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Donovan APA, Rosko L, Ellegood J, Redhead Y, Green JBA, Lerch JP, Huang JK, Basson MA. Pervasive cortical and white matter anomalies in a mouse model for CHARGE syndrome. J Anat 2023; 243:51-65. [PMID: 36914558 PMCID: PMC10273342 DOI: 10.1111/joa.13856] [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: 08/30/2022] [Revised: 01/31/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth, Genital anomalies and Ear abnormalities) syndrome is a disorder caused by mutations in the gene encoding CHD7, an ATP dependent chromatin remodelling factor, and is characterised by a diverse array of congenital anomalies. These include a range of neuroanatomical comorbidities which likely underlie the varied neurodevelopmental disorders associated with CHARGE syndrome, which include intellectual disability, motor coordination deficits, executive dysfunction, and autism spectrum disorder. Cranial imaging studies are challenging in CHARGE syndrome patients, but high-throughput magnetic resonance imaging (MRI) techniques in mouse models allow for the unbiased identification of neuroanatomical defects. Here, we present a comprehensive neuroanatomical survey of a Chd7 haploinsufficient mouse model of CHARGE syndrome. Our study uncovered widespread brain hypoplasia and reductions in white matter volume across the brain. The severity of hypoplasia appeared more pronounced in posterior areas of the neocortex compared to anterior regions. We also perform the first assessment of white matter tract integrity in this model through diffusion tensor imaging (DTI) to assess the potential functional consequences of widespread reductions in myelin, which suggested the presence of white matter integrity defects. To determine if white matter alterations correspond to cellular changes, we quantified oligodendrocyte lineage cells in the postnatal corpus callosum, uncovering reduced numbers of mature oligodendrocytes. Together, these results present a range of promising avenues of focus for future cranial imaging studies in CHARGE syndrome patients.
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Affiliation(s)
- Alex P. A. Donovan
- Centre for Craniofacial and Regenerative BiologyKing's College LondonLondonUK
| | - Lauren Rosko
- Department of BiologyGeorgetown UniversityWashingtonDCUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDCUSA
| | - Jacob Ellegood
- Mouse Imaging CentreThe Hospital for Sick ChildrenTorontoOntarioCanada
| | - Yushi Redhead
- Centre for Craniofacial and Regenerative BiologyKing's College LondonLondonUK
| | - Jeremy B. A. Green
- Centre for Craniofacial and Regenerative BiologyKing's College LondonLondonUK
| | - Jason P. Lerch
- Mouse Imaging CentreThe Hospital for Sick ChildrenTorontoOntarioCanada
- Department of Medical BiophysicsThe University of TorontoTorontoOntarioCanada
- Department of Neurosciences and Mental HealthThe Hospital for Sick ChildrenTorontoOntarioCanada
- Department of Preclinical Imaging, Wellcome Centre for Integrative NeuroimagingUniversity of OxfordOxfordUK
| | - Jeffrey K. Huang
- Department of BiologyGeorgetown UniversityWashingtonDCUSA
- Interdisciplinary Program in NeuroscienceGeorgetown UniversityWashingtonDCUSA
- Centre for Cell ReprogrammingGeorgetown UniversityWashingtonDCUSA
| | - M. Albert Basson
- Centre for Craniofacial and Regenerative BiologyKing's College LondonLondonUK
- MRC Centre for Neurodevelopmental DisordersKing's College LondonLondonUK
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2
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Krueger LA, Morris AC. Eyes on CHARGE syndrome: Roles of CHD7 in ocular development. Front Cell Dev Biol 2022; 10:994412. [PMID: 36172288 PMCID: PMC9512043 DOI: 10.3389/fcell.2022.994412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/19/2022] [Indexed: 11/13/2022] Open
Abstract
The development of the vertebrate visual system involves complex morphogenetic interactions of cells derived from multiple embryonic lineages. Disruptions in this process are associated with structural birth defects such as microphthalmia, anophthalmia, and coloboma (collectively referred to as MAC), and inherited retinal degenerative diseases such as retinitis pigmentosa and allied dystrophies. MAC and retinal degeneration are also observed in systemic congenital malformation syndromes. One important example is CHARGE syndrome, a genetic disorder characterized by coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Mutations in the gene encoding Chromodomain helicase DNA binding protein 7 (CHD7) cause the majority of CHARGE syndrome cases. However, the pathogenetic mechanisms that connect loss of CHD7 to the ocular complications observed in CHARGE syndrome have not been identified. In this review, we provide a general overview of ocular development and congenital disorders affecting the eye. This is followed by a comprehensive description of CHARGE syndrome, including discussion of the spectrum of ocular defects that have been described in this disorder. In addition, we discuss the current knowledge of CHD7 function and focus on its contributions to the development of ocular structures. Finally, we discuss outstanding gaps in our knowledge of the role of CHD7 in eye formation, and propose avenues of investigation to further our understanding of how CHD7 activity regulates ocular and retinal development.
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Affiliation(s)
| | - Ann C. Morris
- Department of Biology, University of Kentucky, Lexington, KY, United States
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3
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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: 8] [Impact Index Per Article: 2.7] [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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4
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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: 15] [Impact Index Per Article: 5.0] [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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Haibach-Beach P, Perreault M, Lieberman L, Foster E. Independent walking and balance in children with CHARGE syndrome. BRITISH JOURNAL OF VISUAL IMPAIRMENT 2020. [DOI: 10.1177/0264619620946068] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Children with CHARGE syndrome (CWCS) are born with multiple physical disabilities, several of which impair balance and the onset of motor milestones. Early motor development problems can include delayed independent walking, which has been found in CWCS. In addition, few studies have examined balance in CWCS and these studies have been limited in scope, necessitating a more comprehensive examination of balance in this population. Motor development occurs as a progression of stages as represented by Seefeldt’s conceptual model. As such, it is essential to examine the association of early development of foundational skills, such as balance, with the onset of motor milestones as they are building blocks to motor competence. The aims of this study are to (1) examine the differential effects of children with and without CHARGE syndrome on balance and (2) examine the association of age of walking to these balance measures. In this study, 27 CWCS and 22 children without CHARGE syndrome, aged 7 to 16 years, were assessed on four components of balance including anticipatory control, reactive postural control, sensory orientation, and dynamic gait using the shortened version of the Balance Evaluation Systems Test (mini-BESTest) and parental reported age of independent walking. Their balance and age of walking were compared to 22 typically developing peers of similar age and gender distribution. Results revealed that CWCS walked three times later than their peers without CHARGE syndrome and had significant deficits on all balance systems assessed with the largest difference occurring in anticipatory control. Anticipatory control is critically important in maintaining static and dynamic postural control. These results indicate a critical need for early functional balance training and compensatory strategies in CWCS.
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Kasah S, Oddy C, Basson MA. Autism-linked CHD gene expression patterns during development predict multi-organ disease phenotypes. J Anat 2018; 233:755-769. [PMID: 30277262 DOI: 10.1111/joa.12889] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2018] [Indexed: 12/24/2022] Open
Abstract
Recent large-scale exome sequencing studies have identified mutations in several members of the CHD (Chromodomain Helicase DNA-binding protein) gene family in neurodevelopmental disorders. Mutations in the CHD2 gene have been linked to developmental delay, intellectual disability, autism and seizures, CHD8 mutations to autism and intellectual disability, whereas haploinsufficiency of CHD7 is associated with executive dysfunction and intellectual disability. In addition to these neurodevelopmental features, a wide range of other developmental defects are associated with mutants of these genes, especially with regards to CHD7 haploinsufficiency, which is the primary cause of CHARGE syndrome. Whilst the developmental expression of CHD7 has been reported previously, limited information on the expression of CHD2 and CHD8 during development is available. Here, we compare the expression patterns of all three genes during mouse development directly. We find high, widespread expression of these genes at early stages of development that gradually becomes restricted during later developmental stages. Chd2 and Chd8 are widely expressed in the developing central nervous system (CNS) at all stages of development, with moderate expression remaining in the neocortex, hippocampus, olfactory bulb and cerebellum of the postnatal brain. Similarly, Chd7 expression is seen throughout the CNS during late embryogenesis and early postnatal development, with strong enrichment in the cerebellum, but displays low expression in the cortex and neurogenic niches in early life. In addition to expression in the brain, novel sites of Chd2 and Chd8 expression are reported. These findings suggest additional roles for these genes in organogenesis and predict that mutation of these genes may predispose individuals to a range of other, non-neurological developmental defects.
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Affiliation(s)
- Sahrunizam Kasah
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Christopher Oddy
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
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