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Tramutola A, Lanzillotta C, Di Domenico F, Head E, Butterfield DA, Perluigi M, Barone E. Brain insulin resistance triggers early onset Alzheimer disease in Down syndrome. Neurobiol Dis 2020; 137:104772. [PMID: 31987911 DOI: 10.1016/j.nbd.2020.104772] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/03/2020] [Accepted: 01/23/2020] [Indexed: 01/08/2023] Open
Abstract
Dysregulation of insulin signaling pathway with reduced downstream neuronal survival and plasticity mechanisms is a fundamental abnormality observed in Alzheimer's disease (AD) brain. This phenomenon, known as brain insulin resistance, is associated with poor cognitive performance and is driven by the uncoupling of insulin receptor (IR) from its direct substrate (IRS1). Considering that Down syndrome (DS) and AD neuropathology share many common features, we investigated metabolic aspects of neurodegeneration, i.e., brain insulin resistance, in DS and whether it would contribute to early onset AD in DS population. Changes of levels and activation of main brain proteins belonging to the insulin signaling pathway (i.e., IR, IRS1, PTEN, GSK3β, PKCζ, AS160, GLUT4) were evaluated. Furthermore, we analyzed whether changes of these proteins were associated with alterations of: (i) proteins regulating brain energy metabolism; (ii) APP cleavage; and (ii) regulation of synaptic plasticity mechanisms in post-mortem brain samples collected from people with DS before and after the development of AD pathology (DSAD) compared with their age-matched controls. We found that DS cases were characterized by key markers of brain insulin resistance (reduced IR and increased IRS1 inhibition) early in life. Furthermore, downstream from IRS1, an overall uncoupling among the proteins of insulin signaling was observed. Dysregulated brain insulin signaling was associated with reduced hexokinase II (HKII) levels and proteins associated with mitochondrial complexes levels as well as with reduced levels of syntaxin in DS cases. Tellingly, these alterations precede the development of AD neuropathology and clinical presentations in DS. We propose that markers of brain insulin resistance rise earlier with age in DS compared with the general population and may contribute to the cognitive impairment associated with the early development of AD in DS.
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Affiliation(s)
- Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - D Allan Butterfield
- Department of Chemistry, Markey Cancer Center, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
| | - 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.
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Abrahamson EE, Head E, Lott IT, Handen BL, Mufson EJ, Christian BT, Klunk WE, Ikonomovic MD. Neuropathological correlates of amyloid PET imaging in Down syndrome. Dev Neurobiol 2019; 79:750-766. [PMID: 31379087 DOI: 10.1002/dneu.22713] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 11/07/2022]
Abstract
Down syndrome (DS) results in an overproduction of amyloid-β (Aβ) peptide associated with early onset of Alzheimer's disease (AD). DS cases have Aβ deposits detectable histologically as young as 12-30 years of age, primarily in the form of diffuse plaques, the type of early amyloid pathology also seen at pre-clinical (i.e., pathological aging) and prodromal stages of sporadic late onset AD. In DS subjects aged >40 years, levels of cortical Aβ deposition are similar to those observed in late onset AD and in addition to diffuse plaques involve cored plaques associated with dystrophic neurites (neuritic plaques), which are of neuropathological diagnostic significance in AD. The purpose of this review is to summarize and discuss findings from amyloid PET imaging studies of DS in reference to postmortem amyloid-based neuropathology. PET neuroimaging applied to subjects with DS has the potential to (a) track the natural progression of brain pathology, including the earliest stages of amyloid accumulation, and (b) determine whether amyloid PET biomarkers predict the onset of dementia. In addition, the question that is still incompletely understood and relevant to both applications is the ability of amyloid PET to detect Aβ deposits in their earliest form.
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Affiliation(s)
- Eric E Abrahamson
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania.,Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Elizabeth Head
- Department of Pathology and Laboratory Medicine, UC Irvine School of Medicine, Orange, California
| | - Ira T Lott
- Department of Neurology, UC Irvine School of Medicine, Orange, California
| | - Benjamin L Handen
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
| | - Bradley T Christian
- Departments of Medical Physics and Psychiatry, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin
| | - William E Klunk
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Milos D Ikonomovic
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania.,Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
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Chen XQ, Mobley WC. Alzheimer Disease Pathogenesis: Insights From Molecular and Cellular Biology Studies of Oligomeric Aβ and Tau Species. Front Neurosci 2019; 13:659. [PMID: 31293377 PMCID: PMC6598402 DOI: 10.3389/fnins.2019.00659] [Citation(s) in RCA: 176] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/07/2019] [Indexed: 01/08/2023] Open
Abstract
Alzheimer disease (AD) represents an oncoming epidemic that without an effective treatment promises to exact extraordinary human and financial burdens. Studies of pathogenesis are essential for defining targets for discovering disease-modifying treatments. Past studies of AD neuropathology provided valuable, albeit limited, insights. Nevertheless, building on these findings, recent studies have provided an increasingly rich harvest of genetic, molecular and cellular data that are creating unprecedented opportunities to both understand and treat AD. Among the most significant are those documenting the presence within the AD brain of toxic oligomeric species of Aβ and tau. Existing data support the view that such species can propagate and spread within neural circuits. To place these findings in context we first review the genetics and neuropathology of AD, including AD in Down syndrome (AD-DS). We detail studies that support the existence of toxic oligomeric species while noting the significant unanswered questions concerning their precise structures, the means by which they spread and undergo amplification and how they induce neuronal dysfunction and degeneration. We conclude by offering a speculative synthesis for how oligomers of Aβ and tau initiate and drive pathogenesis. While 100 years after Alzheimer's first report there is much still to learn about pathogenesis and the discovery of disease-modifying treatments, the application of new concepts and sophisticated new tools are poised to deliver important advances for combatting AD.
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Affiliation(s)
- Xu-Qiao Chen
- Department of Neurosciences, University of California, San Diego, San Diego, CA, United States
| | - William C. Mobley
- Department of Neurosciences, University of California, San Diego, San Diego, CA, United States
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Abstract
Virtually all adults with Down syndrome (DS) show the neuropathological changes of Alzheimer disease (AD) by the age of 40 years. This association is partially due to overexpression of amyloid precursor protein, encoded by APP, as a result of the location of this gene on chromosome 21. Amyloid-β accumulates in the brain across the lifespan of people with DS, which provides a unique opportunity to understand the temporal progression of AD and the epigenetic factors that contribute to the age of dementia onset. This age dependency in the development of AD in DS can inform research into the presentation of AD in the general population, in whom a longitudinal perspective of the disease is not often available. Comparison of the risk profiles, biomarker profiles and genetic profiles of adults with DS with those of individuals with AD in the general population can help to determine common and distinct pathways as well as mechanisms underlying increased risk of dementia. This Review evaluates the similarities and differences between the pathological cascades and genetics underpinning DS and AD with the aim of providing a platform for common exploration of these disorders.
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Affiliation(s)
- Ira T Lott
- Department of Pediatrics and Neurology, School of Medicine, University of California, Irvine, CA, USA.
| | - Elizabeth Head
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
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Percy ME, Lukiw WJ. Is heart disease a risk factor for low dementia test battery scores in older persons with Down syndrome? Exploratory, pilot study, and commentary. INTERNATIONAL JOURNAL OF DEVELOPMENTAL DISABILITIES 2017; 66:22-35. [PMID: 33859818 PMCID: PMC8046177 DOI: 10.1080/20473869.2017.1301023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
OBJECTIVES Certain heart conditions and diseases are common in Down syndrome (DS; trisomy 21), but their role in early onset dementia that is prevalent in older adults with DS has not been evaluated. To address this knowledge gap, we conducted a study of risk factors for low neurocognitive/behavioral scores obtained with a published dementia test battery (DTB). Participants were adults with DS living in New York (N = 29; average age 46 years). We asked three questions. 1. Does having any type of heart disease affect the association between DTB scores and chronological age? 2. Does thyroid status affect the association between heart disease and DTB scores? 3. Are the E4 or E2 alleles of apolipoprotein E (APOE) associated with DTB scores or with heart disease? METHOD The study was retrospective, pilot, and exploratory. It involved analysis of information in a database previously established for the study of aging in DS. Participants had moderate intellectual disability on average. Information for each person included: gender, age, a single DTB score obtained by combining results from individual subscales of the DTB, the presence or absence of heart disease, thyroid status (treated hypothyroidism or normal), and APOE genotype. Trends were visualized by inspection of graphs and contingency tables. Statistical methods used to evaluate associations included Pearson correlation analysis, Fisher's exact tests (2-tailed), and odds ratio analysis. P values were interpreted at the 95% confidence level without Bonferroni correction. P values >.05<.1 were considered trends. RESULTS The negative correlation between DTB scores and age was significant in those with heart disease but not in those without. Heart disease was significantly associated with DTB scores >1 SD below the sample mean; there was a strong association between heart disease and low DTB scores in those with treated hypothyroidism but not in those with normal thyroid status. The APOE genotype was weakly associated with heart disease (E4, predisposing; E2, protective) in males. CONCLUSIONS On the basis of the potentially important findings from the present study, large prospective studies are warranted to confirm and extend the observations. In these, particular heart conditions or diseases and other medical comorbidities in individuals should be documented.
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Affiliation(s)
- Maire E. Percy
- Department of Physiology, University of Toronto, Toronto, Canada
- Department of Obstetrics & Gynaecology, Toronto, Canada
- Surrey Place Centre, Toronto, Canada
| | - Walter J. Lukiw
- LSU Neuroscience Center, New OrleansLA, USA
- Department of Neurology, Louisiana State University Health Sciences Center, New OrleansLA, USA
- Department of Ophthalmology, Louisiana State University Health Sciences Center, New OrleansLA, USA
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Castro P, Zaman S, Holland A. Alzheimer's disease in people with Down's syndrome: the prospects for and the challenges of developing preventative treatments. J Neurol 2017; 264:804-813. [PMID: 27778163 PMCID: PMC5374178 DOI: 10.1007/s00415-016-8308-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/06/2016] [Accepted: 10/07/2016] [Indexed: 12/31/2022]
Abstract
People with Down's syndrome (DS) are at high risk for developing Alzheimer's disease (AD) at a relatively young age. This increased risk is not observed in people with intellectual disabilities for reasons other than DS and for this reason it is unlikely to be due to non-specific effects of having a neurodevelopmental disorder but, instead, a direct consequence of the genetics of DS (trisomy 21). Given the location of the amyloid precursor protein (APP) gene on chromosome 21, the amyloid cascade hypothesis is the dominant theory accounting for this risk, with other genetic and environmental factors modifying the age of onset and the course of the disease. Several potential therapies targeting the amyloid pathway and aiming to modify the course of AD are currently being investigated, which may also be useful for treating AD in DS. However, given that the neuropathology associated with AD starts many years before dementia manifests, any preventative treatment must start well before the onset of symptoms. To enable trials of such interventions, plasma, CSF, brain, and retinal biomarkers are being studied as proxy early diagnostic and outcome measures for AD. In this systematic review, we consider the prospects for the development of potential preventative treatments of AD in the DS population and their evaluation.
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Affiliation(s)
- Paula Castro
- Cambridge Intellectual and Developmental Disabilities Research Group, Department of Psychiatry, University of Cambridge, 18b Trumpington Road, Cambridge, CB2 8AH, UK
| | - Shahid Zaman
- Cambridge Intellectual and Developmental Disabilities Research Group, Department of Psychiatry, University of Cambridge, 18b Trumpington Road, Cambridge, CB2 8AH, UK
| | - Anthony Holland
- Cambridge Intellectual and Developmental Disabilities Research Group, Department of Psychiatry, University of Cambridge, 18b Trumpington Road, Cambridge, CB2 8AH, UK.
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Benromano T, Pick CG, Granovsky Y, Defrin R. Increased Evoked Potentials and Behavioral Indices in Response to Pain Among Individuals with Intellectual Disability. PAIN MEDICINE 2017; 18:1715-1730. [DOI: 10.1093/pm/pnw349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Xing Z, Li Y, Pao A, Bennett AS, Tycko B, Mobley WC, Yu YE. Mouse-based genetic modeling and analysis of Down syndrome. Br Med Bull 2016; 120:111-122. [PMID: 27789459 PMCID: PMC5146682 DOI: 10.1093/bmb/ldw040] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 09/07/2016] [Accepted: 10/03/2016] [Indexed: 11/12/2022]
Abstract
INTRODUCTION Down syndrome (DS), caused by human trisomy 21 (Ts21), can be considered as a prototypical model for understanding the effects of chromosomal aneuploidies in other diseases. Human chromosome 21 (Hsa21) is syntenically conserved with three regions in the mouse genome. SOURCES OF DATA A review of recent advances in genetic modeling and analysis of DS. Using Cre/loxP-mediated chromosome engineering, a substantial number of new mouse models of DS have recently been generated, which facilitates better understanding of disease mechanisms in DS. AREAS OF AGREEMENT Based on evolutionary conservation, Ts21 can be modeled by engineered triplication of Hsa21 syntenic regions in mice. The validity of the models is supported by the exhibition of DS-related phenotypes. AREAS OF CONTROVERSY Although substantial progress has been made, it remains a challenge to unravel the relative importance of specific candidate genes and molecular mechanisms underlying the various clinical phenotypes. GROWING POINTS Further understanding of mechanisms based on data from mouse models, in parallel with human studies, may lead to novel therapies for clinical manifestations of Ts21 and insights to the roles of aneuploidies in other developmental disorders and cancers.
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Affiliation(s)
- Zhuo Xing
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program and Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Yichen Li
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program and Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Annie Pao
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program and Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Abigail S Bennett
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program and Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Benjamin Tycko
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain and Institute for Cancer Genetics, Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - William C Mobley
- Department of Neurosciences, School of Medicine, University of California at San Diego, 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 .,Cellular and Molecular Biology Program, Roswell Park Division of Graduate School, Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY 14263, USA
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Ballard C, Mobley W, Hardy J, Williams G, Corbett A. Dementia in Down's syndrome. Lancet Neurol 2016; 15:622-36. [PMID: 27302127 DOI: 10.1016/s1474-4422(16)00063-6] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 01/22/2016] [Accepted: 02/08/2016] [Indexed: 12/14/2022]
Abstract
Down's syndrome is the most common genetic cause of learning difficulties, and individuals with this condition represent the largest group of people with dementia under the age of 50 years. Genetic drivers result in a high frequency of Alzheimer's pathology in these individuals, evident from neuroimaging, biomarker, and neuropathological findings, and a high incidence of cognitive decline and dementia. However, cognitive assessment is challenging, and diagnostic methods have not been fully validated for use in these patients; hence, early diagnosis remains difficult. Evidence regarding the benefits of cholinesterase inhibitors and other therapeutic options to treat or delay progressive cognitive decline or dementia is very scarce. Despite close similarities with late-onset Alzheimer's disease, individuals with Down's syndrome respond differently to treatment, and a targeted approach to drug development is thus necessary. Genetic and preclinical studies offer opportunities for treatment development, and potential therapies have been identified using these approaches.
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Affiliation(s)
- Clive Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK.
| | - William Mobley
- Center for Neural Circuits and Behavior, School of Medicine, University of California San Diego, San Diego, CA, USA
| | - John Hardy
- Department of Molecular Neuroscience, University College London, London, UK
| | - Gareth Williams
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Anne Corbett
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
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Martin SB, Dowling ALS, Lianekhammy J, Lott IT, Doran E, Murphy MP, Beckett TL, Schmitt FA, Head E. Synaptophysin and synaptojanin-1 in Down syndrome are differentially affected by Alzheimer's disease. J Alzheimers Dis 2015; 42:767-75. [PMID: 24927707 DOI: 10.3233/jad-140795] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adults with Down syndrome (DS) develop Alzheimer's disease (AD) neuropathology by 40 years of age. Synaptophysin (SYN) consistently declines with age and is further reduced with sporadic AD. Thus, we hypothesized that SYN would be reduced in DS with AD. The gene for synaptojanin-1 (SYNJ1), involved in synaptic vesicle recycling, is on chromosome 21. We measured SYN and SYNJ1 in an autopsy series of 39 cases with DS and 28 without DS, along with 7 sporadic AD cases. SYN was significantly lower in DSAD compared with DS alone and similar to sporadic AD. Reduced SYN is associated with AD neuropathology and with Aβ levels in DS, as is seen in sporadic AD. SYNJ1 was significantly higher in DS and correlated with several measures of Aβ. SYNJ1 was higher in DSAD and significantly higher than SYNJ1 in sporadic AD. Although significantly higher in DS, SYNJ1 is further increased with AD neuropathology suggesting interesting differences in a synapse-associated protein that is overexpressed in trisomy 21.
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Affiliation(s)
- Sarah B Martin
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Amy L S Dowling
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Joann Lianekhammy
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Ira T Lott
- Department of Physiology, University of Kentucky, Lexington, KY, USA Department of Pediatrics and Neurology, School of Medicine, University of California-Irvine (UCI), Orange, CA, USA
| | - Eric Doran
- Department of Physiology, University of Kentucky, Lexington, KY, USA Department of Pediatrics and Neurology, School of Medicine, University of California-Irvine (UCI), Orange, CA, USA
| | - M Paul Murphy
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA UK Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
| | - Tina L Beckett
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Elizabeth Head
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY, USA
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Mok KY, Jones EL, Hanney M, Harold D, Sims R, Williams J, Ballard C, Hardy J. Polymorphisms in BACE2 may affect the age of onset Alzheimer's dementia in Down syndrome. Neurobiol Aging 2013; 35:1513.e1-5. [PMID: 24462566 PMCID: PMC3969241 DOI: 10.1016/j.neurobiolaging.2013.12.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/03/2013] [Accepted: 12/19/2013] [Indexed: 02/01/2023]
Abstract
It is known that Alzheimer's disease (AD) presents at an early age in people with Down syndrome (DS). The trisomy 21 in DS provides an opportunity to study the effect of duplicated genes in AD. APP and BACE2 are 2 genes located in chromosome 21 and related to AD. We looked into our cohort of 67 DS cases with dementia for the effect of BACE2 variants in age of onset of dementia. Of the 83 single-nucleotide polymorphisms (SNPs), 6 were associated with age of onset and another 8 SNPs were borderline associated. Our finding also replicated a previous study showing association of rs2252576 with AD.
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Affiliation(s)
- Kin Y Mok
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK; Reta Lila Weston Institute, UCL Institute of Neurology, London, UK.
| | - Emma L Jones
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | | | - Denise Harold
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Henry Wellcome Building for Biomedical Research, Heath Park, Cardiff, UK
| | - Rebecca Sims
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Henry Wellcome Building for Biomedical Research, Heath Park, Cardiff, UK
| | - Julie Williams
- MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, Henry Wellcome Building for Biomedical Research, Heath Park, Cardiff, UK
| | - Clive Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - John Hardy
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK; Reta Lila Weston Institute, UCL Institute of Neurology, London, UK; The London Down Syndrome (LonDownS) Consortium, UK
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12
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de Knegt N, Scherder E. Pain in adults with intellectual disabilities. Pain 2010; 152:971-974. [PMID: 21112699 DOI: 10.1016/j.pain.2010.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 10/27/2010] [Accepted: 11/01/2010] [Indexed: 10/18/2022]
Affiliation(s)
- Nanda de Knegt
- Department of Clinical Neuropsychology, VU University, Amsterdam, Netherlands
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Abstract
Down syndrome is a complex condition that results from having a third copy of human chromosome 21. People with the syndrome experience problems with learning and memory that affect many aspects of their lives. In this issue of Science Translational Medicine, Salehi et al. report on successful drug treatment of learning deficits in an animal model of Down syndrome. This study highlights the function of the norepinephrine-ergic system in Down syndrome and suggests possible treatment options for people with Down syndrome.
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Affiliation(s)
- Frances K Wiseman
- Department of Neurodegenerative Disease, University College London, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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14
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Delabar JM. [New perspectives on molecular and genic therapies in Down syndrome]. Med Sci (Paris) 2010; 26:371-6. [PMID: 20412741 DOI: 10.1051/medsci/2010264371] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Trisomy 21 was first described as a syndrome in the middle of the nineteenth century and associated to a chromosomic anomaly one hundred years later: the most salient feature of this syndrome is a mental retardation of variable intensity. Molecular mapping and DNA sequencing have allowed identifying the gene content of chromosome 21. Molecular quantitative analyses indicated that trisomy is inducing an overexpression for a large part of the triplicated genes and deregulates also pathways involving non HSA21 genes. Together with the physiological description of murine models overexpressing orthologous genes, these data have allowed to elaborate hypotheses on the cause of cognitive impairment. From these hypotheses and using murine models it is now possible to assess the efficiency of various therapeutic strategies. This paper reviews these new perspectives starting from the strategies targeting the level of HSA21 RNAs or HSA21 proteins; then it describes methods targeting activities either of proteins involved in cell cycle pathways or of proteins controlling the synaptic plasticity. It is promising that strategies targeting specific genes or specific pathways are already giving positive results.
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Affiliation(s)
- Jean Maurice Delabar
- Unité de biologie fonctionnelle et adaptative (BFA), EAC CNRS 4413, Université Paris Diderot, Marie-Andrée Lagroua-Weill-Hallé, bâtiment Lamarck, 75205 Paris, France.
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15
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Visu-Petra L, Benga O, Tincaş I, Miclea M. Visual-spatial processing in children and adolescents with Down's syndrome: a computerized assessment of memory skills. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2007; 51:942-952. [PMID: 17991001 DOI: 10.1111/j.1365-2788.2007.01002.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND Several studies have identified better visual-spatial than verbal memory skills in children with Down's syndrome (DS); however, research in both typical development and DS points to a relative dissociation between visual and spatial memory processing, questioning the notion of a unitary visual-spatial memory construct. The insufficient and often contradictory results regarding the visual-spatial memory domain probably reflect the heterogeneity of memory tests employed by these studies and the different memory systems that they evaluate. METHOD We administered five visual-spatial memory tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) to 25 children with DS and to 25 controls matched for mental age (MA) and basic psychomotor speed and accuracy. The memory tasks measure spatial span, visual and spatial recognition, paired associates learning and self-ordered search abilities. RESULTS The results confirm the relative sparing of the spatial short-term memory (STM) capacity in children with DS; however, as memory load increases, in recognition tasks, or when visual and spatial demands are combined, their performance is impaired compared with MA controls. The same impairment is generated by additional executive demands in the self-ordered search task, although search strategy is similar to the one presented by MA controls. CONCLUSIONS We did not find support for a visual vs. spatial dissociation in recognition memory. Performance impairment in the visual-spatial domain parallels the increase in working memory (WM) load or in the executive demands of the task. Possible neurobiological implications of the observed performance on the CANTAB tasks are also considered.
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Affiliation(s)
- L Visu-Petra
- Department of Psychology, Babeş-Bolyai University, Cluj-Napoca, Romania.
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Ball SL, Holland AJ, Hon J, Huppert FA, Treppner P, Watson PC. Personality and behaviour changes mark the early stages of Alzheimer's disease in adults with Down's syndrome: findings from a prospective population-based study. Int J Geriatr Psychiatry 2006; 21:661-73. [PMID: 16802281 DOI: 10.1002/gps.1545] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Research based on retrospective reports by carers suggests that the presentation of dementia in people with Down's syndrome may differ from that typical of Alzheimer's disease (AD) in the general population, with the earliest changes tending to be in personality or behaviour rather than in memory. This is the first long-term prospective study to test the hypothesis that such changes, which are more typical of dementia of frontal type (DFT) in the general population, mark the preclinical stage of AD in DS. METHODS A previously identified population sample of older people with DS, first assessed in 1994 and followed-up 18 months later, were reassessed after a further 5 years. This study focuses on the 55 individuals who took part in the second follow-up. Dementia diagnosis was made using the modified CAMDEX informant interview and neuropsychological assessment was undertaken using the CAMCOG. Progression in clinical presentation was examined and degree of cognitive decline over time (on the CAMCOG and derived measures of executive function (EF) and memory) was compared across groups based on diagnosis and age: AD, DFT, personality/behaviour changes insufficient for a diagnosis of DFT (PBC), no diagnosis <50 years and no diagnosis 50 + years. RESULTS Progression was observed from early changes in personality and behaviour to an increase in characteristics associated with frontal lobe dysfunction and/or a deterioration in memory, prior to the development of full AD. Individuals who met criteria for DFT were significantly more likely to progress to a diagnosis of AD over the following 5 years than those who did not and those with PBC were significantly more likely to progress to a more severe diagnosis (DFT or AD) than those without. In the 5 years prior to diagnosis, participants with PBC and DFT had shown a degree of global cognitive decline intermediate between those with no dementia and those with AD. Both these groups had shown a significant decline in EF but not in memory, while the AD group had shown significant decline on both measures, with a significantly greater degree of decline in memory. Older participants without informant reported changes showed a more generalised pattern of decline. CONCLUSIONS These findings confirm that the early presentation of AD in DS is characterized by prominent personality and behaviour changes, associated with executive dysfunction, providing support for the notion that the functions of the frontal lobes may be compromised early in the course of the disease in this population. This has important implications for the diagnosis, treatment and management of dementia in people with DS.
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Affiliation(s)
- Sarah L Ball
- Section of Developmental Psychiatry, Department of Psychiatry, University of Cambridge, UK.
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17
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Zana M, Szécsényi A, Czibula A, Bjelik A, Juhász A, Rimanóczy A, Szabó K, Vetró A, Szucs P, Várkonyi A, Pákáski M, Boda K, Raskó I, Janka Z, Kálmán J. Age-dependent oxidative stress-induced DNA damage in Down’s lymphocytes. Biochem Biophys Res Commun 2006; 345:726-33. [PMID: 16696946 DOI: 10.1016/j.bbrc.2006.04.167] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 04/28/2006] [Indexed: 11/27/2022]
Abstract
The aim of the present study was to investigate the oxidative status of lymphocytes from children (n=7) and adults (n=18) with Down's syndrome (DS). The basal oxidative condition, the vulnerability to in vitro hydrogen peroxide exposure, and the repair capacity were measured by means of the damage-specific alkaline comet assay. Significantly and age-independently elevated numbers of single strand breaks and oxidized bases (pyrimidines and purines) were found in the nuclear DNA of the lymphocytes in the DS group in the basal condition. These results may support the role of an increased level of endogenous oxidative stress in DS and are similar to those previously demonstrated in Alzheimer's disease. In the in vitro oxidative stress-induced state, a markedly higher extent of DNA damage was observed in DS children as compared with age- and gender-matched healthy controls, suggesting that young trisomic lymphocytes are more sensitive to oxidative stress than normal ones. However, the repair ability itself was not found to be deteriorated in either DS children or DS adults.
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Affiliation(s)
- Marianna Zana
- Department of Psychiatry, Alzheimer's Disease Research Center, Faculty of Medicine, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis St., Szeged, H-6725, Hungary.
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18
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Abstract
Down's syndrome is a genetic disorder that can lead to mental retardation of varying degrees. How this chromosomal abnormality causes mental retardation remains an open question. This paper reviews what is currently known about the neural and cognitive features of Down's syndrome, noting the growing evidence of disproportionate impairment of specific systems such as the hippocampal formation, the prefrontal cortex and the cerebellum. The development of animal models of these defects offers a way of ultimately connecting the genetic disorder to its cognitive consequences.
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Affiliation(s)
- L Nadel
- Department of Psychology and ARL Neural Systems, Memory and Ageing Division, Univeristy of Arizona, Tuscon, Arizona 85721, USA.
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19
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Seidl R, Cairns N, Lubec G. The brain in Down syndrome. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2002:247-61. [PMID: 11771748 DOI: 10.1007/978-3-7091-6262-0_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Down syndrome (trisomy 21) is a genetic disease with developmental brain abnormalities resulting in early mental retardation and precocious, age dependent Alzheimer-type neurodegeneration. We tried to discuss the role of neurodevelopmental abnormalities in connection with aberrant expression of genes on chromosome 21 including amyloid precursor protein (APP), CuZn superoxide dismutase (SOD1) and glial-derived S100 beta protein for neurodegeneration in DS. In this model, alterations in developmental pathways due to aberrant gene expression can impair cellular homeostasis and predispose to neurodegeneration of certain brain regions and types of nerve cells, involving cholinergic, serotonergic and catecholaminergic transmission, by shifting balance toward a pro-apoptotic state.
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Affiliation(s)
- R Seidl
- Department of Pediatrics, University of Vienna, Austria
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20
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Seidl R, Kaehler ST, Prast H, Singewald N, Cairns N, Gratzer M, Lubec G. Serotonin (5-HT) in brains of adult patients with Down syndrome. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2000; 57:221-32. [PMID: 10666678 DOI: 10.1007/978-3-7091-6380-1_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Down syndrome (DS) is a genetic disease with developmental brain abnormalities resulting in early mental retardation and precocious, age dependent Alzheimer-type neurodegeneration. Furthermore, non-cognitive symptoms may be a cardinal feature of functional decline in adults with DS. As the serotonergic system plays a well known role in integrating emotion, cognition and motor function, serotonin (5-HT) and its main metabolite, 5-hydroxyindol-3-acetic acid (5-HIAA) were investigated in post-mortem tissue samples from temporal cortex, thalamus, caudate nucleus, occipital cortex and cerebellum of adult patients with DS, Alzheimer's disease (AD) and controls by use of high performance liquid chromatography (HPLC). In DS, 5-HT was found to be age-dependent significantly decreased in caudate nucleus by 60% (DS: mean +/- SD 58.6 +/- 28.2 vs. Co: 151.7 +/- 58.4 pmol/g wet tissue weight) and in temporal cortex by about 40% (196.8 +/- 108.5 vs. 352.5 +/- 183.0 pmol/g), insignificantly reduced in the thalamus, comparable to controls in cerebellum, whereas occipital cortex showed increased levels (204.5 +/- 138.0 vs. 82.1 +/- 39.1 pmol/g). In all regions of DS samples, alterations of 5-HT were paralleled by levels of 5-HIAA, reaching significance compared to controls in thalamus and caudate nucleus. In AD, 5-HT was insignificantly reduced in temporal cortex and thalamus, unchanged in cerebellum, but significantly elevated in caudate nucleus (414.3 +/- 273.7 vs. 151.7 +/- 58.4 pmol/g) and occipital cortex (146.5 +/- 76.1 vs. 82.1 +/- 39.1 pmol/g). The results of this study confirm and extend putatively specific 5-HT dysfunction in basal ganglia (caudate nucleus) of adult DS, which is not present in AD. These findings may be relevant to the pathogenesis and treatment of cognitive and non-cognitive (behavioral) features in DS.
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Affiliation(s)
- R Seidl
- Department of Pediatrics, University of Vienna, Austria
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21
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Brugge K, Nichols S, Saitoh T, Trauner D. Correlations of glutathione peroxidase activity with memory impairment in adults with Down syndrome. Biol Psychiatry 1999; 46:1682-9. [PMID: 10624550 DOI: 10.1016/s0006-3223(99)00026-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Down syndrome (DS) is a genetic disorder (trisomy 21 in 96% of cases), associated with an excess of a key enzyme involved with free radical metabolism (FRM), superoxide dismutase-1 (SOD-1), that is encoded by a gene on chromosome 21. Consequently, SOD-1 activity is elevated in DS, which also occurs in conditions of oxidative stress, and is associated with a compensatory increase in glutathione peroxidase activity (GSHPx). METHODS This study examined the relationship of memory function with erythrocyte SOD-1, GSHPx and catalase (CAT) activity in 22-51 year old adults with DS. RESULTS Mean erythrocyte SOD-1 (p < .02) and GSHPx (p < .01), but not CAT (p = .76), activities were significantly greater in the DS group than the controls. In the DS group, erythrocyte GSHPx, but not SOD-1 or CAT activities, was significantly correlated with memory function (r = .625, p < .025, df = 13 for savings score, r = .631, p < .01, df = 14 for intrusion errors) but not with intelligence quotients. CONCLUSIONS These observations suggest a possible relationship between altered FRM with memory deficits among adults with DS within the age-range in that an age-related increase in the prevalence for Alzheimer's neuropathology is known to be robust before reaching a plateau of 100%.
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Affiliation(s)
- K Brugge
- Department of Neuroscience, University of California, San Diego, USA
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22
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Royston MC, McKenzie JE, Gentleman SM, Sheng JG, Mann DM, Griffin WS, Mrak RE. Overexpression of s100beta in Down's syndrome: correlation with patient age and with beta-amyloid deposition. Neuropathol Appl Neurobiol 1999; 25:387-93. [PMID: 10564528 DOI: 10.1046/j.1365-2990.1999.00196.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
S100beta is an astrocyte-derived uritotrophic' cytokine which has been implicated in the pathogenesis of Alzheimer's disease. S100beta overexpression by plaque-associated astrocytes correlates with growth of abnormal (strophic') neurites in beta-amyloid plaques, one of the major neuropathological hallmarks of Alzheimer's disease. As the characteristic neuropathological changes of Alzheimer's disease are virtually universal in middle-aged Down's syndrome patients, studies of Down's syndrome patients provide a unique opportunity to investigate the pathophysiological processes underlying the development of Alzheimer-type neuropathological changes. Computerized morphometric analysis was used to quantify astrocyte activation and astrocytic expression of S100beta, and to correlate these with beta-amyloid deposition, in a clinically well-characterized cohort of Down's syndrome subjects, aged 13-65 years. There were significant positive correlations between S100beta expression and patient age, and between S100beta expression and cerebral cortical beta-amyloid deposition. Moreover, the numbers of activated (enlarged) astrocytes overexpressing S100beta showed a significant correlation with the numeric density of beta-amyloid plaques, from the youngest to the oldest ages and within age ranges where pathology is most florid, while no such relationship was found between the numbers of small, non-activated S100beta-immunoreactive cells and numerical density of beta-amyloid plaques. These correlations, together with established functions of S100beta, are consistent with the idea that S100beta overexpression promotes beta-amyloid plaque formation and progression in Down's syndrome.
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Affiliation(s)
- M C Royston
- Department of Old Age Psychiatry, Park House, Hinchingbrooke Health Care NHS Trust, Cambridge, UK
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23
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Royston MC, Mann D, Pickering-Brown S, Owen F, Perry R, Ragbavan R, Khin-Nu C, Tyner S, Day K, Crook R, Hardy J, Roberts GW. ApoE2 allele, Down's syndrome, and dementia. Ann N Y Acad Sci 1996; 777:255-9. [PMID: 8624094 DOI: 10.1111/j.1749-6632.1996.tb34428.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
All individuals with Down's syndrome (trisomy 21-DS) develop the pathogenic hallmarks of Alzheimer's disease in old age (+40 years). The extent of pathology is variable, but it has been shown that the amount of beta-amyloid pathology is variable and related to age and the degree of dementia. Thus, in DS, growing old is associated with a progressive pathological process which results in cognitive decline. However, neuropsychological studies of older DS subjects have identified a clinical dementia in only a proportion of cases. These contradictory observations could be reconciled if some factor existed which modulated the rate and amount of beta-amyloid pathology. Recent studies demonstrate an association between the apolipoprotein E4 (ApoE4) allele and the earlier age of onset in both sporadic and familial AD. Increased amounts of beta-amyloid pathology can also be related to the E4 allele. However, at present there are no data documenting the effects of ApoE genotype on the expression or degree of clinical symptoms of the disease. We have examined the ApoE genotype in a cohort of clinically evaluated elderly patients with DS in order to examine the effects of ApoE genotype on the clinical symptoms of dementia. We report here that, despite the presence of an active disease process, the ApoE E2 allele is associated with longevity and preservation of cognitive functioning.
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Affiliation(s)
- M C Royston
- Department of Psychiatry, Charing Cross and Westminster Medical School, London, United Kingdom
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24
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Benzing WC, Mufson EJ, Armstrong DM. Immunocytochemical distribution of peptidergic and cholinergic fibers in the human amygdala: their depletion in Alzheimer's disease and morphologic alteration in non-demented elderly with numerous senile plaques. Brain Res 1993; 625:125-38. [PMID: 8242391 DOI: 10.1016/0006-8993(93)90145-d] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
As part of an ongoing investigation devoted to understanding the pathogenesis of senile plaques, we employed histochemical and immunocytochemical techniques to examine the distribution and cytologic features of acetylcholinesterase (AChE), choline acetyltransferase (ChAT), somatostatin (SOM), neurotensin (NT) and substance P (SP) containing fibers and neurons within the amygdala of: (1) patients with Alzheimer's disease (AD); (2) age-matched non-demented controls (NC); and (3) a group of non-demented cases, who upon postmortem neuropathologic examination exhibited sufficient numbers of senile plaques to be classified as AD. This latter group was referred to as high plaque non-demented (HPND). For every case, the distribution of immunolabeled fibers and neurons were determined for each transmitter throughout the various subnuclei of the amygdala. In addition, in the AD and HPND cases the topographic distribution of senile plaques was determined throughout the amygdala using thioflavine-S and Bielschowsky silver methods. In the amygdala, the distribution and density of senile plaques were not bound by conventional cytoarchitectural groupings but rather were most dense in the ventromedial regions of the amygdala with decreasing density in dorsal and lateral directions. Importantly, the density and distribution of senile plaques failed to correlate with the normal topography and/or density of the various peptidergic or cholinergic fibers within the amygdala. The finding that plaques do not correlate with the topographic distribution of any specific transmitter system suggests that plaques likely do not arise from the degeneration of a single neurotransmitter system (i.e., the cholinergic system). However, the finding that in AD a transmitter is most markedly depleted in regions of greatest plaque density, suggests certain constituents of the plaque (e.g. beta-amyloid) may be contributing to the degeneration of local fibers. The extent to which a transmitter was depleted in AD patients varied considerably among those four investigated with the cholinergic and NT systems displaying the most dramatic reductions, followed by SP and SOM. Despite these differential reductions in fiber density, all four neurotransmitters were found localized within dystrophic neurites and in most instances these dystrophic neurites were associated with thioflavine-positive senile plaques. In contrast to the AD cases, the HPND cases were characterized by no significant reductions in immunolabeled fibers, although immunostained dystrophic neurites were very prevalent in the HPND cases. These data suggest that dystrophic neurites occur very early in the disease process and likely precede the actual loss of fibers when or if it occurs.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- W C Benzing
- Department of Neurological Sciences, Rush Presb., St. Luke Medical Center, Chicago, IL 60612
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25
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Benzing WC, Brady DR, Mufson EJ, Armstrong DM. Evidence that transmitter-containing dystrophic neurites precede those containing paired helical filaments within senile plaques in the entorhinal cortex of nondemented elderly and Alzheimer's disease patients. Brain Res 1993; 619:55-68. [PMID: 7690677 DOI: 10.1016/0006-8993(93)91595-j] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Within the amygdala of elderly subjects and patients with Alzheimer's disease (AD), we recently found evidence suggesting amyloid beta-protein (A beta P) deposition occurs before the appearance of dystrophic neurites. Moreover, these data suggested dystrophic neurites initially lack evidence of cytoskeletal pathology although with time and further maturation, the dystrophic neurites display an altered cytoskeleton as evidenced by their immunoreactivity to Alz-50 and paired-helical filaments (PHF). These findings are of particular relevance to our understanding of the sequence of pathologic events in AD and thus it has become important to determine whether these events are unique to the amygdala or are representative of a more general pattern which can be found throughout the brain. Using a battery of antibodies to markers that are characteristic of AD pathology (i.e., A beta P, PHF, and Alz-50), three peptidergic neurotransmitters (neurotensin, somatostatin, and substance P), and one neurotransmitter biosynthetic enzyme (choline acetyltransferase), we examined the entorhinal cortex (EC) of three groups of subjects (AD, normal elderly, and a group of nondemented elderly with numerous senile plaques). The EC was studied, in part, because it is well recognized as a brain region displaying severe and, most importantly, early pathologic changes. Like the amygdala, we found evidence that amyloid beta-protein immunoreactive (A beta P-IR) and thioflavine-S-positive senile plaques occur within the EC prior to the appearance of transmitter-, Alz-50-, or PHF-immunoreactive dystrophic neurites. We also observed transmitter-immunoreactive dystrophic neurites in the absence of Alz-50 or PHF-immunolabeled dystrophic neurites and transmitter- and Alz-50-IR dystrophic neurites in the absence of those containing PHF. Collectively, these findings were similar to those seen within the amygdala and thus reinforced the concept that A beta P deposition is the primary event in plaque pathology, and this deposition is subsequently followed by the appearance of dystrophic neurites which retain their transmitter phenotype yet lack an altered cytoskeleton. With time, these dystrophic neurites develop cytoskeletal alterations and become immunoreactive to Alz-50 and PHF.
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Affiliation(s)
- W C Benzing
- FIDIA-Georgetown Institute for the Neurosciences, Georgetown University, Washington, DC 20007
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26
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Benzing WC, Ikonomovic MD, Brady DR, Mufson EJ, Armstrong DM. Evidence that transmitter-containing dystrophic neurites precede paired helical filament and Alz-50 formation within senile plaques in the amygdala of nondemented elderly and patients with Alzheimer's disease. J Comp Neurol 1993; 334:176-91. [PMID: 7690048 DOI: 10.1002/cne.903340203] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Immunocytochemical techniques were employed to examine the temporal ordering whereby amyloid beta-protein (A beta P) and neuronal elements collectively come together to form senile plaques in Alzheimer's disease (AD). Specifically, we addressed three questions: (1) whether A beta P deposition precedes or follows neuritic changes; (2) whether paired helical filament (PHF) formation is an early or late event in the genesis of the dystrophic neurites which participate in plaque formation; and (3) whether the density of senile plaques displays any relationship with the prevalence of PHF or Alz-50 containing neurons. To address these questions we studied the amygdala from a group of patients with AD, a group of nondemented age-matched individuals exhibiting a sufficient number of senile plaques to be classified by neuropathological criteria as AD, and a group of age-matched controls without AD pathology. Amyloid-bearing plaques were demonstrated by A beta P immunolabeling and thioflavine-S staining. Neuritic changes in the form of dystrophic neurites were observed with the aid of antibodies against PHF, Alz-50, as well as antibodies against several neuropeptides (i.e., substance P, somatostatin, and neurotensin) and the acetylcholine biosynthetic enzyme, choline acetyltransferase. By using a graded range of pathologic changes both within and across the patient population to provide us with a means of evaluating plaque deposition from its earliest to most advanced stages of development, we observed in patients and/or regions of the amygdala displaying a mild degree of pathologic change A beta P deposition in the absence of any neuritic changes. With increasing density of A beta P, however, we began to observe dystrophic neurites within plaques. In regions of relatively few plaques, the dystrophic neurites were immunolabeled only with antibodies against the various neurotransmitters and they lacked evidence of cytoskeletal pathology (i.e., Alz-50 or PHF). Only as the density of A beta P increased further within a region, were dystrophic neurites observed that exhibited Alz-50 or PHF. In no instance did we observe a relationship between the density of A beta P deposition and the density of Alz-50 or PHF-immunoreactive neurons. Collectively, our data suggest that the deposition of A beta P is an early pathologic event in senile plaque formation. Thereafter, swollen neurites can be seen in the vicinity of A beta P. This early neuritic response, which can first be visualized by immunolabeling for one or another transmitter substance, is followed by alterations in the cytoskeleton as recognized initially by antibodies to Alz-50 and subsequently by the presence of PHF.
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Affiliation(s)
- W C Benzing
- FIDIA-Georgetown Institute for the Neurosciences, Georgetown University, Washington, D.C. 20007
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27
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Spargo E, Luthert PJ, Janota I, Lantos PL. Beta A4 deposition in the temporal cortex of adults with Down's syndrome. J Neurol Sci 1992; 111:26-32. [PMID: 1402995 DOI: 10.1016/0022-510x(92)90108-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The deposition of beta A4 has been quantified in the temporal cortex of 9 adults (4 male, 5 female) with Down's syndrome (DS), mean age (+/- SD) 54.7 +/- 8.8 years (range 41-67 years) at the time of death. Immunostaining with antibodies, raised to different portions of the beta A4 protein, showed a greater number of deposits than were seen with traditional silver impregnation or amyloid stains. Antibody to beta A4(1-10) identified fewer plaques than the antibody to beta A4(12-28), the mean ratio of beta A4(1-10)/beta A4(12-28) plaques being 0.30 +/- 0.10 (mean +/- SD). Morphologically, 'diffuse' and 'neuritic' deposits could be distinguished but there was no significant difference in the beta A4(1-10)/beta A4(12-28) ratio according to plaque morphology, nor did the ratio change with age. Quantitatively, the beta A4(12-28) load in the temporal cortex of DS patients was high, occupying some 14% of the field area, and it was not related to the age of the subject over the range studied. Similarly, the total beta A4(12-28) plaque count was high and not age-related. The proportion of morphological plaque types visualised by the Glees and Marsland silver impregnation and by beta A4(12-28) immunostaining were compared. In both techniques 'diffuse' plaques (D) were predominant in the younger subjects and the proportion of 'neuritic' plaques (N) increased with age. The relative proportions of cored plaques (Cp) and plaque cores (C) did not change significantly with age.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Spargo
- Department of Neuropathology, Institute of Psychiatry, London, UK
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28
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O'Callaghan E, Buckley P, Redmond O, Stack J, Ennis JT, Larkin C, Waddington JL. Abnormalities of Cerebral Structure in Schizophrenia on Magnetic Resonance Imaging: Interpretation in Relation to the Neurodevelopmental Hypothesis. J R Soc Med 1992; 85:227-31. [PMID: 1433067 PMCID: PMC1294731 DOI: 10.1177/014107689208500416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The nature of abnormalities of cerebral structure evident in schizophrenia on magnetic resonance imaging is considered in relation to the neurodevelopmental hypothesis of the disorder. While schizophrenic patients showed increased ventricular volume, the extent of increase with age was comparable with that evident in controls and was unrelated to duration of illness. Conversely, cortical atrophy was evident only in patients, and this increased markedly with age and duration of illness. Such findings could be suggestive of two distinct pathophysiological processes in schizophrenia, but a schema for their reconciliation with the neurodevelopmental hypothesis is elaborated.
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Affiliation(s)
- E O'Callaghan
- Cluain Mhuire Family Centre, Blackrock, Co Dublin, Ireland
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29
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Mann DM, Purkiss MS, Bonshek RE, Jones D, Brown AM, Stoddart RW. Lectin histochemistry of cerebral microvessels in ageing, Alzheimer's disease and Down's syndrome. Neurobiol Aging 1992; 13:137-43. [PMID: 1531863 DOI: 10.1016/0197-4580(92)90021-o] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A panel of 14 lectins was used to investigate the expression of saccharides by cerebral microvessels (MBV) in ageing, Alzheimer's disease (AD) and Down's syndrome (DS). Broad increases in lectin binding with age may reflect changes in amount and diversity of glycoproteins due to the thickening of the basement membrane (BM) common in older persons. In AD, and in persons over 50 years of age with DS, binding of e-PHA, 1-PHA and PAA was increased beyond that of age alone, as was that of UEA-I and BSA-1B4 in AD, but not in DS. Persons under 50 years of age with DS showed no changes inappropriate to their age. These specific increases in AD and DS may reflect selective disease-related changes in BM and could indicate an impaired blood-brain barrier (bbb) function or integrity. However, because they occur (in DS) after the deposition of amyloid (A4) protein and onset of neurofibrillary degeneration, it is unlikely they induce plaque and tangle formation. Such changes in MBV could stem from the loss of neurones from locus caeruleus, raphe and nucleus basalis (which are thought to innervate MBV and exert control over blood flow and permeability) that occurs in DS after 50 years of age.
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Affiliation(s)
- D M Mann
- Department of Pathological Sciences University of Manchester, Great Britain
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30
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Waddington JL. The pathobiology of lost human potential: schizophrenia as a neurodevelopmental disorder. Ir J Med Sci 1991; 160:402-6. [PMID: 1726713 DOI: 10.1007/bf02957800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J L Waddington
- Department of Clinical Pharmacology, Royal College of Surgeons, Ireland, Dublin
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31
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Hardy J, Allsop D. Amyloid deposition as the central event in the aetiology of Alzheimer's disease. Trends Pharmacol Sci 1991; 12:383-8. [PMID: 1763432 DOI: 10.1016/0165-6147(91)90609-v] [Citation(s) in RCA: 1622] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
While there may be many causes of Alzheimer's disease (AD), the same pathological sequence of events, described here by John Hardy and David Allsop, is likely to occur in all cases. The recent discovery of a pathogenic mutation in the beta-amyloid precursor protein (APP) gene on chromosome 21 suggests that APP Mismetabolism and beta-amyloid deposition are the primary events in the disease process. The occurrence of AD in Down syndrome is consistent with this hypothesis. The pathological cascade for the disease process is most likely to be: beta-amyloid deposition----tau phosphorylation and tangle formation----neuronal death. The development of a biochemical understanding of this pathological cascade will facilitate rational design of drugs to intervene in this process.
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Affiliation(s)
- J Hardy
- Department of Biochemistry and Molecular Genetics, St Mary's Hospital Medical School, London, UK
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