2012 Volume 55 Issue 3 Pages 202-210
Purpose: Matrix metalloproteinase (MMP)-3 is a member of the MMP family, which comprises typical proteinases that degrade the extracellular matrix. MMP-3 is involved in various physiological and pathological processes. Recently, application of MMP-3 to injured pulp tissues was reported to induce angiogenesis and wound healing, but its anti-inflammatory functions are still unknown. The purposes of this study were to evaluate the effects of MMP-3 on inflammatory mediator synthesis from macrophages (RAW264) and mice dental papilla cells (MDP). Methods: RAW264 and MDP were cultured in 10% FBS supplemented D-MEM and MEMα, respectively. They were stimulated by LPS (100 ng/ml) in the presence or absence of MMP-3 (100 ng/ml) Non-LPS-stimulated RAW264 and MDP were used as controls. NO production was measured using the Griess reagent, and inflammatory mediator synthesis was evaluated using real-time PCR. Effects of MMP-3 for cell growth and caspase-3 activity were assessed. Results: Application of MMP-3 down-regulated the NO synthesis from LPS-stimulated macrophages, which showed a typical increase of NO synthesis compared to non-LPS-stimulated macrophages. mRNA of inflammatory mediators (IL-1β, IL-6, TNF-α and Cox2) was highly expressed in LPS-stimulated macrophages, but the application of MMP-3 significantly down-regulated their expression. Cox2 mRNA expression was highly induced in LPS-stimulated MDP, which was down-regulated by MMP-3 application. MMP-3 did not influence the cell growth and caspase-3 activity of RAW264 and MDP. Conclusion: MMP-3 down-regulated the inflammatory-mediator synthesis from LPS-stimulated macrophages and dental papilla cells, suggesting that MMP-3 may be a candidate for reducing pulpal inflammation.
