Effect of continuously compressive pressure on the expression of OPG and ODFmRNA in human periodontal ligament cells in vitro

Objective:To study the effect of continuously compressive pressure(CCP) on the expression of OPG and ODF in human periodontal ligament cells(HPDLCs),to investigate the role of osteoprogerin,(OPG) and osteoclast differentiation factor(ODF) in alveolar bone rebuilding during orthodontic tooth movement.Method:The primary HPDLCs were isolated from human periodontal ligament by explanting with enzymatic digestion with trypsin and collagenase.A pressure model was established,and 1 g/cm~2、2 g/cm~2、3 g/cm~2 top-bottom axial pressure were laid on HPDLCs for 0.5 h、1.5 h、6 h、12 h、24 h and 48 h respectively.The expression of ODF was indicated by the reverse transcription-polymerase chain reaction ( RT-PCR) at messenger RNA(mRNA) level.Result:The expression of ODF mRNA was significantly increased in a time-dependent manner(P0.01) And the expression of OPG mRNA was also strengthed at the end of the increased pressure.In 2 g/cm~2 group the greatest expression of ODF and OPG mRNA could be detected(P(0.05)).Conclusion:CCP can up-regulate the expression of OPG and ODF mRNA in Human periodontal ligament cells.But the increase of the expression of OPG mRNA was later than ODF mRNA.