Basic calcium phosphate crystals cause coordinate induction and secretion of collagenase and stromelysin

✍ Scribed by Geraldine M. McCarthy; Peter G. Mitchell; Janine A. Struve; Herman S. Cheung

• Book ID: 102881430
• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 815 KB
• Volume: 153
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041530118

✦ Synopsis

Synovial fluid basic calcium phosphate crystals (BCP) are often found in severely degenerated joints. Crystalline BCP is a growth factor stimulating fibroblast mitogcnesis and acting as a competence factor similar to platelet-derived growth factor. In human fibroblasts (HF), the synthesis of collagenase and stromelysin is coordinately induced after stimulation with a variety of cytokines and growth factors. We sought to determine whether BCP, like other growth factors, might induce proteases that would damage articular tissue. Northern blot analysis of mRNAfor collagenase and stromelysin in HF stimulated with BCP was performed. Secreted enzymes were analysed by immunoblot using a monoclonal antibody to collagenase and by immunoprecipitation using a polyclonal antibody to stromelysin. Strornelysin activity was confirmed using casein substrate gels. A significant, dose-dependent accumulation of collagenase and stromelysin message was evident after 4 h and continued for at least 24 h in BCP-stimulated cultures. Fortyninc and 54 k D proteins immunoreacting with collagenase antibody were identified in the conditioned media (CM) from BCP-stimulated cultures while 50 and 55 kD proteins were identified by immunoprecipitation with stromelysin antibody. Collagenase activity was increased significantly in the C M from BCP treated cells; casein substrate gels showed cascin degrading bands at molecular weights consistent with stromelysin. BCP stimulates coordinate induction of collagenase and stromelysin which may mediate the joint destruction associated with these crystals. 0 1332 WiIey-Liss, ~n c