辛伐他汀对大鼠系膜细胞增殖、凋亡及细胞内半胱氨酸天冬氨酸蛋白酶3表达的影响

目的 观察辛伐他汀(simvastatin)诱导大鼠系膜细胞增殖、凋亡及可能参与其中的凋亡信号通路，探讨他汀类药物非降脂依赖性肾保护作用的相关机制。方法 四甲基偶氮唑蓝(MTT)比色法测定系膜细胞的增殖状况。透射电子显微镜、碘化丙啶染色(PI)流式细胞仪(FCM)分析检测系膜细胞的凋亡。活化半胱氨酸检测试剂盒定性及定量检测细胞内半胱氨酸天冬氨酸蛋白酶3(caspase-3)的表达。结果 (1)MTT检测显示辛伐他汀可显著抑制大鼠系膜细胞的增殖(P < 0.05)。(2)辛伐他汀处理细胞24 h后，电镜下可见细胞体积缩小、染色质浓染、致密、边移和凋亡小体形成；FCM检测均可见亚二倍体凋亡峰。定量分析发现，系膜细胞数量与辛伐他汀浓度呈剂量依赖性(P < 0.05)。(3)活化半胱氨酸检测到辛伐他汀组细胞内caspase-3的表达，并且随药物浓度和作用时间的增加而增加。结论 辛伐他汀非降脂依赖的肾保护作用的作用机制之一是诱导系膜细胞凋亡，从而抑制其增殖，其机制可能与激活caspase-3有关。

Effects of simvastatin on proliferation, apoptosis and caspase-3 expression of rat mesangial cell

Objective To study the effects of simvastatin on proliferation and apoptosis in rat mesangial cells in vitro, and to investigate the signal pathways involved in apoptosis induced by simvastatin. Methods Cultured mesangial cells were treated with simvastatin. Proliferation of mesangial cells was examined by MTT assay. Simvastatin-treated apoptotic mesangial cells were observed by electron microscopy. Propidium iodide (PI) staining and flow cytometry were employed for quantitative measurement of apoptosis. Caspase-3 activation was determined by CaspGLOW Green Caspase-3 Staining Kit. Results (1)Simvastatin significantly inhibited proliferation of mesangial cells compared with control (P<0.05). (2)Under electron microscopy, mesangial cells with condensed chromatin, shrunken plasma, marginated nuclear chromatin or apoptotic body were observed in simvastatin-treated mesangial cells. Quantitative analysis of apoptotic mesangial cells showed that simvastatin did induce an increased apoptosis rate of rat mesangial cells in a dose-dependent manner. (3)Caspase-3 expression was activated by simvastatin in a dose- and time-dependent manner. Conclusions Proliferation inhibition and apoptosis induction of mesangial cells are involved in the mechanisms of the cholesterol-independent effects of simvastatin on the renal protection. The latter may be induced by activation of caspase-3.