The role of proteases in the pathogenesis of osteoarthritis.

It is proposed that the cartilage contains enzymes which are responsible for the degradation of the principle components of the matrix, the proteoglycan and collagen. Measurement of acid, lysosomal bound proteases, or neutral proteases shows increases in proportion to the severity of the disease. Collagenase activity also increases in human osteoarthritic cartilage in the same manner. In an experimental model of osteoarthritis, induced by mechanical factors, enzymatic activity also increased. By inhibiting the enzyme activity with chelators, the arthritic process could be slowed.