The Interplay Between E-Cadherin, Connexin 43, and Zona Occludens 1 in Retinal Pigment Epithelial Cells
The Interplay Between E-Cadherin, Connexin 43, and Zona Occludens 1 in Retinal Pigment Epithelial Cells
复制标题
视网膜色素上皮细胞中 E-钙粘蛋白、连接蛋白 43 和闭塞带 1 之间的相互作用
DOI：
10.1167/iovs.19-27768
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发表时间：
2019-12-01
影响因子：
4.4
通讯作者：
Wang, Fang
中科院分区：
文献类型：
--
作者：
Bao, Huiqian;Yang, Shuai;Wang, Fang
目的.视网膜色素上皮（RPE）中的细胞间接触涉及粘附连接、间隙连接和紧密连接，其主要分别由E-钙粘蛋白、闭合细胞蛋白1（ZO-1）和连接蛋白43组成。在这里，我们的目的是探讨这些连接相关蛋白之间的关系和相互作用。检测TGF-β 1刺激后早期人原发性RPE中E-cadherin、connexin 43和ZO-1的表达。敲低E-钙粘蛋白，ZO-1，和连接蛋白43进行表征涉及这三种蛋白质的调控网络。采用染料转移法和FITC-葡聚糖渗透试验观察上皮细胞功能的变化。透射电镜观察小鼠视网膜色素上皮细胞间连接的超微结构。免疫荧光染色和免疫共沉淀法观察E-cadherin、ZO-1和connexin 43的共定位和物理结合。在这三种成分中，E-cadherin似乎是TGF-β 1处理后下调的第一种蛋白质。透射电镜观察到小鼠视网膜色素上皮细胞间粘附连接、缝隙连接和紧密连接的超微结构。E-cadherin、ZO-1和连接蛋白43共定位并彼此物理结合。这三种蛋白中的一种的敲低导致另外两种蛋白的下调并损害上皮功能。E-cadherin、ZO-1和connexin 43在物理上相互关联并相互调节。为了加强对细胞间接触的理解，需要一个整体的观点。我们的研究结果为RPE疾病如增殖性玻璃体视网膜病变提供了新的见解。
PURPOSE. Cell-cell contact in retinal pigment epithelium (RPE) involves adherent junctions, gap junctions, and tight junctions, which are primarily composed by E-cadherin, zona occludens 1 (ZO-1), and connexin 43, respectively. Here, we aimed to explore the relationship and interplay between these junction-associated proteins.METHODS. E-cadherin, connexin 43, and ZO-1 expression in human primary RPE in the early phase after TGF-beta 1 stimulation was detected. The knockdown of E-cadherin, ZO-1, and connexin 43 was performed to characterize the regulatory network involving these three proteins. Dye transfer and FITC-dextran permeability assays were conducted to observe the epithelial functional alterations. Transmission electron microscopy (TEM) was used to observe the ultrastructure of the cell-cell junctions in mouse RPE. The immunofluorescence staining and coimmunoprecipitation were performed to observe the colocalization and the physical association of E-cadherin, ZO-1, and connexin 43.RESULTS. Among these three components, E-cadherin appeared to be the first protein that was downregulated after TGF-beta 1 treatment. The ultrastructures of adherent junctions, gap junctions, and tight junctions could be observed in mouse RPE by TEM. E-cadherin, ZO-1, and connexin 43 were colocalized and physically bound to each other. The knockdown of one of these three proteins led to downregulation of the other two proteins and compromised epithelial function.CONCLUSIONS. E-cadherin, ZO-1, and connexin 43 were physically associated with each other and were mutually regulated. To enhance the understanding of cell-cell contacts, a holistic view is needed. Our results provide new insights in RPE disorders such as proliferative vitreoretinopathy.