Cyclic Mechanical Strain Induces Expression Changes in Cultured HDPC

Objective: To investigate the effects of cyclic mechanical strain on expression changes in gene and protein in cultured human dental pulp cells. Methods: Cultured human dental pulp cells were subjected to 0%, 2% or 8% cyclic mechanical strain with Flexcell Tension Plus System for 0.5h, 12h and 24h respectively, and the expression of Col±, DSPP/DSP and OCN were examined by RT-PCR and western blot. Results: Cyclic mechanical strain applied increased the expression of Col±, DSPP/DSP and OCN mRNA and protein in cultured cells. All 3 tested mRNA was up regulated at each check point after 2% or 8% strain applied, except for Col±mRNA in 8% and DSPP mRNA in 2% and 8% strain for 24h. All 3 tested proteins showed increase only at 12h after 2% or 8% cyclic mechanical strain. Conclusion: Cyclic mechanical strain can affect expression of Col±, OCN, DSPP/DSP mRNA and protein in human dental pulp cells in magnitude and time-dependent manners.