title: MicroRNA-195 induced apoptosis in hypoxic chondrocytes by targeting hypoxia-inducible factor 1 alpha.
abstract: OBJECTIVE
  The chondrocytes, the resident cells of cartilage, are maintained and take effects in the whole life upon chronic hypoxic exposure, which hypoxia-inducible factor 1 alpha (HIF-1α) play pivotal roles in response to. Dysregulation of some microRNA (miRNAs) have also been identified to be involved in hypoxia-related physiologic and pathophysiologic responses in some tissues or cell lines. However, the mechanism of miRNAs reponse to hypoxia remain largely unknown in chondrocytes, including the microRNA-195 (miR-195). AIM To investigate the effects of microRNAs (miRNAs) and hypoxia-inducible factor 1 alpha (HIF-1α) on chondrocytes in physiologic environment.
  
  
  METHODS
  We compared the expression of miR-195 and HIF-1α mRNA on hypoxia with that on normoxia in ATDC 5 cells by qRT-PCR. Further experiments was performed to confirmed the relationships of miR-195 and HIF-1α by bioinformatics analysis and dual reporter gene assay. we also assessed the effect of miR-195 on apoptosis in hypoxic ATDC 5 cells by transfect with miR-195 mimics.
  
  
  RESULTS
  It was found the downregulated miR-195 and upregulated HIF-1α were present in hypoxic ATDC 5 cells. miR-195 negatively regulated HIF-1α by targeting its 3'-untranslated region. Moreover, the founding indicated miR-195 greatly increased apoptosis and downregulated HIF-1α mRNA occurred simultaneously in hypoxic chondrocytes.
  
  
  CONCLUSIONS
  We concluded that miR-195 induced apoptosis in hypoxic chondrocytes by directly targeting HIF-1α.
authors.affiliation: Department of Pediatric Orthopedics, The Second Affiliated Hospital of Inner Mongolia Medical University, Mongolia, China. wanlinliu1@126.com.
authors.forename: R
authors.initials: R
authors.lastname: Bai
authors.forename: A-Q
authors.initials: AQ
authors.lastname: Zhao
authors.forename: Z-Q
authors.initials: ZQ
authors.lastname: Zhao
authors.forename: W-L
authors.initials: WL
authors.lastname: Liu
authors.forename: D-M
authors.initials: DM
authors.lastname: Jian
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D015687:Cell Hypoxia / Q000235:genetics; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics*; D035683:MicroRNAs / Q000502:physiology*; D015854:Up-Regulation
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C552722:MIRN195 microRNA, human; D035683:MicroRNAs