Effect of different magnitudes of cyclic stretch on cell factors relating to bone remolding in human periodontal ligament fibroblasts

Abstract

Objective To investigate the effect of different magnitudes of cyclic stretch on cell factors relating to osteogenesis and osteoclastogenesis in human periodontal ligament fibroblasts in vitro. Methods Cyclic stretch of different magnitude (5%, 10% cell surface elongation) was forced on human periodontal ligament fibroblasts in vitro for 1h, 2h, 4h, 8h, 24h, then we investigated OPG, RANKL, RUNX2, Osterix expression. Data was analyzed with SPSS 13.0 soft ware. Results The results showed that under 5% enlongation stretch RUNX2, Osterix expression increased in a time-dependent manner which upregulated later than those in 10% enlongation group following a plateau. Under 5% and 10% enlongation stretch OPG expression increased in a time-dependent manner and there is no difference between these two groups. RANKL expression was inhibited in both of two groups. Conclusions Cyclic stretch could influence on the expression of osteogensis RUNX2, Osterix and osteoclastodesis OPG, RANKL in human periodontal ligament fibroblasts, and different magnitudes of tension stimulate different tendency of cell factor expression in human periodontal ligament fibroblasts. Key words: Cyclic stretch; different magnitudes; human periodontal ligament fibroblasts; bone remolding