title: Inhibition of miR-222-3p activity promoted osteogenic differentiation of hBMSCs by regulating Smad5-RUNX2 signal axis.
abstract: miRNAs are recently found playing important roles in osteogenesis. In this study, we identified that miR-222-3p decreased during osteogenic differentiation of human mesenchymal stem cells (hBMSCs) using Quantitative Real-Time Reverse Transcription PCR (qRT-PCR). Furthermore, we investigated the effect of miR-222-3p on osteogenic differentiation of hBMSCs. Inhibition of miR-222-3p function in hBMSCs using infection of lentiviruses carrying miR-222-3p specific inhibitor promoted expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and matrix mineralization. Whereas, overexpression of miR-222-3p inhibited osteoblast differentiation of hBMSCs in vitro. Moreover, Smad5 and RUNX2, which are the critical transcription factors in osteogenic differentiation, were predicted to be targets of miR-222-3p by bioinformatic analysis. Overexpression of miR-222-3p in hBMSCs significantly suppressed the protein levels of Smad5 and RUNX2, while inhibition of miR-222-3p increased their protein levels. Furthermore, inhibition of miR-222-3p increased phosphorylation of Smad1/5/8, which regulated the expression of osteogenic genes. Our findings suggest that suppression of miR-222-3p activity promoted osteogenic differentiation hBMSCs through regulating Smad5-RUNX2 signaling axis.
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China. Electronic address: jihong@ccmu.edu.cn.
authors.forename: Jihong
authors.initials: J
authors.lastname: Yan
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
authors.forename: Duo
authors.initials: D
authors.lastname: Guo
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
authors.forename: Huaimei
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.affiliation: Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China. Electronic address: deshanzhou2008@163.com.
authors.forename: Deshan
authors.initials: D
authors.lastname: Zhou
mesh_terms: D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D035683:MicroRNAs / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology; D015398:Signal Transduction; D051902:Smad5 Protein / Q000378:metabolism*
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D035683:MicroRNAs; D051902:Smad5 Protein; C525710:MIR222, human; C493709:RUNX2 protein, human; C497797:SMAD5 protein, human
keywords: Mesenchymal stem cells; Osteogenic differentiation; RUNX2; Smad5; miR-222-3p