辛伐他汀对成骨细胞增殖分化及连接蛋白43表达的调控

背景：辛伐他汀对成骨细胞增殖分化的影响以及分子机制尚不完全明了，尤其对连接蛋白43的作用知之甚少。 目的：探讨辛伐他汀对成骨细胞增殖分化及成骨基因和连接蛋白43表达的调控作用。 方法：选取新生SD大鼠，采用颅盖骨消化法培养成骨细胞。采用不同浓度辛伐他汀（0.0625，0.125，0.25，0.5和1.0μmol/L）处理成骨细胞，MTT检测辛伐他汀对成骨细胞增殖作用的影响；碱性磷酸酶活性检测辛伐他汀对成骨细胞分化作用的影响；实时定量RT-PCR和免疫印迹检测细胞成骨基因和间隙连接蛋白43 mRNA和蛋白的表达。 结果与结论：细胞培养第3天，辛伐他汀组各浓度组MTT吸光度值比较差异无显著性意义（P 〉0.05）；但是培养第4天和第5天，辛伐他汀各浓度组MTT吸光度值低于对照组（P 〈0.05）。通过不同浓度辛伐他汀处理成骨细胞后，与对照组比较，成骨细胞碱性磷酸酶活性增加（P〈0.05），且0.25μmol/L 浓度组作用对成骨细胞碱性磷酸酶活性的影响最为显著。采用0.25μmol/L辛伐他汀处理成骨细胞后，辛伐他汀组与对照组比较，成骨细胞骨钙蛋白、碱性磷酸酶、Ⅰ型胶原和连接蛋白43 mRNA和蛋白表达均增加（P 〈0.05）。提示辛伐他汀可能通过上调成骨基因和间隙连接蛋白43 mRNA 和蛋白的表达来抑制成骨细胞增殖和促进其分化，这为他汀类药物治疗骨质疏松症提供新的干预靶点。

Regulatory effects of simvastatin on osteoblast proliferation,differentiation and connexin 43 expression

BACKGROUND：The effects and molecular mechanism of simvastatin on the proliferation and differentiation of osteoblasts remain unclear. Especial y, we do not know much about the effects of connexin 43.
OBJECTIVE：To evaluate the effects of simvastatin on the proliferation and differentiation of osteoblasts and the regulatory effect of simvastatin on the expression of osteogenic genes and connexin 43.
METHODS：Newborn Sprague-Dawley rats were chosen and the cranium digestion method was used to culture osteoblasts. The different concentrations of simvastatin （0.062 5, 0.125, 0.25, 0.5 and 1.0μmol/L） were used to deal with osteoblasts. The proliferative effect of simvastatin on osteoblasts was measured with 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide. The effect of simvastatin on osteoblast differentiation was measured with alkaline phosphatase activities. The mRNA and protein expression of osteogenic genes and connexin 43 were measured by real time quantitative RT-PCR and western blot assay.
RESULTS AND CONCLUSION：There were no significant differences in absorbance values of simvastatin groups at 3 days （P〉0.05）. However, at 4 and 5 days, absorbance values were lower in the simvastatin groups than those in the control group （P〈0.05）. Compared with the control group, alkaline phosphatase activities of osteoblasts were greater in the simvastatin groups （P〈0.05）. Moreover, the effects of 0.25μmol/L simvastatin on alkaline phosphatase activities of osteoblasts were most significant. Osteocalcin, alkaline phosphatase activities, type I col agen and connexin 43 mRNA and protein expressions were increased after treatment with 0.25μmol/L simvastatin （P〈0.05）. These results indicated that simvastatin may inhibit the proliferation and improve the differentiation of osteoblasts by upregulating the mRNA and protein expression of osteogenic genes and connexin 43. These data may provide the new intervention target for osteoporosis treated with statins.