Rab蛋白在β-淀粉样蛋白环境中介导GSK-3抑制剂兴奋性毒性保护作用的机制研究

The glutamate excitotoxicity plays an important role in the pathogenesis of Alzheimer's disease (AD) which is one of the targets of therapeutic research. GSK-3 inhibitors，a multi-target medicine，is widely concerned in the research of AD therapy but the clinical application is unsatisfactory. Our previous studies suggest GSK-3 inhibitors can reduce neuronal NMDA current and protect NMDA excitotoxicity but the protective effect weaken after Aβ intervention. Based on existing research and our preliminary data, we hypothesize that Aβ deposition caused abnormal activation of the Rab protein, so that the NMDA receptor can not be internalized by GSK-3 inhibitors mediated by Rab proteins and lose the protective effect of NMDA excitotoxicity. In this research we will determine that GSK-3 inhibitors lose the NMDA excitotoxicity protection after Aβ intervention or in APP/PS1 transgenic mice. After that we will study the role and mechanism of Rab proteins involved in GSK-3 inhibitors excitotoxicity protection after Aβ intervention and in APP/PS1 mice. Study on the mechanism of Rab protein which was involved in excitotoxicity protection of GSK-3 inhibitors in AD will help us to find new therapeutic target for AD, which has important theoretical significance and application value.

谷氨酸兴奋性毒性在AD发病机制中占有重要地位，也是治疗研究靶点之一。我们前期研究提示GSK-3抑制剂能减少神经元NMDA电流，具有兴奋性毒性保护作用，但在Aβ干预后保护作用减弱。基于现有的研究和预初实验，我们提出如下假说：Aβ沉积后引起Rab蛋白异常激活，使GSK-3抑制剂无法通过Rab蛋白介导NMDA受体内化，而失去对兴奋性毒性的保护作用。研究内容：（1）确定GSK-3抑制剂在Aβ干预后及APP/PS1转基因鼠中失去对NMDA兴奋性毒性的保护；（2）明确Rab蛋白在Aβ干预后及APP/PS1鼠中的功能改变及分布改变；（3）Rab蛋白异常改变对GSK-3抑制剂的兴奋性毒性保护作用的影响及机制探讨。本课题的开展将就GSK-3抑制剂在AD中兴奋性毒性的保护机制及其中Rab蛋白的作用研究提供理论依据，有助于在AD探寻新的潜在治疗和联合用药靶点，具有重要理论意义和应用价值。

项目背景：.阿尔茨海默病（Alzheimer’s disease，AD）是发生在老年期以进行性痴呆和精神行为异常为主的中枢神经系统退行性疾病。迄今，AD的发病机制及治疗靶点的研究仍不明确。本课题旨在通过AD中GSK-3抑制剂对谷氨酸能受体的影响及其机制研究，为明确AD的发病机制及治疗靶点提供有价值的线索。.主要内容：.本研究采用全细胞膜片钳、生化、免疫和动物行为学检测等方法进行AD中谷氨酸能受体的相关研究。我们发现在Aβ处理的大鼠PFC细胞和APP转基因小鼠中GSK-3抑制剂失去了对NMDA受体介导电流的抑制作用及对NMDA兴奋性毒性的保护。通过免疫共沉淀等方法揭示GSK-3抑制剂对 NMDA的调控是通过减少APP小鼠表面表达的NR1和的NR1/PSD-95结合，与Rab5参与的NMDA受体内化密切相关。 .重要结果及关键数据：.创新性地发现GSK-3抑制剂对AD环境中NMDA受体介导的电流调控作用减少及对NMDA兴奋性毒性保护作用消失。并对其中可能机制进行探讨，发现GSK-3抑制剂对 NMDA的调控是通过减少APP小鼠表面表达的NR1和的NR1/PSD-95结合，与Rab5参与的NMDA受体内化密切相关，为GSK-3抑制剂临床用于AD治疗靶点的拓展提供理论依据。. 科学意义：. GSK抑制剂作为AD潜在的治疗靶点药物，在AD环境中由于对NMDA的调控受损，进而失去了谷氨酸兴奋性毒性的保护作用，该结果提出了GSK-3在AD中的新的作用机制及相应的治疗靶点。