Effect Of Low Intensity Pulsed Ultrasound On Osteogenic Differentiation Of Human Periodontal Ligament Cells In Vitro

Purpose:The focus of this current study is to explore such effects on osteogenic differentiation of hPDLCs by LIPUS and potential regulatory mechanisms,to provide the experimental evidences for the promising prospects of LIPUS in periodontal tissue regeneration.Method:LIPUS of different paramaters were used to sonication the cultured hPDLCs.Using Alkali phosphatase activity assay and radioimmunoassay,we studied the influence of LIPUS on ALP activity and osteocalcin synthesis by hPDLCs.We observed integrinβ1,c-fos,c-jun,cbfα1 mRNA expression by RT-PCR.Results:1.The cultured cells were typical hPDLCs,in accordance with literature reported,and were suitable for further experiment.2.LIPUS can promote the activity of ALP and OC with different paramaters.The most optimal parameter of LIPUS is 90mW/cm2-20min/d.3.LIPUS can upregulate the expression of integrinβ1,c-fos,c-jun,cbfa1 mRNA of hPDLCs. Conclusion:1.By increasing the synthesis and activity of osteogenic marker proteins as ALP,OC,LIPUS could promote the osteogenic differentiation of hPDLCs in vitro.2.Integrinβ1,c-fos,c-jun,cbfα1 mRNA expression were upregulated by LIPUS,which suggest those gene may participate in the regulation of LIPUS on hPDLCs osteogenic differentiation.Thus,we speculate,LIPUS act on hPDLCs in the form of mechanical stress,which influence the"ECM-integrin-cytoskeleton"mechanical signaling system at first,transmit the signal into nucleus by ERK1/2 and JNK pathway,induce tigger gene expression such as integrinβ1,c-fos,c-jun,cbfa1 that may play as transcription factor in the upregulation of ALP,OC,which can represent the function status of hPDLCs and server in the osteogenic differentiation.