糖尿病血视网膜内屏障功能损伤新机制：低CTRP3血症的失保护作用及其机理研究

Microvascular leakage caused by blood-retinal barrier function damage is one of the most important mechanisms in the development of diabetic retinopathy (DR). The applicant's previous clinical research found that: CTRP3 is a novel biomarker for diabetic retinopathy. Animal and cell studies have shown that CTRP3 up-regulates the expression of VE-cadherin, which is a key adhesion protein in the formation of vascular barriers, and significantly improves retinal and ear microvascular leakage in mice caused by type 2 diabetes. Based on this, the scientific Microvascular leakage caused by blood-retinal barrier function damage is one of the most important mechanisms in the development of diabetic retinopathy (DR). The applicant's previous clinical research found that: CTRP3 is a novel biomarker for diabetic retinopathy. Animal and cell studies have shown that CTRP3 up-regulates the expression of VE-cadherin, which is a key adhesion protein in the formation of vascular barriers, and significantly improves retinal and ear microvascular leakage in mice caused by type 2 diabetes. Based on this, the scientific hypothesis is proposed: The lack of CTRP3 may cause of damage to the inner retinal barrier function of in the early stage of DR; and supplementation of CTRP3 can improve DR by up-regulating adhesion and tight junction function and enhancing internal barrier function. This project intends to understand the CTRP3 deficiency caused by diabetes is a new mechanism in the early the inner retinal barrier function damage of DR.We intends to investigate the role of pathological CTRP3 signaling induced inner retinal barrier failure in DR. And reveal mechanisms and downstream molecules of CTRP3 signaling. This project will provide a potential target for further clinical intervention DR.

血视网膜内屏障功能损伤导致的微血管渗漏是糖尿病视网膜病变（DR）发展过程中的重要环节之一。申请人前期临床研究发现：人血浆脂肪因子CTRP3水平降低与DR的发生率和严重程度显著相关。动物及细胞研究显示：CTRP3上调粘附蛋白VE-cadherin表达，显著改善2型糖尿病导致的小鼠视网膜和耳微血管渗漏。据此，提出科学假设：CTRP3的缺乏是导致DR早期血视网膜内屏障功能损伤重要原因；而外源性补充CTRP3可以通过上调粘附连接蛋白及其下游紧密连接蛋白表达进而增强内屏障功能，从而有效改善DR。本项目拟采用基因敲除小鼠构建模型动物，阐明由糖尿病导致的CTRP3缺乏是DR早期血视网膜内屏障功能损伤的关键因素；采用模式动物结合细胞实验，研究CTRP3缺乏对血视网膜内屏障功能的失保护作用及其外源性补充有效改善病变的机理。本研究揭示DR早期血视网膜内屏障功能损伤的新发病机制，并为临床防治DR提供潜在靶点。

研究背景：CTRP3作为一个非常有潜力的治疗代谢综合征的手段成为近来的研究热点。血视网膜内屏障功能损伤导致的微血管渗漏是糖尿病视网膜病变（DR）发展过程中的重要环节之一。申请人前期临床研究发现：人血浆脂肪因子CTRP3水平降低与DR的发生率和严重程度显著相关。动物及细胞研究显示：CTRP3上调紧密连接相关蛋白的表达，显著改善2型糖尿病导致的小鼠视网膜和耳微血管渗漏。据此，提出科学假设：CTRP3的缺乏是导致DR早期血视网膜内屏障功能损伤重要原因；而外源性补充CTRP3可以通过上调粘附连接蛋白及其下游紧密连接蛋白表达进而增强内屏障功能，从而有效改善DR。.研究内容：本研究采用基因敲除小鼠构建模型动物，采用模式动物结合细胞实验及分子生物学实验，将CTRP3应用到到视网膜微循环层面，深入分析CTRP3对DR血视网膜内屏障（iBRB）及视网膜血管功能障碍的保护作用及其及机制。在本项目的研究中，申请人不但证实了CTRP3对糖尿病视网膜病变中血管内屏障的保护作用，且进一步发现了CTRP3对糖尿病视网膜病变中微血管舒张功能受损有抑制作用，并探讨其机制。.重要结果及关键数据：CTRP3可以通过AMPK/Occludin/Claudin-5信号通路稳定血视网膜内屏障（iBRB）的紧密连接，防止糖尿病视网膜病变引起的视网膜血管通透性增高；并且CTRP3 通过激活微血管内皮细胞中AMPK/eNOS/NO s信号通路改善糖尿病患者视网膜微血管舒张功能受损。.科学意义：CTRP3对糖尿病患者iBRB及视网膜血管功能障碍的保护作用使视网膜形成一系列损伤之前，早期抑制恶性循环，对DR发挥治疗的作用。本项目的实施为CTRP3成为糖尿病视网膜病变（DR）干预的新思路及新靶点提供重要的理论依据。