哺乳动物瞬时受体电位离子通道TRPM7的结构与功能研究

Stroke is a major cardio-cerebrovascular disease that threatens human life and health in our country. The high morbidity of disability creates a significant burden on patients and their families. However, there are still no effective treatment for stroke. In vivo study of rat brain shows that inhibition or knockdown of Transient Receptor Potential Melastatin 7 ion channel （TRPM7）greatly reduces pyramidal cell death after cerebral ischemia and maintains normal neuronal functions. Therefore, TRPM7 has a great potential to be a new drug target for ischemic stroke. It is of great importance to the development of drugs for the treatment of stroke if we solve the structure of TRPM7. TRPM7 will be overexpressed in mammalian expression system, and then purified with highly stable and homogeneous protein sample. Single particle cryo-electron microscopy will be used to determine the 3-D dimensional structures of TRPM7. Furthermore, our research will be focused on TRPM6 and TRPM7 complex. We will also try to get the structure of TRPM6/7 complex. The structural studies of TRPM7 and TRPM6/7 complex will therefore provide essential insights for the development of improved drug for the treatment of stroke.

中风是威胁我国人民生活健康的重大心脑血管疾病，其高致死致残率对患者和其家人造成重大的负担。但是，目前针对这一重大疾病并无很有效的药物。大鼠的体内实验研究表明，通过抑制或者敲除瞬时受体电位离子通道TRPM7，能够极大地减少脑缺血性锥形神经细胞的死亡，同时还能在较长的时间内保持正常的神经元活性。因此，TRPM7是一种非常有潜力的治疗中风的新型靶点。一旦解析出TRPM7的结构，对治疗中风的药物开发具有非常重要的意义。本研究采用哺乳细胞表达系统大量表达TRPM7蛋白，纯化获得稳定均一的蛋白，之后利用单分子冷冻电镜技术解析TRPM7的三维结构。我们也将对TRPM6和TRPM7复合物进行研究，力争获得复合物结构，为之后中风相关药物的开发提供结构基础。

中风是威胁人类健康的第二大致死疾病，每年都有数百万人因为中风而死亡。我国有中风病人将近7000万人，其中80%是由缺血性中风引起的，因此对于缺血性中风的药物研发一直是研究的重点和热点。TRPM7是非常理想的治疗缺血性中风的靶点，靶向TRPM7的选择性抑制剂的开发将给治疗中风的药物开发提供新思路，解析出TRPM7的结构,基于其结构开发相关的小分子抑制剂，对治疗中风的药物开发具有非常重要的意义。本项目利用BacMam表达系统，成功构建了TRPM7蛋白的最优克隆，并检测了其表达量和稳定性。利用单颗粒冷冻电镜技术解析了TRPM7与镁离子结合的高分辨率结构，揭示了镁离子在TRPM7选择性过滤器传导孔的中心的结合位点，阐明体内镁离子的运输机制，相关研究成果以共同通讯作者身份发表于PNAS杂志上（两篇）。这些发现为理解TRPM亚家族的结构奠定了基础，为相关药物的开发提供新的依据，具有重要的科学意义和临床价值。