Effect of p38 MAP kinase on the production of MMP-1 in human gingival fibroblast-like cells

Tooth movement due to orthodontic force application is characterized by remodeling changes in dental and paradental tissues, including dental pulp, periodontal ligaments, alveolar bone, and gingiva. Although gingival changes have been found to be important for the overall response, they have attracted only minimal attention. We therefore focused on gingival changes during tooth movement. Matrix metalloproteinases (MMPs) concentrations are elevated during orthodontic tooth movement and in compression of the periodontal ligament, and are believed to participate in soft tissue remodeling. Furthermore, many kinds of growth factors, including PDGF, are released from periodontal tissue during orthodontic tooth movement. In the present study, we demonstrated that MMP-1 was produced from human gingival fibroblast-like cells (HGFs) in response to PDGF-bb in a p38 MAP kinase-dependent manner. Blocking of p38 MAP kinase activation by the inhibitor SB203580 significantly inhibited PDGF-bb-induced production of MMP-1 without affecting the total production of MMP-2. These results suggest that PDGF-bb facilitates connective tissue remodeling through induction of the production of the collagenase, MMP-1.