Matrix metalloproteinase-3 (MMP-3) in synovial fluid with temporomandibular joint disorders

Matrix metalloproteinase-3 {MMP-3, stromelysin) is known to degrade certain matrix components, including proteoglycans, fibronectin, laminin and collagens. We lnvestigated the early signs ot cartilage degradation by assaying MMP-3 in the synoviat fluid of human temporomandibular jojnts with internal derangement (ID) or osteoarthritis (OA). Synovial fluid was collected from the upper joint space by direct aspiration {nondiluted synovial fluid) or by pumping with lidocaine (diluted synovial tluid). MMP-3 was visualized by casein enzymography and measured by one-step sandwich enzyme immunoassay using an anti-human MMP-3 antibody that recegnizes both active enzyme and inactive proenzyme. The concentration of MMP-3 with ID in both diluted and non-diluted synevial fluid was signiticantly greater than that with OA or in the asymptomatic controls (p<O.OOI). Enzymatically active components were detected in the non-diluted synovial tluid, but not in the diluted synovial fluid. Active MMP-3 was detected only in the nondiluted synovial fluid with OA, while inactive MMP-3 was observed in the non-dituted synovial fluid both with ID and with OA. These resutts indicate that MMP-3 may be released as preenzyme into the synovial ftuid uring the early stages ot degenerative changes in the TMJ. Subsequently, progressive TMJ destruction may induce the release of active MMP-3. We concluded that MMP-3 assay using synovial fluid may be a useful marker ter the diagnosis of TMJ disorders. (J Osaka Dent Univ 2003 ; 37 : 123-127.}