Related Experiment Video

Updated: Jun 30, 2025

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis
08:55

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis

Published on: August 7, 2018

10.9K

RIPK3 cleavage is dispensable for necroptosis inhibition but restricts NLRP3 inflammasome activation

Hong Tri Tran1,2, Tobias Kratina1, Auriane Coutansais1

  • 1Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.

Cell Death and Differentiation
|March 22, 2024
PubMed

Insights

Caspase-8 cleavage of RIPK3 is not essential for blocking necroptosis during mouse development. Instead, RIPK3 cleavage by caspase-8 restricts pyroptosis and IL-1β secretion, particularly when apoptosis inhibitors are limited.

Area of Science:

  • Cellular and Molecular Biology
  • Immunology
  • Developmental Biology

Background:

  • Caspase-8 is known to inhibit necroptosis by cleaving key proteins like RIPK1, CYLD, and RIPK3.
  • Previous studies indicated RIPK1 cleavage is essential for development, while CYLD cleavage is not, raising questions about RIPK3's role.

Purpose of the Study:

  • To investigate the physiological significance of RIPK3 cleavage by caspase-8 in vivo.
  • To determine if RIPK3 cleavage is critical for preventing necroptosis during mouse embryogenesis.

Main Methods:

  • Generation and analysis of Ripk3D333A/D333A mice with a mutated caspase-8 cleavage site.
  • Assessment of necroptotic sensitivity in Ripk3D333A/D333A cells and mice.
  • Evaluation of pyroptosis and IL-1β secretion under conditions of limited Inhibitors of Apoptosis (IAP).

Main Results:

  • Ripk3D333A/D333A mice are viable, indicating RIPK3 cleavage is not essential for blocking necroptosis during development.
  • Ripk3D333A/D333A cells showed no significant increase in necroptosis sensitivity.
  • RIPK3 cleavage by caspase-8 was found to restrict NLRP3 inflammasome-dependent pyroptosis and IL-1β secretion.

Conclusions:

  • Caspase-8 does not inhibit necroptosis through direct RIPK3 cleavage.
  • RIPK3 cleavage by caspase-8 plays a role in regulating NLRP3 inflammasome activation and pyroptosis.
  • This study highlights a novel function of RIPK3 in controlling inflammatory cell death pathways.

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