The Effect Of Pth (1-34) On Expression Of Matrix Gla Protein And Wnt/β Catenin Signaling Pathways In MG63 Cell Lines

Objective:To observe the effect of PTH(1-34) on expression of matrix Gla protein(MGP) and Wnt/β-catenin signaling pathway, and to study the role of Wnt/β-catenin signaling pathway in the process of PTH regulating MGP in human osteosarcoma cells(MG63) in vitro, thus, to elucidate the possible molecular mechanism of PTH(1-34) in the prevention and treatment of osteoporosis.Methods:(1) Different concentrations of PTH(1-34)(10-9、10-8、10-7M)was treated with MG63 cells;(2) After treatment with 10-7M PTH(1-34)、200ng/ml DKK-1, 10-7M PTH(1-34)+200ng/ml DKK – 1,total mRNA and total protein of MG63 were extracted and analyzed by Western blot and Real-Time quantitative(RT-PCR)to measure the gene expression;(3) Alkaline phosphatase(ALP) staining and activity assay was taken to detect cell differentiation after the intervention of PTH and Dkk-1.Results:1. PTH(1-34) increased the expression of MGP, The experimental groups are in the control group respectively 2.56 times,4.14 times,7.81times( *P<0.05,**P<0.01).and was dose-dependent; 2. ALP activity of MG63 cells was enhanced by PTH, which was suppressed by Dkk-1, an inhibitor of Wnt signaling pathway.Whereas, combination Dkk-1 and PTH blocked ALP activity(P < 0.05); 3. PTH promoted the expression of MGP and several elements of Wnt/β-catenin signaling pathway including LRP5、β-catenin 、Runx2, at mRNA and protein levels,The experimental groups mRNA is in the control groups respetively2.65 times,4.01 times,3.48 times(*P<0.05,**P<0.01); DKK-1 partly blocked the effect of PTH(1-34)on Wnt/β-catenin signaling pathway(P < 0.05) but not on MGP. Conclusion:PTH(1-34) significantly increased the expression of MGP and elements in the Wnt/β-catenin signaling pathway; Wnt/β-catenin signaling pathway and MGP mediate PTH regulation on osteogenosis.