Paracrine Function of Osteopontin on the Osteogenic Differentiation of Dental Pulp Stem Cells

Objective:To study the paracrine function of Osteopontin(OPN)on the osteogenic differentiation of dental pulp stem cells(DPSCs).Methods:Methyl thiazolyl tetra-zolium(MTT)assay was used to evaluate the proliferation rate of DPSCs induced by different concentrations of OPN.The activity of Alkaline phosphatase(ALP)after induced by different concentration of OPN was measured.We select appropriate induction concentration,observe the morphological changes of DPSCs by the inverted phase contrast microscope,detect the mineralize nodules stained by Alizarin red,detect the expression levels of osteogenic related genes including bone sialoprotein(BSP),Runt-related transcription factor 2(Runx-2),osteocalcin(OCN)and collagen-1(Col-1)by reverse transcription polymerase chain reaction(RT-RCR).Results:The results of MTT and ALP activity measurement showed that ALP activity increased and cell proliferation rate dropped with the increase of concentration of OPN.Alizarin red staining showed that mineralized nodules have formed after induced by OPN for 28 day.The expression of osteogenic related genes is positive after 7days.Expression levels of BSP,Runx- 2,Col-1and OCN genes were significantly higher than the control group.Conclusion:The paracrine interaction of OPN contributed to osteogenic differentiation of DPSCs.