miR-187-5p对骨髓间充质干细胞成骨分化能力的调控作用

Regulative function of miR-187-5p in enhancing the differentiation capacity of bone marrow mesenchymal stem cells into osteoblasts

目的利用小鼠骨髓间充质干细胞(BMSCs)的成骨分化模型,探讨miR-187-5p在成骨分化中的表达趋势及调控作用。方法通过切除雌性小鼠双侧卵巢构建小鼠骨质疏松模型;应用qRT-PCR技术检测组织和细胞中miR-187-5p的表达;应用基因转染技术观察过表达或敲减miR-187-5p对BMSCs向成骨分化的影响;应用茜素红和碱性磷酸酶染色检测BMSCs中矿化结节的数量和矿化区域的染色面积。结果qRT-PCR结果显示miR-187-5p在骨质疏松模型小鼠的骨组织及BMSCs中均表达下降。过表达miR-187-5p可提高ALP、Collagen-1、Runx2、BMP4、OCN和OPN等成骨分化相关基因mRNA的表达,促进BMSCs向成骨分化;而敲减miR-187-5p降低ALP等成骨分化相关基因mRNA的表达,抑制BMSCs向成骨分化。在体实验同样证实,过表达miR-187-5p可以显著促进骨质疏松小鼠BMSCs向成骨分化,改善小鼠的骨质疏松表型。结论过表达miR-187-5p促进BMSCs向成骨分化,敲减miR-187-5p抑制BMSCs向成骨分化。

Objective Using the osteoblast differentiation model of mouse bone marrow mesenchymal stem cells( BMSCs),the expression trend and regulatory effect of miR-187-5 p in osteoblast differentiation were investigated. Methods Osteoporosis model was established by excising the bilateral ovaries of female mice. qRT-PCR was used to detect the expression of miR-187-5 p in bone tissues and BMSCs. Gene transfection technique was applied to overexpress or knockdown miR-187-5 p. The number of mineralized nodules and the mineralized staining areas in BMSCs were detected by Alizarin red and alkaline phosphatase staining. Results qRT-PCR result showed that,compare to the sham group,the expression of miR-187-5 p decreased in bone tissue and BMSCs in OVX group. Overexpression of miR-187-5 p effectively increased the mRNA level of osteogenic differentiation-related genes such as ALP,collagen-1,Runx 2,BMP 4,OCN,and OPN,suggesting that the overexpression of miR-187-5 p promoted BMSCs to differentiate into osteoblasts. However, the knockdown of miR-187-5 p effectively reduced the mRNA level of osteogenic differentiation-related genes,suggesting that the knockdown of miR-187-5 p inhibited osteogenic differentiation of BMSCs. In vivo experiments also confirmed that the overexpression of miR-187-5 p significantly promoted osteogenic differentiation of BMSCs in osteoporotic mice and then improved the osteoporotic phenotype of mice. Conclusion Overexpression of miR-187-5 p promotes BMSCs osteoblast differentiation,and miR-187-5 p knockdown inhibits BMSCs osteoblast differentiation.