title: [Effects of tensile strain on the expression of Runx2/Cbfalpha1 in osteoblasts cultivated with inflammatory stimulus].
abstract: OBJECTIVE
  To determine the effects of tensile strain on the expression of core binding factor alpha1 (Runx2/Cbfalpha1) in osteoblasts cultivated in Pg-LPS stimulated RAW264.7 culture supernatant.
  
  
  METHODS
  Osteoblasts MC3T3-E1 were cultivated in LPS stimulated monocyte culture supernatant for 24 h. Then, a four-point bending device was used to perform a single period of tensile strain (1000 microm strain, 3000 microm strain respectively) on osteoblasts for 0 h, 0.5 h, 1 h, 2 h, 3 h, 6 h. Non-inflammatory stimuli were set up as control. The expression of Runxr2/Cbfalpha1 mRNA in MC3T3-E1 cells was examined by real-time RT-PCR.
  
  
  RESULTS
  With the mechanical loading, the expression of Runx2/Cbfalpha1 mRNA increased in both inflammatory and non-inflammatory groups of osteoblasts and reached the peak after 6 h. The inflammatory group had lower expression of Runx2/Cbfalpha1 mRNA than that of the non-inflammatory group (P<0.05). The varied strain level did not change the expression of Runx2/Cbfalpha1 mRNA within 3 hours. But after 6 hours, the 3000 microm strain induced higher expression of Runx2/Cbfalpha1 mRNA than the 1000 microm strain.
  
  
  CONCLUSIONS
  Inflammation inhibits the tensile strain induced expression of Runx2/Cbfalpha1 in osteoblasts. Precaution needs to be paid to orthodontic treatment on patients with quiescent periodontitis.
authors.affiliation: Department of Orthodontics, the Affiliated Hospital of Stomatology, Wenzhou Medical College, Wenzhou 325027, China.
authors.forename: Rong-dang
authors.initials: RD
authors.lastname: Hu
authors.forename: Jie
authors.initials: J
authors.lastname: Ye
authors.forename: Chun-yan
authors.initials: CY
authors.lastname: Xu
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D007249:Inflammation; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013314:Stress, Mechanical; D014087:Tooth Movement Techniques
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D008070:Lipopolysaccharides; D012333:RNA, Messenger; C493716:Runx2 protein, mouse