玉米赤霉烯酮对Leydig细胞凋亡及caspase-9、caspase-3蛋白表达的影响

以不同浓度的玉米赤霉烯酮（Zearalenone，zEA）对大鼠睾丸间质细胞（Leydig）细胞进行染毒，采用噻唑蓝比色法观察了ZEA对Leydig细胞活力的影响；流式细胞术分析检测了ZEA对细胞的凋亡率、线粒体膜电位变化的影响；Westernblotting等技术检测了Bax、Bcl-2、caspase-3、caspase-9、PARP蛋白的表达情况。结果显示，ZEA可明显抑制睾丸Leydig细胞的活力（染毒各组与对照组比较P〈0．05），40mg／L染毒组相对活力为40．67％；与对照组比较，5、10、20mg／LZEA染毒组睾丸Leydig细胞凋亡率均极显著升高（P〈0．05），呈明显剂量关系；线粒体膜电位变化测定显示，各染毒组与对照组比，线粒体膜电位均下降（P〈0．05），且有明显的剂量关系；Westernblotting分析显示，与对照组比较，5、10、20mg／LZEA染毒组Bax、caspase-9、caspase-3、PARP蛋白表达均上调，bel-2蛋白表达均下调。结果表明，ZEA能诱导大鼠睾丸间质细胞发生凋亡，Bax、Bcl-2、caspase-9、caspase-3等基因参与ZEA诱导Leydig细胞凋亡的调控。

Effect of zearalenone on apoptosis and expression of caspase-3 and caspase-9 in Leydig cells

To explore the effects of zearalenone （ZEA） on the Leydig cell apoptosis and its molecular mechanism,cultured rat testicular interstitial cells were exposed to different concentrations of ZEA. Then the cell viability was determined by MTT assay, the apopotise rate and mitochondria membrane potential change wrer analyzed by flow cytometry（FCM） ,and the expression of Bcl-2, caspase-3, caspase-9, PARP protein were observed by Western blotting. The results showed that, compared with the control group,the vitality of cells in all ZEA exposure group was significantly decreased（P〈0. 01） by 40. 67% at 40 mg/L ZEA group, the apoptosis rate in ZEA exposure group （5,10 and 20 mg/L ZEA）was significantly increased （P〈0. 05） ,the mitochondrial membrane potential were significantly decreased（P〈0.05）. Western blotting analysis showed that the expression of Bax,caspase-9,caspase-3 and PARP protein in ZEA exposure group was up-regulated,and Bcl-2 protein was down-regulated compared with the control group. This study demonstrated that ZEA can induce apoptosis mediated by Bax, Bcl-2, caspase-9 and caspase-3 in rat Leydig cells.