Vascular smooth muscle cell growth-promoting factor/F-spondin inhibits angiogenesis via the blockade of integrin αvβ3 on vascular endothelial cells

✍ Scribed by Yoshito Terai; Mayumi Abe; Kaoru Miyamoto; Masamichi Koike; Motoo Yamasaki; Masatsugu Ueda; Minoru Ueki; Yasufumi Sato

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 314 KB
• Volume: 188
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1122

✦ Synopsis

Vascular smooth muscle cell growth-promoting factor (VSGP) was originally isolated from bovine ovarian follicular fluid as a stimulator of vascular smooth muscle cell proliferation. Homology searches indicate that bovine and human VSGPs are orthologs of rat F-spondin. Here, we examined whether recombinant human VSGP/F-spondin affected the biological activities of endothelial cells. VSGP/F-spondin did not affect the proliferation of human umbilical vein endothelial cells (HUVECs); however, it did inhibit VEGF- or bFGF-stimulated HUVEC migration. To clarify the mechanism of this inhibitory effect, we examined the adhesion of HUVECs to extracellular matrix proteins. VSGP/F-spondin specifically inhibited the spreading of HUVECs on vitronectin via the functional blockade of integrin alphavbeta3. As a result, VSGP/F-spondin inhibited the tyrosine phosphorylation of focal adhesion kinase (FAK) when HUVECs were plated on vitronectin. Moreover, VSGP/F-spondin inhibited the activation of Akt when HUVECs on vitronectin were stimulated with VEGF. VSGP/F-spondin inhibited tube formation by HUVECs in vitro and neovascularization in the rat cornea in vivo. These results indicate that VSGP/F-spondin inhibits angiogenesis at least in part by the blockade of endothelial integrin alphavbeta3.