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Kennedy CL, Shuster B, Amanipour R, Milon B, Patel P, Elkon R, Hertzano R. Metformin Protects Against Noise-Induced Hearing Loss in Male Mice. Otol Neurotol 2023; 44:956-963. [PMID: 37641232 PMCID: PMC10510802 DOI: 10.1097/mao.0000000000004002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
HYPOTHESIS Metformin treatment will protect mice from noise-induced hearing loss (NIHL). BACKGROUND We recently identified metformin as the top-ranking, Food and Drug Administration-approved drug to counter inner ear molecular changes induced by permanent threshold shift-inducing noise. This study is designed to functionally test metformin as a potential otoprotective drug against NIHL. METHODS Male and female B6CBAF1/J mice were obtained at 7 to 8 weeks of age. A cohort of the females underwent ovariectomy to simulate menopause and eliminate the effect of ovarian-derived estrogens. At 10 weeks of age, mice underwent a permanent threshold shift-inducing noise exposure (102.5 or 105 dB SPL, 8-16 kHz, 2 h). Auditory brainstem response (ABR) thresholds were obtained at baseline, 24 h after noise exposure, and 1 week after noise exposure. Mice were administered metformin (200 mg/kg/d) or a saline control in their drinking water after the baseline ABR and for the remainder of the study. After the 1-week ABR, mice were euthanized and cochlear tissue was analyzed. RESULTS Metformin treatment reduced the 1-week ABR threshold shift at 16 kHz ( p < 0.01; d = 1.20) and 24 kHz ( p < 0.01; d = 1.15) as well as outer hair cell loss in the 32-45.5 kHz range ( p < 0.0001; d = 2.37) in male mice. In contrast, metformin treatment did not prevent hearing loss or outer hair cell loss in the intact or ovariectomized female mice. CONCLUSIONS Metformin exhibits sex-dependent efficacy as a therapeutic for NIHL. These data compel continued investigation into metformin's protective effects and demonstrate the importance of evaluating the therapeutic efficacy of drugs in subjects of both sexes.
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Affiliation(s)
- Catherine L. Kennedy
- Department of Otorhinolaryngology–Head and Neck Surgery, University of Maryland School of Medicine, Baltimore
| | - Benjamin Shuster
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - Reza Amanipour
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - Beatrice Milon
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - Priya Patel
- Department of Otorhinolaryngology–Head and Neck Surgery, University of Maryland School of Medicine, Baltimore
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ronna Hertzano
- Department of Otorhinolaryngology–Head and Neck Surgery, University of Maryland School of Medicine, Baltimore
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Manohar S, Chen GD, Li L, Liu X, Salvi R. Chronic stress induced loudness hyperacusis, sound avoidance and auditory cortex hyperactivity. Hear Res 2023; 431:108726. [PMID: 36905854 DOI: 10.1016/j.heares.2023.108726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/22/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Hyperacusis, a debilitating loudness intolerance disorder, has been linked to chronic stress and adrenal insufficiency. To investigate the role of chronic stress, rats were chronically treated with corticosterone (CORT) stress hormone. Chronic CORT produced behavioral evidence of loudness hyperacusis, sound avoidance hyperacusis, and abnormal temporal integration of loudness. CORT treatment did not disrupt cochlear or brainstem function as reflected by normal distortion product otoacoustic emissions, compound action potentials, acoustic startle reflexex, and auditory brainstem responses. In contrast, the evoked response from the auditory cortex was enhanced up to three fold after CORT treatment. This hyperactivity was associated with a significant increase in glucocorticoid receptors in auditory cortex layers II/III and VI. Basal serum CORT levels remained normal after chronic CORT stress whereas reactive serum CORT levels evoked by acute restraint stress were blunted (reduced) after chronic CORT stress; similar changes were observed after chronic, intense noise stress. Taken together, our results show for the first time that chronic stress can induce hyperacusis and sound avoidance. A model is proposed in which chronic stress creates a subclinical state of adrenal insufficiency that establishes the necessary conditions for inducing hyperacusis.
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Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Li Li
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Xiaopeng Liu
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA.
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3
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Zhang L, Wang J, Sun H, Feng G, Gao Z. Interactions between the hippocampus and the auditory pathway. Neurobiol Learn Mem 2022; 189:107589. [DOI: 10.1016/j.nlm.2022.107589] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 01/12/2022] [Accepted: 01/29/2022] [Indexed: 12/22/2022]
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Abstract
Emotional stress has accompanied humans since the dawn of time and has played an essential role not only in positive selection and adaptation to an ever-changing environment, but also in the acceleration or even initiation of many illnesses. The three main somatic mechanisms induced by stress are the hypothalamus-pituitary-adrenal axis (HPA axis), the sympathetic-adreno-medullar (SAM) axis, and the immune axis. In this chapter, the stress-induced mechanisms that can affect cochlear physiology are presented and discussed in the context of tinnitus generation and auditory neurobiology. It is concluded that all of the presented mechanisms need to be further investigated. It is advised that clinical practitioners ask patients about stressful events or chronic stress preceding the tinnitus onset and measure the vital signs. Finally, taking into account that tinnitus itself acts as a stressor, the implementation of anti-stress therapies for tinnitus treatment is recommended.
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Cederroth CR, Park JS, Basinou V, Weger BD, Tserga E, Sarlus H, Magnusson AK, Kadri N, Gachon F, Canlon B. Circadian Regulation of Cochlear Sensitivity to Noise by Circulating Glucocorticoids. Curr Biol 2019; 29:2477-2487.e6. [PMID: 31353184 PMCID: PMC6904421 DOI: 10.1016/j.cub.2019.06.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 05/21/2019] [Accepted: 06/20/2019] [Indexed: 01/27/2023]
Abstract
The cochlea possesses a robust circadian clock machinery that regulates auditory function. How the cochlear clock is influenced by the circadian system remains unknown. Here, we show that cochlear rhythms are system driven and require local Bmal1 as well as central input from the suprachiasmatic nuclei (SCN). SCN ablations disrupted the circadian expression of the core clock genes in the cochlea. Because the circadian secretion of glucocorticoids (GCs) is controlled by the SCN and GCs are known to modulate auditory function, we assessed their influence on circadian gene expression. Removal of circulating GCs by adrenalectomy (ADX) did not have a major impact on core clock gene expression in the cochlea. Rather it abolished the transcription of clock-controlled genes involved in inflammation. ADX abolished the known differential auditory sensitivity to day and night noise trauma and prevented the induction of GABA-ergic and glutamate receptors mRNA transcripts. However, these improvements were unrelated to changes at the synaptic level, suggesting other cochlear functions may be involved. Due to this circadian regulation of noise sensitivity by GCs, we evaluated the actions of the synthetic glucocorticoid dexamethasone (DEX) at different times of the day. DEX was effective in protecting from acute noise trauma only when administered during daytime, when circulating glucocorticoids are low, indicating that chronopharmacological approaches are important for obtaining optimal treatment strategies for hearing loss. GCs appear as a major regulator of the differential sensitivity to day or night noise trauma, a mechanism likely involving the circadian control of inflammatory responses.
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Affiliation(s)
| | - Jung-Sub Park
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 17177, Sweden; Department of Otolaryngology, Ajou University School of Medicine, 164, Worldcup-ro, Yeongtong-gu, Suwon 16499, Korea
| | - Vasiliki Basinou
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Benjamin D Weger
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland
| | - Evangelia Tserga
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Heela Sarlus
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Anna K Magnusson
- Department of Clinical Science Intervention and Technology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Nadir Kadri
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm 17177, Sweden
| | - Frédéric Gachon
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland; School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Barbara Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm 17177, Sweden
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Ajduk J, Košec A, Kelava I, Ries M, Gregurić T, Kalogjera L. Recovery From Sudden Sensorineural Hearing Loss May Be Linked to Chronic Stress Levels and Steroid Treatment Resistance. Am J Audiol 2019; 28:315-321. [PMID: 31084569 DOI: 10.1044/2019_aja-18-0127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Purpose This article investigates the possible connections between the level of chronic stress and success of steroid therapy in patients with sudden sensorineural hearing loss (SSNHL). Method A single-center, retrospective, longitudinal cohort study on 55 patients in a tertiary referral otology center was examined. Patients diagnosed with SSNHL between 2014 and 2017 were asked to complete a Measure of Perceived Stress (Brajac, Tkalcic, Dragojević, & Gruber, 2003 ) questionnaire. Inclusion criteria were patients > 18 years of age, SSNHL diagnosed within 4 previous weeks, completed steroid treatment, and complete documentation. Results There were 30 patients (55%) that showed significant improvement in their pure-tone audiogram (PTA) hearing threshold average (≥ 15 dB) after steroid treatment. Two-step cluster analysis identified 3 clusters based on average PTA hearing threshold recovery and average Measure of Perceived Stress scores. The difference between pretreatment and posttreatment hearing levels was significantly higher in the cluster with moderate stress compared to clusters with mild and high stress levels (Kruskal-Wallis test, Friedman test, p < .001). There were no significant differences in average PTA hearing threshold recovery after steroid therapy between groups of patients with mild and severe stress. Conclusion Patients with moderate stress levels show significantly better results after steroid treatment for SSNHL than patients with low or high stress levels.
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Affiliation(s)
- Jakov Ajduk
- School of Medicine, University of Zagreb, Croatia
| | - Andro Košec
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Center Sestre milosrdnice, Zagreb, Croatia
| | - Iva Kelava
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Center Sestre milosrdnice, Zagreb, Croatia
| | - Mihael Ries
- School of Medicine, University of Zagreb, Croatia
| | - Tomislav Gregurić
- Department of Radiology, University Hospital Center Sestre milosrdnice, Zagreb, Croatia
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Glucococorticoid receptor activation exacerbates aminoglycoside-induced damage to the zebrafish lateral line. Hear Res 2019; 377:12-23. [PMID: 30878773 DOI: 10.1016/j.heares.2019.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/18/2018] [Accepted: 03/04/2019] [Indexed: 01/14/2023]
Abstract
Aminoglycoside antibiotics have potent antibacterial properties but cause hearing loss in up to 25% of patients. These drugs are commonly administered in patients with high glucocorticoid stress hormone levels and can be combined with exogenous glucocorticoid treatment. However, the interaction of stress and aminoglycoside-induced hearing loss has not been fully explored. In this study, we investigated the effect of the glucocorticoid stress hormone cortisol on hair cells in the zebrafish lateral line as an important step toward understanding how physiological stressors modulate hair cell survival. We found that 24-hr cortisol incubation sensitized hair cells to neomycin damage. Pharmacological and genetic manipulation demonstrates that sensitization depended on the action of the glucocorticoid receptor but not the mineralocorticoid receptor. Blocking endogenous cortisol production reduced hair cell susceptibility to neomycin, further evidence that glucocorticoids modulate aminoglycoside ototoxicity. Glucocorticoid transcriptional activity was apparent in lateral line hair cells, suggesting a direct action of cortisol in these aminoglycoside-sensitive cells. Our work shows that the stress hormone cortisol can increase hair cell sensitivity to aminoglycoside damage, which highlights the importance of recognizing stress and the impacts of glucocorticoid signaling in both ototoxicity research and clinical practice.
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Milon B, Mitra S, Song Y, Margulies Z, Casserly R, Drake V, Mong JA, Depireux DA, Hertzano R. The impact of biological sex on the response to noise and otoprotective therapies against acoustic injury in mice. Biol Sex Differ 2018; 9:12. [PMID: 29530094 PMCID: PMC5848513 DOI: 10.1186/s13293-018-0171-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Noise-induced hearing loss (NIHL) is the most prevalent form of acquired hearing loss and affects about 40 million US adults. Among the suggested therapeutics tested in rodents, suberoylanilide hydroxamic acid (SAHA) has been shown to be otoprotective from NIHL; however, these results were limited to male mice. METHODS Here we tested the effect of SAHA on the hearing of 10-week-old B6CBAF1/J mice of both sexes, which were exposed to 2 h of octave-band noise (101 dB SPL centered at 11.3 kHz). Hearing was assessed by measuring auditory brainstem responses (ABR) at 8, 16, 24, and 32 kHz, 1 week before, as well as at 24 h and 15-21 days following exposure (baseline, compound threshold shift (CTS) and permanent threshold shift (PTS), respectively), followed by histologic analyses. RESULTS We found significant differences in the CTS and PTS of the control (vehicle injected) mice to noise, where females had a significantly smaller CTS at 16 and 24 kHz (p < 0.0001) and PTS at 16, 24, and 32 kHz (16 and 24 kHz p < 0.001, 32 kHz p < 0.01). This sexual dimorphic effect could not be explained by a differential loss of sensory cells or synapses but was reflected in the amplitude and amplitude progression of wave I of the ABR, which correlates with outer hair cell (OHC) function. Finally, the frequency of the protective effect of SAHA differed significantly between males (PTS, 24 kHz, p = 0.002) and females (PTS, 16 kHz, p = 0.003), and the magnitude of the protection was smaller in females than in males. Importantly, the magnitude of the protection by SAHA was smaller than the effect of sex as a biological factor in the vehicle-injected mice. CONCLUSIONS These results indicate that female mice are significantly protected from NIHL in comparison to males and that therapeutics for NIHL may have a different effect in males and females. The data highlight the importance of analyzing NIHL experiments from males and females, separately. Finally, these data also raise the possibility of effectors in the estrogen signaling pathway as novel therapeutics for NIHL.
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Affiliation(s)
- Béatrice Milon
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Sunayana Mitra
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Yang Song
- 0000 0001 2175 4264grid.411024.2Institute for Genome Science, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Zachary Margulies
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Ryan Casserly
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Virginia Drake
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Jessica A. Mong
- 0000 0001 2175 4264grid.411024.2Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Didier A. Depireux
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA ,0000 0001 0941 7177grid.164295.dInstitute for Systems Research, University of Maryland, College Park, MD 20742 USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD, 21201, USA. .,Institute for Genome Science, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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Bao J, Hungerford M, Luxmore R, Ding D, Qiu Z, Lei D, Yang A, Liang R, Ohlemiller KK. Prophylactic and therapeutic functions of drug combinations against noise-induced hearing loss. Hear Res 2013; 304:33-40. [PMID: 23792074 DOI: 10.1016/j.heares.2013.06.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/31/2013] [Accepted: 06/10/2013] [Indexed: 01/01/2023]
Abstract
Noise is the most common occupational and environmental hazard. Noise-induced hearing loss (NIHL) is the second most common form of sensorineural hearing deficit, after age-related hearing loss (presbycusis). Although promising approaches have been identified for reducing NIHL, currently there are no effective medications to prevent NIHL. Development of an efficacious treatment has been hampered by the complex array of cellular and molecular pathways involved in NIHL. We turned this difficulty into an advantage by asking whether NIHL could be effectively prevented by targeting multiple signaling pathways with a combination of drugs already approved by U.S. Food and Drug Administration (FDA). We previously found that antiepileptic drugs blocking T-type calcium channels had both prophylactic and therapeutic effects for NIHL. NIHL can also be reduced by an up-regulation of glucocorticoid (GC) signaling pathways. Based on these findings, we tested a combination therapy for NIHL that included ethosuximide and zonisamide (anticonvulsants) and dexamethasone and methylprednisolone (synthetic GCs) in mice under exposure conditions typically associated with dramatic permanent threshold shifts (PTS). We first examined possible prophylactic effects for each drug when administered alone 2 h before noise, and calculated the median effective dose (ED50). We then tested for synergistic effects of two-drug combinations (anticonvulsant + GC), and identified combinations with the strongest synergy against NIHL, based on a previously established combination index (CI) metric. We repeated similar tests to determine their therapeutic effects when administered the same drugs 24 h after the noise exposure. Our study shows the feasibility of developing pharmacological intervention in multiple pathways, and discovering drug combinations with optimal synergistic effects in preventing permanent NIHL.
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Affiliation(s)
- Jianxin Bao
- Department of Otolaryngology, Center for Aging, Washington University School of Medicine, 4560 Clayton Avenue, St. Louis, MO 63110, USA.
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Kil SH, Kalinec F. Expression and dexamethasone-induced nuclear translocation of glucocorticoid and mineralocorticoid receptors in guinea pig cochlear cells. Hear Res 2013; 299:63-78. [PMID: 23403298 PMCID: PMC3633732 DOI: 10.1016/j.heares.2013.01.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/14/2013] [Accepted: 01/27/2013] [Indexed: 12/20/2022]
Abstract
Glucocorticoids (GC) are powerful anti-inflammatory agents frequently used to protect the auditory organ against damage associated with a variety of conditions, including noise exposure and ototoxic drugs as well as bacterial and viral infections. In addition to glucocorticoid receptors (GC-R), natural and synthetic GC are known to bind mineralocorticoid receptors (MC-R) with great affinity. We used light and laser scanning confocal microscopy to investigate the expression of GC-R and MC-R in different cell populations of the guinea pig cochlea, and their translocation to different cell compartments after treatment with the synthetic GC dexamethasone. We found expression of both types of receptors in the cytoplasm and nucleus of sensory inner and outer hair cells as well as pillar, Hensen and Deiters cells in the organ of Corti, inner and outer sulcus cells, spiral ganglion neurons and several types of spiral ligament and spiral limbus cells; stria vascularis cells expressed mostly MC-R whereas fibrocytes type IV were positive for GC-R only. GC-R and MC-R were also localized at or near the plasma membrane of pillar cells and outer hair cells, whereas GC-R were found at or near the plasma membrane of Hensen cells only. We investigated the relative levels of receptor expression in the cytoplasm and the nucleus of Hensen cells treated with dexamethasone, and found they varied in a way suggestive of dose-induced translocation. These results suggest that the oto-protective effects of GC could be associated with the concerted activation of genomic and non-genomic, GC-R and MC-R mediated signaling pathways in different regions of the cochlea.
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Affiliation(s)
- Sung-Hee Kil
- Division of Cell Biology and Genetics, House Research Institute, Los Angeles, CA, 90057, USA
| | - Federico Kalinec
- Division of Cell Biology and Genetics, House Research Institute, Los Angeles, CA, 90057, USA
- Departments of Cell & Neurobiology and Otolaryngology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
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Mitic M, Simic I, Djordjevic J, Radojcic MB, Adzic M. Gender-specific effects of fluoxetine on hippocampal glucocorticoid receptor phosphorylation and behavior in chronically stressed rats. Neuropharmacology 2013; 70:100-11. [PMID: 23353902 DOI: 10.1016/j.neuropharm.2012.12.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 12/10/2012] [Accepted: 12/22/2012] [Indexed: 12/13/2022]
Abstract
Chronic psychosocial isolation stress (CPSI) modulates glucocorticoid receptor (GR) functioning in Wistar male rat hippocampus (HIPPO) through alteration of nuclear GR phosphorylation and its upstream kinases signaling, which parallels animal depressive-like behavior. The current study investigated potential gender specificities regarding the effect of chronic therapy by an antidepressant fluoxetine (FLU) on GR signaling in HIPPO and depressive-like behavior in CPSI animals. FLU was administrated to female and male naïve or CPSI rats for 21 days and GR protein, its phosphorylation status and upstream kinases, as well as GR and BDNF mRNA were followed in HIPPO together with animal serum corticosterone (CORT) and depressive-like behavior. The results showed that CPSI increased immobility in males versus hyperactivity in females and disrupted nuclear pGR232-Cdk5 pathway and JNK signaling in a gender-specific way. In contrast, in both genders CPSI increased the nuclear levels of GR and pGR246 but decreased CORT and mRNA levels of GR and BDNF. Concomitant FLU normalized the depressive-like behavior and altered the nuclear pGR232-Cdk5 signaling in a gender-specific manner. In both females and males, FLU reversed the nuclear levels of GR and pGR246 without affecting CORT and GR mRNA levels. In contrast, FLU exhibited gender-specific effect on BDNF mRNA in CPSI animals, by increasing it in females, but not in males. In spite of normalization the total nuclear GR level upon FLU treatment in both gender, down-regulation of GR mRNA is possibly maintained through prevalence of pGR232 isoform only in males. The gender-specific alterations of pGR232-Cdk5 signaling and BDNF gene expression in HIPPO and normalization of depressive-like behavior upon FLU treatment distinguishes this signaling pathway as potential future antidepressant target for gender-specific therapy of stress related mood disorders.
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Affiliation(s)
- Milos Mitic
- Laboratory for Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, PO Box-522-MBE090, 11001 Belgrade, Serbia
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Hasson D, Theorell T, Bergquist J, Canlon B. Acute stress induces hyperacusis in women with high levels of emotional exhaustion. PLoS One 2013; 8:e52945. [PMID: 23301005 PMCID: PMC3534646 DOI: 10.1371/journal.pone.0052945] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 11/22/2012] [Indexed: 11/18/2022] Open
Abstract
Background Hearing problems is one of the top ten public health disorders in the general population and there is a well-established relationship between stress and hearing problems. The aim of the present study was to explore if an acute stress will increase auditory sensitivity (hyperacusis) in individuals with high levels of emotional exhaustion (EE). Methods Hyperacusis was assessed using uncomfortable loudness levels (ULL) in 348 individuals (140 men; 208 women; age 23–71 years). Multivariate analyses (ordered logistic regression), were used to calculate odds ratios, including interacting or confounding effects of age, gender, ear wax and hearing loss (PTA). Two-way ANCOVAs were used to assess possible differences in mean ULLs between EE groups pre- and post-acute stress task (a combination of cold pressor, emotional Stroop and Social stress/video recording). Results There were no baseline differences in mean ULLs between the three EE groups (one-way ANOVA). However, after the acute stress exposure there were significant differences in ULL means between the EE-groups in women. Post-hoc analyses showed that the differences in mean ULLs were between those with high vs. low EE (range 5.5–6.5 dB). Similar results were found for frequencies 0.5 and 1 kHz. The results demonstrate that women with high EE-levels display hyperacusis after an acute stress task. The odds of having hyperacusis were 2.5 (2 kHz, right ear; left ns) and 2.2 (4 kHz, right ear; left ns) times higher among those with high EE compared to those with low levels. All these results are adjusted for age, hearing loss and ear wax. Conclusion Women with high levels of emotional exhaustion become more sensitive to sound after an acute stress task. This novel finding highlights the importance of including emotional exhaustion in the diagnosis and treatment of hearing problems.
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Affiliation(s)
- Dan Hasson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Kraus KS, Canlon B. Neuronal connectivity and interactions between the auditory and limbic systems. Effects of noise and tinnitus. Hear Res 2012; 288:34-46. [DOI: 10.1016/j.heares.2012.02.009] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/09/2011] [Accepted: 02/22/2012] [Indexed: 01/01/2023]
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Hall IC, Sell GL, Chester EM, Hurley LM. Stress-evoked increases in serotonin in the auditory midbrain do not directly result from elevations in serum corticosterone. Behav Brain Res 2012; 226:41-9. [DOI: 10.1016/j.bbr.2011.08.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/26/2011] [Accepted: 08/27/2011] [Indexed: 11/26/2022]
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Meltser I, Canlon B. Protecting the auditory system with glucocorticoids. Hear Res 2011; 281:47-55. [PMID: 21718769 DOI: 10.1016/j.heares.2011.06.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 06/07/2011] [Accepted: 06/09/2011] [Indexed: 01/03/2023]
Abstract
Glucocorticoids are hormones released following stress-related events and function to maintain homeostasis. Glucocorticoid receptors localize, among others, to hair cells, spiral ligament and spiral ganglion neurons. Glucocorticoid receptor-induced protection against acoustic trauma is found by i) pretreatment with glucocorticoid agonists; ii) acute restraint stress; and iii) sound conditioning. In contrast, glucocorticoid receptor antagonists exacerbate hearing loss. These findings have important clinical significance since synthetic glucocorticoids are commonly used to treat hearing loss. However, this treatment has limited success since hearing improvement is often not maintained once the treatment has ended, a fact that reduces the overall appeal for this treatment. It must be realized that despite the widespread use of glucocorticoids to treat hearing disorders, the molecular mechanisms underlying this treatment are not well characterized. This review will give insight into some physiological and biochemical mechanisms underlying glucocorticoid treatment for preventing hearing loss.
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Affiliation(s)
- Inna Meltser
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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Mazurek B, Haupt H, Joachim R, Klapp BF, Stöver T, Szczepek AJ. Stress induces transient auditory hypersensitivity in rats. Hear Res 2009; 259:55-63. [PMID: 19840840 DOI: 10.1016/j.heares.2009.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 07/09/2009] [Accepted: 10/13/2009] [Indexed: 12/31/2022]
Abstract
Exposure to harsh environment induces stress reactions that increase probability of survival. Stress influences the endocrine, nervous and immune systems and affects the functioning of a variety of organs. Numerous researchers demonstrated that a 24-h exposure to an acoustic rodent repellent provokes stress reaction in exposed animals. In addition to the activated hypothalamic-pituitary-adrenal (HPA) axis, exposed animals had pathological reactions in the reproductive organs, bronchia and skin. Here, we examined the effect of above stress model on the auditory system of Wistar rats. We found that 24-h stress decreases the thresholds and increases the amplitudes of auditory brainstem responses and distortion product otoacoustic emissions. Resultant auditory hypersensitivity was transient and most pronounced between 3 and 6h post-stress, returning to control levels one week later. The concentration of corticosterone and tumor necrosis factor alpha was systemically elevated in stressed animals between 3 and 6h post-stress, confirming the activation of the HPA axis. In addition, expression of the HPA-axis-associated genes: glucocorticoid receptor (GR) and hypoxia-inducible factor 1 alpha (Hif1a) was modulated in the auditory tissues. In detail, in the inferior colliculus, we found an up-regulation of GR mRNA 3h post-stress and continuous up-regulation of Hif1a up to 24h post-stress. In the spiral ganglion, we found no differences in gene expression between stressed and control animals. In the organ of Corti, expression of GR mRNA remained stable, whereas that of Hif1a was significantly down-regulated one week after stress. In addition, the expression of an outer hair cell marker prestin was significantly up-regulated 6h post-stress. We conclude that 24-h stress induces transient hypersensitivity of the auditory system and modulates gene expression in a tissue-specific manner. Stress-induced auditory hypersensitivity could have evolutionary consequence by giving animals an advantage of hearing better under stress conditions.
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Affiliation(s)
- Birgit Mazurek
- Molecular Biology Research Laboratory, Department of Otorhinolaryngology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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17
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Meltser I, Tahera Y, Canlon B. Glucocorticoid Receptor and Mitogen-Activated Protein Kinase Activity after Restraint Stress and Acoustic Trauma. J Neurotrauma 2009; 26:1835-45. [DOI: 10.1089/neu.2008.0874] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Inna Meltser
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Yeasmin Tahera
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Barbara Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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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]
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Jin DX, Lin Z, Lei D, Bao J. The role of glucocorticoids for spiral ganglion neuron survival. Brain Res 2009; 1277:3-11. [PMID: 19233145 PMCID: PMC2700197 DOI: 10.1016/j.brainres.2009.02.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 02/09/2009] [Accepted: 02/11/2009] [Indexed: 12/20/2022]
Abstract
Glucocorticoids, which are steroidal stress hormones, have a broad array of biological functions. Synthetic glucocorticoids are frequently used therapeutically for many pathologic conditions, including diseases of the inner ear; however, their exact functions in the cochlea are not completely understood. Recent work has clearly demonstrated the presence of glucocorticoid signaling pathways in the cochlea and elucidated their protective roles against noise-induced hearing loss. Furthermore, indirect evidence suggests the involvement of glucocorticoids in age-related loss of spiral ganglion neurons and extensive studies in the central nervous system demonstrate profound effects of glucocorticoids on neuronal functions. With the advancement of recent pharmacologic and genetic tools, the role of these pathways in the survival of spiral ganglion neurons after noise exposure and during aging should be revealed.
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Affiliation(s)
- David Xu Jin
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Zhaoyu Lin
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Debin Lei
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Jianxin Bao
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110
- The Division of Biology & Biomedical Science and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri, 63110
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Furze A, Kralick D, Vakharia A, Jaben K, Graves R, Adil E, Eshraghi AA, Balkany TJ, Van de Water TR. Dexamethasone and methylprednisolone do not inhibit neuritic outgrowth while inhibiting outgrowth of fibroblasts from spiral ganglion explants. Acta Otolaryngol 2008; 128:122-7. [PMID: 17851911 DOI: 10.1080/00016480701390128] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
CONCLUSION Dexamethasone and methylprednisolone do not inhibit neuritic outgrowth while inhibiting fibroblastic outgrowth from spiral ganglion micro-explants. OBJECTIVES To demonstrate reduced fibroblastic outgrowth while maintaining neurite outgrowth for several corticosteroids using an in vitro test system of neonatal rat spiral ganglion micro-explants. MATERIALS AND METHODS The in vitro test system comprised 3-day-old rat spiral ganglion micro-explants. Dexamethasone, methylprednisolone, triamcinolone acetonide, and human recombinant brain-derived neurotrophic factor (hrBDNF) were tested in vitro. The control was ganglion micro-explants in supplemented Dulbecco's modified Eagle's medium. Areas of the ganglion explant, neurite and fibroblast outgrowth of ganglion explants after 10 days in vitro were imaged, digitized, and analyzed using Image Tool 3.00 on a PC workstation. Areas of neurite and fibroblast outgrowth from the experimental explants were compared against values obtained from control explants. RESULTS Dexamethasone gave the best result of the three corticosteroids tested for inhibiting fibroblast outgrowth while not inhibiting neurite outgrowth from the ganglion micro-explants. Media containing hrBDNF (10 ng/ml) stimulated significantly greater neurite outgrowth than outgrowth from control explants (p < 0.001). Ganglion micro-explants treated with dexamethasone (0.02 mg/ml) and methylprednisolone (0.5 mg/ml) provided the greatest inhibition of fibroblast outgrowth compared with control explants (p < 0.001).
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Affiliation(s)
- Alexis Furze
- Department of Otolaryngology, University of Miami Ear Institute, Miller School of Medicine, Miami, FL, USA
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Yao S, Peng M, Zhu X, Cheng M, Qi X. Heat shock protein72 protects hippocampal neurons from apoptosis induced by chronic psychological stress. Int J Neurosci 2007; 117:1551-64. [PMID: 17917925 DOI: 10.1080/00207450701239285] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
When exposed to nonlethal heat stress (i.e., heat shock preconditioning), HSP72 expression increased in the mammalian brain. HSP72 enhance the viability of neurons and decrease TUNEL-positive neurons under several kinds of stress (e.g., ischemic). Chronic psychological stress is a kind of stress that could cause hippocampal neuron apoptosis. But whether overexpression of HSP72 can decrease TUNEL-positive hippocampal neurons caused by chronic psychological stress is unclear. To investigate the possible protective role of HSP72 in decreasing chronic psychological stress-induced hippocampal neuron apoptosis, this study analyzed HSP72 expression, apoptotic neurons in the hippocampus of mice. Adult mice were divided into four groups unstressed group; chronic psychological stress group; heat shock stress group; heat shock preconditioning plus psychological stress group; receiving no experimental stress, chronic psychological stress, heat shock stress, heat shock preconditioning plus psychological stress separately. Mice were killed after one month, two months, or three months of stress. A three-way ANOVA (psychological stress x heat shock stress x time) revealed a significant effect of heat shock stress in increasing HSP72 expression, decreasing neuronal apoptosis in hippocampus CA3 region caused by chronic psychological stress, and showed that HSP72 protected hippocampus CA3 neurons from chronic psychological stress.
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Affiliation(s)
- Shuqiao Yao
- The Medical Psychological Research Center 2nd Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China.
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Eshraghi AA, Adil E, He J, Graves R, Balkany TJ, Van De Water TR. Local Dexamethasone Therapy Conserves Hearing in an Animal Model of Electrode Insertion Trauma-Induced Hearing Loss. Otol Neurotol 2007; 28:842-9. [PMID: 17471110 DOI: 10.1097/mao.0b013e31805778fc] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HYPOTHESIS The progressive loss of hearing that develops after electrode insertion trauma (EIT) can be attenuated by local dexamethasone (DXM) therapy. BACKGROUND Hearing loss (HL) that develops after cochlear implant EIT occurs in two stages in laboratory animals, that is, an immediate loss followed by a progressive loss. Direct infusion of DXM into the guinea pig cochlea can attenuate both ototoxin- and noise-induced HL. MATERIALS AND METHODS Auditory-evoked brainstem responses (ABRs) of guinea pigs were measured for 4 frequencies (i.e., 0.5, 1, 4, and 16 kHz) before, immediately after, and more than 30 days post-EIT for experimental (EIT,EIT + artificial perilymph, and EIT + DXM) and for the contralateral unoperated cochleae of each group. An electrode analog of 0.14-mm diameter was inserted through a basal turn cochleostomy for a depth of 3 mm and withdrawn. DXM in artificial perilymph was delivered immediately post-EIT into the scala tympani via a miniosmotic pump for 8 days. RESULTS The ABR thresholds of EIT animals increased progressively post-EIT. Contralateral unoperated cochleae had no significant changes in ABR thresholds. Immediately post-EIT, that is, Day 0, the DXM-treated animals exhibited a significant HL at 1, 4, and 16 kHz, but this HL was no longer significant by Day 30 compared with contralateral control ears. CONCLUSION The results from immediate local treatment of the cochlea with DXM in an animal model of EIT-induced HL suggest a novel therapeutic strategy for hearing conservation by attenuating the progressive HL that can result from the process of electrode array insertion during cochlear implantation.
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Affiliation(s)
- Adrien A Eshraghi
- Cochlear Implant Research Program, University of Miami Ear Institute, Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, FL, USA
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Tahera Y, Meltser I, Johansson P, Hansson AC, Canlon B. Glucocorticoid receptor and nuclear factor-kappa B interactions in restraint stress-mediated protection against acoustic trauma. Endocrinology 2006; 147:4430-7. [PMID: 16777974 DOI: 10.1210/en.2006-0260] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The role of glucocorticoid receptors (GRs) in the protective effect of restraint stress (RS) before acoustic trauma was studied in spiral ganglion neurons of CBA mice. RS increased corticosterone and protected against elevated auditory brain stem thresholds caused by acoustic trauma. This protection was inhibited by the pretreatment with a corticosterone synthesis inhibitor, metyrapone (MET), and a GR antagonist (RU486). RS followed by acoustic trauma caused an immediate increase in corticosterone that triggered nuclear translocation of GR, without a change in the expression of GR protein. RU486 + MET before RS and acoustic trauma caused an immediate increase in GR mRNA followed by increased GR protein expression (24 h after trauma). GR signaling was further characterized by analyzing nuclear factor-kappaB (NF kappaB) nuclear translocation and protein expression. NF kappaB nuclear translocation was reduced after acoustic trauma or pretreatment with RU486 + MET before RS and acoustic trauma. On the contrary, RS protected against the trauma-induced NF kappaB reduction of its nuclear translocation in inhibitory-kappaB (I kappaB)-dependent manner. RU486 + MET caused a simultaneous decreased I kappaB expression and NF kappaB nuclear translocation, demonstrating an interference with the I kappaB-mediated activation of NF kappaB. In summary, RS protects the cochlea from acoustic trauma by increasing corticosterone and activating GRs. These results emphasis how GR activity modulates hearing sensitivity and its importance for the rationale use of glucocorticoids in inner ear diseases.
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Affiliation(s)
- Yeasmin Tahera
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
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