Antiapoptotic regulation by hepatitis C virus core protein through up-regulation of inhibitor of caspase-activated DNase

Virology. 2003 Dec 5;317(1):24-35. doi: 10.1016/j.virol.2003.08.028.

Abstract

The hepatitis C virus (HCV) core protein is considered to influence multiple cellular processes. We developed a human hepatoblastoma HepG2-derived inducible cell line, Hep191, which allows tightly regulated expression of the core protein at relatively low but physiological levels under control of the ecdysone-regulated promoter. By transcriptional profiling, we identified differentially expressed genes, some of which are involved in cell growth or apoptosis such as inhibitor of caspase-activated DNase (ICAD), defender against cell death 1, tumor necrosis factor (TNF) receptor 1, and cytochrome c oxidase subunit VIII. Furthermore, we found that core protein expression increases a steady-state level of ICAD protein, possibly through enhancing its promoter activity, and inhibits caspase-3 activity induced by anti-Fas antibody. Since Fas- or TNF-mediated DNA fragmentation is suppressed in the core-induced Hep191 cells, these findings suggest that expression of HCV core at physiological levels confers blocking activity of caspase-activated DNase and consequently inhibiting apoptotic cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis Regulatory Proteins
  • Apoptosis*
  • Caspase 3
  • Caspase Inhibitors
  • Caspases / metabolism
  • DNA Fragmentation
  • Deoxyribonucleases / antagonists & inhibitors
  • Deoxyribonucleases / metabolism
  • Gene Expression Profiling
  • Hepacivirus / metabolism*
  • Hepacivirus / pathogenicity
  • Humans
  • Oligonucleotide Array Sequence Analysis
  • Proteins / genetics
  • Proteins / metabolism*
  • Tumor Cells, Cultured
  • Up-Regulation*
  • Viral Core Proteins / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • Caspase Inhibitors
  • Proteins
  • Viral Core Proteins
  • caspase-activated DNase inhibitor
  • nucleocapsid protein, Hepatitis C virus
  • Deoxyribonucleases
  • CASP3 protein, human
  • Caspase 3
  • Caspases