A growth factor protein or peptide cell growthproliferation , differentiation , healing , or survival . Growth factors are signaling molecules that typically bind to specific cell surface receptors , triggering intracellular signaling pathways that regulate gene expression and cellular behavior.
Key Characteristics: Feature Description Type Proteins or peptides (small signaling molecules) Secretion Secreted by cells like fibroblasts, immune cells, and epithelial cells Receptors Bind to specific transmembrane receptors (often receptor tyrosine kinases) Mode of Action Act in autocrine , paracrine , or endocrine
Major Functions of Growth Factors: Function Role Cell proliferation Stimulate cells to divide and grow Cell differentiation Direct immature cells to become specialized Tissue repair Promote wound healing and regeneration Survival signals Prevent apoptosis (programmed cell death) Development Crucial for embryogenesis and organ formation
Examples of Key Growth Factors: Growth Factor Full Name Function EGF Epidermal Growth Factor Stimulates skin and epithelial cell growth FGF Fibroblast Growth Factor Promotes angiogenesis, wound healing, development VEGF Vascular Endothelial Growth Factor Stimulates formation of blood vessels PDGF Platelet-Derived Growth Factor Promotes cell growth and healing after injury NGF Nerve Growth Factor Supports survival and growth of neurons TGF-β Transforming Growth Factor-beta Regulates immune responses, cell proliferation, and ECM production IGF Insulin -like Growth FactorStimulates systemic body growth, especially during childhood
Mechanism of Action: Growth factor binds to its specific cell surface receptor . Receptor becomes activated (often via phosphorylation ). This triggers intracellular signaling cascades (e.g., MAPK, PI3K/AKT). Results in changes in gene expression and cellular activity. Clinical Relevance: Condition Relevance Cancer Overexpression or dysregulation of growth factors (e.g., EGF, VEGF) can promote uncontrolled cell growth and angiogenesis Wound healing Topical or injected growth factors (e.g., PDGF) used to accelerate tissue repair Regenerative medicine Used to support stem cell differentiation and tissue engineering Neurological disorders NGF and BDNF being studied for neuroprotection and regeneration
Summary Table: Feature Description Molecule Type Protein or peptide Main Function Stimulate cell growth, survival, and differentiation Acts On Specific cell surface receptors Signal Type Paracrine, autocrine, endocrine Key Pathways MAPK, PI3K/AKT, JAK/STAT Clinical Use Cancer treatment, wound healing, regenerative therapy
