PDGFAB

PDGFAB, or platelet-derived growth factor AB, is a heterodimeric member of the PDGF family. It consists of two polypeptide chains, PDGF-A and PDGF-B, which are products of the PDGFA and PDGFB genes. The mature protein is a disulfide-bonded dimer secreted by platelets and various other cell types in response to tissue injury. PDGF-AB can form as a heterodimer in addition to homodimers PDGF-AA and PDGF-BB, and it can activate receptors on target cells.

Binding and signaling: PDGF-AB binds to PDGF receptors PDGFR-α and PDGFR-β, triggering receptor dimerization and autophosphorylation. This leads to activation of downstream pathways such as PI3K-Akt and Ras-MAPK, promoting cell proliferation, survival, migration, and cytoskeletal changes.

Biological roles: In development, PDGF-AB contributes to the formation and stabilization of blood vessels by recruiting pericytes and smooth muscle cells. In adults, it participates in wound healing and tissue remodeling by stimulating fibroblast activity and matrix production. It also influences mesenchymal cell behavior in various tissues.

Clinical and research relevance: Abnormal PDGF signaling is associated with fibrotic diseases, vascular disorders, and cancer progression. Therapeutic strategies include inhibitors of PDGFR signaling, such as receptor tyrosine kinase inhibitors, used in certain cancers and fibrotic conditions. PDGF-AB is primarily studied for its role in normal physiology and pathophysiology of connective tissue and vascular biology, as well as in tissue engineering and regenerative medicine research.