bFGF

Basic fibroblast growth factor (bFGF), also known as FGF2, is a member of the fibroblast growth factor family. It is a heparin-binding growth factor involved in cell proliferation, differentiation, angiogenesis, and tissue repair. The FGF2 gene encodes multiple isoforms produced by alternative translation initiation, including a low molecular weight form (~18 kDa) and several high molecular weight isoforms. Because it lacks a conventional signal peptide, bFGF is secreted via non-classical pathways and can function both outside and inside cells.

In signaling, bFGF binds to fibroblast growth factor receptors (FGFRs) on target cells with the help of heparan sulfate proteoglycans. This induces FGFR dimerization and tyrosine kinase activation, triggering downstream pathways such as MAPK/ERK, PI3K/AKT, and PLCγ. Through these pathways, bFGF promotes cell proliferation, migration, and survival, and influences differentiation. It plays essential roles in angiogenesis, neural development, limb formation, and the maintenance of stem and progenitor cell populations.

Applications and relevance: In vitro, bFGF is widely used to support the culture of various cells, including neural stem cells, neural progenitors, and human pluripotent stem cells, helping maintain proliferation and multipotency. It is explored for regenerative medicine and wound healing and has been investigated for neuroprotection and recovery after ischemic injury. Its mitogenic activity is context-dependent, and excessive signaling can contribute to tumorigenesis in susceptible tissues.

Manufacture and characteristics: Recombinant human bFGF is produced in bacterial or mammalian systems and is available as a stabilized protein. Formulations often include stabilizers such as heparin to enhance stability and activity. The protein is relatively small and active when properly presented to FGFRs in conjunction with HSPGs.