跑台运动通过激活AMPK减少APP/PS1小鼠海马Aβ沉积

Treadmill Exercise Reduces Aβ Deposition in the Hippocampus of APP/PS1 Mice by Activating AMPK

目的:探讨AMPK介导的运动减少APP/PS1小鼠海马Aβ沉积的分子机制。方法:将3月龄C57BL/6品系的APP/PS1小鼠和野生小鼠各48只分别随机分为APP/PS1安静对照组(ADC,n=24)、APP/PS1运动组(ADE,n=24)、野生安静对照组(WTC,n=24)和野生运动组(WTE,n=24)。ADE、WTE组进行12周跑台运动,同时ADC、WTC组置于安静跑台环境。采用ELISA实验测海马ATP、AMP含量,RT-qPCR实验测海马AMPK和BACE1mRNA水平,Western Blot实验测海马AMPK及其磷酸化(p-AMPK)蛋白表达、Sirt1、PPARγ、PGC1α、BACE1、Aβ等蛋白表达,免疫组化实验测海马SPs水平。结果:1) 12周跑台运动可提高APP/PS1小鼠海马, ATP、AMP含量,增加AMP/ATP比值(P<0.05);2)上调AMPK mRNA,上调AMPK蛋白表达及p-AMPK水平,上调Sirt1、PPARγ、PGC1α蛋白表达水平(P<0.05);3)下调BACE1 mRNA和蛋白表达水平(P<0.05),同时下调Aβ蛋白和SPs(P<0.01)。结论:12周跑台运动减少APP/PS1小鼠海马Aβ沉积的分子机制可能和运动激活AMPK,改善海马能量代谢,继而调节AMPK-BACE1通路有关。

Objective: To investigate the molecular mechanism of exercise reducing Aβ deposition through AMPK signaling in the hippocampus of APP/PS1 mice. Methods: 48 APP/PS1 mice and 48 wild type mice of three-month-old C57 BL/6 strain were randomly divided into APP/PS1 quiet control group(ADC, n=24) and exercise group(ADE, n=24), wild type quiet control group(WTC, n=24) and exercise group(WTE, n=24).ADE and WTE mice performed 12-week treadmill exercise training, while ADC and WTC mice were positioned in a quiet running platform environment at the same time. The contents of ATP and AMP in hippocampus were checked by ELISA. AMPK and beta-site amyloid precursor protein cleaving enzyme 1(BACE1) mRNA expression in hippocampus was tested by RT-qPCR. The protein expression of AMPK, Sirt1,PPARγ, PGC1α, BACE1, beta-Amyloid(Aβ) in hippocampus was verified by Western Blot. The Senile plaques(SPs) level in hippocampus was tested by immunohistochemical experiments.Results: 1) 12-week treadmill exercise significantly increased the AMP、ATP content, and the AMP/ATP ratio in the hippocampus of APP/PS1 mice(P 0.05);2) 12-week treadmill exercise significantly up-regulated the mRNA, the protein and its phosphorylation expression of AMPK,and the protein expression of Sirt1、PPARγ and PGC1α in the hippocampus of APP/PS1 mice(P<0.05);3) It also down-regulated the BACE1 mRNA and protein expression(P<0.05), Aβprotein and SPs level(P< 0.01) in the hippocampus of APP/PS1 mice. Conclusion: The molecular mechanism that 12-week treadmill exercise decreased Aβ deposition in the hippocampus of APP/PS1 mice may be related to the activation of AMPK by exercise, which can improve the energy metabolism and regulate the AMPK-BACE1 pathway in the hippocampus of APP/PS1 mice.