2009 Volume 72 Issue 2 Pages 115-116
Inflammation in dental pulp tissue is associated with tissue degradation. Matrix metalloproteinases (MMPs) are believed to participate in this destruction. In the inflamed pulp, many kinds of inflammatory cytokines such as tumor necrosis factor (TNF)-α, are released from the inflammatory tissue. In the present study, we examined the TNF-α to MMP-3 pathway and whether TNF-α affected the production of MMP-3 in dental pulp fibroblasts. TNF-α increased the expression of MMP-3 in a dose-dependent manner in dental pulp fibroblasts. U 1026, which are MAPK/ERK (MEK 1/2) inhibitors, inhibited the MMP-3 production induced by TNF-α in dental pulp fibroblasts. Moreover, in dental pulp fibroblasts cultured with TNF-α, extracellular-regulated kinase 1/2 (ERK 1/2) was phosphorylated in a timedependent manner with the maximum phosphorylation at 30min, and U 0126 abolished this phosphorylation of MEK 1/2 in TNF-α-stimulated dental pulp fibroblasts. These results suggest that TNF-α may enhance pulp tissue destruction during pulp inflammation in part by regulating MMP-3, and that the MEK 1/2-ERK 1/2 pathway is involved with MMP-3 production in dental pulp fibroblasts.
