GluN2A在脑缺血中的作用及其分子机制研究

GluN2A is closely related to cerebral ischemia, but its role in cerebral ischemia still remains controversial. Through in vivo and in vitro experiments, the applicant found that GluN2A promotes neuronal death and survival in the acute injury stage and repair stage, respectively. Based on the above results, we put forward our opinion in Molecular Neurobiology as following: GluN2A plays different roles in the different stages of cerebral ischemia, that is to say, GluN2A mediates pro-death effect in the acute injury stage and pro-survival effect in the repair stage. This project focuses on GluN2A. Through using selective GluN2A antagonists and positive allosteric modulators and carrying out experiments such as RNA interference, virus transfection, immunoprecipitation, immunofluorescence labeling and so on, the role of GluN2A in cerebral ischemia and its molecular mechanism will be deeply explored. The treatment strategy, that is using NMDA receptor antagonist in the acute injury stage and using GluN2A positive allosteric modulators in the repair stage, will also be studied. Through regulating the GluN2A function in the different direction at different stages, not only the cerebral damage may be decreased, but also the neuron survival and regeneration might be enhanced. Also, the interference of NMDA receptor antagonist on the normal physiological function of NMDA receptor may be reduced. By using this treatment strategy, the dilemma that the existing NMDA receptor antagonists can not be used in clinical treatment might be solved. It is also important to the development of anti-cerebral ischemia drugs which are based on NMDA receptor.

GluN2A与脑缺血损伤关系密切，但关于其在脑缺血中扮演何种角色，仍争论不休。通过在体和离体实验，申请人发现，GluN2A在缺血急性损伤期和修复期分别促进神经元死亡和存活。据此，我们在Molecular Neurobiology上提出 “GluN2A在不同脑缺血阶段起不同作用，即脑缺血急性损伤期介导促死亡效应，修复期介导促存活效应”。本课题着眼于GluN2A，通过使用选择性GluN2A拮抗剂和阳性变构调节剂，采用RNA干扰、病毒转染、免疫共沉淀、免疫荧光标记等方法，深入研究GluN2A在脑缺血中的作用及其分子机制，探讨“在脑缺血急性损伤期给予NMDA受体拮抗剂，在修复期给予GluN2A阳性变构调节剂”这一治疗策略的可行性。通过在不同阶段对GluN2A实施不同的调节，该治疗策略既可抑制脑缺血损伤，也可促进脑缺血后神经元的存活和再生，并减轻甚至消除NMDA受体拮抗剂对NMDA受体正常生理功能的

脑缺血已成为威胁人类健康的重大疾病，虽然NMDA受体的过度激活是诱发脑缺血损伤的关键机制之一，但关于NMDA受体GluN2A亚基在脑缺血中起何作用仍存争议。本项目研究发现，对于成熟皮层神经元，GluN2A在脑缺血不同阶段起不同作用，即急性期促死亡，后急性期促存活，但即使在后急性期，GluN2A的过度激活对神经元仍是有害的；与GluN2B相比较，GluN2A介导的促死亡作用较弱，其机制可能与抑制BDNF表达、降低CREB活性、增强nNOS及p38活性等有关；脑缺血再灌后，虽然长期给予GluN2A阳性变构调节剂不能显著减轻脑缺血损伤，但可改善动物的自发活动性和焦虑水平。本项目研究成果在Journal of Neuroscience Research、Frontiers in Pharmacology等刊物发表标注本项目基金号论文8篇，授权国家发明专利1项。