Basic fibroblast growth factor

Basic fibroblast growth factor, also known as bFGF, FGF2 or FGF-β, is a member of the fibroblast growth factor family.

Function

In normal tissue, basic fibroblast growth factor 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 bFGF correlates with the BMI in blood samples. In this study, bFGF 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.

bFGF 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.

FGF9

Glia-activating factor is a protein that in humans is encoded by the FGF9 gene.

Function

The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. This protein was isolated as a secreted factor that exhibits a growth-stimulating effect on cultured glial cells. In nervous system, this protein is produced mainly by neurons and may be important for glial cell development. Expression of the mouse homolog of this gene was found to be dependent on Sonic hedgehog (Shh) signaling. Mice lacking the homolog gene displayed a male-to-female sex reversal phenotype, which suggested a role in testicular embryogenesis.

Interactions

FGF9 has been shown to interact with Fibroblast growth factor receptor 3.

Role in sex determination

FGF9 has also been shown to play a vital role in male development. Once activated by SOX9, it is responsible for forming a feedforward loop with Sox9, increasing the levels of both genes. The absence of Fgf9 causes an individual, even an individual with X and Y chromosomes, to develop into a female, as it is needed to carry out important masculinizing developmental functions such as the multiplication of Sertoli cells and creation of the testis cords.

FGF13

Fibroblast growth factor 13 is a protein that in humans is encoded by the FGF13 gene.

The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth, and invasion. This gene is located to a region associated with Borjeson-Forssman-Lehmann syndrome (BFLS), a syndromal X-linked mental retardation, which suggests it may be a candidate gene for familial cases of the BFL syndrome. The function of this gene has not yet been determined. Two alternatively spliced transcripts encoding different isoforms have been described for this gene.

References

Further reading