丙炔苯丙胺对多巴胺能神经细胞的保护机制

Protective mechanism of deprenyl against neurotoxicity of rotenone on dopaminergic neurons

目的探讨丙炔苯丙胺对多巴胺能神经细胞的保护机制。方法采用神经生长因子(NGF)将大鼠嗜铬细胞瘤细胞(PC12细胞)诱导分化成多巴胺能神经元的细胞模型,经鱼藤酮处理后给予不同浓度的丙炔苯丙胺,观察细胞形态的改变,采用四甲基偶氮唑盐(MTT)法检测细胞活性及代谢状态,2',7'-二氯荧光黄双乙酸盐(DCFH-DA)检测细胞内活性氧(ROS)、还原型谷胱甘肽((GSH)含量及蛋白酶体功能。结果与鱼藤酮组比较, 50μmol／L浓度的丙炔苯丙胺作用24 h后,细胞恢复活力,570 nm处光密度值为0．39±0．01。与未处理组比较,鱼藤酮组ROS水平显著升高(P<0．01),丙炔苯丙胺组较鱼藤酮组显著降低(P<0．01)。鱼藤酮组的GSH含量为(104.76±0．88)μmol／L,显著低于丙炔苯丙胺组的(130．21±0．84)μmol／L(P<0．01)。与未处理组比较,鱼藤酮组的细胞蛋白酶体活性明显降低(P<0．01),丙炔苯丙胺组蛋白酶体活性恢复。结论丙炔苯丙胺能够明显减少鱼藤酮诱导的PC12细胞死亡,其机制可能是抑制氧化应激及保护蛋白酶体。

Objective To investigate the protective mechanism of deprenyl against neurotoxicity of rotenone on dopaminergie neurons. Methods PC12 cells were induced by nerve growth factor to differentiate into dopaminergie neurons, which were then challenged by different concentrations of deprenyl after rotenone treatment. Cell viability was assessed with MTT. The ROS was detected by DCFH-DA staining; the GSH content was detected by fluorescence assay. The proteasome function was assessed by fluorescence enzyme reader. Results After treatment with rotenone for 24 hours, the process-like structure of PC12 cell disappeared, the cells became larger and recovered after treatment with deprenyl. Compared with the control group treated with rotenone alone, the cell viability soon recovered after treatment with a 50 μmol/L concentration deprenyl （D570 0.39 ±0. 01）. DCFH-DA staining also showed decreased ROS in the cells after treatment with deprenyl. The decrement of GSH content was significantly upregulated by deprenyl from （104.76±0.88） μmol/L to （130.21 ± 0.84） μmol/L. The proteasome function of the cells treated by rotenone decreased significantly, but recovered with treatment of deprenyl. Conclusion Rotenone is neurotoxie to dopaminergie neuron, but the cell death rate can be reduced by Deprenyl; the mechanism might be the inhibition of oxidative stress and protection of the proteasome function. （Shanghai Med J, 2007, 30：315-318）