title: Tumor necrosis factor-alpha expression in uvular tissues differs between snorers and apneic patients.
abstract: BACKGROUND
  Inflammatory changes such as subepithelial edema and excessive inflammatory cell infiltration have been observed in uvular tissues of obstructive sleep apnea (OSA) subjects. The levels of proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin-6 are elevated in the serum of apneic patients and have been proposed as mediators of muscle weakness. TNF-alpha has been shown to affect diaphragm contractility in mice and rabbit in vivo.
  
  
  OBJECTIVE
  To assess total and compartmental TNF-alpha expression in uvular tissues of apneic and nonapneic patients.
  
  
  METHODS
  Uvular tissues were collected from 14 snorers without sleep disorders breathing, 14 subjects with OSA (OSA 1 group) whose body mass index (BMI) was similar to that of snorers, and 12 additional obese OSA subjects (OSA 2 group) who underwent an uvulopalatopharyngoplasty. Sections were examined using immunohistochemistry and Western blot analysis. TNF-alpha expression was evaluated in the musculus uvulae (MU), epithelial layer, and perimuscular tissues from proximal uvular sections.
  
  
  RESULTS
  TNF-alpha was more highly expressed in whole uvular protein extracts of apneic groups than in snorers ([mean +/- SEM] snorers, 100.5 +/- 3.0%; OSA 1 group, 127.1 +/- 6.9%; OSA 2 group, 140.7 +/- 11.0%; p = 0.01). In the muscular area, TNF-alpha levels were higher in the more obese OSA subjects than in the other two groups (snorers, 100.3 +/- 3%; OSA 1 group, 107.4 +/- 0.7%; OSA 2 group, 124.1 +/- 4.2%; p = 0.007). In the muscular area, TNF-alpha was correlated with BMI, but no relationship was found with the apnea-hypopnea index.
  
  
  CONCLUSIONS
  We conclude that MU is the major TNF-alpha source in uvular tissue and that TNF-alpha is more highly expressed in the heaviest OSA patients compared to less obese OSA patients and nonapneic snorers.
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada.
authors.forename: Lionel
authors.initials: L
authors.lastname: Loubaki
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Jacques
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada.
authors.forename: Abdelhabib
authors.initials: A
authors.lastname: Semlali
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Biardel
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada. Electronic address: jamila.chakir@med.ulaval.ca.
authors.forename: Jamila
authors.initials: J
authors.lastname: Chakir
authors.affiliation: Centre de Recherche de l'Hôpital Laval, Institut Universitaire de Cardiologie et de Pneumologie, Québec, QC, Canada.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sériès
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000378:metabolism*; D012913:Snoring / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D014609:Uvula / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha