1
|
Ikeuchi M, Inoue M, Miyahara H, Sebastian WA, Miyazaki S, Takeno T, Kiyota K, Yano S, Shiraishi H, Shimizu N, Hanada R, Yoshimura A, Ihara K, Hanada T. A pH imbalance is linked to autophagic dysregulation of inner ear hair cells in Atp6v1ba-deficient zebrafish. Biochem Biophys Res Commun 2024; 699:149551. [PMID: 38277730 DOI: 10.1016/j.bbrc.2024.149551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
V-ATPase is an ATP hydrolysis-driven proton pump involved in the acidification of intracellular organelles and systemic acid-base homeostasis through H+ secretion in the renal collecting ducts. V-ATPase dysfunction is associated with hereditary distal renal tubular acidosis (dRTA). ATP6V1B1 encodes the B1 subunit of V-ATPase that is integral to ATP hydrolysis and subsequent H+ transport. Patients with pathogenic ATP6V1B1 mutations often exhibit an early onset of sensorineural hearing loss. However, the mechanisms underlying this association remain unclear. We employed morpholino oligonucleotide-mediated knockdown and CRISPR/Cas9 gene editing to generate Atp6v1ba-deficient (atp6v1ba-/-) zebrafish as an ortholog model for ATP6V1B1. The atp6v1ba-/- zebrafish exhibited systemic acidosis and significantly smaller otoliths compared to wild-type siblings. Moreover, deficiency in Atp6v1ba led to degeneration of inner ear hair cells, with ultrastructural changes indicative of autophagy. Our findings indicate a critical role of ATP6V1B1 in regulating lysosomal pH and autophagy in hair cells, and the results provide insights into the pathophysiology of sensorineural hearing loss in dRTA. Furthermore, this study demonstrates that the atp6v1ba-/- zebrafish model is a valuable tool for further investigation into disease mechanisms and potential therapies for acidosis-related hearing impairment.
Collapse
Affiliation(s)
- Mayo Ikeuchi
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Department of Pediatrics, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Masanori Inoue
- Department of Pediatrics, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hiroaki Miyahara
- Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Aichi, Japan
| | | | - Shuya Miyazaki
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Takashi Takeno
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Kyoko Kiyota
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Department of Pediatrics, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Shinji Yano
- Institute for Research Management, Oita University, Yufu, Oita, Japan
| | - Hiroshi Shiraishi
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Nobuyuki Shimizu
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Reiko Hanada
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Akihiko Yoshimura
- Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan
| | - Kenji Ihara
- Department of Pediatrics, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshikatsu Hanada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan.
| |
Collapse
|