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The prevalence of TNFα-induced necrosis over apoptosis is determined by TAK1-RIP1 interplay

Seda Çöl Arslan1, Claus Scheidereit

  • 1Max Delbrück Center for Molecular Medicine, Berlin, Germany.

Plos One
|October 22, 2011
PubMed

Insights

Tumor Necrosis Factor-α (TNFα) stimulation triggers programmed necrosis in cells lacking TGFβ-activated Kinase-1 (TAK1). This RIP1-dependent cell death pathway overrides apoptosis, even with active caspases.

Area of Science:

  • Cellular biology
  • Molecular mechanisms of cell death
  • Signal transduction pathways

Background:

  • Programmed necrosis is a secondary cell death pathway.
  • It typically occurs when apoptosis is impaired.
  • Death receptor signaling pathways regulate cell fate.

Purpose of the Study:

  • To investigate the role of TGFβ-activated Kinase-1 (TAK1) in regulating cell death following TNFα stimulation.
  • To elucidate the mechanism by which TAK1 influences the balance between apoptosis and programmed necrosis.
  • To understand the regulation of Receptor Interacting Protein 1 (RIP1) in TNFα-induced cell death.

Main Methods:

  • Utilized TAK1-deficient cell models.
  • Stimulated cells with Tumor Necrosis Factor-α (TNFα).
  • Analyzed RIP1 ubiquitination, necrosome formation, and caspase activation.

Main Results:

  • TAK1 deficiency leads to RIP1-dependent programmed necrosis overriding apoptosis after TNFα stimulation.
  • Caspase activation and RIP1 cleavage do not prevent necrosis in TAK1-deficient cells.
  • TAK1 prevents RIP1 dissociation from TNF receptor I and inhibits necrosome formation independently of its kinase activity.

Conclusions:

  • TAK1 acts as a crucial negative regulator of TNFα-induced programmed necrosis.
  • The decision between apoptosis and necrosis is complex and tightly regulated.
  • Ubiquitinated RIP1 stabilization by TAK1 is critical for preventing necrosome formation.

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