ROCK调节血-视网膜屏障通透性对糖尿病性黄斑水肿的影响及机制研究

Diabetic macular edema (DME) is the leading cause of visual impairment in diabetes patients and shows both high incidence and prevalence. Impairment of retinal vascular barrier triggered by vascular endothelial growth factor (VEGF) is a core of pathophysiology of DME. Although anti-VEGF treatment using neutralizing antibody is the standard therapy in clinics to control DME, its long-term effects of repeated anti-VEGF injections are still unknown. Therefore, it is necessary to search other multitarget of curative approach to this complex disease. Our previous work showed that ROCK inhibitor effectively alleviated the VEGF-induced macular edema, suggesting that ROCK plays a key role in the regulation of BRB, but the mechanism of that remains unclear. Caveolin-1 as a key factor mediates ubiquitination of tight junction proteins on the membrane of vascular endothelial cells. We hypothesize that ROCK1 can directly phosphorylate caveolin-1, mediate the polyubiquitination of claudin-5 endocytosing it to aggresome for degradation. The purpose of this project is to reveal the molecular mechanism of ROCK1/caveolin-1 signaling pathway in regulating BRB, to understand the occurrence and development of DME, to provide theorical basis for finding accurate target of clinical treatment strategies.

糖尿病性黄斑水肿（DME）是糖尿病患者视力损害的主要原因，具有高发病率和患病率。血管内皮生长因子（VEGF）引起的血-视网膜屏障（BRB）损害是DME的病理基础。虽然使用VEGF中和性抗体是DME的标准疗法，但其反复注射的长期效应仍不清楚。因此，寻找更有效的治疗靶点成为研究热点。我们的前期工作显示，ROCK激酶抑制剂可以有效缓解VEGF引起的黄斑水肿，提示ROCK在调节BRB通透性方面起到关键作用，但其机制尚不明确。Caveolin-1是介导血管内皮细胞间紧密连接蛋白泛素化降解的关键因子，我们推测ROCK1可直接磷酸化caveolin-1，介导claudin-5的多泛素化至聚集体内降解，调控BRB通透性。本项目旨在揭示ROCK1/caveolin-1通路调控BRB的分子机制，深入地认识DME的发生、发展过程，为准确的寻找临床治疗靶点、制定针对性的治疗策略提供理论基础。

糖尿病性视网膜病变（DR）是导致全世界成年人视力下降的常见疾病。糖尿病性黄斑水肿（DME）是DR患者中视觉丧失的最主要原因之一。血管内皮生长因子（VEGF）与DME形成密切相关。虽然抗VEGF疗法对DME的治疗是有效的，但在大多数情况下需多次反复注射，并且在一些情况下仍不能发挥其应有的功效。我们的研究首次发现ROCK抑制剂有效阻止VEGF刺激条件下血-视网膜屏障的破坏，并在DME模型小鼠中验证了ROCK作为靶点治疗DME的可行性，揭示ROCK可能是一个新的血-视网膜屏障调节因子。同时，在我们课题组深入研究后还发现，在VEGF增高的病理条件下，视网膜血管内皮细胞中ROCK1被激活，细胞内应力纤维的形成，破坏claudin-5与ZO-1的稳定性，并且ROCK1磷酸化caveolin-1，促进caveolin-1与claudin-5结合，将其内吞至聚集体内进行多聚泛素化降解。因此，本课题揭示了ROCK调控血-视网膜屏障的分子机制，发现新的血-视网膜屏障调节因子和信号通路，并且探究了血-视网膜屏障通透性与糖尿病性黄斑水肿发生之间的关系，为ROCK1/caveolin-1/claudin-5信号通路成为临床治疗靶点、制定针对性的治疗策略提供理论基础。