一氧化氮诱导大鼠肺动脉平滑肌细胞凋亡机制研究

Mechanism of pulmonary arterial smooth muscle cell apoptosis induced by nitric oxide

目的 :研究一氧化氮 (NO)诱导大鼠肺动脉平滑肌细胞 (PASMC)凋亡的作用机制。方法 :体外培养Wistar大鼠PASMC ,加入NO供体硝普钠 (SNP)于常氧和低氧条件下孵育 12h或 2 4h ,通过流式细胞术碘化丙啶染色法观察PASMC细胞周期时段及凋亡亚二倍体峰变化 ,应用细胞免疫化学法检测PASMCcaspase - 3和NF -κB的表达 ,同时行DNA断裂琼脂糖凝胶电泳。结果 :SNP作用后PASMC出现剂量 -依赖性促凋亡作用 (P <0 .0 1) ,表现为凋亡指数与caspase - 3表达的不同程度的增强。随凋亡的进展 ,出现PASMC凋亡核小体DNAladder,同时PASMCNF-κB阳性核表达较对照组少 (P <0 .0 1)。结论 :外源性NO诱导大鼠PASMC凋亡 ,caspase - 3与NF

AIM: To explore the mechanism of apoptosis in pulmonary arterial vascular smooth muscle cells (PASMCs) induced by nitric oxide (NO). METHODS: Wistar rat PASMCs were isolated from explants from the intrapulmonary, incubated with NO donor, sodium nitroprussid (SNP) under 12 or 24 hour normoxic and hypoxic conditions. The cell cycle progression and sub-G 1 of PASMC were analyzed via flow cytometric staining of propidium iodide, and the expression of nuclear transcription factor NF-κB and pro-apoptotic factors caspase-3 were detected using immunochemistry staining. Meanwhile gel electrophoresis of extracted DNA by PASMC was performed. RESULTS: SNP induced PASMC apoptosis in a dose-dependent manner ( P< 0.01), which resulted in an increase in apoptotic index by flow cytometric and immuno-expression of caspase-3 on PASMC, and a decrease in immuno-activity of NF-κB on PASMC ( P< 0.01) accompanied by DNA laddering. CONCLUSION: Exogenous NO induces rat PASMC apoptosis under normoxia and hypoxia , which appears to be affected by stimulated caspase-3 and NF-κB message pathways.