辛伐他汀体内给药对大鼠骨量和骨髓基质干细胞增殖分化的影响

Effects of simvastatin on bone mass and bone marrow mesenchymal stem cells proliferation in rats

背景:辛伐他汀对正常大鼠骨代谢及骨髓基质干细胞增殖分化影响的报道目前不多。目的:观察辛伐他汀体内给药对大鼠骨量和骨髓基质干细胞增殖、分化的影响,及其在此过程中Smad1,2,7mRNA表达水平的变化。方法:16只6周龄雌性SD大鼠按体质量随机均分成2组,对照组每天灌胃蒸馏水,实验组灌胃辛伐他汀20mg/(kgd),持续9周。于最后一次灌胃的第2天取左侧股骨行骨密度和骨组织形态计量学测定;取右侧股骨和胫骨骨髓基质细胞向成骨方向诱导培养,并采用CCK-8法检测定向成骨分化中的骨髓基质干细胞的增殖能力;细胞培养第16,28天检测碱性磷酸酶比活性、碱性磷酸酶染色阳性细胞比;细胞培养第21天,提取总RNA,采用Real-timeRT-PCR检测Smad1,2,的mRNA表达。结果与结论:辛伐他汀体内给药干预9周后,大鼠骨量和骨密度无显著变化,体外培养骨髓基质干细胞所有检测基因mRNA水平、细胞增殖能力、细胞外基质矿化能力、碱性磷酸酶比活性、碱性磷酸酶染色阳性细胞比两组间差异均无显著性意义(P>0.05)。结果显示20mg/(kgd)辛伐他汀体内给药9周对大鼠骨量及骨髓基质干细胞的增殖和分化及Smad1,2,7的表达无显著作用。

BACKGROUND： As a widely used lipid-lowering drug, simvastatin has been rarely reported addressing its effects on bone metabolism and proliferation and differentiation of bone marrow stromal cells （BMSCs）. OBJECTIVE： To investigate the effects of simvastatin on bone mass and differentiation and proliferation of BMSCs in rats, as well as the expression levels of Smad1, 2, 7 mRNA. METHODS： Sixteen 6-week-old female Sprague-Dawley rats were randomized into two groups of eight animals each： simvastatin group, administered daily with 20 mg/kg simvastatin by gavage for 9 weeks; control group, administered with distilled water for 9 weeks. All animals were sacrificed one day after the final administration. The left femora were removed for the measurement of bone histomorphometry and bone mineral density （BMD）. BMSCs derived from the right femora and tibiae were cultured in osteoblastic differentiation-induced medium. Cell Counting Kit-8 （CCK-8） was used to assay the proliferation of BMSCs. Alkaline phosphatase （ALP） activity, ALP staining were performed on the 16th day and von Kossa staining on the 28th day. Real-time RT-PCR was used to evaluate the expression levels of mRNA of Smad1, 2, 7 at the 21st day. RESULTS AND CONCLUSION： After being administrated with simvastatin for 9 weeks, the bone mass and BMD of rats had no significant change. The expression level of mRNA of Smad1, 2, 7 showed no significant change, so were the results of ALP activity, positive cell rate of ALP staining, von Kossa staining, and the proliferation of BMSCs. Administration with 20 mg/kg simvastatin for 9 weeks had no significant effect on bone mass and the differentiation and proliferation of BMSCs in rats, so were the expression levels of Smad1, 2, 7 mRNA.