Establishment of chronic hepatitis C virus infection: Translational evasion of oxidative defence

Real-world treatment outcome of direct-acting antivirals and patient survival rates in chronic hepatitis C virus infection in Eritrea

Reliable real-world data on direct acting anti-retroviral (DAA) uptake and treatment outcomes are lacking for patients with hepatitis C virus (HCV) in sub-Saharan Africa. This study provides data on HCV DAA-based treatment outcomes, mortality, loss-to-follow up, and associated factors among patients in Eritrea. A multicenter retrospective observational cohort study was conducted in two tertiary hospitals in Asmara, Eritrea. A structured checklist was used to collect data from patient's cards. Descriptive and inferential statistics used included means (± Standard deviation (SD), medians (Interquartile range (IQR), chi-squire (χ2), Kaplan-Meier estimates, and multivariate Cox proportional hazard models. A total of 238 patients with median age of 59 years (IQR 50-69 years) were enrolled in the study. Out of the 227 patients initiated on treatment, 125 patients had viral load measurements at 12 weeks after end of treatment (EOT) whereas 102 patients had no viral load measurements at 12 weeks EOT. Among the patients with HCV RNA data post-EOT 12, 116 (92.8%) had sustained viral response (SVR). The prevalence of death and loss-to-follow up (LTFU) were (7.5%, 95% CI 1.7-4.1) and 67 (28.1%, 95% CI 22.3-33.9) translating into an incidence of 1.1 (95% CI 0.8-1.5) per 10,000 person days. Independent predictors of LTFU included the enrollment year (2020: aHR = 2.2, 95% CI 1-4.7; p value = 0.04); Hospital (Hospital B: aHR = 2.2, 95% CI 1-4.7; p value = 0.03) and the FIB-4 score (FIB-Score < 1.45: aHR = 3.7, 95% CI 1.2-11.5; p value = 0.02). The SVR rates achieved in this cohort were high. However, high LTFU and high mortality driven largely by late presentation and suboptimal population screening/case finding, were uncovered. These challenges can be addressed by test-and-treat programs that simultaneously prioritize programmatic screening, decentralization of care, and better patient tracking in the HCV care cascade.

Hepatitis C Virus Proteins Core and NS5A Are Highly Sensitive to Oxidative Stress-Induced Degradation after eIF2α/ATF4 Pathway Activation

Hepatitis C virus (HCV) infection is accompanied by increased oxidative stress and endoplasmic reticulum stress as a consequence of viral replication, production of viral proteins, and pro-inflammatory signals. To overcome the cellular stress, hepatocytes have developed several adaptive mechanisms like anti-oxidant response, activation of Unfolded Protein Response and autophagy to achieve cell survival. These adaptive mechanisms could both improve or inhibit viral replication, however, little is known in this regard. In this study, we investigate the mechanisms by which hepatocyte-like (Huh7) cells adapt to cellular stress in the context of HCV protein overexpression and oxidative stress. Huh7 cells stably expressing individual HCV (Core, NS3/4A and NS5A) proteins were treated with the superoxide anion donor menadione to induce oxidative stress. Production of reactive oxygen species and activation of caspase 3 were quantified. The activation of the eIF2α/ATF4 pathway and changes in the steady state levels of the autophagy-related proteins LC3 and p62 were determined either by quantitative polymerase chain reaction (qPCR) or Western blotting. Huh7 cells expressing Core or NS5A demonstrated reduced oxidative stress and apoptosis. In addition, phosphorylation of eIF2α and increased ATF4 and CHOP expression was observed with subsequent HCV Core and NS5A protein degradation. In line with these results, in liver biopsies from patients with hepatitis C, the expression of ATF4 and CHOP was confirmed. HCV Core and NS5A protein degradation was reversed by antioxidant treatment or silencing of the autophagy adaptor protein p62. We demonstrated that hepatocyte-like cells expressing HCV proteins and additionally exposed to oxidative stress adapt to cellular stress through eIF2a/ATF4 activation and selective degradation of HCV pro-oxidant proteins Core and NS5A. This selective degradation is dependent on p62 and results in increased resistance to apoptotic cell death induced by oxidative stress. This mechanism may provide a new key for the study of HCV pathology and lead to novel clinically applicable therapeutic interventions.

Orange juice as dietary source of antioxidants for patients with hepatitis C under antiviral therapy

Background: HCV causes alterations in liver metabolism, resulting in biochemical and nutritional disorders. Supplementation with antioxidants has been suggested to minimize the diseases effects.

Objective: This study assessed whether orange juice, a source of citrus flavonoids and vitamin C, may contribute to the treatment of patients with chronic hepatitis C.

Design: Anthropometric, hemodynamic, dietary, and biochemical parameters, CRP and liver enzymes were measured in 43 adult patients of both genders who were diagnosed with chronic hepatitis C and were under antiviral therapy. Twenty-three patients were supplemented with orange juice for eight consecutive weeks, while 20 were enrolled as control group.

Results: Following regular use of orange juice, no alterations were found in body mass, fat, and waist circumference. The serum levels of total cholesterol, LDL-cholesterol, CRP and parameters of oxidative stress decreased in the orange juice group. Furthermore, the levels of the liver enzyme AST decreased in those who had high levels before the intervention.

Conclusion: The orange juice was a convenient food in the diet of patients due to the increase in antioxidant capacity and decreased inflammation and cholesterol in blood serum, in addition to maintaining body mass, which protect against the harmful effects caused by the chronic hepatitis C virus.​​​

Hydrogen peroxide induces La cytoplasmic shuttling and increases hepatitis C virus internal ribosome entry site-dependent translation

We have previously shown that physio/pathological levels of hydrogen peroxide (H₂O₂) stimulate translation from the hepatitis C virus (HCV) internal ribosome entry site (IRES) element in tissue-cultured cells. Here, using in vitro translation, we further show that H₂O₂ upregulates HCV IRES-dependent mRNA translation and correlates with an increase in intracellular oxidant level. Using Western blotting, immunocytochemistry, microscopy and affinity pulldown, we show that H₂O₂ stimulates HCV IRES-dependent translation and correlates with nuclear–cytoplasmic shuttling of the La autoantigen, resulting in enhanced binding of cytoplasmic La to HCV IRES RNA. The role of the La protein in H₂O₂-stimulated IRES-dependent translation is further confirmed by the ability of an anti-La antibody to suppress H₂O₂-activated IRES-dependent translation in vitro. This is further supported by the ability of an ectopically expressed dominant, negative La mutant protein to suppress H₂O₂-inducible IRES-mediated translation in Huh7 cells, transiently transfected with a bicistronic reporter and in a sub-genomic replicon cell line resembling a persistent infection. On the other hand, translation from the encephalomyocarditis virus IRES is diminished in the presence of H₂O₂, suggesting that H₂O₂ translational responsiveness is a specific property of the HCV IRES and is not a general phenomenon for all viral IRESs. Altogether, these results suggest that HCV adapts to physio/pathological oxidative stress in the host cell by mediating La cytoplasmic shuttling to enhance its IRES-dependent translation.

HCV-Induced Oxidative Stress: Battlefield-Winning Strategy

About 150 million people worldwide are chronically infected with hepatitis C virus (HCV). The persistence of the infection is controlled by several mechanisms including the induction of oxidative stress. HCV relies on this strategy to redirect lipid metabolism machinery and escape immune response. The 3β-hydroxysterol Δ24-reductase (DHCR24) is one of the newly discovered host markers of oxidative stress. This protein, as HCV-induced oxidative stress responsive protein, may play a critical role in the pathogenesis of HCV chronic infection and associated liver diseases, when aberrantly expressed. The sustained expression of DHCR24 in response to HCV-induced oxidative stress results in suppression of nuclear p53 activity by blocking its acetylation and increasing its interaction with MDM2 in the cytoplasm leading to its degradation, which may induce hepatocarcinogenesis.

Iron homeostasis and its regulators over the course of chronic hepatitis C

ABSTRACT: 

Chronic infection with HCV has been diagnosed in approximately 170 million people worldwide. It is an important cause of chronic, progressive liver fibrosis. Late consequences of chronic HCV infection, including liver cirrhosis and hepatocellular carcinoma, have become the major indications for liver transplantation in developed countries. Particular attention is being paid to iron accumulation in chronic hepatitis C and its relation to the current antiviral therapy's efficacy and safety, risk of exacerbation of oxidative stress, development of metabolic disorders and hepatocarcinogenesis. HCV infection disrupts the synthesis of hepcidin, which regulates extracellular iron content. This article discusses the impact of iron on HCV multiplication and the involvement of impaired iron homeostasis in chronic hepatitis C in terms of the pathogenesis of insulin resistance, fatty liver and hepatocarcinogenesis.