title: Upregulation of relaxin receptors in the PDL by biophysical force.
abstract: OBJECTIVE
  We have previously reported that relaxin (Rln) expression from the ovary is upregulated by orthodontic tooth movement. This study was performed to test the hypothesis that Rln family peptides (Rxfps), the G-protein-coupled Rln receptor, is induced in periodontal ligament (PDL) cells to modulate the molecules involved in periodontal tissue remodeling while applying biophysical force.
  
  
  METHODS
  Rats were implanted with orthodontic appliances to investigate changes to Rxfps in vivo. An in vitro biophysical force analysis was performed to measure the level of Rxfp 1 messenger RNA (mRNA) in primary human PDL cells.
  
  
  RESULTS
  The levels of Rxfp 2 transcription and translation increased in a time-dependent manner during tooth movement. Rxfp 2 was localized in the PDL by immunofluorescence. In vitro analyses revealed that the level of Rxfp 1 mRNA in PDL cells increased significantly with both compression and tension force. The levels of matrix metalloproteinase (MMP)-1, MMP-2, interleukin-6, and vascular endothelial growth factor mRNA, which are important for periodontal tissue remodeling, also changed under force application and Rln treatment.
  
  
  CONCLUSIONS
  PDL cells responded to Rln to modulate effector molecules for periodontal tissue remodeling by upregulating Rxfps expression under a biophysical force.
  
  
  CONCLUSIONS
  Rln and Rxfps may serve as a PDL turnover molecule complex to control orthodontic tooth movement.
authors.affiliation: Dental Science Research Institute, Department of Oral Anatomy, School of Dentistry, Chonnam National University, Gwangju, 500-757, South Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Yang
authors.forename: J W
authors.initials: JW
authors.lastname: Kim
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Kang
authors.forename: U
authors.initials: U
authors.lastname: Ulziisaikhan
authors.forename: H I
authors.initials: HI
authors.lastname: Yoo
authors.forename: Y H
authors.initials: YH
authors.lastname: Moon
authors.forename: J S
authors.initials: JS
authors.lastname: Moon
authors.forename: H M
authors.initials: HM
authors.lastname: Ko
authors.forename: M S
authors.initials: MS
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D008963:Molar; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D018000:Receptors, Peptide / Q000378:metabolism*; D012065:Relaxin / Q000494:pharmacology; D014087:Tooth Movement Techniques; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D042461:Vascular Endothelial Growth Factor A; C033395:relaxin receptors; D012065:Relaxin; D020778:Matrix Metalloproteinase 2; D020781:Matrix Metalloproteinase 1