Qiu Weimin, Kassem Moustapha
Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, J.B. Winsløws Vej 25, 1, DK-5000 Odense C, Denmark.
Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital, J.B. Winsløws Vej 25, 1, DK-5000 Odense C, Denmark; The Danish Stem Cell Center (DanStem), University of Copenhagen, Copenhagen, Denmark.
Biochim Biophys Acta. 2014 Sep;1843(9):2114-21. doi: 10.1016/j.bbamcr.2014.06.004. Epub 2014 Jun 14.
Wnt signaling determines human stromal (mesenchymal) stem cell (hMSC) differentiation fate into the osteoblast or adipocyte lineage. microRNAs (miRNAs) are small RNA molecules of 21-25 nucleotides that regulate many aspects of osteoblast biology. Thus, we examined miRNAs regulated by Wnt signaling in hMSC. We identified miRNA (miR)-141-3p as a Wnt target which in turn inhibited Wnt signaling. Moreover, miR-141-3p inhibited hMSC proliferation by arresting cells at the G1 phase of the cell cycle. miR-141-3p inhibited osteoblast differentiation of hMSC as evidenced by reduced alkaline phosphatase activity, gene expression and in vitro mineralized matrix formation. Bioinformatic studies, Western blot analysis and 3'UTR reporter assay demonstrated that cell division cycle 25A (CDC25A) is a direct target of miR-141-3p. siRNA-mediated knock-down of CDC25A inhibited hMSC proliferation and osteoblast differentiation. In summary, miR-141-3p acts as a negative regulator of hMSC proliferation and osteoblast differentiation. Targeting miR-141-3p could be used as an anabolic therapy of low bone mass diseases, e.g. osteoporosis.
Wnt信号通路决定了人类基质（间充质）干细胞（hMSC）向成骨细胞或脂肪细胞谱系的分化命运。微小RNA（miRNA）是一类21 - 25个核苷酸的小RNA分子，可调控成骨细胞生物学的多个方面。因此，我们研究了hMSC中受Wnt信号通路调控的miRNA。我们鉴定出miRNA（miR）- 141 - 3p是一个Wnt靶标，其反过来又抑制Wnt信号通路。此外，miR - 141 - 3p通过将细胞阻滞在细胞周期的G1期来抑制hMSC增殖。miR - 141 - 3p抑制hMSC的成骨细胞分化，碱性磷酸酶活性降低、基因表达以及体外矿化基质形成均证明了这一点。生物信息学研究、蛋白质免疫印迹分析和3'UTR报告基因检测表明，细胞分裂周期25A（CDC25A）是miR - 141 - 3p的直接靶标。siRNA介导的CDC25A敲低抑制了hMSC增殖和成骨细胞分化。总之，miR - 141 - 3p作为hMSC增殖和成骨细胞分化的负调节因子。靶向miR - 141 - 3p可用于低骨量疾病（如骨质疏松症）的合成代谢治疗。
