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Rubin DA, Clark B, Lam J, Vuong V, Brito J, Fisher KL. Is an Online Asynchronous Progressive Resistance Training Programme Feasible for Individuals With Down Syndrome? JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES 2025; 38:e70040. [PMID: 40129194 DOI: 10.1111/jar.70040] [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: 04/29/2024] [Revised: 03/07/2025] [Accepted: 03/10/2025] [Indexed: 03/26/2025]
Abstract
BACKGROUND Online exercise programming reduces transportation and scheduling barriers. This study explored the feasibility of online resistance training for individuals with Down syndrome. METHOD Thirteen individuals (3 M/10 F, age: 21.7 ± 5.9 years) began a 10-week programme delivered using a website with pre-recorded exercise videos (45-60 min each) for 3 days/week. Surveys were used to obtain feedback and track adherence. At baseline and after 10 weeks, participants completed the 30-s sit-to-stand, modified push-ups and 30-s bicep curl tests. RESULTS 11 (85%) participants completed the programme, and 8 participants (73%) met the ≥ 20 sessions goal. Participants rated (n = 267 ratings) most exercises easy to somewhat easy and exercise videos as fun to a lot of fun (n = 220 ratings, 86.2%). After 10 weeks, participants completed more push-ups (8 ± 6 vs. 12 ± 6; p = 0.031) and biceps curls (7 ± 3 vs. 11 ± 3; p < 0.001). CONCLUSION Remote resistance training programmes may be feasible and should be further evaluated.
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Affiliation(s)
- D A Rubin
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
| | - B Clark
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
| | - J Lam
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
| | - V Vuong
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
| | - J Brito
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
| | - K L Fisher
- Department of Kinesiology, California State University Fullerton, Fullerton, California, USA
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Robinson J, Chawla N, Patel S, Spey E, McNulty O, Kaur G. Neurodevelopmental Abnormalities in Down Syndrome: Assessing Structural and Functional Deficits. Cureus 2024; 16:e76156. [PMID: 39845250 PMCID: PMC11750628 DOI: 10.7759/cureus.76156] [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] [Accepted: 12/21/2024] [Indexed: 01/24/2025] Open
Abstract
Down syndrome (DS) is a genetic intellectual disorder caused by trisomy of chromosome 21 (Hsa21) and presents with a variety of phenotypes. The correlation between the chromosomal abnormality and the resulting symptoms is unclear, partly due to the spectrum of impairments observed. However, it has been determined that trisomy 21 contributes to neurodegeneration and impaired neurodevelopment resulting from decreased neurotransmission, neurogenesis, and synaptic plasticity. DS is linked to synaptic abnormalities and hindered hippocampal neuron development as well. Altered synaptic plasticity in the hippocampus decreases long-term potentiation, leading to short- and long-term learning and memory deficits. Individuals with DS show reduced gray matter, which affects cerebral cortex structure and impairs coordination and thought. Neurotransmitter excess, such as increased gamma-aminobutyric acid (GABA) release, causes over-inhibition and contributes to cognitive deficits. This inhibition also affects hippocampal synaptic plasticity. Additionally, DS often involves neurodegeneration of cholinergic neurons in the basal forebrain, further impairing learning and memory. Reduced glutamate transmission and decreased amyloid precursor protein metabolism contribute to synaptic plasticity deficits and behavioral changes in DS. Decreased neurotransmission, diminished motor neurons, and impaired cerebellar and cerebral development are the main causes of motor deficits in DS. This review discusses the stark structural changes in DS and their functional consequences.
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Affiliation(s)
- Joelle Robinson
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
| | - Nidhi Chawla
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
| | - Shreya Patel
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
| | - Eliana Spey
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
| | - Olivia McNulty
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
| | - Gurjinder Kaur
- Department of Physiology, Touro College of Osteopathic Medicine, Middletown, USA
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Lamantia J, Sloan K, Wallace JM, Roper RJ. Compromised femoral and lumbovertebral bone in the Dp(16)1Yey Down syndrome mouse model. Bone 2024; 181:117046. [PMID: 38336158 PMCID: PMC11000152 DOI: 10.1016/j.bone.2024.117046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/30/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Down syndrome (DS), affecting ∼1 in 800 live births, is caused by the triplication of human chromosome 21 (Hsa21). Individuals with DS have skeletal features including craniofacial abnormalities and decreased bone mineral density (BMD). Lowered BMD can lead to increased fracture risk, with common fracture points at the femoral neck and lumbar spine. While the femur has been studied in DS mouse models, there is little research done on the vertebrae despite evidence that humans with DS have affected vertebrae. Additionally, it is important to establish when skeletal deficits occur to find times of potential intervention. The Dp(16)1Yey DS mouse model has all genes triplicated on mouse chromosome 16 orthologous to Hsa21 and displayed deficits in long bone, including trabecular and cortical deficits in male but not female mice, at 12 weeks. We hypothesized that the long bone and lumbovertebral microarchitecture would exhibit sexually dimorphic deficits in Dp(16)1Yey mice compared to control mice and long bone strength would be diminished in Dp(16)1Yey mice at 6 weeks. The trabecular region of the 4th lumbar (L4) vertebra and the trabecular and cortical regions of the femur were analyzed via micro-computed tomography and 3-point bending in 6-week-old male and female Dp(16)1Yey and control mice. Trabecular and cortical deficits were observed in femurs from male Dp(16)1Yey mice, and cortical deficits were seen in femurs of male and female Dp(16)1Yey mice. Male Dp(16)1Yey femurs had more deficits in bone strength at whole bone and tissue-estimate level properties, but female Dp(16)1Yey mice were also affected. Additionally, the L4 of male and female Dp(16)1Yey mice show trabecular deficits, which have not been previously reported in a DS mouse model. Our results indicate that skeletal deficits associated with DS occur early in skeletal development, are dependent on skeletal compartment and site, are sex dependent, and potential interventions should likely begin early in skeletal development of DS mouse models.
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Affiliation(s)
- Joshua Lamantia
- Department of Biology, Indiana University-Purdue University Indianapolis (IUPUI), United States of America
| | - Kourtney Sloan
- Department of Biology, Indiana University-Purdue University Indianapolis (IUPUI), United States of America
| | - Joseph M Wallace
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis (IUPUI), United States of America
| | - Randall J Roper
- Department of Biology, Indiana University-Purdue University Indianapolis (IUPUI), United States of America.
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Lu QS, Ma L, Jiang WJ, Wang XB, Lu M. KAT7/HMGN1 signaling epigenetically induces tyrosine phosphorylation-regulated kinase 1A expression to ameliorate insulin resistance in Alzheimer's disease. World J Psychiatry 2024; 14:445-455. [PMID: 38617985 PMCID: PMC11008392 DOI: 10.5498/wjp.v14.i3.445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/31/2023] [Accepted: 02/01/2024] [Indexed: 03/19/2024] Open
Abstract
BACKGROUND Epidemiological studies have revealed a correlation between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2D). Insulin resistance in the brain is a common feature in patients with T2D and AD. KAT7 is a histone acetyltransferase that participates in the modulation of various genes. AIM To determine the effects of KAT7 on insulin patients with AD. METHODS APPswe/PS1-dE9 double-transgenic and db/db mice were used to mimic AD and diabetes, respectively. An in vitro model of AD was established by Aβ stimulation. Insulin resistance was induced by chronic stimulation with high insulin levels. The expression of microtubule-associated protein 2 (MAP2) was assessed using immunofluorescence. The protein levels of MAP2, Aβ, dual-specificity tyrosine phosphorylation-regulated kinase-1A (DYRK1A), IRS-1, p-AKT, total AKT, p-GSK3β, total GSK3β, DYRK1A, and KAT7 were measured via western blotting. Accumulation of reactive oxygen species (ROS), malondialdehyde (MDA), and SOD activity was measured to determine cellular oxidative stress. Flow cytometry and CCK-8 assay were performed to evaluate neuronal cell death and proliferation, respectively. Relative RNA levels of KAT7 and DYRK1A were examined using quantitative PCR. A chromatin immunoprecipitation assay was conducted to detect H3K14ac in DYRK1A. RESULTS KAT7 expression was suppressed in the AD mice. Overexpression of KAT7 decreased Aβ accumulation and MAP2 expression in AD brains. KAT7 overexpression decreased ROS and MDA levels, elevated SOD activity in brain tissues and neurons, and simultaneously suppressed neuronal apoptosis. KAT7 upregulated levels of p-AKT and p-GSK3β to alleviate insulin resistance, along with elevated expression of DYRK1A. KAT7 depletion suppressed DYRK1A expression and impaired H3K14ac of DYRK1A. HMGN1 overexpression recovered DYRK1A levels and reversed insulin resistance caused by KAT7 depletion. CONCLUSION We determined that KAT7 overexpression recovered insulin sensitivity in AD by recruiting HMGN1 to enhance DYRK1A acetylation. Our findings suggest that KAT7 is a novel and promising therapeutic target for the resistance in AD.
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Affiliation(s)
- Qun-Shan Lu
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
| | - Lin Ma
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
| | - Wen-Jing Jiang
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
| | - Xing-Bang Wang
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
| | - Mei Lu
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan 250012, Shandong Province, China
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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.
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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
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Bevilacqua Junior DE, Mello ECD, Lage JB, Ribeiro MF, Ferreira AA, Teixeira VDPA, Espindula AP. Analysis of strength and electromyographic activity of lower limbs of individuals with down syndrome assisted in physiotherapy and hippotherapy. J Bodyw Mov Ther 2023; 36:83-88. [PMID: 37949604 DOI: 10.1016/j.jbmt.2023.05.009] [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: 05/11/2021] [Revised: 05/05/2023] [Accepted: 05/27/2023] [Indexed: 11/12/2023]
Abstract
INTRODUCTION one of the characteristics of Down Syndrome (DS) is muscle hypotonia. Different therapeutic approaches have a positive influence, between them Physiotherapy applications with different therapeutic approaches such as Hippotherapy have a positive effect on the physical health and quality of live of individuals with DS. OBJECTIVE to evaluate the effects of both treatments on the strength and electromyographic activity of the lower limbs of children and adolescents with DS. METHODS fourteen individuals, aged between 10 and 18 years, participated in two groups: Physiotherapy group (n = 5) and Hippotherapy group (n = 9). Thirty interventions were performed for each type of therapy, once a week, lasting 30 min. Pre and post-interventions, the 30-Second Chair Stand Test (30s-CST) was used to assess the strength of the lower limbs and the surface electromyography equipment (EMG 800RF) to assess the lower limb myoelectric activity. RESULTS there was a reduction in the post-intervention electromyographic values for both treatments (p˂0.001), with significantly less myoelectric activity in Hippotherapy compared to Physiotherapy for all evaluated muscles (p˂0.001) and a significant increase in muscle strength for the Hippotherapy, post-intervention group (p = 0.0007). CONCLUSION Physiotherapy and Hippotherapy are interventions that promote positive changes in the myoelectric activities of individuals with DS. However, only hippotherapy promoted an increase in strength of the lower limbs.
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Affiliation(s)
- Domingos Emanuel Bevilacqua Junior
- Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil; Associação de Pais e Amigos dos Excepcionais de Uberaba, Minas Gerais, Brazil
| | - Edneia Corrêa de Mello
- Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil; Faculdade de Odontologia de Ribeirão Preto da Universidade de São Paulo, São Paulo, Brazil
| | - Janaine Brandão Lage
- Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil; Associação de Pais e Amigos dos Excepcionais de Uberaba, Minas Gerais, Brazil
| | - Mariane Fernandes Ribeiro
- Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil; Faculdade de Patos de Minas, Pato de Minas, Minas Gerais, Brazil
| | | | | | - Ana Paula Espindula
- Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil; Associação de Pais e Amigos dos Excepcionais de Uberaba, Minas Gerais, Brazil.
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7
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Rozen EJ, Ozeroff CD, Allen MA. RUN(X) out of blood: emerging RUNX1 functions beyond hematopoiesis and links to Down syndrome. Hum Genomics 2023; 17:83. [PMID: 37670378 PMCID: PMC10481493 DOI: 10.1186/s40246-023-00531-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/29/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND RUNX1 is a transcription factor and a master regulator for the specification of the hematopoietic lineage during embryogenesis and postnatal megakaryopoiesis. Mutations and rearrangements on RUNX1 are key drivers of hematological malignancies. In humans, this gene is localized to the 'Down syndrome critical region' of chromosome 21, triplication of which is necessary and sufficient for most phenotypes that characterize Trisomy 21. MAIN BODY Individuals with Down syndrome show a higher predisposition to leukemias. Hence, RUNX1 overexpression was initially proposed as a critical player on Down syndrome-associated leukemogenesis. Less is known about the functions of RUNX1 in other tissues and organs, although growing reports show important implications in development or homeostasis of neural tissues, muscle, heart, bone, ovary, or the endothelium, among others. Even less is understood about the consequences on these tissues of RUNX1 gene dosage alterations in the context of Down syndrome. In this review, we summarize the current knowledge on RUNX1 activities outside blood/leukemia, while suggesting for the first time their potential relation to specific Trisomy 21 co-occurring conditions. CONCLUSION Our concise review on the emerging RUNX1 roles in different tissues outside the hematopoietic context provides a number of well-funded hypotheses that will open new research avenues toward a better understanding of RUNX1-mediated transcription in health and disease, contributing to novel potential diagnostic and therapeutic strategies for Down syndrome-associated conditions.
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Affiliation(s)
- Esteban J Rozen
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA.
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA.
| | - Christopher D Ozeroff
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave., Boulder, CO, 80309, USA
| | - Mary Ann Allen
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., Boulder, CO, 80303, USA.
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, 12700 East 19th Avenue, Aurora, CO, 80045, USA.
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Redhead Y, Gibbins D, Lana-Elola E, Watson-Scales S, Dobson L, Krause M, Liu KJ, Fisher EMC, Green JBA, Tybulewicz VLJ. Craniofacial dysmorphology in Down syndrome is caused by increased dosage of Dyrk1a and at least three other genes. Development 2023; 150:dev201077. [PMID: 37102702 PMCID: PMC10163349 DOI: 10.1242/dev.201077] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 03/21/2023] [Indexed: 04/28/2023]
Abstract
Down syndrome (DS), trisomy of human chromosome 21 (Hsa21), occurs in 1 in 800 live births and is the most common human aneuploidy. DS results in multiple phenotypes, including craniofacial dysmorphology, which is characterised by midfacial hypoplasia, brachycephaly and micrognathia. The genetic and developmental causes of this are poorly understood. Using morphometric analysis of the Dp1Tyb mouse model of DS and an associated mouse genetic mapping panel, we demonstrate that four Hsa21-orthologous regions of mouse chromosome 16 contain dosage-sensitive genes that cause the DS craniofacial phenotype, and identify one of these causative genes as Dyrk1a. We show that the earliest and most severe defects in Dp1Tyb skulls are in bones of neural crest (NC) origin, and that mineralisation of the Dp1Tyb skull base synchondroses is aberrant. Furthermore, we show that increased dosage of Dyrk1a results in decreased NC cell proliferation and a decrease in size and cellularity of the NC-derived frontal bone primordia. Thus, DS craniofacial dysmorphology is caused by an increased dosage of Dyrk1a and at least three other genes.
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Affiliation(s)
- Yushi Redhead
- Centre for Craniofacial Biology and Regenerative Biology, King's College London, London SE1 9RT, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | | | | | | | - Lisa Dobson
- Centre for Craniofacial Biology and Regenerative Biology, King's College London, London SE1 9RT, UK
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Matthias Krause
- Randall Centre for Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Karen J. Liu
- Centre for Craniofacial Biology and Regenerative Biology, King's College London, London SE1 9RT, UK
| | | | - Jeremy B. A. Green
- Centre for Craniofacial Biology and Regenerative Biology, King's College London, London SE1 9RT, UK
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Sloan K, Thomas J, Blackwell M, Voisard D, Lana-Elola E, Watson-Scales S, Roper DL, Wallace JM, Fisher EMC, Tybulewicz VLJ, Roper RJ. Genetic dissection of triplicated chromosome 21 orthologs yields varying skeletal traits in Down syndrome model mice. Dis Model Mech 2023; 16:dmm049927. [PMID: 36939025 PMCID: PMC10163323 DOI: 10.1242/dmm.049927] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/02/2023] [Indexed: 03/21/2023] Open
Abstract
Down syndrome (DS) phenotypes result from triplicated genes, but the effects of three copy genes are not well known. A mouse mapping panel genetically dissecting human chromosome 21 (Hsa21) syntenic regions was used to investigate the contributions and interactions of triplicated Hsa21 orthologous genes on mouse chromosome 16 (Mmu16) on skeletal phenotypes. Skeletal structure and mechanical properties were assessed in femurs of male and female Dp9Tyb, Dp2Tyb, Dp3Tyb, Dp4Tyb, Dp5Tyb, Dp6Tyb, Ts1Rhr and Dp1Tyb;Dyrk1a+/+/- mice. Dp1Tyb mice, with the entire Hsa21 homologous region of Mmu16 triplicated, display bone deficits similar to those of humans with DS and served as a baseline for other strains in the panel. Bone phenotypes varied based on triplicated gene content, sex and bone compartment. Three copies of Dyrk1a played a sex-specific, essential role in trabecular deficits and may interact with other genes to influence cortical deficits related to DS. Triplicated genes in Dp9Tyb and Dp2Tyb mice improved some skeletal parameters. As triplicated genes can both improve and worsen bone deficits, it is important to understand the interaction between and molecular mechanisms of skeletal alterations affected by these genes.
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Affiliation(s)
- Kourtney Sloan
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Jared Thomas
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Matthew Blackwell
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Deanna Voisard
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | | | | | | | - Joseph M. Wallace
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | | | | | - Randall J. Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
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10
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Sarver DC, Xu C, Velez LM, Aja S, Jaffe AE, Seldin MM, Reeves RH, Wong GW. Dysregulated systemic metabolism in a Down syndrome mouse model. Mol Metab 2023; 68:101666. [PMID: 36587842 PMCID: PMC9841171 DOI: 10.1016/j.molmet.2022.101666] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/14/2022] [Accepted: 12/26/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Trisomy 21 is one of the most complex genetic perturbations compatible with postnatal survival. Dosage imbalance arising from the triplication of genes on human chromosome 21 (Hsa21) affects multiple organ systems. Much of Down syndrome (DS) research, however, has focused on addressing how aneuploidy dysregulates CNS function leading to cognitive deficit. Although obesity, diabetes, and associated sequelae such as fatty liver and dyslipidemia are well documented in the DS population, only limited studies have been conducted to determine how gene dosage imbalance affects whole-body metabolism. Here, we conduct a comprehensive and systematic analysis of key metabolic parameters across different physiological states in the Ts65Dn trisomic mouse model of DS. METHODS Ts65Dn mice and euploid littermates were subjected to comprehensive metabolic phenotyping under basal (chow-fed) state and the pathophysiological state of obesity induced by a high-fat diet (HFD). RNA sequencing of liver, skeletal muscle, and two major fat depots were conducted to determine the impact of aneuploidy on tissue transcriptome. Pathway enrichments, gene-centrality, and key driver estimates were performed to provide insights into tissue autonomous and non-autonomous mechanisms contributing to the dysregulation of systemic metabolism. RESULTS Under the basal state, chow-fed Ts65Dn mice of both sexes had elevated locomotor activity and energy expenditure, reduced fasting serum cholesterol levels, and mild glucose intolerance. Sexually dimorphic deterioration in metabolic homeostasis became apparent when mice were challenged with a high-fat diet. While obese Ts65Dn mice of both sexes exhibited dyslipidemia, male mice also showed impaired systemic insulin sensitivity, reduced mitochondrial activity, and elevated fibrotic and inflammatory gene signatures in the liver and adipose tissue. Systems-level analysis highlighted conserved pathways and potential endocrine drivers of adipose-liver crosstalk that contribute to dysregulated glucose and lipid metabolism. CONCLUSIONS A combined alteration in the expression of trisomic and disomic genes in peripheral tissues contribute to metabolic dysregulations in Ts65Dn mice. These data lay the groundwork for understanding the impact of aneuploidy on in vivo metabolism.
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Affiliation(s)
- Dylan C Sarver
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cheng Xu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Leandro M Velez
- Department of Biological Chemistry, University of California, Irvine, Irvine, USA; Center for Epigenetics and Metabolism, University of California Irvine, Irvine, USA
| | - Susan Aja
- Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew E Jaffe
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; The Lieber Institute for Brain Development, Baltimore, MD, USA; Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA; Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Marcus M Seldin
- Department of Biological Chemistry, University of California, Irvine, Irvine, USA; Center for Epigenetics and Metabolism, University of California Irvine, Irvine, USA
| | - Roger H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - G William Wong
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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11
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Seol S, Kwon J, Kang HJ. Cell type characterization of spatiotemporal gene co-expression modules in Down syndrome brain. iScience 2022; 26:105884. [PMID: 36647384 PMCID: PMC9840153 DOI: 10.1016/j.isci.2022.105884] [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: 07/20/2022] [Revised: 11/02/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
Down syndrome (DS) is the most common genetic cause of intellectual disability and increases the risk of other brain-related dysfunctions, like seizures, early-onset Alzheimer's disease, and autism. To reveal the molecular profiles of DS-associated brain phenotypes, we performed a meta-data analysis of the developmental DS brain transcriptome at cell type and co-expression module levels. In the DS brain, astrocyte-, microglia-, and endothelial cell-associated genes show upregulated patterns, whereas neuron- and oligodendrocyte-associated genes show downregulated patterns. Weighted gene co-expression network analysis identified cell type-enriched co-expressed gene modules. We present eight representative cell-type modules for neurons, astrocytes, oligodendrocytes, and microglia. We classified the neuron modules into glutamatergic and GABAergic neurons and associated them with detailed subtypes. Cell type modules were interpreted by analyzing spatiotemporal expression patterns, functional annotations, and co-expression networks of the modules. This study provides insight into the mechanisms underlying brain abnormalities in DS and related disorders.
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Affiliation(s)
- Sihwan Seol
- Department of Life Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Joonhong Kwon
- Department of Life Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Hyo Jung Kang
- Department of Life Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea,Corresponding author
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12
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Zhu B, Parsons T, Foley C, Shaw Y, Dunckley T, Hulme C, Hodge JJL. DYRK1A antagonists rescue degeneration and behavioural deficits of in vivo models based on amyloid-β, Tau and DYRK1A neurotoxicity. Sci Rep 2022; 12:15847. [PMID: 36151233 PMCID: PMC9508268 DOI: 10.1038/s41598-022-19967-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 09/07/2022] [Indexed: 11/29/2022] Open
Abstract
Alzheimer’s disease (AD) involves pathological processing of amyloid precursor protein (APP) into amyloid-β and microtubule associated protein Tau (MAPT) into hyperphosphorylated Tau tangles leading to neurodegeneration. Only 5% of AD cases are familial making it difficult to predict who will develop the disease thereby hindering our ability to treat the causes of the disease. A large population who almost certainly will, are those with Down syndrome (DS), who have a 90% lifetime incidence of AD. DS is caused by trisomy of chromosome 21 resulting in three copies of APP and other AD-associated genes, like dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) overexpression. This implies that DYRK1a inhibitors may have therapeutic potential for DS and AD, however It is not clear how overexpression of each of these genes contributes to the pathology of each disease as well as how effective a DYRK1A inhibitor would be at suppressing any of these. To address this knowledge gap, we used Drosophila models with human Tau, human amyloid-β or fly DYRK1A (minibrain (mnb)) neuronal overexpression resulting in photoreceptor neuron degeneration, premature death, decreased locomotion, sleep and memory loss. DYRK1A small molecule Type 1 kinase inhibitors (DYR219 and DYR533) were effective at suppressing these disease relevant phenotypes confirming their therapeutic potential.
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Affiliation(s)
- Bangfu Zhu
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Tom Parsons
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Christopher Foley
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, USA
| | - Yeng Shaw
- Division of Drug Discovery and Development, Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ, 85721, USA
| | - Travis Dunckley
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ, 85281, USA
| | - Christopher Hulme
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, USA.,Division of Drug Discovery and Development, Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ, 85721, USA
| | - James J L Hodge
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
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13
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Zhu B, Parsons T, Stensen W, Mjøen Svendsen JS, Fugelli A, Hodge JJL. DYRK1a Inhibitor Mediated Rescue of Drosophila Models of Alzheimer’s Disease-Down Syndrome Phenotypes. Front Pharmacol 2022; 13:881385. [PMID: 35928283 PMCID: PMC9345315 DOI: 10.3389/fphar.2022.881385] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/23/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease which is becoming increasingly prevalent due to ageing populations resulting in huge social, economic, and health costs to the community. Despite the pathological processing of genes such as Amyloid Precursor Protein (APP) into Amyloid-β and Microtubule Associated Protein Tau (MAPT) gene, into hyperphosphorylated Tau tangles being known for decades, there remains no treatments to halt disease progression. One population with increased risk of AD are people with Down syndrome (DS), who have a 90% lifetime incidence of AD, due to trisomy of human chromosome 21 (HSA21) resulting in three copies of APP and other AD-associated genes, such as DYRK1A (Dual specificity tyrosine-phosphorylation-regulated kinase 1A) overexpression. This suggests that blocking DYRK1A might have therapeutic potential. However, it is still not clear to what extent DYRK1A overexpression by itself leads to AD-like phenotypes and how these compare to Tau and Amyloid-β mediated pathology. Likewise, it is still not known how effective a DYRK1A antagonist may be at preventing or improving any Tau, Amyloid-β and DYRK1a mediated phenotype. To address these outstanding questions, we characterised Drosophila models with targeted overexpression of human Tau, human Amyloid-β or the fly orthologue of DYRK1A, called minibrain (mnb). We found targeted overexpression of these AD-associated genes caused degeneration of photoreceptor neurons, shortened lifespan, as well as causing loss of locomotor performance, sleep, and memory. Treatment with the experimental DYRK1A inhibitor PST-001 decreased pathological phosphorylation of human Tau [at serine (S) 262]. PST-001 reduced degeneration caused by human Tau, Amyloid-β or mnb lengthening lifespan as well as improving locomotion, sleep and memory loss caused by expression of these AD and DS genes. This demonstrated PST-001 effectiveness as a potential new therapeutic targeting AD and DS pathology.
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Affiliation(s)
- Bangfu Zhu
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Bristol, United Kingdom
| | - Tom Parsons
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Bristol, United Kingdom
| | - Wenche Stensen
- Department of Chemistry, The Arctic University of Norway, Tromsø, Norway
- Pharmasum Therapeutics AS, ShareLab, Forskningsparken i Oslo, Oslo, Norway
| | - John S. Mjøen Svendsen
- Department of Chemistry, The Arctic University of Norway, Tromsø, Norway
- Pharmasum Therapeutics AS, ShareLab, Forskningsparken i Oslo, Oslo, Norway
| | - Anders Fugelli
- Pharmasum Therapeutics AS, ShareLab, Forskningsparken i Oslo, Oslo, Norway
| | - James J. L. Hodge
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Science, University of Bristol, Bristol, United Kingdom
- *Correspondence: James J. L. Hodge,
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14
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Klein JA, Haydar TF. Neurodevelopment in Down syndrome: Concordance in humans and models. Front Cell Neurosci 2022; 16:941855. [PMID: 35910249 PMCID: PMC9334873 DOI: 10.3389/fncel.2022.941855] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Great strides have been made over the past 30 years in understanding the neurodevelopmental changes underlying the intellectual disability (ID) in Down syndrome (DS). Detailed studies of human tissue coupled with findings from rodent and induced pluripotent stem cells (iPSCs) model systems have uncovered the changes in neurogenesis, synaptic connectivity, and myelination that drive the anatomical and physiological changes resulting in the disability. However, there remain significant conflicting data between human studies and the models. To fully understand the development of ID in DS, these inconsistencies need to be reconciled. Here, we review the well documented neurodevelopmental phenotypes found in individuals with DS and examine the degree to which widely used models recapitulate these phenotypes. Resolving these areas of discord will further research on the molecular underpinnings and identify potential treatments to improve the independence and quality of life of people with DS.
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Affiliation(s)
- Jenny A. Klein
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
| | - Tarik F. Haydar
- Children’s National Hospital, Center for Neuroscience Research, Washington, DC, United States
- Departments of Pediatrics, Physiology and Pharmacology, School of Medicine and Health Sciences, George Washington University, Washington, DC, United States
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15
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Austin A, Beresford L, Price G, Cunningham T, Kalmar B, Yon M. Sectioning and Counting of Motor Neurons in the L3 to L6 Region of the Adult Mouse Spinal Cord. Curr Protoc 2022; 2:e428. [PMID: 35617451 DOI: 10.1002/cpz1.428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Histology is the study of the microscopic structure of tissues. This protocol permits the generation of frozen transverse sections of lumbar spinal cord regions L3 to L6. It enables counting of murine ventral horn lumbar motor neurons in a reproducible manner. Methods include spinal column dissection, hydraulic extrusion, and histological processing. The preparation for cryo-sectioning includes embedding lumbar spinal cord in optimal cutting temperature (OCT) medium. The correct orientation of the tissue is critical as calculating the amount of tissue to discard saved time overall. Specific details regarding section thickness and mounting are described. These requirements not only allow optimum coverage of specific regions but also ensure that no individual motor neuron was counted twice. The Nissl bodies of the motor neurons were stained using gallocyanin. The sections obtained are all of a comparable area and quality assurance is consistent. The specificity of the staining enables the scientist to identify and reliably quantify lumbar motor neurons. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Euthanasia of mouse and isolation of spinal cord Basic Protocol 2: Hydraulic extrusion of the spinal cord Basic Protocol 3: Identification of the lumbar region Basic Protocol 4: Embedding cord in OCT Basic Protocol 5: Collection of frozen sections onto slides Basic Protocol 6: Gallocyanin staining Basic Protocol 7: Motor neuron counting.
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Affiliation(s)
- Adele Austin
- Pathology Department, Mary Lyon Centre, Medical Research Council, Harwell, United Kingdom
| | - Lynn Beresford
- Pathology Department, Mary Lyon Centre, Medical Research Council, Harwell, United Kingdom
| | - Georgia Price
- Mouse Models of Neurodegeneration, Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Tom Cunningham
- Mouse Models of Neurodegeneration, Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | | | - Marianne Yon
- Pathology Department, Mary Lyon Centre, Medical Research Council, Harwell, United Kingdom
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16
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Mouse models of aneuploidy to understand chromosome disorders. Mamm Genome 2021; 33:157-168. [PMID: 34719726 PMCID: PMC8913467 DOI: 10.1007/s00335-021-09930-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/20/2021] [Indexed: 12/04/2022]
Abstract
An organism or cell carrying a number of chromosomes that is not a multiple of the haploid count is in a state of aneuploidy. This condition results in significant changes in the level of expression of genes that are gained or lost from the aneuploid chromosome(s) and most cases in humans are not compatible with life. However, a few aneuploidies can lead to live births, typically associated with deleterious phenotypes. We do not understand why phenotypes arise from aneuploid syndromes in humans. Animal models have the potential to provide great insight, but less than a handful of mouse models of aneuploidy have been made, and no ideal system exists in which to study the effects of aneuploidy per se versus those of raised gene dosage. Here, we give an overview of human aneuploid syndromes, the effects on physiology of having an altered number of chromosomes and we present the currently available mouse models of aneuploidy, focusing on models of trisomy 21 (which causes Down syndrome) because this is the most common, and therefore, the most studied autosomal aneuploidy. Finally, we discuss the potential role of carrying an extra chromosome on aneuploid phenotypes, independent of changes in gene dosage, and methods by which this could be investigated further.
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17
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Lana-Elola E, Cater H, Watson-Scales S, Greenaway S, Müller-Winkler J, Gibbins D, Nemes M, Slender A, Hough T, Keskivali-Bond P, Scudamore CL, Herbert E, Banks GT, Mobbs H, Canonica T, Tosh J, Noy S, Llorian M, Nolan PM, Griffin JL, Good M, Simon M, Mallon AM, Wells S, Fisher EMC, Tybulewicz VLJ. Comprehensive phenotypic analysis of the Dp1Tyb mouse strain reveals a broad range of Down syndrome-related phenotypes. Dis Model Mech 2021; 14:dmm049157. [PMID: 34477842 PMCID: PMC8543064 DOI: 10.1242/dmm.049157] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/26/2021] [Indexed: 12/24/2022] Open
Abstract
Down syndrome (DS), trisomy 21, results in many complex phenotypes including cognitive deficits, heart defects and craniofacial alterations. Phenotypes arise from an extra copy of human chromosome 21 (Hsa21) genes. However, these dosage-sensitive causative genes remain unknown. Animal models enable identification of genes and pathological mechanisms. The Dp1Tyb mouse model of DS has an extra copy of 63% of Hsa21-orthologous mouse genes. In order to establish whether this model recapitulates DS phenotypes, we comprehensively phenotyped Dp1Tyb mice using 28 tests of different physiological systems and found that 468 out of 1800 parameters were significantly altered. We show that Dp1Tyb mice have wide-ranging DS-like phenotypes, including aberrant erythropoiesis and megakaryopoiesis, reduced bone density, craniofacial changes, altered cardiac function, a pre-diabetic state, and deficits in memory, locomotion, hearing and sleep. Thus, Dp1Tyb mice are an excellent model for investigating complex DS phenotype-genotype relationships for this common disorder.
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Affiliation(s)
| | - Heather Cater
- MRC Harwell Institute, Harwell Campus, Didcot, OX11 0RD, UK
| | | | | | | | | | | | - Amy Slender
- The Francis Crick Institute, London NW1 1AT, UK
| | - Tertius Hough
- MRC Harwell Institute, Harwell Campus, Didcot, OX11 0RD, UK
| | | | | | | | | | - Helene Mobbs
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge CB2 1QW, UK
| | - Tara Canonica
- School of Psychology, Cardiff University, Cardiff CF10 3AT, UK
| | - Justin Tosh
- The Francis Crick Institute, London NW1 1AT, UK
- UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Suzanna Noy
- UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | | | | | - Julian L. Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, Cambridge CB2 1QW, UK
- Imperial College Dementia Research Institute, Imperial College London, London W12 7TA, UK
| | - Mark Good
- School of Psychology, Cardiff University, Cardiff CF10 3AT, UK
| | - Michelle Simon
- MRC Harwell Institute, Harwell Campus, Didcot, OX11 0RD, UK
| | | | - Sara Wells
- MRC Harwell Institute, Harwell Campus, Didcot, OX11 0RD, UK
| | | | - Victor L. J. Tybulewicz
- The Francis Crick Institute, London NW1 1AT, UK
- Department of Immunology and Inflammation, Imperial College London, London W12 0NN, UK
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18
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Li Y, Xing Z, Yu T, Pao A, Daadi M, Yu YE. Coat Color-Facilitated Efficient Generation and Analysis of a Mouse Model of Down Syndrome Triplicated for All Human Chromosome 21 Orthologous Regions. Genes (Basel) 2021; 12:genes12081215. [PMID: 34440389 PMCID: PMC8393392 DOI: 10.3390/genes12081215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/31/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
Down syndrome (DS) is one of the most complex genetic disorders in humans and a leading genetic cause of developmental delays and intellectual disabilities. The mouse remains an essential model organism in DS research because human chromosome 21 (Hsa21) is orthologously conserved with three regions in the mouse genome. Recent studies have revealed complex interactions among different triplicated genomic regions and Hsa21 gene orthologs that underlie major DS phenotypes. Because we do not know conclusively which triplicated genes are indispensable in such interactions for a specific phenotype, it is desirable that all evolutionarily conserved Hsa21 gene orthologs are triplicated in a complete model. For this reason, the Dp(10)1Yey/+;Dp(16)1Yey/+;Dp(17)1Yey/+ mouse is the most complete model of DS to reflect gene dosage effects because it is the only mutant triplicated for all Hsa21 orthologous regions. Recently, several groups have expressed concerns that efforts needed to generate the triple compound model would be so overwhelming that it may be impractical to take advantage of its unique strength. To alleviate these concerns, we developed a strategy to drastically improve the efficiency of generating the triple compound model with the aid of a targeted coat color, and the results confirmed that the mutant mice generated via this approach exhibited cognitive deficits.
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Affiliation(s)
- Yichen Li
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (Y.L.); (Z.X.); (T.Y.); (A.P.)
| | - Zhuo Xing
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (Y.L.); (Z.X.); (T.Y.); (A.P.)
| | - Tao Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (Y.L.); (Z.X.); (T.Y.); (A.P.)
| | - Annie Pao
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (Y.L.); (Z.X.); (T.Y.); (A.P.)
| | - Marcel Daadi
- Regenerative Medicine and Aging Unit, Texas Biomedical Research Institute, Long School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245, USA;
| | - Y. Eugene Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (Y.L.); (Z.X.); (T.Y.); (A.P.)
- Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY 14203, USA
- Correspondence:
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19
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Toussaint N, Redhead Y, Vidal-García M, Lo Vercio L, Liu W, Fisher EMC, Hallgrímsson B, Tybulewicz VLJ, Schnabel JA, Green JBA. A landmark-free morphometrics pipeline for high-resolution phenotyping: application to a mouse model of Down syndrome. Development 2021; 148:dev188631. [PMID: 33712441 PMCID: PMC7969589 DOI: 10.1242/dev.188631] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/01/2021] [Indexed: 12/20/2022]
Abstract
Characterising phenotypes often requires quantification of anatomical shape. Quantitative shape comparison (morphometrics) traditionally uses manually located landmarks and is limited by landmark number and operator accuracy. Here, we apply a landmark-free method to characterise the craniofacial skeletal phenotype of the Dp1Tyb mouse model of Down syndrome and a population of the Diversity Outbred (DO) mouse model, comparing it with a landmark-based approach. We identified cranial dysmorphologies in Dp1Tyb mice, especially smaller size and brachycephaly (front-back shortening), homologous to the human phenotype. Shape variation in the DO mice was partly attributable to allometry (size-dependent shape variation) and sexual dimorphism. The landmark-free method performed as well as, or better than, the landmark-based method but was less labour-intensive, required less user training and, uniquely, enabled fine mapping of local differences as planar expansion or shrinkage. Its higher resolution pinpointed reductions in interior mid-snout structures and occipital bones in both the models that were not otherwise apparent. We propose that this landmark-free pipeline could make morphometrics widely accessible beyond its traditional niches in zoology and palaeontology, especially in characterising developmental mutant phenotypes.
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Affiliation(s)
- Nicolas Toussaint
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK
| | - Yushi Redhead
- Centre for Craniofacial Biology & Regeneration, King's College London, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | - Marta Vidal-García
- Department of Cell Biology & Anatomy, University of Calgary, Calgary AB T2N 4N1, Canada
| | - Lucas Lo Vercio
- Department of Cell Biology & Anatomy, University of Calgary, Calgary AB T2N 4N1, Canada
| | - Wei Liu
- Department of Cell Biology & Anatomy, University of Calgary, Calgary AB T2N 4N1, Canada
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Benedikt Hallgrímsson
- Department of Cell Biology & Anatomy, University of Calgary, Calgary AB T2N 4N1, Canada
| | - Victor L J Tybulewicz
- The Francis Crick Institute, London NW1 1AT, UK
- Department of Immunology & Inflammation, Imperial College London, London W12 0NN, UK
| | - Julia A Schnabel
- School of Biomedical Engineering and Imaging Sciences, King's College London, UK
| | - Jeremy B A Green
- Centre for Craniofacial Biology & Regeneration, King's College London, UK
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20
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D'Mello SR. MECP2 and the Biology of MECP2 Duplication Syndrome. J Neurochem 2021; 159:29-60. [PMID: 33638179 DOI: 10.1111/jnc.15331] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/21/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022]
Abstract
MECP2 duplication syndrome (MDS), a rare X-linked genomic disorder affecting predominantly males, is caused by duplication of the chromosomal region containing the methyl CpG binding protein-2 (MECP2) gene, which encodes methyl-CpG-binding protein 2 (MECP2), a multi-functional protein required for proper brain development and maintenance of brain function during adulthood. Disease symptoms include severe motor and cognitive impairment, delayed or absent speech development, autistic features, seizures, ataxia, recurrent respiratory infections and shortened lifespan. The cellular and molecular mechanisms by which a relatively modest increase in MECP2 protein causes such severe disease symptoms are poorly understood and consequently there are no treatments available for this fatal disorder. This review summarizes what is known to date about the structure and complex regulation of MECP2 and its many functions in the developing and adult brain. Additionally, recent experimental findings on the cellular and molecular underpinnings of MDS based on cell culture and mouse models of the disorder are reviewed. The emerging picture from these studies is that MDS is a neurodegenerative disorder in which neurons die in specific parts of the central nervous system, including the cortex, hippocampus, cerebellum and spinal cord. Neuronal death likely results from astrocytic dysfunction, including a breakdown of glutamate homeostatic mechanisms. The role of elevations in the expression of glial acidic fibrillary protein (GFAP) in astrocytes and the microtubule-associated protein, Tau, in neurons to the pathogenesis of MDS is discussed. Lastly, potential therapeutic strategies to potentially treat MDS are discussed.
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21
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Martínez de Lagrán M. Mapping behavioral landscapes in Down syndrome animal models. PROGRESS IN BRAIN RESEARCH 2020; 251:145-179. [DOI: 10.1016/bs.pbr.2020.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Aziz NM, Klein JA, Brady MR, Olmos-Serrano JL, Gallo V, Haydar TF. Spatiotemporal development of spinal neuronal and glial populations in the Ts65Dn mouse model of Down syndrome. J Neurodev Disord 2019; 11:35. [PMID: 31839007 PMCID: PMC6913030 DOI: 10.1186/s11689-019-9294-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 11/11/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Down syndrome (DS), caused by the triplication of chromosome 21, results in a constellation of clinical features including changes in intellectual and motor function. Although altered neural development and function have been well described in people with DS, few studies have investigated the etiology underlying the observed motor phenotypes. Here, we examine the development, patterning, and organization of the spinal cord throughout life in the Ts65Dn mouse, a model that recapitulates many of the motor changes observed in people with DS. METHODS Spinal cords from embryonic to adult animals were processed for gene and protein expression (immunofluorescence) to track the spatiotemporal development of excitatory and inhibitory neurons and oligodendroglia. Postnatal analyses were focused on the lumbar region due to the reflex and gait abnormalities found in Ts65Dn mice and locomotive alterations seen in people with DS. RESULTS Between embryonic days E10.5 and E14.5, we found a larger motor neuron progenitor domain in Ts65Dn animals containing more OLIG2-expressing progenitor cells. These disturbed progenitors are delayed in motor neuron production but eventually generate a large number of ISL1+ migrating motor neurons. We found that higher numbers of PAX6+ and NKX2.2+ interneurons (INs) are also produced during this time frame. In the adult lumbar spinal cord, we found an increased level of Hb9 and a decreased level of Irx3 gene expression in trisomic animals. This was accompanied by an increase in Calretinin+ INs, but no changes in other neuronal populations. In aged Ts65Dn animals, both Calbindin+ and ChAT+ neurons were decreased compared to euploid controls. Additionally, in the dorsal corticospinal white matter tract, there were significantly fewer CC1+ mature OLs in 30- and 60-day old trisomic animals and this normalized to euploid levels at 10-11 months. In contrast, the mature OL population was increased in the lateral funiculus, an ascending white matter tract carrying sensory information. In 30-day old animals, we also found a decrease in the number of nodes of Ranvier in both tracts. This decrease normalized both in 60-day old and aged animals. CONCLUSIONS We show marked changes in both spinal white matter and neuronal composition that change regionally over the life span. In the embryonic Ts65Dn spinal cord, we observe alterations in motor neuron production and migration. In the adult spinal cord, we observe changes in oligodendrocyte maturation and motor neuron loss, the latter of which has also been observed in human spinal cord tissue samples. This work uncovers multiple cellular perturbations during Ts65Dn development and aging, many of which may underlie the motor deficits found in DS.
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Affiliation(s)
- Nadine M. Aziz
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Jenny A. Klein
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Morgan R. Brady
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Jose Luis Olmos-Serrano
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Vittorio Gallo
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
| | - Tarik F. Haydar
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118 USA
- Center for Neuroscience Research and District of Columbia Intellectual and Developmental Disabilities Research Center, Children’s National Hospital, Washington, DC 20010 USA
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23
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Yu YE, Xing Z, Do C, Pao A, Lee EJ, Krinsky-McHale S, Silverman W, Schupf N, Tycko B. Genetic and epigenetic pathways in Down syndrome: Insights to the brain and immune system from humans and mouse models. PROGRESS IN BRAIN RESEARCH 2019; 251:1-28. [PMID: 32057305 PMCID: PMC7286740 DOI: 10.1016/bs.pbr.2019.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The presence of an extra copy of human chromosome 21 (Hsa21) leads to a constellation of phenotypic manifestations in Down syndrome (DS), including prominent effects on the brain and immune system. Intensive efforts to unravel the molecular mechanisms underlying these phenotypes may help developing effective therapies, both in DS and in the general population. Here we review recent progress in genetic and epigenetic analysis of trisomy 21 (Ts21). New mouse models of DS based on syntenic conservation of segments of the mouse and human chromosomes are starting to clarify the contributions of chromosomal subregions and orthologous genes to specific phenotypes in DS. The expression of genes on Hsa21 is regulated by epigenetic mechanisms, and with recent findings of highly recurrent gene-specific changes in DNA methylation patterns in brain and immune system cells with Ts21, the epigenomics of DS has become an active research area. Here we highlight the value of combining human studies with mouse models for defining DS critical genes and understanding the trans-acting effects of a simple chromosomal aneuploidy on genome-wide epigenetic patterning. These genetic and epigenetic studies are starting to uncover fundamental biological mechanisms, leading to insights that may soon become therapeutically relevant.
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Affiliation(s)
- Y Eugene Yu
- The Children's Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States; Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY, United States.
| | - Zhuo Xing
- The Children's Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Catherine Do
- Department of Biomedical Research, Division of Genetics & Epigenetics, Hackensack-Meridian Health Center for Discovery and Innovation and Hackensack-Meridian Health School of Medicine at Seton Hall University, Nutley, NJ, United States
| | - Annie Pao
- The Children's Guild Foundation Down Syndrome Research Program, Genetics and Genomics Program and Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Eun Joon Lee
- Department of Biomedical Research, Division of Genetics & Epigenetics, Hackensack-Meridian Health Center for Discovery and Innovation and Hackensack-Meridian Health School of Medicine at Seton Hall University, Nutley, NJ, United States
| | - Sharon Krinsky-McHale
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
| | - Wayne Silverman
- Kennedy Krieger Institute and Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Pediatrics, University of California at Irvine, Irvine, CA, United States
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Benjamin Tycko
- Department of Biomedical Research, Division of Genetics & Epigenetics, Hackensack-Meridian Health Center for Discovery and Innovation and Hackensack-Meridian Health School of Medicine at Seton Hall University, Nutley, NJ, United States.
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24
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Muñiz Moreno MDM, Brault V, Birling MC, Pavlovic G, Herault Y. Modeling Down syndrome in animals from the early stage to the 4.0 models and next. PROGRESS IN BRAIN RESEARCH 2019; 251:91-143. [PMID: 32057313 DOI: 10.1016/bs.pbr.2019.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The genotype-phenotype relationship and the physiopathology of Down Syndrome (DS) have been explored in the last 20 years with more and more relevant mouse models. From the early age of transgenesis to the new CRISPR/CAS9-derived chromosomal engineering and the transchromosomic technologies, mouse models have been key to identify homologous genes or entire regions homologous to the human chromosome 21 that are necessary or sufficient to induce DS features, to investigate the complexity of the genetic interactions that are involved in DS and to explore therapeutic strategies. In this review we report the new developments made, how genomic data and new genetic tools have deeply changed our way of making models, extended our panel of animal models, and increased our understanding of the neurobiology of the disease. But even if we have made an incredible progress which promises to make DS a curable condition, we are facing new research challenges to nurture our knowledge of DS pathophysiology as a neurodevelopmental disorder with many comorbidities during ageing.
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Affiliation(s)
- Maria Del Mar Muñiz Moreno
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Véronique Brault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Marie-Christine Birling
- Université de Strasbourg, CNRS, INSERM, PHENOMIN Institut Clinique de la Souris, Illkirch, France
| | - Guillaume Pavlovic
- Université de Strasbourg, CNRS, INSERM, PHENOMIN Institut Clinique de la Souris, Illkirch, France
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Université de Strasbourg, CNRS, INSERM, PHENOMIN Institut Clinique de la Souris, Illkirch, France.
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25
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Ahlfors H, Anyanwu N, Pakanavicius E, Dinischiotu N, Lana-Elola E, Watson-Scales S, Tosh J, Wiseman F, Briscoe J, Page K, Fisher EMC, Tybulewicz VLJ. Gene expression dysregulation domains are not a specific feature of Down syndrome. Nat Commun 2019; 10:2489. [PMID: 31171815 PMCID: PMC6554309 DOI: 10.1038/s41467-019-10129-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/18/2019] [Indexed: 11/19/2022] Open
Abstract
Down syndrome (DS), trisomy of human chromosome 21 (Hsa21), results in a broad range of phenotypes. A recent study reported that DS cells show genome-wide transcriptional changes in which up- or down-regulated genes are clustered in gene expression dysregulation domains (GEDDs). GEDDs were also reported in fibroblasts derived from a DS mouse model duplicated for some Hsa21-orthologous genes, indicating cross-species conservation of this phenomenon. Here we investigate GEDDs using the Dp1Tyb mouse model of DS, which is duplicated for the entire Hsa21-orthologous region of mouse chromosome 16. Our statistical analysis shows that GEDDs are present both in DS cells and in Dp1Tyb mouse fibroblasts and hippocampus. However, we find that GEDDs do not depend on the DS genotype but occur whenever gene expression changes. We conclude that GEDDs are not a specific feature of DS but instead result from the clustering of co-regulated genes, a function of mammalian genome organisation. Gene expression dysregulation domains (GEDDs) have been reported in Down syndrome (DS) cells, where changes in gene expression are clustered. Here the authors find that, while GEDDs are present in DS cells and in the Dp1Tyb mouse model of DS, GEDDs do not depend on the DS genotype and occur whenever gene expression changes, suggesting they result from the clustering of co-regulated genes as a function of mammalian genome organisation.
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Affiliation(s)
- Helena Ahlfors
- NE Thames Regional Genetics Laboratory, GOSH NHS Foundation Trust, London, WC1N 3JH, UK
| | | | | | | | | | | | - Justin Tosh
- UCL Institute of Neurology, London, WC1N 3BG, UK
| | | | | | - Karen Page
- Department of Mathematics, University College London, London, WC1E 6BT, UK
| | | | - Victor L J Tybulewicz
- The Francis Crick Institute, London, NW1 1AT, UK. .,Imperial College, London, W12 0NN, UK.
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26
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Neuronal overexpression of Alzheimer's disease and Down's syndrome associated DYRK1A/minibrain gene alters motor decline, neurodegeneration and synaptic plasticity in Drosophila. Neurobiol Dis 2019; 125:107-114. [PMID: 30703437 PMCID: PMC6419573 DOI: 10.1016/j.nbd.2019.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/12/2018] [Accepted: 01/25/2019] [Indexed: 11/24/2022] Open
Abstract
Down syndrome (DS) is characterised by abnormal cognitive and motor development, and later in life by progressive Alzheimer's disease (AD)-like dementia, neuropathology, declining motor function and shorter life expectancy. It is caused by trisomy of chromosome 21 (Hsa21), but how individual Hsa21 genes contribute to various aspects of the disorder is incompletely understood. Previous work has demonstrated a role for triplication of the Hsa21 gene DYRK1A in cognitive and motor deficits, as well as in altered neurogenesis and neurofibrillary degeneration in the DS brain, but its contribution to other DS phenotypes is unclear. Here we demonstrate that overexpression of minibrain (mnb), the Drosophila ortholog of DYRK1A, in the Drosophila nervous system accelerated age-dependent decline in motor performance and shortened lifespan. Overexpression of mnb in the eye was neurotoxic and overexpression in ellipsoid body neurons in the brain caused age-dependent neurodegeneration. At the larval neuromuscular junction, an established model for mammalian central glutamatergic synapses, neuronal mnb overexpression enhanced spontaneous vesicular transmitter release. It also slowed recovery from short-term depression of evoked transmitter release induced by high-frequency nerve stimulation and increased the number of boutons in one of the two glutamatergic motor neurons innervating the muscle. These results provide further insight into the roles of DYRK1A triplication in abnormal aging and synaptic dysfunction in DS. Overexpression of minibrain (DYRK1A) causes Down's relevant phenotypes including: Age-dependent degeneration of brain neurons Accelerated age-dependent decline in motor performance and shorted lifespan Modified presynaptic structure and enhanced spontaneous transmitter release Slowed recovery from short-term depression of synaptic transmission
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27
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Glass TJ, Twadell SL, Valmadrid LC, Connor NP. Early impacts of modified food consistency on oromotor outcomes in mouse models of Down syndrome. Physiol Behav 2018; 199:273-281. [PMID: 30496741 DOI: 10.1016/j.physbeh.2018.11.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/16/2018] [Accepted: 11/25/2018] [Indexed: 12/12/2022]
Abstract
Down syndrome (DS) in humans is associated with differences of the central nervous system and oromotor development. DS also increases risks for pediatric feeding challenges, which sometimes involve the use of altered food consistencies. Therefore, experimental food consistency paradigms are of interest to oromotor investigations in mouse models of Down syndrome (DS). The present work reports impacts of an altered food consistency paradigm on the Ts65Dn and Dp(16)1Yey mouse models of DS, and sibling control mice. At weaning, Ts65Dn, Dp(16)1Yey and respective controls were assigned to receive either a hard food or a soft food (eight experimental groups, n = 8-10 per group). Two weeks later, mice were assessed for mastication speeds and then euthanized for muscle analysis. Soft food conditions were associated with significantly smaller weight gain (p = .003), significantly less volitional water intake through licking (p = .0001), and significant reductions in size of anterior digastric myofibers positive for myosin heavy chain isoform (MyHC) 2b (p = .049). Genotype was associated with significant differences in weight gain (p = .004), significant differences in mastication rate (p = .001), significant differences in a measure of anterior digastric muscle size (p = .03), and significant reductions in size of anterior digastric myofibers positive for MyHC 2a (p = .04). In multiple measures, the Ts65Dn model of DS was more affected than other genotype groups. Findings indicate a soft food consistency condition in mice is associated with significant reductions in weight gain and oromotor activity, and may impact digastric muscle. This suggests extended periods of food consistency modifications may have impacts that extend beyond their immediate roles in facilitating deglutition.
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Affiliation(s)
- Tiffany J Glass
- Department of Surgery, University of Wisconsin, Madison, WI, USA.
| | - Sara L Twadell
- Department of Surgery, University of Wisconsin, Madison, WI, USA
| | - Luke C Valmadrid
- Department of Surgery, University of Wisconsin, Madison, WI, USA
| | - Nadine P Connor
- Department of Surgery, University of Wisconsin, Madison, WI, USA; Department of Communication Sciences and Disorders, University of Wisconsin, Madison, WI, USA
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