title: Regulation of lubricin/superficial zone protein by Wnt signalling in bovine synoviocytes.
abstract: Lubricin, homologous to superficial zone protein (SZP), functions as a boundary lubricant in articular cartilage and plays an essential role in the maintenance of joint function and homeostasis. Wnt signalling plays a key role in joint development, including synovial joint formation, and several Wnt proteins are expressed in the synovium and articular cartilage in arthritis. The aim of this study was to determine the role of Wnt signalling on SZP accumulation in synoviocytes. Isolated synoviocytes from bovine knee joints were cultured with Wnt proteins (Wnt-3a and Wnt-5a) and antagonists or agonists of the Wnt-β-catenin pathway or Wnt-Ca(2+) pathway in serum-free chemically defined medium. SZP accumulation in the culture medium was determined by enzyme-linked immunosorbent assay. Wnt-3a suppressed SZP accumulation via a Wnt-β-catenin-dependent pathway. In contrast, Wnt-5a stimulated SZP accumulation via a β-catenin independent pathway. The present investigation provides novel insights into the role of the Wnt signalling pathways in SZP accumulation in synoviocytes and their roles in the homeostasis of normal joints.
authors: Lawrence Ellison Center for Tissue Regeneration and Repair, Department of Orthopedic Surgery, University of California at Davis, Sacramento, CA, USA.
authors: Atsuyuki
authors: A
authors: Inui
authors: Lawrence Ellison Center for Tissue Regeneration and Repair, Department of Orthopedic Surgery, University of California at Davis, Sacramento, CA, USA.
authors: Takashi
authors: T
authors: Iwakura
authors: Lawrence Ellison Center for Tissue Regeneration and Repair, Department of Orthopedic Surgery, University of California at Davis, Sacramento, CA, USA.
authors: A
authors: A
authors: Hari Reddi
mesh_terms: D000818:Animals; D002417:Cattle; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011509:Proteoglycans / Q000378:metabolism*; D013583:Synovial Membrane / Q000166:cytology* / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000378:metabolism; D000099158:Proteoglycan 4
chemical_list: D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D047428:Protein Kinase Inhibitors; D011509:Proteoglycans; D051153:Wnt Proteins; D051176:beta Catenin; C498836:PRG4 protein, Bos taurus; D000099158:Proteoglycan 4
keywords: Wnt; Wnt-3a; Wnt-5a; lubricin; superficial zone protein; synoviocyte; synovium; β-catenin