1
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Bi Z, Ren M, Zhang Y, He S, Song L, Li X, Liu Z. Revisiting the Potency of Tbx2 Expression in Transforming Outer Hair Cells into Inner Hair Cells at Multiple Ages In Vivo. J Neurosci 2024; 44:e1751232024. [PMID: 38688721 PMCID: PMC11154855 DOI: 10.1523/jneurosci.1751-23.2024] [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: 09/17/2023] [Revised: 01/30/2024] [Accepted: 03/24/2024] [Indexed: 05/02/2024] Open
Abstract
The mouse auditory organ cochlea contains two types of sound receptors: inner hair cells (IHCs) and outer hair cells (OHCs). Tbx2 is expressed in IHCs but repressed in OHCs, and neonatal OHCs that misexpress Tbx2 transdifferentiate into IHC-like cells. However, the extent of this switch from OHCs to IHC-like cells and the underlying molecular mechanism remain poorly understood. Furthermore, whether Tbx2 can transform fully mature adult OHCs into IHC-like cells is unknown. Here, our single-cell transcriptomic analysis revealed that in neonatal OHCs misexpressing Tbx2, 85.6% of IHC genes, including Slc17a8, are upregulated, but only 38.6% of OHC genes, including Ikzf2 and Slc26a5, are downregulated. This suggests that Tbx2 cannot fully reprogram neonatal OHCs into IHCs. Moreover, Tbx2 also failed to completely reprogram cochlear progenitors into IHCs. Lastly, restoring Ikzf2 expression alleviated the abnormalities detected in Tbx2+ OHCs, which supports the notion that Ikzf2 repression by Tbx2 contributes to the transdifferentiation of OHCs into IHC-like cells. Our study evaluates the effects of ectopic Tbx2 expression on OHC lineage development at distinct stages of either male or female mice and provides molecular insights into how Tbx2 disrupts the gene expression profile of OHCs. This research also lays the groundwork for future studies on OHC regeneration.
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Affiliation(s)
- Zhenghong Bi
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Minhui Ren
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
- Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Shunji He
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Lei Song
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
- Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai 200125, China
| | - Xiang Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China
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2
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Waas B, Carpenter BS, Franks NE, Merchant OQ, Verhey KJ, Allen BL. Dual and opposing roles for the kinesin-2 motor, KIF17, in Hedgehog-dependent cerebellar development. SCIENCE ADVANCES 2024; 10:eade1650. [PMID: 38669326 PMCID: PMC11051677 DOI: 10.1126/sciadv.ade1650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
While the kinesin-2 motors KIF3A and KIF3B have essential roles in ciliogenesis and Hedgehog (HH) signal transduction, potential role(s) for another kinesin-2 motor, KIF17, in HH signaling have yet to be explored. Here, we investigated the contribution of KIF17 to HH-dependent cerebellar development, where Kif17 is expressed in both HH-producing Purkinje cells and HH-responding cerebellar granule neuron progenitors (CGNPs). Germline Kif17 deletion in mice results in cerebellar hypoplasia due to reduced CGNP proliferation, a consequence of decreased HH pathway activity mediated through decreased Sonic HH (SHH) protein. Notably, Purkinje cell-specific Kif17 deletion partially phenocopies Kif17 germline mutants. Unexpectedly, CGNP-specific Kif17 deletion results in the opposite phenotype-increased CGNP proliferation and HH target gene expression due to altered GLI transcription factor processing. Together, these data identify KIF17 as a key regulator of HH-dependent cerebellar development, with dual and opposing roles in HH-producing Purkinje cells and HH-responding CGNPs.
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Affiliation(s)
- Bridget Waas
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Brandon S. Carpenter
- Department of Molecular and Cellular Biology, College of Science and Mathematics, Kennesaw State University, Kennesaw, GA, 30061, USA
| | - Nicole E. Franks
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Olivia Q. Merchant
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kristen J. Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Benjamin L. Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
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3
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Jarysta A, Tadenev ALD, Day M, Krawchuk B, Low BE, Wiles MV, Tarchini B. Inhibitory G proteins play multiple roles to polarize sensory hair cell morphogenesis. eLife 2024; 12:RP88186. [PMID: 38651641 PMCID: PMC11037916 DOI: 10.7554/elife.88186] [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] [Indexed: 04/25/2024] Open
Abstract
Inhibitory G alpha (GNAI or Gαi) proteins are critical for the polarized morphogenesis of sensory hair cells and for hearing. The extent and nature of their actual contributions remains unclear, however, as previous studies did not investigate all GNAI proteins and included non-physiological approaches. Pertussis toxin can downregulate functionally redundant GNAI1, GNAI2, GNAI3, and GNAO proteins, but may also induce unrelated defects. Here, we directly and systematically determine the role(s) of each individual GNAI protein in mouse auditory hair cells. GNAI2 and GNAI3 are similarly polarized at the hair cell apex with their binding partner G protein signaling modulator 2 (GPSM2), whereas GNAI1 and GNAO are not detected. In Gnai3 mutants, GNAI2 progressively fails to fully occupy the sub-cellular compartments where GNAI3 is missing. In contrast, GNAI3 can fully compensate for the loss of GNAI2 and is essential for hair bundle morphogenesis and auditory function. Simultaneous inactivation of Gnai2 and Gnai3 recapitulates for the first time two distinct types of defects only observed so far with pertussis toxin: (1) a delay or failure of the basal body to migrate off-center in prospective hair cells, and (2) a reversal in the orientation of some hair cell types. We conclude that GNAI proteins are critical for hair cells to break planar symmetry and to orient properly before GNAI2/3 regulate hair bundle morphogenesis with GPSM2.
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Affiliation(s)
| | | | - Matthew Day
- The Jackson LaboratoryBar HarborUnited States
| | | | | | | | - Basile Tarchini
- The Jackson LaboratoryBar HarborUnited States
- Tufts University School of MedicineBostonUnited States
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4
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Strelkova OS, Osgood RT, Tian CJ, Zhang X, Hale E, De-la-Torre P, Hathaway DM, Indzhykulian AA. PKHD1L1 is required for stereocilia bundle maintenance, durable hearing function and resilience to noise exposure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582786. [PMID: 38496629 PMCID: PMC10942330 DOI: 10.1101/2024.02.29.582786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Sensory hair cells of the cochlea are essential for hearing, relying on the mechanosensitive stereocilia bundle at their apical pole for their function. Polycystic Kidney and Hepatic Disease 1-Like 1 (PKHD1L1) is a stereocilia protein required for normal hearing in mice, and for the formation of the transient stereocilia surface coat, expressed during early postnatal development. While the function of the stereocilia coat remains unclear, growing evidence supports PKHD1L1 as a human deafness gene. In this study we carry out in depth characterization of PKHD1L1 expression in mice during development and adulthood, analyze hair-cell bundle morphology and hearing function in aging PKHD1L1-defficient mouse lines, and assess their susceptibility to noise damage. Our findings reveal that PKHD1L1-deficient mice display no disruption to bundle cohesion or tectorial membrane attachment-crown formation during development. However, starting from 6 weeks of age, PKHD1L1-defficient mice display missing stereocilia and disruptions to bundle coherence. Both conditional and constitutive PKHD1L1 knock-out mice develop high-frequency hearing loss progressing to lower frequencies with age. Furthermore, PKHD1L1-deficient mice are susceptible to permanent hearing loss following moderate acoustic overexposure, which induces only temporary hearing threshold shifts in wild-type mice. These results suggest a role for PKHD1L1 in establishing robust sensory hair bundles during development, necessary for maintaining bundle cohesion and function in response to acoustic trauma and aging.
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Affiliation(s)
| | | | | | - Xinyuan Zhang
- Department of Otolaryngology Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Evan Hale
- Department of Otolaryngology Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Pedro De-la-Torre
- Department of Otolaryngology Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Daniel M. Hathaway
- Department of Otolaryngology Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Artur A. Indzhykulian
- Department of Otolaryngology Head and Neck Surgery, Mass Eye and Ear, Harvard Medical School, Boston, MA, United States
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5
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Wang G, Gu Y, Liu Z. Deciphering the genetic interactions between Pou4f3, Gfi1, and Rbm24 in maintaining mouse cochlear hair cell survival. eLife 2024; 12:RP90025. [PMID: 38483314 PMCID: PMC10939501 DOI: 10.7554/elife.90025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024] Open
Abstract
Mammals harbor a limited number of sound-receptor hair cells (HCs) that cannot be regenerated after damage. Thus, investigating the underlying molecular mechanisms that maintain HC survival is crucial for preventing hearing impairment. Intriguingly, Pou4f3-/- or Gfi1-/- HCs form initially but then rapidly degenerate, whereas Rbm24-/- HCs degenerate considerably later. However, the transcriptional cascades involving Pou4f3, Gfi1, and Rbm24 remain undescribed. Here, we demonstrate that Rbm24 expression is completely repressed in Pou4f3-/- HCs but unaltered in Gfi1-/- HCs, and further that the expression of both POU4F3 and GFI1 is intact in Rbm24-/- HCs. Moreover, by using in vivo mouse transgenic reporter assays, we identify three Rbm24 enhancers to which POU4F3 binds. Lastly, through in vivo genetic testing of whether Rbm24 restoration alleviates the degeneration of Pou4f3-/- HCs, we show that ectopic Rbm24 alone cannot prevent Pou4f3-/- HCs from degenerating. Collectively, our findings provide new molecular and genetic insights into how HC survival is regulated.
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Affiliation(s)
- Guangqin Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yunpeng Gu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of SciencesShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Shanghai Center for Brain Science and Brain-Inspired Intelligence TechnologyShanghaiChina
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6
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Dewa KI, Arimura N, Kakegawa W, Itoh M, Adachi T, Miyashita S, Inoue YU, Hizawa K, Hori K, Honjoya N, Yagishita H, Taya S, Miyazaki T, Usui C, Tatsumoto S, Tsuzuki A, Uetake H, Sakai K, Yamakawa K, Sasaki T, Nagai J, Kawaguchi Y, Sone M, Inoue T, Go Y, Ichinohe N, Kaibuchi K, Watanabe M, Koizumi S, Yuzaki M, Hoshino M. Neuronal DSCAM regulates the peri-synaptic localization of GLAST in Bergmann glia for functional synapse formation. Nat Commun 2024; 15:458. [PMID: 38302444 PMCID: PMC10834496 DOI: 10.1038/s41467-023-44579-z] [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: 03/15/2022] [Accepted: 12/19/2023] [Indexed: 02/03/2024] Open
Abstract
In the central nervous system, astrocytes enable appropriate synapse function through glutamate clearance from the synaptic cleft; however, it remains unclear how astrocytic glutamate transporters function at peri-synaptic contact. Here, we report that Down syndrome cell adhesion molecule (DSCAM) in Purkinje cells controls synapse formation and function in the developing cerebellum. Dscam-mutant mice show defects in CF synapse translocation as is observed in loss of function mutations in the astrocytic glutamate transporter GLAST expressed in Bergmann glia. These mice show impaired glutamate clearance and the delocalization of GLAST away from the cleft of parallel fibre (PF) synapse. GLAST complexes with the extracellular domain of DSCAM. Riluzole, as an activator of GLAST-mediated uptake, rescues the proximal impairment in CF synapse formation in Purkinje cell-selective Dscam-deficient mice. DSCAM is required for motor learning, but not gross motor coordination. In conclusion, the intercellular association of synaptic and astrocyte proteins is important for synapse formation and function in neural transmission.
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Affiliation(s)
- Ken-Ichi Dewa
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Nariko Arimura
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan.
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan.
| | - Wataru Kakegawa
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Masayuki Itoh
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Toma Adachi
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Satoshi Miyashita
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of System Pathology for Neurological Disorders, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Yukiko U Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kento Hizawa
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Kei Hori
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Natsumi Honjoya
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Haruya Yagishita
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Shinichiro Taya
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Division of Behavioural Neuropharmacology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Taisuke Miyazaki
- Department of Health Sciences, School of Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0812, Japan
| | - Chika Usui
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Shoji Tatsumoto
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
| | - Akiko Tsuzuki
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Hirotomo Uetake
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
- Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Saitama, 274-8510, Japan
| | - Kazuhisa Sakai
- Department of Ultrastructural Research, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kazuhiro Yamakawa
- Department of Neurodevelopmental Disorder Genetics, Nagoya City University Graduate School of Medicine, Nagoya, Aichi, 467-8601, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578, Tohoku, Japan
| | - Jun Nagai
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Yoshiya Kawaguchi
- Department of Life Science Frontiers, Center for iPS cell Research and Application (CiRA), Kyoto University, Kyoto, 606-8507, Japan
| | - Masaki Sone
- Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Saitama, 274-8510, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Yasuhiro Go
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
- Department of System Neuroscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8585, Japan
- Graduate School of Information Science, University of Hyogo, Kobe, Hyogo, 650-0047, Japan
| | - Noritaka Ichinohe
- Department of Ultrastructural Research, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Kozo Kaibuchi
- Division of Cell Biology, International Center for Brain Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido, 060-8638, Japan
- The University of Texas at Austin, Austin, Texas, 78712-0805, USA
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, Yamanashi, 409-3898, Japan
| | - Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan.
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Jarysta A, Tadenev ALD, Day M, Krawchuk B, Low BE, Wiles MV, Tarchini B. Inhibitory G proteins play multiple roles to polarize sensory hair cell morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.25.542257. [PMID: 37292807 PMCID: PMC10245865 DOI: 10.1101/2023.05.25.542257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Inhibitory G alpha (GNAI or Gαi) proteins are critical for the polarized morphogenesis of sensory hair cells and for hearing. The extent and nature of their actual contributions remains unclear, however, as previous studies did not investigate all GNAI proteins and included non-physiological approaches. Pertussis toxin can downregulate functionally redundant GNAI1, GNAI2, GNAI3 and GNAO proteins, but may also induce unrelated defects. Here we directly and systematically determine the role(s) of each individual GNAI protein in mouse auditory hair cells. GNAI2 and GNAI3 are similarly polarized at the hair cell apex with their binding partner GPSM2, whereas GNAI1 and GNAO are not detected. In Gnai3 mutants, GNAI2 progressively fails to fully occupy the subcellular compartments where GNAI3 is missing. In contrast, GNAI3 can fully compensate for the loss of GNAI2 and is essential for hair bundle morphogenesis and auditory function. Simultaneous inactivation of Gnai2 and Gnai3 recapitulates for the first time two distinct types of defects only observed so far with pertussis toxin: 1) a delay or failure of the basal body to migrate off-center in prospective hair cells, and 2) a reversal in the orientation of some hair cell types. We conclude that GNAI proteins are critical for hair cells to break planar symmetry and to orient properly before GNAI2/3 regulate hair bundle morphogenesis with GPSM2.
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8
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Ledvin L, Gassaway BM, Tawil J, Urso O, Pizzo D, Welsh KA, Bolhuis DL, Fisher D, Bonni A, Gygi SP, Brown NG, Ferguson CJ. The anaphase-promoting complex controls a ubiquitination-phosphoprotein axis in chromatin during neurodevelopment. Dev Cell 2023; 58:2666-2683.e9. [PMID: 37875116 PMCID: PMC10872926 DOI: 10.1016/j.devcel.2023.10.002] [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: 12/13/2022] [Revised: 08/07/2023] [Accepted: 10/03/2023] [Indexed: 10/26/2023]
Abstract
Mutations in the degradative ubiquitin ligase anaphase-promoting complex (APC) alter neurodevelopment by impairing proteasomal protein clearance, but our understanding of their molecular and cellular pathogenesis remains limited. Here, we employ the proteomic-based discovery of APC substrates in APC mutant mouse brain and human cell lines and identify the chromosome-passenger complex (CPC), topoisomerase 2a (Top2a), and Ki-67 as major chromatin factors targeted by the APC during neuronal differentiation. These substrates accumulate in phosphorylated form, suggesting that they fail to be eliminated after mitosis during terminal differentiation. The accumulation of the CPC kinase Aurora B within constitutive heterochromatin and hyperphosphorylation of its target histone 3 are corrected in the mutant brain by pharmacologic Aurora B inhibition. Surprisingly, the reduction of Ki-67, but not H3S10ph, rescued the function of constitutive heterochromatin in APC mutant neurons. These results expand our understanding of how ubiquitin signaling regulates chromatin during neurodevelopment and identify potential therapeutic targets in APC-related disorders.
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Affiliation(s)
- Leya Ledvin
- Pathology Department, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brandon M Gassaway
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jonathan Tawil
- Pathology Department, University of California, San Diego, La Jolla, CA 92093, USA
| | - Olivia Urso
- Pathology Department, University of California, San Diego, La Jolla, CA 92093, USA
| | - Donald Pizzo
- Pathology Department, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kaeli A Welsh
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Derek L Bolhuis
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | | | - Azad Bonni
- Neuroscience Department, Washington University, St. Louis, MO 63110, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas G Brown
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Cole J Ferguson
- Pathology Department, University of California, San Diego, La Jolla, CA 92093, USA.
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9
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Pan Y, Li S, He S, Wang G, Li C, Liu Z, Xiang M. Fgf8 P2A-3×GFP/+: A New Genetic Mouse Model for Specifically Labeling and Sorting Cochlear Inner Hair Cells. Neurosci Bull 2023; 39:1762-1774. [PMID: 37233921 PMCID: PMC10661496 DOI: 10.1007/s12264-023-01069-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/08/2023] [Indexed: 05/27/2023] Open
Abstract
The cochlear auditory epithelium contains two types of sound receptors, inner hair cells (IHCs) and outer hair cells (OHCs). Mouse models for labelling juvenile and adult IHCs or OHCs exist; however, labelling for embryonic and perinatal IHCs or OHCs are lacking. Here, we generated a new knock-in Fgf8P2A-3×GFP/+ (Fgf8GFP/+) strain, in which the expression of a series of three GFP fragments is controlled by endogenous Fgf8 cis-regulatory elements. After confirming that GFP expression accurately reflects the expression of Fgf8, we successfully obtained both embryonic and neonatal IHCs with high purity, highlighting the power of Fgf8GFP/+. Furthermore, our fate-mapping analysis revealed, unexpectedly, that IHCs are also derived from inner ear progenitors expressing Insm1, which is currently regarded as an OHC marker. Thus, besides serving as a highly favorable tool for sorting early IHCs, Fgf8GFP/+ will facilitate the isolation of pure early OHCs by excluding IHCs from the entire hair cell pool.
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Affiliation(s)
- Yi Pan
- Department of Otolaryngology and Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Shuting Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shunji He
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Guangqin Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chao Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
| | - Mingliang Xiang
- Department of Otolaryngology and Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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10
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Sanghrajka RM, Koche R, Medrano H, El Nagar S, Stephen DN, Lao Z, Bayin NS, Ge K, Joyner AL. KMT2D suppresses Sonic hedgehog-driven medulloblastoma progression and metastasis. iScience 2023; 26:107831. [PMID: 37822508 PMCID: PMC10562805 DOI: 10.1016/j.isci.2023.107831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 03/29/2023] [Accepted: 09/01/2023] [Indexed: 10/13/2023] Open
Abstract
The major cause of treatment failure and mortality among medulloblastoma patients is metastasis intracranially or along the spinal cord. The molecular mechanisms driving tumor metastasis in Sonic hedgehog-driven medulloblastoma (SHH-MB) patients, however, remain largely unknown. In this study we define a tumor suppressive role of KMT2D (MLL2), a gene frequently mutated in the most metastatic β-subtype. Strikingly, genetic mouse models of SHH-MB demonstrate that heterozygous loss of Kmt2d in conjunction with activation of the SHH pathway causes highly penetrant disease with decreased survival, increased hindbrain invasion and spinal cord metastasis. Loss of Kmt2d attenuates neural differentiation and shifts the transcriptional/chromatin landscape of primary and metastatic tumors toward a decrease in differentiation genes and tumor suppressors and an increase in genes/pathways implicated in advanced stage cancer and metastasis (TGFβ, Notch, Atoh1, Sox2, and Myc). Thus, secondary heterozygous KMT2D mutations likely have prognostic value for identifying SHH-MB patients prone to develop metastasis.
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Affiliation(s)
- Reeti Mayur Sanghrajka
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Richard Koche
- Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hector Medrano
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Salsabiel El Nagar
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniel N. Stephen
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Zhimin Lao
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - N. Sumru Bayin
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kai Ge
- Adipocyte Biology and Gene Regulation Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Alexandra L. Joyner
- Developmental Biology Program, Sloan Kettering Institute of Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
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11
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Ingle H, Makimaa H, Aggarwal S, Deng H, Foster L, Li Y, Kennedy EA, Peterson ST, Wilen CB, Lee S, Suthar MS, Baldridge MT. IFN-λ derived from nonsusceptible enterocytes acts on tuft cells to limit persistent norovirus. SCIENCE ADVANCES 2023; 9:eadi2562. [PMID: 37703370 PMCID: PMC10499323 DOI: 10.1126/sciadv.adi2562] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/10/2023] [Indexed: 09/15/2023]
Abstract
Norovirus is a leading cause of epidemic viral gastroenteritis, with no currently approved vaccines or antivirals. Murine norovirus (MNoV) is a well-characterized model of norovirus pathogenesis in vivo, and persistent strains exhibit lifelong intestinal infection. Interferon-λ (IFN-λ) is a potent antiviral that rapidly cures MNoV. We previously demonstrated that IFN-λ signaling in intestinal epithelial cells (IECs) controls persistent MNoV, and here demonstrate that IFN-λ acts on tuft cells, the exclusive site of MNoV persistence, to limit infection. While interrogating the source of IFN-λ to regulate MNoV, we confirmed that MDA5-MAVS signaling, required for IFN-λ induction to MNoV in vitro, controls persistent MNoV in vivo. We demonstrate that MAVS in IECs and not immune cells controls MNoV. MAVS in nonsusceptible enterocytes, but not in tuft cells, restricts MNoV, implicating noninfected cells as the IFN-λ source. Our findings indicate that host sensing of MNoV is distinct from cellular tropism, suggesting intercellular communication between IECs for antiviral signaling induction in uninfected bystander cells.
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Affiliation(s)
- Harshad Ingle
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Heyde Makimaa
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Somya Aggarwal
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Hongju Deng
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Lynne Foster
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Yuhao Li
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Elizabeth A. Kennedy
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Stefan T. Peterson
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Craig B. Wilen
- Departments of Laboratory Medicine and Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Sanghyun Lee
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, USA
| | - Mehul S. Suthar
- Department of Pediatrics, Emory School of Medicine, Atlanta, GA, USA
| | - Megan T. Baldridge
- Division of Infectious Diseases, Department of Medicine, Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
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12
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Di Bonito M, Bourien J, Tizzano M, Harrus AG, Puel JL, Avallone B, Nouvian R, Studer M. Abnormal outer hair cell efferent innervation in Hoxb1-dependent sensorineural hearing loss. PLoS Genet 2023; 19:e1010933. [PMID: 37738262 PMCID: PMC10516434 DOI: 10.1371/journal.pgen.1010933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/22/2023] [Indexed: 09/24/2023] Open
Abstract
Autosomal recessive mutation of HOXB1 and Hoxb1 causes sensorineural hearing loss in patients and mice, respectively, characterized by the presence of higher auditory thresholds; however, the origin of the defects along the auditory pathway is still unknown. In this study, we assessed whether the abnormal auditory threshold and malformation of the sensory auditory cells, the outer hair cells, described in Hoxb1null mutants depend on the absence of efferent motor innervation, or alternatively, is due to altered sensory auditory components. By using a whole series of conditional mutant mice, which inactivate Hoxb1 in either rhombomere 4-derived sensory cochlear neurons or efferent motor neurons, we found that the hearing phenotype is mainly reproduced when efferent motor neurons are specifically affected. Our data strongly suggest that the interactions between olivocochlear motor neurons and outer hair cells during a critical postnatal period are crucial for both hair cell survival and the establishment of the cochlear amplification of sound.
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Affiliation(s)
- Maria Di Bonito
- Université Côte d’Azur (UCA), CNRS, Inserm, Institute of Biology Valrose (iBV), Nice, France
| | - Jérôme Bourien
- University of Montpellier, Inserm, CNRS, Institute for Neurosciences of Montpellier (INM), Montpellier, France
| | - Monica Tizzano
- University of Naples Federico II, Department of Biology, Naples, Italy
| | - Anne-Gabrielle Harrus
- University of Montpellier, Inserm, CNRS, Institute for Neurosciences of Montpellier (INM), Montpellier, France
| | - Jean-Luc Puel
- University of Montpellier, Inserm, CNRS, Institute for Neurosciences of Montpellier (INM), Montpellier, France
| | - Bice Avallone
- University of Naples Federico II, Department of Biology, Naples, Italy
| | - Regis Nouvian
- University of Montpellier, Inserm, CNRS, Institute for Neurosciences of Montpellier (INM), Montpellier, France
| | - Michèle Studer
- Université Côte d’Azur (UCA), CNRS, Inserm, Institute of Biology Valrose (iBV), Nice, France
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13
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Veithen M, Huyghe A, Van Den Ackerveken P, Fukada SI, Kokubo H, Breuskin I, Nguyen L, Delacroix L, Malgrange B. Sox9 Inhibits Cochlear Hair Cell Fate by Upregulating Hey1 and HeyL Antagonists of Atoh1. Cells 2023; 12:2148. [PMID: 37681879 PMCID: PMC10486728 DOI: 10.3390/cells12172148] [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: 08/01/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
It is widely accepted that cell fate determination in the cochlea is tightly controlled by different transcription factors (TFs) that remain to be fully defined. Here, we show that Sox9, initially expressed in the entire sensory epithelium of the cochlea, progressively disappears from differentiating hair cells (HCs) and is finally restricted to supporting cells (SCs). By performing ex vivo electroporation of E13.5-E14.5 cochleae, we demonstrate that maintenance of Sox9 expression in the progenitors committed to HC fate blocks their differentiation, even if co-expressed with Atoh1, a transcription factor necessary and sufficient to form HC. Sox9 inhibits Atoh1 transcriptional activity by upregulating Hey1 and HeyL antagonists, and genetic ablation of these genes induces extra HCs along the cochlea. Although Sox9 suppression from sensory progenitors ex vivo leads to a modest increase in the number of HCs, it is not sufficient in vivo to induce supernumerary HC production in an inducible Sox9 knockout model. Taken together, these data show that Sox9 is downregulated from nascent HCs to allow the unfolding of their differentiation program. This may be critical for future strategies to promote fully mature HC formation in regeneration approaches.
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Affiliation(s)
- Mona Veithen
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
| | - Aurélia Huyghe
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
| | - Priscilla Van Den Ackerveken
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
| | - So-ichiro Fukada
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan;
| | - Hiroki Kokubo
- Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minamiku, Hiroshima 734-8551, Japan;
| | - Ingrid Breuskin
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
| | - Laurent Nguyen
- Laboratory of Molecular Regulation of Neurogenesis, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium;
| | - Laurence Delacroix
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
| | - Brigitte Malgrange
- Laboratory of Developmental Neurobiology, GIGA-Neurosciences, University of Liege, 4000 Liege, Belgium; (M.V.); (A.H.); (P.V.D.A.); (I.B.); (L.D.)
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14
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Wang X, Llamas J, Trecek T, Shi T, Tao L, Makmura W, Crump JG, Segil N, Gnedeva K. SoxC transcription factors shape the epigenetic landscape to establish competence for sensory differentiation in the mammalian organ of Corti. Proc Natl Acad Sci U S A 2023; 120:e2301301120. [PMID: 37585469 PMCID: PMC10450657 DOI: 10.1073/pnas.2301301120] [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: 01/24/2023] [Accepted: 06/28/2023] [Indexed: 08/18/2023] Open
Abstract
The auditory organ of Corti is comprised of only two major cell types-the mechanosensory hair cells and their associated supporting cells-both specified from a single pool of prosensory progenitors in the cochlear duct. Here, we show that competence to respond to Atoh1, a transcriptional master regulator necessary and sufficient for induction of mechanosensory hair cells, is established in the prosensory progenitors between E12.0 and 13.5. The transition to the competent state is rapid and is associated with extensive remodeling of the epigenetic landscape controlled by the SoxC group of transcription factors. Conditional loss of Sox4 and Sox11-the two homologous family members transiently expressed in the inner ear at the time of competence establishment-blocks the ability of prosensory progenitors to differentiate as hair cells. Mechanistically, we show that Sox4 binds to and establishes accessibility of early sensory lineage-specific regulatory elements, including ones associated with Atoh1 and its direct downstream targets. Consistent with these observations, overexpression of Sox4 or Sox11 prior to developmental establishment of competence precociously induces hair cell differentiation in the cochlear progenitors. Further, reintroducing Sox4 or Sox11 expression restores the ability of postnatal supporting cells to differentiate as hair cells in vitro and in vivo. Our findings demonstrate the pivotal role of SoxC family members as agents of epigenetic and transcriptional changes necessary for establishing competence for sensory receptor differentiation in the inner ear.
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Affiliation(s)
- Xizi Wang
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Juan Llamas
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Talon Trecek
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Tuo Shi
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Litao Tao
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Welly Makmura
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - J. Gage Crump
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Neil Segil
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
| | - Ksenia Gnedeva
- Caruso Department of Otolaryngology–Head and Neck Surgery, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of University of Southern California, Los Angeles, CA90033
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15
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Nakamura T, Sakaguchi H, Mohri H, Ninoyu Y, Goto A, Yamaguchi T, Hishikawa Y, Matsuda M, Saito N, Ueyama T. Dispensable role of Rac1 and Rac3 after cochlear hair cell specification. J Mol Med (Berl) 2023; 101:843-854. [PMID: 37204479 PMCID: PMC10300165 DOI: 10.1007/s00109-023-02317-4] [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: 11/07/2022] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 05/20/2023]
Abstract
Rac small GTPases play important roles during embryonic development of the inner ear; however, little is known regarding their function in cochlear hair cells (HCs) after specification. Here, we revealed the localization and activation of Racs in cochlear HCs using GFP-tagged Rac plasmids and transgenic mice expressing a Rac1-fluorescence resonance energy transfer (FRET) biosensor. Furthermore, we employed Rac1-knockout (Rac1-KO, Atoh1-Cre;Rac1flox/flox) and Rac1 and Rac3 double KO (Rac1/Rac3-DKO, Atoh1-Cre;Rac1flox/flox;Rac3-/-) mice, under the control of the Atoh1 promoter. However, both Rac1-KO and Rac1/Rac3-DKO mice exhibited normal cochlear HC morphology at 13 weeks of age and normal hearing function at 24 weeks of age. No hearing vulnerability was observed in young adult (6-week-old) Rac1/Rac3-DKO mice even after intense noise exposure. Consistent with prior reports, the results from Atoh1-Cre;tdTomato mice confirmed that the Atoh1 promoter became functional only after embryonic day 14 when the sensory HC precursors exit the cell cycle. Taken together, these findings indicate that although Rac1 and Rac3 contribute to the early development of sensory epithelia in cochleae, as previously shown, they are dispensable for the maturation of cochlear HCs in the postmitotic state or for hearing maintenance following HC maturation. KEY MESSAGES: Mice with Rac1 and Rac3 deletion were generated after HC specification. Knockout mice exhibit normal cochlear hair cell morphology and hearing. Racs are dispensable for hair cells in the postmitotic state after specification. Racs are dispensable for hearing maintenance after HC maturation.
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Affiliation(s)
- Takashi Nakamura
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hirofumi Sakaguchi
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hiroaki Mohri
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Yuzuru Ninoyu
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Akihiro Goto
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Taro Yamaguchi
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, 573-0101, Japan
| | - Yoshitaka Hishikawa
- Department of Anatomy, Histochemistry and Cell Biology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan
| | - Michiyuki Matsuda
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Takehiko Ueyama
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan.
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16
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Xiao Y, Li D. The role of epigenetic modifications in sensory hair cell development, survival, and regulation. Front Cell Neurosci 2023; 17:1210279. [PMID: 37388412 PMCID: PMC10300351 DOI: 10.3389/fncel.2023.1210279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 05/23/2023] [Indexed: 07/01/2023] Open
Abstract
The cochlea is the sensory organ in the periphery, and hair cells are its main sensory cells. The development and survival of hair cells are highly controlled processes. When cells face intracellular and environmental stimuli, epigenetic regulation controls the structure and function of the genome in response to different cell fates. During sensory hair cell development, different histone modifications can induce normal numbers of functional hair cells to generate. When individuals are exposed to environmental-related hair cell damage, epigenetic modification also plays a significant role in the regulation of hair cell fate. Since mammalian hair cells cannot regenerate, their loss can cause permanent sensorineural hearing loss. Many breakthroughs have been achieved in recent years in understanding the signaling pathways that determine hair cell regeneration, and it is fascinating to note that epigenetic regulation plays a significant role in hair cell regeneration. In this review, we discuss the role of epigenetics in inner ear cell development, survival and regeneration and the significant impact on hearing protection.
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17
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Lee JH, Khan MM, Stark AP, Seo S, Norton A, Yao Z, Chen CH, Regehr WG. Cerebellar granule cell signaling is indispensable for normal motor performance. Cell Rep 2023; 42:112429. [PMID: 37141091 PMCID: PMC10258556 DOI: 10.1016/j.celrep.2023.112429] [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: 08/17/2022] [Revised: 02/06/2023] [Accepted: 04/07/2023] [Indexed: 05/05/2023] Open
Abstract
Within the cerebellar cortex, mossy fibers (MFs) excite granule cells (GCs) that excite Purkinje cells (PCs), which provide outputs to the deep cerebellar nuclei (DCNs). It is well established that PC disruption produces motor deficits such as ataxia. This could arise from either decreases in ongoing PC-DCN inhibition, increases in the variability of PC firing, or disruption of the flow of MF-evoked signals. Remarkably, it is not known whether GCs are essential for normal motor function. Here we address this issue by selectively eliminating calcium channels that mediate transmission (CaV2.1, CaV2.2, and CaV2.3) in a combinatorial manner. We observe profound motor deficits but only when all CaV2 channels are eliminated. In these mice, the baseline rate and variability of PC firing are unaltered, and locomotion-dependent increases in PC firing are eliminated. We conclude that GCs are indispensable for normal motor performance and that disruption of MF-induced signals impairs motor performance.
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Affiliation(s)
- Joon-Hyuk Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Mehak M Khan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Amanda P Stark
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Soobin Seo
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Aliya Norton
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Zhiyi Yao
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher H Chen
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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18
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Zanin JP, Pandya MA, Espinoza D, Friedman WJ, Shiflett MW. Excess cerebellar granule neurons induced by the absence of p75NTR during development elicit social behavior deficits in mice. Front Mol Neurosci 2023; 16:1147597. [PMID: 37305555 PMCID: PMC10249730 DOI: 10.3389/fnmol.2023.1147597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/24/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction Recently, the cerebellum has been implicated with non-motor functions, including cognitive and emotional behavior. Anatomical and functional studies demonstrate bidirectional cerebellar connections with brain regions involved in social cognition. Cerebellar developmental abnormalities and injury are often associated with several psychiatric and mental disorders including autism spectrum disorders and anxiety. The cerebellar granule neurons (CGN) are essential for cerebellar function since they provide sensorimotor, proprioceptive, and contextual information to Purkinje cells to modify behavior in different contexts. Therefore, alterations to the CGN population are likely to compromise cerebellar processing and function. Previously we demonstrated that the p75 neurotrophin receptor (p75NTR) was fundamental for the development of the CGN. In the absence of p75NTR, we observed increased proliferation of the granule cell precursors (GCPs), followed by increased GCP migration toward the internal granule layer. The excess granule cells were incorporated into the cerebellar network, inducing alterations in cerebellar circuit processing. Methods In the present study, we used two conditional mouse lines to specifically delete the expression of p75NTR in CGN. In both mouse lines, deletion of the target gene was under the control of the transcription factor Atoh-1 promotor, however, one of the lines was also tamoxifen-inducible. Results We observed a loss of p75NTR expression from the GCPs in all cerebellar lobes. Compared to control animals, both mouse lines exhibited a reduced preference for social interactions when presented with a choice to interact with a mouse or an object. Open-field locomotor behavior and operant reward learning were unaffected in both lines. Lack of preference for social novelty and increased anxiety-related behavior was present in mice with constitutive p75NTR deletion; however, these effects were not present in the tamoxifen-inducible mice with p75NTR deletion that more specifically targeted the GCPs. Discussion Our findings demonstrate that alterations to CGN development by loss of p75NTR alter social behavior, and contribute to the increasing evidence that the cerebellum plays a role in non-motor-related behaviors, including social behavior.
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Affiliation(s)
- Juan Pablo Zanin
- Department of Biological Sciences, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Mansi A. Pandya
- Department of Biological Sciences, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Diego Espinoza
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Wilma J. Friedman
- Department of Biological Sciences, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Michael W. Shiflett
- Department of Psychology, Rutgers, The State University of New Jersey, Newark, NJ, United States
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19
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Li S, He S, Lu Y, Jia S, Liu Z. Epistatic genetic interactions between Insm1 and Ikzf2 during cochlear outer hair cell development. Cell Rep 2023; 42:112504. [PMID: 37171961 DOI: 10.1016/j.celrep.2023.112504] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/17/2023] [Accepted: 04/27/2023] [Indexed: 05/14/2023] Open
Abstract
The cochlea harbors two types of sound receptors, outer hair cells (OHCs) and inner hair cells (IHCs). OHCs transdifferentiate into IHCs in Insm1 mutants, and OHCs in Ikzf2-deficient mice are dysfunctional and maintain partial IHC gene expression. Insm1 potentially acts as a positive but indirect regulator of Ikzf2, considering that Insm1 is expressed earlier than Ikzf2 and primarily functions as a transcriptional repressor. However, direct evidence of this possibility is lacking. Here, we report the following results: first, Insm1 overexpression in IHCs leads to ectopic Ikzf2 expression. Second, Ikzf2 expression is repressed in Insm1-deficient OHCs, and forced expression of Ikzf2 mitigates the OHC abnormality in Insm1 mutants. Last, dual ablation of Insm1 and Ikzf2 generates a similar OHC phenotype as does Insm1 ablation alone. Collectively, our findings reveal the transcriptional cascade from Insm1 to Ikzf2, which should facilitate future investigation of the molecular mechanisms underlying OHC development and regeneration.
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Affiliation(s)
- Shuting Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shunji He
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ying Lu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shiqi Jia
- The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China.
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20
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Zine A, Fritzsch B. Early Steps towards Hearing: Placodes and Sensory Development. Int J Mol Sci 2023; 24:6994. [PMID: 37108158 PMCID: PMC10139157 DOI: 10.3390/ijms24086994] [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: 03/09/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
Sensorineural hearing loss is the most prevalent sensory deficit in humans. Most cases of hearing loss are due to the degeneration of key structures of the sensory pathway in the cochlea, such as the sensory hair cells, the primary auditory neurons, and their synaptic connection to the hair cells. Different cell-based strategies to replace damaged inner ear neurosensory tissue aiming at the restoration of regeneration or functional recovery are currently the subject of intensive research. Most of these cell-based treatment approaches require experimental in vitro models that rely on a fine understanding of the earliest morphogenetic steps that underlie the in vivo development of the inner ear since its initial induction from a common otic-epibranchial territory. This knowledge will be applied to various proposed experimental cell replacement strategies to either address the feasibility or identify novel therapeutic options for sensorineural hearing loss. In this review, we describe how ear and epibranchial placode development can be recapitulated by focusing on the cellular transformations that occur as the inner ear is converted from a thickening of the surface ectoderm next to the hindbrain known as the otic placode to an otocyst embedded in the head mesenchyme. Finally, we will highlight otic and epibranchial placode development and morphogenetic events towards progenitors of the inner ear and their neurosensory cell derivatives.
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Affiliation(s)
- Azel Zine
- LBN, Laboratory of Bioengineering and Nanoscience, University of Montpellier, 34193 Montpellier, France
| | - Bernd Fritzsch
- Department of Biology, CLAS, University of Iowa, Iowa City, IA 52242, USA
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21
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Origin of Neuroblasts in the Avian Otic Placode and Their Distributions in the Acoustic and Vestibular Ganglia. BIOLOGY 2023; 12:biology12030453. [PMID: 36979145 PMCID: PMC10045822 DOI: 10.3390/biology12030453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023]
Abstract
The inner ear is a complex three-dimensional sensorial structure with auditory and vestibular functions. This intricate sensory organ originates from the otic placode, which generates the sensory elements of the membranous labyrinth, as well as all the ganglionic neuronal precursors. How auditory and vestibular neurons establish their fate identities remains to be determined. Their topological origin in the incipient otic placode could provide positional information before they migrate, to later segregate in specific portions of the acoustic and vestibular ganglia. To address this question, transplants of small portions of the avian otic placode were performed according to our previous fate map study, using the quail/chick chimeric graft model. All grafts taking small areas of the neurogenic placodal domain contributed neuroblasts to both acoustic and vestibular ganglia. A differential distribution of otic neurons in the anterior and posterior lobes of the vestibular ganglion, as well as in the proximal, intermediate, and distal portions of the acoustic ganglion, was found. Our results clearly show that, in birds, there does not seem to be a strict segregation of acoustic and vestibular neurons in the incipient otic placode.
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22
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Wu PR, Chiang SY, Midence R, Kao WC, Lai CL, Cheng IC, Chou SJ, Chen CC, Huang CY, Chen RH. Wdr4 promotes cerebellar development and locomotion through Arhgap17-mediated Rac1 activation. Cell Death Dis 2023; 14:52. [PMID: 36681682 PMCID: PMC9867761 DOI: 10.1038/s41419-022-05442-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 01/22/2023]
Abstract
Patients with mutations of WDR4, a substrate adaptor of the CUL4 E3 ligase complex, develop cerebellar atrophy and gait phenotypes. However, the underlying mechanisms remain unexplored. Here, we identify a crucial role of Wdr4 in cerebellar development. Wdr4 deficiency in granule neuron progenitors (GNPs) not only reduces foliation and the sizes of external and internal granular layers but also compromises Purkinje neuron organization and the size of the molecular layer, leading to locomotion defects. Mechanistically, Wdr4 supports the proliferation of GNPs by preventing their cell cycle exit. This effect is mediated by Wdr4-induced ubiquitination and degradation of Arhgap17, thereby activating Rac1 to facilitate cell cycle progression. Disease-associated Wdr4 variants, however, cannot provide GNP cell cycle maintenance. Our study identifies Wdr4 as a previously unappreciated participant in cerebellar development and locomotion, providing potential insights into treatment strategies for diseases with WDR4 mutations, such as primordial dwarfism and Galloway-Mowat syndrome.
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Affiliation(s)
- Pei-Rung Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan.
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, 970, Taiwan.
| | - Shang-Yin Chiang
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - Robert Midence
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 115, Taiwan
| | - Wen-Chao Kao
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - Chun-Lun Lai
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan
| | - I-Cheng Cheng
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan
| | - Shen-Ju Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 115, Taiwan
| | - Chih-Yang Huang
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, 970, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, 404, Taiwan
| | - Ruey-Hwa Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, 115, Taiwan.
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23
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Closing the Gap between the Auditory Nerve and Cochlear Implant Electrodes: Which Neurotrophin Cocktail Performs Best for Axonal Outgrowth and Is Electrical Stimulation Beneficial? Int J Mol Sci 2023; 24:ijms24032013. [PMID: 36768339 PMCID: PMC9916558 DOI: 10.3390/ijms24032013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 01/22/2023] Open
Abstract
Neurotrophins promote neurite outgrowth of auditory neurons and may help closing the gap to cochlear implant (CI) electrodes to enhance electrical hearing. The best concentrations and mix of neurotrophins for this nerve regrowth are unknown. Whether electrical stimulation (ES) during outgrowth is beneficial or may direct axons is another open question. Auditory neuron explant cultures of distinct cochlear turns of 6-7 days old mice were cultured for four days. We tested different concentrations and combinations of BDNF and NT-3 and quantified the numbers and lengths of neurites with an advanced automated analysis. A custom-made 24-well electrical stimulator based on two bulk CIs served to test different ES strategies. Quantification of receptors trkB, trkC, p75NTR, and histological analysis helped to analyze effects. We found 25 ng/mL BDNF to perform best, especially in basal neurons, a negative influence of NT-3 in combined BDNF/NT-3 scenarios, and tonotopic changes in trk and p75NTR receptor stainings. ES largely impeded neurite outgrowth and glia ensheathment in an amplitude-dependent way. Apical neurons showed slight benefits in neurite numbers and length with ES at 10 and 500 µA. We recommend BDNF as a potent drug to enhance the man-machine interface, but CIs should be better activated after nerve regrowth.
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24
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Fritzsch B, Elliott KL, Yamoah EN. Neurosensory development of the four brainstem-projecting sensory systems and their integration in the telencephalon. Front Neural Circuits 2022; 16:913480. [PMID: 36213204 PMCID: PMC9539932 DOI: 10.3389/fncir.2022.913480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/23/2022] [Indexed: 11/18/2022] Open
Abstract
Somatosensory, taste, vestibular, and auditory information is first processed in the brainstem. From the brainstem, the respective information is relayed to specific regions within the cortex, where these inputs are further processed and integrated with other sensory systems to provide a comprehensive sensory experience. We provide the organization, genetics, and various neuronal connections of four sensory systems: trigeminal, taste, vestibular, and auditory systems. The development of trigeminal fibers is comparable to many sensory systems, for they project mostly contralaterally from the brainstem or spinal cord to the telencephalon. Taste bud information is primarily projected ipsilaterally through the thalamus to reach the insula. The vestibular fibers develop bilateral connections that eventually reach multiple areas of the cortex to provide a complex map. The auditory fibers project in a tonotopic contour to the auditory cortex. The spatial and tonotopic organization of trigeminal and auditory neuron projections are distinct from the taste and vestibular systems. The individual sensory projections within the cortex provide multi-sensory integration in the telencephalon that depends on context-dependent tertiary connections to integrate other cortical sensory systems across the four modalities.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology, The University of Iowa, Iowa City, IA, United States
- Department of Otolaryngology, The University of Iowa, Iowa City, IA, United States
- *Correspondence: Bernd Fritzsch,
| | - Karen L. Elliott
- Department of Biology, The University of Iowa, Iowa City, IA, United States
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno, NV, United States
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25
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Zhang H, Li H, Lu M, Wang S, Ma X, Wang F, Liu J, Li X, Yang H, Zhang F, Shen H, Buckley NJ, Gamper N, Yamoah EN, Lv P. Repressor element 1-silencing transcription factor deficiency yields profound hearing loss through K v7.4 channel upsurge in auditory neurons and hair cells. eLife 2022; 11:76754. [PMID: 36125121 PMCID: PMC9525063 DOI: 10.7554/elife.76754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Repressor element 1-silencing transcription factor (REST) is a transcriptional repressor that recognizes neuron-restrictive silencer elements in the mammalian genomes in a tissue- and cell-specific manner. The identity of REST target genes and molecular details of how REST regulates them are emerging. We performed conditional null deletion of Rest (cKO), mainly restricted to murine hair cells (HCs) and auditory neurons (aka spiral ganglion neurons [SGNs]). Null inactivation of full-length REST did not affect the development of normal HCs and SGNs but manifested as progressive hearing loss in adult mice. We found that the inactivation of REST resulted in an increased abundance of Kv7.4 channels at the transcript, protein, and functional levels. Specifically, we found that SGNs and HCs from Rest cKO mice displayed increased Kv7.4 expression and augmented Kv7 currents; SGN’s excitability was also significantly reduced. Administration of a compound with Kv7.4 channel activator activity, fasudil, recapitulated progressive hearing loss in mice. In contrast, inhibition of the Kv7 channels by XE991 rescued the auditory phenotype of Rest cKO mice. Previous studies identified some loss-of-function mutations within the Kv7.4-coding gene, Kcnq4, as a causative factor for progressive hearing loss in mice and humans. Thus, the findings reveal that a critical homeostatic Kv7.4 channel level is required for proper auditory functions.
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Affiliation(s)
- Haiwei Zhang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Hongchen Li
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Mingshun Lu
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Shengnan Wang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Xueya Ma
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Fei Wang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Jiaxi Liu
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Xinyu Li
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Haichao Yang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Fan Zhang
- Department of Pharmacology, Hebei Medical University, Hebei, China
| | - Haitao Shen
- Laboratory of Pathology, Hebei Medical University, Hebei, China
| | - Noel J Buckley
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Nikita Gamper
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada Reno, Reno, United States
| | - Ping Lv
- Department of Pharmacology, Hebei Medical University, Hebei, China
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26
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Joyner AL, Bayin NS. Cerebellum lineage allocation, morphogenesis and repair: impact of interplay amongst cells. Development 2022; 149:dev185587. [PMID: 36172987 PMCID: PMC9641654 DOI: 10.1242/dev.185587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The cerebellum has a simple cytoarchitecture consisting of a folded cortex with three cell layers that surrounds a nuclear structure housing the output neurons. The excitatory neurons are generated from a unique progenitor zone, the rhombic lip, whereas the inhibitory neurons and astrocytes are generated from the ventricular zone. The growth phase of the cerebellum is driven by lineage-restricted progenitor populations derived from each zone. Research during the past decade has uncovered the importance of cell-to-cell communication between the lineages through largely unknown signaling mechanisms for regulating the scaling of cell numbers and cell plasticity during mouse development and following injury in the neonatal (P0-P14) cerebellum. This Review focuses on how the interplay between cell types is key to morphogenesis, production of robust neural circuits and replenishment of cells after injury, and ends with a discussion of the implications of the greater complexity of the human cerebellar progenitor zones for development and disease.
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Affiliation(s)
- Alexandra L. Joyner
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Biochemistry Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - N. Sumru Bayin
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge University, Cambridge CB2 1NQ, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, UK
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27
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Filova I, Pysanenko K, Tavakoli M, Vochyanova S, Dvorakova M, Bohuslavova R, Smolik O, Fabriciova V, Hrabalova P, Benesova S, Valihrach L, Cerny J, Yamoah EN, Syka J, Fritzsch B, Pavlinkova G. ISL1 is necessary for auditory neuron development and contributes toward tonotopic organization. Proc Natl Acad Sci U S A 2022; 119:e2207433119. [PMID: 36074819 PMCID: PMC9478650 DOI: 10.1073/pnas.2207433119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 08/04/2022] [Indexed: 11/18/2022] Open
Abstract
A cardinal feature of the auditory pathway is frequency selectivity, represented in a tonotopic map from the cochlea to the cortex. The molecular determinants of the auditory frequency map are unknown. Here, we discovered that the transcription factor ISL1 regulates the molecular and cellular features of auditory neurons, including the formation of the spiral ganglion and peripheral and central processes that shape the tonotopic representation of the auditory map. We selectively knocked out Isl1 in auditory neurons using Neurod1Cre strategies. In the absence of Isl1, spiral ganglion neurons migrate into the central cochlea and beyond, and the cochlear wiring is profoundly reduced and disrupted. The central axons of Isl1 mutants lose their topographic projections and segregation at the cochlear nucleus. Transcriptome analysis of spiral ganglion neurons shows that Isl1 regulates neurogenesis, axonogenesis, migration, neurotransmission-related machinery, and synaptic communication patterns. We show that peripheral disorganization in the cochlea affects the physiological properties of hearing in the midbrain and auditory behavior. Surprisingly, auditory processing features are preserved despite the significant hearing impairment, revealing central auditory pathway resilience and plasticity in Isl1 mutant mice. Mutant mice have a reduced acoustic startle reflex, altered prepulse inhibition, and characteristics of compensatory neural hyperactivity centrally. Our findings show that ISL1 is one of the obligatory factors required to sculpt auditory structural and functional tonotopic maps. Still, upon Isl1 deletion, the ensuing central plasticity of the auditory pathway does not suffice to overcome developmentally induced peripheral dysfunction of the cochlea.
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Affiliation(s)
- Iva Filova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Kateryna Pysanenko
- Department of Auditory Neuroscience, Institute of Experimental Medicine Czech Academy of Sciences, 14220 Prague, Czechia
| | - Mitra Tavakoli
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Simona Vochyanova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Martina Dvorakova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Romana Bohuslavova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Ondrej Smolik
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Valeria Fabriciova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Petra Hrabalova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Sarka Benesova
- Laboratory of Gene Expression, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Lukas Valihrach
- Laboratory of Gene Expression, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
| | - Jiri Cerny
- Laboratory of Light Microscopy, Institute of Molecular Genetics Czech Academy of Sciences, 14220 Prague, Czechia
| | - Ebenezer N. Yamoah
- Department of Physiology, School of Medicine, University of Nevada, Reno, NV 89557
| | - Josef Syka
- Department of Auditory Neuroscience, Institute of Experimental Medicine Czech Academy of Sciences, 14220 Prague, Czechia
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA 52242-1324
- Department of Otolaryngology, University of Iowa, Iowa City, IA 52242-1324
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology Czech Academy of Sciences, 25250 Vestec, Czechia
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28
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O-GlcNAcylation promotes cerebellum development and medulloblastoma oncogenesis via SHH signaling. Proc Natl Acad Sci U S A 2022; 119:e2202821119. [PMID: 35969743 PMCID: PMC9407465 DOI: 10.1073/pnas.2202821119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cerebellar development relies on a precise coordination of metabolic signaling, epigenetic signaling, and transcriptional regulation. Here, we reveal that O-GlcNAc transferase (OGT) regulates cerebellar neurogenesis and medulloblastoma growth via a Sonic hedgehog (Shh)-Smo-Gli2 pathway. We identified Gli2 as a substrate of OGT, and unveiled cross-talk between O-GlcNAc and epigenetic signaling as a means to regulate Gli2 transcriptional activity. Moreover, genetic ablation or chemical inhibition of OGT significantly suppresses tumor progression and increases survival in a mouse model of Shh subgroup medulloblastoma. Taken together, the data in our study provide a line of inquiry to decipher the signaling mechanisms underlying cerebellar development, and highlights a potential target to investigate related pathologies, such as medulloblastoma. Sonic hedgehog (Shh) signaling plays a critical role in regulating cerebellum development by maintaining the physiological proliferation of granule neuron precursors (GNPs), and its dysregulation leads to the oncogenesis of medulloblastoma. O-GlcNAcylation (O-GlcNAc) of proteins is an emerging regulator of brain function that maintains normal development and neuronal circuitry. Here, we demonstrate that O-GlcNAc transferase (OGT) in GNPs mediate the cerebellum development, and the progression of the Shh subgroup of medulloblastoma. Specifically, OGT regulates the neurogenesis of GNPs by activating the Shh signaling pathway via O-GlcNAcylation at S355 of GLI family zinc finger 2 (Gli2), which in turn promotes its deacetylation and transcriptional activity via dissociation from p300, a histone acetyltransferases. Inhibition of OGT via genetic ablation or chemical inhibition improves survival in a medulloblastoma mouse model. These data uncover a critical role for O-GlcNAc signaling in cerebellar development, and pinpoint a potential therapeutic target for Shh-associated medulloblastoma.
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29
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Abstract
Cochlear hair cells (HCs) in the inner ear are responsible for sound detection. For HC fate specification, the master transcription factor Atoh1 is both necessary and sufficient. Atoh1 expression is dynamic and tightly regulated during development, but the cis-regulatory elements mediating this regulation remain unresolved. Unexpectedly, we found that deleting the only recognized Atoh1 enhancer, defined here as Eh1, failed to impair HC development. By using the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), we discovered two additional Atoh1 enhancers: Eh2 and Eh3. Notably, Eh2 deletion was sufficient for impairing HC development, and concurrent deletion of Eh1 and Eh2 or all three enhancers resulted in nearly complete absence of HCs. Lastly, we showed that Atoh1 binds to all three enhancers, consistent with its autoregulatory function. Our findings reveal that the cooperative action of three distinct enhancers underpins effective Atoh1 regulation during HC development, indicating potential therapeutic approaches for HC regeneration.
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30
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Khouri-Farah N, Guo Q, Morgan K, Shin J, Li JYH. Integrated single-cell transcriptomic and epigenetic study of cell state transition and lineage commitment in embryonic mouse cerebellum. SCIENCE ADVANCES 2022; 8:eabl9156. [PMID: 35363520 PMCID: PMC10938588 DOI: 10.1126/sciadv.abl9156] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Recent studies using single-cell RNA-sequencing have revealed cellular heterogeneity in the developing mammalian cerebellum, yet the regulatory logic underlying this cellular diversity remains to be elucidated. Using integrated single-cell RNA and ATAC analyses, we resolved developmental trajectories of cerebellar progenitors and identified putative trans- and cis-elements that control cell state transition. We reverse engineered gene regulatory networks (GRNs) of each cerebellar cell type. Through in silico simulations and in vivo experiments, we validated the efficacy of GRN analyses and uncovered the molecular control of a posterior transitory zone (PTZ), a distinct progenitor zone residing immediately anterior to the morphologically defined rhombic lip (RL). We showed that perturbing cell fate specification in the PTZ and RL causes posterior cerebellar vermis hypoplasia, the most common cerebellar birth defect in humans. Our study provides a foundation for comprehensive studies of developmental programs of the mammalian cerebellum.
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Affiliation(s)
- Nagham Khouri-Farah
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Qiuxia Guo
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Kerry Morgan
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - Jihye Shin
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
| | - James Y. H. Li
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, 263 Farmington Avenue, Farmington, CT 06030-6403, USA
- Institute for Systems Genomics, University of Connecticut, 400 Farmington Avenue, Farmington, CT 06030-6403, USA
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31
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Fertuzinhos S, Legué E, Li D, Liem KF. A dominant tubulin mutation causes cerebellar neurodegeneration in a genetic model of tubulinopathy. SCIENCE ADVANCES 2022; 8:eabf7262. [PMID: 35171680 PMCID: PMC8849301 DOI: 10.1126/sciadv.abf7262] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Mutations in tubulins cause distinct neurodevelopmental and degenerative diseases termed "tubulinopathies"; however, little is known about the functional requirements of tubulins or how mutations cause cell-specific pathologies. Here, we identify a mutation in the gene Tubb4a that causes degeneration of cerebellar granule neurons and myelination defects. We show that the neural phenotypes result from a cell type-specific enrichment of a dominant mutant form of Tubb4a relative to the expression other β-tubulin isotypes. Loss of Tubb4a function does not underlie cellular pathology but is compensated by the transcriptional up-regulation of related tubulin genes in a cell type-specific manner. This work establishes that the expression of a primary tubulin mutation in mature neurons is sufficient to promote cell-autonomous cell death, consistent with a causative association of microtubule dysfunction with neurodegenerative diseases. These studies provide evidence that mutations in tubulins cause specific phenotypes based on expression ratios of tubulin isotype genes.
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Affiliation(s)
- Sofia Fertuzinhos
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Davis Li
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Karel F. Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
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32
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Elliott KL, Fritzsch B, Yamoah EN, Zine A. Age-Related Hearing Loss: Sensory and Neural Etiology and Their Interdependence. Front Aging Neurosci 2022; 14:814528. [PMID: 35250542 PMCID: PMC8891613 DOI: 10.3389/fnagi.2022.814528] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/03/2022] [Indexed: 12/19/2022] Open
Abstract
Age-related hearing loss (ARHL) is a common, increasing problem for older adults, affecting about 1 billion people by 2050. We aim to correlate the different reductions of hearing from cochlear hair cells (HCs), spiral ganglion neurons (SGNs), cochlear nuclei (CN), and superior olivary complex (SOC) with the analysis of various reasons for each one on the sensory deficit profiles. Outer HCs show a progressive loss in a basal-to-apical gradient, and inner HCs show a loss in a apex-to-base progression that results in ARHL at high frequencies after 70 years of age. In early neonates, SGNs innervation of cochlear HCs is maintained. Loss of SGNs results in a considerable decrease (~50% or more) of cochlear nuclei in neonates, though the loss is milder in older mice and humans. The dorsal cochlear nuclei (fusiform neurons) project directly to the inferior colliculi while most anterior cochlear nuclei reach the SOC. Reducing the number of neurons in the medial nucleus of the trapezoid body (MNTB) affects the interactions with the lateral superior olive to fine-tune ipsi- and contralateral projections that may remain normal in mice, possibly humans. The inferior colliculi receive direct cochlear fibers and second-order fibers from the superior olivary complex. Loss of the second-order fibers leads to hearing loss in mice and humans. Although ARHL may arise from many complex causes, HC degeneration remains the more significant problem of hearing restoration that would replace the cochlear implant. The review presents recent findings of older humans and mice with hearing loss.
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Affiliation(s)
- Karen L. Elliott
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, United States
- *Correspondence: Bernd Fritzsch
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Azel Zine
- LBN, Laboratory of Bioengineering and Nanoscience, University of Montpellier, Montpellier, France
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33
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Filova I, Bohuslavova R, Tavakoli M, Yamoah EN, Fritzsch B, Pavlinkova G. Early Deletion of Neurod1 Alters Neuronal Lineage Potential and Diminishes Neurogenesis in the Inner Ear. Front Cell Dev Biol 2022; 10:845461. [PMID: 35252209 PMCID: PMC8894106 DOI: 10.3389/fcell.2022.845461] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal development in the inner ear is initiated by expression of the proneural basic Helix-Loop-Helix (bHLH) transcription factor Neurogenin1 that specifies neuronal precursors in the otocyst. The initial specification of the neuroblasts within the otic epithelium is followed by the expression of an additional bHLH factor, Neurod1. Although NEUROD1 is essential for inner ear neuronal development, the different aspects of the temporal and spatial requirements of NEUROD1 for the inner ear and, mainly, for auditory neuron development are not fully understood. In this study, using Foxg1Cre for the early elimination of Neurod1 in the mouse otocyst, we showed that Neurod1 deletion results in a massive reduction of differentiating neurons in the otic ganglion at E10.5, and in the diminished vestibular and rudimental spiral ganglia at E13.5. Attenuated neuronal development was associated with reduced and disorganized sensory epithelia, formation of ectopic hair cells, and the shortened cochlea in the inner ear. Central projections of inner ear neurons with conditional Neurod1 deletion are reduced, unsegregated, disorganized, and interconnecting the vestibular and auditory systems. In line with decreased afferent input from auditory neurons, the volume of cochlear nuclei was reduced by 60% in Neurod1 mutant mice. Finally, our data demonstrate that early elimination of Neurod1 affects the neuronal lineage potential and alters the generation of inner ear neurons and cochlear afferents with a profound effect on the first auditory nuclei, the cochlear nuclei.
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Affiliation(s)
- Iva Filova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Romana Bohuslavova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Mitra Tavakoli
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, Institute for Neuroscience, University of Nevada, Reno, NV, United States
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, United States
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenesis, Institute of Biotechnology CAS, Vestec, Czechia
- *Correspondence: Gabriela Pavlinkova,
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34
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Stoner ZA, Ketchum EM, Sheltz-Kempf S, Blinkiewicz PV, Elliott KL, Duncan JS. Fzd3 Expression Within Inner Ear Afferent Neurons Is Necessary for Central Pathfinding. Front Neurosci 2022; 15:779871. [PMID: 35153658 PMCID: PMC8828977 DOI: 10.3389/fnins.2021.779871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/29/2021] [Indexed: 11/29/2022] Open
Abstract
During development the afferent neurons of the inner ear make precise wiring decisions in the hindbrain reflective of their topographic distribution in the periphery. This is critical for the formation of sensory maps capable of faithfully processing both auditory and vestibular input. Disorganized central projections of inner ear afferents in Fzd3 null mice indicate Wnt/PCP signaling is involved in this process and ear transplantation in Xenopus indicates that Fzd3 is necessary in the ear but not the hindbrain for proper afferent navigation. However, it remains unclear in which cell type of the inner ear Fzd3 expression is influencing the guidance of inner ear afferents to their proper synaptic targets in the hindbrain. We utilized Atoh1-cre and Neurod1-cre mouse lines to conditionally knockout Fzd3 within the mechanosensory hair cells of the organ of Corti and within the inner ear afferents, respectively. Following conditional deletion of Fzd3 within the hair cells, the central topographic distribution of inner ear afferents was maintained with no gross morphological defects. In contrast, conditional deletion of Fzd3 within inner ear afferents leads to central pathfinding defects of both cochlear and vestibular afferents. Here, we show that Fzd3 is acting in a cell autonomous manner within inner ear afferents to regulate central pathfinding within the hindbrain.
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Affiliation(s)
- Zachary A. Stoner
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
| | - Elizabeth M. Ketchum
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
| | - Sydney Sheltz-Kempf
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
| | - Paige V. Blinkiewicz
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
| | - Karen L. Elliott
- Department of Biology, University of Iowa, Iowa City, IA, United States
- *Correspondence: Karen L. Elliott,
| | - Jeremy S. Duncan
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States
- Department of Biomedical Sciences, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, United States
- Jeremy S. Duncan,
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35
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Li S, Fan T, Li C, Wang Y, Li J, Liu Z. Fate-mapping analysis of cochlear cells expressing Atoh1 mRNA via a new Atoh1 3*HA-P2A-Cre knockin mouse strain. Dev Dyn 2022; 251:1156-1174. [PMID: 35038200 DOI: 10.1002/dvdy.453] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Atoh1 is recognized to be essential for cochlear hair cell (HC) development. However, Atoh1 temporal and spatial expression patterns remain widely debated. Here, we aimed to obtain evidence to resolve the controversies regarding Atoh1 expression by generating a new knockin mouse strain: Atoh13*HA-P2A-Cre . RESULTS Fate-mapping analysis of Atoh13*HA-P2A-Cre/+ ; Rosa26-CAG-LSL-tdTomato (Ai9)/+ mice enabled us to concurrently characterize the temporal expression of Atoh1 protein (through HA-tag immunostaining) and visualize the cells expressing Atoh1 mRNA (as tdTomato+ cells). Our findings show that whereas Atoh1 mRNA expression is rapidly turned on in early cochlear progenitors, Atoh1 protein is only detected in differentiating HCs or progenitors just committed to the HC fate. Cre activity is also stronger in Atoh13*HA-P2A-Cre/+ than in previous mouse models, because almost all cochlear HCs and nearby supporting cells here are tdTomato+. Furthermore, tdTomato, but not HA, is expressed in middle and apical spiral ganglion neurons. CONCLUSION Collectively, our findings indicate that Atoh13*HA-P2A-Cre can serve as a powerful genetic model in the developmental biology field. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Shuting Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Ting Fan
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, National Health and Family Planning Commission (NHFPC), Shanghai, China
| | - Chao Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yunfeng Wang
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, National Health and Family Planning Commission (NHFPC), Shanghai, China
| | - Jian Li
- Clinical Laboratory Center, Children's Hospital of Fudan University, Shanghai, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
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36
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Ferguson CJ, Urso O, Bodrug T, Gassaway BM, Watson ER, Prabu JR, Lara-Gonzalez P, Martinez-Chacin RC, Wu DY, Brigatti KW, Puffenberger EG, Taylor CM, Haas-Givler B, Jinks RN, Strauss KA, Desai A, Gabel HW, Gygi SP, Schulman BA, Brown NG, Bonni A. APC7 mediates ubiquitin signaling in constitutive heterochromatin in the developing mammalian brain. Mol Cell 2022; 82:90-105.e13. [PMID: 34942119 PMCID: PMC8741739 DOI: 10.1016/j.molcel.2021.11.031] [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: 12/08/2020] [Revised: 10/14/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022]
Abstract
Neurodevelopmental cognitive disorders provide insights into mechanisms of human brain development. Here, we report an intellectual disability syndrome caused by the loss of APC7, a core component of the E3 ubiquitin ligase anaphase promoting complex (APC). In mechanistic studies, we uncover a critical role for APC7 during the recruitment and ubiquitination of APC substrates. In proteomics analyses of the brain from mice harboring the patient-specific APC7 mutation, we identify the chromatin-associated protein Ki-67 as an APC7-dependent substrate of the APC in neurons. Conditional knockout of the APC coactivator protein Cdh1, but not Cdc20, leads to the accumulation of Ki-67 protein in neurons in vivo, suggesting that APC7 is required for the function of Cdh1-APC in the brain. Deregulated neuronal Ki-67 upon APC7 loss localizes predominantly to constitutive heterochromatin. Our findings define an essential function for APC7 and Cdh1-APC in neuronal heterochromatin regulation, with implications for understanding human brain development and disease.
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Affiliation(s)
- Cole J Ferguson
- Department of Neuroscience, Washington University, St. Louis, MO 63110, USA; Department of Pathology & Immunology, Neuropathology Division, Physician-Scientist Training Program, Washington University, St. Louis, MO 63110, USA
| | - Olivia Urso
- Department of Neuroscience, Washington University, St. Louis, MO 63110, USA
| | - Tatyana Bodrug
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | | | | - Pablo Lara-Gonzalez
- Department of Cellular and Molecular Medicine, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Raquel C Martinez-Chacin
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Dennis Y Wu
- Department of Neuroscience, Washington University, St. Louis, MO 63110, USA
| | | | | | - Cora M Taylor
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Barbara Haas-Givler
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, PA 17837, USA
| | - Robert N Jinks
- Department of Biology, Franklin and Marshall College, Lancaster, PA 17603, USA
| | | | - Arshad Desai
- Department of Cellular and Molecular Medicine, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Harrison W Gabel
- Department of Neuroscience, Washington University, St. Louis, MO 63110, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard University, Boston, MA 02138, USA
| | | | - Nicholas G Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Azad Bonni
- Department of Neuroscience, Washington University, St. Louis, MO 63110, USA.
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37
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Du H, Zhou H, Sun Y, Zhai X, Chen Z, Wang Y, Xu Z. The Rho GTPase Cell Division Cycle 42 Regulates Stereocilia Development in Cochlear Hair Cells. Front Cell Dev Biol 2021; 9:765559. [PMID: 34746154 PMCID: PMC8570139 DOI: 10.3389/fcell.2021.765559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022] Open
Abstract
Stereocilia are actin-based cell protrusions on the apical surface of inner ear hair cells, playing a pivotal role in hearing and balancing sensation. The development and maintenance of stereocilia is tightly regulated and deficits in this process usually lead to hearing or balancing disorders. The Rho GTPase cell division cycle 42 (CDC42) is a key regulator of the actin cytoskeleton. It has been reported to localize in the hair cell stereocilia and play important roles in stereocilia maintenance. In the present work, we utilized hair cell-specific Cdc42 knockout mice and CDC42 inhibitor ML141 to explore the role of CDC42 in stereocilia development. Our data show that stereocilia height and width as well as stereocilia resorption are affected in Cdc42-deficient cochlear hair cells when examined at postnatal day 8 (P8). Moreover, ML141 treatment leads to planar cell polarity (PCP) deficits in neonatal hair cells. We also show that overexpression of a constitutively active mutant CDC42 in cochlear hair cells leads to enhanced stereocilia developmental deficits. In conclusion, the present data suggest that CDC42 plays a pivotal role in regulating hair cell stereocilia development.
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Affiliation(s)
- Haibo Du
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Hao Zhou
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Yixiao Sun
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Xiaoyan Zhai
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Zhengjun Chen
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.,School of Life Sciences and Technology, ShanghaiTech University, Shanghai, China
| | - Yanfei Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.,Shandong Provincial Collaborative Innovation Center of Cell Biology, Shandong Normal University, Jinan, China
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38
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Ahmed M, Moon R, Prajapati RS, James E, Basson MA, Streit A. The chromatin remodelling factor Chd7 protects auditory neurons and sensory hair cells from stress-induced degeneration. Commun Biol 2021; 4:1260. [PMID: 34732824 PMCID: PMC8566505 DOI: 10.1038/s42003-021-02788-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 10/08/2021] [Indexed: 11/08/2022] Open
Abstract
Neurons and sensory cells are particularly vulnerable to oxidative stress due to their high oxygen demand during stimulus perception and transmission. The mechanisms that protect them from stress-induced death and degeneration remain elusive. Here we show that embryonic deletion of the chromodomain helicase DNA-binding protein 7 (CHD7) in auditory neurons or hair cells leads to sensorineural hearing loss due to postnatal degeneration of both cell types. Mechanistically, we demonstrate that CHD7 controls the expression of major stress pathway components. In its absence, hair cells are hypersensitive, dying rapidly after brief exposure to stress inducers, suggesting that sound at the onset of hearing triggers their degeneration. In humans, CHD7 haploinsufficiency causes CHARGE syndrome, a disorder affecting multiple organs including the ear. Our findings suggest that CHD7 mutations cause developmentally silent phenotypes that predispose cells to postnatal degeneration due to a failure of protective mechanisms.
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Affiliation(s)
- Mohi Ahmed
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK.
| | - Ruth Moon
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
| | - Ravindra Singh Prajapati
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
- Leukaemia and Stem Cell Biology Group, School of Cancer and Pharmaceutical Sciences, King's College London, London, SE5 9NU, UK
| | - Elysia James
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE1 1UL, UK
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, SE1 1UL, UK
| | - Andrea Streit
- Centre for Craniofacial and Regenerative Biology, Floor 27 Tower Wing, Guy's Hospital, King's College London, London, SE1 9RT, UK.
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39
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Hoshino N, Altarshan Y, Alzein A, Fernando AM, Nguyen HT, Majewski EF, Chen VCF, William Rochlin M, Yu WM. Ephrin-A3 is required for tonotopic map precision and auditory functions in the mouse auditory brainstem. J Comp Neurol 2021; 529:3633-3654. [PMID: 34235739 PMCID: PMC8490280 DOI: 10.1002/cne.25213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/22/2021] [Accepted: 07/02/2021] [Indexed: 01/09/2023]
Abstract
Tonotopy is a prominent feature of the vertebrate auditory system and forms the basis for sound discrimination, but the molecular mechanism that underlies its formation remains largely elusive. Ephrin/Eph signaling is known to play important roles in axon guidance during topographic mapping in other sensory systems, so we investigated its possible role in the establishment of tonotopy in the mouse cochlear nucleus. We found that ephrin-A3 molecules are differentially expressed along the tonotopic axis in the cochlear nucleus during innervation. Ephrin-A3 forward signaling is sufficient to repel auditory nerve fibers in a developmental stage-dependent manner. In mice lacking ephrin-A3, the tonotopic map is degraded and isofrequency bands of neuronal activation upon pure tone exposure become imprecise in the anteroventral cochlear nucleus. Ephrin-A3 mutant mice also exhibit a delayed second wave in auditory brainstem responses upon sound stimuli and impaired detection of sound frequency changes. Our findings establish an essential role for ephrin-A3 in forming precise tonotopy in the auditory brainstem to ensure accurate sound discrimination.
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Affiliation(s)
- Natalia Hoshino
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | - Yazan Altarshan
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | - Ahmad Alzein
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | - Amali M. Fernando
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | - Hieu T. Nguyen
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | - Emma F. Majewski
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
| | | | | | - Wei-Ming Yu
- Department of Biology, Loyola University of Chicago, Chicago, Illinois
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40
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Almasoudi SH, Schlosser G. Otic Neurogenesis in Xenopus laevis: Proliferation, Differentiation, and the Role of Eya1. Front Neuroanat 2021; 15:722374. [PMID: 34616280 PMCID: PMC8488300 DOI: 10.3389/fnana.2021.722374] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/27/2021] [Indexed: 11/15/2022] Open
Abstract
Using immunostaining and confocal microscopy, we here provide the first detailed description of otic neurogenesis in Xenopus laevis. We show that the otic vesicle comprises a pseudostratified epithelium with apicobasal polarity (apical enrichment of Par3, aPKC, phosphorylated Myosin light chain, N-cadherin) and interkinetic nuclear migration (apical localization of mitotic, pH3-positive cells). A Sox3-immunopositive neurosensory area in the ventromedial otic vesicle gives rise to neuroblasts, which delaminate through breaches in the basal lamina between stages 26/27 and 39. Delaminated cells congregate to form the vestibulocochlear ganglion, whose peripheral cells continue to proliferate (as judged by EdU incorporation), while central cells differentiate into Islet1/2-immunopositive neurons from stage 29 on and send out neurites at stage 31. The central part of the neurosensory area retains Sox3 but stops proliferating from stage 33, forming the first sensory areas (utricular/saccular maculae). The phosphatase and transcriptional coactivator Eya1 has previously been shown to play a central role for otic neurogenesis but the underlying mechanism is poorly understood. Using an antibody specifically raised against Xenopus Eya1, we characterize the subcellular localization of Eya1 proteins, their levels of expression as well as their distribution in relation to progenitor and neuronal differentiation markers during otic neurogenesis. We show that Eya1 protein localizes to both nuclei and cytoplasm in the otic epithelium, with levels of nuclear Eya1 declining in differentiating (Islet1/2+) vestibulocochlear ganglion neurons and in the developing sensory areas. Morpholino-based knockdown of Eya1 leads to reduction of proliferating, Sox3- and Islet1/2-immunopositive cells, redistribution of cell polarity proteins and loss of N-cadherin suggesting that Eya1 is required for maintenance of epithelial cells with apicobasal polarity, progenitor proliferation and neuronal differentiation during otic neurogenesis.
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Affiliation(s)
| | - Gerhard Schlosser
- School of Natural Sciences, National University of Galway, Galway, Ireland
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41
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Mackowetzky K, Yoon KH, Mackowetzky EJ, Waskiewicz AJ. Development and evolution of the vestibular apparatuses of the inner ear. J Anat 2021; 239:801-828. [PMID: 34047378 PMCID: PMC8450482 DOI: 10.1111/joa.13459] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/07/2021] [Accepted: 05/06/2021] [Indexed: 12/16/2022] Open
Abstract
The vertebrate inner ear is a labyrinthine sensory organ responsible for perceiving sound and body motion. While a great deal of research has been invested in understanding the auditory system, a growing body of work has begun to delineate the complex developmental program behind the apparatuses of the inner ear involved with vestibular function. These animal studies have helped identify genes involved in inner ear development and model syndromes known to include vestibular dysfunction, paving the way for generating treatments for people suffering from these disorders. This review will provide an overview of known inner ear anatomy and function and summarize the exciting discoveries behind inner ear development and the evolution of its vestibular apparatuses.
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Affiliation(s)
- Kacey Mackowetzky
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Kevin H. Yoon
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | | | - Andrew J. Waskiewicz
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
- Women & Children’s Health Research InstituteUniversity of AlbertaEdmontonAlbertaCanada
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42
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Reddy NC, Majidi SP, Kong L, Nemera M, Ferguson CJ, Moore M, Goncalves TM, Liu HK, Fitzpatrick JAJ, Zhao G, Yamada T, Bonni A, Gabel HW. CHARGE syndrome protein CHD7 regulates epigenomic activation of enhancers in granule cell precursors and gyrification of the cerebellum. Nat Commun 2021; 12:5702. [PMID: 34588434 PMCID: PMC8481233 DOI: 10.1038/s41467-021-25846-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/01/2021] [Indexed: 12/16/2022] Open
Abstract
Regulation of chromatin plays fundamental roles in the development of the brain. Haploinsufficiency of the chromatin remodeling enzyme CHD7 causes CHARGE syndrome, a genetic disorder that affects the development of the cerebellum. However, how CHD7 controls chromatin states in the cerebellum remains incompletely understood. Using conditional knockout of CHD7 in granule cell precursors in the mouse cerebellum, we find that CHD7 robustly promotes chromatin accessibility, active histone modifications, and RNA polymerase recruitment at enhancers. In vivo profiling of genome architecture reveals that CHD7 concordantly regulates epigenomic modifications associated with enhancer activation and gene expression of topologically-interacting genes. Genome and gene ontology studies show that CHD7-regulated enhancers are associated with genes that control brain tissue morphogenesis. Accordingly, conditional knockout of CHD7 triggers a striking phenotype of cerebellar polymicrogyria, which we have also found in a case of CHARGE syndrome. Finally, we uncover a CHD7-dependent switch in the preferred orientation of granule cell precursor division in the developing cerebellum, providing a potential cellular basis for the cerebellar polymicrogyria phenotype upon loss of CHD7. Collectively, our findings define epigenomic regulation by CHD7 in granule cell precursors and identify abnormal cerebellar patterning upon CHD7 depletion, with potential implications for our understanding of CHARGE syndrome. CHARGE syndrome that affects cerebellar development can be caused by haploinsufficiency of the chromatin remodeling enzyme CHD7; however the precise role of CHD7 remains unknown. Here the authors show CHD7 promotes chromatin accessibility and enhancer activity in granule cell precursors and regulates morphogenesis of the cerebellar cortex, where loss of CHD7 triggers cerebellar polymicrogyria.
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Affiliation(s)
- Naveen C Reddy
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Shahriyar P Majidi
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.,MD-PhD Program, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Lingchun Kong
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Mati Nemera
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Cole J Ferguson
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Michael Moore
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tassia M Goncalves
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hai-Kun Liu
- Division of Molecular Neurogenetics, DKFZ-ZMBH Alliance, German Cancer Research Center Im Neunheimer Feld 280, 69120, Heidelberg, Germany
| | - James A J Fitzpatrick
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.,Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Guoyan Zhao
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tomoko Yamada
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Department of Neurobiology, Northwestern University, Evanston, IL, 60201, USA
| | - Azad Bonni
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Harrison W Gabel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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Liu F, Shao J, Yang H, Yang G, Zhu Q, Wu Y, Zhu L, Wu H. Disruption of rack1 suppresses SHH-type medulloblastoma formation in mice. CNS Neurosci Ther 2021; 27:1518-1530. [PMID: 34480519 PMCID: PMC8611787 DOI: 10.1111/cns.13728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 11/27/2022] Open
Abstract
Introduction Medulloblastoma (MB) is a malignant pediatric brain tumor that arises in the cerebellar granular neurons. Sonic Hedgehog subtype of MB (SHH‐MB) is one of the major subtypes of MB in the clinic. However, the molecular mechanisms underlying MB tumorigenesis are still not fully understood. Aims Our previous work demonstrated that the receptor for activated C kinase 1 (Rack1) is essential for SHH signaling activation in granule neuron progenitors (GNPs) during cerebellar development. To investigate the potential role of Rack1 in MB development, human MB tissue array and SHH‐MB genetic mouse model were used to study the expression of function of Rack1 in MB pathogenesis. Results We found that the expression of Rack1 was significantly upregulated in the majority of human cerebellar MB tumors. Genetic ablation of Rack1 expression in SHH‐MB tumor mice could significantly inhibit MB proliferation, reduce the tumor size, and prolong the survival of tumor rescue mice. Interestingly, neither apoptosis nor autophagy levels were affected in Rack1‐deletion rescue mice compared to WT mice, but the expression of Gli1 and HDAC2 was significantly decreased suggesting the inactivation of SHH signaling pathway in rescue mice. Conclusion Our results demonstrated that Rack1 may serve as a potential candidate for the diagnostic marker and therapeutic target of MB, including SHH‐MB.
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Affiliation(s)
- Fengjiao Liu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Jingyuan Shao
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Haihong Yang
- Department of Anesthesiology, The General Hospital of Western Theater Command, Chengdu, China
| | - Guochao Yang
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Zhu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yan Wu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Lingling Zhu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Haitao Wu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China.,Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Chinese Institute for Brain Research, Beijing, China
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44
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Sun S, Li S, Luo Z, Ren M, He S, Wang G, Liu Z. Dual expression of Atoh1 and Ikzf2 promotes transformation of adult cochlear supporting cells into outer hair cells. eLife 2021; 10:66547. [PMID: 34477109 PMCID: PMC8439656 DOI: 10.7554/elife.66547] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 09/02/2021] [Indexed: 12/24/2022] Open
Abstract
Mammalian cochlear outer hair cells (OHCs) are essential for hearing. Severe hearing impairment follows OHC degeneration. Previous attempts at regenerating new OHCs from cochlear supporting cells (SCs) have been unsuccessful, notably lacking expression of the key OHC motor protein, Prestin. Thus, regeneration of Prestin+ OHCs represents a barrier to restore auditory function in vivo. Here, we reported the successful in vivo conversion of adult mouse cochlear SCs into Prestin+ OHC-like cells through the concurrent induction of two key transcriptional factors known to be necessary for OHC development: Atoh1 and Ikzf2. Single-cell RNA sequencing revealed the upregulation of 729 OHC genes and downregulation of 331 SC genes in OHC-like cells. The resulting differentiation status of these OHC-like cells was much more advanced than previously achieved. This study thus established an efficient approach to induce the regeneration of Prestin+ OHCs, paving the way for in vivo cochlear repair via SC transdifferentiation.
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Affiliation(s)
- Suhong Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Shuting Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhengnan Luo
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Minhui Ren
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Shunji He
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Guangqin Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
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45
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Tang Q, Xie MY, Zhang YL, Xue RY, Zhu XH, Yang H. Targeted deletion of Atoh8 results in severe hearing loss in mice. Genesis 2021; 59:e23442. [PMID: 34402594 PMCID: PMC9286369 DOI: 10.1002/dvg.23442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 08/01/2021] [Accepted: 08/02/2021] [Indexed: 11/29/2022]
Abstract
Atoh8, also named Math6, is a bHLH gene reported to have important functions in the developing nervous system, pancreas and kidney. However, the expression pattern and function of Atoh8 in the inner ear are still unclear. To study the function of Atoh8 in the developing mouse inner ear, we performed targeted deletion of Atoh8 by intercrossing Atoh8lacZ/+ mice. We studied the expression pattern of Atoh8 in the inner ear and found interesting results that Atoh8‐null (Atoh8lacZ/lacZ) mice were viable but smaller than their littermates and they were severely hearing impaired, which was confirmed by hearing tests (ABR, DPOAE). We collected 129 viable newborns from 18 litters by crossing Atoh8lacZ/+ mice and found that the distributions of Atoh8lacZ/+, Atoh8lacZ/lacZ and wild type were very close to their expected Mendelian ratio by χ2 testing. However, no remarkable morphological changes in cochleae in mutant mice were detected under plastic sectioning and electron microscopy. No remarkable differences in the expression of Myosin6, Prestin, TrkC, GAD65, Tuj1, or Calretinin were detected between the mutant mice and the control mice. These findings indicate that Atoh8 plays an important role in the development of normal hearing, while further studies are required to elucidate its exact function in hearing.
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Affiliation(s)
- Qi Tang
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Meng-Yao Xie
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yong-Li Zhang
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ruo-Yan Xue
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Hui Zhu
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hua Yang
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Translational Medicine Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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46
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Xu J, Yu D, Dong X, Xie X, Xu M, Guo L, Huang L, Tang Q, Gan L. GATA3 maintains the quiescent state of cochlear supporting cells by regulating p27 kip1. Sci Rep 2021; 11:15779. [PMID: 34349220 PMCID: PMC8338922 DOI: 10.1038/s41598-021-95427-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/26/2021] [Indexed: 01/22/2023] Open
Abstract
Haplo-insufficiency of the GATA3 gene causes hypoparathyroidism, sensorineural hearing loss, and renal disease (HDR) syndrome. Previous studies have shown that Gata3 is required for the development of the prosensory domain and spiral ganglion neurons (SGNs) of the mouse cochlea during embryogenesis. However, its role in supporting cells (SCs) after cell fate specification is largely unknown. In this study, we used tamoxifen-inducible Sox2CreERT2 mice to delete Gata3 in SCs of the neonatal mouse cochlea and showed that loss of Gata3 resulted in the proliferation of SCs, including the inner pillar cells (IPCs), inner border cells (IBCs), and lateral greater epithelium ridge (GER). In addition, loss of Gata3 resulted in the down-regulation of p27kip1, a cell cycle inhibitor, in the SCs of Gata3-CKO neonatal cochleae. Chromatin immunoprecipitation analysis revealed that GATA3 directly binds to p27kip1 promoter and could maintain the quiescent state of cochlear SCs by regulating p27kip1 expression. Furthermore, RNA-seq analysis revealed that loss of Gata3 function resulted in the change in the expression of genes essential for the development and function of cochlear SCs, including Tectb, Cyp26b1, Slitrk6, Ano1, and Aqp4.
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Affiliation(s)
- Jiadong Xu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Dongliang Yu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, Zhejiang, China
| | - Xuhui Dong
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Xiaoling Xie
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Mei Xu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Luming Guo
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Liang Huang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Qi Tang
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
- Department of Otolaryngology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lin Gan
- Department of Ophthalmology and Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA.
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
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An Integrated Perspective of Evolution and Development: From Genes to Function to Ear, Lateral Line and Electroreception. DIVERSITY 2021; 13. [PMID: 35505776 PMCID: PMC9060560 DOI: 10.3390/d13080364] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Four sensory systems (vestibular, lateral line, electroreception, auditory) are unique and project exclusively to the brainstem of vertebrates. All sensory neurons depend on a common set of genes (Eya1, Sox2, Neurog1, Neurod1) that project to a dorsal nucleus and an intermediate nucleus, which differentiate into the vestibular ear, lateral line and electroreception in vertebrates. In tetrapods, a loss of two sensory systems (lateral line, electroreception) leads to the development of a unique ear and auditory system in amniotes. Lmx1a/b, Gdf7, Wnt1/3a, BMP4/7 and Atoh1 define the lateral line, electroreception and auditory nuclei. In contrast, vestibular nuclei depend on Neurog1/2, Ascl1, Ptf1a and Olig3, among others, to develop an independent origin of the vestibular nuclei. A common origin of hair cells depends on Eya1, Sox2 and Atoh1, which generate the mechanosensory cells. Several proteins define the polarity of hair cells in the ear and lateral line. A unique connection of stereocilia requires CDH23 and PCDH15 for connections and TMC1/2 proteins to perceive mechanosensory input. Electroreception has no polarity, and a different system is used to drive electroreceptors. All hair cells function by excitation via ribbons to activate neurons that innervate the distinct target areas. An integrated perspective is presented to understand the gain and loss of different sensory systems.
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48
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Adolphe C, Millar A, Kojic M, Barkauskas DS, Sundström A, Swartling FJ, Hediyeh-Zadeh S, Tan CW, Davis MJ, Genovesi LA, Wainwright BJ. SOX9 Defines Distinct Populations of Cells in SHH Medulloblastoma but Is Not Required for Math1-Driven Tumor Formation. Mol Cancer Res 2021; 19:1831-1839. [PMID: 34330843 DOI: 10.1158/1541-7786.mcr-21-0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/18/2021] [Accepted: 07/19/2021] [Indexed: 11/16/2022]
Abstract
Medulloblastoma is the most common malignant pediatric brain tumor and there is an urgent need for molecularly targeted and subgroup-specific therapies. The stem cell factor SOX9, has been proposed as a potential therapeutic target for the treatment of Sonic Hedgehog medulloblastoma (SHH-MB) subgroup tumors, given its role as a downstream target of Hedgehog signaling and in functionally promoting SHH-MB metastasis and treatment resistance. However, the functional requirement for SOX9 in the genesis of medulloblastoma remains to be determined. Here we report a previously undocumented level of SOX9 expression exclusively in proliferating granule cell precursors (GCP) of the postnatal mouse cerebellum, which function as the medulloblastoma-initiating cells of SHH-MBs. Wild-type GCPs express comparatively lower levels of SOX9 than neural stem cells and mature astroglia and SOX9low GCP-like tumor cells constitute the bulk of both infant (Math1Cre:Ptch1lox/lox ) and adult (Ptch1LacZ/+ ) SHH-MB mouse models. Human medulloblastoma single-cell RNA data analyses reveal three distinct SOX9 populations present in SHH-MB and noticeably absent in other medulloblastoma subgroups: SOX9 + MATH1 + (GCP), SOX9 + GFAP + (astrocytes) and SOX9 + MATH1 + GFAP + (potential tumor-derived astrocytes). To functionally address whether SOX9 is required as a downstream effector of Hedgehog signaling in medulloblastoma tumor cells, we ablated Sox9 using a Math1Cre model system. Surprisingly, targeted ablation of Sox9 in GCPs (Math1Cre:Sox9lox/lox ) revealed no overt phenotype and loss of Sox9 in SHH-MB (Math1Cre:Ptch1lox/lox;Sox9lox/lox ) does not affect tumor formation. IMPLICATIONS: Despite preclinical data indicating SOX9 plays a key role in SHH-MB biology, our data argue against SOX9 as a viable therapeutic target.
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Affiliation(s)
- Christelle Adolphe
- The University of Queensland Diamantina Institute, University of Queensland, Woolloongabba, Queensland, Australia
| | - Amanda Millar
- The University of Queensland Diamantina Institute, University of Queensland, Woolloongabba, Queensland, Australia
| | - Marija Kojic
- The University of Queensland Diamantina Institute, University of Queensland, Woolloongabba, Queensland, Australia
| | - Deborah S Barkauskas
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Anders Sundström
- Department of Immunology, Genetics, and Pathology, Science For Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Fredrik J Swartling
- Department of Immunology, Genetics, and Pathology, Science For Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Soroor Hediyeh-Zadeh
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Victoria, Australia
| | - Chin Wee Tan
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Victoria, Australia
| | - Melissa J Davis
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Victoria, Australia.,Department of Clinical Pathology, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Victoria, Australia
| | - Laura A Genovesi
- The University of Queensland Diamantina Institute, University of Queensland, Woolloongabba, Queensland, Australia
| | - Brandon J Wainwright
- The University of Queensland Diamantina Institute, University of Queensland, Woolloongabba, Queensland, Australia.
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49
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The crosstalk between the Notch, Wnt, and SHH signaling pathways in regulating the proliferation and regeneration of sensory progenitor cells in the mouse cochlea. Cell Tissue Res 2021; 386:281-296. [PMID: 34223978 PMCID: PMC8557196 DOI: 10.1007/s00441-021-03493-w] [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: 12/14/2020] [Accepted: 06/21/2021] [Indexed: 12/04/2022]
Abstract
Sensory hair cells (HCs) are highly susceptible to damage by noise, ototoxic drugs, and aging. Although HCs cannot be spontaneously regenerated in adult mammals, previous studies have shown that signaling pathways are involved in HC regeneration in the damaged mouse cochlea. Here, we used a Notch antagonist (DAPT), a Wnt agonist (QS11), and recombinant Sonic hedgehog (SHH) protein to investigate their concerted actions underlying HC regeneration in the mouse cochlea after neomycin-induced damage both in vivo and in vitro. With DAPT, the numbers of HCs increased, and supporting cell (SC) proliferation was seen in both the intact and damaged cochlear sensory epithelia, while these numbers were unchanged in the presence of QS11. When simultaneously treated with DAPT and QS11, the number of HCs increased dramatically, and much greater SC proliferation was seen in the cochlear epithelium. In transgenic mice with both Notch1 conditional knockout and β-catenin over-expression, cochlear SC proliferation and HC regeneration were more obvious than in either Notch1 knockout or β-catenin over-expressing mice separately. When cochleae were treated with DAPT, QS11, and SHH together, SC proliferation was even greater, and this proliferation was seen in both the HC region and the greater epithelial ridge. High-throughput RNA sequencing was used to identify the differentially expressed genes between all groups, and the results showed that the SHH and Wnt signaling pathways are involved in SC proliferation. Our study suggests that co-regulation of the Notch, Wnt, and SHH signaling pathways promotes extensive cell proliferation and regeneration in the mouse cochlea.
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50
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Yu Y, Yang J, Luan F, Gu G, Zhao R, Wang Q, Dong Z, Tang J, Wang W, Sun J, Lv P, Zhang H, Wang C. Sensorineural Hearing Loss and Mitochondrial Apoptosis of Cochlear Spiral Ganglion Neurons in Fibroblast Growth Factor 13 Knockout Mice. Front Cell Neurosci 2021; 15:658586. [PMID: 34220452 PMCID: PMC8242186 DOI: 10.3389/fncel.2021.658586] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
Deafness is known to occur in more than 400 syndromes and accounts for almost 30% of hereditary hearing loss. The molecular mechanisms underlying such syndromic deafness remain unclear. Furthermore, deafness has been a common feature in patients with three main syndromes, the BÖrjeson-Forssman-Lehmann syndrome, Wildervanck syndrome, and Congenital Generalized Hirsutism, all of which are characterized by loss-of-function mutations in the Fgf13 gene. Whether the pathogenesis of deafness in these syndromes is associated with the Fgf13 mutation is not known. To elucidate its role in auditory function, we generated a mouse line with conditional knockout of the Fgf13 gene in the inner ear (Fgf13 cKO). FGF13 is expressed predominantly in the organ of Corti, spiral ganglion neurons (SGNs), stria vascularis, and the supporting cells. Conditional knockout of the gene in the inner ear led to sensorineural deafness with low amplitude and increased latency of wave I in the auditory brainstem response test but had a normal distortion product otoacoustic emission threshold. Fgf13 deficiency resulted in decreased SGN density from the apical to the basal region without significant morphological changes and those in the number of hair cells. TUNEL and caspase-3 immunocytochemistry assays showed that apoptotic cell death mediated the loss of SGNs. Further detection of apoptotic factors through qRT-PCR suggested the activation of the mitochondrial apoptotic pathway in SGNs. Together, this study reveals a novel role for Fgf13 in auditory function, and indicates that the gene could be a potential candidate for understanding deafness. These findings may provide new perspectives on the molecular mechanisms and novel therapeutic targets for treatment deafness.
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Affiliation(s)
- Yulou Yu
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Jing Yang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Feng Luan
- Department of Otolaryngology, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Guoqiang Gu
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ran Zhao
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Qiong Wang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Zishan Dong
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Junming Tang
- Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, China
| | - Wei Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Jinpeng Sun
- Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ping Lv
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Hailin Zhang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Chuan Wang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
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