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Zhang Y, Tian K, Wei W, Mi W, Lu F, Liu Z, Zhu Q, Zhang X, Geng P, Qiu J, Song Y, Zha D. Translocation of telomerase reverse transcriptase coincided with ATP release in postnatal cochlear supporting cells. Neural Regen Res 2024; 19:1119-1125. [PMID: 37862217 PMCID: PMC10749606 DOI: 10.4103/1673-5374.382862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/15/2023] [Accepted: 06/20/2023] [Indexed: 10/22/2023] Open
Abstract
The spontaneous bursts of electrical activity in the developing auditory system are derived from the periodic release of adenosine triphosphate (ATP) by supporting cells in the Kölliker's organ. However, the mechanisms responsible for initiating spontaneous ATP release have not been determined. Our previous study revealed that telomerase reverse transcriptase (TERT) is expressed in the basilar membrane during the first postnatal week. Its role in cochlear development remains unclear. In this study, we investigated the expression and role of TERT in postnatal cochlea supporting cells. Our results revealed that in postnatal cochlear Kölliker's organ supporting cells, TERT shifts from the nucleus into the cytoplasm over time. We found that the TERT translocation tendency in postnatal cochlear supporting cells in vitro coincided with that observed in vivo. Further analysis showed that TERT in the cytoplasm was mainly located in mitochondria in the absence of oxidative stress or apoptosis, suggesting that TERT in mitochondria plays roles other than antioxidant or anti-apoptotic functions. We observed increased ATP synthesis, release and activation of purine signaling systems in supporting cells during the first 10 postnatal days. The phenomenon that TERT translocation coincided with changes in ATP synthesis, release and activation of the purine signaling system in postnatal cochlear supporting cells suggested that TERT may be involved in regulating ATP release and activation of the purine signaling system. Our study provides a new research direction for exploring the spontaneous electrical activity of the cochlea during the early postnatal period.
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Affiliation(s)
- Yukai Zhang
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Keyong Tian
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Wei Wei
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Wenjuan Mi
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Fei Lu
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Zhenzhen Liu
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Qingwen Zhu
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Xinyu Zhang
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Panling Geng
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Jianhua Qiu
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Yongli Song
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Dingjun Zha
- Department of Otolaryngology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
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Chen J, Gao D, Sun L, Yang J. Kölliker’s organ-supporting cells and cochlear auditory development. Front Mol Neurosci 2022; 15:1031989. [PMID: 36304996 PMCID: PMC9592740 DOI: 10.3389/fnmol.2022.1031989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/23/2022] [Indexed: 11/21/2022] Open
Abstract
The Kölliker’s organ is a transient cellular cluster structure in the development of the mammalian cochlea. It gradually degenerates from embryonic columnar cells to cuboidal cells in the internal sulcus at postnatal day 12 (P12)–P14, with the cochlea maturing when the degeneration of supporting cells in the Kölliker’s organ is complete, which is distinct from humans because it disappears at birth already. The supporting cells in the Kölliker’s organ play a key role during this critical period of auditory development. Spontaneous release of ATP induces an increase in intracellular Ca2+ levels in inner hair cells in a paracrine form via intercellular gap junction protein hemichannels. The Ca2+ further induces the release of the neurotransmitter glutamate from the synaptic vesicles of the inner hair cells, which subsequently excite afferent nerve fibers. In this way, the supporting cells in the Kölliker’s organ transmit temporal and spatial information relevant to cochlear development to the hair cells, promoting fine-tuned connections at the synapses in the auditory pathway, thus facilitating cochlear maturation and auditory acquisition. The Kölliker’s organ plays a crucial role in such a scenario. In this article, we review the morphological changes, biological functions, degeneration, possible trans-differentiation of cochlear hair cells, and potential molecular mechanisms of supporting cells in the Kölliker’s organ during the auditory development in mammals, as well as future research perspectives.
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Affiliation(s)
- Jianyong Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Institute of Ear Science, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Otolaryngology and Translational Medicine, Shanghai, China
| | - Dekun Gao
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Institute of Ear Science, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Otolaryngology and Translational Medicine, Shanghai, China
| | - Lianhua Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Institute of Ear Science, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Otolaryngology and Translational Medicine, Shanghai, China
- *Correspondence: Lianhua Sun Jun Yang
| | - Jun Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Institute of Ear Science, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Otolaryngology and Translational Medicine, Shanghai, China
- *Correspondence: Lianhua Sun Jun Yang
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Ye R, Liu J, Jia Z, Wang H, Wang Y, Sun W, Wu X, Zhao Z, Niu B, Li X, Dai G, Li J. Adenosine Triphosphate (ATP) Inhibits Voltage-Sensitive Potassium Currents in Isolated Hensen's Cells and Nifedipine Protects Against Noise-Induced Hearing Loss in Guinea Pigs. Med Sci Monit 2016; 22:2006-12. [PMID: 27292522 PMCID: PMC4913814 DOI: 10.12659/msm.898150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background There is increasing evidence that adenosine triphosphate (ATP), a well-known neurotransmitter and neuromodulator in the central nervous system, plays an important role as an extracellular chemical messenger in the cochlea. Material/Methods Using a whole-cell recording technique, we studied the effects of ATP on isolated Hensen’s cells, which are supporting cells in the cochlea, to determine if they are involved in the transduction of ions with hair cells. Results ATP (0.1–10 μM) reduced the potassium current (IK+) in the majority of the recorded Hensen’s cells (21 out of 25 cells). An inward current was also induced by high concentrations of ATP (100 μM to 10 mM), which was reversibly blocked by 100 μM suramin (a purinergic antagonist) and blocked by nifedipine (an L-type calcium channel blocker). After the cochleas were perfused with artificial perilymph solutions containing nifedipine and exposed to noise, the amplitude increase in the compound action potential (CAP) threshold and the reduction in cochlear microphonics was lower than when they were exposed to noise alone. Conclusions Our results suggest that ATP can block IK+ channels at a low concentration and induce an inward Ca2+ current at high concentrations, which is reversed by purinergic receptors. Nifedipine may have a partially protective effect on noise-induced hearing loss (NIHL).
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Affiliation(s)
- Rui Ye
- Department of Radiation Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Jun Liu
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Zhiying Jia
- , Xinjiang Cancer Hospital, Urumqi, Xinjiang, China (mainland)
| | - Hongyang Wang
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - YongAn Wang
- , Academy of Military Medical Sciences, Beijing, China (mainland)
| | - Wei Sun
- Center for Hearing & Deafness, State University of New York (SUNY) at Buffalo, Buffalo, NY, American Samoa
| | - Xuan Wu
- Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, Hainan, China (mainland)
| | - Zhifei Zhao
- Department of Radiation Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Baolong Niu
- Department of Radiation Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Xingqi Li
- Department of Radiation Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Guanghai Dai
- Department of Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
| | - Jianxiong Li
- Department of Radiation Oncology, Chinese PLA General Hospital, Beijing, China (mainland)
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Liu J, Liu W, Yang J. ATP-containing vesicles in stria vascular marginal cell cytoplasms in neonatal rat cochlea are lysosomes. Sci Rep 2016; 6:20903. [PMID: 26864824 PMCID: PMC4750035 DOI: 10.1038/srep20903] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 01/13/2016] [Indexed: 01/03/2023] Open
Abstract
We confirmed that ATP is released from cochlear marginal cells in the stria vascular but the cell organelle in which ATP stores was not identified until now. Thus, we studied the ATP-containing cell organelles and suggest that these are lysosomes. Primary cultures of marginal cells of Sprague-Dawley rats aged 1-3 days was established. Vesicles within marginal cells stained with markers were identified under confocal laser scanning microscope and transmission electron microscope (TEM). Then ATP release from marginal cells was measured after glycyl-L-phenylalanine-ß- naphthylamide (GPN) treatment using a bioluminescent assay. Quinacrine-stained granules within marginal cells were labeled with LysoTracker, a lysosome tracer, and lysosomal-associated membrane protein 1(LAMP1), but not labeled with the mitochondrial tracer MitoTracker. Furthermore, LysoTracker-labelled puncta showed accumulation of Mant-ATP, an ATP analog. Treatment with 200 μM GPN quenched fluorescently labeled puncta after incubation with LysoTracker or quinacrine, but not MitoTracker. Quinacrine-labeled organelles observed by TEM were lysosomes, and an average 27.7 percent increase in ATP luminescence was observed in marginal cells extracellular fluid after GPN treatment. ATP-containing vesicles in cochlear marginal cells of the stria vascular from neonatal rats are likely lysosomes. ATP release from marginal cells may be via Ca(2+)-dependent lysosomal exocytosis.
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Affiliation(s)
- Jun Liu
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China
- Department of Otorhinolaryngology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wenjing Liu
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China
| | - Jun Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China
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