Recombinant Human WISP-1

WNT1 inducible signaling pathway protein 1 (WISP-1), also known as CCN4, is a secreted, heparin-binding glycoprotein belonging to the cysteine-rich CCN family (1-2). WISP-1 is expressed in heart, kidney, lung, pancreas, placenta, ovary, small intestine and spleen. It is a downstream regulator in the Wnt/Frizzled-signaling pathway and is associated with cell survival (3). WISP-1 promotes mesenchymal cell proliferation and osteoblastic differentiation while repressing chondrocytic differentiation. Therefore, WISP-1 plays an important regulatory role during bone development and fracture repair (4). It was reported that WISP-1 interacts with sulfated glycoconjugates, decorin and biglycan in the ECM of connective tissue, and possibly prevents their inhibitory activity in tumor cell proliferation (5). WISP-1 attenuates p53-mediated apoptosis in response to DNA damage through activation of AKT kinase and up-regulates the anti-apoptotic Bcl-X(L) protein (5). Mutated or spliced variants of WISP-1 have been implicated in various pathological conditions.