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Tan WJT, Vlajkovic SM. Molecular Characteristics of Cisplatin-Induced Ototoxicity and Therapeutic Interventions. Int J Mol Sci 2023; 24:16545. [PMID: 38003734 PMCID: PMC10671929 DOI: 10.3390/ijms242216545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
Cisplatin is a commonly used chemotherapeutic agent with proven efficacy in treating various malignancies, including testicular, ovarian, cervical, breast, bladder, head and neck, and lung cancer. Cisplatin is also used to treat tumors in children, such as neuroblastoma, osteosarcoma, and hepatoblastoma. However, its clinical use is limited by severe side effects, including ototoxicity, nephrotoxicity, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, and retinal toxicity. Cisplatin-induced ototoxicity manifests as irreversible, bilateral, high-frequency sensorineural hearing loss in 40-60% of adults and in up to 60% of children. Hearing loss can lead to social isolation, depression, and cognitive decline in adults, and speech and language developmental delays in children. Cisplatin causes hair cell death by forming DNA adducts, mitochondrial dysfunction, oxidative stress, and inflammation, culminating in programmed cell death by apoptosis, necroptosis, pyroptosis, or ferroptosis. Contemporary medical interventions for cisplatin ototoxicity are limited to prosthetic devices, such as hearing aids, but these have significant limitations because the cochlea remains damaged. Recently, the U.S. Food and Drug Administration (FDA) approved the first therapy, sodium thiosulfate, to prevent cisplatin-induced hearing loss in pediatric patients with localized, non-metastatic solid tumors. Other pharmacological treatments for cisplatin ototoxicity are in various stages of preclinical and clinical development. This narrative review aims to highlight the molecular mechanisms involved in cisplatin-induced ototoxicity, focusing on cochlear inflammation, and shed light on potential antioxidant and anti-inflammatory therapeutic interventions to prevent or mitigate the ototoxic effects of cisplatin. We conducted a comprehensive literature search (Google Scholar, PubMed) focusing on publications in the last five years.
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Affiliation(s)
- Winston J. T. Tan
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand;
- Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Srdjan M. Vlajkovic
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand;
- Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand
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Zhang C, Ye M, Bush P, Hu BH. Heterogeneity in macrophages along the cochlear spiral in mice: insights from SEM and functional analyses. Front Cell Neurosci 2023; 17:1222074. [PMID: 37692550 PMCID: PMC10485373 DOI: 10.3389/fncel.2023.1222074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
The susceptibility of sensory cells to pathological conditions differs between the apical and basal regions of the cochlea, and the cochlear immune system may contribute to this location-dependent variability. Our previous study found morphological differences in basilar membrane macrophages between the apical and basal regions of the cochlea. However, the details of this site-dependent difference and its underlying structural and biological basis are not fully understood. In this study, we utilized scanning electron microscopy to examine the ultrastructure of macrophages and their surrounding supporting structures. Additionally, we examined the phagocytic activities of macrophages and the expression of immune molecules in both apical and basal regions of the cochlea. We employed two mouse strains (C57BL/6J and B6.129P-Cx3cr1tm1Litt/J) and evaluated three experimental conditions: young normal (1-4 months), aging (11-19 months), and noise-induced damage (120 dB SPL for 1 h). Using scanning electron microscopy, we revealed location-specific differences in basilar membrane macrophage morphology and surface texture, architecture in mesothelial cell layers, and spatial correlation between macrophages and mesothelial cells in both young and older mice. Observations of macrophage phagocytic activities demonstrated that basal macrophages exhibited greater phagocytic activities in aging and noise-damaged ears. Furthermore, we identified differences in the expression of immune molecules between the apical and basal cochlear tissues of young mice. Finally, our study demonstrated that as the cochlea ages, macrophages in the apical and basal regions undergo a transformation in their morphologies, with apical macrophages acquiring certain basal macrophage features and vice versa. Overall, our findings demonstrate apical and basal differences in macrophage phenotypes and functionality, which are related to distinct immune and structural differences in the macrophage surrounding tissues.
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Affiliation(s)
- Celia Zhang
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
- Department of Audiology, University of the Pacific, San Francisco, CA, United States
| | - Mengxiao Ye
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
| | - Peter Bush
- South Campus Instrument Center, University at Buffalo, Buffalo, NY, United States
| | - Bo Hua Hu
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
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Tan WJT, Santos-Sacchi J, Tonello J, Shanker A, Ivanova AV. Pharmacological Modulation of Energy and Metabolic Pathways Protects Hearing in the Fus1/Tusc2 Knockout Model of Mitochondrial Dysfunction and Oxidative Stress. Antioxidants (Basel) 2023; 12:1225. [PMID: 37371955 DOI: 10.3390/antiox12061225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/23/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Tightly regulated and robust mitochondrial activities are critical for normal hearing. Previously, we demonstrated that Fus1/Tusc2 KO mice with mitochondrial dysfunction exhibit premature hearing loss. Molecular analysis of the cochlea revealed hyperactivation of the mTOR pathway, oxidative stress, and altered mitochondrial morphology and quantity, suggesting compromised energy sensing and production. Here, we investigated whether the pharmacological modulation of metabolic pathways using rapamycin (RAPA) or 2-deoxy-D-glucose (2-DG) supplementation can protect against hearing loss in female Fus1 KO mice. Additionally, we aimed to identify mitochondria- and Fus1/Tusc2-dependent molecular pathways and processes critical for hearing. We found that inhibiting mTOR or activating alternative mitochondrial energetic pathways to glycolysis protected hearing in the mice. Comparative gene expression analysis revealed the dysregulation of critical biological processes in the KO cochlea, including mitochondrial metabolism, neural and immune responses, and the cochlear hypothalamic-pituitary-adrenal axis signaling system. RAPA and 2-DG mostly normalized these processes, although some genes showed a drug-specific response or no response at all. Interestingly, both drugs resulted in a pronounced upregulation of critical hearing-related genes not altered in the non-treated KO cochlea, including cytoskeletal and motor proteins and calcium-linked transporters and voltage-gated channels. These findings suggest that the pharmacological modulation of mitochondrial metabolism and bioenergetics may restore and activate processes critical for hearing, thereby protecting against hearing loss.
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Affiliation(s)
- Winston J T Tan
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand
- Department of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT 06510, USA
| | - Joseph Santos-Sacchi
- Department of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT 06510, USA
| | - Jane Tonello
- School of Medicine, Meharry Medical College, Nashville, TN 37208, USA
| | - Anil Shanker
- School of Medicine, Meharry Medical College, Nashville, TN 37208, USA
| | - Alla V Ivanova
- School of Graduate Studies and Research, Meharry Medical College, Nashville, TN 37208, USA
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Tan WJT, Song L. Role of mitochondrial dysfunction and oxidative stress in sensorineural hearing loss. Hear Res 2023; 434:108783. [PMID: 37167889 DOI: 10.1016/j.heares.2023.108783] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 04/19/2023] [Accepted: 04/28/2023] [Indexed: 05/13/2023]
Abstract
Sensorineural hearing loss (SNHL) can either be genetically inherited or acquired as a result of aging, noise exposure, or ototoxic drugs. Although the precise pathophysiological mechanisms underlying SNHL remain unclear, an overwhelming body of evidence implicates mitochondrial dysfunction and oxidative stress playing a central etiological role. With its high metabolic demands, the cochlea, particularly the sensory hair cells, stria vascularis, and spiral ganglion neurons, is vulnerable to the damaging effects of mitochondrial reactive oxygen species (ROS). Mitochondrial dysfunction and consequent oxidative stress in cochlear cells can be caused by inherited mitochondrial DNA (mtDNA) mutations (hereditary hearing loss and aminoglycoside-induced ototoxicity), accumulation of acquired mtDNA mutations with age (age-related hearing loss), mitochondrial overdrive and calcium dysregulation (noise-induced hearing loss and cisplatin-induced ototoxicity), or accumulation of ototoxic drugs within hair cell mitochondria (drug-induced hearing loss). In this review, we provide an overview of our current knowledge on the role of mitochondrial dysfunction and oxidative stress in the development of SNHL caused by genetic mutations, aging, exposure to excessive noise, and ototoxic drugs. We also explore the advancements in antioxidant therapies for the different forms of acquired SNHL that are being evaluated in preclinical and clinical studies.
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Affiliation(s)
- Winston J T Tan
- Department of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT, 06510, USA; Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, 1023, New Zealand.
| | - Lei Song
- Department of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT, 06510, USA; Department of Otolaryngology - Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, 200125, China.
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Frosolini A, Franz L, Daloiso A, de Filippis C, Marioni G. Sudden Sensorineural Hearing Loss in the COVID-19 Pandemic: A Systematic Review and Meta-Analysis. Diagnostics (Basel) 2022; 12. [PMID: 36553146 DOI: 10.3390/diagnostics12123139] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Accumulating data indicate that patients with COVID-19 could be affected by sudden sensorineural hearing loss (SSNHL). The aim of the study was to analyze the epidemiological and clinical trend of SSNHL occurrence during the COVID-19 pandemic by applying a systematic review and meta-analysis approach. METHODS PubMed, Scopus, Web of Science, ScienceDirect, and Cochrane databases were searched. RESULTS The seven included studies had adequate relevance to the topic and the quality was fair. The mean age at SSNHL onset ranged from 39.23 to 62.18 years during the pandemic year period (PYP); a meta-analysis of four studies comparing these data with those of previous periods in the same institutions found a younger age during the PYP (pooled mean -0.2848). The heterogeneity was high (76.1935%) and no frank asymmetry was observed in the funnel plot. The SARS-CoV-2 positivity rate of SSNHL patients ranged from 0% to 57.53%. Standard steroid treatments were applied without significant adverse effects. Comprehensively, hearing improvement was achieved for more than half of the cases. No studies reported long-term follow-up data. CONCLUSIONS Further prospective analyses on large series and a long-term follow up on COVID-related SSNHL cases are necessary to address the open questions regarding the causative link between COVID-19 infection and SSNHL.
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Zahra G, Esmaeil K, Mohammad F, Rashidy-Pour A, Mahdi M, Mahdi A, Ali K. Combined effects of the exposure to silver nanoparticles and noise on hearing function and cochlea structure of the male rats. Life Sci 2022; 304:120724. [PMID: 35718234 DOI: 10.1016/j.lfs.2022.120724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/22/2022] [Accepted: 06/14/2022] [Indexed: 11/24/2022]
Abstract
AIMS This study intended to investigate whether exposure to the combination of noise and Ag-NPs in rats induces cochlear damage and hearing dysfunction. MAIN METHODS A total of 24Wistar rats were divided into four treatment groups and received/exposed to saline (IP), Ag-NPs (100 mg/kg, 5d/w for 4 weeks), 8 kHz narrowband noise (104 dB SPL, 6 h/day, 5d/w for 4 weeks) and Ag-NPs plus noise. The DPOAE, serum levels of MDA and SOD and changes in body weight were assessed. The rat cochlea was further stained for investigating the mRNA expression (TL-6, NOX3, and TNF-), IHC (TUJ-1 and MHC7), and histological alterations. The Ag-NPs characteristics were also analysed by SEM and XRD. KEY FINDINGS DPOAE values were remarkably reduced (p < 0.05) among the exposed groups. Furthermore, exposure to noise and Ag-NPs significantly increased MDA levels and decreased the SOD activity in the serum. In comparison to the control group, the expression of IL-6, TNF-, and NOX3 was shown to be elevated in the Ag-NPs plus noise group. The body weight also increased significantly in all groups with the exception of the Ag-NPs plus noise group. IHC tests showed remarkable down-regulation of TUJ1 and MYO7A. Morphological changes confirmed our findings as well. SEM and XRD data validated the production of Ag-NPs. SIGNIFICANCE According to the findings of this study, sub-acute exposure to noise and Ag-NPs causes permanent damage to the hair cells that are in charge of high-frequency perception.
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Affiliation(s)
- Goodarzi Zahra
- Department of Occupational Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Karami Esmaeil
- Department of Occupational Health Engineering, School of Health, Tehran University of medical sciences, Tehran, Iran
| | - Faridan Mohammad
- Environmental Health Research Center, Department of Occupational Health and Safety at Work Engineering, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Ali Rashidy-Pour
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Mohammadi Mahdi
- Health Promotion Research Center, Zahedan University of Medical Science, Zahedan, Iran
| | - Akbari Mahdi
- Audiology Department Rehabilitation Faculty, Iran University of Medical Science, Tehran, Iran
| | - Khavanin Ali
- Department of Occupational Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Fuentes-Santamaría V, Alvarado JC, Mellado S, Melgar-Rojas P, Gabaldón-Ull MC, Cabanes-Sanchis JJ, Juiz JM. Age-Related Inflammation and Oxidative Stress in the Cochlea Are Exacerbated by Long-Term, Short-Duration Noise Stimulation. Front Aging Neurosci 2022; 14:853320. [PMID: 35450058 PMCID: PMC9016828 DOI: 10.3389/fnagi.2022.853320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/14/2022] [Indexed: 12/29/2022] Open
Abstract
We have previously reported that young adult rats exposed to daily, short-duration noise for extended time periods, develop accelerated presbycusis starting at 6 months of age. Auditory aging is associated with progressive hearing loss, cell deterioration, dysregulation of the antioxidant defense system, and chronic inflammation, among others. To further characterize cellular and molecular mechanisms at the crossroads between noise and age-related hearing loss (ARHL), 3-month-old rats were exposed to a noise-accelerated presbycusis (NAP) protocol and tested at 6 and 16 months of age, using auditory brainstem responses, Real-Time Reverse Transcription-Quantitative PCR (RT-qPCR) and immunocytochemistry. Chronic noise-exposure leading to permanent auditory threshold shifts in 6-month-old rats, resulted in impaired sodium/potassium activity, degenerative changes in the lateral wall and spiral ganglion, increased lipid peroxidation, and sustained cochlear inflammation with advancing age. Additionally, at 6 months, noise-exposed rats showed significant increases in the gene expression of antioxidant enzymes (superoxide dismutase 1/2, glutathione peroxidase 1, and catalase) and inflammation-associated molecules [ionized calcium binding adaptor molecule 1, interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha]. The levels of IL-1β were upregulated in the spiral ganglion and spiral ligament, particularly in type IV fibrocytes; these cells showed decreased levels of connective tissue growth factor and increased levels of 4-hydroxynonenal. These data provide functional, structural and molecular evidence that age-noise interaction contributes to exacerbating presbycusis in young rats by leading to progressive dysfunction and early degeneration of cochlear cells and structures. These findings contribute to a better understanding of NAP etiopathogenesis, which is essential as it affects the life quality of young adults worldwide.
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Affiliation(s)
- Verónica Fuentes-Santamaría
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Juan Carlos Alvarado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Susana Mellado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Pedro Melgar-Rojas
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - María Cruz Gabaldón-Ull
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - José J. Cabanes-Sanchis
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - José M. Juiz
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Albacete, Spain
- Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
- Department of Otolaryngology, Hannover Medical School, NIFE-VIANNA, Cluster of Excellence Hearing4all-German Research Foundation, Hanover, Germany
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Celaya AM, Rodríguez-de la Rosa L, Bermúdez-Muñoz JM, Zubeldia JM, Romá-Mateo C, Avendaño C, Pallardó FV, Varela-Nieto I. IGF-1 Haploinsufficiency Causes Age-Related Chronic Cochlear Inflammation and Increases Noise-Induced Hearing Loss. Cells 2021; 10:cells10071686. [PMID: 34359856 PMCID: PMC8304185 DOI: 10.3390/cells10071686] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 12/18/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1+/- mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.
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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), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
| | - Jose M. Bermúdez-Muñoz
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
| | - José M. Zubeldia
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Allergy Service, Gregorio Marañon General University Hospital, 28009 Madrid, Spain
- Gregorio Marañon Health Research Institute (IiSGM), 28009 Madrid, Spain
| | - Carlos Romá-Mateo
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Spain and FIHCUV-INCLIVA, 46010 Valencia, Spain
| | - Carlos Avendaño
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Department of Anatomy, Histology & Neuroscience, Medical School, Autonomous University of Madrid, 28029 Madrid, Spain
| | - Federico V. Pallardó
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Spain and FIHCUV-INCLIVA, 46010 Valencia, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
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Alves de Sousa F, Pinto Costa R, Xará S, Nóbrega Pinto A, Almeida e Sousa C. SARS-CoV-2 and hearing: An audiometric analysis of COVID-19 hospitalized patients. J Otol 2021; 16:158-164. [PMID: 33558808 PMCID: PMC7857034 DOI: 10.1016/j.joto.2021.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/04/2021] [Accepted: 01/29/2021] [Indexed: 12/19/2022] Open
Abstract
PURPOSE COVID-19 associated hearing loss is still an ongoing matter of debate. No original studies exist on audiological effects of SARS-CoV-2 infection in hospitalized patients. The main objective was to determine whether SARS-CoV-2 may affect auditory function in clinically ill COVID-19 patients. MATERIALS AND METHODS COVID-19 patients with moderate-severe disease and without prior history of hearing abnormalities were enrolled from a tertiary referral center, and matched with controls. Participants performed an audiometric evaluation, and thresholds were compared. RESULTS 120 ears from 60 patients were enrolled. Patients with COVID-19 showed worse mean auditory thresholds starting from 1000 Hz through higher frequencies, when compared to controls (1000 Hz: 18.52 ± 5.49 dB HL in controls vs 25.36 ± 6.79 dB HL in COVID-19, p < 0.001; 2000Hz: 17.50 ± 5.57 dB HL in controls vs 21.96 ± 7.05 dB HL in COVID-19, p = 0.010; 3000Hz: 17.97 ± 8.07 dB HL in controls vs 25 ± 9.38 dB HL in COVID-19, p = 0.003; 4000 Hz: 20.16 ± 10.12 dB HL in controls vs 29.55 ± 11.26 dB HL in COVID-19, p = 0.001; 8000 Hz: 31.09 ± 12.75 dB HL in controls vs 40.71 ± 19.40 dB HL in COVID-19, p = 0.030; Pure Tone Average: 20.42 ± 4.29 dB HL in controls vs 24.85 ± 5.62 dB HL in COVID-19, p = 0.001). Statistical significance persisted after adjusting for confounders such as age, gender and various comorbidities (p < 0.05). CONCLUSIONS SARS-CoV-2 may affect hearing in COVID-19 patients with moderate-severe disease. Results are in line with the previous suggested effects of COVID-19 on auditory system. This study is expected to encourage further research on this topic.
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Affiliation(s)
- Francisco Alves de Sousa
- Centro Hospitalar Universitário do Porto, Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck surgery Department), Largo Prof. Abel Salazar, 4099-001, Porto, Portugal
| | - Rodrigo Pinto Costa
- Unidade de Saúde Familiar Garcia de Orta, ACeS Porto Ocidental, Medicina Geral e Familiar (Family Medicine), R. Pinho Leal 29, 4150-620, Porto, Portugal
| | - Sandra Xará
- Centro Hospitalar Universitário do Porto, Serviço de Doenças Infeciosas (Infectious Diseases Department), Largo Prof. Abel Salazar, 4099-001, Porto, Portugal
| | - Ana Nóbrega Pinto
- Centro Hospitalar Universitário do Porto, Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck surgery Department), Largo Prof. Abel Salazar, 4099-001, Porto, Portugal
| | - Cecília Almeida e Sousa
- Centro Hospitalar Universitário do Porto, Serviço de Otorrinolaringologia e Cirurgia da Cabeça e Pescoço (Otorhinolaryngology and Head & Neck surgery Department), Largo Prof. Abel Salazar, 4099-001, Porto, Portugal
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Li S, Zheng H, Xing Z, Liu Y, Han L, Wang Z, Yu L. The circadian timing of noise exposure influences noise-induced inflammatory responses in the mouse cochlea. Braz J Otorhinolaryngol 2021; 88 Suppl 3:S1-S8. [PMID: 34217678 DOI: 10.1016/j.bjorl.2021.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/06/2021] [Accepted: 05/12/2021] [Indexed: 12/01/2022] Open
Abstract
INTRODUCTION Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss. Nevertheless, the mechanisms of noise-induced hearing loss are still not fully understood. OBJECTIVE To investigate the dynamics of inflammatory responses in the mammalian cochlea following noise trauma at two different times, once during the light cycle and once during the dark. METHODS We challenged C57BL/6J mice with moderate, continuous noise trauma at either 9 a.m. or 9 p.m. Auditory function, histological changes in hair cells, and modifications in gene expression levels of inflammatory mediators were assessed at specific time points. Shifts in auditory brainstem response thresholds were measured at 1, 3, 7 and 14 days after noise exposure to measure potential noise-induced hearing loss. Cochlear basilar-membrane immunofluorescent staining was performed at 3 and 14 days after noise exposure. The mRNA levels of several inflammatory mediators were measured via quantitative real-time polymerase chain reaction before (pre) and after (0, 3, 12, 24 and 72 h) noise exposure. RESULTS We found that all noise-exposed mice developed a temporary threshold shift and that there were no significant differences between daytime and nighttime noise exposures in terms of inducing hearing-threshold shifts. Similarly, we did not detect significant histological changes in hair cells between these two groups. However, we discovered an interesting phenomenon in that the peak mRNA levels of IL-1β, IL-6, CCL2 and TNF-α were higher in day noise-exposed mice compared to those in night noise-exposed mice, and these mRNA levels subsided more slowly in day noise-exposed mice. CONCLUSION Overall, these observations suggest that the circadian timing of noise exposure has a significant effect on noise-induced inflammatory responses in the mouse cochlea and that a greater inflammatory response might occur after daytime exposure.
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Affiliation(s)
- Shichang Li
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Hongwei Zheng
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Zhimin Xing
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Yan Liu
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Lin Han
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Zijing Wang
- Bei Jing Ji Shui Tan Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China
| | - Lisheng Yu
- Peking University People's Hospital, Department of Otorhinolaryngology Head and Neck Surgery, Beijing, PR China.
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11
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Abstract
Neuroinflammation is the central nervous system's response to: injury, infection, and abnormal neural activity. Inflammatory processes are known to mediate many diseases, and recently evidence indicates that neuroinflammation underlies hearing disorders such as presbyacusis, middle-ear disease, ototoxicity, noise-induced hearing loss, and tinnitus. This chapter provides a review of the role of neuroinflammation in the etiology and treatment of tinnitus. Specifically, our research team has demonstrated that both tumor necrosis factor alpha (TNF-α) and calpain signaling pathways are involved in noise-induced tinnitus and that blocking them yielded therapeutic effects on tinnitus. Other efforts such as controlling acute inflammatory response via specialized pro-resolving mediators may help provide insight into preventing and treating tinnitus-related inflammatory processes.
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Affiliation(s)
- Abraham Shulman
- Department of Otolaryngology, State University New York-Downstate, Brooklyn, NY, USA.
| | - Weihua Wang
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Hao Luo
- Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Shaowen Bao
- Department of Physiology, University of Arizona, Tucson, AZ, USA
| | - Grant Searchfield
- Section of Audiology, School of Population Health, University of Auckland, Auckland, New Zealand
| | - Jinsheng Zhang
- Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI, USA.,Department of Communication Sciences and Disorders, Wayne State University College of Liberal Arts and Sciences, Detroit, MI, USA
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Peeleman N, Verdoodt D, Ponsaerts P, Van Rompaey V. On the Role of Fibrocytes and the Extracellular Matrix in the Physiology and Pathophysiology of the Spiral Ligament. Front Neurol 2020; 11:580639. [PMID: 33193034 PMCID: PMC7653186 DOI: 10.3389/fneur.2020.580639] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/10/2020] [Indexed: 12/19/2022] Open
Abstract
The spiral ligament in the cochlea has been suggested to play a significant role in the pathophysiology of different etiologies of strial hearing loss. Spiral ligament fibrocytes (SLFs), the main cell type in the lateral wall, are crucial in maintaining the endocochlear potential and regulating blood flow. SLF dysfunction can therefore cause cochlear dysfunction and thus hearing impairment. Recent studies have highlighted the role of SLFs in the immune response of the cochlea. In contrast to sensory cells in the inner ear, SLFs (more specifically type III fibrocytes) have also demonstrated the ability to regenerate after different types of trauma such as drug toxicity and noise. SLFs are responsible for producing proteins, such as collagen and cochlin, that create an adequate extracellular matrix to thrive in. Any dysfunction of SLFs or structural changes to the extracellular matrix can significantly impact hearing function. However, SLFs may prove useful in restoring hearing by their potential to regenerate cells in the spiral ligament.
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Affiliation(s)
- Noa Peeleman
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Dorien Verdoodt
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - Peter Ponsaerts
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium
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13
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Szepesy J, Miklós G, Farkas J, Kucsera D, Giricz Z, Gáborján A, Polony G, Szirmai Á, Tamás L, Köles L, Varga ZV, Zelles T. Anti-PD-1 Therapy Does Not Influence Hearing Ability in the Most Sensitive Frequency Range, but Mitigates Outer Hair Cell Loss in the Basal Cochlear Region. Int J Mol Sci 2020; 21:ijms21186701. [PMID: 32933159 PMCID: PMC7555949 DOI: 10.3390/ijms21186701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
The administration of immune checkpoint inhibitors (ICIs) often leads to immune-related adverse events. However, their effect on auditory function is largely unexplored. Thorough preclinical studies have not been published yet, only sporadic cases and pharmacovigilance reports suggest their significance. Here we investigated the effect of anti-PD-1 antibody treatment (4 weeks, intraperitoneally, 200 μg/mouse, 3 times/week) on hearing function and cochlear morphology in C57BL/6J mice. ICI treatment did not influence the hearing thresholds in click or tone burst stimuli at 4–32 kHz frequencies measured by auditory brainstem response. The number and morphology of spiral ganglion neurons were unaltered in all cochlear turns. The apical-middle turns (<32 kHz) showed preservation of the inner and outer hair cells (OHCs), whilst ICI treatment mitigated the age-related loss of OHCs in the basal turn (>32 kHz). The number of Iba1-positive macrophages has also increased moderately in this high frequency region. We conclude that a 4-week long ICI treatment does not affect functional and morphological integrity of the inner ear in the most relevant hearing range (4–32 kHz; apical-middle turns), but a noticeable preservation of OHCs and an increase in macrophage activity appeared in the >32 kHz basal part of the cochlea.
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Affiliation(s)
- Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gabriella Miklós
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - János Farkas
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Dániel Kucsera
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Pharmahungary Group, H-6722 Szeged, Hungary
| | - Anita Gáborján
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gábor Polony
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Ágnes Szirmai
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Tamás
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Zoltán V. Varga
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Pharmacology, Institute of Experimental Medicine, H-1083 Budapest, Hungary
- Correspondence: ; Tel.: +36-1-210-4416/56297; Fax: +36-1-210-4412
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Reynolds R, Garner A, Norton J. Sound and Vibration as Research Variables in Terrestrial Vertebrate Models. ILAR J 2020; 60:159-174. [PMID: 32602530 DOI: 10.1093/ilar/ilaa004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 12/31/2022] Open
Abstract
Sound and vibration have been shown to alter animal behavior and induce physiological changes as well as to cause effects at the cellular and molecular level. For these reasons, both environmental factors have a considerable potential to alter research outcomes when the outcome of the study is dependent on the animal existing in a normal or predictable biological state. Determining the specific levels of sound or vibration that will alter research is complex, as species will respond to different frequencies and have varying frequencies where they are most sensitive. In consideration of the potential of these factors to alter research, a thorough review of the literature and the conditions that likely exist in the research facility should occur specific to each research study. This review will summarize the fundamental physical properties of sound and vibration in relation to deriving maximal level standards, consider the sources of exposure, review the effects on animals, and discuss means by which the adverse effects of these factors can be mitigated.
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Affiliation(s)
- Randall Reynolds
- Duke University School of Medicine, Department of Pathology and Division of Laboratory Animal Resources, Durham, NC
| | - Angela Garner
- Duke University School of Medicine, Division of Laboratory Animal Resources, Durham, NC
| | - John Norton
- Duke University School of Medicine, Pathology and Division of Laboratory Animal Resources
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15
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Sahley TL, Anderson DJ, Hammonds MD, Chandu K, Musiek FE. Evidence for a dynorphin-mediated inner ear immune/inflammatory response and glutamate-induced neural excitotoxicity: an updated analysis. J Neurophysiol 2019; 122:1421-1460. [DOI: 10.1152/jn.00595.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acoustic overstimulation (AOS) is defined as the stressful overexposure to high-intensity sounds. AOS is a precipitating factor that leads to a glutamate (GLU)-induced Type I auditory neural excitotoxicity and an activation of an immune/inflammatory/oxidative stress response within the inner ear, often resulting in cochlear hearing loss. The dendrites of the Type I auditory neural neurons that innervate the inner hair cells (IHCs), and respond to the IHC release of the excitatory neurotransmitter GLU, are themselves directly innervated by the dynorphin (DYN)-bearing axon terminals of the descending brain stem lateral olivocochlear (LOC) system. DYNs are known to increase GLU availability, potentiate GLU excitotoxicity, and induce superoxide production. DYNs also increase the production of proinflammatory cytokines by modulating immune/inflammatory signal transduction pathways. Evidence is provided supporting the possibility that the GLU-mediated Type I auditory neural dendritic swelling, inflammation, excitotoxicity, and cochlear hearing loss that follow AOS may be part of a brain stem-activated, DYN-mediated cascade of inflammatory events subsequent to a LOC release of DYNs into the cochlea. In support of a DYN-mediated cascade of events are established investigations linking DYNs to the immune/inflammatory/excitotoxic response in other neural systems.
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Affiliation(s)
- Tony L. Sahley
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, Ohio
- School of Health Sciences, Cleveland State University, Cleveland, Ohio
| | - David J. Anderson
- Department of Chemistry, Cleveland State University, Cleveland, Ohio
| | | | - Karthik Chandu
- Department of Chemistry, Cleveland State University, Cleveland, Ohio
| | - Frank E. Musiek
- Department of Speech, Language, and Hearing Sciences, University of Arizona, Tucson, Arizona
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16
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Köles L, Szepesy J, Berekméri E, Zelles T. Purinergic Signaling and Cochlear Injury-Targeting the Immune System? Int J Mol Sci 2019; 20:ijms20122979. [PMID: 31216722 PMCID: PMC6627352 DOI: 10.3390/ijms20122979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 02/06/2023] Open
Abstract
Hearing impairment is the most common sensory deficit, affecting more than 400 million people worldwide. Sensorineural hearing losses currently lack any specific or efficient pharmacotherapy largely due to the insufficient knowledge of the pathomechanism. Purinergic signaling plays a substantial role in cochlear (patho)physiology. P2 (ionotropic P2X and the metabotropic P2Y) as well as adenosine receptors expressed on cochlear sensory and non-sensory cells are involved mostly in protective mechanisms of the cochlea. They are implicated in the sensitivity adjustment of the receptor cells by a K+ shunt and can attenuate the cochlear amplification by modifying cochlear micromechanics. Cochlear blood flow is also regulated by purines. Here, we propose to comprehend this field with the purine-immune interactions in the cochlea. The role of harmful immune mechanisms in sensorineural hearing losses has been emerging in the horizon of cochlear pathologies. In addition to decreasing hearing sensitivity and increasing cochlear blood supply, influencing the immune system can be the additional avenue for pharmacological targeting of purinergic signaling in the cochlea. Elucidating this complexity of purinergic effects on cochlear functions is necessary and it can result in development of new therapeutic approaches in hearing disabilities, especially in the noise-induced ones.
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Eszter Berekméri
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Ecology, University of Veterinary Medicine, H-1078 Budapest, Hungary.
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary.
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17
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Abbas L, Rivolta MN. The use of animal models to study cell transplantation in neuropathic hearing loss. Hear Res 2019; 377:72-87. [DOI: 10.1016/j.heares.2019.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 01/29/2023]
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Abstract
The cochlea has an immune environment dominated by macrophages under resting conditions. When stressed, circulating monocytes enter the cochlea. These immune mediators, along with cochlear resident cells, organize a complex defense response against pathological challenges. Since the cochlea has minimal exposure to pathogens, most inflammatory conditions in the cochlea are sterile. Although the immune response is initiated for the protection of the cochlea, off-target effects can cause collateral damage to cochlear cells. A better understanding of cochlear immune capacity and regulation would therefore lead to development of new therapeutic treatments. Over the past decade, there have been many advances in our understanding of cochlear immune capacity. In this review, we provide an update and overview of the cellular components of cochlear immune capacity with a focus on macrophages in mammalian cochleae. We describe the composition and distribution of immune cells in the cochlea and suggest that phenotypic and functional characteristics of macrophages have site-specific diversity. We also highlight the response of immune cells to acute and chronic stresses and comment on the potential function of immune cells in cochlear homeostasis and disease development. Finally, we briefly review potential roles for cochlear resident cells in immune activities of the cochlea.
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Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | - Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | - Mitchell D Frye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
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19
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Ghezzi P, Floridi L, Boraschi D, Cuadrado A, Manda G, Levic S, D'Acquisto F, Hamilton A, Athersuch TJ, Selley L. Oxidative Stress and Inflammation Induced by Environmental and Psychological Stressors: A Biomarker Perspective. Antioxid Redox Signal 2018; 28:852-872. [PMID: 28494612 DOI: 10.1089/ars.2017.7147] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE The environment can elicit biological responses such as oxidative stress (OS) and inflammation as a consequence of chemical, physical, or psychological changes. As population studies are essential for establishing these environment-organism interactions, biomarkers of OS or inflammation are critical in formulating mechanistic hypotheses. Recent Advances: By using examples of stress induced by various mechanisms, we focus on the biomarkers that have been used to assess OS and inflammation in these conditions. We discuss the difference between biomarkers that are the result of a chemical reaction (such as lipid peroxides or oxidized proteins that are a result of the reaction of molecules with reactive oxygen species) and those that represent the biological response to stress, such as the transcription factor NRF2 or inflammation and inflammatory cytokines. CRITICAL ISSUES The high-throughput and holistic approaches to biomarker discovery used extensively in large-scale molecular epidemiological exposome are also discussed in the context of human exposure to environmental stressors. FUTURE DIRECTIONS We propose to consider the role of biomarkers as signs and to distinguish between signs that are just indicators of biological processes and proxies that one can interact with and modify the disease process. Antioxid. Redox Signal. 28, 852-872.
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Affiliation(s)
- Pietro Ghezzi
- 1 Brighton & Sussex Medical School , Brighton, United Kingdom
| | - Luciano Floridi
- 2 Oxford Internet Institute, University of Oxford , Oxford, United Kingdom .,3 Alan Turing Institute , London, United Kingdom
| | - Diana Boraschi
- 4 Institute of Protein Biochemistry , National Research Council, Napoli, Italy
| | - Antonio Cuadrado
- 5 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Investigación Sanitaria La Paz (IdiPaz), Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC , Madrid, Spain .,6 Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid , Madrid, Spain
| | - Gina Manda
- 7 "Victor Babes" National Institute of Pathology , Bucharest, Romania
| | - Snezana Levic
- 1 Brighton & Sussex Medical School , Brighton, United Kingdom
| | - Fulvio D'Acquisto
- 8 William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London , London, United Kingdom
| | - Alice Hamilton
- 8 William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London , London, United Kingdom
| | - Toby J Athersuch
- 9 Department of Surgery and Cancer, Faculty of Medicine, and MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London , London, United Kingdom
| | - Liza Selley
- 9 Department of Surgery and Cancer, Faculty of Medicine, and MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London , London, United Kingdom
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20
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Fuentes-Santamaría V, Alvarado JC, Melgar-Rojas P, Gabaldón-Ull MC, Miller JM, Juiz JM. The Role of Glia in the Peripheral and Central Auditory System Following Noise Overexposure: Contribution of TNF-α and IL-1β to the Pathogenesis of Hearing Loss. Front Neuroanat 2017; 11:9. [PMID: 28280462 PMCID: PMC5322242 DOI: 10.3389/fnana.2017.00009] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/09/2017] [Indexed: 12/12/2022] Open
Abstract
Repeated noise exposure induces inflammation and cellular adaptations in the peripheral and central auditory system resulting in pathophysiology of hearing loss. In this study, we analyzed the mechanisms by which noise-induced inflammatory-related events in the cochlea activate glial-mediated cellular responses in the cochlear nucleus (CN), the first relay station of the auditory pathway. The auditory function, glial activation, modifications in gene expression and protein levels of inflammatory mediators and ultrastructural changes in glial-neuronal interactions were assessed in rats exposed to broadband noise (0.5-32 kHz, 118 dB SPL) for 4 h/day during 4 consecutive days to induce long-lasting hearing damage. Noise-exposed rats developed a permanent threshold shift which was associated with hair cell loss and reactive glia. Noise-induced microglial activation peaked in the cochlea between 1 and 10D post-lesion; their activation in the CN was more prolonged reaching maximum levels at 30D post-exposure. RT-PCR analyses of inflammatory-related genes expression in the cochlea demonstrated significant increases in the mRNA expression levels of pro- and anti-inflammatory cytokines, inducible nitric oxide synthase, intercellular adhesion molecule and tissue inhibitor of metalloproteinase-1 at 1 and 10D post-exposure. In noise-exposed cochleae, interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) were upregulated by reactive microglia, fibrocytes, and neurons at all time points examined. In the CN, however, neurons were the sole source of these cytokines. These observations suggest that noise exposure causes peripheral and central inflammatory reactions in which TNF-α and IL-1β are implicated in regulating the initiation and progression of noise-induced hearing loss.
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Affiliation(s)
- Verónica Fuentes-Santamaría
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Juan Carlos Alvarado
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Pedro Melgar-Rojas
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - María C Gabaldón-Ull
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
| | - Josef M Miller
- Center for Hearing and Communication Research and Department of Clinical Neuroscience, Karolinska InstitutetStockholm, Sweden; Kresge Hearing Research Institute, University of MichiganAnn Arbor, MI, USA
| | - José M Juiz
- Instituto de Investigación en Discapacidades NeurológicasAlbacete, Spain; Facultad de Medicina, Universidad de Castilla-La ManchaAlbacete, Spain
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21
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Vethanayagam RR, Yang W, Dong Y, Hu BH. Toll-like receptor 4 modulates the cochlear immune response to acoustic injury. Cell Death Dis 2016; 7:e2245. [PMID: 27253409 PMCID: PMC5143385 DOI: 10.1038/cddis.2016.156] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 12/13/2022]
Abstract
Acoustic overstimulation traumatizes the cochlea, resulting in auditory dysfunction. As a consequence of acoustic injury, the immune system in the cochlea is activated, leading to the production of inflammatory mediators and the infiltration of immune cells. However, the molecular mechanisms responsible for initiating these immune responses remain unclear. Here, we investigate the functional role of Toll-like receptor 4 (Tlr4), a cellular receptor that activates the innate immune system, in the regulation of cochlear responses to acoustic overstimulation. Using a Tlr4 knockout mouse model, we examined how Tlr4 deficiency affects sensory cell pathogenesis, auditory dysfunction and cochlear immune activity. We demonstrate that Tlr4 knockout does not affect sensory cell viability under physiological conditions, but reduces the level of sensory cell damage and cochlear dysfunction after acoustic injury. Together, these findings suggest that Tlr4 promotes sensory cell degeneration and cochlear dysfunction after acoustic injury. Acoustic injury provokes a site-dependent inflammatory response in both the organ of Corti and the tissues of the lateral wall and basilar membrane. Tlr4 deficiency affects these inflammatory responses in a site-dependent manner. In the organ of Corti, loss of Tlr4 function suppresses the production of interleukin 6 (Il6), a pro-inflammatory molecule, after acoustic injury. By contrast, the production of inflammatory mediators, including Il6, persists in the lateral wall and basilar membrane. In addition to immune molecules, Tlr4 knockout inhibits the expression of major histocompatibility complex class II, an antigen-presenting molecule, in macrophages, suggesting that Tlr4 participates in the antigen-presenting function of macrophages after acoustic trauma. Together, these results suggest that Tlr4 regulates multiple aspects of the immune response in the cochlea and contributes to cochlear pathogenesis after acoustic injury.
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Affiliation(s)
- R R Vethanayagam
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - W Yang
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Y Dong
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - B H Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
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Tan WJ, Thorne PR, Vlajkovic SM. Characterisation of cochlear inflammation in mice following acute and chronic noise exposure. Histochem Cell Biol 2016; 146:219-30. [PMID: 27109494 DOI: 10.1007/s00418-016-1436-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 12/17/2022]
Abstract
Oxidative stress has been established as the key mechanism of the cochlear damage underlying noise-induced hearing loss, however, emerging evidence suggests that cochlear inflammation may also be a major contributor. This study aimed to improve our understanding of the cochlear inflammatory response associated with acute and chronic noise exposure. C57BL/6 mice were exposed to acute traumatic noise (100 dBSPL, 8-16 kHz for 24 h) and their cochleae collected at various intervals thereafter, up to 7 days. Using quantitative RT-PCR and immunohistochemistry, changes in expression levels of proinflammatory cytokines (TNF-α, IL-1β), chemokines (CCL2) and cell adhesion molecules (ICAM-1) were studied. All gene transcripts displayed similar dynamics of expression, with an early upregulation at 6 h post-exposure, followed by a second peak at 7 days. ICAM-1 immunoexpression increased significantly in the inferior region of the spiral ligament, peaking 24 h post-exposure. The early expression of proinflammatory mediators likely mediates the recruitment and extravasation of inflammatory cells into the noise-exposed cochlea. The occurrence of the latter expression peak is not clear, but it may be associated with reparative processes initiated in response to cochlear damage. Chronic exposure to moderate noise (90 dBSPL, 8-16 kHz, 2 h/day, up to 4 weeks) also elicited an inflammatory response, reaching a maximum after 2 weeks, suggesting that cochlear damage and hearing loss associated with chronic environmental noise exposure may be linked to inflammatory processes in the cochlea. This study thus provides further insight into the dynamics of the cochlear inflammatory response induced by exposure to acute and chronic noise.
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Tang PC, Watson GM. Proteomic identification of hair cell repair proteins in the model sea anemone Nematostella vectensis. Hear Res 2015; 327:245-56. [PMID: 26183436 DOI: 10.1016/j.heares.2015.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 06/15/2015] [Accepted: 07/09/2015] [Indexed: 12/26/2022]
Abstract
Sea anemones have an extraordinary capability to repair damaged hair bundles, even after severe trauma. A group of secreted proteins, named repair proteins (RPs), found in mucus covering sea anemones significantly assists the repair of damaged hair bundle mechanoreceptors both in the sea anemone Haliplanella luciae and the blind cavefish Astyanax hubbsi. The polypeptide constituents of RPs must be identified in order to gain insight into the molecular mechanisms by which repair of hair bundles is accomplished. In this study, several polypeptides of RPs were isolated from mucus using blue native PAGE and then sequenced using LC-MS/MS. Thirty-seven known polypeptides were identified, including Hsp70s, as well as many polypeptide subunits of the 20S proteasome. Other identified polypeptides included those involved in cellular stress responses, protein folding, and protein degradation. Specific inhibitors of Hsp70s and the 20S proteasome were employed in experiments to test their involvement in hair bundle repair. The results of those experiments suggested that repair requires biologically active Hsp70s and 20S proteasomes. A model is proposed that considers the function of extracellular Hsp70s and 20S proteasomes in the repair of damaged hair cells.
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Affiliation(s)
- Pei-Ciao Tang
- Department of Biology, University of Louisiana Lafayette, USA
| | - Glen M Watson
- Department of Biology, University of Louisiana Lafayette, USA.
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Urrutia RA, Kalinec F. Biology and pathobiology of lipid droplets and their potential role in the protection of the organ of Corti. Hear Res 2015; 330:26-38. [PMID: 25987503 DOI: 10.1016/j.heares.2015.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/17/2015] [Accepted: 04/21/2015] [Indexed: 12/20/2022]
Abstract
The current review article seeks to extend our understanding on the role of lipid droplets within the organ of Corti. In addition to presenting an overview of the current information about the origin, structure and function of lipid droplets we draw inferences from the collective body of knowledge about this cellular organelle to build a conceptual framework to better understanding their role in auditory function. This conceptual model considers that lipid droplets play a significant role in the synthesis, storage, and release of lipids and proteins for energetic use and/or modulating cell signaling pathways. We describe the role and mechanism by which LD play a role in human diseases, and we also review emerging data from our laboratory revealing the potential role of lipid droplets from Hensen cells in the auditory organ. We suggest that lipid droplets might help to develop rapidly and efficiently the resolution phase of inflammatory responses in the mammalian cochlea, preventing inflammatory damage of the delicate inner ear structures and, consequently, sensorineural hearing loss.
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Affiliation(s)
- Raul A Urrutia
- Epigenetics and Chromatin Dynamics Laboratory, Translational Epigenomic Program, Center for Individualized Medicine (CIM) Mayo Clinic, Rochester, MN 55905, USA
| | - Federico Kalinec
- Laboratory of Auditory Cell Biology, Department of Head & Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Murillo-Cuesta S, Rodríguez-de la Rosa L, Contreras J, Celaya AM, Camarero G, Rivera T, Varela-Nieto I. Transforming growth factor β1 inhibition protects from noise-induced hearing loss. Front Aging Neurosci 2015; 7:32. [PMID: 25852546 PMCID: PMC4367183 DOI: 10.3389/fnagi.2015.00032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/28/2015] [Indexed: 12/20/2022] Open
Abstract
Excessive exposure to noise damages the principal cochlear structures leading to hearing impairment. Inflammatory and immune responses are central mechanisms in cochlear defensive response to noise but, if unregulated, they contribute to inner ear damage and hearing loss. Transforming growth factor β (TGF-β) is a key regulator of both responses and high levels of this factor have been associated with cochlear injury in hearing loss animal models. To evaluate the potential of targeting TGF-β as a therapeutic strategy for preventing or ameliorating noise-induced hearing loss (NIHL), we studied the auditory function, cochlear morphology, gene expression and oxidative stress markers in mice exposed to noise and treated with TGF-β1 peptidic inhibitors P17 and P144, just before or immediately after noise insult. Our results indicate that systemic administration of both peptides significantly improved both the evolution of hearing thresholds and the degenerative changes induced by noise-exposure in lateral wall structures. Moreover, treatments ameliorated the inflammatory state and redox balance. These therapeutic effects were dose-dependent and more effective if the TGF-β1 inhibitors were administered prior to inducing the injury. In conclusion, inhibition of TGF-β1 actions with antagonistic peptides represents a new, promising therapeutic strategy for the prevention and repair of noise-induced cochlear damage.
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Affiliation(s)
- 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 (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) 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 (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Julio Contreras
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Veterinary Faculty, Complutense University of Madrid Madrid, Spain
| | - 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 (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain
| | - Guadalupe Camarero
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
| | - Teresa Rivera
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM) Madrid, Spain ; Centre for Biomedical Network Research (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Príncipe de Asturias University Hospital, University of Alcalá, Alcalá de Henares 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 (CIBER), Institute of Health Carlos III (ISCIII) Madrid, Spain ; Hospital La Paz Institute for Health Research (IdiPAZ) Madrid, Spain
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Cai Q, Vethanayagam RR, Yang S, Bard J, Jamison J, Cartwright D, Dong Y, Hu BH. Molecular profile of cochlear immunity in the resident cells of the organ of Corti. J Neuroinflammation 2014; 11:173. [PMID: 25311735 PMCID: PMC4198756 DOI: 10.1186/s12974-014-0173-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/25/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The cochlea is the sensory organ of hearing. In the cochlea, the organ of Corti houses sensory cells that are susceptible to pathological insults. While the organ of Corti lacks immune cells, it does have the capacity for immune activity. We hypothesized that resident cells in the organ of Corti were responsible for the stress-induced immune response of the organ of Corti. This study profiled the molecular composition of the immune system in the organ of Corti and examined the immune response of non-immune epithelial cells to acoustic overstimulation. METHODS Using high-throughput RNA-sequencing and qRT-PCR arrays, we identified immune- and inflammation-related genes in both the cochlear sensory epithelium and the organ of Corti. Using bioinformatics analyses, we cataloged the immune genes expressed. We then examined the response of these genes to acoustic overstimulation and determined how changes in immune gene expression were related to sensory cell damage. RESULTS The RNA-sequencing analysis reveals robust expression of immune-related genes in the cochlear sensory epithelium. The qRT-PCR array analysis confirms that many of these genes are constitutively expressed in the resident cells of the organ of Corti. Bioinformatics analyses reveal that the genes expressed are linked to the Toll-like receptor signaling pathway. We demonstrate that expression of Toll-like receptor signaling genes is predominantly from the supporting cells in the organ of Corti cells. Importantly, our data demonstrate that these Toll-like receptor pathway genes are able to respond to acoustic trauma and that their expression changes are associated with sensory cell damage. CONCLUSION The cochlear resident cells in the organ of Corti have immune capacity and participate in the cochlear immune response to acoustic overstimulation.
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Affiliation(s)
| | | | | | | | | | | | | | - Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo 14214, NY, USA.
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Suckfuell M, Lisowska G, Domka W, Kabacinska A, Morawski K, Bodlaj R, Klimak P, Kostrica R, Meyer T. Efficacy and Safety of AM-111 in the Treatment of Acute Sensorineural Hearing Loss: A Double-Blind, Randomized, Placebo-Controlled Phase II Study. Otol Neurotol 2014; 35:1317-26. [DOI: 10.1097/mao.0000000000000466] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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