Potentiation of tumor necrosis factor-α-induced cell death by rottlerin through a cytochrome-c-independent pathway

Alakananda Basu, Daniel E. Johnson, Matthew D. Woolard

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

The protein kinase C (PKC) signal transduction pathway negatively regulates receptor-initiated cell death. In HeLa cells, tumor necrosis factor-α (TNF)-mediated cell death involved mitochondria and was blocked by the overexpression of Bcl-2. The PKC-specific inhibitor bisindolylmaleimide and the PKCδ inhibitor rottlerin enhanced TNF-induced cell death. We have investigated if potentiation of TNF-induced cell death by rottlerin involved amplification of the mitochondrial pathway. TNF induced cleavage of the proapoptotic protein Bid and release of mitochondrial cytochrome c. Rottlerin enhanced activation of caspase-8 and cleavage of Bid. It also enhanced activation of caspase-9 but it did not increase cytochrome c in the cytosol. It, however, increased release of mitochondrial apoptosis-inducing factor (AIF) to the cytosol. Overexpression of Bcl-2 prevented release of both cytochrome c and AIF to the cytosol. Prolonged exposure (≥6 h) of HeLa cells to rottlerin and TNF decreased the level of cytochrome c but not of AIF in the cytosol. These results suggest that rottlerin activates a cytochrome-c-independent cell death pathway to potentiate cell death by TNF.

Original languageEnglish
Pages (from-to)209-214
Number of pages6
JournalExperimental Cell Research
Volume278
Issue number2
DOIs
StatePublished - 1 Jan 2002

Keywords

  • Bid
  • Caspases
  • Cytochrome c
  • Mitochondria
  • PKC
  • TNF

Fingerprint Dive into the research topics of 'Potentiation of tumor necrosis factor-α-induced cell death by rottlerin through a cytochrome-c-independent pathway'. Together they form a unique fingerprint.

  • Cite this