Inhibition of microRNA-221-5p induces osteogenic differentiation by directly targeting smad3 in myeloma bone disease mesenchymal stem cells
Inhibition of microRNA-221-5p induces osteogenic differentiation by directly targeting smad3 in myeloma bone disease mesenchymal stem cells
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DOI：
10.3892/ol.2019.10992
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发表时间：
2019-12-01
期刊：
影响因子：
2.9
通讯作者：
Zhang, Xi
中科院分区：
文献类型：
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作者：
Fan, Fang-Yi;Deng, Rui;Zhang, Xi
骨髓瘤骨病（Myeloma bone disease， MBD）是多发性骨髓瘤的临床特征之一，它导致成骨细胞功能的衰减。骨髓间充质干细胞具有向成骨细胞分化的高潜力。许多研究报道了microRNAs （miRs）在间充质干细胞（MSC）成骨过程中起着至关重要的作用；然而，miR-221-5p在MBD-MSCs成骨分化中的作用尚不清楚。本研究发现，与正常(N)-MSCs相比，MBD-MSCs的成骨分化能力降低。进一步的实验表明，在成骨细胞诱导后，miR-221-5p在N-MSCs中表达下调，而在MBD-MSCs中表达水平未见明显变化。抑制miR-221-5p可促进MBD-MSCs的成骨分化。生物信息学、荧光素酶报告基因检测、逆转录定量PCR和western blotting检测表明，smad家族成员3 （smad3）是MBD-MSCs中miR-221-5p的直接靶点。smad3和miR-221-5p的表达水平呈负相关。分子机制研究表明，抑制miR-221-5p可通过上调smad3表达调控MBD-MSCs的成骨分化。我们还发现，在miR-221-5p抑制后，PI3K/AKT/mTOR信号通路被激活，这增加了MBD-MSCs的成骨分化能力。本研究可能会提高对miR-221-5p在成骨分化调控中的作用的理解，并可能有助于开发一种新的治疗MBD的方法。
Myeloma bone disease (MBD) is one of the clinical features of multiple myeloma, which contributes to the attenuation of osteoblast function. Bone marrow mesenchymal stem cells exhibit a high potential for differentiation into osteoblasts. A number of studies have reported that microRNAs (miRs) serve a vital role in mesenchymal stem cell (MSC) osteogenesis; however, the role of miR-221-5p in the osteogenic differentiation of MBD-MSCs remains unclear. The present study revealed that the osteogenic differentiation capacity of MBD-MSCs was reduced compared with that of normal (N)-MSCs. Further experiments demonstrated that miR-221-5p expression was downregulated in N-MSCs following osteoblast induction while no obvious alterations in expression levels were observed in MBD-MSCs. The inhibition of miR-221-5p promoted the osteogenic differentiation of MBD-MSCs. Bioinformatics, luciferase reporter assays, reverse transcription-quantitative PCR and western blotting assays indicated that smad family member 3 (smad3) was a direct target of miR-221-5p in MBD-MSCs. A negative association was identified between the expression levels of smad3 and miR-221-5p. Investigations of the molecular mechanism indicated that suppressed miR-221-5p could regulate the osteogenic differentiation of MBD-MSCs by upregulating smad3 expression. It was also identified that the PI3K/AKT/mTOR signaling pathway was activated following miR-221-5p inhibition, and this increased the osteogenic differentiation capacity of MBD-MSCs. The present study may improve the understanding regarding the role of miR-221-5p in the regulation of osteogenic differentiation, and may contribute to the development of a novel therapy for MBD.