title: Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts.
abstract: Specialized epithelial cells in the respiratory tract such as solitary chemosensory cells and brush cells sense the luminal content and initiate protective reflexes in response to the detection of potentially harmful substances. The majority of these cells are cholinergic and utilize the canonical taste signal transduction cascade to detect "bitter" substances such as bacterial quorum sensing molecules. Utilizing two different mouse strains reporting expression of choline acetyltransferase (ChAT), the synthesizing enzyme of acetylcholine (ACh), we detected cholinergic cells in the submucosal glands of the murine larynx and trachea. These cells were localized in the ciliated glandular ducts and were neither found in the collecting ducts nor in alveolar or tubular segments of the glands. ChAT expression in tracheal gland ducts was confirmed by in situ hybridization. The cholinergic duct cells expressed the brush cell marker proteins, villin and cytokeratin-18, and were immunoreactive for components of the taste signal transduction cascade (Gα-gustducin, transient receptor potential melastatin-like subtype 5 channel = TRPM5, phospholipase C(β2)), but not for carbonic anhydrase IV. Furthermore, these cells expressed the bitter taste receptor Tas2r131, as demonstrated utilizing an appropriate reporter mouse strain. Our study identified a previously unrecognized presumptive chemosensory cell type in the duct of the airway submucosal glands that likely utilizes ACh for paracrine signaling. We propose that these cells participate in infection-sensing mechanisms and initiate responses assisting bacterial clearance from the lower airways.
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany; Institute of Anatomy and Cell Biology, Julius-Maximilians-University, Wuerzburg, Germany. Electronic address: gabriela.krasteva-christ@uni-wuerzburg.de.
authors.forename: G
authors.initials: G
authors.lastname: Krasteva-Christ
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Soultanova
authors.affiliation: Institute for Anatomy and Cell Biology, Philipps-University, Marburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Schütz
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Papadakis
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Weiss
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Deckmann
authors.affiliation: Walter-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilian-University, Munich, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Chubanov
authors.affiliation: Walter-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilian-University, Munich, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Gudermann
authors.affiliation: Dept. Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Voigt
authors.affiliation: Dept. Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Meyerhof
authors.affiliation: Department of Pharmacology and Toxicology, University of Saarland School of Medicine, Homburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Boehm
authors.affiliation: Institute for Anatomy and Cell Biology, Philipps-University, Marburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Weihe
authors.affiliation: Institute of Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kummer
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002628:Chemoreceptor Cells / Q000378:metabolism*; D002795:Choline O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D049452:Green Fluorescent Proteins; D007830:Larynx / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D014132:Trachea / Q000166:cytology*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine
keywords: Airways; Chemosensory; Cholinergic; Epithelium; Glands; Innate immunity