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 for-α (TNF-α). Peak collagenase mRNA levels occurred 24 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-α dose-related response to both collagenase and stromelysin-1 mRNA accumulation was also demonstrated. Confirmation of the presence of secreted metalloproteinases in the conditioned media was established by immunoprecipitation of stromelsyin-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-α stimulated samples. Collagenase assays of conditioned media also demonstrated a significant increase in collagenase activity after stimulation by TNF-α. While epidermal growth factor had a minimal effect on stromelysin-1 and collagenase expression, transforming growth factor-β, and insulin-like growth factor-1 did not induce either enzyme activity.
Original language | English (US) |
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Pages (from-to) | 241-249 |
Number of pages | 9 |
Journal | Matrix Biology |
Volume | 14 |
Issue number | 3 |
DOIs | |
State | Published - Apr 1994 |
Externally published | Yes |
Keywords
- collagenase
- fibrochondrocytes
- stromelysin
- tumor necrosis factor-alpha
ASJC Scopus subject areas
- Molecular Biology