Matrix metalloproteinases 2 and 9 in equine synovial fluids.

This research studied the presence and activity of certain enzymes, specifically Matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), in the joint fluids of horses in order to understand their relationship to joint diseases, including arthritis. It found these enzymes were significantly more active in joints affected by disease and could, therefore, play a role in the degradation of joint cartilage.

Study Overview

• The study focused on Matrix metalloproteinases (MMPs), a family of enzymes believed to play a critical role in the destruction of cartilage seen in equine osteoarthritis and other joint diseases.
• Researchers collected synovial fluid, the lubricating fluid in joints, from both healthy horses and those suffering from two types of joint disease, categorized as either aseptic (non-infectious) or septic (infectious).

Enzyme Activity Measurement

• The activity of the gelatinase enzymes, MMP-2 and MMP-9, in the synovial fluid samples was measured using two different methods: gelatin zymography and a gelatin degradation Enzyme-Linked Immunosorbent Assay (ELISA).
• Gelatin zymography is a technique that allows for the detection and measurement of enzyme activity. It uses a gel medium containing a substrate (in this case, gelatin) that the enzyme can break down. The degree of enzymatic degradation can then be visualized and quantified.
• The ELISA, on the other hand, determined the active form of gelatinase in the synovial fluid by measuring the amount of degraded gelatin. It provides an estimate of the net activity of the enzymes present.

Research Findings

• The study found that there were significant increases in the single, monomer forms of both MMP-2 & MMP-9 in the synovial fluids obtained from joints affected by both septic and aseptic diseases when compared to fluids from healthy joints.
• Furthermore, the dimer (double) form of MMP-9 was significantly raised in fluids from joints suffering from septic disease compared to those from normal joints.
• The levels of MMP-9 in both its monomer and dimer form correlated with the white blood cell count in the synovial fluid, indicating an immune response associated with the disease conditions.
• Using the gelatin degradation ELISA, the researchers found significant increases in gelatinase bioactivities in synovial fluids from both aseptic and septic joint disease cases, indicating a heightened enzymatic activity in diseased joints.

Conclusion

• The researchers concluded that the presence of MMP-2 and MMP-9 in their active forms could play a significant role in the degradation of articular cartilage in joint diseases.
• The excess of these enzymes over their inhibitors shows that they might indeed be a significant factor in the perpetuation of these joint diseases.
• Understanding this could potentially lead to the development of new therapies aimed at inhibiting these enzymes and thereby slowing the progression of joint diseases in horses.