1
|
Gautier MK, Kelley CM, Lee SH, Mufson EJ, Ginsberg SD. Maternal choline supplementation rescues early endosome pathology in basal forebrain cholinergic neurons in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease. Neurobiol Aging 2024; 144:30-42. [PMID: 39265450 DOI: 10.1016/j.neurobiolaging.2024.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 07/27/2024] [Accepted: 09/02/2024] [Indexed: 09/14/2024]
Abstract
Individuals with DS develop Alzheimer's disease (AD) neuropathology, including endosomal-lysosomal system abnormalities and degeneration of basal forebrain cholinergic neurons (BFCNs). We investigated whether maternal choline supplementation (MCS) affects early endosome pathology within BFCNs using the Ts65Dn mouse model of DS/AD. Ts65Dn and disomic (2N) offspring from dams administered MCS were analyzed for endosomal pathology at 3-4 months or 10-12 months. Morphometric analysis of early endosome phenotype was performed on individual BFCNs using Imaris. The effects of MCS on the endosomal interactome were interrogated by relative co-expression (RCE) analysis. MCS effectively reduced age- and genotype-associated increases in early endosome number in Ts65Dn and 2N offspring, and prevented increases in early endosome size in Ts65Dn offspring. RCE revealed a loss of interactome cooperativity among endosome genes in Ts65Dn offspring that was restored by MCS. These findings demonstrate MCS rescues early endosome pathology, a driver of septohippocampal circuit dysfunction. The genotype-independent benefits of MCS on endosomal phenotype indicate translational applicability as an early-life therapy for DS as well as other neurodevelopmental/neurodegenerative disorders involving endosomal pathology.
Collapse
Affiliation(s)
- Megan K Gautier
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Pathobiology and Translational Medicine Program, New York University Grossman School of Medicine, New York, NY, USA; NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - Christy M Kelley
- Complex Adaptive Systems Initiative, Arizona State University, Tempe, AZ, USA; Institute for Future Health, Scottsdale, AZ, USA
| | - Sang Han Lee
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - Elliott J Mufson
- Departments of Translational Neuroscience and Neurology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA; Department of Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, USA.
| |
Collapse
|
2
|
Singh N, Richtsmeier JT, Reeves RH. Comparative analysis of craniofacial shape in two mouse models of Down syndrome: Ts65Dn and TcMAC21. J Anat 2024; 244:1007-1014. [PMID: 38264931 PMCID: PMC11095296 DOI: 10.1111/joa.14012] [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: 07/27/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 01/25/2024] Open
Abstract
Mouse models are central to studying and understanding the genotypic-to-phenotypic outcomes of Down syndrome (DS), a complex condition caused by an extra copy of the long arm of human chromosome 21. The recently developed TcMAC21-a transchromosomic mouse strain with comparable gene dosage to human chromosome 21 (Hsa21)-includes more Hsa21 genes than any other model of DS. Recent studies on TcMAC21 have provided valuable insight into the molecular, physiological, and neuroanatomical aspects of the model. However, relatively little is known about the craniofacial phenotype of TcMAC21 mice, particularly as it compares to the widely studied Ts65Dn model. Here we conducted a quantitative study of the cranial morphology of TcMAC21 and Ts65Dn mice and their respective unaffected littermates. Our comparative data comprise forty three-dimensional cranial measurements taken on micro-computed tomography scans of the heads of TcMAC21 and Ts65Dn mice. Our results show that TcMAC21 exhibit similar patterns of craniofacial change to Ts65Dn. However, the DS-specific morphology is more pronounced in Ts65Dn mice. Specifically, Ts65Dn present with more medio-lateral broadening and retraction of the snout compared to TcMAC21. Our findings reveal the complexity of potential gene interaction in the production of craniofacial phenotypes.
Collapse
Affiliation(s)
- Nandini Singh
- California State University, Sacramento, California, USA
| | | | - Roger H Reeves
- Physiology and Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
3
|
López-Hidalgo R, Ballestín R, Lorenzo L, Sánchez-Martí S, Blasco-Ibáñez JM, Crespo C, Nacher J, Varea E. Early chronic fasudil treatment rescues hippocampal alterations in the Ts65Dn model for down syndrome. Neurochem Int 2024; 174:105679. [PMID: 38309665 DOI: 10.1016/j.neuint.2024.105679] [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: 10/06/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/05/2024]
Abstract
Down syndrome (DS) is the most common genetic disorder associated with intellectual disability. To study this syndrome, several mouse models have been developed. Among the most common is the Ts65Dn model, which mimics most of the alterations observed in DS. Ts65Dn mice, as humans with DS, show defects in the structure, density, and distribution of dendritic spines in the cerebral cortex and hippocampus. Fasudil is a potent inhibitor of the RhoA kinase pathway, which is involved in the formation and stabilization of dendritic spines. Our study analysed the effect of early chronic fasudil treatment on the alterations observed in the hippocampus of the Ts65Dn model. We observed that treating Ts65Dn mice with fasudil induced an increase in neural plasticity in the hippocampus: there was an increment in the expression of PSA-NCAM and BDNF, in the dendritic branching and spine density of granule neurons, as well as in cell proliferation and neurogenesis in the subgranular zone. Finally, the treatment reduced the unbalance between excitation and inhibition present in this model. Overall, early chronic treatment with fasudil increases cell plasticity and eliminates differences with euploid animals.
Collapse
Affiliation(s)
- Rosa López-Hidalgo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Raúl Ballestín
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Lorena Lorenzo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Sandra Sánchez-Martí
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - José Miguel Blasco-Ibáñez
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Carlos Crespo
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain
| | - Juan Nacher
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain; CIBERSAM, Spanish National Network for Research in Mental Health, Madrid, Spain; Institute of research of the Clinic Hospital from Valencia (INCLIVA), Valencia, Spain
| | - Emilio Varea
- Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Spain.
| |
Collapse
|
4
|
Gautier MK, Kelley CM, Lee SH, Alldred MJ, McDaid J, Mufson EJ, Stutzmann GE, Ginsberg SD. Maternal choline supplementation protects against age-associated cholinergic and GABAergic basal forebrain neuron degeneration in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease. Neurobiol Dis 2023; 188:106332. [PMID: 37890559 PMCID: PMC10752300 DOI: 10.1016/j.nbd.2023.106332] [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: 08/07/2023] [Revised: 10/02/2023] [Accepted: 10/22/2023] [Indexed: 10/29/2023] Open
Abstract
Down syndrome (DS) is a genetic disorder caused by triplication of human chromosome 21. In addition to intellectual disability, DS is defined by a premature aging phenotype and Alzheimer's disease (AD) neuropathology, including septohippocampal circuit vulnerability and degeneration of basal forebrain cholinergic neurons (BFCNs). The Ts65Dn mouse model recapitulates key aspects of DS/AD pathology, namely age-associated atrophy of BFCNs and cognitive decline in septohippocampal-dependent behavioral tasks. We investigated whether maternal choline supplementation (MCS), a well-tolerated treatment modality, protects vulnerable BFCNs from age- and genotype-associated degeneration in trisomic offspring. We also examined the effect of trisomy, and MCS, on GABAergic basal forebrain parvalbumin neurons (BFPNs), an unexplored neuronal population in this DS model. Unbiased stereological analyses of choline acetyltransferase (ChAT)-immunoreactive BFCNs and parvalbumin-immunoreactive BFPNs were conducted using confocal z-stacks of the medial septal nucleus and the vertical limb of the diagonal band (MSN/VDB) in Ts65Dn mice and disomic (2N) littermates at 3-4 and 10-12 months of age. MCS trisomic offspring displayed significant increases in ChAT-immunoreactive neuron number and density compared to unsupplemented counterparts, as well as increases in the area of the MSN/VDB occupied by ChAT-immunoreactive neuropil. MCS also rescued BFPN number and density in Ts65Dn offspring, a novel rescue of a non-cholinergic cell population. Furthermore, MCS prevented age-associated loss of BFCNs and MSN/VDB regional area in 2N offspring, indicating genotype-independent neuroprotective benefits. These findings demonstrate MCS provides neuroprotection of vulnerable BFCNs and non-cholinergic septohippocampal BFPNs, indicating this modality has translational value as an early life therapy for DS, as well as extending benefits to the aging population at large.
Collapse
Affiliation(s)
- Megan K Gautier
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Pathobiology and Translational Medicine Program, New York University Grossman School of Medicine, New York, NY, USA; NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - Christy M Kelley
- Complex Adaptive Systems Initiative, Arizona State University, Tempe, AZ, USA; Institute for Future Health, Scottsdale, AZ, USA
| | - Sang Han Lee
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Child and Adolescent Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - John McDaid
- Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University/The Chicago Medical School, North Chicago, IL, USA
| | - Elliott J Mufson
- Departments of Translational Neuroscience and Neurology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Grace E Stutzmann
- Center for Neurodegenerative Disease and Therapeutics, Rosalind Franklin University/The Chicago Medical School, North Chicago, IL, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA; Department of Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, USA.
| |
Collapse
|
5
|
Thomazeau A, Lassalle O, Manzoni OJ. Glutamatergic synaptic deficits in the prefrontal cortex of the Ts65Dn mouse model for Down syndrome. Front Neurosci 2023; 17:1171797. [PMID: 37841687 PMCID: PMC10569174 DOI: 10.3389/fnins.2023.1171797] [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] [Received: 02/22/2023] [Accepted: 09/11/2023] [Indexed: 10/17/2023] Open
Abstract
Down syndrome (DS), the most prevalent cause of intellectual disability, stems from a chromosomal anomaly resulting in an entire or partial extra copy of chromosome 21. This leads to intellectual disability and a range of associated symptoms. While there has been considerable research focused on the Ts65Dn mouse model of DS, particularly in the context of the hippocampus, the synaptic underpinnings of prefrontal cortex (PFC) dysfunction in DS, including deficits in working memory, remain largely uncharted territory. In a previous study featuring mBACtgDyrk1a mice, which manifest overexpression of the Dyrk1a gene, a known candidate gene linked to intellectual disability and microcephaly in DS, we documented adverse effects on spine density, alterations in the molecular composition of synapses, and the presence of synaptic plasticity deficits within the PFC. The current study aimed to enrich our understanding of the roles of different genes in DS by studying Ts65Dn mice, which overexpress several genes including Dyrk1a, to compare with our previous work on mBACtgDyrk1a mice. Through ex-vivo electrophysiological experiments, including patch-clamp and extracellular field potential recordings, we identified alterations in the intrinsic properties of PFC layer V/VI pyramidal neurons in Ts65Dn male mice. Additionally, we observed changes in the synaptic plasticity range. Notably, long-term depression was absent in Ts65Dn mice, while synaptic or pharmacological long-term potentiation remained fully expressed in these mice. These findings provide valuable insights into the intricate synaptic mechanisms contributing to PFC dysfunction in DS, shedding light on potential therapeutic avenues for addressing the neurocognitive symptoms associated with this condition.
Collapse
Affiliation(s)
- Aurore Thomazeau
- Côte d’Azur, CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
- Université Aix-Marseille, Marseille, France
- INMED, INSERM U1249, Marseille, France
| | - Olivier Lassalle
- Université Aix-Marseille, Marseille, France
- INMED, INSERM U1249, Marseille, France
| | - Olivier J. Manzoni
- Université Aix-Marseille, Marseille, France
- INMED, INSERM U1249, Marseille, France
| |
Collapse
|
6
|
Alldred MJ, Pidikiti H, Heguy A, Roussos P, Ginsberg SD. Basal forebrain cholinergic neurons are vulnerable in a mouse model of Down syndrome and their molecular fingerprint is rescued by maternal choline supplementation. FASEB J 2023; 37:e22944. [PMID: 37191946 PMCID: PMC10292934 DOI: 10.1096/fj.202202111rr] [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: 12/19/2022] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 05/17/2023]
Abstract
Basal forebrain cholinergic neuron (BFCN) degeneration is a hallmark of Down syndrome (DS) and Alzheimer's disease (AD). Current therapeutics in these disorders have been unsuccessful in slowing disease progression, likely due to poorly understood complex pathological interactions and dysregulated pathways. The Ts65Dn trisomic mouse model recapitulates both cognitive and morphological deficits of DS and AD, including BFCN degeneration and has shown lifelong behavioral changes due to maternal choline supplementation (MCS). To test the impact of MCS on trisomic BFCNs, we performed laser capture microdissection to individually isolate choline acetyltransferase-immunopositive neurons in Ts65Dn and disomic littermates, in conjunction with MCS at the onset of BFCN degeneration. We utilized single population RNA sequencing (RNA-seq) to interrogate transcriptomic changes within medial septal nucleus (MSN) BFCNs. Leveraging multiple bioinformatic analysis programs on differentially expressed genes (DEGs) by genotype and diet, we identified key canonical pathways and altered physiological functions within Ts65Dn MSN BFCNs, which were attenuated by MCS in trisomic offspring, including the cholinergic, glutamatergic and GABAergic pathways. We linked differential gene expression bioinformatically to multiple neurological functions, including motor dysfunction/movement disorder, early onset neurological disease, ataxia and cognitive impairment via Ingenuity Pathway Analysis. DEGs within these identified pathways may underlie aberrant behavior in the DS mice, with MCS attenuating the underlying gene expression changes. We propose MCS ameliorates aberrant BFCN gene expression within the septohippocampal circuit of trisomic mice through normalization of principally the cholinergic, glutamatergic, and GABAergic signaling pathways, resulting in attenuation of underlying neurological disease functions.
Collapse
Affiliation(s)
- Melissa J. Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - Harshitha Pidikiti
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
| | - Adriana Heguy
- Genome Technology Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Panos Roussos
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
- Departments of Genetics and Genomic Sciences and Psychiatry and the Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephen D. Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
- Departments of Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, USA
- NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| |
Collapse
|
7
|
Migration deficits of the neural crest caused by CXADR triplication in a human Down syndrome stem cell model. Cell Death Dis 2022; 13:1018. [PMID: 36470861 PMCID: PMC9722909 DOI: 10.1038/s41419-022-05481-6] [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] [Received: 02/06/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/07/2022]
Abstract
Down syndrome (DS) is the most common chromosomal abnormality in live-born infants and is caused by trisomy of chromosome 21. Most individuals with DS display craniofacial dysmorphology, including reduced sizes of the skull, maxilla, and mandible. However, the underlying pathogenesis remains largely unknown. Since the craniofacial skeleton is mainly formed by the neural crest, whether neural crest developmental defects are involved in the craniofacial anomalies of individuals with DS needs to be investigated. Here, we successfully derived DS-specific human induced pluripotent stem cells (hiPSCs) using a Sendai virus vector. When DS-hiPSCs were induced to differentiate into the neural crest, we found that trisomy 21 (T21) did not influence cell proliferation or apoptosis. However, the migratory ability of differentiated cells was significantly compromised, thus resulting in a substantially lower number of postmigratory cranial neural crest stem cells (NCSCs) in the DS group than in the control group. We further discovered that the migration defects could be partially attributed to the triplication of the coxsackievirus and adenovirus receptor gene (CXADR; an adhesion protein) in the DS group cells, since knockdown of CXADR substantially recovered the cell migratory ability and generation of postmigratory NCSCs in the DS group. Thus, the migratory deficits of neural crest cells may be an underlying cause of craniofacial dysmorphology in individuals with DS, which may suggest potential targets for therapeutic intervention to ameliorate craniofacial or other neural crest-related anomalies in DS.
Collapse
|
8
|
Li Z, Klein JA, Rampam S, Kurzion R, Campbell NB, Patel Y, Haydar TF, Zeldich E. Asynchronous excitatory neuron development in an isogenic cortical spheroid model of Down syndrome. Front Neurosci 2022; 16:932384. [PMID: 36161168 PMCID: PMC9504873 DOI: 10.3389/fnins.2022.932384] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/21/2022] [Indexed: 11/17/2022] Open
Abstract
The intellectual disability (ID) in Down syndrome (DS) is thought to result from a variety of developmental deficits such as alterations in neural progenitor division, neurogenesis, gliogenesis, cortical architecture, and reduced cortical volume. However, the molecular processes underlying these neurodevelopmental changes are still elusive, preventing an understanding of the mechanistic basis of ID in DS. In this study, we used a pair of isogenic (trisomic and euploid) induced pluripotent stem cell (iPSC) lines to generate cortical spheroids (CS) that model the impact of trisomy 21 on brain development. Cortical spheroids contain neurons, astrocytes, and oligodendrocytes and they are widely used to approximate early neurodevelopment. Using single cell RNA sequencing (scRNA-seq), we uncovered cell type-specific transcriptomic changes in the trisomic CS. In particular, we found that excitatory neuron populations were most affected and that a specific population of cells with a transcriptomic profile resembling layer IV cortical neurons displayed the most profound divergence in developmental trajectory between trisomic and euploid genotypes. We also identified candidate genes potentially driving the developmental asynchrony between trisomic and euploid excitatory neurons. Direct comparison between the current isogenic CS scRNA-seq data and previously published datasets revealed several recurring differentially expressed genes between DS and control samples. Altogether, our study highlights the power and importance of cell type-specific analyses within a defined genetic background, coupled with broader examination of mixed samples, to comprehensively evaluate cellular phenotypes in the context of DS.
Collapse
Affiliation(s)
- Zhen Li
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Jenny A. Klein
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
| | - Sanjeev Rampam
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Ronni Kurzion
- Department of Chemistry, Boston University, Boston, MA, United States
| | | | - Yesha Patel
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, United States
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Tarik F. Haydar
- Center for Neuroscience Research, Children’s National Hospital, Washington, DC, United States
| | - Ella Zeldich
- Department of Anatomy and Neurobiology, Boston University, Boston, MA, United States
| |
Collapse
|
9
|
Kirstein M, Cambrils A, Segarra A, Melero A, Varea E. Cholinergic Senescence in the Ts65Dn Mouse Model for Down Syndrome. Neurochem Res 2022; 47:3076-3092. [PMID: 35767135 PMCID: PMC9470680 DOI: 10.1007/s11064-022-03659-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/08/2022] [Accepted: 06/14/2022] [Indexed: 11/29/2022]
Abstract
Down syndrome (DS) induces a variable phenotype including intellectual disabilities and early development of Alzheimer’s disease (AD). Moreover, individuals with DS display accelerated aging that affects diverse organs, among them the brain. The Ts65Dn mouse is the most widely used model to study DS. Progressive loss of cholinergic neurons is one of the hallmarks of AD present in DS and in the Ts65Dn model. In this study, we quantify the number of cholinergic neurons in control and Ts65Dn mice, observing a general reduction in their number with age but in particular, a greater loss in old Ts65Dn mice. Increased expression of the m1 muscarinic receptor in the hippocampus counteracts this loss. Cholinergic neurons in the Ts65Dn mice display overexpression of the early expression gene c-fos and an increase in the expression of β-galactosidase, a marker of senescence. A possible mechanism for senescence induction could be phosphorylation of the transcription factor FOXO1 and its retention in the cytoplasm, which we are able to confirm in the Ts65Dn model. In our study, using Ts65Dn mice, we observe increased cholinergic activity, which induces a process of early senescence that culminates in the loss of these neurons.
Collapse
Affiliation(s)
- Martina Kirstein
- Cell Biology Department, Universitat de València, Dr. Moliner, 50, Burjassot, 46100, València, Spain
| | - Alba Cambrils
- Cell Biology Department, Universitat de València, Dr. Moliner, 50, Burjassot, 46100, València, Spain
| | - Ana Segarra
- Cell Biology Department, Universitat de València, Dr. Moliner, 50, Burjassot, 46100, València, Spain
| | - Ana Melero
- Cell Biology Department, Universitat de València, Dr. Moliner, 50, Burjassot, 46100, València, Spain
| | - Emilio Varea
- Cell Biology Department, Universitat de València, Dr. Moliner, 50, Burjassot, 46100, València, Spain.
| |
Collapse
|
10
|
Kleschevnikov A. GIRK2 Channels in Down Syndrome and Alzheimer's Disease. Curr Alzheimer Res 2022; 19:819-829. [PMID: 36567290 DOI: 10.2174/1567205020666221223122110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/27/2022]
Abstract
Cognitive impairment in Down syndrome (DS) results from the abnormal expression of hundreds of genes. However, the impact of KCNJ6, a gene located in the middle of the 'Down syndrome critical region' of chromosome 21, seems to stand out. KCNJ6 encodes GIRK2 (KIR3.2) subunits of G protein-gated inwardly rectifying potassium channels, which serve as effectors for GABAB, m2, 5HT1A, A1, and many other postsynaptic metabotropic receptors. GIRK2 subunits are heavily expressed in neocortex, cerebellum, and hippocampus. By controlling resting membrane potential and neuronal excitability, GIRK2 channels may thus affect both synaptic plasticity and stability of neural circuits in the brain regions important for learning and memory. Here, we discuss recent experimental data regarding the role of KCNJ6/GIRK2 in neuronal abnormalities and cognitive impairment in models of DS and Alzheimer's disease (AD). The results compellingly show that signaling through GIRK2 channels is abnormally enhanced in mouse genetic models of Down syndrome and that partial suppression of GIRK2 channels with pharmacological or genetic means can restore synaptic plasticity and improve impaired cognitive functions. On the other hand, signaling through GIRK2 channels is downregulated in AD models, such as models of early amyloidopathy. In these models, reduced GIRK2 channel signaling promotes neuronal hyperactivity, causing excitatory-inhibitory imbalance and neuronal death. Accordingly, activation of GABAB/GIRK2 signaling by GIRK channel activators or GABAB receptor agonists may reduce Aβ-induced hyperactivity and subsequent neuronal death, thereby exerting a neuroprotective effect in models of AD.
Collapse
|
11
|
Alldred MJ, Penikalapati SC, Lee SH, Heguy A, Roussos P, Ginsberg SD. Profiling Basal Forebrain Cholinergic Neurons Reveals a Molecular Basis for Vulnerability Within the Ts65Dn Model of Down Syndrome and Alzheimer's Disease. Mol Neurobiol 2021; 58:5141-5162. [PMID: 34263425 DOI: 10.1007/s12035-021-02453-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/13/2021] [Indexed: 12/30/2022]
Abstract
Basal forebrain cholinergic neuron (BFCN) degeneration is a hallmark of Down syndrome (DS) and Alzheimer's disease (AD). Current therapeutics have been unsuccessful in slowing disease progression, likely due to complex pathological interactions and dysregulated pathways that are poorly understood. The Ts65Dn trisomic mouse model recapitulates both cognitive and morphological deficits of DS and AD, including BFCN degeneration. We utilized Ts65Dn mice to understand mechanisms underlying BFCN degeneration to identify novel targets for therapeutic intervention. We performed high-throughput, single population RNA sequencing (RNA-seq) to interrogate transcriptomic changes within medial septal nucleus (MSN) BFCNs, using laser capture microdissection to individually isolate ~500 choline acetyltransferase-immunopositive neurons in Ts65Dn and normal disomic (2N) mice at 6 months of age (MO). Ts65Dn mice had unique MSN BFCN transcriptomic profiles at ~6 MO clearly differentiating them from 2N mice. Leveraging Ingenuity Pathway Analysis and KEGG analysis, we linked differentially expressed gene (DEG) changes within MSN BFCNs to several canonical pathways and aberrant physiological functions. The dysregulated transcriptomic profile of trisomic BFCNs provides key information underscoring selective vulnerability within the septohippocampal circuit. We propose both expected and novel therapeutic targets for DS and AD, including specific DEGs within cholinergic, glutamatergic, GABAergic, and neurotrophin pathways, as well as select targets for repairing oxidative phosphorylation status in neurons. We demonstrate and validate this interrogative quantitative bioinformatic analysis of a key dysregulated neuronal population linking single population transcript changes to an established pathological hallmark associated with cognitive decline for therapeutic development in human DS and AD.
Collapse
Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA.,Departments of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - Sai C Penikalapati
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA
| | - Sang Han Lee
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY, USA
| | - Adriana Heguy
- Genome Technology Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Panos Roussos
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA.,Departments of Genetics and Genomic Sciences and Psychiatry and the Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA. .,Departments of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA. .,Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY, USA. .,NYU Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA.
| |
Collapse
|
12
|
Martinez JL, Zammit MD, West NR, Christian BT, Bhattacharyya A. Basal Forebrain Cholinergic Neurons: Linking Down Syndrome and Alzheimer's Disease. Front Aging Neurosci 2021; 13:703876. [PMID: 34322015 PMCID: PMC8311593 DOI: 10.3389/fnagi.2021.703876] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/17/2021] [Indexed: 12/31/2022] Open
Abstract
Down syndrome (DS, trisomy 21) is characterized by intellectual impairment at birth and Alzheimer's disease (AD) pathology in middle age. As individuals with DS age, their cognitive functions decline as they develop AD pathology. The susceptibility to degeneration of a subset of neurons, known as basal forebrain cholinergic neurons (BFCNs), in DS and AD is a critical link between cognitive impairment and neurodegeneration in both disorders. BFCNs are the primary source of cholinergic innervation to the cerebral cortex and hippocampus, as well as the amygdala. They play a critical role in the processing of information related to cognitive function and are directly engaged in regulating circuits of attention and memory throughout the lifespan. Given the importance of BFCNs in attention and memory, it is not surprising that these neurons contribute to dysfunctional neuronal circuitry in DS and are vulnerable in adults with DS and AD, where their degeneration leads to memory loss and disturbance in language. BFCNs are thus a relevant cell target for therapeutics for both DS and AD but, despite some success, efforts in this area have waned. There are gaps in our knowledge of BFCN vulnerability that preclude our ability to effectively design interventions. Here, we review the role of BFCN function and degeneration in AD and DS and identify under-studied aspects of BFCN biology. The current gaps in BFCN relevant imaging studies, therapeutics, and human models limit our insight into the mechanistic vulnerability of BFCNs in individuals with DS and AD.
Collapse
Affiliation(s)
- Jose L. Martinez
- Cellular and Molecular Biology Graduate Program, University of Wisconsin, Madison, WI, United States
- Waisman Center, University of Wisconsin, Madison, WI, United States
| | - Matthew D. Zammit
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
| | - Nicole R. West
- Cellular and Molecular Biology Graduate Program, University of Wisconsin, Madison, WI, United States
- Waisman Center, University of Wisconsin, Madison, WI, United States
| | - Bradley T. Christian
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
| | - Anita Bhattacharyya
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Cellular and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
| |
Collapse
|
13
|
Pentz R, Iulita MF, Ducatenzeiler A, Videla L, Benejam B, Carmona‐Iragui M, Blesa R, Lleó A, Fortea J, Cuello AC. Nerve growth factor (NGF) pathway biomarkers in Down syndrome prior to and after the onset of clinical Alzheimer's disease: A paired CSF and plasma study. Alzheimers Dement 2021; 17:605-617. [PMID: 33226181 PMCID: PMC8043977 DOI: 10.1002/alz.12229] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/28/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND The discovery that nerve growth factor (NGF) metabolism is altered in Down syndrome (DS) and Alzheimer's disease (AD) brains offered a framework for the identification of novel biomarkers signalling NGF deregulation in AD pathology. METHODS We examined levels of NGF pathway proteins (proNGF, neuroserpin, tissue plasminogen activator [tPA], and metalloproteases [MMP]) in matched cerebrospinal fluid (CSF)/plasma samples from AD-symptomatic (DSAD) and AD-asymptomatic (aDS) individuals with DS, as well as controls (HC). RESULTS ProNGF and MMP-3 were elevated while tPA was decreased in plasma from individuals with DS. CSF from individuals with DS showed elevated proNGF, neuroserpin, MMP-3, and MMP-9. ProNGF and MMP-9 in CSF differentiated DSAD from aDS (area under the curve = 0.86, 0.87). NGF pathway markers associated with CSF amyloid beta and tau and differed by sex. DISCUSSION Brain NGF metabolism changes can be monitored in plasma and CSF, supporting relevance in AD pathology. These markers could assist staging, subtyping, or precision medicine for AD in DS.
Collapse
Affiliation(s)
- Rowan Pentz
- Department of Neurology and NeurosurgeryMcGill UniversityMontrealCanada
| | - M. Florencia Iulita
- Department of Pharmacology and TherapeuticsMcGill UniversityMontrealCanada
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
| | | | - Laura Videla
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
- Barcelona Down Medical CenterFundación Catalana Síndrome de DownBarcelonaSpain
| | - Bessy Benejam
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
- Barcelona Down Medical CenterFundación Catalana Síndrome de DownBarcelonaSpain
| | - María Carmona‐Iragui
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
- Barcelona Down Medical CenterFundación Catalana Síndrome de DownBarcelonaSpain
| | - Rafael Blesa
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
| | - Alberto Lleó
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
| | - Juan Fortea
- Sant Pau Memory UnitDepartment of NeurologyHospital de la Santa Creu i Sant PauBiomedical Research Institute Sant PauUniversitat Autònoma de BarcelonaBarcelonaSpain
- Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED)MadridSpain
- Barcelona Down Medical CenterFundación Catalana Síndrome de DownBarcelonaSpain
| | - A. Claudio Cuello
- Department of Neurology and NeurosurgeryMcGill UniversityMontrealCanada
- Department of Pharmacology and TherapeuticsMcGill UniversityMontrealCanada
- Department of Anatomy and Cell BiologyMcGill UniversityMontrealCanada
- Department of PharmacologyOxford UniversityOxfordUK
| |
Collapse
|
14
|
Saber MM, Karimiavargani M, Uzawa T, Hettiarachchi N, Hamada M, Ito Y, Saitou N. Possible roles for the hominoid-specific DSCR4 gene in human cells. Genes Genet Syst 2021; 96:1-11. [PMID: 33762515 DOI: 10.1266/ggs.20-00012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Down syndrome in humans is caused by trisomy of chromosome 21. DSCR4 (Down syndrome critical region 4) is a de novo-originated protein-coding gene present only in human chromosome 21 and its homologous chromosomes in apes. Despite being located in a medically critical genomic region and an abundance of evidence indicating its functionality, the roles of DSCR4 in human cells are unknown. We used a bioinformatic approach to infer the biological importance and cellular roles of this gene. Our analysis indicates that DSCR4 is likely involved in the regulation of interconnected biological pathways related to cell migration, coagulation and the immune system. We also showed that these predicted biological functions are consistent with tissue-specific expression of DSCR4 in migratory immune system leukocyte cells and neural crest cells (NCCs) that shape facial morphology in the human embryo. The immune system and NCCs are known to be affected in Down syndrome individuals, who suffer from DSCR4 misregulation, which further supports our findings. Providing evidence for the critical roles of DSCR4 in human cells, our findings establish the basis for further experimental investigations that will be necessary to confirm the roles of DSCR4 in the etiology of Down syndrome.
Collapse
Affiliation(s)
- Morteza M Saber
- Population Genetics Laboratory, National Institute of Genetics.,Department of Biological Sciences, Graduate School of Science, University of Tokyo.,Nano Medical Engineering Laboratory, RIKEN.,Department of Electrical Engineering and Bioscience, Faculty of Science and Engineering, Waseda University
| | - Marziyeh Karimiavargani
- Nano Medical Engineering Laboratory, RIKEN.,Graduate School of Science and Engineering, Saitama University
| | | | | | - Michiaki Hamada
- Department of Electrical Engineering and Bioscience, Faculty of Science and Engineering, Waseda University.,Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST)
| | | | - Naruya Saitou
- Population Genetics Laboratory, National Institute of Genetics.,Department of Biological Sciences, Graduate School of Science, University of Tokyo.,Department of Genetics, School of Life Science, Graduate University for Advanced Studies.,Faculty of Medicine, University of the Ryukyus
| |
Collapse
|
15
|
Duchon A, Del Mar Muniz Moreno M, Martin Lorenzo S, Silva de Souza MP, Chevalier C, Nalesso V, Meziane H, Loureiro de Sousa P, Noblet V, Armspach JP, Brault V, Herault Y. Multi-influential genetic interactions alter behaviour and cognition through six main biological cascades in Down syndrome mouse models. Hum Mol Genet 2021; 30:771-788. [PMID: 33693642 PMCID: PMC8161522 DOI: 10.1093/hmg/ddab012] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022] Open
Abstract
Down syndrome (DS) is the most common genetic form of intellectual disability caused by the presence of an additional copy of human chromosome 21 (Hsa21). To provide novel insights into genotype–phenotype correlations, we used standardized behavioural tests, magnetic resonance imaging and hippocampal gene expression to screen several DS mouse models for the mouse chromosome 16 region homologous to Hsa21. First, we unravelled several genetic interactions between different regions of chromosome 16 and how they contribute significantly to altering the outcome of the phenotypes in brain cognition, function and structure. Then, in-depth analysis of misregulated expressed genes involved in synaptic dysfunction highlighted six biological cascades centred around DYRK1A, GSK3β, NPY, SNARE, RHOA and NPAS4. Finally, we provide a novel vision of the existing altered gene–gene crosstalk and molecular mechanisms targeting specific hubs in DS models that should become central to better understanding of DS and improving the development of therapies.
Collapse
Affiliation(s)
- Arnaud Duchon
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Maria Del Mar Muniz Moreno
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Sandra Martin Lorenzo
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Marcia Priscilla Silva de Souza
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Claire Chevalier
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Valérie Nalesso
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Hamid Meziane
- Université de Strasbourg, CNRS, INSERM, Institut Clinique de la Souris (ICS), CELPHEDIA, PHENOMIN, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | | | - Vincent Noblet
- Université de Strasbourg, CNRS UMR 7357, ICube, FMTS, 67000 Strasbourg, France
| | - Jean-Paul Armspach
- Université de Strasbourg, CNRS UMR 7357, ICube, FMTS, 67000 Strasbourg, France
| | - Veronique Brault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Yann Herault
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), department of translational medicine and neurogenetics 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France.,Université de Strasbourg, CNRS, INSERM, Institut Clinique de la Souris (ICS), CELPHEDIA, PHENOMIN, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| |
Collapse
|
16
|
Lanzillotta C, Tramutola A, Di Giacomo G, Marini F, Butterfield DA, Di Domenico F, Perluigi M, Barone E. Insulin resistance, oxidative stress and mitochondrial defects in Ts65dn mice brain: A harmful synergistic path in down syndrome. Free Radic Biol Med 2021; 165:152-170. [PMID: 33516914 DOI: 10.1016/j.freeradbiomed.2021.01.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 02/06/2023]
Abstract
Dysregulation of brain insulin signaling with reduced downstream neuronal survival and plasticity mechanisms are fundamental abnormalities observed in Alzheimer disease (AD). This phenomenon, known as brain insulin resistance, is associated with poor cognitive performance and is driven by the inhibition of IRS1. Since Down syndrome (DS) and AD neuropathology share many common features, we investigated metabolic aspects of neurodegeneration in DS and whether they contribute to early onset AD in DS. We evaluated levels and activation of proteins belonging to the insulin signaling pathway (IR, IRS1, BVR-A, MAPK, PTEN, Akt, GSK3β, PKCζ, AS160, GLUT4) in the frontal cortex of Ts65dn (DS model) (n = 5-6/group) and euploid mice (n = 6/group) at different ages (1, 3, 9 and 18 months). Furthermore, we analyzed whether changes of brain insulin signaling were associated with alterations of: (i) proteins regulating brain energy metabolism (mitochondrial complexes, hexokinase-II, Sirt1); (ii) oxidative stress (OS) markers (iii) APP cleavage; and (iv) proteins mediating synaptic plasticity mechanisms (PSD95, syntaxin-1 and BDNF). Ts65dn mice showed an overall impairment of the above-mentioned pathways, mainly characterized by defects of proteins activation state. Such alterations start early in life (at 1 month, during brain maturation). In particular, accumulation of inhibited IRS1, together with the uncoupling among the proteins downstream from IRS1 (brain insulin resistance), characterize Ts65dn mice. Furthermore, reduced levels of mitochondrial complexes and Sirt1, as well as increased indices of OS also were observed. These alterations precede the accumulation of APP-C99 in Ts65dn mice. Tellingly, oxidative stress levels were negatively associated with IR, IRS1 and AS160 activation as well as mitochondrial complexes levels in Ts65dn mice, suggesting a role for oxidative stress in the observed alterations. We propose that a close link exists among brain insulin resistance, mitochondrial defects and OS that contributes to brain dysfunctions observed in DS, likely favoring the development of AD in DS.
Collapse
Affiliation(s)
- Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - Graziella Di Giacomo
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - Federico Marini
- Department of Chemistry, Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - D Allan Butterfield
- Department of Chemistry and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40506-0055, USA
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185, Roma, Italy.
| |
Collapse
|
17
|
Chen X, Salehi A, Pearn ML, Overk C, Nguyen PD, Kleschevnikov AM, Maccecchini M, Mobley WC. Targeting increased levels of APP in Down syndrome: Posiphen-mediated reductions in APP and its products reverse endosomal phenotypes in the Ts65Dn mouse model. Alzheimers Dement 2021; 17:271-292. [PMID: 32975365 PMCID: PMC7984396 DOI: 10.1002/alz.12185] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/07/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Recent clinical trials targeting amyloid beta (Aβ) and tau in Alzheimer's disease (AD) have yet to demonstrate efficacy. Reviewing the hypotheses for AD pathogenesis and defining possible links between them may enhance insights into both upstream initiating events and downstream mechanisms, thereby promoting discovery of novel treatments. Evidence that in Down syndrome (DS), a population markedly predisposed to develop early onset AD, increased APP gene dose is necessary for both AD neuropathology and dementia points to normalization of the levels of the amyloid precursor protein (APP) and its products as a route to further define AD pathogenesis and discovering novel treatments. BACKGROUND AD and DS share several characteristic manifestations. DS is caused by trisomy of whole or part of chromosome 21; this chromosome contains about 233 protein-coding genes, including APP. Recent evidence points to a defining role for increased expression of the gene for APP and for its 99 amino acid C-terminal fragment (C99, also known as β-CTF) in dysregulating the endosomal/lysosomal system. The latter is critical for normal cellular function and in neurons for transmitting neurotrophic signals. NEW/UPDATED HYPOTHESIS We hypothesize that the increase in APP gene dose in DS initiates a process in which increased levels of full-length APP (fl-APP) and its products, including β-CTF and possibly Aβ peptides (Aβ42 and Aβ40), drive AD pathogenesis through an endosome-dependent mechanism(s), which compromises transport of neurotrophic signals. To test this hypothesis, we carried out studies in the Ts65Dn mouse model of DS and examined the effects of Posiphen, an orally available small molecule shown in prior studies to reduce fl-APP. In vitro, Posiphen lowered fl-APP and its C-terminal fragments, reversed Rab5 hyperactivation and early endosome enlargement, and restored retrograde transport of neurotrophin signaling. In vivo, Posiphen treatment (50 mg/kg/d, 26 days, intraperitoneal [i.p.]) of Ts65Dn mice was well tolerated and demonstrated no adverse effects in behavior. Treatment resulted in normalization of the levels of fl-APP, C-terminal fragments and small reductions in Aβ species, restoration to normal levels of Rab5 activity, reduced phosphorylated tau (p-tau), and reversed deficits in TrkB (tropomyosin receptor kinase B) activation and in the Akt (protein kinase B [PKB]), ERK (extracellular signal-regulated kinase), and CREB (cAMP response element-binding protein) signaling pathways. Remarkably, Posiphen treatment also restored the level of choline acetyltransferase protein to 2N levels. These findings support the APP gene dose hypothesis, point to the need for additional studies to explore the mechanisms by which increased APP gene expression acts to increase the risk for AD in DS, and to possible utility of treatments to normalize the levels of APP and its products for preventing AD in those with DS. MAJOR CHALLENGES FOR THE HYPOTHESIS Important unanswered questions are: (1) When should one intervene in those with DS; (2) would an APP-based strategy have untoward consequences on possible adaptive changes induced by chronically increased APP gene dose; (3) do other genes present on chromosome 21, or on other chromosomes whose expression is dysregulated in DS, contribute to AD pathogenesis; and (4) can one model strategies that combine the use of an APP-based treatment with those directed at other AD phenotypes including p-tau and inflammation. LINKAGE TO OTHER MAJOR THEORIES The APP gene dose hypothesis interfaces with the amyloid cascade hypothesis of AD as well as with the genetic and cell biological observations that support it. Moreover, upregulation of fl-APP protein and products may drive downstream events that dysregulate tau homeostasis and inflammatory responses that contribute to propagation of AD pathogenesis.
Collapse
Affiliation(s)
- Xu‐Qiao Chen
- Department of NeurosciencesUniversity of California San DiegoLa JollaCaliforniaUSA
| | - Ahmad Salehi
- Department of Psychiatry & Behavioral SciencesStanford Medical SchoolPalo AltoCaliforniaUSA
| | - Matthew L. Pearn
- Department of AnesthesiologyUniversity of California San Diego, School of MedicineLa JollaCaliforniaUSA
- V.A. San Diego Healthcare SystemSan DiegoCaliforniaUSA
| | - Cassia Overk
- Department of NeurosciencesUniversity of California San DiegoLa JollaCaliforniaUSA
| | - Phuong D. Nguyen
- Department of NeurosciencesUniversity of California San DiegoLa JollaCaliforniaUSA
| | | | | | - William C. Mobley
- Department of NeurosciencesUniversity of California San DiegoLa JollaCaliforniaUSA
| |
Collapse
|
18
|
Uguagliati B, Al-Absi AR, Stagni F, Emili M, Giacomini A, Guidi S, Nyengaard JR, Bartesaghi R. Early appearance of developmental alterations in the dendritic tree of the hippocampal granule cells in the Ts65Dn model of Down syndrome. Hippocampus 2021; 31:435-447. [PMID: 33464704 DOI: 10.1002/hipo.23303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/22/2020] [Accepted: 01/09/2021] [Indexed: 12/28/2022]
Abstract
Down syndrome (DS), a genetic condition caused by triplication of chromosome 21, is characterized by alterations in various cognitive domains, including hippocampus-dependent memory functions, starting from early life stages. The major causes of intellectual disability in DS are prenatal neurogenesis alterations followed by impairment of dendritic development in early infancy. While there is evidence that the Ts65Dn mouse, the most widely used model of DS, exhibits dendritic alterations in adulthood, no studies are available regarding the onset of dendritic pathology. The goal of the current study was to establish whether this model exhibits early dendritic alterations in the hippocampus, a region whose function is severely damaged in DS. To this purpose, in Golgi-stained brains, we evaluated the dendritic arborization and dendritic spines of the granule cells of the hippocampal dentate gyrus in Ts65Dn mice aged 8 (P8) and 15 (P15) days. While P15 Ts65Dn mice exhibited a notably hypotrophic dendritic arbor and a reduced spine density, P8 mice exhibited a moderate reduction in the number of dendritic ramifications and no differences in spine density in comparison with their euploid counterparts. Both in P8 and P15 mice, spines were longer and had a longer neck, suggesting possible alterations in synaptic function. Moreover, P8 and P15 Ts65Dn mice had more thin spines and fewer stubby spines in comparison with euploid mice. Our study provides novel evidence on the onset of dendritic pathology, one of the causes of intellectual disability in DS, showing that it is already detectable in the dentate gyrus of Ts65Dn pups. This evidence strengthens the suitability of this model of DS as a tool to study dendritic pathology in DS and to test the efficacy of early therapeutic interventions aimed at ameliorating hippocampal development and, therefore, memory functions in children with DS.
Collapse
Affiliation(s)
- Beatrice Uguagliati
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Abdel-Rahman Al-Absi
- Core Centre for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Fiorenza Stagni
- Department for Life Quality Studies, University of Bologna, Rimini, Italy
| | - Marco Emili
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Andrea Giacomini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Sandra Guidi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Jens Randel Nyengaard
- Core Centre for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| |
Collapse
|
19
|
Heinke D, Isenburg JL, Stallings EB, Short TD, Le M, Fisher S, Shan X, Kirby RS, Nguyen HH, Nestoridi E, Nembhard WN, Romitti PA, Salemi JL, Lupo PJ. Prevalence of structural birth defects among infants with Down syndrome, 2013-2017: A US population-based study. Birth Defects Res 2020; 113:189-202. [PMID: 33348463 DOI: 10.1002/bdr2.1854] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 12/28/2022]
Abstract
BACKGROUND Down syndrome is the most common chromosomal disorder at birth and is often accompanied by structural birth defects. Current data on major structural defects in this population are limited. METHODS States and territorial population-based surveillance programs submitted data on identified cases of Down syndrome and identified structural birth defects during 2013-2017. We estimated prevalence by program type and maternal and infant characteristics. Among programs with active case ascertainment, we estimated the prevalence of birth defects by organ system and for specific defects by maternal age (<35, ≥35) and infant sex. RESULTS We identified 13,376 cases of Down syndrome. Prevalence among all programs was 12.7 per 10,000 live births. Among these children, 75% had at least one reported co-occurring birth defect diagnosis code. Among 6,210 cases identified by active programs, 66% had a cardiovascular defect with septal defects being the most common: atrial (32.5%), ventricular (20.6%), and atrioventricular (17.4%). Defect prevalence differed by infant sex more frequently than by maternal age. For example, atrioventricular septal defects were more common in female children (20.1% vs. 15.1%) while limb deficiencies were more prevalent in male children (0.4% vs. 0.1%). CONCLUSIONS Our study provides updated prevalence estimates for structural defects, including rare defects, among children with Down syndrome using one of the largest and most recent cohorts to date. These data may aid clinical care and surveillance.
Collapse
Affiliation(s)
- Dominique Heinke
- Center for Birth Defects Research and Prevention, Massachusetts Department of Public Health, Boston, Massachusetts, USA
| | - Jennifer L Isenburg
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Erin B Stallings
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Tyiesha D Short
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA
| | - Mimi Le
- Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, Texas, USA
| | - Sarah Fisher
- Congenital Malformations Registry, New York State Department of Health, Albany, New York, USA
| | - Xiaoyi Shan
- Arkansas Reproductive Health Monitoring System, Arkansas Children's Research Institute, Little Rock, Arkansas, USA
| | - Russell S Kirby
- College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Hoang H Nguyen
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Eirini Nestoridi
- Center for Birth Defects Research and Prevention, Massachusetts Department of Public Health, Boston, Massachusetts, USA
| | - Wendy N Nembhard
- Department of Epidemiology, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences and Arkansas Center for Birth Defects Research and Prevention, Little Rock, Arkansas, USA
| | - Paul A Romitti
- Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, Iowa, USA
| | - Jason L Salemi
- College of Public Health, University of South Florida, Tampa, Florida, USA
| | - Philip J Lupo
- Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, Texas, USA
| | | |
Collapse
|
20
|
Piriform cortex alterations in the Ts65Dn model for down syndrome. Brain Res 2020; 1747:147031. [PMID: 32726601 DOI: 10.1016/j.brainres.2020.147031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/02/2020] [Accepted: 07/22/2020] [Indexed: 11/22/2022]
Abstract
The piriform cortex is involved in olfactory information processing, that is altered in Down Syndrome. Moreover, piriform cortex has a crucial involvement in epilepsy generation and is one of the first regions affected in Alzheimer's Disease, both maladies being prevalent among Down Syndrome individuals. In this work, we studied the alterations in neuronal morphology, synaptology and structural plasticity in the piriform cortex of the Ts65Dn mouse model, which is the most used model for the study of this syndrome and mimics some of their alterations. We have observed that Ts65Dn piriform cortex displays: a reduction in dendritic arborisation, a higher density of inhibitory synapses (GAD67), a lower density of excitatory synapses (vGLUT1) and a higher density of inhibitory postsynaptic puncta (gephyrin). Under electron microscopy the excitatory presynaptic and postsynaptic elements were larger in trisomic mice than in controls. Similar results were obtained using confocal microscopy. There were less immature neurons in piriform cortex layer II in addition to a reduction in the expression of PSA-NCAM in the neuropil that subsequently can reflect impairment in structural plasticity. These data support the idea of an impaired environment with altered ratio of inhibition and excitation that involves a reduction in plasticity and dendritic atrophy, providing a possible substrate for the olfactory processing impairment observed in DS individuals.
Collapse
|
21
|
Kazuki Y, Gao FJ, Li Y, Moyer AJ, Devenney B, Hiramatsu K, Miyagawa-Tomita S, Abe S, Kazuki K, Kajitani N, Uno N, Takehara S, Takiguchi M, Yamakawa M, Hasegawa A, Shimizu R, Matsukura S, Noda N, Ogonuki N, Inoue K, Matoba S, Ogura A, Florea LD, Savonenko A, Xiao M, Wu D, Batista DA, Yang J, Qiu Z, Singh N, Richtsmeier JT, Takeuchi T, Oshimura M, Reeves RH. A non-mosaic transchromosomic mouse model of down syndrome carrying the long arm of human chromosome 21. eLife 2020; 9:56223. [PMID: 32597754 PMCID: PMC7358007 DOI: 10.7554/elife.56223] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/28/2020] [Indexed: 01/01/2023] Open
Abstract
Animal models of Down syndrome (DS), trisomic for human chromosome 21 (HSA21) genes or orthologs, provide insights into better understanding and treatment options. The only existing transchromosomic (Tc) mouse DS model, Tc1, carries a HSA21 with over 50 protein coding genes (PCGs) disrupted. Tc1 is mosaic, compromising interpretation of results. Here, we “clone” the 34 MB long arm of HSA21 (HSA21q) as a mouse artificial chromosome (MAC). Through multiple steps of microcell-mediated chromosome transfer, we created a new Tc DS mouse model, Tc(HSA21q;MAC)1Yakaz (“TcMAC21”). TcMAC21 is not mosaic and contains 93% of HSA21q PCGs that are expressed and regulatable. TcMAC21 recapitulates many DS phenotypes including anomalies in heart, craniofacial skeleton and brain, molecular/cellular pathologies, and impairments in learning, memory and synaptic plasticity. TcMAC21 is the most complete genetic mouse model of DS extant and has potential for supporting a wide range of basic and preclinical research.
Collapse
Affiliation(s)
- Yasuhiro Kazuki
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Japan.,Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Feng J Gao
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Yicong Li
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Anna J Moyer
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Genetic Medicine, John Hopkins University School of Medicine, Baltimore, United States
| | - Benjamin Devenney
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Kei Hiramatsu
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Japan
| | - Sachiko Miyagawa-Tomita
- Department of Animal Nursing Science, Yamazaki University of Animal Health Technology, Hachioji, Tokyo, Japan.,Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Abe
- Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Kanako Kazuki
- Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Naoyo Kajitani
- Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Narumi Uno
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Japan
| | - Shoko Takehara
- Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Masato Takiguchi
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Japan
| | - Miho Yamakawa
- Chromosome Engineering Research Center (CERC), Tottori University, Yonago, Japan
| | - Atsushi Hasegawa
- Department of Molecular Hematology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ritsuko Shimizu
- Department of Molecular Hematology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Satoko Matsukura
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Naohiro Noda
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Narumi Ogonuki
- Bioresource Engineering Division, RIKEN BioResource Research Center (BRC), Tsukuba, Japan
| | - Kimiko Inoue
- Bioresource Engineering Division, RIKEN BioResource Research Center (BRC), Tsukuba, Japan
| | - Shogo Matoba
- Bioresource Engineering Division, RIKEN BioResource Research Center (BRC), Tsukuba, Japan
| | - Atsuo Ogura
- Bioresource Engineering Division, RIKEN BioResource Research Center (BRC), Tsukuba, Japan
| | - Liliana D Florea
- Department of Genetic Medicine, John Hopkins University School of Medicine, Baltimore, United States
| | - Alena Savonenko
- Departments of Pathology and Neurology, John Hopkins University School of Medicine, Baltimore, United States
| | - Meifang Xiao
- Department of Neuroscience, John Hopkins University School of Medicine, Baltimore, United States
| | - Dan Wu
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Denise As Batista
- Department of Pathology, John Hopkins University School of Medicine, Baltimore, United States
| | - Junhua Yang
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Zhaozhu Qiu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Nandini Singh
- Department of Anthropology, Penn State University, State College, United States
| | - Joan T Richtsmeier
- Division of Biosignaling, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Takashi Takeuchi
- Department of Anthropology, California State University, Sacramento, United States
| | - Mitsuo Oshimura
- Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Japan
| | - Roger H Reeves
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Genetic Medicine, John Hopkins University School of Medicine, Baltimore, United States
| |
Collapse
|
22
|
LaCombe JM, Roper RJ. Skeletal dynamics of Down syndrome: A developing perspective. Bone 2020; 133:115215. [PMID: 31887437 PMCID: PMC7044033 DOI: 10.1016/j.bone.2019.115215] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/05/2019] [Accepted: 12/24/2019] [Indexed: 01/14/2023]
Abstract
Individuals with Down syndrome (DS) display distinctive skeletal morphology compared to the general population, but disparate descriptions, methodologies, analyses, and populations sampled have led to diverging conclusions about this unique skeletal phenotype. As individuals with DS are living longer, they may be at a higher risk of aging disorders such as osteoporosis and increased fracture risk. Sexual dimorphism has been suggested between males and females with DS in which males, not females, experience an earlier decline in bone mineral density (BMD). Unfortunately, studies focusing on skeletal health related to Trisomy 21 (Ts21) are few in number and often too underpowered to answer questions about skeletal development, resultant osteoporosis, and sexual dimorphism, especially in stages of bone accrual. Further confounding the field are the varied methods of bone imaging, analysis, and data interpretation. This review takes a critical look at the current knowledge of DS skeletal phenotypes, both from human and mouse studies, and presents knowledge gaps that need to be addressed, differences in research methodologies and analyses that affect the interpretation of results, and proposes guidelines for overcoming obstacles to understand skeletal traits associated with DS. By examining our current knowledge of bone in individuals with Ts21, a trajectory for future studies may be established to provide meaningful solutions for understanding the development of and improving skeletal structures in individuals with and without DS.
Collapse
Affiliation(s)
- Jonathan M LaCombe
- Department of Biology, Indiana University-Purdue University Indianapolis, United States of America
| | - Randall J Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, United States of America.
| |
Collapse
|
23
|
Johnson LSM. The Trouble with Animal Models in Brain Research. NEUROETHICS AND NONHUMAN ANIMALS 2020. [DOI: 10.1007/978-3-030-31011-0_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
24
|
Alldred MJ, Chao HM, Lee SH, Beilin J, Powers BE, Petkova E, Strupp BJ, Ginsberg SD. Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease. FASEB J 2019; 33:9871-9884. [PMID: 31180719 DOI: 10.1096/fj.201802669rr] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Choline is critical for normative function of 3 major pathways in the brain, including acetylcholine biosynthesis, being a key mediator of epigenetic regulation, and serving as the primary substrate for the phosphatidylethanolamine N-methyltransferase pathway. Sufficient intake of dietary choline is critical for proper brain function and neurodevelopment. This is especially important for brain development during the perinatal period. Current dietary recommendations for choline intake were undertaken without critical evaluation of maternal choline levels. As such, recommended levels may be insufficient for both mother and fetus. Herein, we examined the impact of perinatal maternal choline supplementation (MCS) in a mouse model of Down syndrome and Alzheimer's disease, the Ts65Dn mouse relative to normal disomic littermates, to examine the effects on gene expression within adult offspring at ∼6 and 11 mo of age. We found MCS produces significant changes in offspring gene expression levels that supersede age-related and genotypic gene expression changes. Alterations due to MCS impact every gene ontology category queried, including GABAergic neurotransmission, the endosomal-lysosomal pathway and autophagy, and neurotrophins, highlighting the importance of proper choline intake during the perinatal period, especially when the fetus is known to have a neurodevelopmental disorder such as trisomy.-Alldred, M. J., Chao, H. M., Lee, S. H., Beilin, J., Powers, B. E., Petkova, E., Strupp, B. J., Ginsberg, S. D. Long-term effects of maternal choline supplementation on CA1 pyramidal neuron gene expression in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.
Collapse
Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, USA.,Department of Psychiatry, (NYU) Langone Medical Center, New York, New York, USA
| | - Helen M Chao
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, USA.,Department of Psychiatry, (NYU) Langone Medical Center, New York, New York, USA
| | - Sang Han Lee
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, New York, USA.,Department Neuroscience and Physiology, (NYU) Langone Medical Center, New York, New York, USA
| | - Judah Beilin
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, USA
| | - Brian E Powers
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, USA
| | - Eva Petkova
- Child Psychiatry, Nathan Kline Institute, Orangeburg, New York, USA.,Department of Child and Adolescent Psychiatry, (NYU) Langone Medical Center, New York, New York, USA
| | - Barbara J Strupp
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, USA.,Department of Psychology, Cornell University, Ithaca, New York, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, USA.,Department of Psychiatry, (NYU) Langone Medical Center, New York, New York, USA.,Department Neuroscience and Physiology, (NYU) Langone Medical Center, New York, New York, USA.,New York University (NYU) Neuroscience Institute, NYU Langone Medical Center, New York, New York, USA
| |
Collapse
|
25
|
Lukowski AF, Milojevich HM, Eales L. Cognitive Functioning in Children with Down Syndrome: Current Knowledge and Future Directions. ADVANCES IN CHILD DEVELOPMENT AND BEHAVIOR 2019; 56:257-289. [PMID: 30846049 DOI: 10.1016/bs.acdb.2019.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Infants and children with Down syndrome (DS) can look forward toward bright futures, as individuals with DS are living healthier, more productive lives than ever due to medical advances, opportunities for early and continued intervention, and inclusive education. Despite these advances, infants and children with DS experience challenges in specific domains of cognitive functioning relative to their typically developing (TD) peers. Over the long term, individuals with DS are also more likely to develop Alzheimer's disease relative to the general population. Understanding cognitive functioning early in life may be important in charting cognitive decline over time. This chapter synthesizes the literature on cognitive functioning in infants and children with DS specific to general intelligence or IQ, language development, recall memory, and executive functioning, with additional focus on critical issues and future directions. These research findings provide important information for understanding cognitive competencies and intervention opportunities for children with DS and also serves to provide a foundation from which to plan longitudinal studies examining stability and change in cognitive functioning over time.
Collapse
Affiliation(s)
- Angela F Lukowski
- Department of Psychological Science, UC Irvine, Irvine, CA, United States.
| | - Helen M Milojevich
- Center for Developmental Science, UNC Chapel Hill, Chapel Hill, NC, United States
| | - Lauren Eales
- Institute of Child Development, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
26
|
Kurabayashi N, Nguyen MD, Sanada K. Triple play of DYRK1A kinase in cortical progenitor cells of Trisomy 21. Neurosci Res 2019; 138:19-25. [PMID: 30227164 DOI: 10.1016/j.neures.2018.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/11/2018] [Accepted: 08/11/2018] [Indexed: 12/29/2022]
Abstract
Down syndrome (DS) also known as Trisomy 21 is a genetic disorder that occurs in ∼1 in 800 live births. The disorder is caused by the triplication of all or part of human chromosome 21 and therefore, is thought to arise from the increased dosage of genes found within chromosome 21. The manifestations of the disease include among others physical growth delays and intellectual disability. A prominent anatomical feature of DS is the microcephaly that results from altered brain development. Recent studies using mouse models of DS have shed new light on DYRK1A (dual-specificity tyrosine-phosphorylation-regulated kinase 1A), a gene located on human chromosome 21 that plays a critical role in neocortical development. The present review summarizes effects of the increased dosage of DYRK1A on the proliferative, neurogenic and astrogliogenic potentials of cortical neural progenitor cells, and relates these findings to the clinical manifestations of the disease.
Collapse
Affiliation(s)
- Nobuhiro Kurabayashi
- Molecular Genetics Research Laboratory, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Minh Dang Nguyen
- Hotchkiss Brain Institute, University of Calgary, Departments of Clinical Neurosciences, Cell Biology & Anatomy, Biochemistry & Molecular Biology, 3330 Hospital Drive NW, HMR 151, Calgary, Alberta T2N4N1, Canada
| | - Kamon Sanada
- Molecular Genetics Research Laboratory, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
| |
Collapse
|
27
|
Inoue M, Kajiwara K, Yamaguchi A, Kiyono T, Samura O, Akutsu H, Sago H, Okamoto A, Umezawa A. Autonomous trisomic rescue of Down syndrome cells. J Transl Med 2019; 99:885-897. [PMID: 30760866 PMCID: PMC6760570 DOI: 10.1038/s41374-019-0230-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 01/04/2019] [Accepted: 01/15/2019] [Indexed: 11/10/2022] Open
Abstract
Down syndrome is the most frequent chromosomal abnormality among live-born infants. All Down syndrome patients have mental retardation and are prone to develop early onset Alzheimer's disease. However, it has not yet been elucidated whether there is a correlation between the phenotype of Down syndrome and the extra chromosome 21. In this study, we continuously cultivated induced pluripotent stem cells (iPSCs) with chromosome 21 trisomy for more than 70 weeks, and serendipitously obtained revertant cells with normal chromosome 21 diploids from the trisomic cells during long-term cultivation. Repeated experiments revealed that this trisomy rescue was not due to mosaicism of chromosome 21 diploid cells and occurred at an extremely high frequency. We herewith report the spontaneous correction from chromosome 21 trisomy to disomy without genetic manipulation, chemical treatment or exposure to irradiation. The revertant diploid cells will possibly serve a reference for drug screening and a raw material of regenerative medicinal products for cell-based therapy.
Collapse
Affiliation(s)
- Momoko Inoue
- 0000 0004 0377 2305grid.63906.3aDepartment of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan ,0000 0001 0661 2073grid.411898.dDepartment of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, 105-8471 Japan
| | - Kazuhiro Kajiwara
- 0000 0004 0377 2305grid.63906.3aDepartment of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan ,0000 0001 0661 2073grid.411898.dDepartment of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, 105-8471 Japan
| | - Ayumi Yamaguchi
- 0000 0004 0377 2305grid.63906.3aDepartment of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan
| | - Tohru Kiyono
- 0000 0001 2168 5385grid.272242.3Division of Carcinogenesis and Cancer Prevention, Department of Cell Culture Technology, National Cancer Center Research Institute, Tokyo, 104-0045 Japan
| | - Osamu Samura
- 0000 0001 0661 2073grid.411898.dDepartment of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, 105-8471 Japan
| | - Hidenori Akutsu
- 0000 0004 0377 2305grid.63906.3aDepartment of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535 Japan
| | - Haruhiko Sago
- 0000 0004 0377 2305grid.63906.3aDepartment of Maternal-Fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, 157-8535 Japan
| | - Aikou Okamoto
- 0000 0001 0661 2073grid.411898.dDepartment of Obstetrics and Gynecology, The Jikei University School of Medicine, Tokyo, 105-8471 Japan
| | - Akihiro Umezawa
- Department of Reproductive Biology, National Center for Child Health and Development, Tokyo, 157-8535, Japan.
| |
Collapse
|
28
|
Vásquez-Navarrete J, Martínez AD, Ory S, Baéz-Matus X, González-Jamett AM, Brauchi S, Caviedes P, Cárdenas AM. RCAN1 Knockdown Reverts Defects in the Number of Calcium-Induced Exocytotic Events in a Cellular Model of Down Syndrome. Front Cell Neurosci 2018; 12:189. [PMID: 30034324 PMCID: PMC6043644 DOI: 10.3389/fncel.2018.00189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
In humans, Down Syndrome (DS) is a condition caused by partial or full trisomy of chromosome 21. Genes present in the DS critical region can result in excess gene dosage, which at least partially can account for DS phenotype. Although regulator of calcineurin 1 (RCAN1) belongs to this region and its ectopic overexpression in neurons impairs transmitter release, synaptic plasticity, learning and memory, the relative contribution of RCAN1 in a context of DS has yet to be clarified. In the present work, we utilized an in vitro model of DS, the CTb neuronal cell line derived from the brain cortex of a trisomy 16 (Ts16) fetal mouse, which reportedly exhibits acetylcholine release impairments compared to CNh cells (a neuronal cell line established from a normal littermate). We analyzed single exocytotic events by using total internal reflection fluorescence microscopy (TIRFM) and the vesicular acetylcholine transporter fused to the pH-sensitive green fluorescent protein (VAChT-pHluorin) as a reporter. Our analyses showed that, compared with control CNh cells, the trisomic CTb cells overexpress RCAN1, and they display a reduced number of Ca2+-induced exocytotic events. Remarkably, RCAN1 knockdown increases the extent of exocytosis at levels comparable to those of CNh cells. These results support a critical contribution of RCAN1 to the exocytosis process in the trisomic condition.
Collapse
Affiliation(s)
- Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Stéphane Ory
- Centre National de la Recherche Scientifique (CNRS UPR 3212), Institut des Neurosciences Cellulaires et Intégratives (INCI), Strasbourg, France
| | - Ximena Baéz-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Sebastián Brauchi
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Centro de Biotecnología y Bioingeniería (CeBiB), Departamento de Ingeniería Química, Biotecnología y Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| |
Collapse
|
29
|
Survey of Human Chromosome 21 Gene Expression Effects on Early Development in Danio rerio. G3-GENES GENOMES GENETICS 2018; 8:2215-2223. [PMID: 29760202 PMCID: PMC6027891 DOI: 10.1534/g3.118.200144] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Trisomy for human chromosome 21 (Hsa21) results in Down syndrome (DS), one of the most genetically complex conditions compatible with human survival. Assessment of the physiological consequences of dosage-driven overexpression of individual Hsa21 genes during early embryogenesis and the resulting contributions to DS pathology in mammals are not tractable in a systematic way. A recent study looked at loss-of-function of a subset of Caenorhabditis elegans orthologs of Hsa21 genes and identified ten candidates with behavioral phenotypes, but the equivalent over-expression experiment has not been done. We turned to zebrafish as a developmental model and, using a number of surrogate phenotypes, we screened Hsa21 genes for effects on early embyrogenesis. We prepared a library of 164 cDNAs of conserved protein coding genes, injected mRNA into early embryos and evaluated up to 5 days post-fertilization (dpf). Twenty-four genes produced a gross morphological phenotype, 11 of which could be reproduced reliably. Seven of these gave a phenotype consistent with down regulation of the sonic hedgehog (Shh) pathway; two showed defects indicative of defective neural crest migration; one resulted consistently in pericardial edema; and one was embryonic lethal. Combinatorial injections of multiple Hsa21 genes revealed both additive and compensatory effects, supporting the notion that complex genetic relationships underlie end phenotypes of trisomy that produce DS. Together, our data suggest that this system is useful in the genetic dissection of dosage-sensitive gene effects on early development and can inform the contribution of both individual loci and their combinatorial effects to phenotypes relevant to the etiopathology of DS.
Collapse
|
30
|
Ranjitha Dhanasekaran A, Gardiner KJ. RPPAware: A software suite to preprocess, analyze and visualize reverse phase protein array data. J Bioinform Comput Biol 2018; 16:1850001. [PMID: 29478376 DOI: 10.1142/s0219720018500014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Reverse Phase Protein Arrays (RPPA) is a high-throughput technology used to profile levels of protein expression. Handling the large datasets generated by RPPA can be facilitated by appropriate software tools. Here, we describe RPPAware, a free and intuitive software suite that was developed specifically for analysis and visualization of RPPA data. RPPAware is a portable tool that requires no installation and was built using Java. Many modules of the tool invoke R to utilize the statistical features. To demonstrate the utility of RPPAware, data generated from screening brain regions of a mouse model of Down syndrome with 62 antibodies were used as a case study. The ease of use and efficiency of RPPAware can accelerate data analysis to facilitate biological discovery. RPPAware 1.0 is freely available under GNU General Public License from the project website at http://downsyndrome.ucdenver.edu/iddrc/rppaware/home.htm along with a full documentation of the tool.
Collapse
Affiliation(s)
- A Ranjitha Dhanasekaran
- * Rocky Mountain Alzheimer's Disease Center, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
- † Department of Neurology, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
- ‡ Linda Crnic Institute for Down Syndrome, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Katheleen J Gardiner
- ‡ Linda Crnic Institute for Down Syndrome, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
- § Department of Pediatrics, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
- ¶ Human Medical Genetics and Genomics and Neuroscience Programs, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado 80045, USA
| |
Collapse
|
31
|
Alldred MJ, Chao HM, Lee SH, Beilin J, Powers BE, Petkova E, Strupp BJ, Ginsberg SD. CA1 pyramidal neuron gene expression mosaics in the Ts65Dn murine model of Down syndrome and Alzheimer's disease following maternal choline supplementation. Hippocampus 2018; 28:251-268. [PMID: 29394516 PMCID: PMC5874173 DOI: 10.1002/hipo.22832] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/14/2017] [Accepted: 01/23/2018] [Indexed: 12/15/2022]
Abstract
Although there are changes in gene expression and alterations in neuronal density and afferent inputs in the forebrain of trisomic mouse models of Down syndrome (DS) and Alzheimer's disease (AD), there is a lack of systematic assessments of gene expression and encoded proteins within individual vulnerable cell populations, precluding translational investigations at the molecular and cellular level. Further, no effective treatment exists to combat intellectual disability and basal forebrain cholinergic neurodegeneration seen in DS. To further our understanding of gene expression changes before and following cholinergic degeneration in a well-established mouse model of DS/AD, the Ts65Dn mouse, we assessed RNA expression levels from CA1 pyramidal neurons at two adult ages (∼6 months of age and ∼11 months of age) in both Ts65Dn and their normal disomic (2N) littermates. We further examined a therapeutic intervention, maternal choline supplementation (MCS), which has been previously shown to lessen dysfunction in spatial cognition and attention, and have protective effects on the survival of basal forebrain cholinergic neurons in the Ts65Dn mouse model. Results indicate that MCS normalized expression of several genes in key gene ontology categories, including synaptic plasticity, calcium signaling, and AD-associated neurodegeneration related to amyloid-beta peptide (Aβ) clearance. Specifically, normalized expression levels were found for endothelin converting enzyme-2 (Ece2), insulin degrading enzyme (Ide), Dyrk1a, and calcium/calmodulin-dependent protein kinase II (Camk2a), among other relevant genes. Single population expression profiling of vulnerable CA1 pyramidal neurons indicates that MCS is a viable therapeutic for long-term reprogramming of key transcripts involved in neuronal signaling that are dysregulated in the trisomic mouse brain which have translational potential for DS and AD.
Collapse
Affiliation(s)
- Melissa J. Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY
- Departments of Psychiatry, New York University Langone Medical Center, New York, NY
| | - Helen M. Chao
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY
- Departments of Psychiatry, New York University Langone Medical Center, New York, NY
| | - Sang Han Lee
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY
- Child Psychiatry, Nathan Kline Institute, Orangeburg, NY
- Departments of Psychiatry, New York University Langone Medical Center, New York, NY
- Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY
| | - Judah Beilin
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY
| | | | - Eva Petkova
- Child Psychiatry, Nathan Kline Institute, Orangeburg, NY
- Child and Adolescent Psychiatry, New York University Langone Medical Center, New York, NY
| | - Barbara J. Strupp
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
- Department of Psychology, Cornell University, Ithaca, NY
| | - Stephen D. Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY
- Departments of Psychiatry, New York University Langone Medical Center, New York, NY
- Neuroscience & Physiology, New York University Langone Medical Center, New York, NY
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY
| |
Collapse
|
32
|
Tamplen M, Fowler T, Markey J, Knott PD, Suva LJ, Alliston T. Treatment with anti-Sclerostin antibody to stimulate mandibular bone formation. Head Neck 2018; 40:1453-1460. [PMID: 29522281 PMCID: PMC6037571 DOI: 10.1002/hed.25128] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 11/19/2017] [Accepted: 01/26/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Anti-Sclerostin antibody (Scl-Ab) is a promising new bone anabolic therapy. Although anti-Scl-Ab stimulates bone formation and repair in the appendicular and axial skeleton, its efficacy in the craniofacial skeleton is still poorly understood. METHODS Using an established model of Down syndrome-dependent bone deficiency, 10 Ts65Dn mice and 10 wild-type mice were treated weekly via i.v. tail vein injection with vehicle or anti-Sclerostin for 3 weeks and euthanized 1 week after. RESULTS Wild-type mice treated with the anti-Scl-Ab had increased mandibular bone, trabecular thickness, and alveolar height compared with controls. Anti-Scl-Ab increased Ts65Dn mandibular bone parameters such that they were statistically indistinguishable from those in vehicle-treated wild-type mandibles. CONCLUSION Treatment with anti-Scl-Ab significantly increased mandibular bone mass and alveolar height in wild type mice and normalized mandibular bone mass and alveolar height in Ts65Dn mice. The anti-Scl-Ab therapy represents a novel method for increasing mandibular bone formation.
Collapse
Affiliation(s)
- Matthew Tamplen
- Department of Otolaryngology - Head and Neck Surgery, University of California, San Francisco, California
| | - Tristan Fowler
- Department of Orthopedic Surgery, University of California, San Francisco, California
| | - Jeffery Markey
- Department of Otolaryngology - Head and Neck Surgery, University of California, San Francisco, California
| | - P Daniel Knott
- Department of Otolaryngology - Head and Neck Surgery, University of California, San Francisco, California
| | - Larry J Suva
- Department of Veterinary Physiology, Texas A&M University, College Station, Texas
| | - Tamara Alliston
- Department of Otolaryngology - Head and Neck Surgery, University of California, San Francisco, California.,Department of Orthopedic Surgery, University of California, San Francisco, California
| |
Collapse
|
33
|
|
34
|
Kleschevnikov AM, Yu J, Kim J, Lysenko LV, Zeng Z, Yu YE, Mobley WC. Evidence that increased Kcnj6 gene dose is necessary for deficits in behavior and dentate gyrus synaptic plasticity in the Ts65Dn mouse model of Down syndrome. Neurobiol Dis 2017; 103:1-10. [PMID: 28342823 DOI: 10.1016/j.nbd.2017.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/09/2017] [Accepted: 03/21/2017] [Indexed: 11/15/2022] Open
Abstract
Down syndrome (DS), trisomy 21, is caused by increased dose of genes present on human chromosome 21 (HSA21). The gene-dose hypothesis argues that a change in the dose of individual genes or regulatory sequences on HSA21 is necessary for creating DS-related phenotypes, including cognitive impairment. We focused on a possible role for Kcnj6, the gene encoding Kir3.2 (Girk2) subunits of a G-protein-coupled inwardly-rectifying potassium channel. This gene resides on a segment of mouse Chromosome 16 that is present in one extra copy in the genome of the Ts65Dn mouse, a well-studied genetic model of DS. Kir3.2 subunit-containing potassium channels serve as effectors for a number of postsynaptic metabotropic receptors including GABAB receptors. Several studies raise the possibility that increased Kcnj6 dose contributes to synaptic and cognitive abnormalities in DS. To assess directly a role for Kcnj6 gene dose in cognitive deficits in DS, we produced Ts65Dn mice that harbor only 2 copies of Kcnj6 (Ts65Dn:Kcnj6++- mice). The reduction in Kcnj6 gene dose restored to normal the hippocampal level of Kir3.2. Long-term memory, examined in the novel object recognition test with the retention period of 24h, was improved to the level observed in the normosomic littermate control mice (2N:Kcnj6++). Significantly, both short-term and long-term potentiation (STP and LTP) was improved to control levels in the dentate gyrus (DG) of the Ts65Dn:Kcnj6++- mouse. In view of the ability of fluoxetine to suppress Kir3.2 channels, we asked if fluoxetine-treated DG slices of Ts65Dn:Kcnj6+++ mice would rescue synaptic plasticity. Fluoxetine increased STP and LTP to control levels. These results are evidence that increased Kcnj6 gene dose is necessary for synaptic and cognitive dysfunction in the Ts65Dn mouse model of DS. Strategies aimed at pharmacologically reducing channel function should be explored for enhancing cognition in DS.
Collapse
Affiliation(s)
- Alexander M Kleschevnikov
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
| | - Jessica Yu
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jeesun Kim
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Larisa V Lysenko
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Academy of Biology and Biotechnology of Southern Federal University, 194/1 Stachki Str, Rostov-na-Donu 344090, Russian Federation
| | - Zheng Zeng
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Y Eugene Yu
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program and Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - William C Mobley
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| |
Collapse
|
35
|
Contestabile A, Magara S, Cancedda L. The GABAergic Hypothesis for Cognitive Disabilities in Down Syndrome. Front Cell Neurosci 2017; 11:54. [PMID: 28326014 PMCID: PMC5339239 DOI: 10.3389/fncel.2017.00054] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/14/2017] [Indexed: 12/04/2022] Open
Abstract
Down syndrome (DS) is a genetic disorder caused by the presence of a third copy of chromosome 21. DS affects multiple organs, but it invariably results in altered brain development and diverse degrees of intellectual disability. A large body of evidence has shown that synaptic deficits and memory impairment are largely determined by altered GABAergic signaling in trisomic mouse models of DS. These alterations arise during brain development while extending into adulthood, and include genesis of GABAergic neurons, variation of the inhibitory drive and modifications in the control of neural-network excitability. Accordingly, different pharmacological interventions targeting GABAergic signaling have proven promising preclinical approaches to rescue cognitive impairment in DS mouse models. In this review, we will discuss recent data regarding the complex scenario of GABAergic dysfunctions in the trisomic brain of DS mice and patients, and we will evaluate the state of current clinical research targeting GABAergic signaling in individuals with DS.
Collapse
Affiliation(s)
- Andrea Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT) Genova, Italy
| | - Salvatore Magara
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT) Genova, Italy
| | - Laura Cancedda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT)Genova, Italy; Dulbecco Telethon InstituteGenova, Italy
| |
Collapse
|
36
|
Mojabi FS, Fahimi A, Moghadam S, Moghadam S, Windy McNerneny M, Ponnusamy R, Kleschevnikov A, Mobley WC, Salehi A. GABAergic hyperinnervation of dentate granule cells in the Ts65Dn mouse model of down syndrome: Exploring the role of App. Hippocampus 2016; 26:1641-1654. [PMID: 27701794 DOI: 10.1002/hipo.22664] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2016] [Indexed: 12/20/2022]
Abstract
It has been suggested that increased GABAergic innervation in the hippocampus plays a significant role in cognitive dysfunction in Down syndrome (DS). Bolstering this notion, are studies linking hyper-innervation of the dentate gyrus (DG) by GABAergic terminals to failure in LTP induction in the Ts65Dn mouse model of DS. Here, we used extensive morphometrical methods to assess the status of GABAergic interneurons in the DG of young and old Ts65Dn mice and their 2N controls. We detected an age-dependent increase in GABAergic innervation of dentate granule cells (DGCs) in Ts65Dn mice. The primary source of GABAergic terminals to DGCs somata is basket cells (BCs). For this reason, we assessed the status of these cells and found a significant increase in the number of BCs in Ts65Dn mice compared with controls. Then we aimed to identify the gene/s whose overexpression could be linked to increased number of BCs in Ts65Dn and found that deleting the third copy of App gene in Ts65Dn mice led to normalization of the number of BCs in these mice. Our data suggest that App overexpression plays a major role in the pathophysiology of GABAergic hyperinnervation of the DG in Ts65Dn mice. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Fatemeh S Mojabi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | - Atoossa Fahimi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | | | | | - M Windy McNerneny
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| | | | | | - William C Mobley
- Department of Neurosciences, University of California, San Diego, California
| | - Ahmad Salehi
- VA Palo Alto Health Care System, Palo Alto, California.,Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California
| |
Collapse
|
37
|
Strupp BJ, Powers BE, Velazquez R, Ash JA, Kelley CM, Alldred MJ, Strawderman M, Caudill MA, Mufson EJ, Ginsberg SD. Maternal Choline Supplementation: A Potential Prenatal Treatment for Down Syndrome and Alzheimer's Disease. Curr Alzheimer Res 2016; 13:97-106. [PMID: 26391046 DOI: 10.2174/1567205012666150921100311] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 08/30/2015] [Accepted: 09/10/2015] [Indexed: 01/17/2023]
Abstract
Although Down syndrome (DS) can be diagnosed prenatally, currently there are no effective treatments to lessen the intellectual disability (ID) which is a hallmark of this disorder. Furthermore, starting as early as the third decade of life, DS individuals exhibit the neuropathological hallmarks of Alzheimer's disease (AD) with subsequent dementia, adding substantial emotional and financial burden to their families and society at large. A potential therapeutic strategy emerging from the study of trisomic mouse models of DS is to supplement the maternal diet with additional choline during pregnancy and lactation. Studies demonstrate that maternal choline supplementation (MCS) markedly improves spatial cognition and attentional function, as well as normalizes adult hippocampal neurogenesis and offers protection to basal forebrain cholinergic neurons (BFCNs) in the Ts65Dn mouse model of DS. These effects on neurogenesis and BFCNs correlate significantly with spatial cognition, suggesting functional relationships. In this review, we highlight some of these provocative findings, which suggest that supplementing the maternal diet with additional choline may serve as an effective and safe prenatal strategy for improving cognitive, affective, and neural functioning in DS. In light of growing evidence that all pregnancies would benefit from increased maternal choline intake, this type of recommendation could be given to all pregnant women, thereby providing a very early intervention for individuals with DS, and include babies born to mothers unaware that they are carrying a fetus with DS.
Collapse
Affiliation(s)
- Barbara J Strupp
- Division of Nutritional Sciences and Department of Psychology, Cornell University, Ithaca, NY, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
López-Hidalgo R, Ballestín R, Vega J, Blasco-Ibáñez JM, Crespo C, Gilabert-Juan J, Nácher J, Varea E. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis. Front Neurosci 2016; 10:75. [PMID: 26973453 PMCID: PMC4773601 DOI: 10.3389/fnins.2016.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/17/2016] [Indexed: 01/08/2023] Open
Abstract
Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5'BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5'BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice.
Collapse
Affiliation(s)
- Rosa López-Hidalgo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Raul Ballestín
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Jessica Vega
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - José M. Blasco-Ibáñez
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Carlos Crespo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Javier Gilabert-Juan
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Juan Nácher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| |
Collapse
|
39
|
Salehi A, Ashford JW, Mufson EJ. The Link between Alzheimer's Disease and Down Syndrome. A Historical Perspective. Curr Alzheimer Res 2016; 13:2-6. [PMID: 26487155 PMCID: PMC6368451 DOI: 10.2174/1567205012999151021102914] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | | | - Elliott J Mufson
- Barrow Neurological Institute, Dept. Neurobiology, Phoenix, AZ 85031, USA.
| |
Collapse
|
40
|
Araujo BHS, Torres LB, Guilhoto LMFF. Cerebal overinhibition could be the basis for the high prevalence of epilepsy in persons with Down syndrome. Epilepsy Behav 2015; 53:120-5. [PMID: 26558714 DOI: 10.1016/j.yebeh.2015.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 10/05/2015] [Accepted: 10/06/2015] [Indexed: 01/19/2023]
Abstract
Down syndrome (DS) is the most common cause of genetic intellectual disability, and the trisomy 21 is associated with more than 80 clinical traits, including higher risk for epilepsy. Several hypotheses have been put forward to explain the mechanisms underlying increased seizure susceptibility in DS: inherent structural brain abnormalities, abnormal cortical lamination, disruption of normal dendritic morphology, and underdeveloped synaptic profiles. A deficiency or loss of GABA inhibition is hypothesized to be one of the main alterations related to the epileptogenic process. Paradoxically, enhanced GABA inhibition has also been reported to promote seizures. One major functional abnormality observed in the brains of individuals and mouse models with DS appears to be an imbalance between excitatory and inhibitory neurotransmission, with excessive inhibitory brain function. This review discusses the GABAergic system in the human DS brain and the possible implication of the GABAergic network circuit in the epileptogenic process in individuals where the pathogenetic basis for epilepsy is unknown.
Collapse
Affiliation(s)
- Bruno Henrique Silva Araujo
- Universidade Federal de São Paulo - Unifesp/EPM, Department of Neurology and Neurosurgery - Laboratório de Neurociências, São Paulo, SP, Brazil.
| | - Laila Brito Torres
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Centro Sul Brasileiro de Pesquisa, Extensão e Pós-Graduação, CENSUPEG, Joinville, SC, Brazil
| | - Laura Maria F F Guilhoto
- Universidade Federal de São Paulo - Unifesp/EPM, Department of Neurology and Neurosurgery, São Paulo, SP, Brazil
| |
Collapse
|
41
|
Ng AP, Hu Y, Metcalf D, Hyland CD, Ierino H, Phipson B, Wu D, Baldwin TM, Kauppi M, Kiu H, Di Rago L, Hilton DJ, Smyth GK, Alexander WS. Early lineage priming by trisomy of Erg leads to myeloproliferation in a Down syndrome model. PLoS Genet 2015; 11:e1005211. [PMID: 25973911 PMCID: PMC4431731 DOI: 10.1371/journal.pgen.1005211] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 04/13/2015] [Indexed: 12/12/2022] Open
Abstract
Down syndrome (DS), with trisomy of chromosome 21 (HSA21), is the commonest human aneuploidy. Pre-leukemic myeloproliferative changes in DS foetal livers precede the acquisition of GATA1 mutations, transient myeloproliferative disorder (DS-TMD) and acute megakaryocytic leukemia (DS-AMKL). Trisomy of the Erg gene is required for myeloproliferation in the Ts(1716)65Dn DS mouse model. We demonstrate here that genetic changes specifically attributable to trisomy of Erg lead to lineage priming of primitive and early multipotential progenitor cells in Ts(1716)65Dn mice, excess megakaryocyte-erythroid progenitors, and malignant myeloproliferation. Gene expression changes dependent on trisomy of Erg in Ts(1716)65Dn multilineage progenitor cells were correlated with those associated with trisomy of HSA21 in human DS hematopoietic stem and primitive progenitor cells. These data suggest a role for ERG as a regulator of hematopoietic lineage potential, and that trisomy of ERG in the context of DS foetal liver hemopoiesis drives the pre-leukemic changes that predispose to subsequent DS-TMD and DS-AMKL. An excess number of genes in trisomy on human chromosome 21 leads to the development of specific diseases in human Down syndrome. An excess copy of the gene, ERG, an ETS family transcription factor, has been implicated in abnormal blood system development in Down syndrome. In this study we show how trisomy of Erg in a murine Down syndrome model perturbs hematopoietic progenitor cells in a manner similar to that observed in human Down syndrome by inducing gene expression changes and lineage priming in early multi-potential progenitors. We show that the gene expression signature specifically attributable to trisomy of Erg in the murine model is strongly correlated with gene expression changes in human Down syndrome hematopoietic cells. The data suggest that Erg is an important regulator of megakaryocyte-erythroid lineage specification in multipotential hematopoietic cells and that trisomy of Erg in the context of DS prediposes to a transient myeloproliferative disorder and acute megakaryocyte leukaemia in a multi-step model of leukemogenesis.
Collapse
Affiliation(s)
- Ashley P. Ng
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Yifang Hu
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Donald Metcalf
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Craig D. Hyland
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Helen Ierino
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Belinda Phipson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia
| | - Di Wu
- Centre for Cancer Research, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
- Department of Statistics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Tracey M. Baldwin
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Maria Kauppi
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Hiu Kiu
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Ladina Di Rago
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Douglas J. Hilton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Gordon K. Smyth
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia
| | - Warren S. Alexander
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
42
|
Alldred MJ, Lee SH, Petkova E, Ginsberg SD. Expression profile analysis of vulnerable CA1 pyramidal neurons in young-Middle-Aged Ts65Dn mice. J Comp Neurol 2014; 523:61-74. [PMID: 25131634 DOI: 10.1002/cne.23663] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/07/2014] [Accepted: 08/07/2014] [Indexed: 12/19/2022]
Abstract
Down syndrome (DS) is the most prevalent cause of intellectual disability (ID). Individuals with DS show a variety of cognitive deficits, most notably in hippocampal learning and memory, and display pathological hallmarks of Alzheimer's disease (AD), with neurodegeneration of cholinergic basal forebrain (CBF) neurons. Elucidation of the molecular and cellular underpinnings of neuropathology has been assessed via gene expression analysis in a relevant animal model, termed the Ts65Dn mouse. The Ts65Dn mouse is a segmental trisomy model of DS that mimics DS/AD pathology, notably age-related cognitive dysfunction and degeneration of basal forebrain cholinergic neurons (BFCNs). To determine expression level changes, molecular fingerprinting of cornu ammonis 1 (CA1) pyramidal neurons was performed in adult (4-9 month-old) Ts65Dn mice, at the initiation of BFCN degeneration. To quantitate transcriptomic changes during this early time period, laser capture microdissection (LCM), terminal continuation (TC) RNA amplification, custom-designed microarray analysis, and subsequent validation of individual transcripts by qPCR and protein analysis via immunoblotting was performed. The results indicate significant alterations within CA1 pyramidal neurons of Ts65Dn mice compared with normal disomic (2N) littermates, notably in the downregulation of neurotrophins and their cognate neurotrophin receptors among other classes of transcripts relevant to neurodegeneration. The results of this single-population gene expression analysis at the time of septohippocampal deficits in a trisomic mouse model shed light on a vulnerable circuit that may cause the AD-like pathology invariably seen in DS that could help to identify mechanisms of degeneration, and provide novel gene targets for therapeutic interventions. J. Comp. Neurol. 523:61-74, 2015. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, New York, 10962; Department of Psychiatry, New York University Langone Medical Center, New York, New York, 10016
| | | | | | | |
Collapse
|
43
|
Alldred MJ, Lee SH, Petkova E, Ginsberg SD. Expression profile analysis of hippocampal CA1 pyramidal neurons in aged Ts65Dn mice, a model of Down syndrome (DS) and Alzheimer's disease (AD). Brain Struct Funct 2014; 220:2983-96. [PMID: 25031177 DOI: 10.1007/s00429-014-0839-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 07/02/2014] [Indexed: 11/29/2022]
Abstract
Down syndrome (DS) is caused by the triplication of human chromosome 21 (HSA21) and is the most common genetic cause of intellectual disability, with individuals having deficits in cognitive function including hippocampal learning and memory and neurodegeneration of cholinergic basal forebrain neurons, a pathological hallmark of Alzheimer's disease (AD). To date, the molecular underpinnings driving this pathology have not been elucidated. The Ts65Dn mouse is a segmental trisomy model of DS and like DS/AD pathology, displays age-related cognitive dysfunction and basal forebrain cholinergic neuron (BFCN) degeneration. To determine molecular and cellular changes important for elucidating mechanisms of neurodegeneration in DS/AD pathology, expression profiling studies were performed. Molecular fingerprinting of homogeneous populations of Cornu Ammonis 1 (CA1) pyramidal neurons was performed via laser capture microdissection followed by Terminal Continuation RNA amplification combined with custom-designed microarray analysis and subsequent validation of individual transcripts by qPCR and protein analysis via immunoblotting. Significant alterations were observed within CA1 pyramidal neurons of aged Ts65Dn mice compared to normal disomic (2N) littermates, notably in excitatory and inhibitory neurotransmission receptor families and neurotrophins, including brain-derived neurotrophic factor as well as several cognate neurotrophin receptors. Examining gene and protein expression levels after the onset of BFCN degeneration elucidated transcriptional and translational changes in neurons within a vulnerable circuit that may cause the AD-like pathology seen in DS as these individuals age, and provide rational targets for therapeutic interventions.
Collapse
Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA
| | | | | | | |
Collapse
|
44
|
Ballestín R, Blasco-Ibáñez JM, Crespo C, Nacher J, López-Hidalgo R, Gilabert-Juan J, Moltó D, Varea E. Astrocytes of the murine model for Down Syndrome Ts65Dn display reduced intracellular ionic zinc. Neurochem Int 2014; 75:48-53. [PMID: 24911951 DOI: 10.1016/j.neuint.2014.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/23/2014] [Accepted: 05/29/2014] [Indexed: 11/30/2022]
Abstract
Zinc is an essential trace element that is critical for a large number of structural proteins, enzymatic processes and transcription factors. In the brain, zinc ions are involved in synaptic transmission. The homeostasis of zinc is crucial for cell survival and function, and cells have developed a wide variety of systems to control zinc concentration. Alterations in free zinc concentration have been related with brain dysfunction. Down Syndrome individuals present alterations in free zinc concentration and in some of the proteins related with zinc homeostasis. We have analyzed the amount of free zinc and the zinc chelating protein metallothionein 3 in the astrocytes using primary cultures of the murine model Ts65Dn. We have observed a higher number of zinc positive spots in the cytoplasm of trisomic astrocytes but a decrease in the total concentration of total intracellular free zinc concentration (including the spots) respect to control astrocytes. Using FM1-43 staining, we found that the endocytic function remains unaltered. Therefore, a possible explanation for this lower concentration of free zinc could be the higher concentration of metallothionein 3 present in the cytoplasm of trisomic astrocytes. The blockade of metallothionein 3 expression using an specific siRNA induced an increase in the concentration of free zinc in basal conditions but failed to increase the uptake of zinc after incubation with zinc ions.
Collapse
Affiliation(s)
- Raúl Ballestín
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - José Miguel Blasco-Ibáñez
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Carlos Crespo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Juan Nacher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Rosa López-Hidalgo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain
| | - Javier Gilabert-Juan
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain; Genetics Department, Universitat de València, INCLIVA, CIBERSAM, Spain
| | - Dolores Moltó
- Genetics Department, Universitat de València, INCLIVA, CIBERSAM, Spain
| | - Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de València, Spain.
| |
Collapse
|
45
|
Starbuck JM, Dutka T, Ratliff TS, Reeves RH, Richtsmeier JT. Overlapping trisomies for human chromosome 21 orthologs produce similar effects on skull and brain morphology of Dp(16)1Yey and Ts65Dn mice. Am J Med Genet A 2014; 164A:1981-1990. [PMID: 24788405 DOI: 10.1002/ajmg.a.36594] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 04/06/2014] [Indexed: 12/28/2022]
Abstract
Trisomy 21 results in gene-dosage imbalance during embryogenesis and throughout life, ultimately causing multiple anomalies that contribute to the clinical manifestations of Down syndrome. Down syndrome is associated with manifestations of variable severity (e.g., heart anomalies, reduced growth, dental anomalies, shortened life-span). Craniofacial dysmorphology and cognitive dysfunction are consistently observed in all people with Down syndrome. Mouse models are useful for studying the effects of gene-dosage imbalance on development. We investigated quantitative changes in the skull and brain of the Dp(16)1Yey Down syndrome mouse model and compared these mice to Ts65Dn and Ts1Cje mouse models. Three-dimensional micro-computed tomography images of Dp(16)1Yey and euploid mouse crania were morphometrically evaluated. Cerebellar cross-sectional area, Purkinje cell linear density, and granule cell density were evaluated relative to euploid littermates. Skulls of Dp(16)1Yey and Ts65Dn mice displayed similar changes in craniofacial morphology relative to their respective euploid littermates. Trisomy-based differences in brain morphology were also similar in Dp(16)1Yey and Ts65Dn mice. These results validate examination of the genetic basis for craniofacial and brain phenotypes in Dp(16)1Yey mice and suggest that they, like Ts65Dn mice, are valuable tools for modeling the effects of trisomy 21 on development.
Collapse
Affiliation(s)
- John M Starbuck
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Tara Dutka
- Department of Physiology and Institute for Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Tabetha S Ratliff
- Department of Physiology and Institute for Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Roger H Reeves
- Department of Physiology and Institute for Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Joan T Richtsmeier
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania.,Center for Functional Anatomy and Evolution, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| |
Collapse
|
46
|
Kelley CM, Powers BE, Velazquez R, Ash JA, Ginsberg SD, Strupp BJ, Mufson EJ. Maternal choline supplementation differentially alters the basal forebrain cholinergic system of young-adult Ts65Dn and disomic mice. J Comp Neurol 2014; 522:1390-410. [PMID: 24178831 PMCID: PMC3959592 DOI: 10.1002/cne.23492] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/10/2013] [Accepted: 10/15/2013] [Indexed: 12/29/2022]
Abstract
Down syndrome (DS), trisomy 21, is a multifaceted condition marked by intellectual disability and early presentation of Alzheimer's disease (AD) neuropathological lesions including degeneration of the basal forebrain cholinergic neuron (BFCN) system. Although DS is diagnosable during gestation, there is no treatment option for expectant mothers or DS individuals. Using the Ts65Dn mouse model of DS that displays age-related degeneration of the BFCN system, we investigated the effects of maternal choline supplementation on the BFCN system in adult Ts65Dn mice and disomic (2N) littermates at 4.3-7.5 months of age. Ts65Dn dams were maintained on a choline-supplemented diet (5.1 g/kg choline chloride) or a control, unsupplemented diet with adequate amounts of choline (1 g/kg choline chloride) from conception until weaning of offspring; post weaning, offspring were fed the control diet. Mice were transcardially perfused with paraformaldehyde, and brains were sectioned and immunolabeled for choline acetyltransferase (ChAT) or p75-neurotrophin receptor (p75(NTR) ). BFCN number and size, the area of the regions, and the intensity of hippocampal labeling were determined. Ts65Dn-unsupplemented mice displayed region- and immunolabel-dependent increased BFCN number, larger areas, smaller BFCNs, and overall increased hippocampal ChAT intensity compared with 2N unsupplemented mice. These effects were partially normalized by maternal choline supplementation. Taken together, the results suggest a developmental imbalance in the Ts65Dn BFCN system. Early maternal-diet choline supplementation attenuates some of the genotype-dependent alterations in the BFCN system, suggesting this naturally occurring nutrient as a treatment option for pregnant mothers with knowledge that their offspring is trisomy 21.
Collapse
Affiliation(s)
- Christy M. Kelley
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Brian E. Powers
- Div. Nutritional Sciences and Dept. of Psychology, Cornell University, Ithaca, NY 14853, USA
| | - Ramon Velazquez
- Div. Nutritional Sciences and Dept. of Psychology, Cornell University, Ithaca, NY 14853, USA
| | - Jessica A. Ash
- Div. Nutritional Sciences and Dept. of Psychology, Cornell University, Ithaca, NY 14853, USA
| | - Stephen D. Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA, and Depts. of Psychiatry, and Physiology & Neuroscience, New York University Langone Medical Center, New York, NY 10962, USA
| | - Barbara J. Strupp
- Div. Nutritional Sciences and Dept. of Psychology, Cornell University, Ithaca, NY 14853, USA
| | - Elliott J. Mufson
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| |
Collapse
|
47
|
Briggs JA, Sun J, Shepherd J, Ovchinnikov DA, Chung TL, Nayler SP, Kao LP, Morrow CA, Thakar NY, Soo SY, Peura T, Grimmond S, Wolvetang EJ. Integration-free induced pluripotent stem cells model genetic and neural developmental features of down syndrome etiology. Stem Cells 2014; 31:467-78. [PMID: 23225669 DOI: 10.1002/stem.1297] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 11/21/2012] [Indexed: 01/08/2023]
Abstract
Down syndrome (DS) is the most frequent cause of human congenital mental retardation. Cognitive deficits in DS result from perturbations of normal cellular processes both during development and in adult tissues, but the mechanisms underlying DS etiology remain poorly understood. To assess the ability of induced pluripotent stem cells (iPSCs) to model DS phenotypes, as a prototypical complex human disease, we generated bona fide DS and wild-type (WT) nonviral iPSCs by episomal reprogramming. DS iPSCs selectively overexpressed chromosome 21 genes, consistent with gene dosage, which was associated with deregulation of thousands of genes throughout the genome. DS and WT iPSCs were neurally converted at >95% efficiency and had remarkably similar lineage potency, differentiation kinetics, proliferation, and axon extension at early time points. However, at later time points DS cultures showed a twofold bias toward glial lineages. Moreover, DS neural cultures were up to two times more sensitive to oxidative stress-induced apoptosis, and this could be prevented by the antioxidant N-acetylcysteine. Our results reveal a striking complexity in the genetic alterations caused by trisomy 21 that are likely to underlie DS developmental phenotypes, and indicate a central role for defective early glial development in establishing developmental defects in DS brains. Furthermore, oxidative stress sensitivity is likely to contribute to the accelerated neurodegeneration seen in DS, and we provide proof of concept for screening corrective therapeutics using DS iPSCs and their derivatives. Nonviral DS iPSCs can therefore model features of complex human disease in vitro and provide a renewable and ethically unencumbered discovery platform.
Collapse
Affiliation(s)
- James A Briggs
- Australian Institute for Bioengineering and Nanotechnology,The University of Queensland, St Lucia, Queensland, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Bhutta MF, Cheeseman MT, Herault Y, Yu YE, Brown SDM. Surveying the Down syndrome mouse model resource identifies critical regions responsible for chronic otitis media. Mamm Genome 2013; 24:439-45. [PMID: 24068166 PMCID: PMC3843744 DOI: 10.1007/s00335-013-9475-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/15/2013] [Indexed: 02/06/2023]
Abstract
Chronic otitis media (OM) is common in Down syndrome (DS), but underlying aetiology is unclear. We analysed the entire available mouse resource of partial trisomy models of DS looking for histological evidence of chronic middle-ear inflammation. We found a highly penetrant OM in the Dp(16)1Yey mouse, which carries a complete trisomy of MMU16. No OM was found in the Dp(17)1Yey mouse or the Dp(10)1Yey mouse, suggesting disease loci are located only on MMU16. The Ts1Cje, Ts1RhR, Ts2Yah, and Ts65Dn trisomies and the transchomosomic Tc1 mouse did not develop OM. On the basis of these findings, we propose a two-locus model for chronic middle-ear inflammation in DS, based upon epistasis of the regions of HSA21 not in trisomy in the Tc1 mouse. We also conclude that environmental factors likely play an important role in disease onset.
Collapse
Affiliation(s)
- Mahmood F Bhutta
- Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, Room 6607 Level 6, Headley Way, Oxford, OX3 9DU, UK,
| | | | | | | | | |
Collapse
|
49
|
Begenisic T, Baroncelli L, Sansevero G, Milanese M, Bonifacino T, Bonanno G, Cioni G, Maffei L, Sale A. Fluoxetine in adulthood normalizes GABA release and rescues hippocampal synaptic plasticity and spatial memory in a mouse model of Down syndrome. Neurobiol Dis 2013; 63:12-9. [PMID: 24269730 DOI: 10.1016/j.nbd.2013.11.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/18/2013] [Accepted: 11/12/2013] [Indexed: 11/17/2022] Open
Abstract
Down syndrome (DS) is the most common genetic disorder associated with mental retardation. It has been repeatedly shown that Ts65Dn mice, the major animal model for DS, have severe cognitive and synaptic plasticity dysfunctions caused by excessive inhibition in their temporal lobe structures. Here we employed a multidisciplinary approach spanning from the behavioral to the electrophysiological and molecular level to investigate the effects elicited by fluoxetine on cognitive abilities, hippocampal synaptic plasticity and GABA release in adult Ts65Dn mice. We report that a chronic treatment with fluoxetine administered in the drinking water normalizes GABA release and promotes recovery of spatial memory abilities, spatial working memory for alternation, and hippocampal synaptic plasticity in adult Ts65Dn mice. Our findings might encourage new experimental attempts aimed at investigating the potential of fluoxetine for application in the treatment of major functional deficits in adult people with DS.
Collapse
Affiliation(s)
| | | | | | - Marco Milanese
- Department of Pharmacy, Section of Pharmacology and Toxicology Unit, University of Genova, Genova I-16148, Italy
| | - Tiziana Bonifacino
- Department of Pharmacy, Section of Pharmacology and Toxicology Unit, University of Genova, Genova I-16148, Italy
| | - Giambattista Bonanno
- Department of Pharmacy, Section of Pharmacology and Toxicology Unit, University of Genova, Genova I-16148, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris and University of Pisa, Calambrone, Pisa I-56100, Italy
| | | | | |
Collapse
|
50
|
Briggs JA, Mason EA, Ovchinnikov DA, Wells CA, Wolvetang EJ. Concise review: new paradigms for Down syndrome research using induced pluripotent stem cells: tackling complex human genetic disease. Stem Cells Transl Med 2013; 2:175-84. [PMID: 23413375 DOI: 10.5966/sctm.2012-0117] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Down syndrome (DS) is a complex developmental disorder with diverse pathologies that affect multiple tissues and organ systems. Clear mechanistic description of how trisomy of chromosome 21 gives rise to most DS pathologies is currently lacking and is limited to a few examples of dosage-sensitive trisomic genes with large phenotypic effects. The recent advent of cellular reprogramming technology offers a promising way forward, by allowing derivation of patient-derived human cell types in vitro. We present general strategies that integrate genomics technologies and induced pluripotent stem cells to identify molecular networks driving different aspects of DS pathogenesis and describe experimental approaches to validate the causal requirement of candidate network defects for particular cellular phenotypes. This overall approach should be applicable to many poorly understood complex human genetic diseases, whose pathogenic mechanisms might involve the combined effects of many genes.
Collapse
Affiliation(s)
- James A Briggs
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia
| | | | | | | | | |
Collapse
|