Interleukin-1 alpha stimulates interstitial collagenase gene expression in human dental pulp fibroblast

Interstitial collagenase (matrix metalloprotease-1) is a member of a family of matrix metalloproteases and is thought to play a role in degradation of the extracellular components, such as collagens in normal extracellular matrix remodeling and in many disease processes. We examined interstitial collagenase mRNA expression in human dental pulp fibroblast cultures by Northern blot analysis. These cells did not express interstitial collagenase mRNA in an unstimulated condition. Inflammatory cytokines, such as interleukin-1 alpha, induced interstitial collagenase mRNA expression in these cells. The interstitial collagenase mRNA levels began to increase after 2-h exposure, reaching a maximum after 8 h, then dropping to the unstimulated level at 48 h. These effects were observed in a dose-dependent manner in a dose range of 0.1 to 10 ng/ml. Transforming growth factor-beta reduced the levels of interstitial collagenase mRNA expression that were induced by interleukin-1 alpha. These observations suggest that interstitial collagenase mRNA expression in human dental pulp fibroblasts is regulated by the inflammatory cytokines and that interstitial collagenase may play a role in tissue degradation in inflamed dental pulp.