ABSTRACT
Objective To investigate PSP on bone microstructures,Ca,P,OPG and RANKL of osteoporotic rat model.Methods Thirty female rats randomly divided into five groups:Sham,OVX,H-,M-,L-PSP.Sham and OVX were irrigated stomachsaline;PSP solution was gavaged to other groups.After 8-week,bone microstructures of tibial metaphyseal,Ca,P,OPG and RANKL were measured.Results Body weight,Ca,P,RANKL,Tb.Sp of OVX were significantly increased compared to Sham,OPG,BV/TV,Tb.Th,Tb.N decreased.Body weight of H-,M-PSP,Ca and Tb.Sp of PSP,P and RANKL in H-PSP were decreased compared to OVX,OPG in H-,M-PSP,BV/TV,Tb.Th,Tb.N of PSP group increased.The differences were statistically significant (P ＜ 0.05).Conclusion PSP prevents osteoporosis by improving the microstructure of trabecular bone,reducing bone turnover,increasing OPG and reducing RANKL expression.
ABSTRACT
BACKGROUND:Bone marrow mesenchymal stem cels (BMSCs) have the ability of multi-directional differentiation. Polygonatum sibiricum polysaccharide can promote osteogenetic differentiation of mouse BMSCs by activating Wnt/β-catenin signaling pathway, which is expected to become a new drug for the treatment of osteoporosis. OBJECTIVE:To investigate the effects of Polygonatum sibiricum polysaccharide on Wnt/β-catenin signaling pathway in the osteogenic differentiation of mouse BMSCs. METHODS:The mouse BMSCs were cultured and induced in osteoblast medium containing final concentrations (5, 10, 25, 50mg/L) of Polygonatum sibiricum polysaccharide. The mouse BMSCs treated without Polygonatum sibiricum polysaccharide was set as the negative control group. The morphological changes of cels were observed under an inverted microscope. Alkaline phosphatase (ALP) activity assay was performed by PNPP method. The mineralization nodules were observed and stained with alizarin red S and the number and area fraction were recorded under an inverted microscope. The mRNA expressions of osteogenesis-related genes ALP, Runx2, and osteocalcin were evaluated by quantitative real-time PCR (qRT-PCR). qRT-PCR and western blot were used to determine the expression level of β-catenin. The downstream β-catenin/TCF transcriptional activity was evaluated with the Dual-Luciferase Reporter Assay System. RESULTS AND CONCLUSION: Compared with the control group, polygonatum sibiricum polysaccharide significantly enhanced the alkaline phosphatase activity, the mineralization ability of cels, and the mRNA expression of ALP, Runx2 and osteocalcin in the differentiated BMSCs in a dose dependent manner (P <0.05). After induction, the mRNA expression of β-catenin was the highest on the 3rd day. Polygonatum sibiricum polysaccharide significantly increased the expression of β-catenin (P < 0.05) in the process of promoting the differentiation of BMSCs into osteoblasts, and also promoted the high-level expression of luciferase reporter gene (TOPFlash) which contains wild type TCF binding sites (P < 0.05). These results demonstrate that Polygonatum sibiricum polysaccharide can promote the osteoblast differentiation of mouse BMSCs by activating the Wnt/β-catenin signaling pathway.