1
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Closing the Gap between the Auditory Nerve and Cochlear Implant Electrodes: Which Neurotrophin Cocktail Performs Best for Axonal Outgrowth and Is Electrical Stimulation Beneficial? Int J Mol Sci 2023; 24:ijms24032013. [PMID: 36768339 PMCID: PMC9916558 DOI: 10.3390/ijms24032013] [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: 11/29/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 01/22/2023] Open
Abstract
Neurotrophins promote neurite outgrowth of auditory neurons and may help closing the gap to cochlear implant (CI) electrodes to enhance electrical hearing. The best concentrations and mix of neurotrophins for this nerve regrowth are unknown. Whether electrical stimulation (ES) during outgrowth is beneficial or may direct axons is another open question. Auditory neuron explant cultures of distinct cochlear turns of 6-7 days old mice were cultured for four days. We tested different concentrations and combinations of BDNF and NT-3 and quantified the numbers and lengths of neurites with an advanced automated analysis. A custom-made 24-well electrical stimulator based on two bulk CIs served to test different ES strategies. Quantification of receptors trkB, trkC, p75NTR, and histological analysis helped to analyze effects. We found 25 ng/mL BDNF to perform best, especially in basal neurons, a negative influence of NT-3 in combined BDNF/NT-3 scenarios, and tonotopic changes in trk and p75NTR receptor stainings. ES largely impeded neurite outgrowth and glia ensheathment in an amplitude-dependent way. Apical neurons showed slight benefits in neurite numbers and length with ES at 10 and 500 µA. We recommend BDNF as a potent drug to enhance the man-machine interface, but CIs should be better activated after nerve regrowth.
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2
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Lee MP, Waldhaus J. In vitro and in vivo models: What have we learnt about inner ear regeneration and treatment for hearing loss? Mol Cell Neurosci 2022; 120:103736. [PMID: 35577314 PMCID: PMC9551661 DOI: 10.1016/j.mcn.2022.103736] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/29/2022] [Accepted: 05/10/2022] [Indexed: 01/07/2023] Open
Abstract
The sensory cells of the inner ear, called hair cells, do not regenerate spontaneously and therefore, hair cell loss and subsequent hearing loss are permanent in humans. Conversely, functional hair cell regeneration can be observed in non-mammalian vertebrate species like birds and fish. Also, during postnatal development in mice, limited regenerative capacity and the potential to isolate stem cells were reported. Together, these findings spurred the interest of current research aiming to investigate the endogenous regenerative potential in mammals. In this review, we summarize current in vitro based approaches and briefly introduce different in vivo model organisms utilized to study hair cell regeneration. Furthermore, we present an overview of the findings that were made synergistically using both, the in vitro and in vivo based tools.
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Affiliation(s)
- Mary P Lee
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Joerg Waldhaus
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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3
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Early S, Du E, Boussaty E, Friedman R. Genetics of noise-induced hearing loss in the mouse model. Hear Res 2022; 425:108505. [DOI: 10.1016/j.heares.2022.108505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 03/28/2022] [Accepted: 04/07/2022] [Indexed: 12/01/2022]
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4
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Li W, Quan Y, Huang M, Wei W, Shu Y, Li H, Chen ZY. A Novel in vitro Model Delineating Hair Cell Regeneration and Neural Reinnervation in Adult Mouse Cochlea. Front Mol Neurosci 2022; 14:757831. [PMID: 35082601 PMCID: PMC8785685 DOI: 10.3389/fnmol.2021.757831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
The study of an adult mammalian auditory system, such as regeneration, has been hampered by the lack of an in vitro system in which hypotheses can be tested efficiently. This is primarily due to the fact that the adult inner ear is encased in the toughest bone of the body, whereas its removal leads to the death of the sensory epithelium in culture. We hypothesized that we could take advantage of the integral cochlear structure to maintain the overall inner ear architecture and improve sensory epithelium survival in culture. We showed that by culturing adult mouse cochlea with the (surrounding) bone intact, the supporting cells (SCs) survived and almost all hair cells (HCs) degenerated. To evaluate the utility of the explant culture system, we demonstrated that the overexpression of Atoh1, an HC fate-determining factor, is sufficient to induce transdifferentiation of adult SCs to HC-like cells (HCLCs). Transdifferentiation-derived HCLCs resemble developmentally young HCs and are able to attract adult ganglion neurites. Furthermore, using a damage model, we showed that degenerated adult ganglions respond to regenerated HCLCs by directional neurite outgrowth that leads to HCLC-neuron contacts, strongly supporting the intrinsic properties of the HCLCs in establishing HCLC-neuron connections. The adult whole cochlear explant culture is suitable for diverse studies of the adult inner ear including regeneration, HC-neuron pathways, and inner ear drug screening.
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Affiliation(s)
- Wenyan Li
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yizhou Quan
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
| | - Mingqian Huang
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
| | - Wei Wei
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
| | - Yilai Shu
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Huawei Li
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, China
- *Correspondence: Huawei Li,
| | - Zheng-Yi Chen
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA, United States
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
- Zheng-Yi Chen,
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5
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Ivanchenko MV, Indzhykulian AA, Corey DP. Electron Microscopy Techniques for Investigating Structure and Composition of Hair-Cell Stereociliary Bundles. Front Cell Dev Biol 2021; 9:744248. [PMID: 34746139 PMCID: PMC8569945 DOI: 10.3389/fcell.2021.744248] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/28/2021] [Indexed: 11/18/2022] Open
Abstract
Hair cells—the sensory cells of the vertebrate inner ear—bear at their apical surfaces a bundle of actin-filled protrusions called stereocilia, which mediate the cells’ mechanosensitivity. Hereditary deafness is often associated with morphological disorganization of stereocilia bundles, with the absence or mislocalization within stereocilia of specific proteins. Thus, stereocilia bundles are closely examined to understand most animal models of hereditary hearing loss. Because stereocilia have a diameter less than a wavelength of light, light microscopy is not adequate to reveal subtle changes in morphology or protein localization. Instead, electron microscopy (EM) has proven essential for understanding stereocilia bundle development, maintenance, normal function, and dysfunction in disease. Here we review a set of EM imaging techniques commonly used to study stereocilia, including optimal sample preparation and best imaging practices. These include conventional and immunogold transmission electron microscopy (TEM) and scanning electron microscopy (SEM), as well as focused-ion-beam scanning electron microscopy (FIB-SEM), which enables 3-D serial reconstruction of resin-embedded biological structures at a resolution of a few nanometers. Parameters for optimal sample preparation, fixation, immunogold labeling, metal coating and imaging are discussed. Special attention is given to protein localization in stereocilia using immunogold labeling. Finally, we describe the advantages and limitations of these EM techniques and their suitability for different types of studies.
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Affiliation(s)
- Maryna V Ivanchenko
- Department of Neurobiology, Harvard Medical School, Boston, MA, United States
| | - Artur A Indzhykulian
- Department of Otolaryngology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - David P Corey
- Department of Neurobiology, Harvard Medical School, Boston, MA, United States
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6
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Cortada M, Sauteur L, Lanz M, Levano S, Bodmer D. A deep learning approach to quantify auditory hair cells. Hear Res 2021; 409:108317. [PMID: 34343849 DOI: 10.1016/j.heares.2021.108317] [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: 03/12/2021] [Revised: 06/16/2021] [Accepted: 07/19/2021] [Indexed: 01/16/2023]
Abstract
Hearing loss affects millions of people worldwide. Yet, there are still no curative therapies for sensorineural hearing loss. Frequent causes of sensorineural hearing loss are due to damage or loss of the sensory hair cells, the spiral ganglion neurons, or the synapses between them. Culturing the organ of Corti allows the study of all these structures in an experimental model, which is easy to manipulate. Therefore, the in vitro culture of the neonatal mammalian organ of Corti remains a frequently used experimental system, in which hair cell survival is routinely assessed. However, the analysis of the surviving hair cells is commonly performed via manual counting, which is a time-consuming process and the inter-rater reliability can be an issue. Here, we describe a deep learning approach to quantify hair cell survival in the murine organ of Corti explants. We used StarDist, a publicly available platform and plugin for Fiji (Fiji is just ImageJ), to train and apply our own custom deep learning model. We successfully validated our model in untreated, cisplatin, and gentamicin treated organ of Corti explants. Therefore, deep learning is a valuable approach for quantifying hair cell survival in organ of Corti explants. Moreover, we also demonstrate how the publicly available Fiji plugin StarDist can be efficiently used for this purpose.
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Affiliation(s)
- Maurizio Cortada
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Loïc Sauteur
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Michael Lanz
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Soledad Levano
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland.
| | - Daniel Bodmer
- Department of Biomedicine, University of Basel, Hebelstrasse 20, Basel 4031, Switzerland; Clinic for Otorhinolaryngology, Head and Neck Surgery, University of Basel Hospital, Petersgraben 4, Basel CH-4031, Switzerland.
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7
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Standardized Methodologies to Utilize Exosome Treatment as Potential Nano Substances in Hearing Loss. JOURNAL OF OTORHINOLARYNGOLOGY, HEARING AND BALANCE MEDICINE 2021. [DOI: 10.3390/ohbm2020006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Recently, studies on the mechanism and clinical application of stem cell-derived exosomes have increased. Although the number of patients with hearing loss is increasing, there is no ideal therapy for the recovery of auditory cells of an independent organ in humans. In this review, we proposed the use of stem cell-derived exosomes for treating hearing loss and summarized the exosome research strategy platform for preclinical studies. It is necessary to select a research direction to assess direct or indirect effects on recipients based on the physiological mechanisms of exosomes that deliver useful molecules (called payloads) to recipient cells or tissues. To apply exosomes in the auditory field, researchers should select a model for assessing the toxicity to the auditory cells and analyzing their mechanisms in the recipient tissue. Such in vitro, ex vivo, and in vivo models have been designed and reported in previous studies. The analytical strategies in various models can evaluate the mechanism of exosomes based on exosome surface markers or the payload, thus helping the researchers in finding evidence regarding the efficacy of exosomes. Here, we propose three strategies for exosome application research in the auditory field.
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8
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Fernández-Hernández I, Marsh EB, Bonaguidi MA. Mechanosensory neuron regeneration in adult Drosophila. Development 2021; 148:dev.187534. [PMID: 33597190 DOI: 10.1242/dev.187534] [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: 12/17/2019] [Accepted: 02/09/2021] [Indexed: 01/01/2023]
Abstract
Auditory and vestibular mechanosensory hair cells do not regenerate following injury or aging in the adult mammalian inner ear, inducing irreversible hearing loss and balance disorders for millions of people. Research on model systems showing replacement of mechanosensory cells can provide mechanistic insights into developing new regenerative therapies. Here, we developed lineage tracing systems to reveal the generation of mechanosensory neurons in the Johnston's organ (JO) of intact adult Drosophila, which are the functional counterparts to hair cells in vertebrates. New JO neurons develop cilia and target central brain circuitry. Unexpectedly, mitotic recombination clones point to JO neuron self-replication as a likely source of neuronal plasticity. This mechanism is further enhanced upon treatment with experimental and ototoxic compounds. Our findings introduce a new platform to expedite research on mechanisms and compounds mediating mechanosensory cell regeneration, with nascent implications for hearing and balance restoration.
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Affiliation(s)
- Ismael Fernández-Hernández
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Evan B Marsh
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Michael A Bonaguidi
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA .,Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.,Department of Gerontology, Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.,Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 USA
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9
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Zhao T, Zheng T, Yu H, Hu BH, Hu B, Ma P, Yang Y, Yang N, Hu J, Cao T, Chen G, Yan B, Peshoff M, Hatzoglou M, Geng R, Li B, Zheng QY. Autophagy impairment as a key feature for acetaminophen-induced ototoxicity. Cell Death Dis 2021; 12:3. [PMID: 33414397 PMCID: PMC7791066 DOI: 10.1038/s41419-020-03328-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
Macroautophagy/autophagy is a highly conserved self-digestion pathway that plays an important role in cytoprotection under stress conditions. Autophagy is involved in hepatotoxicity induced by acetaminophen (APAP) in experimental animals and in humans. APAP also causes ototoxicity. However, the role of autophagy in APAP-induced auditory hair cell damage is unclear. In the present study, we investigated autophagy mechanisms during APAP-induced cell death in a mouse auditory cell line (HEI-OC1) and mouse cochlear explant culture. We found that the expression of LC3-II protein and autophagic structures was increased in APAP-treated HEI-OC1 cells; however, the degradation of SQSTM1/p62 protein, the yellow puncta of mRFP-GFP-LC3 fluorescence, and the activity of lysosomal enzymes decreased in APAP-treated HEI-OC1 cells. The degradation of p62 protein and the expression of lysosomal enzymes also decreased in APAP-treated mouse cochlear explants. These data indicate that APAP treatment compromises autophagic degradation and causes lysosomal dysfunction. We suggest that lysosomal dysfunction may be directly responsible for APAP-induced autophagy impairment. Treatment with antioxidant N-acetylcysteine (NAC) partially alleviated APAP-induced autophagy impairment and apoptotic cell death, suggesting the involvement of oxidative stress in APAP-induced autophagy impairment. Inhibition of autophagy by knocking down of Atg5 and Atg7 aggravated APAP-induced ER and oxidative stress and increased apoptotic cell death. This study provides a better understanding of the mechanism responsible for APAP ototoxicity, which is important for future exploration of treatment strategies for the prevention of hearing loss caused by ototoxic medications.
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Affiliation(s)
- Tong Zhao
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Tihua Zheng
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Huining Yu
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, USA
| | - Bing Hu
- Department of Otolaryngology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Peng Ma
- Department of Genetics, School of Pharmacy, Binzhou Medical University, Yantai, China
| | - Ying Yang
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Naidi Yang
- Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, Nanjing, China
| | - Juan Hu
- Department of Otolaryngology-Head & Neck Surgery, Second Affiliated Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, China
| | - Tongtao Cao
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Gang Chen
- School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, China
| | - Bin Yan
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China
| | - Melina Peshoff
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH, USA
| | - Maria Hatzoglou
- Department of Genetics, Case Western Reserve University, Cleveland, OH, USA
| | - Ruishuang Geng
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China.
| | - Bo Li
- Hearing and Speech Rehabilitation Institute, College of Special Education, Binzhou Medical University, Yantai, China.
| | - Qing Yin Zheng
- Department of Otolaryngology, Case Western Reserve University, Cleveland, OH, USA
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10
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Seist R, Tong M, Landegger LD, Vasilijic S, Hyakusoku H, Katsumi S, McKenna CE, Edge ASB, Stankovic KM. Regeneration of Cochlear Synapses by Systemic Administration of a Bisphosphonate. Front Mol Neurosci 2020; 13:87. [PMID: 32765216 PMCID: PMC7381223 DOI: 10.3389/fnmol.2020.00087] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
Sensorineural hearing loss (SNHL) caused by noise exposure and attendant loss of glutamatergic synapses between cochlear spiral ganglion neurons (SGNs) and hair cells is the most common sensory deficit worldwide. We show here that systemic administration of a bisphosphonate to mice 24 h after synaptopathic noise exposure regenerated synapses between inner hair cells and SGNs and restored cochlear function. We further demonstrate that this effect is mediated by inhibition of the mevalonate pathway. These results are highly significant because they suggest that bisphosphonates could reverse cochlear synaptopathy for the treatment of SNHL.
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Affiliation(s)
- Richard Seist
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
- Department of Otorhinolaryngology-Head and Neck Surgery, Paracelsus Medical University, Salzburg, Austria
| | - Mingjie Tong
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Lukas D. Landegger
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
- Department of Otorhinolaryngology-Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Sasa Vasilijic
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Hiroshi Hyakusoku
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
- Department of Otorhinolaryngology, Yokosuka Kyosai Hospital, Kanagawa, Japan
| | - Sachiyo Katsumi
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, CA, United States
| | - Albert S. B. Edge
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
- Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, MA, United States
- Harvard Stem Cell Institute, Cambridge, MA, United States
| | - Konstantina M. Stankovic
- Eaton-Peabody Laboratories, Department of Otolaryngology – Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
- Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, MA, United States
- Harvard Stem Cell Institute, Cambridge, MA, United States
- Program in Therapeutic Science, Harvard Medical School, Boston, MA, United States
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11
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Landegger LD, Vasilijic S, Fujita T, Soares VY, Seist R, Xu L, Stankovic KM. Cytokine Levels in Inner Ear Fluid of Young and Aged Mice as Molecular Biomarkers of Noise-Induced Hearing Loss. Front Neurol 2019; 10:977. [PMID: 31632328 PMCID: PMC6749100 DOI: 10.3389/fneur.2019.00977] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022] Open
Abstract
Sensorineural hearing loss (SNHL) is the most common sensory deficit worldwide, frequently caused by noise trauma and aging, with inflammation being implicated in both pathologies. Here, we provide the first direct measurements of proinflammatory cytokines in inner ear fluid, perilymph, of adolescent and 2-year-old mice. The perilymph of adolescent mice exposed to the noise intensity resulting in permanent auditory threshold elevations had significantly increased levels of IL-6, TNF-α, and CXCL1 6 h after exposure, with CXCL1 levels being most elevated (19.3 ± 6.2 fold). We next provide the first immunohistochemical localization of CXCL1 in specific cochlear supporting cells, and its presumed receptor, Duffy antigen receptor for chemokines (DARC), in hair cells and spiral ganglion neurons. Our results demonstrate the feasibility of molecular diagnostics of SNHL using only 0.5 μL of perilymph, and motivate future sub-μL based diagnostics of human SNHL based on liquid biopsy of the inner ear to guide therapy, promote hearing protection, and monitor response to treatment.
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Affiliation(s)
- Lukas D Landegger
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Department of Otolaryngology, Vienna General Hospital, Medical University of Vienna, Vienna, Austria
| | - Sasa Vasilijic
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Takeshi Fujita
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Vitor Y Soares
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Richard Seist
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Lei Xu
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, United States.,Program in Therapeutic Science, Harvard Medical School, Boston, MA, United States
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12
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Han BR, Lin SC, Espinosa K, Thorne PR, Vlajkovic SM. Inhibition of the Adenosine A 2A Receptor Mitigates Excitotoxic Injury in Organotypic Tissue Cultures of the Rat Cochlea. Cells 2019; 8:cells8080877. [PMID: 31408967 PMCID: PMC6721830 DOI: 10.3390/cells8080877] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/09/2019] [Accepted: 08/09/2019] [Indexed: 12/20/2022] Open
Abstract
The primary loss of cochlear glutamatergic afferent nerve synapses due to noise or ageing (cochlear neuropathy) often presents as difficulties in speech discrimination in noisy conditions (hidden hearing loss (HHL)). Currently, there is no treatment for this condition. Our previous studies in mice with genetic deletion of the adenosine A2A receptor (A2AR) have demonstrated better preservation of cochlear afferent synapses and spiral ganglion neurons after noise exposure compared to wildtype mice. This has informed our current targeted approach to cochlear neuroprotection based on pharmacological inhibition of the A2AR. Here, we have used organotypic tissue culture of the Wistar rat cochlea at postnatal day 6 (P6) to model excitotoxic injury induced by N-methyl-d-aspartate (NMDA)/kainic acid (NK) treatment for 2 h. The excitotoxic injury was characterised by a reduction in the density of neural processes immediately after NK treatment and loss of afferent synapses in the presence of intact sensory hair cells. The administration of istradefylline (a clinically approved A2AR antagonist) reduced deafferentation of inner hair cells and improved the survival of afferent synapses after excitotoxic injury. This study thus provides evidence that A2AR inhibition promotes cochlear recovery from excitotoxic injury, and may have implications for the treatment of cochlear neuropathy and prevention of HHL.
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Affiliation(s)
- Belinda Rx Han
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Shelly Cy Lin
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Kristan Espinosa
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Peter R Thorne
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Srdjan M Vlajkovic
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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13
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Berekméri E, Deák O, Téglás T, Sághy É, Horváth T, Aller M, Fekete Á, Köles L, Zelles T. Targeted single-cell electroporation loading of Ca 2+ indicators in the mature hemicochlea preparation. Hear Res 2018; 371:75-86. [PMID: 30504093 DOI: 10.1016/j.heares.2018.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/30/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
Abstract
Ca2+ is an important intracellular messenger and regulator in both physiological and pathophysiological mechanisms in the hearing organ. Investigation of cellular Ca2+ homeostasis in the mature cochlea is hampered by the special anatomy and high vulnerability of the organ. A quick, straightforward and reliable Ca2+ imaging method with high spatial and temporal resolution in the mature organ of Corti is missing. Cell cultures or isolated cells do not preserve the special microenvironment and intercellular communication, while cochlear explants are excised from only a restricted portion of the organ of Corti and usually from neonatal pre-hearing murines. The hemicochlea, prepared from hearing mice allows tonotopic experimental approach on the radial perspective in the basal, middle and apical turns of the organ. We used the preparation recently for functional imaging in supporting cells of the organ of Corti after bulk loading of the Ca2+ indicator. However, bulk loading takes long time, is variable and non-selective, and causes the accumulation of the indicator in the extracellular space. In this study we show the improved labeling of supporting cells of the organ of Corti by targeted single-cell electroporation in mature mouse hemicochlea. Single-cell electroporation proved to be a reliable way of reducing the duration and variability of loading and allowed subcellular Ca2+ imaging by increasing the signal-to-noise ratio, while cell viability was retained during the experiments. We demonstrated the applicability of the method by measuring the effect of purinergic, TRPA1, TRPV1 and ACh receptor stimulation on intracellular Ca2+ concentration at the cellular and subcellular level. In agreement with previous results, ATP evoked reversible and repeatable Ca2+ transients in Deiters', Hensen's and Claudius' cells. TRPA1 and TRPV1 stimulation by AITC and capsaicin, respectively, failed to induce any Ca2+ response in the supporting cells, except in a single Hensen's cell in which AITC evoked transients with smaller amplitude. AITC also caused the displacement of the tissue. Carbachol, agonist of ACh receptors induced Ca2+ transients in about a third of Deiters' and fifth of Hensen's cells. Here we have presented a fast and cell-specific indicator loading method allowing subcellular functional Ca2+ imaging in supporting cells of the organ of Corti in the mature hemicochlea preparation, thus providing a straightforward tool for deciphering the poorly understood regulation of Ca2+ homeostasis in these cells.
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Affiliation(s)
- Eszter Berekméri
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Orsolya Deák
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Tímea Téglás
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Éva Sághy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Tamás Horváth
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Máté Aller
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Ádám Fekete
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.
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14
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Zhang LW, Cang XH, Chen Y, Guan MX. In vitro culture of mammalian inner ear hair cells. J Zhejiang Univ Sci B 2018; 20:170-179. [PMID: 30187712 DOI: 10.1631/jzus.b1700613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Auditory function in vertebrates depends on the transduction of sound vibrations into electrical signals by inner ear hair cells. In general, hearing loss resulting from hair cell damage is irreversible because the human ear has been considered to be incapable of regenerating or repairing these sensory elements following severe injury. Therefore, regeneration and protection of inner ear hair cells have become an exciting, rapidly evolving field of research during the last decade. However, mammalian auditory hair cells are few in number, experimentally inaccessible, and barely proliferate postnatally in vitro. Various in vitro primary culture systems of inner ear hair cells have been established by different groups, although many challenges remain unresolved. Here, we briefly explain the structure of the inner ear, summarize the published methods of in vitro hair cell cultures, and propose a feasible protocol for culturing these cells, which gave satisfactory results in our study. A better understanding of in vitro hair cell cultures will substantially facilitate research involving auditory functions, drug development, and the isolation of critical molecules involved in hair cell biology.
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Affiliation(s)
- Lu-Wen Zhang
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Institute of Genetics, Zhejiang University and Department of Genetics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xiao-Hui Cang
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Institute of Genetics, Zhejiang University and Department of Genetics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Ye Chen
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Institute of Genetics, Zhejiang University and Department of Genetics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, the Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Institute of Genetics, Zhejiang University and Department of Genetics, Zhejiang University School of Medicine, Hangzhou 310058, China
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