title: Purinergic signaling in the pulmonary neuroepithelial body microenvironment unraveled by live cell imaging.
abstract: Pulmonary neuroepithelial bodies (NEBs) are densely innervated groups of complex sensory airway receptors involved in the regulation of breathing. Together with their surrounding Clara-like cells, they exhibit stem cell potential through their capacity to regenerate depopulated areas of the epithelium following lung injury. We have employed confocal live cell imaging microscopy and novel electrophysiological techniques in a new ex vivo lung slice model to unravel potential purinergic signaling pathways within the NEB microenvironment. Quinacrine histochemistry indicated high amounts of vesicular ATP in NEB cells. Using a "reporter-patching" method adapted to create a uniquely sensitive and selective biosensor for the direct detection of ATP release from NEBs ex vivo, we demonstrated quantal ATP release from NEBs following their depolarization. Enhancing enzymatic extracellular ATP hydrolysis or inhibiting P2 receptors confirmed the central role of ATP in paracrine interactions between NEB cells and Clara-like cells. Combined calcium imaging, pharmacology, and immunohistochemistry showed that ligand-binding to functional P2Y(2) receptors underpins the activation of Clara-like cells. Hence, NEB cells communicate with their cellular neighbors in the NEB microenvironment by releasing ATP, which rapidly evokes purinergic activation of surrounding Clara-like cells. Besides ATP acting on the P2X(3) receptor expressing vagal sensory nerve terminals between NEB cells, local paracrine purinergic signaling within this potential stem cell niche may be important to both normal airway function, airway epithelial regeneration after injury, and/or the pathogenesis of small cell lung carcinomas.
authors.affiliation: Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Ian
authors.initials: I
authors.lastname: De Proost
authors.forename: Isabel
authors.initials: I
authors.lastname: Pintelon
authors.forename: William J
authors.initials: WJ
authors.lastname: Wilkinson
authors.forename: Sofie
authors.initials: S
authors.lastname: Goethals
authors.forename: Inge
authors.initials: I
authors.lastname: Brouns
authors.forename: Luc
authors.initials: L
authors.lastname: Van Nassauw
authors.forename: Daniela
authors.initials: D
authors.lastname: Riccardi
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Timmermans
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Kemp
authors.forename: Dirk
authors.initials: D
authors.lastname: Adriaensen
mesh_terms: D000255:Adenosine Triphosphate / Q000037:antagonists & inhibitors / Q000378:metabolism; D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D007150:Immunohistochemistry; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D046568:Neuroepithelial Bodies / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011726:Pyridinium Compounds / Q000378:metabolism; D011796:Quinacrine / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013498:Suramin / Q000494:pharmacology; D014966:Xanthenes / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; C409648:Fluo 4; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D018048:Receptors, Purinergic P2; D014966:Xanthenes; C052247:4-(4-diethylaminostyryl)-N-methylpyridinium; D013498:Suramin; D000255:Adenosine Triphosphate; D011796:Quinacrine; D002118:Calcium