埃他卡林通过c-JNK信号通路抑制缺氧诱导的人肺血管内皮细胞凋亡

Protective effect of Iptakalim on hypoxia-induced apoptosis in HPAECs through c-JNK

目的:研究KATP通道开放剂埃他卡林在缺氧诱导的肺血管内皮细胞凋亡调节中的作用及机制。方法:细胞分组培养并经过药物及缺氧处理后,分别采用四甲基偶氮唑盐(MTT)法对细胞活性进行测定,同时采用Hoechst 33342染色法检测细胞凋亡,采用Western blot对JNK、磷酸化JNK、caspase-3等蛋白的表达进行检测。结果:缺氧可降低细胞活性,诱导肺动脉内皮细胞凋亡,而埃他卡林可抑制凋亡,这种细胞保护作用可被KATP拮抗剂5-HD阻断;埃他卡林可抑制缺氧引起的c-JNK通路的磷酸化激活,并抑制下游凋亡蛋白caspase-3的表达,与c-JNK抑制剂SP600125作用一致,而5-HD处理组的趋势则相反。结论:埃他卡林可通过开放KATP通道抑制缺氧诱导的肺动脉内皮细胞凋亡,这种保护机制涉及了对c-JNK通路及下游凋亡蛋白的调节。

Objective：The present study was designed to investigate the protective effect of Iptakalim against hypoxia-induced apoptosis in human pulmonary arterial endothelial cells（HPAEC）and the potential mechanisms involved. Methods：After medicine and hypoxia treatment,the MTT assay was performed to measure cell viability. Hoechst 33342 was then used to detect apoptosis.Finally,the expression of phospho-JNK,JNK and caspase-3 was assayed by Western blot. Results：Our study showed that hypoxia significantly decreased the cell viability by inducing cellular apoptosis,while Iptakalim reversed the hypoxia-induced apoptosis, which can be blocked by 5-HD. Iptakalim and SP600125 consistently inhibited the phosphorylation of c-JNK and the expression of caspase-3 induced by hypoxia,and this effect was completely blocked by the 5-HD. Conclusion：Iptakalim protects the HPAEC from hypoxiainduced apoptosis by opening the KATP channels. The possible cellular mechanisms for this protective effect may involve the inhibition of phospho-JNK and the downstream cell death pathways.