title: miR-203 and miR-320 Regulate Bone Morphogenetic Protein-2-Induced Osteoblast Differentiation by Targeting Distal-Less Homeobox 5 (Dlx5).
abstract: MicroRNAs (miRNAs) are a family of small, non-coding RNAs (17-24 nucleotides), which regulate gene expression either by the degradation of the target mRNAs or inhibiting the translation of genes. Recent studies have indicated that miRNA plays an important role in regulating osteoblast differentiation. In this study, we identified miR-203 and miR-320b as important miRNAs modulating osteoblast differentiation. We identifiedDlx5as potential common target by prediction algorithms and confirmed this by knock-down and over expression of the miRNAs and assessingDlx5at mRNA and protein levels and specificity was verified by luciferase reporter assays. We examined the effect of miR-203 and miR-320b on osteoblast differentiation by transfecting with pre- and anti-miRs. Over-expression of miR-203 and miR-320b inhibited osteoblast differentiation, whereas inhibition of miR-203 and miR-320b stimulated alkaline phosphatase activity and matrix mineralization. We show that miR-203 and miR-320b negatively regulate BMP-2-induced osteoblast differentiation by suppressingDlx5, which in turn suppresses the downstream osteogenic master transcription factorRunx2andOsxand together they suppress osteoblast differentiation. Taken together, we propose a role for miR-203 and miR-320b in modulating bone metabolism.
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala 75185, Sweden. navya.laxman@medsci.uu.se.|Science for Life Laboratory, Department of Medical Sciences, Uppsala University Hospital, Uppsala 75185, Sweden. navya.laxman@medsci.uu.se.|Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm 17121, Sweden. navya.laxman@medsci.uu.se.
authors.forename: Navya
authors.initials: N
authors.lastname: Laxman
authors.affiliation: Department of Surgical Sciences, Uppsala University, Uppsala 75185, Sweden. Hans.Mallmin@akademiska.se.
authors.forename: Hans
authors.initials: H
authors.lastname: Mallmin
authors.affiliation: Department of Surgical Sciences, Uppsala University, Uppsala 75185, Sweden. Olof.Nilsson@akademiska.se.
authors.forename: Olle
authors.initials: O
authors.lastname: Nilsson
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala 75185, Sweden. andreas.kindmark@medsci.uu.se.|Science for Life Laboratory, Department of Medical Sciences, Uppsala University Hospital, Uppsala 75185, Sweden. andreas.kindmark@medsci.uu.se.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kindmark
keywords: BMP-2; Dlx5; miRNA; osteoblast differentiation