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Tian C, Yang Y, Wang R, Li Y, Sun F, Chen J, Zha D. Norepinephrine protects against cochlear outer hair cell damage and noise-induced hearing loss via α 2A-adrenergic receptor. BMC Neurosci 2024; 25:5. [PMID: 38291397 PMCID: PMC10829207 DOI: 10.1186/s12868-024-00845-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 01/16/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND The cochlear sympathetic system plays a key role in auditory function and susceptibility to noise-induced hearing loss (NIHL). The formation of reactive oxygen species (ROS) is a well-documented process in NIHL. In this study, we aimed at investigating the effects of a superior cervical ganglionectomy (SCGx) on NIHL in Sprague-Dawley rats. METHODS We explored the effects of unilateral and bilateral Superior Cervical Ganglion (SCG) ablation in the eight-ten weeks old Sprague-Dawley rats of both sexes on NIHL. Auditory function was evaluated by auditory brainstem response (ABR) testing and Distortion product otoacoustic emissions (DPOAEs). Outer hair cells (OHCs) counts and the expression of α2A-adrenergic receptor (AR) in the rat cochlea using immunofluorescence analysis. Cells culture and treatment, CCK-8 assay, Flow cytometry staining and analysis, and western blotting were to explore the mechanisms of SCG fibers may have a protective role in NIHL. RESULTS We found that neither bilateral nor unilateral SCGx protected the cochlea against noise exposure. In HEI-OC1 cells, H2O2-induced oxidative damage and cell death were inhibited by the application of norepinephrine (NE). NE may prevent ROS-induced oxidative stress in OHCs and NIHL through the α2A-AR. CONCLUSION These results demonstrated that sympathetic innervation mildly affected cochlear susceptibility to acoustic trauma by reducing oxidative damage in OHCs through the α2A-AR. NE may be a potential therapeutic strategy for NIHL prevention.
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Affiliation(s)
- Chaoyong Tian
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Yang Yang
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Renfeng Wang
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Yao Li
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Fei Sun
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Jun Chen
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China
| | - Dingjun Zha
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi, 710032, China.
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Aparisi-Climent V, Sequi-Sabater JM, Collar-Del Castillo JI, Sequi-Canet JM. Influence of umbilical cord pH on the outcome of hearing screening with otoacoustic emissions in healthy newborns. Acta Otorrinolaringol Esp (Engl Ed) 2024; 75:1-7. [PMID: 37391167 DOI: 10.1016/j.otoeng.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 12/27/2022] [Indexed: 07/02/2023]
Abstract
The effect of hypoxia on the functioning of the outer hair cells of the cochlea, which are responsible for the response to otoemissions used in neonatal hearing screening, is well known. The aim of this study is to determine the influence of mild to moderate variations in umbilical cord pH at birth on the outcome of hearing screening with otoemissions in healthy newborns without hearing risk factors. The sample is composed of 4536 healthy infants. The results show no significant differences in the hearing screening outcome between the asphyctic (<7.20) and normal pH group. Nor is a figure below 7.20 detected in the sample that is related to an alteration in the screening. When broken down into subgroups with known factors of variation in the screening result, such as gender or lactation, no significant differences in response were detected. Apgar ≤7 is significantly related to pH<7.20. In conclusion, mild-moderate asphyxia associated with delivery of healthy newborns, without auditory risk factors, does not alter the outcome of otoemission screening.
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Affiliation(s)
- Víctor Aparisi-Climent
- Servicio de Pediatría, Hospital Francesc de Borja, Gandía (Valencia), Spain; Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO), Valencia, Spain
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Yeom J, Park J, Park JY. Fluid dynamic simulation for cellular damage due to lymphatic flow within the anatomical arrangement of the outer hair cells in the cochlea. Comput Biol Med 2023; 161:106986. [PMID: 37230014 DOI: 10.1016/j.compbiomed.2023.106986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/29/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
Damage to the sensory hair cells in the cochlea is a major cause of hearing loss since human sensory hair cells do not regenerate naturally after damage. As these sensory hair cells are exposed to a vibrating lymphatic environment, they may be affected by physical flow. It is known that the outer hair cells (OHCs) are physically more damaged by sound than the inner hair cells (IHCs). In this study, the lymphatic flow is compared using computational fluid dynamics (CFD) based on the arrangement of the OHCs, and the effects of such flow on the OHCs is analyzed. In addition, flow visualization is used to validate the Stokes flow. The Stokes flow behavior is attributed to the low Reynolds number, and the same behavior is observed even when the flow direction is reversed. When the distance between the rows of the OHCs is large, each row is independent, but when this distance is short, the flow change in each row influences the other rows. The stimulation caused by flow changes on the OHCs is confirmed through surface pressure and shear stress. The OHCs located at the base with a short distance between the rows receive excess hydrodynamic stimulation, and the tip of the V-shaped pattern receives an excess mechanical force. This study attempts to understand the contributions of lymphatic flow to OHC damage by quantitatively suggesting stimulation of the OHCs and is expected to contribute to the development of OHC regeneration technologies in the future.
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Affiliation(s)
- Jiun Yeom
- School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Junseon Park
- School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Joong Yull Park
- School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea; Department of Intelligent Energy and Industry, Graduate School, Chung-Ang University, Seoul, 06974, Republic of Korea.
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Abstract
Prestin (SLC26A5) is a membrane-based voltage-dependent motor protein responsible for outer hair cell (OHC) somatic electromotility. Its importance for mammalian cochlear amplification has been demonstrated using mouse models lacking prestin (prestin-KO) and expressing dysfunctional prestin, prestinV499G/Y501H (499-prestin-KI). However, it is still not elucidated how prestin contributes to the mechanical amplification process in the cochlea. In this study, we characterized several prestin mouse models in which prestin activity in OHCs was variously manipulated. We found that near-normal cochlear function can be maintained even when prestin activity is significantly reduced, suggesting that the relationship between OHC electromotility and the peripheral sensitivity to sound may not be linear. This result is counterintuitive given the large threshold shifts in prestin-KO and 499-prestin-KI mice, as reported in previous studies. To reconcile these apparently opposing observations, we entertain a voltage- and turgor pressure-based cochlear amplification mechanism that requires prestin but is insensitive to significant reductions in prestin protein expression. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
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Affiliation(s)
- Kazuaki Homma
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60208, USA.
| | - Satoe Takahashi
- Department of Otolaryngology - Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mary Ann Cheatham
- The Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University, Evanston, IL 60208, USA; Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60208, USA.
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He W, Burwood G, Fridberger A, Nuttall AL, Ren T. An outer hair cell-powered global hydromechanical mechanism for cochlear amplification. Hear Res 2022; 423:108407. [PMID: 34922772 PMCID: PMC9156726 DOI: 10.1016/j.heares.2021.108407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/23/2021] [Accepted: 11/30/2021] [Indexed: 11/04/2022]
Abstract
It is a common belief that the mammalian cochlea achieves its exquisite sensitivity, frequency selectivity, and dynamic range through an outer hair cell-based active process, or cochlear amplification. As a sound-induced traveling wave propagates from the cochlear base toward the apex, outer hair cells at a narrow region amplify the low level sound-induced vibration through a local feedback mechanism. This widely accepted theory has been tested by measuring sound-induced sub-nanometer vibrations within the organ of Corti in the sensitive living cochleae using heterodyne low-coherence interferometry and optical coherence tomography. The aim of this short review is to summarize experimental findings on the cochlear active process by the authors' group. Our data show that outer hair cells are able to generate substantial forces for driving the cochlear partition at all audible frequencies in vivo. The acoustically induced reticular lamina vibration is larger and more broadly tuned than the basilar membrane vibration. The reticular lamina and basilar membrane vibrate approximately in opposite directions at low frequencies and in the same direction at the best frequency. The group delay of the reticular lamina is larger than that of the basilar membrane. The magnitude and phase differences between the reticular lamina and basilar membrane vibration are physiologically vulnerable. These results contradict predictions based on the local feedback mechanism but suggest a global hydromechanical mechanism for cochlear amplification. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
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Affiliation(s)
- Wenxuan He
- Department of Otolaryngology, Head and Neck Surgery, Oregon Health & Science University, Portland OR, United States
| | - George Burwood
- Department of Otolaryngology, Head and Neck Surgery, Oregon Health & Science University, Portland OR, United States
| | - Anders Fridberger
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Alfred L Nuttall
- Department of Otolaryngology, Head and Neck Surgery, Oregon Health & Science University, Portland OR, United States
| | - Tianying Ren
- Department of Otolaryngology, Head and Neck Surgery, Oregon Health & Science University, Portland OR, United States.
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Manohar S, Ding D, Jiang H, Li L, Chen GD, Kador P, Salvi R. Combined antioxidants and anti-inflammatory therapies fail to attenuate the early and late phases of cyclodextrin-induced cochlear damage and hearing loss. Hear Res 2021; 414:108409. [PMID: 34953289 DOI: 10.1016/j.heares.2021.108409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/08/2021] [Accepted: 12/06/2021] [Indexed: 11/04/2022]
Abstract
Niemann-Pick C1 (NPC1) is a fatal neurodegenerative disease caused by aberrant cholesterol metabolism. The progression of the disease can be slowed by removing excess cholesterol with high-doses of 2-hyroxypropyl-beta-cyclodextrin (HPβCD). Unfortunately, HPβCD causes hearing loss; the initial first phase involves a rapid destruction of outer hair cells (OHCs) while the second phase, occurring 4-6 weeks later, involves the destruction of inner hair cells (IHCs), pillar cells, collapse of the organ of Corti and spiral ganglion neuron degeneration. To determine whether the first and/or second phase of HPβCD-induced cochlear damage is linked, in part, to excess oxidative stress or neuroinflammation, rats were treated with a single-dose of 3000 mg/kg HPβCD alone or together with one of two combination therapies. Each combination therapy was administered from 2-days before to 6-weeks after the HPβCD treatment. Combination 1 consisted of minocycline, an antibiotic that suppresses neuroinflammation, and HK-2, a multifunctional redox modulator that suppresses oxidative stress. Combination 2 was comprised of minocycline plus N-acetyl cysteine (NAC), which upregulates glutathione, a potent antioxidant. To determine if either combination therapy could prevent HPβCD-induced hearing impairment and cochlear damage, distortion product otoacoustic emissions (DPOAE) were measured to assess OHC function and the cochlear compound action potential (CAP) was measured to assess the function of IHCs and auditory nerve fibers. Cochleograms were prepared to quantify the amount of OHC, IHC and pillar cell (PC) loss. HPβCD significantly reduced DPOAE and CAP amplitudes and caused significant OHC, IHC and OPC losses with losses greater in the high-frequency base of the cochlea than the apex. Neither minocycline + HK-2 (MIN+ HK-2) nor minocycline + NAC (MIN+NAC) prevented the loss of DPOAEs, CAPs, OHCs, IHCs or IPCs caused by HPβCD. These results suggest that oxidative stress and neuroinflammation are unlikely to play major roles in mediating the first or second phase of HPβCD-induced cochlear damage. Thus, HPβCD-induced ototoxicity must be mediated by some other unknown cell-death pathway possibly involving loss of trophic support from damaged support cells or disrupted cholesterol metabolism.
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Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Haiyan Jiang
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Li Li
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Peter Kador
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA; Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, 68198, USA; Therapeutic Vision, Inc., Elkhorn, NE, 68022, USA.
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Seethapathy J, Boominathan P, Uppunda AK, Ninan B. Distortion product otoacoustic emissions in very preterm infants: A longitudinal study. Int J Pediatr Otorhinolaryngol 2021; 146:110745. [PMID: 33940313 DOI: 10.1016/j.ijporl.2021.110745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 03/30/2021] [Accepted: 04/24/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Very preterm infants are at a greater risk of developing neurodevelopmental impairments such as neuro-motor delays, vision and hearing deficits (Roze and Breart, 2004; Saigal and Doyle, 2008) [1,2]. The hearing difficulties in preterm infants vary depending on the co-morbid conditions. However, prematurity itself is considered as a risk factor that influence the functioning of auditory system. AIM The current study aims to compare the DPOAEs in very preterm infants and term infants at 1 month, 3 months and 6 months of age (corrected age in preterm infants). METHOD DPOAEs were recorded in 72 very preterm infants and 30 term infants at 1 month, 3 months and 6 months of age. All these infants had obtained 'pass' results in newborn hearing screening using ABR. DPOAE f2 test frequency was measured at six frequencies (1500 Hz, 2000 Hz, 3000 Hz, 4500 Hz, 6000 Hz and 8000 Hz) with primary tone stimulus intensity L1 equal to 65 dBSPL and L2 equal to 55 dBSPL with primary tone f2/f1 frequency ratio of 1.2. Otoscopic examination and tympanometry was performed prior to DPOAE testing, to ascertain normal middle ear status. RESULTS DPOAE amplitude did not change significantly between two groups from 1 month till 6 months of age (p > 0.05). DPOAE amplitude and noise floor in very preterm infants were not different from term infants and DPOAE amplitude did not vary significantly across f2 frequencies at various time periods. CONCLUSION The current study findings provided evidence that prematurity did not constitute as a factor to influence the results of DPOAE in very preterm infants who passed newborn hearing screening test. Any significant reduction in DPOAE amplitude or absence of DPOAE in very preterm infants has to be considered and monitored effectively, as it may not reflect a developmental process of cochlear function; instead it could indicate the presence of inner ear or middle ear pathology.
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Affiliation(s)
- Jayashree Seethapathy
- Department of Speech, Language and Hearing Sciences. Sri Ramachandra Institute of Higher Education and Research (DU). Chennai, 600 116, India.
| | - Prakash Boominathan
- Department of Speech, Language and Hearing Sciences. Sri Ramachandra Institute of Higher Education and Research (DU). Chennai, 600 116, India
| | - Ajith Kumar Uppunda
- Department of Audiology. All India Institute of Speech and Hearing. Mysore, 570 006, India
| | - Binu Ninan
- Department of Neonatology. Sri Ramachandra Institute of Higher Education and Research (DU). Chennai, 600 116, India; Department of Pediatrics and Neonatology, MGM Healthcare, Chennai, 600029, India.
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Mao B, Wang Y, Balasubramanian T, Urioste R, Wafa T, Fitzgerald TS, Haraczy SJ, Edwards-Hollingsworth K, Sayyid ZN, Wilder D, Sajja VSSS, Wei Y, Arun P, Gist I, Cheng AG, Long JB, Kelley MW. Assessment of auditory and vestibular damage in a mouse model after single and triple blast exposures. Hear Res 2021; 407:108292. [PMID: 34214947 DOI: 10.1016/j.heares.2021.108292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 12/18/2022]
Abstract
The use of explosive devices in war and terrorism has increased exposure to concussive blasts among both military personnel and civilians, which can cause permanent hearing and balance deficits that adversely affect survivors' quality of life. Significant knowledge gaps on the underlying etiology of blast-induced hearing loss and balance disorders remain, especially with regard to the effect of blast exposure on the vestibular system, the impact of multiple blast exposures, and long-term recovery. To address this, we investigated the effects of blast exposure on the inner ear using a mouse model in conjunction with a high-fidelity blast simulator. Anesthetized animals were subjected to single or triple blast exposures, and physiological measurements and tissue were collected over the course of recovery for up to 180 days. Auditory brainstem responses (ABRs) indicated significantly elevated thresholds across multiple frequencies. Limited recovery was observed at low frequencies in single-blasted mice. Distortion Product Otoacoustic Emissions (DPOAEs) were initially absent in all blast-exposed mice, but low-amplitude DPOAEs could be detected at low frequencies in some single-blast mice by 30 days post-blast, and in some triple-blast mice at 180 days post-blast. All blast-exposed mice showed signs of Tympanic Membrane (TM) rupture immediately following exposure and loss of outer hair cells (OHCs) in the basal cochlear turn. In contrast, the number of Inner Hair Cells (IHCs) and spiral ganglion neurons was unchanged following blast-exposure. A significant reduction in IHC pre-synaptic puncta was observed in the upper turns of blast-exposed cochleae. Finally, we found no significant loss of utricular hair cells or changes in vestibular function as assessed by vestibular evoked potentials. Our results suggest that (1) blast exposure can cause severe, long-term hearing loss which may be partially due to slow TM healing or altered mechanical properties of healed TMs, (2) traumatic levels of sound can still reach the inner ear and cause basal OHC loss despite middle ear dysfunction caused by TM rupture, (3) blast exposure may result in synaptopathy in humans, and (4) balance deficits after blast exposure may be primarily due to traumatic brain injury, rather than damage to the peripheral vestibular system.
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Affiliation(s)
- Beatrice Mao
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA.
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | - Tara Balasubramanian
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Rodrigo Urioste
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Talah Wafa
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Tracy S Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Scott J Haraczy
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Kamren Edwards-Hollingsworth
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Zahra N Sayyid
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Donna Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Venkata Siva Sai Sujith Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Irene Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | - Matthew W Kelley
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
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Ding D, Manohar S, Jiang H, Salvi R. Hydroxypropyl-β-cyclodextrin causes massive damage to the developing auditory and vestibular system. Hear Res 2020; 396:108073. [PMID: 32956992 DOI: 10.1016/j.heares.2020.108073] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/03/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
2-hydroxypropyl-β-cyclodextrin (HPβCD), a cholesterol chelator used to treat Niemann-Pick C1 (NPC1) lysosomal storage disease, causes hearing loss in mammals by preferentially destroying outer hair cells. Because cholesterol plays an important role in early neural development, we hypothesized that HPβCD would cause more extensive damage to postnatal cochlear and vestibular structures in than adult rats. This hypothesis was tested by administering HPβCD to adult rats and postnatal day 3 (P3) cochlear and vestibular organ cultures. Adult rats treated with HPβCD developed hearing impairment and outer hair cell loss 3-day post-treatment; damage increased with dose from the high frequency base toward the low-frequency apex. The HPβCD-induced histopathologies were more severe and widespread in cochlear and vestibular cultures at P3 than in adults. HPβCD destroyed both outer and inner hair cells, auditory nerve fibers and spiral ganglion neurons as well as type I and type II vestibular hair cells and vestibular ganglion neurons. The early stage of HPβCD damage involved disruption of hair cell mechanotransduction and destruction of stereocilia. HPβCD-mediated apoptosis in P3 cultures was most-strongly initiated by activation of the extrinsic caspase-8 cell death pathway in cochlear and vestibular hair cells and neurons followed by activation of executioner caspase-3. Thus, HPβCD is toxic to all types of postnatal cochlear and vestibular hair cells and neurons in vitro whereas in vivo it only appears to destroy outer hair cells in adult cochleae. The more severe HPβCD-induced damage in postnatal cultures could be due to greater drug bioavailability in vitro and/or greater vulnerability of the developing inner ear.
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Affiliation(s)
- Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, Buffalo, NY 14214, United States
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, Buffalo, NY 14214, United States
| | - Haiyan Jiang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, Buffalo, NY 14214, United States
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, Buffalo, NY 14214, United States.
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Prabhu P, Shaji SR, Vipinan KM, Ramanunny NV, Nagaraju B. Effect of different blood groups on tympanometric findings and acoustic reflex thresholds. Eur Arch Otorhinolaryngol 2020; 277:3513-3518. [PMID: 32737643 DOI: 10.1007/s00405-020-06244-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 07/24/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE The blood group can have an effect on the auditory system, and it is suggested that it could be an indicator of noise-induced hearing loss. There could be changes in the immittance findings, too, in adults having different blood groups. The present study attempted to determine if there are any differences in tympanometric results (admittance, peak pressure, gradient, resonance frequency, and ear canal volume) and acoustic reflex thresholds (ART) at 500, 1000, 2000 and 4000 Hz between individuals with different blood groups (A positive, B positive, O positive and AB positive). METHODS Eighty normal hearing adults between the age of 18 and 27 years were considered for the study. They were divided into 20 participants, each with blood groups A, B, AB, and O. The immittance findings were recorded from all the participants of the study. RESULTS The results showed that the resonance frequency was slightly higher in blood group O compared to other blood groups. Also, the acoustic reflex thresholds were slightly elevated at all frequencies (ipsilateral and contralateral) for individuals with blood group O. CONCLUSIONS The results of the study suggest possible reduced outer hair cells in persons with blood group O. This could have resulted in elevated acoustic reflex thresholds.
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Affiliation(s)
- Prashanth Prabhu
- All India Institute of Speech and Hearing, Mysore, 570006, Karnataka, India.
| | - Sneha Roslyn Shaji
- All India Institute of Speech and Hearing, Mysore, 570006, Karnataka, India
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Liu X, Ding D, Chen GD, Li L, Jiang H, Salvi R. 2-Hydroxypropyl-β-cyclodextrin Ototoxicity in Adult Rats: Rapid Onset and Massive Destruction of Both Inner and Outer Hair Cells Above a Critical Dose. Neurotox Res 2020; 38:808-823. [PMID: 32607920 DOI: 10.1007/s12640-020-00252-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/24/2020] [Accepted: 06/25/2020] [Indexed: 02/08/2023]
Abstract
2-Hydroxypropyl-β-cyclodextrin (HPβCD), a cholesterol chelator, is being used to treat diseases associated with abnormal cholesterol metabolism such as Niemann-Pick C1 (NPC1). However, the high doses of HPβCD needed to slow disease progression may cause hearing loss. Previous studies in mice have suggested that HPβCD ototoxicity results from selective outer hair cell (OHC) damage. However, it is unclear if HPβCD causes the same type of damage or is more or less toxic to other species such as rats, which are widely used in toxicity research. To address these issues, rats were given a subcutaneous injection of HPβCD between 500 and 4000 mg/kg. Distortion product otoacoustic emissions (DPOAE), the cochlear summating potential (SP), and compound action potential (CAP) were used to assess cochlear function followed by quantitative analysis of OHC and inner hair cell (IHC) loss. The 3000- and 4000-mg/kg doses abolished DPOAE and greatly reduced SP and CAP amplitudes. These functional deficits were associated with nearly complete loss of OHC as well as ~ 80% IHC loss over the basal two thirds of the cochlea. The 2000-mg/kg dose abolished DPOAE and significantly reduced SP and CAP amplitudes at the high frequencies. These deficits were linked to OHC and IHC losses in the high-frequency region of the cochlea. Little or no damage occurred with 500 or 1000 mg/kg of HPβCD. The HPβCD-induced functional and structural deficits in rats occurred suddenly, involved damage to both IHC and OHC, and were more severe than those reported in mice.
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Affiliation(s)
- Xiaopeng Liu
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA
| | - Dalian Ding
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA
| | - Li Li
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA
| | - Haiyan Jiang
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, 14214, USA.
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12
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Ota T, Nin F, Choi S, Muramatsu S, Sawamura S, Ogata G, Sato MP, Doi K, Doi K, Tsuji T, Kawano S, Reichenbach T, Hibino H. Characterisation of the static offset in the travelling wave in the cochlear basal turn. Pflugers Arch 2020; 472:625-635. [PMID: 32318797 PMCID: PMC7239825 DOI: 10.1007/s00424-020-02373-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/18/2020] [Accepted: 03/23/2020] [Indexed: 02/07/2023]
Abstract
In mammals, audition is triggered by travelling waves that are evoked by acoustic stimuli in the cochlear partition, a structure containing sensory hair cells and a basilar membrane. When the cochlea is stimulated by a pure tone of low frequency, a static offset occurs in the vibration in the apical turn. In the high-frequency region at the cochlear base, multi-tone stimuli induce a quadratic distortion product in the vibrations that suggests the presence of an offset. However, vibrations below 100 Hz, including a static offset, have not been directly measured there. We therefore constructed an interferometer for detecting motion at low frequencies including 0 Hz. We applied the interferometer to record vibrations from the cochlear base of guinea pigs in response to pure tones. When the animals were exposed to sound at an intensity of 70 dB or higher, we recorded a static offset of the sinusoidally vibrating cochlear partition by more than 1 nm towards the scala vestibuli. The offset’s magnitude grew monotonically as the stimuli intensified. When stimulus frequency was varied, the response peaked around the best frequency, the frequency that maximised the vibration amplitude at threshold sound pressure. These characteristics are consistent with those found in the low-frequency region and are therefore likely common across the cochlea. The offset diminished markedly when the somatic motility of mechanosensitive outer hair cells, the force-generating machinery that amplifies the sinusoidal vibrations, was pharmacologically blocked. Therefore, the partition offset appears to be linked to the electromotile contraction of outer hair cells.
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Affiliation(s)
- Takeru Ota
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Fumiaki Nin
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
| | - Samuel Choi
- AMED-CREST, AMED, Niigata, 951-8510, Japan.,Department of Electrical and Electronics Engineering, Niigata University, Niigata, 950-2181, Japan
| | - Shogo Muramatsu
- Department of Electrical and Electronics Engineering, Niigata University, Niigata, 950-2181, Japan
| | - Seishiro Sawamura
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Genki Ogata
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Mitsuo P Sato
- Department of Otolaryngology, Kindai University Faculty of Medicine, Osaka, 589-8511, Japan
| | - Katsumi Doi
- Department of Otolaryngology, Kindai University Faculty of Medicine, Osaka, 589-8511, Japan
| | - Kentaro Doi
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, 560-8531, Japan
| | - Tetsuro Tsuji
- Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, 560-8531, Japan.,Department of Advanced Mathematical Sciences, Graduate School of Informatics, Kyoto University, Kyoto, 606-8501, Japan
| | - Satoyuki Kawano
- AMED-CREST, AMED, Niigata, 951-8510, Japan.,Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, 560-8531, Japan
| | - Tobias Reichenbach
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Hiroshi Hibino
- Department of Molecular Physiology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan. .,AMED-CREST, AMED, Niigata, 951-8510, Japan.
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13
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Zhou Y, Takahashi S, Homma K, Duan C, Zheng J, Cheatham MA, Zheng J. The susceptibility of cochlear outer hair cells to cyclodextrin is not related to their electromotile activity. Acta Neuropathol Commun 2018; 6:98. [PMID: 30249300 PMCID: PMC6151916 DOI: 10.1186/s40478-018-0599-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 09/13/2018] [Indexed: 11/26/2022] Open
Abstract
Niemann-Pick Type C1 (NPC1) disease is a fatal neurovisceral disorder caused by dysfunction of NPC1 protein, which plays a role in intracellular cholesterol trafficking. The cholesterol-chelating agent, 2-hydroxypropyl-β-cyclodextrin (HPβCD), is currently undergoing clinical trials for treatment of this disease. Though promising in alleviating neurological symptoms, HPβCD causes irreversible hearing loss in NPC1 patients and outer hair cell (OHC) death in animal models. We recently found that HPβCD-induced OHC death can be significantly alleviated in a mouse model lacking prestin, an OHC-specific motor protein required for the high sensitivity and sharp frequency selectivity of mammalian hearing. Since cholesterol status is known to influence prestin’s electromotility, we examined how prestin contributes to HPβCD-induced OHC death in the disease context using the NPC1 knockout (KO) mouse model (NPC1-KO). We found normal expression and localization of prestin in NPC1-KO OHCs. Whole-cell patch-clamp recordings revealed a significant depolarization of the voltage-operating point of prestin in NPC1-KO mice, suggesting reduced levels of cholesterol in the lateral membrane of OHCs that lack NPC1. OHC loss and elevated thresholds were found for high frequency regions in NPC1-KO mice, whose OHCs retained their sensitivity to HPβCD. To investigate whether prestin’s electromotile function contributes to HPβCD-induced OHC death, the prestin inhibitor salicylate was co-administered with HPβCD to WT and NPC1-KO mice. Neither oral nor intraperitoneal administration of salicylate mitigated HPβCD-induced OHC loss. To further determine the contribution of prestin’s electromotile function, a mouse model expressing a virtually nonelectromotile prestin protein (499-prestin) was subjected to HPβCD treatment. 499-prestin knockin mice showed no resistance to HPβCD-induced OHC loss. As 499-prestin maintains its ability to bind cholesterol, our data imply that HPβCD-induced OHC death is ascribed to the structural role of prestin in maintaining the OHC’s lateral membrane, rather than its motor function.
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14
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Li C, Shu Y, Wang G, Zhang H, Lu Y, Li X, Li G, Song L, Liu Z. Characterizing a novel vGlut3-P2A-iCreER knockin mouse strain in cochlea. Hear Res 2018; 364:12-24. [PMID: 29706463 DOI: 10.1016/j.heares.2018.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/05/2018] [Accepted: 04/12/2018] [Indexed: 12/21/2022]
Abstract
Precise mouse genetic studies rely on specific tools that can label specific cell types. In mouse cochlea, previous studies suggest that vesicular glutamate transporter 3 (vGlut3), also known as Slc17a8, is specifically expressed in inner hair cells (IHCs) and loss of vGlut3 causes deafness. To take advantage of its unique expression pattern, here we generate a novel vGlut3-P2A-iCreER knockin mouse strain. The P2A-iCreER cassette is precisely inserted before stop codon of vGlut3, by which the endogenous vGlut3 is intact and paired with iCreER as well. Approximately, 10.7%, 85.6% and 41.8% of IHCs are tdtomato + when tamoxifen is given to vGlut3-P2A-iCreER/+; Rosa26-LSL-tdtomato/+ reporter strain at P2/P3, P10/P11 and P30/P31, respectively. Tdtomato + OHCs are never observed. Interestingly, besides IHCs, glia cells, but not spiral ganglion neurons (SGNs), are tdtomato+, which is further evidenced by the presence of Sox10+/tdtomato+ and tdtomato+/Prox1(Gata3 or Tuj1)-negative cells in SGN region. We further independently validate vGlut3 expression in SGN region by vGlut3 in situ hybridization and antibody staining. Moreover, total number of tdtomato + glia cells decreased gradually when tamoxifen is given from P2/P3 to P30/P31. Taken together, vGlut3-P2A-iCreER is an efficient genetic tool to specifically target IHCs for gene manipulation, which is complimentary to Prestin-CreER strain exclusively labelling cochlear outer hair cells (OHCs).
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MESH Headings
- Acoustic Stimulation
- Amino Acid Transport Systems, Acidic/genetics
- Amino Acid Transport Systems, Acidic/metabolism
- Animals
- Cochlea/embryology
- Cochlea/metabolism
- Evoked Potentials, Auditory, Brain Stem
- Female
- Gene Knock-In Techniques
- Genes, Reporter
- Genotype
- Hair Cells, Auditory, Outer/metabolism
- Integrases/genetics
- Integrases/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice, Inbred C57BL
- Mice, Transgenic
- Neuroglia/metabolism
- Phenotype
- Reaction Time
- Receptors, Estrogen/drug effects
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Selective Estrogen Receptor Modulators/pharmacology
- Spiral Ganglion/metabolism
- Tamoxifen/pharmacology
- Time Factors
- Red Fluorescent Protein
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Affiliation(s)
- Chao Li
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yilai Shu
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China; Key Laboratory of Hearing Medicine of National Health and Family Planning Commission (NHFPC), Shanghai, China
| | - Guangqin Wang
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - He Zhang
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Lu
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xiang Li
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Gen Li
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lei Song
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhiyong Liu
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China.
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15
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Frilling MJ, Wiet GJ, Godfrey DA, Parli JA, Dunn JD, Ross CD. Effects of surgical lesions on choline acetyltransferase activity in the cat cochlea. Hear Res 2017; 356:16-24. [PMID: 29056431 DOI: 10.1016/j.heares.2017.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/21/2017] [Accepted: 09/27/2017] [Indexed: 11/19/2022]
Abstract
Although it is well established that the choline acetyltransferase (ChAT, the enzyme for acetylcholine synthesis) in the mammalian cochlea is associated with its olivocochlear innervation, the distribution of this innervation in the cochlea varies somewhat among mammalian species. The quantitative distribution of ChAT activity in the cochlea has been reported for guinea pigs and rats. The present study reports the distribution of ChAT activity within the organ of Corti among the three turns of the cat cochlea and the effects of removing olivocochlear innervation either by a lateral cut aimed to totally transect the left olivocochlear bundle or a more medial cut additionally damaging the superior olivary complex on the same side. Similarly to results for guinea pig and rat, the distribution of ChAT activity in the cat outer hair cell region showed a decrease from base to apex, but, unlike in the guinea pig and rat, the cat inner hair cell region did not. As in the rat, little ChAT activity was measured in the outer supporting cell region. As previously reported for whole cat cochlea and for rat cochlear regions, transection of the olivocochlear bundle resulted in almost total loss of ChAT activity in the hair cell regions of the cat cochlea. Lesions of the superior olivary complex resulted in loss of ChAT activity in the inner hair cell region of all cochlear turns only on the lesion side but bilateral losses in the outer hair cell region of all turns. The results are consistent with previous evidence that virtually all cholinergic synapses in the mammalian cochlea are associated with its olivocochlear innervation, that the olivocochlear innervation to the inner hair cell region is predominantly ipsilateral, and that the olivocochlear innervation to the outer hair cells is bilateral.
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Affiliation(s)
- Mark J Frilling
- Division of Otolaryngology and Dentistry, Department of Surgery, and Department of Neurology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Gregory J Wiet
- Department of Otolaryngology, Head and Neck Surgery, The Ohio State University and Nationwide Children's Hospital, Columbus, OH, USA
| | - Donald A Godfrey
- Division of Otolaryngology and Dentistry, Department of Surgery, and Department of Neurology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA.
| | - Judy A Parli
- Department of Physiology, Oral Roberts University School of Medicine, Tulsa, OK, USA
| | - Jon D Dunn
- Department of Anatomy, Oral Roberts University School of Medicine, Tulsa, OK, USA
| | - C David Ross
- Department of Physiology, Oral Roberts University School of Medicine, Tulsa, OK, USA
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16
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Mammano F, Bortolozzi M. Ca 2+ signaling, apoptosis and autophagy in the developing cochlea: Milestones to hearing acquisition. Cell Calcium 2017; 70:117-126. [PMID: 28578918 DOI: 10.1016/j.ceca.2017.05.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/09/2017] [Accepted: 05/09/2017] [Indexed: 12/16/2022]
Abstract
In mammals, the sense of hearing arises through a complex sequence of morphogenetic events that drive the sculpting of the auditory sensory epithelium into its terminally functional three-dimensional shape. While the majority of the underlying mechanisms remain unknown, it has become increasingly clear that Ca2+ signaling is at center stage and plays numerous fundamental roles both in the sensory hair cells and in the matrix of non-sensory, epithelial and supporting cells, which embed them and are tightly interconnected by a dense network of gap junctions formed by connexin 26 (Cx26) and connexin 30 (Cx30) protein subunits. In this review, we discuss the intricate interplay between Ca2+ signaling, connexin expression and function, apoptosis and autophagy in the crucial steps that lead to hearing acquisition.
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Affiliation(s)
- Fabio Mammano
- Department of Physics and Astronomy "G. Galilei", University of Padua, 35131 Padua, Italy; Venetian Institute of Molecular Medicine (VIMM), Foundation for Advanced Biomedical Research, 35129 Padua, Italy; Department of Biomedical Sciences, Institute of Cell Biology and Neurobiology, Italian National Research Council, 00015 Monterotondo, (RM), Italy.
| | - Mario Bortolozzi
- Department of Physics and Astronomy "G. Galilei", University of Padua, 35131 Padua, Italy; Venetian Institute of Molecular Medicine (VIMM), Foundation for Advanced Biomedical Research, 35129 Padua, Italy; Department of Biomedical Sciences, Institute of Protein Biochemistry, Italian National Research Council, 80131 Naples (NA), Italy
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17
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Tang PC, Smith KM, Watson GM. Repair of traumatized mammalian hair cells via sea anemone repair proteins. ACTA ACUST UNITED AC 2016; 219:2265-70. [PMID: 27489215 DOI: 10.1242/jeb.135459] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 05/18/2016] [Indexed: 12/25/2022]
Abstract
Mammalian hair cells possess only a limited ability to repair damage after trauma. In contrast, sea anemones show a marked capability to repair damaged hair bundles by means of secreted repair proteins (RPs). Previously, it was found that recovery of traumatized hair cells in blind cavefish was enhanced by anemone-derived RPs; therefore, the ability of anemone RPs to assist recovery of damaged hair cells in mammals was tested here. After a 1 h incubation in RP-enriched culture media, uptake of FM1-43 by experimentally traumatized murine cochlear hair cells was restored to levels comparable to those exhibited by healthy controls. In addition, RP-treated explants had significantly more normally structured hair bundles than time-matched traumatized control explants. Collectively, these results indicate that anemone-derived RPs assist in restoring normal function and structure of experimentally traumatized hair cells of the mouse cochlea.
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Affiliation(s)
- Pei-Ciao Tang
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
| | - Karen Müller Smith
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
| | - Glen M Watson
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
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18
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Abstract
The perceptual insensitivity to low frequency (LF) sound in humans has led to an underestimation of the physiological impact of LF exposure on the inner ear. It is known, however, that intense, LF sound causes cyclic changes of indicators of inner ear function after LF stimulus offset, for which the term "Bounce" phenomenon has been coined.Here, we show that the mechanical amplification of hair cells (OHCs) is significantly affected after the presentation of LF sound. First, we show the Bounce phenomenon in slow level changes of quadratic, but not cubic, distortion product otoacoustic emissions (DPOAEs). Second, Bouncing in response to LF sound is seen in slow, oscillating frequency and correlated level changes of spontaneous otoacoustic emissions (SOAEs). Surprisingly, LF sound can induce new SOAEs which can persist for tens of seconds. Further, we show that the Bounce persists under free-field conditions, i.e. without an in-ear probe occluding the auditory meatus. Finally, we show that the Bounce is affected by contralateral acoustic stimulation synchronised to the ipsilateral LF sound. These findings clearly demonstrate that the origin of the Bounce lies in the modulation of cochlear amplifier gain. We conclude that activity changes of OHCs are the source of the Bounce, most likely caused by a temporary disturbance of OHC calcium homeostasis. In the light of these findings, the effects of long-duration, anthropogenic LF sound on the human inner ear require further research.
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19
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Araya M, Brownell WE. Nanotechnology in Auditory Research: Membrane Electromechanics in Hearing. Methods Mol Biol 2016; 1427:349-362. [PMID: 27259937 PMCID: PMC4988393 DOI: 10.1007/978-1-4939-3615-1_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The soft, thin membranes that envelop all living cells are 2D, nanoscale, fluid assemblies of phospholipids, sterols, proteins, and other molecules. Mechanical interactions between these components facilitate membrane function, a key example of which is ion flow mediated by the mechanical opening and closing of channels. Hearing and balance are initiated by the modulation of ion flow through mechanoreceptor channels in stereocilia membranes. Cochlear amplification by the outer hair cell involves modulation of ion movement by the membrane protein prestin. Voltage-gated ion channels shape the receptor potential in hair cells and are responsible for the initiation of action potentials that are at the heart of sensory processing in the brain. All three processes require a membrane and their kinetics are modulated by the mechanical (i.e., material) properties of the membrane. This chapter reviews the methodology for measuring the mechanics of cellular membranes and introduces a method for examining membrane electromechanics. The approach allows examination of electromechanically mediated interactions between the different molecular species in the membrane that contribute to the biology of hearing and balance.
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Affiliation(s)
- Mussie Araya
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - William E Brownell
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Otolaryngology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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20
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Abstract
Nonlinear capacitance (NLC) measures are often used as surrogate measures of outer hair cell (OHC) electromotility (eM), since the two are commonly thought to share many biophysical features. The measurement of NLC is simpler than direct measurements of eM and, therefore, many investigators have adopted it. A standard patch-clamp hardware configuration is sufficient for recording NLC, given the proper software interface. Thus, the approach is cost effective. We use the software jClamp since it is tailored to capacitance measurement. Here we detail steps that we use to measure NLC. The walk through includes isolation of guinea pig OHCs, building voltage commands, recording, and analysis.
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Affiliation(s)
- Lei Song
- Department of Surgery, Yale University School of Medicine, 208062, New Haven, CT, 06510, USA
| | - Joseph Santos-Sacchi
- Department of Surgery, Yale University School of Medicine, 208062, New Haven, CT, 06510, USA. .,Department of Neurobiology, Yale University School of Medicine, New Haven, CT, 06510, USA. .,Department of Physiology, Yale University School of Medicine, New Haven, CT, 06510, USA.
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21
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Chumak T, Bohuslavova R, Macova I, Dodd N, Buckiova D, Fritzsch B, Syka J, Pavlinkova G. Deterioration of the Medial Olivocochlear Efferent System Accelerates Age-Related Hearing Loss in Pax2-Isl1 Transgenic Mice. Mol Neurobiol 2015; 53:2368-83. [PMID: 25990412 DOI: 10.1007/s12035-015-9215-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 05/07/2015] [Indexed: 11/28/2022]
Abstract
The development, maturation, and maintenance of the inner ear are governed by temporal and spatial expression cascades of transcription factors that form a gene regulatory network. ISLET1 (ISL1) may be one of the major players in this cascade, and in order to study its role in the regulation of inner ear development, we produced a transgenic mouse overexpressing Isl1 under the Pax2 promoter. Pax2-regulated ISL1 overexpression increases the embryonic ISL1(+) domain and induces accelerated nerve fiber extension and branching in E12.5 embryos. Despite these gains in early development, the overexpression of ISL1 impairs the maintenance and function of hair cells of the organ of Corti. Mutant mice exhibit hyperactivity, circling behavior, and progressive age-related decline in hearing functions, which is reflected in reduced otoacoustic emissions (DPOAEs) followed by elevated hearing thresholds. The reduction of the amplitude of DPOAEs in transgenic mice was first detected at 1 month of age. By 6-9 months of age, DPOAEs completely disappeared, suggesting a functional inefficiency of outer hair cells (OHCs). The timing of DPOAE reduction coincides with the onset of the deterioration of cochlear efferent terminals. In contrast to these effects on efferents, we only found a moderate loss of OHCs and spiral ganglion neurons. For the first time, our results show that the genetic alteration of the medial olivocochlear (MOC) efferent system induces an early onset of age-related hearing loss. Thus, the neurodegeneration of the MOC system could be a contributing factor to the pathology of age-related hearing loss.
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Affiliation(s)
- Tetyana Chumak
- Institute of Experimental Medicine, CAS, Prague, Czechia
| | - Romana Bohuslavova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, CAS, Prague 4, CZ-142 20, Prague, Czechia
| | - Iva Macova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, CAS, Prague 4, CZ-142 20, Prague, Czechia
| | - Nicole Dodd
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, CAS, Prague 4, CZ-142 20, Prague, Czechia
| | | | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Josef Syka
- Institute of Experimental Medicine, CAS, Prague, Czechia
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, CAS, Prague 4, CZ-142 20, Prague, Czechia.
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Wang J, Li X, Zhang Z, Wang H, Li J. Expression of prestin in OHCs is reduced in Spag6 gene knockout mice. Neurosci Lett 2015; 592:42-7. [PMID: 25748314 DOI: 10.1016/j.neulet.2015.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 02/23/2015] [Accepted: 03/03/2015] [Indexed: 01/21/2023]
Abstract
Sperm-associated antigen 6 (Spag6) gene, which encodes an axonemal protein (SPAG6), ubiquitously expresses in tissue and organs containing ciliated cells. The present work was to investigate whether SPAG6 expressed in cochlear hair cells and, if so, to explore the presumable correlations between prestin and SPAG6. The distribution of SPAG6 in organ of Corti and the morphological features of hair cells in basilar membrane were investigated by immunofluorescent staining. The amount of prestin in Spag6 mutant mice was measured by Western blotting and real-time PCR, respectively. Additionally, co-immunoprecipitation tests were performed to confirm the presumed interaction between prestin and SPAG6. We observed that SPAG6 expressed in the cuticular plate in outer hair cells (OHCs) and prestin in the lateral wall of OHCs that located along with SPAG6 at this site. In comparison to Spag6 +/+ mice, Spag6 -/- mice showed apparent morphological abnormity of OHCs and lower intensity of prestin fluorescence. The expression of prestin in Spag6 -/- mice reduced significantly at both protein and mRNA levels. Moreover, co-immunoprecipitation tests demonstrated the interaction between prestin and SPAG6. Taken together, these data indicate that SPAG6 is indispensible for the stability of OHCs by maintaining the normal expression of prestin, which implies that Spag6 gene is essential for mechanosensory function of OHCs.
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Affiliation(s)
- Jinghan Wang
- Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Ji'nan 250021, PR China
| | - Xiaofei Li
- Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Ji'nan 250021, PR China; Shandong Provincial Key Laboratory of Otology, Ji'nan 250021, PR China
| | - Zhibing Zhang
- Department of Obstetrics & Gynecology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Haibo Wang
- Department of Otolaryngology-Head and Neck Surgery, Provincial Hospital Affiliated to Shandong University, Ji'nan 250021, PR China; Shandong Provincial Key Laboratory of Otology, Ji'nan 250021, PR China.
| | - Jianfeng Li
- Department of Pathology and Pathophysiology, School of Medicine, Shandong University, Ji'nan 250012, PR China; Shandong Provincial Key Laboratory of Otology, Ji'nan 250021, PR China.
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Oishi N, Kendall A, Schacht J. Metformin protects against gentamicin-induced hair cell death in vitro but not ototoxicity in vivo. Neurosci Lett 2014; 583:65-9. [PMID: 25240593 DOI: 10.1016/j.neulet.2014.09.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 08/27/2014] [Accepted: 09/08/2014] [Indexed: 01/23/2023]
Abstract
Metformin (N,N-dimethylbiguanidine) is a widely employed oral hypoglycemic agent for the management of type 2 diabetes mellitus. Its antioxidant properties and safe clinical use raise the possibility of preventing gentamicin-induced hearing loss in patients. Therefore, we screened the usefulness of metformin against gentamicin toxicity in murine cochlear explants and in the guinea pig in vivo. We confirmed in organ culture that metformin blocks the gentamicin-induced translocation of endonuclease G into the nucleus of outer hair cells and attenuates hair cell loss. In vivo, gentamicin treatment with 80, 100, or 130mg/kg body weight for 14 days induced significant threshold shifts as determined by auditory brain stem responses. Metformin (30, 75, or 100mg/kg for 14 days) was well tolerated without any indication of auditory side effects. However, co-administration of metformin with gentamicin in various permutations did not prevent loss of auditory function. On the contrary, combined treatment at higher dosages aggravated the gentamicin-induced threshold shifts and caused additional adverse reactions including body weight loss and premature deaths in some animals. These results caution against the use of metformin co-treatment with aminoglycosides and confirm the need for in vivo studies in order to evaluate potentially protective agents selected by in vitro screens.
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Affiliation(s)
- Naoki Oishi
- Department of Otolaryngology - Head and Neck Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan; Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109-5616, USA.
| | - Ann Kendall
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Jochen Schacht
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109-5616, USA
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Liu X, Zheng G, Wu Y, Shen X, Jing J, Yu T, Song H, Chen J, Luo W. Lead exposure results in hearing loss and disruption of the cochlear blood-labyrinth barrier and the protective role of iron supplement. Neurotoxicology 2013; 39:173-81. [PMID: 24144481 DOI: 10.1016/j.neuro.2013.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 10/10/2013] [Accepted: 10/10/2013] [Indexed: 12/17/2022]
Abstract
This study was designed to investigate the impact of lead (Pb(2+)) on the auditory system and its molecular mechanisms. Pb(AC)2 was administrated to male SD rats aged 21-22 d for 8 weeks at a dose of 300ppm. Male guinea pigs were also administrated with 50mg/kg Pb(AC)2 two times a week for 8 weeks. The auditory nerve-brainstem evoked responses (ABR) was recorded and the morphological changes of the outer hair cells (OHCs) were observed with Phallodin-FITC staining. In addition, the integrity of the blood-labyrinth barrier was observed by TEM and the expression of tight junction proteins (TJPs) in the cochlear stria vascularis was determined by immunofluorescence. Our results showed that Pb(2+) exposure resulted in increased ABR threshold in both rats and guinea pigs. Abnormal shapes and loss of OHCs were found in the cochlear basilar membrane following the Pb(2+) exposure. TEM study showed that the tight junctions between the endothelial cells and the border cells were lost and disrupted. Down-regulation of the occludin, ZO-1 and claudin-5 in the stria vascularis suggested that the increased permeability of the blood-labyrinth barrier may attribute to the Pb(2+)-induced decrease of TJPs' expression. Additionally, Fe(2+) supplement partly reversed the Pb(2+)-induced hearing loss and down-regulation of TJPs. Taken together, these data indicate that the disruption of blood-labyrinth barrier by down-regulating the expression of TJPs plays a role in the Pb(2+)-induced hearing loss, and Fe(2+) supplement protects the auditory system against Pb(2+)-induced toxicity and may have significant clinical implications.
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FETONI A, ERAMO S, ROLESI R, TROIANI D, PALUDETTI G. Antioxidant treatment with coenzyme Q-ter in prevention of gentamycin ototoxicity in an animal model. Acta Otorhinolaryngol Ital 2012; 32:103-10. [PMID: 22767971 PMCID: PMC3383078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 12/22/2011] [Indexed: 11/18/2022]
Abstract
Aminoglycosides, such as gentamycin, are well known ototoxic agents. Toxicity occurs via an activation process involving the formation of an iron-gentamycin complex with free radical production. Antioxidants like Q-ter (a soluble formulation of coenzyme Q(10), CoQ(10)), can limit or prevent cellular ototoxic damage. The present study was designed to investigate the possible protective effects of Q-ter on gentamycin ototoxicity in albino guinea pigs (250-300 g). Animals were divided into five experimental groups: I, a sham control group given an intra-peritoneal (I.P.) injection of 0.5 ml saline (SHAM); II, gentamycin group (GM), treated with an injection of gentamycin (100 mg/ kg); III, gentamycin + Q-ter group (GM+Q-ter), treated with gentamycin (same dose as group II) and an I.P. injection of coenzyme Q(10) terclatrate (Q-ter) at 100 mg/kg body weight; IV, injected with gentamycin (100 mg/kg) plus saline; V, treated with Q-ter alone (100 mg/ kg). All animals were treated for 14 consecutive days. Auditory function was evaluated by recording auditory brainstem responses (ABR) at 15 and 30 days from the beginning of treatment. Morphological changes were analyzed by rhodamine-phalloidine staining. Gentamycin-induced progressive high-frequency hearing loss of 45-55 dB SPL. Q-ter therapy slowed and attenuated the progression of hearing loss, yielding a threshold shift of 20 dB. The significant loss of outer hair cells (OHCs) in the cochlear medio-basal turn in gentamycin-treated animals was not observed in the cochleae of animals protected with Q-ter. This study supports the hypothesis that Q-ter interferes with gentamycin-induced free radical formation, and suggests that it may be useful in protecting OHC function from aminoglycoside ototoxicity, thus reducing hearing loss.
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Affiliation(s)
| | - S.L.M. ERAMO
- Human Physiology, Catholic University of Rome, Italy
| | | | - D. TROIANI
- Human Physiology, Catholic University of Rome, Italy,Address for correspondence: Diana Troiani, Institute of Human Physiology, Catholic University of Rome, largo Francesco Vito 1, 00168 Rome, Italy. Tel. +39 06 30154966. E-mail:
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