title: Substrate specificity and activation mechanisms of collagenase from human rheumatoid synovium.
abstract: Substrate specificity studies of collagenase extracted from human rheumatoid synovium suggest that synovial pannus tissue overlying articular cartilage may not be particularly active in degradation of cartilage type II collagen, which, considering the poor inherent healing capacity of the articular hyaline cartilage, may exert a protective function against inadvertant tissue damage. Rheumatoid synovial tissue was also used to establish synovial fibroblast cell lines. Treatment of these cells in monolayer cultures with IL-1 leads to collagenase gene activation, increased collagenase production and an almost complete autoactivation of secreted collagenase. Interleukin-1 also activated stromelysin gene suggesting this as a possible mechanism effecting autoactivation. Latent human fibroblast and macrophage collagenase purified from culture medium were efficiently activated by phenylmercuric chloride but also by gold thioglucose, gold sodium thiomalate and HCIO. These new observations support the Cys73 switch activation mechanism. In contrast to neutrophil collagenase, the activation by gold(I) compounds and HCIO was associated with a change in the apparent molecular weight of the fibroblast procollagenase. In addition, gold(I) compounds rendered collagenase more susceptible to thermal denaturation. Thus the fibroblast-type interstitial collagenase, probably derived from fibroblast- and macrophage-like synoviocytes, seems to provide the predominant collagenolytic potential in human rheumatoid synovial tissue. Furthermore, the conditions in synovitis tissue may be such as to favor at least initial activation of collagenase synthesized and secreted in situ.
authors.affiliation: Institute of Molecular Immunology, Hospital for Joint Diseases, NYU Medical School, NY 10003.
authors.forename: Y T
authors.initials: YT
authors.lastname: Konttinen
authors.forename: O
authors.initials: O
authors.lastname: Lindy
authors.forename: K
authors.initials: K
authors.lastname: Suomalainen
authors.forename: C
authors.initials: C
authors.lastname: Ritchlin
authors.forename: H
authors.initials: H
authors.lastname: Saari
authors.forename: M
authors.initials: M
authors.lastname: Vauhkonen
authors.forename: A
authors.initials: A
authors.lastname: Lauhio
authors.forename: S
authors.initials: S
authors.lastname: Santavirta
authors.forename: T
authors.initials: T
authors.lastname: Sorsa
mesh_terms: D001172:Arthritis, Rheumatoid / Q000201:enzymology*; D006051:Aurothioglucose / Q000494:pharmacology; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D004789:Enzyme Activation; D004790:Enzyme Induction / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D006052:Gold Sodium Thiomalate / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology; D019278:Matrix Metalloproteinase 3; D008666:Metalloendopeptidases / Q000096:biosynthesis; D003012:Microbial Collagenase / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D010663:Phenylmercury Compounds / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013379:Substrate Specificity; D013583:Synovial Membrane / Q000201:enzymology* / Q000473:pathology
chemical_list: D007375:Interleukin-1; D010663:Phenylmercury Compounds; D012333:RNA, Messenger; D006052:Gold Sodium Thiomalate; D006051:Aurothioglucose; D003094:Collagen; D012973:Sodium Hypochlorite; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3; D003012:Microbial Collagenase; C008859:phenylmercuric chloride