miR-187-5p 对骨髓间充质干细胞成骨分化能力的调控作用

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。

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

Objective Using the osteoblast differentiation model of mouse bone marrow mesenchymal stem cells (BMSCs), the expression trend and regulatory effect of miR-187-5p 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-187-5p in bone tissues and BMSCs. Gene transfection technique was applied to overexpress or knockdown miR-187-5p. The number of mineralized nodules and the mineralized staining areas in BMSCs were detected by Alizarin red and alkaline phosphatase staining. Results qRT-PCR results showed that, compare to the sham group, the expression of miR-187-5p decreased in bone tissue and BMSCs in OVX group. Overexpression of miR-187-5p 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-187-5p promoted BMSCs to differentiate into osteoblasts. However, the knockdown of miR-187-5p effectively reduced the mRNA level of osteogenic differentiation-related genes, suggesting that the knockdown of miR-187-5p inhibited osteogenic differentiation of BMSCs. In vivo experiments also confirmed that the overexpression of miR-187-5p significantly promoted osteogenic differentiation of BMSCs in osteoporotic mice and then improved the osteoporotic phenotype of mice. Conclusion Overexpression of miR-187-5p promotes BMSCs osteoblast differentiation, and miR-187-5p knockdown inhibits BMSCs osteoblast differentiation.