1
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Kagoshima H, Ohnishi H, Yamamoto R, Yasumoto A, Tona Y, Nakagawa T, Omori K, Yamamoto N. EBF1 Limits the Numbers of Cochlear Hair and Supporting Cells and Forms the Scala Tympani and Spiral Limbus during Inner Ear Development. J Neurosci 2024; 44:e1060232023. [PMID: 38176908 PMCID: PMC10869149 DOI: 10.1523/jneurosci.1060-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/12/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024] Open
Abstract
Early B-cell factor 1 (EBF1) is a basic helix-loop-helix transcription factor essential for the differentiation of various tissues. Our single-cell RNA sequencing data suggest that Ebf1 is expressed in the sensory epithelium of the mouse inner ear. Here, we found that the murine Ebf1 gene and its protein are expressed in the prosensory domain of the inner ear, medial region of the cochlear duct floor, otic mesenchyme, and cochleovestibular ganglion. Ebf1 deletion in mice results in incomplete formation of the spiral limbus and scala tympani, increased number of cells in the organ of Corti and Kölliker's organ, and aberrant course of the spiral ganglion axons. Ebf1 deletion in the mouse cochlear epithelia caused the proliferation of SOX2-positive cochlear cells at E13.5, indicating that EBF1 suppresses the proliferation of the prosensory domain and cells of Kölliker's organ to facilitate the development of appropriate numbers of hair and supporting cells. Furthermore, mice with deletion of cochlear epithelium-specific Ebf1 showed poor postnatal hearing function. Our results suggest that Ebf1 is essential for normal auditory function in mammals.
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Affiliation(s)
- Hiroki Kagoshima
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Hiroe Ohnishi
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Ryosuke Yamamoto
- Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada
| | - Akiyoshi Yasumoto
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yosuke Tona
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Takayuki Nakagawa
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Koichi Omori
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Norio Yamamoto
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- Department of Otolaryngology, Kobe City Medical Center General Hospital, Hyogo 650-0047, Japan
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2
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De Rosa MA, Bernardi MT, Kleppe S, Walz K. Hearing Loss: Genetic Testing, Current Advances and the Situation in Latin America. Genes (Basel) 2024; 15:178. [PMID: 38397168 PMCID: PMC10888486 DOI: 10.3390/genes15020178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
Congenital hearing loss is the most common birth defect, estimated to affect 2-3 in every 1000 births, with ~50-60% of those related to genetic causes. Technological advances enabled the identification of hundreds of genes related to hearing loss (HL), with important implications for patients, their families, and the community. Despite these advances, in Latin America, the population with hearing loss remains underdiagnosed, with most studies focusing on a single locus encompassing the GJB2/GJB6 genes. Here we discuss how current and emerging genetic knowledge has the potential to alter the approach to diagnosis and management of hearing loss, which is the current situation in Latin America, and the barriers that still need to be overcome.
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Affiliation(s)
- Maria Agustina De Rosa
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EHA, Argentina; (M.A.D.R.); (M.T.B.)
| | - Maria T. Bernardi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EHA, Argentina; (M.A.D.R.); (M.T.B.)
| | - Soledad Kleppe
- Department of Clinical Pediatrics, Hospital Italiano de Buenos Aires, Instituto Universitario Hospital Italiano de Buenos Aires, Buenos Aires C1199ABB, Argentina;
| | - Katherina Walz
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EHA, Argentina; (M.A.D.R.); (M.T.B.)
- John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-418 (M-860), Miami, FL 33136, USA
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3
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Rose KP, Manilla G, Milon B, Zalzman O, Song Y, Coate TM, Hertzano R. Spatially distinct otic mesenchyme cells show molecular and functional heterogeneity patterns before hearing onset. iScience 2023; 26:107769. [PMID: 37720106 PMCID: PMC10502415 DOI: 10.1016/j.isci.2023.107769] [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: 12/16/2022] [Revised: 06/29/2023] [Accepted: 08/25/2023] [Indexed: 09/19/2023] Open
Abstract
The cochlea consists of diverse cellular populations working in harmony to convert mechanical stimuli into electrical signals for the perception of sound. Otic mesenchyme cells (OMCs), often considered a homogeneous cell type, are essential for normal cochlear development and hearing. Despite being the most numerous cell type in the developing cochlea, OMCs are poorly understood. OMCs are known to differentiate into spatially and functionally distinct cell types, including fibrocytes of the lateral wall and spiral limbus, modiolar osteoblasts, and specialized tympanic border cells of the basilar membrane. Here, we show that OMCs are transcriptionally and functionally heterogeneous and can be divided into four distinct populations that spatially correspond to OMC-derived cochlear structures. We also show that this heterogeneity and complexity of OMCs commences during early phases of cochlear development. Finally, we describe the cell-cell communication network of the developing cochlea, inferring a major role for OMC in outgoing signaling.
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Affiliation(s)
- Kevin P. Rose
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gabriella Manilla
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Beatrice Milon
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ori Zalzman
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Thomas M. Coate
- Department of Biology, Georgetown University, Washington, DC 20007, USA
| | - Ronna Hertzano
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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4
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Bernardinelli E, Roesch S, Simoni E, Marino A, Rasp G, Astolfi L, Sarikas A, Dossena S. Novel POU3F4 variants identified in patients with inner ear malformations exhibit aberrant cellular distribution and lack of SLC6A20 transcriptional upregulation. Front Mol Neurosci 2022; 15:999833. [PMID: 36245926 PMCID: PMC9558712 DOI: 10.3389/fnmol.2022.999833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/13/2022] [Indexed: 11/14/2022] Open
Abstract
Hearing loss (HL) is the most common sensory defect and affects 450 million people worldwide in a disabling form. Pathogenic sequence alterations in the POU3F4 gene, which encodes a transcription factor, are causative of the most common type of X-linked deafness (X-linked deafness type 3, DFN3, DFNX2). POU3F4-related deafness is characterized by a typical inner ear malformation, namely an incomplete partition of the cochlea type 3 (IP3), with or without an enlargement of the vestibular aqueduct (EVA). The pathomechanism underlying POU3F4-related deafness and the corresponding transcriptional targets are largely uncharacterized. Two male patients belonging to a Caucasian cohort with HL and EVA who presented with an IP3 were submitted to genetic analysis. Two novel sequence variants in POU3F4 were identified by Sanger sequencing. In cell-based assays, the corresponding protein variants (p.S74Afs*8 and p.C327*) showed an aberrant expression and subcellular distribution and lack of transcriptional activity. These two protein variants failed to upregulate the transcript levels of the amino acid transporter gene SLC6A20, which was identified as a novel transcriptional target of POU3F4 by RNA sequencing and RT-qPCR. Accordingly, POU3F4 silencing by siRNA resulted in downregulation of SLC6A20 in mouse embryonic fibroblasts. Moreover, we showed for the first time that SLC6A20 is expressed in the mouse cochlea, and co-localized with POU3F4 in the spiral ligament. The findings presented here point to a novel role of amino acid transporters in the inner ear and pave the way for mechanistic studies of POU3F4-related HL.
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Affiliation(s)
- Emanuele Bernardinelli
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Sebastian Roesch
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, Salzburg, Austria
| | - Edi Simoni
- Bioacoustic Research Laboratory, Department of Neuroscience, Biomedical Campus Pietro d’Abano, University of Padua, Padua, Italy
| | - Angela Marino
- Department of Chemical, Biological, Pharmaceutical, and Environmental Sciences, University of Messina, Messina, Italy
| | - Gerd Rasp
- Department of Otorhinolaryngology, Head and Neck Surgery, Paracelsus Medical University, Salzburg, Austria
| | - Laura Astolfi
- Bioacoustic Research Laboratory, Department of Neuroscience, Biomedical Campus Pietro d’Abano, University of Padua, Padua, Italy
- Interdepartmental Research Center of International Auditory Processing Project in Venice (I-APPROVE), Department of Neurosciences, University of Padova, Santi Giovanni e Paolo Hospital, ULSS3, Venice, Italy
| | - Antonio Sarikas
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
- *Correspondence: Antonio Sarikas,
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
- Silvia Dossena,
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Defourny J. Considering gene therapy to protect from X-linked deafness DFNX2 and associated neurodevelopmental disorders. IBRAIN 2022; 8:431-441. [PMID: 37786584 PMCID: PMC10529175 DOI: 10.1002/ibra.12068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/10/2022] [Accepted: 09/13/2022] [Indexed: 10/04/2023]
Abstract
Mutations and deletions in the gene or upstream of the gene encoding the POU3F4 transcription factor cause X-linked progressive deafness DFNX2 and additional neurodevelopmental disorders in humans. Hearing loss can be purely sensorineural or mixed, that is, with both conductive and sensorineural components. Affected males show anatomical abnormalities of the inner ear, which are jointly defined as incomplete partition type III. Current approaches to improve hearing and speech skills of DFNX2 patients do not seem to be fully effective. Owing to inner ear malformations, cochlear implantation is surgically difficult and may predispose towards severe complications. Even in cases where implantation is safely performed, hearing and speech outcomes remain highly variable among patients. Mouse models for DFNX2 deafness revealed that sensorineural loss could arise from a dysfunction of spiral ligament fibrocytes in the lateral wall of the cochlea, which leads to reduced endocochlear potential. Highly positive endocochlear potential is critical for sensory hair cell mechanotransduction and hearing. In this context, here, we propose to develop a therapeutic approach in male Pou3f4 -/y mice based on an adeno-associated viral (AAV) vector-mediated gene transfer in cochlear spiral ligament fibrocytes. Among a broad range of AAV vectors, AAV7 was found to show a strong tropism for the spiral ligament. Thus, we suggest that an AAV7-mediated delivery of Pou3f4 complementary DNA in the spiral ligament of Pou3f4 -/y mice could represent an attractive strategy to prevent fibrocyte degeneration and to restore normal cochlear functions and properties, including a positive endocochlear potential, before hearing loss progresses to profound deafness.
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Affiliation(s)
- Jean Defourny
- GIGA‐Neurosciences, Unit of Cell and Tissue BiologyUniversity of Liège, C.H.U. B36LiègeBelgium
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6
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Chen Y, Qiu J, Wu Y, Jia H, Jiang Y, Jiang M, Wang Z, Sheng HB, Hu L, Zhang Z, Wang Z, Li Y, Huang Z, Wu H. Genetic findings of Sanger and nanopore single-molecule sequencing in patients with X-linked hearing loss and incomplete partition type III. Orphanet J Rare Dis 2022; 17:65. [PMID: 35189936 PMCID: PMC8862311 DOI: 10.1186/s13023-022-02235-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 02/06/2022] [Indexed: 12/01/2022] Open
Abstract
Background POU3F4 is the causative gene for X-linked deafness-2 (DFNX2), characterized by incomplete partition type III (IP-III) malformation of the inner ear. The purpose of this study was to investigate the clinical characteristics and molecular findings in IP-III patients by Sanger or nanopore single-molecule sequencing. Methods Diagnosis of IP-III was mainly based on clinical characteristics including radiological and audiological findings. Sanger sequencing of POU3F4 was carried out for these IP-III patients. For those patients with negative results for POU3F4 Sanger sequencing, nanopore long-read single-molecule sequencing was used to identify the possible pathogenic variants. Hearing intervention outcomes of hearing aids (HAs) fitting and cochlear implantation (CI) were also analyzed. Aided pure tone average (PTA) was further compared between two groups of patients according to their different locations of POU3F4 variants: in the exon region or in the upstream region. Results In total, 18 male patients from 14 unrelated families were diagnosed with IP-III. 10 variants were identified in POU3F4 by Sanger sequencing and 6 of these were reported for the first time (p.Gln181*, p.Val215Gly, p.Arg282Gln, p.Gln316*, c.903_912 delins TGCCA and p.Arg205del). Four different deletions that varied from 80 to 486 kb were identified 876–1503 kb upstream of POU3F4 by nanopore long-read single-molecule sequencing. De novo genetic mutations occurred in 21.4% (3/14) of patients with POU3F4 mutations. Among these 18 patients, 7 had bilateral HAs and 10 patients received unilateral CI. The mean aided PTA for HAs and CI users were 41.1 ± 5.18 and 40.3 ± 7.59 dB HL respectively. The mean PTAs for patients with the variants located in the exon and upstream regions were 39.6 ± 6.31 versus 43.0 ± 7.10 dB HL, which presented no significant difference (p = 0.342). Conclusions Among 14 unrelated IP-III patients, 28.6% (4/14) had no definite mutation in exon region of POU3F4. However, possible pathogenic deletions were identified in upstream region of this gene. De novo genetic mutations occurred in 21.4% (3/14) of patients with POU3F4 mutation. There was no significant difference of hearing intervention outcomes between the IP-III patients with variants located in the exon region and in the upstream region. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02235-7.
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7
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Cheeney S, Wright JN, Sie KC, Chapman T. Pearls of Temporal Bone Imaging in Children with Hearing Loss. Semin Ultrasound CT MR 2022; 43:3-18. [PMID: 35164907 DOI: 10.1053/j.sult.2021.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hearing loss is one of the most common indications for temporal bone imaging in children. Hearing loss may be congenital or acquired, and it may be conductive, sensorineural, or mixed audiologically. Temporal bone imaging plays an important role in the assessment and management of this condition. An understanding of the embryology of ear structures better enables the radiologist to interpret abnormalities on imaging of the temporal bone. Here, we provide a general review of ear development and a description of known genetic defects that contribute to congenital ear anomalies associated with hearing loss. We provide appropriate imaging techniques for the temporal bone depending on the clinical presentation and a systematic approach to imaging for children with hearing loss. Diagnostic imaging for developmental anomalies of the ear and cholesteatoma will be discussed.
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Affiliation(s)
- Safia Cheeney
- Department of Radiology, Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - Jason N Wright
- Department of Radiology, Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - Kathleen C Sie
- Department of Otolaryngology, Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - Teresa Chapman
- Department of Radiology, Seattle Children's Hospital, University of Washington, Seattle, Washington.
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8
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The effects of substrate composition and topography on the characteristics and growth of cell cultures of cochlear fibrocytes. Hear Res 2021; 415:108427. [PMID: 34999290 DOI: 10.1016/j.heares.2021.108427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/02/2021] [Accepted: 12/23/2021] [Indexed: 11/22/2022]
Abstract
Spiral ligament fibrocytes of the cochlea play homoeostatic roles in hearing and their degeneration contributes to hearing loss. Culturing fibrocytes in vitro provides a way to evaluate their functional characteristics and study possible therapies for hearing loss. We investigated whether in vivo characteristics of fibrocytes could be recapitulated in vitro by modifying the culture substrates and carried out proof of concept studies for potential transplantation of culture cells into the inner ear. Fibrocytes cultured from 4 to 5-week old CD/1 mice were grown on 2D substrates coated with collagen I, II, V or IX and, after harvesting, onto or into 3D substrates (hydrogels) of collagen I alone or mixed collagen I and II at a 1:1 ratio. We also assessed magnetic nanoparticle (MNP) uptake. Cell counts, immunohistochemical and ultrastructural studies showed that fibrocytes grown on 2D substrates proliferated, formed both small spindle-shaped and large flat cells that avidly took up MNPs. Of the different collagen coatings, only collagen II had an effect, causing a reduced size of the larger cells. On hydrogels, the cells were plump/rounded with extended processes, resembling native cells. They formed networks over the surface and became incorporated into the gel. In all culture formats, the majority co-expressed caldesmon, aquaporin 1, S-100 and sodium potassium ATPase, indicating a mixed or uncharacterised phenotype. Time-course experiments showed a decrease to ∼50% of the starting population by 4d after seeding on collagen I hydrogels, but better survival (∼60%) was found on collagen I + II gels, whilst TEM revealed the presence of apoptotic cells. Cells grown within gels additionally showed necrosis. These results demonstrate that fibrocytes grown in 3D recapitulate in vivo morphology of native fibrocytes, but have poorer survival, compared with 2D. Therefore hydrogel cultures could be used to study fibrocyte function and might also offer avenues for cell-replacement therapies, but need more optimization for therapeutic use. Fibrocyte function could be modified using MNPs in combination, for example, with gene transfection.
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9
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Ng L, Liu Y, Liu H, Forrest D. Cochlear Fibrocyte and Osteoblast Lineages Expressing Type 2 Deiodinase Identified with a Dio2CreERt2 Allele. Endocrinology 2021; 162:bqab179. [PMID: 34436572 PMCID: PMC8475715 DOI: 10.1210/endocr/bqab179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Indexed: 12/16/2022]
Abstract
Type 2 deiodinase (Dio2) amplifies levels of 3,5,3'-L-triiodothyronine (T3), the active form of thyroid hormone, and is essential for cochlear maturation and auditory development. However, cellular routes for endocrine signaling in the compartmentalized, anatomically complex cochlea are little understood. Dio2 generates T3 from thyroxine (T4), a more abundant thyroid hormone precursor in the circulation, and is dramatically induced in the cochlea before the onset of hearing. The evidence implies that specific Dio2-expressing cell types critically mediate T3 signaling but these cell types are poorly defined because Dio2 is expressed transiently at low levels. Here, using a Dio2CreERt2 knockin that activates a fluorescent reporter, we define Dio2-expressing cochlear cell types at high resolution in male or female mice. Dio2-positive cells were detected in vascularized supporting tissues but not in avascular internal epithelia, indicating segregation of T3-generating and T3-responding tissues. In the spiral ligament and spiral limbus, Dio2-positive fibrocytes clustered around vascular networks that convey T4 into cochlear tissues. In the otic capsule, Dio2-positive osteoblasts localized at cartilage surfaces as the bony labyrinth matures. We corroborated the identities of Dio2-positive lineages by RNA-sequencing of individual cells. The results suggest a previously unrecognized role for fibrocytes in mediating hormonal signaling. We discuss a model whereby fibrocytes mediate paracrine-like control of T3 signaling to the organ of Corti and epithelial target tissues.
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Affiliation(s)
- Lily Ng
- Laboratory of Endocrinology and Receptor Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ye Liu
- Laboratory of Endocrinology and Receptor Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hong Liu
- Laboratory of Endocrinology and Receptor Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
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10
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Naxerova K, Di Stefano B, Makofske JL, Watson EV, de Kort MA, Martin TD, Dezfulian M, Ricken D, Wooten EC, Kuroda MI, Hochedlinger K, Elledge SJ. Integrated loss- and gain-of-function screens define a core network governing human embryonic stem cell behavior. Genes Dev 2021; 35:1527-1547. [PMID: 34711655 PMCID: PMC8559676 DOI: 10.1101/gad.349048.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/13/2022]
Abstract
In this Resource/Methodology, Naxerova et al. describe an integrated genome-scale loss- and gain-of-function screening approach to identify genetic networks governing embryonic stem cell proliferation and differentiation into the three germ layers. They identify a deep link between pluripotency maintenance and survival by showing that genetic alterations that cause pluripotency dissolution simultaneously increase apoptosis resistance, and their results show the power of integrated multilayer genetic screening for the robust mapping of complex genetic networks. Understanding the genetic control of human embryonic stem cell function is foundational for developmental biology and regenerative medicine. Here we describe an integrated genome-scale loss- and gain-of-function screening approach to identify genetic networks governing embryonic stem cell proliferation and differentiation into the three germ layers. We identified a deep link between pluripotency maintenance and survival by showing that genetic alterations that cause pluripotency dissolution simultaneously increase apoptosis resistance. We discovered that the chromatin-modifying complex SAGA and in particular its subunit TADA2B are central regulators of pluripotency, survival, growth, and lineage specification. Joint analysis of all screens revealed that genetic alterations that broadly inhibit differentiation across multiple germ layers drive proliferation and survival under pluripotency-maintaining conditions and coincide with known cancer drivers. Our results show the power of integrated multilayer genetic screening for the robust mapping of complex genetic networks.
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Affiliation(s)
- Kamila Naxerova
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Center for Systems Biology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Bruno Di Stefano
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Jessica L Makofske
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Emma V Watson
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Marit A de Kort
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Timothy D Martin
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mohammed Dezfulian
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dominik Ricken
- Center for Systems Biology, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Eric C Wooten
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Mitzi I Kuroda
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Konrad Hochedlinger
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Stephen J Elledge
- Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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11
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Dennison BJC, Larson ED, Fu R, Mo J, Fantauzzo KA. Srsf3 mediates alternative RNA splicing downstream of PDGFRα signaling in the facial mesenchyme. Development 2021; 148:269256. [PMID: 34184034 DOI: 10.1242/dev.199448] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 06/10/2021] [Indexed: 12/13/2022]
Abstract
Signaling through the platelet-derived growth factor receptor alpha (PDGFRα) is crucial for mammalian craniofacial development, although the mechanisms by which the activity of downstream intracellular effectors is regulated to mediate gene expression changes have not been defined. We find that the RNA-binding protein Srsf3 is phosphorylated at Akt consensus sites downstream of PI3K-mediated PDGFRα signaling in mouse palatal mesenchyme cells, leading to its nuclear translocation. We further demonstrate that ablation of Srsf3 in the mouse neural crest lineage leads to facial clefting due to defective cranial neural crest cell proliferation and survival. Finally, we show that Srsf3 regulates the alternative RNA splicing of transcripts encoding protein kinases in the mouse facial process mesenchyme to regulate PDGFRα-dependent intracellular signaling. Collectively, our findings reveal that alternative RNA splicing is an important mechanism of gene expression regulation downstream of PI3K/Akt-mediated PDGFRα signaling in the facial mesenchyme and identify Srsf3 as a critical regulator of craniofacial development.
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Affiliation(s)
- Brenna J C Dennison
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Eric D Larson
- Department of Otolaryngology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rui Fu
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Julia Mo
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Katherine A Fantauzzo
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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12
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Surgical Outcomes With Cochlear Implantation in Patients With Enlarged Cochlear Aperture: A Systematic Review. Otol Neurotol 2021; 42:638-645. [PMID: 33492060 DOI: 10.1097/mao.0000000000003021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Evaluate surgical outcomes in patients with enlarged cochlear aperture (ECA) after cochlear implantation. DATABASES REVIEWED PubMed, EMBASE, and Scopus. METHODS A systematic review was performed using standardized methodology. Studies were included if they included subjects with ECA who underwent cochlear implantation. Exclusion criteria included non-English articles, abstracts, letters/commentaries, case reports, and reviews. Bias was assessed using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. RESULTS Out of 1,688 identified articles, 7 articles representing 23 subjects with ECA were included. Publication rates increased between the period of study from 2009 to 2018. Four studies were level 4 evidence and three studies were level 3 evidence. In total, 20 subjects underwent cochlear implantation. Cerebrospinal fluid gushers were encountered in the majority of cases that reported complications (16/17, 94.1%); one patient developed postoperative meningitis, and another experienced postimplantation facial nerve stimulation. No study provided measurements on cochlear aperture size or defined size criteria used to identify ECA. Four studies recognized X-linked deafness to be associated with ECA, and the most common mutation was in POU3F4 gene. CONCLUSION An association exists between ECA and cerebrospinal fluid gusher, underscoring the importance of reviewing preoperative imaging. Size criteria are not well defined, and there is a paucity of data with respect to normative measurements. Many cases of ECA may give a genetic link. Although level of evidence of current studies remains modest, ECA reports have increased and will likely continue to expand with advancements in imaging and genetic testing.
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13
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Karimi-Boroujeni M, Zahedi-Amiri A, Coombs KM. Embryonic Origins of Virus-Induced Hearing Loss: Overview of Molecular Etiology. Viruses 2021; 13:71. [PMID: 33419104 PMCID: PMC7825458 DOI: 10.3390/v13010071] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 12/19/2022] Open
Abstract
Hearing loss, one of the most prevalent chronic health conditions, affects around half a billion people worldwide, including 34 million children. The World Health Organization estimates that the prevalence of disabling hearing loss will increase to over 900 million people by 2050. Many cases of congenital hearing loss are triggered by viral infections during different stages of pregnancy. However, the molecular mechanisms by which viruses induce hearing loss are not sufficiently explored, especially cases that are of embryonic origins. The present review first describes the cellular and molecular characteristics of the auditory system development at early stages of embryogenesis. These developmental hallmarks, which initiate upon axial specification of the otic placode as the primary root of the inner ear morphogenesis, involve the stage-specific regulation of several molecules and pathways, such as retinoic acid signaling, Sonic hedgehog, and Wnt. Different RNA and DNA viruses contributing to congenital and acquired hearing loss are then discussed in terms of their potential effects on the expression of molecules that control the formation of the auditory and vestibular compartments following otic vesicle differentiation. Among these viruses, cytomegalovirus and herpes simplex virus appear to have the most effect upon initial molecular determinants of inner ear development. Moreover, of the molecules governing the inner ear development at initial stages, SOX2, FGFR3, and CDKN1B are more affected by viruses causing either congenital or acquired hearing loss. Abnormalities in the function or expression of these molecules influence processes like cochlear development and production of inner ear hair and supporting cells. Nevertheless, because most of such virus-host interactions were studied in unrelated tissues, further validations are needed to confirm whether these viruses can mediate the same effects in physiologically relevant models simulating otic vesicle specification and growth.
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Affiliation(s)
- Maryam Karimi-Boroujeni
- School of Rehabilitation Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1H 8M5, Canada;
| | - Ali Zahedi-Amiri
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada;
- Manitoba Centre for Proteomics and Systems Biology, Winnipeg, MB R3E 3P4, Canada
| | - Kevin M. Coombs
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada;
- Manitoba Centre for Proteomics and Systems Biology, Winnipeg, MB R3E 3P4, Canada
- Children’s Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada
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14
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Petrina NE, Marakhonov AV, Zinchenko RA. [Presentation of a rare case of hereditary hearing loss with X-linked recessive inheritance associated with the POU3F4 gene]. Vestn Otorinolaringol 2020; 85:65-69. [PMID: 32885640 DOI: 10.17116/otorino20208504165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Congenital hearing loss is one of the most frequent inherited human pathologies, occurring in 1-2 out of 1000 newborns. X-linked hearing loss occurs in 1-5% of all congenital hearing impairments. The proband (a man) and his affected brother have profound prelingual non-syndromic neurosensory hearing loss. Their parents are healthy. The aim of the study was to determine the cause of hearing loss in a given family and to assess the population frequency of the revealed pathogenic genetic variant. NGS analysis identified a pathogenic variant c.907C>T (p.Pro303Ser) in the POU3F4 gene mapped to the Xq21.1 locus. This is the second case of X-linked hearing loss (DFNX2, OMIM 304400) in Europe, caused by the c.907C>T variant in the POU3F4 gene. DFNX2-hearing loss is manifested with abnormalities of the inner ear, predisposing to the "gusher effect" - otoliquorrhea during stapedoplasty. The brother was diagnosed with a c.907C>T variant in the POU3F4 gene in the hemizygous state while in their mother - in the heterozygous state. Their father had no variant c.907C>T. Molecular genetic analysis showed that the genetic variant c.907C>T was not detected in the control sample of healthy female from the Nogai population, which suggests its low frequency in the population.
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Affiliation(s)
- N E Petrina
- Research Center for Medical Genetics, Moscow, Russia
| | | | - R A Zinchenko
- Research Center for Medical Genetics, Moscow, Russia.,N.A. Semashko National Research Institute of Public Health, Moscow, Russia
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15
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Cochlear Implantation in a Patient with a Novel POU3F4 Mutation and Incomplete Partition Type-III Malformation. Neural Plast 2020; 2020:8829587. [PMID: 32952548 PMCID: PMC7481964 DOI: 10.1155/2020/8829587] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/05/2020] [Accepted: 08/24/2020] [Indexed: 01/01/2023] Open
Abstract
Aims This study is aimed at (1) analyzing the clinical manifestations and genetic features of a novel POU3F4 mutation in a nonsyndromic X-linked recessive hearing loss family and (2) reporting the outcomes of cochlear implantation in a patient with this mutation. Methods A patient who was diagnosed as the IP-III malformation underwent cochlear implantation in our hospital. The genetic analysis was conducted in his family, including the whole-exome sequencing combined with Sanger sequencing and bioinformatic analysis. Clinical features, preoperative auditory and speech performances, and postoperative outcomes of cochlear implant (CI) were assessed on the proband and his family. Results A novel variant c.400_401insACTC (p.Q136LfsX58) in the POU3F4 gene was detected in the family, which was cosegregated with the hearing loss. This variant was absent in 200 normal-hearing persons. The phylogenetic analysis and structure modeling of Pou3f4 protein further confirmed that the novel mutation was pathogenic. The proband underwent cochlear implantation on the right ear at four years old and gained greatly auditory and speech improvement. However, the benefits of the CI declined about three and a half years postoperation. Though the right ear had been reimplanted, the outcomes were still worse than before. Conclusion A novel frame shift variant c.400_401insACTC (p.Q136LfsX58) in the POU3F4 gene was identified in a Chinese family with X-linked inheritance hearing loss. A patient with this mutation and IP-III malformation could get good benefits from CI. However, the outcomes of the cochlear implantation might decline as the patient grows old.
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16
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Hong R, Du Q, Pan Y. New Imaging Findings of Incomplete Partition Type III Inner Ear Malformation and Literature Review. AJNR Am J Neuroradiol 2020; 41:1076-1080. [PMID: 32467182 DOI: 10.3174/ajnr.a6576] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 04/04/2020] [Indexed: 11/07/2022]
Abstract
Incomplete partition type III, also referred to as X-linked deafness, is a rare genetic inner ear malformation. Its characteristic CT findings, including bulbous dilation of the internal auditory canal and absence of the modiolus with the interscalar septa present, have been well-recognized. In this series of 19 cases, we report the abnormalities of the vestibule and semicircular canals and provide a comprehensive description of their CT and MR imaging findings. The inner ear malformations in incomplete partition type III were bilateral and basically symmetric, with involvement of the internal auditory canal, nerve canals in the fundus, cochlea, vestibule, semicircular canals, vestibular aqueduct, otic capsule, round window, oval window, and stapes. An irregular vestibule with a cystic appearance is also a distinctive imaging feature, which could be seen in about 90% of our patients, with a cystic appearance of the semicircular canals present in nearly half of the cases.
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Affiliation(s)
- R Hong
- From the Departments of Radiology (R.H., Y.P.)
| | - Q Du
- Otolaryngology-Head and Neck Surgery (Q.D.), Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai, China
| | - Y Pan
- From the Departments of Radiology (R.H., Y.P.)
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17
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A novel POU domain class 3 transcription factor 4 mutation causes X-linked non-syndromic hearing loss in a Chinese family. Chin Med J (Engl) 2020; 132:2251-2253. [PMID: 31490266 PMCID: PMC6797136 DOI: 10.1097/cm9.0000000000000425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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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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19
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Qin L, Ahn KJ, Wine Lee L, de Charleroy C, Crenshaw EB. Analyses with double knockouts of the Bmpr1a and Bmpr1b genes demonstrate that BMP signaling is involved in the formation of precerebellar mossy fiber nuclei derived from the rhombic lip. PLoS One 2019; 14:e0226602. [PMID: 31869353 PMCID: PMC6927620 DOI: 10.1371/journal.pone.0226602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/01/2019] [Indexed: 11/25/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) have been hypothesized to specify distinct dorsal neural fates. During neural development, BMPs are expressed in the roof plate and adjacent neuroepithelium. Because several hindbrain nuclei that form the proprioceptive/vestibular/auditory sensory network originate from the rhombic lip, near the roof plate, BMP signaling may regulate the development of these nuclei. To test this hypothesis genetically, we have examined the development of the hindbrain in BMP type I receptor knockout mice. Our results demonstrate that BMP signaling is involved in the formation of precerebellar mossy fiber nuclei, which give rise to cerebellar mossy fibers, but is not required for the development of the inferior olivary nucleus, which gives rise to cerebellar climbing fibers.
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Affiliation(s)
- Lihua Qin
- Division of Pediatric Otolaryngology, Mammalian Neurogenetics Group, Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Kyung J. Ahn
- Division of Pediatric Otolaryngology, Mammalian Neurogenetics Group, Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Lara Wine Lee
- Division of Pediatric Otolaryngology, Mammalian Neurogenetics Group, Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Neuroscience Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Charles de Charleroy
- Division of Pediatric Otolaryngology, Mammalian Neurogenetics Group, Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - E. Bryan Crenshaw
- Division of Pediatric Otolaryngology, Mammalian Neurogenetics Group, Center for Childhood Communication, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Neuroscience Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Otorhinolaryngology, Head and Neck Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
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20
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Miwa T, Minoda R, Ishikawa Y, Kajii T, Orita Y, Ohyama T. Role of Dach1 revealed using a novel inner ear-specific Dach1-knockdown mouse model. Biol Open 2019; 8:bio.043612. [PMID: 31405829 PMCID: PMC6737983 DOI: 10.1242/bio.043612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Dach1 gene is expressed in the inner ear of normal mouse embryos in the area that differentiates into the cochlear stria vascularis (SV). We hypothesised that Dach1 downregulation in the inner ear would lead to SV dysplasia. However, because Dach1 knockout is embryonic lethal in mice, the role of Dach1 in the inner ear is unclear. Here, we established inner ear-specific Dach1-knockdown mice and showed that Dach1 downregulation resulted in hearing loss, reduced endocochlear potential and secondary outer hair cell loss. There were no abnormalities in marginal cells and basal cells in the SV or spiral ligament in inner ear-specific Dach1-knockdown mature mice. However, intermediate cell dysplasia and thinning of the SV were observed. Moreover, dynamic changes in the expression of key genes related to the epithelial-mesenchymal transition were observed in the lateral wall of the cochlear epithelium, which differentiated into the SV in inner ear-specific Dach1-knockdown mice at embryonic stages. In summary, suppression of Dach1 expression in the inner ear caused the epithelial-mesenchymal transition in the lateral wall of cochlear epithelium, resulting in loss of intermediate cells in the SV and SV dysplasia. This article has an associated First Person interview with the first author of the paper. Summary: Inner ear-specific downregulation of Dach1 reveals that the epithelial–mesenchymal transition is crucial for the generation of the stria vascularis.
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Affiliation(s)
- Toru Miwa
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan .,Otolaryngology-Head and Neck Surgery, JCHO Kumamoto General Hospital, Kumamoto 8668660, Japan
| | - Ryosei Minoda
- Otolaryngology-Head and Neck Surgery, JCHO Kumamoto General Hospital, Kumamoto 8668660, Japan
| | - Yoshihide Ishikawa
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Tomohito Kajii
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Yorihisa Orita
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Takahiro Ohyama
- USC-Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Zilkha Neurogenetic Institute, USC Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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21
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Aristidou C, Theodosiou A, Bak M, Mehrjouy MM, Constantinou E, Alexandrou A, Papaevripidou I, Christophidou-Anastasiadou V, Skordis N, Kitsiou-Tzeli S, Tommerup N, Sismani C. Position effect, cryptic complexity, and direct gene disruption as disease mechanisms in de novo apparently balanced translocation cases. PLoS One 2018; 13:e0205298. [PMID: 30289920 PMCID: PMC6173455 DOI: 10.1371/journal.pone.0205298] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/21/2018] [Indexed: 12/03/2022] Open
Abstract
The majority of apparently balanced translocation (ABT) carriers are phenotypically normal. However, several mechanisms were proposed to underlie phenotypes in affected ABT cases. In the current study, whole-genome mate-pair sequencing (WG-MPS) followed by Sanger sequencing was applied to further characterize de novo ABTs in three affected individuals. WG-MPS precisely mapped all ABT breakpoints and revealed three possible underlying molecular mechanisms. Firstly, in a t(X;1) carrier with hearing loss, a highly skewed X-inactivation pattern was observed and the der(X) breakpoint mapped ~87kb upstream an X-linked deafness gene namely POU3F4, thus suggesting an underlying long-range position effect mechanism. Secondly, cryptic complexity and a chromothripsis rearrangement was identified in a t(6;7;8;12) carrier with intellectual disability. Two translocations and a heterozygous deletion disrupted SOX5; a dominant nervous system development gene previously reported in similar patients. Finally, a direct gene disruption mechanism was proposed in a t(4;9) carrier with dysmorphic facial features and speech delay. In this case, the der(9) breakpoint directly disrupted NFIB, a gene involved in lung maturation and development of the pons with important functions in main speech processes. To conclude, in contrast to familial ABT cases with identical rearrangements and discordant phenotypes, where translocations are considered coincidental, translocations seem to be associated with phenotype presentation in affected de novo ABT cases. In addition, this study highlights the importance of investigating both coding and non-coding regions to decipher the underlying pathogenic mechanisms in these patients, and supports the potential introduction of low coverage WG-MPS in the clinical investigation of de novo ABTs.
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Affiliation(s)
- Constantia Aristidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Athina Theodosiou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Mads Bak
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Mana M. Mehrjouy
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Efthymia Constantinou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | | | - Nicos Skordis
- Division of Pediatric Endocrinology, Paedi Center for Specialized Pediatrics, Nicosia, Cyprus
- St George’s University of London Medical School at the University of Nicosia, Nicosia, Cyprus
| | - Sophia Kitsiou-Tzeli
- Department of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Niels Tommerup
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- * E-mail:
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22
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Yang LM, Ornitz DM. Sculpting the skull through neurosensory epithelial-mesenchymal signaling. Dev Dyn 2018; 248:88-97. [PMID: 30117627 DOI: 10.1002/dvdy.24664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 12/16/2022] Open
Abstract
The vertebrate skull is a complex structure housing the brain and specialized sensory organs, including the eye, the inner ear, and the olfactory system. The close association between bones of the skull and the sensory organs they encase has posed interesting developmental questions about how the tissues scale with one another. Mechanisms that regulate morphogenesis of the skull are hypothesized to originate in part from the encased neurosensory organs. Conversely, the developing skull is hypothesized to regulate the growth of neurosensory organs, through mechanical forces or molecular signaling. Here, we review studies of epithelial-mesenchymal interactions during inner ear and olfactory system development that may coordinate the growth of the two sensory organs with their surrounding bone. We highlight recent progress in the field and provide evidence that mechanical forces arising from bone growth may affect olfactory epithelium development. Developmental Dynamics 248:88-97, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Lu M Yang
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
| | - David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
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23
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Mao B, Moss CF, Wilkinson GS. Age-dependent gene expression in the inner ear of big brown bats (Eptesicus fuscus). PLoS One 2017; 12:e0186667. [PMID: 29073148 PMCID: PMC5658057 DOI: 10.1371/journal.pone.0186667] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 10/05/2017] [Indexed: 12/25/2022] Open
Abstract
For echolocating bats, hearing is essential for survival. Specializations for detecting and processing high frequency sounds are apparent throughout their auditory systems. Recent studies on echolocating mammals have reported evidence of parallel evolution in some hearing-related genes in which distantly related groups of echolocating animals (bats and toothed whales), cluster together in gene trees due to apparent amino acid convergence. However, molecular adaptations can occur not only in coding sequences, but also in the regulation of gene expression. The aim of this study was to examine the expression of hearing-related genes in the inner ear of developing big brown bats, Eptesicus fuscus, during the period in which echolocation vocalizations increase dramatically in frequency. We found that seven genes were significantly upregulated in juveniles relative to adults, and that the expression of four genes through development correlated with estimated age. Compared to available data for mice, it appears that expression of some hearing genes is extended in juvenile bats. These results are consistent with a prolonged growth period required to develop larger cochlea relative to body size, a later maturation of high frequency hearing, and a greater dependence on high frequency hearing in echolocating bats.
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Affiliation(s)
- Beatrice Mao
- Department of Biology, College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, Maryland, United States of America
| | - Cynthia F. Moss
- Department of Psychological and Brain Sciences, Zanvyl Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, Maryland, United States of America
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Gerald S. Wilkinson
- Department of Biology, College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, Maryland, United States of America
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24
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Guo J, Cheng X, Zhang L, Wang L, Mao Y, Tian G, Xu W, Wu Y, Ma Z, Qin J, Tian M, Jin G, Shi W, Zhang X. Exploration of the Brn4-regulated genes enhancing adult hippocampal neurogenesis by RNA sequencing. J Neurosci Res 2017; 95:2071-2079. [PMID: 28213929 DOI: 10.1002/jnr.24043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 11/09/2022]
Abstract
Adult hippocampal neurogenesis is essential for learning and memory, and its dysfunction is involved in neurodegenerative diseases. However, the molecular mechanisms underlying adult hippocampal neurogenesis are still largely unknown. Our previous studies indicated that the transcription factor Brn4 was upregulated and promoted neuronal differentiation of neural stem cells (NSCs) in the surgically denervated hippocampus in rats. In this study, we use high-throughput RNA sequencing to explore the molecular mechanisms underlying the enhancement of adult hippocampal neurogenesis induced by lentivirus-mediated Brn4 overexpression in vivo. After 10 days of the lentivirus injection, we found that the expression levels of genes related to neuronal development and maturation were significantly increased and the expression levels of genes related to NSC maintenance were significantly decreased, indicating enhanced neurogenesis in the hippocampus after Brn4 overexpression. Through RNA sequencing, we found that 658 genes were differentially expressed in the Brn4-overexpressed hippocampi compared with GFP-overexpressed controls. Many of these differentially expressed genes are involved in NSC division and differentiation. By using quantitative real-time PCR, we validated the expression changes of three genes, including Ctbp2, Notch2, and Gli1, all of which are reported to play key roles in neuronal differentiation of NSCs. Importantly, the expression levels of Ctbp2 and Notch2 were also significantly changed in the hippocampus of Brn4 KO mice, which indicates that the expression levels of Ctbp2 and Notch2 may be directly regulated by Brn4. Our current study provides a solid foundation for further investigation and identifies Ctbp2 and Notch2 as possible downstream targets of Brn4. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Jingjing Guo
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Xiang Cheng
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Lei Zhang
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Linmei Wang
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Yongxin Mao
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Guixiang Tian
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Wenhao Xu
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Yuhao Wu
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Zhi Ma
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Jianbing Qin
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Meiling Tian
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China
| | - Guohua Jin
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
| | - Wei Shi
- Neurosurgery Department, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China
| | - Xinhua Zhang
- Department of Anatomy, Nantong University, Nantong, Jiangsu, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China
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Kanno A, Mutai H, Namba K, Morita N, Nakano A, Ogahara N, Sugiuchi T, Ogawa K, Matsunaga T. Frequency and specific characteristics of the incomplete partition type III anomaly in children. Laryngoscope 2016; 127:1663-1669. [DOI: 10.1002/lary.26245] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 07/11/2016] [Accepted: 07/14/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Ayako Kanno
- Division of Hearing and Balance Research; National Institute of Sensory Organs; National Hospital Organization Tokyo Medical Center; Tokyo Japan
- Department of Otolaryngology; Inagi Municipal Hospital; Tokyo Japan
- Department of Otolaryngology; Keio University School of Medicine; Tokyo Japan
| | - Hideki Mutai
- Division of Hearing and Balance Research; National Institute of Sensory Organs; National Hospital Organization Tokyo Medical Center; Tokyo Japan
| | - Kazunori Namba
- Division of Hearing and Balance Research; National Institute of Sensory Organs; National Hospital Organization Tokyo Medical Center; Tokyo Japan
| | - Noriko Morita
- Department of Otolaryngology; Kobari General Hospital; Chiba Japan
| | - Atsuko Nakano
- Division of Otolaryngology; Chiba Children's Hospital; Chiba Japan
| | - Noboru Ogahara
- Department of Otorhinolaryngology; Kanagawa Children's Medical Center; Kanagawa Japan
| | - Tomoko Sugiuchi
- Department of Otolaryngology; Kanto Rosai Hospital; Kanagawa Japan
| | - Kaoru Ogawa
- Department of Otolaryngology; Keio University School of Medicine; Tokyo Japan
| | - Tatsuo Matsunaga
- Division of Hearing and Balance Research; National Institute of Sensory Organs; National Hospital Organization Tokyo Medical Center; Tokyo Japan
- Medical Genetics Center; National Hospital Organization Tokyo Medical Center; Tokyo Japan
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Gao J, Chen Y, Yang Y, Liang J, Xie J, Liu J, Li S, Zheng G, Xie L, Zhang R. The transcription factor Pf-POU3F4 regulates expression of the matrix protein genes Aspein and Prismalin-14 in pearl oyster (Pinctada fucata). FEBS J 2016; 283:1962-78. [PMID: 26996995 DOI: 10.1111/febs.13716] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 03/02/2016] [Accepted: 03/15/2016] [Indexed: 12/17/2022]
Abstract
UNLABELLED Matrix proteins play key roles in shell formation in the pearl oyster, but little is known about how these proteins are regulated. Here, two POU domain family members, Pf-POU2F1 and Pf-POU3F4, were cloned and characterized. Functional domain analysis revealed that both them have conserved POUS and POUH domains; these domains are important for transcription factor function. The tissue distributions of Pf-POU2F1 and Pf-POU3F4 mRNAs in pearl oyster revealed different expression patterns, and the expression of Pf-POU3F4 mRNA was relatively high in the mantle. The promoters of the matrix protein genes Aspein and Prismalin-14 were cloned using genome-walking PCR. Relatively high transcriptional activities of these promoters were detected in HEK-293T cells. In transient co-transfection assays, Pf-POU3F4 greatly up-regulated the promoter activities of the Aspein and Prismalin-14 genes in a dose-dependent manner. Structural integrity of Pf-POU3F4 was essential for its activation function. One region of the Aspein gene promoter, -181 to -77 bp, and two binding sites in the Prismalin-14 gene promoter, -359 to -337 bp and -100 to -73 bp, were required for activation of Pf-POU3F4. An electrophoresis mobility shift assay demonstrated that Pf-POU3F4 directly bound these sites. Pf-POU3F4 knockdown led to a decrease in Aspein and Prismalin-14 gene expression. Furthermore, expression levels for the Pf-POU3F4 gene were similar to those of the Aspein and Prismalin-14 genes during five development stages. Taken together, these results suggest that the transcription factor Pf-POU3F4 regulates expression of the matrix protein genes Aspein and Prismalin-14 in pearl oyster. DATABASE The nucleotide sequence data of Pf-POU2F1 is available in the GenBank databases under the accession number KM588196. The nucleotide sequence data of Pf-POU3F4 is available in the GenBank databases under the accession number KM519606. The nucleotide sequence data of Aspein gene promoter is available in the GenBank databases under the accession number KM519607. The nucleotide sequence data of Prismalin-14 gene promoter is available in the GenBank databases under the accession number KM519601.
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Affiliation(s)
- Jing Gao
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Yan Chen
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Yi Yang
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Jian Liang
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Jun Xie
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Jun Liu
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Shiguo Li
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Guilang Zheng
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Liping Xie
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
| | - Rongqing Zhang
- Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Science, Tsinghua University, Beijing, China
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Raslan A, Hainz N, Beckmann A, Tschernig T, Meier C. Pannexin-1 expression in developing mouse nervous system: new evidence for expression in sensory ganglia. Cell Tissue Res 2015; 364:29-41. [PMID: 26453396 DOI: 10.1007/s00441-015-2294-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/07/2015] [Indexed: 12/14/2022]
Abstract
Pannexin1 (Panx1) is one of three members of the pannexin protein family. The expression of Panx1 mRNA has been extensively investigated from late embryonic to adult stages. In contrast, expression during early embryonic development is largely unknown. Our aim is to examine the temporal and spatial expression of Panx1 in mouse embryonic development by focusing on embryonic days (E) 9.5 to 12.5. Whole embryos are investigated in order to provide a comprehensive survey. Analyses were performed at the mRNA level by using reverse transcription plus the polymerase chain reaction and whole-mount in situ hybridization. Panx1 mRNA was detected in the heads and bodies of embryos at all developmental stages investigated (E9.5, E10.5, E11.5, E12.5). In particular, the nervous system expressed Panx1 at an early time point. Interestingly, Panx1 expression was found in afferent ganglia of the cranial nerves and spinal cord. This finding is of particular interest in the context of neuropathic pain and other Panx1-related neurological disorders. Our study shows, for the first time, that Panx1 is expressed in the central and peripheral nervous system during early developmental stages. The consequences of Panx1 deficiency or inhibition in a number of experimental paradigms might therefore be predicated on changes during early development.
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Affiliation(s)
- Abdulrahman Raslan
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Nadine Hainz
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Anja Beckmann
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Thomas Tschernig
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany
| | - Carola Meier
- Department of Anatomy and Cell Biology, Saarland University, Building 61, 66424, Homburg, Saar, Germany.
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28
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Potts MB, Siu JJ, Price JD, Salinas RD, Cho MJ, Ramos AD, Hahn J, Margeta M, Oldham MC, Lim DA. Analysis of Mll1 deficiency identifies neurogenic transcriptional modules and Brn4 as a factor for direct astrocyte-to-neuron reprogramming. Neurosurgery 2015; 75:472-82; discussion 482. [PMID: 24887289 DOI: 10.1227/neu.0000000000000452] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Mixed lineage leukemia-1 (Mll1) epigenetically regulates gene expression patterns that specify cellular identity in both embryonic development and adult stem cell populations. In the adult mouse brain, multipotent neural stem cells (NSCs) in the subventricular zone generate new neurons throughout life, and Mll1 is required for this postnatal neurogenesis but not for glial cell differentiation. Analysis of Mll1-dependent transcription may identify neurogenic genes useful for the direct reprogramming of astrocytes into neurons. OBJECTIVE To identify Mll1-dependent transcriptional modules and to determine whether genes in the neurogenic modules can be used to directly reprogram astrocytes into neurons. METHODS We performed gene coexpression module analysis on microarray data from differentiating wild-type and Mll1-deleted subventricular zone NSCs. Key developmental regulators belonging to the neurogenic modules were overexpressed in Mll1-deleted cells and cultured cortical astrocytes, and cell phenotypes were analyzed by immunocytochemistry and electrophysiology. RESULTS Transcriptional modules that correspond to neurogenesis were identified in wild-type NSCs. Modules related to astrocytes and oligodendrocytes were enriched in Mll1-deleted NSCs, consistent with their gliogenic potential. Overexpression of genes selected from the neurogenic modules enhanced the production of neurons from Mll1-deleted cells, and overexpression of Brn4 (Pou3f4) in nonneurogenic cortical astroglia induced their transdifferentiation into electrophysiologically active neurons. CONCLUSION Our results demonstrate that Mll1 is required for the expression of neurogenic but not gliogenic transcriptional modules in a multipotent NSC population and further indicate that specific Mll1-dependent genes may be useful for direct reprogramming strategies.
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Affiliation(s)
- Matthew B Potts
- *Department of Neurological Surgery, ‡The Eli and Edythe Broad Institute of Regeneration Medicine and Stem Cell Research, §Department of Pathology, and ¶Department of Neurology University of California, San Francisco, San Francisco, California; and ‖Surgical Service, San Francisco Veterans Affairs Medical Center, San Francisco, California
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Huh SH, Warchol ME, Ornitz DM. Cochlear progenitor number is controlled through mesenchymal FGF receptor signaling. eLife 2015; 4. [PMID: 25915623 PMCID: PMC4434254 DOI: 10.7554/elife.05921] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/25/2015] [Indexed: 12/16/2022] Open
Abstract
The sensory and supporting cells (SCs) of the organ of Corti are derived from a limited number of progenitors. The mechanisms that regulate the number of sensory progenitors are not known. Here, we show that Fibroblast Growth Factors (FGF) 9 and 20, which are expressed in the non-sensory (Fgf9) and sensory (Fgf20) epithelium during otic development, regulate the number of cochlear progenitors. We further demonstrate that Fgf receptor (Fgfr) 1 signaling within the developing sensory epithelium is required for the differentiation of outer hair cells and SCs, while mesenchymal FGFRs regulate the size of the sensory progenitor population and the overall cochlear length. In addition, ectopic FGFR activation in mesenchyme was sufficient to increase sensory progenitor proliferation and cochlear length. These data define a feedback mechanism, originating from epithelial FGF ligands and mediated through periotic mesenchyme that controls the number of sensory progenitors and the length of the cochlea. DOI:http://dx.doi.org/10.7554/eLife.05921.001 Mammalian ears contain several structures that are involved in hearing. Within the inner ear is a spiral-shaped structure called the cochlea. This contains an array of cells called sensory hair cells that convert sound vibrations into electrical signals, which are then conveyed to the brain. Sounds of differing pitch are detected at different points along the cochlea, so its overall length helps to determine the range of sounds that an individual can hear. In the embryo, sensory hair cells and their associated supporting cells develop from ‘cochlear progenitor’ cells. The final length of the cochlea is determined by the numbers of progenitor cells that commit to becoming either sensory hair cells or supporting cells. Two proteins called FGF9 and FGF20 are involved in the formation of the cochlea. FGF20 promotes the formation of the hair cells and supporting cells, but the precise roles of both proteins are not clear. Here, Huh et al. studied FGF9 and FGF20 in the inner ear of mice at an early stage of development. The experiments show that these proteins work together to control the number of progenitor cells and the length of the cochlea. FGF20 is produced by the same tissue structure (called an ‘epithelium’) that gives rise to the hair cells and supporting cells. In contrast, FGF9 is produced in another epithelium tissue that produces the cells that line the fluid-filled tubes of the inner ear. The experiments also show that both FGF9 and FGF20 act as signals to cells in an adjacent tissue called the mesenchyme, where they activate other proteins known as FGF receptors. These receptors, in turn, regulate an unknown molecule in the mesenchyme that influences the growth of progenitor cells and the length of the cochlea. Sensory hair cells can be injured or lost by excessive sound exposure, some medications and as part of normal aging. These cells are not replaced, and so their loss is a major cause of permanent hearing loss. Understanding the signals that produce the progenitor cells will take us one step closer to being able to grow these cells in the laboratory for use in therapies to replace or repair damaged sensory hair cells. DOI:http://dx.doi.org/10.7554/eLife.05921.002
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Affiliation(s)
- Sung-Ho Huh
- Department of Developmental Biology, Washington University School of Medicine, St Louis, United States
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St Louis, United States
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30
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Bademci G, Lasisi A, Yariz KO, Montenegro P, Menendez I, Vinueza R, Paredes R, Moreta G, Subasioglu A, Blanton S, Fitoz S, Incesulu A, Sennaroglu L, Tekin M. Novel domain-specific POU3F4 mutations are associated with X-linked deafness: examples from different populations. BMC MEDICAL GENETICS 2015; 16:9. [PMID: 25928534 PMCID: PMC4422282 DOI: 10.1186/s12881-015-0149-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/29/2015] [Indexed: 01/17/2023]
Abstract
Background Mutations in the POU3F4 gene cause X-linked deafness type 3 (DFN3), which is characterized by inner ear anomalies. Methods Three Turkish, one Ecuadorian, and one Nigerian families were included based on either inner ear anomalies detected in probands or X-linked family histories. Exome sequencing and/or Sanger sequencing were performed in order to identify the causative DNA variants in these families. Results Four novel, c.707A>C (p.(Glu236Ala)), c.772delG (p.(Glu258ArgfsX30)), c.902C>T (p.(Pro301Leu)), c.987T>C (p.(Ile308Thr)), and one previously reported mutation c.346delG (p.(Ala116ProfsX26)) in POU3F4, were identified. All mutations identified are predicted to affect the POU-specific or POU homeo domains of the protein and co-segregated with deafness in all families. Conclusions Expanding the spectrum of POU3F4 mutations in different populations along with their associated phenotypes provides better understanding of their clinical importance and will be helpful in clinical evaluation and counseling of the affected individuals. Electronic supplementary material The online version of this article (doi:10.1186/s12881-015-0149-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guney Bademci
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA.
| | - Akeem Lasisi
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA. .,Department of Otorhinolaryngology, College of Medicine, University of Ibadan, Ibadan, Nigeria.
| | - Kemal O Yariz
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA.
| | - Paola Montenegro
- Departamento de Genetica, Hospital de Especialidades FFAA, Quito, Ecuador.
| | - Ibis Menendez
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA.
| | - Rodrigo Vinueza
- Departamento de Genetica, Hospital de Especialidades FFAA, Quito, Ecuador.
| | - Rosario Paredes
- Departamento de Genetica, Hospital de Especialidades FFAA, Quito, Ecuador.
| | - Germania Moreta
- Departamento de Genetica, Hospital de Especialidades FFAA, Quito, Ecuador.
| | - Asli Subasioglu
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA. .,Department of Medical Genetics, Izmir Katip Celebi University, Ataturk Training and Research Hospital, Izmir, Turkey.
| | - Susan Blanton
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA.
| | - Suat Fitoz
- Department of Radiodiagnostics, Ankara University School of Medicine, Ankara, Turkey.
| | - Armagan Incesulu
- Department of Otorhinolaryngology, Eskisehir Osmangazi University School of Medicine, Eskisehir, Turkey.
| | - Levent Sennaroglu
- Department of Otorhinolaryngology, Hacettepe University School of Medicine, Ankara, Turkey.
| | - Mustafa Tekin
- John P. Hussmann Institute for Human Genomics and John T. Macdonald Foundation, Department of Human Genetics, Miller school of Medicine, University of Miami, 1501 NW 10th Avenue, BRB-610 (M-860), Miami, FL, 33136, USA.
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31
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Taura A, Ohnishi H, Ochi S, Ebisu F, Nakagawa T, Ito J. Effects of mouse utricle stromal tissues on hair cell induction from induced pluripotent stem cells. BMC Neurosci 2014; 15:121. [PMID: 25373336 PMCID: PMC4226914 DOI: 10.1186/s12868-014-0121-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 10/22/2014] [Indexed: 12/30/2022] Open
Abstract
Background Hair cells are important for maintaining our sense of hearing and balance. However, they are difficult to regenerate in mammals once they are lost. Clarification of the molecular mechanisms underlying inner ear disorders is also impeded by the anatomical limitation of experimental access to the human inner ear. Therefore, the generation of hair cells, possibly from induced pluripotent stem (iPS) cells, is important for regenerative therapy and studies of inner ear diseases. Results We generated hair cells from mouse iPS cells using an established stepwise induction protocol. First, iPS cells were differentiated into the ectodermal lineage by floating culture. Next, they were treated with basic fibroblast growth factor to induce otic progenitor cells. Finally, the cells were co-cultured with three kinds of mouse utricle tissues: stromal tissue, stromal tissue + sensory epithelium, and the extracellular matrix of stromal tissue. Hair cell-like cells were successfully generated from iPS cells using mouse utricle stromal tissues. However, no hair cell-like cells with hair bundle-like structures were formed using other tissues. Conclusions Hair cell-like cells were induced from mouse iPS cells using mouse utricle stromal tissues. Certain soluble factors from mouse utricle stromal cells might be important for induction of hair cells from iPS cells.
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Raft S, Coate TM, Kelley MW, Crenshaw EB, Wu DK. Pou3f4-mediated regulation of ephrin-b2 controls temporal bone development in the mouse. PLoS One 2014; 9:e109043. [PMID: 25299585 PMCID: PMC4192298 DOI: 10.1371/journal.pone.0109043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/01/2014] [Indexed: 12/25/2022] Open
Abstract
The temporal bone encases conductive and sensorineural elements of the ear. Mutations of POU3F4 are associated with unique temporal bone abnormalities and X-linked mixed deafness (DFNX2/DFN3). However, the target genes and developmental processes controlled by POU3F4 transcription factor activity have remained largely uncharacterized. Ephrin-B2 (Efnb2) is a signaling molecule with well-documented effects on cell adhesion, proliferation, and migration. Our analyses of targeted mouse mutants revealed that Efnb2 loss-of-function phenocopies temporal bone abnormalities of Pou3f4 hemizygous null neonates: qualitatively identical malformations of the stapes, styloid process, internal auditory canal, and cochlear capsule were present in both mutants. Using failed/insufficient separation of the stapes and styloid process as a quantitative trait, we found that single gene Efnb2 loss-of-function and compound Pou3f4/Efnb2 loss-of-function caused a more severe phenotype than single gene Pou3f4 loss-of-function. Pou3f4 and Efnb2 gene expression domains overlapped at the site of impending stapes-styloid process separation and at subcapsular mesenchyme surrounding the cochlea; at both these sites, Efnb2 expression was attenuated in Pou3f4 hemizygous null mutants relative to control. Results of immunoprecipitation experiments using chromatin isolated from nascent middle ear mesenchyme supported the hypothesis of a physical association between Pou3f4 and specific non-coding sequence of Efnb2. We propose that Efnb2 is a target of Pou3f4 transcription factor activity and an effector of mesenchymal patterning during temporal bone development.
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Affiliation(s)
- Steven Raft
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thomas M. Coate
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Matthew W. Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - E. Bryan Crenshaw
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Doris K. Wu
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
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Chervenak AP, Bank LM, Thomsen N, Glanville-Jones HC, Jonathan S, Millen KJ, Arkell RM, Barald KF. The role of Zic genes in inner ear development in the mouse: Exploring mutant mouse phenotypes. Dev Dyn 2014; 243:1487-98. [PMID: 25178196 DOI: 10.1002/dvdy.24186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 07/23/2014] [Accepted: 08/25/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Murine Zic genes (Zic1-5) are expressed in the dorsal hindbrain and in periotic mesenchyme (POM) adjacent to the developing inner ear. Zic genes are involved in developmental signaling pathways in many organ systems, including the ear, although their exact roles haven't been fully elucidated. This report examines the role of Zic1, Zic2, and Zic4 during inner ear development in mouse mutants in which these Zic genes are affected. RESULTS Zic1/Zic4 double mutants don't exhibit any apparent defects in inner ear morphology. By contrast, inner ears from Zic2(kd/kd) and Zic2(Ku/Ku) mutants have severe but variable morphological defects in endolymphatic duct/sac and semicircular canal formation and in cochlear extension in the inner ear. Analysis of otocyst patterning in the Zic2(Ku/Ku) mutants by in situ hybridization showed changes in the expression patterns of Gbx2 and Pax2. CONCLUSIONS The experiments provide the first genetic evidence that the Zic genes are required for morphogenesis of the inner ear. Zic2 loss-of-function doesn't prevent initial otocyst patterning but leads to molecular abnormalities concomitant with morphogenesis of the endolymphatic duct. Functional hearing deficits often accompany inner ear dysmorphologies, making Zic2 a novel candidate gene for ongoing efforts to identify the genetic basis of human hearing loss.
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Affiliation(s)
- Andrew P Chervenak
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan; Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, Michigan
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Cai DC, Fonteijn H, Guadalupe T, Zwiers M, Wittfeld K, Teumer A, Hoogman M, Arias-Vásquez A, Yang Y, Buitelaar J, Fernández G, Brunner HG, van Bokhoven H, Franke B, Hegenscheid K, Homuth G, Fisher SE, Grabe HJ, Francks C, Hagoort P. A genome-wide search for quantitative trait loci affecting the cortical surface area and thickness of Heschl's gyrus. GENES BRAIN AND BEHAVIOR 2014; 13:675-85. [DOI: 10.1111/gbb.12157] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 07/10/2014] [Accepted: 07/24/2014] [Indexed: 12/21/2022]
Affiliation(s)
- D.-C. Cai
- Institute of Psychology; Chinese Academy of Sciences; Beijing China
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Graduate University of Chinese Academy of Sciences; Beijing China
| | - H. Fonteijn
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
| | | | - M. Zwiers
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - K. Wittfeld
- German Center for Neurodegenerative Diseases (DZNE), Rostock/Greifswald; Greifswald Germany
| | | | - M. Hoogman
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - A. Arias-Vásquez
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - Y. Yang
- Institute of Psychology; Chinese Academy of Sciences; Beijing China
| | - J. Buitelaar
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - G. Fernández
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - H. G. Brunner
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - H. van Bokhoven
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | - B. Franke
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
- Departments of Human Genetics, Psychiatry and Cognitive Neuroscience; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
| | | | - G. Homuth
- Interfaculty Institute for Genetics and Functional Genomics; University Medicine Greifswald; Greifswald
| | - S. E. Fisher
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
| | - H. J. Grabe
- German Center for Neurodegenerative Diseases (DZNE), Rostock/Greifswald; Greifswald Germany
- Department of Psychiatry and Psychotherapy; University Medicine Greifswald, HELIOS Hospital Stralsund; Stralsund Germany
| | - C. Francks
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
| | - P. Hagoort
- Max Planck Institute for Psycholinguistics
- Donders Institute for Brain, Cognition and Behaviour; Radboud University Nijmegen; Nijmegen The Netherlands
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Bohnenpoll T, Trowe MO, Wojahn I, Taketo MM, Petry M, Kispert A. Canonical Wnt signaling regulates the proliferative expansion and differentiation of fibrocytes in the murine inner ear. Dev Biol 2014; 391:54-65. [PMID: 24727668 DOI: 10.1016/j.ydbio.2014.03.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/27/2014] [Accepted: 03/29/2014] [Indexed: 01/18/2023]
Abstract
Otic fibrocytes tether the cochlear duct to the surrounding otic capsule but are also critically involved in maintenance of ion homeostasis in the cochlea, thus, perception of sound. The molecular pathways that regulate the development of this heterogenous group of cells from mesenchymal precursors are poorly understood. Here, we identified epithelial Wnt7a and Wnt7b as possible ligands of Fzd-mediated β-catenin (Ctnnb1)-dependent (canonical) Wnt signaling in the adjacent undifferentiated periotic mesenchyme (POM). Mice with a conditional deletion of Ctnnb1 in the POM exhibited a complete failure of fibrocyte differentiation, a severe reduction of mesenchymal cells surrounding the cochlear duct, loss of pericochlear spaces, a thickening and partial loss of the bony capsule and a secondary disturbance of cochlear duct coiling shortly before birth. Analysis at earlier stages revealed that radial patterning of the POM in two domains with highly condensed cartilaginous precursors and more loosely arranged inner mesenchymal cells occurred normally but that proliferation in the inner domain was reduced and cytodifferentiation failed. Cells with mis/overexpression of a stabilized form of Ctnnb1 in the entire POM mesenchyme sorted to the inner mesenchymal compartment and exhibited increased proliferation. Our analysis suggests that Wnt signals from the cochlear duct epithelium are crucial to induce differentiation and expansion of fibrocyte precursor cells. Our findings emphasize the importance of epithelial-mesenchymal signaling in inner ear development.
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Affiliation(s)
- Tobias Bohnenpoll
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Irina Wojahn
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | | | - Marianne Petry
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Andreas Kispert
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
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Yang S, Li X, Li K, Fan B, Tang Z. A genome-wide scan for signatures of selection in Chinese indigenous and commercial pig breeds. BMC Genet 2014; 15:7. [PMID: 24422716 PMCID: PMC3898232 DOI: 10.1186/1471-2156-15-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 01/09/2014] [Indexed: 11/18/2022] Open
Abstract
Background Modern breeding and artificial selection play critical roles in pig domestication and shape the genetic variation of different breeds. China has many indigenous pig breeds with various characteristics in morphology and production performance that differ from those of foreign commercial pig breeds. However, the signatures of selection on genes implying for economic traits between Chinese indigenous and commercial pigs have been poorly understood. Results We identified footprints of positive selection at the whole genome level, comprising 44,652 SNPs genotyped in six Chinese indigenous pig breeds, one developed breed and two commercial breeds. An empirical genome-wide distribution of Fst (F-statistics) was constructed based on estimations of Fst for each SNP across these nine breeds. We detected selection at the genome level using the High-Fst outlier method and found that 81 candidate genes show high evidence of positive selection. Furthermore, the results of network analyses showed that the genes that displayed evidence of positive selection were mainly involved in the development of tissues and organs, and the immune response. In addition, we calculated the pairwise Fst between Chinese indigenous and commercial breeds (CHN VS EURO) and between Northern and Southern Chinese indigenous breeds (Northern VS Southern). The IGF1R and ESR1 genes showed evidence of positive selection in the CHN VS EURO and Northern VS Southern groups, respectively. Conclusions In this study, we first identified the genomic regions that showed evidences of selection between Chinese indigenous and commercial pig breeds using the High-Fst outlier method. These regions were found to be involved in the development of tissues and organs, the immune response, growth and litter size. The results of this study provide new insights into understanding the genetic variation and domestication in pigs.
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Affiliation(s)
| | | | | | - Bin Fan
- Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P,R, China.
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Parzefall T, Shivatzki S, Lenz DR, Rathkolb B, Ushakov K, Karfunkel D, Shapira Y, Wolf M, Mohr M, Wolf E, Sabrautzki S, de Angelis MH, Frydman M, Brownstein Z, Avraham KB. Cytoplasmic mislocalization of POU3F4 due to novel mutations leads to deafness in humans and mice. Hum Mutat 2013; 34:1102-10. [PMID: 23606368 DOI: 10.1002/humu.22339] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 04/08/2013] [Indexed: 11/12/2022]
Abstract
POU3F4 is a POU domain transcription factor that is required for hearing. In the ear, POU3F4 is essential for mesenchymal remodeling of the bony labyrinth and is the causative gene for DFNX2 human nonsyndromic deafness. Ear abnormalities underlie this form of deafness, characterized previously in multiple spontaneous, radiation-induced and transgenic mouse mutants. Here, we report three novel mutations in the POU3F4 gene that result in profound hearing loss in both humans and mice. A p.Gln79* mutation was identified in a child from an Israeli family, revealed by massively parallel sequencing (MPS). This strategy demonstrates the strength of MPS for diagnosis with only one affected individual. A second mutation, p.Ile285Argfs*43, was identified by Sanger sequencing. A p.Cys300* mutation was found in an ENU-induced mutant mouse, schwindel (sdl), by positional cloning. The mutation leads to a predicted truncated protein, similar to the human mutations, providing a relevant mouse model. The p.Ile285Argfs*43 and p.Cys300* mutations lead to a shift of Pou3f4 nuclear localization to the cytoplasm, demonstrated in cellular localization studies and in the inner ears of the mutant mice. The discovery of these mutations facilitates a deeper comprehension of the molecular basis of inner ear defects due to mutations in the POU3F4 transcription factor.
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Affiliation(s)
- Thomas Parzefall
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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38
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Jan TA, Chai R, Sayyid ZN, van Amerongen R, Xia A, Wang T, Sinkkonen ST, Zeng YA, Levin JR, Heller S, Nusse R, Cheng AGL. Tympanic border cells are Wnt-responsive and can act as progenitors for postnatal mouse cochlear cells. Development 2013; 140:1196-206. [PMID: 23444352 DOI: 10.1242/dev.087528] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Permanent hearing loss is caused by the irreversible damage of cochlear sensory hair cells and nonsensory supporting cells. In the postnatal cochlea, the sensory epithelium is terminally differentiated, whereas tympanic border cells (TBCs) beneath the sensory epithelium are proliferative. The functions of TBCs are poorly characterized. Using an Axin2(lacZ) Wnt reporter mouse, we found transient but robust Wnt signaling and proliferation in TBCs during the first 3 postnatal weeks, when the number of TBCs decreases. In vivo lineage tracing shows that a subset of hair cells and supporting cells is derived postnatally from Axin2-expressing TBCs. In cochlear explants, Wnt agonists stimulated the proliferation of TBCs, whereas Wnt inhibitors suppressed it. In addition, purified Axin2(lacZ) cells were clonogenic and self-renewing in culture in a Wnt-dependent manner, and were able to differentiate into hair cell-like and supporting cell-like cells. Taken together, our data indicate that Axin2-positive TBCs are Wnt responsive and can act as precursors to sensory epithelial cells in the postnatal cochlea.
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Affiliation(s)
- Taha Adnan Jan
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
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Coate TM, Kelley MW. Making connections in the inner ear: recent insights into the development of spiral ganglion neurons and their connectivity with sensory hair cells. Semin Cell Dev Biol 2013; 24:460-9. [PMID: 23660234 PMCID: PMC3690159 DOI: 10.1016/j.semcdb.2013.04.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 04/15/2013] [Indexed: 01/18/2023]
Abstract
In mammals, auditory information is processed by the hair cells (HCs) located in the cochlea and then rapidly transmitted to the CNS via a specialized cluster of bipolar afferent connections known as the spiral ganglion neurons (SGNs). Although many anatomical aspects of SGNs are well described, the molecular and cellular mechanisms underlying their genesis, how they are precisely arranged along the cochlear duct, and the guidance mechanisms that promote the innervation of their hair cell targets are only now being understood. Building upon foundational studies of neurogenesis and neurotrophins, we review here new concepts and technologies that are helping to enrich our understanding of the development of the nervous system within the inner ear.
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Affiliation(s)
- Thomas M Coate
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
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40
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Ishii J, Sato H, Sakaeda M, Shishido-Hara Y, Hiramatsu C, Kamma H, Shimoyamada H, Fujiwara M, Endo T, Aoki I, Yazawa T. POU domain transcription factor BRN2 is crucial for expression of ASCL1, ND1 and neuroendocrine marker molecules and cell growth in small cell lung cancer. Pathol Int 2013; 63:158-68. [DOI: 10.1111/pin.12042] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 02/09/2013] [Indexed: 11/30/2022]
Affiliation(s)
| | - Hanako Sato
- Department of Anatomy; St. Marianna University School of Medicine; Kawasaki
| | | | | | - Chie Hiramatsu
- Department of Anatomy; St. Marianna University School of Medicine; Kawasaki
| | - Hiroshi Kamma
- Department of Pathology; Kyorin University School of Medicine; Mitaka
| | | | | | | | - Ichiro Aoki
- Department of Pathology; Yokohama City University Graduate School of Medicine; Yokohama
| | - Takuya Yazawa
- Department of Pathology; Kyorin University School of Medicine; Mitaka
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Hroudova M, Vojta P, Strnad H, Krejcik Z, Ridl J, Paces J, Vlcek C, Paces V. Diversity, phylogeny and expression patterns of Pou and Six homeodomain transcription factors in hydrozoan jellyfish Craspedacusta sowerbyi. PLoS One 2012; 7:e36420. [PMID: 22558464 PMCID: PMC3340352 DOI: 10.1371/journal.pone.0036420] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/31/2012] [Indexed: 01/10/2023] Open
Abstract
Formation of all metazoan bodies is controlled by a group of selector genes including homeobox genes, highly conserved across the entire animal kingdom. The homeobox genes from Pou and Six classes are key members of the regulation cascades determining development of sensory organs, nervous system, gonads and muscles. Besides using common bilaterian models, more attention has recently been targeted at the identification and characterization of these genes within the basal metazoan phyla. Cnidaria as a diploblastic sister group to bilateria with simple and yet specialized organs are suitable models for studies on the sensory organ origin and the associated role of homeobox genes. In this work, Pou and Six homeobox genes, together with a broad range of other sensory-specific transcription factors, were identified in the transcriptome of hydrozoan jellyfish Craspedacusta sowerbyi. Phylogenetic analyses of Pou and Six proteins revealed cnidarian-specific sequence motifs and contributed to the classification of individual factors. The majority of the Craspedacusta sowerbyi Pou and Six homeobox genes are predominantly expressed in statocysts, manubrium and nerve ring, the tissues with sensory and nervous activities. The described diversity and expression patterns of Pou and Six factors in hydrozoan jellyfish highlight their evolutionarily conserved functions. This study extends the knowledge of the cnidarian genome complexity and shows that the transcriptome of hydrozoan jellyfish is generally rich in homeodomain transcription factors employed in the regulation of sensory and nervous functions.
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Affiliation(s)
- Miluse Hroudova
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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42
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Coate TM, Raft S, Zhao X, Ryan AK, Crenshaw EB, Kelley MW. Otic mesenchyme cells regulate spiral ganglion axon fasciculation through a Pou3f4/EphA4 signaling pathway. Neuron 2012; 73:49-63. [PMID: 22243746 DOI: 10.1016/j.neuron.2011.10.029] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2011] [Indexed: 10/14/2022]
Abstract
Peripheral axons from auditory spiral ganglion neurons (SGNs) form an elaborate series of radially and spirally oriented projections that interpret complex aspects of the auditory environment. However, the developmental processes that shape these axon tracts are largely unknown. Radial bundles are comprised of dense SGN fascicles that project through otic mesenchyme to form synapses within the cochlea. Here, we show that radial bundle fasciculation and synapse formation are disrupted when Pou3f4 (DFNX2) is deleted from otic mesenchyme. Further, we demonstrate that Pou3f4 binds to and directly regulates expression of Epha4, Epha4⁻/⁻ mice present similar SGN defects, and exogenous EphA4 promotes SGN fasciculation in the absence of Pou3f4. Finally, Efnb2 deletion in SGNs leads to similar fasciculation defects, suggesting that ephrin-B2/EphA4 interactions are critical during this process. These results indicate a model whereby Pou3f4 in the otic mesenchyme establishes an Eph/ephrin-mediated fasciculation signal that promotes inner radial bundle formation.
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Affiliation(s)
- Thomas M Coate
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
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Monks DC, Morrow BE. Identification of putative retinoic acid target genes downstream of mesenchymal Tbx1 during inner ear development. Dev Dyn 2012; 241:563-73. [PMID: 22275070 DOI: 10.1002/dvdy.23731] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2011] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The T-box transcription factor Tbx1 is expressed in the otic vesicle and surrounding mesoderm of the periotic mesenchyme (POM) during inner ear development. Mesenchymal Tbx1 is essential for inner ear development, with conditional mutants displaying defects in both the auditory and vestibular systems. We have previously reported that mesodermal Tbx1 loss of function mutants (Mest-KO) have reduced expression of retinoic acid (RA) metabolic genes, Cyp26a1 and Cyp26c1, in the POM, consistent with other studies showing an increase in mesodermal RA reporter expression in Tbx1-/- embryos. However, putative RA effector genes whose expression is altered downstream of increased otic mesenchymal-epithelial RA signaling have remained elusive. RESULTS Here we report the identification of 18 retinoic acid responsive genes altered in Mest-KO conditional mutants by microarray gene profiling. Nine were chosen for biological validation including quantitative RT-PCR and in situ hybridization (Otor, Mia, Col2a1, Clu, Adm, Myt1, Dlx3, Itgb3, and Itga2b). CONCLUSION Here study provides a series of newly identified RA effector genes for inner ear development downstream of mesenchymal Tbx1 that may contribute to the inner ear phenotype observed in Tbx1 loss of function mouse models.
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Affiliation(s)
- Dennis C Monks
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Makishima T, Hochman L, Armstrong P, Rosenberger E, Ridley R, Woo M, Perachio A, Wood S. Inner ear dysfunction in caspase-3 deficient mice. BMC Neurosci 2011; 12:102. [PMID: 21988729 PMCID: PMC3208590 DOI: 10.1186/1471-2202-12-102] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 10/12/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Caspase-3 is one of the most downstream enzymes activated in the apoptotic pathway. In caspase-3 deficient mice, loss of cochlear hair cells and spiral ganglion cells coincide closely with hearing loss. In contrast with the auditory system, details of the vestibular phenotype have not been characterized. Here we report the vestibular phenotype and inner ear anatomy in the caspase-3 deficient (Casp3(-/-)) mouse strain. RESULTS Average ABR thresholds of Casp3(-/-) mice were significantly elevated (P < 0.05) compared to Casp3(+/-) mice and Casp3(+/+) mice at 3 months of age. In DPOAE testing, distortion product 2F1-F2 was significantly decreased (P < 0.05) in Casp3(-/-) mice, whereas Casp3(+/-) and Casp3(+/+) mice showed normal and comparable values to each other. Casp3(-/-) mice were hyperactive and exhibited circling behavior when excited. In lateral canal VOR testing, Casp3(-/-) mice had minimal response to any of the stimuli tested, whereas Casp3(+/-) mice had an intermediate response compared to Casp3(+/+) mice. Inner ear anatomical and histological analysis revealed gross hypomorphism of the vestibular organs, in which the main site was the anterior semicircular canal. Hair cell numbers in the anterior- and lateral crista, and utricle were significantly smaller in Casp3(-/-) mice whereas the Casp3(+/-) and Casp3(+/+) mice had normal hair cell numbers. CONCLUSIONS These results indicate that caspase-3 is essential for correct functioning of the cochlea as well as normal development and function of the vestibule.
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Affiliation(s)
- Tomoko Makishima
- Department of Otolaryngology, University of Texas Medical Branch, Galveston, Texas, USA.
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Huang S, Han D, Yuan Y, Wang G, Kang D, Zhang X, Yan X, Meng X, Dong M, Dai P. Extremely discrepant mutation spectrum of SLC26A4 between Chinese patients with isolated Mondini deformity and enlarged vestibular aqueduct. J Transl Med 2011; 9:167. [PMID: 21961810 PMCID: PMC3204245 DOI: 10.1186/1479-5876-9-167] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 09/30/2011] [Indexed: 11/16/2022] Open
Abstract
Background Mutations in SLC26A4 cause Pendred syndrome (hearing loss with goiter) or DFNB4 (non-syndromic hearing loss with inner ear malformation, such as enlarged vestibular aqueduct or Mondini deformity). The relationship between mutations in SLC26A4 and Mondini deformity without enlarged vestibular aqueduct has not been studied in any Chinese deaf population. The purpose of this study was to assess whether mutations in the SLC26A4 gene cause Mondini deformity without an enlarged vestibular aqueduct (isolated Mondini deformity) in a Chinese population. Methods In total, 144 patients with sensorineural hearing loss were included and subjected to high-resolution temporal bone CT. Among them, 28 patients with isolated Mondini dysplasia (MD group), 50 patients with enlarged vestibular aqueduct with Mondini dysplasia (EVA with MD group), 50 patients with enlarged vestibular aqueduct without Mondini dysplasia (EVA group), and 16 patients with other types of inner ear malformations (IEM group) were identified. The coding exons of SLC26A4 were analyzed in all subjects. Results DNA sequence analysis of SLC26A4 was performed in all 144 patients. In the different groups, the detection rate of the SLC26A4 mutation differed. In the isolated MD group, only one single allelic mutation in SLC26A4 was found in one patient (1/28, 3.6%). In the EVA with MD group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0%) and three patients (3/50, 6.0%), respectively. Also, in the EVA group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0%) and three patients (3/50, 6.0%), respectively. These percentages were identical to those in the EVA plus MD group. Only two patients carried monoallelic mutations of the SLC26A4 gene in the IEM group (2/16, 12.5%). There were significant differences in the frequency of SLC26A4 mutation among the groups (P < 0.001). The detection rate of SLC26A4 mutation in the isolated MD group was significantly lower than in the EVA group (with or without MD; P < 0.001), and there was no significant difference in the detection rate of SLC26A4 between the MD group and IEM group (P > 0.5). Conclusion Although mutations in the SLC26A4 gene were frequently found in Chinese EVA patients with and without MD, there was no evidence to show a relationship between isolated MD and the SLC26A4 gene in the Chinese population examined. Hearing impairment in patients with isolated MD may be caused by factors other than mutations in the SLC26A4 gene.
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Affiliation(s)
- Shasha Huang
- Department of Otolaryngology, PLA General Hospital, Beijing, People's Republic of China
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Brown AS, Epstein DJ. Otic ablation of smoothened reveals direct and indirect requirements for Hedgehog signaling in inner ear development. Development 2011; 138:3967-76. [PMID: 21831920 DOI: 10.1242/dev.066126] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In mouse embryos lacking sonic hedgehog (Shh), dorsoventral polarity within the otic vesicle is disrupted. Consequently, ventral otic derivatives, including the cochlear duct and saccule, fail to form, and dorsal otic derivatives, including the semicircular canals, endolymphatic duct and utricle, are malformed or absent. Since inner ear patterning and morphogenesis are heavily dependent on extracellular signals derived from tissues that are also compromised by the loss of Shh, the extent to which Shh signaling acts directly on the inner ear for its development is unclear. To address this question, we generated embryos in which smoothened (Smo), an essential transducer of Hedgehog (Hh) signaling, was conditionally inactivated in the otic epithelium (Smo(ecko)). Ventral otic derivatives failed to form in Smo(ecko) embryos, whereas vestibular structures developed properly. Consistent with these findings, we demonstrate that ventral, but not dorsal, otic identity is directly dependent on Hh. The role of Hh in cochlear-vestibular ganglion (cvg) formation is more complex, as both direct and indirect signaling mechanisms are implicated. Our data suggest that the loss of cvg neurons in Shh(-/-) animals is due, in part, to an increase in Wnt responsiveness in the otic vesicle, resulting in the ectopic expression of Tbx1 in the neurogenic domain and subsequent repression of Ngn1 transcription. A mitogenic role for Shh in cvg progenitor proliferation was also revealed in our analysis of Smo(ecko) embryos. Taken together, these data contribute to a better understanding of the intrinsic and extrinsic signaling properties of Shh during inner ear development.
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Affiliation(s)
- Alexander S Brown
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA 19104, USA
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Stankovic KM, Hennessey AM, Herrmann B, Mankarious LA. Cochlear implantation in children with congenital X-linked deafness due to novel mutations in POU3F4 gene. Ann Otol Rhinol Laryngol 2011; 119:815-22. [PMID: 21250553 DOI: 10.1177/000348941011901205] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES We report novel mutations in the POU3F4 gene resulting in congenital X-linked deafness DFN3, and describe the results of cochlear implantation in 4 boys (3 siblings) followed for an average of 3.5 years. METHODS The diagnosis of DFN3 was made in infant boys on the basis of the radiologic criteria of an underdeveloped modiolus, a wide cochlear fossette, and the presence of all cochlear turns. The POU3F4 gene was sequenced. A standard, transmastoid, facial recess approach was used for cochlear implantation. A lumbar drain was placed before the operation. RESULTS The identified mutations in the POU3F4 gene were novel (p.R167X in the 3 siblings) or recently reported (p.S310del). A high-flow cerebrospinal fluid leak through the cochleostomy was encountered in each patient and was ultimately controlled. Although the implants functioned properly, the auditory perceptual abilities did not progress past sound detection in the 3 siblings, or past closed-set word identification in the non-sibling, who achieved better speech perception with contralateral amplification. Three boys (2 siblings) show signs of other learning disorders; 1 boy was too young for a complete assessment. CONCLUSIONS Preoperative gene mutation analysis in DFN3 patients who are considering cochlear implantation may help in long-term counseling and in avoidance of postoperative complications. Limited auditory perception and language acquisition may result. Amplification may sometimes be a better alternative than cochlear implantation, despite the severity of the hearing loss.
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Affiliation(s)
- Konstantina M Stankovic
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114-3096, USA
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48
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Haugas M, Lilleväli K, Hakanen J, Salminen M. Gata2 is required for the development of inner ear semicircular ducts and the surrounding perilymphatic space. Dev Dyn 2011; 239:2452-69. [PMID: 20652952 DOI: 10.1002/dvdy.22373] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Gata2 has essential roles in the development of many organs. During mouse inner ear morphogenesis, it is expressed in otic vesicle and the surrounding periotic mesenchyme from early on, but no defects in the ear development of Gata2 null mice have been observed before lethality at embryonic day (E) 10.5. Here, we used conditional gene targeting to reveal the role of Gata2 at later stages of inner ear development. We show that Gata2 is critically required from E14.5-E15.5 onward for vestibular morphogenesis. Without Gata2 the semicircular ducts fail to grow to their normal size and the surrounding mesenchymal cells are not removed properly to generate the perilymphatic space. Gata2 is the first factor known to control the clearing of the vestibular perilymphatic mesenchyme, but interestingly, it is not required for the formation of the cochlear perilymphatic areas, suggesting distinct molecular control for these processes.
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Affiliation(s)
- Maarja Haugas
- Department of Veterinary Biosciences, University of Helsinki, Finland
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49
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Fritzsch B, Jahan I, Pan N, Kersigo J, Duncan J, Kopecky B. Dissecting the molecular basis of organ of Corti development: Where are we now? Hear Res 2011; 276:16-26. [PMID: 21256948 DOI: 10.1016/j.heares.2011.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 01/11/2011] [Accepted: 01/13/2011] [Indexed: 11/28/2022]
Abstract
This review summarizes recent progress in our understanding of the molecular basis of cochlear duct growth, specification of the organ of Corti, and differentiation of the different types of hair cells. Studies of multiple mutations suggest that developing hair cells are involved in stretching the organ of Corti through convergent extension movements. However, Atoh1 null mutants have only undifferentiated and dying organ of Corti precursors but show a near normal extension of the cochlear duct, implying that organ of Corti precursor cells can equally drive this process. Some factors influence cochlear duct growth by regulating the cell cycle and proliferation. Shortened cell cycle and premature cell cycle exit can lead to a shorter organ of Corti with multiple rows of hair cells (e.g., Foxg1 null mice). Other genes affect the initial formation of a cochlear duct with or without affecting the organ of Corti. Such observations are consistent with evolutionary data that suggest some developmental uncoupling of cochlear duct from organ of Corti formation. Positioning the organ of Corti requires multiple genes expressed in the organ of Corti and the flanking region. Several candidate factors have emerged but how they cooperate to specify the organ of Corti and the topology of hair cells remains unclear. Atoh1 is required for differentiation of all hair cells, but regulation of inner versus outer hair cell differentiation is still unidentified. In summary, the emerging molecular complexity of organ of Corti development demands further study before a rational approach towards regeneration of unique types of hair cells in specific positions is possible.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology, College of Liberal Arts and Sciences, 143 BB, University of Iowa, Iowa City, IA 52242, USA.
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Robert-Moreno À, Naranjo S, de la Calle-Mustienes E, Gómez-Skarmeta JL, Alsina B. Characterization of new otic enhancers of the pou3f4 gene reveal distinct signaling pathway regulation and spatio-temporal patterns. PLoS One 2010; 5:e15907. [PMID: 21209840 PMCID: PMC3013142 DOI: 10.1371/journal.pone.0015907] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 11/26/2010] [Indexed: 02/01/2023] Open
Abstract
POU3F4 is a member of the POU-homedomain transcription factor family with a prominent role in inner ear development. Mutations in the human POU3F4 coding unit leads to X-linked deafness type 3 (DFN3), characterized by conductive hearing loss and progressive sensorineural deafness. Microdeletions found 1 Mb 5' upstream of the coding region also displayed the same phenotype, suggesting that cis-regulatory elements might be present in that region. Indeed, we and others have recently identified several enhancers at the 1 Mb 5' upstream interval of the pou3f4 locus. Here we characterize the spatio-temporal patterns of these regulatory elements in zebrafish transgenic lines. We show that the most distal enhancer (HCNR 81675) is activated earlier and drives GFP reporter expression initially to a broad ear domain to progressively restrict to the sensory patches. The proximal enhancer (HCNR 82478) is switched later during development and promotes expression, among in other tissues, in sensory patches from its onset. The third enhancer (HCNR 81728) is also active at later stages in the otic mesenchyme and in the otic epithelium. We also characterize the signaling pathways regulating these enhancers. While HCNR 81675 is regulated by very early signals of retinoic acid, HCNR 82478 is regulated by Fgf activity at a later stage and the HCNR 81728 enhancer is under the control of Hh signaling. Finally, we show that Sox2 and Pax2 transcription factors are bound to HCNR 81675 genomic region during otic development and specific mutations to these transcription factor binding sites abrogates HCNR 81675 enhancer activity. Altogether, our results suggest that pou3f4 expression in inner ear might be under the control of distinct regulatory elements that fine-tune the spatio-temporal activity of this gene and provides novel data on the signaling mechanisms controlling pou3f4 function.
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Affiliation(s)
- Àlex Robert-Moreno
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra/Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
| | - Silvia Naranjo
- Centro Andaluz de Biología del Desarrollo, CSIC/Universidad Pablo de Olavide, Sevilla, Spain
| | | | | | - Berta Alsina
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra/Parc de Recerca Biomèdica de Barcelona, Barcelona, Spain
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