Recombinant Human CTGF/CCN2 Protein, CF

Connective Tissue Growth Factor (CTGF), also known as CCN2, is a 36-38 kDa member of the CCN (CYR61/CTGF/NOV) family of secreted matricellular proteins (1). Like other CCN proteins, mature human CTGF consists of IGF-binding protein domain, a vWF-C domain, a TSP-1 domain, and a cysteine knot heparin-binding domain (2). Human CTGF shares 94% amino acid (aa) sequence identity with mouse and rat CTGF. Alternative splicing generates an additional isoform with a 27 aa deletion within the TSP-1 domain. CTGF promotes cell adhesion through interactions with a range of cell surface molecules including heparan sulfate proteoglycans (HSPG), LRPAP, and Integrins  alpha M, alpha V beta 3, alpha 6 beta 1, alpha IIb beta 3 (3-7). It also binds to and regulates signaling through the Wnt receptors LRP6 and Frizzled-8 and the NGF receptors TrkA and NGF R (8, 9). In addition, CTGF binds directly to BMP-4, TGF-beta 1, TGF-beta 2, and VEGF 165 (10, 11). It blocks BMP-4 and VEGF induced responses but enhances TGF-beta induced responses (10-13). Within VEGF complexes, CTGF can be degraded by a variety of proteases, resulting in restoration of angiogenic activity (11). CTGF promotes fibroblast differentiation from mesenchymal stem cells and their production of type I Collagen and Tenascin C (5, 14). It promotes chondrocyte proliferation and cartilage matrix synthesis (15-17). CTGF is expressed in vascular mural and endothelial cells (EC) during development and promotes pericyte-EC association and angiogenesis (2, 17, 18, 19). It is expressed in the cerebral cortex and olfactory bulb and plays an important role in nervous system development (8, 12).