title: Involvement of microRNAs in regulation of osteoblastic differentiation in mouse induced pluripotent stem cells.
abstract: BACKGOROUND: MicroRNAs (miRNAs), which regulate biological processes by annealing to the 3'-untranslated region (3'-UTR) of mRNAs to reduce protein synthesis, have been the subject of recent attention as a key regulatory factor in cell differentiation. The effects of some miRNAs during osteoblastic differentiation have been investigated in mesenchymal stem cells, however they still remains to be determined in pluripotent stem cells.
  
  
  RESULTS
  Bone morphogenic proteins (BMPs) are potent activators of osteoblastic differentiation. In the present study, we profiled miRNAs during osteoblastic differentiation of mouse induced pluripotent stem (iPS) cells by BMP-4, in which expression of important osteoblastic markers such as Rux2, osterix, osteopontin, osteocalcin, PTHR1 and RANKL were significantly increased. A miRNA array analysis revealed that six miRNAs including miR-10a, miR-10b, miR-19b, miR-9-3p, miR-124a and miR-181a were significantly downregulated. Interestingly, miR-124a and miR-181a directly target the transcription factors Dlx5 and Msx2, both of which were increased by about 80-and 30-fold, respectively. In addition, transfection of miR-124a and miR-181a into mouse osteo-progenitor MC3T3-E1 cells significantly reduced expression of Dlx5, Runx2, osteocalcin and ALP, and Msx2 and osteocalcin, respectively. Finally, transfection of the anti-miRNAs of these six miRNAs, which are predicted to target Dlx5 and Msx2, into mouse iPS cells resulted in a significant increase in several osteoblastic differentiation markers such as Rux2, Msx2 and osteopontin.
  
  
  CONCLUSIONS
  In the present study, we demonstrate that six miRNAs including miR-10a, miR-10b, miR-19b, miR-9-3p, miR-124a and miR-181a miRNAs, especially miR-124a and miR-181a, are important regulatory factors in osteoblastic differentiation of mouse iPS cells.
authors.affiliation: Division of Molecular and Genetic Medicine, Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medicine, Tottori University, Yonago, Tottori, Japan.
authors.forename: Hideharu
authors.initials: H
authors.lastname: Okamoto
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Matsumi
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Hoshikawa
authors.forename: Kazuko
authors.initials: K
authors.lastname: Takubo
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ryoke
authors.forename: Goshi
authors.initials: G
authors.lastname: Shiota
mesh_terms: D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism
chemical_list: D055415:Bone Morphogenetic Protein 4; D035683:MicroRNAs