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Okada M, Ogawa H, Takagi T, Nishihara E, Yoshida T, Hyodo J, Shinomori Y, Honda N, Fujiwara T, Teraoka M, Yamada H, Hirano SI, Hato N. A double-blinded, randomized controlled clinical trial of hydrogen inhalation therapy for idiopathic sudden sensorineural hearing loss. Front Neurosci 2022; 16:1024634. [PMID: 36507329 PMCID: PMC9731512 DOI: 10.3389/fnins.2022.1024634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/08/2022] [Indexed: 11/25/2022] Open
Abstract
Background Hydrogen (H2) has been reported to be effective in reducing hearing loss due to several causes in animal studies. However, no study has examined the effectiveness of H2 in treating hearing loss in humans. Thus, we investigated whether H2 is effective for the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL). Materials and methods We conducted a double-blind randomized controlled trial at six hospitals between June 2019 and March 2022. The study protocol and trial registration have been published in the Japan Registry of Clinical Trials (jRCT, No. jRCTs06119004). We randomly assigned patients with ISSNHL to receive either H2 (H2 group) or air as a placebo (control group) through inhalation combined with the administration of systemic glucocorticoids and prostaglandin E1. The primary outcome was the hearing threshold and changes in hearing threshold 3 months after therapy. In contrast, the secondary outcomes included the proportion of patients with a good prognosis (complete recovery or marked improvement). Results Sixty-five patients with ISSNHL (31 and 34 in the H2 and control groups, respectively) were included in this study. The hearing threshold 3 months after treatment was not significantly different between the groups; 39.0 decibels (dB) (95% confidence interval [CI]: 28.7-49.3) and 49.5 dB (95% CI: 40.3-58.7) in the H2 and control groups, respectively. In contrast, the changes in hearing threshold 3 months after treatment was 32.7 dB (95% CI: 24.2-41.3) and 24.2 dB (95% CI: 18.1-30.3) in the H2 and control groups, respectively. Consequently, the changes in hearing threshold were significantly better in the H2 group than in the control group (P = 0.048). However, no adverse effects due to the inhalation of H2 gas have been reported. Conclusion This is the first study to investigate the efficacy of H2 for the treatment of ISSNHL in humans. The results suggest that H2 therapy may be effective for ISSNHL treatment. Clinical trial registration [https://jrct.niph.go.jp/re/reports/detail/10442], identifier [jRCTs06119004].
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Affiliation(s)
- Masahiro Okada
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan,*Correspondence: Masahiro Okada,
| | - Hideo Ogawa
- Department of Otolaryngology, Head and Neck Surgery, Ehime Prefectural Central Hospital, Matsuyama, Japan
| | - Taro Takagi
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan,Department of Otolaryngology, Ehime Prefectural Niihama Hospital, Niihama, Japan
| | - Eriko Nishihara
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan,Department of Otolaryngology, Ehime Prefectural Niihama Hospital, Niihama, Japan
| | - Tadashi Yoshida
- Department of Otolaryngology, Head and Neck Surgery, Uwajima City Hospital, Uwajima, Japan
| | - Jun Hyodo
- Department of Otolaryngology, Takanoko Hospital, Matsuyama, Japan
| | - Yusuke Shinomori
- Department of Otolaryngology, Matsuyama Red Cross Hospital, Matsuyama, Japan
| | - Nobumitsu Honda
- Department of Otolaryngology, Head and Neck Surgery, Ehime Prefectural Central Hospital, Matsuyama, Japan
| | - Takashi Fujiwara
- Department of Public Health Research, Kurashiki Clinical Research Institute, Kurashiki, Japan
| | - Masato Teraoka
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan
| | - Hiroyuki Yamada
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan
| | - Shin-ichi Hirano
- Department of Research and Development, MiZ Company Limited, Kamakura, Japan
| | - Naohito Hato
- Department of Otolaryngology, Head and Neck Surgery, Ehime University Graduate School of Medicine, Toon, Japan
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2
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Ye B, Wang Q, Hu H, Shen Y, Fan C, Chen P, Ma Y, Wu H, Xiang M. Restoring autophagic flux attenuates cochlear spiral ganglion neuron degeneration by promoting TFEB nuclear translocation via inhibiting MTOR. Autophagy 2019; 15:998-1016. [PMID: 30706760 PMCID: PMC6526833 DOI: 10.1080/15548627.2019.1569926] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Macroautophagy/autophagy dysfunction is associated with many neurodegenerative diseases. TFEB (transcription factor EB), an important molecule that regulates lysosomal and autophagy function, is regarded as a potential target for treating some neurodegenerative diseases. However, the relationship between autophagy dysfunction and spiral ganglion neuron (SGN) degeneration and the role of TFEB in SGN degeneration has not yet been established. Here, we showed that in degenerated SGNs, induced by sensory epithelial cell loss in the cochlea of mice following kanamycin and furosemide administration, the lipofuscin area and oxidative stress level were increased, the nuclear-to-cytoplasmic TFEB ratio was decreased, and the late stage of autophagic flux was impaired. After autophagy dysfunction was partially ameliorated with an MTOR inhibitor, which promoted TFEB translocation into the nucleus from the cytoplasm, we found that the lysosomal deficits were significantly relieved, the oxidative stress level was reduced, and the density of surviving SGNs and auditory nerve fibers was increased. The results in the present study reveal that autophagy dysfunction is an important component of SGN degeneration, and TFEB may be a potential target for attenuating SGN degeneration following sensory epithelial cell loss in the cochlea of mice. Abbreviations: 3-NT: 3-nitrotyrosine; 4-HNE: 4-hydroxynonenal; 8-OHdG: 8-hydroxy-2ʹ-deoxyguanosine; ABR: auditory brainstem response; APP: amyloid beta (A4) precursor protein; CLEAR: coordinated lysosomal expression and regulation; CTSB: cathespin B; CTSD: cathespin D; SAMR1: senescence-accelerated mouse/resistance 1; SAMP8: senescence-accelerated mouse/prone 8; MAPK1/ERK2: mitogen-activated protein kinase 1; MTOR: mechanistic target of rapamycin kinase; SGN: spiral ganglion neuron; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscope; TFEB: transcription factor EB
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Affiliation(s)
- Bin Ye
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Quan Wang
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Haixia Hu
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Yilin Shen
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Cui Fan
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Penghui Chen
- b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Yan Ma
- b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Hao Wu
- b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
| | - Mingliang Xiang
- a Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,b Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, The Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.,c Ear Institute , Shanghai Jiao tong University School of Medicine , Shanghai , China
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3
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Ye B, Fan C, Shen Y, Wang Q, Hu H, Xiang M. The Antioxidative Role of Autophagy in Hearing Loss. Front Neurosci 2019; 12:1010. [PMID: 30686976 PMCID: PMC6333736 DOI: 10.3389/fnins.2018.01010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/17/2018] [Indexed: 01/01/2023] Open
Abstract
Autophagy, a highly conserved cellular mechanism, plays an essential role in the development and pathology of many central and peripheral nervous system diseases. The auditory system, especially hair cells (HCs) and spiral ganglion neurons (SGNs) in the inner ear, are postmitotic cells, which are extremely reliant on cellular homeostasis and energy supply. Therefore, autophagy may be involved in contributing to and facilitating the normal function of inner ear cells. Recently, studies on hearing loss induced by ototoxic drugs, noise exposure and other factors have revealed that autophagy could serve in an antioxidative capacity and could possess the potential to treat sensorineural hearing loss (SNHL). Therefore, here we review previous studies concerning autophagy and SNHL to gain insight into the role of autophagic mechanisms in inner ear disorders.
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Affiliation(s)
- Bin Ye
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Cui Fan
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Yilin Shen
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Quan Wang
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Haixia Hu
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Mingliang Xiang
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
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Ding D, Jiang H, Chen GD, Longo-Guess C, Muthaiah VPK, Tian C, Sheppard A, Salvi R, Johnson KR. N-acetyl-cysteine prevents age-related hearing loss and the progressive loss of inner hair cells in γ-glutamyl transferase 1 deficient mice. Aging (Albany NY) 2017; 8:730-50. [PMID: 26977590 PMCID: PMC4925825 DOI: 10.18632/aging.100927] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 02/18/2016] [Indexed: 02/07/2023]
Abstract
Genetic factors combined with oxidative stress are major determinants of age-related hearing loss (ARHL), one of the most prevalent disorders of the elderly. Dwarf grey mice, Ggt1dwg/dwg, are homozygous for a loss of function mutation of the γ-glutamyl transferase 1 gene, which encodes an important antioxidant enzyme critical for the resynthesis of glutathione (GSH). Since GSH reduces oxidative damage, we hypothesized that Ggt1dwg/dwg mice would be susceptible to ARHL. Surprisingly, otoacoustic emissions and cochlear microphonic potentials, which reflect cochlear outer hair cell (OHC) function, were largely unaffected in mutant mice, whereas auditory brainstem responses and the compound action potential were grossly abnormal. These functional deficits were associated with an unusual and selective loss of inner hair cells (IHC), but retention of OHC and auditory nerve fibers. Remarkably, hearing deficits and IHC loss were completely prevented by N-acetyl-L-cysteine, which induces de novo synthesis of GSH; however, hearing deficits and IHC loss reappeared when treatment was discontinued. Ggt1dwg/dwgmice represent an important new model for investigating ARHL, therapeutic interventions, and understanding the perceptual and electrophysiological consequences of sensory deprivation caused by the loss of sensory input exclusively from IHC.
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Affiliation(s)
- Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Haiyan Jiang
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | | | | | - Cong Tian
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Adam Sheppard
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA
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5
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Noack V, Pak K, Jalota R, Kurabi A, Ryan AF. An Antioxidant Screen Identifies Candidates for Protection of Cochlear Hair Cells from Gentamicin Toxicity. Front Cell Neurosci 2017; 11:242. [PMID: 28867994 PMCID: PMC5563352 DOI: 10.3389/fncel.2017.00242] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/31/2017] [Indexed: 12/24/2022] Open
Abstract
Reactive oxygen species are important elements in ototoxic damage to hair cells (HCs), appearing early in the damage process. Higher levels of natural antioxidants are positively correlated with resistance to ototoxins and many studies have shown that exogenous antioxidants can protect HCs from damage. While a very wide variety of antioxidants with different characteristics and intracellular targets exist, most ototoxicity studies have focused upon one or a few well-characterized compounds. Relatively little research has attempted to determine the comparative efficacy of large variety of different antioxidants. This has been in part due to the lack of translation between cell culture and in vivo measures of efficacy. To circumvent this limitation, we used an in vitro assay based on micro-explants from the basal and middle turns of the neonatal mouse organ of Corti to screen a commercial redox library of diverse antioxidant compounds for their ability to protect mammalian HCs from a high dose of the ototoxic antibiotic gentamicin. The library included several antioxidants that have previously been studied as potential treatments for HC damage, as well as many antioxidants that have never been applied to ototoxicity. The micro-explants were treated with 200 μM gentamicin alone, gentamicin plus one of three dosages of a redox compound, the highest dosage of compound alone, or were untreated. HC counts were determined before the gentamicin insult and at 1, 2, and 3 days afterward to evaluate the HC survival. From a total of 81 antioxidant compounds, 13 exhibited significant protection of HCs. These included members of a variety of antioxidant classes with several novel antioxidants, not previously tested on HCs, appearing to alleviate the damaging gentamicin effect. Some compounds previously shown to be protective of HCs were correspondingly protective in this in vitro screen, while others were not. Finally, one of the three pro-oxidant compounds included in the library as well as six antioxidants exhibited evidence of toxicity in the absence of gentamicin. The results demonstrate the wide variability in the ability of antioxidants to protect HCs from high-dose gentamicin damage, and identify promising candidate leads for further study as potential drug targets. HIGHLIGHTS • A medium-throughput assay based on micro-explants of the organ of Corti was developed to screen mammalian cochlear hair cells for protection from damage by ototoxins.• Eighty one antioxidants and 3 pro-oxidants were evaluated for hair cell protection from high-dose gentamicin.• Thirteen antioxidants were significantly protective, while 6 proved to be damaging.• The use of a common assay permitted an evaluation of the relative capacity of different antioxidants for the protection of hair cells.
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Affiliation(s)
- Volker Noack
- Department of Surgery and Otolaryngology, School of Medicine, University of California, San Diego, La JollaCA, United States
| | - Kwang Pak
- Department of Surgery and Otolaryngology, School of Medicine, University of California, San Diego, La JollaCA, United States.,VA San Diego Healthcare System, San DiegoCA, United States
| | - Rahul Jalota
- Department of Surgery and Otolaryngology, School of Medicine, University of California, San Diego, La JollaCA, United States
| | - Arwa Kurabi
- Department of Surgery and Otolaryngology, School of Medicine, University of California, San Diego, La JollaCA, United States
| | - Allen F Ryan
- Department of Surgery and Otolaryngology, School of Medicine, University of California, San Diego, La JollaCA, United States.,VA San Diego Healthcare System, San DiegoCA, United States
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Lee JH, Kim MS, Park BR. Vestibular end organ injury induced by middle ear treatment with ferric chloride in rats. Hum Exp Toxicol 2016; 36:146-159. [DOI: 10.1177/0960327116639365] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sensorineural hearing loss, ataxia, pyramidal signs, and vestibular deficits characterize superficial siderosis of the central nervous system. This study investigated changes in vestibular function, free radical formation, and phosphorylated cJun expression in the vestibular end organs after middle ear treatment with a ferric chloride (FeCl3) solution. A single injection of 70% FeCl3 solution into the unilateral middle ear cavity caused static vestibular symptoms, such as spontaneous nystagmus and head tilt. Asymmetric expression of c-Fos protein was observed in the bilateral vestibular nuclei and prepositus hypoglossal nuclei within 6 h after injection. Histopathologic examinations revealed partial hair cell loss, degeneration of the supporting stroma, and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells in the neuroepithelial layer of the crista ampullaris in FeCl3-treated animals. 5-(And-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate, acetyl ester and diaminofluorescein–2 diacetate fluorescence and immunoreactivity for nitrotyrosine increased markedly in the sensory neuroepithelial layer and nerve bundles of the crista ampullaris after 2 h. Strong immunoreactivity for phospho-cJun and cJun was observed in the type I hair cells of the crista ampullaris 120 h after injection. Thus, a single short-term treatment with a high concentration of FeCl3 in the unilateral middle ear cavity can induce activation of intracellular signals for cJun protein and oxidative stress through the formation of reactive oxygen species and nitric oxide in vestibular sensory receptors, resulting in vestibular dysfunction. These results suggest that activation of intracellular signals for cJun protein and oxidative stress may be a key component of the pathogenesis of vestibular deficits in patients with superficial siderosis.
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Affiliation(s)
- JH Lee
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, USA
| | - MS Kim
- Department of Physiology, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan, Korea
| | - BR Park
- Department of Physiology, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan, Korea
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Choi J, Chang J, Jun HJ, Im GJ, Chae SW, Lee SH, Kwon SY, Jung HH, Chung AY, Park HC. Protective role of edaravone against neomycin-induced ototoxicity in zebrafish. J Appl Toxicol 2014; 34:554-61. [PMID: 24795994 DOI: 10.1002/jat.2964] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Aminoglycosides such as neomycin are one of the most commonly prescribed types of antibiotics worldwide. However, these drugs appear to generate free radicals within the inner ear, which can result in permanent hearing loss. We evaluated the effects of edaravone, a neuroprotective agent, on neomycin-induced ototoxicity in transgenic zebrafish. The 5-day post fertilization (dpf) zebrafish larvae were exposed to 125 μM neomycin and various concentrations of edaravone for 1 h. Hair cell survival was calculated as average numbers of the hair cells in the control group, which was not exposed to neomycin. Ultrastructural changes were evaluated using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Edaravone protected against neomycin-induced hair cell loss in the neuromasts (1000 μM: 11.6 ± 1.1 cells, neomycin only: 5.5 ± 0.5 cells; n = 10, P<0.05) and decreased the TUNEL reaction for detecting apoptosis. In ultrastructural analysis, structures of mitochondria and hair cells within neuromasts were preserved in zebrafish exposed to 125 μM neomycin and 1000 μM edaravone for 1 h. Edaravone protected against neomycin-induced hair cell loss by preventing apoptosis.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Antipyrine/analogs & derivatives
- Antipyrine/pharmacology
- Apoptosis/drug effects
- Cells, Cultured
- Dose-Response Relationship, Drug
- Edaravone
- Embryo, Nonmammalian/drug effects
- Embryo, Nonmammalian/ultrastructure
- Hair Cells, Auditory/drug effects
- Hair Cells, Auditory/ultrastructure
- In Situ Nick-End Labeling
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Microscopy, Electron, Transmission
- Mitochondria/drug effects
- Mitochondria/ultrastructure
- Neomycin/toxicity
- Neuroprotective Agents/pharmacology
- Zebrafish/embryology
- Zebrafish/genetics
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Inoue Y, Yabe T, Okada K, Nakamura Y. Effect of edaravone on acute brainstem–cerebellar infarction with vertigo and sudden hearing loss. Auris Nasus Larynx 2014; 41:303-6. [DOI: 10.1016/j.anl.2013.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 09/26/2013] [Accepted: 10/04/2013] [Indexed: 11/29/2022]
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Hong SJ, Im GJ, Chang J, Chae SW, Lee SH, Kwon SY, Jung HH, Chung AY, Park HC, Choi J. Protective effects of edaravone against cisplatin-induced hair cell damage in zebrafish. Int J Pediatr Otorhinolaryngol 2013; 77:1025-31. [PMID: 23628221 DOI: 10.1016/j.ijporl.2013.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/31/2013] [Accepted: 04/06/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Edaravone is known to have a potent free radical scavenging effect. The objective of the present study was to evaluate the effects of edaravone on cisplatin-induced ototoxicity in transgenic zebrafish (Brn3C: EGFP). METHODS Five day post-fertilization zebrafish larvae were exposed to 1000 μM cisplatin and 50 μM, 100 μM, 250 μM, 500 μM, 750 μM, and 1000 μM concentrations of edaravone for 4h. Hair cells within neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed by fluorescence microscopy and confocal microscopy (n=10). Hair cell survival was calculated as a percentage of the hair cells in the control group that were not exposed to cisplatin. Ultrastructural changes were evaluated using scanning electron microscopy and transmission electron microscopy. RESULTS Edaravone protected cisplatin-induced hair cell loss of neuromasts (edaravone 750 μM: 8.7 ± 1.5 cells, cisplatin 1000 μM only: 3.7 ± 0.9 cells; n=10, p<0.0001) and decreased the Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) reaction. Structures of mitochondria and hair cell within neuromasts in ultrastructural analysis were preserved in zebrafish exposed to 1000 μM cisplatin and 750 μM edaravone for 4h. CONCLUSIONS Edaravone attenuated cisplatin-induced hair cell damage in zebrafish. The results of the current study suggest that cisplatin induces apoptosis, and the apoptotic cell death can be prevented by treatment with edaravone in zebrafish.
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Affiliation(s)
- Seok Jin Hong
- Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Ansan-City, South Korea
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Gyo K. Experimental study of transient cochlear ischemia as a cause of sudden deafness. World J Otorhinolaryngol 2013; 3:1-15. [DOI: 10.5319/wjo.v3.i1.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/18/2013] [Accepted: 02/06/2013] [Indexed: 02/06/2023] Open
Abstract
The etiology of sudden deafness or idiopathic sudden sensorineural hearing loss (ISSHL) remains unclear. Over the past 15 years, we have investigated the mechanisms of ischemic-induced hearing loss using a gerbil model of transient cochlear ischemia. In the gerbil, cochlear ischemia can be induced by occluding the bilateral vertebral arteries simultaneously at the neck, because the posterior communicating arteries of the Circle of Willis close spontaneously around 1 mo after birth. When 15 min ischemia was loaded on this animal, permanent hearing loss of about 25 dB and the death of hair cells, especially inner hair cells were induced. These pathological changes were mainly due to lack of an energy source, glutamate excitotoxicity, and the production of free radicals, especially superoxide and nitrous oxide species. Ischemic damage could be prevented by various procedures, such as cooling the cochlea, intratympanic administration of insulin-like growth factor 1 or AM-111 (an anti-apoptotic agent), and systemic administration of prednisolone (steroid), edarabone (free radical scavenger), ginsenoside Rb1 (Kanpo), hematopoietic stem cells, glia-cell derived neurotrophic factor, and liposome-encapsulated hemoglobin (artificial red blood cells). We also found that the cochlea was protected by the ischemic tolerance, indicating that minor cochlear ischemia alleviates or prevents inner ear damage in subsequent severe cochlear ischemia. As ISSHL usually occurs suddenly, with no preceding sign or symptom, we suggest that most ISSHL cases are caused by circulatory disturbance, probably at the stria vascularis.
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11
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Effect of high dose intravenous vitamin C on idiopathic sudden sensorineural hearing loss: a prospective single-blind randomized controlled trial. Eur Arch Otorhinolaryngol 2012. [PMID: 23208525 DOI: 10.1007/s00405-012-2294-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The aim of this prospective single-blind randomized controlled study was to evaluate the therapeutic efficacy of high dose intravenous vitamin C (HDVC) added to systemic steroid in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). Between August 2010 and August 2011, 72 ISSNHL patients who participated in this study were randomly allocated to two groups: 36 to a control group, members of which were given systemic steroid treatment for 15 days, and 36 to a HDVC group, members of which were given HDVC (200 mg/kg/day) for 10 days in addition to steroid therapy followed by oral vitamin C (2,000 mg) for 30 days after discharge. Finally, we analyzed each group: 35 as a control group and 32 as a HDVC group. Auditory evaluations were performed by pure tone audiometry (PTA) before and ~1 month after treatment using Siegel's criteria. HDVC group showed significantly greater complete and partial recovery improvement (p = 0.035). In addition, the complete recovery rate in the HDVC group was more than twice that of the control group (p = 0.031). In the HDVC group, PTA improved from 67.6 ± 19.8 dB HL before treatment to 37.1 ± 28.8 dB HL at 1 month after treatment, whereas in the control group, PTA improved from 70.3 ± 12.4 to 47.6 ± 25.2 dB HL, which represented a significant intergroup difference (p = 0.030). In conclusion, HDVC may enhance hearing recovery in ISSNHL patients, which suggests that HDVC reduces levels of reactive oxygen metabolites produced by inner ear ischemia or inflammation, and that HDVC could be considered for the treatment of ISSNHL.
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Abstract
OBJECTIVE AM-111, a cell-permeable peptide inhibitor of c-Jun N-terminal kinase, was investigated for its protective effects against ischemic damage of the cochlea in gerbils. METHODS Transient cochlear ischemia was introduced in animals by occluding the bilateral vertebral arteries for l5 minutes. Then, 10 μl of AM-111 at a concentration of l, 10, or 100 μM in hyaluronic acid gel formulation was applied onto the round window 30 minutes after the insult. Gel without active substance was used in a control group. Treatment effects were evaluated by auditory brainstem response (ABR) and histology of the inner ear. RESULTS In controls, transient cochlear ischemia caused a 25.0 ± 5.0 dB increase in the ABR threshold at 8 kHz and a decrease of 13.3 ± 2.3% in inner hair cells at the basal turn on Day 7. Ischemic damage was mild at 2 and 4 kHz. When the animals were treated with AM-111 at 100 μM, cochlear damage was significantly reduced: the increase in ABR threshold was 3.3 ± 2.4 dB at 8 kHz, and the inner hair cell loss was 3.1 ± 0.6% at the basal turn on Day 7. The effects of AM-111 were concentration dependent: 100 μM was more effective than 1 or 10 μM. CONCLUSION Direct application of AM-111 in gel formulation on the round window was effective in preventing acute hearing loss because of transient cochlear ischemia.
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Tabuchi K, Nishimura B, Tanaka S, Hayashi K, Hirose Y, Hara A. Ischemia-reperfusion injury of the cochlea: pharmacological strategies for cochlear protection and implications of glutamate and reactive oxygen species. Curr Neuropharmacol 2011; 8:128-34. [PMID: 21119884 PMCID: PMC2923367 DOI: 10.2174/157015910791233123] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 01/15/2010] [Accepted: 02/04/2010] [Indexed: 11/22/2022] Open
Abstract
A large amount of energy produced by active aerobic metabolism is necessary for the cochlea to maintain its function. This makes the cochlea vulnerable to blockade of cochlear blood flow and interruption of the oxygen supply. Although certain forms of human idiopathic sudden sensorineural hearing loss reportedly arise from ischemic injury, the pathological mechanism of cochlear ischemia-reperfusion injury has not been fully elucidated. Recent animal studies have shed light on the mechanisms of cochlear ischemia-reperfusion injury. It will help in the understanding of the pathology of cochlear ischemia-reperfusion injury to classify this injury into ischemic injury and reperfusion injury. Excitotoxicity, mainly observed during the ischemic period, aggravates the injury of primary auditory neurons. On the other hand, oxidative damage induced by hydroxyl radicals and nitric oxide enhances cochlear reperfusion injury. This article briefly summarizes the generation mechanisms of cochlear ischemia-reperfusion injury and potential therapeutic targets that could be developed for the effective management of this injury type.
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Affiliation(s)
- Keiji Tabuchi
- Department of Otolaryngology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.
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14
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Abstract
Perturbation of cochlear microcirculation, that is, ischemia is a major cause of hearing impairment. Earlier studies examined the short-term (≤7 days) effect of cochlear ischemia. This study characterized the long-term (4 weeks) functional and morphological changes in adult guinea pig cochleae subject to transient ischemia by clamping the labyrinthine artery for 0.25-3 h. Notably, cochlear ischemia for over 1 h caused an increase of auditory brainstem response thresholds and loss of high-frequency hearing, basal-turn hair cells, and spiral ganglions. Auditory recovery may be possible after 30-min ischemia. The extent of the functional and morphological changes depended on the ischemia period, and the changes progressed in extent from the apical to the basal turn in an orderly fashion.
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Abstract
CONCLUSION Hydrogen gas effectively protected against the morphological and functional vestibular hair cell damage by reactive oxygen species (ROS). OBJECTIVE ROS are generally produced by oxidative stress. In the inner ear, ROS levels increase as a result of noise trauma and ototoxic drugs and induce damage. It is thus important to control ROS levels in the inner ear. The protective effects of hydrogen gas in cochlear hair cells have been reported previously. METHODS This study examined the effects of hydrogen gas on mouse vestibular hair cell damage by ROS using antimycin A. RESULTS In the group *exposed to hydrogen gas, vestibular hair cells were morphologically well preserved and their mechano-electrical transduction activities were relatively well maintained when compared with controls. Hydroxyphenyl fluorescein (HPF) fluorescence in vestibular tissue was also reduced by hydrogen gas.
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Affiliation(s)
- Akiko Taura
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University, Kyoto, Japan
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Edaravone, a free radical scavenger, in the treatment of idiopathic sudden sensorineural hearing loss with profound hearing loss. Auris Nasus Larynx 2010; 37:42-6. [DOI: 10.1016/j.anl.2009.04.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/26/2009] [Accepted: 04/21/2009] [Indexed: 11/24/2022]
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Asplund MS, Lidian A, Linder B, Takumida M, Anniko M. Protective effect of edaravone against tobramycin-induced ototoxicity. Acta Otolaryngol 2009; 129:8-13. [PMID: 18607936 DOI: 10.1080/00016480802008199] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
CONCLUSION It is suggested that simultaneous treatment with the radical scavenger edaravone has an effective protective effect against tobramycin ototoxicity in rat. Even if the edaravone treatment is postponed for 7 days, it can still prevent hearing loss, but a 14 day delay cannot protect from ototoxicity. OBJECTIVES With the aim of alleviating hearing loss caused by aminoglycoside ototoxicity, we performed a trial to assess the hearing protective efficacy of the radical scavenger edaravone. MATERIALS AND METHODS In part one of the study, 21 male Sprague-Dawley albino rats were used; 2 rats served as controls for the safety of edaravone. Eight rats each received 10 subcutaneous injections (s.c.) of tobramycin (160 mg/kg b.w.) once daily and saline injection intraperitoneally for 2 weeks. Eleven rats were given 10 s.c. tobramycin injections simultaneously with an intraperitoneal injection of edaravone (3 mg/kg b.w.). In part two, tobramycin was injected in 13 rats (as above). Five of these received two edaravone injections 7 days later and four rats similarly 14 days later. Auditory brainstem response (ABR) was used to assess hearing. RESULTS All rats treated only with tobramycin showed a deterioration of hearing. None of the rats given simultaneous treatment with tobramycin and edaravone demonstrated hearing loss. A 7 day delay in edaravone injection still prevented hearing loss, but a 14 day delay had only a temporary prophylactic effect.
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Tanigawa T, Tanaka H, Hayashi K, Nakayama M, Iwasaki S, Banno S, Takumida M, Brodie H, Inafuku S. Effects of hydrogen peroxide on vestibular hair cells in the guinea pig: importance of cell membrane impairment preceding cell death. Acta Otolaryngol 2008; 128:1196-202. [PMID: 18607894 DOI: 10.1080/00016480801918539] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
CONCLUSION Our findings indicate that oxidative stress induces morphological changes in vestibular hair cells and subsequently leads to cell death after 2.5 h. OBJECTIVES The aim of this study was to confirm the direct effects of oxidative stress on vestibular hair cells. MATERIALS AND METHODS Vestibular hair cells isolated from guinea pigs were loaded with 1 or 10 mM H2O2, and morphological changes were observed. In addition, in a viability/cytotoxicity assay system, the numbers of dead cells in isolated cristae ampullares were counted 1, 3, and 5 h after loading with H2O2 or artificial perilymph (control). RESULTS Reactive oxygen, in the form of H2O2, directly affects the cell membrane of isolated vestibular hair cells and causes swelling of the cell body, bleb formation, and shortening of the neck region. Morphological changes occur within 30 min after loading with H2O2, but a significant increase in the number of dead cells is noted only after 3 h.
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Abstract
Over the last decade, important advances have been made to support the fact that reactive oxygen species (ROS) are generated and play a harmful role during the acute and late stages of cerebral ischemia. Several drugs, such as radical scavengers and antioxidants, have been evaluated in preclinical and clinical studies. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut, Mitsubishi Tanabe Pharma Corporation) is a novel antioxidant that is currently used in Japan for the treatment of patients in the acute stage of cerebral infarction. Edaravone scavenges ROS and inhibits proinflammatory responses after brain ischemia in animals and humans. In particular, postischemic inflammation, leading to brain edema and infarction due to neuronal damage and endothelial cell death, can be ameliorated by edaravone. In addition to these antistroke effects, edaravone has also been shown to prevent oxidative damage to various extracerebral organs. Therefore, in addition to its usefulness in the treatment of stroke, edaravone is expected to play an integral role in the treatment of many oxidative stress-related diseases.
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Affiliation(s)
- Toshiaki Watanabe
- Department of REDOX Medicinal Science, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
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Hatano M, Uramoto N, Okabe Y, Furukawa M, Ito M. Vitamin E and vitamin C in the treatment of idiopathic sudden sensorineural hearing loss. Acta Otolaryngol 2008; 128:116-21. [PMID: 17851951 DOI: 10.1080/00016480701387132] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
CONCLUSION The results of this study suggest that the administration of vitamin E and vitamin C to patients with idiopathic sudden sensorineural hearing loss (ISSHL) has beneficial effects by reducing the level of reactive oxygen metabolites produced by inner ear ischaemia and reperfusion injury after treatment. OBJECTIVES The purpose of this study was to investigate the efficacy of antioxidant vitamin E and vitamin C in the treatment of ISSHL. PATIENTS AND METHODS In a retrospective chart review, a total of 87 patients were enrolled who fulfilled the following inclusion criteria: 1) sudden onset of sensorineural hearing loss, 2) cause of hearing loss unknown, 3) hearing loss did not fluctuate, 4) arithmetic mean of hearing levels at 250, 500, 1000, 2000 and 4000 Hz exceeded 40 dB and 5) treatment was started within 14 days from the onset of hearing loss. All the patients were treated with steroids and/or alprostadil. In the study group, patients additionally received vitamin E (tocopherol nicotinate, 600 mg/day) and vitamin C (1200 mg/day) orally. RESULTS The hearing gain after therapy was 29.4 dB and the improvement rate was 63.3% in the study group, compared with 18.5 dB and 44.0% in the control group. Significant improvement was seen in the hearing gain and recovery rate in the study group.
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Affiliation(s)
- Miyako Hatano
- Department of Otolaryngology-Head and Neck Surgery, Kouseiren Takaoka Hospital, Takaoka, Japan
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Yoshida T, Hakuba N, Morizane I, Fujita K, Cao F, Zhu P, Uchida N, Kameda K, Sakanaka M, Gyo K, Hata R. Hematopoietic stem cells prevent hair cell death after transient cochlear ischemia through paracrine effects. Neuroscience 2007; 145:923-30. [PMID: 17320298 DOI: 10.1016/j.neuroscience.2006.12.067] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2006] [Revised: 12/21/2006] [Accepted: 12/23/2006] [Indexed: 01/01/2023]
Abstract
Transplantation of hematopoietic stem cells (HSCs) is regarded to be a potential approach for promoting repair of damaged organs. Here, we investigated the influence of hematopoietic stem cells on progressive hair cell degeneration after transient cochlear ischemia in gerbils. Transient cochlear ischemia was produced by extracranial occlusion of the bilateral vertebral arteries just before their entry into the transverse foramen of the cervical vertebra. Intrascalar injection of HSCs prevented ischemia-induced hair cell degeneration and ameliorated hearing impairment. We also showed that the protein level of glial cell line-derived neurotrophic factor (GDNF) in the organ of Corti was upregulated after cochlear ischemia and that treatment with HSCs augmented this ischemia-induced upregulation of GDNF. A tracking study revealed that HSCs injected into the cochlea were retained in the perilymphatic space of the cochlea, although they neither transdifferentiated into cochlear cell types nor fused with the injured hair cells after ischemia, suggesting that HSCs had therapeutic potential possibly through paracrine effects. Thus, we propose HSCs as a potential new therapeutic strategy for hearing loss.
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Affiliation(s)
- T Yoshida
- Department of Otolaryngology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
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Terashita T, Saito S, Miyawaki K, Hyodo M, Kobayashi N, Shimokawa T, Saito K, Matsuda S, Gyo K. Localization of prosaposin in rat cochlea. Neurosci Res 2006; 57:372-8. [PMID: 17156877 DOI: 10.1016/j.neures.2006.11.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 10/20/2006] [Accepted: 11/07/2006] [Indexed: 01/23/2023]
Abstract
Prosaposin, the precursor of the sphingolipid hydrolase activator proteins called saposins A, B, C, and D, is abundant in the nervous system and muscles. Besides its role as the precursor of saposins, prosaposin is reported to function as a neurotrophic factor, initiating neural differentiation and preventing neuronal cell death in vivo and in vitro. In this study, we examined the localization and synthesis of prosaposin in the rat cochlea. Intense prosaposin immunoreactivity was observed in the organ of Corti, stria vascularis, and spiral ganglion. In an immuno-electron microscopic study, prosaposin immunoreactivity was found mainly in lysosomal granules of the cells in these regions. In the lysosome, prosaposin does not always colocalize with cathepsin D, but was localized mainly in the dark area of the lysosome. Prosaposin mRNA was observed in these same regions. Our results suggest that prosaposin plays a role in homeostasis in the peripheral auditory system.
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Affiliation(s)
- Takehiro Terashita
- Department of Basic Medical Research and Education, Ehime University School of Medicine, Shitsukawa, Toon, Ehime, Japan.
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Takumida M, Anniko M. Protective effect of edaravone against the ototoxicity of Pseudomonas aeruginosa exotoxin A. Acta Otolaryngol 2006; 126:15-9. [PMID: 16308249 DOI: 10.1080/00016480510038563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
CONCLUSION Our findings suggest that edaravone can protect against cochlear damage caused by Pseudomonas aeruginosa exotoxin A (PaExoA). OBJECTIVE To analyze the protective effect of a free radical scavenger, edaravone, against the ototoxicity resulting from exposure of the middle ear to PaExoA. MATERIAL AND METHODS In nine groups of albino rats the following solutions were instilled either via the tympanic membrane into the round window niche [intratympanically (i.t.)] or intravenously (i.v.): edaravone (i.v.); edaravone (i.t.); PaExoA (i.t.) + edaravone (i.t.; simultaneously); PaExoA (i.t.) + edaravone (i.t.; 1 h after); PaExoA (i.t.) + edaravone (i.t.; 24 h after); PaExoA (i.t.) + edaravone (i.v.; simultaneously); PaExoA (i.t.) + edaravone (i.v.; 1 h after); PaExoA (i.t.) + edaravone (i.v.; 24 h after); PaExoA (i.t.) + saline (i.v.). Frequency-specific (2-20 kHz) auditory brainstem responses were measured to determine hearing thresholds before and 2, 5 and 10 days after instillation. RESULTS PaExoA had penetrated from the middle ear into the cochlea and caused hearing loss. This impairment was blocked by intratympanic injection of edaravone when given simultaneously or 1 h after the first instillation of PaExoA, or by intravenous injection of edaravone when given simultaneously. There were significant differences in protective effect between the intratympanic and intravenous routes.
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Affiliation(s)
- Masaya Takumida
- Department of Otolaryngology, Faculty of Medicine, Hiroshima University, Minamiku, Hiroshima, Japan.
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Tanaka K, Takemoto T, Sugahara K, Okuda T, Mikuriya T, Takeno K, Hashimoto M, Shimogori H, Yamashita H. Post-exposure administration of edaravone attenuates noise-induced hearing loss. Eur J Pharmacol 2005; 522:116-21. [PMID: 16202992 DOI: 10.1016/j.ejphar.2005.08.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 08/08/2005] [Accepted: 08/15/2005] [Indexed: 10/25/2022]
Abstract
We investigated the effects of the antioxidant edaravone against acoustic trauma in guinea pigs. Edaravone (1.722 x 10(-2) M) was infused into the right ear by an osmotic pump, and the left ear was untreated for control. Animals received edaravone 9 h before (-9 h group, n = 7) and 9 h (+9 h group, n = 8), 21 h (+21 h group, n = 7) and 33 h (+33 h group, n = 4) after 3-h exposure to 130-dB noise. Seven days after noise exposure, we examined the shift in auditory brainstem response thresholds and histopathologic characteristics of the sensory epithelia. The smallest shift in auditory brainstem response threshold and smallest proportion of missing outer hair cells were observed in the +9 h group. This result was supported by immunohistochemical analysis of 4-hydroxy-2-nonenal. Our data suggest that edaravone may be clinically effective in the treatment of acoustic trauma, especially if given within 21 h of noise exposure.
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Affiliation(s)
- Kuniyoshi Tanaka
- Department of Otolaryngology, Yamaguchi University School of Medicine, Ube, Japan
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