远志皂苷元对PC12细胞tau蛋白磷酸化和O-GlcNAc糖基化的影响

Effect of tenuigenin on O-GlcNAc glycosylation and phosphorylation of tau protein in PC12 cells

[目的]观察远志皂苷元对体外培养的PC12细胞tau蛋白磷酸化和O-GlcNAc糖基化的影响。[方法]应用低糖培养PC12细胞模拟O-GlcNAc糖基化水平的下降,四甲基偶氮唑盐微量酶反应比色(MTT)法检测细胞存活率;采用Western blot方法检测O-GlcNAc糖基化和tau蛋白磷酸化水平。[结果]远志皂苷元能明显改善PC12细胞存活率,与对照组相比,模型组O-GlcNAc糖基化表达降低,tau蛋白磷酸化水平升高。与模型组相比,远志皂苷元处理组未发生O-GlcNAc糖基化表达降低,tau蛋白未发生过度磷酸化。[结论]tau蛋白磷酸化在某些位点受到O-GlcNAc糖基化修饰的负性调节,远志皂苷元在一定程度上可以升高O-GlcNAc糖基化表达,降低tau蛋白磷酸化水平。

[Objective] To study the effect of tenuigenin on O-GlcNAc glycosylation and phosphorylation of tau protein in PC12 cells.[Methods] The level of O-GlcNAcylation in differenciated PC12 cells was modulated by changing the concentration of the sugar in culture medium.Then,the consequent changes of tau phosphorylation at various phosphorylation sites were examined by using Western blot.MTT method was used for the detection of cell survival rate.[Results] Tenuigenin could significantly improve the survival rate of PC12 cells.Compared with the control group,the expression of O-GlcNAc glycosylation in model group decreased,and phosphorylation of tau protein increased.Tenuigenin could increase the expression of O-GlcNAc glycosylation and decrease the expression of phosphorylation of tau protein.[Conclusion] These results suggest that O-GlcNAcylation negatively modulates tau phosphorylation at some phosphorylation sites,and tenuigenin could increase O-GlcNAc expression and decrease phosphorylation of tau protein.