title: [Expression of transforming growth factor-beta 1 mRNA and osteopontin mRNA in UMR-106 cells under mechanical stimulation].
abstract: OBJECTIVE
  To investigate the effects of the mechanical stretching on the expression of osteopontin (OPN) mRNA and transforming growth factor-beta 1 (TGF beta 1) mRNA in a rat osteosarcoma cell line (UMR-106), and to unveil the cellular mechanism of mechanical force-induced bone remodeling.
  
  
  METHODS
  An apparatus was designed and fabricated by which force was loaded onto the cultured cells in vitro. Digoxin-labeled cDNA probes were used for in situ hybridization in combination with image analysis technique to relatively quantify the intensities of the hybridization signals.
  
  
  RESULTS
  Various magnitudes and durations of the mechanical stretching did exert different influences on the intensities of the mRNAs' expression. Of all the combinations, the low tension/frequency group showed the most remarkable alteration of TGF-beta 1, as increased from 0.0899 to 0.1756 (P < 0.01). Some putative relations lay between the expressions of the OPN mRNA and the TGF-beta 1 mRNA.
  
  
  CONCLUSIONS
  The mechanical stretching can inevitably influence the expression of OPN mRNA and TGF-beta 1 mRNA. The beneficial alteration obtained in using low tension/frequency action mode suggests and verifies the use of relatively constant and light force to move teeth in clinical orthodontics.
authors.affiliation: Department of Orthodontics, School of Stomatology, Beijing Medical University, Beijing 100081, China.
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: M
authors.initials: M
authors.lastname: Fu
authors.forename: S
authors.initials: S
authors.lastname: Li
mesh_terms: D000818:Animals; D009971:Orthodontics, Corrective; D010006:Osteoblasts / Q000378:metabolism*; D053495:Osteopontin; D010812:Physical Stimulation; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D012795:Sialoglycoproteins / Q000096:biosynthesis* / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053495:Osteopontin