VEGF

Vascular endothelial growth factors (VEGFs) are a family of secreted polypeptides that are crucial to the normal development and maintenance of the vascular and lymphatic systems. VEGFs belong to the VEGF/PDGF group of the cystine-knot superfamily of signaling molecules, which are all characterized by having a cystine-knot structure formed by eight cysteine residues. VEGFs have been found in all vertebrate species so far examined and are highly conserved between species.
VEGF-A, also called VEGF, is the prototypical member of VEGF family that includes placental growth factor (PLGF), VEGF-B, VEGF-C, and VEGF-D (also known as c-Fos-induced growth factor, FIGF), and the viral VEGF-Es. Among them, VEGF-A exists in four different isoforms (comprising 121, 165, 189 and 206 amino acids in humans), which are generated by alternative splicing of a single pre-mRNA species. VEGF-A is a mitogen and survival factor for vascular endothelial cells while also promoting vascular endothelial cell and monocyte motility. VEGF-B also promotes angiogenesis. VEGF-C participates in lymphangiogenesis during embryogenesis and in the maintenance of differentiated lymphatic endothelium in adults. VEGF-D stimulates growth of vascular and lymphatic endothelial cells. Although first described in the placenta, PlGF is expressed in a wide variety of cells, tissues, and organs and participates inangiogenesis, wound healing, and the inflammatory response.