title: Long non-coding RNA HOTAIR inhibits miR-17-5p to regulate osteogenic differentiation and proliferation in non-traumatic osteonecrosis of femoral head.
abstract: OBJECTIVE
  The biological functions of non-coding RNAs (ncRNAs) have been widely identified in many human diseases. In the present study, the relationship between long non-coding RNA HOTAIR and microRNA-17-5p (miR-17-5p) and their roles in osteogenic differentiation and proliferation in non-traumatic osteonecrosis of femoral head (ONFH) were investigated.
  
  
  METHODS
  The expression levels of HOTAIR and miR-17-5p in the mesenchymal stem cells (MSCs) derived from patients with non-traumatic ONFH and osteoarthritis (OA) were examined by real-time PCR. BMP-2 induced human MSCs from bone marrow (hMSC-BM) were used for osteogenic differentiation.
  
  
  RESULTS
  It was observed that the expression level of miR-17-5p was lower and the level of HOTAIR was higher in samples of non-traumatic ONFH compared with OA. HOTAIR downregulation induced by si-HOTAIR led to the increase of miR-17-5p expression and the decrease of miR-17-5p target gene SMAD7 expression. The values of osteogenic differentiation markers, including RUNX2 and COL1A1 mRNA expression and ALP activity, were also elevated by si-HOTAIR. However, the increase of these values was canceled by miR-17-5p inhibitor or SMAD7 upregulation.
  
  
  CONCLUSIONS
  HOTAIR played a role in regulating osteogenic differentiation and proliferation through modulating miR-17-5p and its target gene SMAD7 in non-traumatic ONFH.
authors.affiliation: Department of Orthopaedic, Linyi People's Hospital, Linyi, Shandong, China.
authors.forename: Biaofang
authors.initials: B
authors.lastname: Wei
authors.affiliation: Department of Orthopaedic, First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Department of Orthopaedic, Linyi People's Hospital, Linyi, Shandong, China.
authors.forename: Baoxiang
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Department of Orthopaedic, Linyi People's Hospital, Linyi, Shandong, China.
authors.forename: Xiaxia
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Orthopaedic, Linyi People's Hospital, Linyi, Shandong, China.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
mesh_terms: D000943:Antigens, Differentiation; D016022:Case-Control Studies; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D005271:Femur Head Necrosis / Q000235:genetics / Q000473:pathology*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D010003:Osteoarthritis / Q000235:genetics / Q000473:pathology*; D010012:Osteogenesis / Q000235:genetics*; D062085:RNA, Long Noncoding / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D051906:Smad7 Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D000943:Antigens, Differentiation; C561566:HOTAIR long untranslated RNA, human; C524941:MIRN17 microRNA, human; D035683:MicroRNAs; D062085:RNA, Long Noncoding; C497806:SMAD7 protein, human; D051906:Smad7 Protein