Effects of simvastatin on differentiation of osteoblasts derived from human bone marrow stromal cells

AIM:To investigate the effects of simvastatin(SIM)on differentiation of osteoblast derived from the cultured human bone marrow stromal cells(hBMSCs).METHODS:hBMSCs derivedfrom human were cultured in vitro and divided into 2 groups:Control group(G1),SIM group(G2).After subculturing,the medium of treatment group(G2)were added 10-7M simvastatin.Real time RT-PCR was performed to evaluate the mRNA expressionsof BMP-2,Smad1,β-catenin,LRP5,Frizzled2 at day 7,14 and 21 after subculturing;The protein level expression of β-catenin was assessed by immuhistochemistry staining;Alkaline phosphatase staining was used to assess osteoblast differentiation at day 7 after subculturing;Von Kossa staining was used to assess extracellular matrix mineralization and at day 21 after subculturing.RESULTS:The expression levels of mRNA of BMP2 in group G2 were significantly higher than those of group G1 at 3 time points;The expression levels of mRNA of Smad1 in group G2 were significantly higher than those of group G1 at 14 and 21 d subculturing,and the mRNA expression levels of other detected genes showed no significant difference between two groups at each time point.Immuhistochemistry staining:No significant difference was found of the protein expression levels of β-catenin at the 3 time points between the 2 groups.the expression level of ALP and the capability of extracellular matrix mineralization in G2 group was significantlyhigher than that of G1 group.CONCLUSION:Treatment with simvastatin(1×10-7mol/L)could promote osteoblastogenesis of HBMSCs in vitro,probably partially from activing TGF-β/BMPs signaling pathway and upregulating expression of its signaling moleculars.No change was found of expression levels of the detected genes of Wnt/β-catenin signaling pathway after simvastatin treatment,further study should be performed to detect the role of Wnt/β-catenin signaling pathway in osteoblastogenesis-promoting effect of simvastatin on hBMSCs.