针刺改善阿尔茨海默病大鼠海马区葡萄糖代谢的机制研究

Currently the study of Alzheimer's disease (AD) focuses on how to prevent and delay its early progress. The patients in early stage have shown the impairment of brain glucose metabolism, which is closely linked with the abnormal accumulation of amyloid and Tau protein. The previous NSFC subject that the applicant involved used PET-CT to observe the brain energy metabolism by using acupuncture at Du meridian points "Renzhong(Du26)" and "Baihui(Du20)" on the rats suffering from Alzheimer's disease (AD) . The results showed that the glucose uptake of hippocampus in acupuncture group was significantly increased.Based on the previous experiment and the clinical fact that acupuncture at Du meridian can improve the symptoms of AD, this project proposes the scientific hypothesis that the mechanism of acupuncture improving glucose metabolism in AD hippocampus lies in it can promote the glucose transport at blood-brain barrier and regulate insulin and glucagon mediated signal pathways in hippocampus. Based on the understanding of Chinese and western medicine on AD and the specificity of acupoints, the project aims at the overall adjustment of acupuncture, to study the protein metabolism and gene expression at the molecular level, attempting to clarify the modern scientific mechanism of using acupuncture at Du meridian to improve the blood glucose metabolism in hippocampus, so to provide experimental evidence for prevention and treatment of AD by acupuncture, as well as supply some innovative attempts to guide modern experimental research with traditional Chinese medicine theory .

目前阿尔茨海默病(Alzheimer’s disease，AD)的研发重点在于如何预防和延缓其早期的进展，而AD患者早期即出现了大脑葡萄糖代谢损伤，且与淀粉样蛋白和Tau蛋白异常积聚有密切关联。申请人参与的前项NSFC 课题利用PET-CT观察了针刺督脉腧穴“人中”和“百会”对AD大鼠脑内能量代谢的影响，结果提示针刺可改善海马区葡萄糖代谢。本项目基于前期的实验依据，以及针刺督脉腧穴可改善AD临床症状的事实依据，提出科学假说：针刺对血脑屏障处葡萄糖转运的促进及海马区胰岛素和胰高血糖素介导的信号通路的调节是改善AD海马区葡萄糖代谢的机制。拟从中西医学对AD的认识出发，着眼于针刺的整体调节作用，在分子水平对蛋白代谢和基因表达开展研究。试图阐明针刺督脉腧穴改善AD大鼠海马区葡萄糖代谢的科学机制，为针刺防治AD提供实验依据，也为应用传统中医理论指导现代实验研究提供创新性尝试。

目前阿尔茨海默病(Alzheimer’s disease，AD)的研发重点在于如何预防和延缓其早期的进展。大量的临床和基础研究数据证实，患者在疾病早期就已经出现了大脑葡萄糖代谢损伤，其损伤先于临床症状出现，甚至提前数十年。因而可以在AD发病早期，使用靶向于葡萄糖代谢水平的治疗方法，改善大脑糖代谢状态，预防和治疗AD。本项目研究了针刺对阿尔茨海默病大鼠行为学及海马区β淀粉样蛋白表达的影响，针刺对血脑屏障（BBB）处葡萄糖转运蛋白1(GLUT1)的影响，针刺对海马区胰岛素信号通路PI3K-Akt相关标志物含量及活性的影响，针刺对海马区胰高血糖素信号通路c AMP及蛋白激酶A(PKA)含量及活性的影响，以及针刺对海马区GLP- 1分泌的作用。结果显示：（1）行为学检测结果：①在定位航行实验中，针刺组大鼠逃避潜伏期明显缩短（P<0.01）。②空间探索实验中，针刺组大鼠穿越平台次数显著增加P<0.01）（2）HE染色结果显示，针刺组神经元细胞形态较为正常，结构相对完整，排列较整齐。（3）TUNEL染色结果显示，针刺组大鼠海马区凋亡细胞明显减少（P<0.01）。（4）免疫组化染色结果：①针刺组大鼠海马区Aβ、Tau、p-tau的表达显著降低（P<0.01）。②针刺组大鼠海马区GLUT1、GLUT3、GLUT4的表达均显著增高(P<0.01）。（5）Western blot检测结果：针刺组大鼠海马区INSR、PI3K、AKT蛋白表达水平均明显增高（P<0.01），GSK-3β蛋白表达明显降低（P<0.01）。（6）针刺组AD大鼠海马区的cAMP、PKA、GLP-1蛋白水平均上升，小肠及海马区GLP-1基因表达均增强（P＜0.05）。提示针刺百会、水沟可改善AD大鼠的学习记忆能力，可减轻AD大鼠海马神经元病理损害，具有一定的脑保护作用，能修复和激活中枢胰岛素PI3K/AKT信号通路，有效调节AD大鼠海马区葡萄糖代谢关键转运蛋白表达，从而综合提高AD大鼠海马区葡萄糖代谢水平。针刺督脉腧穴可以改善AD大鼠的学习记忆能力，还可能与拮抗cAMP/PKA信号通路异常表达有关。