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Detection and Isolation of Apoptotic Bodies to High Purity
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Detection and Isolation of Apoptotic Bodies to High Purity

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Functional dichotomy of A20 in apoptotic and necrotic cell death

Peter Storz1, Heike Döppler, Christiane Ferran

  • 1Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA. pstorz@bidmc.harvard.edu

The Biochemical Journal
|November 6, 2004
PubMed

Insights

Reactive oxygen species (ROS) are implicated in disease. This study reveals that the protein A20, contrary to expectations, promotes cell death during oxidative stress by inhibiting survival signals.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Pathophysiology

Background:

  • Reactive oxygen species (ROS) are crucial in human pathologies, influencing cell death and gene transcription.
  • Nuclear factor kappaB (NF-kappaB) is a key transcription factor in oxidative stress responses.
  • A20, a zinc-finger protein regulated by NF-kappaB, typically promotes cell survival in tumor necrosis factor-alpha signaling.

Purpose of the Study:

  • To investigate the role of A20 in oxidative stress-induced cell death.
  • To elucidate the mechanism by which A20 influences NF-kappaB signaling under oxidative stress.
  • To determine if A20 promotes apoptosis or necrosis in response to ROS.

Main Methods:

  • RNA interference (RNAi) to silence A20 expression.
  • Exposure of cells to reactive oxygen species (ROS).
  • Analysis of NF-kappaB activation, IkappaB alpha degradation, and cell death pathways (apoptosis vs. necrosis).

Main Results:

  • Oxidative stress up-regulates A20, which enhances cell death by necrosis, not apoptosis.
  • A20 functions in a negative-feedback loop, blocking NF-kappaB activation and survival signaling.
  • Silencing A20 increases NF-kappaB induction and cell survival under high oxidative stress.
  • A20 inhibits the degradation of inhibitory protein kappaB alpha (IkappaB alpha).

Conclusions:

  • A20 plays a novel role in oxidative stress by terminating NF-kappaB-dependent survival signals.
  • A20 sensitizes cells to death by necrosis, rather than promoting apoptosis.
  • The level of A20 expression influences cellular protection against oxidative stress-induced death.

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