Effect of simvastatin on bone formation and osteogenic differentiation of bone marrow stromal cells in young rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Recently simvastatin has been shown to stimulate osteogenic differentiation and bone formation, but there is no report about the effect of simvastatin on the bone development of young rats.OBJECTIVE: To evaluate the effects of simvastatin on osteogenic relative genes of proximal tibia trabecular bone and osteogenic differentiation of bone marrow stromal cells (BMSCs).METHODS: Twenty 1-week-old Spragua-Dawley young rats were randomly and equally divided into simvastatin and control groups. Rats in the simvastatin group were treated with a subcutaneous injection of simvastatin[5 mg/(kg·d)] for 2 weeks, while rats in the control group were treated with placebo for 2 weeks. The expressions of bone morphogenetic protein-2 (BMP-2), matrix metalloproteinase-13 (MMP-13), and vascular endothelial growth factor (VEGF) of trabecular bone in the tibia were analyzed by mmunohistochemicel staining. BMSCs harvested from the rat femur were osteogenic-differentiation cultured. Alkaline phosphatase (ALP) staining was performed on day 14, real-time PCR analysis was applied to investigate the BMP2, RUNX2,Osterix, MSX2, DLX3, DLX5 mRNA expressions during osteogenic differentiation in vitro on day 21, and von Kossa staining was detected on day 28.RESULTS AND CONCLUSION: ① There was no significant difference in the expressions of BMP-2, MMP-13, and VEGF between simvastatin and control groups. ② The percentages of ALP positive-stained cells were about 30% and there was no significant difference between the two groups (P ＞ 0.05). ③There was no significant difference in the expressions of BMP-2,RUNX2, Osterix, MSX2, DLX3, DLX5 mRNA in osteoganic differentiation-induced BMSCs. ④ von Kossa staining demonstrated that dark brown calcified spots in various sizes were observed, but there was no significant difference in size and density between simvastatin and control groups. A subcutaneous injection of simvastatin[5 mg/(kg·d)] for 2 weeks could not remarkably affect osteogenic relative genes of bone trabecula and osteogenic differentiation of BMSCs.