Transforming Growth Factor Beta (TGF-β)
A multifunctional growth factor family that regulates cell proliferation, differentiation, immune function, and extracellular matrix production. TGF-β is a key regulator of wound healing and fibrosis. It stimulates collagen production by fibroblasts but excessive TGF-β activity can lead to scar formation.
Technical Context
The TGF-β superfamily includes TGF-β1/2/3, BMPs, activins, and inhibins. TGF-β signals through serine/threonine kinase receptors (TGFβRI/ALK5 and TGFβRII) → Smad2/3 phosphorylation → Smad4 complex → nuclear translocation → gene transcription. TGF-β has context-dependent effects: pro-fibrotic (stimulating fibroblast→myofibroblast differentiation, collagen synthesis, TIMP production) and anti-inflammatory (suppressing immune cell activation). In wound healing, TGF-β1 is the predominant isoform driving scar formation; TGF-β3 is associated with scarless foetal healing. The TGF-β/Smad pathway is the primary driver of pathological fibrosis in multiple organs. Anti-fibrotic peptide research targets TGF-β signalling modulation to promote regenerative rather than scarring healing. Palovarotene (a retinoic acid receptor gamma agonist for FOP) works through a pathway that intersects with BMP/TGF-β superfamily signalling.