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Steevens AR, Glatzer JC, Kellogg CC, Low WC, Santi PA, Kiernan AE. SOX2 is required for inner ear growth and cochlear nonsensory formation before sensory development. Development 2019; 146:dev.170522. [PMID: 31152002 DOI: 10.1242/dev.170522] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 05/13/2019] [Indexed: 12/16/2022]
Abstract
The transcription factor sex determining region Y-box 2 (SOX2) is required for the formation of hair cells and supporting cells in the inner ear and is a widely used sensory marker. Paradoxically, we demonstrate via fate mapping that, initially, SOX2 primarily marks nonsensory progenitors in the mouse cochlea, and is not specific to all sensory regions until late otic vesicle stages. SOX2 fate mapping reveals an apical-to-basal gradient of SOX2 expression in the sensory region of the cochlea, reflecting the pattern of cell cycle exit. To understand SOX2 function, we undertook a timed-deletion approach, revealing that early loss of SOX2 severely impaired morphological development of the ear, whereas later deletions resulted in sensory disruptions. During otocyst stages, SOX2 shifted dramatically from a lateral to medial domain over 24-48 h, reflecting the nonsensory-to-sensory switch observed by fate mapping. Early loss or gain of SOX2 function led to changes in otic epithelial volume and progenitor proliferation, impacting growth and morphological development of the ear. Our study demonstrates a novel role for SOX2 in early otic morphological development, and provides insights into the temporal and spatial patterns of sensory specification in the inner ear.
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Affiliation(s)
- Aleta R Steevens
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jenna C Glatzer
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Courtney C Kellogg
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Walter C Low
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455, USA
| | - Peter A Santi
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Amy E Kiernan
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA .,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
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Miller SJ, Glatzer JC, Hsieh YC, Rothstein JD. Cortical astroglia undergo transcriptomic dysregulation in the G93A SOD1 ALS mouse model. J Neurogenet 2018; 32:322-335. [PMID: 30398075 PMCID: PMC6444185 DOI: 10.1080/01677063.2018.1513508] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 08/06/2018] [Indexed: 12/13/2022]
Abstract
Astroglia are the most abundant glia cell in the central nervous system, playing essential roles in maintaining homeostasis. Key functions of astroglia include, but are not limited to, neurotransmitter recycling, ion buffering, immune modulation, neurotrophin secretion, neuronal synaptogenesis and elimination, and blood-brain barrier maintenance. In neurological diseases, it is well appreciated that astroglia play crucial roles in the disease pathogenesis. In amyotrophic lateral sclerosis (ALS), a motor neuron degenerative disease, astroglia in the spinal cord and cortex downregulate essential transporters, among other proteins, that exacerbate disease progression. Spinal cord astroglia undergo dramatic transcriptome dysregulation. However, in the cortex, it has not been well studied what effects glia, especially astroglia, have on upper motor neurons in the pathology of ALS. To begin to shed light on the involvement and dysregulation that astroglia undergo in ALS, we isolated pure grey-matter cortical astroglia and subjected them to microarray analysis. We uncovered a vast number of genes that show dysregulation at end-stage in the ALS mouse model, G93A SOD1. Many of these genes play essential roles in ion homeostasis and the Wnt-signaling pathway. Several of these dysregulated genes are common in ALS spinal cord astroglia, while many of them are unique. This database serves as an approach for understanding the significance of dysfunctional genes and pathways in cortical astroglia in the context of motor neuron disease, as well as determining regional astroglia heterogeneity, and providing insight into ALS pathogenesis.
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Affiliation(s)
- Sean J. Miller
- Dept. of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205
- Cellular and Molecular Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD 21205
| | - Jenna C. Glatzer
- Dept. of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205
- Cellular and Molecular Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD 21205
| | - Yi-chun Hsieh
- Dept. of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD 21205
| | - Jeffrey D. Rothstein
- Dept. of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205
- Cellular and Molecular Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD 21205
- Dept. of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD 21205
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Abstract
Neurons of the cochleovestibular ganglion (CVG) transmit hearing and balance information to the brain. During development, a select population of early otic progenitors express NEUROG1, delaminate from the otocyst, and coalesce to form the neurons that innervate all inner ear sensory regions. At present, the selection process that determines which otic progenitors activate NEUROG1 and adopt a neuroblast fate is incompletely understood. The transcription factor SOX2 has been implicated in otic neurogenesis, but its requirement in the specification of the CVG neurons has not been established. Here we tested SOX2's requirement during inner ear neuronal specification using a conditional deletion paradigm in the mouse. SOX2 deficiency at otocyst stages caused a near-absence of NEUROG1-expressing neuroblasts, increased cell death in the neurosensory epithelium, and significantly reduced the CVG volume. Interestingly, a milder decrease in neurogenesis was observed in heterozygotes, indicating SOX2 levels are important. Moreover, fate-mapping experiments revealed that the timing of SOX2 expression did not parallel the established vestibular-then-auditory sequence. These results demonstrate that SOX2 is required for the initial events in otic neuronal specification including expression of NEUROG1, although fate-mapping results suggest SOX2 may be required as a competence factor rather than a direct initiator of the neural fate.
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Affiliation(s)
- Aleta R Steevens
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY, USA
| | | | - Jenna C Glatzer
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY, USA
| | - Amy E Kiernan
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY, USA. .,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA.
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Grima JC, Daigle JG, Arbez N, Cunningham KC, Zhang K, Ochaba J, Geater C, Morozko E, Stocksdale J, Glatzer JC, Pham JT, Ahmed I, Peng Q, Wadhwa H, Pletnikova O, Troncoso JC, Duan W, Snyder SH, Ranum LPW, Thompson LM, Lloyd TE, Ross CA, Rothstein JD. Mutant Huntingtin Disrupts the Nuclear Pore Complex. Neuron 2017; 94:93-107.e6. [PMID: 28384479 PMCID: PMC5595097 DOI: 10.1016/j.neuron.2017.03.023] [Citation(s) in RCA: 229] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/30/2017] [Accepted: 03/13/2017] [Indexed: 01/01/2023]
Abstract
Huntington's disease (HD) is caused by an expanded CAG repeat in the Huntingtin (HTT) gene. The mechanism(s) by which mutant HTT (mHTT) causes disease is unclear. Nucleocytoplasmic transport, the trafficking of macromolecules between the nucleus and cytoplasm, is tightly regulated by nuclear pore complexes (NPCs) made up of nucleoporins (NUPs). Previous studies offered clues that mHTT may disrupt nucleocytoplasmic transport and a mutation of an NUP can cause HD-like pathology. Therefore, we evaluated the NPC and nucleocytoplasmic transport in multiple models of HD, including mouse and fly models, neurons transfected with mHTT, HD iPSC-derived neurons, and human HD brain regions. These studies revealed severe mislocalization and aggregation of NUPs and defective nucleocytoplasmic transport. HD repeat-associated non-ATG (RAN) translation proteins also disrupted nucleocytoplasmic transport. Additionally, overexpression of NUPs and treatment with drugs that prevent aberrant NUP biology also mitigated this transport defect and neurotoxicity, providing future novel therapy targets.
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Affiliation(s)
- Jonathan C Grima
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - J Gavin Daigle
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nicolas Arbez
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kathleen C Cunningham
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ke Zhang
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joseph Ochaba
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Charlene Geater
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Eva Morozko
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Jennifer Stocksdale
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Jenna C Glatzer
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jacqueline T Pham
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ishrat Ahmed
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Qi Peng
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Harsh Wadhwa
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Olga Pletnikova
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Juan C Troncoso
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wenzhen Duan
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Solomon H Snyder
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Laura P W Ranum
- Center for NeuroGenetics, Departments of Molecular Genetics and Microbiology and Neurology, College of Medicine, Genetics Institute, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
| | - Leslie M Thompson
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Thomas E Lloyd
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher A Ross
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jeffrey D Rothstein
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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