Depletion of the mitochondrial electron transport abrogates the cytotoxic and gene-inductive effects of TNF

EMBO J. 1993 Aug;12(8):3095-104.


Tumor necrosis factor (TNF) has cytotoxic and gene-inductive activities on several cell types. Previous studies on L929 fibrosarcoma cells have revealed that the mitochondrial electron transport system plays a key role in inducing TNF cytotoxicity, presumably by the formation of reactive oxygen intermediates (ROI). Here we report that mitochondria-derived intermediates are not only cytotoxic but, in addition, function as signal transducers of TNF-induced gene expression. The activation of NF kappa B, which fulfills an important role in TNF-induced gene transcription, could be blocked by interference with the mitochondrial electron transport system. Furthermore, antimycin A, a mitochondrial inhibitor that increases the generation of ROI, potentiated TNF-triggered NF kappa B activation. The dual role of mitochondria-derived intermediates in cytotoxicity and immediate-early gene induction of TNF was further substantiated by isolating L929 subclones which lacked a functional respiratory chain. This depletion of the mitochondrial oxidative metabolism resulted in resistance towards TNF cytotoxicity, as well as in inhibition of NF kappa B activation and interleukin-6 gene induction by TNF. These findings suggest that mitochondria are the source of second messenger molecules and serve as common mediators of the TNF-cytotoxic and gene-regulatory signaling pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Survival / drug effects
  • Cells, Cultured
  • Electron Transport*
  • Gene Expression Regulation / drug effects
  • Interleukin-6 / genetics
  • Mice
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Molecular Sequence Data
  • NF-kappa B / biosynthesis
  • NF-kappa B / genetics
  • Oligodeoxyribonucleotides
  • Reactive Oxygen Species / metabolism
  • Signal Transduction
  • Transcriptional Activation
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / pharmacology*
  • Tumor Necrosis Factor-alpha / toxicity


  • Interleukin-6
  • NF-kappa B
  • Oligodeoxyribonucleotides
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha