磷脂酰肌醇-3激酶/Akt在体外神经干细胞存活和分化中作用的实验研究

The experimental study on phosphatidylinositol 3-kinase/Akt in neural stem cells in vitro

目的:探讨磷脂酰肌醇-3激酶/Akt信号途径在体外培养神经干细胞存活、分化中的作用。方法:分为对照组、wortmannin组和LY294002组;免疫组化检测Nestin、NSE和S100的表达;TUNEL评价细胞凋亡率;Western Blotting检测磷酸化Akt、Caspase-9的表达。结果:随着wortmannin和LY294002浓度增大,细胞凋亡率逐渐增加。随着wortmannin和LY294002浓度增大,磷酸化Akt的表达逐渐减弱。高浓度时磷酸化的Caspase-9表达减弱。结论:神经干细胞存活依赖于PI3K/Akt途径的活化,其机制可能是PI3K/Akt活化后,促进了Caspase-9等蛋白的磷酸化,抑制了细胞凋亡事件的发生。

Objective ：To discuss the function of PI3K （phosphatidylinositol - 3 kinase）/Akt signal pathway in proliferation and differentiation of neural stem cells （NSCs）. Methods：Control group, wortmannin group and LY294002 group were randomly assigned.The expression of Nestin, NSE and S100 were detected by immunohistochemistry. The ratio of cell apoptosis was estimated by TUNEL staining and the expressions of phosphorylated Akt and Caspase- 9 were detected by Western blotting. Results：With the increase in concentration of wortmannin and LY294002, the ratio of NSCs apoptosis increased. The results of Western blotting indicated that the expression of phosphorylated Akt decreased when the concentration of wortmannin and LY294002 increased. High concentration of wortmannin and LY294002 inhitited Akt phosphorylated. At the same time, the expression of phosphorylated Caspase - 9 decreased. Conclusion ：The survival of NSCs depends on the activation of PI3K/Akt pathway, but PI3K/Akt pathway may have little function in the differentiation of NSCs.