However, GW182, a critical component of processing bodies (GW bodies) that is recruited by Ago2 to target messenger RNA (mRNA), has not been assessed in HCV

infection. To characterize the role of GW182 in the pathogenesis of HCV infection, we determined its transcription and protein expression in an HCV J6/JFH1 RG7204 in vivo culture system. Transcript and protein levels of GW182 as well as HCV RNA and protein expression increased with alcohol exposure. Specific silencing of mRNA expression by small interfering RNA against GW182 significantly decreased HCV RNA and protein expression. Overexpression of GW182 significantly increased HCV RNA and protein expression in HCV J6/JFH1 infected Huh7.5 cells. Furthermore, GW182 colocalized and coimmunoprecipitated with heat shock protein 90 (HSP90), which increased upon alcohol exposure with and without HCV infection

and enhanced HCV gene expression. The use of an HSP90 inhibitor or knockdown of HSP90 decreased GW182 and miR-122 expression and significantly reduced HCV replication. Conclusion: Overall, our results suggest that GW182 protein that is linked to miR-122 biogenesis and HSP90, which has been shown to stabilize the RISC, are novel host proteins selleck chemicals that regulate HCV infection during alcohol abuse. (HEPATOLOGY 2013) Hepatitis C virus (HCV) is estimated to infect at least 2%-3% of the world’s population. Despite clinical observation

and medical advice regarding the devastating consequence of alcohol use during HCV infection, some patients consume alcohol with the increased risk of rapid disease progression to liver cirrhosis, fibrosis, and even hepatocellular carcinoma.1-6 The molecular mechanisms of how alcohol exacerbates HCV infection and worsens HCV disease outcome remain to be elucidated. HCV, a positive-sense RNA virus of the Flaviviridae family, can hijack host cofactors to facilitate its replication. Of those, microRNA-122 (miR-122), an miRNA representing 70% of all miRNAs in hepatocytes,7, 8 was recently identified to play a critical role in the HCV life cycle9-11 and has been a promising target for antiviral drug development.12 Several groups, including ours, have demonstrated that ethanol can modulate microRNA expression in selleck chemicals llc the liver.13-16 Traditionally, miRNAs function by binding to the 3′ untranslated region (UTR) of target genes suppressing gene transcription and translation. However, miR-122 binds to the 5′ UTR of the viral genome promoting HCV replication.9, 17, 18 It is unknown whether miR-122 regulation of HCV RNA translation or RNA accumulation requires direct association with protein complexes similar to the miRNA-induced silencing complex, or if the activity of miR-122 involves HCV RNA translocation to messenger RNA (mRNA)-processing bodies (P-bodies).