Caspases在缺氧性脑微血管内皮细胞凋亡中的作用

目的研究caspases在缺氧性脑微血管内皮细胞凋亡中的作用。方法用氰化钠合并无糖培养基造成培养的牛脑微血管内皮细胞缺氧；用台盼蓝染色、TUNEL及流式细胞仪计数方法观察细胞受损和凋亡情况；用免疫细胞化学染色法观察受损细胞中caspase-3的表达。结果氰化钠合并无糖培养基可损伤牛脑微血管内皮细胞，使细胞发生凋亡，受损细胞中caspase-3大量表达。广谱caspases抑制剂、选择性caspase-1，-3和-6抑制剂均能显著减少细胞死亡数目、caspase-1和-6抑制剂可以抑制caspase-3的表达。结论Caspases在缺氧性脑微血管内皮细胞凋亡过程中起重要作用，在caspases的蛋白酶级联切割反应中caspase-3位于caspase-1和-6的下游。

Effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia

Aim To study the effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia in vitro . Methods The 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. Results NaCN 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. Conclusion The 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.