%0 Journal Article
%T Endothelial progenitor cells and integrins: adhesive needs
%A Francisco Caiado
%A S¨Śrgio Dias
%J Fibrogenesis & Tissue Repair
%D 2012
%I BioMed Central
%R 10.1186/1755-1536-5-4
%X The cardiovascular system is the first functional organ system to develop in the vertebrate embryo and is required for embryonic survival to regulate multiple homeostatic functions in the developing embryo [1]. New blood vessel formation (neovascularization) is an essential mechanism determining the formation, but also the maintenance, of the cardiovascular system. It is thought to depend mainly on two processes, angiogenesis and vasculogenesis.Angiogenesis is the process by which new vessels are formed by the activation, proliferation and migration of endothelial cells (ECs). Vasculogenesis is defined as the process by which new vessels are generated, by the migration and differentiation of vascular endothelial growth factor receptor 2 positive (VEGFR-2+) mesodermal precursors, termed angioblasts and/or hemangioblasts, into ECs that coalesce to form a primary vascular plexus during embryonic development [2].The existence of an equivalent process during adulthood - postnatal vasculogenesis - has been intriguing vascular and hematologic researchers since the early 20th century, when the first studies describing blood vessel formation from peripheral blood (PB) and bone-marrow (BM) mononuclear cells were published. These studies suggested the existence of a population of cells in the PB and/or BM capable of generating ECs when cultured under specific conditions [3-5]. However, it was only in 1997 that Asahara et al. [6] isolated and characterized CD34+ or VEGFR-2+ cell populations for the first time, derived from PB capable of differentiating into ECs in vitro when plated on fibronectin (FN) and exposed to angiogenic growth factor stimuli, namely vascular endothelial growth factor (VEGF). Accordingly, using an in vivo animal model of hind limb ischemia, these authors showed that CD34+ and VEGFR-2+ cells were incorporated into newly formed vessels and acquired the expression of EC antigens. These cells where thus termed endothelial progenitor cells (EPCs) [6]. In accor
%U http://www.fibrogenesis.com/content/5/1/4