OBJECTIVETo observe the expression of asporin, bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) in cultured human periodontal ligament cells in vitro under relative centrifugal force.

METHODSHuman periodontal ligament cell was cultured in vitro and applied 30 ×g centrifugal force for 0, 1, 2, 6, 10 hours. The expression of asporin, BMP-2 and ALP was observed with real time-PCR.

RESULTSAll the cells showed normal figuration. The expression of asporin, BMP-2, ALP in no force loading group did not have any statistical significance change (P > 0.05). In 1 hour force loading group, the expressions of asporin and BMP-2 were 0.50 ± 0.05 and 0.40 ± 0.13. In 2 hour force loading group, the expressions of asporin and BMP-2 were 0.42 ± 0.09 and 0.58 ± 0.19, which decreased significantly from no force loading group (P < 0.05). The expression of asporin and BMP-2 increased significantly in 6 hour force loading group than in 1 and 2 hour force loading groups (P < 0.05). Then the expression of asporin decreased to no force loading group level (P > 0.05) and the expression of BMP-2 decreased rapidly lower than no force loading group level (P < 0.05). During the 10 hour interval of stress loading, the expression of asporin and BMP-2 showed a positive correlation (r = 0.995, P < 0.05).

CONCLUSIONSThe expression of asporin in human periodontal ligament cell was stable. Short and light centrifugal force could up-regulate the expression of asporin rapidly, and suppress the abnormal BMP-2 expression back to baseline level.