红景天苷抑制模拟微重力诱导的肺微血管内皮细胞凋亡

摘要

目的 研究红景天苷(Sal)抑制模拟微重力诱导的肺微血管内皮细胞凋亡作用并探讨其可能的机制.方法 采用回转器回转细胞模拟微重力效应,将传代培养的人肺微血管内皮细胞分为3组:对照组、回转组、回转+Sal预处理组,采用AnnexinV-FITC试剂盒对细胞染色,以流式细胞仪进行细胞凋亡检测,另通过Real-time PCR检测Bcl-2、Bax及Caspase-3基因表达情况,Westernblot法检测P13K、p-Akt与Caspase-3的蛋白表达情况.结果 流式细胞仪定量结果表明回转72h后HPMEC的凋亡率显著高于同步对照组,Bcl-2基因表达降低,而Bax与Caspase-3基因表达升高,并且P13K和p-Akt蛋白表达减低,Caspase-3蛋白表达升高;而Sal预处理后细胞凋亡率较回转组降低,Bcl-2基因表达升高,而Bax与Caspase-3基因表达下降,同时P13K和p-Akt蛋白表达上升,Caspase-3蛋白表达下降.结论 红景天苷可以抑制模拟微重力诱导的肺微血管内皮细胞凋亡,其机制可能为影响了PI3k/Akt通路.%Objective To investigate the inhibitory effect of salidroside (Sal) on pulmonary microvascular endothelial cell (HPMEC) apoptosis induced by simulated microgravity and its mechanism. Methods Human pulmonary microvascular endothelial cells cultured in vitro were divided into control group, clinorotation group and clinorotation+Sal pretreatment groups. Microgravity was simulated by clinorotation. The apoptotic rate of HPMECs was detected by flow cytometry using Annexin V-FITC staining, and the expressions of bcl-2, bax, and caspase-3 at the mRNA and protein levels were determined by real-time PCR and Western blotting, respectively. Results A 72-h clinorotation significantly induced apoptosis in HPMECs. Real-time PCR results demonstrated a significantly lowered bcl-2 but increased bax and caspase-3 mRNA expressions in clinorotation group as compared with those in the control group. Western blotting showed that clinorotation inhibited the protein expressions of PI3K and p-AKT and increased caspase-3 protein expression. Salidroside significantly inhibited the cell apoptosis, reversed the expressions of Bcl-2 and Bax, and attenuated the decrease in the protein expression of PI3K and phosphorylation level of AKT. Salidroside also antagonized the activation of caspase-3. Conclusion PI3K/AKT pathway and caspase 3 are involved in the apoptosis of HPMVECs induced by clinorotation, and the effect of clinorotation can be reversed by salidroside, suggesting the potential value of salidroside for application in spaceflight.