title: Rho-kinase-dependent F-actin rearrangement is involved in the inhibition of PI3-kinase/Akt during ischemia-reperfusion-induced endothelial cell apoptosis.
abstract: Activation of cytoskeleton regulator Rho-kinase during ischemia-reperfusion (I/R) plays a major role in I/R injury and apoptosis. Since Rho-kinase is a negative regulator of the pro-survival phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway, we hypothesized that inhibition of Rho-kinase can prevent I/R-induced endothelial cell apoptosis by maintaining PI3-kinase/Akt activity and that protective effects of Rho-kinase inhibition are facilitated by prevention of F-actin rearrangement. Human umbilical vein endothelial cells were subjected to 1 h of simulated ischemia and 1 or 24 h of simulated reperfusion after treatment with Rho-kinase inhibitor Y-27632, PI3-kinase inhibitor wortmannin, F-actin depolymerizers cytochalasinD and latrunculinA and F-actin stabilizer jasplakinolide. Intracellular ATP levels decreased following I/R. Y-27632 treatment reduced I/R-induced apoptosis by 31% (P < 0.01) and maintained Akt activity. Both effects were blocked by co-treatment with wortmannin. Y-27632 treatment prevented the formation of F-actin bundles during I/R. Similar results were observed with cytochalasinD treatment. In contrast, latrunculinA and jasplakinolide treatment did not prevent the formation of F-actin bundles during I/R and had no effect on I/R-induced apoptosis. Apoptosis and Akt activity were inversely correlated (R (2) = 0.68, P < 0.05). In conclusion, prevention of F-actin rearrangement by Rho-kinase inhibition or by cytochalasinD treatment attenuated I/R-induced endothelial cell apoptosis by maintaining PI3-kinase and Akt activity.
authors.affiliation: Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. m.vanderheijden@vumc.nl
authors.forename: Melanie
authors.initials: M
authors.lastname: van der Heijden
authors.forename: Amanda M G
authors.initials: AM
authors.lastname: Versteilen
authors.forename: Pieter
authors.initials: P
authors.lastname: Sipkema
authors.forename: Geerten P
authors.initials: GP
authors.lastname: van Nieuw Amerongen
authors.forename: Rene J P
authors.initials: RJ
authors.lastname: Musters
authors.forename: A B Johan
authors.initials: AB
authors.lastname: Groeneveld
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000187:drug effects; D000577:Amides / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002478:Cells, Cultured; D015638:Cytochalasin D / Q000494:pharmacology; D047630:Depsipeptides / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors*; D011725:Pyridines / Q000494:pharmacology; D015427:Reperfusion Injury / Q000473:pathology; D053778:Thiazolidines / Q000494:pharmacology; D000077191:Wortmannin; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*
chemical_list: D000199:Actins; D000577:Amides; D000730:Androstadienes; D019086:Bridged Bicyclo Compounds, Heterocyclic; D047630:Depsipeptides; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011725:Pyridines; D053778:Thiazolidines; C057531:jasplakinolide; C108830:Y 27632; D015638:Cytochalasin D; D051057:Proto-Oncogene Proteins c-akt; D054460:rho-Associated Kinases; C037067:latrunculin A; D000077191:Wortmannin