Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul, 110-744, Korea.
Mol Cells. 2013 Nov;36(5):465-71. doi: 10.1007/s10059-013-0228-1. Epub 2013 Nov 8.
The hyaloid vessel is a transient vascular network that nourishes the lens and the primary vitreous in the early developmental periods. In hyaloid vessels devoid of the support of astrocytes, we demonstrate that tight junction proteins, zonula occludens-1 and occludin, are regularly expressed at the junction of endothelial cells. To figure out the factor influencing the formation of tight junctions in hyaloid vessels, we further progress to investigate the interactions between endothelial cells and pericytes, two representative constituent cells in hyaloid vessels. Interestingly, endothelial cells interact with pericytes in the early postnatal periods and the interaction between two cell types provokes the up-regulation of transforming growth factor β1. Further in vitro experiments demonstrate that transforming growth factor β1 induces the activation of Smad2 and Smad3 and the formation of tight junction proteins. Taken together, in hyaloid vessels, pericytes seem to regulate the formation of tight junctions by the interaction with endothelial cells even without the support of astrocytes. Additionally, we suggest that the hyaloid vessel is a valuable system that can be utilized for the investigation of cell-cell interaction in the formation of tight junctions in developing vasculatures.
玻璃血管是一种短暂的血管网络，在早期发育阶段为晶状体和初级玻璃体提供营养。在缺乏星形胶质细胞支持的玻璃血管中，我们证明紧密连接蛋白，封闭蛋白-1 和封闭蛋白，在血管内皮细胞的连接处正常表达。为了弄清楚影响玻璃血管紧密连接形成的因素，我们进一步研究内皮细胞和周细胞之间的相互作用，这两种细胞是玻璃血管的代表性组成细胞。有趣的是，内皮细胞在出生后早期与周细胞相互作用，两种细胞类型的相互作用会引起转化生长因子 β1 的上调。进一步的体外实验表明，转化生长因子 β1 诱导 Smad2 和 Smad3 的激活以及紧密连接蛋白的形成。总之，在玻璃血管中，周细胞似乎通过与内皮细胞的相互作用来调节紧密连接的形成，即使没有星形胶质细胞的支持。此外，我们认为玻璃血管是一个有价值的系统，可以用于研究发育中的脉管系统中紧密连接形成的细胞-细胞相互作用。
