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Hurley S, Mohan C, Suetterlin P, Ellingford R, Riegman KLH, Ellegood J, Caruso A, Michetti C, Brock O, Evans R, Rudari F, Delogu A, Scattoni ML, Lerch JP, Fernandes C, Basson MA. Distinct, dosage-sensitive requirements for the autism-associated factor CHD8 during cortical development. Mol Autism 2021; 12:16. [PMID: 33627187 PMCID: PMC7905672 DOI: 10.1186/s13229-020-00409-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND CHD8 haploinsufficiency causes autism and macrocephaly with high penetrance in the human population. Chd8 heterozygous mice exhibit relatively subtle brain overgrowth and little gene expression changes in the embryonic neocortex. The purpose of this study was to generate new, sub-haploinsufficient Chd8 mouse models to allow us to identify and study the functions of CHD8 during embryonic cortical development. METHODS To examine the possibility that certain phenotypes may only appear at sub-heterozygous Chd8 levels in the mouse, we created an allelic series of Chd8-deficient mice to reduce CHD8 protein levels to approximately 35% (mild hypomorph), 10% (severe hypomorph) and 0% (neural-specific conditional knockout) of wildtype levels. We used RNA sequencing to compare transcriptional dysregulation, structural MRI and brain weight to investigate effects on brain size, and cell proliferation, differentiation and apoptosis markers in immunostaining assays to quantify changes in neural progenitor fate. RESULTS Mild Chd8 hypomorphs displayed significant postnatal lethality, with surviving animals exhibiting more pronounced brain hyperplasia than heterozygotes. Over 2000 genes were dysregulated in mild hypomorphs, including autism-associated neurodevelopmental and cell cycle genes. We identify increased proliferation of non-ventricular zone TBR2+ intermediate progenitors as one potential cause of brain hyperplasia in these mutants. Severe Chd8 hypomorphs displayed even greater transcriptional dysregulation, including evidence for p53 pathway upregulation. In contrast to mild hypomorphs, these mice displayed reduced brain size and increased apoptosis in the embryonic neocortex. Homozygous, conditional deletion of Chd8 in early neuronal progenitors resulted in pronounced brain hypoplasia, partly caused by p53 target gene derepression and apoptosis in the embryonic neocortex. Limitations Our findings identify an important role for the autism-associated factor CHD8 in controlling the proliferation of intermediate progenitors in the mouse neocortex. We propose that CHD8 has a similar function in human brain development, but studies on human cells are required to confirm this. Because many of our mouse mutants with reduced CHD8 function die shortly after birth, it is not possible to fully determine to what extent reduced CHD8 function results in autism-associated behaviours in mice. CONCLUSIONS Together, these findings identify important, dosage-sensitive functions for CHD8 in p53 pathway repression, neurodevelopmental gene expression and neural progenitor fate in the embryonic neocortex. We conclude that brain development is acutely sensitive to reduced CHD8 expression and that the varying sensitivities of different progenitor populations and cellular processes to CHD8 dosage result in non-linear effects on gene transcription and brain growth. Shaun Hurley, Conor Mohan and Philipp Suetterlin have contributed equally to this work.
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Affiliation(s)
- Shaun Hurley
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Conor Mohan
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Philipp Suetterlin
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Robert Ellingford
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | | | - Jacob Ellegood
- Department of Medical Biophysics, Mouse Imaging Centre, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Angela Caruso
- Department of Cell Biology and Neuroscience, Neurotoxicology and Neuroendocrinology Section, Istituto Superiore Di Sanità, Rome, Italy
- Department of Psychology, School of Behavioural Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Caterina Michetti
- Department of Cell Biology and Neuroscience, Neurotoxicology and Neuroendocrinology Section, Istituto Superiore Di Sanità, Rome, Italy
- Centre for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Genova, Italy
| | - Olivier Brock
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Romy Evans
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Fabrizio Rudari
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Alessio Delogu
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Maria Luisa Scattoni
- Department of Cell Biology and Neuroscience, Neurotoxicology and Neuroendocrinology Section, Istituto Superiore Di Sanità, Rome, Italy
| | - Jason P Lerch
- Department of Medical Biophysics, Mouse Imaging Centre, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Cathy Fernandes
- MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- MRC Centre for Neurodevelopmental Disorders, 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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Suetterlin P, Hurley S, Mohan C, Riegman KLH, Pagani M, Caruso A, Ellegood J, Galbusera A, Crespo-Enriquez I, Michetti C, Yee Y, Ellingford R, Brock O, Delogu A, Francis-West P, Lerch JP, Scattoni ML, Gozzi A, Fernandes C, Basson MA. Altered Neocortical Gene Expression, Brain Overgrowth and Functional Over-Connectivity in Chd8 Haploinsufficient Mice. Cereb Cortex 2019; 28:2192-2206. [PMID: 29668850 PMCID: PMC6018918 DOI: 10.1093/cercor/bhy058] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Indexed: 12/13/2022] Open
Abstract
Truncating CHD8 mutations are amongst the highest confidence risk factors for autism spectrum disorder (ASD) identified to date. Here, we report that Chd8 heterozygous mice display increased brain size, motor delay, hypertelorism, pronounced hypoactivity, and anomalous responses to social stimuli. Whereas gene expression in the neocortex is only mildly affected at midgestation, over 600 genes are differentially expressed in the early postnatal neocortex. Genes involved in cell adhesion and axon guidance are particularly prominent amongst the downregulated transcripts. Resting-state functional MRI identified increased synchronized activity in cortico-hippocampal and auditory-parietal networks in Chd8 heterozygous mutant mice, implicating altered connectivity as a potential mechanism underlying the behavioral phenotypes. Together, these data suggest that altered brain growth and diminished expression of important neurodevelopmental genes that regulate long-range brain wiring are followed by distinctive anomalies in functional brain connectivity in Chd8+/- mice. Human imaging studies have reported altered functional connectivity in ASD patients, with long-range under-connectivity seemingly more frequent. Our data suggest that CHD8 haploinsufficiency represents a specific subtype of ASD where neuropsychiatric symptoms are underpinned by long-range over-connectivity.
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Affiliation(s)
- Philipp Suetterlin
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Shaun Hurley
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Conor Mohan
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Kimberley L H Riegman
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Marco Pagani
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, 38068 Rovereto, TN, Italy
| | - Angela Caruso
- Research Coordination and Support Service, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Jacob Ellegood
- Department of Medical Biophysics, University of Toronto, Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada M5T 3H7
| | - Alberto Galbusera
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, 38068 Rovereto, TN, Italy
| | - Ivan Crespo-Enriquez
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Yohan Yee
- Department of Medical Biophysics, University of Toronto, Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada M5T 3H7
| | - Robert Ellingford
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Olivier Brock
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 9NU, UK
| | - Alessio Delogu
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London SE5 9NU, UK
| | - Philippa Francis-West
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK
| | - Jason P Lerch
- Department of Medical Biophysics, University of Toronto, Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada M5T 3H7
| | - Maria Luisa Scattoni
- Research Coordination and Support Service, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Alessandro Gozzi
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, 38068 Rovereto, TN, Italy
| | - Cathy Fernandes
- MRC Social, Genetic & Developmental Psychiatry Centre, PO82, Institute of Psychiatry, Psychology & Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.,MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, King's College London, London SE1 9RT, UK.,MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK
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Whittaker DE, Kasah S, Donovan APA, Ellegood J, Riegman KLH, Volk HA, McGonnell I, Lerch JP, Basson MA. Distinct cerebellar foliation anomalies in a CHD7 haploinsufficient mouse model of CHARGE syndrome. Am J Med Genet C Semin Med Genet 2017; 175. [PMID: 29168327 PMCID: PMC5765394 DOI: 10.1002/ajmg.c.31595] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/22/2017] [Accepted: 09/24/2017] [Indexed: 11/13/2022]
Abstract
Mutations in the gene encoding the ATP dependent chromatin‐remodeling factor, CHD7 are the major cause of CHARGE (Coloboma, Heart defects, Atresia of the choanae, Retarded growth and development, Genital‐urinary anomalies, and Ear defects) syndrome. Neurodevelopmental defects and a range of neurological signs have been identified in individuals with CHARGE syndrome, including developmental delay, lack of coordination, intellectual disability, and autistic traits. We previously identified cerebellar vermis hypoplasia and abnormal cerebellar foliation in individuals with CHARGE syndrome. Here, we report mild cerebellar hypoplasia and distinct cerebellar foliation anomalies in a Chd7 haploinsufficient mouse model. We describe specific alterations in the precise spatio‐temporal sequence of fissure formation during perinatal cerebellar development responsible for these foliation anomalies. The altered cerebellar foliation pattern in Chd7 haploinsufficient mice show some similarities to those reported in mice with altered Engrailed, Fgf8 or Zic1 gene expression and we propose that mutations or polymorphisms in these genes may modify the cerebellar phenotype in CHARGE syndrome. Our findings in a mouse model of CHARGE syndrome indicate that a careful analysis of cerebellar foliation may be warranted in patients with CHARGE syndrome, particularly in patients with cerebellar hypoplasia and developmental delay.
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Affiliation(s)
- Danielle E Whittaker
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom.,Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Sahrunizam Kasah
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Alex P A Donovan
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Jacob Ellegood
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kimberley L H Riegman
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Holger A Volk
- Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Imelda McGonnell
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Jason P Lerch
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
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Donovan APA, Yu T, Ellegood J, Riegman KLH, de Geus C, van Ravenswaaij-Arts C, Fernandes C, Lerch JP, Basson MA. Cerebellar Vermis and Midbrain Hypoplasia Upon Conditional Deletion of Chd7 from the Embryonic Mid-Hindbrain Region. Front Neuroanat 2017; 11:86. [PMID: 29046629 PMCID: PMC5632662 DOI: 10.3389/fnana.2017.00086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/14/2017] [Indexed: 01/24/2023] Open
Abstract
Reduced fibroblast growth factor (FGF) signaling from the mid-hindbrain or isthmus organizer (IsO) during early embryonic development results in hypoplasia of the midbrain and cerebellar vermis. We previously reported evidence for reduced Fgf8 expression and FGF signaling in the mid-hindbrain region of embryos heterozygous for Chd7, the gene mutated in CHARGE (Coloboma, Heart defects, choanal Atresia, Retarded growth and development, Genitourinary anomalies and Ear defects) syndrome. However, Chd7+/- animals only exhibit mild cerebellar vermis anomalies. As homozygous deletion of Chd7 is embryonic lethal, we conditionally deleted Chd7 from the early embryonic mid-hindbrain region to identify the function of CHD7 in mid-hindbrain development. Using a combination of high resolution structural MRI and histology, we report striking midbrain and cerebellar vermis hypoplasia in the homozygous conditional mutants. We show that cerebellar vermis hypoplasia is associated with reduced embryonic Fgf8 expression and an expanded roof plate in rhombomere 1 (r1). These findings identify an essential role for Chd7 in regulating mid-hindbrain development via Fgf8.
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Affiliation(s)
- Alex P A Donovan
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Tian Yu
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Jacob Ellegood
- Department of Medical Biophysics, University of Toronto, Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada
| | - Kimberley L H Riegman
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom
| | - Christa de Geus
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Conny van Ravenswaaij-Arts
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Cathy Fernandes
- MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
| | - Jason P Lerch
- Department of Medical Biophysics, University of Toronto, Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - M Albert Basson
- Centre for Craniofacial and Regenerative Biology, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, King's College London, London, United Kingdom
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