title: Effects of phonation time and magnitude dose on vocal fold epithelial genes, barrier integrity, and function.
abstract: OBJECTIVE
  To investigate the effects of increasing time and magnitude doses of vibration exposure on transcription of the vocal fold's junctional proteins, structural alterations, and functional tissue outcomes.
  
  
  METHODS
  Animal study.
  
  
  METHODS
  100 New Zealand White breeder rabbits were studied. Dependent variables were measured in response to increasing time doses (30, 60, or 120 minutes) and magnitude doses (control, modal intensity, and raised intensity) of vibration exposure. Messenger RNA expression of occludin, zonula occluden-1 (ZO-1), E-cadherin, β-catenin, interleukin 1β, cyclooxygenase-2, transforming growth factor β-1, and fibronectin were measured. Tissue structural alterations were assessed using transmission electron microscopy (TEM). Transepithelial resistance was used to measure functional tissue outcomes.
  
  
  RESULTS
  Occludin gene expression was downregulated in vocal folds exposed to 120-minute time doses of raised-intensity phonation, relative to control, and modal-intensity phonation. ZO-1 gene expression was upregulated following a 120-minute time dose of modal-intensity phonation, compared to control, and downregulated after a 120-minute time dose of raised-intensity phonation, compared to modal-intensity phonation. E-cadherin gene expression was downregulated after a 120-minute time dose of raised-intensity phonation, compared to control and modal-intensity phonation. TEM revealed extensive desquamation of the stratified squamous epithelial cells with increasing time and magnitude doses of vibration exposure. A general observation of lower transepithelial resistance measures was made in tissues exposed to raised-intensity phonation compared to all other groups.
  
  
  CONCLUSIONS
  This study provides evidence of vocal fold tissue responses to varying time and magnitude doses of vibration exposure.
  
  
  METHODS
  NA.
authors: Department of Otolaryngology, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors: Tsuyoshi
authors: T
authors: Kojima
authors: Carla V
authors: CV
authors: Valenzuela
authors: Carolyn K
authors: CK
authors: Novaleski
authors: Mark
authors: M
authors: Van Deusen
authors: Joshua R
authors: JR
authors: Mitchell
authors: C Gaelyn
authors: CG
authors: Garrett
authors: M Preeti
authors: MP
authors: Sivasankar
authors: Bernard
authors: B
authors: Rousseau
mesh_terms: D000818:Animals; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D062793:Occludin / Q000096:biosynthesis / Q000235:genetics; D010699:Phonation / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics*; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis / Q000235:genetics; D014827:Vocal Cords / Q000378:metabolism* / Q000648:ultrastructure; D051176:beta Catenin / Q000096:biosynthesis / Q000235:genetics
chemical_list: D015820:Cadherins; D053583:Interleukin-1beta; D062793:Occludin; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D051176:beta Catenin; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human
keywords: Epithelial barrier; junctional complex; phonotrauma; vocal fold