title: [miR-125b regulates osteogenic differentiation of human bone marrow mesenchymal stem cells by targeting Smad4].
abstract: OBJECTIVE
  To investigate whether miR-125b regulates the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs) by modulating Smad4, a predicted target in silicon.
  
  
  METHODS
  Smad4 3'-UTR-luciferase vector was constructed and dual-luciferase reporter gene assay was employed to examine the effect of miR-125b on luciferase activity. MSCs were isolated and cultured from human bone marrow, and then transfected with miR-125b mimics followed by induction of osteogenic differentiation. qRT-PCR and Western blot were used to detect the expressions of Smad4 mRNA and protein. MSCs were induced into the osteoblasts after transfecting with Smad4 siRNA, and the effect of Smad4 downregulation on osteogenic differentiation was observed by AKP activity and RUNX2 mRNA levels.
  
  
  RESULTS
  miR-216b bound Smad4 3'-UTR and inhibited the luciferase activity (P<0.05). Smad4 mRNA and protein expressions were significantly down-regulated in the MSCs induced into osteogenic differentiation when miR-125b was overexpressed. Downregulation of Smad4 suppressed the AKP activity and RUNX2 mRNA expression, indicating that Smad4 siRNA simulated at least in part the function of miR-125b as the regulator of MSCs osteogenic differentiation.
  
  
  CONCLUSIONS
  miR-125b can suppress MSCs osteogenic differentiation by directly targeting Smad4.
authors: Department of Orthopedics, Affiliated Nanhua Hospital of University of South China, Hengyang Hunan,China.
authors: Xihong
authors: X
authors: Lu
authors: Min
authors: M
authors: Deng
authors: Honghui
authors: H
authors: He
authors: Dehui
authors: D
authors: Zeng
authors: Wei
authors: W
authors: Zhang
mesh_terms: D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D035683:MicroRNAs / Q000502:physiology*; D010006:Osteoblasts / Q000166:cytology*; D010012:Osteogenesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051901:Smad4 Protein / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D055815:Young Adult
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; C531888:MIRN125 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C493709:RUNX2 protein, human; C497796:SMAD4 protein, human; D051901:Smad4 Protein