Human articular cartilage contains 2 distinct metalloproteases which degrade proteoglycan. One protease acts optimally at pH 5.3 and the other at pH 7.2. In addition, cartilage contains a tissue inhibitor of metalloproteases (TIMP) that inhibites both proteases. Methods have been developed for the estimation of metalloproteases and TIMP in extracts of cartilage prepared in buffered 2 M guanidine-HCl. In osteoarthritic cartilage, levels of the 2 metalloproteases increase 3-fold or more, while the levels of TIMP remains constant. It is postulated that a balance is maintained between inhibitor and metalloprotease levels in normal cartilage and that in osteoarthritis increased secretion of proteases upsets this balance and results in degradation of the extracellular matrix.
|Original language||English (US)|
|Number of pages||2|
|Journal||Journal of Rheumatology|
|Issue number||SPEC. NO.|
|State||Published - Jan 1 1987|
ASJC Scopus subject areas
- Immunology and Allergy