Hepatitis B virus induces expression of antioxidant response element-regulated genes by activation of Nrf2

J Biol Chem. 2010 Dec 24;285(52):41074-86. doi: 10.1074/jbc.M110.145862. Epub 2010 Oct 18.

Abstract

The expression of a variety of cytoprotective genes is regulated by short cis-acting elements in their promoters, called antioxidant response elements (AREs). A central regulator of ARE-mediated gene expression is the NF-E2-related factor 2 (Nrf2). Human hepatitis B virus (HBV) induces a strong activation of Nrf2/ARE-regulated genes in vitro and in vivo. This is triggered by the HBV-regulatory proteins (HBx and LHBs) via c-Raf and MEK. The Nrf2/ARE-mediated induction of cytoprotective genes by HBV results in a better protection of HBV-positive cells against oxidative damage as compared with control cells. Furthermore, there is a significantly increased expression of the Nrf2/ARE-regulated proteasomal subunit PSMB5 in HBV-positive cells that is associated with a decreased level of the immunoproteasome subunit PSMB5i. In accordance with this finding, HBV-positive cells display a higher constitutive proteasome activity and a decreased activity of the immunoproteasome as compared with control cells even after interferon α/γ treatment. The HBV-dependent induction of Nrf2/ARE-regulated genes might ensure survival of the infected cell, shape the immune response to HBV, and thereby promote establishment of the infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism*
  • Antiviral Agents / pharmacology
  • Gene Expression Regulation*
  • Hep G2 Cells
  • Hepatitis B / genetics
  • Hepatitis B / metabolism*
  • Hepatitis B virus / genetics
  • Hepatitis B virus / metabolism*
  • Humans
  • Interferon-alpha / pharmacology
  • Interferon-gamma / pharmacology
  • Mice
  • Mice, Knockout
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidative Stress / drug effects
  • Oxidative Stress / genetics
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Response Elements*
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Viral Regulatory and Accessory Proteins

Substances

  • Antioxidants
  • Antiviral Agents
  • Interferon-alpha
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Nfe2l2 protein, mouse
  • Trans-Activators
  • Viral Regulatory and Accessory Proteins
  • hepatitis B virus X protein
  • Interferon-gamma
  • PSMB5 protein, human
  • Proteasome Endopeptidase Complex
  • Psmb5 protein, mouse