鱼藤酮对SH-SY5Y细胞线粒体膜电位的影响

Study on the Role of Mitochondrial ATP-sensitive Potassium Channel in Rotenone Induced SH-SY5Y Cells Injury

[目的]探讨环境毒素鱼藤酮对人多巴胺能神经母细胞瘤(SH-SY5Y)细胞线粒体膜电位的影响以及线粒体ATP敏感性钾通道(MitochondrialATP-sensitivepotassiumchannel,mKATPchannel)在其中的作用。[方法]先用0、5、20、100nmol/L浓度的鱼藤酮单独处理SH-SY5Y细胞,观察鱼藤酮与线粒体膜电位下降的量效关系;然后在此4组中分别按加和不加mKATP通道抑制剂5-羟葵酸(5-Hydroxydecanoate,5-HD)0.5mmol/L和(或)激活剂二氮嗪(Diazoxide,DZX)1.0mmol/L与不同浓度鱼藤酮共同作用,观察细胞线粒体膜电位的变化。细胞线粒体膜电位的检测采用罗丹明绿色荧光负载、流式细胞仪测量荧光强度的方法。[结果]5、20和100nmol/L鱼藤酮作用24h分别导致SH-SY5Y细胞线粒体膜电位下降至对照组的91.76%、71.21%和49.65%,膜电位下降程度与鱼藤酮剂量相关;DZX单独作用使线粒体膜电位下降了13.45%,DZX与5和20nmol/L鱼藤酮共同作用分别下降至对照组的75.32%和66.06%,比同浓度鱼藤酮单独作用更加明显;5-HD可抵消DZX的上述作用,5-HD与5nmol/L鱼藤酮共同作用时可减轻鱼藤酮引起的细胞膜电位下降。[结论]鱼藤酮可以引起SH-SY5Y细胞线粒体膜电位下降;小剂量鱼藤酮(5和20nmol/L)能开放mKATP通道,该作用可被5-HD逆转;与DZX相比,小剂量鱼藤酮只能激活某一类型的mKATP通道,这是它导致线粒体膜电位下降的机制之一。大剂量鱼藤酮降低线粒体膜电位的机制中mKATP通道的作用较小。

[ Objective ] To study the role of Mitochondrial ATP-sensitive potassium channel （ mKATP channel ） in Rotenone induced SH-SY5Y cells injury. [ Method ] SH-SY5Y cells were exposed to different concentrations of rotenone together with mKATP channel activator 5-Hydruxydeeanoate （ 5-HD ） .and/or inhibitor Diazoxide （ DZX ）. Cultured cells were separated as 16 groups depending on Rotenone coneentration and the existance of other drugs or not. The cell mitochondrial membrane potential was determined by incubating the cells with rodanmine 123, a mitoehondria special dye, followed by flow cytometry analysis for fluorescence signals. [Results ] 5-100 nmol/L Rotenone caused decrease of SH-SYSY cell mitoehondrial membrane potential on concentration depended matter. 1 mmol/L DZX decreased the mitochondrial membrane potential about 13.45 percents. DZX together with 5 nmol/L or 20 nmol/L rotenone, which were more active than rotenone alone, decreased the mitoehondrial membrane potential to 72.36 or 66.06 percent respectively. When 5-HD co-affect with DZX and/or rotenone, the descents of mitoehondrial membrane potential were significant reduced. [ Conclusion ] Opening the mKATP channel may be one of the mechanisms how Rolenone caused decrease of mitochondrial membrane potential in SH-SY5Y cells. Compared with DZX, rotenone may only be able to open part of the mKATP channels. The effect of mKATP channels is much significant in low concentrations （ 5 nmol/L and 20 nmol/L ） of rotenone rather than in high concentration of it.