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Maruyama A, Kawashima Y, Fukunaga Y, Makabe A, Nishio A, Tsutsumi T. Susceptibility of mouse cochlear hair cells to cisplatin ototoxicity largely depends on sensory mechanoelectrical transduction channels both Ex Vivo and In Vivo. Hear Res 2024; 447:109013. [PMID: 38718672 DOI: 10.1016/j.heares.2024.109013] [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: 01/28/2024] [Revised: 03/28/2024] [Accepted: 04/18/2024] [Indexed: 05/25/2024]
Abstract
Cisplatin, a highly effective chemotherapeutic drug for various human cancers, induces irreversible sensorineural hearing loss as a side effect. Currently there are no highly effective clinical strategies for the prevention of cisplatin-induced ototoxicity. Previous studies have indicated that short-term cisplatin ototoxicity primarily affects the outer hair cells of the cochlea. Therefore, preventing the entry of cisplatin into hair cells may be a promising strategy to prevent cisplatin ototoxicity. This study aimed to investigate the entry route of cisplatin into mouse cochlear hair cells. The competitive inhibitor of organic cation transporter 2 (OCT2), cimetidine, and the sensory mechanoelectrical transduction (MET) channel blocker benzamil, demonstrated a protective effect against cisplatin toxicity in hair cells in cochlear explants. Sensory MET-deficient hair cells explanted from Tmc1Δ;Tmc2Δ mice were resistant to cisplatin toxicity. Cimetidine showed an additive protective effect against cisplatin toxicity in sensory MET-deficient hair cells. However, in the apical turn, cimetidine, benzamil, or genetic ablation of sensory MET channels showed limited protective effects, implying the presence of other entry routes for cisplatin to enter the hair cells in the apical turn. Systemic administration of cimetidine failed to protect cochlear hair cells from ototoxicity caused by systemically administered cisplatin. Notably, outer hair cells in MET-deficient mice exhibited no apparent deterioration after systemic administration of cisplatin, whereas the outer hair cells in wild-type mice showed remarkable deterioration. The susceptibility of mouse cochlear hair cells to cisplatin ototoxicity largely depends on the sensory MET channel both ex vivo and in vivo. This result justifies the development of new pharmaceuticals, such as a specific antagonists for sensory MET channels or custom-designed cisplatin analogs which are impermeable to sensory MET channels.
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MESH Headings
- Cisplatin/toxicity
- Animals
- Ototoxicity/prevention & control
- Ototoxicity/metabolism
- Ototoxicity/physiopathology
- Mechanotransduction, Cellular/drug effects
- Organic Cation Transporter 2/metabolism
- Organic Cation Transporter 2/genetics
- Organic Cation Transporter 2/antagonists & inhibitors
- Cimetidine/pharmacology
- Antineoplastic Agents/toxicity
- Hair Cells, Auditory/drug effects
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/pathology
- Hair Cells, Auditory, Outer/drug effects
- Hair Cells, Auditory, Outer/pathology
- Hair Cells, Auditory, Outer/metabolism
- Mice, Inbred C57BL
- Mice
- Membrane Proteins
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Affiliation(s)
- Ayako Maruyama
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Yoshiyuki Kawashima
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
| | - Yoko Fukunaga
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54, Kawara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Ayane Makabe
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Ayako Nishio
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Takeshi Tsutsumi
- Department of Otolaryngology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
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Pasdelou MP, Byelyayeva L, Malmström S, Pucheu S, Peytavy M, Laullier H, Hodges DB, Tzafriri AR, Naert G. Ototoxicity: a high risk to auditory function that needs to be monitored in drug development. Front Mol Neurosci 2024; 17:1379743. [PMID: 38756707 PMCID: PMC11096496 DOI: 10.3389/fnmol.2024.1379743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/15/2024] [Indexed: 05/18/2024] Open
Abstract
Hearing loss constitutes a major global health concern impacting approximately 1.5 billion people worldwide. Its incidence is undergoing a substantial surge with some projecting that by 2050, a quarter of the global population will experience varying degrees of hearing deficiency. Environmental factors such as aging, exposure to loud noise, and the intake of ototoxic medications are implicated in the onset of acquired hearing loss. Ototoxicity resulting in inner ear damage is a leading cause of acquired hearing loss worldwide. This could be minimized or avoided by early testing of hearing functions in the preclinical phase of drug development. While the assessment of ototoxicity is well defined for drug candidates in the hearing field - required for drugs that are administered by the otic route and expected to reach the middle or inner ear during clinical use - ototoxicity testing is not required for all other therapeutic areas. Unfortunately, this has resulted in more than 200 ototoxic marketed medications. The aim of this publication is to raise awareness of drug-induced ototoxicity and to formulate some recommendations based on available guidelines and own experience. Ototoxicity testing programs should be adapted to the type of therapy, its indication (targeting the ear or part of other medications classes being potentially ototoxic), and the number of assets to test. For multiple molecules and/or multiple doses, screening options are available: in vitro (otic cell assays), ex vivo (cochlear explant), and in vivo (in zebrafish). In assessing the ototoxicity of a candidate drug, it is good practice to compare its ototoxicity to that of a well-known control drug of a similar class. Screening assays provide a streamlined and rapid method to know whether a drug is generally safe for inner ear structures. Mammalian animal models provide a more detailed characterization of drug ototoxicity, with a possibility to localize and quantify the damage using functional, behavioral, and morphological read-outs. Complementary histological measures are routinely conducted notably to quantify hair cells loss with cochleogram. Ototoxicity studies can be performed in rodents (mice, rats), guinea pigs and large species. However, in undertaking, or at the very least attempting, all preclinical investigations within the same species, is crucial. This encompasses starting with pharmacokinetics and pharmacology efficacy studies and extending through to toxicity studies. In life read-outs include Auditory Brainstem Response (ABR) and Distortion Product OtoAcoustic Emissions (DPOAE) measurements that assess the activity and integrity of sensory cells and the auditory nerve, reflecting sensorineural hearing loss. Accurate, reproducible, and high throughput ABR measures are fundamental to the quality and success of these preclinical trials. As in humans, in vivo otoscopic evaluations are routinely carried out to observe the tympanic membrane and auditory canal. This is often done to detect signs of inflammation. The cochlea is a tonotopic structure. Hair cell responsiveness is position and frequency dependent, with hair cells located close to the cochlea apex transducing low frequencies and those at the base transducing high frequencies. The cochleogram aims to quantify hair cells all along the cochlea and consequently determine hair cell loss related to specific frequencies. This measure is then correlated with the ABR & DPOAE results. Ototoxicity assessments evaluate the impact of drug candidates on the auditory and vestibular systems, de-risk hearing loss and balance disorders, define a safe dose, and optimize therapeutic benefits. These types of studies can be initiated during early development of a therapeutic solution, with ABR and otoscopic evaluations. Depending on the mechanism of action of the compound, studies can include DPOAE and cochleogram. Later in the development, a GLP (Good Laboratory Practice) ototoxicity study may be required based on otic related route of administration, target, or known potential otic toxicity.
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YAMAGUCHI T, YONEYAMA M, ONAKA Y, OGITA K. A novel model of sensorineural hearing loss induced by repeated exposure to moderate noise in mice: the preventive effect of resveratrol. J Vet Med Sci 2024; 86:381-388. [PMID: 38369331 PMCID: PMC11061573 DOI: 10.1292/jvms.23-0477] [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: 11/24/2023] [Accepted: 02/04/2024] [Indexed: 02/20/2024] Open
Abstract
Sensorineural hearing loss (SNHL) induced by noise has increased in recent years due to personal headphone use and noisy urban environments. The study shows a novel model of gradually progressive SNHL induced by repeated exposure to moderate noise (8-kHz octave band noise, 90-dB sound pressure level) for 1 hr exposure per day in BALB/cCr mice. The results showed that the repeated exposure led to gradually progressive SNHL, which was dependent on the number of exposures, and resulted in permanent hearing loss after 5 exposures. Repeated exposure to noise causes a loss of synapses between the inner hair cells and the peripheral terminals of the auditory nerve fibers. Additionally, there is a reduction in the expression levels of c-fos and Arc, both of which are indicators of cochlear nerve responses to noise exposure. Oral administration of resveratrol (RSV, 50 mg/kg/day) during the noise exposure period significantly prevented the noise exposure-induced synapse loss and SNHL. Furthermore, the study found that RSV treatment prevented the noise-induced increase in the gene expression levels of the proinflammatory cytokine interleukin-1β in the cochlea. These results demonstrated the potential usefulness of RSV in preventing noise-induced SNHL in the animal model established as gradually progressive SNHL.
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Affiliation(s)
- Taro YAMAGUCHI
- Laboratory of Pharmacology, Faculty of Pharmaceutical
Sciences, Setsunan University, Osaka, Japan
| | - Masanori YONEYAMA
- Laboratory of Pharmacology, Faculty of Pharmaceutical
Sciences, Setsunan University, Osaka, Japan
| | - Yusuke ONAKA
- Laboratory of Pharmacology, Faculty of Pharmaceutical
Sciences, Setsunan University, Osaka, Japan
| | - Kiyokazu OGITA
- Faculty of Pharmaceutical Sciences, Setsunan University,
Osaka, Japan
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Gao Y, Wu F, He W, Cai Z, Pang J, Zheng Y. Reactive Oxygen Species-Related Disruptions to Cochlear Hair Cell and Stria Vascularis Consequently Leading to Radiation-Induced Sensorineural Hearing Loss. Antioxid Redox Signal 2024; 40:470-491. [PMID: 37476961 DOI: 10.1089/ars.2022.0161] [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] [Indexed: 07/22/2023]
Abstract
Aims: Radiation-induced sensorineural hearing loss (RISNHL) is one of the major side effects of radiotherapy for head and neck cancers. At present, no effective clinical treatment or prevention is available for RISNHL. This study thus aimed to investigate the cochlear pathology so that the underlying mechanisms of RISNHL may be elucidated, consequently paving the way for potential protective strategies to be developed. Results: Functional and morphological impairment in the stria vascularis (SV) was observed after irradiation (IR), as indicated by endocochlear potential (EP) reduction, hyperpermeability, and SV atrophy. The expression of zonulae occludins-1 was found to have decreased after IR. The loss of outer hair cells (OHCs) occurred later than SV damage. The disruption to the SV and OHCs could be attributed to reactive oxygen species (ROS)-related damage. In addition, EP shifts and the loss of OHCs were reduced when ROS was reduced by N-acetylcysteine (NAC) in C57BL/6 mice, attenuating auditory threshold shifts. Innovation: The damage to the SV was found to occur before OHC loss. ROS-related damage accounted for SV damage and OHC loss. The incidences of SV damage and OHC loss were decreased through ROS modulation by NAC, subsequently preventing RISNHL, suggesting the possible role of NAC as a possible protective agent against RISNHL. Conclusion: The findings from this study suggest oxidative stress-induced early SV injury and late OHC loss to be the key factors leading to RISNHL. NAC prevents IR-induced OHC loss, and attenuates auditory brainstem response and EP shifts by regulating the level of oxidative stress. Antioxid. Redox Signal. 40, 470-491.
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Affiliation(s)
- Yiming Gao
- 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
- 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
| | - Fan Wu
- 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
- 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
| | - Wuhui He
- 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
- 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
| | - Ziyi Cai
- 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
- 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
| | - Jiaqi Pang
- 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
- 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
| | - Yiqing Zheng
- 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
- 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
- Shenshan Medical Center, Sun Yat-Sen Memorial Hospital, Shanwei, China
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Wu F, Hu R, Huang X, Lou J, Cai Z, Chen G, Zhao W, Xiong H, Sha SH, Zheng Y. CFTR potentiator ivacaftor protects against noise-induced hair cell loss by increasing Nrf2 and reducing oxidative stress. Biomed Pharmacother 2023; 166:115399. [PMID: 37657258 PMCID: PMC10528730 DOI: 10.1016/j.biopha.2023.115399] [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: 06/12/2023] [Revised: 08/23/2023] [Accepted: 08/26/2023] [Indexed: 09/03/2023] Open
Abstract
Over-production of reactive oxygen species (ROS) in the inner ear can be triggered by a variety of pathological events identified in animal models after traumatic noise exposure. Our previous research found that inhibition of the AMP-activated protein kinase alpha subunit (AMPKα) protects against noise-induced cochlear hair cell loss and hearing loss by reducing ROS accumulation. However, the molecular pathway through which AMPKα exerts its antioxidative effect is still unclear. In this study, we have investigated a potential target of AMPKα and ROS, cystic fibrosis transmembrane conductance regulator (CFTR), and the protective effect against noise-induced hair cell loss of an FDA-approved CFTR potentiator, ivacaftor, in FVB/NJ mice, mouse explant cultures, and HEI-OC1 cells. We found that noise exposure increases phosphorylation of CFTR at serine 737 (p-CFTR, S737), which reduces wildtype CFTR function, resulting in oxidative stress in cochlear sensory hair cells. Pretreatment with a single dose of ivacaftor maintains CFTR function by preventing noise-increased p-CFTR (S737). Furthermore, ivacaftor treatment increases nuclear factor E2-related factor 2 (Nrf2) expression, diminishes ROS formation, and attenuates noise-induced hair cell loss and hearing loss. Additionally, inhibition of noise-induced AMPKα activation by compound C also diminishes p-CFTR (S737) expression. In line with these in-vivo results, administration of hydrogen peroxide to cochlear explants or HEI-OC1 cells increases p-CFTR (S737) expression and induces sensory hair cell or HEI-OC1 cell damage, while application of ivacaftor halts these effects. Although ivacaftor increases Nrf2 expression and reduces ROS accumulation, cotreatment with ML385, an Nrf2 inhibitor, abolishes the protective effects of ivacaftor against hydrogen-peroxide-induced HEI-OC1 cell death. Our results indicate that noise-induced sensory hair cell damage is associated with p-CFTR. Ivacaftor has potential for treatment of noise-induced hearing loss by maintaining CFTR function and increasing Nrf2 expression for support of redox homeostasis in sensory hair cells.
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Affiliation(s)
- Fan Wu
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China; Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC, USA
| | - Rui Hu
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Shenshan Medical Center, Memorial Hospital of Sun Yat-sen University, Shanwei, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Xueping Huang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Jintao Lou
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Ziyi Cai
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Guisheng Chen
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Wenji Zhao
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Hao Xiong
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China
| | - Su-Hua Sha
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC, USA.
| | - Yiqing Zheng
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Shenshan Medical Center, Memorial Hospital of Sun Yat-sen University, Shanwei, Guangdong, China; Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou 510120, China.
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Cortada M, Levano S, Hall MN, Bodmer D. mTORC2 regulates auditory hair cell structure and function. iScience 2023; 26:107687. [PMID: 37694145 PMCID: PMC10484995 DOI: 10.1016/j.isci.2023.107687] [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: 03/30/2023] [Revised: 07/14/2023] [Accepted: 08/17/2023] [Indexed: 09/12/2023] Open
Abstract
mTOR broadly controls cell growth, but little is known about the role of mTOR complex 2 (mTORC2) in the inner ear. To investigate the role of mTORC2 in sensory hair cells (HCs), we generated HC-specific Rictor knockout (HC-RicKO) mice. HC-RicKO mice exhibited early-onset, progressive, and profound hearing loss. Increased DPOAE thresholds indicated outer HC dysfunction. HCs are lost, but this occurs after hearing loss. Ultrastructural analysis revealed stunted and absent stereocilia in outer HCs. In inner HCs, the number of synapses was significantly decreased and the remaining synapses displayed a disrupted actin cytoskeleton and disorganized Ca2+ channels. Thus, the mTORC2 signaling pathway plays an important role in regulating auditory HC structure and function via regulation of the actin cytoskeleton. These results provide molecular insights on a central regulator of cochlear HCs and thus hearing.
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Affiliation(s)
- Maurizio Cortada
- Department of Biomedicine, University of Basel, CH-4031 Basel, Switzerland
| | - Soledad Levano
- Department of Biomedicine, University of Basel, CH-4031 Basel, Switzerland
| | | | - Daniel Bodmer
- Department of Biomedicine, University of Basel, CH-4031 Basel, Switzerland
- Clinic for Otorhinolaryngology, Head and Neck Surgery, University of Basel Hospital, CH-4031 Basel, Switzerland
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Kobayashi Y, Sugahara K, Takemoto Y, Tsuda J, Hirose Y, Hashimoto M, Yamashita H. Protective effect of astaxanthin nanoemulsion on mammalian inner ear hair cells. PeerJ 2023; 11:e15562. [PMID: 37701833 PMCID: PMC10494832 DOI: 10.7717/peerj.15562] [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: 11/26/2020] [Accepted: 05/24/2023] [Indexed: 09/14/2023] Open
Abstract
Background Aminoglycoside antibiotics are used for treating certain acute infections. However, these drugs cause ototoxicity by inducing inner ear hair cell death. Aims/Objectives We investigated the protective effect of a nanoemulsion of the carotenoid astaxanthin on mammalian inner ear hair cells against neomycin-induced ototoxicity. Material and Methods Dose-response relationship, quantification of hair cell loss, and reactive oxygen species production were assayed in response to neomycin with and without astaxanthin in cultured utricles of CBA/N mice. In addition, auditory brain response (ABR) and hair cell loss after exposure to the nanoformulation and loud noise were examined in vivo in guinea pigs. Results Astaxanthin suppressed neomycin-induced reduction of hair cells by reducing the production of hydroxy radicals. Furthermore, hair cell loss in the second rotation of the cochlea was significantly lower in the astaxanthin group than in the noise-only group. Conclusions and Significance The blood-labyrinth barrier limits the successful delivery of drugs for inner ear complications. However, in the nanoemulsion form, astaxanthin can penetrate the round window (fenestra ovale) membrane, enabling topical administration. Thus, astaxanthin nanoemulsion could be useful in treating ototoxicity in individuals with inner ear complications.
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Affiliation(s)
- Yuki Kobayashi
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Kazuma Sugahara
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Yosuke Takemoto
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Junko Tsuda
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Yoshinobu Hirose
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Makoto Hashimoto
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Hiroshi Yamashita
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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8
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Lai R, Fang Q, Wu F, Pan S, Haque K, Sha SH. Prevention of noise-induced hearing loss by calpain inhibitor MDL-28170 is associated with upregulation of PI3K/Akt survival signaling pathway. Front Cell Neurosci 2023; 17:1199656. [PMID: 37484825 PMCID: PMC10359991 DOI: 10.3389/fncel.2023.1199656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2023] [Indexed: 07/25/2023] Open
Abstract
Introduction Noise-induced calcium overload in sensory hair cells has been well documented as an early step in the pathogenesis of noise-induced hearing loss (NIHL). Alterations in cellular calcium homeostasis mediate a series of cellular events, including activation of calcium-dependent protein kinases and phosphatases. Using cell-membrane- and blood-brain-barrier-permeable calpain-1 (μ-calpain) and calpain-2 (m-calpain) inhibitor MDL-28170, we tested the involvement of calpains, a family of calcium-dependent cysteine proteases, and the potential of MDL-28170 in preventing NIHL. Methods CBA/J mice at the age of 12 weeks were exposed to broadband noise with a frequency spectrum from 2-20 kHz for 2 h at 101 dB sound pressure level to induce permanent hearing loss as measured by auditory brainstem response and distortion product otoacoustic emissions. Morphological damage was assessed by quantification of remaining sensory hair cells and inner hair cell synapses 2 weeks after the exposure. Results MDL-28170 treatment by intraperitoneal injection significantly attenuated noise-induced functional deficits and cochlear pathologies. MDL-28170 treatment also prevented noise-induced cleavage of alpha-fodrin, a substrate for calpain-1. Furthermore, MDL-28170 treatment prevented reduction of PI3K/Akt signaling after exposure to noise and upregulated p85α and p-Akt (S473) in outer hair cells. Discussion These results indicate that noise-induced calpain activation negatively regulates PI3K/Akt downstream signaling, and that prevention of NIHL by treatment with MDL-28170 is associated with upregulation of PI3K/Akt survival signaling pathways.
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Affiliation(s)
- Ruosha Lai
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
- Department of Otolaryngology, Head and Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Qiaojun Fang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Fan Wu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Song Pan
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Khujista Haque
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Su-Hua Sha
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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Moysan L, Fazekas F, Fekete A, Köles L, Zelles T, Berekméri E. Ca 2+ Dynamics of Gap Junction Coupled and Uncoupled Deiters' Cells in the Organ of Corti in Hearing BALB/c Mice. Int J Mol Sci 2023; 24:11095. [PMID: 37446272 DOI: 10.3390/ijms241311095] [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: 04/24/2023] [Revised: 06/19/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
ATP, as a paracrine signalling molecule, induces intracellular Ca2+ elevation via the activation of purinergic receptors on the surface of glia-like cochlear supporting cells. These cells, including the Deiters' cells (DCs), are also coupled by gap junctions that allow the propagation of intercellular Ca2+ waves via diffusion of Ca2+ mobilising second messenger IP3 between neighbouring cells. We have compared the ATP-evoked Ca2+ transients and the effect of two different gap junction (GJ) blockers (octanol and carbenoxolone, CBX) on the Ca2+ transients in DCs located in the apical and middle turns of the hemicochlea preparation of BALB/c mice (P14-19). Octanol had no effect on Ca2+ signalling, while CBX inhibited the ATP response, more prominently in the middle turn. Based on astrocyte models and using our experimental results, we successfully simulated the Ca2+ dynamics in DCs in different cochlear regions. The mathematical model reliably described the Ca2+ transients in the DCs and suggested that the tonotopical differences could originate from differences in purinoceptor and Ca2+ pump expressions and in IP3-Ca2+ release mechanisms. The cochlear turn-dependent effect of CBX might be the result of the differing connexin isoform composition of GJs along the tonotopic axis. The contribution of IP3-mediated Ca2+ signalling inhibition by CBX cannot be excluded.
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Affiliation(s)
- Louise Moysan
- Department of Zoology, University of Veterinary Medicine Budapest, H-1078 Budapest, Hungary
| | - Fruzsina Fazekas
- Department of Zoology, University of Veterinary Medicine Budapest, H-1078 Budapest, Hungary
| | - Adam Fekete
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - László Köles
- Department of Oral Biology, Semmelweis University, H-1089 Budapest, Hungary
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary
| | - Tibor Zelles
- Department of Oral Biology, Semmelweis University, H-1089 Budapest, Hungary
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, H-1083 Budapest, Hungary
| | - Eszter Berekméri
- Department of Zoology, University of Veterinary Medicine Budapest, H-1078 Budapest, Hungary
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary
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10
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Cutri RM, Lin J, Nguyen NV, Shakya D, Shibata SB. Neomycin-Induced Deafness in Neonatal Mice. J Neurosci Methods 2023; 391:109852. [PMID: 37031766 DOI: 10.1016/j.jneumeth.2023.109852] [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: 02/02/2023] [Revised: 03/26/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
BACKGROUND Hearing impairment is a rising public health issue, and current therapeutics fail to restore normal auditory sensation. Animal models are essential to a better understanding of the pathophysiology of deafness and developing therapeutics to restore hearing. NEW METHODS Wild-type CBA/CaJ neonatal mice P2-5 were used in this study. Neomycin suspension (500nl of 50 or 100mg/ml) was micro-injected into the endolymphatic space. Cochlear morphology was examined 3 and 7 days after injection; hair cell (HC) loss, supporting cell morphology, and neurite denervation pattern were assessed with whole-mounts. At 2 and 4 weeks post-injection, the spiral ganglion neuron (SGN) density was analyzed with cryostat sections. Audiometric responses were measured with auditory brain response (ABR) at 4 weeks. RESULTS Rapid and complete degeneration of the inner and outer HCs occurred as early as 3 days post-injection. Subsequently, time- and dose-dependent degeneration patterns were observed along the axis of the cochlear membranous labyrinth forming a flat epithelium. Likewise, the SGN histology demonstrated significant cell density reduction at 2 and 4 weeks. The ABR threshold measurements confirmed profound deafness at 4 weeks. COMPARISON WITH EXISTING METHODS Compared to previously described local and systemic aminoglycoside injections, this method provides a reliable, robust, and rapid deafening model with a single infusion of neomycin in neonatal mice. This model also allows for investigating the effects of inner ear damage during auditory maturation. CONCLUSIONS A single injection of neomycin into the endolymphatic space induces robust HC loss and denervation in neonatal mice.
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Affiliation(s)
- Raffaello M Cutri
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Joshua Lin
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Nhi V Nguyen
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA
| | - Dejan Shakya
- Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Seiji B Shibata
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA.
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11
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Iwasa Y, Klimara MJ, Yoshimura H, Walls WD, Omichi R, West CA, Shibata SB, Ranum PT, Smith RJ. Mutation-agnostic RNA interference with engineered replacement rescues Tmc1-related hearing loss. Life Sci Alliance 2023; 6:6/3/e202201592. [PMID: 36574989 PMCID: PMC9795038 DOI: 10.26508/lsa.202201592] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 12/28/2022] Open
Abstract
Hearing loss is the most common sensory deficit, of which genetic etiologies are a frequent cause. Dominant and recessive mutations in TMC1, a gene encoding the pore-forming subunit of the hair cell mechanotransduction channel, cause DFNA36 and DFNB7/11, respectively, accounting for ∼2% of genetic hearing loss. Previous work has established the efficacy of mutation-targeted RNAi in treatment of murine models of autosomal dominant non-syndromic deafness. However, application of such approaches is limited by the infeasibility of development and validation of novel constructs for each variant. We developed an allele-non-specific approach consisting of mutation-agnostic RNAi suppression of both mutant and WT alleles, co-delivered with a knockdown-resistant engineered WT allele with or without the use of woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) to augment transgene expression. This therapeutic construct was delivered into the mature murine model of DFNA36 with an AAV vector and achieved robust hair cell and auditory brainstem response preservation. However, WPRE-enhanced Tmc1 expression resulted in inferior outcomes, suggesting a role for gene dosage optimization in future TMC1 gene therapy development.
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Affiliation(s)
- Yoichiro Iwasa
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Miles J Klimara
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology - Head and Neck Surgery, University of Iowa, Iowa City, IA, USA
| | - Hidekane Yoshimura
- Department of Otolaryngology - Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - William D Walls
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology - Head and Neck Surgery, University of Iowa, Iowa City, IA, USA
| | - Ryotaro Omichi
- Department of Otolaryngology - Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Cody A West
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology - Head and Neck Surgery, University of Iowa, Iowa City, IA, USA
| | - Seiji B Shibata
- Department of Otolaryngology Head and Neck Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Paul T Ranum
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA
| | - Richard Jh Smith
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology - Head and Neck Surgery, University of Iowa, Iowa City, IA, USA
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12
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Ma PW, Wang WL, Chen JW, Yuan H, Lu PH, Gao W, Ding XR, Lun YQ, Liang R, He ZH, Yang Q, Lu LJ. Treatment with the Ferroptosis Inhibitor Ferrostatin-1 Attenuates Noise-Induced Hearing Loss by Suppressing Ferroptosis and Apoptosis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3373828. [PMID: 36531206 PMCID: PMC9750774 DOI: 10.1155/2022/3373828] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/29/2022] [Accepted: 11/12/2022] [Indexed: 08/17/2023]
Abstract
Hair cell death induced by excessive reactive oxygen species (ROS) has been identified as the major pathogenesis of noise-induced hearing loss (NIHL). Recent studies have demonstrated that cisplatin- and neomycin-induced ototoxicity can be alleviated by ferroptosis inhibitors. However, whether ferroptosis inhibitors have a protective effect against NIHL remains unknown. We investigated the protective effect of the ferroptosis inhibitor ferrostatin-1 (Fer-1) on NIHL in vivo in CBA/J mice and investigated the protective effect of Fer-1 on tert-butyl hydroperoxide (TBHP)-induced hair cell damage in vitro in cochlear explants and HEI-OC1 cells. We observed ROS overload and lipid peroxidation, which led to outer hair cell (OHC) apoptosis and ferroptosis, in the mouse cochlea after noise exposure. The expression level of apoptosis-inducing factor mitochondria-associated 2 (AIFM2) was substantially increased following elevation of the expression of its upstream protein P53 after noise exposure. The ferroptosis inhibitor Fer-1was demonstrated to enter the inner ear after the systemic administration. Administration of Fer-1 significantly alleviated noise-induced auditory threshold elevation and reduced the loss of OHCs, inner hair cell (IHC) ribbon synapses, and auditory nerve fibers (ANFs) caused by noise. Mechanistically, Fer-1 significantly reduced noise- and TBHP-induced lipid peroxidation and iron accumulation in hair cells, alleviating ferroptosis in cochlear cells consequently. Furthermore, Fer-1 treatment decreased the levels of TfR1, P53, and AIFM2. These results suggest that Fer-1 exerted its protective effects by scavenging of ROS and inhibition of TfR1-mediated ferroptosis and P53-AIFM2 signaling pathway-mediated apoptosis. Our findings suggest that Fer-1 is a promising drug for treating NIHL because of its ability to inhibit noise-induced hair cell apoptosis and ferroptosis, opening new avenues for the treatment of NIHL.
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Affiliation(s)
- Peng-Wei Ma
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Wei-Long Wang
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Jia-Wei Chen
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Hao Yuan
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Pei-Heng Lu
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Wei Gao
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Xue-Rui Ding
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Yu-Qiang Lun
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Rui Liang
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Zu-Hong He
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qian Yang
- Department of Experimental Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Lian-Jun Lu
- Department of Otolaryngology Head and Neck Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, China
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13
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Noise overstimulation of young adult UMHET4 mice accelerates age-related hearing loss. Hear Res 2022; 424:108601. [PMID: 36126618 DOI: 10.1016/j.heares.2022.108601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 08/16/2022] [Accepted: 09/03/2022] [Indexed: 11/22/2022]
Abstract
Many factors contribute to hearing loss commonly found in older adults. There can be natural aging of cellular elements, hearing loss previously induced by environmental factors such as noise or ototoxic drugs as well as genetic and epigenetic influences. Even when noise overstimulation does not immediately cause permanent hearing loss it has recently been shown to increase later age-related hearing loss (ARHL). The present study further investigated this condition in the UMHET4 mouse model by comparing a small arms fire (SAF)-like impulse noise exposure that has the greatest immediate effect in more apical cochlear regions to a broadband noise (BBN) exposure that has the greatest immediate effect in more basal cochlear regions. Both noise exposures were given at levels that only induced temporary auditory brainstem response (ABR) threshold shifts (TS). Mice were noise exposed at 5 months of age followed by ABR assessment at 6, 12, 18, 21, and 24 months of age. Mice that received the SAF-like impulse noise had accelerated age-related TS at 4 kHz that appeared at 12 months of age (significantly increased compared to no-noise controls). This increased TS at 4 kHz continued at 18 and 21 months but was no longer significantly greater at 24 months of age. The SAF-like impulse noise also induced a significantly greater mean TS at 48 kHz, first appearing at 18 months of age and continuing to be significantly greater than controls at 21 and 24 months. The BBN induced a different pace and pattern of enhanced age-related ABR TS. The mean TS for the BBN group first became significantly greater than controls at 18 months of age and only at 48 kHz. It remained significantly greater than controls at 21 months but was no longer significantly greater at 24 months of age. Results, therefore, show different influences on ARHL for the two different noise exposure conditions. Noise-induced enhancement appears to provide more an acceleration than overall total increase in ARHL.
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14
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Burwood G, Hakizimana P, Nuttall AL, Fridberger A. Best frequencies and temporal delays are similar across the low-frequency regions of the guinea pig cochlea. SCIENCE ADVANCES 2022; 8:eabq2773. [PMID: 36149949 PMCID: PMC9506724 DOI: 10.1126/sciadv.abq2773] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The cochlea maps tones with different frequencies to distinct anatomical locations. For instance, a faint 5000-hertz tone produces brisk responses at a place approximately 8 millimeters into the 18-millimeter-long guinea pig cochlea, but little response elsewhere. This place code pervades the auditory pathways, where neurons have "best frequencies" determined by their connections to the sensory cells in the hearing organ. However, frequency selectivity in cochlear regions encoding low-frequency sounds has not been systematically studied. Here, we show that low-frequency hearing works according to a unique principle that does not involve a place code. Instead, sound-evoked responses and temporal delays are similar across the low-frequency regions of the cochlea. These findings are a break from theories considered proven for 100 years and have broad implications for understanding information processing in the brainstem and cortex and for optimizing the stimulus delivery in auditory implants.
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Affiliation(s)
- George Burwood
- Oregon Hearing Research Center, Department of Otolaryngology–Head and Neck Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Pierre Hakizimana
- Department of Biomedical and Clinical Sciences, Linköping University, SE-581 83 Linköping, Sweden
| | - Alfred L Nuttall
- Oregon Hearing Research Center, Department of Otolaryngology–Head and Neck Surgery, Oregon Health & Science University, Portland, OR 97239, USA
- Corresponding author. (A.L.N.); (A.F.)
| | - Anders Fridberger
- Oregon Hearing Research Center, Department of Otolaryngology–Head and Neck Surgery, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical and Clinical Sciences, Linköping University, SE-581 83 Linköping, Sweden
- Corresponding author. (A.L.N.); (A.F.)
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15
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Xia L, Ripley S, Jiang Z, Yin X, Yu Z, Aiken SJ, Wang J. Synaptopathy in Guinea Pigs Induced by Noise Mimicking Human Experience and Associated Changes in Auditory Signal Processing. Front Neurosci 2022; 16:935371. [PMID: 35873820 PMCID: PMC9298651 DOI: 10.3389/fnins.2022.935371] [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: 05/03/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Noise induced synaptopathy (NIS) has been researched extensively since a large amount of synaptic loss without permanent threshold shift (PTS) was found in CBA mice after a brief noise exposure. However, efforts to translate these results to humans have met with little success—and might not be possible since noise exposure used in laboratory animals is generally different from what is experienced by human subjects in real life. An additional problem is a lack of morphological data and reliable functional methods to quantify loss of afferent synapses in humans. Based on evidence for disproportionate synaptic loss for auditory nerve fibers (ANFs) with low spontaneous rates (LSR), coding-in-noise deficits (CIND) have been speculated to be the major difficulty associated with NIS without PTS. However, no robust evidence for this is available in humans or animals. This has led to a re-examination of the role of LSR ANFs in signal coding in high-level noise. The fluctuation profile model has been proposed to support a role for high-SR ANFs in the coding of high-level noise in combination with efferent control of cochlear gain. This study aimed to induce NIS by a low-level, intermittent noise exposure mimicking what is experienced in human life and examined the impact of the NIS on temporal processing under masking. It also evaluated the role of temporal fluctuation in evoking efferent feedback and the effects of NIS on this feedback.
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Affiliation(s)
- Li Xia
- Department of Otolaryngology-Head and Neck Surgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Sara Ripley
- School of Communication Sciences and Disorders, Dalhousie University, Halifax, NS, Canada
| | - Zhenhua Jiang
- Department of Otolaryngology-Head and Neck Surgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Xue Yin
- Department of Otolaryngology-Head and Neck Surgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Zhiping Yu
- School of Communication Sciences and Disorders, Dalhousie University, Halifax, NS, Canada
| | - Steve J Aiken
- School of Communication Sciences and Disorders, Dalhousie University, Halifax, NS, Canada
| | - Jian Wang
- Department of Otolaryngology-Head and Neck Surgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China.,School of Communication Sciences and Disorders, Dalhousie University, Halifax, NS, Canada
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Peixoto Pinheiro B, Müller M, Bös M, Guezguez J, Burnet M, Tornincasa M, Rizzetto R, Rolland JF, Liberati C, Lohmer S, Adel Y, Löwenheim H. A potassium channel agonist protects hearing function and promotes outer hair cell survival in a mouse model for age-related hearing loss. Cell Death Dis 2022; 13:595. [PMID: 35817766 PMCID: PMC9273644 DOI: 10.1038/s41419-022-04915-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 01/21/2023]
Abstract
Age-related hearing loss (ARHL) is the most common sensory impairment mainly caused by degeneration of sensory hair cells in the cochlea with no causal medical treatment available. Auditory function and sensory hair cell survival critically depend on the Kv7.4 (KCNQ4) channel, a voltage-gated potassium channel expressed in outer hair cells (OHCs), with its impaired function or reduced activity previously associated with ARHL. Here, we investigated the effect of a potent small-molecule Kv7.4 agonist on ARHL in the senescence-accelerated mouse prone 8 (SAMP8) model. For the first time in vivo, we show that Kv7.4 activation can significantly reduce age-related threshold shifts of auditory brainstem responses as well as OHC loss in the SAMP8 model. Pharmacological activation of Kv7.4 thus holds great potential as a therapeutic approach for ARHL as well as other hearing impairments related to Kv7.4 function.
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Affiliation(s)
- Barbara Peixoto Pinheiro
- grid.10392.390000 0001 2190 1447Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, 72076 Tübingen, Germany
| | - Marcus Müller
- grid.10392.390000 0001 2190 1447Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, 72076 Tübingen, Germany
| | - Michael Bös
- Acousia Therapeutics, 72070 Tübingen, Germany
| | | | | | - Mara Tornincasa
- grid.427692.c0000 0004 1794 5078Axxam, Bresso, 20091 Milan, Italy
| | | | | | - Chiara Liberati
- grid.427692.c0000 0004 1794 5078Axxam, Bresso, 20091 Milan, Italy
| | - Stefan Lohmer
- grid.427692.c0000 0004 1794 5078Axxam, Bresso, 20091 Milan, Italy
| | - Youssef Adel
- grid.10392.390000 0001 2190 1447Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, 72076 Tübingen, Germany
| | - Hubert Löwenheim
- grid.10392.390000 0001 2190 1447Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, 72076 Tübingen, Germany
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Kim Y, Lee SY, Kim MY, Park K, Han JH, Kim JH, Kim BJ, Choi BY. Auditory Phenotype and Histopathologic Findings of a Mutant Nlrp3 Expression Mouse Model. Front Neurol 2022; 13:890256. [PMID: 35812087 PMCID: PMC9263128 DOI: 10.3389/fneur.2022.890256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/19/2022] [Indexed: 11/19/2022] Open
Abstract
Objective The pathogenesis of hearing loss in autoinflammatory disorders due to activation of the inflammasome remains incompletely understood. Previously no animals expressing mutant Nlrp3 (NOD-, LRR- and pyrin domain-containing protein 3) survived to an age when hearing evaluation was possible due to embryonic lethality. We aimed to establish a novel mouse model that manifests quantifiable hearing loss with other syndromic features due to alteration of Nlrp3 and investigate the audiologic and histopathologic phenotype in the cochlea to clarify how the genetic alterations of NLRP3 could induce autoinflammatory hearing loss. Methods To induce inner ear expression of the mutant Nlrp3, Nlrp3D301NneoR mice were bred with Gfi1Cre knock-in mice for conditional mutant Nlrp3 activation in the cochlea and hematopoietic cells. Hearing thresholds were measured. Hematoxylin-eosin sections of the cochlea, brain, kidney, and liver were examined under light microscopy. Immunohistochemical analyses using polyclonal anti-NLRP3 antibodies on cochlear whole-mount preparations and frozen sections were performed. Results We, for the first time in the literature, established a mouse model that manifests quantifiable hearing loss due to Nlrp3 alteration. ABR recordings of Nlrp3D301NneoR/+; Gfi1Cre/+ mice, albeit with limited life expectancy, exhibited severe to profound hearing loss at postnatal day 20 (P20). There was overall overexpression of mutant Nlrp3, and mutant Nlrp3 expression was noted in the spiral prominence, the outer sulcus region (Claudius cells and outer sulcus cells), the organ of Corti, the inner sulcus, and the spiral ganglion neurons in the cochlea. The hematoxylin-eosin sections of Nlrp3D301NneoR/+; Gfi1Cre/+ mice cochleae at P12 exhibited a disorganized organ of Corti between the outer hair cells/supporting Deiters' cells and basilar membrane compared with the normal phenotype mice, leading to a collapsed Nuel's space. This morphologic feature gradually returned to normal by P15. Varying degrees of inflammation with lymphocytic infiltrations were observed in the brain, kidney, and liver. Conclusion We report the first mutant Nlrp3 overexpression mouse model (Nlrp3D301NneoR/+; Gfi1Cre/+) that shows obvious overexpression of Nlrp3 in the cochlea, a transient developmental lag of the cochlea, and severe to profound hearing loss. We expect that this mouse line, which models human autoinflammatory hearing loss, could provide a valuable tool to elucidate the underlying pathogenic mechanism of inflammasome activation-mediated hearing loss.
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Affiliation(s)
- Yehree Kim
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Sang-Yeon Lee
- Department of Otorhinolaryngology, Seoul National University Hospital, Seoul, South Korea
| | - Min Young Kim
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Kyusun Park
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Jung Ho Kim
- Department of Pathology, Seoul National University Hospital, Seoul, South Korea
| | - Bong Jik Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Chungnam National University, Chungnam National University Sejong Hospital, Sejong, South Korea
- *Correspondence: Bong Jik Kim
| | - Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, South Korea
- Byung Yoon Choi
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18
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Wu F, Hill K, Fang Q, He Z, Zheng H, Wang X, Xiong H, Sha SH. Traumatic-noise-induced hair cell death and hearing loss is mediated by activation of CaMKKβ. Cell Mol Life Sci 2022; 79:249. [PMID: 35438341 PMCID: PMC9844253 DOI: 10.1007/s00018-022-04268-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/14/2022] [Accepted: 03/20/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND The Ca2+/calmodulin-dependent protein kinase kinases (CaMKKs) are serine/threonine-directed protein kinases that are activated following increases in intracellular calcium, playing a critical role in neuronal signaling. Inner-ear-trauma-induced calcium overload in sensory hair cells has been well documented in the pathogenesis of traumatic noise-induced hair cell death and hearing loss, but there are no established pharmaceutical therapies available due to a lack of specific therapeutic targets. In this study, we investigated the activation of CaMKKβ in the inner ear after traumatic noise exposure and assessed the prevention of noise-induced hearing loss (NIHL) with RNA silencing. RESULTS Treatment with short hairpin RNA of CaMKKβ (shCaMKKβ) via adeno-associated virus transduction significantly knocked down CaMKKβ expression in the inner ear. Knockdown of CaMKKβ significantly attenuated noise-induced hair cell loss and hearing loss (NIHL). Additionally, pretreatment with naked CaMKKβ small interfering RNA (siCaMKKβ) attenuated noise-induced losses of inner hair cell synapses and OHCs and NIHL. Furthermore, traumatic noise exposure activates CaMKKβ in OHCs as demonstrated by immunolabeling for p-CaMKI. CaMKKβ mRNA assessed by fluorescence in-situ hybridization and immunolabeling for CaMKKβ in OHCs also increased after the exposure. Finally, pretreatment with siCaMKKβ diminished noise-induced activation of AMPKα in OHCs. CONCLUSIONS These findings demonstrate that traumatic-noise-induced OHC loss and hearing loss occur primarily via activation of CaMKKβ. Targeting CaMKKβ is a key strategy for prevention of noise-induced hearing loss. Furthermore, our data suggest that noise-induced activation of AMPKα in OHCs occurs via the CaMKKβ pathway.
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Affiliation(s)
- Fan Wu
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA.,Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Kayla Hill
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA
| | - Qiaojun Fang
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA.,School of Life Sciences and Technology, Southeast University, Nanjing 210096, China
| | - Zuhong He
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA
| | - Hongwei Zheng
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA
| | - Xianren Wang
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA
| | - Hao Xiong
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA
| | - Su-Hua Sha
- Department of Pathology and Laboratory Medicine, The Medical University of South Carolina, Charleston, SC 29425, USA.,Correspondence should be addressed to: Dr. Su-Hua Sha • Department of Pathology and Laboratory Medicine • Medical University of South Carolina • Walton Research Building, Room 403-E • 39 Sabin Street, Charleston, SC 29425, USA. Telephone: 843-792-8324; Fax: 843-792-0368;
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19
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c-Myb protects cochlear hair cells from cisplatin-induced damage via the PI3K/Akt signaling pathway. Cell Death Dis 2022; 8:78. [PMID: 35210433 PMCID: PMC8873213 DOI: 10.1038/s41420-022-00879-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/27/2022] [Accepted: 02/09/2022] [Indexed: 12/31/2022]
Abstract
The transcription factor c-Myb is vital for cell survival, proliferation, differentiation, and apoptosis. We have previously reported that c-Myb knockdown exacerbates neomycin-induced damage to cochlea cells. However, the function and regulation of c-Myb in the mammalian inner ear remains unclear. Here, we first found that the expression of c-Myb in cochlear HCs was downregulated after cisplatin damage in vivo. Next, to investigate the role of c-Myb in HCs treated with cisplatin, the recombinant virus AAV-ie-CAG-Myb-HA (AAV-c-Myb) that overexpresses c-Myb was constructed and transfected into HCs. The protein expression of c-Myb was effectively up-regulated in cultured cochlear HCs after the virus transfection, which increased cochlear HC viability, decreased HC apoptosis and reduced intracellular reactive oxygen species (ROS) levels after cisplatin injury in vitro. The overexpression of c-Myb in HCs after AAV-c-Myb transfection in vivo also promoted HC survival, improved the hearing function of mice and reduced HC apoptosis after cisplatin injury. Furthermore, c-Myb-HC conditional knockout mice (Prestin; c-Myb-cKO) in which c-Myb expression is downregulated only in cochlear OHCs were generated and the cisplatin-induced HCs loss, apoptosis and hearing deficit were all exacerbated in Prestin; c-Myb-cKO mice treated with cisplatin in vivo. Finally, mechanistic studies showed that upregulation of the PI3K/Akt signaling pathway by c-Myb contributed to the increased HC survival after cisplatin exposure in vitro. The findings from this work suggest that c-Myb might serve as a new target for the prevention of cisplatin-induced HC damage and hearing loss.
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20
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Liu J, Antisdel J, Liu C, Chen M, Dong P, Fahlman R, Ma F, Yu Y. Extensive hearing loss induced by low‐frequency noise exposure. Laryngoscope Investig Otolaryngol 2022; 7:564-570. [PMID: 35434351 PMCID: PMC9008144 DOI: 10.1002/lio2.752] [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: 11/11/2021] [Revised: 01/14/2022] [Accepted: 01/20/2022] [Indexed: 11/21/2022] Open
Abstract
Background With little attention given to low‐frequency traffic noise and our understanding that cochlear function may be highly susceptible to low‐frequency noise, there is an urgent need to determine traffic noise‐induced hearing loss (NIHL), not only the hearing loss at low frequency but also the possible high‐frequency hearing loss. Methods The current study aims to investigate the potential for extensive hearing loss induced by exposure to 0.063 kHz octave band noise (OBN), which is an important component of low‐frequency traffic noise. The threshold of auditory brainstem response (ABR) was used to evaluate hearing function before and after noise exposure. Chinchillas were randomly assigned into seven different groups. Group 63‐3 h/6 h, Group 2 k‐3 h/6 h, and group 4 k‐3 h/6 h were exposed for either 3 or 6 h to 0.063, 2, and 4 kHz OBN at 90 dB SPL, respectively. The control group was not exposed to noise. Results Significant ABR threshold‐shifts (TS) were observed at 0.88, 2, 4, and 5.7 kHz in Group 63‐6 h, and at 2.8 and 4 kHz in Group 2 k‐6 h, and at 5.7 kHz in Group 4 k‐6 h. ABR‐TS were consistent with outer hair cell (OHC) losses, exposure to 0.063 kHz OBN at 90 dB SPL for 6 h induced large‐scale losses of OHC both in low‐ and high‐frequency region. Conclusions Exposure to 0.063 kHz low‐frequency OBN at 90 dB SPL for 6 h leads to significant hearing loss over an extensive range from low to high frequencies.
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Affiliation(s)
- Junping Liu
- Department of Otolaryngology – Head Neck Surgery, Mindong Hospital The Affiliated Mindong Hospital of Fujian Medical University Fuan China
| | - Jastin Antisdel
- Department of Otolaryngology – Head Neck Surgery Saint Louis University St. Louis Missouri USA
| | - Changming Liu
- Department of Otolaryngology – Head Neck Surgery, Mindong Hospital The Affiliated Mindong Hospital of Fujian Medical University Fuan China
| | - Miaoan Chen
- Department of Otolaryngology – Head Neck Surgery, Mindong Hospital The Affiliated Mindong Hospital of Fujian Medical University Fuan China
| | - Pin Dong
- Department of Otolaryngology – Head Neck Surgery The First Hospital of Shanghai Jiaotong University Shanghai China
| | - Richard Fahlman
- Faculty of Medicine University of Alberta Edmonton Alberta Canada
| | - Furong Ma
- Department of Otolaryngology – Head Neck Surgery The Third Hospital of Peking University Beijing China
| | - Yongqiang Yu
- Department of Otolaryngology – Head Neck Surgery, Mindong Hospital The Affiliated Mindong Hospital of Fujian Medical University Fuan China
- Department of Otolaryngology – Head Neck Surgery Saint Louis University St. Louis Missouri USA
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21
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Badash I, Quiñones PM, Oghalai KJ, Wang J, Lui CG, Macias-Escriva F, Applegate BE, Oghalai JS. Endolymphatic Hydrops is a Marker of Synaptopathy Following Traumatic Noise Exposure. Front Cell Dev Biol 2021; 9:747870. [PMID: 34805158 PMCID: PMC8602199 DOI: 10.3389/fcell.2021.747870] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/20/2021] [Indexed: 12/28/2022] Open
Abstract
After acoustic trauma, there can be loss of synaptic connections between inner hair cells and auditory neurons in the cochlea, which may lead to hearing abnormalities including speech-in-noise difficulties, tinnitus, and hyperacusis. We have previously studied mice with blast-induced cochlear synaptopathy and found that they also developed a build-up of endolymph, termed endolymphatic hydrops. In this study, we used optical coherence tomography to measure endolymph volume in live CBA/CaJ mice exposed to various noise intensities. We quantified the number of synaptic ribbons and postsynaptic densities under the inner hair cells 1 week after noise exposure to determine if they correlated with acute changes in endolymph volume measured in the hours after the noise exposure. After 2 h of noise at an intensity of 95 dB SPL or below, both endolymph volume and synaptic counts remained normal. After exposure to 2 h of 100 dB SPL noise, mice developed endolymphatic hydrops and had reduced synaptic counts in the basal and middle regions of the cochlea. Furthermore, round-window application of hypertonic saline reduced the degree of endolymphatic hydrops that developed after 100 dB SPL noise exposure and partially prevented the reduction in synaptic counts in the cochlear base. Taken together, these results indicate that endolymphatic hydrops correlates with noise-induced cochlear synaptopathy, suggesting that these two pathologic findings have a common mechanistic basis.
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Affiliation(s)
- Ido Badash
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States
| | - Patricia M Quiñones
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States
| | - Kevin J Oghalai
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - Juemei Wang
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States
| | - Christopher G Lui
- Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Frank Macias-Escriva
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States
| | - Brian E Applegate
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States.,Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States.,Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
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22
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Stewart CE, Bauer DS, Altschuler RA, King WM. Transient peripheral vestibular hypofunction measured with vestibular short-latency evoked potentials following noise exposure in rats. J Neurophysiol 2021; 126:1547-1554. [PMID: 34550030 PMCID: PMC8782663 DOI: 10.1152/jn.00131.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Exposure to 120 dB sound pressure level (SPL) band-limited noise results in delayed onset latency and reduced vestibular short-latency evoked potential (VsEP) responses. These changes are still present 4 wk after noise overstimulation. Noise-induced hearing loss (NIHL) has been shown to vary in extent and duration based on the noise intensity. This study investigated whether noise-induced peripheral vestibular hypofunction (NPVH) would also decrease in extent and/or duration with less intense noise exposure. In the present study, rats were exposed to a less intense noise (110 dB SPL) but for the same duration (6 h) and frequency range (500–4,000 Hz) as used in previous studies. The VsEP was assessed 1, 3, 7, 14, 21, and 28 days after noise exposure. In contrast to 120 dB SPL noise exposure, the 110 dB SPL noise exposures produced smaller deficits in VsEP responses that fully recovered in 62% (13/21) of animals within 1 wk. These findings suggest that NPVH, a loss or attenuation of VsEP responses with a requirement for elevated stimulus intensity to elicit measurable responses, is similar to NIHL, that is, lower sound levels produce a smaller or transient deficit. These results show that it will be important to determine the extent and duration of vestibular hypofunction for different noise exposure conditions and their impact on balance. NEW & NOTEWORTHY This is the first study to show a temporary noise-induced peripheral vestibular hypofunction that recovers following exposure to continuous noise.
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Affiliation(s)
- Courtney E Stewart
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan.,Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - David S Bauer
- Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - Richard A Altschuler
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan.,Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - William Michael King
- Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
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23
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Yang CH, Hwang CF, Chuang JH, Lian WS, Wang FS, Yang MY. Systemic toll-like receptor 9 agonist CpG oligodeoxynucleotides exacerbates aminoglycoside ototoxicity. Hear Res 2021; 411:108368. [PMID: 34678647 DOI: 10.1016/j.heares.2021.108368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 09/20/2021] [Accepted: 10/01/2021] [Indexed: 02/08/2023]
Abstract
The Toll-like receptor (TLR) signaling pathway is the key regulator of the innate immune system in response to systemic infection. Several studies have reported that the systemic TLR4 agonist lipopolysaccharide exacerbates aminoglycoside ototoxicity, but the influence of virus-associated TLR7 and TLR9 signaling cascades on the cochlea is unclear. The present study aimed to investigate the auditory effects of systemic TLR7 and TLR9 agonists during chronic kanamycin treatment. CBA/CaJ mice received the TLR7 agonist gardiquimod or TLR9 agonist CpG oligodeoxynucleotides (ODN) one day before kanamycin injection and on the 5th and 10th days during a 14-day course of kanamycin treatment. We observed that systemic gardiquimod or CpG ODN alone did not affect the baseline auditory brainstem response (ABR) threshold. Three weeks after kanamycin treatment, gardiquimod did not significantly change ABR threshold shifts, whereas CpG ODN significantly increased kanamycin-induced ABR threshold shifts. Furthermore, outer hair cell (OHC) evaluation revealed that CpG ODN reduced distortion product otoacoustic emission amplitudes and increased kanamycin-induced OHC loss. CpG ODN significantly elevated cochlear Irf-7, Tnf-α, Il-1, and Il-6 transcript levels. In addition, an increased number of Iba-1+ cells, which represented activated macrophages, was observed in the cochlea treated with CpG ODN. Our results indicated that systemic CpG ODN exacerbated kanamycin-induced ototoxicity and increased cochlear inflammation. This study implies that patients with underlying virus infection may experience more severe aminoglycoside-induced hearing loss if it occurs.
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Affiliation(s)
- Chao-Hui Yang
- Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Chung-Feng Hwang
- Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Jiin-Haur Chuang
- Division of Pediatric Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan
| | - Wei-Shiung Lian
- Core Laboratory for Phenomics & Diagnostics, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Feng-Sheng Wang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan; Core Laboratory for Phenomics & Diagnostics, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - Ming-Yu Yang
- Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan.
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24
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Peixoto Pinheiro B, Adel Y, Knipper M, Müller M, Löwenheim H. Auditory Threshold Variability in the SAMP8 Mouse Model of Age-Related Hearing Loss: Functional Loss and Phenotypic Change Precede Outer Hair Cell Loss. Front Aging Neurosci 2021; 13:708190. [PMID: 34408646 PMCID: PMC8366269 DOI: 10.3389/fnagi.2021.708190] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/09/2021] [Indexed: 11/13/2022] Open
Abstract
Age-related hearing loss (ARHL) is the most common sensory deficit in aging society, which is accompanied by increased speech discrimination difficulties in noisy environments, social isolation, and cognitive decline. The audiometric degree of ARHL is largely correlated with sensory hair cell loss in addition to age-related factors not captured by histopathological analysis of the human cochlea. Previous studies have identified the senescence-accelerated mouse prone strain 8 (SAMP8) as a model for studying ARHL and age-related modifications of the cochlear redox environment. However, the SAMP8 population exhibits a large variability in auditory function decline over age, whose underlying cause remains unknown. In this study, we analyzed auditory function of SAMP8 mice by measuring auditory brainstem response (ABR) thresholds at the age of 6 weeks (juvenile), 12 weeks (young adult), and 24 weeks (adult). Consistent with previous studies, SAMP8 mice exhibit an early progressive, age-related decline of hearing acuity. However, a spatiotemporal cytohistological analysis showed that the significant increase in threshold variability was not concurrently reflected in outer hair cell (OHC) loss observed in the lower and upper quartiles of the ABR threshold distributions over age. This functional loss was found to precede OHC loss suggesting that age-related phenotypic changes may be contributing factors not represented in cytohistological analysis. The expression of potassium channels KCNQ4 (KV7.4), which mediates the current IK,n crucial for the maintenance of OHC membrane potential, and KCNQ1 (KV7.1), which is an essential component in potassium circulation and secretion into the endolymph generating the endocochlear potential, showed differences between these quartiles and age groups. This suggests that phenotypic changes in OHCs or the stria vascularis due to variable oxidative deficiencies in individual mice may be predictors of the observed threshold variability in SAMP8 mice and their progressive ARHL. In future studies, further phenotypic predictors affected by accumulated metabolic challenges over age need to be investigated as potentially underlying causes of ARHL preceding irreversible OHC loss in the SAMP8 mouse model.
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Affiliation(s)
- Barbara Peixoto Pinheiro
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Youssef Adel
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Marlies Knipper
- Molecular Physiology of Hearing, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Marcus Müller
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Hubert Löwenheim
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
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25
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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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26
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Cortada M, Sauteur L, Lanz M, Levano S, Bodmer D. A deep learning approach to quantify auditory hair cells. Hear Res 2021; 409:108317. [PMID: 34343849 DOI: 10.1016/j.heares.2021.108317] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/16/2021] [Accepted: 07/19/2021] [Indexed: 01/16/2023]
Abstract
Hearing loss affects millions of people worldwide. Yet, there are still no curative therapies for sensorineural hearing loss. Frequent causes of sensorineural hearing loss are due to damage or loss of the sensory hair cells, the spiral ganglion neurons, or the synapses between them. Culturing the organ of Corti allows the study of all these structures in an experimental model, which is easy to manipulate. Therefore, the in vitro culture of the neonatal mammalian organ of Corti remains a frequently used experimental system, in which hair cell survival is routinely assessed. However, the analysis of the surviving hair cells is commonly performed via manual counting, which is a time-consuming process and the inter-rater reliability can be an issue. Here, we describe a deep learning approach to quantify hair cell survival in the murine organ of Corti explants. We used StarDist, a publicly available platform and plugin for Fiji (Fiji is just ImageJ), to train and apply our own custom deep learning model. We successfully validated our model in untreated, cisplatin, and gentamicin treated organ of Corti explants. Therefore, deep learning is a valuable approach for quantifying hair cell survival in organ of Corti explants. Moreover, we also demonstrate how the publicly available Fiji plugin StarDist can be efficiently used for this purpose.
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Affiliation(s)
- Maurizio Cortada
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Loïc Sauteur
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Michael Lanz
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Soledad Levano
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Daniel Bodmer
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland; Clinic for Otorhinolaryngology, Head and Neck Surgery, University of Basel Hospital, Petersgraben 4, Basel CH-4031, Switzerland.
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27
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Kimura E, Mizutari K, Kurioka T, Kawauchi S, Satoh Y, Sato S, Shiotani A. Effect of shock wave power spectrum on the inner ear pathophysiology in blast-induced hearing loss. Sci Rep 2021; 11:14704. [PMID: 34282183 PMCID: PMC8289960 DOI: 10.1038/s41598-021-94080-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/29/2021] [Indexed: 11/10/2022] Open
Abstract
Blast exposure can induce various types of hearing impairment, including permanent hearing loss, tinnitus, and hyperacusis. Herein, we conducted a detailed investigation of the cochlear pathophysiology in blast-induced hearing loss in mice using two blasts with different characteristics: a low-frequency dominant blast generated by a shock tube and a high-frequency dominant shock wave generated by laser irradiation (laser-induced shock wave). The pattern of sensorineural hearing loss (SNHL) was low-frequency- and high-frequency-dominant in response to the low- and high-frequency blasts, respectively. Pathological examination revealed that cochlear synaptopathy was the most frequent cochlear pathology after blast exposure, which involved synapse loss in the inner hair cells without hair cell loss, depending on the power spectrum of the blast. This pathological change completely reflected the physiological analysis of wave I amplitude using auditory brainstem responses. Stereociliary bundle disruption in the outer hair cells was also dependent on the blast’s power spectrum. Therefore, we demonstrated that the dominant frequency of the blast power spectrum was the principal factor determining the region of cochlear damage. We believe that the presenting models would be valuable both in blast research and the investigation of various types of hearing loss whose pathogenesis involves cochlear synaptopathy.
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Affiliation(s)
- Eiko Kimura
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Kunio Mizutari
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
| | - Takaomi Kurioka
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Satoko Kawauchi
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Yasushi Satoh
- Department of Biochemistry, National Defense Medical College, Saitama, 359-8513, Japan
| | - Shunichi Sato
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Saitama, 359-8513, Japan
| | - Akihiro Shiotani
- Department of Otolaryngology-Head and Neck Surgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
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28
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Zhang C, Li Q, Chen M, Lu T, Min S, Li S. The role of oxidative stress in the susceptibility of noise-impaired cochleae to synaptic loss induced by intracochlear electrical stimulation. Neuropharmacology 2021; 196:108707. [PMID: 34246683 DOI: 10.1016/j.neuropharm.2021.108707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/15/2021] [Accepted: 07/06/2021] [Indexed: 11/20/2022]
Abstract
Intracochlear electrical stimulation (ES) generated by cochlear implants (CIs) is used to activate auditory nerves to restore hearing perception in deaf subjects and those with residual hearing who use electroacoustic stimulation (EAS) technology. Approximately 1/3 of EAS recipients experience loss of residual hearing a few months after ES activation, but the underlying mechanism is unknown. Clinical evidence indicates that the loss is related to the previous history of noise-induced hearing loss (NIHL). In this report, we investigated the impact of intracochlear ES on oxidative stress levels and synaptic counts in inner hair cells (IHCs) of the apical, middle and basal regions of guinea pigs with normal hearing (NH) and NIHL. Our results demonstrated that intracochlear ES with an intensity of 6 dB above the thresholds of electrically evoked compound action potentials (ECAPs) could induce the elevation of oxidative stress levels, resulting in a loss of IHC synapses near the electrodes in the basal and middle regions of the NH cochleae. Furthermore, the apical region of cochleae with NIHL were more susceptible to synaptic loss induced by relatively low-intensity ES than that of NH cochleae, resulting from the additional elevation of oxidative stress levels and the reduced antioxidant capability throughout the whole cochlea.
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Affiliation(s)
- Chen Zhang
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China
| | - Qiang Li
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China
| | - Min Chen
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China
| | - Tianhao Lu
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China
| | - Shiyao Min
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China
| | - Shufeng Li
- Department of Otolaryngology - Head and Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China; NHC Key Laboratory of Hearing Medicine, Shanghai, China.
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Beaulac HJ, Gilels F, Zhang J, Jeoung S, White PM. Primed to die: an investigation of the genetic mechanisms underlying noise-induced hearing loss and cochlear damage in homozygous Foxo3-knockout mice. Cell Death Dis 2021; 12:682. [PMID: 34234110 PMCID: PMC8263610 DOI: 10.1038/s41419-021-03972-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023]
Abstract
The prevalence of noise-induced hearing loss (NIHL) continues to increase, with limited therapies available for individuals with cochlear damage. We have previously established that the transcription factor FOXO3 is necessary to preserve outer hair cells (OHCs) and hearing thresholds up to two weeks following mild noise exposure in mice. The mechanisms by which FOXO3 preserves cochlear cells and function are unknown. In this study, we analyzed the immediate effects of mild noise exposure on wild-type, Foxo3 heterozygous (Foxo3+/-), and Foxo3 knock-out (Foxo3-/-) mice to better understand FOXO3's role(s) in the mammalian cochlea. We used confocal and multiphoton microscopy to examine well-characterized components of noise-induced damage including calcium regulators, oxidative stress, necrosis, and caspase-dependent and caspase-independent apoptosis. Lower immunoreactivity of the calcium buffer Oncomodulin in Foxo3-/- OHCs correlated with cell loss beginning 4 h post-noise exposure. Using immunohistochemistry, we identified parthanatos as the cell death pathway for OHCs. Oxidative stress response pathways were not significantly altered in FOXO3's absence. We used RNA sequencing to identify and RT-qPCR to confirm differentially expressed genes. We further investigated a gene downregulated in the unexposed Foxo3-/- mice that may contribute to OHC noise susceptibility. Glycerophosphodiester phosphodiesterase domain containing 3 (GDPD3), a possible endogenous source of lysophosphatidic acid (LPA), has not previously been described in the cochlea. As LPA reduces OHC loss after severe noise exposure, we treated noise-exposed Foxo3-/- mice with exogenous LPA. LPA treatment delayed immediate damage to OHCs but was insufficient to ultimately prevent their death or prevent hearing loss. These results suggest that FOXO3 acts prior to acoustic insult to maintain cochlear resilience, possibly through sustaining endogenous LPA levels.
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MESH Headings
- Animals
- Cell Death
- Disease Models, Animal
- Female
- Forkhead Box Protein O3/deficiency
- Forkhead Box Protein O3/genetics
- Gene Expression Regulation
- Hair Cells, Auditory, Outer/drug effects
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/pathology
- Hearing
- Hearing Loss, Noise-Induced/drug therapy
- Hearing Loss, Noise-Induced/genetics
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Homozygote
- Lysophospholipids/metabolism
- Lysophospholipids/pharmacology
- Male
- Mice, Knockout
- Noise
- Phosphoric Diester Hydrolases/genetics
- Phosphoric Diester Hydrolases/metabolism
- Time Factors
- Mice
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Affiliation(s)
- Holly J Beaulac
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Felicia Gilels
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Department of Pathology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Jingyuan Zhang
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Department of Otolaryngology, Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston Children's Hospital Center for Life Science, Boston, MA, USA
| | - Sarah Jeoung
- University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Patricia M White
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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Sex differences in the auditory functions of rodents. Hear Res 2021; 419:108271. [PMID: 34074560 DOI: 10.1016/j.heares.2021.108271] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 04/07/2021] [Accepted: 04/28/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND In humans, it is well known that females have better hearing than males. The mechanism of this influence of sex on auditory function in humans is not well understood. Testing the hypothesis of underlying mechanisms often relies on preclinical research, a field in which sex bias still exists unconsciously. Rodents are popular research models in hearing, thus it is crucial to understand the sex differences in these rodent models when studying health and disease in humans. OBJECTIVES This review aims to summarize the existing sex differences in the auditory functions of rodent species including mouse, rat, Guinea pig, Mongolian gerbil, and chinchilla. In addition, a concise summary of the hearing characteristics and the advantages and the drawbacks of conducting auditory experiments in each rodent species is provided. DESIGNS Manuscripts were identified in PubMed and Ovid Medline for the queries "Rodent", "Sex Characteristics", and "Hearing or Auditory Function". Manuscripts were included if they were original research, written in English, and use rodents. The content of each manuscript was screened for the sex of the rodents and the discussion of sex-based results. CONCLUSIONS The sex differences in auditory function of rodents are prevalent and influenced by multiple factors including physiological mechanisms, sex-based anatomical variations, and stimuli from the external environment. Such differences may play a role in understanding and explaining sex differences in hearing of humans and need to be taken into consideration for developing clinical therapies aim to improve auditory performances.
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Altschuler RA, Kabara L, Martin C, Kanicki A, Stewart CE, Kohrman DC, Dolan DF. Rapamycin Added to Diet in Late Mid-Life Delays Age-Related Hearing Loss in UMHET4 Mice. Front Cell Neurosci 2021; 15:658972. [PMID: 33897373 PMCID: PMC8058174 DOI: 10.3389/fncel.2021.658972] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/11/2021] [Indexed: 01/30/2023] Open
Abstract
Our previous study demonstrated rapamycin added to diet at 4 months of age had significantly less age-related outer hair cell loss in the basal half of the cochlea at 22 months of age compared to mice without rapamycin. The present study tested adding rapamycin to diet later in life, at 14 months of age, and added a longitudinal assessment of auditory brain stem response (ABR). The present study used UMHET4 mice, a 4 way cross in which all grandparental strains lack the Cdh23753A allele that predisposes to early onset, progressive hearing loss. UMHET4 mice typically have normal hearing until 16-17 months, then exhibit threshold shifts at low frequencies/apical cochlea and later in more basal high frequency regions. ABR thresholds at 4, 12, 24, and 48 kHz were assessed at 12, 18, and 24 months of age and compared to baseline ABR thresholds acquired at 5 months of age to determine threshold shifts (TS). There was no TS at 12 months of age at any frequency tested. At 18 months of age mice with rapamycin added to diet at 14 months had a significantly lower mean TS at 4 and 12 kHz compared to mice on control diet with no significant difference at 24 and 48 kHz. At 24 months of age, the mean 4 kHz TS in rapamycin diet group was no longer significantly lower than the control diet group, while the 12 kHz mean remained significantly lower. Mean TS at 24 and 48 kHz in the rapamycin diet group became significantly lower than in the control diet group at 24 months. Hair cell counts at 24 months showed large loss in the apical half of most rapamycin and control diet mice cochleae with no significant difference between groups. There was only mild outer hair cell loss in the basal half of rapamycin and control diet mice cochleae with no significant difference between groups. The results show that a later life addition of rapamycin can decrease age-related hearing loss in the mouse model, however, it also suggests that this decrease is a delay/deceleration rather than a complete prevention.
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Affiliation(s)
- Richard A Altschuler
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,VA Ann Arbor Health Care System, Ann Arbor, MI, United States.,Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Lisa Kabara
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Catherine Martin
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Ariane Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Courtney E Stewart
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,VA Ann Arbor Health Care System, Ann Arbor, MI, United States
| | - David C Kohrman
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - David F Dolan
- Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
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He ZH, Pan S, Zheng HW, Fang QJ, Hill K, Sha SH. Treatment With Calcineurin Inhibitor FK506 Attenuates Noise-Induced Hearing Loss. Front Cell Dev Biol 2021; 9:648461. [PMID: 33777956 PMCID: PMC7994600 DOI: 10.3389/fcell.2021.648461] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/11/2021] [Indexed: 11/13/2022] Open
Abstract
Attenuation of noise-induced hair cell loss and noise-induced hearing loss (NIHL) by treatment with FK506 (tacrolimus), a calcineurin (CaN/PP2B) inhibitor used clinically as an immunosuppressant, has been previously reported, but the downstream mechanisms of FK506-attenuated NIHL remain unknown. Here we showed that CaN immunolabeling in outer hair cells (OHCs) and nuclear factor of activated T-cells isoform c4 (NFATc4/NFAT3) in OHC nuclei are significantly increased after moderate noise exposure in adult CBA/J mice. Consequently, treatment with FK506 significantly reduces moderate-noise-induced loss of OHCs and NIHL. Furthermore, induction of reactive oxygen species (ROS) by moderate noise was significantly diminished by treatment with FK506. In agreement with our previous finding that autophagy marker microtubule-associated protein light chain 3B (LC3B) does not change in OHCs under conditions of moderate-noise-induced permanent threshold shifts, treatment with FK506 increases LC3B immunolabeling in OHCs after exposure to moderate noise. Additionally, prevention of NIHL by treatment with FK506 was partially abolished by pretreatment with LC3B small interfering RNA. Taken together, these results indicate that attenuation of moderate-noise-induced OHC loss and hearing loss by FK506 treatment occurs not only via inhibition of CaN activity but also through inhibition of ROS and activation of autophagy.
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Affiliation(s)
| | | | | | | | | | - Su-Hua Sha
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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Jung SY, Yoo J, Yang KJ, Jang SY, Yi G, Kim DK, Koo H. Intratympanic administration of alpha-lipoic acid-loaded pluronic F-127 nanoparticles ameliorates acute hearing loss. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2021; 32:102329. [PMID: 33181275 DOI: 10.1016/j.nano.2020.102329] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/07/2020] [Accepted: 10/14/2020] [Indexed: 10/23/2022]
Abstract
We used antioxidant-containing nanoparticles (NPs) to treat acute hearing loss. Alpha-lipoic acid (ALA) served as the antioxidant; we employed Pluronic F127 to fabricate NPs. In vitro, ALA-NPs protected cells of the organ of Corti in HEI-OC1 mice, triggering nuclear translocation of NRF2 and increases in the levels of antioxidant proteins, including Nrf2, HO-1, SOD-1, and SOD-2. In vivo, the hearing of mice that received ALA-NP injections into the middle ear cavity was better preserved after induction of ototoxicity than in control animals. The cochlear Nrf2 level increased in test mice, indicating that the ALA-NPs protected hearing via the antioxidant mechanism observed in vitro. ALA-NPs effectively protected against acute hearing loss by activating the Nrf2/HO-1 pathway.
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Affiliation(s)
- So Young Jung
- Clinical Research Institute, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Jihye Yoo
- Department of Medical Life Sciences and Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Keum-Jin Yang
- Clinical Research Institute, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea
| | - Seok-Young Jang
- Department of Medical Life Sciences and Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Gawon Yi
- Department of Medical Life Sciences and Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dong-Kee Kim
- Department of Otolaryngology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, Republic of Korea.
| | - Heebeom Koo
- Department of Medical Life Sciences and Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; Catholic Photomedicine Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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34
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Fok C, Bogosanovic M, Pandya M, Telang R, Thorne PR, Vlajkovic SM. Regulator of G Protein Signalling 4 (RGS4) as a Novel Target for the Treatment of Sensorineural Hearing Loss. Int J Mol Sci 2020; 22:ijms22010003. [PMID: 33374915 PMCID: PMC7792627 DOI: 10.3390/ijms22010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/16/2020] [Accepted: 12/19/2020] [Indexed: 12/20/2022] Open
Abstract
We and others have previously identified signalling pathways associated with the adenosine A1 receptor (A1R) as important regulators of cellular responses to injury in the cochlea. We have shown that the “post-exposure” treatment with adenosine A1R agonists confers partial protection against acoustic trauma and other forms of sensorineural hearing loss (SNHL). The aim of this study was to determine if increasing A1R responsiveness to endogenous adenosine would have the same otoprotective effect. This was achieved by pharmacological targeting of the Regulator of G protein Signalling 4 (RGS4). RGS proteins inhibit signal transduction pathways initiated by G protein-coupled receptors (GPCR) by enhancing GPCR deactivation and receptor desensitisation. A molecular complex between RGS4 and neurabin, an intracellular scaffolding protein expressed in neural and cochlear tissues, is the key negative regulator of A1R activity in the brain. In this study, Wistar rats (6–8 weeks) were exposed to traumatic noise (110 dBSPL, 8–16 kHz) for 2 h and a small molecule RGS4 inhibitor CCG-4986 was delivered intratympanically in a Poloxamer-407 gel formulation for sustained drug release 24 or 48 h after noise exposure. Intratympanic administration of CCG-4986 48 h after noise exposure attenuated noise-induced permanent auditory threshold shifts by up to 19 dB, whilst the earlier drug administration (24 h) led to even better preservation of auditory thresholds (up to 32 dB). Significant improvement of auditory thresholds and suprathreshold responses was linked to improved survival of sensorineural tissues and afferent synapses in the cochlea. Our studies thus demonstrate that intratympanic administration of CCG-4986 can rescue cochlear injury and hearing loss induced by acoustic overexposure. This research represents a novel paradigm for the treatment of various forms of SNHL based on regulation of GPCR.
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Alvarado JC, Fuentes-Santamaría V, Melgar-Rojas P, Gabaldón-Ull MC, Cabanes-Sanchis JJ, Juiz JM. Oral Antioxidant Vitamins and Magnesium Limit Noise-Induced Hearing Loss by Promoting Sensory Hair Cell Survival: Role of Antioxidant Enzymes and Apoptosis Genes. Antioxidants (Basel) 2020; 9:E1177. [PMID: 33255728 PMCID: PMC7761130 DOI: 10.3390/antiox9121177] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 01/01/2023] Open
Abstract
Noise induces oxidative stress in the cochlea followed by sensory cell death and hearing loss. The proof of principle that injections of antioxidant vitamins and Mg2+ prevent noise-induced hearing loss (NIHL) has been established. However, effectiveness of oral administration remains controversial and otoprotection mechanisms are unclear. Using auditory evoked potentials, quantitative PCR, and immunocytochemistry, we explored effects of oral administration of vitamins A, C, E, and Mg2+ (ACEMg) on auditory function and sensory cell survival following NIHL in rats. Oral ACEMg reduced auditory thresholds shifts after NIHL. Improved auditory function correlated with increased survival of sensory outer hair cells. In parallel, oral ACEMg modulated the expression timeline of antioxidant enzymes in the cochlea after NIHL. There was increased expression of glutathione peroxidase-1 and catalase at 1 and 10 days, respectively. Also, pro-apoptotic caspase-3 and Bax levels were diminished in ACEMg-treated rats, at 10 and 30 days, respectively, following noise overstimulation, whereas, at day 10 after noise exposure, the levels of anti-apoptotic Bcl-2, were significantly increased. Therefore, oral ACEMg improves auditory function by limiting sensory hair cell death in the auditory receptor following NIHL. Regulation of the expression of antioxidant enzymes and apoptosis-related proteins in cochlear structures is involved in such an otoprotective mechanism.
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Affiliation(s)
- Juan C. Alvarado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
| | - Verónica Fuentes-Santamaría
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
| | - Pedro Melgar-Rojas
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
| | - María C. Gabaldón-Ull
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
| | - José J. Cabanes-Sanchis
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
| | - José M. Juiz
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, Universidad de Castilla-La Mancha, 02008 Albacete, Spain; (V.F.-S.); (P.M.-R.); (M.C.G.-U.); (J.J.C.-S.)
- Department of Otolaryngology, Hannover Medical School, NIFE-VIANNA, Cluster of Excellence Hearing4all-German Research Foundation, 30625 Hannover, Germany
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Szepesy J, Miklós G, Farkas J, Kucsera D, Giricz Z, Gáborján A, Polony G, Szirmai Á, Tamás L, Köles L, Varga ZV, Zelles T. Anti-PD-1 Therapy Does Not Influence Hearing Ability in the Most Sensitive Frequency Range, but Mitigates Outer Hair Cell Loss in the Basal Cochlear Region. Int J Mol Sci 2020; 21:ijms21186701. [PMID: 32933159 PMCID: PMC7555949 DOI: 10.3390/ijms21186701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
The administration of immune checkpoint inhibitors (ICIs) often leads to immune-related adverse events. However, their effect on auditory function is largely unexplored. Thorough preclinical studies have not been published yet, only sporadic cases and pharmacovigilance reports suggest their significance. Here we investigated the effect of anti-PD-1 antibody treatment (4 weeks, intraperitoneally, 200 μg/mouse, 3 times/week) on hearing function and cochlear morphology in C57BL/6J mice. ICI treatment did not influence the hearing thresholds in click or tone burst stimuli at 4–32 kHz frequencies measured by auditory brainstem response. The number and morphology of spiral ganglion neurons were unaltered in all cochlear turns. The apical-middle turns (<32 kHz) showed preservation of the inner and outer hair cells (OHCs), whilst ICI treatment mitigated the age-related loss of OHCs in the basal turn (>32 kHz). The number of Iba1-positive macrophages has also increased moderately in this high frequency region. We conclude that a 4-week long ICI treatment does not affect functional and morphological integrity of the inner ear in the most relevant hearing range (4–32 kHz; apical-middle turns), but a noticeable preservation of OHCs and an increase in macrophage activity appeared in the >32 kHz basal part of the cochlea.
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Affiliation(s)
- Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gabriella Miklós
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - János Farkas
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Dániel Kucsera
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Pharmahungary Group, H-6722 Szeged, Hungary
| | - Anita Gáborján
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gábor Polony
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Ágnes Szirmai
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Tamás
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Zoltán V. Varga
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Pharmacology, Institute of Experimental Medicine, H-1083 Budapest, Hungary
- Correspondence: ; Tel.: +36-1-210-4416/56297; Fax: +36-1-210-4412
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Li Q, Chen M, Zhang C, Lu T, Min S, Li S. Opposite Roles of NT-3 and BDNF in Synaptic Remodeling of the Inner Ear Induced by Electrical Stimulation. Cell Mol Neurobiol 2020; 41:1665-1682. [PMID: 32770528 DOI: 10.1007/s10571-020-00935-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/01/2020] [Indexed: 12/11/2022]
Abstract
With the development of neural prostheses, neural plasticity including synaptic remodeling under electrical stimulation is drawing more and more attention. Indeed, intracochlear electrical stimulation used to restore hearing in deaf can induce the loss of residual hearing and synapses of the inner hair cells (IHCs). However, the mechanism under this process is largely unknown. Considering that the guinea pig is always a suitable and convenient choice for the animal model of cochlea implant (CI), in the present study, normal-hearing guinea pigs were implanted with CIs. Four-hour electrical stimulation with the intensity of 6 dB above electrically evoked compound action potential (ECAP) threshold (which can decrease the quantity of IHC synapses and the excitability of the auditory nerve) resulted in the upregulation of Bdnf (p < 0.0001) and downregulation of Nt-3 (p < 0.05). Intracochlear perfusion of exogenous NT-3 or TrkC/Fc (which blocks NT-3) can, respectively, resist or aggravate the synaptic loss induced by electrical stimulation. In contrast, local delivery of exogenous BDNF or TrkB/Fc (which blocks BDNF) to the cochlea, respectively, exacerbated or protected against the synaptic loss caused by electrical stimulation. Notably, the synaptic changes were only observed in the basal and middle halves of the cochlea. All the findings above suggested that NT-3 and BDNF may play opposite roles in the remodeling of IHC synapses induced by intracochlear electrical stimulation, i.e. NT-3 and BDNF promoted the regeneration and degeneration of IHC synapses, respectively.
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Affiliation(s)
- Qiang Li
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Min Chen
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Chen Zhang
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Tianhao Lu
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Shiyao Min
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Shufeng Li
- ENT Institute and Department of Otolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China. .,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China.
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The integrity of cochlear hair cells is established and maintained through the localization of Dia1 at apical junctional complexes and stereocilia. Cell Death Dis 2020; 11:536. [PMID: 32678080 PMCID: PMC7366933 DOI: 10.1038/s41419-020-02743-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 02/07/2023]
Abstract
Dia1, which belongs to the diaphanous-related formin family, influences a variety of cellular processes through straight actin elongation activity. Recently, novel DIA1 mutants such as p.R1213X (p.R1204X) and p.A265S, have been reported to cause an autosomal dominant sensorineural hearing loss (DFNA1). Additionally, active DIA1 mutants induce progressive hearing loss in a gain-of-function manner. However, the subcellular localization and pathological function of DIA1(R1213X/R1204X) remains unknown. In the present study, we demonstrated the localization of endogenous Dia1 and the constitutively active DIA1 mutant in the cochlea, using transgenic mice expressing FLAG-tagged DIA1(R1204X) (DIA1-TG). Endogenous Dia1 and the DIA1 mutant were regionally expressed at the organ of Corti and the spiral ganglion from early life; alongside cochlear maturation, they became localized at the apical junctional complexes (AJCs) between hair cells (HCs) and supporting cells (SCs). To investigate HC vulnerability in the DIA1-TG mice, we exposed 4-week-old mice to moderate noise, which induced temporary threshold shifts with cochlear synaptopathy and ultrastructural changes in stereocilia 4 weeks post noise exposure. Furthermore, we established a knock-in (KI) mouse line expressing AcGFP-tagged DIA1(R1213X) (DIA1-KI) and confirmed mutant localization at AJCs and the tips of stereocilia in HCs. In MDCKAcGFP-DIA1(R1213X) cells with stable expression of AcGFP-DIA1(R1213X), AcGFP-DIA1(R1213X) revealed marked localization at microvilli on the apical surface of cells and decreased localization at cell-cell junctions. The DIA1-TG mice demonstrated hazy and ruffled circumferential actin belts at AJCs and abnormal stereocilia accompanied with HC loss at 5 months of age. In conclusion, Dia1 plays a pivotal role in the development and maintenance of AJCs and stereocilia, ensuring cochlear and HC integrity. Subclinical/latent vulnerability of HCs may be the cause of progressive hearing loss in DFNA1 patients, thus suggesting new therapeutic targets for preventing HC degeneration and progressive hearing loss associated with DFNA1.
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Patel S, Shah L, Dang N, Tan X, Almudevar A, White PM. SIRT3 promotes auditory function in young adult FVB/nJ mice but is dispensable for hearing recovery after noise exposure. PLoS One 2020; 15:e0235491. [PMID: 32658908 PMCID: PMC7357743 DOI: 10.1371/journal.pone.0235491] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/16/2020] [Indexed: 01/08/2023] Open
Abstract
Noise-induced hearing loss (NIHL) affects millions of people worldwide and presents a large social and personal burden. Pharmacological activation of SIRT3, a regulator of the mitochondrial oxidative stress response, has a protective effect on hearing thresholds after traumatic noise damage in mice. In contrast, the role of endogenously activated SIRT3 in hearing recovery has not been established. Here we tested the hypothesis that SIRT3 is required in mice for recovery of auditory thresholds after a noise exposure that confers a temporary threshold shift (TTS). SIRT3-specific immunoreactivity is present in outer hair cells, around the post-synaptic regions of inner hair cells, and faintly within inner hair cells. Prior to noise exposure, homozygous Sirt3-KO mice have slightly but significantly higher thresholds than their wild-type littermates measured by the auditory brainstem response (ABR), but not by distortion product otoacoustic emissions (DPOAE). Moreover, homozygous Sirt3-KO mice display a significant reduction in the progression of their peak 1 amplitude at higher frequencies prior to noise exposure. After exposure to a single sub-traumatic noise dose that does not permanently reduce cochlear function, compromise cell survival, or damage synaptic structures in wild-type mice, there was no difference in hearing function between the two genotypes, measured by ABR and DPOAE. The numbers of hair cells and auditory synapses were similar in both genotypes before and after noise exposure. These loss-of-function studies complement previously published gain-of-function studies and help refine our understanding of SIRT3’s role in cochlear homeostasis under different damage paradigms. They suggest that SIRT3 may promote spiral ganglion neuron function. They imply that cellular mechanisms of homeostasis, in addition to the mitochondrial oxidative stress response, act to restore hearing after TTS. Finally, we present a novel application of a biomedical statistical analysis for identifying changes between peak 1 amplitude progressions in ABR waveforms after damage.
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Affiliation(s)
- Sally Patel
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Lisa Shah
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Natalie Dang
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Xiaodong Tan
- Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Anthony Almudevar
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Patricia M. White
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- * E-mail:
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Hair Cell Transduction Efficiency of Single- and Dual-AAV Serotypes in Adult Murine Cochleae. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:1167-1177. [PMID: 32518805 PMCID: PMC7270144 DOI: 10.1016/j.omtm.2020.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/07/2020] [Indexed: 01/03/2023]
Abstract
Gene delivery is a key component for the treatment of genetic hearing loss. To date, a myriad of adeno-associated virus (AAV) serotypes and surgical approaches have been employed to deliver transgenes to cochlear hair cells, but the efficacy of dual transduction remains unclear. Herein, we investigated cellular tropism of single injections of AAV serotype 1 (AAV1), AAV2, AAV8, AAV9, and Anc80L65, and quantitated dual-vector co-transduction rates following co-injection of AAV2 and AAV9 vectors in adult murine cochlea. We used the combined round window membrane and canal fenestration (RWM+CF) injection technique for vector delivery. Single AAV2 injections were most robust and transduced 96.7% ± 1.1% of inner hair cells (IHCs) and 83.9% ± 2.0% of outer hair cells (OHCs) throughout the cochlea without causing hearing impairment or hair cell loss. Dual AAV2 injection co-transduced 96.9% ± 1.7% of IHCs and 65.6% ± 8.95% of OHCs. Together, RWM+CF-injected single or dual AAV2 provides the highest auditory hair cell transduction efficiency of the AAV serotypes we studied. These findings broaden the application of cochlear gene therapy targeting hair cells.
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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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Fan L, Zhang Z, Wang H, Li C, Xing Y, Yin S, Chen Z, Wang J. Pre-exposure to Lower-Level Noise Mitigates Cochlear Synaptic Loss Induced by High-Level Noise. Front Syst Neurosci 2020; 14:25. [PMID: 32477075 PMCID: PMC7235317 DOI: 10.3389/fnsys.2020.00025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/16/2020] [Indexed: 12/20/2022] Open
Abstract
The auditory sensory organs appear to be less damaged by exposure to high-level noise that is presented after exposure to non-traumatizing low-level noise. This phenomenon is known as the toughening or conditioning effect. Functionally, it is manifested by a reduced threshold shift, and morphologically by a reduced hair cell loss. However, it remains unclear whether prior exposure to toughening noise can mitigate the synaptic loss induced by exposure to damaging noise. Since the cochlear afferent synapse between the inner hair cells and primary auditory neurons has been identified as a novel site involved in noise-induced cochlear damage, we were interested in assessing whether this synapse can be toughened. In the present study, the synaptic loss was induced by a damaging noise exposure (106 dB SPL) and compared across Guinea pigs who had and had not been previously exposed to a toughening noise (85 dB SPL). Results revealed that the toughening noise heavily reduced the synaptic loss observed 1 day after exposure to the damaging noise. Although it was significant, the protective effect of the toughening noise on permanent synaptic loss was much smaller. Compared with cases in the control group without noise exposure, coding deficits were seen in both toughened groups, as reflected in the compound action potential (CAP) by signals with amplitude modulation. In general, the pre-exposure to the toughening noise resulted in a significantly reduced synaptic loss by the high-level noise. However, this morphological protection was not accompanied by a robust functional benefit.
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Affiliation(s)
- Liqiang Fan
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Zhen Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Hui Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Chunyan Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Yazhi Xing
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Shankai Yin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Zhengnong Chen
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
| | - Jian Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.,Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China.,School of Communication Sciences and Disorders, Faculty of Health, Dalhousie University, Halifax, NS, Canada
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Chen J, Liu Z, Yan H, Xing W, Mi W, Wang R, Li W, Chen F, Qiu J, Zha D. miR-182 prevented ototoxic deafness induced by co-administration of kanamycin and furosemide in rats. Neurosci Lett 2020; 723:134861. [PMID: 32105765 DOI: 10.1016/j.neulet.2020.134861] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/19/2020] [Accepted: 02/22/2020] [Indexed: 12/12/2022]
Abstract
Ototoxic drugs may induce auditory sensory hair cell loss and permanent deafness; however, there is still no effective treatments or prevention strategies for this side effect. A recent study found that microRNA182 (miR-182) protected cochlear hair cells from ototoxic drug-induced apoptosis in vitro. However, it remains unclear whether miR-182 can protect drug-induced deafness in vivo. In this study, we overexpressed cochlear miR-182 in Sprague-Dawley rats by trans-round window niche delivery of miR-182 mimics. The rats subsequently received intraperitoneal injections of kanamycin and furosemide to induce acute cochlear outer hair cell death and permanent deafness. Auditory brainstem response tests showed that miR-182 attenuated permanent threshold shifts. Consistent with this result, miR-182 reduced the loss of outer hair cells and missing stereocilia. miR-182 treatment also increased the level of phosphoinositide-3 kinase regulatory subunit p85α in the outer hair cells after co-administration of kanamycin and furosemide. Our findings suggest that miR-182 has powerful protective potential against ototoxic drug-induced acute auditory sensory hair cell loss and permanent deafness.
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Affiliation(s)
- Jun Chen
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Zhenzhen Liu
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Hui Yan
- Department of Otolaryngology, the Bingtuan Hospital, the Second Affiliated Hospital, School of Medicine, Shihezi University, Xinjiang 830002, China
| | - Wei Xing
- Department of Otolaryngology, Sanitarial District, Lintong Sanatorium of Lanzhou Military Region, Xi'an, 710600, China
| | - Wenjuan Mi
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Renfeng Wang
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Wei Li
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Fuquan Chen
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China
| | - Jianhua Qiu
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China.
| | - Dingjun Zha
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an710032, China.
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Han S, Du Z, Liu K, Gong S. Nicotinamide riboside protects noise-induced hearing loss by recovering the hair cell ribbon synapses. Neurosci Lett 2020; 725:134910. [PMID: 32171805 DOI: 10.1016/j.neulet.2020.134910] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/18/2020] [Accepted: 03/10/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Nicotinamide riboside (NR) has been proved to protect the hearing. To achieve animal models of temporary threshold shift (TTS) and permanent threshold shift (PTS) respectively, evaluate the dynamic change of ribbon synapse before and after NR administration. METHODS Mice were divided into control group, noise exposure (NE) group and NR group. The noise was exposed to NE and NR group, and NR was injected before noise exposure. Auditory brainstem response (ABR), ribbon synapse count and cochlear morphology were tested, as well as the concentration of hydrogen peroxide (H2O2) and ATP. RESULTS Ribbon synapse count decrease with the intensity of noise exposure, and the cochlear morphology remains stable during TTS and was damaged during PTS. NR promotes the oxidation resistance to protect the synapse and the inner ear morphology. CONCLUSION Our findings suggest that TTS mice are more vulnerable to noise, and NR can promote the recovery of the synapse count to protect the animals' hearing.
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Affiliation(s)
- Shuguang Han
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
| | - Zhengde Du
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
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Systemic Fluorescent Gentamicin Enters Neonatal Mouse Hair Cells Predominantly Through Sensory Mechanoelectrical Transduction Channels. J Assoc Res Otolaryngol 2020; 21:137-149. [PMID: 32152768 DOI: 10.1007/s10162-020-00746-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 02/10/2020] [Indexed: 01/25/2023] Open
Abstract
Systemically administered aminoglycoside antibiotics can enter inner ear hair cells and trigger apoptosis. However, the in vivo route(s) by which aminoglycoside antibiotics enter hair cells remains controversial. Aminoglycosides can enter mouse hair cells by endocytosis or by permeation through transmembrane ion channels such as sensory mechanoelectrical transduction (MET) channels, transient receptor potential (TRP) channels, P2X channels, Piezo2-containing ion channels, or a combination of these routes. Transmembrane channel-like 1 (TMC1) and TMC2 are essential for sensory MET and appear to be the pore-forming components of sensory MET channels. The present study tested the hypothesis that systemic fluorescent gentamicin enters mouse hair cells predominantly through sensory MET channels. We employed Tmc1Δ, Tmc2Δ, and Tmc1::mCherry mice. In Tmc1::mCherry mice, the transgene was integrated on the X chromosome, resulting in mosaic expression of TMC1-mCherry in the hair cells of female heterozygous mice. After systemic administration of gentamicin-conjugated Texas Red (GTTR) into Tmc1Δ;Tmc2Δ mice and wild-type mice at postnatal day 4 (P4), robust GTTR fluorescence was detected in wild-type hair cells, whereas little or no GTTR fluorescence was detected in Tmc1Δ;Tmc2Δ hair cells. When GTTR was injected into developing mice at P0, P2, P4, or P6, the GTTR fluorescent intensity gradually increased from P0 to P4 in wild-type hair cells, whereas the intensity was stably low from P0 through P6 in Tmc1Δ;Tmc2Δ hair cells. The increase in the GTTR intensity coincided with the spatio-temporal onset of sensory MET in wild-type hair cells. In Tmc1::mCherry cochleae, only hair cells that showed a significant uptake of systemic GTTR took up FM1-43. Transmission electron microscopy could detect no disruption of normal endocytosis at the apical surface of Tmc1Δ;Tmc2Δ hair cells in vitro. These results provide substantial novel evidence that in vivo gentamicin enters neonatal mouse hair cells predominantly through sensory MET channels and not via endocytosis.
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46
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Zhang Z, Fan L, Xing Y, Wang J, Aiken S, Chen Z, Wang J. Temporary Versus Permanent Synaptic Loss from Repeated Noise Exposure in Guinea Pigs and C57 Mice. Neuroscience 2020; 432:94-103. [PMID: 32114095 DOI: 10.1016/j.neuroscience.2020.02.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/07/2020] [Accepted: 02/23/2020] [Indexed: 01/14/2023]
Abstract
A single brief noise exposure can cause a significant loss of cochlear afferent synapses without causing permanent threshold shift. Previously we reported that the initial synaptic loss is partially reversible in Guinea pigs, indicating that synaptic loss can be categorized as either temporary or permanent. Since synaptic loss is biased to innervating auditory nerve fibers (ANFs) with low spontaneous spike rates (SSR), which are critical to the coding of in-background noise, coding-in-noise deficits (CIND) have been predicted to result from noise-induced synaptic damage. However, recent study of the noise masking of amplitude-modulation (AM) evoked compound action potentials (CAP) tailed to find evidence for such deficits in either mice or Guinea pigs. The present study sought to determine the effects of repeated noise exposure on temporary and permanent synaptic loss in Guinea pigs and C57 mice, whether such effects were additive, and whether repeated noise exposure induced CIND in Guinea pigs. The results show that the second noise exposure caused much less temporary synaptic loss and no additional permanent loss in Guinea pigs; however, an additional permanent loss was seen after the second noise was in the mice, although it was not significant. In Guinea pigs, the observed increased masking of the AM CAP provides evidence for CIND after repeated noise exposure.
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Affiliation(s)
- Zhen Zhang
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Liqiang Fan
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Yazhi Xing
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Jiping Wang
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Steve Aiken
- School of Communication Sciences and Disorders, Dalhousie University, Halifax, Canada
| | - Zhengnong Chen
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
| | - Jian Wang
- Otolaryngology Research Institute, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China; School of Communication Sciences and Disorders, Dalhousie University, Halifax, Canada.
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Stewart CE, Bauer DS, Kanicki AC, Altschuler RA, King WM. Intense noise exposure alters peripheral vestibular structures and physiology. J Neurophysiol 2019; 123:658-669. [PMID: 31875485 DOI: 10.1152/jn.00642.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The otolith organs play a critical role in detecting linear acceleration and gravity to control posture and balance. Some afferents that innervate these structures can be activated by sound and are at risk for noise overstimulation. A previous report demonstrated that noise exposure can abolish vestibular short-latency evoked potential (VsEP) responses and damage calyceal terminals. However, the stimuli that were used to elicit responses were weaker than those established in previous studies and may have been insufficient to elicit VsEP responses in noise-exposed animals. The goal of this study was to determine the effect of an established noise exposure paradigm on VsEP responses using large head-jerk stimuli to determine if noise induces a stimulus threshold shift and/or if large head-jerks are capable of evoking VsEP responses in noise-exposed rats. An additional goal is to relate these measurements to the number of calyceal terminals and hair cells present in noise-exposed vs. non-noise-exposed tissue. Exposure to intense continuous noise significantly reduced VsEP responses to large stimuli and abolished VsEP responses to small stimuli. This finding confirms that while measurable VsEP responses can be elicited from noise-lesioned rat sacculi, larger head-jerk stimuli are required, suggesting a shift in the minimum stimulus necessary to evoke the VsEP. Additionally, a reduction in labeled calyx-only afferent terminals was observed without a concomitant reduction in the overall number of calyces or hair cells. This finding supports a critical role of calretinin-expressing calyceal-only afferents in the generation of a VsEP response.NEW & NOTEWORTHY This study identifies a change in the minimum stimulus necessary to evoke vestibular short-latency evoked potential (VsEP) responses after noise-induced damage to the vestibular periphery and reduced numbers of calretinin-labeled calyx-only afferent terminals in the striolar region of the sacculus. These data suggest that a single intense noise exposure may impact synaptic function in calyx-only terminals in the striolar region of the sacculus. Reduced calretinin immunolabeling may provide insight into the mechanism underlying noise-induced changes in VsEP responses.
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Affiliation(s)
- C E Stewart
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - D S Bauer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - A C Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - R A Altschuler
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - W M King
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
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48
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Wu F, Xiong H, Sha S. Noise-induced loss of sensory hair cells is mediated by ROS/AMPKα pathway. Redox Biol 2019; 29:101406. [PMID: 31926629 PMCID: PMC6933152 DOI: 10.1016/j.redox.2019.101406] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/25/2019] [Accepted: 12/09/2019] [Indexed: 12/25/2022] Open
Abstract
The formation of reactive oxygen species (ROS) is a well-documented process in noise-induced hearing loss (NIHL). We have also previously shown that activation of 5' adenosine monophosphate (AMP)-activated protein kinase (AMPKα) at its catalytic residue T172 is one of the key reactions triggering noise-induced outer hair cell (OHC) death. In this study, we are addressing the link between ROS formation and activation of AMPKα in OHCs after noise exposure. In-vivo treatment of CBA/J mice with the antioxidant N-acetyl cysteine (NAC) reduced noise-induced ROS formation (as assessed by the relative levels of 4-hydroxynonenal and 3-nitrotyrosine) and activation of AMPKα in OHCs. Forskolin, an activator of adenylyl cyclase (AC) and an antioxidant, significantly increased cyclic adenosine monophosphate (cAMP) and decreased ROS formation and noise-induced activation of AMPKα. Consequently, treatment with forskolin attenuated noise-induced losses of OHCs and NIHL. In HEI-OC1 cells, H2O2-induced activation of AMPKα and cell death were inhibited by the application of forskolin. The sum of our data indicates that noise activates AMPKα in OHCs through formation of ROS and that noise-exposure-induced OHC death is mediated by a ROS/AMPKα-dependent pathway. Forskolin may serve as a potential compound for prevention of NIHL.
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Affiliation(s)
- Fan Wu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA; Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hao Xiong
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA; Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Suhua Sha
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA.
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Abstract
Auditory processing in the cochlea depends on the integrity of the mechanosensory hair cells. Over a lifetime, hearing loss can be acquired from numerous etiologies such as exposure to excessive noise, the use of ototoxic medications, bacterial or viral ear infections, head injuries, and the aging process. Loss of sensory hair cells is a common pathological feature of the varieties of acquired hearing loss. Additionally, the inner hair cell synapse can be damaged by mild insults. Therefore, surface preparations of cochlear epithelia, in combination with immunolabeling techniques and confocal imagery, are a very useful tool for the investigation of cochlear pathologies, including losses of ribbon synapses and sensory hair cells, changes in protein levels in hair cells and supporting cells, hair cell regeneration, and determination of report gene expression (i.e., GFP) for verification of successful transduction and identification of transduced cell types. The cochlea, a bony spiral-shaped structure in the inner ear, holds the auditory sensory end organ, the organ of Corti (OC). Sensory hair cells and surrounding supporting cells in the OC are contained in the cochlear duct and rest on the basilar membrane, organized in a tonotopic fashion with high-frequency detection occurring in the base and low-frequency in the apex. With the availability of molecular and genetic information and the ability to manipulate genes by knockout and knock-in techniques, mice have been widely used in biological research, including in hearing science. However, the adult mouse cochlea is miniscule, and the cochlear epithelium is encapsulated in a bony labyrinth, making microdissection difficult. Although dissection techniques have been developed and used in many laboratories, this modified microdissection method using cell and tissue adhesive is easier and more convenient. It can be used in all types of adult mouse cochleae following decalcification.
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Affiliation(s)
- Qiao-Jun Fang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina; MOE Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University
| | - Fan Wu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina
| | - Renjie Chai
- MOE Key Laboratory of Developmental Genes and Human Disease, Institute of Life Sciences, Southeast University
| | - Su-Hua Sha
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina;
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Lee JH, Lee MY, Chung PS, Jung JY. Photobiomodulation using low-level 808 nm diode laser rescues cochlear synaptopathy after acoustic overexposure in rat. JOURNAL OF BIOPHOTONICS 2019; 12:e201900145. [PMID: 31240853 DOI: 10.1002/jbio.201900145] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/21/2019] [Accepted: 06/23/2019] [Indexed: 06/09/2023]
Abstract
A certain degree of noise can cause hearing problems without a permanent change in the hearing threshold, which is called hidden hearing loss and results from partial loss of auditory synapses. Photobiomodulation (PBM) enhances neural growth and connections in the peripheral nervous systems. In this study, we assessed whether PBM could rescue cochlear synaptopathy after acoustic overexposure in rat. PBM was performed for 7 days after noise exposure. The auditory brainstem responses (ABRs) were acquired before and after noise exposure using a tone and a paired-click stimulus. Auditory response to paired click sound with short time interval was performed to evaluate auditory temporal processing ability. In the result, hearing threshold recovered 2 weeks after noise exposure in both groups. Peak wave 1 amplitude of the ABR and ABR recovery threshold did not recover in the noise only group, whereas it fully recovered in the noise + PBM group. The number of synaptic ribbons was significantly different in the control and noise only groups, while there was no difference between the control and noise + PBM group. These results indicate that PBM rescued peak wave 1 amplitude and maintained the auditory temporal processing ability resulting from a loss of synaptic ribbons after acoustic overexposure.
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Affiliation(s)
- Jae-Hun Lee
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, South Korea
- Interdiscriplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, South Korea
| | - Min Young Lee
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, South Korea
- Interdiscriplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, South Korea
- Department of Otolaryngology Head and Neck Surgery, Dankook University Hospital, Cheonan, South Korea
| | - Phil-Sang Chung
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, South Korea
- Interdiscriplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, South Korea
- Department of Otolaryngology Head and Neck Surgery, Dankook University Hospital, Cheonan, South Korea
| | - Jae Yun Jung
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, South Korea
- Interdiscriplinary Program for Medical Laser, College of Medicine, Dankook University, Cheonan, South Korea
- Department of Otolaryngology Head and Neck Surgery, Dankook University Hospital, Cheonan, South Korea
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