辛伐他汀对大鼠骨量及骨髓基质干细胞增殖、分化过程中Smad1,2,7表达的影响

Effects of simvastatin on bone mass and the expression level of mRNA of Smad1,2,7 in the proliferation and differentiation of bone marrow stromal cells in rats

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。方法16只6w龄雌性SD大鼠按体重随机分成2组,每组8只:第一组(G1),实验组,辛伐他汀灌胃20mg/kg·d(S20),持续6w;第二组(G2),对照组,每天蒸馏水灌胃(N),持续6w。于最后一次灌胃的第二天处死所有大鼠,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细胞向成骨方向诱导培养,并作如下检测:采用Cell Counting Kit-8(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16d和28d分别检测碱性磷酸酶(ALP)比活性、ALP染色和von Kossa染色;细胞培养第21d,提取总RNA,采用Real-time RT-PCR检测Smad1、2、7的mRNA的表达。结果辛伐他汀体内给药干扰6w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、矿化能力(von Kossa染色)、ALP比活性、ALP染色两组间均无显著差别。结论辛伐他汀体内给药6w对大鼠骨量及骨髓基质干细胞的增殖和分化无显著作用。

Objective To investigate the effects of simvastatin on bone mass and differentiation and proliferation of the cultured bone marrow stromal eells（BMSC） in rats. Methods Sixteen 6-week-old female Sprague-Dawley rats were randomized into two groups of eight animals each： G1, administered daily with 20 mg/kg of simvastatin by gavage for six weeks; G2, control group with Vehicle for six 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）. BMSC were derived from the right femora and tibiae. The cells were differentiated into osteoblast. Cell Counting Kit-8 （CCK-8） was used to assay the proliferation of BMSC. Alkaline phosphatase （ALP） activity, ALP staining were performed on the 16^th d and von Kossa staining on the 28^th d. Real-time RT-PCR was used to evaluate the expression level of mRNA of Smadl,2,7 on the 21th d. Results After being administrated with simvastatin for 6 weeks, the bone mass and bone mineral density （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, ALP staining, yon Kossa staining, and the proliferation of BMSC. Conclusions Administrated with simvastatin for six weeks has no significant effect on bone mass and the differentiation and proliferation of BMSC in rats.