Growth Factors

PDGF is a potent mitogen for cells of mesenchymal origin, including fibroblasts, smooth muscle cells, and glial cells . It is synthesized, stored in the alpha granules of platelets, and released upon platelet activation . PDGF is also produced by other cells such as smooth muscle cells, activated macrophages, and endothelial cells . The expression patterns and tissue distribution of PDGF vary, with significant roles in blood vessel formation, cell proliferation, and chemotaxis .

PDGF plays a crucial role in various biological processes, including cell proliferation, survival, migration, and differentiation . It is involved in tissue remodeling, cellular differentiation, and inductive events in patterning and morphogenesis . PDGF also contributes to immune responses and pathogen recognition by regulating the activity of immune cells .

PDGF exerts its effects by binding to its receptors, PDGFRα and PDGFRβ, on the cell surface . Upon binding, these receptors dimerize and undergo autophosphorylation, activating downstream signaling cascades such as the PI3K pathway and reactive oxygen species (ROS)-mediated activation of the STAT3 pathway . These signaling pathways lead to various cellular responses, including changes in cell shape, motility, and gene expression .

The expression and activity of PDGF are tightly regulated at multiple levels. Transcriptional regulation involves various transcription factors that bind to the promoter regions of PDGF genes . Post-translational modifications, such as phosphorylation and glycosylation, also play a role in modulating PDGF activity . Additionally, feedback mechanisms and interactions with other signaling pathways contribute to the fine-tuning of PDGF signaling .

PDGF has numerous applications in biomedical research, diagnostics, and therapeutics. It is used in medicine to promote the healing of chronic ulcers and in orthopedic surgery and periodontics to stimulate bone regeneration and repair . PDGF is also being investigated for its potential in treating neurodegenerative diseases, such as Parkinson’s disease, due to its neurotrophic properties .

Throughout the life cycle, PDGF plays a vital role in development, aging, and disease. During embryonic development, PDGF drives the proliferation and differentiation of mesenchymal cells and progenitor populations . In adulthood, PDGF is involved in tissue maintenance and repair . Overexpression of PDGF has been linked to various diseases, including atherosclerosis, fibrotic disorders, and malignancies .