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Vecchi JT, Claussen AD, Hansen MR. Decreasing the physical gap in the neural-electrode interface and related concepts to improve cochlear implant performance. Front Neurosci 2024; 18:1425226. [PMID: 39114486 PMCID: PMC11303154 DOI: 10.3389/fnins.2024.1425226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/11/2024] [Indexed: 08/10/2024] Open
Abstract
Cochlear implants (CI) represent incredible devices that restore hearing perception for those with moderate to profound sensorineural hearing loss. However, the ability of a CI to restore complex auditory function is limited by the number of perceptually independent spectral channels provided. A major contributor to this limitation is the physical gap between the CI electrodes and the target spiral ganglion neurons (SGNs). In order for CI electrodes to stimulate SGNs more precisely, and thus better approximate natural hearing, new methodologies need to be developed to decrease this gap, (i.e., transitioning CIs from a far-field to near-field device). In this review, strategies aimed at improving the neural-electrode interface are discussed in terms of the magnitude of impact they could have and the work needed to implement them. Ongoing research suggests current clinical efforts to limit the CI-related immune response holds great potential for improving device performance. This could eradicate the dense, fibrous capsule surrounding the electrode and enhance preservation of natural cochlear architecture, including SGNs. In the long term, however, optimized future devices will likely need to induce and guide the outgrowth of the peripheral process of SGNs to be in closer proximity to the CI electrode in order to better approximate natural hearing. This research is in its infancy; it remains to be seen which strategies (surface patterning, small molecule release, hydrogel coating, etc.) will be enable this approach. Additionally, these efforts aimed at optimizing CI function will likely translate to other neural prostheses, which face similar issues.
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Affiliation(s)
- Joseph T. Vecchi
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, Iowa City, IA, United States
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, United States
| | - Alexander D. Claussen
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, United States
| | - Marlan R. Hansen
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, Iowa City, IA, United States
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, United States
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2
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Liu J, Stohl J, Overath T. Hidden hearing loss: Fifteen years at a glance. Hear Res 2024; 443:108967. [PMID: 38335624 DOI: 10.1016/j.heares.2024.108967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/15/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024]
Abstract
Hearing loss affects approximately 18% of the population worldwide. Hearing difficulties in noisy environments without accompanying audiometric threshold shifts likely affect an even larger percentage of the global population. One of the potential causes of hidden hearing loss is cochlear synaptopathy, the loss of synapses between inner hair cells (IHC) and auditory nerve fibers (ANF). These synapses are the most vulnerable structures in the cochlea to noise exposure or aging. The loss of synapses causes auditory deafferentation, i.e., the loss of auditory afferent information, whose downstream effect is the loss of information that is sent to higher-order auditory processing stages. Understanding the physiological and perceptual effects of this early auditory deafferentation might inform interventions to prevent later, more severe hearing loss. In the past decade, a large body of work has been devoted to better understand hidden hearing loss, including the causes of hidden hearing loss, their corresponding impact on the auditory pathway, and the use of auditory physiological measures for clinical diagnosis of auditory deafferentation. This review synthesizes the findings from studies in humans and animals to answer some of the key questions in the field, and it points to gaps in knowledge that warrant more investigation. Specifically, recent studies suggest that some electrophysiological measures have the potential to function as indicators of hidden hearing loss in humans, but more research is needed for these measures to be included as part of a clinical test battery.
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Affiliation(s)
- Jiayue Liu
- Department of Psychology and Neuroscience, Duke University, Durham, USA.
| | - Joshua Stohl
- North American Research Laboratory, MED-EL Corporation, Durham, USA
| | - Tobias Overath
- Department of Psychology and Neuroscience, Duke University, Durham, USA
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3
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Fei G, Dandan S, Haiyan W, Shuai Z, Xiaopin S, Yu H, Yi Y, Rong C, Jin H, Xiaoming S, Lei Y. Exogenous neuritin restores auditory following cochlear spiral ganglion neuron denervation of gerbils. Neurosci Res 2024; 200:8-19. [PMID: 37926219 DOI: 10.1016/j.neures.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023]
Abstract
Spiral ganglion neurons (SGNs) transmit sound signals received by hair cells to the auditory center to produce hearing. The quantity and function are important for maintaining normal hearing function. Limited by the regenerative capacity, SGNs are unable to regenerate spontaneously after injury. Various neurotrophic factors play an important role in the regeneration process. Neuritin is a neurite growth factor that plays an important role in neural plasticity and nerve injury repair. In this study, we used bioinformatics analysis to show that neuritin was negatively correlated with cochlear damage. Then, we aimed to establish a cochlear spiral ganglion-specific sensorineural deafness model in gerbils using ouabain and determine the effects of exogenous neuritin protein in protecting damaged cochlear SGNs and repairing damaged auditory nerve function. The provides a new research strategy and scientific basis for the prevention and treatment of sensorineural deafness caused by the loss of SGNs. We were discovered that neuritin is expressed throughout the development of the gerbil cochlea, primarily in the SGNs and Corti regions. The expression of neuritin was negatively correlated with the sensorineural deafness induced by ouabain. In vitro and in vivo revealed that neuritin significantly maintained the number and arrangement of SGNs and nerve fibers in the damaged cochlea and effectively protected the high-frequency listening function of gerbils.
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Affiliation(s)
- Gui Fei
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, PR China.
| | - Song Dandan
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, PR China; Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Wang Haiyan
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Zhang Shuai
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, PR China
| | - Sun Xiaopin
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Hong Yu
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Yang Yi
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Chen Rong
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China
| | - Huang Jin
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, PR China.
| | - Song Xiaoming
- Department of Preventive Medicine, School of Public Health, Hangzhou Normal University, Hangzhou, Zhejiang 311121, PR China.
| | - Yang Lei
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, PR China.
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4
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Terracina S, Ferraguti G, Tarani L, Fanfarillo F, Tirassa P, Ralli M, Iannella G, Polimeni A, Lucarelli M, Greco A, Fiore M. Nerve Growth Factor and Autoimmune Diseases. Curr Issues Mol Biol 2023; 45:8950-8973. [PMID: 37998739 PMCID: PMC10670231 DOI: 10.3390/cimb45110562] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023] Open
Abstract
NGF plays a crucial immunomodulatory role and increased levels are found in numerous tissues during autoimmune states. NGF directly modulates innate and adaptive immune responses of B and T cells and causes the release of neuropeptides and neurotransmitters controlling the immune system activation in inflamed tissues. Evidence suggests that NGF is involved in the pathogenesis of numerous immune diseases including autoimmune thyroiditis, chronic arthritis, multiple sclerosis, systemic lupus erythematosus, mastocytosis, and chronic granulomatous disease. Furthermore, as NGF levels have been linked to disease severity, it could be considered an optimal early biomarker to identify therapeutic approach efficacy. In conclusion, by gaining insights into how these molecules function and which cells they interact with, future studies can devise targeted therapies to address various neurological, immunological, and other disorders more effectively. This knowledge may pave the way for innovative treatments based on NGF manipulation aimed at improving the quality of life for individuals affected by diseases involving neurotrophins.
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Affiliation(s)
- Sergio Terracina
- Department of Experimental Medicine, Sapienza University of Rome, 00185 Rome, Italy
| | - Giampiero Ferraguti
- Department of Experimental Medicine, Sapienza University of Rome, 00185 Rome, Italy
| | - Luigi Tarani
- Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Francesca Fanfarillo
- Department of Experimental Medicine, Sapienza University of Rome, 00185 Rome, Italy
| | - Paola Tirassa
- Institute of Biochemistry and Cell Biology (IBBC-CNR), Department of Sensory Organs, Sapienza University of Rome, 00185 Rome, Italy
| | - Massimo Ralli
- Department of Sensory Organs, Sapienza University of Rome, 00185 Roma, Italy
| | - Giannicola Iannella
- Department of Sensory Organs, Sapienza University of Rome, 00185 Roma, Italy
| | - Antonella Polimeni
- Department of Odontostomatological and Maxillofacial Sciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Marco Lucarelli
- Department of Experimental Medicine, Sapienza University of Rome, 00185 Rome, Italy
- Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University of Rome, 00185 Rome, Italy
| | - Antonio Greco
- Department of Sensory Organs, Sapienza University of Rome, 00185 Roma, Italy
| | - Marco Fiore
- Institute of Biochemistry and Cell Biology (IBBC-CNR), Department of Sensory Organs, Sapienza University of Rome, 00185 Rome, Italy
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5
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Eftekharian A, Khajavi M, Moghadam S, Eftekharian K, Azadeh Ranjbar L, Rezaei A. Comparison Between the Effect of Intra-Scalar Methylprednisolone and Sodium Hyaluronate in Impedance and Electrically Evoked Compound Action Potentials in Cochlear Implant Patients. Indian J Otolaryngol Head Neck Surg 2023; 75:285-290. [PMID: 37206779 PMCID: PMC10188670 DOI: 10.1007/s12070-022-03429-y] [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: 06/01/2022] [Accepted: 12/18/2022] [Indexed: 01/01/2023] Open
Abstract
To evaluate and compare the effect of intra-scalar methylprednisolone and sodium hyaluronate on cochlear implants' impedance and electrically evoked compound action potentials thresholds. In a prospective randomized clinical trial, 103 children with pre-lingual hearing loss candidates for cochlear implantation at a tertiary hospital were divided into three groups based on intervention. Intraoperatively, one group received intra-scalar methylprednisolone, the second sodium hyaluronate, and the third group was the control group. Impedance and electrically evoked compound action potentials (e-ECAP) thresholds on long-term follow-up were evaluated and compared in these three groups. Significant decrease in impedance and e-ECAP thresholds were observed in all groups in a 4-year follow-up. No statistically significant difference was observed among all mentioned groups. Impedance and e-ECAP thresholds decrease in the long term, and using topical intra-scalar Healon or methylprednisolone may not significantly affect these parameters.
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Affiliation(s)
- Ali Eftekharian
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdi Khajavi
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soodabeh Moghadam
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kourosh Eftekharian
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leyla Azadeh Ranjbar
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alireza Rezaei
- Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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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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Ferraguti G, Terracina S, Micangeli G, Lucarelli M, Tarani L, Ceccanti M, Spaziani M, D'Orazi V, Petrella C, Fiore M. NGF and BDNF in pediatrics syndromes. Neurosci Biobehav Rev 2023; 145:105015. [PMID: 36563920 DOI: 10.1016/j.neubiorev.2022.105015] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/02/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Neurotrophins (NTs) as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) play multiple roles in different settings including neuronal development, function and survival in both the peripheral and the central nervous systems from early stages. This report aims to provide a summary and subsequent review of evidences on the role of NTs in rare and non-common pediatric human diseases associated with changes in neurodevelopment. A variety of diseases has been analyzed and many have been linked to NTs neurobiological effects, including chronic granulomatous disease, hereditary sensory and autonomic neuropathy, Duchenne muscular dystrophy, Bardet-Biedl syndrome, Angelman syndrome, fragile X syndrome, trisomy 16, Williams-Beuren syndrome, Prader-Willi syndrome, WAGR syndrome, fetal alcohol spectrum disorders, Down syndrome and Klinefelter Syndrome. NTs alterations have been associated with numerous pathologic manifestations including cognitive defects, behavioral abnormalities, epilepsy, obesity, tumorigenesis as well as muscle-skeletal, immunity, bowel, pain sensibility and cilia diseases. In this report, we discuss that further studies are needed to clear a possible therapeutic role of NTs in these still often uncurable diseases.
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Affiliation(s)
- Giampiero Ferraguti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Sergio Terracina
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Ginevra Micangeli
- Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, Italy
| | - Marco Lucarelli
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Luigi Tarani
- Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, Italy
| | - Mauro Ceccanti
- SITAC, Società Italiana per il Trattamento dell'Alcolismo e le sue Complicanze, Rome, Italy
| | - Matteo Spaziani
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Valerio D'Orazi
- Department of Surgical Sciences, Sapienza University of Rome, Rome, Italy
| | - Carla Petrella
- Institute of Biochemistry and Cell Biology, IBBC-CNR, Rome, Italy.
| | - Marco Fiore
- Institute of Biochemistry and Cell Biology, IBBC-CNR, Rome, Italy.
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8
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The effect of the surgical approach and cochlear implant electrode on the structural integrity of the cochlea in human temporal bones. Sci Rep 2022; 12:17068. [PMID: 36224234 PMCID: PMC9556579 DOI: 10.1038/s41598-022-21399-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 09/27/2022] [Indexed: 12/30/2022] Open
Abstract
Cochlear implants (CI) restore hearing of severely hearing-impaired patients. Although this auditory prosthesis is widely considered to be very successful, structural cochlear trauma during cochlear implantation is an important problem, reductions of which could help to improve hearing outcomes and to broaden selection criteria. The surgical approach in cochlear implantation, i.e. round window (RW) or cochleostomy (CO), and type of electrode-array, perimodiolar (PM) or lateral wall (LW), are variables that might influence the probability of severe trauma. We investigated the effect of these two variables on scalar translocation (STL), a specific type of severe trauma. Thirty-two fresh frozen human cadaveric ears were evenly distributed over four groups receiving either RW or CO approach, and either LW or PM array. Conventional radiological multiplanar reconstruction (MPR) was compared with a reconstruction method that uncoils the spiral shape of the cochlea (UCR). Histological analysis showed that RW with PM array had STL rate of 87% (7/8), CO approach with LW array 75% (6/8), RW approach with LW array 50% (4/8) and CO approach with PM array 29% (2/7). STL assessment using UCR showed a higher inter-observer and histological agreement (91 and 94% respectively), than that using MPR (69 and 74% respectively). In particular, LW array positions were difficult to assess with MPR. In conclusion, the interaction between surgical approach and type of array should be preoperatively considered in cochlear implant surgery. UCR technique is advised for radiological assessment of CI positions, and in general it might be useful for pathologies involving the inner ear or other complex shaped bony tubular structures.
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9
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Aragona M, Porcino C, Guerrera MC, Montalbano G, Laurà R, Cometa M, Levanti M, Abbate F, Cobo T, Capitelli G, Vega JA, Germanà A. The BDNF/TrkB Neurotrophin System in the Sensory Organs of Zebrafish. Int J Mol Sci 2022; 23:ijms23052621. [PMID: 35269763 PMCID: PMC8910639 DOI: 10.3390/ijms23052621] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/21/2022] [Accepted: 02/25/2022] [Indexed: 12/15/2022] Open
Abstract
The brain-derived neurotrophic factor (BDNF) was discovered in the last century, and identified as a member of the neurotrophin family. BDNF shares approximately 50% of its amino acid with other neurotrophins such as NGF, NT-3 and NT-4/5, and its linear amino acid sequences in zebrafish (Danio rerio) and human are 91% identical. BDNF functions can be mediated by two categories of receptors: p75NTR and Trk. Intriguingly, BDNF receptors were highly conserved in the process of evolution, as were the other NTs’ receptors. In this review, we update current knowledge about the distribution and functions of the BDNF-TrkB system in the sensory organs of zebrafish. In fish, particularly in zebrafish, the distribution and functions of BDNF and TrkB in the brain have been widely studied. Both components of the system, associated or segregated, are also present outside the central nervous system, especially in sensory organs including the inner ear, lateral line system, retina, taste buds and olfactory epithelium.
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Affiliation(s)
- Marialuisa Aragona
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Caterina Porcino
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Maria Cristina Guerrera
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Giuseppe Montalbano
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Rosaria Laurà
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Marzio Cometa
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Maria Levanti
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Francesco Abbate
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
| | - Teresa Cobo
- Departamento de Cirugía y Especialidades Médico-Quirúrgicas, Universidad de Oviedo, 33006 Oviedo, Spain;
| | - Gabriel Capitelli
- Faculty of Medical Sciences, University of Buenos Aires, Viamonte 1053, CABA, Buenos Aires 1056, Argentina;
| | - José A. Vega
- Grupo SINPOS, Universidad de Oviedo, 33003 Oviedo, Spain;
- Departamento de Morfología y Biología Celular, Universidad de Oviedo, 33006 Oviedo, Spain
- Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago 7500912, Chile
| | - Antonino Germanà
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (C.P.); (M.C.G.); (G.M.); (R.L.); (M.C.); (M.L.); (F.A.)
- Correspondence:
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10
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Garadat SN, Colesa DJ, Swiderski DL, Raphael Y, Pfingst BE. Estimating health of the implanted cochlea using psychophysical strength-duration functions and electrode configuration. Hear Res 2022; 414:108404. [PMID: 34883366 PMCID: PMC8761176 DOI: 10.1016/j.heares.2021.108404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 11/17/2021] [Accepted: 11/25/2021] [Indexed: 02/03/2023]
Abstract
It is generally believed that the efficacy of cochlear implants is partly dependent on the condition of the stimulated neural population. Cochlear pathology is likely to affect the manner in which neurons respond to electrical stimulation, potentially resulting in differences in perception of electrical stimuli across cochlear implant recipients and across the electrode array in individual cochlear implant users. Several psychophysical and electrophysiological measures have been shown to predict cochlear health in animals and were used to assess conditions near individual stimulation sites in humans. In this study, we examined the relationship between psychophysical strength-duration functions and spiral ganglion neuron density in two groups of guinea pigs with cochlear implants who had minimally-overlapping cochlear health profiles. One group was implanted in a hearing ear (N = 10) and the other group was deafened by cochlear perfusion of neomycin, inoculated with an adeno-associated viral vector with an Ntf3-gene insert (AAV.Ntf3) and implanted (N = 14). Psychophysically measured strength-duration functions for both monopolar and tripolar electrode configurations were then compared for the two treatment groups. Results were also compared to their histological outcomes. Overall, there were considerable differences between the two treatment groups in terms of their psychophysical performance as well as the relation between their functional performance and histological data. Animals in the neomycin-deafened, neurotrophin-treated, and implanted group (NNI) exhibited steeper strength-duration function slopes; slopes were positively correlated with SGN density (steeper slopes in animals that had higher SGN densities). In comparison, the implanted hearing (IH) group had shallower slopes and there was no relation between slopes and spiral ganglion density. Across all animals, slopes were negatively correlated with ensemble spontaneous activity levels (shallower slopes with higher ensemble spontaneous activity levels). We hypothesize that differences in strength-duration function slopes between the two treatment groups were related to the condition of the inner hair cells, which generate spontaneous activity that could affect the across-fiber synchrony and/or the size of the population of neural elements responding to electrical stimulation. In addition, it is likely that spiral ganglion neuron peripheral processes were present in the IH group, which could affect membrane properties of the stimulated neurons. Results suggest that the two treatment groups exhibited distinct patterns of variation in conditions near the stimulating electrodes that altered detection thresholds. Overall, the results of this study suggest a complex relationship between psychophysical detection thresholds for cochlear implant stimulation and nerve survival in the implanted cochlea. This relationship seems to depend on the characteristics of the electrical stimulus, the electrode configuration, and other biological features of the implanted cochlea such as the condition of the inner hair cells and the peripheral processes.
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Affiliation(s)
- Soha N Garadat
- Department of Hearing and Speech Sciences, The University of Jordan, Amman 11942, Jordan; Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109-5616, USA.
| | - Deborah J Colesa
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Donald L Swiderski
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Yehoash Raphael
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109-5616, USA
| | - Bryan E Pfingst
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109-5616, USA
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11
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Rousset F, Schmidbauer D, Fink S, Adel Y, Obexer B, Müller M, Glueckert R, Löwenheim H, Senn P. Phoenix auditory neurons as 3R cell model for high throughput screening of neurogenic compounds. Hear Res 2021; 414:108391. [PMID: 34844170 DOI: 10.1016/j.heares.2021.108391] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/25/2022]
Abstract
Auditory neurons connect the sensory hair cells from the inner ear to the brainstem. These bipolar neurons are relevant targets for pharmacological intervention aiming at protecting or improving the hearing function in various forms of sensorineural hearing loss. In the research laboratory, neurotrophic compounds are commonly used to improve survival and to promote regeneration of auditory neurons. One important roadblock delaying eventual clinical applications of these strategies in humans is the lack of powerful in vitro models allowing high throughput screening of otoprotective and regenerative compounds. The recently discovered auditory neuroprogenitors (ANPGs) derived from the A/J mouse with an unprecedented capacity to self-renew and to provide mature auditory neurons offer the possibility to overcome this bottleneck. In the present study, we further characterized the new phoenix ANPGs model and compared it to the current gold-standard spiral ganglion organotypic explant (SGE) model to assay neurite outgrowth, neurite length and glutamate-induced Ca2+ response in response to neurotrophin-3 (NT-3) and brain derived neurotrophic factor (BDNF) treatment. Whereas both, SGEs and phoenix ANPGs exhibited a robust and sensitive response to neurotrophins, the phoenix ANPGs offer a considerable range of advantages including high throughput suitability, lower experimental variability, single cell resolution and an important reduction of animal numbers. The phoenix ANPGs in vitro model therefore provides a robust high-throughput platform to screen for otoprotective and regenerative neurotrophic compounds in line with 3R principles and is of interest for the field of auditory neuroscience.
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Affiliation(s)
- Francis Rousset
- The Inner Ear & Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Switzerland.
| | - Dominik Schmidbauer
- Inner Ear Laboratory, Department of Otolaryngology, Medical University of Innsbruck, Austria
| | - Stefan Fink
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, Germany
| | - Youssef Adel
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, Germany
| | - Benjamin Obexer
- Inner Ear Laboratory, Department of Otolaryngology, Medical University of Innsbruck, Austria
| | - Marcus Müller
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, Germany
| | - Rudolf Glueckert
- Inner Ear Laboratory, Department of Otolaryngology, Medical University of Innsbruck, Austria.
| | - Hubert Löwenheim
- Translational Hearing Research, Tübingen Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, University of Tübingen, Germany
| | - Pascal Senn
- The Inner Ear & Olfaction Lab, Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Switzerland; Department of Clinical Neurosciences, Service of ORL & Head and Neck Surgery, University Hospital of Geneva, Switzerland
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12
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Shew M, Wichova H, Warnecke A, Lenarz T, Staecker H. Evaluating Neurotrophin Signaling Using MicroRNA Perilymph Profiling in Cochlear Implant Patients With and Without Residual Hearing. Otol Neurotol 2021; 42:e1125-e1133. [PMID: 33973949 DOI: 10.1097/mao.0000000000003182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HYPOTHESIS MicroRNAs predicted to regulate neurotrophin signaling can be found in human perilymph. BACKGROUND Animal and human temporal bone studies suggest that spiral ganglion health can affect cochlear implant (CI) outcomes. Neurotrophins have been identified as a key factor in the maintenance of spiral ganglion health. Changes in miRNAs may regulate neurotrophin signaling and may reflect neurotrophin expression levels. METHODS Perilymph sampling was carried out in 18 patients undergoing cochlear implantation or stapedotomy. Expression of miRNAs in perilymph was evaluated using an Agilent miRNA gene chip. Using ingenuity pathway analysis (IPA) software, miRNAs targeting neurotrophin signaling pathway genes present in a cochlear cDNA library were annotated. Expression levels of miRNAs in perilymph were correlated to the patients' preoperative pure-tone average. RESULTS Expression of mRNAs coding for neurotrophins and their receptors were identified in tissue obtained from normal human cochlea during skull base surgery. We identified miRNAs predicted to regulate these signaling cascades, including miR-1207-5p, miR-4651, miR-103-3p, miR-100-5p, miR-221-3p, miR-200-3p. There was a correlation between poor preoperative hearing and lower expression of miR-1207 (predicted to regulate NTR3) and miR-4651 (predicted to regulate NTR2). Additionally, miR-3960, miR-4481, and miR-675 showed significant differences in expression level when comparing mild and profound hearing loss patients. CONCLUSIONS Expression of some miRNAs that are predicted to regulate neurotrophin signaling in the perilymph of cochlear implant patients vary with the patient's level of residual hearing. These miRNAs may serve as biomarkers for changes in neurotrophin signaling.
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Affiliation(s)
- Matthew Shew
- Department of Otolaryngology Head and Neck Surgery, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Helena Wichova
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
| | - Athanasia Warnecke
- Department of Otolaryngology, Medizinische Hochschule Hannover, Hannover
- Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 1077), Germany
| | - Thomas Lenarz
- Department of Otolaryngology, Medizinische Hochschule Hannover, Hannover
- Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 1077), Germany
| | - Hinrich Staecker
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas
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Schvartz-Leyzac KC, Colesa DJ, Buswinka CJ, Rabah AM, Swiderski DL, Raphael Y, Pfingst BE. How electrically evoked compound action potentials in chronically implanted guinea pigs relate to auditory nerve health and electrode impedance. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 148:3900. [PMID: 33379919 PMCID: PMC7863685 DOI: 10.1121/10.0002882] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 10/07/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
This study examined how multiple measures based on the electrically evoked compound action potential (ECAP) amplitude-growth functions (AGFs) were related to estimates of neural [spiral ganglion neuron (SGN) density and cell size] and electrode impedance measures in 34 specific pathogen free pigmented guinea pigs that were chronically implanted (4.9-15.4 months) with a cochlear implant electrode array. Two interphase gaps (IPGs) were used for the biphasic pulses and the effect of the IPG on each ECAP measure was measured ("IPG effect"). When using a stimulus with a constant IPG, SGN density was related to the across-subject variance in ECAP AGF linear slope, peak amplitude, and N1 latency. The SGN density values also help to explain a significant proportion of variance in the IPG effect for AGF linear slope and peak amplitude measures. Regression modeling revealed that SGN density was the primary dependent variable contributing to across-subject variance for ECAP measures; SGN cell size did not significantly improve the fitting of the model. Results showed that simple impedance measures were weakly related to most ECAP measures but did not typically improve the fit of the regression model.
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Affiliation(s)
- Kara C Schvartz-Leyzac
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Deborah J Colesa
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Christopher J Buswinka
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Andrew M Rabah
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
| | - Bryan E Pfingst
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109-5616, USA
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14
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Frick C, Fink S, Schmidbauer D, Rousset F, Eickhoff H, Tropitzsch A, Kramer B, Senn P, Glueckert R, Rask-Andersen H, Wiesmüller KH, Löwenheim H, Müller M. Age-Dependency of Neurite Outgrowth in Postnatal Mouse Cochlear Spiral Ganglion Explants. Brain Sci 2020; 10:E580. [PMID: 32839381 PMCID: PMC7564056 DOI: 10.3390/brainsci10090580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The spatial gap between cochlear implants (CIs) and the auditory nerve limits frequency selectivity as large populations of spiral ganglion neurons (SGNs) are electrically stimulated synchronously. To improve CI performance, a possible strategy is to promote neurite outgrowth toward the CI, thereby allowing a discrete stimulation of small SGN subpopulations. Brain-derived neurotrophic factor (BDNF) is effective to stimulate neurite outgrowth from SGNs. METHOD TrkB (tropomyosin receptor kinase B) agonists, BDNF, and five known small-molecule BDNF mimetics were tested for their efficacy in stimulating neurite outgrowth in postnatal SGN explants. To modulate Trk receptor-mediated effects, TrkB and TrkC ligands were scavenged by an excess of recombinant receptor proteins. The pan-Trk inhibitor K252a was used to block Trk receptor actions. RESULTS THF (7,8,3'-trihydroxyflavone) partly reproduced the BDNF effect in postnatal day 7 (P7) mouse cochlear spiral ganglion explants (SGEs), but failed to show effectiveness in P4 SGEs. During the same postnatal period, spontaneous and BDNF-stimulated neurite outgrowth increased. The increased neurite outgrowth in P7 SGEs was not caused by the TrkB/TrkC ligands, BDNF and neurotrophin-3 (NT-3). CONCLUSIONS The age-dependency of induction of neurite outgrowth in SGEs was very likely dependent on presently unidentified factors and/or molecular mechanisms which may also be decisive for the age-dependent efficacy of the small-molecule TrkB receptor agonist THF.
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Affiliation(s)
- Claudia Frick
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
- Department of Microbiome Science, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Stefan Fink
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Dominik Schmidbauer
- Inner Ear Laboratory Innsbruck, Medical University Innsbruck, 6020 Innsbruck, Austria; (D.S.); (R.G.)
| | - Francis Rousset
- The Inner Ear & Olfaction Lab, Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland; (F.R.); (P.S.)
| | - Holger Eickhoff
- EMC Microcollections GmbH, 72070 Tübingen, Germany; (H.E.); (K.-H.W.)
| | - Anke Tropitzsch
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Benedikt Kramer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Mannheim, 68167 Mannheim, Germany
| | - Pascal Senn
- The Inner Ear & Olfaction Lab, Department of Clinical Neurosciences, Faculty of Medicine, University of Geneva, 1206 Geneva, Switzerland; (F.R.); (P.S.)
| | - Rudolf Glueckert
- Inner Ear Laboratory Innsbruck, Medical University Innsbruck, 6020 Innsbruck, Austria; (D.S.); (R.G.)
- Tirol Kliniken Innsbruck, University Clinic of Otolaryngology, 6020 Innsbruck, Austria
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, University of Uppsala, 751 85 Uppsala, Sweden;
| | | | - Hubert Löwenheim
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
| | - Marcus Müller
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen Medical Center, 72076 Tübingen, Germany; (C.F.); (A.T.); (B.K.); (H.L.); (M.M.)
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15
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Germanà A, Guerrera MC, Laurà R, Levanti M, Aragona M, Mhalhel K, Germanà G, Montalbano G, Abbate F. Expression and Localization of BDNF/TrkB System in the Zebrafish Inner Ear. Int J Mol Sci 2020; 21:ijms21165787. [PMID: 32806650 PMCID: PMC7460859 DOI: 10.3390/ijms21165787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is involved in multiple and fundamental functions of the central and peripheral nervous systems including sensory organs. Despite recent advances in knowledge on the functional significance of BDNF and TrkB in the regulation of the acoustic system of mammals, the localization of BDNF/TrkB system in the inner ear of zebrafish during development, is not well known. Therefore, the goal of the present study is to analyze the age-dependent changes using RT-PCR, Western Blot and single and double immunofluorescence of the BDNF and its specific receptor in the zebrafish inner ear. The results showed the mRNA expression and the cell localization of BDNF and TrkB in the hair cells of the crista ampullaris and in the neuroepithelium of the utricle, saccule and macula lagena, analyzed at different ages. Our results demonstrate that the BDNF/TrkB system is present in the sensory cells of the inner ear, during whole life. Therefore, this system might play a key role in the development and maintenance of the hair cells in adults, suggesting that the zebrafish inner ear represents an interesting model to study the involvement of the neurotrophins in the biology of sensory cells
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16
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Van De Water TR. Historical Aspects of Gene Therapy and Stem Cell Therapy in the Treatment of Hearing and Balance Disorder. Anat Rec (Hoboken) 2020; 303:390-407. [DOI: 10.1002/ar.24332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/18/2019] [Accepted: 11/22/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Thomas R. Van De Water
- Cochlear Implant Research Program, Department of Otolaryngology, University of Miami Ear InstituteUniversity of Miami Miller School of Medicine Miami Florida
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17
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Anderson CR, Xie C, Su MP, Garcia M, Blackshaw H, Schilder AGM. Local Delivery of Therapeutics to the Inner Ear: The State of the Science. Front Cell Neurosci 2019; 13:418. [PMID: 31649507 PMCID: PMC6794458 DOI: 10.3389/fncel.2019.00418] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 08/30/2019] [Indexed: 12/24/2022] Open
Abstract
Background: Advances in the understanding of the genetic and molecular etiologies of inner ear disorders have enabled the identification of therapeutic targets and innovative delivery approaches to the inner ear. As this field grows, the need for knowledge about effective delivery of therapeutics to the inner ear has become a priority. This review maps all clinical and pre-clinical research published in English in the field to date, to guide both researchers and clinicians about local drug delivery methods in the context of novel therapeutics. Methods: A systematic search was conducted using customized strategies in Cochrane, pubmed and EMBASE databases from inception to 30/09/2018. Two researchers undertook study selection and data extraction independently. Results: Our search returned 12,200 articles, of which 837 articles met the inclusion criteria. 679 were original research and 158 were reviews. There has been a steady increase in the numbers of publications related to inner ear therapeutics delivery over the last three decades, with a sharp rise over the last 2 years. The intra-tympanic route accounts for over 70% of published articles. Less than one third of published research directly assesses delivery efficacy, with most papers using clinical efficacy as a surrogate marker. Conclusion: Research into local therapeutic delivery to the inner ear has undergone a recent surge, improving our understanding of how novel therapeutics can be delivered. Direct assessment of delivery efficacy is challenging, especially in humans, and progress in this area is key to understanding how to make decisions about delivery of novel hearing therapeutics.
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Affiliation(s)
- Caroline R. Anderson
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Carol Xie
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Matthew P. Su
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Maria Garcia
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Helen Blackshaw
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Anne G. M. Schilder
- evidENT, Ear Institute, University College London, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
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18
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Schvartz-Leyzac KC, Colesa DJ, Buswinka CJ, Swiderski DL, Raphael Y, Pfingst BE. Changes over time in the electrically evoked compound action potential (ECAP) interphase gap (IPG) effect following cochlear implantation in Guinea pigs. Hear Res 2019; 383:107809. [PMID: 31630082 DOI: 10.1016/j.heares.2019.107809] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 12/30/2022]
Abstract
The electrically-evoked compound action potential (ECAP) is correlated with spiral ganglion neuron (SGN) density in cochlear implanted animals. In a previous study, we showed that ECAP amplitude growth function (AGF) linear slopes for stimuli with a constant interphase gap (IPG) changed significantly over time following implantation. Related studies have also shown that 1) IPG sensitivity for ECAP measures ("IPG Effect") is related to SGN density in animals and 2) the ECAP IPG Effect is related to speech recognition performance in humans with cochlear implants. The current study examined how the ECAP IPG Effect changed following cochlear implantation in four non-deafened guinea pigs with residual inner hair cells (IHCs) and 5 deafened, neurotrophin-treated guinea pigs. Simple impedances were measured on the same days as the ECAP measures. Generally, non-deafened implanted animals with higher SGN survival demonstrated higher ECAP AGF linear slope and peak amplitude values than the deafened, implanted guinea pigs. The ECAP IPG Effect for the AGF slopes and peak amplitudes was also larger in the hearing animals. The N1 latencies for a constant IPG were not different between groups, but the N1 latency IPG Effect was smaller in the non-deafened, implanted animals. Similar to previously reported results, ECAP measures using a fixed or changing IPG required as many as three months after implantation before a stable point could be calculated, but this was dependent on the animal and condition. For all ECAP measures most animals showed greater variance in the first 30 days post-implantation. Post-implantation changes in ECAPs and impedances were not correlated with one another. Results from this study are helpful for estimating the mechanisms underlying ECAP characteristics and have implications for clinical application of the ECAP measures in long-term human cochlear implant recipients. Specifically, these measures could help to monitor neural health over a period of time, or during a time of stability these measures could be used to help select electrode sites for activation in clinical programming.
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Affiliation(s)
- Kara C Schvartz-Leyzac
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA; Hearing Rehabilitation Center, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 475 W. Market Place, Building 1, Suite A, Ann Arbor, MI, 48108.
| | - Deborah J Colesa
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Christopher J Buswinka
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
| | - Bryan E Pfingst
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-5616, USA
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19
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Bertram S, Roll L, Reinhard J, Groß K, Dazert S, Faissner A, Volkenstein S. Pleiotrophin increases neurite length and number of spiral ganglion neurons in vitro. Exp Brain Res 2019; 237:2983-2993. [PMID: 31515588 DOI: 10.1007/s00221-019-05644-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 09/03/2019] [Indexed: 11/28/2022]
Abstract
Acoustic trauma, aging, genetic defects or ototoxic drugs are causes for sensorineural hearing loss involving sensory hair cell death and secondary degeneration of spiral ganglion neurons. Auditory implants are the only available therapy for severe to profound sensorineural hearing loss when hearing aids do not provide a sufficient speech discrimination anymore. Neurotrophic factors represent potential therapeutic candidates to improve the performance of cochlear implants (CIs) by the support of spiral ganglion neurons (SGNs). Here, we investigated the effect of pleiotrophin (PTN), a well-described neurotrophic factor for different types of neurons that is expressed in the postnatal mouse cochlea. PTN knockout mice exhibit severe deficits in auditory brainstem responses, which indicates the importance of PTN in inner ear development and function and makes it a promising candidate to support SGNs. Using organotypic explants and dissociated SGN cultures, we investigated the influence of PTN on the number of neurons, neurite number and neurite length. PTN significantly increased the number and neurite length of dissociated SGNs. We further verified the expression of important PTN-associated receptors in the SG. mRNA of anaplastic lymphoma kinase, αv integrin, β3 integrin, receptor protein tyrosine phosphatase β/ζ, neuroglycan C, low-density lipoprotein receptor-related protein 1 and syndecan 3 was detected in the inner ear. These results suggest that PTN may be a novel candidate to improve sensorineural hearing loss treatment in the future.
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Affiliation(s)
- Sebastian Bertram
- Department of Otorhinolaryngology, Head and Neck Surgery, St. Elisabeth-Hospital, Ruhr-University Bochum, Bleichstr. 15, 44787, Bochum, Germany
| | - Lars Roll
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Katharina Groß
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Stefan Dazert
- Department of Otorhinolaryngology, Head and Neck Surgery, St. Elisabeth-Hospital, Ruhr-University Bochum, Bleichstr. 15, 44787, Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Stefan Volkenstein
- Department of Otorhinolaryngology, Head and Neck Surgery, St. Elisabeth-Hospital, Ruhr-University Bochum, Bleichstr. 15, 44787, Bochum, Germany.
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20
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Pinyon JL, von Jonquieres G, Crawford EN, Duxbury M, Al Abed A, Lovell NH, Klugmann M, Wise AK, Fallon JB, Shepherd RK, Birman CS, Lai W, McAlpine D, McMahon C, Carter PM, Enke YL, Patrick JF, Schilder AG, Marie C, Scherman D, Housley GD. Neurotrophin gene augmentation by electrotransfer to improve cochlear implant hearing outcomes. Hear Res 2019; 380:137-149. [DOI: 10.1016/j.heares.2019.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 12/14/2022]
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21
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Bas E, Anwar MR, Goncalves S, Dinh CT, Bracho OR, Chiossone JA, Van De Water TR. Laminin-coated electrodes improve cochlear implant function and post-insertion neuronal survival. Neuroscience 2019; 410:97-107. [PMID: 31059743 DOI: 10.1016/j.neuroscience.2019.04.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 12/20/2022]
Abstract
The benefits of Cochlear implant (CI) technology depend among other factors on the proximity of the electrode array to the spiral ganglion neurons. Laminin, a component of the extracellular matrix, regulates Schwann cell proliferation and survival as well as reorganization of actin fibers within their cytoskeleton, which is necessary for myelination of peripheral axons. In this study we explore the effectiveness of laminin-coated electrodes in promoting neuritic outgrowth from auditory neurons towards the electrode array and the ability to reduce acoustic and electric auditory brainstem response (i.e. aABR and eABR) thresholds. In vitro: Schwann cells and neurites are attracted towards laminin-coated surfaces with longer neuritic processes in laminin-coated dishes compared to uncoated dishes. In vivo: Animals implanted with laminin-coated electrodes experience significant decreases in eABR and aABR thresholds at selected frequencies compared to the results from the uncoated electrodes group. At 1 month post implantation there were a greater number of spiral ganglion neurons and neuritic processes projecting into the scala tympani of animals implanted with laminin-coated electrodes compared to animals with uncoated electrodes. These data suggest that Schwann cells are attracted towards laminin-coated electrodes and promote neuritic outgrowth/ guidance and promote the survival of spiral ganglion neurons following electrode insertion trauma.
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Affiliation(s)
- Esperanza Bas
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America.
| | - Mir R Anwar
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Stefania Goncalves
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Christine T Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Olena R Bracho
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Juan A Chiossone
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Thomas R Van De Water
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
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de Vries I, Schmitt H, Lenarz T, Prenzler N, Alvi S, Staecker H, Durisin M, Warnecke A. Detection of BDNF-Related Proteins in Human Perilymph in Patients With Hearing Loss. Front Neurosci 2019; 13:214. [PMID: 30971872 PMCID: PMC6445295 DOI: 10.3389/fnins.2019.00214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/25/2019] [Indexed: 12/05/2022] Open
Abstract
The outcome of cochlear implantation depends on multiple variables including the underlying health of the cochlea. Brain derived neurotrophic factor (BDNF) has been shown to support spiral ganglion neurons and to improve implant function in animal models. Whether endogenous BDNF or BDNF-regulated proteins can be used as biomarkers to predict cochlear health and implant outcome has not been investigated yet. Gene expression of BDNF and downstream signaling molecules were identified in tissue of human cochleae obtained from normal hearing patients (n = 3) during skull base surgeries. Based on the gene expression data, bioinformatic analysis was utilized to predict the regulation of proteins by BDNF. The presence of proteins corresponding to these genes was investigated in perilymph (n = 41) obtained from hearing-impaired patients (n = 38) during cochlear implantation or skull base surgery for removal of vestibular schwannoma by nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). Analyzed by mass spectrometry were 41 perilymph samples despite three patients undergoing bilateral cochlear implantation. These particular BDNF regulated proteins were not detectable in any of the perilymph samples. Subsequently, targeted analysis of the perilymph proteome data with Ingenuity Pathway Analysis (IPA) identified further proteins in human perilymph that could be regulated by BDNF. These BDNF regulated proteins were correlated to the presence of residual hearing (RH) prior to implantation and to the performance data with the cochlear implant after 1 year. There was overall a decreased level of expression of BDNF-regulated proteins in profoundly hearing-impaired patients compared to patients with some RH. Phospholipid transfer protein was positively correlated to the preoperative hearing level of the patients. Our data show that combination of gene expression arrays and bioinformatic analysis can aid in the prediction of downstream signaling proteins related to the BDNF pathway. Proteomic analysis of perilymph may help to identify the presence or absence of these molecules in the diseased organ. The impact of such prediction algorithms on diagnosis and treatment needs to be established in further studies.
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Affiliation(s)
- Ines de Vries
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Heike Schmitt
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
| | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
| | - Nils Prenzler
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Sameer Alvi
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, MO, United States
| | - Hinrich Staecker
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, MO, United States
| | - Martin Durisin
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany
| | - Athanasia Warnecke
- Department of Otolaryngology, Hannover Medical School, Hanover, Germany.,Cluster of Excellence Hearing4all, German Research Foundation, Hannover Medical School, Hanover, Germany
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Lee MY, Park YH. Potential of Gene and Cell Therapy for Inner Ear Hair Cells. BIOMED RESEARCH INTERNATIONAL 2018; 2018:8137614. [PMID: 30009175 PMCID: PMC6020521 DOI: 10.1155/2018/8137614] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 04/11/2018] [Accepted: 05/15/2018] [Indexed: 02/06/2023]
Abstract
Sensorineural hearing loss is caused by the loss of sensory hair cells (HCs) or a damaged afferent nerve pathway to the auditory cortex. The most common option for the treatment of sensorineural hearing loss is hearing rehabilitation using hearing devices. Various kinds of hearing devices are available but, despite recent advancements, their perceived sound quality does not mimic that of the "naïve" cochlea. Damage to crucial cochlear structures is mostly irreversible and results in permanent hearing loss. Cochlear HC regeneration has long been an important goal in the field of hearing research. However, it remains challenging because, thus far, no medical treatment has successfully regenerated cochlear HCs. Recent advances in genetic modulation and developmental techniques have led to novel approaches to generating HCs or protecting against HC loss, to preserve hearing. In this review, we present and review the current status of two different approaches to restoring or protecting hearing, gene therapy, including the newly introduced CRISPR/Cas9 genome editing, and stem cell therapy, and suggest the future direction.
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Affiliation(s)
- Min Yong Lee
- Department of Otorhinolaryngology and Head & Neck Surgery, Dankook University Hospital, Cheonan, Chungnam, Republic of Korea
| | - Yong-Ho Park
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
- Brain Research Institute, College of Medicine, Chungnam National University, Daejeon, Republic of Korea
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Yang T, Choi JE, Soh D, Tobin K, Joiner ML, Hansen M, Lee A. CaBP1 regulates Ca v1 L-type Ca 2+ channels and their coupling to neurite growth and gene transcription in mouse spiral ganglion neurons. Mol Cell Neurosci 2018; 88:342-352. [PMID: 29548764 DOI: 10.1016/j.mcn.2018.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/07/2018] [Accepted: 03/12/2018] [Indexed: 12/19/2022] Open
Abstract
CaBP1 is a Ca2+ binding protein that is widely expressed in neurons in the brain, retina, and cochlea. In heterologous expression systems, CaBP1 interacts with and regulates voltage-gated Cav Ca2+ channels but whether this is the case in neurons is unknown. Here, we investigated the cellular functions of CaBP1 in cochlear spiral ganglion neurons (SGNs), which express high levels of CaBP1. Consistent with the role of CaBP1 as a suppressor of Ca2+-dependent inactivation (CDI) of Cav1 (L-type) channels, Cav1 currents underwent greater CDI in SGNs from mice lacking CaBP1 (C-KO) than in wild-type (WT) SGNs. The coupling of Cav1 channels to downstream signaling pathways was also disrupted in C-KO SGNs. Activity-dependent repression of neurite growth was significantly blunted and unresponsive to Cav1 antagonists in C-KO SGNs in contrast to WT SGNs. Moreover, Cav1-mediated Ca2+ signals and phosphorylation of cAMP-response element binding protein were reduced in C-KO SGNs compared to WT SGNs. Our findings establish a role for CaBP1 as an essential regulator of Cav1 channels in SGNs and their coupling to downstream pathways controlling activity-dependent transcription and neurite growth.
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Affiliation(s)
- Tian Yang
- Departments of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
| | - Ji-Eun Choi
- Departments of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
| | - Daniel Soh
- Departments of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
| | - Kevin Tobin
- Departments of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
| | - Mei-Ling Joiner
- Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA 52242, USA
| | - Marlan Hansen
- Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA 52242, USA; Neurosurgery, University of Iowa, Iowa City, IA 52242, USA
| | - Amy Lee
- Departments of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA; Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA 52242, USA; Neurology, University of Iowa, Iowa City, IA 52242, USA.
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Effects of brain-derived neurotrophic factor (BDNF) on the cochlear nucleus in cats deafened as neonates. Hear Res 2016; 342:134-143. [PMID: 27773647 DOI: 10.1016/j.heares.2016.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/23/2016] [Accepted: 10/15/2016] [Indexed: 01/11/2023]
Abstract
Many previous studies have shown significant neurotrophic effects of intracochlear delivery of BDNF in preventing degeneration of cochlear spiral ganglion (SG) neurons after deafness in rodents and our laboratory has shown similar results in developing cats deafened prior to hearing onset. This study examined the morphology of the cochlear nucleus (CN) in a group of neonatally deafened cats from a previous study in which infusion of BDNF elicited a significant improvement in survival of the SG neurons. Five cats were deafened by systemic injections of neomycin sulfate (60 mg/kg, SQ, SID) starting one day after birth, and continuing for 16-18 days until auditory brainstem response (ABR) testing demonstrated profound bilateral hearing loss. The animals were implanted unilaterally at about 1 month of age using custom-designed electrodes with a drug-delivery cannula connected to an osmotic pump. BDNF (94 μg/ml; 0.25 μl/hr) was delivered for 10 weeks. The animals were euthanized and studied at 14-23 weeks of age. Consistent with the neurotrophic effects of BDNF on SG survival, the total CN volume in these animals was significantly larger on the BDNF-treated side than on the contralateral side. However, total CN volume, both ipsi- and contralateral to the implants in these deafened juvenile animals, was markedly smaller than the CN in normal adult animals, reflecting the severe effects of deafness on the central auditory system during development. Data from the individual major CN subdivisions (DCN, Dorsal Cochlear Nucleus; PVCN, Posteroventral Cochlear Nucleus; AVCN, Anteroventral Cochlear Nucleus) also were analyzed. A significant difference was observed between the BDNF-treated and control sides only in the AVCN. Measurements of the cross-sectional areas of spherical cells showed that cells were significantly larger in the AVCN ipsilateral to the implant than on the contralateral side. Further, the numerical density of spherical cells was significantly lower in the AVCN ipsilateral to the implant than on the contralateral side, consistent with the larger AVCN volume observed with BDNF treatment. Together, findings indicate significant neurotrophic effects of intracochlear BDNF infusion on the developing CN.
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Frick C, Müller M, Wank U, Tropitzsch A, Kramer B, Senn P, Rask-Andersen H, Wiesmüller KH, Löwenheim H. Biofunctionalized peptide-based hydrogels provide permissive scaffolds to attract neurite outgrowth from spiral ganglion neurons. Colloids Surf B Biointerfaces 2016; 149:105-114. [PMID: 27736723 DOI: 10.1016/j.colsurfb.2016.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/03/2016] [Accepted: 10/03/2016] [Indexed: 12/15/2022]
Abstract
Cochlear implants (CI) allow for hearing rehabilitation in patients with sensorineural hearing loss or deafness. Restricted CI performance results from the spatial gap between spiral ganglion neurons and the CI, causing current spread that limits spatially restricted stimulation and impairs frequency resolution. This may be substantially improved by guiding peripheral processes of spiral ganglion neurons towards and onto the CI electrode contacts. An injectable, peptide-based hydrogel was developed which may provide a permissive scaffold to facilitate neurite growth towards the CI. To test hydrogel capacity to attract spiral ganglion neurites, neurite outgrowth was quantified in an in vitro model using a custom-designed hydrogel scaffold and PuraMatrix®. Neurite attachment to native hydrogels is poor, but significantly improved by incorporation of brain-derived neurotrophic factor (BDNF), covalent coupling of the bioactive laminin epitope IKVAV and the incorporation a full length laminin to hydrogel scaffolds. Incorporation of full length laminin protein into a novel custom-designed biofunctionalized hydrogel (IKVAV-GGG-SIINFEKL) allows for neurite outgrowth into the hydrogel scaffold. The study demonstrates that peptide-based hydrogels can be specifically biofunctionalized to provide a permissive scaffold to attract neurite outgrowth from spiral ganglion neurons. Such biomaterials appear suitable to bridge the spatial gap between neurons and the CI.
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Affiliation(s)
- Claudia Frick
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, DE-72076 Tübingen, Germany.
| | - Marcus Müller
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, DE-72076 Tübingen, Germany.
| | - Ute Wank
- EMC microcollections GmbH, DE-72070 Tübingen, Germany.
| | - Anke Tropitzsch
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, DE-72076 Tübingen, Germany.
| | - Benedikt Kramer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, DE-72076 Tübingen, Germany.
| | - Pascal Senn
- Department of Clinical Neurosciences, Service of Otorhinolaryngology, Head & Neck Surgery, HUG, University Hospital of Geneva, CH-1211 Genève 14, Switzerland.
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, Departments of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
| | | | - Hubert Löwenheim
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, DE-72076 Tübingen, Germany.
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High mobility group box 1 (HMGB1): dual functions in the cochlear auditory neurons in response to stress? Histochem Cell Biol 2016; 147:307-316. [PMID: 27704212 DOI: 10.1007/s00418-016-1506-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2016] [Indexed: 12/19/2022]
Abstract
High mobility group box 1 (HMGB1) is a DNA-binding protein that facilitates gene transcription and may act extracellularly as a late mediator of inflammation. The roles of HMGB1 in the pathogenesis of the spiral ganglion neurons (SGNs) of the cochlea are currently unknown. In the present study, we tested the hypothesis that early phenotypical changes in the SGNs of the amikacin-poisoned rat cochlea are mediated by HMGB1. Our results showed that a marked downregulation of HMGB1 had occurred by completion of amikacin treatment, coinciding with acute damage at the dendrite extremities of the SGNs. A few days later, during the recovery of the SGN dendrites, the protein was re-expressed and transiently accumulated within the nuclei of the SGNs. The phosphorylated form of the transcription factor c-Jun (p-c-Jun) was concomitantly detected in the nuclei of the SGNs where it often co-localized with HMGB1, while the anti-apoptotic protein BCL2 was over-expressed in the cytoplasm. In animals co-treated with amikacin and the histone deacetylase inhibitor trichostatin A, both HMGB1 and p-c-Jun were exclusively found within the cytoplasm. The initial disappearance of HMGB1 from the affected SGNs may be due to its release into the external medium, where it may have a cytokine-like function. Once re-expressed and translocated into the nucleus, HMGB1 may facilitate the transcriptional activity of p-c-Jun, which in turn may promote repair mechanisms. Our study therefore suggests that HMGB1 can positively influence the survival of SGNs following ototoxic exposure via both its extracellular and intranuclear functions.
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Jin Y, Lyu AR, Park SJ, Xu J, Cui J, Sohn KC, Hur GM, Jin Y, Park YH. Early Postnatal NT-3 Gene Delivery Enhances Hearing Acquisition in the Developmental Period. Laryngoscope 2016; 126:E379-E385. [DOI: 10.1002/lary.26130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/07/2016] [Accepted: 05/11/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Yongde Jin
- Department of Otolaryngology-Head and Neck Surgery; Yanbian University Hospital; Yanji China
| | - Ah-Ra Lyu
- Department of Otolaryngology-Head and Neck Surgery , College of Medicine; Chungnam National University; Daejeon Republic of Korea
- Department of Medical Science; Chungnam National University; Daejeon Republic of Korea
| | - Sung-Jae Park
- Department of Otolaryngology-Head and Neck Surgery , College of Medicine; Chungnam National University; Daejeon Republic of Korea
| | - Jun Xu
- Department of Otolaryngology-Head and Neck Surgery; Yanbian University Hospital; Yanji China
- Department of Otolaryngology-Head and Neck Surgery , College of Medicine; Chungnam National University; Daejeon Republic of Korea
| | - Jie Cui
- Department of Otolaryngology-Head and Neck Surgery; Yanbian University Hospital; Yanji China
| | - Kyung-Cheol Sohn
- Department of Dermatology , College of Medicine; Chungnam National University; Daejeon Republic of Korea
| | - Gang Min Hur
- Department of Pharmacology , College of Medicine; Chungnam National University; Daejeon Republic of Korea
| | - Yulian Jin
- Department of Otolaryngology-Head and Neck Surgery; Yanbian University Hospital; Yanji China
| | - Yong-Ho Park
- Department of Otolaryngology-Head and Neck Surgery , College of Medicine; Chungnam National University; Daejeon Republic of Korea
- Brain Research Institute , College of Medicine; Chungnam National University; Daejeon Republic of Korea
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Magnetic Beads Enhance Adhesion of NIH 3T3 Fibroblasts: A Proof-of-Principle In Vitro Study for Implant-Mediated Long-Term Drug Delivery to the Inner Ear. PLoS One 2016; 11:e0150057. [PMID: 26918945 PMCID: PMC4769079 DOI: 10.1371/journal.pone.0150057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/09/2016] [Indexed: 12/13/2022] Open
Abstract
Introduction Long-term drug delivery to the inner ear may be achieved by functionalizing cochlear implant (CI) electrodes with cells providing neuroprotective factors. However, effective strategies in order to coat implant surfaces with cells need to be developed. Our vision is to make benefit of electromagnetic field attracting forces generated by CI electrodes to bind BDNF-secreting cells that are labelled with magnetic beads (MB) onto the electrode surfaces. Thus, the effect of MB-labelling on cell viability and BDNF production were investigated. Materials and Methods Murine NIH 3T3 fibroblasts—genetically modified to produce BDNF—were labelled with MB. Results Atomic force and bright field microscopy illustrated the internalization of MB by fibroblasts after 24 h of cultivation. Labelling cells with MB did not expose cytotoxic effects on fibroblasts and allowed adhesion on magnetic surfaces with sufficient BDNF release. Discussion Our data demonstrate a novel approach for mediating enhanced long-term adhesion of BDNF-secreting fibroblasts on model electrode surfaces for cell-based drug delivery applications in vitro and in vivo. This therapeutic strategy, once transferred to cells suitable for clinical application, may allow the biological modifications of CI surfaces with cells releasing neurotrophic or other factors of interest.
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Novel High Content Screen Detects Compounds That Promote Neurite Regeneration from Cochlear Spiral Ganglion Neurons. Sci Rep 2015; 5:15960. [PMID: 26521685 PMCID: PMC4629150 DOI: 10.1038/srep15960] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/06/2015] [Indexed: 12/21/2022] Open
Abstract
The bipolar spiral ganglion neurons (SGN) carry sound information from cochlear hair cells to the brain. After noise, antibiotic or toxic insult to the cochlea, damage to SGN and/or hair cells causes hearing impairment. Damage ranges from fiber and synapse degeneration to dysfunction and loss of cells. New interventions to regenerate peripheral nerve fibers could help reestablish transfer of auditory information from surviving or regenerated hair cells or improve results from cochlear implants, but the biochemical mechanisms to target are largely unknown. Presently, no drugs exist that are FDA approved to stimulate the regeneration of SGN nerve fibers. We designed an original phenotypic assay to screen 440 compounds of the NIH Clinical Collection directly on dissociated mouse spiral ganglia. The assay detected one compound, cerivastatin, that increased the length of regenerating neurites. The effect, mimicked by other statins at different optimal concentrations, was blocked by geranylgeraniol. These results demonstrate the utility of screening small compound libraries on mixed cultures of dissociated primary ganglia. The success of this screen narrows down a moderately sized library to a single compound which can be elevated to in-depth in vivo studies, and highlights a potential new molecular pathway for targeting of hearing loss drugs.
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Abstract
Cochlear implantation and cochlear implants (CIs) have a long history filled with innovations that have resulted in the high-performing device's currently available. Several promising technologies have been reviewed in this article, which hold the promise to drive performance even higher. Remote CI programming, totally implanted devices, improved neural health and survival through targeted drug therapy and delivery, intraneural electrode placement, electroacoustical stimulation and hybrid CIs, and methods to enhance the neural-prosthesis interface are evolving areas of innovation reviewed in this article.
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Affiliation(s)
- Joseph P Roche
- Department of Otolaryngology - Head and Neck Surgery, The University of Iowa Carver College of Medicine, 21151 Pomerantz Family Pavilion, 200 Hawkins Drive, Iowa City, IA 52242-1089, USA
| | - Marlan R Hansen
- Department of Otolaryngology - Head and Neck Surgery, The University of Iowa Carver College of Medicine, 21151 Pomerantz Family Pavilion, 200 Hawkins Drive, Iowa City, IA 52242-1089, USA; Department of Neurosurgery, The University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, IA 52242-1089, USA.
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Fransson A, de Medina P, Paillasse MR, Silvente-Poirot S, Poirot M, Ulfendahl M. Dendrogenin A and B two new steroidal alkaloids increasing neural responsiveness in the deafened guinea pig. Front Aging Neurosci 2015; 7:145. [PMID: 26257649 PMCID: PMC4513558 DOI: 10.3389/fnagi.2015.00145] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 07/13/2015] [Indexed: 12/20/2022] Open
Abstract
Aim: To investigate the therapeutic potential for treating inner ear damage of two new steroidal alkaloid compounds, Dendrogenin A and Dendrogenin B, previously shown to be potent inductors of cell differentiation. Methods: Guinea pigs, unilaterally deafened by neomycin infusion, received a cochlear implant followed by immediate or a 2-week delayed treatment with Dendrogenin A, Dendrogenin B, and, as comparison artificial perilymph and glial cell-line derived neurotrophic factor. After a 4-week treatment period the animals were sacrificed and the cochleae processed for morphological analysis. Electrically-evoked auditory brainstem responses (eABRs) were measured weekly throughout the experiment. Results: Following immediate or delayed Dendrogenin treatment the electrical responsiveness was significantly maintained, in a similar extent as has been shown using neurotrophic factors. Histological analysis showed that the spiral ganglion neurons density was only slightly higher than the untreated group. Conclusions: Our results suggest that Dendrogenins constitute a new class of drugs with strong potential to improve cochlear implant efficacy and to treat neuropathy/synaptopathy related hearing loss. That electrical responsiveness was maintained despite a significantly reduced neural population suggests that the efficacy of cochlear implants is more related to the functional state of the spiral ganglion neurons than merely their number.
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Affiliation(s)
- Anette Fransson
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
| | | | | | | | - Marc Poirot
- INSERM UMR 1037, Cancer Research Center of Toulouse Toulouse, France
| | - Mats Ulfendahl
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
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Abstract
Partial loss and subsequent recovery of cochlear implant function in the first few weeks following cochlear implant surgery has been observed in previous studies using psychophysical detection thresholds. In the current study, we explored this putative manifestation of insertion trauma using objective functional measures: electrically-evoked compound action potential (ECAP) amplitude-growth functions (ECAP amplitude as a function of stimulus level). In guinea pigs implanted in a hearing ear with good post-implant hearing and good spiral ganglion neuron (SGN) survival, consistent patterns of ECAP functions were observed. The slopes of ECAP growth functions were moderately steep on the day of implant insertion, decreased to low levels over the first few days after implantation and then increased slowly over several weeks to reach a relatively stable level. In parallel, ECAP thresholds increased over time after implantation and then recovered, although more quickly, to a relatively stable low level as did thresholds for eliciting a facial twitch. Similar results were obtained in animals deafened but treated with an adenovirus with a neurotrophin gene insert that resulted in good SGN preservation. In contrast, in animals implanted in deaf ears that had relatively poor SGN survival, ECAP slopes reached low levels within a few days after implantation and remained low. These results are consistent with the idea that steep ECAP growth functions require a healthy population of auditory nerve fibers and that cochlear implant insertion trauma can temporarily impair the function of a healthy SGN population.
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Sethi M, Mishra S, Vasudeva N, Kaul J. Morphometrical Analysis of Developing Cochlear Ganglion Neurons: A Light Microscopic Fetal Study. J Clin Diagn Res 2015; 9:AC01-4. [PMID: 26266105 PMCID: PMC4525494 DOI: 10.7860/jcdr/2015/11323.5997] [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: 09/18/2014] [Accepted: 01/28/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND AIM The cochlear or spiral ganglion neurons are the initial bridge between the external world of sound and its discernment in the brain. As the developing human fetal cochlea is known to start functioning in mid gestational period, its anatomical details when compared with adults could vary with each gestational age. The aim of current study was to assess morphometrical parameter of developing human fetal cochlear ganglion neurons and comparison of data in each gestational period. MATERIALS AND METHODS Ten aborted human fetuses from 14th to 28th weeks of gestation were procured from Department of Obstetrics and Gynaecology of associated hospital, after obtaining ethical clearance and were processed for studying under light microscope. Area of neurons from each gestational age was measured on histophotomicrographs using image Proplus software. Standard statistical method was used to calculate area range and percentage of small and large ganglion neurons. RESULTS The neuronal area increased progressively in successively higher gestation age fetuses. In the fetus belonging to lowest gestational age the area ranged from 4-37μm2 while in highest gestational age fetus its range was 10-58.3μm2. The small ganglion neurons were higher in 14 weeks (65.5%) fetuses and 16-20 weeks (81.03%) fetuses, while in higher gestational age fetuses' large ganglion neuronal population was higher (62-66%). CONCLUSION A baseline morphometrical representation of fetal cochlear ganglion neurons could be of relevance in advanced human experimental studies on effect of neurotrophic factors in human fetuses with congenital deafness. It has been found that these factors directly influence neuronal maturation assessed by progressive increase in soma size and survival.
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Affiliation(s)
- Madhu Sethi
- Assistant Professor, Department of Anatomy, Dr. Baba Sahab Ambedkar Medical College & Hospital, Rohini, New Delhi, India
| | - Sabita Mishra
- Professor, Department of Anatomy, Maulana Azad Medical CollegeNew Delhi, India
| | - Neelam Vasudeva
- Director Professor and Head, Department of Anatomy, Maulana Azad Medical College, New Delhi, India
| | - J.M. Kaul
- Professor and Head, Department of Anatomy, Dr. Baba Sahab Ambedkar Medical College & Hospital, Rohini, New Delhi, India
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36
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Wan G, Corfas G. No longer falling on deaf ears: mechanisms of degeneration and regeneration of cochlear ribbon synapses. Hear Res 2015; 329:1-10. [PMID: 25937135 DOI: 10.1016/j.heares.2015.04.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 04/01/2015] [Accepted: 04/20/2015] [Indexed: 01/02/2023]
Abstract
Cochlear ribbon synapses are required for the rapid and precise neural transmission of acoustic signals from inner hair cells to the spiral ganglion neurons. Emerging evidence suggests that damage to these synapses represents an important form of cochlear neuropathy that might be highly prevalent in sensorineural hearing loss. In this review, we discuss our current knowledge on how ribbon synapses are damaged by noise and during aging, as well as potential strategies to promote ribbon synapse regeneration for hearing restoration.
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Affiliation(s)
- Guoqiang Wan
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gabriel Corfas
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109, USA.
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37
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Khalin I, Alyautdin R, Kocherga G, Bakar MA. Targeted delivery of brain-derived neurotrophic factor for the treatment of blindness and deafness. Int J Nanomedicine 2015; 10:3245-67. [PMID: 25995632 PMCID: PMC4425321 DOI: 10.2147/ijn.s77480] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative causes of blindness and deafness possess a major challenge in their clinical management as proper treatment guidelines have not yet been found. Brain-derived neurotrophic factor (BDNF) has been established as a promising therapy against neurodegenerative disorders including hearing and visual loss. Unfortunately, the blood–retinal barrier and blood–cochlear barrier, which have a comparable structure to the blood–brain barrier prevent molecules of larger sizes (such as BDNF) from exiting the circulation and reaching the targeted cells. Anatomical features of the eye and ear allow use of local administration, bypassing histo-hematic barriers. This paper focuses on highlighting a variety of strategies proposed for the local administration of the BDNF, like direct delivery, viral gene therapy, and cell-based therapy, which have been shown to successfully improve development, survival, and function of spiral and retinal ganglion cells. The similarities and controversies for BDNF treatment of posterior eye diseases and inner ear diseases have been analyzed and compared. In this review, we also focus on the possibility of translation of this knowledge into clinical practice. And finally, we suggest that using nanoparticulate drug-delivery systems may substantially contribute to the development of clinically viable techniques for BDNF delivery into the cochlea or posterior eye segment, which, ultimately, can lead to a long-term or permanent rescue of auditory and optic neurons from degeneration.
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Affiliation(s)
- Igor Khalin
- Faculty of Medicine and Defence Health, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Renad Alyautdin
- Scientific Centre for Expertise of Medical Application Products, Moscow, Russia
| | - Ganna Kocherga
- Ophthalmic Microsurgery Department, International Medical Center Oftalmika, Kharkiv, Ukraine
| | - Muhamad Abu Bakar
- Faculty of Medicine and Defence Health, National Defence University of Malaysia, Kuala Lumpur, Malaysia
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Pfingst BE, Zhou N, Colesa DJ, Watts MM, Strahl SB, Garadat SN, Schvartz-Leyzac KC, Budenz CL, Raphael Y, Zwolan TA. Importance of cochlear health for implant function. Hear Res 2015; 322:77-88. [PMID: 25261772 PMCID: PMC4377117 DOI: 10.1016/j.heares.2014.09.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/14/2014] [Accepted: 09/16/2014] [Indexed: 01/17/2023]
Abstract
Amazing progress has been made in providing useful hearing to hearing-impaired individuals using cochlear implants, but challenges remain. One such challenge is understanding the effects of partial degeneration of the auditory nerve, the target of cochlear implant stimulation. Here we review studies from our human and animal laboratories aimed at characterizing the health of the implanted cochlea and the auditory nerve. We use the data on cochlear and neural health to guide rehabilitation strategies. The data also motivate the development of tissue-engineering procedures to preserve or build a healthy cochlea and improve performance obtained by cochlear implant recipients or eventually replace the need for a cochlear implant. This article is part of a Special Issue entitled .
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Affiliation(s)
- Bryan E Pfingst
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA.
| | - Ning Zhou
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA; East Carolina University, Greenville, NC, USA
| | - Deborah J Colesa
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - Melissa M Watts
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | | | - Soha N Garadat
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA; The University of Jordan, Amman, Jordan
| | | | - Cameron L Budenz
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - Yehoash Raphael
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - Teresa A Zwolan
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
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BDNF-TrkB axis regulates migration of the lateral line primordium and modulates the maintenance of mechanoreceptor progenitors. PLoS One 2015; 10:e0119711. [PMID: 25751404 PMCID: PMC4353718 DOI: 10.1371/journal.pone.0119711] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 01/16/2015] [Indexed: 12/12/2022] Open
Abstract
BDNF and its specialized receptor TrkB are expressed in the developing lateral line system of zebrafish, but their role in this organ is unknown. To tackle this problem in vivo, we used transgenic animals expressing fluorescent markers in different cell types of the lateral line and combined a BDNF gain-of-function approach by BDNF mRNA overexpression and by soaking embryos in a solution of BDNF, with a loss-of-function approach by injecting the antisence ntrk2b-morpholino and treating embryos with the specific Trk inhibitor K252a. Subsequent analysis demonstrated that the BDNF-TrkB axis regulates migration of the lateral line primordium. In particular, BDNF-TrkB influences the expression level of components of chemokine signaling including Cxcr4b, and the generation of progenitors of mechanoreceptors, at the level of expression of Atoh1a-Atp2b1a.
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40
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Differential effects of AAV.BDNF and AAV.Ntf3 in the deafened adult guinea pig ear. Sci Rep 2015; 5:8619. [PMID: 25726967 DOI: 10.1038/srep08619] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 01/27/2015] [Indexed: 01/14/2023] Open
Abstract
Cochlear hair cell loss results in secondary regression of peripheral auditory fibers (PAFs) and loss of spiral ganglion neurons (SGNs). The performance of cochlear implants (CI) in rehabilitating hearing depends on survival of SGNs. Here we compare the effects of adeno-associated virus vectors with neurotrophin gene inserts, AAV.BDNF and AAV.Ntf3, on guinea pig ears deafened systemically (kanamycin and furosemide) or locally (neomycin). AAV.BDNF or AAV.Ntf3 was delivered to the guinea pig cochlea one week following deafening and ears were assessed morphologically 3 months later. At that time, neurotrophins levels were not significantly elevated in the cochlear fluids, even though in vitro and shorter term in vivo experiments demonstrate robust elevation of neurotrophins with these viral vectors. Nevertheless, animals receiving these vectors exhibited considerable re-growth of PAFs in the basilar membrane area. In systemically deafened animals there was a negative correlation between the presence of differentiated supporting cells and PAFs, suggesting that supporting cells influence the outcome of neurotrophin over-expression aimed at enhancing the cochlear neural substrate. Counts of SGN in Rosenthal's canal indicate that BDNF was more effective than NT-3 in preserving SGNs. The results demonstrate that a transient elevation in neurotrophin levels can sustain the cochlear neural substrate in the long term.
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41
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Abstract
Close-field electroporation gene delivery using the cochlear implant electrode array enhances the bionic ear (Pinyon et al., this issue).
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42
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Gurman P, Miranda OR, Clayton K, Rosen Y, Elman NM. Clinical applications of biomedical microdevices for controlled drug delivery. Mayo Clin Proc 2015; 90:93-108. [PMID: 25484235 DOI: 10.1016/j.mayocp.2014.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/11/2014] [Accepted: 10/02/2014] [Indexed: 01/20/2023]
Abstract
Miniaturization of devices to micrometer and nanometer scales, combined with the use of biocompatible and functional materials, has created new opportunities for the implementation of drug delivery systems. Advances in biomedical microdevices for controlled drug delivery platforms promise a new generation of capabilities for the treatment of acute conditions and chronic illnesses, which require high adherence to treatment, in which temporal control over the pharmacokinetic profiles is critical. In addition, clinical conditions that require a combination of drugs with specific pharmacodynamic profiles and local delivery will benefit from drug delivery microdevices. This review provides a summary of various clinical applications for state-of-the-art controlled drug delivery microdevices, including cancer, endocrine and ocular disorders, and acute conditions such as hemorrhagic shock. Regulatory considerations for clinical translation of drug delivery microdevices are also discussed. Drug delivery microdevices promise a remarkable gain in clinical outcomes and a substantial social impact. A review of articles covering the field of microdevices for drug delivery was performed between January 1, 1990, and January 1, 2014, using PubMed as a search engine.
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Affiliation(s)
- Pablo Gurman
- Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge; Department of Materials Science, University of Texas at Dallas, Richardson
| | - Oscar R Miranda
- Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge
| | - Kevin Clayton
- Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge
| | - Yitzhak Rosen
- Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge
| | - Noel M Elman
- Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge.
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Wan G, Gómez-Casati ME, Gigliello AR, Liberman MC, Corfas G. Neurotrophin-3 regulates ribbon synapse density in the cochlea and induces synapse regeneration after acoustic trauma. eLife 2014; 3. [PMID: 25329343 PMCID: PMC4227045 DOI: 10.7554/elife.03564] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/09/2014] [Indexed: 12/23/2022] Open
Abstract
Neurotrophin-3 (Ntf3) and brain derived neurotrophic factor (Bdnf) are critical for sensory neuron survival and establishment of neuronal projections to sensory epithelia in the embryonic inner ear, but their postnatal functions remain poorly understood. Using cell-specific inducible gene recombination in mice we found that, in the postnatal inner ear, Bbnf and Ntf3 are required for the formation and maintenance of hair cell ribbon synapses in the vestibular and cochlear epithelia, respectively. We also show that supporting cells in these epithelia are the key endogenous source of the neurotrophins. Using a new hair cell CreER(T) line with mosaic expression, we also found that Ntf3's effect on cochlear synaptogenesis is highly localized. Moreover, supporting cell-derived Ntf3, but not Bbnf, promoted recovery of cochlear function and ribbon synapse regeneration after acoustic trauma. These results indicate that glial-derived neurotrophins play critical roles in inner ear synapse density and synaptic regeneration after injury.
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Affiliation(s)
- Guoqiang Wan
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - Maria E Gómez-Casati
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - Angelica R Gigliello
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
| | - M Charles Liberman
- Department of Otology and Laryngology, Harvard Medical School, Boston, United States
| | - Gabriel Corfas
- F M Kirby Neurobiology Center, Boston Children's Hospital, Boston, United States
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44
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Liu H, Zhou Y, Chen S, Bu M, Xin J, Li S. Current sustained delivery strategies for the design of local neurotrophic factors in treatment of neurological disorders. Asian J Pharm Sci 2013. [DOI: 10.1016/j.ajps.2013.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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45
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Abstract
Animal studies on inner ear development, repair and regeneration provide understanding of molecular pathways that can be harnessed for treating inner ear disease. Use of transgenic mouse technology, in particular, has contributed knowledge of genes that regulate development of hair cells and innervation, and of molecular players that can induce regeneration, but this technology is not applicable for human treatment, for practical and ethical reasons. Therefore other means for influencing gene expression in the inner ear are needed. We describe several gene vectors useful for inner ear gene therapy and the practical aspects of introducing these vectors into the ear. We then review the progress toward using gene transfer for therapies in both auditory and balance systems, and discuss the technological milestones needed to advance to clinical application of these methods.
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Affiliation(s)
- Hideto Fukui
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, 1150 West Medical Center Dr., Ann Arbor, MI 48109-5648, USA
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46
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Van De Water TR. Historical Aspects of Inner Ear Anatomy and Biology that Underlie the Design of Hearing and Balance Prosthetic Devices. Anat Rec (Hoboken) 2012; 295:1741-59. [PMID: 23045252 DOI: 10.1002/ar.22598] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 12/19/2022]
Abstract
This review presents some of the major historical events that advanced the body of knowledge of the anatomy of the inner ear and its sensory receptors as well as the biology of these receptors that underlies the sensory functions of hearing and balance. This knowledge base of the inner ear's structure/function has been an essential factor for the design and construction of prosthetic devices to aid patients with deficits in their senses of hearing and balance. Prosthetic devices are now available for severely hearing impaired and deaf patients to restore hearing and are known as cochlear implants and auditory brain stem implants. A prosthetic device for patients with balance disorders is being perfected and is in an animal model testing phase with another prosthetic device for controlling intractable dizziness in Meniere's patients currently being evaluated in clinical testing. None of this would have been possible without the pioneering studies and discoveries of the investigators mentioned in this review and with the work of many other talented investigators to numerous to be covered in this review.
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Affiliation(s)
- Thomas R Van De Water
- Cochlear Implant Research Program, University of Miami Ear Institute, Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida 33136-1015, USA.
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