Control of vascular morphogenesis and homeostasis through the angiopoietin–Tie system

Abstract

Angiogenesis, the growth of blood vessels, is a fundamental biological process that controls embryonic development and is also involved in numerous life-threatening human diseases. Much work in the field of angiogenesis research has centred on the vascular endothelial growth factor (VEGF)–VEGF receptor system. The Tie receptors and their angiopoietin (Ang) ligands have been identified as the second vascular tissue-specific receptor Tyr kinase system. Ang–Tie signalling is essential during embryonic vessel assembly and maturation, and functions as a key regulator of adult vascular homeostasis. The structural characteristics and the spatio-temporal regulation of the expression of receptors and ligands provide unique insights into the functions of this vascular signalling system.