多聚(ADP-核糖)聚合酶和半胱天冬蛋白酶-3在过氧亚硝基阴离子致气道上皮细胞损伤中的作用

Role of PARP and caspase-3 in the airway epithelial injury induced by peroxynitrite

目的 :探讨过氧亚硝基阴离子 (ONOO-)介导气道上皮细胞损伤的作用机制。方法 :在培养的大鼠气道上皮细胞 (RTE) ,观察应用多聚 (ADP -核糖 )聚合酶 (PARP)抑制剂 3 -氨基苯甲酰胺 (3 -AB)和半胱天冬氨酸蛋白酶 - 3 (caspase - 3 )抑制剂Ac -DEVD -CHO后 ,外源性给予ONOO-对RTE细胞乳酸脱氢酶 (LDH)释放、凋亡百分率的影响 ,用Westernblot分析PARP裂解片段。结果 :3 -AB不能完全抑制ONOO-引起的RTE细胞LDH释放率的增高。 3 -AB对ONOO-引起的RTE细胞凋亡无明显影响。Ac -DEVD -CHO呈剂量依赖性抑制ONOO-诱导的RTE细胞凋亡。ONOO-致RTE细胞凋亡过程中有PARP的裂解。结论 :PARP活化是ONOO-介导RTE细胞损伤的途径之一 ,过度的PARP活化参与了ONOO-所致的RTE细胞坏死 ;caspase -

AIM: To study the mechanism responsible for ONOO --induced the airway epithelial injury. METHODS: Effects of 3-aminobenzamide(3-AB), a poly-(ADP-ribose) polymerase(PARP) inhibitor, and Ac-DEVD-CHO, a caspase-3 inhibitor, on LDH release and apoptosis of cultured rat tracheal epithelial (RTE) cells induced by ONOO - were examined. The cleavage of PARP was analysed by Western blot. RESULTS: 3-AB inhibited the release of LDH induced by ONOO - partially, and had no effect on the apoptosis of RTE cells. Caspase-3 inhibitor Ac-DEVD-CHO obviously prevented the apoptosis of RTE cells induced by ONOO - in a dose-dependent manner. The cleavage of PARP was observed in the process of apoptosis of RTE cells induced by ONOO -. CONCLUSIONS: PARP activation represents one of the pathways of ONOO --mediated epithelial injury, and the excessive activation of PARP contributes to the necrosis in RTE cells induced by ONOO -. Cleavage of PARP by activated caspase-3 plays a crucial role in the apoptosis of RTE cells induced by ONOO -.