马钱苷通过抑制蛋白磷酸酶2A催化亚基C磷酸化降低tau蛋白过度磷酸化

发布时间：2018-03-06 05:33

本文选题：马钱苷　切入点：tau蛋白过度磷酸化　出处：《首都医科大学学报》2016年06期 　论文类型：期刊论文

【摘要】：目的探讨马钱苷对tau蛋白过度磷酸化的影响及其作用机制。方法马钱苷(500、1 000μmol/L)与人神经母细胞瘤细胞株(SK-N-SH细胞)预孵育24 h,之后加入PI3K抑制剂Wortmannin(WT)及PKA抑制剂GF-109203X(GFX)与SK-N-SH细胞孵育3 h,采用Western blotting方法观察马钱苷对tau蛋白在Thr205、Thr217、PHF-1位点的磷酸化,GSK-3β-Ser9、GSK-3β、PP2A催化亚基C(protein phosphatase 2A catalytic subunit C,PP2Ac)磷酸化/甲基化及PP2Ac的表达。结果 WT/GFX明显抑制pGSK-3β-ser9的表达,引起GSK-3β活性增高,从而导致tau蛋白Thr205、Thr217、PHF-1位点高度磷酸化。马钱苷能够明显抑制模型细胞tau蛋白在Thr205、Thr217、PHF-1位点的过度磷酸化,但是不能增高p-GSK-3β-ser9的表达,提示马钱苷抑制tau蛋白磷酸化的作用不是通过影响GSK-3β通路实现的。但是实验显示马钱苷能够抑制PP2A催化亚基C Tyr307位点的磷酸化,但对Leu309位点甲基化无影响。结论马钱苷能够抑制tau蛋白过度磷酸化,机制可能与其抑制PP2A催化亚基C Tyr307位点的磷酸化,提高PP2A活性有关,与GSK-3β通路无关。
[Abstract]:Objective to investigate the effect and mechanism of equinoside on the hyperphosphorylation of tau protein. Methods PI3K inhibitor Wortmanning WTand PKA inhibitor GF-109203XGFX) were preincubated with human neuroblastoma cell line SK-N-SH for 24 h. After incubation for 3 h, Western blotting was used to observe the phosphorylation / methylation of phosphatase 2A catalytic subunit PP2Acand PP2Ac expression of tau protein at Thr205 and Thr217PHF-1 site. Results WT/GFX significantly inhibited the expression of pGSK-3 尾 -ser9. The activity of GSK-3 尾 was increased, which resulted in the high phosphorylation of tau protein Thr205, Thr217PHF-1, which could inhibit the excessive phosphorylation of tau protein in Thr205, Thr217PHF-1, but could not increase the expression of p-GSK-3 尾 -ser9. The results suggest that the inhibition of tau protein phosphorylation by equinosine is not achieved by affecting the GSK-3 尾 pathway, but it is shown that equinosine can inhibit the phosphorylation of C Tyr307 site of PP2A catalytic subunit. Conclusion the mechanism may be related to the inhibition of the phosphorylation of PP2A catalytic subunit C Tyr307 site and the increase of PP2A activity, but not to GSK-3 尾 pathway.
【作者单位】：首都医科大学宣武医院药物研究室北京市神经药物工程研究中心北京脑重大疾病研究院神经变性病教育部重点实验室;
【基金】：国家自然科学基金项目(81473373) 北京市自然科学基金项目(7164315) 北京市卫生系统高层次卫生技术人才(2014-2-014) 北京市新世纪百千万人才工程(008-0014)~~
【分类号】：R749.16

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