Matrix metalloproteinases 2 and 9 in equine synovial fluids

Abstract

Summary Matrix metalloproteinases (MMPs) may be important in the destruction of cartilage seen in equine osteoarthritis and may be detectable in synovial fluid. Synovial fluids were obtained from normal equine joints and from joints of horses with aseptic and septic joint diseases. The total MMP gelatinase enzyme activities were measured by gelatin zymography and image analysis of the gels. The bioactivity of gelatinase in synovial fluid was determined by a gelatin degradation ELISA. Potential MMP‐2 & MMP‐9 monomer enzyme activities were significantly elevated in both septic and aseptic joint disease synovial fluids in comparison to fluids from normal joints. The dimer form of MMP‐9 enzyme activity was significantly elevated in fluids from septic joint disease cases in comparison to fluids from normal joints, but not fluids from horses with aseptic joint diseases. MMP‐9 monomer and dimer levels in synovial fluids correlated with the synovial fluid white blood cell count. Using the gelatin degradation ELISA to measure net active gelatinases, significant increases in gelatinase bioactivities were seen in synovial fluids from both aseptic and septic joint disease cases. The enzymes in equine joint diseases were present in a bioactive form, in that they were present in the activated form and present in excess of inhibitors, and could therefore be important in the degradation of articular cartilage in joint disease.

Metalloproteinases and tumor necrosis factor-alpha activities in synovial fluids of horses: correlation with articular cartilage alterations

“…The occurrence of the active form of the MMP-9 monomer was associated to the presence of a degenerative process. These results are in agreement with the data from Clegg et al [9] who found a rise in MMP-9 activities in a broad range of aseptic joint diseases. In osteoarthritic joints, Brama et al [3] also found the MMP-9 activity was nearly twice as high as in normal joints, but, in OCD joints, MMPs activity was not significantly different from normal control joints.…”

“…This assay is highly specific, because it is based on a direct enzyme-substrate interaction, and gives information on the molecular weights of the enzymes (latent or active form). The gelatinases found in this study were comparable to those reported by Clegg et al [9] from aseptic and septic joint samples.…”

“…Clegg et al [9] also demonstrated that MMP-2 was present in both normal and abnormal equine synovial fluids: the levels of MMP-2 were significantly higher in both aseptic and septic equine joint disease in comparison with synovial fluids from horses with no diagnosed joint disease. Johnson et al [14] observed an increase in the activity of 66 kDa proteinases in the laminitic tissues and suggest that the 72 kDa are converted to 66 kDa by proteolytic cleavage.…”

“…In ESF joints, the increase of MMP-9 levels cannot be explained by cartilage alterations only. ESF probably results from a synovial inflammatory reaction, and it is reported that infiltrating inflammatory cells produce MMP-9 monomer and dimer in equine joints [8,9].…”

Diagnostic Value of MMP-2 and MMP-9 in Synovial Fluid for Identifying Osteoarthritis in the Distal Interphalangeal Joint in Horses

“…Matrix metalloproteinases (MMPs) are a family of nine or more highly homologous Zn(++)-endopeptidases that collectively cleave most, if not all, of the constituents of the extracellular matrix (Birkedal-Hansen et al 1993). They are important in remodelling events and the migration of cells through the extracellular matrix (Birkedal-Hansen et al 1993;Allan et al 1995;Clegg et al 1997;Koolwijk et al 1995) and also in tumour growth and metastasis, promoting the migration and invasion of cells (Sier et al 2000).…”