Objective          To determine the effect of purmorphamine on the osteogenic differentiation in human periodontal ligament stem cells (PDLSCs) under dynamic strain.       Methods        PDLSCs were isolated from freshly extracted teeth and identified with flow cytometry for expression of STRO-1 and CD146

and then subcultured into six-well flexible-bottomed Uniflex culture plates. When 80% confluence was achieved

purmorphamine

an activator of the hedgehog (Hh) signaling pathway

was added into the wells in mineralization induction medium at the concentration of 1 μmol/L

and dynamic strains were applied to PDLSCs with the Flexcell FX-4000T Tension Plus System for 24 h. Then the mRNA expression of osteoblastic related indexes of Runx2

ALP and Hh pathway markers GLI1

PTCH1

SMO was detected by real-time PCR.       Results         After 24 h loading

the gene expression of osteogenic markers Runx2 and ALP and Hh pathway markers (GLI1

PTCH1 and SMO) was all increased (P0.05). And the group with purmorphamine treatment showed much higher expression of these genes than  the control group and the only mechanical loading group (P0.05).       Conclusion        Purmorphamine promotes osteogenic differentiation in PDLSCs under dynamic tensile

probably through activation of Hh signal pathway.