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Canine osteoarthritis: Effects of endogenous neutral metalloproteoglycanases on articular cartilage proteoglycans
Author(s) -
Pelletier J. P.,
MartelPelletier J.,
Malemud C. J.
Publication year - 1988
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.1100060309
Subject(s) - cartilage , osteoarthritis , hyaluronic acid , chondroitin sulfate , chemistry , proteoglycan , chondroitin , sepharose , biochemistry , endogeny , extracellular matrix , glycosaminoglycan , anatomy , pathology , medicine , enzyme , alternative medicine
The aim of this study was to analyze the mechanisms by which neutral metalloproteoglycanases (NMPE) degrade proteoglycans (PGs) in the cartilage of an experimental model of osteoarthritis (OA). We demonstrated that chondrocytes in osteoarthritic cartilage synthesize PGs with the same functional characteristics as those found in normal cartilage. Osteoarthritic cartilage contains NMPE in both active and latent forms. Both forms can degrade newly synthesized and endogenous PG macromolecules, as indicated by the reduced hydrodynamic size found in the two PG populations of osteoarthritic cartilage. PG monomers, derived from the included fraction of Sepharose CL2B chromatography, were unable to form aggregates with hyaluronic acid. Reduction and alkylation showed that PG monomers from osteoarthritic cartilage had a small hydrodynamic size, especially after activation with aminophenylmercuric acetate. No significant differences were observed in the size of the chondroitin sulfate chain when normal cartilage was compared with its osteoarthritic equivalent. These results suggest that the proteolytic degradation of cartilage matrix PGs by NMPE occurs at both the hyaluronate‐binding region and at the chondroitin sulfate‐rich region of the core protein.