Recombinant Human TGF-β3

Transforming growth factor-beta 3 (TGF-β3), also known as TGFB3, is a member of the TGF beta family of growth factors along with TGF-β1 and -2. The members of this family can be expressed by most cell types and are proposed to act as cellular switches that regulate immune function, proliferation and epithelial-mesenchymal transition (1). These cytokines are secreted in precursor form consisting of a bioactive C-terminal domain attached to an N-terminal domain known as latency associated protein (LAP). Cleavage of LAP results in the mature protein, which functions as a disulfide-linked homodimer. TGF-β3 and these homodimers of LAP remain non-covalently associated after secretion, forming the latent TGF-β3 complex (2). Activation of this latent complex is accomplished by actions from plasmin, MMPs, thrombospondin 1 and some integrins (3). The receptor for TGF-β3 is TGF-β RII which phosphorylates, and activates another receptor, either ALK-5 or ALK-1. This second complex activates Smad proteins that regulate transcription. TGF-β3 is involved in oxygen-dependent differentiation processes during placental development and pregnancy disorders (4) and it also plays an important role in wound repair and scarring (5). TGF-β3 is believed to regulate molecules involved in cellular adhesion and extracellular matrix (ECM) formation during the process of palate development, without it, mammals develop a deformity known as a cleft palate (6). Similarly, TGF-β3 also plays an essential role in controlling the development of lungs in mammals, also by regulating cell adhesion and ECM formation in this tissue (6). Defects in the TGF-β3 gene are a cause of familial arrhythmogenic right ventricular dysplasia 1 (ARVD1) (7). ARVD1 is an autosomal dominant disease characterized by partial degeneration of the myocardium of the right ventricle, electrical instability and sudden death.