Effect and mechanism of Polygonatum sibiricum polysaccharide on osteogenic differentiation of bone mesenchymal stem cells(BMSCs)

Objective:To investigate the effects and mechanisms of Polygonatum sibiricum polysaccharide(PSP)on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs).Methods:The mouse BMSCs were cultured and induced in osteoblast medium(OBM)containing finalconcentrations(0 mg/L,12.5 mg/L,25 mg/L,and 50 mg/L)of PSP.The proliferation and cytotoxicity of BMSCs were detected by MTT assay.Alkaline phosphatase(ALP)and Alizarin red S staining were performed after 7 days' ossification-inducing culture.The mRNA expressions of ALP,Runx2 and osteocalcin(OCN)were determined by fluorescence quantitative PCR(qPCR).The mRNA and protein expressions of Tafazzin(TAZ)(a key effector of Hippo pathway)were measured by qPCR and western blotting,respectively.Results:PSP was non-cytotoxicwithin the dose range of 12.5-50 mg/L and had no impact on the proliferation of BMSCs.The activity of ALP,the intensity of ALP staining,and the formation of mineralized nodules were increased by PSP treatment(25 and50 mg/L)(P<0.01).Moreover,administration of 25 mg/L PSP significantly enhanced the mRNA levels of osteoblastic differentiation makers ALP,Runx2 and OCN as well as the mRNA and protein expressions of TAZ(P<0.01).Conclusion:PSP could promote osteogenic differentiation of BMSCs,and the mechanisms might be related to the activation of TAZ in the Hippo signaling pathway.