scholarly journals Editorial. The Role of Autophagy in Hepatitis C Virus Infection

2012 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Jun Cheng ◽  
Min Quan ◽  
Liang Wu ◽  
Qi Wang

Abstract Hepatitis C virus (HCV) infects ≈2% of the world’s population. HCV infection not only causes acute and chronic hepatitis, but also leads to liver cirrhosis and hepatocellular carcinoma (HCC). The molecular pathogenesis of HCV infection has been explored and many evidence indicated that autophagy is an important process for its life cycle, although autophagy was thought as a mechanism to eliminate invaded HCV from hepatocyte. Structural and non-structural proteins of HCV are important regulators of autophagy, and HCV uses autophagy as a necessary step in its replication. Down-regulation of innate immune response by HCV through unfolded protein response (UPR) and autophagy induction was used as a pathway to establish chronic HCV infection in the liver. Meanwhile, the infected hepatocyte is also using autophagy mechanism to eradicate HCV virus from liver. The study on relationship between HCV and autophagy will pave the new way to understand HCV life cycle and to find new strategy for prevention and treatment of liver diseases caused by HCV infection.

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Helene Minyi Liu ◽  
Michael Gale

Exposure to hepatitis C virus (HCV) usually results in persistent infection that often develops into chronic liver disease. Interferon-alpha (IFN) treatment comprises the foundation of current approved therapy for chronic HCV infection but is limited in overall efficacy. IFN is a major effector of innate antiviral immunity and is naturally produced in response to viral infection when viral pathogen-associated molecular patterns (PAMPs) are recognized as nonself and are bound by cellular pathogen recognition receptors (PRRs), including Toll-like receptors (TLRs) and the RIG-I-like receptors (RLRs). Within hepatocytes, RIG-I is a major PRR of HCV infection wherein PAMP interactions serve to trigger intracellular signaling cascades in the infected hepatocyte to drive IFN production and the expression of interferon-stimulated genes (ISGs). ISGs function to limit virus replication, modulate the immune system, and to suppress virus spread. However, studies of HCV-host interactions have revealed several mechanisms of innate immune regulation and evasion that feature virus control of PRR signaling and regulation of hepatic innate immune programs that may provide a molecular basis for viral persistence.


2011 ◽  
Vol 152 (22) ◽  
pp. 876-881
Author(s):  
Alajos Pár

The review discusses the genetic polymorphisms involved in the pathogenesis of hepatitis C virus (HCV) infection, that may determine the outcome of disease. In this field earlier both certain major histocompatibility complex (MHC) alleles and some cytokine gene variants have also been studied. Recently, the genome-wide association study (GWAS) and targeted single nucleotide polymorphism (SNP) analysis have revealed that a variant in the promoter region of interleukin-28B (IL-28B) gene is strongly linked to viral clearance and it may be the strongest pretreatment predictor of treatment response in chronic hepatitis C. Last year it was shown that two genetic variants leading to inosine triphosphatase deficiency protect against haemolytic anemia in patients receiving ribavirin during antiviral treatment for chronic HCV infection. Orv. Hetil., 2011, 152, 876–881.


2003 ◽  
Vol 77 (19) ◽  
pp. 10237-10249 ◽  
Author(s):  
Kohji Moriishi ◽  
Tamaki Okabayashi ◽  
Kousuke Nakai ◽  
Kyoji Moriya ◽  
Kazuhiko Koike ◽  
...  

ABSTRACT Hepatitis C virus (HCV) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. In this study, we have identified proteasome activator PA28γ (11S regulator γ) as an HCV core binding protein by using yeast two-hybrid system. This interaction was demonstrated not only in cell culture but also in the livers of HCV core transgenic mice. These findings are extended to human HCV infection by the observation of this interaction in liver specimens from a patient with chronic HCV infection. Neither the interaction of HCV core protein with other PA28 subtypes nor that of PA28γ with other Flavivirus core proteins was detected. Deletion of the PA28γ-binding region from the HCV core protein or knockout of the PA28γ gene led to the export of the HCV core protein from the nucleus to the cytoplasm. Overexpression of PA28γ enhanced the proteolysis of the HCV core protein. Thus, the nuclear retention and stability of the HCV core protein is regulated via a PA28γ-dependent pathway through which HCV pathogenesis may be exerted.


2017 ◽  
Vol 40 (10) ◽  
pp. 531-541 ◽  
Author(s):  
Fabrizio Fabrizi ◽  
Francesca M. Donato ◽  
Piergiorgio Messa

The frequency of hepatitis C virus (HCV) infection remains high in patients with chronic kidney disease (CKD) and plays a detrimental role in mortality in this population. According to the latest survey, the adjusted hazard ratio for HCV-positive versus HCV-negative patients on long-term dialysis was 1.12 (95% CI, 1.05 to 1.20) and 1.10 (95% CI, 0.98 to 1.22) for all-cause and cardiovascular mortality, respectively. An impairment on quality of life has also been documented in HCV-infected patients undergoing regular dialysis. Most clinicians have been so far reluctant to treat hepatitis C in patients with advanced CKD, due to concerns regarding low efficacy and safety of interferon-based regimens. The advent of all-oral, direct-acting antivirals (DAAs) has revolutionized treatment paradigms for HCV, including patients with other comorbidities such as CKD. Two combinations of DAAs have been recently approved for the treatment of HCV in advanced CKD: elbasvir/grazoprevir (evaluated in 1 randomized controlled trial) and ombitasvir/paritaprevir/ritonavir/dasabuvir with or without ribavirin (examined in some observational, single-arm studies). These antiviral combinations have provided high safety and efficacy (SVR12 rates >90%) in HCV-infected patients with stage 4–5 CKD. Sofosbuvir, a nucleotide analogue inhibitor of the HCV NS5B polymerase, is the cornerstone of most anti-HCV current regimens but is not currently recommended for patients with severe renal insufficiency (eGFR <30 mL/min per 1.73 m2). However, several small-sized studies have been published on the safety and efficacy of sofosbuvir-based regimens for patients with hepatitis C on maintenance dialysis>; overall, the viral response was satisfactory (SVR12 rates ranging between 58% and 100%) with a few drug-related drop-outs. Studies are in progress to assess whether ribavirin-free antiviral combinations with novel DAAs are a viable option for patients with severe renal impairment and chronic HCV infection.


1994 ◽  
Vol 39 (9) ◽  
pp. 2022-2031 ◽  
Author(s):  
Shinjiro Sato ◽  
Shigetoshi Fujiyama ◽  
Motohiko Tanaka ◽  
Masafumi Goto ◽  
Yuko Taura ◽  
...  

2009 ◽  
Vol 83 (20) ◽  
pp. 10427-10436 ◽  
Author(s):  
Shuhei Taguwa ◽  
Hiroto Kambara ◽  
Hiroko Omori ◽  
Hideki Tani ◽  
Takayuki Abe ◽  
...  

ABSTRACT Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a component of the replication complex consisting of several host and viral proteins. We have previously reported that human butyrate-induced transcript 1 (hB-ind1) recruits heat shock protein 90 (Hsp90) and FK506-binding protein 8 (FKBP8) to the replication complex through interaction with NS5A. To gain more insights into the biological functions of hB-ind1 in HCV replication, we assessed the potential cochaperone-like activity of hB-ind1, because it has significant homology with cochaperone p23, which regulates Hsp90 chaperone activity. The chimeric p23 in which the cochaperone domain was replaced with the p23-like domain of hB-ind1 exhibited cochaperone activity comparable to that of the authentic p23, inhibiting the glucocorticoid receptor signaling in an Hsp90-dependent manner. Conversely, the chimeric hB-ind1 in which the p23-like domain was replaced with the cochaperone domain of p23 resulted in the same level of recovery of HCV propagation as seen in the authentic hB-ind1 in cells with knockdown of the endogenous hB-ind1. Immunofluorescence analyses revealed that hB-ind1 was colocalized with NS5A, FKBP8, and double-stranded RNA in the HCV replicon cells. HCV replicon cells exhibited a more potent unfolded-protein response (UPR) than the parental and the cured cells upon treatment with an inhibitor for Hsp90. These results suggest that an Hsp90-dependent chaperone pathway incorporating hB-ind1 is involved in protein folding in the membranous web for the circumvention of the UPR and that it facilitates HCV replication.


2015 ◽  
Vol 9 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Tatsuo Kanda ◽  
Masato Nakamura ◽  
Reina Sasaki ◽  
Shin Yasui ◽  
Shingo Nakamoto ◽  
...  

Direct-acting antivirals with or without peginterferon α (PEG-IFN α) plus ribavirin are now available for the treatment of hepatitis C virus (HCV) infection. Direct-acting antivirals are potent inhibitors of HCV replication, but some of them occasionally possess serious adverse events. We experienced a 64-year-old female with chronic HCV genotype 1b infection who showed elevated alanine aminotransferase of 528 IU/l at week 9 after the commencement of treatment of simeprevir with PEG-IFN α-2a plus ribavirin. However, she achieved sustained virological response at week 24 after the end of treatment. In Japan, we also have to treat elderly patients infected with HCV and/or advanced hepatic fibrosis. Until an effective interferon-free regimen is established, direct-acting antivirals with PEG-IFN plus ribavirin may still play a role in the treatment for certain patients. To avoid serious results from adverse events, careful attention and follow-up will be needed in the treatment course of simeprevir with PEG-IFN plus ribavirin for chronic HCV infection.


2001 ◽  
Vol 45 (2) ◽  
pp. 517-524 ◽  
Author(s):  
Jeffrey M. Jacobson ◽  
Lawrence Feinman ◽  
Leonard Liebes ◽  
Nancy Ostrow ◽  
Victoria Koslowski ◽  
...  

ABSTRACT Hypericin is a natural derivative of the common St. Johns wort plant, Hypericum perforatum. It has in vitro activity against several viruses, including bovine diarrhea virus, a pestivirus with structural similarities to hepatitis C virus (HCV). We conducted a phase I dose escalation study to determine the safety and antiviral activity of hypericin in patients with chronic HCV infection. The first 12 patients received an 8-week course of 0.05 mg of hypericin per kg of body weight orally once a day; 7 patients received an 8-week course of 0.10 mg/kg orally once a day. At the end of the 8-week period of treatment, no subject had a change of plasma HCV RNA level of more than 1.0 log10. Five of 12 subjects receiving the 0.05-mg/kg/day dosing schedule and 6 of 7 subjects receiving the 0.10-mg/kg/day dosing schedule developed phototoxic reactions. No other serious adverse events associated with hypericin use occurred. The pharmacokinetic data revealed a long elimination half-life (mean values of 36.1 and 33.8 h, respectively, for the doses of 0.05 and 0.1 mg/kg) and mean area under the curve determinations of 1.5 and 3.1 μg/ml × hr, respectively. In sum, hypericin given orally in doses of 0.05 and 0.10 mg/kg/d caused considerable phototoxicity and had no detectable anti-HCV activity in patients with chronic HCV infection.


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