title: [Expression of HIF-1α and VEGF in human dental pulp cells under mechanical stretch].
abstract: OBJECTIVE
  To examine the expression of HIF-1α and VEGF after application of mechanical stretch on human dental pulp cells (HDPCs), and to investigate the role of them in maintaining homeostasis of dental pulp during orthodontic movement.
  
  
  METHODS
  HDPCs were subjected to 15% elongation by 1.0 Hz stretching frequency for 6, 12, 24, 48 and 72 h. The expression of HIF-1α and VEGF mRNA was measured by real-time polymerase chain reaction (PCR). SPSS12.0 software package was applied for statistical analysis.
  
  
  RESULTS
  At the initial time point, HIF-1α mRNA had a weak expression. The mRNA level of HIF-1α increased gradually and then decreased towards its pre-pressure levels. The mRNA level of VEGF was upregulated in a time-dependent manner.
  
  
  CONCLUSIONS
  The mRNA expression of HIF-1α and VEGF was enhanced by mechanical stress in HDPCs, which indicates that HIF-1α and VEGF may play an important role in retaining homeostasis of dental pulp during orthodontic movement.
authors.affiliation: Department of Orthodontics, Shandong University, Shandong Province, China. weifl@sdu.edu.cn
authors.forename: Fu-lan
authors.initials: FL
authors.lastname: Wei
authors.forename: Jie
authors.initials: J
authors.lastname: Geng
authors.forename: Chun-ling
authors.initials: CL
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Ben-jun
authors.initials: BJ
authors.lastname: Zhang
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
mesh_terms: D003782:Dental Pulp; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D013314:Stress, Mechanical; D042461:Vascular Endothelial Growth Factor A
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A