Multiple matrix metalloproteinases in type II collagen induced arthritis.

To study the relative contribution of various matrix degrading enzymes in the pathogenesis of arthritis, changes in the levels of various matrix metalloprtoteinases (MMPs) during the progression of collagen induced arthritis was studied in experimental animals. Arthritis was induced in male wistar rats by injecting an emulsion containing collagen type II and Freund's complete adjuvant. The duration of the experiment was 35 days. Synovial effusate was collected at regular intervals after induction. At the end of the experiment serum and cartilage were collected and analysed. Synovial fluid of osteoarthritic patients was also analyzed. Levels of MMP-2, MMP-3, MMP-9 and MT1-MMP were found to be high in synovial effusate and cartilage of experimental animals. In synovial effusate of arthritic animals the expression of MMP-3 was found to be high during the early stages while increase in MMP-2 and MMP-9 occurred at later stages. Synovial fluid of osteoarthritic patients also showed elevated levels of MMP-2, MMP-3 and MMP-9. Our results indicated that sequential action of MMPs such as MMP-3, MMP-2 and MMP-9 can cause degradation of articular cartilage extracellular matrix.