Ba H Do1,2, Toyoaki Ohbuchi1, Tetsuro Wakasugi1, Hiroki Koizumi1, Mitsuru Yokoyama3, Nobusuke Hohchi1, Hideaki Suzuki1. 1. 1 Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. 2. 2 Department of Otorhinolaryngology, Ha Noi Medical University, Ha Noi, Vietnam. 3. 3 Shared-Use Research Center, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Abstract
Background Airway mucociliary transport is an important function for the clearance of inhaled foreign particulates in the respiratory tract. The present study aimed at investigating the regulatory mechanism of acetylcholine (Ach)-induced ciliary beat of the human nasal mucosa in ex vivo. Methods The inferior turbinate mucosa was collected from patients with chronic hypertrophic rhinitis during endoscopic surgery. The mucosa was cut into thin strips, and ciliary movement was observed under a phase-contrast light microscope with a high-speed digital video camera. The sample was alternatively subjected to scanning electron microscopic observation. Results Cilia on the turbinate epithelium were well preserved at the ultrastructural level. The baseline ciliary beat frequency (CBF) was 6.45 ± 0.32 Hz. CBF was significantly increased by stimulation with 100 µM Ach and 100 µM adenosine triphosphate. The Ach-induced CBF increase was completely inhibited by removing extracellular Ca2+. Significant inhibition of the Ach-induced CBF was also observed by the addition of 1 µM atropine, 40 µM 2-aminoethoxydiphenyl borate (inositol trisphosphate [IP3] receptor antagonist), 10 µM carbenoxolone (pannexin-1 blocker), 1 mM probenecid (pannexin-1 blocker), 100 µM pyridoxalphosphate-6-azophenyl-20,40-disulfonic acid (P2X antagonist), and 300 µM flufenamic acid (connexin blocker). Meanwhile, 30 nM bafilomycin A1 (vesicular transport inhibitor) did not inhibit the Ach-induced CBF increase. CONCLUSIONS: These results indicate that the regulatory mechanism of the Ach-induced ciliary beat is dependent on extracellular Ca2+ and involves the muscarinic Ach receptor, IP3 receptor, pannexin-1 channel, purinergic P2X receptor, and connexin channel. We proposed a tentative intracellular signaling pathway of the Ach-induced ciliary beat, in which the pannexin-1-P2X unit may play a central role in ciliary beat regulation.
Background Airway mucociliary transport is an important function for the clearance of inhaled foreign particulates in the respiratory tract. The present study aimed at investigating the regulatory mechanism of acetylcholine (Ach)-induced ciliary beat of the human nasal mucosa in ex vivo. Methods The inferior turbinate mucosa was collected from patients with chronic hypertrophic rhinitis during endoscopic surgery. The mucosa was cut into thin strips, and ciliary movement was observed under a phase-contrast light microscope with a high-speed digital video camera. The sample was alternatively subjected to scanning electron microscopic observation. Results Cilia on the turbinate epithelium were well preserved at the ultrastructural level. The baseline ciliary beat frequency (CBF) was 6.45 ± 0.32 Hz. CBF was significantly increased by stimulation with 100 µM Ach and 100 µM adenosine triphosphate. The Ach-induced CBF increase was completely inhibited by removing extracellular Ca2+. Significant inhibition of the Ach-induced CBF was also observed by the addition of 1 µM atropine, 40 µM 2-aminoethoxydiphenyl borate (inositol trisphosphate [IP3] receptor antagonist), 10 µM carbenoxolone (pannexin-1 blocker), 1 mM probenecid (pannexin-1 blocker), 100 µM pyridoxalphosphate-6-azophenyl-20,40-disulfonic acid (P2X antagonist), and 300 µM flufenamic acid (connexin blocker). Meanwhile, 30 nM bafilomycin A1 (vesicular transport inhibitor) did not inhibit the Ach-induced CBF increase. CONCLUSIONS: These results indicate that the regulatory mechanism of the Ach-induced ciliary beat is dependent on extracellular Ca2+ and involves the muscarinic Ach receptor, IP3 receptor, pannexin-1 channel, purinergic P2X receptor, and connexin channel. We proposed a tentative intracellular signaling pathway of the Ach-induced ciliary beat, in which the pannexin-1-P2X unit may play a central role in ciliary beat regulation.
Authors: Alexander Nastev; J Ulrich Sommer; Wieland Behr; Boris A Stuck; C Emika Mueller; Angela Schell; Benedikt Kramer; Daniel Haeussler; Karl Hoermann; Richard Birk Journal: In Vivo Date: 2020 Nov-Dec Impact factor: 2.155
Authors: Leigh Anne Swayne; Scott R Johnstone; Chen Seng Ng; Juan C Sanchez-Arias; Miranda E Good; Silvia Penuela; Alexander W Lohman; Abigail G Wolpe; Victor E Laubach; Michael Koval; Brant E Isakson Journal: Am J Physiol Lung Cell Mol Physiol Date: 2020-06-10 Impact factor: 6.011