Platelet-derived growth factor (PDGF) is expressed as homo and heterodimers: PDGF-AB FDGF-AA, PDGF-BB, PDGF-CC and PDGF-DD. The PDGF gene is highly conserved and is mapped to human chromosome 7p22.3. The active form of PDGF exists as disulfide-linked dimers. It consists of cystine-knot-fold growth factor domain, which is highly conserved, except for the N-terminal prodomain, which shows variation in length among the isoforms.
PDGF is a chemoattractant for fibroblasts, smooth muscle cells, monocytes and neutrophils. Also, it acts on fibroblasts and other cells that initiate healing and tissue restoration.
Platelet-derived growth factor (PDGF), not only functions as a growth factor, but also participates in chemotaxis for triggering cell movement. Elevated levels of placental PDGF is observed during the late first and third-trimester pregnancies. PDGF is associated with wound healing. PDGFRα (PDGF receptor α ) phosphorylation, mediated by PDGFA activates pathways associated with cancer. PDGFA has been indicated to induce growth and metastasis in human hepatocellular carcinoma. Vascular endothelial growth factor expression is regulated by PDGF-AA autocrine signaling and is known to promote tumor angiogenesis in vivo. PDGF-BB isomer is found to be critical in angiogenesis and is highly expressed in tumor, mediating oncogenic pericyte recruitment. PDGF-BB is an important regulator of bone homeostasis, repair and regeneration.
The principal mitogen found in mammalian serum, released from platelets during clot formation. Elicits mitogenesis of mesoderm-derived cells, increased extracellular matrix synthesis, and chemotaxis and activation of neutrophils, monocytes and fibroblasts. Mitogenic for dermal and tendon fibroblasts, vascular smooth muscle cells, glial cells and chondrocytes. Appears to interact with transforming growth factor-β1 in accelerating wound healing. However, platelet-derived growth factor (PDGF) may also be pathogenic in arteriosclerosis and neoplasia.
Isolated from human platelets, predominantly containing two covalently linked subunits (A and B).
Lyophilized from a 0.2-μm filtered solution in 40% acetonitrile plus 0.1% TFA
The mitogenic activity is tested in culture using Swiss 3T3 cells or NR6-3T3 fibroblasts.