Abstract: 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.