Effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia

AimTo study the effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia in vitro.MethodsThe cultured bovine cerebromicrovascular endothelial cells were exposed to NaCN in glucose-free medium.Cell viability was determined by trypan blue staining.Cell apoptosis was defined by terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and flow cytometry.The expression of caspase-3 was detected by immunocytochemical method.Four caspase inhibitors were used to validate the effect of caspases on cell apoptosis.ResultsNaCN in glucose-free medium initiated cerebromicrovascular endothelial cell injury markedly and typical apoptotic cells were found in this model.The expression of caspase-3 increased significantly.Four caspase inhibitors decreased the number of injuried cells.Selective inhibitor of caspase-1 and -6 reduced expression of caspase-3 significantly.ConclusionThe results suggest that caspases family plays an important role in cerebromicrovascular endothelial cell apoptosis induced by NaCN and caspase-3 acts on the downsteam of caspase-1 and -6 in protease cascade action to induce apoptosis.