TY - JOUR
T1 - Tracheal brush cells release acetylcholine in response to bitter tastants for paracrine and autocrine signaling
AU - Hollenhorst, Monika I.
AU - Jurastow, Innokentij
AU - Nandigama, Rajender
AU - Appenzeller, Silke
AU - Li, Lei
AU - Vogel, Jörg
AU - Wiederhold, Stephanie
AU - Althaus, Mike
AU - Empting, Martin
AU - Altmüller, Janine
AU - Hirsch, Anna K.H.
AU - Flockerzi, Veit
AU - Canning, Brendan J.
AU - Saliba, Antoine Emmanuel
AU - Krasteva-Christ, Gabriela
N1 - Funding Information:
The authors thank Tamara Papadakis (Institute for Anatomy and Cell Biology, Justus‐Liebig‐University Giessen, Germany), Nora Aouragh and Hassan Kanj (Institute for Anatomy and Cell Biology, Saarland University, Germany) for skillful technical assistance and Dr Stephan Maxeiner (Institute of Anatomy and Cell Biology, Saarland University, Germany) for critical reading of the manuscript. We thank Saskia Evers for assistance in in vivo Ca imaging in isolated tracheas. We thank Dr P. Scholz and Dr S. Osterloh (Department of Cell Physiology, Ruhr‐University Bochum, Germany) for sharing their expertise regarding RNA‐seq from primary cells and for providing the photos shown in Figure A. We thank Dr Jürgen Wess for providing the muscarinic receptor‐deficient mouse strains. The authors declare that no conflicts of interest exist. This work was supported by the German Research Society (DFG SFB TRR 152 project P01 to VF, project P22 to GKC, KR4338/1‐1 to GKC) and the Helmholtz Association's Initiative and Networking Fund (AKHH). 2+
Funding Information:
The authors thank Tamara Papadakis (Institute for Anatomy and Cell Biology, Justus-Liebig-University Giessen, Germany), Nora Aouragh and Hassan Kanj (Institute for Anatomy and Cell Biology, Saarland University, Germany) for skillful technical assistance and Dr Stephan Maxeiner (Institute of Anatomy and Cell Biology, Saarland University, Germany) for critical reading of the manuscript. We thank Saskia Evers for assistance in in vivo Ca2+ imaging in isolated tracheas. We thank Dr P. Scholz and Dr S. Osterloh (Department of Cell Physiology, Ruhr-University Bochum, Germany) for sharing their expertise regarding RNA-seq from primary cells and for providing the photos shown in Figure A. We thank Dr Jürgen Wess for providing the muscarinic receptor-deficient mouse strains. The authors declare that no conflicts of interest exist. This work was supported by the German Research Society (DFG SFB TRR 152 project P01 to VF, project P22 to GKC, KR4338/1-1 to GKC) and the Helmholtz Association's Initiative and Networking Fund (AKHH).
Publisher Copyright:
© 2019 The Authors. The FASEB Journal published by Wiley Periodicals, Inc. on behalf of Federation of American Societies for Experimental Biology
PY - 2020/1/1
Y1 - 2020/1/1
N2 - For protection from inhaled pathogens many strategies have evolved in the airways such as mucociliary clearance and cough. We have previously shown that protective respiratory reflexes to locally released bacterial bitter “taste” substances are most probably initiated by tracheal brush cells (BC). Our single-cell RNA-seq analysis of murine BC revealed high expression levels of cholinergic and bitter taste signaling transcripts (Tas2r108, Gnat3, Trpm5). We directly demonstrate the secretion of acetylcholine (ACh) from BC upon stimulation with the Tas2R agonist denatonium. Inhibition of the taste transduction cascade abolished the increase in [Ca2+]i in BC and subsequent ACh-release. ACh-release is regulated in an autocrine manner. While the muscarinic ACh-receptors M3R and M1R are activating, M2R is inhibitory. Paracrine effects of ACh released in response to denatonium included increased [Ca2+]i in ciliated cells. Stimulation by denatonium or with Pseudomonas quinolone signaling molecules led to an increase in mucociliary clearance in explanted tracheae that was Trpm5- and M3R-mediated. We show that ACh-release from BC via the bitter taste cascade leads to immediate paracrine protective responses that can be boosted in an autocrine manner. This mechanism represents the initial step for the activation of innate immune responses against pathogens in the airways.
AB - For protection from inhaled pathogens many strategies have evolved in the airways such as mucociliary clearance and cough. We have previously shown that protective respiratory reflexes to locally released bacterial bitter “taste” substances are most probably initiated by tracheal brush cells (BC). Our single-cell RNA-seq analysis of murine BC revealed high expression levels of cholinergic and bitter taste signaling transcripts (Tas2r108, Gnat3, Trpm5). We directly demonstrate the secretion of acetylcholine (ACh) from BC upon stimulation with the Tas2R agonist denatonium. Inhibition of the taste transduction cascade abolished the increase in [Ca2+]i in BC and subsequent ACh-release. ACh-release is regulated in an autocrine manner. While the muscarinic ACh-receptors M3R and M1R are activating, M2R is inhibitory. Paracrine effects of ACh released in response to denatonium included increased [Ca2+]i in ciliated cells. Stimulation by denatonium or with Pseudomonas quinolone signaling molecules led to an increase in mucociliary clearance in explanted tracheae that was Trpm5- and M3R-mediated. We show that ACh-release from BC via the bitter taste cascade leads to immediate paracrine protective responses that can be boosted in an autocrine manner. This mechanism represents the initial step for the activation of innate immune responses against pathogens in the airways.
KW - acetylcholine
KW - brush cells
KW - mucociliary clearance
KW - single-cell RNA-seq
KW - taste
UR - http://www.scopus.com/inward/record.url?scp=85077676943&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85077676943&partnerID=8YFLogxK
U2 - 10.1096/fj.201901314RR
DO - 10.1096/fj.201901314RR
M3 - Article
C2 - 31914675
AN - SCOPUS:85077676943
SN - 0892-6638
VL - 34
SP - 316
EP - 332
JO - FASEB Journal
JF - FASEB Journal
IS - 1
ER -