title: Induction of stromelysin-1 and collagenase synthesis in fibrochondrocytes by tumor necrosis factor-alpha.
abstract: Stromelysin-1 and collagenase mRNA levels were assayed in fibrochondrocytes by Northern blot analysis at 0, 2, 4, 8 and 24 h after stimulation with tissue necrosis factor-alpha (TNF-alpha). Peak collagenase mRNA levels occurred 24 h after stimulation and were increased nine-fold over the level at time 0. Stromelysin-1 mRNA levels peaked 8 h after stimulation, with a five-fold increase over the level at time 0. A TNF-alpha dose-related response to both collagenase and stromelysin-1 mRNA accumulation was also demonstrated. Confirmation of the presence of secreted metallo-proteinases in the conditioned media was established by immunoprecipitation of stromelysin-1 and Western blotting of collagenase. Both enzymes were secreted in latent forms. Consistent with stromelysin-1 activity, substrate gels demonstrated a doublet of caseinase activity with molecular masses at 57 kDa and 59 kDa in TNF-alpha stimulated samples. Collagenase assays of conditioned media also demonstrated a significant increase in collagenase activity after stimulation by TNF-alpha. While epidermal growth factor had a minimal effect on stromelysin-1 and collagenase expression, transforming growth factor-beta, and insulin-like growth factor-1 did not induce either enzyme activity.
authors.affiliation: Department of Medicine, Medical College of Wisconsin, Milwaukee.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Jasser
authors.forename: P G
authors.initials: PG
authors.lastname: Mitchell
authors.forename: H S
authors.initials: HS
authors.lastname: Cheung
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D017364:Collagenases / Q000096:biosynthesis* / Q000235:genetics; D046508:Culture Techniques; D004790:Enzyme Induction / Q000187:drug effects; D019278:Matrix Metalloproteinase 3; D008592:Menisci, Tibial / Q000187:drug effects / Q000378:metabolism; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000235:genetics; D010447:Peptide Hydrolases / Q000096:biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D010447:Peptide Hydrolases; D017364:Collagenases; D008666:Metalloendopeptidases; C030895:caseinase; D019278:Matrix Metalloproteinase 3