Neutral proteases in human osteoarthritic synovium: quantification and characterization.

In this study, we measured the levels of neutral metallo- and serine proteases in human osteoarthritic synovium. These enzymes degrade both collagen and proteoglycan macromolecules. They were analyzed by tissue culture methodology and direct extraction. We have demonstrated that in human osteoarthritic synovium, there is a correlation between neutral enzyme activity and the severity of synovial inflammation. Tissue culture studies have shown that the human osteoarthritic synovial membrane produces metalloproteases, such as collagenase, proteoglycanase and gelatinase. These enzymes were further characterized by their molecular weight. Extracts of osteoarthritic synovial tissues showed the presence of serine proteases, with apparent Mr of 25,000.