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Cell models for Down syndrome-Alzheimer’s disease research. Neuronal Signal 2022; 6:NS20210054. [PMID: 35449591 PMCID: PMC8996251 DOI: 10.1042/ns20210054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/07/2022] [Accepted: 03/21/2022] [Indexed: 11/29/2022] Open
Abstract
Down syndrome (DS) is the most common chromosomal abnormality and leads to intellectual disability, increased risk of cardiac defects, and an altered immune response. Individuals with DS have an extra full or partial copy of chromosome 21 (trisomy 21) and are more likely to develop early-onset Alzheimer’s disease (AD) than the general population. Changes in expression of human chromosome 21 (Hsa21)-encoded genes, such as amyloid precursor protein (APP), play an important role in the pathogenesis of AD in DS (DS-AD). However, the mechanisms of DS-AD remain poorly understood. To date, several mouse models with an extra copy of genes syntenic to Hsa21 have been developed to characterise DS-AD-related phenotypes. Nonetheless, due to genetic and physiological differences between mouse and human, mouse models cannot faithfully recapitulate all features of DS-AD. Cells differentiated from human-induced pluripotent stem cells (iPSCs), isolated from individuals with genetic diseases, can be used to model disease-related cellular and molecular pathologies, including DS. In this review, we will discuss the limitations of mouse models of DS and how these can be addressed using recent advancements in modelling DS using human iPSCs and iPSC-mouse chimeras, and potential applications of iPSCs in preclinical studies for DS-AD.
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Ponroy Bally B, Murai KK. Astrocytes in Down Syndrome Across the Lifespan. Front Cell Neurosci 2021; 15:702685. [PMID: 34483840 PMCID: PMC8416355 DOI: 10.3389/fncel.2021.702685] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/30/2021] [Indexed: 11/23/2022] Open
Abstract
Down Syndrome (DS) is the most common genetic cause of intellectual disability in which delays and impairments in brain development and function lead to neurological and cognitive phenotypes. Traditionally, a neurocentric approach, focusing on neurons and their connectivity, has been applied to understanding the mechanisms involved in DS brain pathophysiology with an emphasis on how triplication of chromosome 21 leads to alterations in neuronal survival and homeostasis, synaptogenesis, brain circuit development, and neurodegeneration. However, recent studies have drawn attention to the role of non-neuronal cells, especially astrocytes, in DS. Astrocytes comprise a large proportion of cells in the central nervous system (CNS) and are critical for brain development, homeostasis, and function. As triplication of chromosome 21 occurs in all cells in DS (with the exception of mosaic DS), a deeper understanding of the impact of trisomy 21 on astrocytes in DS pathophysiology is warranted and will likely be necessary for determining how specific brain alterations and neurological phenotypes emerge and progress in DS. Here, we review the current understanding of the role of astrocytes in DS, and discuss how specific perturbations in this cell type can impact the brain across the lifespan from early brain development to adult stages. Finally, we highlight how targeting, modifying, and/or correcting specific molecular pathways and properties of astrocytes in DS may provide an effective therapeutic direction given the important role of astrocytes in regulating brain development and function.
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Affiliation(s)
- Blandine Ponroy Bally
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
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Tian X, Xie B, Zou Z, Jiao Y, Lin LE, Chen CL, Hsu CC, Peng J, Yang Z. Multimodal Imaging of Amyloid Plaques: Fusion of the Single-Probe Mass Spectrometry Image and Fluorescence Microscopy Image. Anal Chem 2019; 91:12882-12889. [PMID: 31536324 PMCID: PMC6885010 DOI: 10.1021/acs.analchem.9b02792] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. The formation of amyloid plaques by aggregated amyloid beta (Aβ) peptides is a primary event in AD pathology. Understanding the metabolomic features and related pathways is critical for studying plaque-related pathological events (e.g., cell death and neuron dysfunction). Mass spectrometry imaging (MSI), due to its high sensitivity and ability to obtain the spatial distribution of metabolites, has been applied to AD studies. However, limited studies of metabolites in amyloid plaques have been performed due to the drawbacks of the commonly used techniques such as matrix-assisted laser desorption/ionization MSI. In the current study, we obtained high spatial resolution (∼17 μm) MS images of the AD mouse brain using the Single-probe, a microscale sampling and ionization device, coupled to a mass spectrometer under ambient conditions. The adjacent slices were used to obtain fluorescence microscopy images to locate amyloid plaques. The MS image and the fluorescence microscopy image were fused to spatially correlate histological protein hallmarks with metabolomic features. The fused images produced significantly improved spatial resolution (∼5 μm), allowing for the determination of fine structures in MS images and metabolomic biomarkers representing amyloid plaques.
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Affiliation(s)
- Xiang Tian
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Boer Xie
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - Zhu Zou
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Yun Jiao
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - Li-En Lin
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Lin Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Cheng-Chih Hsu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Junmin Peng
- Departments of Structural Biology and Developmental Neurobiology, Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
| | - Zhibo Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
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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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Perez SE, Miguel JC, He B, Malek-Ahmadi M, Abrahamson EE, Ikonomovic MD, Lott I, Doran E, Alldred MJ, Ginsberg SD, Mufson EJ. Frontal cortex and striatal cellular and molecular pathobiology in individuals with Down syndrome with and without dementia. Acta Neuropathol 2019; 137:413-436. [PMID: 30734106 PMCID: PMC6541490 DOI: 10.1007/s00401-019-01965-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 02/06/2023]
Abstract
Although, by age 40, individuals with Down syndrome (DS) develop amyloid-β (Aβ) plaques and tau-containing neurofibrillary tangles (NFTs) linked to cognitive impairment in Alzheimer's disease (AD), not all people with DS develop dementia. Whether Aβ plaques and NFTs are associated with individuals with DS with (DSD +) and without dementia (DSD -) is under-investigated. Here, we applied quantitative immunocytochemistry and fluorescent procedures to characterize NFT pathology using antibodies specific for tau phosphorylation (pS422, AT8), truncation (TauC3, MN423), and conformational (Alz50, MC1) epitopes, as well as Aβ and its precursor protein (APP) to frontal cortex (FC) and striatal tissue from DSD + to DSD - cases. Expression profiling of single pS422 labeled FC layer V and VI neurons was also determined using laser capture microdissection and custom-designed microarray analysis. Analysis revealed that cortical and striatal Aβ plaque burdens were similar in DSD + and DSD - cases. In both groups, most FC plaques were neuritic, while striatal plaques were diffuse. By contrast, FC AT8-positive NFTs and neuropil thread densities were significantly greater in DSD + compared to DSD -, while striatal NFT densities were similar between groups. FC pS422-positive and TauC3 NFT densities were significantly greater than Alz50-labeled NFTs in DSD + , but not DSD - cases. Putaminal, but not caudate pS422-positive NFT density, was significantly greater than TauC3-positive NFTs. In the FC, AT8 + pS422 + Alz50, TauC3 + pS422 + Alz50, pS422 + Alz50, and TauC3 + pS422 positive NFTs were more frequent in DSD + compared to DSD- cases. Single gene-array profiling of FC pS422 positive neurons revealed downregulation of 63 of a total of 864 transcripts related to Aβ/tau biology, glutamatergic, cholinergic, and monoaminergic metabolism, intracellular signaling, cell homeostasis, and cell death in DSD + compared DSD - cases. These observations suggest that abnormal tau aggregation plays a critical role in the development of dementia in DS.
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Affiliation(s)
- Sylvia E Perez
- Department of Neurobiology and Neurology, Barrow Neurological Institute, 350 W. Thomas St, Phoenix, AZ, 85013, USA
- School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Jennifer C Miguel
- Department of Neurobiology and Neurology, Barrow Neurological Institute, 350 W. Thomas St, Phoenix, AZ, 85013, USA
| | - Bin He
- Department of Neurobiology and Neurology, Barrow Neurological Institute, 350 W. Thomas St, Phoenix, AZ, 85013, USA
| | | | - Eric E Abrahamson
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA, 15213, USA
- Departments of Neurology and Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Milos D Ikonomovic
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA, 15213, USA
- Departments of Neurology and Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Ira Lott
- Departments of Pediatrics and Neurology, University of California, Irvine, CA, 92697, USA
| | - Eric Doran
- Departments of Pediatrics and Neurology, University of California, Irvine, CA, 92697, USA
| | - Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA
- Departments of Psychiatry, NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10021, USA
| | - Stephen D Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA
- Departments of Psychiatry, NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10021, USA
- Departments of Neuroscience and Physiology, The NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10021, USA
| | - Elliott J Mufson
- Department of Neurobiology and Neurology, Barrow Neurological Institute, 350 W. Thomas St, Phoenix, AZ, 85013, USA.
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Schoeppe F, Rossi A, Levin J, Reiser M, Stoecklein S, Ertl-Wagner B. Increased cerebral microbleeds and cortical superficial siderosis in pediatric patients with Down syndrome. Eur J Paediatr Neurol 2019; 23:158-164. [PMID: 30279085 DOI: 10.1016/j.ejpn.2018.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 07/19/2018] [Accepted: 09/04/2018] [Indexed: 01/11/2023]
Abstract
BACKGROUND Patients with Down syndrome carry a third copy of the amyloid precursor protein gene, which is localized on chromosome 21. Consequently, these patients are prone to develop early-onset Alzheimer disease and cerebral amyloid angiopathy. Post-mortem studies suggest increased amyloid deposition to be already detectable in children with Down syndrome. The aim of our study was to evaluate if amyloid-related changes in pediatric Down syndrome patients can be detected in vivo using MRI biomarkers of cerebral microbleeds and cortical superficial siderosis. MATERIALS AND METHODS This retrospective study included 12 patients with Down syndrome (mean age = 5.0 years) and 12 age-matched control subjects (mean age = 4.8 years). Frequency and location of microbleeds and siderosis were assessed on blood-sensitive MRI sequences in a consensus reading by two radiologists applying a modified Microbleed Anatomical Rating Scale. RESULTS Down syndrome patients showed a significantly higher mean microbleeds count and likelihood of siderosis than age-matched controls. Across groups, the highest microbleeds count was found in lobar regions (gray and white matter of frontal, parietal, temporal, and occipital lobes, and the insula), while fewer microbleeds were located in subcortical and infratentorial regions. The number of microbleeds increased over time in all three Down syndrome patients with a follow-up exam. CONCLUSION In vivo MRI biomarkers can support the diagnosis of early-onset cerebral amyloid angiopathy, which might already be present in pediatric Down syndrome patients. This might contribute to clinical decision-making and potentially to the development of therapeutic and prophylactic approaches, as cerebral amyloid angiopathy increases the risk for intracranial hemorrhage and may be associated with increased risk of developing Alzheimer disease.
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Affiliation(s)
- Franziska Schoeppe
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Andrea Rossi
- Department of Pediatric Neuroradiology, Instituto Giannina Gaslini, Via G. Gaslini 5, I-16147, Genoa, Italy
| | - Johannes Levin
- Department of Neurology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377, Munich, Germany
| | - Maximilian Reiser
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Sophia Stoecklein
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Birgit Ertl-Wagner
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany; Department of Radiology, The Hospital for Sick Children, 555 University Ave, Toronto, ON M5G1X8, Canada
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GABA A receptor subunit deregulation in the hippocampus of human foetuses with Down syndrome. Brain Struct Funct 2017; 223:1501-1518. [PMID: 29168008 PMCID: PMC5869939 DOI: 10.1007/s00429-017-1563-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 11/05/2017] [Indexed: 11/01/2022]
Abstract
The function, regulation and cellular distribution of GABAA receptor subunits have been extensively documented in the adult rodent brain and are linked to numerous neurological disorders. However, there is a surprising lack of knowledge on the cellular (sub-) distribution of GABAA receptor subunits and of their expressional regulation in developing healthy and diseased foetal human brains. To propose a role for GABAA receptor subunits in neurodevelopmental disorders, we studied the developing hippocampus of normal and Down syndrome foetuses. Among the α1-3 and γ2 subunits probed, we find significantly altered expression profiles of the α1, α3 and γ2 subunits in developing Down syndrome hippocampi, with the α3 subunit being most affected. α3 subunits were selectively down-regulated in all hippocampal subfields and developmental periods tested in Down syndrome foetuses, presenting a developmental mismatch by their adult-like distribution in early foetal development. We hypothesized that increased levels of the amyloid precursor protein (APP), and particularly its neurotoxic β-amyloid (1-42) fragment, could disrupt α3 gene expression, likely by facilitating premature neuronal differentiation. Indeed, we find increased APP content in the hippocampi of the Down foetuses. In a corresponding cellular model, soluble β-amyloid (1-42) administered to cultured SH-SY5Y neuroblastoma cells, augmented by retinoic acid-induced differentiation towards a neuronal phenotype, displayed a reduction in α3 subunit levels. In sum, this study charts a comprehensive regional and subcellular map of key GABAA receptor subunits in identified neuronal populations in the hippocampus of healthy and Down syndrome foetuses and associates increased β-amyloid load with discordant down-regulation of α3 subunits.
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Buss L, Fisher E, Hardy J, Nizetic D, Groet J, Pulford L, Strydom A. Intracerebral haemorrhage in Down syndrome: protected or predisposed? F1000Res 2016; 5. [PMID: 27239286 PMCID: PMC4870990 DOI: 10.12688/f1000research.7819.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/06/2016] [Indexed: 01/08/2023] Open
Abstract
Down syndrome (DS), which arises from trisomy of chromosome 21, is associated with deposition of large amounts of amyloid within the central nervous system. Amyloid accumulates in two compartments: as plaques within the brain parenchyma and in vessel walls of the cerebral microvasculature. The parenchymal plaque amyloid is thought to result in an early onset Alzheimer’s disease (AD) dementia, a phenomenon so common amongst people with DS that it could be considered a defining feature of the condition. The amyloid precursor protein (
APP) gene lies on chromosome 21 and its presence in three copies in DS is thought to largely drive the early onset AD. In contrast, intracerebral haemorrhage (ICH), the main clinical consequence of vascular amyloidosis, is a more poorly defined feature of DS. We review recent epidemiological data on stroke (including haemorrhagic stroke) in order to make comparisons with a rare form of familial AD due to duplication (i.e. having three copies) of the
APP region on chromosome 21, here called ‘dup-APP’, which is associated with more frequent and severe ICH. We conclude that although people with DS are at increased risk of ICH, this is less common than in dup-APP, suggesting the presence of mechanisms that act protectively. We review these mechanisms and consider comparative research into DS and dup-APP that may yield further pathophysiological insight.
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Affiliation(s)
- Lewis Buss
- Division of Psychiatry, University College London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - Elizabeth Fisher
- Institute of Neurology, University College London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - John Hardy
- Institute of Neurology, University College London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - Dean Nizetic
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore; Blizard Institute, Barts and the London School of Medicine, Queen Mary, University of London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - Jurgen Groet
- Blizard Institute, Barts and the London School of Medicine, Queen Mary, University of London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - Laura Pulford
- Institute of Neurology, University College London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
| | - André Strydom
- Division of Psychiatry, University College London, London, UK; London Down Syndrome (LonDownS) Consortium, University College London, London, UK
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Cecchini MP, Viviani D, Sandri M, Hähner A, Hummel T, Zancanaro C. Olfaction in People with Down Syndrome: A Comprehensive Assessment across Four Decades of Age. PLoS One 2016; 11:e0146486. [PMID: 26730728 PMCID: PMC4701393 DOI: 10.1371/journal.pone.0146486] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 12/17/2015] [Indexed: 11/26/2022] Open
Abstract
Background Down syndrome (DS) shows neuropathology similar to Alzheimer disease, which presents olfactory impairment. Previous work showed olfactory impairment in DS, but a comprehensive evaluation of olfactory function in DS is lacking. Methods We investigated a large number (n = 56; M = 31, F = 25) DS participants (age range18-57y) using the “Sniffin’ Sticks” Extended test. This comprises three subtests (threshold, discrimination, and identification) yielding a global score (TDI) defining normosmia, hyposmia, and functional anosmia. To the best of our knowledge, this is the second largest group of DS people investigated for olfactory function ever. Age- and sex matched euploid individuals (n = 53) were the control. Results In DS, TDI was lower (16.7±5.13 vs. 35.4±3.74; P<0.001), with DS people performing worse in any subtests (P<0.001 for all); 27 DS participants showed functional anosmia (i.e., TDI<16). In DS, age was weakly and negatively correlated with TDI (r = -0.28, P = 0.036) and identification (r = -0.34, P = 0.012). When participants were stratified in young adults (18-29y) and older adults (30-61y), a significant effect of age was found for identification in both DS (young adults, 8.3±2.58; older adults, 6.9±2.99; P = 0.031) and control (young-adult, 14.3±1.18, older adult, 13.0±1.54; P = 0.016). Conclusion Olfactory function is overall severely impaired in DS people and may be globally impaired at relatively young age, despite of reportedly normal smell. However, specificity of this olfactory profile to DS should be considered with some caution because cognition was not evaluated in all DS participants and comparison with a control group of non-DS individuals having cognitive disabilities was lacking. Further study is required to longitudinally assess olfactory dysfunction in DS and to correlate it with brain pathology.
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Affiliation(s)
- Maria Paola Cecchini
- Department of Neurological and Movement Sciences, Anatomy and Histology Section, University of Verona, Verona, Italy
- * E-mail:
| | - Dario Viviani
- U.O. Pediatria, Ospedale Sacro Cuore Don Calabria, Negrar, Italy
| | - Marco Sandri
- Department of Neurological and Movement Sciences, Anatomy and Histology Section, University of Verona, Verona, Italy
| | - Antje Hähner
- Smell & Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Dresden, Germany
| | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Dresden, Germany
| | - Carlo Zancanaro
- Department of Neurological and Movement Sciences, Anatomy and Histology Section, University of Verona, Verona, Italy
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Wiseman FK, Al-Janabi T, Hardy J, Karmiloff-Smith A, Nizetic D, Tybulewicz VLJ, Fisher EMC, Strydom A. A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome. Nat Rev Neurosci 2015; 16:564-74. [PMID: 26243569 PMCID: PMC4678594 DOI: 10.1038/nrn3983] [Citation(s) in RCA: 337] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Down syndrome, which arises in individuals carrying an extra copy of chromosome 21, is associated with a greatly increased risk of early-onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP)--an Alzheimer disease risk factor--although the possession of extra copies of other chromosome 21 genes may also play a part. Further study of the mechanisms underlying the development of Alzheimer disease in people with Down syndrome could provide insights into the mechanisms that cause dementia in the general population.
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Affiliation(s)
- Frances K Wiseman
- Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Tamara Al-Janabi
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Road, London W1T 7NF, UK
| | - John Hardy
- Department of Molecular Neuroscience, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Annette Karmiloff-Smith
- Centre for Brain and Cognitive Development, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Dean Nizetic
- Lee Kong Chian School of Medicine, Nanyang Technological University, Novena Campus, 11 Mandalay Road, Singapore 308232; and the Blizard Institute, Barts and the London School of Medicine, Queen Mary University of London, 4 Newark Street, London E1 2AT, UK
| | | | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - André Strydom
- Division of Psychiatry, University College London, Maple House, 149 Tottenham Court Road, London W1T 7NF, UK
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Abstract
Extensive evidence has indicated that the breakdown of myelin is associated with Alzheimer's disease (AD) since the vulnerability of oligodendrocytes under Alzheimer's pathology easily induces the myelin breakdown and the loss of the myelin sheath which might be the initiating step in the changes of the earliest stage of AD prior to appearance of amyloid and tau pathology. Considerable research implicated that beta-amyloid (Aβ)-mediated oligodendrocyte dysfunction and myelin breakdown may be via neuroinflammation, oxidative stress and/or apoptosis. It also seems that the oligodendrocyte dysfunction is triggered by the formation of neurofibrillary tangles (NFTs) through inflammation and oxidative stress as the common pathophysiological base. Impaired repair of oligodendrocyte precursor cells (OPCs) might possibly enhance the disease progress under decreased self-healing ability from aging process and pathological factors including Aβ pathology and/or NFTs. Thus, these results have suggested that targeting oligodendrocytes may be a novel therapeutic intervention for the prevention and treatment of AD.
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Affiliation(s)
- Zhiyou Cai
- a Department of Neurology, Renmin Hospital , Hubei University of Medicine, Shiyan Renmin Hospital , Shiyan , Hubei Province , China
| | - Ming Xiao
- b Department of Anatomy , Nanjing Medical University , Nanjing , Jiangsu , China
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12
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Fernandez F, Reeves RH. Assessing cognitive improvement in people with Down syndrome: important considerations for drug-efficacy trials. Handb Exp Pharmacol 2015; 228:335-80. [PMID: 25977089 DOI: 10.1007/978-3-319-16522-6_12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Experimental research over just the past decade has raised the possibility that learning deficits connected to Down syndrome (DS) might be effectively managed by medication. In the current chapter, we touch on some of the work that paved the way for these advances and discuss the challenges associated with translating them. In particular, we highlight sources of phenotypic variability in the DS population that are likely to impact performance assessments. Throughout, suggestions are made on how to detect meaningful changes in cognitive-adaptive function in people with DS during drug treatment. The importance of within-subjects evaluation is emphasized.
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Affiliation(s)
- Fabian Fernandez
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA,
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Factors determining disease duration in Alzheimer's disease: a postmortem study of 103 cases using the Kaplan-Meier estimator and Cox regression. BIOMED RESEARCH INTERNATIONAL 2014; 2014:623487. [PMID: 24579083 PMCID: PMC3919116 DOI: 10.1155/2014/623487] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 11/05/2013] [Accepted: 11/24/2013] [Indexed: 12/04/2022]
Abstract
Factors associated with duration of dementia in a consecutive series of 103 Alzheimer's disease (AD) cases were studied using the Kaplan-Meier estimator and Cox regression analysis (proportional hazard model). Mean disease duration was 7.1 years (range: 6 weeks–30 years, standard deviation = 5.18); 25% of cases died within four years, 50% within 6.9 years, and 75% within 10 years. Familial AD cases (FAD) had a longer duration than sporadic cases (SAD), especially cases linked to presenilin (PSEN) genes. No significant differences in duration were associated with age, sex, or apolipoprotein E (Apo E) genotype. Duration was reduced in cases with arterial hypertension. Cox regression analysis suggested longer duration was associated with an earlier disease onset and increased senile plaque (SP) and neurofibrillary tangle (NFT) pathology in the orbital gyrus (OrG), CA1 sector of the hippocampus, and nucleus basalis of Meynert (NBM). The data suggest shorter disease duration in SAD and in cases with hypertensive comorbidity. In addition, degree of neuropathology did not influence survival, but spread of SP/NFT pathology into the frontal lobe, hippocampus, and basal forebrain was associated with longer disease duration.
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Fernandez F, Edgin JO. Poor Sleep as a Precursor to Cognitive Decline in Down Syndrome : A Hypothesis. ACTA ACUST UNITED AC 2013; 3:124. [PMID: 24558640 PMCID: PMC3928031 DOI: 10.4172/2161-0460.1000124] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We propose that sleep disruption is a lever arm that influences how cognition emerges in development and then declines in response to Alzheimer disease in people with Down syndrome. Addressing sleep disruptions might be an overlooked way to improve cognitive outcomes in this population. This article is a contribution to a Special Issue on Down Syndrome curated by the editors of the Journal of Alzheimer’s Disease & Parkinsonism.
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Affiliation(s)
- Fabian Fernandez
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jamie O Edgin
- Department of Psychology and Cognitive Science Program, Sonoran University, Center for Excellence in Developmental Disabilities, University of Arizona, Tucson, AZ 85721, USA
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15
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Alzheimer's Disease and the Amyloid β-Protein. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 107:101-24. [DOI: 10.1016/b978-0-12-385883-2.00012-6] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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16
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Jia YL, Jing LJ, Li JY, Lu JJ, Han R, Wang SY, Peng T, Jia YJ. Expression and significance of DSCAM in the cerebral cortex of APP transgenic mice. Neurosci Lett 2011; 491:153-7. [PMID: 21241773 DOI: 10.1016/j.neulet.2011.01.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Revised: 01/09/2011] [Accepted: 01/10/2011] [Indexed: 12/21/2022]
Abstract
Down syndrome cell adhesion molecule (DSCAM) plays important roles in the regulation of synaptogenesis, neurite outgrowth, axon guidance and synapse formation. Overexpression of DSCAM in Down syndrome (DS) may be involved in the pathogenesis of mental retardation through an inhibitory action on synaptogenesis/neurite outgrowth, and in the precocious dementia associated with an amyloid precursor protein (APP) dosage effect with enhanced plaque formation. In this report we examined the expression of DSCAM in the cerebral cortex of APP transgenic mice versus age-matched wild-type mice. We found that the level of DSCAM expression increased with increasing age in both groups of mice, up to a maximum at 3 months old. The level of DSCAM expression in APP transgenic mice was significantly higher than in the age-matched wild types. We propose that overexpression of DSCAM in the cerebral cortex might play an important role in the learning and memory defects of APP transgenic mice.
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Affiliation(s)
- Yong-Lin Jia
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jian She Road, Zhengzhou, Henan Province 450052, China.
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Jang H, Arce FT, Ramachandran S, Capone R, Lal R, Nussinov R. β-Barrel topology of Alzheimer's β-amyloid ion channels. J Mol Biol 2010; 404:917-34. [PMID: 20970427 PMCID: PMC7291702 DOI: 10.1016/j.jmb.2010.10.025] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 10/06/2010] [Accepted: 10/15/2010] [Indexed: 11/19/2022]
Abstract
Emerging evidence supports the ion channel mechanism for Alzheimer's disease pathophysiology wherein small β-amyloid (Aβ) oligomers insert into the cell membrane, forming toxic ion channels and destabilizing the cellular ionic homeostasis. Solid-state NMR-based data of amyloid oligomers in solution indicate that they consist of a double-layered β-sheets where each monomer folds into β-strand-turn-β-strand and the monomers are stacked atop each other. In the membrane, Aβ peptides are proposed to be β-type structures. Experimental structural data available from atomic force microscopy (AFM) imaging of Aβ oligomers in membranes reveal heterogeneous channel morphologies. Previously, we modeled the channels in a non-tilted organization, parallel with the cross-membrane normal. Here, we modeled a β-barrel-like organization. β-Barrels are common in transmembrane toxin pores, typically consisting of a monomeric chain forming a pore, organized in a single-layered β-sheet with antiparallel β-strands and a right-handed twist. Our explicit solvent molecular dynamics simulations of a range of channel sizes and polymorphic turns and comparisons of these with AFM image dimensions support a β-barrel channel organization. Different from the transmembrane β-barrels where the monomers are folded into a circular β-sheet with antiparallel β-strands stabilized by the connecting loops, these Aβ barrels consist of multimeric chains forming double β-sheets with parallel β-strands, where the strands of each monomer are connected by a turn. Although the Aβ barrels adopt the right-handed β-sheet twist, the barrels still break into heterogeneous, loosely attached subunits, in good agreement with AFM images and previous modeling. The subunits appear mobile, allowing unregulated, hence toxic, ion flux.
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Affiliation(s)
- Hyunbum Jang
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
| | - Fernando Teran Arce
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Srinivasan Ramachandran
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ricardo Capone
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ratnesh Lal
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ruth Nussinov
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA
- Department of Human Molecular Genetics, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Department of Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Jang H, Arce FT, Ramachandran S, Capone R, Azimova R, Kagan BL, Nussinov R, Lal R. Truncated beta-amyloid peptide channels provide an alternative mechanism for Alzheimer's Disease and Down syndrome. Proc Natl Acad Sci U S A 2010; 107:6538-43. [PMID: 20308552 PMCID: PMC2851998 DOI: 10.1073/pnas.0914251107] [Citation(s) in RCA: 185] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Full-length amyloid beta peptides (Abeta(1-40/42)) form neuritic amyloid plaques in Alzheimer's disease (AD) patients and are implicated in AD pathology. However, recent transgenic animal models cast doubt on their direct role in AD pathology. Nonamyloidogenic truncated amyloid-beta fragments (Abeta(11-42) and Abeta(17-42)) are also found in amyloid plaques of AD and in the preamyloid lesions of Down syndrome, a model system for early-onset AD study. Very little is known about the structure and activity of these smaller peptides, although they could be the primary AD and Down syndrome pathological agents. Using complementary techniques of molecular dynamics simulations, atomic force microscopy, channel conductance measurements, calcium imaging, neuritic degeneration, and cell death assays, we show that nonamyloidogenic Abeta(9-42) and Abeta(17-42) peptides form ion channels with loosely attached subunits and elicit single-channel conductances. The subunits appear mobile, suggesting insertion of small oligomers, followed by dynamic channel assembly and dissociation. These channels allow calcium uptake in amyloid precursor protein-deficient cells. The channel mediated calcium uptake induces neurite degeneration in human cortical neurons. Channel conductance, calcium uptake, and neurite degeneration are selectively inhibited by zinc, a blocker of amyloid ion channel activity. Thus, truncated Abeta fragments could account for undefined roles played by full length Abetas and provide a unique mechanism of AD and Down syndrome pathologies. The toxicity of nonamyloidogenic peptides via an ion channel mechanism necessitates a reevaluation of the current therapeutic approaches targeting the nonamyloidogenic pathway as avenue for AD treatment.
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Affiliation(s)
- Hyunbum Jang
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, MD 21702
| | - Fernando Teran Arce
- Center for Nanomedicine and Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Srinivasan Ramachandran
- Center for Nanomedicine and Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Ricardo Capone
- Center for Nanomedicine and Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Rushana Azimova
- Semel Neuropsychiatric Institute, The David Geffen School of Medicine, University of California at Los Angeles and Greater Los Angeles Veterans Administration Health System, Los Angeles, CA 90024; and
| | - Bruce L. Kagan
- Semel Neuropsychiatric Institute, The David Geffen School of Medicine, University of California at Los Angeles and Greater Los Angeles Veterans Administration Health System, Los Angeles, CA 90024; and
| | - Ruth Nussinov
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, MD 21702
- Department of Human Molecular Genetics and Biochemistry, The Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ratnesh Lal
- Center for Nanomedicine and Department of Medicine, University of Chicago, Chicago, IL 60637
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Communication breaks-Down: from neurodevelopment defects to cognitive disabilities in Down syndrome. Prog Neurobiol 2010; 91:1-22. [PMID: 20097253 DOI: 10.1016/j.pneurobio.2010.01.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 12/10/2009] [Accepted: 01/14/2010] [Indexed: 12/31/2022]
Abstract
Down syndrome (DS) is the leading cause of genetically-defined intellectual disability and congenital birth defects. Despite being one of the first genetic diseases identified, only recently, thanks to the phenotypic analysis of DS mouse genetic models, we have begun to understand how trisomy may impact cognitive function. Cognitive disabilities in DS appear to result mainly from two pathological processes: neurogenesis impairment and Alzheimer-like degeneration. In DS brain, suboptimal network architecture and altered synaptic communication arising from neurodevelopmental impairment are key determinants of cognitive defects. Hypocellularity and hypoplasia start at early developmental stages and likely depend upon impaired proliferation of neuronal precursors, resulting in reduction of numbers of neurons and synaptic contacts. The impairment of neuronal precursor proliferation extends to adult neurogenesis and may affect learning and memory. Neurodegenerative mechanisms also contribute to DS cognitive impairment. Early onset Alzheimer disease occurs with extremely high incidence in DS patients and is causally-related to overexpression of beta-amyloid precursor protein (betaAPP), which is one of the triplicated genes in DS. In this review, we will survey the available findings on neurodevelopmental and neurodegenerative changes occurring in DS throughout life. Moreover, we will discuss the potential mechanisms by which defects in neurogenesis and neurodegenerative processes lead to altered formation of neural circuits and impair cognitive function, in connection with findings on pharmacological treatments of potential benefit for DS.
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20
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Murphy C, Solomon ES, Haase L, Wang M, Morgan CD. Olfaction in aging and Alzheimer's disease: event-related potentials to a cross-modal odor-recognition memory task discriminate ApoE epsilon4+ and ApoE epsilon 4- individuals. Ann N Y Acad Sci 2009; 1170:647-57. [PMID: 19686207 DOI: 10.1111/j.1749-6632.2009.04486.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative condition that affects more than 5 million Americans. Currently, a definitive and unequivocal diagnosis of AD can only be confirmed histopathogically via postmortem autopsy, demonstrating the need for objective measures of cognitive functioning for those at risk for AD. The single most important genetic risk factor of AD is the apolipoprotein E (ApoE) epsilon4 allele. The present study investigated olfactory and cognitive processing deficits in ApoE epsilon4(+) individuals using a cross-modal recognition memory task and an objective electrophysiological measure, the event-related potential (ERP). Ten epsilon4(+) individuals (5 M, 5 F, mean [M]= 75.1 years) and 10 age- and gender-matched epsilon4(-) individuals (5 M, 5 F, M = 71 years) sequentially encoded a set of 16 olfactory stimuli and were subsequently shown names of odors previously presented (targets) or not (foils). EEG activity was recorded from 19 electrodes as participants distinguished targets from foils using a two-button mouse. P3 latencies were significantly longer in epsilon4(+) individuals, and intraclass correlations demonstrated differential activity between the two groups. These findings are consistent with a compensatory hypothesis, which posits that nondemented epsilon4(+) individuals will expend greater effort in cognitive processing or engage in alternative strategies and therefore require greater activation of neural tissue or recruitment of different neural populations. The findings also suggest that cross-modal ERP studies of recognition memory discriminate early neurocognitive changes in ApoE epsilon4(+) and ApoE epsilon4(-) individuals and may contribute to identifying the phenotype of persons who will develop Alzheimer's disease.
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Affiliation(s)
- Claire Murphy
- San Diego State University, San Diego, California 92120-4913, USA.
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21
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Monitoring the amyloid beta-peptide in vivo--caveat emptor. Drug Discov Today 2009; 14:241-51. [PMID: 19135168 DOI: 10.1016/j.drudis.2008.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 11/27/2008] [Accepted: 12/02/2008] [Indexed: 12/26/2022]
Abstract
As a wave of 'disease modifying' (DM) therapies for Alzheimer's disease (AD) progresses towards the later stages of clinical development, an evaluation of our ability to measure relevant pharmacodynamic effects of such therapies is warranted. Reducing accumulation of amyloid beta (Abeta)-peptide in the brain parenchyma is the primary objective of most current DM approaches. Although a number of methods are available to measure Abeta in blood, cerebrospinal fluid (CSF) and the cerebrum, putative DM-induced changes in the levels of the peptides may not be fully captured, and the reasons for any such changes are not fully understood. Additional candidate biofluid (tau and isoprostanes) and imaging (MRI, FDG-PET) measures may provide alternative supporting evidence of drug activity and subsequent clinical efficacy in patient populations.
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22
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Englund H, Annerén G, Gustafsson J, Wester U, Wiltfang J, Lannfelt L, Blennow K, Höglund K. Increase in beta-amyloid levels in cerebrospinal fluid of children with Down syndrome. Dement Geriatr Cogn Disord 2008; 24:369-74. [PMID: 17914261 DOI: 10.1159/000109215] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Individuals with Down syndrome (DS) invariably develop Alzheimer's disease (AD) during their life span. It is therefore of importance to study young DS patients when trying to elucidate early events in AD pathogenesis. AIM To investigate how levels of different amyloid-beta (Abeta) peptides, as well as tau and phosphorylated tau, in cerebrospinal fluid (CSF) from children with DS change over time. The first CSF sample was taken at 8 months and the following two samples at 20-40 and 54 months of age. RESULTS Individual levels of the Abeta peptides, as well as total Abeta levels in CSF increased over time when measured with Western blot. Tau in CSF decreased whereas there was no change in levels of phosphorylated tau over time. CONCLUSION The increasing levels of Abeta in CSF during early childhood of DS patients observed in this study are probably due to the trisomy of the Abeta precursor APP, which leads to an overproduction of Abeta. Despite the increased CSF concentrations of Abeta, there were no signs of an AD-indicating tau pattern in CSF, since the levels of total tau decreased and phosphorylated tau remained unchanged. This observation further strengthens the theory of Abeta pathology preceding tau pathology in AD.
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Affiliation(s)
- Hillevi Englund
- Department of Public Health and Caring Sciences, Section of Molecular Geriatrics, Uppsala University, and Department of Women's and Children's Health, Uppsala University Children's Hospital, Sweden
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Abstract
Converging lines of evidence suggest that progressive accumulation of the amyloid beta-protein (A beta) plays a central role in the genesis of Alzheimer's disease, but it was long assumed that A beta had to be assembled into extracellular amyloid fibrils to exert its cytotoxic effects. Over the past decade, data have emerged from the use of synthetic A beta peptides, cell culture models, beta-amyloid precursor protein transgenic mice and human brain to suggest that pre-fibrillar, diffusible assemblies of A beta are also deleterious. Although the precise molecular identity of these soluble toxins remains unsettled, accumulating evidence suggests that soluble forms of A beta are indeed the proximate effectors of synapse loss and neuronal injury. Here we review recent progress in understanding the role of soluble oligomers in Alzheimer's disease.
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Affiliation(s)
- Dominic M Walsh
- Laboratory for Neurodegenerative Research, The Conway Institute, University College Dublin, Belfield, Dublin, Republic of Ireland.
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Oide T, Kinoshita T, Arima K. Regression stage senile plaques in the natural course of Alzheimer's disease. Neuropathol Appl Neurobiol 2006; 32:539-56. [PMID: 16972888 DOI: 10.1111/j.1365-2990.2006.00767.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Resolution process of cerebroparenchymal amyloid beta-protein (Abeta) deposition has become of increasing interest in the light of recent advance in the Abeta-vaccination therapy for Alzheimer's disease (AD). However, the neuropathological features of degraded and disappearing senile plaque remain poorly characterized, especially in the natural course of the disease. To clarify the natural removal processes of Abeta burden in the brain with AD, we devised a triple-step staining method: Bodian for dystrophic neurites, anti-glial fibrillary acidic protein for astrocytes, and anti-Abeta. We thus examined 24 autopsied AD brains. A novel form of senile plaques, termed 'remnant plaques', was identified. Remnant plaques were characterized by mesh-like astroglial fibrils within the entire plaque part, Abeta deposit debris exhibiting weak Abeta immunoreactivity, and only a few slender dystrophic neurites. In remnant plaques, amyloid burden was apparently decreased. The density of remnant plaques increased significantly with disease duration. Dual-labelling immunohistochemistry revealed many Abeta-immunoreactive granules in astrocytes and a modest number in microglia, both of which accumulated in senile plaques. We consider amyloid deposits of diffuse and neuritic plaques to be shredded by astrocytic processes from the marginal zone of plaques, and to gradually disintegrate into smaller compartments. Cerebroparenchymal Abeta deposits undergo degradation. After a long-standing resolution process, diffuse and neuritic plaques may finally proceed to remnant plaques. Astrocytes are actively engaged in the natural Abeta clearance mechanism in advanced stage AD brains, which may provide clues for developing new therapeutic strategies for AD.
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Affiliation(s)
- T Oide
- Department of Laboratory Medicine, Musashi Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
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25
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D'Andrea MR, Cole GM, Ard MD. The microglial phagocytic role with specific plaque types in the Alzheimer disease brain. Neurobiol Aging 2004; 25:675-83. [PMID: 15172747 DOI: 10.1016/j.neurobiolaging.2003.12.026] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Revised: 12/10/2003] [Accepted: 12/15/2003] [Indexed: 10/26/2022]
Abstract
Alzheimer disease (AD) involves glial inflammation associated with amyloid plaques. The role of the microglial cells in the AD brain is controversial, as it remains unclear if the microglia form the amyloid fibrils of plaques or react to them in a macrophage-phagocytic role. Also, it is not known why microglia are preferentially associated with some amyloid plaque types. This review will provide substantial evidence to support the phagocytic role of microglia in the brain as well as explain why microglia are generally associated with specific plaque types that may be explained through their unique mechanisms of formation. In summary, the data presented suggests that plaque associated microglial activation is typically subsequent to specific amyloid plaque formations in the AD brain.
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Affiliation(s)
- Michael R D'Andrea
- Drug Discovery, Johnson & Johnson Pharmaceutical Research and Development, D404, Spring House, PA 19477, USA.
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Adlard PA, Cummings BJ. Alzheimer’s disease—a sum greater than its parts? Neurobiol Aging 2004; 25:725-33; discussion 743-6. [PMID: 15165695 DOI: 10.1016/j.neurobiolaging.2003.12.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Accepted: 12/10/2003] [Indexed: 10/26/2022]
Affiliation(s)
- Paul A Adlard
- Institute for Brain Aging and Dementia, University of California, 1113 Gillespie N.R.F., Irvine, CA 92697-4540, USA.
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27
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Gordon MN, Holcomb LA, Jantzen PT, DiCarlo G, Wilcock D, Boyett KW, Connor K, Melachrino J, O'Callaghan JP, Morgan D. Time course of the development of Alzheimer-like pathology in the doubly transgenic PS1+APP mouse. Exp Neurol 2002; 173:183-95. [PMID: 11822882 DOI: 10.1006/exnr.2001.7754] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Doubly transgenic mice expressing both a mutated amyloid precursor protein and a mutated presenilin-1 protein accumulate A(beta) deposits as they age. The early A(beta) deposits were found to be primarily composed of fibrillar A(beta) and resembled compact amyloid plaques. As the mice aged, nonfibrillar A(beta) deposits increased in number and spread to regions not typically associated with amyloid plaques in Alzheimer's disease. The fibrillar, amyloid-containing deposits remained restricted to cortical and hippocampal structures and did not increase substantially beyond the 12-month time point. Even at early time points, the fibrillar deposits were associated with dystrophic neurites and activated astrocytes expressing elevated levels of glial fibrillary acidic protein. Microglia similarly demonstrated increased staining for complement receptor-3 in the vicinity of A(beta) deposits at early time points. However, when MHC-II staining was used to assess the degree of microglial activation, full activation was not detected until mice were 12 months or older. Overall, the regional pattern of A(beta) staining resembles that found in Alzheimer disease; however, a progression from diffuse A(beta) to more compact amyloid deposits is not observed in the mouse model. It is noted that the activation of microglia at 12 months is coincident with the apparent stabilization of fibrillar A(beta) deposits, raising the possibility that activated microglia might clear fibrillar A(beta) deposits at a rate similar to their rate of formation, thereby establishing a relatively steady-state level of amyloid-containing deposits.
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Affiliation(s)
- Marcia N Gordon
- Alzheimer Research Laboratory, Department of Pharmacology, University of South Florida, Tampa, Florida 33612-4799, USA
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Lott IT, Head E. Down syndrome and Alzheimer's disease: a link between development and aging. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2002; 7:172-8. [PMID: 11553933 DOI: 10.1002/mrdd.1025] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A subset of aged individuals with Down syndrome (DS) exhibits the clinical features of Alzheimer's disease (AD) but our ability to detect dementia in this population is hampered by developmental differences as well as the sensitivity of existing test tools. Despite the apparent clinical heterogeneity in aged individuals with DS, age-associated neuropathology is a consistent feature. This is due to the fact that trisomy 21 leads to a dose-dependent increase in the production of the amyloid precursor protein and subsequently the production of the amyloidogenic fragments leading to early and predominant senile plaque formation. A review of the existing literature indicates that oxidative damage and neuroinflammation may interact to accelerate the disease process particularly in individuals with DS over the age of 40 years. By combining clinical information with measures of brain-region specific neuropathology we can "work backwards" and identify the earliest and most sensitive clinical change that may signal the onset of AD. For the past 50 years, investigators in the fields of mental retardation, developmental disabilities, and aging have been interested in the curious link between AD and DS. The morphologic and biochemical origins of AD are seen in the early years of the lifespan for individuals with DS. Study of the process by which AD evolves in DS affords an opportunity to understand an important link between development and aging. This review will focus on advances in the molecular and clinical basis of this association.
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Affiliation(s)
- I T Lott
- Department of Pediatrics, University of California, Irvine, Orange, CA 92868, USA.
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29
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Kalanj-Bognar S, Rundek T, Furac I, Demarin V, Cosović C. Leukocyte lysosomal enzymes in Alzheimer's disease and Down's syndrome. J Gerontol A Biol Sci Med Sci 2002; 57:B16-21. [PMID: 11773202 DOI: 10.1093/gerona/57.1.b16] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous studies suggested the possibility of accelerated lysosomal degradation of brain gangliosides in Alzheimer's disease (AD). As AD pathology affects both neural and nonneural tissues, the aim of this study was to determine possible changes of glycosphingolipid metabolism in available peripheral cells in AD and Down's syndrome (DS). The activities of several lysosomal enzymes involved in catabolism of gangliosides and sulfatides were measured in leukocytes from subjects with dementia of the Alzheimer type, DS, and age-matched controls, by fluorimetry and spectrophotometry using specific substrates. The results showed a statistically significant increase of beta-galactosidase activity in both dementia of the Alzheimer type and DS leukocytes when compared with age-matched controls (p <.01 and p <.05, respectively; Student's t test). Not significantly increased activities of beta-galactosidase, beta-hexosaminidase, beta-hexosaminidase A, and slightly decreased activity of arylsulfatase A were observed in control leukocytes with aging. Our results indicate that a metabolic dysfunction and the acceleration of at least some lysosomal catabolic pathways are present in AD and DS nonneural cells.
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30
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Nijjar RK, Murphy C. Olfactory impairment increases as a function of age in persons with Down syndrome. Neurobiol Aging 2002; 23:65-73. [PMID: 11755021 DOI: 10.1016/s0197-4580(01)00263-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Neuropathology similar to that found in the brains of patients with Alzheimer's disease (AD) has consistently been observed in older individuals with Down syndrome (DS) and this neuropathology is particularly prevalent in areas involved in olfaction. The present study investigated the effects of age on the expression of olfactory impairment in Down syndrome to address the hypothesis that older adults with DS show greater deficits in olfactory function compared with younger persons with DS and compared with age and IQ matched control groups. Between group differences showed that persons with DS had significant deficits in olfactory functioning compared to the two control groups. Further, within the DS group, older adults performed more poorly than the young adults or children. Results support the hypothesis that in a group of persons at risk for AD because of DS, olfactory impairment is greater in older individuals, suggesting progressive impairment over time. Deficits in olfactory function may be useful in signalling incipient dementia in DS.
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Affiliation(s)
- Rani K Nijjar
- Department of Psychology, San Diego State University, San Diego, CA, USA
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31
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Koistinaho M, Ort M, Cimadevilla JM, Vondrous R, Cordell B, Koistinaho J, Bures J, Higgins LS. Specific spatial learning deficits become severe with age in beta -amyloid precursor protein transgenic mice that harbor diffuse beta -amyloid deposits but do not form plaques. Proc Natl Acad Sci U S A 2001; 98:14675-80. [PMID: 11724968 PMCID: PMC64740 DOI: 10.1073/pnas.261562998] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2001] [Indexed: 11/18/2022] Open
Abstract
Memory impairment progressing to dementia is the main clinical symptom of Alzheimer's disease (AD). AD is characterized histologically by the presence of beta-amyloid (Abeta) plaques and neurofibrillary tangles in specific brain regions. Although Abeta derived from the Abeta precursor protein (beta-APP) is believed to play a central etiological role in AD, it is not clear whether soluble and/or fibrillar forms are responsible for the memory deficit. We have generated and previously described mice expressing human wild-type beta-APP(751) isoform in neurons. These transgenic mice recapitulate early histopathological features of AD and form Abeta deposits but no plaques. Here we describe a specific and progressive learning and memory impairment in these animals. In the Morris water maze, a spatial memory task sensitive to hippocampal damage, one pedigree already showed significant differences in acquisition in 3-month-old mice that increased in severity with age and were expressed clearly in 6-month- and 2-year-old animals. The second transgenic pedigree displayed a milder impairment with a later age of onset. Performance deficits significantly decreased during the 6 days of training in young but not in aged transgenic animals. Both pedigrees of the transgenic mice differed from wild-type mice by less expressed increase of escape latencies after the platform position had been changed in the reversal experiment and by failure to prefer the goal quadrant in probe trials. Both pedigrees performed at wild-type level in a number of other tests (open field exploration and passive and active place avoidance). The results suggest that plaque formation is not a necessary condition for the neuronal beta-APP(751) transgene-induced memory impairment, which may be caused by beta-APP overexpression, isoform misexpression, or elevated soluble Abeta.
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Affiliation(s)
- M Koistinaho
- Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4-Krc, Czech Republic
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32
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Wetter S, Murphy C. Apolipoprotein E ε4 positive individuals demonstrate delayed olfactory event-related potentials. Neurobiol Aging 2001; 22:439-47. [PMID: 11378251 DOI: 10.1016/s0197-4580(01)00215-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Apolipoprotein E epsilon4 positive individuals have deficits in the ability to identify and remember odors, as demonstrated by psychophysical measures of olfactory function. The purpose of the present study was to identify olfactory deficits in this population using an objective electrophysiological measure: the olfactory event-related potential (OERP). Olfactory and auditory ERPs were recorded from the Fz, Cz, and Pz electrode sites in 10 epsilon4 positive individuals and 10 age and gender-matched epsilon4 negative individuals in a single-stimulus paradigm. The results indicate: (1) individuals who are positive for the apolipoprotein E epsilon4 allele demonstrated delays (of approximately 100 ms) in the processing of olfactory information compared to those who are epsilon4 negative; (2) OERP latency is more sensitive than psychophysical measures of olfactory function; (3) delays in the cognitive P3 component of the OERP are associated with deficits in the ability to identify an odor; and (4) unlike the moderate ranges found in auditory ERP, OERP latency showed high sensitivity and specificity in classifying epsilon4 positive and negative individuals.
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Affiliation(s)
- S Wetter
- SDSU/UCSD Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA
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33
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Abstract
Alzheimer's disease (AD) is the most common cause of progressive decline of cognitive function in aged humans, and is characterized by the presence of numerous senile plaques and neurofibrillary tangles accompanied by neuronal loss. Some, but not all, of the neuropathological alterations and cognitive impairment in AD can be reproduced genetically and pharmacologically in animals. It should be possible to discover novel drugs that slow the progress or alleviate the clinical symptoms of AD by using these animal models. We review the recent progress in the development of animal models of AD and discuss how to use these model animals to evaluate novel anti-dementia drugs.
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Affiliation(s)
- K Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Showa-ku, 466-8560, Nagoya, Japan
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34
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Huse JT, Doms RW. Closing in on the amyloid cascade: recent insights into the cell biology of Alzheimer's disease. Mol Neurobiol 2000; 22:81-98. [PMID: 11414282 DOI: 10.1385/mn:22:1-3:081] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Accumulation of the amyloid-beta (A beta) peptide in the central nervous system (CNS) is considered by many to be the crucial pathological insult that ultimately leads to the development of Alzheimer's disease (AD). Regulating the production and/or aggregation of A beta could therefore be of considerable benefit to patients afflicted with AD. It has long been known that A beta is derived from the proteolytic processing of the amyloid precursor protein (APP) by two enzymatic activities, beta-secretase and gamma-secretase. Recent breakthroughs have led to the identification of the aspartyl protease BACE (beta-site APP-cleaving enzyme) as beta-secretase and the probable identification of the presenilin proteins as gamma-secretases. This review discusses what is know about BACE and the presenilins, focusing on their capacity as secretases, as well as the options for therapeutic advancement the careful characterization of these proteins will provide. These findings are presented in the context of the "amyloid cascade hypothesis" and its physiological relevance in AD pathogenesis.
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Affiliation(s)
- J T Huse
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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35
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Anderson AJ, Stoltzner S, Lai F, Su J, Nixon RA. Morphological and biochemical assessment of DNA damage and apoptosis in Down syndrome and Alzheimer disease, and effect of postmortem tissue archival on TUNEL. Neurobiol Aging 2000; 21:511-24. [PMID: 10924764 DOI: 10.1016/s0197-4580(00)00126-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have previously shown that Alzheimer disease (AD) brain exhibits terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) for DNA damage and morphological evidence for apoptosis. Down syndrome (DS) is a neurodegenerative disorder that exhibits significant neuropathological parallels with AD. In accordance with these parallels and the need to clarify the mechanism of cell death in DS and AD, we investigated two principal issues in the present study. First, we investigated the hypothesis that TUNEL labeling for DNA damage and morphological evidence for apoptosis is also present in the DS brain. All DS cases employed had a neuropathological diagnosis of AD. Analysis of these cases showed that DS brain exhibits a significant increase in the number of TUNEL-labeled nuclei relative to controls matched for age, Postmortem Delay, and Archival Length, and that a subset of TUNEL-positive nuclei exhibits apoptotic morphologies. We also report that Archival Length in 10% formalin can significantly affect TUNEL labeling in postmortem human brain, and therefore, that Archival Length must be controlled for as a variable in this type of study. Second, we investigated whether biochemical evidence for the mechanism of cell death in DS and AD could be detected. To address this question we employed pulsed-field gel electrophoresis (PFGE) as a sensitive method to evaluate DNA integrity. Although apoptotic oligonucleosomal laddering has not previously been observed in AD, PFGE of DNA from control, DS and AD brain in the present study revealed evidence of high molecular weight DNA fragmentation indicative of apoptosis. This represents biochemical support for an apoptotic mechanism of cell death in DS and AD.
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Affiliation(s)
- A J Anderson
- Institute for Brain Aging and Dementia, University of California, Irvine, 1113 Gillespie NRF, Irvine, CA 92697-4540, USA.
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36
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Azizeh BY, Head E, Ibrahim MA, Torp R, Tenner AJ, Kim RC, Lott IT, Cotman CW. Molecular dating of senile plaques in the brains of individuals with Down syndrome and in aged dogs. Exp Neurol 2000; 163:111-22. [PMID: 10785449 DOI: 10.1006/exnr.2000.7359] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
beta-Amyloid (Abeta) is a constituent of senile plaques found with increasing age in individuals with Down syndrome (DS) and in the canine model of aging. Sections of DS and dog brain were immunostained using an affinity-purified polyclonal antibody for a posttranslationally modified Abeta with a racemized aspartate at position 7 (d7C16). The immunostaining characteristics of d7C16 Abeta in DS and dog brain indicate that it is present in all plaque subtypes, including the thioflavin-S-negative diffuse plaques that develop with age in dogs. The youngest DS case exhibited weak immunolabeling for d7C16 but the extent of d7C16-positive plaques increased with age. In addition, d7C16-positive plaques were initially found in clusters in the superficial layers of the frontal and entorhinal cortex but, with advancing age, increasing numbers appeared in deeper layers, suggesting a progression of Abeta deposition from superficial to deeper cortical layers. Ultrastructural studies in DS brain were confirmed using perfused dog brain and provided consistent results; thioflavin-S-negative diffuse plaques consist of fibrillar Abeta and racemized Abeta is associated with thicker and more highly interwoven fibrils than nonracemized Abeta. The use of antibodies to modified forms of the Abeta protein should provide insight into the progression of plaque pathology in DS and Alzheimer's disease brain.
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Affiliation(s)
- B Y Azizeh
- Institute for Brain Aging and Dementia, University of California at Irvine, Irvine, California 92697-4540, USA
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37
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Wetter S, Murphy C. Individuals with Down's syndrome demonstrate abnormal olfactory event-related potentials. Clin Neurophysiol 1999; 110:1563-9. [PMID: 10479023 DOI: 10.1016/s1388-2457(99)00086-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Recent research has demonstrated that individuals with Down's syndrome (DS) develop plaques and tangles in the brain similar to people with Alzheimer's disease. As a result, they show increased dementia and decreased olfactory functioning compared to healthy individuals. The olfactory event-related potential (OERP) has been used as an objective quantitative measure of olfactory functioning in normal and clinical populations. The present study investigated the utility of the latency and amplitude of the OERP components in examining olfactory dysfunction in DS individuals. METHODS OERPs were recorded monopolarly at the Fz, Cz and Pz electrode sites, using amyl acetate at a 60 s inter-stimulus interval, from individuals with DS (mean age 26.0 years) and age-matched normal controls. Participants were screened for nasal health and odor thresholds were assessed. Dementia was assessed using the dementia rating scale (DRS). RESULTS Results indicate that DS subjects have significantly longer latencies in the sensory (N1, P2, and N2) and cognitive (P3) components of the OERP than normal controls. Odor threshold was significantly associated with sensory OERP components. In addition, DS subjects with a higher level of dementia showed significantly longer P3 latencies than those with lower dementia levels. CONCLUSIONS The study suggests that the OERP may be a useful measure of olfactory dysfunction in DS which may precede developing dementia in this population.
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Affiliation(s)
- S Wetter
- Department of Psychology, San Diego State University, CA 92120-4913, USA
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38
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39
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Eikelenboom P, Rozemuller JM, van Muiswinkel FL. Inflammation and Alzheimer's disease: relationships between pathogenic mechanisms and clinical expression. Exp Neurol 1998; 154:89-98. [PMID: 9875271 DOI: 10.1006/exnr.1998.6920] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
During the past 15 years a variety of inflammatory proteins has been identified in the brains of patients with Alzheimer's disease (AD) postmortem. There is now considerable evidence that in AD the deposition of amyloid-beta (A beta) protein precedes a cascade of events that ultimately leads to a local "brain inflammatory response." Here we reviewed the evidence (i) that inflammatory mechanisms can be a part of the relevant etiological factors for AD in patients with head trauma, ischemia, and Down's syndrome; (ii) that in cerebral A beta disorders the clinical symptoms are determined to a great extent by the site of inflammation; and (iii) that a brain inflammatory response can explain some poorly understood characteristics of the clinical picture, among others the susceptibility of AD patients to delirium. The present data indicate that inflammatory processes in the brain contribute to the etiology, the pathogenesis, and the clinical expression of AD.
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Affiliation(s)
- P Eikelenboom
- Department of Psychiatry, Graduate School Neurosciences Amsterdam, Vrije Universiteit, Valeriuskliniek, The Netherlands
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40
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Kato S, Gondo T, Hoshii Y, Takahashi M, Yamada M, Ishihara T. Confocal observation of senile plaques in Alzheimer's disease: senile plaque morphology and relationship between senile plaques and astrocytes. Pathol Int 1998; 48:332-40. [PMID: 9704339 DOI: 10.1111/j.1440-1827.1998.tb03915.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Senile plaques in the brains of Alzheimer's disease (AD) were examined by confocal laser scanning microscopy (CLSM) with the following three findings. First, in sections stained with Congo red, the serial CLSM images of optical sections clearly revealed that a classic plaque is composed of a plaque core and a corona. Radially arranged process-like structures, corresponding to bundles of amyloid fibrils, formed amyloid cores and stronger signals were detected in the center of some cores. Second, in sections stained with Congo red and anti-glial fibrillary acidic protein (GFAP), reactive astrocytes were found around the senile plaques and many astrocytic processes surrounded the plaque cores and some processes had penetrated into them. Third, three-dimensional reconstruction on classic plaque revealed that the surface of classic plaque showed a 'coral-like' appearance.
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Affiliation(s)
- S Kato
- Department of Psychiatry Medicine, Yamaguchi University School of Medicine, Japan.
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41
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Sugihara S, Saunders AM, Ogawa A, Nakazato Y, Saido TC, Yamaguchi H. Characteristics of cerebral ? amyloid deposition in four non-demented patients in their forties with a high apolipoprotein E ?4 allele frequency. Neuropathology 1997. [DOI: 10.1111/j.1440-1789.1997.tb00061.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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42
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Kuroki K, Uchida K, Kiatipattanasakul W, Nakamura SI, Yamaguchi R, Nakayama H, Doi K, Tateyama S. Immunohistochemical detection of tau protein in various non-human animal brains. Neuropathology 1997. [DOI: 10.1111/j.1440-1789.1997.tb00034.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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43
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Lalowski M, Golabek A, Lemere CA, Selkoe DJ, Wisniewski HM, Beavis RC, Frangione B, Wisniewski T. The "nonamyloidogenic" p3 fragment (amyloid beta17-42) is a major constituent of Down's syndrome cerebellar preamyloid. J Biol Chem 1996; 271:33623-31. [PMID: 8969231 DOI: 10.1074/jbc.271.52.33623] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Down's syndrome (DS) patients show accelerated Alzheimer's disease (AD) neuropathology, which consists of preamyloid lesions followed by the development of neuritic plaques and neurofibrillary tangles. The major constituents of preamyloid and neuritic plaques are amyloid beta (Abeta) peptides. Preamyloid lesions are defined as being Abeta immunoreactive lesions, which unlike neuritic plaque amyloid are Congo red-negative and largely nonfibrillar ultrastructurally. DS patients can develop extensive preamyloid deposits in the cerebellum, without neuritic plaques; hence, DS cerebellums are a source of relatively pure preamyloid. We biochemically characterized the composition of DS preamyloid and compared it to amyloid in the neuritic plaques and leptomeninges in the same patients. We found that Abeta17-42 or p3 is a major Abeta peptide of DS cerebellar preamyloid. This 26-residue peptide is also present in low quantities in neuritic plaques. We suggest that preamyloid can now be defined biochemically as lesions in which a major Abeta peptide is p3.
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Affiliation(s)
- M Lalowski
- Department of Pathology, New York University Medical Center, New York, New York 10016, USA.
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44
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Abstract
This article reviews the significance of changes in the level of cerebrospinal fluid acetylcholinesterase or cholinesterase in patients with Alzheimer's disease or other dementias. Evidence has shown that the methodology of assaying cerebrospinal fluid acetylcholinesterase or cholinesterase is reliable and the activity of the enzyme is stable. Low acetylcholinesterase or cholinesterase levels presenting in cerebrospinal fluid of a demented individual may confirm the clinical diagnosis of Alzheimer's disease or other organic dementia. A low activity of acetylcholinesterase or cholinesterase existing in cerebrospinal fluid of a non-demented individual may indicate a brain at risk, or that the person is in the preclinical stage of dementia. Recognition of the presence of the preclinical stage may be very beneficial for explaining the real meaning of the 'overlap' in the biochemistry and pathology between dementia and non-dementia, and also very important for prevention and treatment. Therefore, the strategy of prevention and of treatment should no longer be designed to inhibit acetylcholinesterase activity. In contrast, it should be designed to enhance the neuronal acetylcholinesterase activity or to delay the degeneration of brain acetylcholinesterase system.
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Affiliation(s)
- Z X Shen
- Department of Neurology, Xuan-Wu Hospital, Beijing, China
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45
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Bancher C, Leitner H, Jellinger K, Eder H, Setinek U, Fischer P, Wegiel J, Wisniewski HM. On the relationship between measles virus and Alzheimer neurofibrillary tangles in subacute sclerosing panencephalitis. Neurobiol Aging 1996; 17:527-33. [PMID: 8832626 DOI: 10.1016/0197-4580(96)00069-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have studied the relationship between measles virus and the accumulation of abnormally phosphorylated tau (PHF-tau) in nine cases of subacute sclerosing panencephalitis (SSPE). By assessing the presence of viral intranuclear inclusions and neurofibrillary tangles (NFT) in each case, we found no correlation between presence and amount of measles virus and the numbers of neurons containing PHF-tau. Immunohistochemical double labeling in a case with long duration of disease and severe histopathologic change revealed no strict colocalization of measles virus antigen and PHF-tau throughout different brain regions. In areas containing both antigens, most neurons carrying measles virus did not have a tangle and vice versa, eventhough some colocalization beyond that expected by chance was observed in specific cortical areas. These results indicate that, although secondary to viral infection, NFT formation in SSPE is not restricted to cells carrying viral antigen. Conversely, measles virus infected cells do not necessarily accumulate PHF-tau. This lack of colocalization at the cellular level, throughout different brain areas and among different cases suggests that the formation of NFT in SSPE is not directly induced by the infectious agent. The formation of NFT in this disease appears to be elicited through a specific type of tissue damage and, thus, to be an epiphenomenon. This pathogenetic detail may be of interest for our understanding of the role of neurofibrillary degeneration in the pathogenesis of other more frequent neurodegenerative diseases with cytoskeletal pathology.
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Affiliation(s)
- C Bancher
- Ludwig Boltzmann Institute of Clinical Neurobiology, Lainz Hospital, Vienna, Austria
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46
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Abstract
Down's Syndrome subjects over 40 years old show neuropathology similar to that of Alzheimer's disease. The olfactory system is particularly vulnerable in Alzheimer's disease, both anatomically and functionally. Several measures of sensory and cognitive functioning were studied in the older Down's Syndrome patient, with the hypothesis of significant olfactory dysfunction. Participants were 23 Down's subjects, and 23 controls. The Dementia Rating Scale showed mean scores of 103 for Down's subjects and 141 for controls. Down's subjects showed significant deficits in odor detection threshold, odor identification, and odor recognition memory. Normal performance in a taste threshold task, similar to the olfactory threshold task in subject demands, suggested that the Down's syndrome subjects' poor performance was not due to task demands. Deficits in olfaction may provide a sensitive and early indicator of the deterioration and progression of the brain in older subjects with Down's Syndrome.
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Affiliation(s)
- C Murphy
- San Diego State University, Department of Psychology, CA 92182, USA
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47
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Wisniewski T, Lalowski M, Bobik M, Russell M, Strosznajder J, Frangione B. Amyloid beta 1-42 deposits do not lead to Alzheimer's neuritic plaques in aged dogs. Biochem J 1996; 313 ( Pt 2):575-80. [PMID: 8573095 PMCID: PMC1216946 DOI: 10.1042/bj3130575] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In alzheimer's disease, amyloid beta (A beta) is deposited in senile plaques and amyloid angiopathy. Longer A beta peptides, which extend to residue 42 (A beta 42), have been suggested to be critical for the seeding of amyloid. Aged dogs develop cerebral vessel amyloid and parenchymal preamyloid lesions. Preamyloid in humans is related to senile plaques, whereas in dogs such progression is rare. We evaluated the composition of aged canine vessel amyloid and preamyloid both biochemically and immunohistochemically. The vessel amyloid extended mainly to residue 40 (A beta 40), while preamyloid contained a mixture of A beta 17-42 and A beta 42, with minimal A beta 40. Our results suggest other factors besides A beta 42 are important for neuritic plaque formation.
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Affiliation(s)
- T Wisniewski
- Department of Neurology, New York University Medical Center, NY 10016, USA
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48
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Siman R, Greenberg BD. Alzheimer’s Disease. Neurotherapeutics 1996. [DOI: 10.1007/978-1-59259-466-5_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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49
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Abstract
To assess the role of microglial cells in senile plaque (SP) formation, we examined the density and distribution of microglia in the temporal neocortex of three groups of nondemented individuals, chosen to represent sequential stages of SP formation (no SP, n = 14; diffuse plaques (DP) only, n = 12; both DP and neuritic plaques (NP), n = 14) and patients with Alzheimer's disease (AD, n = 11). The mean density of microglia was significantly greater in the AD group. In nondemented individuals, the presence of NP but not DP was associated with an increased number of microglial cells. Most NP (91%) were focally associated with microglial cells. DP less commonly contained microglia, however, individuals with some NP had microglia within a greater proportion of their DP (47%) than did those with only DP (19%). These findings suggest that: (a) microglia are not involved in the formation of DP; (b) the presence of NP is associated with both an overall increase in microglia and the focal aggregation of cells around NP; (c) microglia may be locally involved in the conversion of DP into NP. This final point represents the most significant aspect of this study, providing the first quantitative evidence to support a specific role for microglia in the formation of NP from DP.
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Affiliation(s)
- I R Mackenzie
- Department of Pathology (Neuropathology), University of Western Ontario, London, Canada
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50
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Sugihara S, Ogawa A, Nakazato Y, Yamaguchi H. Cerebral beta amyloid deposition in patients with malignant neoplasms: its prevalence with aging and effects of radiation therapy on vascular amyloid. Acta Neuropathol 1995; 90:135-41. [PMID: 7484088 DOI: 10.1007/bf00294312] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We examined immunohistochemically 123 autopsy brains from patients aged between 30 to 59, who died as a result of malignant neoplasms. Using antiserum to amyloid beta protein (A beta), we found that cerebral A beta deposits began in the subjects' fifth decade; its prevalence was 0%, 9.8% and 21.5% in the fourth, fifth and sixth decades, respectively. The major form of A beta deposition was diffuse-type plaques, although one third of the brains with A beta deposition showed amyloid angiopathy. Subpial A beta deposition is frequently associated with amyloid angiopathy. The prevalence of cerebral A beta deposits was about two times higher in the patients who had received brain radiation therapy (27.8%) compared to non-radiated patients (14.8%). Amyloid angiopathy was much more prominent (P < 0.05) with radiation therapy (22.2%) than without (8.0%). We found that cerebral A beta-deposition is dependent on aging, even in patients with malignant tumors and at beginning in their forties, and that brain radiation therapy is a possible risk factor of A beta deposition, especially in the form of amyloid angiopathy.
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Affiliation(s)
- S Sugihara
- Department of Pathology, Gunma Cancer Center, Japan
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