Lipid rafts mediate H2O2 prosurvival effects in cultured endothelial cells

FASEB J. 2006 Jul;20(9):1501-3. doi: 10.1096/fj.05-5359fje. Epub 2006 Jun 5.


Reactive oxygen species (ROS) generated during pathological events, such as inflammation and ischemia-reperfusion, activates both proapoptotic and antiapoptotic signaling programs in endothelial cells. Because cholesterol-rich, plasma membrane rafts serve as platforms for organizing and integrating signaling transduction processes, we asked whether these membrane regions play a mechanistic role in H2O2-induced responses. Bovine aortic endothelial cell cultures exposed to a 500-microM bolus of H2O2 showed progressive activation of caspase 3 and an increase in the number of TUNEL-positive cells. Pretreatment with either wortmannin or PD 098059 heightened these apoptotic responses, demonstrating that both PI3 kinase/Akt and ERK1/2 serve as signaling mediators to alleviate H2O2 cytotoxic effects. To investigate the role of lipid rafts in these signaling processes, endothelial cells were pretreated with methyl-beta-cyclodextrin (CD) or filipin to ablate raft structures. H2O2-induced phosphorylation of Akt and ERK 1/2 was attenuated, while caspase 3 and the number of TUNEL positive cells was enhanced in CD-pretreated cells exposed to H2O2. Reconstitution of raft domains restored H2O2-induced Akt and ERK1/2 phosphorylation, which was concomitant with reduction of caspase 3 activation and DNA fragmentation. Taken together, our findings suggest that plasma membrane compartments rich in cholesterol participate in signal transduction pathways activated by oxidative stress.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Aorta
  • Apoptosis / drug effects
  • Cattle
  • Cell Survival / drug effects*
  • Cells, Cultured
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / physiology*
  • Enzyme Inhibitors / pharmacology
  • Hydrogen Peroxide / pharmacology*
  • In Situ Nick-End Labeling
  • Membrane Microdomains / physiology*
  • Phosphorylation
  • Reactive Oxygen Species
  • Wortmannin


  • Androstadienes
  • Enzyme Inhibitors
  • Reactive Oxygen Species
  • Hydrogen Peroxide
  • Wortmannin