Background information
Platelet-derived growth factor AB (PDGF-AB) is a disulfide-linked heterodimer of two chains termed subunit A and B, which form different members of the PDGF family including the homodimers PDGF-AA and PDGF-BB. PDGF-AB is synthesized by megakaryocytes and stored in alpha granules in platelets, from which it is released upon stimulation with thrombin or other signals related to inflammation and injury (IL-1, IL-6, TNF-α). PDGF-AB is also produced by macrophages, endothelial cells, fibroblast, and is present in the nervous system and in muscles. By binding PDGF receptors alpha and beta (PDGFR-α and PDGFR-β), PDGF-AB acts as a potent mitogen on several mesenchymal-derived cells, including fibroblasts, smooth muscle cells, and cells of the connective tissue. PDGF-AB is not released to the circulation, but acts in the tissues in an autocrine and paracrine fashion. It is involved in hyperplasia, chemotaxis, wound healing, in the development of the nervous system, and in osteogenic differentiation. PDGFs are studied as therapeutic targets in tissue regeneration and engraftment, as well as in atherosclerosis, and fibrotic disorders and malignancies.
