title: In vitro study of enhanced osteogenesis induced by HIF-1α-transduced bone marrow stem cells.
abstract: OBJECTIVE
  Hypoxia-inducible factor 1α (HIF-1α) is a pivotal regulator of hypoxic and ischaemic vascular responses that drives transcriptional activation of hundreds of genes involved in vascular reactivity, angiogenesis and arteriogenesis. Previous reports based on gene knockout technology have demonstrated that HIF-1α can promote osteogenesis. However, this protein is easily degraded in a normoxic state, which makes in vitro studies of HIF-1α-induced mesenchymal stem cell (MSC) osteogenesis difficult. For better understanding of HIF-1α promoting osteogenesis, the role of HIF-1α-induced MSC osteogenesis in the normoxic state has been investigated here.
  
  
  METHODS
  HIF-1α was made to overexpress using a lentiviral vector, and its effects on bone marrow-derived mesenchymal stem cell (BMSC) osteogenesis were investigated. Real-time quantitative and western blotting (to assess expression levels of angiogenic and osteogenic related genes regulated by Lenti-HIF-1α), alkaline phosphatase (ALP) and alizarin red-S staining analyses, were performed.
  
  
  RESULTS
  In HIF-1α gene-transfected BMSCs, expression levels of angiogenic, cartilaginous and osteogenic genes were all increased significantly compared to Lenti LacZ-transfected cells, at both mRNA and protein levels. ALP activity and alizarin red-S staining were significantly enhanced in HIF-1α transduced cells compared to control cells, on day 21.
  
  
  CONCLUSIONS
  These results indicate that Lenti-HIF-1α can induce BMSC overexpression levels of angiogenic and osteogenic genes in vitro in the normoxic state. Further study will be focused on whether HIF-1α can also improve bone repair in vivo.
authors.affiliation: School of Stomatology, Tongji University, Shanghai, China.
authors.forename: D
authors.initials: D
authors.lastname: Zou
authors.forename: W
authors.initials: W
authors.lastname: Han
authors.forename: S
authors.initials: S
authors.lastname: You
authors.forename: D
authors.initials: D
authors.lastname: Ye
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000166:cytology*; D017931:DNA Primers / Q000235:genetics; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D066298:In Vitro Techniques; D007511:Ischemia; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology; D009389:Neovascularization, Pathologic; D010012:Osteogenesis; D051381:Rats; D011916:Rats, Inbred F344; D013234:Stem Cells / Q000166:cytology*
chemical_list: D000880:Anthraquinones; D017931:DNA Primers; C497444:Hif1a protein, rat; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C004468:Alizarin Red S; D000469:Alkaline Phosphatase