Basic fibroblast growth factor

Fibroblast growth factor 2, also known as basic fibroblast growth factor (bFGF) and FGF-β, is a growth factor and signaling protein encoded by the FGF2 gene. It binds to and exerts effects via specific fibroblast growth factor receptor (FGFR) proteins, themselves a family of closely related molecules. Fibroblast growth factor protein was first purified in 1975; soon thereafter three variants were isolated: 'basic FGF' (FGF2); Heparin-binding growth factor-2; and Endothelial cell growth factor-2. Gene sequencing revealed that this group is the same FGF2 protein and is a member of a family of FGF proteins. Like other FGF family members, basic fibroblast growth factor possess broad mitogenic and cell survival activities, and is involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. In normal tissue, bFGF is present in basement membranes and in the subendothelial extracellular matrix of blood vessels. It stays membrane-bound as long as there is no signal peptide. It has been hypothesized that, during both wound healing of normal tissues and tumor development, the action of heparan sulfate-degrading enzymes activates bFGF, thus mediating the formation of new blood vessels, a process known as angiogenesis. In addition, it is synthesized and secreted by human adipocytes and the concentration of FGF2 correlates with the BMI in blood samples. It was also shown to act on preosteoblasts – in the form of an increased proliferation – after binding to fibroblast growth factor receptor 1 and activating phosphoinositide 3-kinase. FGF2 has been shown in preliminary animal studies to protect the heart from injury associated with a heart attack, reducing tissue death and promoting improved function after reperfusion. Recent evidence has shown that low levels of FGF2 play a key role in the incidence of excessive anxiety. Additionally, FGF2 is a critical component of human embryonic stem cell culture medium; the growth factor is necessary for the cells to remain in an undifferentiated state, although the mechanisms by which it does this are poorly defined.