海马缝隙连接参与卒中后抑郁发病的机制研究

Post-stroke depression (PSD) is a common complication of stroke, with an incidence of 29% to 70%, which seriously affects the prognosis and quality of life in stroke patients. Our previous studies suggested that the pathophysiological changes in the hippocampus are closely related to the pathogenesis of PSD. Recent research have suggested that gap junction(GJ)-mediated abnormal cell-cell information transmission may be involved in the occurrence of multiple neuropsychiatric diseases and the abnormal expression of connexin (Cx) may be related to the occurrence of primary depression, but the specific pathogenesis remains unclear. There is no relevant research report on the relationship between hippocampal gap junction and PSD. This project is intended to via: 1. Use of scrap-loading LY dye transfer （SLDY）, transmission electron microscope, immunohistochemistry, Western-blot and real-time fluorescent quantitative PCR and other experimental techniques to study the function and ultrastructure of GJ and the expression of Cx36, Cx43, Cx36mRNA, Cx43mRNA of hippocampus in PSD rats. 2. we applied the connexin agonist (All-trans retinoic acid) and connexin blocker(carbenoxolone) to intervene the PSD model rats and observed the behavior changes of rats, functional and ultrastructural changes of the gap junction. In order to provide a theoretical basis and experimental basis for seeking new targets for the prevention and treatment of PSD, we study the correlation between gap junctions and PSD and explore the pathogenesis of PSD in cell communication.

卒中后抑郁（PSD）是脑卒中常见并发症，发生率为29%～70%，严重影响卒中患者的预后和生存质量。课题组前期工作提示，海马病理生理变化与PSD发病关系密切，近期有研究认为海马缝隙连接介导的细胞间信息传递异常可能参与了多种神经精神疾病的发生，缝隙连接蛋白（Cx）表达异常可能与原发性抑郁症的发生相关，但具体机制尚未明确。海马缝隙连接与PSD关系如何目前未见相关研究报道。本项目拟通过：1.使用染料示踪法、电镜观察法、免疫组织化学、蛋白免疫印迹、实时荧光定量PCR等实验技术，对照研究PSD大鼠海马缝隙连接功能、超微结构和Cx36、Cx43及其mRNA表达；2.应用缝隙连接激动剂（全反式维甲酸）和缝隙连接阻滞剂（甘珀酸）干预后，观测PSD大鼠的行为学、海马缝隙连接功能和超微结构改变情况。研究缝隙连接与PSD发生的相关性，探讨PSD细胞通讯方面的发病机制，为寻求防治PSD新靶点提供理论基础和实验依据。

由国家自然科学基金委资助的项目“海马缝隙连接参与卒中后抑郁发病的机制研究”（计划资助时间：2019.01-2022.12，编号：81860226），自2019年1月起一直按照计划任务项目书要求一直开展着相应研究。本项目首次研究卒中后抑郁（post-stroke depression, PSD）与海马缝隙连接间的关系，并通过使用缝隙连接激动剂ATRA和缝隙连接阻滞剂CBX干预PSD大鼠，验证海马缝隙连接与PSD发生的相关性。实验结果发现PSD大鼠在旷场实验中穿格次数和穿越总距离较正常组大鼠下降，大鼠海马缝隙连接中的Cx36、Cx43表达与PSD的发生具有密切相关性。Cx36、Cx43在PSD大鼠模型中表达较正常组大鼠降低，PSD大鼠模型海马缝隙连接功能也较正常组大鼠下降，且海马星形胶质细胞缝隙连接宽度较正常组增宽。使用CBX干预后的PSD大鼠模型Cx36、Cx43表达较PSD组进一步降低，行为学中旷场实验也提示较于PSD组CBX组大鼠穿格次数及穿越总距离进一步下降，同时电镜提示CBX组大鼠海马星形胶质细胞缝隙连接宽度较PSD组大鼠的增宽，当使用ATRA干预后则出现与CBX相反的结果。这些结果表明大脑海马缝隙连接可能参与PSD的发病机制，通过干预海马缝隙连接或可干预PSD的疾病过程，进而达到治疗的目的。同时这也为海马缝隙连接作为PSD的治疗靶点提供了理论基础。截止2022年12月，本研究已完成大部分实验，故向国家自然科学基金委申请结题。