电针对阿尔茨海默病小鼠海马胰岛素信号通路相关蛋白表达的影响

Effect of electroacupuncture on the expression of insulin signal pathway related proteins in hippocampus in mice with Alzheimer’s disease

目的:观察电针对阿尔茨海默病(AD)小鼠海马胰岛素磷脂酰肌醇-3激酶/糖原合成酶激酶-3α(PI3K/GSK3α)信号通路相关蛋白表达的影响,探讨电针改善AD病理特征的调节机制。方法:将12只雄性APP/PS1双转基因小鼠随机分为模型组和治疗组,每组6只;另以6只雄性野生型小鼠作为对照组。治疗组小鼠电针"百会"及双侧"肾俞",连续波,频率2 Hz,每天1次,7 d为一疗程,共治疗2个疗程。采用免疫组化法及Western blot检测各组小鼠海马PI3K/GSK3α信号通路相关蛋白P85α、P110α、GSK3α及pS21GSK3α分布和表达水平,并观察海马老年斑(SP)数量的变化。结果:P85α、P110α、GSK3α及pS^21GSK3α蛋白均主要分布于海马神经元的细胞质内,模型组和治疗组GSK3α蛋白还分布于神经元轴突上。免疫组化结果显示,与对照组比较,模型组小鼠海马GSK3α分布水平明显升高(P<0.001),pS^21GSK3α、P85α及P110α的分布水平明显降低(P<0.01,P<0.001);与模型组比较,治疗组小鼠海马GSK3α分布水平明显降低(P<0.001),pS^21GSK3α、P85α及P110α分布水平明显升高(P<0.05,P<0.001)。Western blot结果显示,与对照组比较,模型组小鼠海马pS^21GSK3α、P85α、P110α蛋白表达量及pS^21GSK3α/GSK3α比值均明显降低(P<0.001),GSK3α蛋白表达量升高(P<0.05);与模型组比较,治疗组小鼠海马pS^21GSK3α、P85α、P110α蛋白表达量及pS^21GSK3α/GSK3α比值均明显升高(P<0.01,P<0.001),GSK3α表达量降低(P<0.05)。与对照组比较,模型组小鼠海马SP数量明显增多(P<0.001);与模型组比较,治疗组小鼠海马SP数量明显减少(P<0.01)。结论:电针刺激能够有效调节AD模型小鼠海马内胰岛素PI3K/GSK3α信号通路上相关蛋白的表达,从而减少老年斑的形成和沉积。

Objective To observe the effect of electroacupuncture(EA)on the expression of insulin phosphatidylinositol-3kinase/glycogen synthetase kinase-3α(PI3K/GSK3α)signal pathway related proteins in the hippocampus in mice with Alzheimer’s disease(AD),and to explore the regulatory mechanism of EA on improving the pathological characteristics of AD.Methods Twelve male APP/PS1 double transgenic mice were randomly divided a model group and a treatment group,6 mice in each group;another 6 wild-type male mice were taken as the control group.The mice in the treatment group were treated with EA(continuous wave,2 Hz of frequency)at"Baihui"(GV 20)and bilateral"Shenshu"(BL 23),once a day;7-day treatment was taken as a course of treatment,and 2 courses of treatment were given.The immunohistochemistry method and Western blot method were used to detect the distribution and expression level of hippocampal PI3K/GSK3αsignal pathway related proteins P85α,P110α,GSK3αand pS^21GSK3α,and the number of hippocampal senile plaques(SP)was observed.Results The proteins of P85α,P110α,GSK3αand pS^21GSK3αwere mainly distributed in the cytoplasm of hippocampal neurons,and the GSK3αwas also distributed in the axons of neurons in the model group and the treatment group.The immunohistochemistry results showed that the distribution level of GSK3αin the hippocampus in the model group was significantly higher than that in the control group(P<0.001),and the distribution level of pS^21GSK3α,P85αand P110αwas significantly decreased(P<0.01,P<0.001);compared with the model group,the distribution level of GSK3αin the hippocampus in the treatment group was significantly decreased(P<0.001),and the distribution level of pS^21GSK3α,P85αand P110αin hippocampus was significantly increased(P<0.05,P<0.001).The Western blot results showed compared with the control group,the expression of pS^21GSK3α,P85αand P110αas well as the ratio of pS^21GSK3α/GSK3αin the hippocampus in the model group were significantly decreased(P<0.001),and the expression of GSK3αwas increased(P<0.05);compared with the model group,the expression of pS^21GSK3α,P85α,P110αand the ratio of pS^21GSK3α/GSK3αin the hippocampus in the treatment group were significantly increased(P<0.01,P<0.001),and the expression of GSK3αwas decreased(P<0.05).Compared with the control group,the number of hippocampal SP in the model group was significantly increased(P<0.001);compared with the model group,the number of hippocampal SP in the treatment group was significantly decreased(P<0.01).Conclusion EA could effectively regulate the expression of PI3K/GSK3αsignal pathway related proteins in the hippocampus in mice with AD,so as to reduce the formation and deposition of SP.