APOE4通过Calpain/p35-p25/Cdk5增加tau蛋白磷酸化  

APOE4 Increase the Phosphorylation of Tau Protein through Calpain/p35-p25/Cdk5

作　　者：赵发雪 赵琳 张春云 邱瑜[1] ZHAO Fa-xue;ZHAO Lin;ZHANG Chun-yun;QIU Yu(Shanghai Jiao Tong University School of Medicine,Shanghai,200020,China)

机构地区：[1]上海交通大学医学院,上海200020

出　　处：《现代生物医学进展》2021年第9期1607-1611,共5页Progress in Modern Biomedicine

基　　金：上海市自然科学基金项目(20ZR1430100);上海市卫生健康委员会卫生行业临床研究专项资助(20194Y0056);国家自然科学基金青年基金项目(81803499)。

摘　　要：目的:探究载脂蛋白APOE4对小鼠海马组织中tau蛋白磷酸化的作用.方法:采用6月龄人载脂蛋白APOE3,APOE4转基因纯合小鼠,用Western Blot检测小鼠海马组织中tau蛋白的磷酸化程度及Calpain蛋白、p35/25、CDK5等蛋白表达水平.使用脑立体定位术向小鼠侧脑室注射Ca^(2+)螯合剂EGTA或二甲基亚砜DMSO两次,给药时间间隔4小时,第二次给药结束后两小时内处死小鼠.检测海马中Calpain蛋白、CDK5、p35/25及tau蛋白的磷酸化的变化情况.结果:①与野生型小鼠和APOE3-TR小鼠相比,APOE4-TR小鼠海马中tau蛋白在Ser396,Thr181及Thr231位点的磷酸化均显著性增高,同时Calpain2、p35/25和CDK5的表达水平也增加.②使用Ca^(2+)螯合剂EGTA后,与对照DMSO给药组相比,Ca^(2+)螯合剂EGTA给药组小鼠海马组织中tau蛋白在Ser396位的磷酸化显著下降,但未检测到tau蛋白在Thr181及Thr231位点的磷酸发生显著性变化,同时Calpain 2蛋白、p35/25和CDK5的表达水平降低.结论:人载脂蛋白APOE4引起小鼠海马tau蛋白磷酸化异常增高,并且可能是通过Cal-pain/p35-p25/CDK5信号通路调控tau蛋白Ser396位点磷酸化.Objective:Explore the effect of apolipoprotein APOE4 on the hyperphosphorylation of tau protein in mouse hip-pocampal neurons.Methods:6-month-old human apolipoprotein APOE3,APOE4 transgenic homozygous mice was used to detect the phosphorylation of tau protein and Calpain protein,CDK5,p35/25 in the hippocampus by western Blot.Ca^(2+)chelating agent EGTA or dimethyl sulfoxide DMSO was stereotactically injected into the lateral ventricle of the mouse two times with four hours'interval.The mice were sacrificed within two hours after the second administration to detect the changes in the phosphorylation of Calpain protein,CDK5,p35/25 and tau protein in the hippocampus.Results:①Compared to wild-type and APOE3-TR mice,The phosphorylation of tau protein at Ser396,Thr181 and Thr231 sites in the hippocampus of APOE4-TR mice were significantly increased.Meanwhile,the expres-sions of Calpain 2,p35/25 and CDK5 were also increased.nd.②Compared with the control group,Ca^(2+)chelating agent EGTA de-creased the phosphorylation of tau protein at Ser396 site in the hippocampus significantly.However,no significant changes were detected in Thr181 and Thr231 sites of phosphorylation of tau protein.Moreover,the expression levels of Calpain 2,p35/25 and CDK5 were also decreased.Conclusions:Human apolipoprotein APOE4 caused abnormally increased phosphorylation of tau protein in the hippocampus of mice.Moreover,the phosphorylation of tau at Ser396 may be regulated by calpain/p35-p25/CDK5 signaling pathway.

关 键 词：载脂蛋白APOE4 钙调蛋白激酶 TAU蛋白过度磷酸化 

分 类 号：R-33[医药卫生] Q593.2[生物学—生物化学]