Endothelial Cell-Pericyte Interdigitation is Mediator of Angiogenesis?

点击翻译按钮获取中文摘要

Under in vitro conditions pericytes have been shown to inhibit the proliferation of cultured endothelial cells. This inhibitory effect of pericytes appeared to be mediated by a activated form of TGFbeta depended on the formation of cell-cell contacts between endothelial cells and pericytes, and is mediated by uPA-plasmin activity. However, the endothelial cell and pericyte contacts during coculture have been detected only light microscopy, and the detailed structures of these contact has been unresolved. Meantime, in vivo angiogenesis, immature capillaries possess many endothelial cell and pericyte contacts, such as endothelial cell-pericyte interdigitations (EPI). I have demonstrated that the number of EPI increases with ongoing maturation of newly formed capillaries, and suggested pericytes do indeed to inhibit endothelial cells proliferation in a manner requiring the physical proximity effort by the EPI.The present study revealed in angiogenic sites that uPA expression was preferentially in EPI and TGFbeta was present throughout the stroma including EPI.These findings suggest a functional interplay between uPA expression and endothelial cells maturation, and support the idea that endothelial cells proliferating inhibitor function by TGFbeta activated by uPA during angiogenesis to mediate at EPI.