title: miR-223 Regulates Adipogenic and Osteogenic Differentiation of Mesenchymal Stem Cells Through a C/EBPs/miR-223/FGFR2 Regulatory Feedback Loop.
abstract: Several miRNAs have recently been identified to regulate adipocyte or osteoblast differentiation or both. In this study, miR-223 was found to be involved in the reciprocal regulation of adipocyte and osteoblast differentiation. miR-223 was induced in primary cultured mouse marrow stromal cell, mesenchymal line C3H10T1/2 and stromal line ST2 after adipogenic treatment. Conversely, it was reduced in preosteoblast MC3T3-E1 after osteogenic treatment. Supplementing miR-223 levels using synthetic miR-223 mimics significantly suppressed the growth of the C3H10T1/2 and ST2 cells and induced the progenitor cells to fully differentiate into adipocytes, along with induction of adipocyte-specific transcription factors peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein-α (C/EBPα), and marker genes aP2 and adipsin. By contrast, depletion of the endogenous miR-223 using synthetic miR-223 inhibitor repressed the progenitor cells to differentiate. The effects of miR-223 on adipocyte formation from ST2 cells were also demonstrated by using lentivirus that overexpresses miR-223. Conversely, supplementing miR-223 blocked ST2 to differentiate into osteoblasts. Fibroblast growth factor receptor 2 (Fgfr2), a critical regulator of osteoblast, was shown to be a direct target of miR-223 by using dual luciferase reporter assay. Knockdown of Fgfr2 in C3H10T1/2 downregulated phosphorylation of ERK1/2 and upregulated expression of C/EBPα and dramatically enhanced the differentiation of the cells into adipocytes. Further investigation of mechanisms that control miR-223 expression demonstrated that C/EBPs induced miR-223 expression through binding to the promoter regions of the miR-223. Taken together, our study provides evidences that miR-223 regulates adipocyte and osteoblast differentiation through a novel C/EBPs/miR-223/FGFR2 regulatory feedback loop.
authors: Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Institute of Endocrinology, and cTianjin Medical University, Tianjin, People's Republic of China.
authors: Xiaohui
authors: X
authors: Guan
authors: Yifei
authors: Y
authors: Gao
authors: Jie
authors: J
authors: Zhou
authors: Jun
authors: J
authors: Wang
authors: Fang
authors: F
authors: Zheng
authors: Fei
authors: F
authors: Guo
authors: Ailing
authors: A
authors: Chang
authors: Xiaoxia
authors: X
authors: Li
authors: Baoli
authors: B
authors: Wang
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D050156:Adipogenesis / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010012:Osteogenesis / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; C544877:MIRN223 microRNA, mouse; D035683:MicroRNAs; D051497:Receptor, Fibroblast Growth Factor, Type 2
keywords: Adipocyte; CCAAT/enhancer binding protein; Fibroblast growth factor receptor 2; Osteoblast; microRNA