Editing Angiogenesis (section)

====FGF====
{{Further|Fibroblast growth factor}}

The [[fibroblast growth factor]] (FGF) family with its prototype members [[FGF-1]] (acidic FGF) and [[FGF-2]] (basic FGF) consists to date of at least 22 known members.<ref>{{cite journal | vauthors = Ornitz DM, Itoh N | title = Fibroblast growth factors | journal = Genome Biology | volume = 2 | issue = 3 | pages = REVIEWS3005 | year = 2001 | pmid = 11276432 | pmc = 138918 | doi = 10.1186/gb-2001-2-3-reviews3005 | doi-access = free }}</ref> Most are single-chain peptides of 16-18 kDa and display high affinity to heparin and heparan sulfate. In general, FGFs stimulate a variety of cellular functions by binding to cell surface FGF-receptors in the presence of heparin proteoglycans. The FGF-receptor family is composed of seven members, and all the receptor proteins are single-chain receptor tyrosine kinases that become activated through autophosphorylation induced by a mechanism of FGF-mediated receptor dimerization. Receptor activation gives rise to a signal transduction cascade that leads to gene activation and diverse biological responses, including cell differentiation, proliferation, and matrix dissolution, thus initiating a process of mitogenic activity critical for the growth of endothelial cells, fibroblasts, and smooth muscle cells.
FGF-1, unique among all 22 members of the FGF family, can bind to all seven FGF-receptor subtypes, making it the broadest-acting member of the FGF family, and a potent mitogen for the diverse cell types needed to mount an angiogenic response in damaged (hypoxic) tissues, where upregulation of FGF-receptors occurs.<ref>{{cite journal | vauthors = Blaber M, DiSalvo J, Thomas KA | title = X-ray crystal structure of human acidic fibroblast growth factor | journal = Biochemistry | volume = 35 | issue = 7 | pages = 2086–2094 | date = February 1996 | pmid = 8652550 | doi = 10.1021/bi9521755 | citeseerx = 10.1.1.660.7607 }}</ref> FGF-1 stimulates the proliferation and differentiation of all cell types necessary for building an arterial vessel, including endothelial cells and smooth muscle cells; this fact ''distinguishes FGF-1 from other pro-angiogenic growth factors'', such as [[vascular endothelial growth factor]] (VEGF), which primarily drives the formation of new capillaries.<ref name="Stegmann"/><ref>{{cite journal | vauthors = Khurana R, Simons M | title = Insights from angiogenesis trials using fibroblast growth factor for advanced arteriosclerotic disease | journal = Trends in Cardiovascular Medicine | volume = 13 | issue = 3 | pages = 116–122 | date = April 2003 | pmid = 12691676 | doi = 10.1016/S1050-1738(02)00259-1 }}</ref>

Besides FGF-1, one of the most important functions of fibroblast growth factor-2 (FGF-2 or [[bFGF]]) is the promotion of endothelial cell proliferation and the physical organization of endothelial cells into tube-like structures, thus promoting angiogenesis. FGF-2 is a more potent angiogenic factor than VEGF or PDGF ([[platelet-derived growth factor]]); however, it is less potent than FGF-1. As well as stimulating blood vessel growth, aFGF (FGF-1) and bFGF (FGF-2) are important players in wound healing. They stimulate the proliferation of fibroblasts and endothelial cells that give rise to angiogenesis and developing granulation tissue; both increase blood supply and fill up a wound space/cavity early in the wound-healing process.