Oxidant-induced cell death and Nrf2-dependent antioxidative response are controlled by Fra-1/AP-1

Mol Cell Biol. 2012 May;32(9):1694-709. doi: 10.1128/MCB.06390-11. Epub 2012 Mar 5.

Abstract

AP-1 (Jun/Fos) transcription factors play key roles in various biological processes, including cell death. Here we report a novel role for Fra-1 in oxidant-induced cell death controlled by modulating antioxidant gene expression. Fra-1-deficient (Fra-1(Δ/Δ)) mouse embryonic fibroblasts (MEFs) and primary lung fibroblasts (PLFs) were remarkably resistant to H(2)O(2)- and diquat-induced cell death, compared to their wild-type (Fra-1(+/+)) counterparts. Fra-1 deficiency ablated oxidant-induced mitochondrion-dependent apoptosis. Fra-1(Δ/Δ) cells had elevated basal levels of antioxidant enzymes and intracellular glutathione (GSH), which were further stimulated by oxidants. Loss of Fra-1 led to an increased half-life of transcription factor Nrf2 and increased recruitment of this protein to the promoters of antioxidant genes and increased their expression. Depletion of intracellular GSH or RNA interference (RNAi)-mediated knockdown of Nqo1, Hmox1, and Nrf2 restored oxidant-induced cell death in Fra-1(Δ/Δ) cells. Thus, Fra-1 appears to increase susceptibility to oxidants and promotes cell death by attenuating Nrf2-driven antioxidant responses.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Death / drug effects
  • Cells, Cultured
  • Fibroblasts / metabolism
  • Lung / metabolism
  • Mice
  • Mice, Knockout
  • Mitochondrial Membranes / metabolism
  • NF-E2-Related Factor 2 / metabolism*
  • Oxidants / pharmacology*
  • Protein Binding
  • Proto-Oncogene Proteins c-fos / deficiency
  • Proto-Oncogene Proteins c-fos / metabolism*
  • Transcription Factor AP-1 / metabolism*

Substances

  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Oxidants
  • Proto-Oncogene Proteins c-fos
  • Transcription Factor AP-1
  • fos-related antigen 1