Regulation of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases by basic fibroblast growth factor and dexamethasone in periodontal ligament cells

Background and Objectives: In this study, we investigated the effect of basic fibroblast growth factor (bFGF) and dexamethasone (Dex) on mRNA expressions of collagen (COL) type I, III and X, matrix metalloproteinases (MMP)‐1, ‐2, ‐3 and ‐9 and tissue inhibitors of metalloproteinases (TIMP)‐1 and ‐2, and also on mineralization and morphology of periodontal ligament (PDL) cells. Material and Methods: Periodontal ligament cells were obtained from premolar teeth extracted for orthodontic reasons. Periodontal ligament cells were cultured with Dulbecco’s modified Eagle’s medium containing: (1) 5% fetal bovine serum (FBS); (2) 5% FBS + ascorbic acid (AA, 50 μg/mL); (3) 5% FBS + Dex (10^?7 m ) + AA; (4) 5% FBS + bFGF (10 ng/mL) + AA; or (5) 5% FBS + Dex (10^?7 m ) + bFGF + AA. Cells within each group were evaluated for gene expression profile using semi‐quantitative reverse transcriptase‐polymerase chain reaction for COL I, III and X, MMP‐1, ‐2, ‐3 and ‐9 and TIMP‐1 and ‐2 on days 14 and 21 and for biomineralization by von Kossa stain in vitro on day 21. Images of PDL cells were examined using a phase contrast microscope. Results: Basic fibroblast growth factor stimulated MMP‐1, MMP‐3 and MMP‐9 mRNA expressions and inhibited TIMP‐2 mRNA expression. Treatment of cells with Dex + bFGF led to downregulation of MMP‐1, MMP‐3 and MMP‐9 transcripts. Whilst AA alone and Dex alone induced biomineralization of PDL cells, bFGF blocked the mineralization activity of the cells. In the Dex + bFGF group, more mineral nodules were noted when compared to AA alone and Dex alone groups. Conclusion: The addition of Dex to culture reversed bFGF‐mediated inhibition of mineralization. Use of combined bFGF and Dex to regulate PDL cell function may be a good therapeutic option to obtain periodontal regeneration.