title: [Changes of microRNA and target gene expression levels in osteogenic differentiation of human bone marrow mesenchymal stem cells].
abstract: OBJECTIVE
  To clarify the trends of expression levels of several up-regulated micro RNA (miRNA) in tissues of atrophic bone nonunion and mRNAs and proteins of their related target genes in osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs), and to explore their biological functions.
  
  
  METHODS
  The hBMSCs were isolated from bone marrow of iliac bone by gradient centrifugation, and cultured. Osteogenic culture medium was used for osteogenic differentiation of the 4th generation of hBMSCs. The changes of corresponding miRNAs, mRNA and protein expression levels of related target genes were observed at 0 hour, 12 hours, 1 day, 2 days, 4 days, 7 days, and 14 days, by quantitative real-time PCR and Western blot.
  
  
  RESULTS
  In the process of hBMSCs osteogenic differentiation, the mRNA and protein expression levels of osteoblastic target genes [alkaline phosphatase liver/bone/kidney (ALPL), bone morphogenetic protein 2 (BMP-2), and platelet-derived factor alpha polypeptide (PDGF-A)] at most time points increased significantly when compared with the values at 0 hour except that of BMP-2 decreased at 12 hours and 1 day, with maximum changes at 1 to 7 days. The miRNA expression levels, mRNA and protein expression levels changed significantly at different time points, while the trends of hsa-miRNA-149 and hsa-miRNA-654-5p changes were negatively correlated with the trends of ALPL and BMP-2 mRNA and protein expression changes respectively (P < 0.05). There was no obviously negative correlation between the trends of hsa-miRNA-221 change and PDGF-A change (P > 0.05).
  
  
  CONCLUSIONS
  In the osteogenic differentiation process of hBMSCs, hsa-miRNA-149* and hsa-miRNA-654-5p are closely related with the mRNA and protein regulation of ALPL and BMP-2, respectively.
authors.affiliation: Department of Orthopaedics, Chinese PLA General Hospital, Beijing, 100853, P.R. China.
authors.forename: Junqiang
authors.initials: J
authors.lastname: Wei
authors.forename: Boxun
authors.initials: B
authors.lastname: Zhang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zheng
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.forename: Xuezhong'
authors.initials: X
authors.lastname: Tian
authors.forename: Peifu
authors.initials: P
authors.lastname: Tang
authors.forename: Qing
authors.initials: Q
authors.lastname: Song
authors.forename: Tanshi
authors.initials: T
authors.lastname: Li
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D006801:Humans; D007085:Ilium / Q000166:cytology; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010012:Osteogenesis; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; C551557:MIRN149 microRNA, human; D035683:MicroRNAs; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; C075278:platelet-derived growth factor A; D000469:Alkaline Phosphatase