IGF-1对MPP~+诱导PC12细胞凋亡的保护作用及其机制

目的探讨胰岛素样生长因子-1(IGF-1)对1-甲基-4-苯基吡啶离子(MPP+)诱导的PC12细胞凋亡的保护作用及机制。方法以250μmol/L的MPP+损伤PC12细胞作为帕金森病(PD)细胞模型,实验分组如下:空白对照组、MPP+组,IGF-1+MPP+组和抑制剂组。抑制剂组再分为:(1)空白对照组;(2)MPP+组;(3)IGF-1组;(4)IGF-1+MPP+组;(5)MPP++LiCL组;(6)IGF-1+MPP++LiCL组。孵育24h后采用AO-EB法检测细胞凋亡率;采用MTT法检测细胞存活率;孵育4h之后采用Western Blot免疫印迹法检测糖原合成酶激酶-3β(GSK-3β)、phospho-GSK-3β蛋白表达。结果(1)100nmol的IGF-1对MPP+处理的PC12细胞有保护作用,减少了MPP+所致的细胞凋亡。(2)LiCL起到了与IGF-1相似的对PC12细胞的保护作用。(3)总GSK-3β含量各处理组没有太大改变,但磷酸化的GSK-3β含量IGF-1组高于与MPP+单独处理组。结论IGF-1可减少MPP+所致的细胞凋亡,其保护作用与上调磷酸化的GSK-3β的表达相关。

Protective mechanism of IGF-1 on MPP~+ induced neurotoxicity in PC12 cells

Objective To investigate the protective mechanism of IGF-1 on MPP~+ induced neurotoxicity in PC12 cells.Methods PC12 cells impaired by MPP~+(250μmol/L)were used as the cell model of Parkinson' s disease.The cultured cells were divided into such groups:control group,MPP~+ group,MPP~+ + IGF-1 group and inhibitor group.Inhibitor group was divided into control subgroup,MPP~+ subgroup,IGF-1 subgroup,IGF-1 + MPP~+ subgroup,IGF-1+MPP~+ +LiCL subgroup and MPP~+ + LiCL subgroup.After incubation for 24h ,methyl thiazolyl tetrazolium(MTT)was used to assay the viability of the PC12 cells.After incubation for 4h,western blot was used to detect the expression level of GSK-3β,phospho-GSK-3β.Results 100nmol/L IGF-1 protected PC12 cells from MPP~+.LiCL took a protective effect on PC12 cells as well as IGF-1.The level of total-GSK-3βhad not changed after all the treatment,however,the level of phospho-GSK-3β is higher in IGF-1 treated group than which treated with MPP~+.Conclusion These findings indicate that IGF-1 protects against apoptosis in PC12 cells exposed to MPP~+ ,that protective effect is associated with an up-regulation of phosphoGSK-3β.