title: Increased hypoxia-inducible factor 1α expression in lung cells of horses with recurrent airway obstruction.
abstract: BACKGROUND
  Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological processes responsible for the development and the persistence of airway inflammation are still largely unknown. Hypoxia-inducible factor (Hif) is mainly known as a major regulator of energy homeostasis and cellular adaptation to hypoxia. More recently however, Hif also emerged as an essential regulator of innate immune responses. Here, we aimed at investigating the potential involvement of Hif1-α in myeloid cells in horse with recurrent airway obstruction.
  
  
  RESULTS
  In vitro, we observed that Hif is expressed in equine myeloid cells after hay dust stimulation and regulates genes such as tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGF-A). We further showed in vivo that airway challenge with hay dust upregulated Hif1-α mRNA expression in myeloid cells from the bronchoalveolar lavage fluid (BALF) of healthy and RAO-affected horses, with a more pronounced effect in cells from RAO-affected horses. Finally, Hif1-α mRNA expression in BALF cells from challenged horses correlated positively with lung dysfunction.
  
  
  CONCLUSIONS
  Taken together, our results suggest an important role for Hif1-α in myeloid cells during hay dust-induced inflammation in horses with RAO. We therefore propose that future research aiming at functional inactivation of Hif1 in lung myeloid cells could open new therapeutic perspectives for RAO.
authors.affiliation: Laboratory of Cellular and Molecular Physiology, GIGA-Research and Faculty of Veterinary Medicine, University of Liège, B34-Avenue de l'Hôpital, 1, 4000, Liège, Belgium. M.Toussaint@ulg.ac.be
authors.forename: Marie
authors.initials: M
authors.lastname: Toussaint
authors.forename: Laurence
authors.initials: L
authors.lastname: Fievez
authors.forename: Christophe J
authors.initials: CJ
authors.lastname: Desmet
authors.forename: Dimitri
authors.initials: D
authors.lastname: Pirottin
authors.forename: Frédéric
authors.initials: F
authors.lastname: Farnir
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bureau
authors.forename: Pierre
authors.initials: P
authors.lastname: Lekeux
mesh_terms: D000818:Animals; D000996:Antitussive Agents / Q000494:pharmacology; D002478:Cells, Cultured; D004391:Dust; D005786:Gene Expression Regulation / Q000502:physiology*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism / Q000662:veterinary; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism; D008173:Lung Diseases, Obstructive / Q000378:metabolism / Q000662:veterinary*; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D009665:Noscapine / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D000996:Antitussive Agents; D004391:Dust; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016209:Interleukin-8; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D009665:Noscapine