Neovascularization depends on vascular cell proliferation and on the stabilization of vessels by association of vascular smooth muscle–like pericytes with ECs. Here we show that integrin α4β1 (VLA-4) and VCAM-1 promote close intercellular adhesion between ECs and pericytes and that this interaction is required for blood vessel formation. Integrin α4β1 is expressed by proliferating but not quiescent ECs, while its ligand VCAM-1 is expressed by proliferating but not quiescent mural cells. Antagonists of this integrin-ligand pair block the adhesion of mural cells to proliferating endothelia in vitro and in vivo, thereby inducing apoptosis of ECs and pericytes and inhibiting neovascularization. These studies indicate that integrin α4β1 and VCAM-1 facilitate a critical cell-cell adhesion event required for survival of endothelial and mural cells during vascularization.
Barbara Garmy-Susini, Hui Jin, Yuhong Zhu, Rou-Jia Sung, Rosa Hwang, Judy Varner
Usage data is cumulative from August 2021 through August 2022.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.