Leakage-Resistant Blood Vessels in Mice Transgenically Overexpressing Angiopoietin-1

TLDR

Angiopoietin‑1 and VEGF are endothelial cell–specific growth factors. In transgenic mice, Ang1 overexpression produced nonleaky, inflammation‑resistant vessels, whereas VEGF induced leaky vessels; coexpression enhanced angiogenesis but retained Ang1’s leak‑resistance, suggesting Ang1 could reduce microvascular leakage and, with VEGF, promote growth of nonleaky vessels.

Abstract

Angiopoietin-1 (Ang1) and vascular endothelial growth factor (VEGF) are endothelial cell–specific growth factors. Direct comparison of transgenic mice overexpressing these factors in the skin revealed that the VEGF-induced blood vessels were leaky, whereas those induced by Ang1 were nonleaky. Moreover, vessels in Ang1-overexpressing mice were resistant to leaks caused by inflammatory agents. Coexpression of Ang1 and VEGF had an additive effect on angiogenesis but resulted in leakage-resistant vessels typical of Ang1. Ang1 therefore may be useful for reducing microvascular leakage in diseases in which the leakage results from chronic inflammation or elevated VEGF and, in combination with VEGF, for promoting growth of nonleaky vessels.