title: Dietary n-3 fatty acids have suppressive effects on mucin upregulation in mice infected with Pseudomonas aeruginosa.
abstract: BACKGROUND
  Mucin hypersecretion and mucus plugging in the airways are characteristic features of chronic respiratory diseases like cystic fibrosis (CF) and contribute to morbidity and mortality. In CF, Pseudomonas aeruginosa superinfections in the lung exacerbate inflammation and alter mucus properties. There is increasing evidence that n-3 polyunsaturated fatty acids (PUFAs) exhibit anti-inflammatory properties in many inflammatory diseases while n-6 PUFA arachidonic acid (AA) favors inflammatory mediators such as eicosanoids prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) that may enhance inflammatory reactions. This suggests that n-3 PUFAs may have a protective effect against mucus over-production in airway diseases. Therefore, we hypothesized that n-3 PUFAs may downregulate mucins expression.
  
  
  METHODS
  We designed an absolute real-time PCR assay to assess the effect of a 5-week diet enriched either with n-3 or n-6 PUFAs on the expression of large mucins in the lungs of mice infected by P. aeruginosa.
  
  
  RESULTS
  Dietary fatty acids did not influence mucin gene expression in healthy mice. Lung infection induced an increase of the secreted gel-forming mucin Muc5b and a decrease of the membrane bound mucin Muc4. These deregulations are modulated by dietary fatty acids with a suppressive effect of n-3 PUFAs on mucin (increase of Muc5b from 19-fold up to 3.6 x 10(5)-fold for the n-3 PUFAs treated group and the control groups, respectively, 4 days post-infection and decrease of Muc4 from 15-fold up to 3.2 x 10(4)-fold for the control and the n-3 PUFAs treated groups, respectively, 4 days post-infection).
  
  
  CONCLUSIONS
  Our data suggest that n-3 PUFAs enriched diet represents an inexpensive strategy to prevent or treat mucin overproduction in pulmonary bacterial colonization.
authors.affiliation: INSERM, U837, JPARC Research Centre, IMPRT, place de Verdun, Lille, France. tetaert@lille.inserm.fr
authors.forename: Daniel
authors.initials: D
authors.lastname: Tetaert
authors.forename: Maud
authors.initials: M
authors.lastname: Pierre
authors.forename: Dominique
authors.initials: D
authors.lastname: Demeyer
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Husson
authors.forename: Laurent
authors.initials: L
authors.lastname: Béghin
authors.forename: Claude
authors.initials: C
authors.lastname: Galabert
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gottrand
authors.forename: Christopher
authors.initials: C
authors.lastname: Beermann
authors.forename: Benoit
authors.initials: B
authors.lastname: Guery
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Desseyn
mesh_terms: D000284:Administration, Oral; D000818:Animals; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009077:Mucins / Q000378:metabolism*; D011552:Pseudomonas Infections / Q000178:diet therapy / Q000378:metabolism*; D016896:Treatment Outcome; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015525:Fatty Acids, Omega-3; D009077:Mucins