Role of intercellular communication in pathogenesis of diabetic retinopathy

本项目的总体目标是检验Cx43表达减少 以及随后由高葡萄糖/糖尿病导致的细胞间通讯改变 糖尿病患者视网膜毛细血管中的细胞死亡和血管稳态破坏 视网膜病变这一假设是基于高葡萄糖会降低Cx43的发现。 在微血管内皮细胞和视网膜周细胞中表达， 连接细胞间通讯我们目前的研究表明，Cx43减少 表达触发细胞凋亡（修订稿，IOVS）。整体工作 一种假说认为，Cx43表达的减少会引发血管细胞死亡，这是一个显著的 以及与糖尿病视网膜病变的发展相关的早期病变，反过来， 减少视网膜血管细胞中的细胞间通讯， 血管稳态已知视网膜血管细胞死亡通过细胞凋亡发生，但它是一种细胞凋亡。 目前尚不清楚在糖尿病视网膜病变的发展过程中细胞凋亡是如何被触发的。 初步数据表明，血管细胞之间的通讯，即内皮细胞 细胞-内皮细胞、内皮细胞-周细胞和周细胞-周细胞对于它们的 细胞间通讯中断可引发细胞凋亡， 干扰它们通过细胞内连接蛋白（Cx）通道形成功能单位的作用 交叉点本建议的具体重点是确定（一）减少的影响 视网膜内皮细胞和周细胞中的Cx43表达，（ii）高血糖- 诱导过量ECM合成调节视网膜内皮细胞Cx43表达 和周细胞，以及（iii）Cx43表达减少是否诱导紧密连接 视网膜内皮细胞功能障碍。多种细胞生物学、分子生物学 生物和生化技术，包括反义寡核苷酸介导的特异性 基因表达下调，刮载染料转移技术，荧光 显微镜和Western blot方法将用于研究高浓度的 葡萄糖诱导的Cx43表达抑制和细胞间通讯减少， 视网膜细胞活力和功能。这些研究的结果将提供更好的 理解Cx43表达和间隙改变背后的细胞间通讯 视网膜血管细胞连接通道及其在血管破裂中的作用 与糖尿病视网膜病变相关的体内平衡。该机构的一项重要使命是 寻找治疗和预防糖尿病视网膜病变引起的并发症。拟议 该项目预计将提供重要的发现，可以帮助更好地了解 糖尿病视网膜病变的发病机制。

The overall goal of this project is to test the hypothesis that reduced Cx43 expression and subsequent altered cell-cell communication triggered by high glucose/diabetes leads to cell death and breakdown of vascular homeostasis in the retinal capillaries in diabetic retinopathy. The hypothesis is based on findings that high glucose reduces Cx43 expression in microvascular endothelial cells and retinal pericytes and compromises gap junction intercellular communication. Our current study showed reduced Cx43 expression triggers apoptosis (manuscript under revision, IOVS). The overall working hypothesis is that reduced Cx43 expression triggers vascular cell death, a prominent and early lesion associated with the development of diabetic retinopathy, which in turn, reduces cell-cell communication in the retinal vascular cells and ultimately disrupts vascular homeostasis. Retinal vascular cell death is known to occur by apoptosis but it is unknown how apoptosis is triggered during the development of diabetic retinopathy. Preliminary data suggests that communication between vascular cells, that is endothelial cell-endothelial cell, endothelial cell-pericyte, and pericyte-pericyte is essential for their survival, and that disruption in cell-cell communication may trigger apoptosis and interfere with their role to form a functional unit via the connexin (Cx) channels in cell junctions. The specific focus of this proposal is to determine (i) the effect of reduced Cx43 expression in retinal endothelial cells and pericytes, (ii) whether high glucose- induced excess ECM synthesis modulates Cx43 expression in retinal endothelial cells and pericytes, and (iii) whether reduced Cx43 expression induces tight junction dysfunction in the retinal endothelial cells. A variety of cell biological, molecular biological and biochemical techniques including antisense oligo mediated specific downregulation of gene expression, scrape load dye transfer technique, fluorescence microscopy and Western blot method will be used for studying the consequence of high glucose-induced inhibition of Cx43 expression and reduced cell-cell communication on retinal cell viability and function. Findings from these studies will provide a better understanding of cell-cell communication underlying altered Cx43 expression and gap junction channels in retinal vascular cells and their role in breakdown of vascular homeostasis associated with diabetic retinopathy. An important mission of the agency is to find a cure and prevent complications arising from diabetic retinopathy. The proposed project is expected to provide important findings that can help in better understanding the pathogenesis of diabetic retinopathy.