Signaling pathways from membrane lipid rafts to JNK1 activation in reactive nitrogen species-induced non-apoptotic cell death

Cell Death Differ. 2008 Feb;15(2):386-97. doi: 10.1038/sj.cdd.4402273. Epub 2007 Nov 16.

Abstract

At present, the signaling pathways controlling reactive nitrogen species (RNS)-induced non-apoptotic cell death are relatively less understood. In this work, various RNS donors are found to induce caspase-independent non-apoptotic cell death in mouse embryonic fibroblasts (MEF). In search of the molecular mechanisms, we first established the role of c-Jun N-terminal kinase (JNK) in RNS-induced non-apoptotic cell death. RNS readily activate JNK, and the jnk1-/- MEF are resistant to RNS-induced cell death. Moreover, the reconstitution of JNK1 effectively restores the sensitivity to RNS. Next, we identified tumor necrosis factor receptor-associated factor 2 (TRAF2) and apoptosis signal-regulating kinase 1 (ASK1) as the essential upstream molecules for RNS-induced JNK activation and cell death. RNS fail to activate JNK and induce cell death in traf2-/- MEF; and reconstitution of TRAF2 effectively restores the responsiveness of traf2-/- MEF to RNS. Moreover, RNS-induced ASK1 activation is impaired in traf2-/- cells and overexpression of a mutant ASK1 protein suppresses RNS-induced cell death in wild-type MEF cells. Last, we explored the signaling events upstream of TRAF2 and found that translocation of TRAF2 and JNK1 onto membrane lipid rafts is required for RNS-mediated JNK1 activation and cell death. Taken together, data from our study reveal a novel signaling pathway regulating RNS-induced JNK1 activation and non-apoptotic cell death.

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • Cell Death*
  • Cell Line
  • Dactinomycin / pharmacology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • MAP Kinase Kinase 4 / metabolism*
  • MAP Kinase Kinase Kinase 5 / metabolism*
  • Membrane Microdomains / drug effects
  • Membrane Microdomains / metabolism*
  • Mice
  • Mice, Mutant Strains
  • Protein Synthesis Inhibitors / pharmacology
  • Reactive Nitrogen Species / metabolism*
  • Signal Transduction*
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Protein Synthesis Inhibitors
  • Reactive Nitrogen Species
  • T2bp protein, mouse
  • Tumor Necrosis Factor-alpha
  • Dactinomycin
  • MAP Kinase Kinase Kinase 5
  • Map3k5 protein, mouse
  • MAP Kinase Kinase 4