运动缓解AD小鼠海马Aβ沉积和Tau蛋白异常磷酸化的机制研究

With the aging of human population, the number of patients with Alzheimer's disease (AD) has been significantly increased. AD is a progressive neurodegenerative disorder for which there are few therapeutics that affect the underlying disease pathophysiology. Many researches are dedicated to alleviate AD by physical exercise. In this grant proposal, APP/Tau transgenic AD mice will be used as research object. The method of behavior test- - - - Morris Water Maze and Object Novel Recognition Test will be used to examine the effects of learning and memory in mice following the exercise training. The morphological methods of immunohistochemistry will be used to examine the effects of exercise training on deposition of β-amyloid protein and abnormal phosphorylation of Tau in hippocampus of mice. The most important objective of this research is to determine whether exercise training can decrease the β-amyloid protein by promoting the gene and protein expression of NEP, IDE, ECE, ACE, MT1-MMP, LRP-1, IVIG as well as by restraining the gene and protein expression of BACE; whether exercise training can promote the gene and protein expression of PP2B, PP2A, PP2C and PP1 or by restraining MAPK, GSK-3, CDK-5 and PKA to lead dephosphorylation of abnormally phosphorylated Tau in mouse brain. Our proposed studies would offer new insights into the neurobiological processes of AD that may ultimately lead to new interventions for prevention and treatment of AD.

随着人口的老龄化，阿尔茨海默病（AD）患者也呈现增多趋势，大量研究致力于通过运动来缓解AD。本研究以APP/Tau转基因AD小鼠为研究对象，通过Morris水迷宫测试和新奇事物识别测试等行为学方法检测运动对转基因AD小鼠学习和记忆能力的影响，同时检测运动对小鼠海马β-淀粉样蛋白（Aβ）斑块和异常磷酸化Tau蛋白等形态学的影响。重点研究运动能否通过促进NEP、IDE、ECE、ACE、MT1-MMP、LRP-1、IVIG和抑制BACE来减少海马Aβ的含量；运动能否通过促进异常Tau蛋白去磷酸化的PP2B、PP2A、PP2C、PP1和抑制Tau蛋白异常磷酸化的MAPK、GSK-3、CDK-5、PKA来减少异常磷酸化的Tau蛋白水平，为揭示运动预防和缓解AD的分子机制提供实验依据。

本课题以3月龄APP/PS1转基因AD小鼠(APP/PS1 transgenic AD mice)为研究对象，探讨自主跑轮运动对转基因AD小鼠认知功能及其海马β-淀粉样蛋白（β-amyloid，Aβ）沉积，以及海马中Aβ产生和清除的相关酶的影响，以探讨自主运动预防阿尔茨海默病(Alzheimer's disease，AD)的可能分子生物学机制。本研究选取转基因小鼠30只，随机分为转基因自主运动组（TE组，n=15）和转基因对照组（TC组，n=15），同时选取野生型小鼠30只，随机分为自主运动组（E组，n=15）和对照组（C组，n=15），各组小鼠正常饲养，而运动组给予16周的自主跑轮运动。结果发现16周的自主跑轮运动显著缩短了转基因AD小鼠的Morris水迷宫潜伏期和总路程，说明自主运动促进了转基因AD小鼠的空间学习和记忆能力；通过对小鼠脑组织切片的免疫组织化学实验，我们发现自主运动能够显著减少转基因AD小鼠脑内Aβ沉积的水平；通过对海马蛋白的Western blot实验检测，我们发现自主运动能够显著抑制了转基因AD小鼠海马β-分泌酶BACE1的蛋白表达、促进了α-分泌酶ADAM10的蛋白表达，同时自主运动显著促进Aβ清除的降解酶NEP、IDE、ACE和MMP9的蛋白表达水平，说明自主运动可通过抑制转基因小鼠海马Aβ的生成和促进Aβ的清除的方式抑制海马Aβ的沉积，进而预防或缓解AD的发病。因此，本研究是对该研究领域的一个重要补充。本课题组成员已发表了6篇相关的核心期刊论文和1篇普通期刊论文。此外，我们已完成了2篇SCI论文的写作，正处于投稿和修改中。