1
|
Chan J, Telang R, Kociszewska D, Thorne PR, Vlajkovic SM. A High-Fat Diet Induces Low-Grade Cochlear Inflammation in CD-1 Mice. Int J Mol Sci 2022; 23:ijms23095179. [PMID: 35563572 PMCID: PMC9101486 DOI: 10.3390/ijms23095179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023] Open
Abstract
There is growing evidence for a relationship between gut dysbiosis and hearing loss. Inflammatory bowel disease, diet-induced obesity (DIO), and type 2 diabetes have all been linked to hearing loss. Here, we investigated the effect of a chronic high-fat diet (HFD) on the development of inner ear inflammation using a rodent model. Three-week-old CD-1 (Swiss) mice were fed an HFD or a control diet for ten weeks. After ten weeks, mouse cochleae were harvested, and markers of cochlear inflammation were assessed at the protein level using immunohistochemistry and at the gene expression level using quantitative real-time RT-PCR. We identified increased immunoexpression of pro-inflammatory biomarkers in animals on an HFD, including intracellular adhesion molecule 1 (ICAM1), interleukin 6 receptor α (IL6Rα), and toll-like-receptor 2 (TLR2). In addition, increased numbers of ionized calcium-binding adapter molecule 1 (Iba1) positive macrophages were found in the cochlear lateral wall in mice on an HFD. In contrast, gene expression levels of inflammatory markers were not affected by an HFD. The recruitment of macrophages to the cochlea and increased immunoexpression of inflammatory markers in mice fed an HFD provide direct evidence for the association between HFD and cochlear inflammation.
Collapse
|
2
|
Ríos JD, Hughes CK, Lally J, Wienandt N, Esquivel C, Serhan CN, Weitzel EK. Neuroprotectin D1 Attenuates Blast Overpressure Induced Reactive Microglial Cells in the Cochlea. Laryngoscope 2021; 131:E2018-E2025. [PMID: 33427310 DOI: 10.1002/lary.29337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVE/HYPOTHESIS We examined a neuroinflammatory response associated with glial activation in the cochlea exposed to blast overpressure and evaluated the potential therapeutic efficacy of specialized pro-resolving mediators such as neuroprotectin D1, NPD1; (10R, 17S-dihydroxy-4Z, 7Z, 11E, 13E, 15Z, 19Z-docosahexaenoic acid) in a rodent blast-induced auditory injury model. STUDY DESIGN Animal Research. METHODS A compressed-air driven shock tube was used to expose anesthetized adult male Long-Evan rats to shock waves simulating an open-field blast exposure. Approximately 30 minutes after blast exposure, rats were treated with NPD1 (100 ng/kg body wt.) or vehicle delivered intravenously via tail vein injection. Rats were then euthanized 48 hours after blast exposure. Unexposed rats were included as controls. Tissue sections containing both middle and inner ear were prepared with hematoxylin-eosin staining to elucidate histopathological changes associated with blast exposure. Cochlear tissues were evaluated for relative expression of ionized calcium-binding adaptor 1 (Iba1), as an indicator of microglial activation by immunohistochemistry and western blot analyses. RESULTS Our animal model resulted in an acute injury mechanism manifested by damage to the tympanic membrane, hemorrhage, infiltration of inflammatory cells, and increased expression of Iba1 protein. Moreover, therapeutic intervention with NPD1 significantly reduced Iba1 expression in the cochlea, suggesting a reduction of a neuroinflammatory response caused by blast overpressure. CONCLUSIONS Blast overpressure resulted in an increased expression of proteins involved in gliosis within the auditory system, which were reduced by NPD1. Treatment of NPD1 suggests an effective strategy to reduce or halt auditory microglial cell activation due to primary blast exposure. LEVEL OF EVIDENCE NA Laryngoscope, 131:E2018-E2025, 2021.
Collapse
Affiliation(s)
- José David Ríos
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Charlotte K Hughes
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - John Lally
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Nathan Wienandt
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Carlos Esquivel
- Department of Defense (DoD) Hearing Center of Excellence, Defense Health Agency, Joint Base San Antonio-Lackland, San Antonio, Texas, U.S.A
| | - Charles N Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital and Department of Anesthesia, Perioperative and Pain Medicine, Harvard Medical School, Boston, Massachusetts, U.S.A
| | - Erik K Weitzel
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A.,Department of Defense (DoD) Hearing Center of Excellence, Defense Health Agency, Joint Base San Antonio-Lackland, San Antonio, Texas, U.S.A
| |
Collapse
|
3
|
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] [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.
Collapse
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
| |
Collapse
|
4
|
The Effect of Systemic Steroid on Hearing Preservation After Cochlear Implantation via Round Window Approach: A Guinea Pig Model. Otol Neurotol 2017; 38:962-969. [DOI: 10.1097/mao.0000000000001453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
5
|
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] [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.
Collapse
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
| |
Collapse
|
6
|
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: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [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.
Collapse
|
7
|
Trune DR, Kempton B, Hausman FA, Larrain BE, MacArthur CJ. Correlative mRNA and protein expression of middle and inner ear inflammatory cytokines during mouse acute otitis media. Hear Res 2015; 326:49-58. [PMID: 25922207 DOI: 10.1016/j.heares.2015.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/23/2015] [Accepted: 04/16/2015] [Indexed: 12/20/2022]
Abstract
Although the inner ear has long been reported to be susceptible to middle ear disease, little is known of the inflammatory mechanisms that might cause permanent sensorineural hearing loss. Recent studies have shown inner ear tissues are capable of expressing inflammatory cytokines during otitis media. However, little quantitative information is available concerning cytokine gene expression in the inner ear and the protein products that result. Therefore, this study was conducted of mouse middle and inner ear during acute otitis media to measure the relationship between inflammatory cytokine genes and their protein products with quantitative RT-PCR and ELISA, respectively. Balb/c mice were inoculated transtympanically with heat-killed Haemophilus influenzae and middle and inner ear tissues collected for either quantitative RT-PCR microarrays or ELISA multiplex arrays. mRNA for several cytokine genes was significantly increased in both the middle and inner ear at 6 h. In the inner ear, these included MIP-2 (448 fold), IL-6 (126 fold), IL-1β (7.8 fold), IL-10 (10.7 fold), TNFα (1.8 fold), and IL-1α (1.5 fold). The 24 h samples showed a similar pattern of gene expression, although generally at lower levels. In parallel, the ELISA showed the related cytokines were present in the inner ear at concentrations higher by 2-122 fold higher at 18 h, declining slightly from there at 24 h. Immunohistochemistry with antibodies to a number of these cytokines demonstrated they occurred in greater amounts in the inner ear tissues. These findings demonstrate considerable inflammatory gene expression and gene products in the inner ear following acute otitis media. These higher cytokine levels suggest one potential mechanism for the permanent hearing loss seen in some cases of acute and chronic otitis media.
Collapse
Affiliation(s)
- Dennis R Trune
- Oregon Hearing Research Center, Department of Otolaryngology Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
| | - Beth Kempton
- Oregon Hearing Research Center, Department of Otolaryngology Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA
| | - Frances A Hausman
- Oregon Hearing Research Center, Department of Otolaryngology Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA
| | - Barbara E Larrain
- Oregon Hearing Research Center, Department of Otolaryngology Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA
| | - Carol J MacArthur
- Oregon Hearing Research Center, Department of Otolaryngology Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
8
|
Dinh CT, Goncalves S, Bas E, Van De Water TR, Zine A. Molecular regulation of auditory hair cell death and approaches to protect sensory receptor cells and/or stimulate repair following acoustic trauma. Front Cell Neurosci 2015; 9:96. [PMID: 25873860 PMCID: PMC4379916 DOI: 10.3389/fncel.2015.00096] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/03/2015] [Indexed: 12/20/2022] Open
Abstract
Loss of auditory sensory hair cells (HCs) is the most common cause of hearing loss. This review addresses the signaling pathways that are involved in the programmed and necrotic cell death of auditory HCs that occur in response to ototoxic and traumatic stressor events. The roles of inflammatory processes, oxidative stress, mitochondrial damage, cell death receptors, members of the mitogen-activated protein kinase (MAPK) signal pathway and pro- and anti-cell death members of the Bcl-2 family are explored. The molecular interaction of these signal pathways that initiates the loss of auditory HCs following acoustic trauma is covered and possible therapeutic interventions that may protect these sensory HCs from loss via apoptotic or non-apoptotic cell death are explored.
Collapse
Affiliation(s)
- Christine T Dinh
- University of Miami Ear Institute, University of Miami Miller School of Medicine Miami, FL, USA
| | - Stefania Goncalves
- University of Miami Ear Institute, University of Miami Miller School of Medicine Miami, FL, USA
| | - Esperanza Bas
- University of Miami Ear Institute, University of Miami Miller School of Medicine Miami, FL, USA
| | - Thomas R Van De Water
- University of Miami Ear Institute, University of Miami Miller School of Medicine Miami, FL, USA
| | - Azel Zine
- Integrative and Adaptive Neurosciences, Aix-Marseille Université, CNRS, UMR 7260 Marseille, France ; Faculty of Pharmacy, Biophysics Department, University of Montpellier Montpellier, France
| |
Collapse
|
9
|
Haake SM, Dinh CT, Chen S, Eshraghi AA, Van De Water TR. Dexamethasone protects auditory hair cells against TNFα-initiated apoptosis via activation of PI3K/Akt and NFκB signaling. Hear Res 2009; 255:22-32. [DOI: 10.1016/j.heares.2009.05.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 05/01/2009] [Accepted: 05/04/2009] [Indexed: 12/13/2022]
|
10
|
Trune DR, Zheng QY. Mouse models for human otitis media. Brain Res 2009; 1277:90-103. [PMID: 19272362 DOI: 10.1016/j.brainres.2009.02.047] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 02/11/2009] [Accepted: 02/23/2009] [Indexed: 12/20/2022]
Abstract
Otitis media (OM) remains the most common childhood disease and its annual costs exceed $5 billion. Its potential for permanent hearing impairment also emphasizes the need to better understand and manage this disease. The pathogenesis of OM is multifactorial and includes infectious pathogens, anatomy, immunologic status, genetic predisposition, and environment. Recent progress in mouse model development is helping to elucidate the respective roles of these factors and to significantly contribute toward efforts of OM prevention and control. Genetic predisposition is recognized as an important factor in OM and increasing numbers of mouse models are helping to uncover the potential genetic bases for human OM. Furthermore, the completion of the mouse genome sequence has offered a powerful set of tools for investigating gene function and is generating a rich resource of mouse mutants for studying the genetic factors underlying OM.
Collapse
Affiliation(s)
- Dennis R Trune
- Oregon Hearing Research Center, Mail Code NRC04, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, OR 97239-3098, USA
| | | |
Collapse
|
11
|
Tadros SF, D'Souza M, Zettel ML, Zhu X, Lynch-Erhardt M, Frisina RD. Serotonin 2B receptor: Upregulated with age and hearing loss in mouse auditory system. Neurobiol Aging 2007; 28:1112-23. [PMID: 16822592 DOI: 10.1016/j.neurobiolaging.2006.05.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/03/2006] [Accepted: 05/09/2006] [Indexed: 12/20/2022]
Abstract
Serotonin (5-HT) is a monoamine neurotransmitter. Serotonin may modulate afferent fiber discharges in the cochlea, inferior colliculus (IC) and auditory cortex. Specific functions of serotonin are exerted upon its interaction with specific receptors; one of those receptors is the serotonin 2B receptor. The aim of this study was to investigate the differences in gene expression of serotonin 2B receptors with age in cochlea and IC, and the possible correlation between gene expression and functional hearing measurements in CBA/CaJ mice. Immunohistochemical examinations of protein expression of IC in mice of different age groups were also performed. Gene expression results showed that serotonin 2B receptor gene was upregulated with age in both cochlea and IC. A significant correlation between gene expression and functional hearing results was established. Immunohistochemical protein expression studies of IC showed more serotonin 2B receptor cells in old mice relative to young adult mice, particularly in the external nucleus. We conclude that serotonin 2B receptors may play a role in the pathogenesis of age-related hearing loss.
Collapse
MESH Headings
- Acoustic Stimulation/methods
- Aging
- Analysis of Variance
- Animals
- Auditory Pathways/physiopathology
- Auditory Threshold/physiology
- Dose-Response Relationship, Radiation
- Evoked Potentials, Auditory, Brain Stem/physiology
- Gene Expression Profiling
- Hearing Loss/pathology
- Mice
- Mice, Inbred CBA
- Models, Animal
- Oligonucleotide Array Sequence Analysis/methods
- Otoacoustic Emissions, Spontaneous/physiology
- RNA, Messenger/biosynthesis
- Receptor, Serotonin, 5-HT2B/genetics
- Receptor, Serotonin, 5-HT2B/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Up-Regulation/physiology
Collapse
Affiliation(s)
- Sherif F Tadros
- Department of Otolaryngology, University of Rochester School of Medicine & Dentistry, Rochester, NY 14642-8629, USA
| | | | | | | | | | | |
Collapse
|
12
|
Moriyama M, Yoshida K, Ichimiya I, Suzuki M. Nitric oxide production from cultured spiral ligament fibrocytes: effects of corticosteroids. Acta Otolaryngol 2007; 127:676-81. [PMID: 17573561 DOI: 10.1080/00016480600987859] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONCLUSION This is the first report of nitric oxide (NO) production by cultured spiral ligament (SL) fibrocytes. The data suggest that dexamethasone (Dex) suppresses NO production by SL fibrocytes. Given that SL fibrocytes play a role in cochlear fluid and ion homeostasis, glucocorticoids may suppress cochlear malfunction caused by NO production in SL fibrocytes. OBJECTIVE To investigate NO production by cultured SL fibrocytes and regulation of NO production by Dex in mouse secondary cell cultures. MATERIALS AND METHODS Cultured SL fibrocytes were stimulated with tumor necrosis factor-alpha (TNF-alpha), and NO production was visualized with membrane-permeable 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM diacetate). Inducible nitric oxide synthase (NOSII) messenger RNA (mRNA) was measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS After TNF-alpha stimulation, the fluorescence intensity increased in a time-dependent manner. This increase in fluorescence intensity was suppressed by a nonspecific NOS inhibitor, N(G)-nitro L-arginine methyl ester (L-NAME), and Dex. After TNF-alpha stimulation, expression of NOSII mRNA was observed. Expression of NOSII mRNA was inhibited by Dex.
Collapse
Affiliation(s)
- Masaomi Moriyama
- Department of Otolaryngology, Faculty of Medicine, Oita University, Oita, Japan
| | | | | | | |
Collapse
|
13
|
Bachor E, Blevins NH, Karmody C, Kühnel T. Otologic manifestations of relapsing polychondritis. Auris Nasus Larynx 2006; 33:135-41. [PMID: 16427754 DOI: 10.1016/j.anl.2005.11.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 09/26/2005] [Accepted: 11/11/2005] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Relapsing polychondritis (RP) is an episodic disease most likely of autoimmune etiology, characterized by recurrent inflammation of cartilaginous structures. METHODS Retrospective case study at two tertiary referral centers with presentation of nine patients with otologic involvement of RP, review of the spectrum of otologic disorders seen, and treatment. RESULTS The clinical course of otologic manifestations of RP was highly variable and ranged from mild to moderate. In 6/9 patients there was an association with other autoimmune disorders. In addition to recurrent auricular chondritis, which was present in 8/9 patients, our patients had otitis externa, chronic myringitis, Eustachian tube dysfunction, conductive hearing loss, sensorineural hearing loss, and tinnitus. All patients had their diagnosis of RP made on the basis of their otologic involvement and the response to systemic corticosteroids. CONCLUSION The diagnosis of RP is primarily clinical, but laboratory studies and biopsy may contribute as well. Once the diagnosis is suspected, the otolaryngologist should consider consultation with a rheumatologist to assist in the management of additional systemic manifestations.
Collapse
Affiliation(s)
- Edgar Bachor
- Universitäts-HNO Klinik, Franz-Josef-Strauss-Allee 11, D-93053 Regensburg, Germany.
| | | | | | | |
Collapse
|
14
|
Fujioka M, Kanzaki S, Okano HJ, Masuda M, Ogawa K, Okano H. Proinflammatory cytokines expression in noise-induced damaged cochlea. J Neurosci Res 2006; 83:575-83. [PMID: 16429448 DOI: 10.1002/jnr.20764] [Citation(s) in RCA: 234] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent studies have showed that inflammatory responses occur in inner ear under various damaging conditions including noise-overstimulation. We evaluated the time-dependent expression of proinflammatory cytokines in noise-exposed rat cochlea. Among several detected cytokines, real-time RT-PCR showed that interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) were significantly induced 3 hr after noise exposure, and quickly downregulated to the basal level. Tumor necrosis factor-alpha (TNF-alpha) was also slightly upregulated immediately after noise exposure. Immunohistochemical analysis showed that IL-6 expression was distinctively induced within the lateral side of the spiral ligament. Sequential expression analysis showed that IL-6 immunoreactivity was initially found in the cytoplasm of lateral wall cells, including Type IV and III fibrocytes, and expanded broader throughout the lateral wall, finally to the stria vascularis. Because of the negative Iba-1 staining, IL-6 expression in the early-phase was not due to macrophage or microglia activation. IL-6 was also detected in spiral ganglion neurons at 12 and 24 hr after noise exposure. Our data demonstrates the production of proinflammatory cytokines, including TNF-alpha, IL-1beta, and IL-6, in early phase of noise overstimulated cochlea. IL-6 expression was observed in the spiral ligament, stria vascularis, and spiral ganglion neurons. These cytokines, produced by the cochlear structure itself in response to noise exposure, may initiate an inflammatory response and have some role in the mechanism of noise-induced cochlear damage.
Collapse
Affiliation(s)
- Masato Fujioka
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
15
|
Santos RLP, Hassan MJ, Sikandar S, Lee K, Ali G, Martin PE, Wambangco MAL, Ahmad W, Leal SM. DFNB68, a novel autosomal recessive non-syndromic hearing impairment locus at chromosomal region 19p13.2. Hum Genet 2006; 120:85-92. [PMID: 16703383 PMCID: PMC2909094 DOI: 10.1007/s00439-006-0188-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Accepted: 04/09/2006] [Indexed: 11/29/2022]
Abstract
From a large collection of families with autosomal recessive non-syndromic hearing impairment (NSHI) from Pakistan, linkage has been established for two unrelated consanguineous families to 19p13.2. This new locus was assigned the name DFNB68. A 10 cM genome scan and additional fine mapping were carried out using microsatellite marker loci. Linkage was established for both families to DFNB68 with maximum multipoint LOD scores of 4.8 and 4.6. The overlap of the homozygous regions between the two families was bounded by D19S586 and D19S584, which limits the locus interval to 1.9 cM and contains 1.4 Mb. The genes CTL2, KEAP1 and CDKN2D were screened but were negative for functional sequence variants.
Collapse
Affiliation(s)
- Regie Lyn P. Santos
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Alkek Building N1619.01, Houston, TX 77030, USA. Genetic Epidemiology Unit, Department of Epidemiology and Biostatistics, Erasmus Medical Centre, Rotterdam, The Netherlands
| | | | - Shaheen Sikandar
- Department of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Kwanghyuk Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Alkek Building N1619.01, Houston, TX 77030, USA
| | - Ghazanfar Ali
- Department of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Protacio E. Martin
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Alkek Building N1619.01, Houston, TX 77030, USA
| | - Michael Angelo L. Wambangco
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Alkek Building N1619.01, Houston, TX 77030, USA
| | - Wasim Ahmad
- Department of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Suzanne M. Leal
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Alkek Building N1619.01, Houston, TX 77030, USA
| |
Collapse
|
16
|
Maeda K, Yoshida K, Ichimiya I, Suzuki M. Dexamethasone inhibits tumor necrosis factor-alpha-induced cytokine secretion from spiral ligament fibrocytes. Hear Res 2005; 202:154-60. [PMID: 15811707 DOI: 10.1016/j.heares.2004.08.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 08/11/2004] [Indexed: 12/15/2022]
Abstract
To investigate the effect of proinflammatory cytokines on spiral ligament (SL) fibrocytes and regulation of cytokines by dexamethasone (Dex), in vitro studies were performed in murine secondary cell cultures. Cultured SL fibrocytes were stimulated with tumor necrosis factor-alpha (TNF-alpha), and the secretion of various mediators was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcribed-polymerase chain reaction (RT-PCR). After stimulation with TNF-alpha, levels of keratinocyte-derived cytokine (KC), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) were elevated in the culture supernatant, and their corresponding messenger RNAs were detected in the cultured fibrocytes. When the cultures were incubated with both TNF-alpha and Dex, the levels of KC, MCP-1, MIP-2 and IL-6 were significantly lower than those in cultures treated with TNF-alpha alone. The data suggest that Dex suppresses the inflammatory response in SL fibrocytes. Given that SL fibrocytes play a role in cochlear fluid and ion homeostasis, glucocorticoids may suppress the cochlear malfunction caused by SL inflammation.
Collapse
Affiliation(s)
- Keiko Maeda
- Department of Otolaryngology, Faculty of Medicine, Oita University, Hasama-machi, Japan
| | | | | | | |
Collapse
|
17
|
Bachor E, Kremmer S, Kreuzfelder E, Jahnke K, Seidahmadi S. Antiphospholipid antibodies in patients with sensorineural hearing loss. Eur Arch Otorhinolaryngol 2005; 262:622-6. [PMID: 15731904 DOI: 10.1007/s00405-004-0877-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Accepted: 08/13/2004] [Indexed: 12/20/2022]
Abstract
Sensorineural hearing loss can be associated with autoimmune diseases and the presence of antiphospholipid antibodies. Sixty patients (mean age 47 years, range 18-76 years) with sudden sensorineural hearing loss were studied with audiograms, stapedial thresholds, otoacoustic emissions, positional and caloric testing. The serologic testing included antibodies against phosphatidylserine and beta(2)-glycoprotein. Additionally, a group of 34 patients (mean age 65 years, range 31-81 years) with normal tension glaucoma was examined because in a previous study these patients were reported to have elevated concentrations of antiphospholipid antibodies with a coincidence of progressive sensorineural hearing loss. The baseline for antiphospholipid antibody levels was established in a control group of 40 healthy blood donors. In 12 of the 60 patients with sudden sensorineural hearing loss, levels of antiphospholipid antibodies were elevated. Antiphosphatidylserine IgM antibodies were significantly lower compared to controls and patients with the combination of hearing loss and normal tension glaucoma (Fisher's exact two-sided test, P < 0.01). Our data suggest that antibodies against beta2-glycoprotein seem to coincidence with an acute event, such as sudden sensorineural hearing loss, whereas antibodies against phosphatidylserine IgG are detectable in the prolonged sequel, such as in patients with progressive sensorineural hearing loss and normal tension glaucoma.
Collapse
Affiliation(s)
- Edgar Bachor
- Department of Otorhinolaryngology, University Hospital Essen, Germany.
| | | | | | | | | |
Collapse
|