猪链球菌烯醇化酶干扰核糖体蛋白SA在脂筏区的定位并诱导脑微血管内皮细胞凋亡的机制研究

核糖体蛋白SA（RPSA）是近年来发现参与致病的重要宿主蛋白，目前证实脑膜炎细菌通过与RPSA结合进入细胞并穿越血脑屏障而致病。本课题组前期研究却发现脑膜炎型猪链球菌2型（SS2）菌株并不通过RPSA进入细胞，而是依靠其毒力因子烯醇化酶（Eno）干扰猪脑微血管内皮细胞（BMEC）膜表面RPSA在脂筏的正常定位，诱导细胞凋亡从而破坏血脑屏障的完整性，促进细菌入脑。目前尚无RPSA介导病原相关的凋亡现象和机制的报道。本项目拟以Eno和BMEC互作模型为研究平台，采用免疫荧光、冷冻电镜、基因编辑技术和RPSA条件性缺失鼠，系统研究Eno刺激下RPSA 的表达定位、修饰、脂筏结合特征、凋亡相关分子及信号的活化与功能，深入揭示Eno干扰RPSA在脂筏的定位并诱导细胞凋亡的调控机制。这一研究成果有助于推动链球菌脑膜炎的深入研究，增加对病原性凋亡新的认知，并为广泛揭示RPSA相关的病理作用提供借鉴。

Ribosomal protein SA (rPSA) is an important host protein that has been found to be involved in the pathogenesis in recent years. At present, it has been confirmed that meningitis bacteria can cause disease by combining with RPSA into cells and crossing the blood-brain barrier (BBB). However, the previous study of our group found that S.suis type 2 (SS2) strain caused meningitis did not enter the brain through RPSA, but relied on its virulence factor enolase (Eno) to interfere with the normal location of RPSA on the membrane surface of porcine brain microvascular endothelial cells (BMEC) in the lipid raft, inducing cell apoptosis, thus destroying the integrity of blood-brain barrier and promoting bacteria to enter the brain. At present, there is no RPSA mediated apoptosis phenomenon and mechanism. In this project, the interaction model of Eno and BMEC is used as the research platform, we will systematically study the expression and location of RPSA of BMEC, the relationship change and binding proteins of RPSA and lipid rafts, and activation of apoptosis related molecules and signals with the technologies of immunofluorescence, frozen electron microscopy, gene editing technology and RPSA conditionally deficient mice when BMECs are stimulated with Eno protein. Then we are going to explore deeply the mechanism of RPSA mediating apoptosis through its location out of lipid raft by SS2 Eno interference. This research is helpful to promote the in-depth study of streptococcal meningitis, increase the new cognition of pathogenic apoptosis, and provide reference for widely revealing the related pathological functions of RPSA.