Hepatitis C virus infection inhibits P-body granule formation in human livers

J Hepatol. 2015 Apr;62(4):785-90. doi: 10.1016/j.jhep.2014.11.018. Epub 2014 Nov 21.

Abstract

Background & aims: Decoding the myriad of interactions that hepatitis C virus (HCV) establishes with infected cells is mandatory to obtain a complete understanding of HCV biology and its associated pathogenesis. We and others have previously found that HCV infection disrupts the formation of P-bodies in cell culture. These are cytoplasmic RNA granules with key roles in post-transcriptional regulation of gene expression. Therefore, P-body disruption might have consequences beyond viral propagation. However, whether P-body disruption occurs also in vivo is unknown. Aim of this study was to address this important issue.

Methods: Formalin-fixed paraffin-embedded liver biopsies from four groups of patients (healthy donors, patients with non-virus related liver inflammation, HCV- and HBV-infected patients) were immunostained to detect DDX6 and Dcp1, two core P-body components. Changes in the localization of these proteins were assessed by confocal microscopy.

Results: HCV specifically inhibited P-body formation in hepatocytes from human livers regardless of viral genotype, inflammation grade or whether the infection was recent or long established. Importantly, this alteration was reversed once HCV was eliminated by therapy. Furthermore, we observed in vivo an unexpected heterogeneity in P-body composition, which might reflect functional specializations.

Conclusions: This is the first comprehensive in vivo P-body analysis that links a pathogenic condition to P-body alterations. Because of their role in gene expression, the alteration of P-bodies should be further studied to understand fully complex HCV-associated pathologies.

Keywords: HCV; Liver; P-bodies; in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cytoplasmic Granules / physiology*
  • DEAD-box RNA Helicases* / biosynthesis
  • DEAD-box RNA Helicases* / immunology
  • Endopeptidases* / biosynthesis
  • Endopeptidases* / immunology
  • Female
  • Hepacivirus* / pathogenicity
  • Hepacivirus* / physiology
  • Hepatitis C, Chronic* / immunology
  • Hepatitis C, Chronic* / metabolism
  • Hepatocytes / metabolism
  • Host-Pathogen Interactions
  • Humans
  • Male
  • Middle Aged
  • Proto-Oncogene Proteins* / biosynthesis
  • Proto-Oncogene Proteins* / immunology
  • Viral Load

Substances

  • Proto-Oncogene Proteins
  • Endopeptidases
  • dipeptidyl carboxypeptidase
  • DDX6 protein, human
  • DEAD-box RNA Helicases