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Lao H, Zhu Y, Yang M, Wang L, Tang J, Xiong H. Characteristics of spatial protein expression in the mouse cochlear sensory epithelia: Implications for age-related hearing loss. Hear Res 2024; 446:109006. [PMID: 38583350 DOI: 10.1016/j.heares.2024.109006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/27/2024] [Accepted: 04/01/2024] [Indexed: 04/09/2024]
Abstract
Hair cells in the cochlear sensory epithelia serve as mechanosensory receptors, converting sound into neuronal signals. The basal sensory epithelia are responsible for transducing high-frequency sounds, while the apex handles low-frequency sounds. Age-related hearing loss predominantly affects hearing at high frequencies and is indicative of damage to the basal sensory epithelia. However, the precise mechanism underlying this site-selective injury remains unclear. In this study, we employed a microscale proteomics approach to examine and compare protein expression in different regions of the cochlear sensory epithelia (upper half and lower half) in 1.5-month-old (normal hearing) and 6-month-old (severe high-frequency hearing loss without hair cell loss) C57BL/6J mice. A total of 2,386 proteins were detected, and no significant differences in protein expression were detected in the upper half of the cochlear sensory epithelia between the two age groups. The expression of 20 proteins in the lower half of the cochlear sensory epithelia significantly differed between the two age groups (e.g., MATN1, MATN4, and AQP1). Moreover, there were 311 and 226 differentially expressed proteins between the upper and lower halves of the cochlear sensory epithelia in 1.5-month-old and 6-month-old mice, respectively. The expression levels of selected proteins were validated by Western blotting. These findings suggest that the spatial differences in protein expression within the cochlear sensory epithelia may play a role in determining the susceptibility of cells at different sites of the cochlea to age-related damage.
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Affiliation(s)
- Huilin Lao
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Yafeng Zhu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Mei Yang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Lingshuo Wang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jie Tang
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China.
| | - Hao Xiong
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China.
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He S, Skidmore J, Bruce IC, Oleson JJ, Yuan Y. Peripheral Neural Synchrony in Postlingually Deafened Adult Cochlear Implant Users. Ear Hear 2024:00003446-990000000-00264. [PMID: 38503720 DOI: 10.1097/aud.0000000000001502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
OBJECTIVES This paper reports a noninvasive method for quantifying neural synchrony in the cochlear nerve (i.e., peripheral neural synchrony) in cochlear implant (CI) users, which allows for evaluating this physiological phenomenon in human CI users for the first time in the literature. In addition, this study assessed how peripheral neural synchrony was correlated with temporal resolution acuity and speech perception outcomes measured in quiet and in noise in postlingually deafened adult CI users. It tested the hypothesis that peripheral neural synchrony was an important factor for temporal resolution acuity and speech perception outcomes in noise in postlingually deafened adult CI users. DESIGN Study participants included 24 postlingually deafened adult CI users with a Cochlear™ Nucleus® device. Three study participants were implanted bilaterally, and each ear was tested separately. For each of the 27 implanted ears tested in this study, 400 sweeps of the electrically evoked compound action potential (eCAP) were measured at four electrode locations across the electrode array. Peripheral neural synchrony was quantified at each electrode location using the phase-locking value (PLV), which is a measure of trial-by-trial phase coherence among eCAP sweeps/trials. Temporal resolution acuity was evaluated by measuring the within-channel gap detection threshold (GDT) using a three-alternative, forced-choice procedure in a subgroup of 20 participants (23 implanted ears). For each ear tested in these participants, GDTs were measured at two electrode locations with a large difference in PLVs. For 26 implanted ears tested in 23 participants, speech perception performance was evaluated using consonant-nucleus-consonant (CNC) word lists presented in quiet and in noise at signal to noise ratios (SNRs) of +10 and +5 dB. Linear Mixed effect Models were used to evaluate the effect of electrode location on the PLV and the effect of the PLV on GDT after controlling for the stimulation level effects. Pearson product-moment correlation tests were used to assess the correlations between PLVs, CNC word scores measured in different conditions, and the degree of noise effect on CNC word scores. RESULTS There was a significant effect of electrode location on the PLV after controlling for the effect of stimulation level. There was a significant effect of the PLV on GDT after controlling for the effects of stimulation level, where higher PLVs (greater synchrony) led to lower GDTs (better temporal resolution acuity). PLVs were not significantly correlated with CNC word scores measured in any listening condition or the effect of competing background noise presented at an SNR of +10 dB on CNC word scores. In contrast, there was a significant negative correlation between the PLV and the degree of noise effect on CNC word scores for a competing background noise presented at an SNR of +5 dB, where higher PLVs (greater synchrony) correlated with smaller noise effects on CNC word scores. CONCLUSIONS This newly developed method can be used to assess peripheral neural synchrony in CI users, a physiological phenomenon that has not been systematically evaluated in electrical hearing. Poorer peripheral neural synchrony leads to lower temporal resolution acuity and is correlated with a larger detrimental effect of competing background noise presented at an SNR of 5 dB on speech perception performance in postlingually deafened adult CI users.
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Affiliation(s)
- Shuman He
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
- Department of Audiology, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Jeffrey Skidmore
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
| | - Ian C Bruce
- Department of Electrical & Computer Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Jacob J Oleson
- Department of Biostatistics, The University of Iowa, Iowa City, Iowa, USA
| | - Yi Yuan
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
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3
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He S, Skidmore J, Bruce IC, Oleson JJ, Yuan Y. Peripheral neural synchrony in post-lingually deafened adult cochlear implant users. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2023.07.07.23292369. [PMID: 37461681 PMCID: PMC10350140 DOI: 10.1101/2023.07.07.23292369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Objective This paper reports a noninvasive method for quantifying neural synchrony in the cochlear nerve (i.e., peripheral neural synchrony) in cochlear implant (CI) users, which allows for evaluating this physiological phenomenon in human CI users for the first time in the literature. In addition, this study assessed how peripheral neural synchrony was correlated with temporal resolution acuity and speech perception outcomes measured in quiet and in noise in post-lingually deafened adult CI users. It tested the hypothesis that peripheral neural synchrony was an important factor for temporal resolution acuity and speech perception outcomes in noise in post-lingually deafened adult CI users. Design Study participants included 24 post-lingually deafened adult CI users with a Cochlear™ Nucleus® device. Three study participants were implanted bilaterally, and each ear was tested separately. For each of the 27 implanted ears tested in this study, 400 sweeps of the electrically evoked compound action potential (eCAP) were measured at four electrode locations across the electrode array. Peripheral neural synchrony was quantified at each electrode location using the phase locking value (PLV), which is a measure of trial-by-trial phase coherence among eCAP sweeps/trials. Temporal resolution acuity was evaluated by measuring the within-channel gap detection threshold (GDT) using a three-alternative, forced-choice procedure in a subgroup of 20 participants (23 implanted ears). For each ear tested in these participants, GDTs were measured at two electrode locations with a large difference in PLVs. For 26 implanted ears tested in 23 participants, speech perception performance was evaluated using Consonant-Nucleus-Consonant (CNC) word lists presented in quiet and in noise at signal-to-noise ratios (SNRs) of +10 and +5 dB. Linear Mixed effect Models were used to evaluate the effect of electrode location on the PLV and the effect of the PLV on GDT after controlling for the stimulation level effects. Pearson product-moment correlation tests were used to assess the correlations between PLVs, CNC word scores measured in different conditions, and the degree of noise effect on CNC word scores. Results There was a significant effect of electrode location on the PLV after controlling for the effect of stimulation level. There was a significant effect of the PLV on GDT after controlling for the effects of stimulation level, where higher PLVs (greater synchrony) led to lower GDTs (better temporal resolution acuity). PLVs were not significantly correlated with CNC word scores measured in any listening condition or the effect of competing background noise presented at a SNR of +10 dB on CNC word scores. In contrast, there was a significant negative correlation between the PLV and the degree of noise effect on CNC word scores for a competing background noise presented at a SNR of +5 dB, where higher PLVs (greater synchrony) correlated with smaller noise effects on CNC word scores. Conclusions This newly developed method can be used to assess peripheral neural synchrony in CI users, a physiological phenomenon that has not been systematically evaluated in electrical hearing. Poorer peripheral neural synchrony leads to lower temporal resolution acuity and is correlated with a larger detrimental effect of competing background noise presented at a SNR of 5 dB on speech perception performance in post-lingually deafened adult CI users.
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Affiliation(s)
- Shuman He
- Department of Otolaryngology – Head and Neck Surgery, The Ohio State University, 915 Olentangy River Road, Columbus, OH 43212
- Department of Audiology, Nationwide Children’s Hospital, 700 Children’s Drive, Columbus, OH 43205
| | - Jeffrey Skidmore
- Department of Otolaryngology – Head and Neck Surgery, The Ohio State University, 915 Olentangy River Road, Columbus, OH 43212
| | - Ian C. Bruce
- Department of Electrical & Computer Engineering, McMaster University, Hamilton, ON, L8S 4K1, Canada
| | - Jacob J. Oleson
- Department of Biostatistics, The University of Iowa, Iowa City, IA 52242
| | - Yi Yuan
- Department of Otolaryngology – Head and Neck Surgery, The Ohio State University, 915 Olentangy River Road, Columbus, OH 43212
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Hosoya M, Iwabu K, Kitama T, Nishiyama T, Oishi N, Okano H, Ozawa H. Development of cochlear spiral ligament fibrocytes of the common marmoset, a nonhuman model animal. Sci Rep 2023; 13:11789. [PMID: 37479821 PMCID: PMC10362005 DOI: 10.1038/s41598-023-39003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023] Open
Abstract
Spiral ligament fibrocytes generate potassium gradients, which hair cells require to convert mechanical sound waves into electrical palsy. Together with the stria vascularis, they regulate endolymph electrolyte homeostasis. Developing spiral ligament fibrocytes and generating endocochlear potential with an appropriate endolymph ion composition are essential for hearing. Understanding spiral ligament fibrocyte development is useful for studying age-related and genetic hearing loss, as well as for regenerative therapy and cochlear immunology. Despite interspecies differences, most studies of cochlear development have been conducted in rodent models due to the difficulty of using human fetal samples. This study investigated the cochlear development of spiral ligament fibrocytes in a small New World monkey species, the common marmoset (Callithrix jacchus). We examined the developmental expression of specific genes in spiral ligament fibrocytes, including those essential for the generation of endolymphatic potential. Our results showed that this animal model of spiral ligament fibrocyte development is similar to that of humans and is a suitable alternative for the analysis of human cochlear development. The time course established in this study will be useful for studying the primate-specific developmental biology of the inner ear, which may lead to novel treatment strategies for human hearing loss.
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Affiliation(s)
- Makoto Hosoya
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Kaho Iwabu
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tsubasa Kitama
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Takanori Nishiyama
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Naoki Oishi
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
- Laboratory for Marmoset Neural Architecture, Center for Brain Science, RIKEN, 2-1 Hirosawa Wako, Saitama, 351-0193, Japan
| | - Hiroyuki Ozawa
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, 35 Shinanomachi Shinjuku-ku, Tokyo, 160-8582, Japan
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Lang H, Noble KV, Barth JL, Rumschlag JA, Jenkins TR, Storm SL, Eckert MA, Dubno JR, Schulte BA. The Stria Vascularis in Mice and Humans Is an Early Site of Age-Related Cochlear Degeneration, Macrophage Dysfunction, and Inflammation. J Neurosci 2023; 43:5057-5075. [PMID: 37268417 PMCID: PMC10324995 DOI: 10.1523/jneurosci.2234-22.2023] [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: 12/05/2022] [Revised: 04/19/2023] [Accepted: 05/25/2023] [Indexed: 06/04/2023] Open
Abstract
Age-related hearing loss, or presbyacusis, is a common degenerative disorder affecting communication and quality of life for millions of older adults. Multiple pathophysiologic manifestations, along with many cellular and molecular alterations, have been linked to presbyacusis; however, the initial events and causal factors have not been clearly established. Comparisons of the transcriptome in the lateral wall (LW) with other cochlear regions in a mouse model (of both sexes) of "normal" age-related hearing loss revealed that early pathophysiological alterations in the stria vascularis (SV) are associated with increased macrophage activation and a molecular signature indicative of inflammaging, a common form of immune dysfunction. Structure-function correlation analyses in mice across the lifespan showed that the age-dependent increase in macrophage activation in the stria vascularis is associated with a decline in auditory sensitivity. High-resolution imaging analysis of macrophage activation in middle-aged and aged mouse and human cochleas, along with transcriptomic analysis of age-dependent changes in mouse cochlear macrophage gene expression, support the hypothesis that aberrant macrophage activity is an important contributor to age-dependent strial dysfunction, cochlear pathology, and hearing loss. Thus, this study highlights the SV as a primary site of age-related cochlear degeneration and aberrant macrophage activity and dysregulation of the immune system as early indicators of age-related cochlear pathology and hearing loss. Importantly, novel new imaging methods described here now provide a means to analyze human temporal bones in a way that had not previously been feasible and thereby represent a significant new tool for otopathological evaluation.SIGNIFICANCE STATEMENT Age-related hearing loss is a common neurodegenerative disorder affecting communication and quality of life. Current interventions (primarily hearing aids and cochlear implants) offer imperfect and often unsuccessful therapeutic outcomes. Identification of early pathology and causal factors is crucial for the development of new treatments and early diagnostic tests. Here, we find that the SV, a nonsensory component of the cochlea, is an early site of structural and functional pathology in mice and humans that is characterized by aberrant immune cell activity. We also establish a new technique for evaluating cochleas from human temporal bones, an important but understudied area of research because of a lack of well-preserved human specimens and difficult tissue preparation and processing approaches.
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Affiliation(s)
- Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Kenyaria V Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Jeremy L Barth
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Jeffrey A Rumschlag
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Tyreek R Jenkins
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Shelby L Storm
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Mark A Eckert
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Judy R Dubno
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Bradley A Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
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6
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Parker A, Parham K, Skoe E. Age-related declines to serum prestin levels in humans. Hear Res 2022; 426:108640. [DOI: 10.1016/j.heares.2022.108640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 10/10/2022] [Accepted: 10/19/2022] [Indexed: 11/04/2022]
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Chen HL, Tan CT, Wu CC, Liu TC. Effects of Diet and Lifestyle on Audio-Vestibular Dysfunction in the Elderly: A Literature Review. Nutrients 2022; 14:nu14224720. [PMID: 36432406 PMCID: PMC9698578 DOI: 10.3390/nu14224720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/27/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The world's age-related health concerns continue to rise. Audio-vestibular disorders, such as hearing loss, tinnitus, and vertigo, are common complaints in the elderly and are associated with social and public health burdens. Various preventative measures can ease their impact, including healthy food consumption, nutritional supplementation, and lifestyle modification. We aim to provide a comprehensive summary of current possible strategies for preventing the age-related audio-vestibular dysfunction. METHODS A PubMed, Embase, and Cochrane review databases search was conducted to identify the relationship between diet, lifestyle, and audio-vestibular dysfunction. "Diet", "nutritional supplement", "lifestyle", "exercise", "physical activity", "tinnitus", "vertigo" and "age-related hearing loss" were used as keywords. RESULTS Audio-vestibular dysfunction develops and progresses as a result of age-related inflammation and oxidative stress. Diets with anti-inflammatory and antioxidant effects have been proposed to alleviate this illness. A high-fat diet may induce oxidative stress and low protein intake is associated with hearing discomfort in the elderly. Increased carbohydrate and sugar intake positively correlate with the incidence of audio-vestibular dysfunction, whereas a Mediterranean-style diet can protect against the disease. Antioxidants in the form of vitamins A, C, and E; physical activity; good sleep quality; smoking cessation; moderate alcohol consumption; and avoiding noise exposure are also beneficial. CONCLUSIONS Adequate diet or nutritional interventions with lifestyle modification may protect against developing audio-vestibular dysfunction in elderly individuals.
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Affiliation(s)
- Hsin-Lin Chen
- Department of Surgical Oncology, National Taiwan University Cancer Center Hospital, Taipei 100, Taiwan
- Department of Otolaryngology, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Ching-Ting Tan
- Department of Otolaryngology, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei 100, Taiwan
- Department of Medical Research, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu 302, Taiwan
- Department of Medical Genetics, National Taiwan University Hospital, Taipei 100, Taiwan
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei 100, Taiwan
- Correspondence: (C.-C.W.); (T.-C.L.)
| | - Tien-Chen Liu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei 100, Taiwan
- Correspondence: (C.-C.W.); (T.-C.L.)
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8
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Shehabi AM, Prendergast G, Plack CJ. The Relative and Combined Effects of Noise Exposure and Aging on Auditory Peripheral Neural Deafferentation: A Narrative Review. Front Aging Neurosci 2022; 14:877588. [PMID: 35813954 PMCID: PMC9260498 DOI: 10.3389/fnagi.2022.877588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Animal studies have shown that noise exposure and aging cause a reduction in the number of synapses between low and medium spontaneous rate auditory nerve fibers and inner hair cells before outer hair cell deterioration. This noise-induced and age-related cochlear synaptopathy (CS) is hypothesized to compromise speech recognition at moderate-to-high suprathreshold levels in humans. This paper evaluates the evidence on the relative and combined effects of noise exposure and aging on CS, in both animals and humans, using histopathological and proxy measures. In animal studies, noise exposure seems to result in a higher proportion of CS (up to 70% synapse loss) compared to aging (up to 48% synapse loss). Following noise exposure, older animals, depending on their species, seem to either exhibit significant or little further synapse loss compared to their younger counterparts. In humans, temporal bone studies suggest a possible age- and noise-related auditory nerve fiber loss. Based on the animal data obtained from different species, we predict that noise exposure may accelerate age-related CS to at least some extent in humans. In animals, noise-induced and age-related CS in separation have been consistently associated with a decreased amplitude of wave 1 of the auditory brainstem response, reduced middle ear muscle reflex strength, and degraded temporal processing as demonstrated by lower amplitudes of the envelope following response. In humans, the individual effects of noise exposure and aging do not seem to translate clearly into deficits in electrophysiological, middle ear muscle reflex, and behavioral measures of CS. Moreover, the evidence on the combined effects of noise exposure and aging on peripheral neural deafferentation in humans using electrophysiological and behavioral measures is even more sparse and inconclusive. Further research is necessary to establish the individual and combined effects of CS in humans using temporal bone, objective, and behavioral measures.
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Affiliation(s)
- Adnan M. Shehabi
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom
- Department of Audiology and Speech Therapy, Birzeit University, Birzeit, Palestine
| | - Garreth Prendergast
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom
| | - Christopher J. Plack
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, United Kingdom
- Department of Psychology, Lancaster University, Lancaster, United Kingdom
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9
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Trpchevska N, Freidin MB, Broer L, Oosterloo BC, Yao S, Zhou Y, Vona B, Bishop C, Bizaki-Vallaskangas A, Canlon B, Castellana F, Chasman DI, Cherny S, Christensen K, Concas MP, Correa A, Elkon R, Mengel-From J, Gao Y, Giersch ABS, Girotto G, Gudjonsson A, Gudnason V, Heard-Costa NL, Hertzano R, Hjelmborg JVB, Hjerling-Leffler J, Hoffman HJ, Kaprio J, Kettunen J, Krebs K, Kähler AK, Lallemend F, Launer LJ, Lee IM, Leonard H, Li CM, Lowenheim H, Magnusson PKE, van Meurs J, Milani L, Morton CC, Mäkitie A, Nalls MA, Nardone GG, Nygaard M, Palviainen T, Pratt S, Quaranta N, Rämö J, Saarentaus E, Sardone R, Satizabal CL, Schweinfurth JM, Seshadri S, Shiroma E, Shulman E, Simonsick E, Spankovich C, Tropitzsch A, Lauschke VM, Sullivan PF, Goedegebure A, Cederroth CR, Williams FMK, Nagtegaal AP, Nelis M, Mägi R, Esko T. Genome-wide association meta-analysis identifies 48 risk variants and highlights the role of the stria vascularis in hearing loss. Am J Hum Genet 2022; 109:1077-1091. [PMID: 35580588 PMCID: PMC9247887 DOI: 10.1016/j.ajhg.2022.04.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/15/2022] [Indexed: 02/08/2023] Open
Abstract
Hearing loss is one of the top contributors to years lived with disability and is a risk factor for dementia. Molecular evidence on the cellular origins of hearing loss in humans is growing. Here, we performed a genome-wide association meta-analysis of clinically diagnosed and self-reported hearing impairment on 723,266 individuals and identified 48 significant loci, 10 of which are novel. A large proportion of associations comprised missense variants, half of which lie within known familial hearing loss loci. We used single-cell RNA-sequencing data from mouse cochlea and brain and mapped common-variant genomic results to spindle, root, and basal cells from the stria vascularis, a structure in the cochlea necessary for normal hearing. Our findings indicate the importance of the stria vascularis in the mechanism of hearing impairment, providing future paths for developing targets for therapeutic intervention in hearing loss.
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Affiliation(s)
- Natalia Trpchevska
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Maxim B Freidin
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Linda Broer
- Department of Internal Medicine, Erasmus Medical Center, 3015 CE Rotterdam, the Netherlands
| | - Berthe C Oosterloo
- Department of Otorhinolaryngology, Erasmus Medical Center, 3015 CE Rotterdam, the Netherlands
| | - Shuyang Yao
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Barbara Vona
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany; Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Otolaryngology-Head & Neck Surgery, University of Tübingen Medical Center, 72076 Tübingen, Germany
| | - Charles Bishop
- Department of Otolaryngology and Communicative Sciences, The University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Argyro Bizaki-Vallaskangas
- Department of Otolaryngology, University of Tampere, 33100 Tampere, Finland; Pirkanmaan Sairaanhoitopiiri, 33520 Tampere, Finland
| | - Barbara Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Fabio Castellana
- Unit of Data Sciences and Technology Innovation for Population Health, National Institute of Gastroenterology "Saverio de Bellis", Research Hospital, Castellana Grotte, 70124 Bari, Italy
| | - Daniel I Chasman
- Division of Preventative Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Stacey Cherny
- Department of Anatomy and Anthropology and Department of Epidemiology and Preventive Medicine, Sackler Faculty of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Kaare Christensen
- The Danish Twin Registry, Department of Public Health, University of Southern Denmark, 5000 Odense C, Denmark; Department of Clinical Genetics, Odense University Hospital, 5000 Odense C, Denmark; Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, 5000 Odense C, Denmark
| | - Maria Pina Concas
- Institute for Maternal and Child Health - IRCCS, Burlo Garofolo, 34127 Trieste, Italy
| | - Adolfo Correa
- Jackson Heart Study, The University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Ran Elkon
- Department of Human Molecular Genetics & Biochemistry, Sackler School of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
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- Estonian Genome Centre, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Jonas Mengel-From
- The Danish Twin Registry, Department of Public Health, University of Southern Denmark, 5000 Odense C, Denmark; Department of Clinical Genetics, Odense University Hospital, 5000 Odense C, Denmark
| | - Yan Gao
- Jackson Heart Study, The University of Mississippi Medical Center, Jackson, MS 39216, USA; Department of Population Health Science, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Anne B S Giersch
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Giorgia Girotto
- Institute for Maternal and Child Health - IRCCS, Burlo Garofolo, 34127 Trieste, Italy; Department of Medicine, Surgery and Health Sciences, University of Trieste, 34139 Trieste, Italy
| | | | - Vilmundur Gudnason
- Icelandic Heart Association, 201 Kopavogur, Iceland; Faculty of Medicine, University of Iceland, 101 Reykjavik, Iceland
| | - Nancy L Heard-Costa
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; Framingham Heart Study, Framingham, MA 01702, USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland Baltimore, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland Baltimore, Baltimore, MD 21201, USA; Institute for Genome Sciences, University of Maryland Baltimore, Baltimore, MD 21201, USA
| | - Jacob V B Hjelmborg
- The Danish Twin Registry, Department of Public Health, University of Southern Denmark, 5000 Odense C, Denmark
| | - Jens Hjerling-Leffler
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Howard J Hoffman
- Division of Scientific Programs, Epidemiology and Statistics Program, National Institute on Deafness and Other Communications Disorders (NIDCD), NIH, Bethesda, MD 20892, USA
| | - Jaakko Kaprio
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland
| | - Johannes Kettunen
- Computational Medicine, Center for Life Course Health Research, Faculty of Medicine, University of Oulu, 90220 Oulu, Finland; Biocenter Oulu, University of Oulu, 90220 Oulu, Finland; Finnish Institute for Health and Welfare, 00271 Helsinki, Finland
| | - Kristi Krebs
- Estonian Genome Centre, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Anna K Kähler
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Francois Lallemend
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Lenore J Launer
- Laboratory of Epidemiology and Population Sciences, Intramural Research Program National Institute on Aging, Bethesda, MD 20892, USA
| | - I-Min Lee
- Division of Preventative Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hampton Leonard
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA; Center for Alzheimer's and Related Dementias, National Institutes of Health, Bethesda, MD 20892, USA; Data Tecnica International, Glen Echo, MD 20812, USA
| | - Chuan-Ming Li
- Division of Scientific Programs, Epidemiology and Statistics Program, National Institute on Deafness and Other Communications Disorders (NIDCD), NIH, Bethesda, MD 20892, USA
| | - Hubert Lowenheim
- Department of Otolaryngology-Head & Neck Surgery, University of Tübingen Medical Center, 72076 Tübingen, Germany
| | - Patrik K E Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Joyce van Meurs
- Department of Internal Medicine, Erasmus Medical Center, 3015 CE Rotterdam, the Netherlands
| | - Lili Milani
- Estonian Genome Centre, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Cynthia C Morton
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Obstetrics and Gynecology and of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Manchester Centre for Audiology and Deafness, University of Manchester, Manchester M13 9PL, UK
| | - Antti Mäkitie
- Department of Otorhinolaryngology - Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland
| | - Mike A Nalls
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA; Center for Alzheimer's and Related Dementias, National Institutes of Health, Bethesda, MD 20892, USA; Data Tecnica International, Glen Echo, MD 20812, USA
| | | | - Marianne Nygaard
- The Danish Twin Registry, Department of Public Health, University of Southern Denmark, 5000 Odense C, Denmark; Department of Clinical Genetics, Odense University Hospital, 5000 Odense C, Denmark
| | - Teemu Palviainen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland
| | - Sheila Pratt
- Department of Communication Science & Disorders, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Nicola Quaranta
- Otolaryngology Unit, Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari Aldo Moro, 70121 Bari, Italy
| | - Joel Rämö
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland
| | - Elmo Saarentaus
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland
| | - Rodolfo Sardone
- Unit of Data Sciences and Technology Innovation for Population Health, National Institute of Gastroenterology "Saverio de Bellis", Research Hospital, Castellana Grotte, 70124 Bari, Italy
| | - Claudia L Satizabal
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; Framingham Heart Study, Framingham, MA 01702, USA; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases and Department of Population Health Sciences, University of Texas Health Sciences Center, San Antonio, TX 78229, USA
| | - John M Schweinfurth
- Department of Otolaryngology and Communicative Sciences, The University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Sudha Seshadri
- Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA; Framingham Heart Study, Framingham, MA 01702, USA; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases and Department of Population Health Sciences, University of Texas Health Sciences Center, San Antonio, TX 78229, USA
| | - Eric Shiroma
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, Baltimore, MD 21224, USA
| | - Eldad Shulman
- Department of Human Molecular Genetics & Biochemistry, Sackler School of Medicine, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Eleanor Simonsick
- Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, Baltimore, MD 21224, USA
| | - Christopher Spankovich
- Department of Otolaryngology and Communicative Sciences, The University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Anke Tropitzsch
- Department of Otolaryngology-Head & Neck Surgery, University of Tübingen Medical Center, 72076 Tübingen, Germany
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Patrick F Sullivan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Genetics, University of North Carolina, Chapel Hill, NC 27516, USA
| | - Andre Goedegebure
- Department of Otorhinolaryngology, Erasmus Medical Center, 3015 CE Rotterdam, the Netherlands
| | - Christopher R Cederroth
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden; National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, Ropewalk House, NG1 5DU Nottingham, UK; Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, NG7 2UH Nottingham, UK.
| | - Frances M K Williams
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Andries Paul Nagtegaal
- Department of Otorhinolaryngology, Erasmus Medical Center, 3015 CE Rotterdam, the Netherlands
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10
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Elliott KL, Fritzsch B, Yamoah EN, Zine A. Age-Related Hearing Loss: Sensory and Neural Etiology and Their Interdependence. Front Aging Neurosci 2022; 14:814528. [PMID: 35250542 PMCID: PMC8891613 DOI: 10.3389/fnagi.2022.814528] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/03/2022] [Indexed: 12/19/2022] Open
Abstract
Age-related hearing loss (ARHL) is a common, increasing problem for older adults, affecting about 1 billion people by 2050. We aim to correlate the different reductions of hearing from cochlear hair cells (HCs), spiral ganglion neurons (SGNs), cochlear nuclei (CN), and superior olivary complex (SOC) with the analysis of various reasons for each one on the sensory deficit profiles. Outer HCs show a progressive loss in a basal-to-apical gradient, and inner HCs show a loss in a apex-to-base progression that results in ARHL at high frequencies after 70 years of age. In early neonates, SGNs innervation of cochlear HCs is maintained. Loss of SGNs results in a considerable decrease (~50% or more) of cochlear nuclei in neonates, though the loss is milder in older mice and humans. The dorsal cochlear nuclei (fusiform neurons) project directly to the inferior colliculi while most anterior cochlear nuclei reach the SOC. Reducing the number of neurons in the medial nucleus of the trapezoid body (MNTB) affects the interactions with the lateral superior olive to fine-tune ipsi- and contralateral projections that may remain normal in mice, possibly humans. The inferior colliculi receive direct cochlear fibers and second-order fibers from the superior olivary complex. Loss of the second-order fibers leads to hearing loss in mice and humans. Although ARHL may arise from many complex causes, HC degeneration remains the more significant problem of hearing restoration that would replace the cochlear implant. The review presents recent findings of older humans and mice with hearing loss.
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Affiliation(s)
- Karen L. Elliott
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, United States
- *Correspondence: Bernd Fritzsch
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Azel Zine
- LBN, Laboratory of Bioengineering and Nanoscience, University of Montpellier, Montpellier, France
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11
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Noble K, Brown L, Elvis P, Lang H. Cochlear Immune Response in Presbyacusis: a Focus on Dysregulation of Macrophage Activity. J Assoc Res Otolaryngol 2022; 23:1-16. [PMID: 34642854 PMCID: PMC8782976 DOI: 10.1007/s10162-021-00819-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/25/2021] [Indexed: 02/03/2023] Open
Abstract
Age-related hearing loss, or presbyacusis, is a prominent chronic degenerative disorder that affects many older people. Based on presbyacusis pathology, the degeneration occurs in both sensory and non-sensory cells, along with changes in the cochlear microenvironment. The progression of age-related neurodegenerative diseases is associated with an altered microenvironment that reflects chronic inflammatory signaling. Under these conditions, resident and recruited immune cells, such as microglia/macrophages, have aberrant activity that contributes to chronic neuroinflammation and neural cell degeneration. Recently, researchers identified and characterized macrophages in human cochleae (including those from older donors). Along with the age-related changes in cochlear macrophages in animal models, these studies revealed that macrophages, an underappreciated group of immune cells, may play a critical role in maintaining the functional integrity of the cochlea. Although several studies deciphered the molecular mechanisms that regulate microglia/macrophage dysfunction in multiple neurodegenerative diseases, limited studies have assessed the mechanisms underlying macrophage dysfunction in aged cochleae. In this review, we highlight the age-related changes in cochlear macrophage activities in mouse and human temporal bones. We focus on how complement dysregulation and the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 inflammasome could affect macrophage activity in the aged peripheral auditory system. By understanding the molecular mechanisms that underlie these regulatory systems, we may uncover therapeutic strategies to treat presbyacusis and other forms of sensorineural hearing loss.
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Affiliation(s)
- Kenyaria Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Akouos, Inc, Boston, MA, 02210, USA
| | - LaShardai Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Biology, Winthrop University, Rock Hill, SD, 29733, USA
| | - Phillip Elvis
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA.
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12
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Hu Y, Li D, Wei H, Zhou S, Chen W, Yan X, Cai J, Chen X, Chen B, Liao M, Chai R, Tang M. Neurite Extension and Orientation of Spiral Ganglion Neurons Can Be Directed by Superparamagnetic Iron Oxide Nanoparticles in a Magnetic Field. Int J Nanomedicine 2021; 16:4515-4526. [PMID: 34239302 PMCID: PMC8259836 DOI: 10.2147/ijn.s313673] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/21/2021] [Indexed: 12/19/2022] Open
Abstract
Introduction Neuroregeneration is a major challenge in neuroscience for treating degenerative diseases and for repairing injured nerves. Numerous studies have shown the importance of physical stimulation for neuronal growth and development, and here we report an approach for the physical guidance of neuron orientation and neurite growth using superparamagnetic iron oxide (SPIO) nanoparticles and magnetic fields (MFs). Methods SPIO nanoparticles were synthesized by classic chemical co-precipitation methods and then characterized by transmission electron microscope, dynamic light scattering, and vibrating sample magnetometer. The cytotoxicity of the prepared SPIO nanoparticles and MF was determined using CCK-8 assay and LIVE/DEAD assay. The immunofluorescence images were captured by a laser scanning confocal microscopy. Cell migration was evaluated using the wound healing assay. Results The prepared SPIO nanoparticles showed a narrow size distribution, low cytotoxicity, and superparamagnetism. SPIO nanoparticles coated with poly-L-lysine could be internalized by spiral ganglion neurons (SGNs) and showed no cytotoxicity at concentrations less than 300 µg/mL. The neurite extension of SGNs was promoted after internalizing SPIO nanoparticles with or without an external MF, and this might be due to the promotion of growth cone development. It was also confirmed that SPIO can regulate cell migration and can direct neurite outgrowth in SGNs preferentially along the direction imposed by an external MF. Conclusion Our results provide a fundamental understanding of the regulation of cell behaviors under physical cues and suggest alternative treatments for sensorineural hearing loss caused by the degeneration of SGNs.
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Affiliation(s)
- Yangnan Hu
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Dan Li
- School of Biology, Food and Environment, Hefei University, Hefei, 230601, People's Republic of China
| | - Hao Wei
- Department of Otorhinolaryngology Head and Neck Surgery, Drum Tower Clinical Medical College, Nanjing Medical University, Nanjing, 210000, People's Republic of China
| | - Shan Zhou
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Wei Chen
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Xiaoqian Yan
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Jaiying Cai
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Xiaoyan Chen
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Bo Chen
- Materials Science and Devices Institute, Suzhou University of Science and Technology, Suzhou, 215009, People's Republic of China
| | - Menghui Liao
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China
| | - Renjie Chai
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, People's Republic of China
| | - Mingliang Tang
- State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, People's Republic of China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, People's Republic of China.,Department of Cardiovascular Surgery of the First Affiliated Hospital & Institute for Cardiovascular Science, Medical College, Soochow University, Suzhou, 215000, People's Republic of China
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13
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Eckert MA, Harris KC, Lang H, Lewis MA, Schmiedt RA, Schulte BA, Steel KP, Vaden KI, Dubno JR. Translational and interdisciplinary insights into presbyacusis: A multidimensional disease. Hear Res 2021; 402:108109. [PMID: 33189490 PMCID: PMC7927149 DOI: 10.1016/j.heares.2020.108109] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 12/18/2022]
Abstract
There are multiple etiologies and phenotypes of age-related hearing loss or presbyacusis. In this review we summarize findings from animal and human studies of presbyacusis, including those that provide the theoretical framework for distinct metabolic, sensory, and neural presbyacusis phenotypes. A key finding in quiet-aged animals is a decline in the endocochlear potential (EP) that results in elevated pure-tone thresholds across frequencies with greater losses at higher frequencies. In contrast, sensory presbyacusis appears to derive, in part, from acute and cumulative effects on hair cells of a lifetime of environmental exposures (e.g., noise), which often result in pronounced high frequency hearing loss. These patterns of hearing loss in animals are recognizable in the human audiogram and can be classified into metabolic and sensory presbyacusis phenotypes, as well as a mixed metabolic+sensory phenotype. However, the audiogram does not fully characterize age-related changes in auditory function. Along with the effects of peripheral auditory system declines on the auditory nerve, primary degeneration in the spiral ganglion also appears to contribute to central auditory system aging. These inner ear alterations often correlate with structural and functional changes throughout the central nervous system and may explain suprathreshold speech communication difficulties in older adults with hearing loss. Throughout this review we highlight potential methods and research directions, with the goal of advancing our understanding, prevention, diagnosis, and treatment of presbyacusis.
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Affiliation(s)
- Mark A Eckert
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA.
| | - Kelly C Harris
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Hainan Lang
- Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA
| | - Morag A Lewis
- King's College London, Wolfson Centre for Age-Related Diseases, London SE1 1UL, United Kingdom
| | - Richard A Schmiedt
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Bradley A Schulte
- Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA; Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Karen P Steel
- King's College London, Wolfson Centre for Age-Related Diseases, London SE1 1UL, United Kingdom
| | - Kenneth I Vaden
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Judy R Dubno
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA; Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA
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14
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Jeng JY, Carlton A, Johnson SL, Brown SDM, Holley MC, Bowl MR, Marcotti W. Biophysical and morphological changes in inner hair cells and their efferent innervation in the ageing mouse cochlea. J Physiol 2021; 599:269-287. [PMID: 33179774 PMCID: PMC7612127 DOI: 10.1113/jp280256] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/01/2020] [Indexed: 09/18/2023] Open
Abstract
KEY POINTS Age-related hearing loss is a progressive hearing loss involving environmental and genetic factors, leading to a decrease in hearing sensitivity, threshold and speech discrimination. We compared age-related changes in inner hair cells (IHCs) between four mouse strains with different levels of progressive hearing loss. The surface area of apical coil IHCs (9-12 kHz cochlear region) decreases by about 30-40% with age. The number of BK channels progressively decreases with age in the IHCs from most mouse strains, but the basolateral membrane current profile remains unchanged. The mechanoelectrical transducer current is smaller in mice harbouring the hypomorphic Cdh23 allele Cdh23ahl (C57BL/6J; C57BL/6NTac), but not in Cdh23-repaired mice (C57BL/6NTacCdh23+ ), indicating that it could contribute to the different progression of hearing loss among mouse strains. The degree of efferent rewiring onto aged IHCs, most likely coming from the lateral olivocochlea fibres, was correlated with hearing loss in the different mouse strains. ABSTRACT Inner hair cells (IHCs) are the primary sensory receptors of the mammalian cochlea, transducing acoustic information into electrical signals that are relayed to the afferent neurons. Functional changes in IHCs are a potential cause of age-related hearing loss. Here, we have investigated the functional characteristics of IHCs from early-onset hearing loss mice harbouring the allele Cdh23ahl (C57BL/6J and C57BL/6NTac), from late-onset hearing loss mice (C3H/HeJ), and from mice corrected for the Cdh23ahl mutation (C57BL/6NTacCdh23+ ) with an intermediate hearing phenotype. There was no significant loss of IHCs in the 9-12 kHz cochlear region up to at least 15 months of age, but their surface area decreased progressively by 30-40% starting from ∼6 months of age. Although the size of the BK current decreased with age, IHCs retained a normal KCNQ4 current and resting membrane potential. These basolateral membrane changes were most severe for C57BL/6J and C57BL/6NTac, less so for C57BL/6NTacCdh23+ and minimal or absent in C3H/HeJ mice. We also found that lateral olivocochlear (LOC) efferent fibres re-form functional axon-somatic connections with aged IHCs, but this was seen only sporadically in C3H/HeJ mice. The efferent post-synaptic SK2 channels appear prior to the establishment of the efferent contacts, suggesting that IHCs may play a direct role in re-establishing the LOC-IHC synapses. Finally, we showed that the size of the mechanoelectrical transducer (MET) current from IHCs decreased significantly with age in mice harbouring the Cdh23ahl allele but not in C57BL/6NTacCdh23+ mice, indicating that the MET apparatus directly contributes to the progression of age-related hearing loss.
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Affiliation(s)
- Jing-Yi Jeng
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Adam Carlton
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Stuart L. Johnson
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Steve D. M. Brown
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire, OX11 0RD, UK
| | - Matthew C. Holley
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Michael R. Bowl
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire, OX11 0RD, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
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15
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Bermúdez‐Muñoz JM, Celaya AM, Hijazo‐Pechero S, Wang J, Serrano M, Varela‐Nieto I. G6PD overexpression protects from oxidative stress and age-related hearing loss. Aging Cell 2020; 19:e13275. [PMID: 33222382 PMCID: PMC7744953 DOI: 10.1111/acel.13275] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 09/03/2020] [Accepted: 10/18/2020] [Indexed: 12/17/2022] Open
Abstract
Aging of the auditory system is associated with the incremental production of reactive oxygen species (ROS) and the accumulation of oxidative damage in macromolecules, which contributes to cellular malfunction, compromises cell viability, and, ultimately, leads to functional decline. Cellular detoxification relies in part on the production of NADPH, which is an important cofactor for major cellular antioxidant systems. NADPH is produced principally by the housekeeping enzyme glucose‐6‐phosphate dehydrogenase (G6PD), which catalyzes the rate‐limiting step in the pentose phosphate pathway. We show here that G6PD transgenic mice (G6PD‐Tg), which show enhanced constitutive G6PD activity and NADPH production along life, have lower auditory thresholds than wild‐type mice during aging, together with preserved inner hair cell (IHC) and outer hair cell (OHC), OHC innervation, and a conserved number of synapses per IHC. Gene expression of antioxidant enzymes was higher in 3‐month‐old G6PD‐Tg mice than in wild‐type counterparts, whereas the levels of pro‐apoptotic proteins were lower. Consequently, nitration of proteins, mitochondrial damage, and TUNEL+ apoptotic cells were all lower in 9‐month‐old G6PD‐Tg than in wild‐type counterparts. Unexpectedly, G6PD overexpression triggered low‐grade inflammation that was effectively resolved in young mice, as shown by the absence of cochlear cellular damage and macrophage infiltration. Our results lead us to propose that NADPH overproduction from an early stage is an efficient mechanism to maintain the balance between the production of ROS and cellular detoxification power along aging and thus prevents hearing loss progression.
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Affiliation(s)
- Jose M. Bermúdez‐Muñoz
- Institute for Biomedical Research “Alberto Sols” (IIBM) Spanish National Research Council‐Autonomous University of Madrid (CSIC‐UAM Madrid Spain
- Rare Diseases Networking Biomedical Research Centre (CIBERER) CIBER Carlos III Institute of Health Madrid Spain
| | - Adelaida M. Celaya
- Institute for Biomedical Research “Alberto Sols” (IIBM) Spanish National Research Council‐Autonomous University of Madrid (CSIC‐UAM Madrid Spain
- Rare Diseases Networking Biomedical Research Centre (CIBERER) CIBER Carlos III Institute of Health Madrid Spain
| | - Sara Hijazo‐Pechero
- Institute for Biomedical Research “Alberto Sols” (IIBM) Spanish National Research Council‐Autonomous University of Madrid (CSIC‐UAM Madrid Spain
| | - Jing Wang
- INSERM ‐ UMR 1051 Institut des Neurosciences de Montpellier Montpellier France
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB) Barcelona Spain
| | - Isabel Varela‐Nieto
- Institute for Biomedical Research “Alberto Sols” (IIBM) Spanish National Research Council‐Autonomous University of Madrid (CSIC‐UAM Madrid Spain
- Rare Diseases Networking Biomedical Research Centre (CIBERER) CIBER Carlos III Institute of Health Madrid Spain
- Hospital La Paz Institute for Health Research (IdiPAZ) Madrid Spain
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16
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He L, Guo JY, Liu K, Wang GP, Gong SS. Research progress on flat epithelium of the inner ear. Physiol Res 2020; 69:775-785. [PMID: 32901490 DOI: 10.33549/physiolres.934447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sensorineural hearing loss and vertigo, resulting from lesions in the sensory epithelium of the inner ear, have a high incidence worldwide. The sensory epithelium of the inner ear may exhibit extreme degeneration and is transformed to flat epithelium (FE) in humans and mice with profound sensorineural hearing loss and/or vertigo. Various factors, including ototoxic drugs, noise exposure, aging, and genetic defects, can induce FE. Both hair cells and supporting cells are severely damaged in FE, and the normal cytoarchitecture of the sensory epithelium is replaced by a monolayer of very thin, flat cells of irregular contour. The pathophysiologic mechanism of FE is unclear but involves robust cell division. The cellular origin of flat cells in FE is heterogeneous; they may be transformed from supporting cells that have lost some features of supporting cells (dedifferentiation) or may have migrated from the flanking region. The epithelial-mesenchymal transition may play an important role in this process. The treatment of FE is challenging given the severe degeneration and loss of both hair cells and supporting cells. Cochlear implant or vestibular prosthesis implantation, gene therapy, and stem cell therapy show promise for the treatment of FE, although many challenges remain to be overcome.
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Affiliation(s)
- L He
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China. ,
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17
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Keithley EM. Pathology and mechanisms of cochlear aging. J Neurosci Res 2020; 98:1674-1684. [PMID: 31066107 PMCID: PMC7496655 DOI: 10.1002/jnr.24439] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/22/2019] [Accepted: 04/23/2019] [Indexed: 12/21/2022]
Abstract
Presbycusis, or age-related hearing loss (ARHL), occurs in most mammals with variations in the age of onset, rate of decline, and magnitude of degeneration in the central nervous system and inner ear. The affected cochlear structures include the stria vascularis and its vasculature, spiral ligament, sensory hair cells and auditory neurons. Dysfunction of the stria vascularis results in a reduced endocochlear potential. Without this potential, the cochlear amplification provided by the electro-motility of the outer hair cells is insufficient, and a high-frequency hearing-loss results. Degeneration of the sensory cells, especially the outer hair cells also leads to hearing loss due to lack of amplification. Neuronal degeneration, another hallmark of ARHL, most likely underlies difficulties with speech discrimination, especially in noisy environments. Noise exposure is a major cause of ARHL. It is well-known to cause sensory cell degeneration, especially the outer hair cells at the high frequency end of the cochlea. Even loud, but not uncomfortable, sound levels can lead to synaptopathy and ultimately neuronal degeneration. Even in the absence of a noisy environment, aged cells degenerate. This pathology most likely results from damage to mitochondria and contributes to degenerative changes in the stria vascularis, hair cells, and neurons. The genetic underpinnings of ARHL are still unknown and most likely involve various combinations of genes. At present, the only effective strategy for reducing ARHL is prevention of noise exposure. If future strategies can improve mitochondrial activity and reduce oxidative damage in old age, these should also bring relief.
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Affiliation(s)
- Elizabeth M. Keithley
- Division of Otolaryngology ‐ Head and Neck SurgeryUniversity of CaliforniaSan DiegoCalifornia
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18
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Jeng JY, Johnson SL, Carlton AJ, DeTomasi L, Goodyear R, DeFaveri F, Furness DN, Wells S, Brown SDM, Holley MC, Richardson GP, Mustapha M, Bowl MR, Marcotti W. Age-related changes in the biophysical and morphological characteristics of mouse cochlear outer hair cells. J Physiol 2020; 598:3891-3910. [PMID: 32608086 PMCID: PMC7612122 DOI: 10.1113/jp279795] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 06/25/2020] [Indexed: 09/01/2023] Open
Abstract
KEY POINTS Age-related hearing loss (ARHL) is a very heterogeneous disease, resulting from cellular senescence, genetic predisposition and environmental factors (e.g. noise exposure). Currently, we know very little about age-related changes occurring in the auditory sensory cells, including those associated with the outer hair cells (OHCs). Using different mouse strains, we show that OHCs undergo several morphological and biophysical changes in the ageing cochlea. Ageing OHCs also exhibited the progressive loss of afferent and efferent synapses. We also provide evidence that the size of the mechanoelectrical transducer current is reduced in ageing OHCs, highlighting its possible contribution in cochlear ageing. ABSTRACT Outer hair cells (OHCs) are electromotile sensory receptors that provide sound amplification within the mammalian cochlea. Although OHCs appear susceptible to ageing, the progression of the pathophysiological changes in these cells is still poorly understood. By using mouse strains with a different progression of hearing loss (C57BL/6J, C57BL/6NTac, C57BL/6NTacCdh23+ , C3H/HeJ), we have identified morphological, physiological and molecular changes in ageing OHCs (9-12 kHz cochlear region). We show that by 6 months of age, OHCs from all strains underwent a reduction in surface area, which was not a sign of degeneration. Although the ageing OHCs retained a normal basolateral membrane protein profile, they showed a reduction in the size of the K+ current and non-linear capacitance, a readout of prestin-dependent electromotility. Despite these changes, OHCs have a normal Vm and retain the ability to amplify sound, as distortion product otoacoustic emission thresholds were not affected in aged, good-hearing mice (C3H/HeJ, C57BL/6NTacCdh23+ ). The loss of afferent synapses was present in all strains at 15 months. The number of efferent synapses per OHCs, defined as postsynaptic SK2 puncta, was reduced in aged OHCs of all strains apart from C3H mice. Several of the identified changes occurred in aged OHCs from all mouse strains, thus representing a general trait in the pathophysiological progression of age-related hearing loss, possibly aimed at preserving functionality. We have also shown that the mechanoelectrical transduction (MET) current from OHCs of mice harbouring the Cdh23ahl allele is reduced with age, highlighting the possibility that changes in the MET apparatus could play a role in cochlear ageing.
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Affiliation(s)
- Jing-Yi Jeng
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Stuart L. Johnson
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Adam J Carlton
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Lara DeTomasi
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Richard Goodyear
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Francesca DeFaveri
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | | | - Sara Wells
- Mary Lyon Centre, MRC Harwell Institute, Oxfordshire, UK
| | | | - Matthew C. Holley
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Guy P. Richardson
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Mirna Mustapha
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Michael R. Bowl
- Mammalian Genetics Unit, MRC Harwell Institute, Oxfordshire, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
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19
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Using Sox2 to alleviate the hallmarks of age-related hearing loss. Ageing Res Rev 2020; 59:101042. [PMID: 32173536 DOI: 10.1016/j.arr.2020.101042] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023]
Abstract
Age-related hearing loss (ARHL) is the most prevalent sensory deficit. ARHL reduces the quality of life of the growing population, setting seniors up for the enhanced mental decline. The size of the needy population, the structural deficit, and a likely research strategy for effective treatment of chronic neurosensory hearing in the elderly are needed. Although there has been profound advancement in auditory regenerative research, there remain multiple challenges to restore hearing loss. Thus, additional investigations are required, using novel tools. We propose how the (1) flat epithelium, remaining after the organ of Corti has deteriorated, can be converted to the repaired-sensory epithelium, using Sox2. This will include (2) developing an artificial gene regulatory network transmitted by (3) large viral vectors to the flat epithelium to stimulate remnants of the organ of Corti to restore hair cells. We hope to unite with our proposal toward the common goal, eventually restoring a functional human hearing organ by transforming the flat epithelial cells left after the organ of Corti loss.
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20
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Kaur C, Saini S, Pal I, Kumar P, Chandra Sati H, Jacob TG, Bhardwaj DN, Roy TS. Age-related changes in the number of cresyl-violet-stained, parvalbumin and NMDAR 2B expressing neurons in the human spiral ganglion. Hear Res 2020; 388:107883. [PMID: 31981822 DOI: 10.1016/j.heares.2020.107883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 01/11/2023]
Abstract
Animal-studies associate age-related hearing loss (presbycusis) with decreasing number of spiral ganglion neurons (SGNs) in Rosenthal's canal (RC) of cochlea. The excitatory neurotransmitter for SGNs is glutamate (through its receptor NMDAR 2B), which can be neurotoxic through Ca2+ overload. Neurotoxicity is balanced by calcium-binding proteins (CBPs) like Parvalbumin (PV), which is the predominant CBP of the SGNs. To estimate the volume of the RC and total number of SGNs that are immunoreactive to PV and NMDAR 2B, we used unbiased stereology in 35 human cochleae derived from cadavers of persons from 2nd to 8th decade of life (subsequently statistically divided into two groups) and compared them to the total number of cresyl violet (CV) stained SGNs. We also estimated the volume of individual neurons and their nuclei. Regression analysis was made on estimated parameters against age. Hierarchical-cluster analysis was done on the neuronal against neuronal nuclear volumes.The average volume of the RC did not change with increasing age (p = 0.4115). The total number of SGNs (CV-stained and those separately expressing PV and NMDAR 2B) significantly decreased with age (p < 0.001). We identified three distinct populations of neurons on the basis of their volumes among SGNs. Thus, there is significant age-related decline in the total number of SGNs, which starts early in life. It may be due to ambient noise and inadequate neutralisation of excitotoxicity.
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Affiliation(s)
- Charanjeet Kaur
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Shubhi Saini
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Indra Pal
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Punit Kumar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Hem Chandra Sati
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tony George Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Daya Nand Bhardwaj
- Department of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
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21
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Furness DN. Forgotten Fibrocytes: A Neglected, Supporting Cell Type of the Cochlea With the Potential to be an Alternative Therapeutic Target in Hearing Loss. Front Cell Neurosci 2019; 13:532. [PMID: 31866825 PMCID: PMC6908467 DOI: 10.3389/fncel.2019.00532] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/15/2019] [Indexed: 12/31/2022] Open
Abstract
Cochlear fibrocytes are a homeostatic supporting cell type embedded in the vascularized extracellular matrix of the spiral ligament, within the lateral wall. Here, they participate in the connective tissue syncytium that enables potassium recirculation into the scala media to take place and ensures development of the endolymphatic potential that helps drive current into hair cells during acoustic stimulation. They have also been implicated in inflammatory responses in the cochlea. Some fibrocytes interact closely with the capillaries of the vasculature in a way which suggests potential involvement, together with the stria vascularis, also in the blood-labyrinth barrier. Several lines of evidence suggests that pathology of the fibrocytes, along with other degenerative changes in this region, contribute to metabolic hearing loss (MHL) during aging that is becoming recognized as distinct from, and potentially a precursor for, sensorineural hearing loss (SNHL). This pathology may underlie a significant proportion of cases of presbycusis. Some evidence points also to an association between fibrocyte degeneration and Ménière’s disease (MD). Fibrocytes are mesenchymal; this characteristic, and their location, make them amenable to potential cell therapy in the form of cell replacement or genetic modification to arrest the process of degeneration that leads to MHL. This review explores the properties and roles of this neglected cell type and suggests potential therapeutic approaches, such as cell transplantation or genetic engineering of fibrocytes, which could be used to prevent this form of presbycusis or provide a therapeutic avenue for MD.
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Affiliation(s)
- David N Furness
- School of Life Sciences, Keele University, Keele, United Kingdom
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22
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Bullen A, Forge A, Wright A, Richardson GP, Goodyear RJ, Taylor R. Ultrastructural defects in stereocilia and tectorial membrane in aging mouse and human cochleae. J Neurosci Res 2019; 98:1745-1763. [DOI: 10.1002/jnr.24556] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/24/2019] [Accepted: 10/28/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Anwen Bullen
- UCL Ear Institute University College London London UK
| | - Andrew Forge
- UCL Ear Institute University College London London UK
| | | | - Guy P. Richardson
- Sussex Neuroscience School of Life Sciences University of Sussex Falmer, Brighton UK
| | - Richard J. Goodyear
- Sussex Neuroscience School of Life Sciences University of Sussex Falmer, Brighton UK
| | - Ruth Taylor
- UCL Ear Institute University College London London UK
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23
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Shin SA, Lyu AR, Jeong SH, Kim TH, Park MJ, Park YH. Acoustic Trauma Modulates Cochlear Blood Flow and Vasoactive Factors in a Rodent Model of Noise-Induced Hearing Loss. Int J Mol Sci 2019; 20:ijms20215316. [PMID: 31731459 PMCID: PMC6862585 DOI: 10.3390/ijms20215316] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 12/12/2022] Open
Abstract
Noise exposure affects the organ of Corti and the lateral wall of the cochlea, including the stria vascularis and spiral ligament. Although the inner ear vasculature and spiral ligament fibrocytes in the lateral wall consist of a significant proportion of cells in the cochlea, relatively little is known regarding their functional significance. In this study, 6-week-old male C57BL/6 mice were exposed to noise trauma to induce transient hearing threshold shift (TTS) or permanent hearing threshold shift (PTS). Compared to mice with TTS, mice with PTS exhibited lower cochlear blood flow and lower vessel diameter in the stria vascularis, accompanied by reduced expression levels of genes involved in vasodilation and increased expression levels of genes related to vasoconstriction. Ultrastructural analyses by transmission electron microscopy revealed that the stria vascularis and spiral ligament fibrocytes were more damaged by PTS than by TTS. Moreover, mice with PTS expressed significantly higher levels of proinflammatory cytokines in the cochlea (e.g., IL-1β, IL-6, and TNF-α). Overall, our findings suggest that cochlear microcirculation and lateral wall pathologies are differentially modulated by the severity of acoustic trauma and are associated with changes in vasoactive factors and inflammatory responses in the cochlea.
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Affiliation(s)
- Sun-Ae Shin
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon 35015, Korea; (S.-A.S.); (A.-R.L.)
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea;
| | - Ah-Ra Lyu
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon 35015, Korea; (S.-A.S.); (A.-R.L.)
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea;
| | - Seong-Hun Jeong
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea;
| | - Tae Hwan Kim
- Biomedical Convergence Research Center, Chungnam National University Hospital, Daejeon 35015, Korea;
| | - Min Jung Park
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon 35015, Korea; (S.-A.S.); (A.-R.L.)
- Brain Research Institute, College of Medicine, Chungnam National University, Daejeon 35015, Korea
- Correspondence: (M.J.P.); (Y.-H.P.); Tel.: +82-42-280-7697(M.J.P.); Fax: +82-42-253-4059 (M.J.P.)
| | - Yong-Ho Park
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon 35015, Korea; (S.-A.S.); (A.-R.L.)
- Brain Research Institute, College of Medicine, Chungnam National University, Daejeon 35015, Korea
- Correspondence: (M.J.P.); (Y.-H.P.); Tel.: +82-42-280-7697(M.J.P.); Fax: +82-42-253-4059 (M.J.P.)
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24
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Noble KV, Liu T, Matthews LJ, Schulte BA, Lang H. Age-Related Changes in Immune Cells of the Human Cochlea. Front Neurol 2019; 10:895. [PMID: 31474935 PMCID: PMC6707808 DOI: 10.3389/fneur.2019.00895] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 08/02/2019] [Indexed: 12/12/2022] Open
Abstract
Age-related hearing loss is a chronic degenerative disorder affecting one in two individuals above the age of 75. Current population projections predict a steady climb in the number of older individuals making the search for interventions to prevent or reverse this disorder even more critical. There is growing acceptance that aberrant activity of resident or infiltrating immune cells, such as macrophages, is a major factor contributing to the onset and progression of age-related degenerative diseases. However, how macrophage populations and their functionally-driven morphological characteristics change with age in the human cochlea remains largely unknown. In this study, we employed immunohistochemical approaches along with confocal and super-resolution imaging, three-dimensional reconstructions, and quantitative analysis to determine age-related changes in macrophage numbers and morphology as well as interactions with other cell-types and structures of the auditory nerve and lateral wall in the human cochlea. In the cochlea of human ears from young and middle aged adults those macrophages in the auditory nerve assumed a worm-like structure in contrast to those in the spiral ligament or associated with the dense microvascular network in the stria vascularis which exhibited a highly ramified morphology. Macrophages in both the auditory nerve and cochlear lateral wall showed morphological alterations with age. The population of activated macrophages in the auditory nerve increased in cochleas obtained from older donors. Dual-immunohistochemical staining with macrophage, myelin, and neuronal markers revealed increased interactions of macrophages with the glial and neuronal components of the aged auditory nerve. These findings implicate the involvement of abnormal macrophage-glia interactions in age-related physiological and pathological alterations in the human cochlea. There is clearly a need to further investigate the contribution of macrophage-associated inflammatory dysregulation in human presbyacusis.
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Affiliation(s)
- Kenyaria V. Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Ting Liu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Lois J. Matthews
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, United States
| | - Bradley A. Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, United States
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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25
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Liu T, Li G, Noble KV, Li Y, Barth JL, Schulte BA, Lang H. Age-dependent alterations of Kir4.1 expression in neural crest-derived cells of the mouse and human cochlea. Neurobiol Aging 2019; 80:210-222. [PMID: 31220650 PMCID: PMC6679794 DOI: 10.1016/j.neurobiolaging.2019.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 04/02/2019] [Accepted: 04/11/2019] [Indexed: 11/18/2022]
Abstract
Age-related hearing loss (or presbyacusis) is a progressive pathophysiological process. This study addressed the hypothesis that degeneration/dysfunction of multiple nonsensory cell types contributes to presbyacusis by evaluating tissues obtained from young and aged CBA/CaJ mouse ears and human temporal bones. Ultrastructural examination and transcriptomic analysis of mouse cochleas revealed age-dependent pathophysiological alterations in 3 types of neural crest-derived cells, namely intermediate cells in the stria vascularis, outer sulcus cells in the cochlear lateral wall, and satellite cells in the spiral ganglion. A significant decline in immunoreactivity for Kir4.1, an inwardly rectifying potassium channel, was seen in strial intermediate cells and outer sulcus cells in the ears of older mice. Age-dependent alterations in Kir4.1 immunostaining also were observed in satellite cells ensheathing spiral ganglion neurons. Expression alterations of Kir4.1 were observed in these same cell populations in the aged human cochlea. These results suggest that degeneration/dysfunction of neural crest-derived cells maybe an important contributing factor to both metabolic and neural forms of presbyacusis.
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Affiliation(s)
- Ting Liu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Gang Li
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology, Tinnitus and Hyperacusis Center, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Kenyaria V Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Yongxi Li
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Jeremy L Barth
- Department of Regenerative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Bradley A Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA.
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26
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Celaya AM, Sánchez-Pérez I, Bermúdez-Muñoz JM, Rodríguez-de la Rosa L, Pintado-Berninches L, Perona R, Murillo-Cuesta S, Varela-Nieto I. Deficit of mitogen-activated protein kinase phosphatase 1 (DUSP1) accelerates progressive hearing loss. eLife 2019; 8:39159. [PMID: 30938680 PMCID: PMC6464786 DOI: 10.7554/elife.39159] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 04/01/2019] [Indexed: 12/12/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) such as p38 and the c-Jun N-terminal kinases (JNKs) are activated during the cellular response to stress signals. Their activity is regulated by the MAPK-phosphatase 1 (DUSP1), a key component of the anti-inflammatory response. Stress kinases are well-described elements of the response to otic injury and the otoprotective potential of JNK inhibitors is being tested in clinical trials. By contrast, there are no studies exploring the role of DUSP1 in hearing and hearing loss. Here we show that Dusp1 expression is age-regulated in the mouse cochlea. Dusp1 gene knock-out caused premature progressive hearing loss, as confirmed by auditory evoked responses in Dusp1-/- mice. Hearing loss correlated with cell death in hair cells, degeneration of spiral neurons and increased macrophage infiltration. Dusp1-/- mouse cochleae showed imbalanced redox status and dysregulated expression of cytokines. These data suggest that DUSP1 is essential for cochlear homeostasis in the response to stress during ageing.
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Affiliation(s)
- Adelaida M Celaya
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Isabel Sánchez-Pérez
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain.,Biochemistry Department, Faculty of Medicine, Autonomous University of Madrid, Madrid, Spain.,Biomedicine Unit UCLM-CSIC, Madrid, Spain
| | - Jose M Bermúdez-Muñoz
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Laura Pintado-Berninches
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Rosario Perona
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Silvia Murillo-Cuesta
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
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27
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Poorna Pillutla SV, Kaur C, Roy TS, Jacob TG. Estimation of Volume of Stria Vascularis and the Length of Its Capillaries in the Human Cochlea. J Microsc Ultrastruct 2019; 7:117-123. [PMID: 31548922 PMCID: PMC6753699 DOI: 10.4103/jmau.jmau_12_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background: The stria vascularis (SV) is a vascularized epithelium that secretes endolymph and is located on the lateral wall of the membranous cochlea. The capillaries of SV directly influence the composition of the endolymph and hence the generation of impulses by the hair-cells that are auditory receptors and thus affect hearing. Therefore, the real morphology of the SV would be very important for understanding the hearing system. There are few reliable reports of the morphology of the human SV. Aims and Objectives: In this research, we have estimated the volume of the SV and total length of strial capillaries in the apical, middle and basal turns of the human cochlea by updated stereological techniques. Methods: The point-counting Cavalieri's method and hemispherical volume probes were applied on stained, 40 μm-thick serial sections of five celloidin-embedded, decalcified cochleae. Results: The mean age of persons at the time of death was 51 ± 15.25 years, the mean volume of the SV was 0.56 ± 0.054 mm3 and the mean length of the SV capillaries was 289.08 ± 72.96 mm. We also estimated the same parameters with different stereological parameters, probes and in differently stained sections and checked the relationship and limits of agreement between different methods by paired t-test and Bland-Altman plot. We found agreement in our results. Conclusion: We provide reliable baseline data on the real morphology of the human SV.
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Affiliation(s)
| | - Charanjeet Kaur
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tony George Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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Kaur C, Pal I, Saini S, Jacob T, Nag T, Thakar A, Bhardwaj D, Roy T. Comparison of unbiased stereological estimation of total number of cresyl violet stained neurons and parvalbumin positive neurons in the adult human spiral ganglion. J Chem Neuroanat 2018. [DOI: 10.1016/j.jchemneu.2017.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mady LJ, Sukato DC, Fruit J, Palmer C, Raz Y, Hirsch BE, McCall AA. Hearing Preservation: Does Electrode Choice Matter? Otolaryngol Head Neck Surg 2017; 157:837-847. [PMID: 28608735 DOI: 10.1177/0194599817707167] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective Evaluate if electrode design affects hearing preservation (HP) following cochlear implantation (CI) with full-length electrodes. Study Design Case series with chart review. Setting Tertiary referral academic center. Subjects and Methods Forty-five adults with low-frequency hearing (≤85 dB at 250 and 500 Hz) who underwent unilateral CI with full-length electrode arrays made by 1 manufacturer were included. HP was calculated with (1) mean low-frequency pure-tone average (LFPTA) at 250 and 500 Hz (MEAN method), (2) a percentile method across the audiometric frequency spectrum generating an S-value (HEARRING method), and (3) functional if hearing remained ≤85 dB at 250 and 500 Hz. Audiometric testing was performed approximately 1 month and 1 year postoperatively, yielding short-term and long-term results, respectively. Results Of 45 patients who underwent CI, 46.7% received lateral wall (LW) and 53.3% received perimodiolar (PM) electrodes. At short-term follow-up, LW electrodes were associated with significantly better HP than PM (LFPTA method: 27.7 vs 39.3 dB, P < .05; S-value method: 48.2 vs 21.8%, P < .05). In multivariate regression of short-term outcomes, LW electrode use was a significant predictor of better HP ( P < .05). At long-term follow-up, electrode type was not associated with HP. Younger patient age was the only significant predictor of long-term HP on multivariate analysis ( P < .05). Conclusion The LW electrode is associated with short-term HP, suggesting its design is favorable for limiting trauma to the cochlea during and directly following CI. Other factors, including age, are relevant for maintaining HP over the long term. The data support further investigation into what modifiable factors may promote long-term HP.
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Affiliation(s)
- Leila J Mady
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Daniel C Sukato
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Jenifer Fruit
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Catherine Palmer
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,2 Department of Communication Science and Disorders, University of Pittsburgh, Pennsylvania, USA
| | - Yael Raz
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,3 Department of Otolaryngology/Head and Neck Surgery, Oregon Health and Sciences University, Portland, Oregon, USA
| | - Barry E Hirsch
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.,2 Department of Communication Science and Disorders, University of Pittsburgh, Pennsylvania, USA
| | - Andrew A McCall
- 1 Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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30
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Yan W, Liu W, Qi J, Fang Q, Fan Z, Sun G, Han Y, Zhang D, Xu L, Wang M, Li J, Chen F, Liu D, Chai R, Wang H. A Three-Dimensional Culture System with Matrigel Promotes Purified Spiral Ganglion Neuron Survival and Function In Vitro. Mol Neurobiol 2017; 55:2070-2084. [PMID: 28283883 DOI: 10.1007/s12035-017-0471-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/23/2017] [Indexed: 12/01/2022]
Abstract
In vitro culture of spiral ganglion neurons (SGNs) is a useful approach to investigate numerous aspects of neuronal behavior and to identify potential therapeutic targets for SGN protection and regeneration. However, the isolation of SGNs and the long-term maintenance of their structure and function in vitro remain challenging. In this study, we isolated SGNs from Bhlhb5-cre and Rosa26-tdTomato mice with fluorescence-activated cell sorting and determined the cell purity. We then encapsulated the pure SGNs in matrigel and cultured the SGNs in vitro. We found that the three-dimensional (3D)-matrigel culture environment significantly suppressed apoptosis and improved SGN survival in vitro, which enabled the long-term culture of SGNs for up to 6 months. The 3D-matrigel system also significantly promoted neurite outgrowth of the SGNs, increased the cells' polarity, promoted the area of growth cones, and significantly increased the synapse density of the SGNs. More importantly, the 3D-matrigel system helped to maintain and promote the electrophysiological properties of the SGNs. In conclusion, the 3D-matrigel culture system promoted the survival of purified SGNs in vitro and maintained their morphological structure and function and thus could be a useful tool for studying the physiology and pathophysiology of purified SGNs in long-term culture.
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Affiliation(s)
- Wenqing Yan
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Wenwen Liu
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Jieyu Qi
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China.,Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Qixiu Road 19, Nantong, 226001, China.,Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, 210096, China
| | - Qiaojun Fang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China.,Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Qixiu Road 19, Nantong, 226001, China.,Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, 210096, China
| | - Zhaomin Fan
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Gaoying Sun
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Yuechen Han
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Daogong Zhang
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Lei Xu
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Mingming Wang
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Jianfeng Li
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Otology, Jinan, China
| | - Fangyi Chen
- Department of Biology, South University of Science and Technology of China, Shenzhen, China
| | - Dong Liu
- Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Qixiu Road 19, Nantong, 226001, China.
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China. .,Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Qixiu Road 19, Nantong, 226001, China. .,Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, 210096, China.
| | - Haibo Wang
- Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China. .,Shandong Provincial Key Laboratory of Otology, Jinan, China.
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Landegger LD, Psaltis D, Stankovic KM. Human audiometric thresholds do not predict specific cellular damage in the inner ear. Hear Res 2016; 335:83-93. [PMID: 26924453 PMCID: PMC5970796 DOI: 10.1016/j.heares.2016.02.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 02/23/2016] [Indexed: 11/21/2022]
Abstract
INTRODUCTION As otology enters the field of gene therapy and human studies commence, the question arises whether audiograms - the current gold standard for the evaluation of hearing function - can consistently predict cellular damage within the human inner ear and thus should be used to define inclusion criteria for trials. Current assumptions rely on the analysis of small groups of human temporal bones post mortem or from psychophysical identification of cochlear "dead regions" in vivo, but a comprehensive study assessing the correlation between audiometric thresholds and cellular damage within the cochlea is lacking. METHODS A total of 131 human temporal bones from 85 adult individuals (ages 19-92 years, median 69 years) with sensorineural hearing loss due to various etiologies were analyzed. Cytocochleograms - which quantify loss of hair cells, neurons, and strial atrophy along the length of the cochlea - were compared with subjects' latest available audiometric tests prior to death (time range 5 h-22 years, median 24 months). The Greenwood function and the equivalent rectangular bandwidth were used to infer, from cytocochleograms, cochlear locations corresponding to frequencies tested in clinical audiograms. Correlation between audiometric thresholds at clinically tested frequencies and cell type-specific damage in those frequency regions was examined by calculating Spearman's correlation coefficients. RESULTS Similar audiometric profiles reflected widely different cellular damage in the cochlea. In our diverse group of patients, audiometric thresholds tended to be more influenced by hair cell loss than by neuronal loss or strial atrophy. Spearman's correlation coefficient across frequencies was at most 0.7 and often below 0.5, with 1.0 indicating perfect correlation. CONCLUSIONS Audiometric thresholds do not predict specific cellular damage in the human inner ear. Our study highlights the need for better non- or minimally-invasive tools, such as cochlear endoscopy, to establish cellular-level diagnosis and thereby guide therapy and monitor response to treatment.
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Affiliation(s)
- Lukas D Landegger
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02141, United States; Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, United States; Department of Otolaryngology, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
| | - Demetri Psaltis
- Optics Laboratory, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), BM 4102 (Bâtiment BM), Station 17, 1015 Lausanne, Switzerland.
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02141, United States; Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, United States; Harvard Program in Speech and Hearing Bioscience and Technology, 260 Longwood Avenue, Boston, MA 02115, United States.
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Lang H, Xing Y, Brown LN, Samuvel DJ, Panganiban CH, Havens LT, Balasubramanian S, Wegner M, Krug EL, Barth JL. Neural stem/progenitor cell properties of glial cells in the adult mouse auditory nerve. Sci Rep 2015; 5:13383. [PMID: 26307538 PMCID: PMC4549618 DOI: 10.1038/srep13383] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/24/2015] [Indexed: 12/14/2022] Open
Abstract
The auditory nerve is the primary conveyor of hearing information from sensory hair cells to the brain. It has been believed that loss of the auditory nerve is irreversible in the adult mammalian ear, resulting in sensorineural hearing loss. We examined the regenerative potential of the auditory nerve in a mouse model of auditory neuropathy. Following neuronal degeneration, quiescent glial cells converted to an activated state showing a decrease in nuclear chromatin condensation, altered histone deacetylase expression and up-regulation of numerous genes associated with neurogenesis or development. Neurosphere formation assays showed that adult auditory nerves contain neural stem/progenitor cells (NSPs) that were within a Sox2-positive glial population. Production of neurospheres from auditory nerve cells was stimulated by acute neuronal injury and hypoxic conditioning. These results demonstrate that a subset of glial cells in the adult auditory nerve exhibit several characteristics of NSPs and are therefore potential targets for promoting auditory nerve regeneration.
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Affiliation(s)
- Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Yazhi Xing
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - LaShardai N Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Devadoss J Samuvel
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Clarisse H Panganiban
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Luke T Havens
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | | | - Michael Wegner
- Institute of Biochemistry, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91054, Germany
| | - Edward L Krug
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
| | - Jeremy L Barth
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina 29425, United States
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Low JCM, Ober TJ, McKinley GH, Stankovic KM. Quantitative polarized light microscopy of human cochlear sections. BIOMEDICAL OPTICS EXPRESS 2015; 6:599-606. [PMID: 25780749 PMCID: PMC4354578 DOI: 10.1364/boe.6.000599] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/13/2015] [Indexed: 05/31/2023]
Abstract
Dysfunction of the inner ear is the most common cause of sensorineural hearing loss, which is the most common sensory deficit worldwide. Conventional imaging modalities are unable to depict the microanatomy of the human inner ear, hence the need to explore novel imaging modalities. We provide the first characterization of the polarization dependent optical properties of human cochlear sections using quantitative polarized light microscopy (qPLM). Eight pediatric cadaveric cochlear sections, aged 0 (term) to 24 months, were selected from the US National Temporal Bone Registry, imaged with qPLM and analyzed using Image J. Retardance of the bony otic capsule and basilar membrane were substantially higher than that of the stria vascularis, spiral ganglion neurons, organ of Corti and spiral ligament across the half turns of the spiraling cochlea. qPLM provides quantitative information about the human inner ear, and awaits future exploration in vivo.
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Affiliation(s)
- Jacob C. M. Low
- The University of Manchester, Oxford Road, Manchester, M13 9PL,
UK
| | - Thomas J. Ober
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139,
USA
| | - Gareth H. McKinley
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139,
USA
| | - Konstantina M. Stankovic
- Massachusetts Eye and Ear Infirmary, Department of Otolaryngology and Eaton Peabody Laboratories, 243 Charles Street, Boston, Massachusetts 02114,
USA
- Department of Otology and Laryngology, Harvard Medical School, Boston, Massachusetts,
USA
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34
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Ayoob AM, Borenstein JT. The role of intracochlear drug delivery devices in the management of inner ear disease. Expert Opin Drug Deliv 2014; 12:465-79. [PMID: 25347140 DOI: 10.1517/17425247.2015.974548] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
INTRODUCTION Diseases of the inner ear include those of the auditory and vestibular systems, and frequently result in disabling hearing loss or vertigo. Despite a rapidly expanding pipeline of potential cochlear therapeutics, the inner ear remains a challenging organ for targeted drug delivery, and new technologies are required to deliver these therapies in a safe and efficacious manner. In addition to traditional approaches for direct inner ear drug delivery, novel microfluidics-based systems are under development, promising improved control over pharmacokinetics over longer periods of delivery, ultimately with application towards hair cell regeneration in humans. AREAS COVERED Advances in the development of intracochlear drug delivery systems are reviewed, including passive systems, active microfluidic technologies and cochlear prosthesis-mediated delivery. This article provides a description of novel delivery systems and their potential future clinical applications in treating inner ear disease. EXPERT OPINION Recent progresses in microfluidics and miniaturization technologies are enabling the development of wearable and ultimately implantable drug delivery microsystems. Progress in this field is being spurred by the convergence of advances in molecular biology, microfluidic flow control systems and models for drug transport in the inner ear. These advances will herald a new generation of devices, with near-term applications in preclinical models, and ultimately with human clinical use for a range of diseases of the inner ear.
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Hao X, Xing Y, Moore MW, Zhang J, Han D, Schulte BA, Dubno JR, Lang H. Sox10 expressing cells in the lateral wall of the aged mouse and human cochlea. PLoS One 2014; 9:e97389. [PMID: 24887110 PMCID: PMC4041576 DOI: 10.1371/journal.pone.0097389] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/17/2014] [Indexed: 12/20/2022] Open
Abstract
Age-related hearing loss (presbycusis) is a common human disorder, affecting one in three Americans aged 60 and over. Previous studies have shown that presbyacusis is associated with a loss of non-sensory cells in the cochlear lateral wall. Sox10 is a transcription factor crucial to the development and maintenance of neural crest-derived cells including some non-sensory cell types in the cochlea. Mutations of the Sox10 gene are known to cause various combinations of hearing loss and pigmentation defects in humans. This study investigated the potential relationship between Sox10 gene expression and pathological changes in the cochlear lateral wall of aged CBA/CaJ mice and human temporal bones from older donors. Cochlear tissues prepared from young adult (1–3 month-old) and aged (2–2.5 year-old) mice, and human temporal bone donors were examined using quantitative immunohistochemical analysis and transmission electron microscopy. Cells expressing Sox10 were present in the stria vascularis, outer sulcus and spiral prominence in mouse and human cochleas. The Sox10+ cell types included marginal and intermediate cells and outer sulcus cells, including those that border the scala media and those extending into root processes (root cells) in the spiral ligament. Quantitative analysis of immunostaining revealed a significant decrease in the number of Sox10+ marginal cells and outer sulcus cells in aged mice. Electron microscopic evaluation revealed degenerative alterations in the surviving Sox10+ cells in aged mice. Strial marginal cells in human cochleas from donors aged 87 and older showed only weak immunostaining for Sox10. Decreases in Sox10 expression levels and a loss of Sox10+ cells in both mouse and human aged ears suggests an important role of Sox10 in the maintenance of structural and functional integrity of the lateral wall. A loss of Sox10+ cells may also be associated with a decline in the repair capabilities of non-sensory cells in the aged ear.
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Affiliation(s)
- Xinping Hao
- Department of Otolaryngology – Head & Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Yazhi Xing
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Michael W. Moore
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Jianning Zhang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology, Shanghai Yueyang Integrated Medicine Hospital, Shanghai, China
| | - Demin Han
- Department of Otolaryngology – Head & Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- * E-mail: (HL); (DH)
| | - Bradley A. Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Judy R. Dubno
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- * E-mail: (HL); (DH)
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Possible role of gap junction intercellular channels and connexin 43 in satellite glial cells (SGCs) for preservation of human spiral ganglion neurons : A comparative study with clinical implications. Cell Tissue Res 2013; 355:267-78. [PMID: 24241398 PMCID: PMC3921454 DOI: 10.1007/s00441-013-1735-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 09/19/2013] [Indexed: 12/22/2022]
Abstract
Human spiral ganglion (SG) neurons show remarkable survival properties and maintain electric excitability for a long time after complete deafness and even separation from the organ of Corti, features essential for cochlear implantation. Here, we analyze and compare the localization and distribution of gap junction (GJ) intercellular channels and connexin 43 (Cx43) in cells surrounding SG cell bodies in man and guinea pig by using transmission electron microscopy and confocal immunohistochemistry. GJs and Cx43 expression has been recognized in satellite glial cells (SGCs) in non-myelinating sensory ganglia including the human SG. In man, SG neurons can survive as mono-polar or "amputated" cells with unbroken central projections following dendrite degeneration and consolidation of the dendrite pole. Cx43-mediated GJ signaling between SGCs is believed to play a key role in this "healing" process and could explain the unique preservation of human SG neurons and the persistence of cochlear implant function.
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Audiologic performance after cochlear implantation in children with X-linked deafness: comparison with deaf children with a normal inner ear structure. Otol Neurotol 2013; 34:544-8. [PMID: 23470556 DOI: 10.1097/mao.0b013e3182839864] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare audiologic performances of cochlear implantation (CI) in children with X-linked deafness with those of CI in age- and sex-matched children with normal cochleae. PATIENTS We identified 4 patients with X-linked deafness and selected 10 age- and sex-matched deaf patients with normal cochleae between April 1999 and April 2012. MAIN OUTCOME MEASURES Auditory brainstem responses, Categories of Auditory Performance (CAP), and Meaningful Auditory Integration Scale (MAIS). RESULTS The ages of patients with X-linked deafness at the time of implantation ranged between 1.3 and 13.6 years, with a mean age of 5.3 years. All patients were male subjects and showed severe-to-profound hearing loss. Patient 1 lacked ABR in both ears. Patients 2, 3, and 4 showed ABR in the contralateral ear, at 70, 70, and 90 dB nHL, respectively. All 4 patients had bilateral X-linked cochlear anomaly and experienced cerebrospinal fluid (CSF) gushers. Straight electrodes were used in Patients 1 and 3, with perimodiolar electrodes used in the others. Patients 2 and 3, who were about the same age, had CAP scores of 6 or more at 18 months after activation of the implant despite the use of different electrode arrays. There were no statistically significant differences in MAIS and CAP scores between each patient with X-linked deafness and the control group. CONCLUSION The audiologic performances of patient with X-linked deafness after CI are comparable to those of patients with normal inner ear structure after CI.
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Yang WP, Xu Y, Guo WW, Liu HZ, Hu BH. Modulation of Mcl-1 expression reduces age-related cochlear degeneration. Neurobiol Aging 2013; 34:2647-58. [PMID: 23790646 DOI: 10.1016/j.neurobiolaging.2013.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 05/11/2013] [Accepted: 05/16/2013] [Indexed: 10/26/2022]
Abstract
Mcl-1 is an anti-apoptotic member of the Bcl-2 family that modulates apoptosis-related signaling pathways and promotes cell survival. We have previously demonstrated a reduction of Mcl-1 expression in aging cochleae. To investigate whether restoring Mcl-1 expression would reduce aging-related cochlear degeneration, we developed a rat model of Mcl-1 overexpression. A plasmid encoding human Mcl-1/enhanced green fluorescent protein was applied to the round window of the cochlea. This in vivo treatment transfected both the sensory and supporting cells of the cochlear sensory epithelium and enhanced Mcl-1 expression at both the mRNA and the protein level. The upregulation of Mcl-1 expression reduced the progression of age-related cochlear dysfunction and sensory cell death. Furthermore, the transfection of Mcl-1 exerted its protective effect by suppressing cochlear apoptosis at the mitochondrial level. This study demonstrates that the genetic modulation of Mcl-1 expression reduces the progression of age-related cochlear degeneration.
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Affiliation(s)
- Wei Ping Yang
- Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, People's Republic of China
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Kasagi H, Kuhara T, Okada H, Sueyoshi N, Kurihara H. Mesenchymal stem cell transplantation to the mouse cochlea as a treatment for childhood sensorineural hearing loss. Int J Pediatr Otorhinolaryngol 2013; 77:936-42. [PMID: 23561635 DOI: 10.1016/j.ijporl.2013.03.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 03/04/2013] [Accepted: 03/07/2013] [Indexed: 12/20/2022]
Abstract
OBJECTIVE There is no treatment established for congenital sensorineural hearing loss because the majority of the cases are hereditary. Although congenital sensorineural hearing loss is thought to be hereditary, this hearing loss occur postnatally. We hypothesized that the transplantation of MSCs (mesenchymal stem cells) to the cochlea would be an effective therapy for stopping or delaying the progression of sensorineural hearing loss in childhood. METHODS Cultured mouse MSCs were labeled with EGFP (enhanced green fluorescence protein) using retroviruses. EGFP-MSCs were transplanted into the posterior semicircular canal of mice at 2-3 weeks (young group) and 24-26 weeks (adult group) of age by a novel perilymphatic perfusion technique. Engraftment of MSCs was evaluated immunohistologically at 1 week and 2 weeks after transplantation. RESULTS In young mice, migrated MSCs were detected in the cochlea tissue by immunofluorescence for EGFP and by immunohistochemistry for fibronectin. The differentiation of migrated MSCs into fibrocyte-like cells was demonstrated by immunofluorescence for connexin 26. There were no adverse effects on auditory function by MSC transplantation, and the auditory brain stem responses threshold did not significantly shift after surgery. In contrast, neither MSC migration nor differentiation was detected in the adult mice canal after MSC transplantation. CONCLUSION The bone marrow derived MSCs were successfully transplanted into the cochlea of young mice by the perilymphatic perfusion technique and were further differentiated into fibrocyte-like cells without any adverse effects on auditory function.
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Affiliation(s)
- Hiromi Kasagi
- Department of Otorhinolaryngology, Juntendo University School of Medicine, Japan.
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Xing Y, Samuvel DJ, Stevens SM, Dubno JR, Schulte BA, Lang H. Age-related changes of myelin basic protein in mouse and human auditory nerve. PLoS One 2012; 7:e34500. [PMID: 22496821 PMCID: PMC3320625 DOI: 10.1371/journal.pone.0034500] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 03/06/2012] [Indexed: 11/19/2022] Open
Abstract
Age-related hearing loss (presbyacusis) is the most common type of hearing impairment. One of the most consistent pathological changes seen in presbyacusis is the loss of spiral ganglion neurons (SGNs). Defining the cellular and molecular basis of SGN degeneration in the human inner ear is critical to gaining a better understanding of the pathophysiology of presbyacusis. However, information on age-related cellular and molecular alterations in the human spiral ganglion remains scant, owing to the very limited availably of human specimens suitable for high resolution morphological and molecular analysis. This study aimed at defining age-related alterations in the auditory nerve in human temporal bones and determining if immunostaining for myelin basic protein (MBP) can be used as an alternative approach to electron microscopy for evaluating myelin degeneration. For comparative purposes, we evaluated ultrastructural alternations and changes in MBP immunostaining in aging CBA/CaJ mice. We then examined 13 temporal bones from 10 human donors, including 4 adults aged 38-46 years (middle-aged group) and 6 adults aged 63-91 years (older group). Similar to the mouse, intense immunostaining of MBP was present throughout the auditory nerve of the middle-aged human donors. Significant declines in MBP immunoreactivity and losses of MBP(+) auditory nerve fibers were observed in the spiral ganglia of both the older human and aged mouse ears. This study demonstrates that immunostaining for MBP in combination with confocal microscopy provides a sensitive, reliable, and efficient method for assessing alterations of myelin sheaths in the auditory nerve. The results also suggest that myelin degeneration may play a critical role in the SGN loss and the subsequent decline of the auditory nerve function in presbyacusis.
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Affiliation(s)
- Yazhi Xing
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Devadoss J. Samuvel
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Shawn M. Stevens
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Judy R. Dubno
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Bradley A. Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Otolaryngology – Head & Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- * E-mail:
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Makary CA, Shin J, Kujawa SG, Liberman MC, Merchant SN. Age-related primary cochlear neuronal degeneration in human temporal bones. J Assoc Res Otolaryngol 2011; 12:711-7. [PMID: 21748533 DOI: 10.1007/s10162-011-0283-2] [Citation(s) in RCA: 266] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 06/26/2011] [Indexed: 10/18/2022] Open
Abstract
In cases of acquired sensorineural hearing loss, death of cochlear neurons is thought to arise largely as a result of sensory-cell loss. However, recent studies of acoustic overexposure report massive degeneration of the cochlear nerve despite complete hair cell survival (Kujawa and Liberman, J Neurosci 29:14077-14085, 2009). To assess the primary loss of spiral ganglion cells (SGCs) in human ears, neuronal counts were performed in 100 temporal bones from 100 individuals, aged newborn to 100 years, selected to include only cases with a normal population of inner and outer hair cells. Ganglion cell counts declined at a mean rate of 100 cells per year of life. There were no significant gender or inter-aural differences, and a slight increase in degeneration in the basal turn re upper turns was not statistically significant. The age-related decline in SGCs was significantly less than that in prior studies that included ears with hair cell loss (Otte et al., Laryngoscope 88:1231-1246, 1978), but significantly more than for analogous data on vestibular ganglion cells in cases without vestibular hair cell loss (Velazquez-Villasenor et al., Ann Otol Rhinol Laryngol Suppl 181:14-19, 2000). The age-related decline in SGC counts may contribute to the well-known decline in hearing-in-noise performance, and the data will help in interpretation of histopathological findings from temporal bones with known otologic disease.
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Affiliation(s)
- Chadi A Makary
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA 02114-3006, USA
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Mahendrasingam S, Macdonald JA, Furness DN. Relative time course of degeneration of different cochlear structures in the CD/1 mouse model of accelerated aging. J Assoc Res Otolaryngol 2011; 12:437-53. [PMID: 21399990 DOI: 10.1007/s10162-011-0263-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 02/22/2011] [Indexed: 12/20/2022] Open
Abstract
Presbycusis (age-related hearing loss) can result from various cochlear pathologies. We have studied the time course of degeneration in a mouse that shows accelerated presbycusis, the CD/1 mouse, as a possible model to investigate stem-cell strategies to prevent or ameliorate presbycusic changes. CD/1 mice from 0 to 72 weeks old were examined by light and electron microscopy. Early pathological changes were detected in basal turn spiral ligament fibrocytes and spiral ganglion, but the latter was variable as both satellite cells and neurons were normal in some cochleae. Light microscopic counts in the spiral ligament of 20-week-old mice revealed that of the five main types (types I-V), only type V fibrocytes showed no reduction in numbers compared with 3-week-old animals, and type IV showed the greatest losses. However, all types of fibrocyte showed subtle damage when examined using electron microscopy, in the form of swollen mitochondria, as early as 2 weeks. The extent of mitochondrial damage showed a degree of correspondence with the light microscopic pattern of fibrocyte loss in that types III and IV fibrocytes had the most abnormal mitochondria and type V the least, especially at early stages. By 10-15 weeks, ultrastructural features of fibrocyte damage were similar to longer term changes reported in gerbils. Stria vascularis, spiral ganglion and hair cells showed few consistent early signs of damage but became increasingly affected, lagging behind the fibrocyte damage. Our data suggest that fibrocyte pathology may precede other presbycusic changes; breakdown of homeostatic mechanisms to which they contribute may cause the subsequent degeneration of the hair cells. Overall, there were many similarities to presbycusic changes in other rodents and humans. Therefore, the features of accelerated aging in this mouse make it a suitable model for rapidly assessing possible strategies to prevent or ameliorate presbycusic changes.
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Affiliation(s)
- Shanthini Mahendrasingam
- Institute for Science and Technology in Medicine and the School of Life Sciences, Keele University, Staffordshire, UK
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Ohlemiller KK, Dahl AR, Gagnon PM. Divergent aging characteristics in CBA/J and CBA/CaJ mouse cochleae. J Assoc Res Otolaryngol 2010; 11:605-23. [PMID: 20706857 DOI: 10.1007/s10162-010-0228-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 07/21/2010] [Indexed: 11/24/2022] Open
Abstract
Two inbred mouse strains, CBA/J and CBA/CaJ, have been used nearly interchangeably as 'good hearing' standards for research in hearing and deafness. We recently reported, however, that these two strains diverge after 1 year of age, such that CBA/CaJ mice show more rapid elevation of compound action potential (CAP) thresholds at high frequencies (Ohlemiller, Brain Res. 1277: 70-83, 2009). One contributor is progressive decline in endocochlear potential (EP) that appears only in CBA/CaJ. Here, we explore the cellular bases of threshold and EP disparities in old CBA/J and CBA/CaJ mice. Among the major findings, both strains exhibit a characteristic age (∼18 months in CBA/J and 24 months in CBA/CaJ) when females overtake males in sensitivity decline. Strain differences in progression of hearing loss are not due to greater hair cell loss in CBA/CaJ, but instead appear to reflect greater neuronal loss, plus more pronounced changes in the lateral wall, leading to EP decline. While both male and female CBA/CaJ show these pathologies, they are more pronounced in females. A novel feature that differed sharply by strain was moderate loss of outer sulcus cells (or 'root' cells) in spiral ligament of the upper basal turn in old CBA/CaJ mice, giving rise to deep indentations and void spaces in the ligament. We conclude that CBA/CaJ mice differ both quantitatively and qualitatively from CBA/J in age-related cochlear pathology, and model different types of presbycusis.
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Affiliation(s)
- Kevin K Ohlemiller
- Program in Audiology and Communication Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Palmgren B, Jin Z, Ma H, Jiao Y, Olivius P. beta-Bungarotoxin application to the round window: an in vivo deafferentation model of the inner ear. Hear Res 2010; 265:70-6. [PMID: 20184947 DOI: 10.1016/j.heares.2010.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 02/13/2010] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
Abstract
Hearing impairment can be caused by a primary lesion to the spiral ganglion neurons (SGNs) with the hair cells kept intact, for example via tumours, trauma or auditory neuropathy. To mimic these conditions in animal models various methods of inflicting damage to the inner ear have been used. However, only a few methods have a selective effect on the SGNs, which is of importance since it might be clinically more relevant to study hearing impairment with the hair cells undamaged. beta-Bungarotoxin is a venom of the Taiwan banded krait, which in vitro has been shown to induce apoptosis in neurons, leaving remaining cochlear cells intact. We wanted to create an in vivo rat model of selective damage to primary auditory neurons. Under deep anaesthesia, 41 rats received beta-Bungarotoxin or saline to the round window niche. At postoperative intervals between days 3 and 21 auditory brainstem response (ABR) measurement, immunohistochemistry, SGN quantification and cochlear surface preparation were performed. The results in the beta-Bungarotoxin-treated ears, as compared with sham-operated ears, show significantly increased ABR thresholds at all postoperative intervals, illustrating a severe to profound hearing loss at all tested frequencies (3.5, 7, 16 and 28 kHz). Quantification of the SGNs showed no obvious reduction in neuronal numbers until 14 days postoperatively. Between days 14 and 21 a significant reduction in SGN numbers was observed. Cochlear surface preparation and immunohistochemistry showed that the hair cells were intact. Our results illustrate that in vivo application of beta-Bungarotoxin to the round window niche is a feasible way of deafening rats by SGN reduction while the hair cells are kept intact.
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Affiliation(s)
- Björn Palmgren
- Center for Hearing and Communication Research, Karolinska University Hospital, 171 76 Stockholm, Sweden.
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Vascular Findings in the Stria Vascularis of Patients With Unilateral or Bilateral Ménière's Disease. Otol Neurotol 2009; 30:1006-12. [DOI: 10.1097/mao.0b013e3181b4ec89] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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46
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Immunocytochemical traits of type IV fibrocytes and their possible relations to cochlear function and pathology. J Assoc Res Otolaryngol 2009; 10:369-82. [PMID: 19277783 DOI: 10.1007/s10162-009-0165-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Accepted: 02/16/2009] [Indexed: 12/17/2022] Open
Abstract
One of the more consistent and least understood changes in the aging human cochlea is the progressive loss of fibrocytes within the spiral ligament. This report presents an animal model for type IV fibrocyte loss, along with immunocytochemical evidence that noise-induced loss of these cells may account for previously unexplained hearing losses. The remarkably low threshold for noise-induced loss of type IV fibrocytes, approximately 24 dB less than the threshold for adjacent hair cell destruction, may account for the prevalence of missing fibrocytes in humans. In mice, changes in the spectrum of traumatizing noise had little effect upon the site of loss of the fibrocytes, suggesting that the primary site of damage that induced the loss was the basal-most cochlear turn, a site expected to be damaged by all three noise bands. Type IV fibrocytes were found to immunostain for connective tissue growth factor (CTGF) and for transforming growth factor beta receptor 3, a receptor that is known to activate CTGF expression. Type IV fibrocytes lack immunostaining for adenosine triphosphatase and connexins that are key players in potassium ion uptake and transmission, which suggests that they play little, if any, role in potassium recycling from perilymphatic space to the endolymphatic space. Consequently, their loss probably does not directly reduce this process. Immunostaining for a receptor for CTGF, low-density-lipoprotein-related protein 1, indicated that CTGF acts as an autocrine and a paracrine agent within the cochlea. The lack of CTGF paracrine effects following noise-induced loss of type IV fibrocytes may account for previously unexplained hearing losses.
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47
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A mouse model for degeneration of the spiral ligament. J Assoc Res Otolaryngol 2009; 10:161-72. [PMID: 19212789 DOI: 10.1007/s10162-008-0147-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 10/27/2008] [Indexed: 01/26/2023] Open
Abstract
Previous studies have indicated the importance of the spiral ligament (SL) in the pathogenesis of sensorineural hearing loss. The aim of this study was to establish a mouse model for SL degeneration as the basis for the development of new strategies for SL regeneration. We injected 3-nitropropionic acid (3-NP), an inhibitor of succinate dehydrogenase, at various concentrations into the posterior semicircular canal of adult C57BL/6 mice. Saline-injected animals were used as controls. Auditory function was monitored by measurements of auditory brain stem responses (ABRs). On postoperative day 14, cochlear specimens were obtained after the measurement of the endocochlear potential (EP). Animals that were injected with 5 or 10 mM 3-NP showed a massive elevation of ABR thresholds along with extensive degeneration of the cochleae. Cochleae injected with 1 mM 3-NP exhibited selective degeneration of the SL fibrocytes but alterations in EP levels and ABR thresholds were not of sufficient magnitude to allow for testing functional recovery after therapeutic interventions. Animals injected with 3 mM 3-NP showed a reduction of around 50% in the EP along with a significant loss of SL fibrocytes, although degeneration of spiral ganglion neurons and hair cells was still present in certain regions. These findings indicate that cochleae injected with 3 mM 3-NP may be useful in investigations designed to test the feasibility of new therapeutic manipulations for functional SL regeneration.
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Chen GD, Li M, Tanaka C, Bielefeld EC, Hu BH, Kermany MH, Salvi R, Henderson D. Aging outer hair cells (OHCs) in the Fischer 344 rat cochlea: Function and morphology. Hear Res 2009; 248:39-47. [DOI: 10.1016/j.heares.2008.11.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 11/20/2008] [Accepted: 11/21/2008] [Indexed: 12/24/2022]
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Ohlemiller KK, Rice MER, Lett JM, Gagnon PM. Absence of strial melanin coincides with age-associated marginal cell loss and endocochlear potential decline. Hear Res 2008; 249:1-14. [PMID: 19141317 DOI: 10.1016/j.heares.2008.12.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 12/15/2008] [Accepted: 12/16/2008] [Indexed: 11/20/2022]
Abstract
Cochlear stria vascularis contains melanin-producing intermediate cells that play a critical role in the production of the endocochlear potential (EP) and in maintaining the high levels of K(+) that normally exist in scala media. The melanin produced by intermediate cells can be exported to the intrastrial space, where it may be taken up by strial marginal cells and basal cells. Because melanin can act as an antioxidant and metal chelator, evidence for its role in protecting the stria and organ of Corti against noise, ototoxins, and aging has long been sought. While some evidence supports a protective role of melanin against noise and ototoxins, no evidence yet presented has demonstrated a clear role for melanin in maintaining the EP during aging. We tested this by comparing basal turn EPs and a host of cochlear cellular metrics in aging C57BL/6 (B6) mice and C57BL/6-Tyr(c-2J) mice. The latter mice carry a naturally occurring inactivating mutation of the tyrosinase locus, and produce no strial melanin. Because these two strains are coisogenic, and because pigmented B6 mice show essentially no age-related EP decline, they provide an ideal test of importance of melanin in the aging stria. Pigmented and albino B6 mice showed identical rates of hearing loss and sensory cell loss. However, after two years of age, basal turn EPs significantly diverged, with 42% of albinos showing EPs below 100 mV versus only 18% of pigmented mice. The clearest anatomical correlate of this EP difference was significantly reduced strial thickness in the albinos that was highly correlated with loss of marginal cells. Combined with findings in human temporal bones, plus recent work in BALB/c mice and gerbils, the present findings point to a common etiology in strial presbycusis whereby EP reduction is principally linked to marginal cell loss or dysfunction. For any individual, genetic background, environmental influences, and stochastic events may work together to determine whether marginal cell density or function falls below some critical level, and thus whether EP decline occurs.
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Affiliation(s)
- Kevin K Ohlemiller
- Fay and Carl Simons Center for the Biology of Hearing and Deafness/Central Institute for the Deaf at Washington University, St. Louis, MO, USA.
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Ishiyama G, Tokita J, Lopez I, Tang Y, Ishiyama A. Unbiased stereological estimation of the spiral ligament and stria vascularis volumes in aging and Ménière's disease using archival human temporal bones. J Assoc Res Otolaryngol 2007; 8:8-17. [PMID: 17160359 PMCID: PMC2538411 DOI: 10.1007/s10162-006-0057-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 09/06/2006] [Accepted: 10/01/2006] [Indexed: 11/26/2022] Open
Abstract
The present study applies the unbiased stereological technique-Cavalieri principle to measure the volumes of the stria vascularis (SV) and the spiral ligament (SL) using postmortem archival human temporal bones from normal young and older subjects and subjects with Ménière's disease. Normative data was obtained from subjects without ages ranging from 15 to 84 years old who had no history of audiovestibular disease (N=25). For comparison purposes, the normative specimens were divided into three groups: group 1 (n=8) had ages ranging from 15 to 38 years old, average age=23.9; group 2 (n=8) had ages ranging from 51 to 59 years old, average age=55.1; group 3 (n=9) had ages ranging from 64 to 84 years old, average age=74.3. The average SV volume of group 3 (0.479 mm3) was significantly lower than that of group 1 (0.705 mm3) (p<0.0005) and was significantly lower than that of group 2 (0.603 mm3) (p=0.01). The average SL volume of group 3 (8.42 mm3) was significantly lower than that of group 1 (9.54 mm3) (p<0.05), but was not significantly lower than that of group 2 (8.58 mm3). Five subjects with Ménière's disease, confirmed by histopathological examination (ages ranging from 63 to 91 years old, average age=73.4), were studied. The average SV volume in Ménière's subjects (0.378 mm3) was significantly lower than age-matched controls (p<0.05). The average SL volume in Ménière's subjects (7.01 mm3) was also significantly lower than age-matched controls (p<0.05). The SV and SL volumes were unaffected by gender. The present study demonstrates for the first time the use of the unbiased stereological technique-Cavalieri principle-as a reliable and efficient method to obtain volumetric estimates of the SV and the SL by using archival human temporal bone specimens.
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Affiliation(s)
- Gail Ishiyama
- Neurology Department, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
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