title: A sensory neuronal ion channel essential for airway inflammation and hyperreactivity in asthma.
abstract: Asthma is an inflammatory disorder caused by airway exposures to allergens and chemical irritants. Studies focusing on immune, smooth muscle, and airway epithelial function revealed many aspects of the disease mechanism of asthma. However, the limited efficacies of immune-directed therapies suggest the involvement of additional mechanisms in asthmatic airway inflammation. TRPA1 is an irritant-sensing ion channel expressed in airway chemosensory nerves. TRPA1-activating stimuli such as cigarette smoke, chlorine, aldehydes, and scents are among the most prevalent triggers of asthma. Endogenous TRPA1 agonists, including reactive oxygen species and lipid peroxidation products, are potent drivers of allergen-induced airway inflammation in asthma. Here, we examined the role of TRPA1 in allergic asthma in the murine ovalbumin model. Strikingly, genetic ablation of TRPA1 inhibited allergen-induced leukocyte infiltration in the airways, reduced cytokine and mucus production, and almost completely abolished airway hyperreactivity to contractile stimuli. This phenotype is recapitulated by treatment of wild-type mice with HC-030031, a TRPA1 antagonist. HC-030031, when administered during airway allergen challenge, inhibited eosinophil infiltration and prevented the development of airway hyperreactivity. Trpa1(-/-) mice displayed deficiencies in chemically and allergen-induced neuropeptide release in the airways, providing a potential explanation for the impaired inflammatory response. Our data suggest that TRPA1 is a key integrator of interactions between the immune and nervous systems in the airways, driving asthmatic airway inflammation following inhaled allergen challenge. TRPA1 may represent a promising pharmacological target for the treatment of asthma and other allergic inflammatory conditions.
authors.affiliation: Department of Pharmacology, Yale University School of Medicine, 333 Cedar St., New Haven, CT 06520, USA.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Caceres
authors.forename: Marian
authors.initials: M
authors.lastname: Brackmann
authors.forename: Maxwell D
authors.initials: MD
authors.lastname: Elia
authors.forename: Bret F
authors.initials: BF
authors.lastname: Bessac
authors.forename: Donato
authors.initials: D
authors.lastname: del Camino
authors.forename: Marc
authors.initials: M
authors.lastname: D'Amours
authors.forename: JoAnn S
authors.initials: JS
authors.lastname: Witek
authors.forename: Chistopher M
authors.initials: CM
authors.lastname: Fanger
authors.forename: Jayhong A
authors.initials: JA
authors.lastname: Chong
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Hayward
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Homer
authors.forename: Lauren
authors.initials: L
authors.lastname: Cohn
authors.forename: Xiaozhu
authors.initials: X
authors.lastname: Huang
authors.forename: Magdalene M
authors.initials: MM
authors.lastname: Moran
authors.forename: Sven-Eric
authors.initials: SE
authors.lastname: Jordt
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000503:physiopathology*; D007107:Immune System / Q000276:immunology / Q000503:physiopathology; D007249:Inflammation / Q000276:immunology / Q000503:physiopathology; D051379:Mice; D018345:Mice, Knockout; D011984:Sensory Receptor Cells / Q000276:immunology / Q000502:physiology*; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000502:physiology*
chemical_list: D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse