血管内皮生长因子负反馈拮抗剂对血管通透性的调控作用及分子机理研究

The destruction of vascular integrity and the increase of vascular permeability induce edema, aggravate the progress of cardiovascular and cerebrovascular diseases, and contribute to tumor metastasis and multiple sclerosis. The regulation of vascular endothelial cell adhesion and transcytosis is very important for this pathological process. Vascular endothelial growth factor (VEGF) is a pro-permeability factor, and anti-VEGF drugs are widely used in clinical, but there are many limitations. Therefore, the demand for the development of new specific VEGF inhibitors is increasingly urgent. Previous studies showed that VEGF negatively feedback antagonist Sprouty4 regulated vascular endothelial cell adhesion and migration, but its effects and mechanisms on permeability is unclear. We are going to investigate the regulation of Sprouty4 on endothelial cell barrier function in vivo with VEGF-induced vascular permeability models in the specific overexpression and depletion mice, and to examine the effects of Sprouty4 on VEGF-induced c-Src activation and vascular endothelial cadherin and Caveolin-1 expression and tyrosine phosphorylation in primary human endothelial cells in vitro. These research results are expected to further reveal the molecular mechanisms of vascular permeability regulation, which has important theoretical and clinical significance.

血管完整性的破坏和通透性的升高会诱发水肿，加重心脑血管疾病进展，有助于肿瘤转移及导致多发性硬化症。血管内皮细胞粘附连接和转胞吞作用的调节和对于这一病理过程非常重要。血管内皮细胞生长因子(VEGF)是一种促血管通透性因子，VEGF抗体药物在临床上广泛使用但存在不少局限性。因此，开发新型特异性的VEGF抑制剂的需求日益紧迫。之前的研究表明，VEGF负反馈拮抗剂Sprouty4可以调控内皮细胞的黏附和迁移，但对内皮细胞通透性的作用及机制尚不明确。我们将在特异性过表达和敲除小鼠体内采用VEGF诱导的血管通透性模型来研究Sprouty4对内皮细胞屏障功能的调控作用，并在人原代内皮细胞过表达和沉默的体外实验中测试Sprouty4对VEGF诱导的酪氨酸激酶c-Src活化及其介导的血管内皮钙粘蛋白和微囊蛋白1的表达和酪氨酸磷酸化。研究成果有望进一步揭示血管通透性调控的分子机制，具有重要的理论及临床意义。

血管通透性失调导致许多疾病，并影响疾病的发病率和治疗。血管内皮生长因子（VEGF）是一种促血管通透性分子，其抗体药物在临床上应用广泛但存在不少局限性。因此，开发新型特异性的VEGF抑制剂的需求日益紧迫。酪氨酸激酶抑制剂Sprouty4是一种VEGF负反馈拮抗剂，之前报道其可以调控血管内皮细胞的黏附与迁移， 但对血管通透性的作用及机制尚不明确。本项目旨在体内与体外通过特异性过表达和敲除实验来研究Sprouty4对血管内皮细胞屏障功能的调控作用及其分子机制。本项目研究结果表明，Sprouty4通过抑制VEGF诱导的Src磷酸化来下调血管内皮钙粘蛋白（VE-cadherin）的磷酸化水平，进而阻碍VE-cadherin的泛素化和蛋白酶体降解，最终达到减少血管通透性的作用。本项目研究成果将有望将Sprouty4 确认为一个新型血管内皮屏障功能调节蛋白，并且丰富我们对血管通透性相关疾病的认识，为特异性调节在病理状态下过量VEGF诱导的血管通透性异常提供新的治疗策略，为心血管疾病、多发性硬化症和癌症等血管通透性相关疾病的基础及临床研究提供新的思路。