1
|
Bordeynik-Cohen M, Sperber M, Ebbers L, Messika-Gold N, Krohs C, Koffler-Brill T, Noy Y, Elkon R, Nothwang HG, Avraham KB. Shared and organ-specific gene-expression programs during the development of the cochlea and the superior olivary complex. RNA Biol 2023; 20:629-640. [PMID: 37602850 PMCID: PMC10443965 DOI: 10.1080/15476286.2023.2247628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
The peripheral and central auditory subsystems together form a complex sensory network that allows an organism to hear. The genetic programs of the two subsystems must therefore be tightly coordinated during development. Yet, their interactions and common expression pathways have never been systematically explored. MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression and are essential for normal development of the auditory system. We performed mRNA and small-RNA sequencing of organs from both auditory subsystems at three critical developmental timepoints (E16, P0, P16) to obtain a comprehensive and unbiased insight of their expression profiles. Our analysis reveals common and organ-specific expression patterns for differentially regulated mRNAs and miRNAs, which could be clustered with a particular selection of functions such as inner ear development, Wnt signalling, K+ transport, and axon guidance, based on gene ontology. Bioinformatics detected enrichment of predicted targets of specific miRNAs in the clusters and predicted regulatory interactions by monitoring opposite trends of expression of miRNAs and their targets. This approach identified six miRNAs as strong regulatory candidates for both subsystems. Among them was miR-96, an established critical factor for proper development in both subsystems, demonstrating the strength of our approach. We suggest that other miRNAs identified by this analysis are also common effectors of proper hearing acquirement. This first combined comprehensive analysis of the developmental program of the peripheral and central auditory systems provides important data and bioinformatics insights into the shared genetic program of the two sensory subsystems and their regulation by miRNAs.
Collapse
Affiliation(s)
- Mor Bordeynik-Cohen
- Laboratory of Neural and Sensory Genomics, Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michal Sperber
- Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lena Ebbers
- Neurogenetics group and Cluster of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Naama Messika-Gold
- Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Constanze Krohs
- Neurogenetics group and Cluster of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Tal Koffler-Brill
- Laboratory of Neural and Sensory Genomics, Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yael Noy
- Laboratory of Neural and Sensory Genomics, Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hans Gerd Nothwang
- Neurogenetics group and Cluster of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Karen B. Avraham
- Laboratory of Neural and Sensory Genomics, Department of Human Molecular Genetics & Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
2
|
Comprehensive Etiologic Analyses in Pediatric Cochlear Implantees and the Clinical Implications. Biomedicines 2022; 10:biomedicines10081846. [PMID: 36009393 PMCID: PMC9405031 DOI: 10.3390/biomedicines10081846] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/18/2022] [Accepted: 07/29/2022] [Indexed: 11/17/2022] Open
Abstract
Cochlear implantation is the treatment of choice for children with profound sensorineural hearing impairment (SNHI), yet the outcomes of cochlear implants (CI) vary significantly across individuals. To investigate the CI outcomes in pediatric patients with SNHI due to various etiologies, we prospectively recruited children who underwent CI surgery at two tertiary referral CI centers from 2010 to 2021. All patients underwent comprehensive history taking, next generation sequencing (NGS)-based genetic examinations, and imaging studies. The CI outcomes were evaluated using Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scores. Of the 160 pediatric cochlear implantees (76 females and 84 males) included in this study, comprehensive etiological work-up helped achieve clinical diagnoses in 83.1% (133/160) of the patients, with genetic factors being the leading cause (61.3%). Imaging studies identified certain findings in 31 additional patients (19.3%). Four patients (2.5%) were identified with congenital cytomegalovirus infection (cCMV), and 27 patients (16.9%) remained with unknown etiologies. Pathogenic variants in the four predominant non-syndromic SNHI genes (i.e., SLC26A4, GJB2, MYO15A, and OTOF) were associated with favorable CI outcomes (Chi-square test, p = 0.023), whereas cochlear nerve deficiency (CND) on imaging studies was associated with unfavorable CI outcomes (Chi-square test, p < 0.001). Our results demonstrated a clear correlation between the etiologies and CI outcomes, underscoring the importance of thorough etiological work-up preoperatively in pediatric CI candidates.
Collapse
|
3
|
Central auditory deficits associated with genetic forms of peripheral deafness. Hum Genet 2021; 141:335-345. [PMID: 34435241 PMCID: PMC9034985 DOI: 10.1007/s00439-021-02339-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/09/2021] [Indexed: 01/11/2023]
Abstract
Since the 1990s, the study of inherited hearing disorders, mostly those detected at birth, in the prelingual period or in young adults, has led to the identification of their causal genes. The genes responsible for more than 140 isolated (non-syndromic) and about 400 syndromic forms of deafness have already been discovered. Studies of mouse models of these monogenic forms of deafness have provided considerable insight into the molecular mechanisms of hearing, particularly those involved in the development and/or physiology of the auditory sensory organ, the cochlea. In parallel, studies of these models have also made it possible to decipher the pathophysiological mechanisms underlying hearing impairment. This has led a number of laboratories to investigate the potential of gene therapy for curing these forms of deafness. Proof-of-concept has now been obtained for the treatment of several forms of deafness in mouse models, paving the way for clinical trials of cochlear gene therapy in patients in the near future. Nevertheless, peripheral deafness may also be associated with central auditory dysfunctions and may extend well beyond the auditory system itself, as a consequence of alterations to the encoded sensory inputs or involvement of the causal deafness genes in the development and/or functioning of central auditory circuits. Investigating the diversity, causes and underlying mechanisms of these central dysfunctions, the ways in which they could impede the expected benefits of hearing restoration by peripheral gene therapy, and determining how these problems could be remedied is becoming a research field in its own right. Here, we provide an overview of the current knowledge about the central deficits associated with genetic forms of deafness.
Collapse
|
4
|
Krohs C, Bordeynik-Cohen M, Messika-Gold N, Elkon R, Avraham KB, Nothwang HG. Expression pattern of cochlear microRNAs in the mammalian auditory hindbrain. Cell Tissue Res 2021; 383:655-666. [PMID: 33156384 PMCID: PMC7904729 DOI: 10.1007/s00441-020-03290-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 08/24/2020] [Indexed: 12/28/2022]
Abstract
The auditory system comprises the auditory periphery, engaged in sound transduction and the central auditory system, implicated in auditory information processing and perception. Recently, evidence mounted that the mammalian peripheral and central auditory systems share a number of genes critical for proper development and function. This bears implication for auditory rehabilitation and evolution of the auditory system. To analyze to which extent microRNAs (miRNAs) belong to genes shared between both systems, we characterize the expression pattern of 12 cochlea-abundant miRNAs in the central auditory system. Quantitative real-time PCR (qRT-PCR) demonstrated expression of all 12 genes in the cochlea, the auditory hindbrain and the non-auditory prefrontal cortex (PFC) at embryonic stage (E)16 and postnatal stages (P)0 and P30. Eleven of them showed differences in expression between tissues and nine between the developmental time points. Hierarchical cluster analysis revealed that the temporal expression pattern in the auditory hindbrain was more similar to the PFC than to the cochlea. Spatiotemporal expression analysis by RNA in situ hybridization demonstrated widespread expression throughout the cochlear nucleus complex (CNC) and the superior olivary complex (SOC) during postnatal development. Altogether, our data indicate that miRNAs represent a relevant class of genetic factors functioning across the auditory system. Given the importance of gene regulatory network (GRN) components for development, physiology and evolution, the 12 miRNAs provide promising entry points to gain insights into their molecular underpinnings in the auditory system.
Collapse
Affiliation(s)
- Constanze Krohs
- Neurogenetics Group and Cluster of Excellence Hearing4All, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Mor Bordeynik-Cohen
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Naama Messika-Gold
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Hans Gerd Nothwang
- Neurogenetics Group and Cluster of Excellence Hearing4All, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
- Research Center for Neurosensory Science, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
- Department of Neuroscience, Center of Excellence Hearing4All, Carl Von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
| |
Collapse
|
5
|
Lee SY, Shim YJ, Han JH, Song JJ, Koo JW, Oh SH, Lee S, Oh DY, Choi BY. The molecular etiology of deafness and auditory performance in the postlingually deafened cochlear implantees. Sci Rep 2020; 10:5768. [PMID: 32238869 PMCID: PMC7113281 DOI: 10.1038/s41598-020-62647-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/02/2020] [Indexed: 11/09/2022] Open
Abstract
Recent advances in molecular genetic testing (MGT) have improved identification of genetic aetiology of candidates for cochlear implantation (CI). However, whether genetic information increases CI outcome predictability in post-lingual deafness remains unclear. Therefore, we evaluated the outcomes of CI with respect to genetic aetiology and clinical predictors by comparing the data of study subjects; those with an identified genetic aetiology (GD group), and those without identifiable variants (GUD group). First, we identified the genetic aetiology in 21 of 40 subjects and also observed genetic etiologic heterogeneity. The GD group demonstrated significantly greater improvement in speech perception scores over a 1-year period than did the GUD group. Further, inverse correlation between deafness duration and the 1-year improvement in speech perception scores was tighter in the GD group than in the GUD group. The weak correlation between deafness duration and CI outcomes in the GUD group might suggest the pathophysiology underlying GUD already significantly involves the cortex, leading to lesser sensitivity to further cortex issues such as deafness duration. Under our MGT protocol, the correlation between deafness duration and CI outcomes were found to rely on the presence of identifiable genetic aetiology, strongly advocating early CI in individual with proven genetic aetiologies.
Collapse
Affiliation(s)
- Sang-Yeon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Ye Ji Shim
- Department of Otorhinolaryngology-Head and Neck Surgery, Healthcare System Gangnam Center, Seoul National University Hospital, Seoul, South Korea
| | - Jin-Hee Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Jae-Jin Song
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Ja-Won Koo
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, South Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Doo-Yi Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea.
| |
Collapse
|
6
|
Michalski N, Petit C. Genes Involved in the Development and Physiology of Both the Peripheral and Central Auditory Systems. Annu Rev Neurosci 2019; 42:67-86. [DOI: 10.1146/annurev-neuro-070918-050428] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genetic approach, based on the study of inherited forms of deafness, has proven to be particularly effective for deciphering the molecular mechanisms underlying the development of the peripheral auditory system, the cochlea and its afferent auditory neurons, and how this system extracts the physical parameters of sound. Although this genetic dissection has provided little information about the central auditory system, scattered data suggest that some genes may have a critical role in both the peripheral and central auditory systems. Here, we review the genes controlling the development and function of the peripheral and central auditory systems, focusing on those with demonstrated intrinsic roles in both systems and highlighting the current underappreciation of these genes. Their encoded products are diverse, from transcription factors to ion channels, as are their roles in the central auditory system, mostly evaluated in brainstem nuclei. We examine the ontogenetic and evolutionary mechanisms that may underlie their expression at different sites.
Collapse
Affiliation(s)
- Nicolas Michalski
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75015 Paris, France;,
- Institut National de la Santé et de la Recherche Médicale, UMRS 1120, 75015 Paris, France
- Sorbonne Universités, 75005 Paris, France
| | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75015 Paris, France;,
- Institut National de la Santé et de la Recherche Médicale, UMRS 1120, 75015 Paris, France
- Sorbonne Universités, 75005 Paris, France
- Syndrome de Usher et Autres Atteintes Rétino-Cochléaires, Institut de la Vision, 75012 Paris, France
- Collège de France, 75005 Paris, France
| |
Collapse
|
7
|
Shearer AE, Hansen MR. Auditory synaptopathy, auditory neuropathy, and cochlear implantation. Laryngoscope Investig Otolaryngol 2019; 4:429-440. [PMID: 31453354 PMCID: PMC6703118 DOI: 10.1002/lio2.288] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/17/2019] [Accepted: 06/13/2019] [Indexed: 02/03/2023] Open
Abstract
Cochlear implantation has become the standard-of-care for adults and children with severe to profound hearing loss. There is growing evidence that qualitative as well as quantitative deficits in the auditory nerve may affect cochlear implant (CI) outcomes. Auditory neuropathy spectrum disorder (ANSD) is characterized by dysfunctional transmission of sound from the cochlea to the brain due to defective synaptic function or neural conduction. In this review, we examine the precise mechanisms of genetic lesions causing ANSD and the effect of these lesions on CI outcomes. Reviewed data show that individuals with lesions that primarily affect the cochlear sensory system and the synapse, which are bypassed by the CI, have optimal CI outcomes. Individuals with lesions that affect the auditory nerve show poor performance with CIs, likely because neural transmission of the electrical signal from the CI is affected. We put forth a nuanced molecular classification of ANSD that has implications for preoperative counseling for patients with this disorder prior to cochlear implantation. We propose that description of ANSD patients should be based on the molecular site of lesion typically derived from genetic evaluation (synaptopathy vs. neuropathy) as this has implications for expected CI outcomes. Improvements in our understanding of genetic site of lesions and their effects on CI function should lead to better CI outcomes, not just for individuals with auditory neuropathy, but all individuals with hearing loss.
Collapse
Affiliation(s)
- Aiden Eliot Shearer
- Department of Otolaryngology-Head and Neck Surgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A
| | - Marlan R Hansen
- Department of Otolaryngology-Head and Neck Surgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A.,Department of Neurosurgery University of Iowa Carver College of Medicine Iowa City Iowa U.S.A
| |
Collapse
|
8
|
Eckrich S, Hecker D, Sorg K, Blum K, Fischer K, Münkner S, Wenzel G, Schick B, Engel J. Cochlea-Specific Deletion of Ca v1.3 Calcium Channels Arrests Inner Hair Cell Differentiation and Unravels Pitfalls of Conditional Mouse Models. Front Cell Neurosci 2019; 13:225. [PMID: 31178698 PMCID: PMC6538774 DOI: 10.3389/fncel.2019.00225] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/03/2019] [Indexed: 12/29/2022] Open
Abstract
Inner hair cell (IHC) Cav1.3 Ca2+ channels are multifunctional channels mediating Ca2+ influx for exocytosis at ribbon synapses, the generation of Ca2+ action potentials in pre-hearing IHCs and gene expression. IHCs of deaf systemic Cav1.3-deficient (Cav1.3-/-) mice stay immature because they fail to up-regulate voltage- and Ca2+-activated K+ (BK) channels but persistently express small conductance Ca2+-activated K+ (SK2) channels. In pre-hearing wildtype mice, cholinergic neurons from the superior olivary complex (SOC) exert efferent inhibition onto spontaneously active immature IHCs by activating their SK2 channels. Because Cav1.3 plays an important role for survival, health and function of SOC neurons, SK2 channel persistence and lack of BK channels in systemic Cav1.3-/- IHCs may result from malfunctioning neurons of the SOC. Here we analyze cochlea-specific Cav1.3 knockout mice with green fluorescent protein (GFP) switch reporter function, Pax2::cre;Cacna1d-eGFPflex/flexand Pax2::cre;Cacna1d-eGFPflex/-. Profound hearing loss, lack of BK channels and persistence of SK2 channels in Pax2::cre;Cacna1d-eGFPflex/- mice recapitulated the phenotype of systemic Cav1.3-/- mice, indicating that in wildtype mice, regulation of SK2 and BK channel expression is independent of Cav1.3 expression in SOC neurons. In addition, we noticed dose-dependent GFP toxicity leading to death of basal coil IHCs of Pax2::cre;Cacna1d-eGFPflex/flex mice, likely because of high GFP concentration and small repair capacity. This and the slower time course of Pax2-driven Cre recombinase in switching two rather than one Cacna1d-eGFPflex allele lead us to study Pax2::cre;Cacna1d-eGFPflex/- mice. Notably, control Cacna1d-eGFPflex/- IHCs showed a significant reduction in Cav1.3 channel cluster sizes and currents, suggesting that the intronic construct interfered with gene translation or splicing. These pitfalls are likely to be a frequent problem of many genetically modified mice with complex or multiple gene-targeting constructs or fluorescent proteins. Great caution and appropriate controls are therefore required.
Collapse
Affiliation(s)
- Stephanie Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Dietmar Hecker
- Department of Otorhinolaryngology, Saarland University, Homburg, Germany
| | - Katharina Sorg
- Department of Otorhinolaryngology, Saarland University, Homburg, Germany
| | - Kerstin Blum
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Kerstin Fischer
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Stefan Münkner
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| | - Gentiana Wenzel
- Department of Otorhinolaryngology, Saarland University, Homburg, Germany
| | - Bernhard Schick
- Department of Otorhinolaryngology, Saarland University, Homburg, Germany
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany
| |
Collapse
|
9
|
Schlüter T, Berger C, Rosengauer E, Fieth P, Krohs C, Ushakov K, Steel KP, Avraham KB, Hartmann AK, Felmy F, Nothwang HG. miR-96 is required for normal development of the auditory hindbrain. Hum Mol Genet 2018; 27:860-874. [DOI: 10.1093/hmg/ddy007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 12/30/2017] [Indexed: 12/17/2022] Open
Affiliation(s)
- Tina Schlüter
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Christina Berger
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians University Munich, 82152 Martinsried, Germany
| | - Elena Rosengauer
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Pascal Fieth
- Computational Theoretical Physics Group, Institute of Physics, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Constanze Krohs
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Kathy Ushakov
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Karen P Steel
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alexander K Hartmann
- Computational Theoretical Physics Group, Institute of Physics, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Felix Felmy
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians University Munich, 82152 Martinsried, Germany
- Institute of Zoology, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany
| | - Hans Gerd Nothwang
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| |
Collapse
|
10
|
Ebbers L, Weber M, Nothwang HG. Activity-dependent formation of a vesicular inhibitory amino acid transporter gradient in the superior olivary complex of NMRI mice. BMC Neurosci 2017; 18:75. [PMID: 29073893 PMCID: PMC5659004 DOI: 10.1186/s12868-017-0393-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 10/13/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the mammalian superior olivary complex (SOC), synaptic inhibition contributes to the processing of binaural sound cues important for sound localization. Previous analyses demonstrated a tonotopic gradient for postsynaptic proteins mediating inhibitory neurotransmission in the lateral superior olive (LSO), a major nucleus of the SOC. To probe, whether a presynaptic molecular gradient exists as well, we investigated immunoreactivity against the vesicular inhibitory amino acid transporter (VIAAT) in the mouse auditory brainstem. RESULTS Immunoreactivity against VIAAT revealed a gradient in the LSO and the superior paraolivary nucleus (SPN) of NMRI mice, with high expression in the lateral, low frequency processing limb and low expression in the medial, high frequency processing limb of both nuclei. This orientation is opposite to the previously reported gradient of glycine receptors in the LSO. Other nuclei of the SOC showed a uniform distribution of VIAAT-immunoreactivity. No gradient was observed for the glycine transporter GlyT2 and the neuronal protein NeuN. Formation of the VIAAT gradient was developmentally regulated and occurred around hearing-onset between postnatal days 8 and 16. Congenital deaf Claudin14 -/- mice bred on an NMRI background showed a uniform VIAAT-immunoreactivity in the LSO, whereas cochlear ablation in NMRI mice after hearing-onset did not affect the gradient. Additional analysis of C57Bl6/J, 129/SvJ and CBA/J mice revealed a strain-specific formation of the gradient. CONCLUSIONS Our results identify an activity-regulated gradient of VIAAT in the SOC of NRMI mice. Its absence in other mouse strains adds a novel layer of strain-specific features in the auditory system, i.e. tonotopic organization of molecular gradients. This calls for caution when comparing data from different mouse strains frequently used in studies involving transgenic animals. The presence of strain-specific differences offers the possibility of genetic mapping to identify molecular factors involved in activity-dependent developmental processes in the auditory system. This would provide an important step forward concerning improved auditory rehabilitation in cases of congenital deafness.
Collapse
Affiliation(s)
- Lena Ebbers
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Maren Weber
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Hans Gerd Nothwang
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| |
Collapse
|
11
|
Di Bonito M, Studer M. Cellular and Molecular Underpinnings of Neuronal Assembly in the Central Auditory System during Mouse Development. Front Neural Circuits 2017; 11:18. [PMID: 28469562 PMCID: PMC5395578 DOI: 10.3389/fncir.2017.00018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/01/2017] [Indexed: 11/13/2022] Open
Abstract
During development, the organization of the auditory system into distinct functional subcircuits depends on the spatially and temporally ordered sequence of neuronal specification, differentiation, migration and connectivity. Regional patterning along the antero-posterior axis and neuronal subtype specification along the dorso-ventral axis intersect to determine proper neuronal fate and assembly of rhombomere-specific auditory subcircuits. By taking advantage of the increasing number of transgenic mouse lines, recent studies have expanded the knowledge of developmental mechanisms involved in the formation and refinement of the auditory system. Here, we summarize several findings dealing with the molecular and cellular mechanisms that underlie the assembly of central auditory subcircuits during mouse development, focusing primarily on the rhombomeric and dorso-ventral origin of auditory nuclei and their associated molecular genetic pathways.
Collapse
|
12
|
O'Leary TP, Shin S, Fertan E, Dingle RN, Almuklass A, Gunn RK, Yu Z, Wang J, Brown RE. Reduced acoustic startle response and peripheral hearing loss in the 5xFAD mouse model of Alzheimer's disease. GENES BRAIN AND BEHAVIOR 2017; 16:554-563. [DOI: 10.1111/gbb.12370] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/30/2016] [Accepted: 01/23/2017] [Indexed: 12/20/2022]
Affiliation(s)
- T. P. O'Leary
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - S. Shin
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - E. Fertan
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - R. N. Dingle
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - A. Almuklass
- Department of Basic Medical Sciences; King Saud Bin Abdulaziz University for Health Science; Riyadh Saudi Arabia
| | - R. K. Gunn
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - Z. Yu
- Department of School of Human Communication Disorders; Dalhousie University; Halifax Nova Scotia Canada
| | - J. Wang
- Department of School of Human Communication Disorders; Dalhousie University; Halifax Nova Scotia Canada
| | - R. E. Brown
- Department of Psychology & Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| |
Collapse
|
13
|
Abstract
From the therapeutic perspective, the etiology and pathophysiology of hearing loss can be classified based on the extent of the primary cause. Hearing loss can have very different consequences for cell preservation in the organ of Corti and the spiral ganglion. These not only have implications for prosthetic therapy outcome, but may also influence the potential for future causal molecular therapies. Etiologies leading to deficits that are limited to one or a few molecules without having an effect on cell survival have the greatest potential for future causal therapy using molecular and cellular approaches. Preliminary success for molecular therapy was recently reported in animal experiments. Unfortunately, the incidence of these types of hearing loss is very low and in the future the therapy of hearing loss will therefore also require several different approaches. In addition to peripheral pathophysiology, hearing loss has consequences on the functioning of the brain, which can vary greatly due to individual adaptation to the situation without hearing. The authors therefore argue for individualization of the diagnostics and therapy that focus not only the symptom of hearing loss, but also the individual pathophysiology and consequences. Only with individualized therapy can the success of treating hearing disorders be significantly improved.
Collapse
|
14
|
Ebbers L, Runge K, Nothwang HG. Differential patterns of histone methylase EHMT2 and its catalyzed histone modifications H3K9me1 and H3K9me2 during maturation of central auditory system. Cell Tissue Res 2016; 365:247-64. [PMID: 27083448 DOI: 10.1007/s00441-016-2401-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/24/2016] [Indexed: 12/31/2022]
Abstract
Histone methylation is an important epigenetic mark leading to changes in DNA accessibility and transcription. Here, we investigate immunoreactivity against the euchromatic histone-lysine N-methyltransferase EHMT2 and its catalyzed mono- and dimethylation marks at histone 3 lysine 9 (H3K9me1 and H3K9me2) during postnatal differentiation of the mouse central auditory system. In the brainstem, expression of EHMT2 was high in the first postnatal week and down-regulated thereafter. In contrast, immunoreactivity in the auditory cortex (AC) remained high during the first year of life. This difference might be related to distinct demands for adult plasticity. Analyses of two deaf mouse models, namely Cldn14 (-/-) and Cacna1d (-/-), demonstrated that sound-driven or spontaneous activity had no influence on EHMT2 immunoreactivity. The methylation marks H3K9me1 and H3K9me2 were high throughout the auditory system up to 1 year. Young auditory neurons showed immunoreactivity against both methylations at similar intensities, whereas many mature neurons showed stronger labeling for either H3K9me1 or H3K9me2. These differences were only poorly correlated with cell types. To identify methyltransferases contributing to the persistent H3K9me1 and H3K9me2 marks in the adult brainstem, EHMT1 and the retinoblastoma-interacting zinc-finger protein RIZ1 were analyzed. Both were down-regulated during brainstem development, similar to EHMT2. Contrary to EHMT2, EHMT1 was also down-regulated in adult cortical areas. Together, our data reveal a marked difference in EHMT2 levels between mature brainstem and cortical areas and a decoupling between EHMT2 abundance and histone 3 lysine 9 methylations during brainstem differentiation. Furthermore, EHMT1 and EHMT2 are differentially expressed in cortical areas.
Collapse
Affiliation(s)
- Lena Ebbers
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Karen Runge
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Hans Gerd Nothwang
- Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany. .,Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
| |
Collapse
|
15
|
Ebbers L, Satheesh SV, Janz K, Rüttiger L, Blosa M, Hofmann F, Morawski M, Griesemer D, Knipper M, Friauf E, Nothwang HG. L-type Calcium Channel Cav1.2 Is Required for Maintenance of Auditory Brainstem Nuclei. J Biol Chem 2015; 290:23692-710. [PMID: 26242732 DOI: 10.1074/jbc.m115.672675] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 12/13/2022] Open
Abstract
Cav1.2 and Cav1.3 are the major L-type voltage-gated Ca(2+) channels in the CNS. Yet, their individual in vivo functions are largely unknown. Both channel subunits are expressed in the auditory brainstem, where Cav1.3 is essential for proper maturation. Here, we investigated the role of Cav1.2 by targeted deletion in the mouse embryonic auditory brainstem. Similar to Cav1.3, loss of Cav1.2 resulted in a significant decrease in the volume and cell number of auditory nuclei. Contrary to the deletion of Cav1.3, the action potentials of lateral superior olive (LSO) neurons were narrower compared with controls, whereas the firing behavior and neurotransmission appeared unchanged. Furthermore, auditory brainstem responses were nearly normal in mice lacking Cav1.2. Perineuronal nets were also unaffected. The medial nucleus of the trapezoid body underwent a rapid cell loss between postnatal days P0 and P4, shortly after circuit formation. Phosphorylated cAMP response element-binding protein (CREB), nuclear NFATc4, and the expression levels of p75NTR, Fas, and FasL did not correlate with cell death. These data demonstrate for the first time that both Cav1.2 and Cav1.3 are necessary for neuronal survival but are differentially required for the biophysical properties of neurons. Thus, they perform common as well as distinct functions in the same tissue.
Collapse
Affiliation(s)
- Lena Ebbers
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Somisetty V Satheesh
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Katrin Janz
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Lukas Rüttiger
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Maren Blosa
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Franz Hofmann
- the Institut für Pharmakologie und Toxikologie, Technische Universität, Biedersteiner Strasse 29, D-80802 München, and
| | - Markus Morawski
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Désirée Griesemer
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Marlies Knipper
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Eckhard Friauf
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Hans Gerd Nothwang
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany, the Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| |
Collapse
|
16
|
Willaredt MA, Schlüter T, Nothwang HG. The gene regulatory networks underlying formation of the auditory hindbrain. Cell Mol Life Sci 2015; 72:519-535. [PMID: 25332098 PMCID: PMC11113740 DOI: 10.1007/s00018-014-1759-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/24/2014] [Accepted: 10/09/2014] [Indexed: 01/28/2023]
Abstract
Development and evolution of auditory hindbrain nuclei are two major unsolved issues in hearing research. Recent characterization of transgenic mice identified the rhombomeric origins of mammalian auditory nuclei and unraveled genes involved in their formation. Here, we provide an overview on these data by assembling them into rhombomere-specific gene regulatory networks (GRNs), as they underlie developmental and evolutionary processes. To explore evolutionary mechanisms, we compare the GRNs operating in the mammalian auditory hindbrain with data available from the inner ear and other vertebrate groups. Finally, we propose that the availability of genomic sequences from all major vertebrate taxa and novel genetic techniques for non-model organisms provide an unprecedented opportunity to investigate development and evolution of the auditory hindbrain by comparative molecular approaches. The dissection of the molecular mechanisms leading to auditory structures will also provide an important framework for auditory processing disorders, a clinical problem difficult to tackle so far. These data will, therefore, foster basic and clinical hearing research alike.
Collapse
Affiliation(s)
- Marc A Willaredt
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
| | - Tina Schlüter
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany
| | - Hans Gerd Nothwang
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
- Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111, Oldenburg, Germany.
| |
Collapse
|
17
|
The emerging framework of mammalian auditory hindbrain development. Cell Tissue Res 2015; 361:33-48. [DOI: 10.1007/s00441-014-2110-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 12/22/2014] [Indexed: 02/06/2023]
|