Molecular mediators of angiogenesis

Abstract

Angiogenesis, or the formation of new blood vessels from the preexisting vasculature, is a key component in numerous physiologic and pathologic responses and has broad impact in many medical and surgical specialties. In this review, we discuss the key cellular steps that lead to the neovascularization of tissues and highlight the main molecular mechanisms and mediators in this process. We include discussions on proteolytic enzymes, cell-matrix interactions, and pertinent cell signaling pathways and end with a survey of the mechanisms that lead to the stabilization and maturation of neovasculatures.

Figure 1

Diagrammatic description of the steps involved in angiogenesis. A) A stable vascular structure comprised of an endothelial monolayer surrounded by mural tissue (i.e. basement membrane, pericytes, and adventitia); B) Destabilized vessel demonstrating the disruption of mural tissue by endothelial cells; C) Endothelial cell invasion into perivascular tissue and subsequent sprout formation; D) Endothelial cell lumenogenesis and tube formation with inosculation (not shown) to other pre-existing vascular structures; E) Stabilization of the capillary sprout by recruitment of pericytes and deposition of basement membrane.