Fibroblast growth factors (FGFs) are a large group of small polypeptide growth factors, some of which play key roles in pulmonary biology. Their molecular sizes vary from 17 to 34 kDa and they share a wide range of amino acid homology with highly conserved gene structures and amino acid sequences. They also share the common property of avidity for heparin, which enables them to bind to components of extracellular matrices and cell surfaces. FGFs form a trimolecular complex with heparin-like molecules (e.g., heparan sulfate) and one of four polypeptide tyrosine kinase receptors. The chemical heterogeneity of heparan sulfate and alternative splicing of FGF receptors both determine FGF binding specificity and receptor dimerization and activation. Functions for FGFs are, in many cases, narrowly defined to specific stages of development or repair, while others are broadly applied to physiological maintenance and responses to injury. FGF signaling has been shown to affect cell proliferation, cell survival, chemotaxis, migration, and cell adhesion. FGFs are known to play specific roles in tumorigenesis and pulmonary fibrosis, and have unique capacities to protect against DNA damage induced by oxidants and some environmental toxicants.
- Extracellular matrix
- Heparin-finding growth factors
- Lung development and repair
- Pulmonary fibrosis