Inverse dose- and time-dependent effect of basic fibroblast growth factor on the gene expression of collagen type I and matrix metalloproteinase-1 byperiodontal ligament cells in culture

Background: Growth factors are known to play a major role in the regenerati on of the periodontium. Basic fibroblast growth factor (bFGF) is a polypept ide growth factor considered to have a role in chemotaxis and mitogenesis o f periodontal ligament cells (PLC). The aim of this study was to assess the dose-dependent effect of bFGF administration on the levels of gene express ion of collagen type I (a1) (col I), collagen type III (col III), and colla genase-1 (MMP-1) in PLC. Methods: PLC were cultured in different concentrations of bFGF (0.1 to 10 n g of bFGF) for 14 and 21 days. At each time point, the gene expression of t he examined molecules was assessed semi-quantitatively by reverse transcrip tion-polymerase chain reaction (RT-PCR) assay. Results: The results indicated that bFGF exhibits an inverse time- and dose -dependent effect on the gene expression of col I and MMP-1: it simultaneou sly downregulates the gene expression of col I and upregulates the gene exp ression of MMP-1. On the other hand, bFGF had no dose-dependent effect on c ol III gene expression. The effect of bFGF on the expression of the three g enes was modulated by the time of incubation with bFGE Conclusions: These results suggest that bFGF is one of the important regula tors involved in the active remodeling of col I in the periodontal ligament and possibly in other connective tissues.