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Bader K, Dalhoff E, Dierkes L, Braun LH, Gummer AW, Zelle D. Reliable Long-Term Serial Evaluation of Cochlear Function Using Pulsed Distortion-Product Otoacoustic Emissions: Analyzing Levels and Pressure Time Courses. Ear Hear 2024; 45:1326-1338. [PMID: 38809242 PMCID: PMC11325968 DOI: 10.1097/aud.0000000000001522] [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] [Received: 08/27/2023] [Accepted: 04/10/2024] [Indexed: 05/30/2024]
Abstract
OBJECTIVES To date, there is no international standard on how to use distortion-product otoacoustic emissions (DPOAEs) in serial measurements to accurately detect changes in the function of the cochlear amplifier due, for example, to ototoxic therapies, occupational noise, or the development of regenerative therapies. The use of clinically established standard DPOAE protocols for serial monitoring programs appears to be hampered by multiple factors, including probe placement and calibration effects, signal-processing complexities associated with multiple sites of emission generation as well as suboptimal selection of stimulus parameters. DESIGN Pulsed DPOAEs were measured seven times within 3 months for f2 = 1 to 14 kHz and L2 = 25 to 80 dB SPL in 20 ears of 10 healthy participants with normal hearing (mean age = 32.1 ± 9.7 years). L1 values were computed from individual optimal-path parameters derived from the corresponding individual DPOAE level map in the first test session. Three different DPOAE metrics for evaluating the functional state of the cochlear amplifier were investigated with respect to their test-retest reliability: (1) the interference-free, nonlinear-distortion component level ( LOD ), (2) the time course of the DPOAE-envelope levels, LDP ( t ), and (3) the squared, zero-lag correlation coefficient ( ) between the time courses of the DPOAE-envelope pressures, pDP ( t ), measured in two sessions. The latter two metrics include the two main DPOAE components and their state of interference. RESULTS Collated over all sessions and frequencies, the median absolute difference for LOD was 1.93 dB and for LDP ( t ) was 2.52 dB; the median of was 0.988. For the low ( f2 = 1 to 3 kHz), mid ( f2 = 4 to 9 kHz), and high ( f2 = 10 to 14 kHz) frequency ranges, the test-retest reliability of LOD increased with increasing signal to noise ratio (SNR). CONCLUSIONS On the basis of the knowledge gained from this study on the test-retest reliability of pulsed DPOAE signals and the current literature, we propose a DPOAE protocol for future serial monitoring applications that takes into account the following factors: (1) separation of DPOAE components, (2) use of individually optimal stimulus parameters, (3) SNR of at least 15 dB, (4) accurate pressure calibration, (5) consideration of frequency- and level-dependent test-retest reliabilities and corresponding reference ranges, and (6) stimulus levels L2 that are as low as possible with sufficient SNR to capture the nonlinear functional state of the cochlear amplifier operating at its highest gain.
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Affiliation(s)
- Katharina Bader
- Department of Otolaryngology, Head and Neck Surgery, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Ernst Dalhoff
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Linda Dierkes
- Department of Otolaryngology, Head and Neck Surgery, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Lore Helene Braun
- Department of Radiooncology, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Anthony W. Gummer
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Dennis Zelle
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- Earlab GmbH, Tübingen, Germany
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Ma X, Guo J, Tian M, Fu Y, Jiang P, Zhang Y, Chai R. Advance and Application of Single-cell Transcriptomics in Auditory Research. Neurosci Bull 2024; 40:963-980. [PMID: 38015350 PMCID: PMC11250760 DOI: 10.1007/s12264-023-01149-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/03/2023] [Indexed: 11/29/2023] Open
Abstract
Hearing loss and deafness, as a worldwide disability disease, have been troubling human beings. However, the auditory organ of the inner ear is highly heterogeneous and has a very limited number of cells, which are largely uncharacterized in depth. Recently, with the development and utilization of single-cell RNA sequencing (scRNA-seq), researchers have been able to unveil the complex and sophisticated biological mechanisms of various types of cells in the auditory organ at the single-cell level and address the challenges of cellular heterogeneity that are not resolved through by conventional bulk RNA sequencing (bulk RNA-seq). Herein, we reviewed the application of scRNA-seq technology in auditory research, with the aim of providing a reference for the development of auditory organs, the pathogenesis of hearing loss, and regenerative therapy. Prospects about spatial transcriptomic scRNA-seq, single-cell based genome, and Live-seq technology will also be discussed.
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Affiliation(s)
- Xiangyu Ma
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Jiamin Guo
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Mengyao Tian
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Yaoyang Fu
- Department of Psychiatry, Affiliated Hangzhou First People's Hospital, Zhejiang University school of Medicine, Hangzhou, 310030, China
| | - Pei Jiang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Yuan Zhang
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China
- Research Institute of Otolaryngology, Nanjing, 210008, China
| | - Renjie Chai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China.
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, 101408, China.
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China.
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Sun Q, Zhang L, Chen T, Li N, Tan F, Gu X, Zhou Y, Zhang Z, Lu Y, Lu J, Qian X, Guan B, Qi J, Ye F, Chai R. AAV-mediated Gpm6b expression supports hair cell reprogramming. Cell Prolif 2024; 57:e13620. [PMID: 38400824 PMCID: PMC11216921 DOI: 10.1111/cpr.13620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/04/2024] [Accepted: 01/27/2024] [Indexed: 02/26/2024] Open
Abstract
Irreversible damage to hair cells (HCs) in the cochlea leads to hearing loss. Cochlear supporting cells (SCs) in the murine cochlea have the potential to differentiate into HCs. Neuron membrane glycoprotein M6B (Gpm6b) as a four-transmembrane protein is a potential regulator of HC regeneration according to our previous research. In this study, we found that AAV-ie-mediated Gpm6b overexpression promoted SC-derived organoid expansion. Enhanced Gpm6b prevented the normal decrease in SC plasticity as the cochlea develops by supporting cells re-entry cell cycle and facilitating the SC-to-HC transformation. Also, overexpression of Gpm6b in the organ of Corti through the round window membrane injection facilitated the trans-differentiation of Lgr5+ SCs into HCs. In conclusion, our results suggest that Gpm6b overexpression promotes HC regeneration and highlights a promising target for hearing repair using the inner ear stem cells combined with AAV.
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Affiliation(s)
- Qiuhan Sun
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Liyan Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Tian Chen
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Nianci Li
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Fangzhi Tan
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Xingliang Gu
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Yinyi Zhou
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Ziyu Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Yicheng Lu
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Jie Lu
- Northern Jiangsu People's Hospital Affiliated to Yangzhou University/Clinical Medical CollegeYangzhou UniversityYangzhouChina
| | - Xiaoyun Qian
- Department of Otolaryngology‐Head and Neck Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical SchoolJiangsu Provincial Key Medical Discipline(Laboratory)NanjingChina
| | - Bing Guan
- Northern Jiangsu People's Hospital Affiliated to Yangzhou University/Clinical Medical CollegeYangzhou UniversityYangzhouChina
| | - Jieyu Qi
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
| | - Fanglei Ye
- Department of OtologyThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina
| | - Renjie Chai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High‐Tech Key Laboratory for Bio‐Medical ResearchSoutheast UniversityNanjingChina
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengduChina
- Co‐Innovation Center of NeuroregenerationNantong UniversityNantongChina
- Institute for Stem Cells and RegenerationChinese Academy of ScienceBeijingChina
- Southeast University Shenzhen Research InstituteShenzhenChina
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Wang C, Wang X, Zheng H, Yao J, Xiang Y, Liu D. The ndrg2 Gene Regulates Hair Cell Morphogenesis and Auditory Function during Zebrafish Development. Int J Mol Sci 2023; 24:10002. [PMID: 37373150 PMCID: PMC10297845 DOI: 10.3390/ijms241210002] [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] [Received: 04/27/2023] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Damages of sensory hair cells (HCs) are mainly responsible for sensorineural hearing loss, however, its pathological mechanism is not yet fully understood due to the fact that many potential deafness genes remain unidentified. N-myc downstream-regulated gene 2 (ndrg2) is commonly regarded as a tumor suppressor and a cell stress-responsive gene extensively involved in cell proliferation, differentiation, apoptosis and invasion, while its roles in zebrafish HC morphogenesis and hearing remains unclear. Results of this study suggested that ndrg2 was highly expressed in the HCs of the otic vesicle and neuromasts via in situ hybridization and single-cell RNA sequencing. Ndrg2 loss-of-function larvae showed decreased crista HCs, shortened cilia, and reduced neuromasts and functional HCs, which could be rescued by the microinjection of ndrg2 mRNA. Moreover, ndrg2 deficiency induced attenuated startle response behaviors to sound vibration stimuli. Mechanistically, there were no detectable HC apoptosis and supporting cell changes in the ndrg2 mutants, and HCs were capable of recovering by blocking the Notch signaling pathway, suggesting that ndrg2 was implicated in HC differentiation mediated by Notch. Overall, our study demonstrates that ndrg2 plays crucial roles in HC development and auditory sensory function utilizing the zebrafish model, which provides new insights into the identification of potential deafness genes and regulation mechanism of HC development.
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Affiliation(s)
- Cheng Wang
- Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; (C.W.); (J.Y.); (Y.X.)
| | - Xin Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong 226001, China;
| | - Hao Zheng
- School of Medicine, Nantong University, Nantong 226001, China;
| | - Jia Yao
- Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; (C.W.); (J.Y.); (Y.X.)
| | - Yuqing Xiang
- Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; (C.W.); (J.Y.); (Y.X.)
| | - Dong Liu
- Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; (C.W.); (J.Y.); (Y.X.)
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong 226001, China;
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5
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Cutri RM, Lin J, Nguyen NV, Shakya D, Shibata SB. Neomycin-Induced Deafness in Neonatal Mice. J Neurosci Methods 2023; 391:109852. [PMID: 37031766 DOI: 10.1016/j.jneumeth.2023.109852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/26/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
BACKGROUND Hearing impairment is a rising public health issue, and current therapeutics fail to restore normal auditory sensation. Animal models are essential to a better understanding of the pathophysiology of deafness and developing therapeutics to restore hearing. NEW METHODS Wild-type CBA/CaJ neonatal mice P2-5 were used in this study. Neomycin suspension (500nl of 50 or 100mg/ml) was micro-injected into the endolymphatic space. Cochlear morphology was examined 3 and 7 days after injection; hair cell (HC) loss, supporting cell morphology, and neurite denervation pattern were assessed with whole-mounts. At 2 and 4 weeks post-injection, the spiral ganglion neuron (SGN) density was analyzed with cryostat sections. Audiometric responses were measured with auditory brain response (ABR) at 4 weeks. RESULTS Rapid and complete degeneration of the inner and outer HCs occurred as early as 3 days post-injection. Subsequently, time- and dose-dependent degeneration patterns were observed along the axis of the cochlear membranous labyrinth forming a flat epithelium. Likewise, the SGN histology demonstrated significant cell density reduction at 2 and 4 weeks. The ABR threshold measurements confirmed profound deafness at 4 weeks. COMPARISON WITH EXISTING METHODS Compared to previously described local and systemic aminoglycoside injections, this method provides a reliable, robust, and rapid deafening model with a single infusion of neomycin in neonatal mice. This model also allows for investigating the effects of inner ear damage during auditory maturation. CONCLUSIONS A single injection of neomycin into the endolymphatic space induces robust HC loss and denervation in neonatal mice.
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Affiliation(s)
- Raffaello M Cutri
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Joshua Lin
- Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
| | - Nhi V Nguyen
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA
| | - Dejan Shakya
- Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Seiji B Shibata
- Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angeles, CA 90033, USA.
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6
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Schvartz-Leyzac KC, Colesa DJ, Swiderski DL, Raphael Y, Pfingst BE. Cochlear Health and Cochlear-implant Function. J Assoc Res Otolaryngol 2023; 24:5-29. [PMID: 36600147 PMCID: PMC9971430 DOI: 10.1007/s10162-022-00882-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/24/2022] [Indexed: 01/06/2023] Open
Abstract
The cochlear implant (CI) is widely considered to be one of the most innovative and successful neuroprosthetic treatments developed to date. Although outcomes vary, CIs are able to effectively improve hearing in nearly all recipients and can substantially improve speech understanding and quality of life for patients with significant hearing loss. A wealth of research has focused on underlying factors that contribute to success with a CI, and recent evidence suggests that the overall health of the cochlea could potentially play a larger role than previously recognized. This article defines and reviews attributes of cochlear health and describes procedures to evaluate cochlear health in humans and animal models in order to examine the effects of cochlear health on performance with a CI. Lastly, we describe how future biologic approaches can be used to preserve and/or enhance cochlear health in order to maximize performance for individual CI recipients.
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Affiliation(s)
- Kara C Schvartz-Leyzac
- Department of Otolaryngology-Head and Neck Surgery, Michigan Medicine, Kresge Hearing Research Institute, University of Michigan, 1150 Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, 135 Rutledge Ave, Charleston, SC, 29425, USA
| | - Deborah J Colesa
- Department of Otolaryngology-Head and Neck Surgery, Michigan Medicine, Kresge Hearing Research Institute, University of Michigan, 1150 Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Donald L Swiderski
- Department of Otolaryngology-Head and Neck Surgery, Michigan Medicine, Kresge Hearing Research Institute, University of Michigan, 1150 Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Yehoash Raphael
- Department of Otolaryngology-Head and Neck Surgery, Michigan Medicine, Kresge Hearing Research Institute, University of Michigan, 1150 Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Bryan E Pfingst
- Department of Otolaryngology-Head and Neck Surgery, Michigan Medicine, Kresge Hearing Research Institute, University of Michigan, 1150 Medical Center Drive, Ann Arbor, MI, 48109-5616, USA.
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7
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Wang J, Zheng J, Wang H, He H, Li S, Zhang Y, Wang Y, Xu X, Wang S. Gene therapy: an emerging therapy for hair cells regeneration in the cochlea. Front Neurosci 2023; 17:1177791. [PMID: 37207182 PMCID: PMC10188948 DOI: 10.3389/fnins.2023.1177791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Sensorineural hearing loss is typically caused by damage to the cochlear hair cells (HCs) due to external stimuli or because of one's genetic factors and the inability to convert sound mechanical energy into nerve impulses. Adult mammalian cochlear HCs cannot regenerate spontaneously; therefore, this type of deafness is usually considered irreversible. Studies on the developmental mechanisms of HC differentiation have revealed that nonsensory cells in the cochlea acquire the ability to differentiate into HCs after the overexpression of specific genes, such as Atoh1, which makes HC regeneration possible. Gene therapy, through in vitro selection and editing of target genes, transforms exogenous gene fragments into target cells and alters the expression of genes in target cells to activate the corresponding differentiation developmental program in target cells. This review summarizes the genes that have been associated with the growth and development of cochlear HCs in recent years and provides an overview of gene therapy approaches in the field of HC regeneration. It concludes with a discussion of the limitations of the current therapeutic approaches to facilitate the early implementation of this therapy in a clinical setting.
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Affiliation(s)
- Jipeng Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jianwei Zheng
- Department of Biliary-Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haiyan Wang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Haoying He
- Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shuang Li
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Ya Zhang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - You Wang
- Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- *Correspondence: You Wang,
| | - Xiaoxiang Xu
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- Xiaoxiang Xu,
| | - Shuyi Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
- Shuyi Wang,
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Chen ZR, Guo JY, He L, Liu S, Xu JY, Yang ZJ, Su W, Liu K, Gong SS, Wang GP. Co-transduction of dual-adeno-associated virus vectors in the neonatal and adult mouse utricles. Front Mol Neurosci 2022; 15:1020803. [PMID: 36340687 PMCID: PMC9629838 DOI: 10.3389/fnmol.2022.1020803] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/23/2022] [Indexed: 01/09/2024] Open
Abstract
Adeno-associated virus (AAV)-mediated gene transfer is an efficient method of gene over-expression in the vestibular end organs. However, AAV has limited usefulness for delivering a large gene, or multiple genes, due to its small packaging capacity (< 5 kb). Co-transduction of dual-AAV vectors can be used to increase the packaging capacity for gene delivery to various organs and tissues. However, its usefulness has not been well validated in the vestibular sensory epithelium. In the present study, we characterized the co-transduction of dual-AAV vectors in mouse utricles following inoculation of two AAV-serotype inner ear (AAV-ie) vectors via canalostomy. Firstly, co-transduction efficiencies were compared between dual-AAV-ie vectors using two different promoters: cytomegalovirus (CMV) and CMV early enhancer/chicken β-actin (CAG). In the group of dual AAV-ie-CAG vectors, the co-transduction rates for striolar hair cells (HCs), extrastriolar HCs, striolar supporting cells (SCs), and extrastriolar SCs were 23.14 ± 2.25%, 27.05 ± 2.10%, 57.65 ± 7.21%, and 60.33 ± 5.69%, respectively. The co-transduction rates in the group of dual AAV-ie-CMV vectors were comparable to those in the dual AAV-ie-CAG group. Next, we examined the co-transduction of dual-AAV-ie-CAG vectors in the utricles of neonatal mice and damaged adult mice. In the neonatal mice, co-transduction rates were 52.88 ± 3.11% and 44.93 ± 2.06% in the striolar and extrastriolar HCs, respectively, which were significantly higher than those in adult mice. In the Pou4f3+/DTR mice, following diphtheria toxin administration, which eliminated most HCs and spared the SCs, the co-transduction rate of SCs was not significantly different to that of normal utricles. Transgene expression persisted for up to 3 months in the adult mice. Furthermore, sequential administration of two AAV-ie-CAG vectors at an interval of 1 week resulted in a higher co-transduction rate in HCs than concurrent delivery. The auditory brainstem responses and swim tests did not reveal any disruption of auditory or vestibular function after co-transduction with dual-AAV-ie vectors. In conclusion, dual-AAV-ie vectors allow efficient co-transduction in the vestibular sensory epithelium and facilitate the delivery of large or multiple genes for vestibular gene therapy.
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Affiliation(s)
- Zhong-Rui Chen
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Jing-Ying Guo
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Lu He
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Shan Liu
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Jun-Yi Xu
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Zi-Jing Yang
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Wei Su
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Ke Liu
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Shu-Sheng Gong
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Guo-Peng Wang
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
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9
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Hearing loss drug discovery and medicinal chemistry: Current status, challenges, and opportunities. PROGRESS IN MEDICINAL CHEMISTRY 2022; 61:1-91. [PMID: 35753714 DOI: 10.1016/bs.pmch.2022.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Hearing loss is a severe high unmet need condition affecting more than 1.5 billion people globally. There are no licensed medicines for the prevention, treatment or restoration of hearing. Prosthetic devices, such as hearing aids and cochlear implants, do not restore natural hearing and users struggle with speech in the presence of background noise. Hearing loss drug discovery is immature, and small molecule approaches include repurposing existing drugs, combination therapeutics, late-stage discovery optimisation of known chemotypes for identified molecular targets of interest, phenotypic tissue screening and high-throughput cell-based screening. Hearing loss drug discovery requires the integration of specialist therapeutic area biology and otology clinical expertise. Small molecule drug discovery projects in the global clinical portfolio for hearing loss are here collated and reviewed. An overview is provided of human hearing, inner ear anatomy, inner ear delivery, types of hearing loss and hearing measurement. Small molecule experimental drugs in clinical development for hearing loss are reviewed, including their underpinning biology, discovery strategy and activities, medicinal chemistry, calculated physicochemical properties, pharmacokinetics and clinical trial status. SwissADME BOILED-Egg permeability modelling is applied to the molecules reviewed, and these results are considered. Non-small molecule hearing loss assets in clinical development are briefly noted in this review. Future opportunities in hearing loss drug discovery for human genomics and targeted protein degradation are highlighted.
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Foster AC, Jacques BE, Piu F. Hearing loss: The final frontier of pharmacology. Pharmacol Res Perspect 2022; 10:e00970. [PMID: 35599339 PMCID: PMC9124819 DOI: 10.1002/prp2.970] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 04/22/2022] [Indexed: 11/25/2022] Open
Abstract
Despite a prevalence greater than cancer or diabetes, there are no currently approved drugs for the treatment of hearing loss. Research over the past two decades has led to a vastly improved understanding of the cellular and molecular mechanisms in the cochlea that lead to hearing deficits and the advent of novel strategies to combat them. Combined with innovative methods that enable local drug delivery to the inner ear, these insights have paved the way for promising therapies that are now under clinical investigation. In this review, we will outline this renaissance of cochlear biology and drug development, focusing on noise, age-related, and chemotherapy-induced hearing dysfunction.
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Liu SS, Yang R. Inner Ear Drug Delivery for Sensorineural Hearing Loss: Current Challenges and Opportunities. Front Neurosci 2022; 16:867453. [PMID: 35685768 PMCID: PMC9170894 DOI: 10.3389/fnins.2022.867453] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/02/2022] [Indexed: 12/20/2022] Open
Abstract
Most therapies for treating sensorineural hearing loss are challenged by the delivery across multiple tissue barriers to the hard-to-access anatomical location of the inner ear. In this review, we will provide a recent update on various pharmacotherapy, gene therapy, and cell therapy approaches used in clinical and preclinical studies for the treatment of sensorineural hearing loss and approaches taken to overcome the drug delivery barriers in the ear. Small-molecule drugs for pharmacotherapy can be delivered via systemic or local delivery, where the blood-labyrinth barrier hinders the former and tissue barriers including the tympanic membrane, the round window membrane, and/or the oval window hinder the latter. Meanwhile, gene and cell therapies often require targeted delivery to the cochlea, which is currently achieved via intra-cochlear or intra-labyrinthine injection. To improve the stability of the biomacromolecules during treatment, e.g., RNAs, DNAs, proteins, additional packing vehicles are often required. To address the diverse range of biological barriers involved in inner ear drug delivery, each class of therapy and the intended therapeutic cargoes will be discussed in this review, in the context of delivery routes commonly used, delivery vehicles if required (e.g., viral and non-viral nanocarriers), and other strategies to improve drug permeation and sustained release (e.g., hydrogel, nanocarriers, permeation enhancers, and microfluidic systems). Overall, this review aims to capture the important advancements and key steps in the development of inner ear therapies and delivery strategies over the past two decades for the treatment and prophylaxis of sensorineural hearing loss.
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Affiliation(s)
- Sophie S. Liu
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, United States
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Rong Yang
- Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, United States
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
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Promotion of In Vitro Hair Cell-like Cell Differentiation from Human Embryonic Stem Cells through the Regulation of Notch Signaling. Metabolites 2021; 11:metabo11120873. [PMID: 34940631 PMCID: PMC8709284 DOI: 10.3390/metabo11120873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 11/25/2022] Open
Abstract
The Notch signaling pathway plays an important role in otic neurogenesis by regulating the differentiation of inner ear hair cells and supporting cells. Notch-regulated differentiation is required for the regeneration of hair cells in the inner ear. The temporal expression pattern of Notch ligands and receptors during in vitro hair cell-like cell differentiation from human embryonic stem cells (hESCs) was detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Subsequently, pAJ-U6-shRNA-CMV-Puro/GFP recombinant lentiviral vectors encoding short hairpin RNAs were used to silence JAG-1, JAG-2, and DLL-1, according to the temporal expression pattern of Notch ligands. Then, the effect of each ligand on the in vitro differentiation of hair cells was examined by RT-PCR, immunofluorescence, and scanning electron microscopy (SEM). The results showed that the individual deletion of JAG-2 or DLL-1 had no significant effect on the differentiation of hair cell-like cells. However, the simultaneous inhibition of both DLL-1 and JAG-2 increased the number of hair cell-like cells and decreased the number of supporting cells. JAG-2 and DLL-1 may have a synergistic role in in vitro hair cell differentiation.
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Glavin CC, Siegel J, Dhar S. Distortion Product Otoacoustic Emission (DPOAE) Growth in Aging Ears with Clinically Normal Behavioral Thresholds. J Assoc Res Otolaryngol 2021; 22:659-680. [PMID: 34591199 DOI: 10.1007/s10162-021-00805-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/28/2021] [Indexed: 02/06/2023] Open
Abstract
Age-related hearing loss (ARHL) is a devastating public health issue. To successfully address ARHL using existing and future treatments, it is imperative to detect the earliest signs of age-related auditory decline and understand the mechanisms driving it. Here, we explore early signs of age-related auditory decline by characterizing cochlear function in 199 ears aged 10-65 years, all of which had clinically defined normal hearing (i.e., behavioral thresholds ≤ 25 dB HL from .25 to 8 kHz bilaterally) and no history of noise exposure. We characterized cochlear function by measuring behavioral thresholds in two paradigms (traditional audiometric thresholds from .25 to 8 kHz and Békésy tracking thresholds from .125 to 20 kHz) and distortion product otoacoustic emission (DPOAE) growth functions at f2 = 2, 4, and 8 kHz. Behavioral thresholds through a standard clinical frequency range (up to 8 kHz) showed statistically, but not clinically, significant declines across increasing decades of life. In contrast, DPOAE growth measured in the same frequency range showed clear declines as early 30 years of age, particularly across moderate stimulus levels (L2 = 25-45 dB SPL). These substantial declines in DPOAE growth were not fully explained by differences in behavioral thresholds measured in the same frequency region. Additionally, high-frequency Békésy tracking thresholds above ~11.2 kHz showed frank declines with increasing age. Collectively, these results suggest that early age-related cochlear decline (1) begins as early as the third or fourth decade of life, (2) is greatest in the cochlear base but apparent through the length of the cochlear partition, (3) cannot be detected fully by traditional clinical measures, and (4) is likely due to a complex mix of etiologies.
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Affiliation(s)
- Courtney Coburn Glavin
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Frances Searle Building 1-240, 2240 Campus Drive, Evanston, IL, 60208, USA.
| | - Jonathan Siegel
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Frances Searle Building 1-240, 2240 Campus Drive, Evanston, IL, 60208, USA
- Knowles Hearing Center, Northwestern University, Evanston, IL, USA
| | - Sumitrajit Dhar
- Roxelyn and Richard Pepper Department of Communication Sciences & Disorders, Northwestern University, Frances Searle Building 1-240, 2240 Campus Drive, Evanston, IL, 60208, USA
- Knowles Hearing Center, Northwestern University, Evanston, IL, USA
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Wnt Modulation Enhances Otic Differentiation by Facilitating the Enucleation Process but Develops Unnecessary Cardiac Structures. Int J Mol Sci 2021; 22:ijms221910306. [PMID: 34638648 PMCID: PMC8508801 DOI: 10.3390/ijms221910306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 01/08/2023] Open
Abstract
Otic organoids have the potential to resolve current challenges in hearing loss research. The reproduction of the delicate and complex structure of the mammalian cochlea using organoids requires high efficiency and specificity. Recent attempts to strengthen otic organoids have focused on the effects of the Wnt signaling pathway on stem cell differentiation. One important aspect of this is the evaluation of undesirable effects of differentiation after Wnt activation. In the present study, we differentiated mouse embryonic stem cell embryoid bodies (EB) into otic organoids and observed two morphologies with different cell fates. EBs that underwent a core ejection process, or ‘enucleation,’ were similar to previously reported inner ear organoids. Meanwhile, EBs that retained their core demonstrated features characteristic of neural organoids. The application of a Wnt agonist during the maturation phase increased enucleation, as well as otic organoid formation, in turn leading to sensory hair cell-like cell generation. However, with a longer incubation period, Wnt activation also led to EBs with ‘beating’ organoids that exhibited spontaneous movement. This observation emphasizes the necessity of optimizing Wnt enhancement for the differentiation of specific cells, such as those found in the inner ear.
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Kempfle JS. Endoscopic-Assisted Drug Delivery for Inner Ear Regeneration. Otolaryngol Clin North Am 2021; 54:189-200. [PMID: 33243375 DOI: 10.1016/j.otc.2020.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sensorineural hearing loss is caused by irreversible loss of auditory hair cells and/or neurons and is increasing in prevalence. Hair cells and neurons do not regenerate after damage, but novel regeneration therapies based on small molecule drugs, gene therapy, and cell replacement strategies offer promising therapeutic options. Endogenous and exogenous regeneration techniques are discussed in context of their feasibility for hair cell and neuron regeneration. Gene therapy and treatment of synaptopathy represent promising future therapies. Minimally invasive endoscopic ear surgery offers a viable approach to aid in delivery of pharmacologic compounds, cells, or viral vectors to the inner ear for all of these techniques.
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Affiliation(s)
- Judith S Kempfle
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Eaton-Peabody Laboratories, C360, 243 Charles Street, Boston, MA 02114, USA.
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Bader K, Dierkes L, Braun LH, Gummer AW, Dalhoff E, Zelle D. Test-retest reliability of distortion-product thresholds compared to behavioral auditory thresholds. Hear Res 2021; 406:108232. [PMID: 33984603 DOI: 10.1016/j.heares.2021.108232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 10/21/2022]
Abstract
When referred to baseline measures, serial monitoring of pure-tone behavioral thresholds and distortion-product otoacoustic emissions (DPOAEs) can be used to detect the progression of cochlear damage. Semi-logarithmic DPOAE input-output (I/O) functions enable the computation of estimated distortion-product thresholds (EDPTs) by means of linear regression, a metric that provides a quantitative estimate of hearing loss due to cochlear-amplifier degradation. DPOAE wave interference and a suboptimal choice of stimulus levels limit the accuracy of EDPTs. This work identifies the test-retest reliability of EDPTs derived from short-pulse DPOAE level maps (EDPTLM), a method that circumvents limitations associated with both wave interference and suboptimal choice of stimulus levels. The test-retest reliability was compared to that of EDPTs derived from semi-logarithmic I/O functions (EDPTI/O) and that of behavioral thresholds acquired with pure-tone audiometry (PTA) and modified Békésy tracking audiometry (TA) to provide a foundation for identifying and interpreting significant threshold shifts. The DPOAE-based auditory thresholds (EDPTLM and EDPTI/O) and behavioral thresholds (PTA and TA) were recorded seven times within three months at 14 frequencies with f2 = 1-14 kHz in 20 ears from ten subjects with normal hearing (4PTA0.5-4kHz < 20 dB HL). To obtain EDPTLM, short-pulse DPOAEs were recorded using 21 L1,L2 pairs. Reconstruction of DPOAE growth behavior as a function of L1 and L2 using nonlinear curve fitting enabled the derivation of EDPTLM for each frequency. Test-retest reliability was determined using three different approaches: 1) centered thresholds, 2) average threshold differences, and 3) average absolute threshold differences, between each possible test session (N = 21). Test-retest reliability based on centered thresholds and average threshold differences showed no statistically significant difference between EDPTLM, EDPTI/O, PTA, and TA for the pooled analysis incorporating all stimulus frequencies. Average absolute threshold differences presented small but significant differences in test-retest reliability with median values of 3.00 dB for PTA, 3.20 dB for TA, 3.34 dB for EDPTLM, and 3.51 dB for EDPTI/O. A considerable frequency dependence of test-retest reliability was found; namely, the highest test-retest reliability was for EDPTLM at f2 = 11 - 14 kHz. Otherwise, at lower frequencies, the highest test-retest reliability was for TA at f2 =1 - 2 kHz. Overall, the test-retest reliability of EDPTLM was better than that of EDPTI/O and was similar to that for behavioral thresholds. Hence, deriving EDPTLM from individual level maps is a promising and sensitive method for objectively monitoring the state of the cochlea. Furthermore, the detection of an equidirectional threshold change at a single frequency in both EDPTLM and TA might allow reducing the threshold shift as indication of a follow-up examination from the clinical standard of 10 dB down to 5 dB. This stricter indicator might be beneficial when monitoring cochlear damage, for example ototoxicity, in the presence of (remnant) cochlear amplification at baseline.
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Affiliation(s)
- Katharina Bader
- Department of Otolaryngology, Head and Neck Surgery, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Linda Dierkes
- Department of Otolaryngology, Head and Neck Surgery, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Lore Helene Braun
- Department of Radiooncology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany; Current address: Department of Radiooncology, Marienhospital Stuttgart, Böheimstraße 37, 70199 Stuttgart, Germany
| | - Anthony W Gummer
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Ernst Dalhoff
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Dennis Zelle
- Section of Physiological Acoustics and Communication, Department of Otolaryngology, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany; Current address: Redwave Medical GmbH, Hans-Knöll-Str. 6, 07745 Jena, Germany
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Chang SY, Lee MY. Photobiomodulation with a wavelength > 800 nm induces morphological changes in stem cells within otic organoids and scala media of the cochlea. Lasers Med Sci 2021; 36:1917-1925. [PMID: 33604771 DOI: 10.1007/s10103-021-03268-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 02/09/2021] [Indexed: 12/31/2022]
Abstract
Photobiomodulation (PBM) is a therapeutic approach to certain diseases based on light energy. Currently, stem cells (SCs) are being considered as putative treatments for previously untreatable diseases. One medical condition that could be treated using SCs is sensorineural hearing loss. Theoretically, if properly delivered and differentiated, SCs could replace lost hair cells in the cochlea. However, this is not currently possible due to the structural complexity and limited survival of SCs within the cochlea. PBM facilitates SC differentiation into other target cells in multiple lineages. Using light with a wavelength > 800 nm, which can penetrate the inner ear through the tympanic membrane, we assessed morphological changes of mouse embryonic stem cells (mESCs) during "otic organoid" generation, and within the scala media (SM) of the cochlea, after light energy stimulation. We observed enhanced differentiation, which was confirmed by an increased number of otic vesicles and increased cell attachment inside the SM. These results suggest that > 800-nm light affected the morphology of mESCs within otic organoids and SM of the cochlea. Based on our results, light energy could be used to enhance otic sensory differentiation, despite the structural complexity of the inner ear and limited survival time of SCs within the cochleae. Additional studies to refine the light energy delivery technology and maximize the effect on otic differentiation are required.
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Affiliation(s)
- So-Young Chang
- Beckman Laser Institute Korea, Dankook University, 119 Dandae-ro, Cheonan, 31116, Republic of Korea
| | - Min Young Lee
- Beckman Laser Institute Korea, Dankook University, 119 Dandae-ro, Cheonan, 31116, Republic of Korea. .,Department of Otolaryngology-Head & Neck Surgery, College of Medicine, Dankook University, 119 Dandae-ro, Cheonan, 31116, Republic of Korea.
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Lee S, Song JJ, Beyer LA, Swiderski DL, Prieskorn DM, Acar M, Jen HI, Groves AK, Raphael Y. Combinatorial Atoh1 and Gfi1 induction enhances hair cell regeneration in the adult cochlea. Sci Rep 2020; 10:21397. [PMID: 33293609 PMCID: PMC7722738 DOI: 10.1038/s41598-020-78167-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
Mature mammalian cochlear hair cells (HCs) do not spontaneously regenerate once lost, leading to life-long hearing deficits. Attempts to induce HC regeneration in adult mammals have used over-expression of the HC-specific transcription factor Atoh1, but to date this approach has yielded low and variable efficiency of HC production. Gfi1 is a transcription factor important for HC development and survival. We evaluated the combinatorial effects of Atoh1 and Gfi1 over-expression on HC regeneration using gene transfer methods in neonatal cochlear explants, and in vivo in adult mice. Adenoviral over-expression of Atoh1 and Gfi1 in cultured neonatal cochlear explants resulted in numerous ectopic HC-like cells (HCLCs), with significantly more cells in Atoh1 + Gfi1 cultures than Atoh1 alone. In vitro, ectopic HCLCs emerged in regions medial to inner HCs as well as in the stria vascularis. In vivo experiments were performed in mature Pou4f3DTR mice in which HCs were completely and specifically ablated by administration of diphtheria toxin. Adenoviral expression of Atoh1 or Atoh1 + Gfi1 in cochlear supporting cells induced appearance of HCLCs, with Atoh1 + Gfi1 expression leading to 6.2-fold increase of new HCLCs after 4 weeks compared to Atoh1 alone. New HCLCs were detected throughout the cochlea, exhibited immature stereocilia and survived for at least 8 weeks. Combinatorial Atoh1 and Gfi1 induction is thus a promising strategy to promote HC regeneration in the mature mammalian cochlea.
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Affiliation(s)
- Sungsu Lee
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
- Department of Otolaryngology - Head and Neck Surgery, Chonnam National University Hospital, Gwangju, South Korea
| | - Jae-Jun Song
- Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, South Korea
| | - Lisa A Beyer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Diane M Prieskorn
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Melih Acar
- Department of Medical Biology, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Hsin-I Jen
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA.
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