Force-induced apoptosis mediated by the Rac/Pak/p38 signalling pathway is regulated by filamin A

Biochem J. 2012 Jul 1;445(1):57-67. doi: 10.1042/BJ20112119.

Abstract

Cells in mechanically challenged environments cope with high-amplitude exogenous forces that can lead to cell death, but the mechanisms that mediate force-induced apoptosis and the identity of mechanoprotective cellular factors are not defined. We assessed apoptosis in NIH 3T3 and HEK (human embryonic kidney)-293 cells exposed to tensile forces applied through β1-integrins. Apoptosis was mediated by Rac-dependent activation of p38α. Depletion of Pak1 (p21-activated kinase 1), a downstream effector of Rac, prevented force-induced p38 activation and apoptosis. Rac was recruited to sites of force transfer by filamin A, which inhibited force-induced apoptosis mediated by Rac and p38α. We conclude that, in response to tensile force, filamin A regulates Rac-dependent signals, which induce apoptosis through Pak1 and p38.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Caspase 3 / metabolism
  • Cells, Cultured
  • Contractile Proteins / metabolism*
  • Filamins
  • Humans
  • Immunoblotting
  • Kidney / cytology
  • Kidney / metabolism
  • Mechanotransduction, Cellular*
  • Mice
  • Microfilament Proteins / metabolism*
  • NIH 3T3 Cells
  • RNA, Small Interfering / genetics
  • Signal Transduction*
  • p21-Activated Kinases / antagonists & inhibitors
  • p21-Activated Kinases / genetics
  • p21-Activated Kinases / metabolism*
  • p38 Mitogen-Activated Protein Kinases / metabolism*
  • rac1 GTP-Binding Protein / metabolism*

Substances

  • Contractile Proteins
  • Filamins
  • Microfilament Proteins
  • RNA, Small Interfering
  • p21-Activated Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Caspase 3
  • rac1 GTP-Binding Protein