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Zhang C, Adler HJ, Manohar S, Salvi R, Sun W, Ye M, Hu BH. Galectin-3 protects auditory function in female mice. Hear Res 2022; 424:108602. [PMID: 36103788 DOI: 10.1016/j.heares.2022.108602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 11/04/2022]
Abstract
Sex differences in the development of sensorineural hearing loss have been recognized in various inner ear disorders, but the molecular basis for such differences is poorly understood. Autosomal genes have been shown to cause sex differences in disease susceptibility, but many genes exerting sex-dependent effects on auditory function remain to be identified. Galectin-3 (Gal-3), a protein encoded by the autosomal gene Lgals3, is a member of the β-galactoside-binding protein family, and has been linked to multiple biological processes, including immune responses, apoptosis, and cell adhesion. Here, we investigated auditory function and hair cell integrity in Gal-3 knockout (KO, Lgals3-/-) and wild-type (WT, Lgals3+/+) mice from age 1 to 6 months. KO mice show a more rapid age-related increase in ABR thresholds compared to WT mice. Noticeably, the threshold deterioration in female KO mice is significantly greater than in the male KO and WT mice. The ABR threshold elevation manifests over a broad frequency range in female KO mice, whereas the threshold elevations are confined to high frequencies in the male KO and WT mice. Moreover, DPOAE input/output functions reveal a similar pattern of auditory dysfunction, with the female KO mice displaying a significantly greater reduction in DPOAE amplitudes than male KO mice and WT mice of both sexes. Finally, age-related outer hair cell loss is greater for female KO mice compared to male KO mice and WT mice of both sexes. Together, these results indicate that Gal-3 deficiency exacerbates age-related cochlear degeneration and auditory dysfunction in female mice. Our study identifies Gal-3 as a sex-dependent molecule for maintaining female cochlear integrity.
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Affiliation(s)
- Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Henry J Adler
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Wei Sun
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Mengxiao Ye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
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Sun F, Zhang J, Chen L, Yuan Y, Guo X, Dong L, Sun J. Epac1 Signaling Pathway Mediates the Damage and Apoptosis of Inner Ear Hair Cells after Noise Exposure in a Rat Model. Neuroscience 2021; 465:116-127. [PMID: 33838290 DOI: 10.1016/j.neuroscience.2021.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/12/2021] [Accepted: 03/26/2021] [Indexed: 01/21/2023]
Abstract
To investigate the role of the exchange protein directly activated by cAMP (Epac) signaling pathway in inner ear hair cell damage and apoptosis after noise exposure, we analyzed the expression level of Epac1 in a rat model of noise-induced hearing loss (NIHL), based on rat exposure to a 4-kHz and 106-dB sound pressure level (SPL) for 8 h. Loss of outer hair cells (OHCs), mitochondrial lesions, and hearing loss were examined after treatment with the Epac agonist, 8-CPT, or the Epac inhibitor, ESI-09. The effects of 8-CPT and ESI-09 on cell proliferation and apoptosis were examined by CCK-8 assays, holographic microscopy imaging, and Annexin-V FITC/PI staining in HEI-OC1 cells. The effects of 8-CPT and ESI-09 on Ca2+ entry were evaluated by confocal Ca2+ fluorescence measurement. We found that the expression level of Epac1 was significantly increased in the cochlear tissue after noise exposure. In NIHL rats, 8-CPT increased the loss of OHCs, mitochondrial lesions, and hearing loss compared to control rats, while ESI-09 produced the opposite effects. Oligomycin was used to induce HEI-OC1 cell damage in vitro. In HEI-OC1 cells treated with oligomycin, 8-CPT and ESI-09 increased and reduced cell apoptosis, respectively. Moreover, 8-CPT promoted Ca2+ uptake in HEI-OC1 cells, while ESI-09 inhibited this process. In conclusion, our data provide strong evidence that the Epac1 signaling pathway mediates early pathological damage in NIHL, and that Epac1 inhibition protects from NIHL, identifying Epac1 as a new potential therapeutic target for NIHL.
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Affiliation(s)
- Fanfan Sun
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Hefei 230001, China; Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, China
| | - Junge Zhang
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Hefei 230001, China
| | - Li Chen
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Hefei 230001, China
| | - Yuhao Yuan
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, China
| | - Xiaotao Guo
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Hefei 230001, China
| | - Liuyi Dong
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, China.
| | - Jiaqiang Sun
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Hefei 230001, China.
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Wu J, Ye J, Kong W, Zhang S, Zheng Y. Programmed cell death pathways in hearing loss: A review of apoptosis, autophagy and programmed necrosis. Cell Prolif 2020; 53:e12915. [PMID: 33047870 PMCID: PMC7653260 DOI: 10.1111/cpr.12915] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/23/2020] [Accepted: 09/09/2020] [Indexed: 02/05/2023] Open
Abstract
Programmed cell death (PCD)—apoptosis, autophagy and programmed necrosis—is any pathological form of cell death mediated by intracellular processes. Ototoxic drugs, ageing and noise exposure are some common pathogenic factors of sensorineural hearing loss (SNHL) that can induce the programmed death of auditory hair cells through different pathways, and eventually lead to the loss of hair cells. Furthermore, several mutations in apoptotic genes including DFNA5, DFNA51 and DFNB74 have been suggested to be responsible for the new functional classes of monogenic hearing loss (HL). Therefore, in this review, we elucidate the role of these three forms of PCD in different types of HL and discuss their guiding significance for HL treatment. We believe that further studies of PCD pathways are necessary to understand the pathogenesis of HL and guide scientists and clinicians to identify new drug targets for HL treatment.
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Affiliation(s)
- Junhao Wu
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Ye
- College of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Weili Kong
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Shouyue Zhang
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Yun Zheng
- Department of Otolaryngology, Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
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Breitzler L, Lau IH, Fonseca PJ, Vasconcelos RO. Noise-induced hearing loss in zebrafish: investigating structural and functional inner ear damage and recovery. Hear Res 2020; 391:107952. [DOI: 10.1016/j.heares.2020.107952] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/19/2020] [Accepted: 03/16/2020] [Indexed: 12/20/2022]
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Loss of sestrin 2 potentiates the early onset of age-related sensory cell degeneration in the cochlea. Neuroscience 2017; 361:179-191. [PMID: 28818524 DOI: 10.1016/j.neuroscience.2017.08.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 01/22/2023]
Abstract
Sestrin 2 (SESN2) is a stress-inducible protein that protects tissues from oxidative stress and delays the aging process. However, its role in maintaining the functional and structural integrity of the cochlea is largely unknown. Here, we report the expression of SESN2 protein in the sensory epithelium, particularly in hair cells. Using C57BL/6J mice, a mouse model of age-related cochlear degeneration, we observed a significant age-related reduction in SESN2 expression in cochlear tissues that was associated with early onset hearing loss and accelerated age-related sensory cell degeneration that progressed from the base toward the apex of the cochlea. Hair cell death occurred by caspase-8 mediated apoptosis. Compared to C57BL/6J control mice, Sesn2 KO mice displayed enhanced expression of proinflammatory genes and activation of basilar membrane macrophages, suggesting that loss of SESN2 function provokes the immune response. Together, these results suggest that Sesn2 plays an important role in cochlear homeostasis and immune responses to stress.
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Xu Y, Yang WP, Hu BH, Yang S, Henderson D. Involvement of p53 and Bcl-2 in sensory cell degeneration in aging rat cochleae. Acta Otolaryngol 2017; 137:572-580. [PMID: 28093932 DOI: 10.1080/00016489.2016.1274425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONCLUSION p53 and Bcl-2 (B-cell lymphoma 2) are involved in the process of sensory cell degeneration in aging cochleae. OBJECTIVE To determine molecular players in age-related hair cell degeneration, this study examined the changes in p53 and Bcl-2 expression at different stages of apoptotic and necrotic death of hair cells in aging rat cochleae. METHODS Young (3-4 months) and aging (23-24 months) Fisher 344/NHsd rats were used. The thresholds of the auditory brainstem response (ABR) were measured to determine the auditory function. Immunolabeling was performed to determine the expression of p53 and Bcl-2 proteins in the sensory epithelium. Propidium iodide staining was performed to determine the morphologic changes in hair cell nuclei. RESULTS Aging rats exhibited a significant elevation in ABR thresholds at all tested frequencies (p < 0.001). The p53 and Bcl-2 immunoreactivity was increased in aging hair cells showing the early signs of apoptotic changes in their nuclei. The Bcl-2 expression increase was also observed in hair cells displaying early signs of necrosis. As the hair cell degenerative process advanced, p53 and Bcl-2 immunoreactivity became reduced or absent. In the areas where no detectable nuclear staining was present, p53 and Bcl-2 immunoreactivity was absent.
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Affiliation(s)
- Yang Xu
- Department of Respiratory Diseases, Chinese PLA General Hospital, Beijing, PR China
| | - Wei Ping Yang
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, NY, USA
- Department of Otolaryngology and Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, PR China
| | - Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, NY, USA
| | - Shiming Yang
- Department of Otolaryngology and Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, PR China
| | - Donald Henderson
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, NY, USA
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8
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Ototoxicity of 12 mg/kg cisplatin in the Fischer 344/NHsd rat using multiple dosing strategies. Anticancer Drugs 2016; 27:780-6. [DOI: 10.1097/cad.0000000000000395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dong Y, Guo CR, Ding Y, Zhang Y, Song HY, Peng YT, Zhang T, Shi JR. Effects of Erlong Zuoci decoction on the age-related hearing loss in C57BL/6J mice. JOURNAL OF ETHNOPHARMACOLOGY 2016; 181:59-65. [PMID: 26826327 DOI: 10.1016/j.jep.2016.01.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/12/2015] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Erlong Zuoci decoction (ELZCD), a typical traditional Chinese medicine (TCM) prescription, has long been clinically used in treatment of deafness and tinnitus with the syndrome of "kidney yin deficiency". However, there are few studies to investigate its pharmacological mechanisms. Until now, there is not report about its effects on the age-related hearing loss (ARHL). AIM OF STUDY The present study was conducted to observe the effects of ELZCD on the ARHL in C57BL/6J mice and explore the mechanisms. MATERIALS AND METHODS ELZCD was fed to C57BL/6J mice from 3 months to 6 months in ELZCD group as a dose of 6g/kg/d. And the same volume of saline was fed to mice in ARHL group. 3-months-old C57BL/6J mice were used as control group. High performance liquid chromatography (HPLC) was used for the quality control of ELZCD. Auditory brainstem response (ABR) was used to assess the hearing function of mice. The morphologic changes were observed by hematoxylin eosin (HE) staining. Apoptosis was tested by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) method. Mitochondrial damage was detected by transmission electron microscopy (TEM). Quantitative RT-PCR (qRT-PCR) was used to observe the mRNA expression of p53 and Bak. Fluorescence immunohistochemical technique was used to test the protein expression of p53 and Bak. RESULTS The hearing threshold of ARHL group was higher than that of control group (P<0.001) and ELZCD decreased the rise of hearing threshold levels of ARHL mice (P<0.001), which suggested ELZCD inhibited the hearing loss of ARHL mice. HE staining showed that ELZCD decreased the spiral ganglion (SG) cell damage and loss in ARHL. TUNEL test showed that the apoptotic SG cells increased in ARHL group compared to control group and decreased in ELZCD group compared to ARHL group. TEM observation showed that mitochondrial damage was obvious in SG cells of ARHL group and ELZCD inhibited the mitochondrial damage. The qRT-PCR results showed that the mRNA expression of p53 and Bak in ARHL group increased compared to that of control group (P<0.05), and ELZCD reduced the elevated mRNA expression levels of p53 and Bak (P<0.01, P<0.05). In addition, ELZCD inhibited the increased proteins expression (green fluorescence) of p53 and Bak. CONCLUSION The results demonstrated that ELZCD prevented ARHL in C57BL/6J mice and p53/Bak-mediated mitochondrial apoptosis of SG cells might be involved in the mechanisms.
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Affiliation(s)
- Yang Dong
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Chun-Rong Guo
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yue Ding
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hai-Yan Song
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yin-Ting Peng
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Tong Zhang
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jian-Rong Shi
- Experimental Teaching Center, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Ding L, Liu J, Shen HX, Pan LP, Liu QD, Zhang HD, Han L, Shuai LG, Ding EM, Zhao QN, Wang BS, Zhu BL. Analysis of plasma microRNA expression profiles in male textile workers with noise-induced hearing loss. Hear Res 2015; 333:275-282. [PMID: 26278637 DOI: 10.1016/j.heares.2015.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 07/29/2015] [Accepted: 08/11/2015] [Indexed: 01/11/2023]
Abstract
BACKGROUND Circulating microRNAs (miRNAs) have attracted interests as non-invasive biomarkers of physiological and pathological conditions, which may be applied in noise-induced hearing loss (NIHL). However, no epidemiology studies have yet examined the potential effects of NIHL or noise exposure on miRNA expression profiles. OBJECTIVES We sought to identify permanent NIHL-related miRNAs and to predict the biological functions of the putative genes encoding the indicated miRNAs. METHODS In the discovery stage, we used a microarray assay to detect the miRNA expression profiles between pooled plasma samples from 10 noise-exposed individuals with normal hearing and 10 NIHL patients. In addition, we conducted a preliminary validation of six candidate miRNAs in the same 20 workers. Subsequently, three miRNAs were selected for expanded validation in 23 non-exposed individuals with normal hearing and 46 noise-exposed textile workers which including 23 noise-exposed workers with normal hearing and 23 NIHL patients. Moreover, we predicted the biological functions of the putative target genes using a Gene Ontology (GO) function enrichment analysis. RESULTS In the discovery stage, compared with the noise exposures with normal hearing, 73 miRNAs demonstrated at least a 1.5-fold differential expression in the NIHL patients. In the preliminary validation, compared with the noise exposures, the plasma levels of miR-16-5p, miR-24-3p, miR-185-5p and miR-451a were all upregulated (P < 0.001) in the NIHL patients. In the expanded validation stage, compared with the non-exposures, the plasma levels of miR-24, miR-185-5p and miR-451a were all significantly downregulated (P < 0.001) in the exposures. And compared with the noise exposures, the plasma levels of miR-185-5p and miR-451a were slightly elevated (P < 0.001) in the NIHL patients, which were consistent with the results of preliminary validation and microarray analysis. CONCLUSION The two indicated plasma miRNAs may be biomarkers of indicating responses to noise exposure. However, further studies are necessary to prove the causal association between miRNAs changes and noise exposure, and to determine whether these two miRNAs are clear biomarkers to noise exposure.
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Affiliation(s)
- Lu Ding
- Suzhou Municipal Center for Disease Prevention and Control, Suzhou, Jiangsu, China
| | - Jing Liu
- Department of Occupational and Environmental Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Huan-Xi Shen
- Kunshan Municipal Center for Disease Prevention and Control, Suzhou, Jiangsu, China
| | - Li-Ping Pan
- Department of Occupational and Environmental Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qing-Dong Liu
- Department of Occupational and Environmental Health, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Heng-Dong Zhang
- Department of Prevention and Control for Occupational Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu, China
| | - Lei Han
- Department of Prevention and Control for Occupational Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu, China
| | - Li-Guo Shuai
- School of Mechanical Engineering, Southeast University, Nanjing, Jiangsu, China
| | - En-Min Ding
- Department of Occupational and Environmental Health, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qiu-Ni Zhao
- Department of Occupational and Environmental Health, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Bo-Shen Wang
- Department of Occupational and Environmental Health, School of Public Health, Nantong University, Nantong, Jiangsu, China
| | - Bao-Li Zhu
- Department of Prevention and Control for Occupational Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu, China.
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Yang CH, Schrepfer T, Schacht J. Age-related hearing impairment and the triad of acquired hearing loss. Front Cell Neurosci 2015; 9:276. [PMID: 26283913 PMCID: PMC4515558 DOI: 10.3389/fncel.2015.00276] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 07/06/2015] [Indexed: 02/03/2023] Open
Abstract
Understanding underlying pathological mechanisms is prerequisite for a sensible design of protective therapies against hearing loss. The triad of age-related, noise-generated, and drug-induced hearing loss displays intriguing similarities in some cellular responses of cochlear sensory cells such as a potential involvement of reactive oxygen species (ROS) and apoptotic and necrotic cell death. On the other hand, detailed studies have revealed that molecular pathways are considerably complex and, importantly, it has become clear that pharmacological protection successful against one form of hearing loss will not necessarily protect against another. This review will summarize pathological and pathophysiological features of age-related hearing impairment (ARHI) in human and animal models and address selected aspects of the commonality (or lack thereof) of cellular responses in ARHI to drugs and noise.
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Affiliation(s)
- Chao-Hui Yang
- Department of Otolaryngology, Kresge Hearing Research Institute, University of Michigan Ann Arbor, MI, USA ; Division of Otology, Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine Kaohsiung, Taiwan
| | - Thomas Schrepfer
- Department of Otolaryngology, Kresge Hearing Research Institute, University of Michigan Ann Arbor, MI, USA
| | - Jochen Schacht
- Department of Otolaryngology, Kresge Hearing Research Institute, University of Michigan Ann Arbor, MI, USA
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Cai Q, Whitcomb C, Eggleston J, Sun W, Salvi R, Hu BH. Round window closure affects cochlear responses to suprathreshold stimuli. Laryngoscope 2013; 123:E116-21. [PMID: 24114866 DOI: 10.1002/lary.24394] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 07/31/2013] [Accepted: 08/13/2013] [Indexed: 11/11/2022]
Abstract
OBJECTIVES/HYPOTHESIS The round window acts as a vent for releasing inner ear pressure and facilitating basilar membrane vibration. Loss of this venting function affects cochlear function, which leads to hearing impairment. In an effort to identify functional changes that might be used in clinical diagnosis of round window atresia, the current investigation was designed to examine how the cochlea responds to suprathreshold stimuli following round window closure. STUDY DESIGN Prospective, controlled, animal study. METHODS A rat model of round window occlusion (RWO) was established. With this model, the thresholds of auditory brainstem responses (ABR) and the input/output (IO) functions of distortion product otoacoustic emissions (DPOAEs) and acoustic startle responses were examined. RESULTS Round window closure caused a mild shift in the thresholds of the auditory brainstem response (13.5 ± 9.1 dB). It also reduced the amplitudes of the distortion product otoacoustic emissions and the slope of the input/output functions. This peripheral change was accompanied by a significant reduction in the amplitude, but not the threshold, of the acoustic startle reflex, a motor response to suprathreshold sounds. CONCLUSIONS In addition to causing mild increase in the threshold of the auditory brainstem response, round window occlusion reduced the slopes of both distortion product otoacoustic emissions and startle reflex input/output functions. These changes differ from those observed for typical conductive or sensory hearing loss, and could be present in patients with round window atresia. However, future clinical observations in patients are needed to confirm these findings.
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Affiliation(s)
- Qunfeng Cai
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York
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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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Patel M, Cai Q, Ding D, Salvi R, Hu Z, Hu BH. The miR-183/Taok1 target pair is implicated in cochlear responses to acoustic trauma. PLoS One 2013; 8:e58471. [PMID: 23472202 PMCID: PMC3589350 DOI: 10.1371/journal.pone.0058471] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 02/05/2013] [Indexed: 12/31/2022] Open
Abstract
Acoustic trauma, one of the leading causes of sensorineural hearing loss, induces sensory hair cell damage in the cochlea. Identifying the molecular mechanisms involved in regulating sensory hair cell death is critical towards developing effective treatments for preventing hair cell damage. Recently, microRNAs (miRNAs) have been shown to participate in the regulatory mechanisms of inner ear development and homeostasis. However, their involvement in cochlear sensory cell degeneration following acoustic trauma is unknown. Here, we profiled the expression pattern of miRNAs in the cochlear sensory epithelium, defined miRNA responses to acoustic overstimulation, and explored potential mRNA targets of miRNAs that may be responsible for the stress responses of the cochlea. Expression analysis of miRNAs in the cochlear sensory epithelium revealed constitutive expression of 176 miRNAs, many of which have not been previously reported in cochlear tissue. Exposure to intense noise caused significant threshold shift and apoptotic activity in the cochleae. Gene expression analysis of noise-traumatized cochleae revealed time-dependent transcriptional changes in the expression of miRNAs. Target prediction analysis revealed potential target genes of the significantly downregulated miRNAs, many of which had cell death- and apoptosis-related functions. Verification of the predicted targets revealed a significant upregulation of Taok1, a target of miRNA-183. Moreover, inhibition of miR-183 with morpholino antisense oligos in cochlear organotypic cultures revealed a negative correlation between the expression levels of miR-183 and Taok1, suggesting the presence of a miR-183/Taok1 target pair. Together, miRNA profiling as well as the target analysis and validation suggest the involvement of miRNAs in the regulation of the degenerative process of the cochlea following acoustic overstimulation. The miR-183/Taok1 target pair is likely to play a role in this regulatory process.
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Affiliation(s)
- Minal Patel
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Qunfeng Cai
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Dalian Ding
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Richard Salvi
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Zihua Hu
- Center for Computational Research, New York State Center of Excellence in Bioinformatics & Life Sciences, Department of Ophthalmology, Department of Biostatistics, Department of Medicine, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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Yang WP, Guo WW, Liu HZ, Xu Y, Chen L, Hu BH. Age-related changes in the ratio of Mcl-1/Bax expression in the rat cochlea. Acta Otolaryngol 2012; 132:123-32. [PMID: 22201517 DOI: 10.3109/00016489.2011.631191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
CONCLUSION Down-regulation of the ratio of Mcl-1/Bax expression may contribute to age-related sensory cell degeneration in the cochlea. OBJECTIVE To better understand the involvement of Bcl-2 family members in the regulation of age-related sensory cell death, we examined the expression patterns of Bcl-2-associated protein X (Bax) and its suppressor, myeloid cell leukemia 1 (Mcl-1) in young and aging rat cochleae. METHODS Young (2-3 months) and aging (27-28 months) Fischer rats were used. The auditory brainstem response (ABR) thresholds elicited by tone bursts at 4, 8, 16, 32, and 40 kHz were measured. The expression patterns of Mcl-1 and Bax genes at both the mRNA and protein levels were examined using a real-time RT-PCR assay and Western blot. Distribution of Mcl-1 and Bax expression in the cochlear sensory epithelia was evaluated using immunohistology and nuclear staining. RESULTS Aging cochleae exhibited a significant elevation of ABR thresholds. This change was accompanied by significant reduction in Mcl-1 expression at both the mRNA and the protein levels and in the ratio of expression levels of Mcl-1/Bax genes in the aging subjects. Importantly, the changes in Mcl-1 and Bax expression are spatially related to the sensory cells showing the sign of degeneration.
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Affiliation(s)
- Wei Ping Yang
- Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, PR China.
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Tanaka C, Coling DE, Manohar S, Chen GD, Hu BH, Salvi R, Henderson D. Expression pattern of oxidative stress and antioxidant defense-related genes in the aging Fischer 344/NHsd rat cochlea. Neurobiol Aging 2012; 33:1842.e1-14. [PMID: 22300951 DOI: 10.1016/j.neurobiolaging.2011.12.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2011] [Revised: 12/13/2011] [Accepted: 12/22/2011] [Indexed: 10/14/2022]
Abstract
The biological mechanisms that give rise to age-related hearing loss (ARHL) are still poorly understood. However, there is growing recognition that oxidative stress may be an important factor. To address this issue, we measured the changes in the expression of cochlear oxidative stress and antioxidant defense-related genes in young (2 months old), middle-aged (12 months old), and old (21-25 months old) Fischer 344/NHsd (F344/NHsd) rats and compared gene expression changes with ARHL. A quantitative real-time reverse transcription polymerase chain reaction array revealed a significant age-related downregulation of only 1 gene, stearoyl-coenzyme A desaturase 1, and upregulation of 12 genes: 24-dehydrocholesterol reductase; aminoadipate-semialdehyde synthase; cytoglobin; dual oxidase 2; glutathione peroxidase 3; glutathione peroxidase 6; glutathione S-transferase, kappa 1; glutathione reductase; nicotinamide adenine dinucleotide phosphate (NAD(P)H) dehydrogenase, quinone 1; solute carrier Family 38, Member 5; thioredoxin interacting protein; and vimentin. Statistical analyses revealed significant correlations between gene expression and auditory function in 8 genes. Our results identified specific subsets of oxidative stress genes that appear to play an important role in ARHL in the Fischer 344/NHsd rat.
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Affiliation(s)
- Chiemi Tanaka
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, NY, USA.
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Fetoni AR, Picciotti PM, Paludetti G, Troiani D. Pathogenesis of presbycusis in animal models: a review. Exp Gerontol 2011; 46:413-25. [PMID: 21211561 DOI: 10.1016/j.exger.2010.12.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 11/04/2010] [Accepted: 12/15/2010] [Indexed: 12/14/2022]
Abstract
Presbycusis is the most common cause of hearing loss in aged subjects, reducing individual's communicative skills. Age related hearing loss can be defined as a progressive, bilateral, symmetrical hearing loss due to age related degeneration and it can be considered a multifactorial complex disorder, with both environmental and genetic factors contributing to the aetiology of the disease. The decline in hearing sensitivity caused by ageing is related to the damage at different levels of the auditory system (central and peripheral). Histologically, the aged cochlea shows degeneration of the stria vascularis, the sensorineural epithelium, and neurons of the central auditory pathways. The mechanisms responsible for age-associated hearing loss are still incompletely characterized. This work aims to give a broad overview of the scientific findings related to presbycusis, focusing mainly on experimental studies in animal models.
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Affiliation(s)
- Anna R Fetoni
- Institute of Otolaryngology, School of Medicine, Catholic University of Rome, Largo A. Gemelli, 8 00168 Rome, Italy.
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Hu BH, Cai Q. Acoustic overstimulation modifies Mcl-1 expression in cochlear sensory epithelial cells. J Neurosci Res 2010; 88:1812-21. [PMID: 20091770 DOI: 10.1002/jnr.22333] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Acoustic overstimulation causes apoptotic cell death in the cochlea. This death process is mediated, in part, by the mitochondrial signaling pathway involving Bcl-2 family proteins. Myeloid cell leukemia sequence 1 (Mcl-l) is an antiapoptotic member of the Bcl-2 family. Its involvement in noise-induced hair cell death has not been characterized. Here we report the endogenous expression and the noise-induced expression of Mcl-1 in Sprague Dawley rat cochleae. In the sensory epithelia of normal cochleae, there is strong constitutive expression of Mcl-1 mRNA, with an expression level higher than that of many other Bcl-2 family genes. The Mcl-1 protein is preferentially expressed in outer hair cells. After exposure to a high level of continuous noise at 115-dB sound pressure level for 1 hr, Mcl-1 expression displays a time-dependent alteration, with up-regulation of Mcl-1 mRNA at 4 hr postexposure and protein up-regulation at 1 day postexposure. Western blot analysis reveals the up-regulated Mcl-1 as the full-length form of Mcl-1. Immunolabeling of the Mcl-1 protein reveals the early increase in Mcl-1 immunoreactivity in the nuclear region of the hair cells displaying apoptotic phenotypes and a subsequent increase in survival hair cells. These results suggest that Mcl-1 is involved in the regulation of hair cell pathogenesis resulting from acoustic stress, possibly by influencing the nuclear events of apoptosis.
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Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York 14214, USA.
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Syka J. The Fischer 344 rat as a model of presbycusis. Hear Res 2010; 264:70-8. [DOI: 10.1016/j.heares.2009.11.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/12/2009] [Accepted: 11/04/2009] [Indexed: 10/20/2022]
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Coling D, Chen S, Chi LH, Jamesdaniel S, Henderson D. Age-related changes in antioxidant enzymes related to hydrogen peroxide metabolism in rat inner ear. Neurosci Lett 2009; 464:22-5. [PMID: 19679169 DOI: 10.1016/j.neulet.2009.08.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 08/06/2009] [Accepted: 08/06/2009] [Indexed: 01/21/2023]
Abstract
Oxidative stress is a pervasive factor in aging and has been implicated in noise-induced cochlear pathology. In this study, we measured the activities of two enzymes that catalyze the removal of hydrogen peroxide (H(2)O(2)), catalase and glutathione peroxidase (Gpx), in 3- and 24-month-old Fisher-344 rats, and reduced and oxidized glutathione in 3-, 12-, and 24-month-old rats. There was an increase in Gpx activity in vascular tissue (spiral ligament and stria vascularis), but no change in modiolar, sensory or vestibular tissue of the cochlea. The elevation in vascular tissue was age-related. We observed a significant elevation of catalase activity in vestibular tissue, a tendency for age-related elevation in the modiolus, but no change in vascular or sensory cochlear tissue. These findings suggest that increased Gpx activity in vascular cochlear tissue may be an age-related compensation for a decrease in glutathione and a decline in the redox state measured by the ratio of reduced to oxidized glutathione.
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Affiliation(s)
- Donald Coling
- Center for Hearing and Deafness, University at Buffalo, UB South Campus, Buffalo, NY 14214, United States.
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Tanaka C, Bielefeld EC, Chen GD, Li M, Henderson D. Ameliorative effects of an augmented acoustic environment on age-related hearing loss in middle-aged Fischer 344/NHsd rats. Laryngoscope 2009; 119:1374-9. [PMID: 19418535 DOI: 10.1002/lary.20244] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVES/HYPOTHESIS To investigate the effects of an augmented acoustic environment (AAE) on age-related hearing loss (ARHL) and outer hair cell (OHC) pathology in middle-aged Fischer 344/NHsd (F344/NHsd) rats. METHODS Eleven F344/NHsd rats were divided into two groups: 1) the AAE group (n = 5), which was exposed to 4-20 kHz broadband noise at 80 dB SPL for 12 h/d, 5 d/wk for 13 weeks starting from 16 months of age; and 2) the control group (n = 6), which did not receive the AAE during the same time span. Auditory brainstem response thresholds were obtained at different time points, and OHC pathology was examined after 13 weeks of AAE using propidium iodide and antiprestin antibody staining. RESULTS The AAE-treated rats showed smaller mean threshold shifts (-1 to -3 dB) at 20-40 kHz than the control group (7.5-16.7 dB) at 13 weeks. No significant group differences were observed in the percentage of missing OHCs or abnormal OHC nuclei. However, examination of prestin in a pair of AAE and control rats revealed more uniform prestin staining intensity among OHCs in the AAE-treated cochlea than in the control cochlea. CONCLUSIONS Thirteen-week AAE treatment in the middle-aged F344/NHsd rats slowed progression of ARHL. The AAE did not show a significant effect on OHC degeneration, but it is speculated that the AAE may maintain the integrity of prestin to preserve OHC functionality. However, further study is warranted to understand the protective mechanism of AAE as an intervention against ARHL.
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Affiliation(s)
- Chiemi Tanaka
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA.
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