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Chen HK, Hsieh YW, Hsu HY, Liu TY, Zhang YT, Lin CD, Tsai FJ. Increased risk of hearing loss associated with MT-RNR1 gene mutations: a real-world investigation among Han Taiwanese Population. BMC Med Genomics 2024; 17:155. [PMID: 38840095 PMCID: PMC11155076 DOI: 10.1186/s12920-024-01921-8] [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: 04/14/2024] [Accepted: 05/23/2024] [Indexed: 06/07/2024] Open
Abstract
BACKGROUND Previous studies have implicated inherited mutations in mitochondrial DNA (mtDNA) in sensorineural hearing loss (SNHL). However, the definitive association between mitochondrial 12S rRNA (MT-RNR1) variants and hearing loss in the population has not been well established, particularly in Asia. The objective of this retrospective cohort study was to assess the association between MT-RNR1 variants and the risk of SNHL in patients in Taiwan. METHODS The cohort included 306,068 participants from Taiwan between January 2003 and December 2020. Participants were classified based on genetic variants, particularly mitochondrial mutations (rs267606618, rs267606619, rs267606617). MT-RNR1 variant cases were matched 1:10 with non-mutant patients by age, gender, and visit year, excluding those with pre-existing hearing loss. The primary endpoint was SNHL, identified using specific ICD-TM codes with a 90% positive predictive value. Medication exposure history was determined via self-report or electronic medical records in the hospital. Cox proportional hazard regression models were used to assess the association between MT-RNR1 variants and hearing loss, adjusting for various covariates. Kaplan-Meier survival curves and log-rank tests compared hearing loss incidence between groups. RESULTS The mean age of the mtDNA variants group is 32.4 years, with a standard deviation of 19.2 years. The incidence density of hearing loss for the mutation group was 36.42 per 10,000 person-years (95% Confidence Interval [CI], 27.21-47.73), which was higher than the 23.77per 10,000 person-years (95% CI, 21.32-26.42) in the wild-type group (p = 0.0036). Additionally, diabetes mellitus was associated with an increased risk of developing SNHL in individuals with MT-RNR1 variants (adjusted hazard ratio = 1.76 [95% CI, 1.00-3.09], p < 0.05). CONCLUSION This study highlights the increased risk of hearing loss in patients carrying MT-RNR1 variants, particularly those with diabetes mellitus. Future research that integrates genetic and clinical data is crucial for developing more precise interventions to monitor and treat hearing loss in this vulnerable population.
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Affiliation(s)
- Hou-Kuang Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, China Medical University Hospital, Taichung, Taiwan
| | - Yow-Wen Hsieh
- Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan
- School of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan
| | - Hsing-Yu Hsu
- Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan
- Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ting-Yuan Liu
- Million-person precision medicine initiative, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Ting Zhang
- Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan
| | - Chia-Der Lin
- Department of Otorhinolaryngology-Head and Neck Surgery, China Medical University Hospital, Taichung, Taiwan.
| | - Fuu-Jen Tsai
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.
- Division of Pediatric Genetics, Children's Hospital of China Medical University, Taichung, Taiwan.
- Department of Biotechnology and Bioinformatics, Asia University, Taichung, Taiwan.
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2
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Lao H, Zhu Y, Yang M, Wang L, Tang J, Xiong H. Characteristics of spatial protein expression in the mouse cochlear sensory epithelia: Implications for age-related hearing loss. Hear Res 2024; 446:109006. [PMID: 38583350 DOI: 10.1016/j.heares.2024.109006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/27/2024] [Accepted: 04/01/2024] [Indexed: 04/09/2024]
Abstract
Hair cells in the cochlear sensory epithelia serve as mechanosensory receptors, converting sound into neuronal signals. The basal sensory epithelia are responsible for transducing high-frequency sounds, while the apex handles low-frequency sounds. Age-related hearing loss predominantly affects hearing at high frequencies and is indicative of damage to the basal sensory epithelia. However, the precise mechanism underlying this site-selective injury remains unclear. In this study, we employed a microscale proteomics approach to examine and compare protein expression in different regions of the cochlear sensory epithelia (upper half and lower half) in 1.5-month-old (normal hearing) and 6-month-old (severe high-frequency hearing loss without hair cell loss) C57BL/6J mice. A total of 2,386 proteins were detected, and no significant differences in protein expression were detected in the upper half of the cochlear sensory epithelia between the two age groups. The expression of 20 proteins in the lower half of the cochlear sensory epithelia significantly differed between the two age groups (e.g., MATN1, MATN4, and AQP1). Moreover, there were 311 and 226 differentially expressed proteins between the upper and lower halves of the cochlear sensory epithelia in 1.5-month-old and 6-month-old mice, respectively. The expression levels of selected proteins were validated by Western blotting. These findings suggest that the spatial differences in protein expression within the cochlear sensory epithelia may play a role in determining the susceptibility of cells at different sites of the cochlea to age-related damage.
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Affiliation(s)
- Huilin Lao
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Yafeng Zhu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Mei Yang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Lingshuo Wang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jie Tang
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China.
| | - Hao Xiong
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China.
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3
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Liu Z, Zhang H, Hong G, Bi X, Hu J, Zhang T, An Y, Guo N, Dong F, Xiao Y, Li W, Zhao X, Chu B, Guo S, Zhang X, Chai R, Fu X. Inhibition of Gpx4-mediated ferroptosis alleviates cisplatin-induced hearing loss in C57BL/6 mice. Mol Ther 2024; 32:1387-1406. [PMID: 38414247 PMCID: PMC11081921 DOI: 10.1016/j.ymthe.2024.02.029] [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: 10/23/2023] [Revised: 01/29/2024] [Accepted: 02/24/2024] [Indexed: 02/29/2024] Open
Abstract
Cisplatin-induced hearing loss is a common side effect of cancer chemotherapy in clinics; however, the mechanism of cisplatin-induced ototoxicity is still not completely clarified. Cisplatin-induced ototoxicity is mainly associated with the production of reactive oxygen species, activation of apoptosis, and accumulation of intracellular lipid peroxidation, which also is involved in ferroptosis induction. In this study, the expression of TfR1, a ferroptosis biomarker, was upregulated in the outer hair cells of cisplatin-treated mice. Moreover, several key ferroptosis regulator genes were altered in cisplatin-damaged cochlear explants based on RNA sequencing, implying the induction of ferroptosis. Ferroptosis-related Gpx4 and Fsp1 knockout mice were established to investigate the specific mechanisms associated with ferroptosis in cochleae. Severe outer hair cell loss and progressive damage of synapses in inner hair cells were observed in Atoh1-Gpx4-/- mice. However, Fsp1-/- mice showed no significant hearing phenotype, demonstrating that Gpx4, but not Fsp1, may play an important role in the functional maintenance of HCs. Moreover, findings showed that FDA-approved luteolin could specifically inhibit ferroptosis and alleviate cisplatin-induced ototoxicity through decreased expression of transferrin and intracellular concentration of ferrous ions. This study indicated that ferroptosis inhibition through the reduction of intracellular ferrous ions might be a potential strategy to prevent cisplatin-induced hearing loss.
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MESH Headings
- Animals
- Cisplatin/adverse effects
- Ferroptosis/drug effects
- Ferroptosis/genetics
- Mice
- Hearing Loss/chemically induced
- Hearing Loss/genetics
- Hearing Loss/metabolism
- Mice, Knockout
- Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism
- Phospholipid Hydroperoxide Glutathione Peroxidase/genetics
- Mice, Inbred C57BL
- Disease Models, Animal
- Receptors, Transferrin/metabolism
- Receptors, Transferrin/genetics
- Reactive Oxygen Species/metabolism
- Lipid Peroxidation/drug effects
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/drug effects
- Hair Cells, Auditory, Outer/pathology
- Ototoxicity/etiology
- Ototoxicity/metabolism
- Antineoplastic Agents/adverse effects
- Apoptosis/drug effects
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Affiliation(s)
- Ziyi Liu
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Hanbing Zhang
- Department of Otorhinolaryngology, Qilu Hospital of Shandong University, NHC Key Laboratory of Otorhinolaryngology (Shandong University), Jinan, Shandong 250012, China
| | - Guodong Hong
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Xiuli Bi
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Jun Hu
- Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Tiancheng Zhang
- Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yachun An
- School of Life Science, Shandong University, Qingdao, Shandong 266237, China
| | - Na Guo
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Fengyue Dong
- School of Life Science, Shandong University, Qingdao, Shandong 266237, China
| | - Yu Xiao
- School of Life Science, Shandong University, Qingdao, Shandong 266237, China
| | - Wen Li
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Xiaoxu Zhao
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Bo Chu
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250102, China
| | - Siwei Guo
- School of Life Science, Shandong University, Qingdao, Shandong 266237, China
| | - Xiaohan Zhang
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China
| | - Renjie Chai
- Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, Jiangsu 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China; Department of Neurology, Aerospace Center Hospital, School of Life Science, Beijing Institute of Technology, Beijing 100081, China; Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; Southeast University Shenzhen Research Institute, Shenzhen, Guangdong 518063, China.
| | - Xiaolong Fu
- Medical Science and Technology Innovation Center, Institute of Brain Science and Brain-inspired Research, Shandong Provincial Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China.
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Teraoka M, Hato N, Inufusa H, You F. Role of Oxidative Stress in Sensorineural Hearing Loss. Int J Mol Sci 2024; 25:4146. [PMID: 38673731 PMCID: PMC11050000 DOI: 10.3390/ijms25084146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/27/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Hearing is essential for communication, and its loss can cause a serious disruption to one's social life. Hearing loss is also recognized as a major risk factor for dementia; therefore, addressing hearing loss is a pressing global issue. Sensorineural hearing loss, the predominant type of hearing loss, is mainly due to damage to the inner ear along with a variety of pathologies including ischemia, noise, trauma, aging, and ototoxic drugs. In addition to genetic factors, oxidative stress has been identified as a common mechanism underlying several cochlear pathologies. The cochlea, which plays a major role in auditory function, requires high-energy metabolism and is, therefore, highly susceptible to oxidative stress, particularly in the mitochondria. Based on these pathological findings, the potential of antioxidants for the treatment of hearing loss has been demonstrated in several animal studies. However, results from human studies are insufficient, and future clinical trials are required. This review discusses the relationship between sensorineural hearing loss and reactive oxidative species (ROS), with particular emphasis on age-related hearing loss, noise-induced hearing loss, and ischemia-reperfusion injury. Based on these mechanisms, the current status and future perspectives of ROS-targeted therapy for sensorineural hearing loss are described.
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Affiliation(s)
- Masato Teraoka
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Ehime University, Toon 791-0295, Ehime, Japan;
| | - Naohito Hato
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Ehime University, Toon 791-0295, Ehime, Japan;
| | - Haruhiko Inufusa
- Division of Anti-Oxidant Research, Life Science Research Center, Gifu University, Yanagito 1-1, Gifu 501-1194, Japan; (H.I.); (F.Y.)
| | - Fukka You
- Division of Anti-Oxidant Research, Life Science Research Center, Gifu University, Yanagito 1-1, Gifu 501-1194, Japan; (H.I.); (F.Y.)
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5
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Herb M. NADPH Oxidase 3: Beyond the Inner Ear. Antioxidants (Basel) 2024; 13:219. [PMID: 38397817 PMCID: PMC10886416 DOI: 10.3390/antiox13020219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.
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Affiliation(s)
- Marc Herb
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50935 Cologne, Germany;
- German Centre for Infection Research, Partner Site Bonn-Cologne, 50931 Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
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6
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Pisani A, Paciello F, Montuoro R, Rolesi R, Galli J, Fetoni AR. Antioxidant Therapy as an Effective Strategy against Noise-Induced Hearing Loss: From Experimental Models to Clinic. Life (Basel) 2023; 13:life13041035. [PMID: 37109564 PMCID: PMC10144536 DOI: 10.3390/life13041035] [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: 03/08/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Cochlear redox unbalance is the main mechanism of damage involved in the pathogenesis of noise-induced-hearing loss. Indeed, the increased free radical production, in conjunction with a reduced efficacy of the endogenous antioxidant system, plays a key role in cochlear damage induced by noise exposure. For this reason, several studies focused on the possibility to use exogenous antioxidant to prevent or attenuate noise-induce injury. Thus, several antioxidant molecules, alone or in combination with other compounds, have been tested in both experimental and clinical settings. In our findings, we tested the protective effects of several antioxidant enzymes, spanning from organic compounds to natural compounds, such as nutraceuticals of polyphenols. In this review, we summarize and discuss the strengths and weaknesses of antioxidant supplementation focusing on polyphenols, Q-Ter, the soluble form of CoQ10, Vitamin E and N-acetil-cysteine, which showed great otoprotective effects in different animal models of noise induced hearing loss and which has been proposed in clinical trials.
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Affiliation(s)
- Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Raffaele Montuoro
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Rolando Rolesi
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Jacopo Galli
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
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7
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Kashio A, Yamada C, Yasuhara K, Kamogashira T, Someya S, Yamasoba T. Taurine, Coenzyme Q 10, and Hydrogen Water Prevents Germanium Dioxide-Induced Mitochondrial Dysfunction and Associated Sensorineural Hearing Loss in mouse. Hear Res 2023; 428:108678. [PMID: 36577362 DOI: 10.1016/j.heares.2022.108678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 11/26/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Mitochondrial dysfunction has been implicated in numerous common diseases as well as aging and plays an important role in the pathogenesis of sensorineural hearing loss (SNHL). In the current study, we showed that supplementation with germanium dioxide (GeO2) in CBA/J mice resulted in SNHL due to the degeneration of the stria vascularis and spiral ganglion, which were associated with down-regulation of mitochondrial respiratory chain associated genes and up-regulation in apoptosis associated genes in the cochlea. Supplementation with taurine, coenzyme Q10, or hydrogen-rich water, attenuated the cochlear degeneration and associated SNHL induced by GeO2. These results suggest that daily supplements or consumption of antioxidants, such as taurine, coenzyme Q10, and hydrogen-rich water, may be a promising intervention to slow SNHL associated with mitochondrial dysfunction.
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Affiliation(s)
- Akinori Kashio
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Chikako Yamada
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Kazuo Yasuhara
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Teru Kamogashira
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan
| | - Shinichi Someya
- Department of Aging and Geriatric Research, University of Florida, Gainesville, Florida, United States of America
| | - Tatsuya Yamasoba
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
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Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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White K, Someya S. The roles of NADPH and isocitrate dehydrogenase in cochlear mitochondrial antioxidant defense and aging. Hear Res 2023; 427:108659. [PMID: 36493529 DOI: 10.1016/j.heares.2022.108659] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 11/04/2022] [Accepted: 11/23/2022] [Indexed: 11/26/2022]
Abstract
Hearing loss is the third most prevalent chronic health condition affecting older adults. Age-related hearing loss affects one in three adults over 65 years of age and is caused by both extrinsic and intrinsic factors, including genetics, aging, and exposure to noise and toxins. All cells possess antioxidant defense systems that play an important role in protecting cells against these factors. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) serves as a co-factor for antioxidant enzymes such as glutathione reductase and thioredoxin reductase and is produced by glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase 1 (IDH1) or malic enzyme 1 in the cytosol, while in the mitochondria, NADPH is generated from mitochondrial transhydrogenase, glutamate dehydrogenase, malic enzyme 3 or IDH2. There are three isoforms of IDH: cytosolic IDH1, and mitochondrial IDH2 and IDH3. Of these, IDH2 is thought to be the major supplier of NADPH to the mitochondrial antioxidant defense system. The NADP+/NADPH and NAD+/NADH couples are essential for maintaining a large array of biological processes, including cellular redox state, and energy metabolism, mitochondrial function. A growing body of evidence indicates that mitochondrial dysfunction contributes to age-related structural or functional changes of cochlear sensory hair cells and neurons, leading to hearing impairments. In this review, we describe the current understanding of the roles of NADPH and IDHs in cochlear mitochondrial antioxidant defense and aging.
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Affiliation(s)
- Karessa White
- Charlie Brigade Support Medical Company, 2/1 ABCT, United States Army, Fort Riley, KS, USA
| | - Shinichi Someya
- Department of Physiology and Aging, University of Florida, Gainesville, Florida, USA.
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10
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The Role of Mitophagy in Various Neurological Diseases as a Therapeutic Approach. Cell Mol Neurobiol 2022:10.1007/s10571-022-01302-8. [DOI: 10.1007/s10571-022-01302-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/24/2022] [Indexed: 11/05/2022]
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11
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Effects of pyrroloquinoline quinone on noise-induced and age-related hearing loss in mice. Sci Rep 2022; 12:15911. [PMID: 36151123 PMCID: PMC9508078 DOI: 10.1038/s41598-022-19842-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/05/2022] [Indexed: 11/10/2022] Open
Abstract
We investigated whether the oxidoreductase cofactor pyrroloquinoline quinone (PQQ) prevents noise-induced and age-related hearing loss (NIHL and ARHL) in mice. To assess NIHL, 8 week-old mice with and without PQQ administration were exposed to noise for 4 h. PQQ was orally administered for one week before and after noise exposure and subcutaneously once before noise exposure. For ARHL evaluation, mice were given drinking water with or without PQQ starting at 2 months of age. In the NIHL model, PQQ-treated mice had auditory brainstem response (ABR) thresholds of significantly reduced elevation at 8 kHz, a significantly increased number of hair cells at the basal turn, and significantly better maintained synapses beneath the inner hair cells compared to controls. In the ARHL model, PQQ significantly attenuated the age-related increase in ABR thresholds at 8 and 32 kHz at 10 months of age compared to controls. In addition, the hair cells, spiral ganglion cells, ribbon synapses, stria vascularis and nerve fibers were all significantly better maintained in PQQ-treated animals compared to controls at 10 months of age. These physiological and histological results demonstrate that PQQ protects the auditory system from NIHL and ARHL in mice.
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12
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Serra LSM, Araújo JGD, Novanta G, Lauand L, Silva EMD, Kückelhaus SAS, Sampaio ALL. Melatonin prevents age-related hearing loss in the murin experimental model. Braz J Otorhinolaryngol 2022; 88 Suppl 3:S103-S108. [DOI: 10.1016/j.bjorl.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 04/06/2022] [Accepted: 06/05/2022] [Indexed: 11/27/2022] Open
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Nitrative Stress and Auditory Dysfunction. Pharmaceuticals (Basel) 2022; 15:ph15060649. [PMID: 35745568 PMCID: PMC9227425 DOI: 10.3390/ph15060649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/12/2022] [Accepted: 05/20/2022] [Indexed: 11/24/2022] Open
Abstract
Nitrative stress is increasingly recognized as a critical mediator of apoptotic cell death in many pathological conditions. The accumulation of nitric oxide along with superoxide radicals leads to the generation of peroxynitrite that can eventually result in the nitration of susceptible proteins. Nitrotyrosine is widely used as a biomarker of nitrative stress and indicates oxidative damage to proteins. Ototoxic insults, such as exposure to noise and ototoxic drugs, enhance the generation of 3-nitrotyrosine in different cell types in the cochlea. Nitrated proteins can disrupt critical signaling pathways and eventually lead to apoptosis and loss of sensory receptor cells in the cochlea. Accumulating evidence shows that selective targeting of nitrative stress attenuates cellular damage. Anti-nitrative compounds, such as peroxynitrite decomposition catalysts and inducible nitric oxide synthase inhibitors, prevent nitrative stress-mediated auditory damage. However, the role of nitrative stress in acquired hearing loss and its potential significance as a promising interventional target is yet to be fully characterized. This review provides an overview of nitrative stress mechanisms, the induction of nitrative stress in the auditory tissue after ototoxic insults, and the therapeutic value of targeting nitrative stress for mitigating auditory dysfunction.
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Sakata A, Kashio A, Koyama H, Uranaka T, Iwasaki S, Fujimoto C, Kinoshita M, Yamasoba T. Long-Term Progression and Rapid Decline in Hearing Loss in Patients with a Point Mutation at Nucleotide 3243 of the Mitochondrial DNA. Life (Basel) 2022; 12:life12040543. [PMID: 35455034 PMCID: PMC9033132 DOI: 10.3390/life12040543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 11/16/2022] Open
Abstract
Patients with m.3243A>G mutation of mitochondrial DNA develop bilaterally symmetric sensorineural hearing loss. However, it is unclear how fast their hearing loss progresses over time, and whether they experience rapid progression of hearing loss. In the present study, we conducted a long-term hearing evaluation in patients with MELAS or MIDD who harbored the m.3243A>G mutation of mitochondrial DNA. A retrospective chart review was performed on 15 patients with this mutation who underwent pure-tone audiometry at least once a year for more than two years. The mean follow-up period was 12.8 years. The mean progression rate of hearing loss was 5.5 dB per year. Hearing loss progressed rapidly to be profoundly deaf in seven patients during the observation period. Heteroplasmy and age-corrected heteroplasmy levels correlated with the age of onset of hearing loss. These results indicate that patients with m.3243A>G mutation have a gradual progression of hearing loss in the early stages and rapid decline in hearing to be profoundly deaf in approximately half of the patients. Although it is possible to predict the age of onset of hearing loss from heteroplasmy and age-corrected heteroplasmy levels, it is difficult to predict whether and when the rapid hearing loss will occur.
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Affiliation(s)
- Aki Sakata
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Akinori Kashio
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Hajime Koyama
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Tsukasa Uranaka
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Shinichi Iwasaki
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, Nagoya City University, Aichi 467-8601, Japan
| | - Chisato Fujimoto
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Makoto Kinoshita
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Tatsuya Yamasoba
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
- Correspondence: ; Tel.: +81-3-3815-5411
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Age-related Activation of Cyclic GMP-AMP synthase-Stimulator of Interferon Genes Signaling in the Auditory System is Associated with Presbycusis in C57BL/6J Male Mice. Neuroscience 2022; 481:73-84. [PMID: 34848262 DOI: 10.1016/j.neuroscience.2021.11.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/29/2021] [Accepted: 11/20/2021] [Indexed: 11/21/2022]
Abstract
Presbycusis, or age-related hearing loss (ARHL), is primarily associated with sensory or transduction nerve cell degeneration in the peripheral and/or central auditory systems. During aging, the auditory system shows mitochondrial dysfunction and increased inflammatory responses. Mitochondrial dysfunction promotes leakage of mitochondrial DNA (mtDNA) into the cytosol, which activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to induce type I interferon and inflammatory responses. However, whether this pathway is involved in the occurrence and development of ARHL is unknown. This study aimed to determine whether there are age-related changes in the levels of cytosolic mtDNA and cGAS-STING pathway activation in the auditory pathway and to explore their relationship with ARHL. The results showed that cGAS-positive immunoreactive cells were observed in the cochlea, inferior colliculus, and auditory cortex. Levels of cytosolic mtDNA, cGAS, STING, phosphorylated interferon regulatory factor 3, and cytokines were significantly increased in the cochlea, inferior colliculus, and auditory cortex of 6-, 9-, and 12-month-old mice compared with 3-month-old mice. These findings suggested that cytosolic mtDNA may play an important role in the pathogenesis of ARHL by activating cGAS-STING-mediated type I interferon and inflammatory responses.
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Zhang L, Chen S, Sun Y. Mechanism and Prevention of Spiral Ganglion Neuron Degeneration in the Cochlea. Front Cell Neurosci 2022; 15:814891. [PMID: 35069120 PMCID: PMC8766678 DOI: 10.3389/fncel.2021.814891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 12/09/2021] [Indexed: 12/14/2022] Open
Abstract
Sensorineural hearing loss (SNHL) is one of the most prevalent sensory deficits in humans, and approximately 360 million people worldwide are affected. The current treatment option for severe to profound hearing loss is cochlear implantation (CI), but its treatment efficacy is related to the survival of spiral ganglion neurons (SGNs). SGNs are the primary sensory neurons, transmitting complex acoustic information from hair cells to second-order sensory neurons in the cochlear nucleus. In mammals, SGNs have very limited regeneration ability, and SGN loss causes irreversible hearing loss. In most cases of SNHL, SGN damage is the dominant pathogenesis, and it could be caused by noise exposure, ototoxic drugs, hereditary defects, presbycusis, etc. Tremendous efforts have been made to identify novel treatments to prevent or reverse the damage to SGNs, including gene therapy and stem cell therapy. This review summarizes the major causes and the corresponding mechanisms of SGN loss and the current protection strategies, especially gene therapy and stem cell therapy, to promote the development of new therapeutic methods.
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Affiliation(s)
- Li Zhang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sen Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Institute of Otorhinolaryngology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Jain S, Narne VK. Auditory Profile of Children With Some Rare Neurodevelopmental Disorders. RESEARCH ANTHOLOGY ON PEDIATRIC AND ADOLESCENT MEDICINE 2022. [DOI: 10.4018/978-1-6684-5360-5.ch014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurodevelopmental disorder is an umbrella term comprising many muscular, skeletal, metabolic, endocrinal, systemic, and immune-related diseases, which are caused due to the improper/inaccurate development of the central nervous system. Most of these disorders are highly prevalent, but some express rarely in human beings. Such disorders with least prevalence rates are known as rare neurodevelopmental disorders. The sensory system is affected in all individuals with these rare neurodevelopmental disorders, although to a varying extent. Sensory processing in terms of hearing loss is reported by many researchers in many rare neurodevelopmental disorders, but the pathophysiology of audiological findings are seldom investigated. In this chapter, the authors highlight the possible relationship between underlying cause and the resultant audiological symptoms in some of the rare neurodevelopmental disorders. Further, the research studies on the audiological profiling in such disorders are discussed.
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Li Q, Zang Y, Sun Z, Zhang W, Liu H. Long noncoding RNA Gm44593 attenuates oxidative stress from age-related hearing loss by regulating miR-29b/WNK1. Bioengineered 2021; 13:573-582. [PMID: 34967279 PMCID: PMC8805810 DOI: 10.1080/21655979.2021.2012062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Long noncoding RNA has been reported to play important role in various disease. However, the function of lncRNA in age-related hearing loss still unclear. The aim of our study is to investigate the function and mechanism of lncRNA Gm44593 in AHL. ATP content, JC-1 assay, mitochondrial content, cell death rates and dual-luciferase reporter assay were performed to assess the function of lncRNA Gm44593 in HEI-OC1 cells. The expression of lncRNA Gm44593 was significantly upregulated upon H2O2 and starvation treatment. Overexpression of lncRNA Gm44593 manifestly reduced the cell death rates. The ATP content, mtDNA content and mitochondrial membrane potential were alleviated upon overexpression of lncRNA Gm44593. We also proved that miR-29b is the direct target of lncRNA Gm44593. Overexpression of miR-29b completely restored the effect induced by lncRNA Gm44593. In addition, we provided evidences that WNK1 is the direct target of miR-29b. Our research uncovers a potential role of lncRNA Gm44593 in age-related hearing loss. We provide new insights into potential therapeutic targets for the amelioration of age-related hearing loss.
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Affiliation(s)
- Qian Li
- Otolaryngology Head and Neck Surgery, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China
| | - Yanzi Zang
- Otolaryngology Head and Neck Surgery, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China
| | - Zhanwei Sun
- Otolaryngology Head and Neck Surgery, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China
| | - Wenqi Zhang
- Otolaryngology Head and Neck Surgery, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China
| | - Hongjian Liu
- Otolaryngology Head and Neck Surgery, People's Hospital of Zhengzhou University, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China
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Muderris T, Yar Sağlam AS, Unsal D, Mülazimoğlu S, Sevil E, Kayhan H. Efficiency of resveratrol in the prevention and treatment of age-related hearing loss. Exp Ther Med 2021; 23:40. [PMID: 34849155 DOI: 10.3892/etm.2021.10962] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 07/28/2021] [Indexed: 11/06/2022] Open
Abstract
Age-related hearing loss (ARHL) is a major public health concern, which is characterized by gradual, progressive sensorineural hearing loss and deterioration of sound localization, with no effective treatment available to date. The aim of the present study was to evaluate the efficacy of resveratrol to prevent and treat ARHL. For this purpose, 32 male C57BL/6 mice were assigned to four groups: Early treatment, late treatment, control and sham control. The experiment lasted for 15 months. Treatment was started at three months of age in the early treatment group and at sixth months in the late treatment group. The auditory brainstem response test was performed once every three months. At the end of the study period, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, NF-κB, Bcl-2, Bcl-xL, Bax, Bcl-2 homologous antagonist/killer (Bak), caspase-3 and caspase-9 levels in the cochlear tissues of the animals were analyzed by reverse transcription-quantitative PCR. Hearing thresholds of the mice in the early treatment group were better than those in the other groups (P<0.001) at the end of the study. However, hearing levels in the late treatment group were not significantly different from those in the control groups (P>0.05), although mean thresholds were lower. The threshold shift in the early treatment group was significantly lower at all frequencies when compared with those in the control groups (P<0.001). The mRNA expression levels of pro-apoptotic genes Bax and Bak were lower (P<0.05), anti-apoptotic genes Bcl-2 and Bcl-xL were higher (P<0.05), NF-κB, COX-2 and iNOS as genes that have a role in inflammation and caspase-3 and caspase-9 as genes with a vital role in apoptosis were lower (P<0.05) in the early treatment group when compared with the late treatment and control groups. These results suggested that resveratrol is effective in the prevention of ARHL, particularly when started prior to the beginning of hearing loss.
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Affiliation(s)
- Togay Muderris
- Department of Otorhinolaryngology, Head and Neck Surgery, Izmir Bakircay University Faculty of Medicine, 35610 Izmir, Turkey
| | - Atiye Seda Yar Sağlam
- Department of Medical Biology and Genetics, Gazi University Faculty of Medicine, 06500 Ankara, Turkey
| | - Döndü Unsal
- Department of Audiology, Ataturk Education and Research Hospital, 06800 Ankara, Turkey
| | - Selçuk Mülazimoğlu
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara University Faculty of Medicine, 06230 Ankara, Turkey
| | - Ergün Sevil
- Department of Otorhinolaryngology, Head and Neck Surgery, Alanya Alaaddin Keykubat University, 07400 Antalya, Turkey
| | - Handan Kayhan
- Department of Medical Biology and Genetics, Gazi University Faculty of Medicine, 06500 Ankara, Turkey
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20
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Salam SA, Mostafa F, Alnamshan MM, Elshewemi SS, Sorour JM. Thymoquinone ameliorates age-related hearing loss in C57BL/6J mice by modulating Sirt1 activity and Bak1 expression. Biomed Pharmacother 2021; 143:112149. [PMID: 34507120 DOI: 10.1016/j.biopha.2021.112149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/27/2021] [Accepted: 08/31/2021] [Indexed: 01/10/2023] Open
Abstract
Age-related hearing loss (AHL) is the most common sensory disorder of aged population. Currently, one of the most important sources of experimental medicine for AHL is medicinal plants. This study performed the first investigation of the effect of thymoquinone (TQ), a potent antioxidant, on AHL. Here, we used inbred C57BL/6J mice (B6 mice) as a successful experimental model of the early onset of AHL. The behavioral assessment of hearing revealed that the injection of a high dose of TQ (40 mg/kg; TQ40) significantly improved the auditory sensitivity of B6 mice at all tested frequencies (8, 16 and 22 kHz). Histological sections of cochlea from B6 mice injected with a low dose (20 mg/kg; TQ20) and high dose showed relatively less degenerative signs in the modiolus, hair cells and spiral ligaments, the main constituents of the cochlea. In addition, TQ40 completely restored the normal pattern of hair cells in B6 mice, as shown in scanning electron micrographs. Our data indicated that TQ20 and TQ40 reduced levels of Bak1-mediated apoptosis in the cochlea of B6 mice. Interestingly, the level of Sirt1, a positive regulator of autophagy, was significantly increased in B6 mice administered TQ40. In conclusion, TQ relieves the symptoms of AHL by downregulating Bak1 and activating Sirt1 in the cochlea of B6 mice.
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Affiliation(s)
- Sherine Abdel Salam
- Department of Zoology, Faculty of Science, Alexandria University, Alexandria 21511, Egypt.
| | - Fatma Mostafa
- Department of Zoology, Faculty of Science, Alexandria University, Alexandria 21511, Egypt.
| | - Mashael M Alnamshan
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia.
| | - Salma S Elshewemi
- Department of Zoology, Faculty of Science, Alexandria University, Alexandria 21511, Egypt.
| | - Jehan M Sorour
- Department of Zoology, Faculty of Science, Alexandria University, Alexandria 21511, Egypt.
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Istradefylline Mitigates Age-Related Hearing Loss in C57BL/6J Mice. Int J Mol Sci 2021; 22:ijms22158000. [PMID: 34360766 PMCID: PMC8348536 DOI: 10.3390/ijms22158000] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/20/2022] Open
Abstract
Age-related hearing loss (ARHL) is the most common sensory disorder among older people, and yet, the treatment options are limited to medical devices such as hearing aids and cochlear implants. The high prevalence of ARHL mandates the development of treatment strategies that can prevent or rescue age-related cochlear degeneration. In this study, we investigated a novel pharmacological strategy based on inhibition of the adenosine A2A receptor (A2AR) in middle aged C57BL/6 mice prone to early onset ARHL. C57BL/6J mice were treated with weekly istradefylline (A2AR antagonist; 1 mg/kg) injections from 6 to 12 months of age. Auditory function was assessed using auditory brainstem responses (ABR) to tone pips (4–32 kHz). ABR thresholds and suprathreshold responses (wave I amplitudes and latencies) were evaluated at 6, 9, and 12 months of age. Functional outcomes were correlated with quantitative histological assessments of sensory hair cells. Cognitive function was assessed using the Morris water maze and the novel object recognition test, and the zero maze test was used to assess anxiety-like behaviour. Weekly injections of istradefylline attenuated ABR threshold shifts by approximately 20 dB at mid to high frequencies (16–32 kHz) but did not improve ABR suprathreshold responses. Istradefylline treatment improved hair cell survival in a turn-dependent manner, whilst the cognitive function was unaffected by istradefylline treatment. This study presents the first evidence for the rescue potential of istradefylline in ARHL and highlights the role of A2AR in development of age-related cochlear degeneration.
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Kawashima T, Harai K, Fujita N, Takahashi R. Ninjinyoeito Has a Protective Effect on the Auditory Nerve and Suppresses the Progression of Age-Related Hearing Loss in Mice. Front Nutr 2020; 7:528864. [PMID: 33163504 PMCID: PMC7583632 DOI: 10.3389/fnut.2020.528864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 09/01/2020] [Indexed: 12/02/2022] Open
Abstract
Currently, there are limited reports available regarding the treatment and prevention of progressive age-related hearing loss. This is because age-related hearing loss is not a critical disease with direct fatalities and has several well-established countermeasures such as hearing aids and cochlear implants. This study evaluated the efficacy of Ninjinyoeito (NYT) in the treatment of age-related hearing loss. C57BL/6J mice were divided into three groups: baseline group, untreated group, and NYT-treated group, with the latter receiving NYT treatment for 2 months. The mice were fed with NYT extract mixed with 4% mouse normal chow. Hearing loss was confirmed by a reduction in intact cell density of the auditory nerve from the age of 5–7 months. The suppression of hearing loss with aging and decrease in the intact cell density of the auditory nerve were significant in mice fed with NYT for 2 months. NYT has been reported to improve blood flow and enhance mitochondrial activity and may exert its protective effects on spiral neurons through these mechanisms. There was no decrease in the size of the stria vascularis from the age of 5–7 months in C57BL/6J mice. The present model failed to reveal the effect of NYT on atrophy of the stria vascularis of the cochlear duct. In conclusion, NYT appears to have a protective effect on the auditory nerve and suppress the progression of age-related hearing loss by reducing age-related auditory nerve degeneration.
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Affiliation(s)
| | - Kenji Harai
- Kampo Research Laboratories, Kracie Pharma, Ltd., Tokyo, Japan
| | - Nina Fujita
- Kampo Research Laboratories, Kracie Pharma, Ltd., Tokyo, Japan
| | - Ryuji Takahashi
- Kampo Research Laboratories, Kracie Pharma, Ltd., Tokyo, Japan
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23
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Perkins G, Lee JH, Park S, Kang M, Perez-Flores MC, Ju S, Phillips G, Lysakowski A, Gratton MA, Yamoah EN. Altered Outer Hair Cell Mitochondrial and Subsurface Cisternae Connectomics Are Candidate Mechanisms for Hearing Loss in Mice. J Neurosci 2020; 40:8556-8572. [PMID: 33020216 PMCID: PMC7605424 DOI: 10.1523/jneurosci.2901-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 11/21/2022] Open
Abstract
Organelle crosstalk is vital for cellular functions. The propinquity of mitochondria, ER, and plasma membrane promote regulation of multiple functions, which include intracellular Ca2+ flux, and cellular biogenesis. Although the purposes of apposing mitochondria and ER have been described, an understanding of altered organelle connectomics related to disease states is emerging. Since inner ear outer hair cell (OHC) degeneration is a common trait of age-related hearing loss, the objective of this study was to investigate whether the structural and functional coupling of mitochondria with subsurface cisternae (SSC) was affected by aging. We applied functional and structural probes to equal numbers of male and female mice with a hearing phenotype akin to human aging. We discovered the polarization of cristae and crista junctions in mitochondria tethered to the SSC in OHCs. Aging was associated with SSC stress and decoupling of mitochondria with the SSC, mitochondrial fission/fusion imbalance, a remarkable reduction in mitochondrial and cytoplasmic Ca2+ levels, reduced K+-induced Ca2+ uptake, and marked plasticity of cristae membranes. A model of structure-based ATP production predicts profound energy stress in older OHCs. This report provides data suggesting that altered membrane organelle connectomics may result in progressive hearing loss.
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Affiliation(s)
- Guy Perkins
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | | | | | | | | | - Saeyeon Ju
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | - Grady Phillips
- Washington University School of Medicine, St. Louis, Missouri 63110
| | - Anna Lysakowski
- Departments of Anatomy and Cell Biology and Otolaryngology, University of Illinois at Chicago, Chicago, Illinois 60612
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Wu J, Ye J, Kong W, Zhang S, Zheng Y. Programmed cell death pathways in hearing loss: A review of apoptosis, autophagy and programmed necrosis. Cell Prolif 2020; 53:e12915. [PMID: 33047870 PMCID: PMC7653260 DOI: 10.1111/cpr.12915] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/23/2020] [Accepted: 09/09/2020] [Indexed: 02/05/2023] Open
Abstract
Programmed cell death (PCD)—apoptosis, autophagy and programmed necrosis—is any pathological form of cell death mediated by intracellular processes. Ototoxic drugs, ageing and noise exposure are some common pathogenic factors of sensorineural hearing loss (SNHL) that can induce the programmed death of auditory hair cells through different pathways, and eventually lead to the loss of hair cells. Furthermore, several mutations in apoptotic genes including DFNA5, DFNA51 and DFNB74 have been suggested to be responsible for the new functional classes of monogenic hearing loss (HL). Therefore, in this review, we elucidate the role of these three forms of PCD in different types of HL and discuss their guiding significance for HL treatment. We believe that further studies of PCD pathways are necessary to understand the pathogenesis of HL and guide scientists and clinicians to identify new drug targets for HL treatment.
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Affiliation(s)
- Junhao Wu
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Ye
- College of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Weili Kong
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Shouyue Zhang
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Yun Zheng
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
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Nam YH, Jeong SY, Kim YH, Rodriguez I, Nuankaew W, Bhawal UK, Hong BN, Kang TH. Anti-aging effects of Korean Red Ginseng (KRG) in differentiated embryo chondrocyte (DEC) knockout mice. J Ginseng Res 2020; 45:183-190. [PMID: 33437170 PMCID: PMC7790900 DOI: 10.1016/j.jgr.2020.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/06/2020] [Accepted: 09/11/2020] [Indexed: 01/15/2023] Open
Abstract
Background The circadian rhythm is the internal clock that controls sleep-wake cycles, metabolism, cognition, and several processes in the body, and its disruption has been associated with aging. The differentiated embryo chondrocyte (Dec) gene is related to circadian rhythm. To our knowledge, there are no reports of the relationship between dec gene expression and KRG effect. Therefore, we treated Dec gene knockout (KO) aging mice with KRG to study anti-aging related effects and possible mechanisms. Methods We evaluated KRG and expression of Dec genes in an ototoxicity model. Dec genes expression in livers of aging mice was further analyzed. Then, we assessed the effects of DEC KO on hearing function in mice by ABR. Finally, we performed DNA microarray to identify KRG-related gene expression changes in mouse liver and assessed the results using KEGG analysis. Results KRG decreased the expression of Dec genes in ototoxicity model, which may contribute to its anti-aging efficacy. Moreover, KRG suppressed Dec genes expression in liver of wild type indicating inhibition of senescence. ABR test indicated that KRG improved auditory function in aging mouse, demonstrating KRG efficacy on aging related diseases. Conclusion Finally, in KEGG analysis of 238 genes that were activated and 158 that were inhibited by KRG in DEC KO mice, activated genes were involved in proliferation signaling, mineral absorption, and PPAR signaling whereas the inhibited genes were involved in arachidonic acid metabolism and peroxisomes. Our data indicate that inhibition of senescence-related Dec genes may explain the anti-aging efficacy of KRG.
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Affiliation(s)
- Youn Hee Nam
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Seo Yule Jeong
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Yun Hee Kim
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Isabel Rodriguez
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Wanlapa Nuankaew
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Ujjal K. Bhawal
- Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Chiba, Japan
| | - Bin Na Hong
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
| | - Tong Ho Kang
- Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, Republic of Korea
- Corresponding author. Department of Oriental Medicine Biotechnology, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Gyeonggi, 17104, Republic of Korea
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Keithley EM. Pathology and mechanisms of cochlear aging. J Neurosci Res 2020; 98:1674-1684. [PMID: 31066107 PMCID: PMC7496655 DOI: 10.1002/jnr.24439] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/22/2019] [Accepted: 04/23/2019] [Indexed: 12/21/2022]
Abstract
Presbycusis, or age-related hearing loss (ARHL), occurs in most mammals with variations in the age of onset, rate of decline, and magnitude of degeneration in the central nervous system and inner ear. The affected cochlear structures include the stria vascularis and its vasculature, spiral ligament, sensory hair cells and auditory neurons. Dysfunction of the stria vascularis results in a reduced endocochlear potential. Without this potential, the cochlear amplification provided by the electro-motility of the outer hair cells is insufficient, and a high-frequency hearing-loss results. Degeneration of the sensory cells, especially the outer hair cells also leads to hearing loss due to lack of amplification. Neuronal degeneration, another hallmark of ARHL, most likely underlies difficulties with speech discrimination, especially in noisy environments. Noise exposure is a major cause of ARHL. It is well-known to cause sensory cell degeneration, especially the outer hair cells at the high frequency end of the cochlea. Even loud, but not uncomfortable, sound levels can lead to synaptopathy and ultimately neuronal degeneration. Even in the absence of a noisy environment, aged cells degenerate. This pathology most likely results from damage to mitochondria and contributes to degenerative changes in the stria vascularis, hair cells, and neurons. The genetic underpinnings of ARHL are still unknown and most likely involve various combinations of genes. At present, the only effective strategy for reducing ARHL is prevention of noise exposure. If future strategies can improve mitochondrial activity and reduce oxidative damage in old age, these should also bring relief.
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Affiliation(s)
- Elizabeth M. Keithley
- Division of Otolaryngology ‐ Head and Neck SurgeryUniversity of CaliforniaSan DiegoCalifornia
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27
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Wu H, Sun H, He Z, Chen X, Li Y, Zhao X, Kong W, Kong W. The effect and mechanism of 19S proteasome PSMD11/Rpn6 subunit in D-Galactose induced mimetic aging models. Exp Cell Res 2020; 394:112093. [PMID: 32450067 DOI: 10.1016/j.yexcr.2020.112093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/14/2020] [Accepted: 05/16/2020] [Indexed: 11/30/2022]
Abstract
Regulating proteasome activity is a potent therapeutic aspect of age-related hearing loss, which has been proven to protect neurons from age-related damaging. PSMD11, subunit of the 19S proteasome regulatory particle, is known to mainly up-regulate proteasome activity and prolong aging. However, the mechanism of PSMD11 in age-related hearing loss has not been deeply explored. In the present study, we explore the function and mechanism of PSMD11 protecting neurons in d-Galactose (D-Gal) mimetic aging models. Age-related pathologies were detected by Taq-PCR, ABR, Transmission electron microscopy, toluidine blue and β-galactosidase staining. The relative expressions of the proteins were explored by Western blotting, oxyblot, immunoprecipitation and immunofluorescence. Flow cytometry was used to manifest the oxidative state. We discovered that proteasome activity was impaired with aging, and that ROS and toxic protein accumulated in D-Gal induced aging models. PSMD11 changed with aging, and was associated with the metabolism of proteasome activity in the D-Gal treated models. Moreover, the knockdown or overexpression of PSMD11 was sufficient to change the oxidative state caused by D-Gal. Our results also demonstrated that PSMD11 could bond to AMPKα1/2 in the auditory cortex and PC12 cells, and AMPKα2 but not AMPKα1 was efficient to regulate the function of PSMD11. Deeper insights into the mechanisms of regulating PSMD11 for the anti-aging process are needed, and may offer novel therapeutic methods for central presbycusis.
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Affiliation(s)
- Han Wu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Haiying Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Zuhong He
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Xi Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Yongqin Li
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Xueyan Zhao
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Wen Kong
- Departments of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, China.
| | - Weijia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Tian C, Kim YJ, Hali S, Choo OS, Lee JS, Jung SK, Choi YU, Park CB, Choung YH. Suppressed expression of LDHB promotes age-related hearing loss via aerobic glycolysis. Cell Death Dis 2020; 11:375. [PMID: 32415082 PMCID: PMC7229204 DOI: 10.1038/s41419-020-2577-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 04/20/2020] [Indexed: 12/26/2022]
Abstract
Age-dependent decrease of mitochondrial energy production and cellular redox imbalance play significant roles in age-related hearing loss (ARHL). Lactate dehydrogenase B (LDHB) is a key glycolytic enzyme that catalyzes the interconversion of pyruvate and lactate. LDH activity and isoenzyme patterns are known to be changed with aging, but the role of LDHB in ARHL has not been studied yet. Here, we found that LDHB knockout mice showed hearing loss at high frequencies, which is the typical feature of ARHL. LDHB knockdown caused downregulation of mitochondrial functions in auditory cell line, University of Bristol/organ of Corti 1 (UB/OC1) with decreased NAD+ and increased hypoxia inducing factor-1α. LDHB knockdown also enhanced the death of UB/OC1 cells with ototoxic gentamicin treatment. On the contrary, the induction of LDHB expression caused enhanced mitochondrial functions, including changes in mitochondrial respiratory subunits, mitochondrial membrane potentials, ATP, and the NAD+/NADH ratio. Thus, we concluded that suppression of LDHB activity may be closely related with the early onset or progression of ARHL.
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Affiliation(s)
- Chunjie Tian
- Department of Otolaryngology, Dali Bai Autonomous Prefecture People's Hospital, Dali, Yunnan, 671000, China
| | - Yeon Ju Kim
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea
| | - Sai Hali
- Institute for Medical Sciences, Ajou University School of Medicine, Suwon, 16499, Republic of Korea
| | - Oak-Sung Choo
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea.,Department of Medical Sciences, Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Jin-Sol Lee
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea.,Department of Biomedical Sciences, BK21 Plus Research Center for Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Seo-Kyung Jung
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea.,Department of Biomedical Sciences, BK21 Plus Research Center for Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Youn-Uk Choi
- Department of Physiology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea
| | - Chan Bae Park
- Department of Physiology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea.
| | - Yun-Hoon Choung
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea. .,Department of Medical Sciences, Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea. .,Department of Biomedical Sciences, BK21 Plus Research Center for Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea.
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Abstract
OBJECTIVE A/J mice are a mouse model of age-related hearing loss (AHL) with progressive degeneration of outer hair cells (OHCs), spiral ganglion neurons (SGNs), and stria vascularis. This study was carried out to observe the otoprotective effects of α-lipoic acid on A/J mice. METHODS A/J mouse pups at postnatal day 7 were randomly distributed into the untreated group, the dimethyl sulfoxide (DMSO) group, and the α-lipoic acid + DMSO group. α-lipoic acid was given to the mice intraperitoneally at a dosage of 50 μg/g body weight every other day. Time course auditory-evoked brainstem response (ABR) thresholds were tested. OHC loss was counted and the densities of SGNs and the width of stria vascularis were measured at 4 and 8 weeks of age. RESULTS Measurement of the ABR thresholds revealed that hearing loss in A/J mice was attenuated by α-lipoic acid at age from 3 to 8 weeks. Moreover, preservation effects of OHCs, SGNs, and stria vascularis by α-lipoic acid were observed in the cochleae of A/J mice at 4 and 8 weeks of age. CONCLUSION Hearing loss in A/J mice can be attenuated by α-lipoic acid. The otoprotective effects of α-lipoic acid on A/J mice may be obtained by preserving OHCs, SGNs, and stria vascularis in the cochleae. The oxidative damage related to gene mutations may be a potential target for AHL prevention and therapy.
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Serra LSM, de Araújo JG, Vieira ALS, da Silva EM, de Andrade RR, Kückelhaus SAS, Sampaio ALL. Role of melatonin in prevention of age-related hearing loss. PLoS One 2020; 15:e0228943. [PMID: 32040524 PMCID: PMC7010238 DOI: 10.1371/journal.pone.0228943] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/27/2020] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Age-related hearing loss (ARHL) is a consequence of aging of the auditory system. The best known mechanism of cell death in ARHL is apoptosis due to increased production of reactive oxygen species. In this context, it is hypothesized that melatonin, owing to its high antioxidant potential and its action in the mitochondria, helps prevent or delay outer hair cell dysfunction (HCD). AIMS To evaluate the effect of melatonin on the prevention of HCD dysfunction in the ARHL process in a susceptible murine C57BL/6J model. METHOD C57BL/6J animals were divided into two groups: control (CG) and melatonin (MG). The CG received a saline and ethanol solution and the MG, melatonin (10 mg/kg/day). The solutions were offered daily (50 μl) orally over a 10-month period. Distortion Product Otoacoustic Emissions (DPOAE) measurements were conducted once a month. RESULTS There was a decrease in DPOAE values in both groups over time and a differentiation between them from the 10th month of life onwards. At 10 months, the MG maintained higher DPOAE values than the CG at all frequencies tested. CONCLUSION The use of melatonin has otoprotective effects on HCD in the ARHL process in the C57BL/6J model.
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Affiliation(s)
| | - Juliana Gusmão de Araújo
- Laboratory of Otorhinolaryngology Research, University of Brasilia, Brasília, Distrito Federal, Brazil
| | | | | | - Rafael Rocha de Andrade
- Laboratory of Experimental Surgery, University of Brasilia, Brasília, Distrito Federal, Brazil
| | | | - André Luiz Lopes Sampaio
- Laboratory of Otorhinolaryngology Research, University of Brasilia, Brasília, Distrito Federal, Brazil
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Bullen A, Forge A, Wright A, Richardson GP, Goodyear RJ, Taylor R. Ultrastructural defects in stereocilia and tectorial membrane in aging mouse and human cochleae. J Neurosci Res 2019; 98:1745-1763. [DOI: 10.1002/jnr.24556] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/24/2019] [Accepted: 10/28/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Anwen Bullen
- UCL Ear Institute University College London London UK
| | - Andrew Forge
- UCL Ear Institute University College London London UK
| | | | - Guy P. Richardson
- Sussex Neuroscience School of Life Sciences University of Sussex Falmer, Brighton UK
| | - Richard J. Goodyear
- Sussex Neuroscience School of Life Sciences University of Sussex Falmer, Brighton UK
| | - Ruth Taylor
- UCL Ear Institute University College London London UK
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32
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Advances in cochlear implantation for hereditary deafness caused by common mutations in deafness genes. JOURNAL OF BIO-X RESEARCH 2019. [DOI: 10.1097/jbr.0000000000000037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Du ZD, He L, Tu C, Guo XA, Yu S, Liu K, Gong S. Mitochondrial DNA 3,860-bp Deletion Increases with Aging in the Auditory Nervous System of C57BL/6J Mice. ORL J Otorhinolaryngol Relat Spec 2019; 81:92-100. [PMID: 31129670 DOI: 10.1159/000499475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Mitochondrial DNA (mtDNA) is sensitive to oxidative damage during aging, which can result in mtDNA mutations. A previous study reported that a 3,860-bp mtDNA deletion, similar to a 4,977-bp mtDNA deletion in humans, is also common occurrence in murine tissues, and increases in the brain and liver with aging. However, no previous study evaluated both topics in the murine auditory nervous system. METHODS We compared mtDNA oxidative damage, mitochondrial ultrastructural changes, and the frequency of the 3,860-bp deletion in the peripheral (spiral ganglion, SG) and central (auditory cortex, AC) auditory nervous system of C57BL/6J mice aged 2, 12, and 18 months. RESULTS We found that the threshold of auditory brainstem response increased with age along with the signal of 8-hydroxy-2'-deoxyguanosine - a marker of DNA oxidative damage - in the mitochondria of SG and AC neurons. The mitochondrial ultrastructural damage also increased with aging in the SG and AC neurons. Moreover, the relative amount of mtDNA 3,860-bp deletion in 12- and 18-month-old mice was significantly higher in the SG and AC as compared to 2-month-old mice. CONCLUSION These results suggest that the mtDNA 3,860-bp deletion is common in the auditory nervous system of mice and increases with age and may contribute to age-related hearing loss.
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Affiliation(s)
- Zheng-De Du
- Department of Otorhinolaryngology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lu He
- Department of Otorhinolaryngology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Chunmei Tu
- Department of Otorhinolaryngology, First People's Hospital of Jinan, Jinan, China
| | - Xiao-An Guo
- Department of Otorhinolaryngology, First Affiliated Hospital of China Medical University, Shenyang, China
| | - Shukui Yu
- Department of Otorhinolaryngology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Ke Liu
- Department of Otorhinolaryngology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Shusheng Gong
- Department of Otorhinolaryngology, Beijing Friendship Hospital, Capital Medical University, Beijing, China,
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Zhang J, Wang N, Xu A. Cmah deficiency may lead to age-related hearing loss by influencing miRNA-PPAR mediated signaling pathway. PeerJ 2019; 7:e6856. [PMID: 31149396 PMCID: PMC6526899 DOI: 10.7717/peerj.6856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/26/2019] [Indexed: 12/26/2022] Open
Abstract
Background Previous evidence has indicated CMP-Neu5Ac hydroxylase (Cmah) disruption inducesaging-related hearing loss (AHL). However, its function mechanisms remain unclear. This study was to explore the mechanisms of AHL by using microarray analysis in the Cmah deficiency animal model. Methods Microarray dataset GSE70659 was available from the Gene Expression Omnibus database, including cochlear tissues from wild-type and Cmah-null C57BL/6J mice with old age (12 months, n = 3). Differentially expressed genes (DEGs) were identified using the Linear Models for Microarray data method and a protein–protein interaction (PPI) network was constructed using data from the Search Tool for the Retrieval of Interacting Genes database followed by module analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery. The upstream miRNAs and potential small-molecule drugs were predicted by miRwalk2.0 and Connectivity Map, respectively. Results A total of 799 DEGs (449 upregulated and 350 downregulated) were identified. Upregulated DEGs were involved in Cell adhesion molecules (ICAM1, intercellular adhesion molecule 1) and tumor necrosis factor (TNF) signaling pathway (FOS, FBJ osteosarcoma oncogene; ICAM1), while downregulated DEGs participated in PPAR signaling pathway (PPARG, peroxisome proliferator-activated receptor gamma). A PPI network was constructed, in which FOS, ICAM1 and PPARG were ranked as hub genes and PPARG was a transcription factor to regulate other target genes (ICAM1, FOS). Function analysis of two significant modules further demonstrated PPAR signaling pathway was especially important. Furthermore, mmu-miR-130b-3p, mmu-miR-27a-3p, mmu-miR-27b-3p and mmu-miR-721 were predicted to regulate PPARG. Topiramate were speculated to be a potential small-molecule drug to reverse DEGs in AHL. Conclusions PPAR mediated signaling pathway may be an important mechanism for AHL. Downregulation of the above miRNAs and use of topiramate may be potential treatment strategies for ALH by upregulating PPARG.
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Affiliation(s)
- Juhong Zhang
- Department of Otolaryngology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Southern Medical University Affiliated Fengxian Hospital, Shanghai, China
| | - Na Wang
- Department of Otolaryngology/Head and Neck Surgery, the Second Hospital of Shandong University, Jinan, China
| | - Anting Xu
- Department of Otolaryngology/Head and Neck Surgery, the Second Hospital of Shandong University, Jinan, China.,NHC. Key Laboratory of Otorhinolaryngology, Shandong University, Jinan, China
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Fetoni AR, Paciello F, Rolesi R, Paludetti G, Troiani D. Targeting dysregulation of redox homeostasis in noise-induced hearing loss: Oxidative stress and ROS signaling. Free Radic Biol Med 2019; 135:46-59. [PMID: 30802489 DOI: 10.1016/j.freeradbiomed.2019.02.022] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/04/2019] [Accepted: 02/18/2019] [Indexed: 12/20/2022]
Abstract
Hearing loss caused by exposure to recreational and occupational noise remains a worldwide disabling condition and dysregulation of redox homeostasis is the hallmark of cochlear damage induced by noise exposure. In this review we discuss the dual function of ROS to both promote cell damage (oxidative stress) and cell adaptive responses (ROS signaling) in the cochlea undergoing a stressful condition such as noise exposure. We focus on animal models of noise-induced hearing loss (NIHL) and on the function of exogenous antioxidants to maintaining a physiological role of ROS signaling by distinguishing the effect of exogenous "direct" antioxidants (i.e. CoQ10, NAC), that react with ROS to decrease oxidative stress, from the exogenous "indirect" antioxidants (i.e. nutraceutics and phenolic compounds) that can activate cellular redox enzymes through the Keap1-Nrf2-ARE pathway. The anti-inflammatory properties of Nrf2 signaling are discussed in relation to the ROS/inflammation interplay in noise exposure. Unveiling the mechanisms of ROS regulating redox-associated signaling pathways is essential in providing relevant targets for innovative and effective therapeutic strategies against NIHL.
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Affiliation(s)
- Anna Rita Fetoni
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy; CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Fabiola Paciello
- Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy; CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gaetano Paludetti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Diana Troiani
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.
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Shen H, Liu W, Geng Q, Li H, Lu M, Liang P, Zhang B, Yamoah EN, Lv P. Age-Dependent Up-Regulation of HCN Channels in Spiral Ganglion Neurons Coincide With Hearing Loss in Mice. Front Aging Neurosci 2018; 10:353. [PMID: 30459593 PMCID: PMC6232381 DOI: 10.3389/fnagi.2018.00353] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/17/2018] [Indexed: 01/05/2023] Open
Abstract
Age-related hearing loss (AHL) is the most common sensory disorder in the elderly population, and the etiologies are diverse. To understand the underlying mechanisms of AHL, one strategy is to identify correlates of the disease for comprehensive evaluation of treatment approaches. Dysfunction and degeneration of spiral ganglion neurons (SGNs) are major contributors to AHL. Previously, we showed that one of the changes in the aging auditory system is SGN excitability increase in mice. Since hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play important roles in determining neuronal excitability, we predicted that HCN channels in SGNs are involved in AHL. To investigate the contribution of HCN channels to AHL, we examined the expression and biophysical properties of HCN channels in SGNs from adult (2–3 months) and 11–12-month-old mice. We report a dramatic increase of HCN channel current (Ih) in SGNs in old mice (11–12 months old). The results matched well with increased expression of HCN1 and HCN2 subunits, suggesting that upregulation of HCN channels in SGNs is one of the important facets of the aging SGNs. Moreover, the activity of Ih produced a major impact on the firing properties of SGNs in older mice. The upregulation of Ih may contribute to AHL by regulating SGN excitability. We assessed whether increased SGNs excitability dovetail with neurodegeneration. Apoptosis-inducing factor (AIF)-mediated apoptosis in SGNs was observed in old mice and activation of HCN channels mediates AIF activation. Thus, these findings demonstrate stark correlation between age-dependent increased expression of HCN channels and Ih, and apoptosis in SGNs, which may contribute towards the varied mechanisms of AHL.
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Affiliation(s)
- Haitao Shen
- Laboratory of Pathology, Hebei Medical University, Shijiazhuang, China
| | - Weilin Liu
- Division of Cardiovascular Medicine, Hebei Province Geriatric Hospital, Shijiazhuang, China
| | - Qiaowei Geng
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Hongchen Li
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Mingshun Lu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Peng Liang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Bo Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Ebenezer N Yamoah
- Department of Physiology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Ping Lv
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
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Null Mutation of the Fascin2 Gene by TALEN Leading to Progressive Hearing Loss and Retinal Degeneration in C57BL/6J Mice. G3-GENES GENOMES GENETICS 2018; 8:3221-3230. [PMID: 30082328 PMCID: PMC6169377 DOI: 10.1534/g3.118.200405] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Fascin2 (FSCN2) is an actin cross-linking protein that is mainly localized in retinas and in the stereocilia of hair cells. Earlier studies showed that a deletion mutation in human FASCIN2 (FSCN2) gene could cause autosomal dominant retinitis pigmentosa. Recent studies have indicated that a missense mutation in mouse Fscn2 gene (R109H) can contribute to the early onset of hearing loss in DBA/2J mice. To explore the function of the gene, Fscn2 was knocked out using TALEN (transcription activator-like effector nucleases) on the C57BL/6J background. Four mouse strains with deletions of 1, 4, 5, and 41 nucleotides in the target region of Fscn2 were developed. F1 heterozygous (Fscn2+/- ) mice carrying the same deletion of 41 nucleotides were mated to generate the Fscn2-/- mice. As a result, the Fscn2-/- mice showed progressive hearing loss, as measured in the elevation of auditory brainstem-response thresholds. The hearing impairment began at age 3 weeks at high-stimulus frequencies and became most severe at age 24 weeks. Moreover, degeneration of hair cells and loss of stereocilia were remarkable in Fscn2-/- mice, as revealed by F-actin staining and scanning electron microscopy. Furthermore, compared to the controls, the Fscn2-/- mice displayed significantly lower electroretinogram amplitudes and thinner retinas at 8, 16, and 24 weeks. These results demonstrate that, in C57BL/6Jmice, Fscn2 is essential for maintaining ear and eye function and that a null mutation of Fscn2 leads to progressive hearing loss and retinal degeneration.
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Fu X, Sun X, Zhang L, Jin Y, Chai R, Yang L, Zhang A, Liu X, Bai X, Li J, Wang H, Gao J. Tuberous sclerosis complex-mediated mTORC1 overactivation promotes age-related hearing loss. J Clin Invest 2018; 128:4938-4955. [PMID: 30247156 DOI: 10.1172/jci98058] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 08/08/2018] [Indexed: 12/29/2022] Open
Abstract
The underlying molecular mechanisms of age-related hearing loss (ARHL) in humans and many strains of mice have not been fully characterized. This common age-related disorder is assumed to be closely associated with oxidative stress. Here, we demonstrate that mTORC1 signaling is highly and specifically activated in the cochlear neurosensory epithelium (NSE) in aging mice, and rapamycin injection prevents ARHL. To further examine the specific role of mTORC1 signaling in ARHL, we generated murine models with NSE-specific deletions of Raptor or Tsc1, regulators of mTORC1 signaling. Raptor-cKO mice developed hearing loss considerably more slowly than WT littermates. Conversely, Tsc1 loss led to the early-onset death of cochlear hair cells and consequently accelerated hearing loss. Tsc1-cKO cochleae showed features of oxidative stress and impaired antioxidant defenses. Treatment with rapamycin and the antioxidant N-acetylcysteine rescued Tsc1-cKO hair cells from injury in vivo. In addition, we identified the peroxisome as the initial signaling organelle involved in the regulation of mTORC1 signaling in cochlear hair cells. In summary, our findings identify overactive mTORC1 signaling as one of the critical causes of ARHL and suggest that reduction of mTORC1 activity in cochlear hair cells may be a potential strategy to prevent ARHL.
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Affiliation(s)
- Xiaolong Fu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Xiaoyang Sun
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Linqing Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Yecheng Jin
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Renjie Chai
- Key Laboratory for Development Genes and Human Disease, Southeast University, Nanjing, China
| | - Lili Yang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Aizhen Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China.,Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Xiangguo Liu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Xiaochun Bai
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jianfeng Li
- Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Haibo Wang
- Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
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Golomb BA. Diplomats' Mystery Illness and Pulsed Radiofrequency/Microwave Radiation. Neural Comput 2018; 30:2882-2985. [PMID: 30183509 DOI: 10.1162/neco_a_01133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Importance: A mystery illness striking U.S. and Canadian diplomats to Cuba (and now China) "has confounded the FBI, the State Department and US intelligence agencies" (Lederman, Weissenstein, & Lee, 2017). Sonic explanations for the so-called health attacks have long dominated media reports, propelled by peculiar sounds heard and auditory symptoms experienced. Sonic mediation was justly rejected by experts. We assessed whether pulsed radiofrequency/microwave radiation (RF/MW) exposure can accommodate reported facts in diplomats, including unusual ones. Observations: (1) Noises: Many diplomats heard chirping, ringing or grinding noises at night during episodes reportedly triggering health problems. Some reported that noises were localized with laser-like precision or said the sounds seemed to follow them (within the territory in which they were perceived). Pulsed RF/MW engenders just these apparent "sounds" via the Frey effect. Perceived "sounds" differ by head dimensions and pulse characteristics and can be perceived as located behind in or above the head. Ability to hear the "sounds" depends on high-frequency hearing and low ambient noise. (2) Signs/symptoms: Hearing loss and tinnitus are prominent in affected diplomats and in RF/MW-affected individuals. Each of the protean symptoms that diplomats report also affect persons reporting symptoms from RF/MW: sleep problems, headaches, and cognitive problems dominate in both groups. Sensations of pressure or vibration figure in each. Both encompass vision, balance, and speech problems and nosebleeds. Brain injury and brain swelling are reported in both. (3) Mechanisms: Oxidative stress provides a documented mechanism of RF/MW injury compatible with reported signs and symptoms; sequelae of endothelial dysfunction (yielding blood flow compromise), membrane damage, blood-brain barrier disruption, mitochondrial injury, apoptosis, and autoimmune triggering afford downstream mechanisms, of varying persistence, that merit investigation. (4) Of note, microwaving of the U.S. embassy in Moscow is historically documented. Conclusions and relevance: Reported facts appear consistent with pulsed RF/MW as the source of injury in affected diplomats. Nondiplomats citing symptoms from RF/MW, often with an inciting pulsed-RF/MW exposure, report compatible health conditions. Under the RF/MW hypothesis, lessons learned for diplomats and for RF/MW-affected civilians may each aid the other.
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Tavanai E, Mohammadkhani G, Farahani S, Jalaie S. Protective Effects of Silymarin Against Age-Related Hearing Loss in an Aging Rat Model. Indian J Otolaryngol Head Neck Surg 2018; 71:1248-1257. [PMID: 31750160 DOI: 10.1007/s12070-018-1294-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 03/07/2018] [Indexed: 01/21/2023] Open
Abstract
Age-related hearing loss (ARHL) is one of the most common chronic degenerative disorders. Several studies have indicated that supplementation with some antioxidants can slow down the progression of ARHL. Despite several lines of evidence about the potent antioxidant and anti-aging effects of silymarin, its protective effect against ARHL has not evaluated yet. The aim of the current study was to investigate the effects of silymarin in prevention of ARHL in a d-Galactose-induced aging rat model for the first time. 45 male wistar rats aged 3-month old were divided into 5 groups: group 1, 2 and 3 received 500 mg/kg/day d-Gal plus 100, 200 and 300 mg/kg/day silymarin respectively for 8 weeks, placebo group received 500 mg/kg/day d-Gal plus propylene glycol as placebo, and control group received normal saline during this period of time. Auditory brainstem responses were measured at several frequencies (4, 6, 8, 12 and 16 kHz) before and after the intervention. Placebo group and group 3 showed significant ABR threshold increase across frequencies of 4, 6, 16 kHz compared with the other groups (P < 0.05). However, rats treated with silymarin 100 and 200 mg/kg/day plus d-Gal did not show any significant ABR threshold shifts. Similarly, ABR amplitude of P2 at 4, 8 kHz and P1, P4 at 4 kHz in the placebo group and group 3 were decreased significantly compared with other groups (P < 0.05). However, no significant differences are found in ABR absolute and inter-peak latencies between groups (P > 0.05). The findings indicates that silymarin with doses of 100 and 200 mg/kg/day has protective effect against ARHL and it can be supplemented into the diet of older people to slow down the progression of age-related hearing loss.
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Affiliation(s)
- Elham Tavanai
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Pich-e-Shemiran, Enghelab Ave, Tehran, Iran
| | - Ghassem Mohammadkhani
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Pich-e-Shemiran, Enghelab Ave, Tehran, Iran
| | - Saeid Farahani
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Pich-e-Shemiran, Enghelab Ave, Tehran, Iran
| | - Shohreh Jalaie
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Pich-e-Shemiran, Enghelab Ave, Tehran, Iran
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Sánchez-Rodríguez C, Cuadrado E, Riestra-Ayora J, Sanz-Fernández R. Polyphenols protect against age-associated apoptosis in female rat cochleae. Biogerontology 2018; 19:159-169. [PMID: 29363005 DOI: 10.1007/s10522-018-9747-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/18/2018] [Indexed: 01/13/2023]
Abstract
Dietary antioxidants, polyphenols, have been found to be beneficial in protecting against the generation of oxidative stress in various diseases associated with aging. Age-related hearing loss (AHL) is the number one neurodegenerative disorder on our aged population. Sprague-Dawley rats divided into five groups according to their age (3, 6, 12, 18 and 24 months old) and treated with 100 mg/day/kg body weight of polyphenols were used. Then, cochleae were harvested to measure caspase activities (- 3, - 8 and - 9), caspase-3 gene expression, ATP levels, Bax, BcL-2 and p53 levels. 8-OHdG levels (marker of DNA oxidative damage) and annexin-V were also measured in cochleae. Increased levels of caspase-3 and 9 in cochlea were observed with age and this effect was attenuated by polyphenol treatment. In addition, ATP and Bcl-2 levels in older rats were recovered after administration of polyphenols, while Bax and p53 levels protein decreased. Oral supplementation with polyphenols also reduces DNA oxidative damage of cochlear cell. Treatment with polyphenols inhibits the activation of age-related apoptotic signaling by decreasing oxidative stress inside the rat cochlea.
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Affiliation(s)
| | - Esperanza Cuadrado
- Department of biochemistry, University Hospital of Getafe, Carretera de Toledo, km 12, Getafe, 500, Madrid, Spain
| | - Juan Riestra-Ayora
- European University of Madrid, Calle del Tajo S/N, Villaviciosa de Odón, 28670, Madrid, Spain
- Department of Otolaryngology, University Hospital of Getafe, Carretera de Toledo, km 12, Getafe, 500, Madrid, Spain
| | - Ricardo Sanz-Fernández
- European University of Madrid, Calle del Tajo S/N, Villaviciosa de Odón, 28670, Madrid, Spain
- Department of Otolaryngology, University Hospital of Getafe, Carretera de Toledo, km 12, Getafe, 500, Madrid, Spain
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Abstract
OBJECTIVE To critically review and evaluate the proposed mechanisms and documented results of the therapeutics currently in active clinical drug trials for the treatment of sensorineural hearing loss. DATA SOURCES US National Institutes of Health (NIH) Clinical Trials registry, MEDLINE/PubMed. STUDY SELECTION & DATA EXTRACTION A review of the NIH Clinical Trials registry identified candidate hearing loss therapies, and supporting publications were acquired from MEDLINE/PubMed. Proof-of-concept, therapeutic mechanisms, and clinical outcomes were critically appraised. DATA SYNTHESIS Twenty-two active clinical drug trials registered in the United States were identified, and six potentially therapeutic molecules were reviewed. Of the six molecules reviewed, four comprised mechanisms pertaining to mitigating oxidative stress pathways that presumably lead to inner ear cell death. One remaining therapy sought to manipulate the cell death cascade, and the last remaining therapy was a novel cell replacement therapy approach to introduce a transcription factor that promotes hair cell regeneration. CONCLUSION A common theme in recent clinical trials registered in the United States appears to be the targeting of cell death pathways and influence of oxidant stressors on cochlear sensory neuroepithelium. In addition, a virus-delivered cell replacement therapy would be the first of its kind should it prove safe and efficacious. Significant challenges for bringing these bench-to-bedside therapies to market remain. It is never assured that results in non-human animal models translate to effective therapies in the setting of human biology. Moreover, as additional processes are described in association with hearing loss, such as an immune response and loss of synaptic contacts, additional pathways for targeting become available.
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Affiliation(s)
- Matthew G. Crowson
- Division of Head & Neck Surgery & Communication Sciences, Department of Surgery, Duke University Medical Center, Durham, NC USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head & Neck Surgery, Anatomy and Neurobiology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD USA
| | - Debara Tucci
- Division of Head & Neck Surgery & Communication Sciences, Department of Surgery, Duke University Medical Center, Durham, NC USA
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Gao L, Ge R, Xie G, Yao D, Li P, Wang O, Ma X, Han F. Hearing Improvement in A/J Mice via the Mouse Nerve Growth Factor. Clin Exp Otorhinolaryngol 2017; 10:303-308. [PMID: 28264554 PMCID: PMC5678043 DOI: 10.21053/ceo.2016.01354] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 12/26/2016] [Accepted: 01/19/2017] [Indexed: 12/13/2022] Open
Abstract
Objectives To investigate the otoprotective effects of mouse nerve growth factor (mNGF) in A/J mice. Methods The mice at postnatal day 7 (P7) were randomly separated into a mNGF treated group (mNGF group) and a distilled water (for injection) treated group (control group). The mNGF dissolved in distilled water or distilled water alone was given to the mice once every other day from P7 by intramuscular injection in the hips. The otoprotective effects of mNGF in A/J mice were observed in a time course manner. The thresholds of auditory-evoked brainstem response (ABR) were tested from the age of the 3rd to the 8th week. Sections of the inner ears were stained by hematoxylin and eosin, and spiral ganglion neurons (SGNs) were observed at the age of the 3rd, the 6th,and the 8th week. Counts of whole mount outer hair cells (OHCs) in the cochleae were made at the age of 8 weeks. Expression of apoptosis related genes was determined by quantitative real-time polymerase chain reaction and Western blotting. Results ABR thresholds of the mNGF group were significantly lower than those of the control group at the age of the 6th and the 8th week. Moreover, the mNGF preserved OHC and SGN in the mouse cochleae in this period. Further experiments showed that the expression of caspase genes (including caspase-3) was inhibited in the mouse inner ears in the mNGF group. Conclusion The mNGF improves hearing in A/J mice by preserving SGN and OHC in the cochleae.
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Affiliation(s)
- Lixiang Gao
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China.,Department of Neurology, University Hospital of Binzhou Medical University, Binzhou, China
| | - Ruli Ge
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China.,Department of Neurology, University Hospital of Binzhou Medical University, Binzhou, China
| | - Gang Xie
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China
| | - Dandan Yao
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China
| | - Ping Li
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China
| | - Oumei Wang
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China
| | - Xiufang Ma
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China.,Department of Otorhinolaryngology Head and Neck Surgery, University Hospital of Binzhou Medical University, Binzhou, China
| | - Fengchan Han
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, Yantai, China.,Department of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, China
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Reduced expression of citrate synthase leads to excessive superoxide formation and cell apoptosis. Biochem Biophys Res Commun 2017; 485:388-394. [PMID: 28216161 DOI: 10.1016/j.bbrc.2017.02.067] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 02/13/2017] [Indexed: 02/04/2023]
Abstract
A/J mice are a mouse model of age-related hearing loss. It has been demonstrated that a mutation in gene of citrate synthase (CS) contributes to the early onset of hearing loss occurring at about one month of age. To understand the effects of a decreased CS activity that results from the mutation in Cs gene on hearing loss in A/J mice, human kidney cell line (293T) was transiently transfected with short hairpin RNA for Cs (shRNA-Cs) to reduce expression of CS. In comparison with those of cells transfected with a scrambled sequence (shRNA-NC), the oxygen consumption rate and adenosine trisphosphate (ATP) production level were decreased in 293T cells transfected with shRNA-Cs. Meanwhile, excessive superoxide production was induced as determined by mitochondrial superoxide formation assay (MitoSOX) and superoxide dismutase 2 (SOD2) detection. Moreover, the expression levels of BIP (binding immunoglobulin protein) and CHOP (CCAAT/enhancer-binding protein-homologous protein), markers of endoplasmic reticulum stress, were upregulated. Furthermore, apoptosis related molecule caspase-3 and the mitochondrial membrane potential were reduced. It is therefore concluded that downregulation of Cs expression in 293T cells leads to low level of ATP production, excessive superoxide formation and cell apoptosis, which implies a possible mechanism for hearing loss in A/J mice.
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Functionally and morphologically damaged mitochondria observed in auditory cells under senescence-inducing stress. NPJ Aging Mech Dis 2017. [PMID: 28649420 PMCID: PMC5445612 DOI: 10.1038/s41514-017-0002-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We aimed at determining the mitochondrial function in premature senescence model of auditory cells. Short exposure to H2O2 (1 h, 0.1 mM) induced premature cellular senescence in House Ear Institute-Organ of Corti 1 auditory cells. The transmission electron microscopy analysis revealed that damaged mitochondria and autophagosomes containing dense organelles appeared in the auditory cells after short exposure to H2O2. The branch and junction parameters of the skeletonized image of the mitochondria were found to decrease significantly in H2O2-treated cells. A branched reticulum of tubules was poorly formed, featuring coexistence of numerous tiny clusters along with few relatively large entities in the H2O2-treated cells. In terms of bioenergetics, H2O2-treatment led to the dose-dependent decrease in mitochondrial membrane potential in the auditory cells. The fragmented mitochondria (fusion < fission) were in a low potential. In addition, the potential of hyperfused mitochondria (fusion > fission) was slightly lower than the control cells. The short-time exposure of live auditory cells to H2O2 damaged the mitochondrial respiratory capacity without any effect on the baseline ATP production rates. The vulnerability of the mitochondrial membrane potential to the uncoupling reagent was increased after H2O2 treatment. Our findings indicated that the mitochondrial dysfunction due to the decline in the O2 consumption rate should be the first event of premature senescence process in the auditory cells, resulting in the imbalance of mitochondrial fusion/fission and the collapse of the mitochondrial network.
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Tavanai E, Mohammadkhani G. Role of antioxidants in prevention of age-related hearing loss: a review of literature. Eur Arch Otorhinolaryngol 2016; 274:1821-1834. [PMID: 27858145 DOI: 10.1007/s00405-016-4378-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 11/08/2016] [Indexed: 01/21/2023]
Abstract
Age-related hearing loss (ARHL), also known as presbycusis, is one of the most prevalent chronic degenerative conditions. It is characterized by a decline in auditory function. ARHL is caused by the interaction of multiple factors, including cochlear aging, environment, genetic predisposition, and health comorbidities. The primary pathology of ARHL includes the hair cells loss, stria vascularis atrophy, and loss of spiral ganglion neurons as well as the changes in central auditory pathways. The research to date suggests that oxidative stress and mitochondrial DNA deletion (mtDNA) play a major role in pathophysiology of ARHL. Therefore, similar to other otological conditions, several studies have also showed that antioxidants can slow ARHL, but some also indicate that antioxidant therapy is not a magic elixir that will prevent or treat hearing loss associated with aging completely, but why? All available clinical trials, including animal and human studies, in English language that examined the protective effects of antioxidants against ARHL were reviewed. Materials were obtained by searching ELSEVIER, PubMed, Scopus, Web of knowledge, Google Scholar databases, Clinical trials, and Cochrane database of systematic reviews. Although ARHL has been shown to be slowed by supplementation with antioxidants, particularly in laboratory animals, a few studies have investigated the effect of interventions against ARHL in humans. High-quality clinical trials are needed to investigate if ARHL can be delayed or prevented in humans. However, it seems that targeting several cell-death pathways is better than targeting the only oxidative stress pathway.
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Affiliation(s)
- Elham Tavanai
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Piche-Shemiran, Enghelab Ave, Tehran, Iran
| | - Ghassem Mohammadkhani
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Piche-Shemiran, Enghelab Ave, Tehran, Iran.
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Kasica N, Podlasz P, Sundvik M, Tamas A, Reglodi D, Kaleczyc J. Protective Effects of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Against Oxidative Stress in Zebrafish Hair Cells. Neurotox Res 2016; 30:633-647. [PMID: 27557978 PMCID: PMC5047952 DOI: 10.1007/s12640-016-9659-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/26/2016] [Accepted: 08/09/2016] [Indexed: 12/30/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide, with known antiapoptotic functions. Our previous in vitro study has demonstrated the ameliorative role of PACAP-38 in chicken hair cells under oxidative stress conditions, but its effects on living hair cells is now yet known. Therefore, the aim of the present study was to investigate in vivo the protective role of PACAP-38 in hair cells found in zebrafish (Danio rerio) sense organs-neuromasts. To induce oxidative stress the 5-day postfertilization (dpf) zebrafish larvae were exposed to 1.5 mM H2O2 for 15 min or 1 h. This resulted in an increase in caspase-3 and p-38 MAPK level in the hair cells as well as in an impairment of the larvae basic behavior. To investigate the ameliorative role of PACAP-38, the larvae were incubated with a mixture of 1.5 mM H2O2 and 100 nM PACAP-38 following 1 h preincubation with 100 nM PACAP-38 only. PACAP-38 abilities to prevent hair cells from apoptosis were investigated. Whole-mount immunohistochemistry and confocal microscopy analyses revealed that PACAP-38 treatment decreased the cleaved caspase-3 level in the hair cells, but had no influence on p-38 MAPK. The analyses of basic locomotor activity supported the protective role of PACAP-38 by demonstrating the improvement of the fish behavior after PACAP-38 treatment. In summary, our in vivo findings demonstrate that PACAP-38 protects zebrafish hair cells from oxidative stress by attenuating oxidative stress-induced apoptosis.
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Affiliation(s)
- Natalia Kasica
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, box 105J, 10-719, Olsztyn, Poland.
| | - Piotr Podlasz
- Department of Pathophysiology, Forensic Veterinary and Administration, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719, Olsztyn, Poland
| | - Maria Sundvik
- Department of Anatomy, Neuroscience Center, University of Helsinki, Haartmaninkatu 8 (Biomedicum Helsinki), 00290, Helsinki, Finland
| | - Andrea Tamas
- Department of Anatomy, University of Pecs, Szigeti 12, 7624, Pecs, Hungary
| | - Dora Reglodi
- Department of Anatomy, University of Pecs, Szigeti 12, 7624, Pecs, Hungary
| | - Jerzy Kaleczyc
- Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, box 105J, 10-719, Olsztyn, Poland
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Han F, Wang O, Cai Q. Anti-apoptotic treatment in mouse models of age-related hearing loss. J Otol 2016; 11:7-12. [PMID: 29937804 PMCID: PMC6002598 DOI: 10.1016/j.joto.2016.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 01/05/2023] Open
Abstract
Age-related hearing loss (AHL), or presbycusis, is the most common neurodegenerative disorder and top communication deficit of the aged population. Genetic predisposition is one of the major factors in the development of AHL. Generally, AHL is associated with an age-dependent loss of sensory hair cells, spiral ganglion neurons and stria vascularis cells in the inner ear. Although the mechanisms leading to genetic hearing loss are not completely understood, caspase-family proteases function as important signals in the inner ear pathology. It is now accepted that mouse models are the best tools to study the mechanism of genetic hearing loss or AHL. Here, we provide a brief review of recent studies on hearing improvement in mouse models of AHL by anti-apoptotic treatment.
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Affiliation(s)
- Fengchan Han
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
- Institute of Neurobiology, School of Special Education, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
- Corresponding author. Key Laboratory for Genetic Hearing Disorders in Shandong, and Institute of Neurobiology, School of Special Education, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China.
| | - Oumei Wang
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
- Institute of Neurobiology, School of Special Education, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
| | - Quanxiang Cai
- Key Laboratory for Genetic Hearing Disorders in Shandong, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
- Institute of Neurobiology, School of Special Education, Binzhou Medical University, 346 Guanhai Road, Yantai 264003, Shandong, PR China
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Dong Y, Guo CR, Ding Y, Zhang Y, Song HY, Peng YT, Zhang T, Shi JR. Effects of Erlong Zuoci decoction on the age-related hearing loss in C57BL/6J mice. JOURNAL OF ETHNOPHARMACOLOGY 2016; 181:59-65. [PMID: 26826327 DOI: 10.1016/j.jep.2016.01.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/12/2015] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Erlong Zuoci decoction (ELZCD), a typical traditional Chinese medicine (TCM) prescription, has long been clinically used in treatment of deafness and tinnitus with the syndrome of "kidney yin deficiency". However, there are few studies to investigate its pharmacological mechanisms. Until now, there is not report about its effects on the age-related hearing loss (ARHL). AIM OF STUDY The present study was conducted to observe the effects of ELZCD on the ARHL in C57BL/6J mice and explore the mechanisms. MATERIALS AND METHODS ELZCD was fed to C57BL/6J mice from 3 months to 6 months in ELZCD group as a dose of 6g/kg/d. And the same volume of saline was fed to mice in ARHL group. 3-months-old C57BL/6J mice were used as control group. High performance liquid chromatography (HPLC) was used for the quality control of ELZCD. Auditory brainstem response (ABR) was used to assess the hearing function of mice. The morphologic changes were observed by hematoxylin eosin (HE) staining. Apoptosis was tested by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method. Mitochondrial damage was detected by transmission electron microscopy (TEM). Quantitative RT-PCR (qRT-PCR) was used to observe the mRNA expression of p53 and Bak. Fluorescence immunohistochemical technique was used to test the protein expression of p53 and Bak. RESULTS The hearing threshold of ARHL group was higher than that of control group (P<0.001) and ELZCD decreased the rise of hearing threshold levels of ARHL mice (P<0.001), which suggested ELZCD inhibited the hearing loss of ARHL mice. HE staining showed that ELZCD decreased the spiral ganglion (SG) cell damage and loss in ARHL. TUNEL test showed that the apoptotic SG cells increased in ARHL group compared to control group and decreased in ELZCD group compared to ARHL group. TEM observation showed that mitochondrial damage was obvious in SG cells of ARHL group and ELZCD inhibited the mitochondrial damage. The qRT-PCR results showed that the mRNA expression of p53 and Bak in ARHL group increased compared to that of control group (P<0.05), and ELZCD reduced the elevated mRNA expression levels of p53 and Bak (P<0.01, P<0.05). In addition, ELZCD inhibited the increased proteins expression (green fluorescence) of p53 and Bak. CONCLUSION The results demonstrated that ELZCD prevented ARHL in C57BL/6J mice and p53/Bak-mediated mitochondrial apoptosis of SG cells might be involved in the mechanisms.
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Affiliation(s)
- Yang Dong
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Chun-Rong Guo
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yue Ding
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hai-Yan Song
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yin-Ting Peng
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Tong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jian-Rong Shi
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Stebbings KA, Choi HW, Ravindra A, Llano DA. The impact of aging, hearing loss, and body weight on mouse hippocampal redox state, measured in brain slices using fluorescence imaging. Neurobiol Aging 2016; 42:101-9. [PMID: 27143426 DOI: 10.1016/j.neurobiolaging.2016.03.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/18/2016] [Accepted: 03/05/2016] [Indexed: 01/21/2023]
Abstract
The relationships between oxidative stress in the hippocampus and other aging-related changes such as hearing loss, cortical thinning, or changes in body weight are not yet known. We measured the redox ratio in a number of neural structures in brain slices taken from young and aged mice. Hearing thresholds, body weight, and cortical thickness were also measured. We found striking aging-related increases in the redox ratio that were isolated to the stratum pyramidale, while such changes were not observed in thalamus or cortex. These changes were driven primarily by changes in flavin adenine dinucleotide, not nicotinamide adenine dinucleotide hydride. Multiple regression analysis suggested that neither hearing threshold nor cortical thickness independently contributed to this change in hippocampal redox ratio. However, body weight did independently contribute to predicted changes in hippocampal redox ratio. These data suggest that aging-related changes in hippocampal redox ratio are not a general reflection of overall brain oxidative state but are highly localized, while still being related to at least one marker of late aging, weight loss at the end of life.
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Affiliation(s)
- Kevin A Stebbings
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Hyun W Choi
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Aditya Ravindra
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Daniel Adolfo Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
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