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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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Wong EC, Lopez IA, Ishiyama A, Ishiyama G. Expression of Brain-Derived Neurotrophic Factor in Human Spiral Ganglia Neurons after Cochlear Implantation. Otol Neurotol 2024; 45:326-333. [PMID: 38238917 PMCID: PMC10922350 DOI: 10.1097/mao.0000000000004104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
BACKGROUND Brain-derived neurotrophic factor (BDNF) is an important factor in the development and neuroprotection of afferent auditory pathways. In this study, we investigated the expression of BDNF in the afferent auditory pathway after cochlear implantation (CI), hypothesizing that electrical stimulation after CI stimulates BDNF expression in the afferent auditory pathway. METHODS Archival human temporal bones from eight patients with a history of CI and five patients with normal hearing (ages 65-93 years old) were studied. Temporal bone specimens were immunoreacted with rabbit polyclonal antibodies against BDNF and mouse monoclonal antibodies against pan-neurofilaments. In cases of unilateral CI, the BDNF expression was compared with the contralateral unimplanted ear and normal temporal bones without hearing loss. RESULTS BDNF immunoreactivity (IR) localized to the spiral ganglion neurons (SGNs) somata and the surrounding satellite cells. BDNF-IR in the spiral ganglia was similar in the apical, middle, and basal hook regions. Neurofilament IR localized to SGN nerve fibers in both implanted and unimplanted cochleae. BDNF-IR in the SGN and satellite cells was significantly increased in the implanted specimens compared with the unimplanted specimens ( p < 0.05) and the normal hearing specimens ( p < 0.05). BDNF-IR expression was similar in the unimplanted cochlea and in the normal cochlea. BDNF protein expression was increased despite complete loss of the organ of Corti hair cells and supporting cells. Even in the cases of CI with a 6-mm first-generation electrode, BDNF expression was upregulated throughout the cochlea. CONCLUSIONS BDNF expression in the SGN appears to be upregulated by the electrical stimulation from CI. This study provides evidence that the electrical stimulation from CI may stimulate the expression of BDNF, playing a neuroprotective role in the rehabilitation of hearing in the deafened ear.
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Affiliation(s)
| | | | | | - Gail Ishiyama
- UCLA Department of Head and Neck Surgery
- UCLA Department of Neurology
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3
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Vink HA, Ramekers D, Foster AC, Versnel H. The efficacy of a TrkB monoclonal antibody agonist in preserving the auditory nerve in deafened guinea pigs. Hear Res 2023; 439:108895. [PMID: 37837701 DOI: 10.1016/j.heares.2023.108895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 08/31/2023] [Accepted: 10/02/2023] [Indexed: 10/16/2023]
Abstract
The auditory nerve typically degenerates following loss of cochlear hair cells or synapses. In the case of hair cell loss neural degeneration hinders restoration of hearing through a cochlear implant, and in the case of synaptopathy suprathreshold hearing is affected, potentially degrading speech perception in noise. It has been established that neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) can mitigate auditory nerve degeneration. Several potential BDNF mimetics have also been investigated for neurotrophic effects in the cochlea. A recent in vitro study showed favorable effects of M3, a TrkB monoclonal antibody agonist, when compared with BDNF. In the present study we set out to examine the effect of M3 on auditory nerve preservation in vivo. Thirty-one guinea pigs were bilaterally deafened, and unilaterally treated with a single 3-µl dose of 7 mg/ml, 0.7 mg/ml M3 or vehicle-only by means of a small gelatin sponge two weeks later. During the experiment and analyses the experimenters were blinded to the three treatment groups. Four weeks after treatment, we assessed the treatment effect (1) histologically, by quantifying survival of SGCs and their peripheral processes (PPs); and (2) electrophysiologically, with two different paradigms of electrically evoked compound action potential (eCAP) recordings shown to be indicative of neural health: single-pulse stimulation with varying inter-phase gap (IPG), and pulse-train stimulation with varying inter-pulse interval. We observed a consistent and significant preservative effect of M3 on SGC survival in the lower basal turn (approximately 40% more survival than in the untreated contralateral cochlea), but also in the upper middle and lower apical turn of the cochlea. This effect was similar for the two treatment groups. Survival of PPs showed a trend similar to that of the SGCs, but was only significantly higher for the highest dose of M3. The protective effect of M3 on SGCs was not reflected in any of the eCAP measures: no statistically significant differences were observed between groups in IPG effect nor between the M3 treatment groups and the control group using the pulse-train stimulation paradigm. In short, while a clear effect of M3 was observed on SGC survival, this was not clearly translated into functional preservation.
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Affiliation(s)
- Henk A Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands
| | | | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, the Netherlands; UMC Utrecht Brain Center, Utrecht University, Utrecht, the Netherlands.
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Ranjbar N, Shahbazi A, Nourizadeh N, Namvar Arefi H, Kheirkhah MT. Relationship Between Serum Levels of Brain-Derived Neurotrophic Factor (BDNF) and Hearing Loss and Tinnitus. Indian J Otolaryngol Head Neck Surg 2023; 75:507-513. [PMID: 37206834 PMCID: PMC10188841 DOI: 10.1007/s12070-023-03600-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Tinnitus and hearing loss are common problems that can be investigated via subjective and objective approaches. Previous studies have suggested a potential relationship between serum levels of Brain-Derived Neurotrophic Factor (BDNF) and tinnitus, reporting it as a potential objective biomarker for tinnitus. Therefore, the present study aimed to investigate the serum levels of BDNF in patients with tinnitus and/or hearing loss. Sixty patients were divided into 3 groups: Normal hearing with tinnitus (NH-T), hearing Loss with tinnitus (HL-T), and hearing loss without tinnitus (HL-NT). Moreover, 20 healthy participants were assigned to the control group or NH-NT. All participants were assessed using comprehensive audiological evaluations, serum BDNF level assessment, Tinnitus Handicap Inventory (THI), and Beck's Depression Inventory (BDI). There were significant intergroup differences in serum BDNF levels (p < 0.05), with the HL-T group showing the lowest BDNF levels. Moreover, the NH-T group had lower levels of BDNF compared to the HL-NT group. On the other hand, serum BDNF levels were significantly decreased in patients with an increased hearing threshold (p < 0.05). Also, serum BDNF levels had no significant relationship with tinnitus duration and loudness, as well as THI and BDI scores. The present study was the first to illustrate the importance of serum BDNF levels as a possible biomarker for predicting the severity of hearing loss and tinnitus in the affected patients. Also, it is possible that BDNF assessment can help find effective therapeutic methods for patients with hearing problems. Supplementary Information The online version contains supplementary material available at 10.1007/s12070-023-03600-z.
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Affiliation(s)
- Nastaran Ranjbar
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Shahbazi
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Navid Nourizadeh
- Otorhinolaryngology-Head and Neck Surgery Department , Imam Reza Educational Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Namvar Arefi
- Department of Audiology, School of Rehabilitation Sciences , Iran University of Medical Science, Tehran, Iran
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Effects of erinacine A-enriched Hericium erinaceus on elderly hearing-impaired patients: A double-blind, randomized, placebo-controlled clinical trial. J Funct Foods 2022. [DOI: 10.1016/j.jff.2022.105220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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St. Peter M, Brough DE, Lawrence A, Nelson-Brantley J, Huang P, Harre J, Warnecke A, Staecker H. Improving Control of Gene Therapy-Based Neurotrophin Delivery for Inner Ear Applications. Front Bioeng Biotechnol 2022; 10:892969. [PMID: 35721868 PMCID: PMC9204055 DOI: 10.3389/fbioe.2022.892969] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Survival and integrity of the spiral ganglion is vital for hearing in background noise and for optimal functioning of cochlear implants. Numerous studies have demonstrated that supplementation of supraphysiologic levels of the neurotrophins BDNF and NT-3 by pumps or gene therapy strategies supports spiral ganglion survival. The endogenous physiological levels of growth factors within the inner ear, although difficult to determine, are likely extremely low within the normal inner ear. Thus, novel approaches for the long-term low-level delivery of neurotrophins may be advantageous. Objectives: This study aimed to evaluate the long-term effects of gene therapy-based low-level neurotrophin supplementation on spiral ganglion survival. Using an adenovirus serotype 28-derived adenovector delivery system, the herpes latency promoter, a weak, long expressing promoter system, has been used to deliver the BDNF or NTF3 genes to the inner ear after neomycin-induced ototoxic injury in mice. Results: Treatment of the adult mouse inner ear with neomycin resulted in acute and chronic changes in endogenous neurotrophic factor gene expression and led to a degeneration of spiral ganglion cells. Increased survival of spiral ganglion cells after adenoviral delivery of BDNF or NTF3 to the inner ear was observed. Expression of BDNF and NT-3 could be demonstrated in the damaged organ of Corti after gene delivery. Hearing loss due to overexpression of neurotrophins in the normal hearing ear was avoided when using this novel vector–promoter combination. Conclusion: Combining supporting cell-specific gene delivery via the adenovirus serotype 28 vector with a low-strength long expressing promoter potentially can provide long-term neurotrophin delivery to the damaged inner ear.
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Affiliation(s)
| | | | - Anna Lawrence
- Department of Otolaryngology, University of Kansas School of Medicine, Kansas City, KS, United States
| | | | - Peixin Huang
- Department of Otolaryngology, University of Kansas School of Medicine, Kansas City, KS, United States
| | - Jennifer Harre
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
| | - Hinrich Staecker
- Department of Otolaryngology, University of Kansas School of Medicine, Kansas City, KS, United States
- *Correspondence: Hinrich Staecker,
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Wollet M, Kim JH. Brain-Derived Neurotrophic Factor Is Involved in Activity-Dependent Tonotopic Refinement of MNTB Neurons. Front Neural Circuits 2022; 16:784396. [PMID: 35185479 PMCID: PMC8850952 DOI: 10.3389/fncir.2022.784396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/07/2022] [Indexed: 01/21/2023] Open
Abstract
In the mammalian brain, auditory brainstem nuclei are arranged topographically according to acoustic frequency responsiveness. During postnatal development, the axon initial segment (AIS) of principal neurons undergoes structural refinement depending on location along the tonotopic axis within the medial nucleus of the trapezoid body (MNTB). However, the molecular mechanisms underlying the structural refinement of the AIS along the tonotopic axis in the auditory brainstem have not been explored. We tested the hypothesis that brain-derived neurotrophic factor (BDNF) is a molecular mediator of the structural development of the MNTB in an activity-dependent manner. Using BDNF heterozygous mutant (BDNF+/- ) mice, we examined the impact of global BDNF reduction on structural and functional development of MNTB neurons by assessing AIS structure and associated intrinsic neuronal properties. BDNF reduction inhibits the structural and functional differentiation of principal neurons along the tonotopic axis in the MNTB. Augmented sound input during the critical period of development has been shown to enhance the structural refinement of the AIS of MNTB neurons. However, in BDNF +/- mice, MNTB neurons did not show this activity-dependent structural modification of the AIS following repeated sound stimulation. In addition, BDNF+/- mice lacked a defined isofrequency band of neuronal activity following exposure to 16 kHz sound, suggesting degradation of tonotopy. Taken together, structural development and functional refinement of auditory brainstem neurons require physiological levels of BDNF to establish proper tonotopic gradients.
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Affiliation(s)
| | - Jun Hee Kim
- Department of Cellular and Integrative Physiology, UT Health San Antonio, San Antonio, TX, United States
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8
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Tisi A, Rovers J, Vink HA, Ramekers D, Maccarone R, Versnel H. No Protective Effects of Hair Cells or Supporting Cells in Ototoxically Deafened Guinea Pigs upon Administration of BDNF. Brain Sci 2021; 12:2. [PMID: 35053747 PMCID: PMC8773526 DOI: 10.3390/brainsci12010002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022] Open
Abstract
We investigated whether treatment with brain-derived neurotrophic factor (BDNF), which is known to protect spiral ganglion cells (SGCs), could also protect hair cells (HCs) and supporting cells (SCs) in the organ of Corti of a guinea pig model of sensorineural hearing loss. Hearing loss was induced by administration of kanamycin/furosemide and two BDNF treatments were performed: (1) by gelatin sponge (BDNF-GS) with acute cochlear implantation (CI), and (2) through a mini-osmotic pump (BDNF-OP) with chronic CI. Outer HCs (OHCs), inner HCs (IHCs), Border, Phalangeal, Pillar, Deiters', and Hensen's cells were counted. The BDNF-GS cochleas had significantly fewer OHCs compared to the untreated ones, while the IHC and SC numbers did not differ between treated and untreated cochleas. The BDNF-OP group showed similar cell numbers to the untreated group. SGC packing density was not correlated with the total number of SCs for either BDNF group. Our data suggest that: (1) BDNF does not prevent cell death in the organ of Corti, and that the protection of SGCs could result from a direct targeting by BDNF; (2) BDNF might induce a different function/activity of the remaining cells in the organ of Corti (independently from cell number).
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Affiliation(s)
- Annamaria Tisi
- Department of Applied Clinical Sciences and Biotechnology, University of L′Aquila, 67100 L′Aquila, Italy; (A.T.); (R.M.)
| | - Jochebed Rovers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
| | - Henk A. Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Rita Maccarone
- Department of Applied Clinical Sciences and Biotechnology, University of L′Aquila, 67100 L′Aquila, Italy; (A.T.); (R.M.)
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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Sorg K, Heimann L, Lana GM, Langenbucher A, Schick B, Arzt E, Wenzel GI. Optoacoustically induced auditory brainstem responses in the mouse model enhanced through an absorbing film. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210173R. [PMID: 34480448 PMCID: PMC8414560 DOI: 10.1117/1.jbo.26.9.098001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Optoacoustic stimulation offers an alternative stimulation strategy for the hearing organ. To serve as the base for a novel auditory prosthesis, the optoacoustic stimulation must be biocompatible and energy-saving. AIM Enhancing the efficiency of optoacoustic stimulation while reducing the energy input in a suited animal model. APPROACH Optoacoustically induced auditory brainstem responses (oABRs) were recorded after the pulsed laser irradiation of the tympanic membrane (TM) in mice. The results were compared with the ABRs induced through acoustic click stimulation. In addition, self-adhesive absorbing films were applied on the TM before the optoacoustic stimulation to investigate their effect on the resulting ABRs. RESULTS Using an absorbing film on the TM during optical stimulation led to considerably enhanced oABR wave I amplitude values compared with the stimulation of the bare TM. When using our stimulation strategy, we induced oABR waves in the 50% to 60% range of the acoustical stimulation reached with 80-dB SPL click stimuli. CONCLUSIONS The mouse model can be used for certain developmental work for an optoacoustic auditory prosthesis. Using absorbing films on the TM during optical stimulation considerably enhances oABR wave I amplitude. Optimization of the stimulation strategy could further enhance the efficiency within biocompatibility margins.
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Affiliation(s)
- Katharina Sorg
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Larissa Heimann
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Gabriela Moreira Lana
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Achim Langenbucher
- Saarland University, Department of Experimental Ophthalmology, Homburg, Germany
| | - Bernhard Schick
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Eduard Arzt
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Gentiana Ioana Wenzel
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
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Moreira Lana G, Sorg K, Wenzel GI, Hecker D, Hensel R, Schick B, Kruttwig K, Arzt E. Self‐Adhesive Silicone Microstructures for the Treatment of Tympanic Membrane Perforations. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202100057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Gabriela Moreira Lana
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
- Department of Materials Science and Engineering Saarland University Campus D2 2 Saarbrücken 66123 Germany
| | - Katharina Sorg
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Gentiana Ioana Wenzel
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Dietmar Hecker
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - René Hensel
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology Saarland University Medical Center Homburg 66421 Germany
| | - Klaus Kruttwig
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
| | - Eduard Arzt
- INM – Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
- Department of Materials Science and Engineering Saarland University Campus D2 2 Saarbrücken 66123 Germany
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11
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Kurioka T, Mogi S, Tanaka M, Yamashita T. Activity-Dependent Neurodegeneration and Neuroplasticity of Auditory Neurons Following Conductive Hearing Loss in Adult Mice. Cell Mol Neurobiol 2021; 41:31-42. [PMID: 32180095 DOI: 10.1007/s10571-020-00829-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/09/2020] [Indexed: 10/24/2022]
Abstract
We examined the functional and structural changes of auditory neurons (ANs) in adult mice after conductive hearing loss (CHL). Earplugs (EPs) were bilaterally inserted in male 8-week-old mice for 4 weeks [EP(+) group] and subsequently removed for 4 weeks [EP(+/-) group]. We examined the control mice [EP(-) group] with no EPs inserted at 12 weeks. The auditory brainstem response (ABR) was measured to determine the cochlear function before and after EP insertion, after EP removal, and at 4 weeks following EP removal. We examined the cochleae for hair cell (HC) and spiral ganglion neuron survival, synaptic and neural properties, and AN myelination. There was a significant elevation of the ABR threshold across all tested frequencies after EP insertion. After removing the occlusion, these threshold shifts were fully recovered. Compared with the EP(-) mice, the EP(+) mice showed a significant decrease in the ABR peak 1 amplitude and a significantly prolonged latency at all tested frequencies. There was no significant effect of auditory deprivation on the survival of HCs and ANs. Conversely, auditory deprivation caused significant damage to the synapses and myelin and a significant decrease in the AN size. Although functional changes in the ABR amplitude and latency did not fully recover in the EP(+/-) mice, almost all anatomical changes were fully recovered in the EP(+/-) mice; however, cochlear synapses only showed partial recovery. These results suggest that auditory activities are required to maintain peripheral auditory synapses and myelination in adults. The auditory deprivation model allows for assessment of the mechanisms of synaptopathy and demyelination in the auditory periphery, and synaptic and myelin regeneration in sensorineural hearing loss.
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Affiliation(s)
- Takaomi Kurioka
- Department of Otorhinolaryngology, Head and Neck Surgery, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara-shi, Kanagawa, 252-0374, Japan.
| | - Sachiyo Mogi
- Department of Otorhinolaryngology, Head and Neck Surgery, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara-shi, Kanagawa, 252-0374, Japan
| | - Manabu Tanaka
- Bio-Imaging Center, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara-shi, Kanagawa, Japan
| | - Taku Yamashita
- Department of Otorhinolaryngology, Head and Neck Surgery, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara-shi, Kanagawa, 252-0374, Japan
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12
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Takahashi M, Sanchez JT. Effects of Neurotrophin-3 on Intrinsic Neuronal Properties at a Central Auditory Structure. Neurosci Insights 2020; 15:2633105520980442. [PMID: 33354669 PMCID: PMC7734498 DOI: 10.1177/2633105520980442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 11/23/2020] [Indexed: 11/15/2022] Open
Abstract
Neurotrophins, a class of growth factor proteins that control neuronal proliferation, morphology, and apoptosis, are found ubiquitously throughout the nervous system. One particular neurotrophin (NT-3) and its cognate tyrosine receptor kinase (TrkC) have recently received attention as a possible therapeutic target for synaptopathic sensorineural hearing loss. Additionally, research shows that NT-3-TrkC signaling plays a role in establishing the sensory organization of frequency topology (ie, tonotopic order) in the cochlea of the peripheral inner ear. However, the neurotrophic effects of NT-3 on central auditory properties are unclear. In this study we examined whether NT-3-TrkC signaling affects the intrinsic electrophysiological properties at a first-order central auditory structure in chicken, known as nucleus magnocellularis (NM). Here, the expression pattern of specific neurotrophins is well known and tightly regulated. By using whole-cell patch-clamp electrophysiology, we show that NT-3 application to brainstem slices does not affect intrinsic properties of high-frequency neuronal regions but had robust effects for low-frequency neurons, altering voltage-dependent potassium functions, action potential repolarization kinetics, and passive membrane properties. We suggest that NT-3 may contribute to the precise establishment and organization of tonotopy in the central auditory pathway by playing a specialized role in regulating the development of intrinsic neuronal properties of low-frequency NM neurons.
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Affiliation(s)
- Momoko Takahashi
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
| | - Jason Tait Sanchez
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
- The Hugh Knowles Hearing Research Center, Northwestern University, Evanston, IL, USA
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13
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Schulze J, Staecker H, Wedekind D, Lenarz T, Warnecke A. Expression pattern of brain-derived neurotrophic factor and its associated receptors: Implications for exogenous neurotrophin application. Hear Res 2020; 413:108098. [PMID: 33143996 DOI: 10.1016/j.heares.2020.108098] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/24/2020] [Accepted: 10/19/2020] [Indexed: 01/20/2023]
Abstract
The application of neurotrophins such as brain-derived neurotrophic factor (BDNF) is a promising pharmacological approach in cochlear implant research. Several in vitro and in vivo studies demonstrated that treatment with neurotrophins support the spiral ganglion neuron (SGN) survival and the synapses. Of the more than 40 companies that are working in the field of inner ear therapeutics, only one company is currently advancing BDNF towards clinical translation. Thus, there are no approved clinical therapies with neurotrophins, their precursors or neurotrophin-like substances. For a better understanding of the mechanisms of BDNF in the inner ear, we analysed the expression of mature BDNF (mBDNF), its pro-form proBDNF and their respective receptors the low affinity p75 neurotrophin receptor (p75NTR) and the neurotrophic receptor tyrosine kinase 2 (NTRK2). In the adult murine inner ear, mBDNF is expressed in the inner and outer hair cells (IHC and OHC) of the organ of Corti and in the spiral ganglion of the Rosenthal's canal, whereas proBDNF is only detected in the supporting cells below the OHC. The corresponding receptors NTRK2 and p75NTR are expressed in the spiral ganglion whereof p75NTR is stronger expressed. For more insights in the effects of mBDNF and proBDNF on inner ear specific cells, we treated primary dissociated SGN with different concentrations of mBDNF and proBDNF alone and in combination. Interestingly, treatment with proBDNF is not toxic for SGN but simultaneously not protective. However, combined treatment of mBDNF and proBDNF maintained and perhaps slightly increased the protective effect of mBDNF. Thus, the mixture of mBDNF and proBDNF could be the new direction for the development of BDNF-based therapeutics in cochlear implantation and could represent more precisely the natural environment.
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Affiliation(s)
- Jennifer Schulze
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1).
| | - Hinrich Staecker
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas, USA
| | - Dirk Wedekind
- Department of experimental animal science, Hannover Medical School, Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1)
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1)
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14
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Farnoosh G, Mahmoudian-Sani MR. Effects of Growth Factors and the MicroRNA-183 Family on Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells Towards Auditory Neuron-Like Cells. STEM CELLS AND CLONING-ADVANCES AND APPLICATIONS 2020; 13:79-89. [PMID: 32982315 PMCID: PMC7490102 DOI: 10.2147/sccaa.s248526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 08/17/2020] [Indexed: 11/30/2022]
Abstract
Introduction Hearing Loss (HL) is known as the most common sensory processing disorder across the world. An effective treatment which has been currently used for patients suffering from this condition is cochlear implant (CI). The major limitation of this treatment is the need for a healthy auditory neuron (AN). Accordingly, mesenchymal cells (MCs) are regarded as good candidates for cell-based therapeutic approaches. The present study aimed to investigate the potentials of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) for differentiation towards ANs along with using treatments with growth factors and microRNA (miRNA) transfection in vitro. Methods To this end, neurospheres derived from hBM-MSCs were treated via basic fibroblast growth factor (bFGF), neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF) as growth factors N2 and B27 supplements, as well as miRNA-96, -182, -183 transfected into hBM-MSCs in order to evaluate the differentiation of such cells into ANs. Results Treatments with growth factors demonstrated a significant increase in neurogenin 1 (Ngn1) and sex determining region Y-box 2 (SOX2) markers; but tubulin, microtubule-associated protein 2 (MAP2), and GATA binding protein 3 (GATA3) markers were not statistically significant. The findings also revealed that miRNA-182 expression in miRNA-183 family could boost the expressions of some AN marker (ie, Ngn1, SOX2, peripherin, and nestin) in vitro. Discussion It can be concluded that miRNA is probably a good substitute for growth factors used in differentiating into ANs. Transdifferentiation of hBM-MSCs into ANs, which does not occur under normal conditions, may be thus facilitated by miRNAs, especially miRNA-182, or via a combination of miRNA and growth factors.
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Affiliation(s)
- Gholamreza Farnoosh
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammad-Reza Mahmoudian-Sani
- Thalassemia and Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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15
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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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16
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Blakley BW, Seaman M, Alenezi A. Brain-derived nerve growth factor in the cochlea - a reproducibility study. J Otolaryngol Head Neck Surg 2020; 49:37. [PMID: 32503640 PMCID: PMC7275362 DOI: 10.1186/s40463-020-00432-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 05/24/2020] [Indexed: 11/14/2022] Open
Abstract
Objective Brain-derived nerve growth factor (BDNF) plays an important role in cochlear development so it is plausible that it could restore hearing loss if delivered directly into the cochlea. We wished to confirm our previous report that a single intracochlear injection of brain-derived nerve growth factor (BDNF) was beneficial for hearing in guinea pigs. We wished to assess the reproducibility of our results and assess possible improved methods with a view to developing a clinical treatment for sensorineural hearing loss. Methods CDDP was used to create partial hearing loss in 25 guinea pigs. After 30 days the animals underwent ABR testing and unilateral BDNF injection through the round window in one ear and saline injection into the other ear. After allowing possible effects to stabilize, thirty days later, ABR threshold testing was repeated to assess change in threshold. Results Final ABR thresholds were 60–70 dB and were about 11 dB better in the ears treated with BDNF. Conclusion Our original finding that Intracochlear BDNF can improve hearing in guinea pigs was confirmed, but the improvement demonstrated by the methods in this paper is too small for clinical application.
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Affiliation(s)
- Brian W Blakley
- Department of Otolaryngology, University of Manitoba, Winnipeg, Manitoba, R3A 1R9, Canada.
| | - Michael Seaman
- Department of Otolaryngology, University of Manitoba, Winnipeg, Manitoba, R3A 1R9, Canada
| | - Abdulrahman Alenezi
- Department of Otolaryngology, University of Manitoba, Winnipeg, Manitoba, R3A 1R9, Canada
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17
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Grandi FC, De Tomasi L, Mustapha M. Single-Cell RNA Analysis of Type I Spiral Ganglion Neurons Reveals a Lmx1a Population in the Cochlea. Front Mol Neurosci 2020; 13:83. [PMID: 32523514 PMCID: PMC7261882 DOI: 10.3389/fnmol.2020.00083] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
In the mature cochlea, each inner hair cell (IHC) is innervated by multiple spiral ganglion neurons of type I (SGNI). SGNIs are morphologically and electro-physiologically diverse. Also, they differ in their susceptibility to noise insult. However, the molecular underpinnings of their identity and physiological differences remain poorly understood. In this study, we developed a novel triple transgenic mouse, which enabled the isolation of pure populations of SGNIs and the analysis of a 96-gene panel via single-cell qPCR. We found three distinct populations of Type I SGNs, which were marked by their exclusive expression of Lmx1a, Slc4a4, or Mfap4/Fzd2, respectively, at postnatal days P3, P8, and P12. Our data suggest that afferent SGN subtypes are established genetically before the onset of hearing and that the expression of key physiological markers, such as ion channels, is heterogeneous and may be underlying the heterogeneous firing proprieties of SGNIs.
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Affiliation(s)
| | - Lara De Tomasi
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Mirna Mustapha
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, United States
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18
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Hwang JH, Chen CC, Lee LY, Chiang HT, Wang MF, Chan YC. Hericium erinaceus enhances neurotrophic factors and prevents cochlear cell apoptosis in senescence accelerated mice. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.103832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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19
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Kucharava K, Brand Y, Albano G, Sekulic-Jablanovic M, Glutz A, Xian X, Herz J, Bodmer D, Fuster DG, Petkovic V. Sodium-hydrogen exchanger 6 (NHE6) deficiency leads to hearing loss, via reduced endosomal signalling through the BDNF/Trk pathway. Sci Rep 2020; 10:3609. [PMID: 32107410 PMCID: PMC7046661 DOI: 10.1038/s41598-020-60262-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 02/07/2020] [Indexed: 01/03/2023] Open
Abstract
Acid-base homeostasis is critical for normal growth, development, and hearing function. The sodium-hydrogen exchanger 6 (NHE6), a protein mainly expressed in early and recycling endosomes, plays an important role in regulating organellar pH. Mutations in NHE6 cause complex, slowly progressive neurodegeneration. Little is known about NHE6 function in the mouse cochlea. Here, we found that all NHE isoforms were expressed in wild-type (WT) mouse cochlea. Nhe6 knockout (KO) mice showed significant hearing loss compared to WT littermates. Immunohistochemistry in WT mouse cochlea showed that Nhe6 was localized in the organ of Corti (OC), spiral ganglion (SG), stria vascularis (SV), and afferent nerve fibres. The middle and the inner ears of WT and Nhe6 KO mice were not different morphologically. Given the putative role of NHE6 in early endosomal function, we examined Rab GTPase expression in early and late endosomes. We found no change in Rab5, significantly lower Rab7, and higher Rab11 levels in the Nhe6 KO OC, compared to WT littermates. Because Rabs mediate TrkB endosomal signalling, we evaluated TrkB phosphorylation in the OCs of both strains. Nhe6 KO mice showed significant reductions in TrkB and Akt phosphorylation in the OC. In addition, we examined genes used as markers of SG type I (Slc17a7, Calb1, Pou4f1, Cal2) and type II neurons (Prph, Plk5, Cacna1g). We found that all marker gene expression levels were significantly elevated in the SG of Nhe6 KO mice, compared to WT littermates. Anti-neurofilament factor staining showed axon loss in the cochlear nerves of Nhe6 KO mice compared to WT mice. These findings indicated that BDNF/TrkB signalling was disrupted in the OC of Nhe6 KO mice, probably due to TrkB reduction, caused by over acidification in the absence of NHE6. Thus, our findings demonstrated that NHEs play important roles in normal hearing in the mammalian cochlea.
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Affiliation(s)
- Krystsina Kucharava
- Department of Biomedicine, and Clinic for Otolaryngology, Head and Neck Surgery, Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Yves Brand
- Clinic for Otolaryngology, Head and Neck Surgery, Kantonsspital Graubünden, Chur, 7000, Switzerland
| | - Giuseppe Albano
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, and NCCR Transcure, University of Bern, Bern, Switzerland
| | - Marijana Sekulic-Jablanovic
- Department of Biomedicine, and Clinic for Otolaryngology, Head and Neck Surgery, Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Andrea Glutz
- Department of Biomedicine, and Clinic for Otolaryngology, Head and Neck Surgery, Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Xunde Xian
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Joachim Herz
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Daniel Bodmer
- Department of Biomedicine, and Clinic for Otolaryngology, Head and Neck Surgery, Hospital Basel, University of Basel, Basel, 4031, Switzerland
| | - Daniel G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, and NCCR Transcure, University of Bern, Bern, Switzerland
| | - Vesna Petkovic
- Department of Biomedicine, and Clinic for Otolaryngology, Head and Neck Surgery, Hospital Basel, University of Basel, Basel, 4031, Switzerland.
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20
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Brooks PM, Rose KP, MacRae ML, Rangoussis KM, Gurjar M, Hertzano R, Coate TM. Pou3f4-expressing otic mesenchyme cells promote spiral ganglion neuron survival in the postnatal mouse cochlea. J Comp Neurol 2020; 528:1967-1985. [PMID: 31994726 DOI: 10.1002/cne.24867] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/20/2022]
Abstract
During inner ear development, primary auditory neurons named spiral ganglion neurons (SGNs) are surrounded by otic mesenchyme cells, which express the transcription factor Pou3f4. Mutations in Pou3f4 are associated with DFNX2, the most common form of X-linked deafness and typically include developmental malformations of the middle ear and inner ear. It is known that interactions between Pou3f4-expressing mesenchyme cells and SGNs are important for proper axon bundling during development. However, Pou3f4 continues to be expressed through later phases of development, and potential interactions between Pou3f4 and SGNs during this period had not been explored. To address this, we documented Pou3f4 protein expression in the early postnatal mouse cochlea and compared SGNs in Pou3f4 knockout mice and littermate controls. In Pou3f4y/- mice, SGN density begins to decline by the end of the first postnatal week, with approximately 25% of SGNs ultimately lost. This period of SGN loss in Pou3f4y/- cochleae coincides with significant elevations in SGN apoptosis. Interestingly, this period also coincides with the presence of a transient population of Pou3f4-expressing cells around and within the spiral ganglion. To determine if Pou3f4 is normally required for SGN peripheral axon extension into the sensory domain, we used a genetic sparse labeling approach to track SGNs and found no differences compared with controls. We also found that Pou3f4 loss did not lead to changes in the proportions of Type I SGN subtypes. Overall, these data suggest that otic mesenchyme cells may play a role in maintaining SGN populations during the early postnatal period.
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Affiliation(s)
- Paige M Brooks
- Department of Biology, Georgetown University, Washington, District of Columbia
| | - Kevin P Rose
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, University of Maryland, Baltimore, Maryland
| | - Meaghan L MacRae
- Department of Biology, Georgetown University, Washington, District of Columbia
| | | | - Mansa Gurjar
- Department of Biology, Georgetown University, Washington, District of Columbia
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, University of Maryland, Baltimore, Maryland.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, University of Maryland, Baltimore, Maryland.,Institute for Genome Sciences, University of Maryland School of Medicine, University of Maryland, Baltimore, Maryland
| | - Thomas M Coate
- Department of Biology, Georgetown University, Washington, District of Columbia
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21
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Kondo T, Saigo S, Ugawa S, Kato M, Yoshikawa Y, Miyoshi N, Tanabe K. Prebiotic effect of fructo-oligosaccharides on the inner ear of DBA/2 J mice with early-onset progressive hearing loss. J Nutr Biochem 2019; 75:108247. [PMID: 31707282 DOI: 10.1016/j.jnutbio.2019.108247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/08/2019] [Accepted: 09/10/2019] [Indexed: 01/01/2023]
Abstract
Nutrition and dietary habits contribute to the onset and progression of sensorineural hearing loss (SNHL). Fructo-oligosaccharides (FOS) are non-digestible oligosaccharides and are known as prebiotics, which enhance short-chain fatty acid (SCFA) production and antioxidant activity. Although a substantial number of studies have shown that FOS play a role in the prevention of lifestyle-related diseases as prebiotics, little is known about the effects on the inner ear. The purpose of this study is to investigate the effect of FOS on gene expression and spiral ganglion neuron (SGN) protection in the inner ear of DBA/2 J mice, which is a model for early-onset progressive hearing loss. DBA/2 J mice were fed either control diet or FOS diet contained 10% (w/w) of FOS for 8 weeks. Analysis of mice fed the FOS diet revealed a change in intestinal flora including an inversion of the ratio of Bacteroidetes and Firmicutes, which was followed by a significant increase in SCFAs in the cecum and a decrease in an oxidative stress marker in the serum. In the inner ear, gene expression of neurotrophin, brain-derived neurotrophic factor (BDNF), its receptor, tyrosine kinase receptor b (Trkb), and the SCFA receptor, free fatty acid receptor 3 (FFAR3), were increased by FOS. In addition, the survival rate of SGNs in the inner ear was maintained in FOS-fed mice. Altogether, these results suggest that a compositional variation of the intestinal flora due to a prebiotic effect may be involved in the progression of SNHL.
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Affiliation(s)
- Takako Kondo
- Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, 3-40 Shioji-cho, Mizuho-ku, Nagoya, Aichi 467-8610, Japan.
| | - Saori Saigo
- Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, 3-40 Shioji-cho, Mizuho-ku, Nagoya, Aichi 467-8610, Japan.
| | - Shinya Ugawa
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Nagoya City University, 1Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan.
| | - Mai Kato
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Yuto Yoshikawa
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Noriyuki Miyoshi
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Kenichi Tanabe
- Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, 3-40 Shioji-cho, Mizuho-ku, Nagoya, Aichi 467-8610, Japan.
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22
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Nunez DA, Wijesinghe P, Nabi S, Yeh D, Garnis C. microRNAs in sudden hearing loss. Laryngoscope 2019; 130:E416-E422. [PMID: 31603566 DOI: 10.1002/lary.28327] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/10/2019] [Accepted: 09/05/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVES To compare the circulating microRNA (miRNA) expression profiles between sudden sensory neural hearing loss (SSNHL) patients and age-matched normal hearing controls. STUDY DESIGN Prospective cohort multi-center study. METHODS Patients presenting within 28 days of onset of SSNHL were prospectively recruited along with contemporaneous age-matched controls. Pooled sera of four patient (n = 09, mean age = 53.0 years; 07, 55.0; 10, 52.9; 10, 51.6) and two control (09, 51.2 and 03, 50.0) groups were assessed using a TaqMan Low Density Array. The patients' sera were also divided into two pools, untreated (04, 57.7) and treated (32, 52.6) for additional analysis. miRNA expression level was derived from cycle threshold (Ct) values normalized to a global mean. Inter-group mean Ct differences with fold changes ≥2.0 and ≤0.5 at P < .05 were considered significant. Bioinformatic databases were used to identify putative target mRNAs or validated genes and their functional annotations. RESULTS Thirty-six SSNHL patients (mean age 53.0 ± standard deviation (SD) 15.2 years) and 12 controls (50.9 ± 11.9) were studied. Eight miRNAs hsa-miR-590-5p/ -186-5p/ -195-5p/ -140-3p/ -128-3p/ -132-3p/ -375-3p, and -30a-3p were identified as significantly differentially expressed in SSNHL patients. Most of these miRNAs were abundantly identified in the nervous system and the putative target messenger RNAs (mRNAs) were enriched in signaling pathways such as phosphatidyl inositol 3 kinase/protein Kinase B (PI3K/Akt), Ras and mitogen-activated protein kinase (MAPK). CONCLUSION These findings suggest the possible cellular signaling pathways that underlie the disruption of auditory signal transmission in SSNHL. LEVEL OF EVIDENCE 2 Laryngoscope, 130:E416-E422, 2020.
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Affiliation(s)
- Desmond A Nunez
- Division of Otolaryngology, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada.,Division of Otolaryngology-Head and Neck Surgery, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Printha Wijesinghe
- Division of Otolaryngology, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Shahin Nabi
- Division of Otolaryngology, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.,Division of Otolaryngology-Head and Neck Surgery, Lion Gates Hospital, North Vancouver, British Columbia, Canada
| | - David Yeh
- Division of Otolaryngology-Head and Neck Surgery, Lion Gates Hospital, North Vancouver, British Columbia, Canada
| | - Cathie Garnis
- Division of Otolaryngology, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia, Canada
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23
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Sorg K, Stahn P, Pillong L, Hinsberger MP, Heimann L, Foth HJ, Schick B, Wenzel GI. First biocompatibility margins for optical stimulation at the eardrum via 532-nm laser pulses in a mouse model. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-10. [PMID: 31436071 PMCID: PMC6983485 DOI: 10.1117/1.jbo.24.8.085003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
Hearing impairment affects ∼460 million people worldwide. Conservative therapies, such as hearing aids, bone conduction systems, and middle ear implants, do not always sufficiently compensate for this deficit. The optical stimulation is currently under investigation as an alternative stimulation strategy for the activation of the hearing system. To assess the biocompatibility margins of this emerging technology, we established a method applicable in whole-mount preparations of murine tympanic membranes (TM). We irradiated the TM of anesthetized mice with 532-nm laser pulses at an average power of 50, 89, 99, and 125 mW at two different locations of the TM and monitored the hearing function with auditory brainstem responses. Laser-power-dependent negative side effects to the TM were observed at power levels exceeding 89 mW. Although we did not find any significant negative effects of optical stimulation on the hearing function in these mice, based on the histology results further studies are necessary for optimization of the used parameters.
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Affiliation(s)
- Katharina Sorg
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Patricia Stahn
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Lukas Pillong
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Marius P. Hinsberger
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Larissa Heimann
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Hans-Jochen Foth
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Bernhard Schick
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Gentiana I. Wenzel
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
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24
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Hoshino T, Terunuma T, Takai J, Uemura S, Nakamura Y, Hamada M, Takahashi S, Yamamoto M, Engel JD, Moriguchi T. Spiral ganglion cell degeneration-induced deafness as a consequence of reduced GATA factor activity. Genes Cells 2019; 24:534-545. [PMID: 31141264 DOI: 10.1111/gtc.12705] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/18/2019] [Accepted: 05/21/2019] [Indexed: 12/19/2022]
Abstract
Zinc-finger transcription factors GATA2 and GATA3 are both expressed in the developing inner ear, although their overlapping versus distinct activities in adult definitive inner ear are not well understood. We show here that GATA2 and GATA3 are co-expressed in cochlear spiral ganglion cells and redundantly function in the maintenance of spiral ganglion cells and auditory neural circuitry. Notably, Gata2 and Gata3 compound heterozygous mutant mice had a diminished number of spiral ganglion cells due to enhanced apoptosis, which resulted in progressive hearing loss. The decrease in spiral ganglion cellularity was associated with lowered expression of neurotrophin receptor TrkC that is an essential factor for spiral ganglion cell survival. We further show that Gata2 null mutants that additionally bear a Gata2 YAC (yeast artificial chromosome) that counteracts the lethal hematopoietic deficiency due to complete Gata2 loss nonetheless failed to complement the deficiency in neonatal spiral ganglion neurons. Furthermore, cochlea-specific Gata2 deletion mice also had fewer spiral ganglion cells and resultant hearing impairment. These results show that GATA2 and GATA3 redundantly function to maintain spiral ganglion cells and hearing. We propose possible mechanisms underlying hearing loss in human GATA2- or GATA3-related genetic disorders.
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Affiliation(s)
- Tomofumi Hoshino
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.,Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Tsumoru Terunuma
- Department of Otolaryngology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.,Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Jun Takai
- Division of Medical Biochemistry, Tohoku Medical Pharmaceutical University, Sendai, Japan
| | - Satoshi Uemura
- Division of Medical Biochemistry, Tohoku Medical Pharmaceutical University, Sendai, Japan
| | - Yasuhiro Nakamura
- Division of Pathology, Tohoku Medical Pharmaceutical University, Sendai, Japan
| | - Michito Hamada
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | | - Takashi Moriguchi
- Division of Medical Biochemistry, Tohoku Medical Pharmaceutical University, Sendai, Japan
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25
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Sonntag M, Blosa M, Schmidt S, Reimann K, Blum K, Eckrich T, Seeger G, Hecker D, Schick B, Arendt T, Engel J, Morawski M. Synaptic coupling of inner ear sensory cells is controlled by brevican-based extracellular matrix baskets resembling perineuronal nets. BMC Biol 2018; 16:99. [PMID: 30253762 PMCID: PMC6156866 DOI: 10.1186/s12915-018-0566-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/15/2018] [Indexed: 02/08/2023] Open
Abstract
Background Perineuronal nets (PNNs) are specialized aggregations of extracellular matrix (ECM) molecules surrounding specific neurons in the central nervous system (CNS). PNNs are supposed to control synaptic transmission and are frequently associated with neurons firing at high rates, including principal neurons of auditory brainstem nuclei. The origin of high-frequency activity of auditory brainstem neurons is the indefatigable sound-driven transmitter release of inner hair cells (IHCs) in the cochlea. Results Here, we show that synaptic poles of IHCs are ensheathed by basket-like ECM complexes formed by the same molecules that constitute PNNs of neurons in the CNS, including brevican, aggreccan, neurocan, hyaluronan, and proteoglycan link proteins 1 and 4 and tenascin-R. Genetic deletion of brevican, one of the main components, resulted in a massive degradation of ECM baskets at IHCs, a significant impairment in spatial coupling of pre- and postsynaptic elements and mild impairment of hearing. Conclusions These ECM baskets potentially contribute to control of synaptic transmission at IHCs and might be functionally related to PNNs of neurons in the CNS. Electronic supplementary material The online version of this article (10.1186/s12915-018-0566-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mandy Sonntag
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Maren Blosa
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Sophie Schmidt
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Katja Reimann
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Kerstin Blum
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Tobias Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Gudrun Seeger
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Dietmar Hecker
- Department of Otorhinolaryngology, School of Medicine, Saarland University, Homburg, Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology, School of Medicine, Saarland University, Homburg, Germany
| | - Thomas Arendt
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Markus Morawski
- Paul-Flechsig-Institute of Brain Research, Medical Faculty, University of Leipzig, Leipzig, Germany.
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26
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Akil O, Blits B, Lustig LR, Leake PA. Virally Mediated Overexpression of Glial-Derived Neurotrophic Factor Elicits Age- and Dose-Dependent Neuronal Toxicity and Hearing Loss. Hum Gene Ther 2018; 30:88-105. [PMID: 30183384 DOI: 10.1089/hum.2018.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Contemporary cochlear implants (CI) are generally very effective for remediation of severe to profound sensorineural hearing loss, but outcomes are still highly variable. Auditory nerve survival is likely one of the major factors underlying this variability. Neurotrophin therapy therefore has been proposed for CI recipients, with the goal of improving outcomes by promoting improved survival of cochlear spiral ganglion neurons (SGN) and/or residual hair cells. Previous studies have shown that glial-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor, and neurotrophin-3 can rescue SGNs following insult. The current study was designed to determine whether adeno-associated virus vector serotype 5 (AAV-5) encoding either green fluorescent protein or GDNF can transduce cells in the mouse cochlea to express useful levels of neurotrophin and to approximate the optimum therapeutic dose(s) for transducing hair cells and SGN. The findings demonstrate that AAV-5 is a potentially useful gene therapy vector for the cochlea, resulting in extremely high levels of transgene expression in the cochlear inner hair cells and SGN. However, overexpression of human GDNF in newborn mice caused severe neurological symptoms and hearing loss, likely due to Purkinje cell loss and cochlear nucleus pathology. Thus, extremely high levels of transgene protein expression should be avoided, particularly for proteins that have neurological function in neonatal subjects.
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Affiliation(s)
- Omar Akil
- 1 Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California
| | - Bas Blits
- 2 Department of Research and Development, UniQure Biopharma B.V., Amsterdam, The Netherlands
| | - Lawrence R Lustig
- 3 Department of Otolaryngology-Head and Neck Surgery, Columbia University Medical Center, New York, New York
| | - Patricia A Leake
- 1 Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, San Francisco, California
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27
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Alemi R, Motassadi Zarandy M, Joghataei MT, Eftekharian A, Zarrindast MR, Vousooghi N. Plasticity after pediatric cochlear implantation: Implication from changes in peripheral plasma level of BDNF and auditory nerve responses. Int J Pediatr Otorhinolaryngol 2018; 105:103-110. [PMID: 29447794 DOI: 10.1016/j.ijporl.2017.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/09/2017] [Accepted: 12/12/2017] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Sensory neural hearing loss could lead to some structural and physiological changes in the auditory pathways, such as alteration in the expression of neurotrophins. These factors, especially Brain-Derived Neurotrophic Factor (BDNF), play an important role in synaptic functions and experience-related plasticity. Restoring cochlear function after hearing loss is possible through cochlear implantation (CI). Evaluation of the blood concentration changes of neurotrophins as prerequisites of plasticity could help scientists to determine the prognosis of CI as in the candidacy procedure or enhancing prosthesis function by adding the exact needed amount of BDNF to the electrode array. METHODS Here we have studied the plasma BDNF concentration before CI surgery and 6 months after using CI device in 15 pediatric CI recipients and compared this level with changes of BDNF concentration in 10 children who were using hearing aid (H.A). In addition, we searched for a possible correlation between post-surgery plasma BDNF concentration and electrical compound action potential (ECAP) and comfort-level (C-level) thresholds. RESULTS Plasma BDNF concentration in children with CI increased significantly after CI surgery, while this difference in H.A group was not significant. Analysis of repeated measures of ECAP and C-level thresholds in CI group showed that there were some kinds of steadiness during follow- up sessions for ECAP thresholds in basal and E16 of middle electrodes, whereas C-level thresholds for all selected electrodes increased significantly up to six months follow-up. Interestingly, we did not find any significant correlation between post-surgery plasma BDNF concentration and ECAP or C-level threshold changes. CONCLUSION It is concluded that changes in C-level threshold and steady state of ECAP thresholds and significant changes in BDNF concentration could be regarded as an indicator of experienced-related plasticity after CI stimulation.
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Affiliation(s)
- Razieh Alemi
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Cochlear Implant Center and Department of Otorhinolaryngology, Amir Aalam Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Motassadi Zarandy
- Cochlear Implant Center and Department of Otorhinolaryngology, Amir Aalam Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Eftekharian
- Department of Otorhinolaryngology, Loghman Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zarrindast
- Genetics Laboratory, Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Department of Cognitive Neuroscience, Institute for Cognitive Science Studies, Tehran, Iran; Genomic Center, School of Advanced Sciences, Tehran Medical Branch, Islamic Azad University, Tehran, Iran
| | - Nasim Vousooghi
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; Genetics Laboratory, Iranian National Center for Addiction Studies (INCAS), Tehran University of Medical Sciences, Tehran, Iran; Research Center for Cognitive and Behavioral Sciences, Tehran University of Medical Sciences, Tehran, Iran.
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28
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Fransson A, Tornøe J, Wahlberg LU, Ulfendahl M. The feasibility of an encapsulated cell approach in an animal deafness model. J Control Release 2017; 270:275-281. [PMID: 29269144 PMCID: PMC5819869 DOI: 10.1016/j.jconrel.2017.12.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/15/2017] [Accepted: 12/17/2017] [Indexed: 01/18/2023]
Abstract
For patients with profound hearing loss a cochlear implant (CI) is the only treatment today. The function of a CI depends in part of the function and survival of the remaining spiral ganglion neurons (SGN). It is well known from animal models that inner ear infusion of neurotrophic factors prevents SGN degeneration and maintains electrical responsiveness in deafened animals. The purpose with this study was to investigate the effects of a novel encapsulated cell (EC) device releasing neurotrophic factors in the deafened guinea pig. The results showed that an EC device releasing glial cell line-derived neurotrophic factor (GDNF) or brain-derived neurotrophic factor (BDNF) implanted for four weeks in deafened guinea pigs significantly preserved the SGNs and maintained their electrical responsiveness. There was a significant difference between BDNF and GDNF in favour of GDNF. This study, demonstrating positive structural and functional effects in the deafened inner ear, suggests that an implanted EC device releasing biologically protective substances offers a feasible approach for treating progressive hearing impairment.
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Affiliation(s)
- Anette Fransson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | | | | | - Mats Ulfendahl
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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29
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α2δ2 Controls the Function and Trans-Synaptic Coupling of Cav1.3 Channels in Mouse Inner Hair Cells and Is Essential for Normal Hearing. J Neurosci 2017; 36:11024-11036. [PMID: 27798183 DOI: 10.1523/jneurosci.3468-14.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/03/2016] [Indexed: 11/21/2022] Open
Abstract
The auxiliary subunit α2δ2 modulates the abundance and function of voltage-gated calcium channels. Here we show that α2δ2 mRNA is expressed in neonatal and mature hair cells. A functional α2δ2-null mouse, the ducky mouse (du), showed elevated auditory brainstem response click and frequency-dependent hearing thresholds. Otoacoustic emissions were not impaired pointing to normal outer hair cell function. Peak Ca2+ and Ba2+ currents of mature du/du inner hair cells (IHCs) were reduced by 30-40%, respectively, and gating properties, such as the voltage of half-maximum activation and voltage sensitivity, were altered, indicating that Cav1.3 channels normally coassemble with α2δ2 at IHC presynapses. The reduction of depolarization-evoked exocytosis in du/du IHCs reflected their reduced Ca2+ currents. Ca2+- and voltage-dependent K+ (BK) currents and the expression of the pore-forming BKα protein were normal. Cav1.3 and Cavβ2 protein expression was unchanged in du/du IHCs, forming clusters at presynaptic ribbons. However, the close apposition of presynaptic Cav1.3 clusters with postsynaptic glutamate receptor GluA4 and PSD-95 clusters was significantly impaired in du/du mice. This implies that, in addition to controlling the expression and gating properties of Cav1.3 channels, the largely extracellularly localized α2δ2 subunit moreover plays a so far unknown role in mediating trans-synaptic alignment of presynaptic Ca2+ channels and postsynaptic AMPA receptors. SIGNIFICANCE STATEMENT Inner hair cells possess calcium channels that are essential for transmitting sound information into synaptic transmitter release. Voltage-gated calcium channels can coassemble with auxiliary subunit α2δ isoforms 1-4. We found that hair cells of the mouse express the auxiliary subunit α2δ2, which is needed for normal hearing thresholds. Using a mouse model with a mutant, nonfunctional α2δ2 protein, we showed that the α2δ2 protein is necessary for normal calcium currents and exocytosis in inner hair cells. Unexpectedly, the α2δ2 protein is moreover required for the optimal spatial alignment of presynaptic calcium channels and postsynaptic glutamate receptor proteins across the synaptic cleft. This suggests that α2δ2 plays a novel role in organizing the synapse.
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30
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Hu H, Ye B, Zhang L, Wang Q, Liu Z, Ji S, Liu Q, Lv J, Ma Y, Xu Y, Wu H, Huang F, Xiang M. Efr3a Insufficiency Attenuates the Degeneration of Spiral Ganglion Neurons after Hair Cell Loss. Front Mol Neurosci 2017; 10:86. [PMID: 28424585 PMCID: PMC5372784 DOI: 10.3389/fnmol.2017.00086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/10/2017] [Indexed: 01/19/2023] Open
Abstract
Sensorineural hearing loss (SNHL) is caused by an irreversible impairment of cochlear hair cells and subsequent progressive degeneration of spiral ganglion neurons (SGNs). Eighty-five requiring 3 (Efr3) is a plasma membrane protein conserved from yeast to human, and knockout of Efr3a was reported to facilitate the survival of hippocampal newborn neurons in adult mice. Previously, we found Efr3a expression in the auditory neural pathway is upregulated soon after the destruction of hair cells. Here we conducted a time-course analysis of drug-caused damage to hearing ability, hair cells and SGNs in Efr3a knocking down mice (Efr3a−/+, Efr3a KD) and their wild type littermates. Functional examination showed that both groups of mice suffered from serious hearing loss with a higher level of severity in wild type (WT) mice. Morphologic observation following drugs administration showed that both WT and Efr3a KD mice went through progressive loss of hair cells and SGNs, in association with degenerative changes in the perikarya, intracellular organelles, cell body conformation in SGNs, and the changes of SGNs in WT mice were more severe than in Efr3a KD mice. These beneficial effects of Efr3a KD could be ascribed to an increase in the expression of some neurotrophic factors and their receptors in Efr3a KD mice. Our results indicate that Efr3a insufficiency suppresses drug-caused SNHL neurodegeneration in association with an increase in the expression of some neurotrophic factors and their receptors, which may be targeted in the treatment of neurodegeneration.
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Affiliation(s)
- Haixia Hu
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China.,Ear Institute, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Bin Ye
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China.,Ear Institute, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Le Zhang
- Shanghai Advanced Research Institute, University of Chinese Academy of Sciences, Chinese Academy of SciencesShanghai, China
| | - Quan Wang
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China.,Ear Institute, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Zhiwei Liu
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing UniversityNanjing, China
| | - Suying Ji
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Institute of Biological Science, Chinese Academy of SciencesShanghai, China
| | - Qiuju Liu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Institute of Biological Science, Chinese Academy of SciencesShanghai, China
| | - Jingrong Lv
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Yan Ma
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Ying Xu
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing UniversityNanjing, China
| | - Hao Wu
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China.,Ear Institute, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Fude Huang
- Shanghai Advanced Research Institute, University of Chinese Academy of Sciences, Chinese Academy of SciencesShanghai, China.,Institute of Neuroscience and State Key Laboratory of Neuroscience, Institute of Biological Science, Chinese Academy of SciencesShanghai, China
| | - Mingliang Xiang
- Department of Otolaryngology and Head and Neck Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China.,Ear Institute, Shanghai Jiao Tong University School of MedicineShanghai, China
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Ramku E, Ramku R, Spanca D, Zhjeqi V. Functional Pattern of Increasing Concentrations of Brain-Derived Neurotrophic Factor in Spiral Ganglion: Implications for Research on Cochlear Implants. Open Access Maced J Med Sci 2017; 5:121-125. [PMID: 28507614 PMCID: PMC5420760 DOI: 10.3889/oamjms.2017.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 02/22/2017] [Accepted: 02/25/2017] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND: As previously various studies have suggested application of brain-derived neurotrophic factor (BDNF) may be considered as a promising future therapy for hearing deficits, in particular for the improvement of cochlear neurone loss during cochlear implantation. AIM: The present study’s aim was to establish the upper threshold of the concentration of BDNF in Naval Medical Research Institute (NMRI) mice spiral ganglion outgrowth. METHODS: Spiral ganglion explants were prepared from post-natal day 4 (p4) (NMRI) mice of both sexes under the approval and guidelines of the regional council of Hearing Research Institute Tubingen. RESULTS: Spiral ganglion explants were cultured at postnatal days 4 in the presence of different concentrations of BDNF as described under methods. We chose an age of postnatal day (P4) and concentrations of BDNF 0; 6; 12.5; 25 and 50 ƞg/ml. Averaged neurite outgrowth is measured in 4 different cultures that were treated with different concentrations. Results show that with increasing concentrations of BDNF, the neurite density increases. CONCLUSION: The present finding show evidence that BDNF has a clear incremental effect on the number of neurites of spiral ganglia in the prehearing organ, but less on the neurite length. The upper threshold of exogenous BNDF concentration on spiral ganglion explant is 25 ƞg/ml. This means that concentration beyond this level has no further incremental impact. Therefore our suggestion for hydrogel concentration in NMRA mice in future research should be 25 ƞg/ml.
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Affiliation(s)
- Emina Ramku
- University Clinical Center, Prishtina, Kosovo
| | - Refik Ramku
- Private Polyclinic OTOKIRURGJIA, Prishtina, Kosovo
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Jiang D, Du J, Zhang X, Zhou W, Zong L, Dong C, Chen K, Chen Y, Chen X, Jiang H. miR-124 promotes the neuronal differentiation of mouse inner ear neural stem cells. Int J Mol Med 2016; 38:1367-1376. [PMID: 28025992 PMCID: PMC5065304 DOI: 10.3892/ijmm.2016.2751] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 08/08/2016] [Indexed: 12/31/2022] Open
Abstract
MicroRNAs (miRNAs or miRs) act as key regulators in neuronal development, synaptic morphogenesis and plasticity. However, their role in the neuronal differentiation of inner ear neural stem cells (NSCs) remains unclear. In this study, 6 miRNAs were selected and their expression patterns during the neuronal differentiation of inner ear NSCs were examined by RT-qPCR. We demonstrated that the culture of spiral ganglion stem cells present in the inner ears of newborn mice gave rise to neurons in vitro. The expression patterns of miR-124, miR-132, miR-134, miR-20a, miR-17-5p and miR-30a-5p were examined during a 14-day neuronal differentiation period. We found that miR-124 promoted the neuronal differentiation of and neurite outgrowth in mouse inner ear NSCs, and that the changes in the expression of tropomyosin receptor kinase B (TrkB) and cell division control protein 42 homolog (Cdc42) during inner ear NSC differentiation were associated with miR-124 expression. Our findings indicate that miR-124 plays a role in the neuronal differentiation of inner ear NSCs. This finding may lead to the development of novel strategies for restoring hearing in neurodegenerative diseases.
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Affiliation(s)
- Di Jiang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Jintao Du
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xuemei Zhang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Wei Zhou
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Lin Zong
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Chang Dong
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Kaitian Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Yu Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xihui Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Hongyan Jiang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
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Kurioka T, Lee MY, Heeringa AN, Beyer LA, Swiderski DL, Kanicki AC, Kabara LL, Dolan DF, Shore SE, Raphael Y. Selective hair cell ablation and noise exposure lead to different patterns of changes in the cochlea and the cochlear nucleus. Neuroscience 2016; 332:242-57. [PMID: 27403879 DOI: 10.1016/j.neuroscience.2016.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 06/14/2016] [Accepted: 07/01/2016] [Indexed: 01/21/2023]
Abstract
In experimental animal models of auditory hair cell (HC) loss, insults such as noise or ototoxic drugs often lead to secondary changes or degeneration in non-sensory cells and neural components, including reduced density of spiral ganglion neurons, demyelination of auditory nerve fibers and altered cell numbers and innervation patterns in the cochlear nucleus (CN). However, it is not clear whether loss of HCs alone leads to secondary degeneration in these neural components of the auditory pathway. To elucidate this issue, we investigated changes of central components after cochlear insults specific to HCs using diphtheria toxin receptor (DTR) mice expressing DTR only in HCs and exhibiting complete HC loss when injected with diphtheria toxin (DT). We showed that DT-induced HC ablation has no significant impacts on the survival of auditory neurons, central synaptic terminals, and myelin, despite complete HC loss and profound deafness. In contrast, noise exposure induced significant changes in synapses, myelin and CN organization even without loss of inner HCs. We observed a decrease of neuronal size in the auditory pathway, including peripheral axons, spiral ganglion neurons, and CN neurons, likely due to loss of input from the cochlea. Taken together, selective HC ablation and noise exposure showed different patterns of pathology in the auditory pathway and the presence of HCs is not essential for the maintenance of central synaptic connectivity and myelination.
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Affiliation(s)
- Takaomi Kurioka
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Otorhinolaryngology-Head and Neck Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Min Young Lee
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Amarins N Heeringa
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Lisa A Beyer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Ariane C Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Lisa L Kabara
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - David F Dolan
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Susan E Shore
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA.
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Dcc Mediates Functional Assembly of Peripheral Auditory Circuits. Sci Rep 2016; 6:23799. [PMID: 27040640 PMCID: PMC4819185 DOI: 10.1038/srep23799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/11/2016] [Indexed: 01/12/2023] Open
Abstract
Proper structural organization of spiral ganglion (SG) innervation is crucial for normal hearing function. However, molecular mechanisms underlying the developmental formation of this precise organization remain not well understood. Here, we report in the developing mouse cochlea that deleted in colorectal cancer (Dcc) contributes to the proper organization of spiral ganglion neurons (SGNs) within the Rosenthal's canal and of SGN projections toward both the peripheral and central auditory targets. In Dcc mutant embryos, mispositioning of SGNs occurred along the peripheral auditory pathway with misrouted afferent fibers and reduced synaptic contacts with hair cells. The central auditory pathway simultaneously exhibited similar defective phenotypes as in the periphery with abnormal exit of SGNs from the Rosenthal's canal towards central nuclei. Furthermore, the axons of SGNs ascending into the cochlear nucleus had disrupted bifurcation patterns. Thus, Dcc is necessary for establishing the proper spatial organization of SGNs and their fibers in both peripheral and central auditory pathways, through controlling axon targeting and cell migration. Our results suggest that Dcc plays an important role in the developmental formation of peripheral and central auditory circuits, and its mutation may contribute to sensorineural hearing loss.
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Cochlear afferent innervation development. Hear Res 2015; 330:157-69. [DOI: 10.1016/j.heares.2015.07.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/02/2015] [Accepted: 07/21/2015] [Indexed: 01/11/2023]
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Sundaresan S, Balasubbu S, Mustapha M. Thyroid hormone is required for the pruning of afferent type II spiral ganglion neurons in the mouse cochlea. Neuroscience 2015; 312:165-78. [PMID: 26592716 DOI: 10.1016/j.neuroscience.2015.11.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 12/13/2022]
Abstract
Afferent connections to the sensory inner (IHCs) and outer hair cells (OHCs) in the cochlea refine and functionally mature during the thyroid hormone (TH)-critical period of inner ear development that occurs perinatally in rodents. In this study, we investigated the effects of hypothyroidism on afferent type II innervation to outer hair cells using the Snell dwarf mouse (Pit1(dw)). Using a transgenic approach to specifically label type II spiral ganglion neurons (SGNs), we found that lack of TH causes persistence of excess type II SGN connections to the OHCs, as well as continued expression of the hair cell functional marker, otoferlin (OTOF), in the OHCs beyond the maturation period. We also observed a concurrent delay in efferent attachment to the OHCs. Supplementing with TH during the early postnatal period from postnatal day (P) 3 to P4 reversed the defect in type II SGN pruning but did not alter OTOF expression. Our results show that hypothyroidism causes a defect in the large-scale pruning of afferent type II SGNs in the cochlea, and a delay in efferent attachment and the maturation of OTOF expression. Our data suggest that the state of maturation of hair cells, as determined by OTOF expression, may not regulate the pruning of their afferent innervation.
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Affiliation(s)
- S Sundaresan
- Department of Otolaryngology-Head & Neck Surgery, 300 Pasteur Drive, Stanford University, Stanford, CA 94035, United States
| | - S Balasubbu
- Department of Otolaryngology-Head & Neck Surgery, 300 Pasteur Drive, Stanford University, Stanford, CA 94035, United States
| | - M Mustapha
- Department of Otolaryngology-Head & Neck Surgery, 300 Pasteur Drive, Stanford University, Stanford, CA 94035, United States.
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Chumak T, Rüttiger L, Lee SC, Campanelli D, Zuccotti A, Singer W, Popelář J, Gutsche K, Geisler HS, Schraven SP, Jaumann M, Panford-Walsh R, Hu J, Schimmang T, Zimmermann U, Syka J, Knipper M. BDNF in Lower Brain Parts Modifies Auditory Fiber Activity to Gain Fidelity but Increases the Risk for Generation of Central Noise After Injury. Mol Neurobiol 2015; 53:5607-27. [PMID: 26476841 PMCID: PMC5012152 DOI: 10.1007/s12035-015-9474-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 10/05/2015] [Indexed: 11/24/2022]
Abstract
For all sensory organs, the establishment of spatial and temporal cortical resolution is assumed to be initiated by the first sensory experience and a BDNF-dependent increase in intracortical inhibition. To address the potential of cortical BDNF for sound processing, we used mice with a conditional deletion of BDNF in which Cre expression was under the control of the Pax2 or TrkC promoter. BDNF deletion profiles between these mice differ in the organ of Corti (BDNFPax2-KO) versus the auditory cortex and hippocampus (BDNFTrkC-KO). We demonstrate that BDNFPax2-KO but not BDNFTrkC-KO mice exhibit reduced sound-evoked suprathreshold ABR waves at the level of the auditory nerve (wave I) and inferior colliculus (IC) (wave IV), indicating that BDNF in lower brain regions but not in the auditory cortex improves sound sensitivity during hearing onset. Extracellular recording of IC neurons of BDNFPax2 mutant mice revealed that the reduced sensitivity of auditory fibers in these mice went hand in hand with elevated thresholds, reduced dynamic range, prolonged latency, and increased inhibitory strength in IC neurons. Reduced parvalbumin-positive contacts were found in the ascending auditory circuit, including the auditory cortex and hippocampus of BDNFPax2-KO, but not of BDNFTrkC-KO mice. Also, BDNFPax2-WT but not BDNFPax2-KO mice did lose basal inhibitory strength in IC neurons after acoustic trauma. These findings suggest that BDNF in the lower parts of the auditory system drives auditory fidelity along the entire ascending pathway up to the cortex by increasing inhibitory strength in behaviorally relevant frequency regions. Fidelity and inhibitory strength can be lost following auditory nerve injury leading to diminished sensory outcome and increased central noise.
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Affiliation(s)
- Tetyana Chumak
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Lukas Rüttiger
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Sze Chim Lee
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Dario Campanelli
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Annalisa Zuccotti
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany.,Department of Clinical Neurobiology, University Hospital and DKFZ Heidelberg, In Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Wibke Singer
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Jiří Popelář
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Katja Gutsche
- Instituto de Biologíay Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, E-47003, Valladolid, Spain
| | - Hyun-Soon Geisler
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Sebastian Philipp Schraven
- Department of Otolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, Comprehensive Hearing Center, University of Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Germany
| | - Mirko Jaumann
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | | | - Jing Hu
- Centre for Integrative Neuroscience, University of Tübingen, Otfried-Müller-Straße 25, 72076, Tübingen, Germany
| | - Thomas Schimmang
- Instituto de Biologíay Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, E-47003, Valladolid, Spain
| | - Ulrike Zimmermann
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany
| | - Josef Syka
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Marlies Knipper
- Department of Otolaryngology, Hearing Research Centre Tübingen, Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076, Tübingen, Germany.
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Scharinger A, Eckrich S, Vandael DH, Schönig K, Koschak A, Hecker D, Kaur G, Lee A, Sah A, Bartsch D, Benedetti B, Lieb A, Schick B, Singewald N, Sinnegger-Brauns MJ, Carbone E, Engel J, Striessnig J. Cell-type-specific tuning of Cav1.3 Ca(2+)-channels by a C-terminal automodulatory domain. Front Cell Neurosci 2015; 9:309. [PMID: 26379493 PMCID: PMC4547004 DOI: 10.3389/fncel.2015.00309] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/27/2015] [Indexed: 11/13/2022] Open
Abstract
Cav1.3 L-type Ca(2+)-channel function is regulated by a C-terminal automodulatory domain (CTM). It affects channel binding of calmodulin and thereby tunes channel activity by interfering with Ca(2+)- and voltage-dependent gating. Alternative splicing generates short C-terminal channel variants lacking the CTM resulting in enhanced Ca(2+)-dependent inactivation and stronger voltage-sensitivity upon heterologous expression. However, the role of this modulatory domain for channel function in its native environment is unkown. To determine its functional significance in vivo, we interrupted the CTM with a hemagglutinin tag in mutant mice (Cav1.3DCRD(HA/HA)). Using these mice we provide biochemical evidence for the existence of long (CTM-containing) and short (CTM-deficient) Cav1.3 α1-subunits in brain. The long (HA-labeled) Cav1.3 isoform was present in all ribbon synapses of cochlear inner hair cells. CTM-elimination impaired Ca(2+)-dependent inactivation of Ca(2+)-currents in hair cells but increased it in chromaffin cells, resulting in hyperpolarized resting potentials and reduced pacemaking. CTM disruption did not affect hearing thresholds. We show that the modulatory function of the CTM is affected by its native environment in different cells and thus occurs in a cell-type specific manner in vivo. It stabilizes gating properties of Cav1.3 channels required for normal electrical excitability.
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Affiliation(s)
- Anja Scharinger
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Stephanie Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University Homburg, Germany
| | - David H Vandael
- Laboratory of Cellular and Molecular Neuroscience, Department of Drug Science, Nanostructured Interfaces and Surfaces Center, University of Torino Torino, Italy
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany
| | - Alexandra Koschak
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Dietmar Hecker
- Department of Otorhinolaryngology, Saarland University Homburg, Germany
| | - Gurjot Kaur
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa Iowa City, IA, USA
| | - Anupam Sah
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany
| | - Bruno Benedetti
- Department of Physiology and Medical Physics, Innsbruck Medical University Innsbruck, Austria
| | - Andreas Lieb
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Bernhard Schick
- Department of Otorhinolaryngology, Saarland University Homburg, Germany
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Martina J Sinnegger-Brauns
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Emilio Carbone
- Laboratory of Cellular and Molecular Neuroscience, Department of Drug Science, Nanostructured Interfaces and Surfaces Center, University of Torino Torino, Italy
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University Homburg, Germany
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
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Lustig LR, Alemi S, Sun Y, Grabowski G, Akil O. Role of saposin C and D in auditory and vestibular function. Laryngoscope 2015. [PMID: 26198053 DOI: 10.1002/lary.25479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVES/HYPOTHESIS Saposins are small proteins derived from a precursor protein, prosaposin. Each of the four saposins (A-D) is necessary for the activity of lysosomal glycosphingolipid hydrolases. Individual saposin mutations lead to lysosomal storage diseases, some of which are associated with hearing loss. Here we evaluate the effects of the loss of saposins C and D on auditory and vestibular function in transgenic mice. METHODS Transgenic mice with either loss of saposin C function or a combined loss of saposin C + D function were studied. Light microscopy and immunofluorescence were used to evaluate histologic and morphologic changes in the auditory and vestibular organs. Acoustic brainstem response thresholds and distortion product otoacoustic emissions were used to study the auditory phenotype. RESULTS A null mutation of saposin C did not result in any identifiable histologic changes or loss of hearing through postnatal day 55. Combined losses of saposins C and D similarly did not result in any changes in organ of Corti histology or loss of hearing. However, inclusions within the vestibular end organs was noted, consistent with afferent and efferent neuronal sprouting, although to a much milder degree than seen in the previously studied prosaposin knockout mouse. CONCLUSIONS Loss of saposin C and D function, although causing mild phenotypic changes in the vestibular end organs, otherwise results in minimal functional impairment and no changes in the auditory system. It is more likely that the auditory and vestibular effects of the loss of prosaposin are mediated through the actions of saposin A and/or B. LEVEL OF EVIDENCE NA.
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Affiliation(s)
- Lawrence R Lustig
- Department of Otolaryngology-Head & Neck Surgery, Columbia University Medical Center, New York, New York
| | - Sean Alemi
- Department of Otolaryngology-Head & Neck Surgery, University of California, San Francisco, San Francisco, California
| | - Ying Sun
- Department of Human Genetics, University of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | - Gregory Grabowski
- Department of Human Genetics, University of Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A
| | - Omar Akil
- Department of Otolaryngology-Head & Neck Surgery, University of California, San Francisco, San Francisco, California
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40
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Knipper M, Panford-Walsh R, Singer W, Rüttiger L, Zimmermann U. Specific synaptopathies diversify brain responses and hearing disorders: you lose the gain from early life. Cell Tissue Res 2015; 361:77-93. [PMID: 25843689 PMCID: PMC4487345 DOI: 10.1007/s00441-015-2168-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/05/2015] [Indexed: 01/08/2023]
Abstract
Before hearing onset, inner hair cell (IHC) maturation proceeds under the influence of spontaneous Ca(2+) action potentials (APs). The temporal signature of the IHC Ca(2+) AP is modified through an efferent cholinergic feedback from the medial olivocochlear bundle (MOC) and drives the IHC pre- and post-synapse phenotype towards low spontaneous (spike) rate (SR), high-threshold characteristics. With sensory experience, the IHC pre- and post-synapse phenotype matures towards the instruction of low-SR, high-threshold and of high-SR, low-threshold auditory fiber characteristics. Corticosteroid feedback together with local brain-derived nerve growth factor (BDNF) and catecholaminergic neurotransmitters (dopamine) might be essential for this developmental step. In this review, we address the question of whether the control of low-SR and high-SR fiber characteristics is linked to various degrees of vulnerability of auditory fibers in the mature system. In particular, we examine several IHC synaptopathies in the context of various hearing disorders and exemplified shortfalls before and after hearing onset.
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Affiliation(s)
- Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | | | - Wibke Singer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Lukas Rüttiger
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
| | - Ulrike Zimmermann
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany
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Romero-Guevara R, Cencetti F, Donati C, Bruni P. Sphingosine 1-phosphate signaling pathway in inner ear biology. New therapeutic strategies for hearing loss? Front Aging Neurosci 2015; 7:60. [PMID: 25954197 PMCID: PMC4407579 DOI: 10.3389/fnagi.2015.00060] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/08/2015] [Indexed: 12/13/2022] Open
Abstract
Hearing loss is one of the most prevalent conditions around the world, in particular among people over 60 years old. Thus, an increase of this affection is predicted as result of the aging process in our population. In this context, it is important to further explore the function of molecular targets involved in the biology of inner ear sensory cells to better individuate new candidates for therapeutic application. One of the main causes of deafness resides into the premature death of hair cells and auditory neurons. In this regard, neurotrophins and growth factors such as insulin like growth factor are known to be beneficial by favoring the survival of these cells. An elevated number of published data in the last 20 years have individuated sphingolipids not only as structural components of biological membranes but also as critical regulators of key biological processes, including cell survival. Ceramide, formed by catabolism of sphingomyelin (SM) and other complex sphingolipids, is a strong inducer of apoptotic pathway, whereas sphingosine 1-phosphate (S1P), generated by cleavage of ceramide to sphingosine and phosphorylation catalyzed by two distinct sphingosine kinase (SK) enzymes, stimulates cell survival. Interestingly S1P, by acting as intracellular mediator or as ligand of a family of five distinct S1P receptors (S1P1–S1P5), is a very powerful bioactive sphingolipid, capable of triggering also other diverse cellular responses such as cell migration, proliferation and differentiation, and is critically involved in the development and homeostasis of several organs and tissues. Although new interesting data have become available, the information on S1P pathway and other sphingolipids in the biology of the inner ear is limited. Nonetheless, there are several lines of evidence implicating these signaling molecules during neurogenesis in other cell populations. In this review, we discuss the role of S1P during inner ear development, also as guidance for future studies.
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Affiliation(s)
- Ricardo Romero-Guevara
- Department Scienze Biomediche Sperimentali e Cliniche "Mario Serio", University of Florence Firenze, Italy
| | - Francesca Cencetti
- Department Scienze Biomediche Sperimentali e Cliniche "Mario Serio", University of Florence Firenze, Italy
| | - Chiara Donati
- Department Scienze Biomediche Sperimentali e Cliniche "Mario Serio", University of Florence Firenze, Italy
| | - Paola Bruni
- Department Scienze Biomediche Sperimentali e Cliniche "Mario Serio", University of Florence Firenze, Italy
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Wong ACY, Ryan AF. Mechanisms of sensorineural cell damage, death and survival in the cochlea. Front Aging Neurosci 2015; 7:58. [PMID: 25954196 PMCID: PMC4404918 DOI: 10.3389/fnagi.2015.00058] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/05/2015] [Indexed: 12/20/2022] Open
Abstract
The majority of acquired hearing loss, including presbycusis, is caused by irreversible damage to the sensorineural tissues of the cochlea. This article reviews the intracellular mechanisms that contribute to sensorineural damage in the cochlea, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. These data have primarily been generated in hearing loss not directly related to age. However, there is evidence that similar mechanisms operate in presbycusis. Moreover, accumulation of damage from other causes can contribute to age-related hearing loss (ARHL). Potential therapeutic interventions to balance opposing but interconnected cell damage and survival pathways, such as antioxidants, anti-apoptotics, and pro-inflammatory cytokine inhibitors, are also discussed.
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Affiliation(s)
- Ann C Y Wong
- Department of Surgery/Division of Otolaryngology, University of California, San Diego School of Medicine La Jolla, CA, USA ; Department of Physiology and Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales Sydney, NSW, Australia
| | - Allen F Ryan
- Department of Surgery/Division of Otolaryngology, University of California, San Diego School of Medicine La Jolla, CA, USA ; Veterans Administration Medical Center La Jolla, CA, USA ; Department of Neurosciences, University of California, San Diego School of Medicine La Jolla, CA, USA
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Overexpression of X-Linked Inhibitor of Apoptotic Protein (XIAP) reduces age-related neuronal degeneration in the mouse cochlea. Gene Ther 2014; 21:967-74. [PMID: 25142138 PMCID: PMC4978537 DOI: 10.1038/gt.2014.77] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 06/18/2014] [Accepted: 06/24/2014] [Indexed: 12/05/2022]
Abstract
Previously, we showed that age-related hearing loss (AHL) was delayed in C57BL6 mice overexpressing X-Linked Inhibitor of Apoptotic Protein (XIAP), and the delayed AHL was associated with attenuated hair cell (HC) loss in XIAP-overexpressing mice. Similar to other reports, the HC loss in aged mice was restricted to the basal turn in this previous study, and occurred slightly at the apical end of the cochlea, showing considerably less spread than the frequency region of hearing loss. In the present study, we examined whether and how AHL is related to the degeneration of neuronal innervation of the cochlea and if the overexpression of XIAP exerts a protective effect against age-related degeneration in both afferent and efferent cochlear neurites. In contrast to HC loss, degeneration of both afferent and efferent neurites spread to the middle turns of the cochlea. Moreover, XIAP-overexpressing mice lost fewer HC afferent dendrites and efferent axons, as well as fewer spiral ganglion neurons (SGNs) between 3– 14 months of age in comparison to wild-type littermates. The results suggest that age-related degeneration of cochlear neurites may be independent of HC loss. Further, the inhibition of apoptosis by XIAP appears to reduce degeneration of both afferent and efferent cochlear neurites.
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Is there a relationship between brain-derived neurotrophic factor for driving neuronal auditory circuits with onset of auditory function and the changes following cochlear injury or during aging? Neuroscience 2014; 283:26-43. [PMID: 25064058 DOI: 10.1016/j.neuroscience.2014.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/15/2014] [Accepted: 07/17/2014] [Indexed: 01/06/2023]
Abstract
Brain-derived neurotrophic factor, BDNF, is one of the most important neurotrophic factors acting in the peripheral and central nervous system. In the auditory system its function was initially defined by using constitutive knockout mouse mutants and shown to be essential for survival of neurons and afferent innervation of hair cells in the peripheral auditory system. Further examination of BDNF null mutants also revealed a more complex requirement during re-innervation processes involving the efferent system of the cochlea. Using adult mouse mutants defective in BDNF signaling, it could be shown that a tonotopical gradient of BDNF expression within cochlear neurons is required for maintenance of a specific spatial innervation pattern of outer hair cells and inner hair cells. Additionally, BDNF is required for maintenance of voltage-gated potassium channels (KV) in cochlear neurons, which may form part of a maturation step within the ascending auditory pathway with onset of hearing and might be essential for cortical acuity of sound-processing and experience-dependent plasticity. A presumptive harmful role of BDNF during acoustic trauma and consequences of a loss of cochlear BDNF during aging are discussed in the context of a partial reversion of this maturation step. We compare the potentially beneficial and harmful roles of BDNF for the mature auditory system with those BDNF functions known in other sensory circuits, such as the vestibular, visual, olfactory, or somatosensory system.
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Immunohistochemical localization of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in the superior olivary complex of mice after radiofrequency exposure. Neurosci Lett 2014; 564:78-82. [DOI: 10.1016/j.neulet.2014.02.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/22/2014] [Accepted: 02/06/2014] [Indexed: 11/22/2022]
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Dettling J, Franz C, Zimmermann U, Lee SC, Bress A, Brandt N, Feil R, Pfister M, Engel J, Flamant F, Rüttiger L, Knipper M. Autonomous functions of murine thyroid hormone receptor TRα and TRβ in cochlear hair cells. Mol Cell Endocrinol 2014; 382:26-37. [PMID: 24012852 DOI: 10.1016/j.mce.2013.08.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/22/2013] [Accepted: 08/29/2013] [Indexed: 11/18/2022]
Abstract
Thyroid hormone acts on gene transcription by binding to its nuclear receptors TRα1 and TRβ. Whereas global deletion of TRβ causes deafness, global TRα-deficient mice have normal hearing thresholds. Since the individual roles of the two receptors in cochlear hair cells are still unclear, we generated mice with a hair cell-specific mutation of TRα1 or deletion of TRβ using the Cre-loxP system. Hair cell-specific TRβ mutant mice showed normal hearing thresholds but delayed BK channel expression in inner hair cells, slightly stronger outer hair cell function, and slightly reduced amplitudes of auditory brainstem responses. In contrast, hair cell-specific TRα mutant mice showed normal timing of BK channel expression, slightly reduced outer hair cell function, and slightly enhanced amplitudes of auditory brainstem responses. Our data demonstrate that TRβ-related deafness originates outside of hair cells and that TRα and TRβ play opposing, non-redundant roles in hair cells. A role for thyroid hormone receptors in controlling key regulators that shape signal transduction during development is discussed. Thyroid hormone may act through different thyroid hormone receptor activities to permanently alter the sensitivity of auditory neurotransmission.
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Affiliation(s)
- Juliane Dettling
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Christoph Franz
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Ulrike Zimmermann
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Sze Chim Lee
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Andreas Bress
- Molecular Genetics, THRC, Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Niels Brandt
- Department of Biophysics, Saarland University, 66421 Homburg/Saar, Germany
| | - Robert Feil
- Department of Signal Transduction & Transgenic Models, Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Markus Pfister
- Molecular Genetics, THRC, Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Jutta Engel
- Department of Biophysics, Saarland University, 66421 Homburg/Saar, Germany
| | - Frédéric Flamant
- Institut de Génomique Fonctionnelle, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon cedex 07, Lyon, France
| | - Lukas Rüttiger
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany
| | - Marlies Knipper
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology, University of Tübingen, Elfriede-Aulhorn-Str. 5, 72076 Tübingen, Germany.
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Topographic and quantitative evaluation of gentamicin-induced damage to peripheral innervation of mouse cochleae. Neurotoxicology 2013; 40:86-96. [PMID: 24308912 DOI: 10.1016/j.neuro.2013.11.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 11/11/2013] [Accepted: 11/11/2013] [Indexed: 11/24/2022]
Abstract
Ototoxicity induced by aminoglycoside antibiotics appears to occur both in hair cells (HCs) and the cochlear nerves that innervate them. Although HC loss can be easily quantified, neuronal lesions are difficult to quantify because two types of afferent dendrites and two types of efferent axons are tangled beneath the hair cells. In the present study, ototoxicity was induced by gentamicin in combination with the diuretic agent furosemide. Neuronal lesions were quantified in cochlear whole-mount preparations combined with microsections across the habenular perforate (HP) openings to achieve a clear picture of the topographic relationship between neuronal damage and HC loss. Multiple immunostaining methods were employed to differentiate the two types of afferent dendrites and two types of efferent axons. The results show that co-administration of gentamicin and furosemide resulted in a typical dynamic pattern of HC loss that spread from the basal turn to the outer hair cells to the apex and inner hair cells, depending on the dose and survival time after drug administration. Lesions of the innervation appeared to occur at two stages. At the early stage (2-4 days), the loss of labeling of the two types of afferent dendrites was more obvious than the loss of labeled efferent axons. At the late stage (2-4 weeks), the loss of labeled efferent axons was more rapid. In the high-dose gentamicin group, the loss of outer HCs was congruent with afferent dendrite loss at the early stage and efferent axon loss at the late stage. In the low-dose gentamicin group, the loss of labeling for cochlear innervation was more severe and widespread. Thus, we hypothesize that the gentamicin-induced damage to cochlear innervation occurs independently of hair cell loss.
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Vandenbosch R, Chocholova E, Robe PA, Wang Y, Lambert C, Moonen G, Lallemend F, Malgrange B, Hadjab S. A role for the canonical nuclear factor-κB pathway in coupling neurotrophin-induced differential survival of developing spiral ganglion neurons. Front Cell Neurosci 2013; 7:242. [PMID: 24348336 PMCID: PMC3842586 DOI: 10.3389/fncel.2013.00242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/14/2013] [Indexed: 11/13/2022] Open
Abstract
Neurotrophins are key players of neural development by controlling cell death programs. However, the signaling pathways that mediate their selective responses in different populations of neurons remain unclear. In the mammalian cochlea, sensory neurons differentiate perinatally into type I and II populations both expressing TrkB and TrkC, which bind respectively brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3). How these two neuronal populations respond differentially to these two neurotrophins remains unknown. Here, we report in rat the segregation of the nuclear factor-κB (NFκB) subunit p65 specifically within the type II population postnatally. Using dissociated cultures of embryonic and postnatal spiral ganglion neurons, we observed a specific requirement of NFκB for BDNF but not NT3-dependent neuronal survival during a particular postnatal time window that corresponds to a period of neuronal cell death and hair cell innervation refinement in the developing cochlea. Consistently, postnatal p65 knockout mice showed a specific decreased number in type II spiral ganglion neurons. Taken together, these results identify NFκB as a type II neuron-specific factor that participates in the selective survival effects of BDNF and NT3 signaling on developing spiral ganglion neurons.
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Affiliation(s)
- Renaud Vandenbosch
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium
| | - Eva Chocholova
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium
| | - Pierre A Robe
- Department of Human Genetics, University of Liège Liège, Belgium ; Groupe Interdisciplinaire de Génoprotéomique Appliquée-Research Center, University of Liège Liège, Belgium
| | - Yiqiao Wang
- Department of Neuroscience, Karolinska Institute Stockholm, Sweden
| | - Cécile Lambert
- Bone and Cartilage Research Unit, Institute of Pathology, Centre Hospitalier Universitaire du Sart-Tilman Liège, Belgium
| | - Gustave Moonen
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium ; Department of Neurology, Centre Hospitalier Universitaire du Sart Tilman Liège, Belgium
| | - François Lallemend
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium ; Department of Neuroscience, Karolinska Institute Stockholm, Sweden
| | - Brigitte Malgrange
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium
| | - Saïda Hadjab
- Groupe Interdisciplinaire de Génoprotéomique Appliquée-Neurosciences, Developmental Neurobiology Unit, University of Liège Liège, Belgium ; Department of Neuroscience, Karolinska Institute Stockholm, Sweden
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Zuccotti A, Lee SC, Campanelli D, Singer W, Satheesh SV, Patriarchi T, Geisler HS, Köpschall I, Rohbock K, Nothwang HG, Hu J, Hell JW, Schimmang T, Rüttiger L, Knipper M. L-type CaV1.2 deletion in the cochlea but not in the brainstem reduces noise vulnerability: implication for CaV1.2-mediated control of cochlear BDNF expression. Front Mol Neurosci 2013; 6:20. [PMID: 23950737 PMCID: PMC3739414 DOI: 10.3389/fnmol.2013.00020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/20/2013] [Indexed: 01/24/2023] Open
Abstract
Voltage-gated L-type Ca2+ channels (L-VGCCs) like CaV1.2 are assumed to play a crucial role for controlling release of trophic peptides including brain-derived neurotrophic factor (BDNF). In the inner ear of the adult mouse, besides the well-described L-VGCC CaV1.3, CaV1.2 is also expressed. Due to lethality of constitutive CaV1.2 knock-out mice, the function of this ion channel as well as its putative relationship to BDNF in the auditory system is entirely elusive. We recently described that BDNF plays a differential role for inner hair cell (IHC) vesicles release in normal and traumatized condition. To elucidate a presumptive role of CaV1.2 during this process, two tissue-specific conditional mouse lines were generated. To distinguish the impact of CaV1.2 on the cochlea from that on feedback loops from higher auditory centers CaV1.2 was deleted, in one mouse line, under the Pax2 promoter (CaV1.2Pax2) leading to a deletion in the spiral ganglion neurons, dorsal cochlear nucleus, and inferior colliculus. In the second mouse line, the Egr2 promoter was used for deleting CaV1.2 (CaV1.2Egr2) in auditory brainstem nuclei. In both mouse lines, normal hearing threshold and equal number of IHC release sites were observed. We found a slight reduction of auditory brainstem response wave I amplitudes in the CaV1.2Pax2 mice, but not in the CaV1.2Egr2 mice. After noise exposure, CaV1.2Pax2 mice had less-pronounced hearing loss that correlated with maintenance of ribbons in IHCs and less reduced activity in auditory nerve fibers, as well as in higher brain centers at supra-threshold sound stimulation. As reduced cochlear BDNF mRNA levels were found in CaV1.2Pax2 mice, we suggest that a CaV1.2-dependent step may participate in triggering part of the beneficial and deteriorating effects of cochlear BDNF in intact systems and during noise exposure through a pathway that is independent of CaV1.2 function in efferent circuits.
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Affiliation(s)
- Annalisa Zuccotti
- Molecular Physiology of Hearing, Hearing Research Center Tübingen, Department of Otolaryngology, University of Tübingen Tübingen, Germany
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Brand Y, Sung M, Chavez E, Wei E, Pak KK, Housley GD, Bodmer D, Ryan AF. Neural cell adhesion molecule L1 modulates type I but not type II inner ear spiral ganglion neurite outgrowth in an in vitro alternate choice assay. J Mol Neurosci 2013; 51:663-70. [PMID: 23760987 DOI: 10.1007/s12031-013-0040-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 05/27/2013] [Indexed: 12/17/2022]
Abstract
L1, a neural cell adhesion molecule of the immunoglobulin superfamily, is widely expressed in the nervous system and important in axonal outgrowth, guidance, synapse formation, and signaling. Gene deletion studies emphasize the significance of L1 during development of the central nervous system and L1 is crucial for the topographic targeting of retinal axons. In contrast to the brain and retina, the role of L1 in the inner ear is largely unknown. While previous studies have localized L1 in the developing inner ear of the chicken and mouse, its function during the innervation of the cochlea still remains largely unclear. We therefore investigated the functional role of L1 in the mammalian inner ear. Our aim was to determine whether or not L1 can modulate type I and/or type II spiral ganglion neuron outgrowth using an in vitro alternate choice assay. We found that L1, presented in stripe micropatterns, provide directional cues to neonatal rodent type I but not type II inner ear spiral ganglion neurites. The results suggest that L1 may play a role in axonal pathfinding of type I spiral ganglion dendrites toward their inner hair cell targets but not of type II toward the outer hair cells.
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Affiliation(s)
- Yves Brand
- Department of Surgery/Otolaryngology, UCSD School of Medicine, 9500 Gilman Drive MC0666, La Jolla, CA, 92093, USA
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