Osteogenic differentiation (OD) of bone marrow mesenchymal stem cells (BMSCs) is critically important for mitigation of osteoporosis. Glucocorticoids (GCs) are extensively used for treating chronic inflammation, although long‐term exposure to GCs is capable of triggering osteoporosis. microRNAs (miRNAs) have been reported to play a critical role in bone diseases. In the present study, we treated BMSCs with dexamethasone (DEX) during OD to stimulate GC‐mediated osteoporosis. Microarray and quantitative polymerase chain reaction (Q‐PCR) assays demonstrated that miR‐199a was upregulated during OD of BMSCs, while DEX treatment caused a significant reduction in miR‐199a. Alkaline phosphatase (ALP) activity, Alizarin red (AR) staining, and Q‐PCR were applied to assess the role of miRNA‐199a overexpression in DEX‐triggered OD inhibition. miR‐199a was able to rescue OD and ALP activity, which were inhibited by DEX. Additionally, we observed that ALP, BMP2, COL1A1, and Runx2 were increased after transfection of miRNA‐199a mimics. Furthermore, we confirmed that miRNA‐199a facilitates OD of BMSCs through direct inhibition of Klotho protein and messenger RNA expression affecting the downstream fibroblast growth factor receptor 1/extracellular‐signal‐regulated kinase and Janus kinase 1/signal transducer and activator of transcription 1 pathways. This study indicates that miR‐199a plays a critical role in preventing GC‐mediated osteoblast differentiation and may function as a promising miRNA biomarker for osteoporosis.

中文翻译：

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MicroRNA-199a通过体外调节Klotho表达来抵消糖皮质激素对骨髓间充质干细胞成骨分化的抑制作用。

骨髓间充质干细胞（BMSC）的成骨分化（OD）对于缓解骨质疏松症至关重要。糖皮质激素（GCs）被广泛用于治疗慢性炎症，尽管长期暴露于GCs会引发骨质疏松症。据报道，microRNA（miRNA）在骨骼疾病中起关键作用。在本研究中，我们在OD期间用地塞米松（DEX）治疗BMSC，以刺激GC介导的骨质疏松症。微阵列和定量聚合酶链反应（Q-PCR）分析表明，BMSC的OD期间miR-199a被上调，而DEX处理导致miR-199a显着减少。碱性磷酸酶（ALP）活性，茜素红（AR）染色和Q-PCR用于评估miRNA-199a过表达在DEX触发的OD抑制中的作用。miR-199a能够挽救被DEX抑制的OD和ALP活性。此外，我们观察到转染miRNA-199a模拟物后，ALP，BMP2，COL1A1和Runx2有所增加。此外，我们证实，miRNA-199a通过直接抑制Klotho蛋白和信使RNA的表达来促进BMSC的OD，从而影响下游成纤维细胞生长因子受体1 /细胞外信号调节激酶和Janus激酶1 /信号转导子和转录激活子1通路。 。这项研究表明，miR-199a在防止GC介导的成骨细胞分化中起着至关重要的作用，并且可能作为骨质疏松症的有希望的miRNA生物标志物。miRNA-199a模拟物转染后，Runx2和Runx2增加。此外，我们证实，miRNA-199a通过直接抑制Klotho蛋白和信使RNA的表达来促进BMSC的OD，从而影响下游成纤维细胞生长因子受体1 /细胞外信号调节激酶和Janus激酶1 /信号转导子和转录激活子1通路。 。这项研究表明，miR-199a在防止GC介导的成骨细胞分化中起着至关重要的作用，并且可能作为骨质疏松症的有希望的miRNA生物标志物。miRNA-199a模拟物转染后，Runx2和Runx2增加。此外，我们证实，miRNA-199a通过直接抑制Klotho蛋白和信使RNA的表达来促进BMSC的OD，从而影响下游成纤维细胞生长因子受体1 /细胞外信号调节激酶和Janus激酶1 /信号转导子和转录激活子1通路。 。这项研究表明，miR-199a在防止GC介导的成骨细胞分化中起着关键作用，并且可能作为骨质疏松症的有前途的miRNA生物标记物。我们证实miRNA‐199a通过直接抑制Klotho蛋白和信使RNA的表达来促进BMSC的OD，从而影响下游成纤维细胞生长因子受体1 /细胞外信号调节激酶和Janus激酶1 /信号转导子和转录激活子1通路。这项研究表明，miR-199a在防止GC介导的成骨细胞分化中起着至关重要的作用，并且可能作为骨质疏松症的有希望的miRNA生物标志物。我们证实miRNA‐199a通过直接抑制Klotho蛋白和信使RNA的表达来促进BMSC的OD，从而影响下游成纤维细胞生长因子受体1 /细胞外信号调节激酶和Janus激酶1 /信号转导子和转录激活子1通路。这项研究表明，miR-199a在防止GC介导的成骨细胞分化中起着至关重要的作用，并且可能作为骨质疏松症的有希望的miRNA生物标志物。