1
|
Clifford RE, Hertzano R, Ohlemiller KK. Untangling the genomics of noise-induced hearing loss and tinnitus: Contributions of Mus musculus and Homo sapiens. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:4007. [PMID: 31795683 PMCID: PMC7273513 DOI: 10.1121/1.5132552] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/07/2019] [Accepted: 06/24/2019] [Indexed: 05/23/2023]
Abstract
Acoustic trauma is a feature of the industrial age, in general, and mechanized warfare, in particular. Noise-induced hearing loss (NIHL) and tinnitus have been the number 1 and number 2 disabilities at U.S. Veterans hospitals since 2006. In a reversal of original protocols to identify candidate genes associated with monogenic deafness disorders, unbiased genome-wide association studies now direct animal experiments in order to explore genetic variants common in Homo sapiens. However, even these approaches must utilize animal studies for validation of function and understanding of mechanisms. Animal research currently focuses on genetic expression profiles since the majority of variants occur in non-coding regions, implying regulatory divergences. Moving forward, it will be important in both human and animal research to define the phenotypes of hearing loss and tinnitus, as well as exposure parameters, in order to extricate genes related to acoustic trauma versus those related to aging. It has become clear that common disorders like acoustic trauma are influenced by large numbers of genes, each with small effects, which cumulatively lead to susceptibility to a disorder. A polygenic risk score, which aggregates these small effect sizes of multiple genes, may offer a more accurate description of risk for NIHL and/or tinnitus.
Collapse
Affiliation(s)
- Royce E Clifford
- Division of Otolaryngology-Head and Neck Surgery, University of California School of Medicine, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, James T. Frenkil Building, 16 South Eutaw Street, Suite 500, Baltimore, Maryland 21201, USA
| | - Kevin K Ohlemiller
- Washington University School of Medicine, Department of Otolaryngology, Central Institute for the Deaf at Washington University School of Medicine, Fay and Carl Simons Center for Hearing and Deafness, 660 South Euclid Avenue, Saint Louis, Missouri 63110, USA
| |
Collapse
|
2
|
Abstract
The identification of transcriptional differences has served as an important starting point in understanding the molecular mechanisms behind biological processes and systems. The developmental biology of the inner ear, the biology of hearing and of course the pathology of deafness are all processes that warrant a molecular description if we are to improve human health. To this end, technological innovation has meant that larger scale analysis of gene transcription has been possible for a number of years now, extending our molecular analysis of genes to beyond those that are currently in vogue for a given system. In this review, some of the contributions gene profiling has made to understanding developmental, pathological and physiological processes in the inner ear are highlighted.
Collapse
Affiliation(s)
- Thomas Schimmang
- Instituto de Biología y Genética MolecularUniversidad de Valladolid y Consejo Superior de Investigaciones CientíficasValladolidSpain
| | - Mark Maconochie
- School of Biological and Chemical SciencesQueen Mary University of LondonLondonUK
| |
Collapse
|
3
|
High quality RNA extraction of the mammalian cochlea for qRT-PCR and transcriptome analyses. Hear Res 2015; 325:42-8. [PMID: 25818515 DOI: 10.1016/j.heares.2015.03.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/08/2015] [Accepted: 03/13/2015] [Indexed: 11/23/2022]
Abstract
Molecular investigations of the hearing organ, the cochlea, have been hampered due to the difficulty of isolating pure RNA and in quantities sufficient enough for quantitative real-time RT-PCR or microarray analysis. The complex architecture of the cochlea, the presence of liquids, bone and cartilage tissue, are a major hurdle in obtaining contamination-free RNA to a level that does not affect downstream applications. Here, we present a protocol to extract RNA from the mouse cochlea, with yields and quality suitable for real-time RT-PCR or Affymetrix labeling. In contrast to current methods, such as TRIZOL or column-based extraction, this protocol combines the two and, within 4 h, yields a 2 μg of total RNA from a single pair of adult mouse cochleae. This protocol allows the isolation of RNA molecules from the mammalian cochlea providing access to whole-transcript expression analyses.
Collapse
|
4
|
Alagramam KN, Stepanyan R, Jamesdaniel S, Chen DHC, Davis RR. Noise exposure immediately activates cochlear mitogen-activated protein kinase signaling. Noise Health 2015; 16:400-9. [PMID: 25387536 DOI: 10.4103/1463-1741.144418] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Noise-induced hearing loss (NIHL) is a major public health issue worldwide. Uncovering the early molecular events associated with NIHL would reveal mechanisms leading to the hearing loss. Our aim is to investigate the immediate molecular responses after different levels of noise exposure and identify the common and distinct pathways that mediate NIHL. Previous work showed mice exposed to 116 decibels sound pressure level (dB SPL) broadband noise for 1 h had greater threshold shifts than the mice exposed to 110 dB SPL broadband noise, hence we used these two noise levels in this study. Groups of 4-8-week-old CBA/CaJ mice were exposed to no noise (control) or to broadband noise for 1 h, followed by transcriptome analysis of total cochlear RNA isolated immediately after noise exposure. Previously identified and novel genes were found in all data sets. Following exposure to noise at 116 dB SPL, the earliest responses included up-regulation of 243 genes and down-regulation of 61 genes, while a similar exposure at 110 dB SPL up-regulated 155 genes and down-regulated 221 genes. Bioinformatics analysis indicated that mitogen-activated protein kinase (MAPK) signaling was the major pathway in both levels of noise exposure. Nevertheless, both qualitative and quantitative differences were noticed in some MAPK signaling genes, after exposure to different noise levels. Cacna1b , Cacna1g , and Pla2g6 , related to calcium signaling were down-regulated after 110 dB SPL exposure, while the fold increase in the expression of Fos was relatively lower than what was observed after 116 dB SPL exposure. These subtle variations provide insight on the factors that may contribute to the differences in NIHL despite the activation of a common pathway.
Collapse
Affiliation(s)
- Kumar N Alagramam
- Department of Otolaryngology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | | | |
Collapse
|
5
|
Hertzano R, Elkon R. High throughput gene expression analysis of the inner ear. Hear Res 2012; 288:77-88. [PMID: 22710153 DOI: 10.1016/j.heares.2012.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 12/30/2011] [Accepted: 01/02/2012] [Indexed: 12/25/2022]
Abstract
The mouse auditory and vestibular epithelia consist of a complex array of many different cell types. Over the last decade microarrays were used to characterize gene expression in the inner ear. Studies were performed on wild type mice to identify deafness genes, transcriptional networks activated during development, or identify miRNA with a functional role in the ear. Other studies focused on the molecular response of the inner ear to stimuli ranging from ototoxic medications to hypergravity and caloric restriction. Finally, microarrays were used to identify transcriptional networks activated downstream of deafness genes. As template-free high throughput gene expression profiling methods such as RNA-seq are increasingly popular, we offer a critical review of the data generated over the last decade relating to microarrays for gene expression profiling of the inner ear. Moreover, as most of the published data is available through the gene expression omnibus (GEO), we demonstrate the feasibility of integrating data from independent experiments to reach novel insights.
Collapse
Affiliation(s)
- Ronna Hertzano
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland, 16 S Eutaw St. Suite 500, Baltimore, MD 21201, USA.
| | | |
Collapse
|
6
|
Mazurek B, Yu Y, Haupt H, Szczepek AJ, Olze H. Salicylate modulates Hsp70 expression in the explanted organ of Corti. Neurosci Lett 2011; 501:67-71. [PMID: 21782002 DOI: 10.1016/j.neulet.2011.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/20/2011] [Accepted: 05/03/2011] [Indexed: 11/16/2022]
Abstract
Heat shock protein 70 (Hsp70, Hspa1a) is known to play a protective role in the inner ear and in the nervous system. Our recent study demonstrated that the induction of Hsp70 by geldanamycin protected the auditory hair cells against ototoxic insult. Here, using the explanted organ of Corti (OC), we characterized the effect of sodium salicylate on the expression of Hsp70. Using the real-time RT-PCR; after 27 h in standard culture, we observed an increase in the Hsp70 transcript number. After 48 h in culture, the number of Hsp70 transcripts increased further, as compared to the freshly isolated tissues or explant cultured for 27 h. Three hours after the addition of 2.5mM sodium salicylate, the expression of Hsp70 mRNA increased significantly. Interestingly, Hsp70 protein level remained unaffected by the addition of salicylate, as shown by immunoblotting and Hsp70-ELISA. Confocal microscopy imaging demonstrated predominant localization of Hsp70 protein with or without salicylate exposure to the fibrocytes of spiral limbus. Our results suggest that in the OC, explanting process induces expression of Hsp70 in limbal fibrocytes and that this expression can be enhanced by salicylate but only on mRNA and not on the protein level.
Collapse
Affiliation(s)
- Birgit Mazurek
- Molecular Biology Research Laboratory, Department of Otorhinolaryngology, Charité - Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany.
| | | | | | | | | |
Collapse
|
7
|
Hwang JH, Chen JC, Yang SY, Wang MF, Chan YC. Expression of tumor necrosis factor-α and interleukin-1β genes in the cochlea and inferior colliculus in salicylate-induced tinnitus. J Neuroinflammation 2011; 8:30. [PMID: 21477330 PMCID: PMC3087687 DOI: 10.1186/1742-2094-8-30] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Accepted: 04/09/2011] [Indexed: 01/21/2023] Open
Abstract
Background Changes in the gene expressions for tumor necrosis factor-α (TNF-α) and/or interleukin-1β (IL-1β) during tinnitus have not been previously reported. We evaluated tinnitus and mRNA expression levels of TNF-α, IL-1β, and N-methyl D-aspartate receptor subunit 2B (NR2B) genes in cochlea and inferior colliculus (IC) of mice after intraperitoneal injections of salicylate. Methods Forty-eight 3-month-old male SAMP8 mice were randomly and equally divided into two groups: salicylate-treated and saline-treated. All mice were trained to perform an active avoidance task for 5 days. Once conditioned, an active avoidance task was performed 2 hours after daily intraperitoneal injections of saline, either alone or containing 300 mg/kg sodium salicylate. Total numbers of times (tinnitus score) the mice climbed during the inter-trial silent period for 10 trials were recorded daily for 4 days (days 7 to 10), and then mice were euthanized for determination of mRNA expression levels of TNF-α, IL-1β, and NR2B genes in cochlea and IC at day 10. Results Tinnitus scores increased in response to daily salicylate treatments. The mRNA expression levels of TNF-α increased significantly for the salicylate-treated group compared to the control group in both cochlea (1.89 ± 0.22 vs. 0.87 ± 0.07, P < 0.0001) and IC (2.12 ± 0.23 vs. 1.73 ± 0.22, p = 0.0040). mRNA expression levels for the IL-1β gene also increased significantly in the salicylate group compared to the control group in both cochlea (3.50 ± 1.05 vs. 2.80 ± 0.28, p < 0.0001) and IC (2.94 ± 0.51 versus 1.24 ± 0.52, p = 0.0013). Linear regression analysis revealed a significant positive association between tinnitus scores and expression levels of TNF-α, IL-1β, and NR2B genes in cochlea and IC. In addition, expression levels of the TNF-α gene were positively correlated with those of the NR2Bgene in both cochlea and IC; whereas, the expression levels of the IL-1β gene was positively correlated with that of the NR2B gene in IC, but not in cochlea. Conclusion We conclude that salicylate treatment resulting in tinnitus augments expression of the TNF-α and IL-1β genes in cochlea and IC of mice, and we suggest that these proinflammatory cytokines might lead to tinnitus directly or via modulating the NMDA receptor.
Collapse
Affiliation(s)
- Juen-Haur Hwang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | | | | | | |
Collapse
|
8
|
Hwang JH, Chen JC, Yang SY, Wang MF, Liu TC, Chan YC. Expression of COX-2 and NMDA receptor genes at the cochlea and midbrain in salicylate-induced tinnitus. Laryngoscope 2011; 121:361-4. [PMID: 21271589 DOI: 10.1002/lary.21283] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 07/28/2010] [Indexed: 11/11/2022]
Abstract
OBJECTIVE/HYPOTHESIS The expression of the genes for cyclooxygenase (COX) and NMDA receptor (NR) has seldom been reported in tinnitus. We hypothesized that expression of COX-2 and NR was altered in the cochlea and midbrain in salicylate-induced tinnitus. STUDY DESIGN Experimental study on mice. METHODS We evaluated the tinnitus score and mRNA expression levels of COX-2 and NR subtype 2B (NR2B) in the cochlea and midbrain in response to intraperitoneal injections of salicylate for 4 days. RESULTS At day 4 of tinnitus induction, the mean weights of the whole body and midbrain did not change greatly in both control and salicylate groups. The tinnitus score was not elevated from day 1 to day 4 in the control group, but increased day by day in the salicylate group. The mRNA expression level of COX-2 decreased slightly in the salicylate group in the cochlea (1.1 ± 0.33 vs. 1.3 ± 0.49, P = .0752) and in the midbrain (0.9 ± 0.10 versus 1.0 ± 0.35, P = .0489). Inversely, the expression levels of the NR2B gene increased moderately in the salicylate group in the cochlea (3.7 ± 0.47 versus 2.3 ± 1.13, P < 0.0001) and in the midbrain (1.6 ± 0.64 versus 1.0 ± 0.44, P = .0007). CONCLUSIONS Salicylate induced tinnitus and altered the expression of the COX-2 and NR2B genes in the cochlea and midbrain of mice. These findings might contribute to further understanding of pathophysiology and therapy of tinnitus.
Collapse
Affiliation(s)
- Juen-Haur Hwang
- Department of Otolaryngology, Buddhist Dalin Tzu-Chi General Hospital, Chiayi, Taiwan
| | | | | | | | | | | |
Collapse
|
9
|
Expression of Insulin-like Growth Factors in a Mouse Model of Salicylate Ototoxicity. Clin Exp Otorhinolaryngol 2010; 3:115-21. [PMID: 20978631 PMCID: PMC2958504 DOI: 10.3342/ceo.2010.3.3.115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 07/17/2010] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES Insulin-like growth factors (IGFs) are known to be neurotrophic factors, and they efficiently signal to cells to grow, differentiate and survive. The purpose of study was to identify the expressions of IGFs in mice with salicylate ototoxicity, which is a typical reversible hearing loss model. METHODS The mice were given intraperitoneal injections of salicylate (400 mg/kg) and about a 30 dB threshold shift was achieved at 3 hours. The expressions of IGF-1 and 2 were confirmed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Localization of IGFs was confirmed using confocal immunofluorescence imaging. For in-vitro study on the HEI-OC1 auditory cells, the cell viability was calculated and the apoptotic features of the nuclei were observed with Hoechst staining. RESULTS The expressions of the IGFs mRNA and protein were significantly increased in the salicylate ototoxicity groups compared with that of the normal control group. Salicylate induced apoptosis and decreased viability of the HEI-OC1 auditory cells in a time- and dose-dependent manner. The expressions of IGFs were localized in the stria vascularis, and these IGFs play a protective role in the in-vivo condition of salicylate ototoxicity. CONCLUSION IGFs were highly expressed in the mice with salicylate ototoxicity, and this expression was mainly focused in the stria vascularis in the salicylate intoxicated mice. The systemic action of IGFs, which were expressed in the vascular-rich stria vascularis, can act as a major protective mechanism in a mouse model of salicylate ototoxicity.
Collapse
|
10
|
Knipper M, Zimmermann U, Müller M. Molecular aspects of tinnitus. Hear Res 2010; 266:60-9. [DOI: 10.1016/j.heares.2009.07.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 07/28/2009] [Accepted: 07/28/2009] [Indexed: 01/18/2023]
|
11
|
Kizawa K, Kitahara T, Horii A, Maekawa C, Kuramasu T, Kawashima T, Nishiike S, Doi K, Inohara H. Behavioral assessment and identification of a molecular marker in a salicylate-induced tinnitus in rats. Neuroscience 2010; 165:1323-32. [DOI: 10.1016/j.neuroscience.2009.11.048] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 11/19/2009] [Accepted: 11/19/2009] [Indexed: 11/30/2022]
|
12
|
Jung HH, Kim HJ, Im GJ, Chang J, Choi J, Chae SW. Differential protein expression profiles in salicylate ototoxicity of the mouse cochlea. Hear Res 2009; 255:121-8. [PMID: 19540324 DOI: 10.1016/j.heares.2009.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 06/10/2009] [Indexed: 10/20/2022]
Abstract
The purpose of this study was to investigate protein expression profiles of salicylate ototoxicity using proteomic analysis, and to identify whether salicylates induce apoptosis in organotypic culture of mouse cochlear cells. The adult mice were injected intraperitoneally with 400mg/kg of sodium salicylate. Approximately 30dB threshold shift was observed 3h after the injection, and the hearing threshold returned to normal range within 3 days. Proteomic analysis of mouse cochlea was performed 3h after salicylate injection, because this was the time to show maximal ototoxic effect in salicylate intoxication. Expression pattern of proteomic analysis at 3h was compared with those of normal cochlea and cochlea 3 days after salicylate injection. Sixteen proteins were transiently up-regulated threefolds or more at 3h after the injection compared with normal cochlea, and three proteins were down-regulated at 3h. Similar protein expression profiles were also observed between normal and 3 days group. These up-regulated and down-regulated proteins at 3h were analyzed by MALDI-TOF MS. The mRNA expressions of nine selected genes from 16 up-regulated protein profiles were also investigated by RT-PCR, and their expression levels at 3h were found to be higher than those of normal cochlea. We also confirmed the ototoxicity of salicylate in organotypic culture of cochlear cells using MTT assay, Hoechst staining and DNA laddering assay in vitro, and found that salicylate decreased the viability of cells in a time and dose-dependent manner, and that induced apoptosis in organotypic culture of cochlear cells. This study demonstrated that some proteins can be related to salicylate ototoxicity, and provides basic information about candidate proteins which are related to pathologic changes in salicylate-induced ototoxicity.
Collapse
Affiliation(s)
- Hak Hyun Jung
- Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Republic of Korea.
| | | | | | | | | | | |
Collapse
|
13
|
Semjidsuren GU, Im GJ, Lee SH, Park SJ, Hwang HY, Jung HH. Differential gene expression profiles of the olfactory bulb after nasal obstruction in neonatal rats. Otolaryngol Head Neck Surg 2008; 138:648-54. [PMID: 18439473 DOI: 10.1016/j.otohns.2007.12.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/20/2007] [Accepted: 12/26/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Microarray technique is a useful tool to identify functional gene candidates. In this study, we evaluated the gene expression profiles in the olfactory bulbs of normal rats and naris-occluded rats using the gene microarray technique. STUDY DESIGN AND METHODS To induce atrophic change in the olfactory bulb, we performed a unilateral nasal obstruction by electronic cauterization on postnatal day 1 rats. Differential gene expression profiles of the nasal obstruction group and the normal control group at postnatal day 35 were analyzed with a DNA microarray. RESULTS Microarray revealed 41 genes that were upregulated at least 2-fold in the nasal obstruction group compared with the control group. Among these upregulated genes, increased expression levels of 20 functional genes were confirmed by semiquantitative reverse transcription-polymerase chain reaction. CONCLUSION This study examines candidate genes associated with the development, apoptosis, and signal transduction of the olfactory bulb. These results may explain the fact that blockage of airflow by inflammation and nasal polyps causes deprivation of olfactory functions in vivo.
Collapse
Affiliation(s)
- Gan-Undram Semjidsuren
- Department of Biomedical Sciences, College of Medicine, Korea University, Sungbuk-Gu, Seoul, Korea
| | | | | | | | | | | |
Collapse
|