis and 2) class 3 obesity. We found that exposure of stellate cells to high glucose and palmitate increased IL-6 and soluble gp130 (sgp130) secretion. In line with this, plasma sgp130 in both patient cohorts positively correlated with HbA1c, and subjects with diabetes had higher circulating levels of IL-6 and trans-signaling coreceptors. Plasma sgp130 strongly correlated with liver stiffness and was significantly increased in subjects with F4 fibrosis stage. Monocyte activation was associated with reduced sIL-6R secretion. These data suggest that hyperglycemia and hyperlipidemia can directly impact IL-6 trans-signaling and that this may be linked to enhanced severity of NAFLD in patients with concomitant diabetes. ARTICLE HIGHLIGHTS: IL-6 and its circulating coreceptor sgp130 are increased in people with fatty liver disease and steatohepatitis. High glucose and lipids stimulated IL-6 and sgp130 secretion from hepatic stellate cells. sgp130 levels correlated with HbA1c, and diabetes concurrent with steatohepatitis further increased circulating levels of all IL-6 trans-signaling mediators. Circulating sgp130 positively correlated with liver stiffness and hepatic fibrosis. Metabolic stress to liver associated with fatty liver disease might shift the balance of IL-6 classical versus trans-signaling, promoting liver fibrosis that is accelerated by diabetes.

Targeted impairment of innate antiviral responses in the liver of chronic hepatitis C patients.

BACKGROUND & AIMS: Innate sensing of viral infection activates a global defense response including type I interferon (IFN) and IFN-stimulated genes (ISGs) expression. We previously reported that HCV NS3/4A protease, an essential protein in viral polyprotein processing, can abrogate antiviral signaling pathways and effectors' response when ectopically expressed in human hepatocytes by cleaving antiviral adaptor CARDIF. However, whether HCV mediates evasion of innate immunity in patients with chronic infection remains unclear. METHODS: In this study, paired liver biopsies and corresponding purified hepatocytes of chronic hepatitis C patients and controls were subjected to transcriptional analysis of selected innate immune genes and to CARDIF protein detection. RESULTS: We report that an antiviral response is largely supported by infected hepatocytes as demonstrated by upregulation of the representative antiviral genes ISG15, ISG56, and OASL as well as chemokines genes CXCL9, CXCL10, and CXCL11 measured in both HCV-derived liver biopsies and hepatocytes; that the mRNA levels of these indicator ISGs correlate inversely with HCV RNA level; and more importantly that expression of the early responsive IRF3-dependent genes type I IFNß, type III IL28A/IL29, and chemokine CCL5 are severely compromised and associated to a global decrease of CARDIF adaptor in infected hepatocytes. CONCLUSIONS: Altogether the data argue for a strong viral strategy that counteracts the host's early antiviral response of hepatocytes from chronic patients without impairing ISGs induced via classical IFN pathway.

Hepatocellular apoptosis in mice is associated with early upregulation of mitochondrial glucose metabolism.

Hepatocyte death due to apoptosis is a hallmark of almost every liver disease. Manipulation of cell death regulatory steps during the apoptotic process is therefore an obvious goal of biomedical research. To clarify whether metabolic changes occur prior to the characteristic apoptotic events, we used ex vivo multinuclear NMR-spectroscopy to study metabolic pathways of [U-(13)C]glucose in mouse liver during Fas-induced apoptosis. We addressed whether these changes could be associated with protection against apoptosis afforded by Epidermal Growth Factor (EGF). Our results show that serum alanine and aspartate aminotransferase levels, caspase-3 activity, BID cleavage and changes in cellular energy stores were not observed before 3 h following anti-Fas injection. However, as early as 45 min after anti-Fas treatment, we observed upregulation of carbon entry (i.e. flux) from glucose into the Krebs-cycle via pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC) (up to 139% and 123% of controls, respectively, P < 0.001). This was associated with increased glutathione synthesis. EGF treatment significantly attenuated Fas-induced apoptosis, liver injury and the late decrease in energy stores, as well as the early fluxes through PDH and PC which were comparable to untreated controls. Using ex vivo multinuclear NMR-spectroscopic analysis, we have shown that Fas receptor activation in mouse liver time-dependently affects specific metabolic pathways of glucose. These early upregulations in glucose metabolic pathways occur prior to any visible signs of apoptosis and may have the potential to contribute to the initiation of apoptosis by maintaining mitochondrial energy production and cellular glutathione stores.