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

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-3活化裂解PARP在ONOO^-致RTE细胞凋亡过程中起重要作用。

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

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 -.