Growth differentiation factor 5 (GDF-5) is a member of the bone morphogenetic protein (BMP) subclass of the transforming growth factor beta (TGF-β) superfamily. It binds a receptor complex comprising BMPR1B and BMPR2, which then activates the SMAD signaling pathway (Carreira et al.; Nishitoh et al.; Osório et al.). GDF-5 enhances chondrogenic differentiation of mesenchymal stem cells, skeletogenesis, and dendrite growth during development (Coleman et al.; Francis-West et al.). Studies in rat demonstrated that GDF-5 regulates patterning, neurogenesis, astrogliogenesis, and neuronal specification (Gajavelli et al.; Krieglstein et al.; O'Keeffe et al.).
