Effects of compression force on fibroblast growth factor-2 and receptor activator of nuclear factor kappa B ligand production by periodontal ligament cells in vitro

Background and Objective: Mechanical stress by an orthodontic appliance induces biologically active substances. Fibroblast growth factor is a multifunctional cytokine that has various effects on fibroblast cells, and fibroblast growth factor-2 plays an important role in remodeling of the periodontal ligament. The receptor activator of nuclear factor kappa B ligand (RANKL) is an important protein involved in osteoclastogenesis and we recently reported that RANKL levels were increased by compression force in vitro. In the present study, we investigated the effects of compression force on fibroblast growth factor-2 and RANKL production by human periodontal ligament cells. Material and Methods: Compression force (0.5-4.0 g/cm(2)) was applied to human periodontal ligament cells for 0-24 h. The amounts of soluble RANKL (sRANKL) and fibroblast growth factor-2 were measured using an enzyme-linked immunosorbent assay, whereas mRNA levels were determined by the reverse transcription-polymerase chain reaction. Furthermore, anti-fibroblast growth factor-2 was added to the cell culture media and we measured the release of sRANKL and fibroblast growth factor-2 by enzyme-linked immunosorbent assay. Results: Compression force induced higher levels of sRANKL and fibroblast growth factor-2 in both a time- and magnitude-dependent manner. Treatment with anti-fibroblast growth factor-2 inhibited the release of sRANKL. Conclusion: Fibroblast growth factor-2 may be partly involved in osteoclastogenesis during orthodontic tooth movement.