title: Expression of LIF and LIFR in periodontal tissue during orthodontic tooth movement.
abstract: OBJECTIVE
  To test the hypothesis that leukemia inhibitor factor (LIF) and LIF receptor (LIFR) are expressed in periodontal tissue and that their expression may be upregulated during orthodontic tooth movement.
  
  
  METHODS
  Forces of 0.3 N were applied to move the upper left first molars mesially in 24 rats. These forces were kept constant for 3, 7, and 14 days and followed by animal sacrifice. The contralateral molars served as control. The rate of tooth movement was measured by Image J software. Paraffin-embedded sections of the upper jaws were prepared for histological and immunohistochemical analysis to test the LIF and LIFR expression.
  
  
  RESULTS
  Loaded teeth showed a significantly higher rate of tooth movement. The periodontium of the moved teeth experienced tissue remodeling, while there was no obvious change in the contralateral controls. Furthermore, LIF and LIFR were expressed in the periodontal tissue, and there were statistically significant differences between the loaded and unloaded teeth at 3 and 14 days. LIF presented significantly higher expression on the tension side compared with the pressure side at 3 days.
  
  
  CONCLUSIONS
  Both LIF and LIFR exist in the periodontal tissue, and continuous orthodontic forces induce the upregulation of LIF/LIFR production, suggesting that LIF/LIFR may play important roles in periodontium remodeling.
authors: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Hospital and School of Stomatology, Wuhan University, Wuhan, China.
authors: Youde
authors: Y
authors: Liang
authors: Yi
authors: Y
authors: Zhou
authors: Tao
authors: T
authors: Jiang
authors: Zhen
authors: Z
authors: Zhang
authors: Su
authors: S
authors: Wang
authors: Yining
authors: Y
authors: Wang
mesh_terms: D000818:Animals; D003799:Dental Stress Analysis; D005260:Female; D053605:Leukemia Inhibitory Factor / Q000096:biosynthesis*; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit / Q000096:biosynthesis*; D010010:Osteoclasts / Q000378:metabolism; D010513:Periodontal Ligament / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014087:Tooth Movement Techniques; D015854:Up-Regulation
chemical_list: D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; C507842:Lifr protein, rat