Ambroxol-enhanced ciliary beating via voltage-gated Ca2+ channels in mouse airway ciliated cells

Daichi Saito; Chihiro Suzuki; Saori Tanaka; Shigekuni Hosogi; Kotoku Kawaguchi; Shinji Asano; Shohta Okamoto; Makoto Yasuda; Shigeru Hirano; Toshio Inui; Yoshinori Marunaka; Takashi Nakahari

doi:10.1016/j.ejphar.2023.175496

Ambroxol-enhanced ciliary beating via voltage-gated Ca²⁺ channels in mouse airway ciliated cells

Eur J Pharmacol. 2023 Feb 15:941:175496. doi: 10.1016/j.ejphar.2023.175496. Epub 2023 Jan 12.

Authors

Affiliations

¹ Research Laboratory for Epithelial Physiology, Research Organization of Science and Technology, BKC Ritsumeikan University, Kusatsu, 525-8577, Japan; Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu, 525-8577, Japan.
² Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan.
³ Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto, 607-8414, Japan.
⁴ Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu, 525-8577, Japan.
⁵ Research Laboratory for Epithelial Physiology, Research Organization of Science and Technology, BKC Ritsumeikan University, Kusatsu, 525-8577, Japan; Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.
⁶ Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.
⁷ Research Laboratory for Epithelial Physiology, Research Organization of Science and Technology, BKC Ritsumeikan University, Kusatsu, 525-8577, Japan; Saisei Mirai Clinics, Moriguchi, 570-0012, Japan.
⁸ Research Laboratory for Epithelial Physiology, Research Organization of Science and Technology, BKC Ritsumeikan University, Kusatsu, 525-8577, Japan; Medical Research Institute, Kyoto Industrial Health Association, Kyoto, 604-8472, Japan.
⁹ Research Laboratory for Epithelial Physiology, Research Organization of Science and Technology, BKC Ritsumeikan University, Kusatsu, 525-8577, Japan; Medical Research Institute, Kyoto Industrial Health Association, Kyoto, 604-8472, Japan. Electronic address: nakahari@fc.ritsumei.ac.jp.

PMID: 36642128
DOI: 10.1016/j.ejphar.2023.175496

Abstract

Ambroxol (ABX) facilitates the mucociliary clearance (MC) by enhancing ciliary beating in airways. In this study, we focused on airway ciliary beating enhanced by ABX. However, little is known about the ABX-stimulated Ca²⁺ signalling activating airway ciliary beating. Airway ciliated cells isolated from mice lungs were observed by a high-speed video microscope, and the activities of beating cilia were assessed by CBF (ciliary beat frequency) and CBD (ciliary bend distance, an index of amplitude). ABX (10 μM) enhanced the CBF and CBD by 30%, and the enhancement was inhibited by nifedipine (20 μM, a L-type voltage-gated Ca²⁺ channel (Ca_V) inhibitor), or a Ca²⁺-free solution (approximately 50%). Pre-treatment with BAPTA-AM (10 μM, a chelator of intracellular Ca²⁺) abolished ABX-stimulated increases in CBF, CBD and [Ca²⁺]_i. Thus, ABX increases [Ca²⁺]_i (intracellular Ca²⁺ concentration) by stimulating Ca²⁺ release from the internal stores and nifedipine-sensitive Ca²⁺ entry. A previous study demonstrated the expression of Ca_V1.2 in airway cilia. ABX enhanced CBF, CBD and [Ca²⁺]_i even in a high extracellular K⁺ concentration (155.5 mM), suggesting that it activates Ca_V1.2 except by depolarization. These enhancements were inhibited by nifedipine. In conclusion, ABX, which increases [Ca²⁺]_i by stimulating Ca²⁺ release from internal stores and Ca²⁺ entry through Ca_V1.2s, enhanced CBF and CBD in airway ciliated cells. ABX is a novel agonist that modulates Ca_V1.2 of airway beating cilia to enhance CBF and CBD.

Keywords: Airway ciliary beating; Ambroxol; Ca(V); Intracellular Ca(2+) concentration; Nifedipine.

MeSH terms

Ambroxol*
Animals
Cells, Cultured
Cilia / metabolism
Epithelial Cells
Mice
Nifedipine / pharmacology

Substances

Ambroxol
Nifedipine