Disruption of Claudin-1 Expression by miRNA-182 Alters the Susceptibility to Viral Infectivity in HCV Cell Models.

HCV entry involves a complex interplay between viral and host molecules. During post-binding interactions, the viral E2 complexes with CD81 receptor for delivery to the tight junction proteins CLDN1 and OCLN, which aid in viral internalization. Targeting HCV entry receptors represents an appealing approach to inhibit viral infectivity. This study aimed at investigating the impact of targeting CLDN1 by microRNAs on HCV infectivity. miR-155 was previously shown to target the 3'UTR of CLDN1 mRNA. Therefore, miR-155 was used as a control in this study. In-silico analysis and luciferase reporter assay were utilized to identify potential targeting miRNAs. The impact of the identified miRNAs on CLDN1 mRNA and protein expression was examined by qRT-PCR, indirect immunofluorescence and western blotting, respectively. The role of the selected miRNAs on HCV infectivity was assessed by measuring the viral load following the ectopic expression of the selected miRNAs. miR-182 was identified in-silico and by experimental validation to target CLDN1. Both miR-155 and miR-182 inhibited CLDN1 mRNA and protein expression in infected Huh7 cells. Ectopic expression of miR-155 increased, while miR-182 reduced the viral load. In conclusion, despite repressing CLDN1, the impact of miR-155 and miR-182 on HCV infectivity is contradictory. Ectopic miR-182 expression is suggested as an upstream regulator of the entry factor CLDN1, harnessing HCV infection.

Correction to: Ectopic delivery of miR-200c diminishes hepatitis C virus infectivity through transcriptional and translational repression of Occludin.

The author would like to correct the errors in the online published article.

Ectopic delivery of miR-200c diminishes hepatitis C virus infectivity through transcriptional and translational repression of Occludin.

Occludin (OCLN) is an essential factor for HCV entry through interacting with other surface receptors. The aim of this study was to investigate the epigenetic regulation of Occludin expression and to study its impact on viral infectivity. microRNAs expression was assessed using qRT-PCR, while OCLN protein expression was investigated by indirect immunofluorescence and Western blotting. Viral infectivity was assessed by measuring viral-load using qRT-PCR. In silico analysis predicted that miR-200c targeted the OCLN 3'UTR, which was further experimentally confirmed. miR-122 was previously validated to target the 3'UTR of OCLN and was used as a control. We report a significant down-regulation of miR-200c in liver tissues of HCV-infected patients. Ectopic expression of both miR-122 and miR-200c in Huh7 cells reduced OCLN mRNA and protein levels. Viral infectivity was significantly reduced by miR-200c but enhanced by miR-122. This work sheds light on miR-200c as a novel regulator of HCV infectivity through the regulation of OCLN.

miR-148a and miR-30a limit HCV-dependent suppression of the lipid droplet protein, ADRP, in HCV infected cell models.

Hepatitis C Virus (HCV) promotes lipid droplet (LD) formation and perturbs the expression of the LD associated PAT proteins ADRP and TIP47, to promote its own lifecycle. HCV enhances TIP47 and suppresses ADRP by displacing it from LD surface in infected cell models. We have previously shown that suppression of TIP47 by miR-148a and miR-30a decreased intracellular LDs and HCV RNA. Thus, this study aimed at examining whether this microRNA-mediated suppression of HCV would limit HCV-dependent displacement of ADRP from LDs. ADRP expression was examined in 21 HCV-infected liver biopsies and 9 healthy donor liver tissues as well as in HCV-infected Huh7 cells using qRT-PCR. miR-148a and miR-30a expression was manipulated using specific oligos in JFH-1 infected, oleic acid treated cells, to study their impact on ADRP expression using qRT-PCR, and immunofluorescence microscopy. Intracellular HCV RNA was assessed using qRT-PCR. ADRP is down regulated in patients as well as HCVcc-JFH-I infected cell models. Forcing the expression of both miRNAs induced ADRP on the mRNA and protein levels. This study shows that HCV suppresses hepatic ADRP expression in infected patients and cell lines. Forcing the expression of miR-148a and miR-30a limits the suppressive effect of HCV on ADRP. J. Med. Virol. 89:653-659, 2017. © 2016 Wiley Periodicals, Inc.