1
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Johns JD, Olszewski R, Strepay D, Lopez IA, Ishiyama A, Hoa M. Emerging Mechanisms in the Pathogenesis of Menière's Disease: Evidence for the Involvement of Ion Homeostatic or Blood-Labyrinthine Barrier Dysfunction in Human Temporal Bones. Otol Neurotol 2023; 44:1057-1065. [PMID: 37733989 PMCID: PMC10840868 DOI: 10.1097/mao.0000000000004016] [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: 09/23/2023]
Abstract
HYPOTHESIS Analysis of human temporal bone specimens of patients with Menière's disease (MD) may demonstrate altered expression of gene products related to barrier formation and ionic homeostasis within cochlear structures compared with control specimens. BACKGROUND MD represents a challenging otologic disorder for investigation. Despite attempts to define the pathogenesis of MD, there remain many gaps in our understanding, including differences in protein expression within the inner ear. Understanding these changes may facilitate the identification of more targeted therapies for MD. METHODS Human temporal bones from patients with MD (n = 8) and age-matched control patients (n = 8) were processed with immunohistochemistry stains to detect known protein expression related to ionic homeostasis and barrier function in the cochlea, including CLDN11, CLU, KCNJ10, and SLC12A2. Immunofluorescence intensity analysis was performed to quantify protein expression in the stria vascularis, organ of Corti, and spiral ganglion neuron (SGN). RESULTS Expression of KCNJ10 was significantly reduced in all cochlear regions, including the stria vascularis (9.23 vs 17.52, p = 0.011), OC (14.93 vs 29.16, p = 0.014), and SGN (7.69 vs 18.85, p = 0.0048) in human temporal bone specimens from patients with MD compared with control, respectively. CLDN11 (7.40 vs 10.88, p = 0.049) and CLU (7.80 vs 17.51, p = 0.0051) expression was significantly reduced in the SGN. CONCLUSION The results of this study support that there may be differences in the expression of proteins related to ionic homeostasis and barrier function within the cochlea, potentially supporting the role of targeted therapies to treat MD.
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Affiliation(s)
- J. Dixon Johns
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
- Department of Otolaryngology, Georgetown University School of Medicine, Washington DC, USA
| | - Rafal Olszewski
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Dillon Strepay
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Ivan A. Lopez
- Department of Head & Neck Surgery, University of California School of Medicine, Los Angeles, CA, USA
| | - Akira Ishiyama
- Department of Head & Neck Surgery, University of California School of Medicine, Los Angeles, CA, USA
| | - Michael Hoa
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
- Department of Otolaryngology, Georgetown University School of Medicine, Washington DC, USA
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2
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Trigila AP, Castagna VC, Berasain L, Montini D, Rubinstein M, Gomez-Casati ME, Franchini LF. Accelerated Evolution Analysis Uncovers PKNOX2 as a Key Transcription Factor in the Mammalian Cochlea. Mol Biol Evol 2023; 40:msad128. [PMID: 37247388 PMCID: PMC10337857 DOI: 10.1093/molbev/msad128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 04/12/2023] [Accepted: 04/17/2023] [Indexed: 05/31/2023] Open
Abstract
The genetic bases underlying the evolution of morphological and functional innovations of the mammalian inner ear are poorly understood. Gene regulatory regions are thought to play an important role in the evolution of form and function. To uncover crucial hearing genes whose regulatory machinery evolved specifically in mammalian lineages, we mapped accelerated noncoding elements (ANCEs) in inner ear transcription factor (TF) genes and found that PKNOX2 harbors the largest number of ANCEs within its transcriptional unit. Using reporter gene expression assays in transgenic zebrafish, we determined that four PKNOX2-ANCEs drive differential expression patterns when compared with ortholog sequences from close outgroup species. Because the functional role of PKNOX2 in cochlear hair cells has not been previously investigated, we decided to study Pknox2 null mice generated by CRISPR/Cas9 technology. We found that Pknox2-/- mice exhibit reduced distortion product otoacoustic emissions (DPOAEs) and auditory brainstem response (ABR) thresholds at high frequencies together with an increase in peak 1 amplitude, consistent with a higher number of inner hair cells (IHCs)-auditory nerve synapsis observed at the cochlear basal region. A comparative cochlear transcriptomic analysis of Pknox2-/- and Pknox2+/+ mice revealed that key auditory genes are under Pknox2 control. Hence, we report that PKNOX2 plays a critical role in cochlear sensitivity at higher frequencies and that its transcriptional regulation underwent lineage-specific evolution in mammals. Our results provide novel insights about the contribution of PKNOX2 to normal auditory function and to the evolution of high-frequency hearing in mammals.
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Affiliation(s)
- Anabella P Trigila
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Valeria C Castagna
- Facultad de Medicina, Instituto de Farmacología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lara Berasain
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Dante Montini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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3
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Molecular and cytological profiling of biological aging of mouse cochlear inner and outer hair cells. Cell Rep 2022; 39:110665. [PMID: 35417713 PMCID: PMC9069708 DOI: 10.1016/j.celrep.2022.110665] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/08/2022] [Accepted: 03/21/2022] [Indexed: 12/12/2022] Open
Abstract
Age-related hearing loss (ARHL) negatively impacts quality of life in the elderly population. The prevalent cause of ARHL is loss of mechanosensitive cochlear hair cells (HCs). The molecular and cellular mechanisms of HC degeneration remain poorly understood. Using RNA-seq transcriptomic analyses of inner and outer HCs isolated from young and aged mice, we show that HC aging is associated with changes in key molecular processes, including transcription, DNA damage, autophagy, and oxidative stress, as well as genes related to HC specialization. At the cellular level, HC aging is characterized by loss of stereocilia, shrinkage of HC soma, and reduction in outer HC mechanical properties, suggesting that functional decline in mechanotransduction and cochlear amplification precedes HC loss and contributes to ARHL. Our study reveals molecular and cytological profiles of aging HCs and identifies genes such as Sod1, Sirt6, Jund, and Cbx3 as biomarkers and potential therapeutic targets for ameliorating ARHL. Using RNA-seq, advanced imaging, and electrophysiology, Liu et al. reveal molecular and cytological profiles of aging cochlear hair cells. Their study also suggests that a functional decline in mechanotransduction and cochlear amplification precedes hair cell loss and contributes to age-related hearing loss.
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4
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CRISPR/Cas9-mediated pou4f3 knockout induces defects in the development of the zebrafish inner ear. JOURNAL OF BIO-X RESEARCH 2021. [DOI: 10.1097/jbr.0000000000000102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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5
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Xu Z, Rai V, Zuo J. TUB and ZNF532 Promote the Atoh1-Mediated Hair Cell Regeneration in Mouse Cochleae. Front Cell Neurosci 2021; 15:759223. [PMID: 34819838 PMCID: PMC8606527 DOI: 10.3389/fncel.2021.759223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/15/2021] [Indexed: 12/31/2022] Open
Abstract
Hair cell (HC) regeneration is a promising therapy for permanent sensorineural hearing loss caused by HC loss in mammals. Atoh1 has been shown to convert supporting cells (SCs) to HCs in neonatal cochleae; its combinations with other factors can improve the efficiency of HC regeneration. To identify additional transcription factors for efficient Atoh1-mediated HC regeneration, here we optimized the electroporation procedure for explant culture of neonatal mouse organs of Corti and tested multiple transcription factors, Six2, Ikzf2, Lbh, Arid3b, Hmg20 a, Tub, Sall1, and Znf532, for their potential to promote Atoh1-mediated conversion of SCs to HCs. These transcription factors are expressed highly in HCs but differentially compared to the converted HCs based on previous studies, and are also potential co-reprograming factors for Atoh1-mediated SC-to-HC conversion by literature review. P0.5 cochlear explants were electroporated with these transcription factors alone or jointly with Atoh1. We found that Sox2+ progenitors concentrated within the lateral greater epithelial ridge (GER) can be electroporated efficiently with minimal HC damage. Atoh1 ectopic expression promoted HC regeneration in Sox2+ lateral GER cells. Transcription factors Tub and Znf532, but not the other six tested, promoted the HC regeneration mediated by Atoh1, consistent with previous studies that Isl1 promotes Atoh1-mediated HC conversionex vivo and in vivo and that both Tub and Znf532 are downstream targets of Isl1. Thus, our studies revealed an optimized electroporation method that can transfect the Sox2+ lateral GER cells efficiently with minimal damage to the endogenous HCs. Our results also demonstrate the importance of the Isl1/Tub/Znf532 pathway in promoting Atoh1-mediated HC regeneration.
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Affiliation(s)
- Zhenhang Xu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States.,Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, China
| | - Vikrant Rai
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
| | - Jian Zuo
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
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6
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Fursultiamine Prevents Drug-Induced Ototoxicity by Reducing Accumulation of Reactive Oxygen Species in Mouse Cochlea. Antioxidants (Basel) 2021; 10:antiox10101526. [PMID: 34679662 PMCID: PMC8533091 DOI: 10.3390/antiox10101526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/04/2021] [Accepted: 09/23/2021] [Indexed: 01/19/2023] Open
Abstract
Drug-induced hearing loss is a major type of acquired sensorineural hearing loss. Cisplatin and aminoglycoside antibiotics have been known to cause ototoxicity, and excessive accumulation of intracellular reactive oxygen species (ROS) are suggested as the common major pathology of cisplatin- and aminoglycoside antibiotics-induced ototoxicity. Fursultiamine, also called thiamine tetrahydrofurfuryl disulfide, is a thiamine disulfide derivative that may have antioxidant effects. To evaluate whether fursultiamine can prevent cisplatin- and kanamycin-induced ototoxicity, we investigated their preventive potential using mouse cochlear explant culture system. Immunofluorescence staining of mouse cochlear hair cells showed that fursultiamine pretreatment reduced cisplatin- and kanamycin-induced damage to both inner and outer hair cells. Fursultiamine attenuated mitochondrial ROS accumulation as evidenced by MitoSOX Red staining and restored mitochondrial membrane potential in a JC-1 assay. In addition, fursultiamine pretreatment reduced active caspase-3 and TUNEL signals after cisplatin or kanamycin treatment, indicating that fursultiamine decreased apoptotic hair cell death. This study is the first to show a protective effect of fursultiamine against cisplatin- and aminoglycoside antibiotics-induced ototoxicity. Our results suggest that fursultiamine could act as an antioxidant and anti-apoptotic agent against mitochondrial oxidative stress.in cochlear hair cells.
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7
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Deletion of Clusterin Protects Cochlear Hair Cells against Hair Cell Aging and Ototoxicity. Neural Plast 2021; 2021:9979157. [PMID: 34194490 PMCID: PMC8181089 DOI: 10.1155/2021/9979157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/15/2021] [Accepted: 04/28/2021] [Indexed: 01/06/2023] Open
Abstract
Hearing loss is a debilitating disease that affects 10% of adults worldwide. Most sensorineural hearing loss is caused by the loss of mechanosensitive hair cells in the cochlea, often due to aging, noise, and ototoxic drugs. The identification of genes that can be targeted to slow aging and reduce the vulnerability of hair cells to insults is critical for the prevention of sensorineural hearing loss. Our previous cell-specific transcriptome analysis of adult cochlear hair cells and supporting cells showed that Clu, encoding a secreted chaperone that is involved in several basic biological events, such as cell death, tumor progression, and neurodegenerative disorders, is expressed in hair cells and supporting cells. We generated Clu-null mice (C57BL/6) to investigate its role in the organ of Corti, the sensory epithelium responsible for hearing in the mammalian cochlea. We showed that the deletion of Clu did not affect the development of hair cells and supporting cells; hair cells and supporting cells appeared normal at 1 month of age. Auditory function tests showed that Clu-null mice had hearing thresholds comparable to those of wild-type littermates before 3 months of age. Interestingly, Clu-null mice displayed less hair cell and hearing loss compared to their wildtype littermates after 3 months. Furthermore, the deletion of Clu is protected against aminoglycoside-induced hair cell loss in both in vivo and in vitro models. Our findings suggested that the inhibition of Clu expression could represent a potential therapeutic strategy for the alleviation of age-related and ototoxic drug-induced hearing loss.
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8
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Liu H, Giffen KP, Grati M, Morrill SW, Li Y, Liu X, Briegel KJ, He DZ. Transcription co-factor LBH is necessary for the survival of cochlear hair cells. J Cell Sci 2021; 134:237781. [PMID: 33674448 DOI: 10.1242/jcs.254458] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/11/2021] [Indexed: 11/20/2022] Open
Abstract
Hearing loss affects ∼10% of adults worldwide. Most sensorineural hearing loss is caused by the progressive loss of mechanosensitive hair cells (HCs) in the cochlea. The molecular mechanisms underlying HC maintenance and loss remain poorly understood. LBH, a transcription co-factor implicated in development, is abundantly expressed in outer hair cells (OHCs). We used Lbh-null mice to identify its role in HCs. Surprisingly, Lbh deletion did not affect differentiation and the early development of HCs, as nascent HCs in Lbh knockout mice had normal looking stereocilia. The stereocilia bundle was mechanosensitive and OHCs exhibited the characteristic electromotility. However, Lbh-null mice displayed progressive hearing loss, with stereocilia bundle degeneration and OHC loss as early as postnatal day 12. RNA-seq analysis showed significant gene enrichment of biological processes related to transcriptional regulation, cell cycle, DNA damage/repair and autophagy in Lbh-null OHCs. In addition, Wnt and Notch pathway-related genes were found to be dysregulated in Lbh-deficient OHCs. Our study implicates, for the first time, loss of LBH function in progressive hearing loss, and demonstrates a critical requirement of LBH in promoting HC survival in adult mice.
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Affiliation(s)
- Huizhan Liu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Kimberlee P Giffen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - M'Hamed Grati
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Seth W Morrill
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Yi Li
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA.,Department of Otorhinolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, 100730 Beijing, China
| | - Xuezhong Liu
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Karoline J Briegel
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - David Z He
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
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9
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Wang S, Lee MP, Jones S, Liu J, Waldhaus J. Mapping the regulatory landscape of auditory hair cells from single-cell multi-omics data. Genome Res 2021; 31:1885-1899. [PMID: 33837132 DOI: 10.1101/gr.271080.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/23/2021] [Indexed: 11/25/2022]
Abstract
Auditory hair cells transduce sound to the brain and in mammals these cells reside together with supporting cells in the sensory epithelium of the cochlea, called the organ of Corti. To establish the organ's delicate function during development and differentiation, spatiotemporal gene expression is strictly controlled by chromatin accessibility and cell type-specific transcription factors, jointly representing the regulatory landscape. Bulk-sequencing technology and cellular heterogeneity obscured investigations on the interplay between transcription factors and chromatin accessibility in inner ear development. To study the formation of the regulatory landscape in hair cells, we collected single-cell chromatin accessibility profiles accompanied by single-cell RNA data from genetically labeled murine hair cells and supporting cells after birth. Using an integrative approach, we predicted cell type-specific activating and repressing functions of developmental transcription factors. Furthermore, by integrating gene expression and chromatin accessibility datasets, we reconstructed gene regulatory networks. Then, using a comparative approach, 20 hair cell-specific activators and repressors, including putative downstream target genes, were identified. Clustering of target genes resolved groups of related transcription factors and was utilized to infer their developmental functions. Finally, the heterogeneity in the single-cell data allowed us to spatially reconstruct transcriptional as well as chromatin accessibility trajectories, indicating that gradual changes in the chromatin accessibility landscape were lagging behind the transcriptional identity of hair cells along the organ's longitudinal axis. Overall, this study provides a strategy to spatially reconstruct the formation of a lineage specific regulatory landscape using a single-cell multi-omics approach.
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Affiliation(s)
- Shuze Wang
- University of Michigan, Kresge Hearing Research Institute
| | - Mary P Lee
- University of Michigan, Kresge Hearing Research Institute
| | - Scott Jones
- University of Michigan, Kresge Hearing Research Institute
| | | | - Joerg Waldhaus
- University of Michigan, Kresge Hearing Research Institute;
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10
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Chan YH, Liu TC, Liao CK, Cheng YF, Tsai CH, Lu YC, Hu CJ, Lin HJ, Lee YL, Wu CC, Hsu CJ. Consumption of betel quid contributes to sensorineural hearing impairment through arecoline-induced oxidative stress. Sci Rep 2019; 9:14554. [PMID: 31601870 PMCID: PMC6787045 DOI: 10.1038/s41598-019-49815-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 08/22/2019] [Indexed: 11/09/2022] Open
Abstract
Betel quid is one of the most widely used psychoactive substances, and is consumed by approximately 10% of the world’s population. In addition to its carcinogenicity, betel quid has also been reported to affect many organs, including the brain, heart, lungs, gastrointestinal tract, and reproductive organs. As betel quid contains several neurotoxic ingredients, we hypothesize that it also possesses ototoxicity and may lead to sensorineural hearing impairment (SNHI). In this study, we investigated the contribution of betel quid consumption to SNHI in a large clinical cohort, and validated the pathogenetic mechanisms in ex vivo tissue explants. We enrolled a total of 2364 volunteers, and determined their audiologic results based on Z-scores converted from their original frequency-specific hearing thresholds. Using generalized linear regression, we identified a positive correlation between betel quid consumption and the Z-scores across different frequencies. Subsequently, we explored the toxicity of arecoline, the main neuroactive component of betel quid, on tissue explants from murine cochleae. Arecoline reduced cell activity in the explant cultures and induced apoptosis in the hair cells, probably through the effects of oxidative stress. These findings have expanded the potential hazards of betel quid to common neurological disorders, and provide insights into preventive strategies against SNHI caused by neurotoxic substances.
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Affiliation(s)
- Yen-Hui Chan
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Otolaryngology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
| | - Tien-Chen Liu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chun-Kang Liao
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yen-Fu Cheng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Otolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ching-Hui Tsai
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Ying-Chang Lu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chin-Ju Hu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hung-Ju Lin
- Health Management Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Yungling Leo Lee
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan. .,Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan.
| | - Chuan-Jen Hsu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Otolaryngology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
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11
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Helios is a key transcriptional regulator of outer hair cell maturation. Nature 2018; 563:696-700. [PMID: 30464345 PMCID: PMC6542691 DOI: 10.1038/s41586-018-0728-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/25/2018] [Indexed: 11/09/2022]
Abstract
The sensory cells that are responsible for hearing include the cochlear inner hair cells (IHCs) and outer hair cells (OHCs), with the OHCs being necessary for sound sensitivity and tuning1. Both cell types are thought to arise from common progenitors; however, our understanding of the factors that control the fate of IHCs and OHCs remains limited. Here we identify Ikzf2 (which encodes Helios) as an essential transcription factor in mice that is required for OHC functional maturation and hearing. Helios is expressed in postnatal mouse OHCs, and in the cello mouse model a point mutation in Ikzf2 causes early-onset sensorineural hearing loss. Ikzf2cello/cello OHCs have greatly reduced prestin-dependent electromotile activity, a hallmark of OHC functional maturation, and show reduced levels of crucial OHC-expressed genes such as Slc26a5 (which encodes prestin) and Ocm. Moreover, we show that ectopic expression of Ikzf2 in IHCs: induces the expression of OHC-specific genes; reduces the expression of canonical IHC genes; and confers electromotility to IHCs, demonstrating that Ikzf2 can partially shift the IHC transcriptome towards an OHC-like identity.
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12
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Li Y, Liu H, Giffen KP, Chen L, Beisel KW, He DZZ. Transcriptomes of cochlear inner and outer hair cells from adult mice. Sci Data 2018; 5:180199. [PMID: 30277483 PMCID: PMC6167952 DOI: 10.1038/sdata.2018.199] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/02/2018] [Indexed: 01/09/2023] Open
Abstract
Inner hair cells (IHCs) and outer hair cells (OHCs) are the two anatomically and functionally distinct types of mechanosensitive receptor cells in the mammalian cochlea. The molecular mechanisms defining their morphological and functional specializations are largely unclear. As a first step to uncover the underlying mechanisms, we examined the transcriptomes of IHCs and OHCs isolated from adult CBA/J mouse cochleae. One thousand IHCs and OHCs were separately collected using the suction pipette technique. RNA sequencing of IHCs and OHCs was performed and their transcriptomes were analyzed. The results were validated by comparing some IHC and OHC preferentially expressed genes between present study and published microarray-based data as well as by real-time qPCR. Antibody-based immunocytochemistry was used to validate preferential expression of SLC7A14 and DNM3 in IHCs and OHCs. These data are expected to serve as a highly valuable resource for unraveling the molecular mechanisms underlying different biological properties of IHCs and OHCs as well as to provide a road map for future characterization of genes expressed in IHCs and OHCs.
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Affiliation(s)
- Yi Li
- Department of Otorhinolaryngology, Beijing Tongren Hospital, Beijing Capital Medical University, Beijing 100730, China
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
| | - Huizhan Liu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
| | - Kimberlee P. Giffen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
| | - Lei Chen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
- Chongqing Academy of Animal Science, Chongqing 402460, China
| | - Kirk W. Beisel
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
| | - David Z. Z. He
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68170, USA
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13
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Liu H, Chen L, Giffen KP, Stringham ST, Li Y, Judge PD, Beisel KW, He DZZ. Cell-Specific Transcriptome Analysis Shows That Adult Pillar and Deiters' Cells Express Genes Encoding Machinery for Specializations of Cochlear Hair Cells. Front Mol Neurosci 2018; 11:356. [PMID: 30327589 PMCID: PMC6174830 DOI: 10.3389/fnmol.2018.00356] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/11/2018] [Indexed: 11/13/2022] Open
Abstract
The mammalian auditory sensory epithelium, the organ of Corti, is composed of hair cells and supporting cells. Hair cells contain specializations in the apical, basolateral and synaptic membranes. These specializations mediate mechanotransduction, electrical and mechanical activities and synaptic transmission. Supporting cells maintain homeostasis of the ionic and chemical environment of the cochlea and contribute to the stiffness of the cochlear partition. While spontaneous proliferation and transdifferentiation of supporting cells are the source of the regenerative response to replace lost hair cells in lower vertebrates, supporting cells in adult mammals no longer retain that capability. An important first step to revealing the basic biological properties of supporting cells is to characterize their cell-type specific transcriptomes. Using RNA-seq, we examined the transcriptomes of 1,000 pillar and 1,000 Deiters' cells, as well as the two types of hair cells, individually collected from adult CBA/J mouse cochleae using a suction pipette technique. Our goal was to determine whether pillar and Deiters' cells, the commonly targeted cells for hair cell replacement, express the genes known for encoding machinery for hair cell specializations in the apical, basolateral, and synaptic membranes. We showed that both pillar and Deiters' cells express these genes, with pillar cells being more similar to hair cells than Deiters' cells. The fact that adult pillar and Deiters' cells express the genes cognate to hair cell specializations provides a strong molecular basis for targeting these cells for mammalian hair cell replacement after hair cells are lost due to damage.
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Affiliation(s)
- Huizhan Liu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
| | - Lei Chen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States.,Chongqing Academy of Animal Science, Chongqing, China
| | - Kimberlee P Giffen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
| | - Sean T Stringham
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
| | - Yi Li
- Department of Otorhinolaryngology-Head and Neck Surgery, Beijing Tonren Hospital, Capital Medical University, Beijing, China
| | - Paul D Judge
- Department of Otolaryngology-Head and Neck Surgery, University of Nebraska Medical Center, Omaha, NE, United States
| | - Kirk W Beisel
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
| | - David Z Z He
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States
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14
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Booth KT, Azaiez H, Jahan I, Smith RJH, Fritzsch B. Intracellular Regulome Variability Along the Organ of Corti: Evidence, Approaches, Challenges, and Perspective. Front Genet 2018; 9:156. [PMID: 29868110 PMCID: PMC5951964 DOI: 10.3389/fgene.2018.00156] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/13/2018] [Indexed: 12/13/2022] Open
Abstract
The mammalian hearing organ is a regular array of two types of hair cells (HCs) surrounded by six types of supporting cells. Along the tonotopic axis, this conserved radial array of cell types shows longitudinal variations to enhance the tuning properties of basilar membrane. We present the current evidence supporting the hypothesis that quantitative local variations in gene expression profiles are responsible for local cell responses to global gene manipulations. With the advent of next generation sequencing and the unprecedented array of technologies offering high throughput analyses at the single cell level, transcriptomics will become a common tool to enhance our understanding of the inner ear. We provide an overview of the approaches and landmark studies undertaken to date to analyze single cell variations in the organ of Corti and discuss the current limitations. We next provide an overview of the complexity of known regulatory mechanisms in the inner ear. These mechanisms are tightly regulated temporally and spatially at the transcription, RNA-splicing, mRNA-regulation, and translation levels. Understanding the intricacies of regulatory mechanisms at play in the inner ear will require the use of complementary approaches, and most probably, a combinatorial strategy coupling transcriptomics, proteomics, and epigenomics technologies. We highlight how these data, in conjunction with recent insights into molecular cell transformation, can advance attempts to restore lost hair cells.
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Affiliation(s)
- Kevin T Booth
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa, Iowa City, IA, United States.,Interdisciplinary Graduate Program in Molecular Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Hela Azaiez
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa, Iowa City, IA, United States
| | - Israt Jahan
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa, Iowa City, IA, United States
| | - Bernd Fritzsch
- Molecular Otolaryngology and Renal Research Laboratories, Department of Otolaryngology, University of Iowa, Iowa City, IA, United States.,Department of Biology, University of Iowa, Iowa City, IA, United States
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15
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Barta CL, Liu H, Chen L, Giffen KP, Li Y, Kramer KL, Beisel KW, He DZ. RNA-seq transcriptomic analysis of adult zebrafish inner ear hair cells. Sci Data 2018; 5:180005. [PMID: 29406519 PMCID: PMC5800389 DOI: 10.1038/sdata.2018.5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/11/2017] [Indexed: 02/03/2023] Open
Abstract
Although hair cells are the sensory receptors of the auditory and vestibular systems in the ears of all vertebrates, hair cell properties are different between non-mammalian vertebrates and mammals. To understand the basic biological properties of hair cells from non-mammalian vertebrates, we examined the transcriptome of adult zebrafish auditory and vestibular hair cells. GFP-labeled hair cells were isolated from inner-ear sensory epithelia of a pou4f3 promoter-driven GAP-GFP line of transgenic zebrafish. One thousand hair cells and 1,000 non-sensory surrounding cells (nsSCs) were separately collected for each biological replicate, using the suction pipette technique. RNA sequencing of three biological replicates for the two cell types was performed and analyzed. Comparisons between hair cells and nsSCs allow identification of enriched genes in hair cells, which may underlie hair cell specialization. Our dataset provides an extensive resource for understanding the molecular mechanisms underlying morphology, function, and pathology of adult zebrafish hair cells. It also establishes a framework for future characterization of genes expressed in hair cells and the study of hair cell evolution.
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Affiliation(s)
- Cody L Barta
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | - Huizhan Liu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | - Lei Chen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA.,Chongqing Academy of Animal Science, Chongqing 402460, China
| | - Kimberlee P Giffen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | - Yi Li
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA.,Department of Otorhinolaryngology-Head and Neck Surgery, Beijing Tonren Hospital, Capital Medical University, Beijing 100730, China
| | - Kenneth L Kramer
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | - Kirk W Beisel
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
| | - David Z He
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska 68178, USA
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16
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Apoptosis in inner ear sensory hair cells. J Otol 2017; 12:151-164. [PMID: 29937851 PMCID: PMC6002637 DOI: 10.1016/j.joto.2017.08.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 07/31/2017] [Accepted: 08/04/2017] [Indexed: 01/13/2023] Open
Abstract
Apoptosis, or controlled cell death, is a normal part of cellular lifespan. Cell death of cochlear hair cells causes deafness; an apoptotic process that is not well understood. Worldwide, 1.3 billion humans suffer some form of hearing loss, while 360 million suffer debilitating hearing loss as a direct result of the absence of these cochlear hair cells (Worldwide Hearing, 2014). Much is known about apoptosis in other systems and in other cell types thanks to studies done since the mid-20th century. Here we review current literature on apoptosis in general, and causes of deafness and cochlear hair cells loss as a result of apoptosis. The family of B-cell lymphoma (Bcl) proteins are among the most studied and characterized. We will review current literature on the Bcl2 and Bcl6 protein interactions in relation to apoptosis and their possible roles in vulnerability and survival of cochlear hair cells.
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17
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Liu H, Li Y, Chen L, Zhang Q, Pan N, Nichols DH, Zhang WJ, Fritzsch B, He DZZ. Organ of Corti and Stria Vascularis: Is there an Interdependence for Survival? PLoS One 2016; 11:e0168953. [PMID: 28030585 PMCID: PMC5193441 DOI: 10.1371/journal.pone.0168953] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/08/2016] [Indexed: 01/08/2023] Open
Abstract
Cochlear hair cells and the stria vascularis are critical for normal hearing. Hair cells transduce mechanical stimuli into electrical signals, whereas the stria is responsible for generating the endocochlear potential (EP), which is the driving force for hair cell mechanotransduction. We questioned whether hair cells and the stria interdepend for survival by using two mouse models. Atoh1 conditional knockout mice, which lose all hair cells within four weeks after birth, were used to determine whether the absence of hair cells would affect function and survival of stria. We showed that stria morphology and EP remained normal for long time despite a complete loss of all hair cells. We then used a mouse model that has an abnormal stria morphology and function due to mutation of the Mitf gene to determine whether hair cells are able to survive and transduce sound signals without a normal electrochemical environment in the endolymph. A strial defect, reflected by missing intermediate cells in the stria and by reduction of EP, led to systematic outer hair cell death from the base to the apex after postnatal day 18. However, an 18-mV EP was sufficient for outer hair cell survival. Surprisingly, inner hair cell survival was less vulnerable to reduction of the EP. Our studies show that normal function of the stria is essential for adult outer hair cell survival, while the survival and normal function of the stria vascularis do not depend on functional hair cells.
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Affiliation(s)
- Huizhan Liu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Yi Li
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
- Department of Otorhinolaryngology, Beijing Tongren Hospital, Beijing Capital Medical University, Beijing, China
| | - Lei Chen
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
- Chongqing Academy of Animal Science, Chongqing, China
| | - Qian Zhang
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Ning Pan
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - David H. Nichols
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Weiping J. Zhang
- Department of Pathophysiology, Second Military Medical University, Shanghai, China
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - David Z. Z. He
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska, United States of America
- * E-mail:
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18
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A Novel Nonsense Mutation of POU4F3 Gene Causes Autosomal Dominant Hearing Loss. Neural Plast 2016; 2016:1512831. [PMID: 27999687 PMCID: PMC5143711 DOI: 10.1155/2016/1512831] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/11/2016] [Accepted: 10/24/2016] [Indexed: 11/18/2022] Open
Abstract
POU4F3 gene encodes a transcription factor which plays an essential role in the maturation and maintenance of hair cells in cochlea and vestibular system. Several mutations of POU4F3 have been reported to cause autosomal dominant nonsyndromic hearing loss in recent years. In this study, we describe a pathogenic nonsense mutation located in POU4F3 in a four-generation Chinese family. Target region capture sequencing was performed to search for the candidate mutations from 81 genes related to nonsyndromic hearing loss in this family. A novel nonsense mutation of POU4F3, c.337C>T (p. Gln113⁎), was identified in a Chinese family characterized by late-onset progressive nonsyndromic hearing loss. The novel mutation cosegregated with hearing loss in this family and was absent in 200 ethnicity-matched controls. The mutation led to a stop codon and thus a truncated protein with no functional domains remained. Transient transfection and immunofluorescence assay revealed that the subcellular localization of the truncated protein differed markedly from normal protein, which could be the underlying reason for complete loss of its normal function. Here, we report the first nonsense mutation of POU4F3 associated with progressive hearing loss and explored the possible underlying mechanism. Routine examination of POU4F3 is necessary for the genetic diagnosis of hereditary hearing loss in the future.
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