辛伐他汀对大鼠骨量及骨髓基质干细胞增殖、分化的影响

Effects of simvastatin on bone mass and 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9周龄雌性SD大鼠按体重随机分成2组,每组8只:第1组(G1),对照组,每天蒸馏水灌胃(N);第2组(G2),实验组,辛伐他汀灌胃20mg·kg-1.d-1(S20),持续3周,于最后1次灌胃的第2天处死所有大鼠,取右侧股骨行骨密度和骨组织形态计量学测定;取左侧股骨和胫骨骨髓细胞分别向成骨、成脂方向诱导培养,并作如下检测:(1)成骨组: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16d,提取总RNA,采用Real-time RT-PCR检测骨形态发生蛋白-2(bone morphogenetic protein-2,BMP-2)、碱性磷酸酶(ALP)、破骨细胞分化因子(RANKL) mRNA的表达;(2)成脂组:采用CCK-8法检测定向成脂分化中的骨髓基质干细胞的增殖能力;细胞培养第18d,检测LPL比活性,并提取总RNA,采用Real-time RT-PCR检测脂蛋白脂酶(LPL) mRNA的表达。结果辛伐他汀体内给药干扰21d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、LPL比活性两组间差异均无显著性。结论辛伐他汀体内给药3周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 cells（BMSC） in rats.Methods Sixteen 9-week-old female Sprague-Dawley rats were randomized into two groups of eight animals each： G1, control group with Vehicle for three weeks; G2, administered daily with 20 mg· kg^-1 of simvastatin by gavage for three weeks. All animals were sacrificed one day after the final administration. The right femora were removed for the measurement of bone histomorphometry and bone mineral density （BMD）. BMSC were derived from the left femora and tibiae. The cells were divided into two groups for differentiation into osteoblast （ group A, GA） and adipocyte （ group B, GB ） separately. Cell Counting Kit-8 （CCK-8） was used to assay the proliferation of BMSC. For group A, 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 BMP-2,ALP, RANKL on the 16^th d. For group B, lipoprotein lipase （LPL） activity and expression level of mRNA of LPL were detected on the 18^th d. Results After being administrated with simvastatin for 3 weeks, the bone mass and bone mineral density （BMD） of rats had no significant change between two groups. The expression level of mRNA of BMP-2,ALP,RANKL and LPL showed no significant change, so were the results of ALP activity, ALP staining, von Kossa staining, LPL activity and the proliferation of BMSC. Conclusion Administrated with simvastatin for three weeks has no significant effect on bone mass and the differentiation and proliferation of BMSC in rats.