title: [Smokeless tobacco extract affects biological properties of the pre-osteoblast cell line MC3T3-E1 ].
abstract: OBJECTIVE
  To investigate the effects of smokeless tobacco extract (STE) on biological properties of osteoblast, and to identify possible pathological mechanisms of osseointegration.
  
  
  METHODS
  MC3T3-E1 Sub-clone 14 cells were cultured in the presence of STE at 0 (control group),0. 01,0. 1,1,5,10 g/L. The cell proliferation was measured by MTT assay 1 d, 3 d, 5 d, and 7 d after exposure. The F-actin cytoskeleton of MC3T3 was stained with Rhodamine and DAPI, and then examined under a confocal laser scanning microscope 24 h after exposure to STE. The mRNA expressions of interleukin-6 (IL-6) and core-binding factor αl(Cbfαl) were quantified by real- time PCR (RT-qPCR) 48 h after exposure to STE.
  
  
  RESULTS
  The MTT assay showed that 0. 01-10 g/L STE inhibited MC3T3 proliferation (P<0. 05). Prolonged time enabled 5-10 g/L STE to inhibit MC3T3 proliferation (P<0. 05). Network structure in F-actin cytoskeleton was demonstrated in the controls. In the cells exposed to STE, F-actin cytoskeleton started to change with disruptive structures. As the concentration of STE increased, the changes became more significant. STE increased the mRNA expression of IL-6 at the concentration of 5 g/L and 10 g/L (P<0.05), decreased the mRNA expression of Cbfα1 at the concentration of 0. 1-10 g/L (PO<0. 05).
  
  
  CONCLUSIONS
  Tobacco may inhibit osteoblast proliferation, destroy F-actin cytoskeleton structure, increase the mRNA expression of IL-6 and decrease the mRNA expression of Cbfα1, and inhibit cell differentiation and adhesion accordingly. Smoking is a disadvantage to osseointegration.
authors.affiliation: Department of Stomatology, Binzhou Medical University, Yantai, China.
authors.lastname: Xue Peng-fei
authors.forename: Yu-dong
authors.initials: YD
authors.lastname: Hou
authors.forename: Yun-tao
authors.initials: YT
authors.lastname: Zhang
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Pan
authors.forename: Xin
authors.initials: X
authors.lastname: Sun
authors.forename: Long
authors.initials: L
authors.lastname: Sun
mesh_terms: D016475:3T3 Cells / Q000187:drug effects; D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D050657:Core Binding Factor alpha Subunits / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects*; D014030:Tobacco, Smokeless / Q000009:adverse effects*
chemical_list: D050657:Core Binding Factor alpha Subunits; D015850:Interleukin-6; C406688:core binding factor alpha