1
|
Serrano ME, Kim E, Siow B, Ma D, Rojo L, Simmons C, Hayward D, Gibbins D, Singh N, Strydom A, Fisher EM, Tybulewicz VL, Cash D. Investigating brain alterations in the Dp1Tyb mouse model of Down syndrome. Neurobiol Dis 2023; 188:106336. [PMID: 38317803 PMCID: PMC7615598 DOI: 10.1016/j.nbd.2023.106336] [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: 02/07/2024] Open
Abstract
Down syndrome (DS) is one of the most common birth defects and the most prevalent genetic form of intellectual disability. DS arises from trisomy of chromosome 21, but its molecular and pathological consequences are not fully understood. In this study, we compared Dp1Tyb mice, a DS model, against their wild-type (WT) littermates of both sexes to investigate the impact of DS-related genetic abnormalities on the brain phenotype. We performed in vivo whole brain magnetic resonance imaging (MRI) and hippocampal 1H magnetic resonance spectroscopy (MRS) on the animals at 3 months of age. Subsequently, ex vivo MRI scans and histological analyses were conducted post-mortem. Our findings unveiled the following neuroanatomical and biochemical alterations in the Dp1Tyb brains: a smaller surface area and a rounder shape compared to WT brains, with DS males also presenting smaller global brain volume compared with the counterpart WT. Regional volumetric analysis revealed significant changes in 26 out of 72 examined brain regions, including the medial prefrontal cortex and dorsal hippocampus. These alterations were consistently observed in both in vivo and ex vivo imaging data. Additionally, high-resolution ex vivo imaging enabled us to investigate cerebellar layers and hippocampal sub-regions, revealing selective areas of decrease and remodelling in these structures. An analysis of hippocampal metabolites revealed an elevation in glutamine and the glutamine/glutamate ratio in the Dp1Tyb mice compared to controls, suggesting a possible imbalance in the excitation/inhibition ratio. This was accompanied by the decreased levels of taurine. Histological analysis revealed fewer neurons in the hippocampal CA3 and DG layers, along with an increase in astrocytes and microglia. These findings recapitulate multiple neuroanatomical and biochemical features associated with DS, enriching our understanding of the potential connection between chromosome 21 trisomy and the resultant phenotype.
Collapse
Affiliation(s)
- Maria Elisa Serrano
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Eugene Kim
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Bernard Siow
- The Francis Crick Institute, London, United Kingdom
| | - Da Ma
- Department of Internal Medicine Section of Gerontology and Geriatric Science, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Loreto Rojo
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Camilla Simmons
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | | | | | - Nisha Singh
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
| | - Andre Strydom
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Elizabeth M.C. Fisher
- UCL Queen Square Motor Neuron Disease Centre, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
| | | | - Diana Cash
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| |
Collapse
|
2
|
Xiao Y, Hu M, Lin Q, Zhang T, Li S, Shu L, Song X, Xu X, Meng W, Li X, Xu H, Mo X. Dopey2 and Pcdh7 orchestrate the development of embryonic neural stem cells/ progenitors in zebrafish. iScience 2023; 26:106273. [PMID: 36936789 PMCID: PMC10014312 DOI: 10.1016/j.isci.2023.106273] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/18/2023] [Accepted: 02/20/2023] [Indexed: 02/27/2023] Open
Abstract
DOPEY2 has been shown to be associated with Down syndrome and PCDH7 might be involved in Rett syndrome and MECP2 duplication syndrome. The mechanism how both proteins play roles in these syndromes are largely unknown. Here, we show that Dopey2 and Pcdh7 balance the proliferation and differentiation of neural stem cells and progenitors during embryonic neurogenesis to generate proper size and architecture of zebrafish brains. Dopey2 and Pcdh7 mutually restricted expression of each other in zebrafish embryos. Dopey2 was responsible for the proliferation of neural stem cells/progenitors, whereas Pcdh7 was responsible for the differentiation of neural stem cells/progenitors. Both proteins were shown to orchestrate the proper development and arrangement of neural cells in zebrafish embryonic brains. The results provide an insight into mechanisms to understand how the embryonic brain is constituted and how developmental defects occur in the brains of patients with Down syndrome, Rett syndrome, or MECP2 duplication syndrome.
Collapse
Affiliation(s)
- Yue Xiao
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Min Hu
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Qiyan Lin
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Ting Zhang
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Siying Li
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Linjuan Shu
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Xiuli Song
- Hangzhou HuaAn Biotechnology Co.Ltd, Hangzhou, China
| | - Xiaoyong Xu
- Hangzhou HuaAn Biotechnology Co.Ltd, Hangzhou, China
| | - Wentong Meng
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Xue Li
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Hong Xu
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
| | - Xianming Mo
- Department of Pediatric Surgery, Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
- Corresponding author
| |
Collapse
|
3
|
Shiohama T, Tsujimura K. Quantitative Structural Brain Magnetic Resonance Imaging Analyses: Methodological Overview and Application to Rett Syndrome. Front Neurosci 2022; 16:835964. [PMID: 35450016 PMCID: PMC9016334 DOI: 10.3389/fnins.2022.835964] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
Congenital genetic disorders often present with neurological manifestations such as neurodevelopmental disorders, motor developmental retardation, epilepsy, and involuntary movement. Through qualitative morphometric evaluation of neuroimaging studies, remarkable structural abnormalities, such as lissencephaly, polymicrogyria, white matter lesions, and cortical tubers, have been identified in these disorders, while no structural abnormalities were identified in clinical settings in a large population. Recent advances in data analysis programs have led to significant progress in the quantitative analysis of anatomical structural magnetic resonance imaging (MRI) and diffusion-weighted MRI tractography, and these approaches have been used to investigate psychological and congenital genetic disorders. Evaluation of morphometric brain characteristics may contribute to the identification of neuroimaging biomarkers for early diagnosis and response evaluation in patients with congenital genetic diseases. This mini-review focuses on the methodologies and attempts employed to study Rett syndrome using quantitative structural brain MRI analyses, including voxel- and surface-based morphometry and diffusion-weighted MRI tractography. The mini-review aims to deepen our understanding of how neuroimaging studies are used to examine congenital genetic disorders.
Collapse
Affiliation(s)
- Tadashi Shiohama
- Department of Pediatrics, Chiba University Hospital, Chiba, Japan
- *Correspondence: Tadashi Shiohama,
| | - Keita Tsujimura
- Group of Brain Function and Development, Nagoya University Neuroscience Institute of the Graduate School of Science, Nagoya, Japan
- Research Unit for Developmental Disorders, Institute for Advanced Research, Nagoya University, Nagoya, Japan
- Department of Radiology, Harvard Medical School, Boston, MA, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States
| |
Collapse
|