白藜芦醇上调人肺泡上皮细胞SIRT1表达抑制高氧诱导的细胞凋亡

Resveratrol inhibits hyperxia-induced cell apoptosis through up-regulating SIRT1expression in HPAECs

目的探讨去乙酰化酶SIRT1激动剂白黎芦醇(Res)对高氧诱导人肺泡上皮细胞(HPAEC)凋亡的保护作用。方法体外培养HPAEC,随机分为对照组、高氧组、Res组。培养24 h,采用免疫细胞化学SP法检测caspase-9、X联锁凋亡抑制蛋白(XIAP)、SIRT1蛋白的表达,采用Mito SOXTM、JC-1标记结合激光共聚焦显微镜分别检测HPAEC线粒体内活性氧(ROS)及其膜电位的变化,Western blot法检测SIRT1蛋白的表达,annexin V-FITC/碘化丙啶(PI)双标记结合流式细胞术检测HPAEC细胞凋亡率的变化。结果对照组相比,高氧组HPAEC中caspase-9蛋白表达增强、线粒体内ROS增加、细胞凋亡率增加,而XIAP、SIRT1蛋白的表达减少、膜电位降低;与高氧组相比,Res组HPAEC中caspase-9的表达减弱、线粒体内ROS产生减少、细胞凋亡率降低,XIAP、SIRT1蛋白表达增强、膜电位增高。结论 Res通过上调HPAEC中SIRT1的表达,减少ROS的产生从而维持细胞膜电位抑制肺泡上皮细胞凋亡,减轻高氧所致肺损伤。

Objective To investigate the protection effect of sirtuin 1 （SIRT1） agonist resveratrol （Res） against the apoptosis of human pulmonary alveolar epithelial cells （HPAECs） induced by hyperxia. Methods The HPAECs in vitro were randomly divided into three groups： control group, hyperxia group, Res group. After 24-hour culture, the expressions of caspase-9, X-linked inhibitor of apoptosis protein （XIAP）, SIRT1 proteins were measured by SP immunohistochemistry. The changes of reactive oxygen species （ROS） marked with MitoSOXTM and membrane potential marked with JC-1 in mitochondrion were detected by laser scanning confocal microscopy. The expression of SIRT1 protein was determined by Western blotting, and the change of cell apoptosis rate was analyzed by flow cytometry combined with annexin V-FITC/PI staining. Results Compared with the control group, the expression of caspase-9, the generation of ROS in mitochondrion of HPAECs and the cell apoptosis rate increased obviously. The expressions of both XlAP and SIRT1 and membrane potential decreased evidently in the hyperxia group. Compared with the hyperxia group, the expression of caspase-9, the generation of ROS in mitochondrion of HPAECs and the cell apoptosis rate went down obviously. The expressions of XIAP and SIRT1, and the membrane potential went up evidently in the Res group. Conclusion By up-regulating the expression of SIRT1 in of HPAECs and depressing the generation of ROS, Res inhibits the apoptosis of HPAECs and maintains the cell membrane potential, thus effectively alleviating hyperxia-induced lung injury.