ApoE4在U87细胞中可增加GSK-3β的表达及Tau的磷酸化  

ApoE4 increases glycogen synthase kinase 3β expression and Tau phosphorylation in U87 cells

作　　者：何颜结 卫佩如 伍巧燕 张馨宇[3] 张兴梅[1] 刘晓加[2] 王方[1] 

机构地区：[1]南方医科大学基础医学院神经生物学教研室,广东广州510515 [2]南方医科大学神经内科,广东广州510515 [3]南方医科大学南方医院第一临床医学院,广东广州510515

出　　处：《南方医科大学学报》2016年第7期904-908,共5页Journal of Southern Medical University

基　　金：国家自然科学基金(81471388);广东省自然科学基金(2015A030313235);广州市科技计划项目(2014J4100148);教育部大学生创新创业训练计划项目(201312121020)~~

摘　　要：目的探讨Apo E4与GSK-3β及Tau蛋白超磷酸化之间的关系,为研究Apo E4在阿尔茨海默病(AD)中的作用机制提供实验依据。方法分别将对照质粒载体p IRES-EGFP、重组质粒Apo E4/p IRES-EGFP和Apo E3/p IRES-EGFP转染U87脑星形胶质细胞系,用免疫蛋白印迹法(Western blotting)检测p-Tau/Tau及GSK-3β蛋白水平的变化。在U87细胞中转入干扰Apo E表达的si RNA(Apo E-si RNA)及对照si RNA,检测p-Tau/Tau及GSK-3β蛋白的改变情况。将质粒转染前后及si RNA干扰前后目标蛋白的含量或磷酸化水平的改变进行统计学比较。结果与对照组相比,GSK-3β蛋白水平的相对值分别为:Apo E4组(1.819±0.130,P<0.01,n=3)和Apo E3组(1.336±0.130,P<0.01,n=3),差异具显著差异,且Apo E4和Apo E3组比较也具有显著性差异(P<0.01)。同样,相对于对照组,Apo E4和Apo E3组的磷酸化Tau蛋白(p-Tau)的相对值分别为1.587±0.027(P<0.01,n=3)和1.436±0.026(P<0.01,n=3),均具显著差异;且Apo E4组较Apo E3组的促进作用更强,两组间具显著差异(P<0.01)。此外,用Apo E-si RNA干扰后,U87细胞中GSK-3β的表达和p-Tau水平均较对照组显著降低,分别为0.544±0.058(P<0.001,n=3)和0.474±0.060(P<0.01,n=3)。结论 AD危险因子Apo E4可能通过上调GSK-3β的表达而促进Tau的磷酸化。Objective To explore the relations among apolipoprotein E4,Tau protein and glycogen synthase kinase 3β（GSK-3β）.Methods U87 cells were transfected with p IRES-EGFP（control） or the recombinant plasmids Apo E4/p IRES-EGFP or Apo E3/p IRES-EGFP,and the expression levels of p-Tau/Tau and GSK-3β in the cells were examined with Western blotting.To further confirm the effect of Apo E on GSK-3β and p-Tau expressions,a short interfering RNA（si RNA） targeting Apo E（Apo E-si RNA）was transfected into U87 cells via Lipofectamine 2000 and the protein expressions were examined 24 h later.Results Compared with those in the control group,the expressions levels of both GSK-3β and p-Tau/Tau increased significantly in the cells transfected with Apo E4 and Apo E3 plasmids（P〈0.01）,and the Apo E4 plasmid produced a more potent effect than the Apo E3 plasmid on the protein expressions（P〈0.01）.Apo E knockdown resulted in significantly reduced expressions of GSK-3β（P〈0.001） and p-Tau（P〈0.01） in the cells.Conclusion Apo E4 can enhance Tau phosphorylation though upregulating GSK-3β,which sheds light on a new role of Apo E4 in Alzheimer＇s disease.

关 键 词：载脂蛋白E 阿尔茨海默病(AD) TAU蛋白 糖原合酶激酶3Β 

分 类 号：R749.16[医药卫生—神经病学与精神病学]