Rizzolo L J
Department of Surgery/Anatomy, Yale University School of Medicine, New Haven, Connecticut 06520-8062, USA.
Histol Histopathol. 1997 Oct;12(4):1057-67.
The retinal pigment epithelium (RPE) is a monolayer that separates the outer surface of the neural retina from the choriocapillaris. Because the choriocapillaris is fenestrated, it is the RPE that forms the outer blood-retinal barrier and regulates the environment of the outer retina. Like all epithelia and endothelia, the ability of RPE to regulate transepithelial transport depends upon two properties: apical tight junctions to retard diffusion through the paracellular spaces of the monolayer, and an asymmetric distribution of proteins to regulate vectorial transport across the monolayer. During development, these properties form gradually. Initially, the tight junctions are leaky, and the RPE exhibits only partial polarity. As the neural retina and choriocapillaris develop, there are progressive changes in the composition of the apical junctional complexes, the expression of cell adhesion proteins, and the distribution of membrane and cytoskeletal proteins. Development can be used to dissect the multiple mechanisms that establish and maintain polarity and barrier function. These mechanisms are regulated by the interactions that develop between the RPE and its neighboring tissues. This review discusses the remodeling of the apical, lateral and basal plasma membranes of RPE that occurs during normal development, and establishes a framework to integrate the data obtained from multiple species. It examines the progress in understanding how environmental interactions regulate this development.
视网膜色素上皮（RPE）是一层将神经视网膜的外表面与脉络膜毛细血管分开的单层细胞。由于脉络膜毛细血管有窗孔，所以是RPE形成了外血视网膜屏障并调节外视网膜的环境。与所有上皮细胞和内皮细胞一样，RPE调节跨上皮运输的能力取决于两个特性：顶端紧密连接以阻止通过单层细胞旁间隙的扩散，以及蛋白质的不对称分布以调节跨单层细胞的向量运输。在发育过程中，这些特性逐渐形成。最初，紧密连接是渗漏的，RPE仅表现出部分极性。随着神经视网膜和脉络膜毛细血管的发育，顶端连接复合体的组成、细胞粘附蛋白的表达以及膜蛋白和细胞骨架蛋白的分布都有渐进性变化。发育可用于剖析建立和维持极性及屏障功能的多种机制。这些机制受RPE与其邻近组织之间形成的相互作用调节。本综述讨论了正常发育过程中RPE顶端、侧面和基底质膜的重塑，并建立了一个整合从多个物种获得的数据的框架。它审视了在理解环境相互作用如何调节这种发育方面取得的进展。
