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Sukreet S, Rafii MS, Rissman RA. From understanding to action: Exploring molecular connections of Down syndrome to Alzheimer's disease for targeted therapeutic approach. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2024; 16:e12580. [PMID: 38623383 PMCID: PMC11016820 DOI: 10.1002/dad2.12580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 03/05/2024] [Accepted: 03/08/2024] [Indexed: 04/17/2024]
Abstract
Down syndrome (DS) is caused by a third copy of chromosome 21. Alzheimer's disease (AD) is a neurodegenerative condition characterized by the deposition of amyloid-beta (Aβ) plaques and neurofibrillary tangles in the brain. Both disorders have elevated Aβ, tau, dysregulated immune response, and inflammation. In people with DS, Hsa21 genes like APP and DYRK1A are overexpressed, causing an accumulation of amyloid and neurofibrillary tangles, and potentially contributing to an increased risk of AD. As a result, people with DS are a key demographic for research into AD therapeutics and prevention. The molecular links between DS and AD shed insights into the underlying causes of both diseases and highlight potential therapeutic targets. Also, using biomarkers for early diagnosis and treatment monitoring is an active area of research, and genetic screening for high-risk individuals may enable earlier intervention. Finally, the fundamental mechanistic parallels between DS and AD emphasize the necessity for continued research into effective treatments and prevention measures for DS patients at risk for AD. Genetic screening with customized therapy approaches may help the DS population in current clinical studies and future biomarkers.
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Affiliation(s)
- Sonal Sukreet
- Department of NeurosciencesUniversity of California‐San DiegoLa JollaCaliforniaUSA
| | - Michael S. Rafii
- Department of Neurology, Alzheimer's Therapeutic Research InstituteKeck School of Medicine of the University of Southern CaliforniaSan DiegoCaliforniaUSA
| | - Robert A. Rissman
- Department of NeurosciencesUniversity of California‐San DiegoLa JollaCaliforniaUSA
- Department Physiology and Neuroscience, Alzheimer’s Therapeutic Research InstituteKeck School of Medicine of the University of Southern CaliforniaSan DiegoCaliforniaUSA
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Banerjee G, Collinge J, Fox NC, Lashley T, Mead S, Schott JM, Werring DJ, Ryan NS. Clinical considerations in early-onset cerebral amyloid angiopathy. Brain 2023; 146:3991-4014. [PMID: 37280119 PMCID: PMC10545523 DOI: 10.1093/brain/awad193] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 04/16/2023] [Accepted: 05/01/2023] [Indexed: 06/08/2023] Open
Abstract
Cerebral amyloid angiopathy (CAA) is an important cerebral small vessel disease associated with brain haemorrhage and cognitive change. The commonest form, sporadic amyloid-β CAA, usually affects people in mid- to later life. However, early-onset forms, though uncommon, are increasingly recognized and may result from genetic or iatrogenic causes that warrant specific and focused investigation and management. In this review, we firstly describe the causes of early-onset CAA, including monogenic causes of amyloid-β CAA (APP missense mutations and copy number variants; mutations of PSEN1 and PSEN2) and non-amyloid-β CAA (associated with ITM2B, CST3, GSN, PRNP and TTR mutations), and other unusual sporadic and acquired causes including the newly-recognized iatrogenic subtype. We then provide a structured approach for investigating early-onset CAA, and highlight important management considerations. Improving awareness of these unusual forms of CAA amongst healthcare professionals is essential for facilitating their prompt diagnosis, and an understanding of their underlying pathophysiology may have implications for more common, late-onset, forms of the disease.
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Affiliation(s)
- Gargi Banerjee
- MRC Prion Unit at University College London (UCL), Institute of Prion Diseases, UCL, London, W1W 7FF, UK
| | - John Collinge
- MRC Prion Unit at University College London (UCL), Institute of Prion Diseases, UCL, London, W1W 7FF, UK
| | - Nick C Fox
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Disorders, UCL Queen Square Institute of Neurology, London, W1 1PJ, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Simon Mead
- MRC Prion Unit at University College London (UCL), Institute of Prion Diseases, UCL, London, W1W 7FF, UK
| | - Jonathan M Schott
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT, UK
| | - David J Werring
- Stroke Research Centre, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Natalie S Ryan
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, London, WC1E 6BT, UK
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Sipilä JOT. Adult-Onset Neuroepidemiology in Finland: Lessons to Learn and Work to Do. J Clin Med 2023; 12:3972. [PMID: 37373667 DOI: 10.3390/jcm12123972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Finland is a relatively small genetic isolate with a genetically non-homogenous population. Available Finnish data on neuroepidemiology of adult-onset disorders are limited, and this paper describes the conclusions that can be drawn and their implications. Apparently, Finnish people have a (relatively) high risk of developing Unverricht-Lundborg disease (EPM1), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), Spinal muscular atrophy, Jokela type (SMAJ) and adult-onset dystonia. On the other hand, some disorders, such as Friedreich's ataxia (FRDA) and Wilson's disease (WD), are almost absent or completely absent in the population. Valid and timely data concerning even many common disorders, such as stroke, migraine, neuropathy, Alzheimer's disease and Parkinson's disease, are unavailable, and there are virtually no data on many less-common neurological disorders, such as neurosarcoidosis or autoimmune encephalitides. There also appear to be marked regional differences in the incidence and prevalence of many diseases, suggesting that non-granular nationwide data may be misleading in many cases. Concentrated efforts to advance neuroepidemiological research in the country would be of clinical, administrative and scientific benefit, but currently, all progress is blocked by administrative and financial obstacles.
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Affiliation(s)
- Jussi O T Sipilä
- Department of Neurology, North Karelia Central Hospital, Siun Sote, 80210 Joensuu, Finland
- Clinical Neurosciences, Faculty of Medicine, University of Turku, 20014 Turku, Finland
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Young-Pearse TL, Lee H, Hsieh YC, Chou V, Selkoe DJ. Moving beyond amyloid and tau to capture the biological heterogeneity of Alzheimer's disease. Trends Neurosci 2023; 46:426-444. [PMID: 37019812 PMCID: PMC10192069 DOI: 10.1016/j.tins.2023.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/28/2023] [Accepted: 03/09/2023] [Indexed: 04/05/2023]
Abstract
Alzheimer's disease (AD) manifests along a spectrum of cognitive deficits and levels of neuropathology. Genetic studies support a heterogeneous disease mechanism, with around 70 associated loci to date, implicating several biological processes that mediate risk for AD. Despite this heterogeneity, most experimental systems for testing new therapeutics are not designed to capture the genetically complex drivers of AD risk. In this review, we first provide an overview of those aspects of AD that are largely stereotyped and those that are heterogeneous, and we review the evidence supporting the concept that different subtypes of AD are important to consider in the design of agents for the prevention and treatment of the disease. We then dive into the multifaceted biological domains implicated to date in AD risk, highlighting studies of the diverse genetic drivers of disease. Finally, we explore recent efforts to identify biological subtypes of AD, with an emphasis on the experimental systems and data sets available to support progress in this area.
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Affiliation(s)
- Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Hyo Lee
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Yi-Chen Hsieh
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Vicky Chou
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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Farrell C, Mumford P, Wiseman FK. Rodent Modeling of Alzheimer's Disease in Down Syndrome: In vivo and ex vivo Approaches. Front Neurosci 2022; 16:909669. [PMID: 35747206 PMCID: PMC9209729 DOI: 10.3389/fnins.2022.909669] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/16/2022] [Indexed: 12/30/2022] Open
Abstract
There are an estimated 6 million people with Down syndrome (DS) worldwide. In developed countries, the vast majority of these individuals will develop Alzheimer's disease neuropathology characterized by the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles within the brain, which leads to the early onset of dementia (AD-DS) and reduced life-expectancy. The mean age of onset of clinical dementia is ~55 years and by the age of 80, approaching 100% of individuals with DS will have a dementia diagnosis. DS is caused by trisomy of chromosome 21 (Hsa21) thus an additional copy of a gene(s) on the chromosome must cause the development of AD neuropathology and dementia. Indeed, triplication of the gene APP which encodes the amyloid precursor protein is sufficient and necessary for early onset AD (EOAD), both in people who have and do not have DS. However, triplication of other genes on Hsa21 leads to profound differences in neurodevelopment resulting in intellectual disability, elevated incidence of epilepsy and perturbations to the immune system. This different biology may impact on how AD neuropathology and dementia develops in people who have DS. Indeed, genes on Hsa21 other than APP when in three-copies can modulate AD-pathogenesis in mouse preclinical models. Understanding this biology better is critical to inform drug selection for AD prevention and therapy trials for people who have DS. Here we will review rodent preclinical models of AD-DS and how these can be used for both in vivo and ex vivo (cultured cells and organotypic slice cultures) studies to understand the mechanisms that contribute to the early development of AD in people who have DS and test the utility of treatments to prevent or delay the development of disease.
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Rethinking IRPs/IRE system in neurodegenerative disorders: Looking beyond iron metabolism. Ageing Res Rev 2022; 73:101511. [PMID: 34767973 DOI: 10.1016/j.arr.2021.101511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/21/2021] [Accepted: 11/04/2021] [Indexed: 12/11/2022]
Abstract
Iron regulatory proteins (IRPs) and iron regulatory element (IRE) systems are well known in the progression of neurodegenerative disorders by regulating iron related proteins. IRPs are also regulated by iron homeostasis. However, an increasing number of studies have suggested a close relationship between the IRPs/IRE system and non-iron-related neurodegenerative disorders. In this paper, we reviewed that the IRPs/IRE system is not only controlled by iron ions, but also regulated by such factors as post-translational modification, oxygen, nitric oxide (NO), heme, interleukin-1 (IL-1), and metal ions. In addition, by regulating the transcription of non-iron related proteins, the IRPs/IRE system functioned in oxidative metabolism, cell cycle regulation, abnormal proteins aggregation, and neuroinflammation. Finally, by emphasizing the multiple regulations of IRPs/IRE system and its potential relationship with non-iron metabolic neurodegenerative disorders, we provided new strategies for disease treatment targeting IRPs/IRE system.
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Martinez JL, Zammit MD, West NR, Christian BT, Bhattacharyya A. Basal Forebrain Cholinergic Neurons: Linking Down Syndrome and Alzheimer's Disease. Front Aging Neurosci 2021; 13:703876. [PMID: 34322015 PMCID: PMC8311593 DOI: 10.3389/fnagi.2021.703876] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/17/2021] [Indexed: 12/31/2022] Open
Abstract
Down syndrome (DS, trisomy 21) is characterized by intellectual impairment at birth and Alzheimer's disease (AD) pathology in middle age. As individuals with DS age, their cognitive functions decline as they develop AD pathology. The susceptibility to degeneration of a subset of neurons, known as basal forebrain cholinergic neurons (BFCNs), in DS and AD is a critical link between cognitive impairment and neurodegeneration in both disorders. BFCNs are the primary source of cholinergic innervation to the cerebral cortex and hippocampus, as well as the amygdala. They play a critical role in the processing of information related to cognitive function and are directly engaged in regulating circuits of attention and memory throughout the lifespan. Given the importance of BFCNs in attention and memory, it is not surprising that these neurons contribute to dysfunctional neuronal circuitry in DS and are vulnerable in adults with DS and AD, where their degeneration leads to memory loss and disturbance in language. BFCNs are thus a relevant cell target for therapeutics for both DS and AD but, despite some success, efforts in this area have waned. There are gaps in our knowledge of BFCN vulnerability that preclude our ability to effectively design interventions. Here, we review the role of BFCN function and degeneration in AD and DS and identify under-studied aspects of BFCN biology. The current gaps in BFCN relevant imaging studies, therapeutics, and human models limit our insight into the mechanistic vulnerability of BFCNs in individuals with DS and AD.
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Affiliation(s)
- Jose L. Martinez
- Cellular and Molecular Biology Graduate Program, University of Wisconsin, Madison, WI, United States
- Waisman Center, University of Wisconsin, Madison, WI, United States
| | - Matthew D. Zammit
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
| | - Nicole R. West
- Cellular and Molecular Biology Graduate Program, University of Wisconsin, Madison, WI, United States
- Waisman Center, University of Wisconsin, Madison, WI, United States
| | - Bradley T. Christian
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
| | - Anita Bhattacharyya
- Waisman Center, University of Wisconsin, Madison, WI, United States
- Department of Cellular and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States
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Johnson ECB, Ho K, Yu GQ, Das M, Sanchez PE, Djukic B, Lopez I, Yu X, Gill M, Zhang W, Paz JT, Palop JJ, Mucke L. Behavioral and neural network abnormalities in human APP transgenic mice resemble those of App knock-in mice and are modulated by familial Alzheimer's disease mutations but not by inhibition of BACE1. Mol Neurodegener 2020; 15:53. [PMID: 32921309 PMCID: PMC7489007 DOI: 10.1186/s13024-020-00393-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most frequent and costly neurodegenerative disorder. Although diverse lines of evidence suggest that the amyloid precursor protein (APP) is involved in its causation, the precise mechanisms remain unknown and no treatments are available to prevent or halt the disease. A favorite hypothesis has been that APP contributes to AD pathogenesis through the cerebral accumulation of the amyloid-β peptide (Aβ), which is derived from APP through sequential proteolytic cleavage by BACE1 and γ-secretase. However, inhibitors of these enzymes have failed in clinical trials despite clear evidence for target engagement. METHODS To further elucidate the roles of APP and its metabolites in AD pathogenesis, we analyzed transgenic mice overexpressing wildtype human APP (hAPP) or hAPP carrying mutations that cause autosomal dominant familial AD (FAD), as well as App knock-in mice that do not overexpress hAPP but have two mouse App alleles with FAD mutations and a humanized Aβ sequence. RESULTS Although these lines of mice had marked differences in cortical and hippocampal levels of APP, APP C-terminal fragments, soluble Aβ, Aβ oligomers and age-dependent amyloid deposition, they all developed cognitive deficits as well as non-convulsive epileptiform activity, a type of network dysfunction that also occurs in a substantive proportion of humans with AD. Pharmacological inhibition of BACE1 effectively reduced levels of amyloidogenic APP C-terminal fragments (C99), soluble Aβ, Aβ oligomers, and amyloid deposits in transgenic mice expressing FAD-mutant hAPP, but did not improve their network dysfunction and behavioral abnormalities, even when initiated at early stages before amyloid deposits were detectable. CONCLUSIONS hAPP transgenic and App knock-in mice develop similar pathophysiological alterations. APP and its metabolites contribute to AD-related functional alterations through complex combinatorial mechanisms that may be difficult to block with BACE inhibitors and, possibly, also with other anti-Aβ treatments.
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Affiliation(s)
- Erik C. B. Johnson
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Kaitlyn Ho
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Melanie Das
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Pascal E. Sanchez
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Isabel Lopez
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Xinxing Yu
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Michael Gill
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
| | - Weiping Zhang
- NHC Key Laboratory of Hormones and Development, Tianjin Institute of Endocrinology, Tianjin Medical University Metabolic Diseases Hospital, Tianjin, China
| | - Jeanne T. Paz
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Jorge J. Palop
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA 94158 USA
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158 USA
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Handen BL, Lott IT, Christian BT, Schupf N, OBryant S, Mapstone M, Fagan AM, Lee JH, Tudorascu D, Wang M, Head E, Klunk W, Ances B, Lai F, Zaman S, Krinsky‐McHale S, Brickman AM, Rosas HD, Cohen A, Andrews H, Hartley S, Silverman W. The Alzheimer's Biomarker Consortium-Down Syndrome: Rationale and methodology. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12065. [PMID: 32775597 PMCID: PMC7396809 DOI: 10.1002/dad2.12065] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Adults with Down syndrome (DS) are at exceptionally high risk for Alzheimer's disease (AD), with virtually all individuals developing key neuropathological features by age 40. Identifying biomarkers of AD progression in DS can provide valuable insights into pathogenesis and suggest targets for disease modifying treatments. METHODS We describe the development of a multi-center, longitudinal study of biomarkers of AD in DS. The protocol includes longitudinal examination of clinical, cognitive, blood and cerebrospinal fluid-based biomarkers, magnetic resonance imaging and positron emission tomography measures (at 16-month intervals), as well as genetic modifiers of AD risk and progression. RESULTS Approximately 400 individuals will be enrolled in the study (more than 370 to date). The methodological approach from the administrative, clinical, neuroimaging, omics, neuropathology, and statistical cores is provided. DISCUSSION This represents the largest U.S.-based, multi-site, biomarker initiative of AD in DS. Findings can inform other multidisciplinary networks studying AD in the general population.
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Affiliation(s)
- Benjamin L. Handen
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Ira T. Lott
- IrvineSchool of MedicineDepartment of PediatricsUniversity of CaliforniaOrangeCaliforniaUSA
| | | | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Sid OBryant
- Department of Pharmacology and Neuroscience and Institute for Translational ResearchUniversity of North Texas Health Science CenterFort WorthTexasUSA
| | - Mark Mapstone
- IrvineDepartment of NeurologyUniversity of CaliforniaIrvineCaliforniaUSA
| | - Anne M. Fagan
- Department of NeurologyWashington University in St. LouisSt LouisMissouriUSA
| | - Joseph H. Lee
- Department of Neurology Center, Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityCollege of Physicians and SurgeonsNew YorkNew YorkUSA
| | - Dana Tudorascu
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Mei‐Cheng Wang
- Johns Hopkins Bloomberg School of Public HealthBaltimoreMarylandUSA
| | - Elizabeth Head
- IrvineDepartment of PathologyUniversity of CaliforniaIrvineCaliforniaUSA
| | - William Klunk
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Beau Ances
- Washingston University School of Medicine in St. LouisSt. LouisMissouriUSA
| | - Florence Lai
- Massachusetts General HospitalDepartment of NeurologyHarvard Medical SchoolCharlestownMassachusettsUSA
| | - Shahid Zaman
- School of Clinical MedicineDepartment of PsychiatryUniversity of CambridgeCambridgeUK
| | - Sharon Krinsky‐McHale
- Department of PsychologyNYS Institute for Basic Research in Developmental DisabilitiesStaten IslandNew YorkUSA
| | - Adam M. Brickman
- Department of Neurology Center, Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia UniversityCollege of Physicians and SurgeonsNew YorkNew YorkUSA
| | - H. Diana Rosas
- Massachusetts General HospitalDepartments of Neurology and RadiologyHarvard Medical SchoolCharlestownMassachusettsUSA
| | - Annie Cohen
- Department of PsychiatryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Howard Andrews
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Sigan Hartley
- Waisman CenterUniversity of Wisconsin MadisonMadisonWisconsinUSA
| | - Wayne Silverman
- IrvineSchool of MedicineDepartment of PediatricsUniversity of CaliforniaOrangeCaliforniaUSA
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D’Argenio V, Sarnataro D. New Insights into the Molecular Bases of Familial Alzheimer's Disease. J Pers Med 2020; 10:jpm10020026. [PMID: 32325882 PMCID: PMC7354425 DOI: 10.3390/jpm10020026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/14/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022] Open
Abstract
Like several neurodegenerative disorders, such as Prion and Parkinson diseases, Alzheimer's disease (AD) is characterized by spreading mechanism of aggregated proteins in the brain in a typical "prion-like" manner. Recent genetic studies have identified in four genes associated with inherited AD (amyloid precursor protein-APP, Presenilin-1, Presenilin-2 and Apolipoprotein E), rare mutations which cause dysregulation of APP processing and alterations of folding of the derived amyloid beta peptide (A). Accumulation and aggregation of A in the brain can trigger a series of intracellular events, including hyperphosphorylation of tau protein, leading to the pathological features of AD. However, mutations in these four genes account for a small of the total genetic risk for familial AD (FAD). Genome-wide association studies have recently led to the identification of additional AD candidate genes. Here, we review an update of well-established, highly penetrant FAD-causing genes with correlation to the protein misfolding pathway, and novel emerging candidate FAD genes, as well as inherited risk factors. Knowledge of these genes and of their correlated biochemical cascade will provide several potential targets for treatment of AD and aging-related disorders.
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Affiliation(s)
- Valeria D’Argenio
- CEINGE-Biotecnologie Avanzate scarl, via G. Salvatore 486, 80145 Naples, Italy
- Department of Human Sciences and Quality of Life Promotion, San Raffaele Open University, via di val Cannuta 247, 00166 Rome, Italy
- Correspondence: (V.D.); (D.S.); Tel.: +39-081-3737909 (V.D.); +39-081-7464575 (D.S.)
| | - Daniela Sarnataro
- Department of Molecular Medicine and Medical Biotechnology, Federico II University, via S. Pansini 5, 80131 Naples, Italy
- Correspondence: (V.D.); (D.S.); Tel.: +39-081-3737909 (V.D.); +39-081-7464575 (D.S.)
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Greenberg SM, Bacskai BJ, Hernandez-Guillamon M, Pruzin J, Sperling R, van Veluw SJ. Cerebral amyloid angiopathy and Alzheimer disease - one peptide, two pathways. Nat Rev Neurol 2020; 16:30-42. [PMID: 31827267 PMCID: PMC7268202 DOI: 10.1038/s41582-019-0281-2] [Citation(s) in RCA: 416] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/22/2022]
Abstract
The shared role of amyloid-β (Aβ) deposition in cerebral amyloid angiopathy (CAA) and Alzheimer disease (AD) is arguably the clearest instance of crosstalk between neurodegenerative and cerebrovascular processes. The pathogenic pathways of CAA and AD intersect at the levels of Aβ generation, its circulation within the interstitial fluid and perivascular drainage pathways and its brain clearance, but diverge in their mechanisms of brain injury and disease presentation. Here, we review the evidence for and the pathogenic implications of interactions between CAA and AD. Both pathologies seem to be driven by impaired Aβ clearance, creating conditions for a self-reinforcing cycle of increased vascular Aβ, reduced perivascular clearance and further CAA and AD progression. Despite the close relationship between vascular and plaque Aβ deposition, several factors favour one or the other, such as the carboxy-terminal site of the peptide and specific co-deposited proteins. Amyloid-related imaging abnormalities that have been seen in trials of anti-Aβ immunotherapy are another probable intersection between CAA and AD, representing overload of perivascular clearance pathways and the effects of removing Aβ from CAA-positive vessels. The intersections between CAA and AD point to a crucial role for improving vascular function in the treatment of both diseases and indicate the next steps necessary for identifying therapies.
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Affiliation(s)
- Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Brian J Bacskai
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Mar Hernandez-Guillamon
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jeremy Pruzin
- Center for Alzheimer Research and Treatment, Brigham & Women's Hospital, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Reisa Sperling
- Center for Alzheimer Research and Treatment, Brigham & Women's Hospital, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susanne J van Veluw
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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12
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Cannavo C, Tosh J, Fisher EMC, Wiseman FK. Using mouse models to understand Alzheimer's disease mechanisms in the context of trisomy of chromosome 21. PROGRESS IN BRAIN RESEARCH 2019; 251:181-208. [PMID: 32057307 DOI: 10.1016/bs.pbr.2019.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
People who have Down syndrome are at significantly elevated risk of developing early onset Alzheimer's disease that causes dementia (AD-DS). Here we review recent progress in modeling the development of AD-DS in mouse models. These studies provide insight into mechanisms underlying Alzheimer's disease and generate new clinical research questions. In addition, they suggest potential new targets for disease prevention therapies.
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Affiliation(s)
- Claudia Cannavo
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; UK Dementia Research Institute at University College, London, United Kingdom
| | - Justin Tosh
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom
| | - Elizabeth M C Fisher
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; The London Down Syndrome Consortium (LonDownS), London, United Kingdom
| | - Frances K Wiseman
- Department of Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom; The London Down Syndrome Consortium (LonDownS), London, United Kingdom; UK Dementia Research Institute at University College, London, United Kingdom.
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13
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Affiliation(s)
- Ann D Cohen
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, University of California, Irvine, California
| | - Joseph H Lee
- Department of Epidemiology, Department of Neurology, Columbia University Medical Center, Sergievsky Center, Taub Institute, New York, New York
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14
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Banerjee G, Adams ME, Jaunmuktane Z, Alistair Lammie G, Turner B, Wani M, Sawhney IMS, Houlden H, Mead S, Brandner S, Werring DJ. Early onset cerebral amyloid angiopathy following childhood exposure to cadaveric dura. Ann Neurol 2019; 85:284-290. [PMID: 30597599 PMCID: PMC6492172 DOI: 10.1002/ana.25407] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 11/21/2018] [Accepted: 12/22/2018] [Indexed: 01/04/2023]
Abstract
Amyloid-β transmission has been described in patients both with and without iatrogenic Creutzfeldt-Jakob disease; however, there is little information regarding the clinical impact of this acquired amyloid-β pathology during life. Here, for the first time, we describe in detail the clinical and neuroimaging findings in 3 patients with early onset symptomatic amyloid-β cerebral amyloid angiopathy following childhood exposure to cadaveric dura (by neurosurgical grafting in 2 patients and tumor embolization in a third). Our observations provide further in vivo evidence that cerebral amyloid angiopathy might be caused by transmission of amyloid-β seeds (prions) present in cadaveric dura and have diagnostic relevance for younger patients presenting with suspected cerebral amyloid angiopathy. Ann Neurol 2019; 1-7 ANN NEUROL 2019;85:284-290.
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Affiliation(s)
- Gargi Banerjee
- Stroke Research Centre, Department of Brain Repair and RehabilitationUniversity College London Queen Square Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondon
| | - Matthew E. Adams
- Lysholm Department of NeuroradiologyNational Hospital for Neurology and NeurosurgeryLondon
| | - Zane Jaunmuktane
- Department of Molecular NeuroscienceUniversity College London Queen Square Institute of NeurologyLondon
- Division of NeuropathologyNational Hospital for Neurology and NeurosurgeryLondon
| | | | - Ben Turner
- Barts and London School of Medicine and DentistryQueen Mary University of London and Royal London HospitalLondon
| | - Mushtaq Wani
- Morriston HospitalAbertawe Bro Morgannwg University Health BoardSwansea
| | | | - Henry Houlden
- Department of Molecular NeuroscienceUniversity College London Queen Square Institute of NeurologyLondon
| | - Simon Mead
- Medical Research Council Prion Unit at University College LondonUniversity College London Institute of Prion DiseasesLondon
- National Prion ClinicNational Hospital for Neurology and NeurosurgeryLondon
| | - Sebastian Brandner
- Division of NeuropathologyNational Hospital for Neurology and NeurosurgeryLondon
- Department of Neurodegenerative DiseaseUniversity College London Queen Square Institute of NeurologyLondonUnited Kingdom
| | - David J. Werring
- Stroke Research Centre, Department of Brain Repair and RehabilitationUniversity College London Queen Square Institute of Neurology and National Hospital for Neurology and NeurosurgeryLondon
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15
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Mann DMA, Davidson YS, Robinson AC, Allen N, Hashimoto T, Richardson A, Jones M, Snowden JS, Pendleton N, Potier MC, Laquerrière A, Prasher V, Iwatsubo T, Strydom A. Patterns and severity of vascular amyloid in Alzheimer's disease associated with duplications and missense mutations in APP gene, Down syndrome and sporadic Alzheimer's disease. Acta Neuropathol 2018; 136:569-587. [PMID: 29770843 PMCID: PMC6132946 DOI: 10.1007/s00401-018-1866-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/04/2018] [Accepted: 05/10/2018] [Indexed: 01/11/2023]
Abstract
In this study, we have compared the severity of amyloid plaque formation and cerebral amyloid angiopathy (CAA), and the subtype pattern of CAA pathology itself, between APP genetic causes of AD (APPdup, APP mutations), older individuals with Down syndrome (DS) showing the pathology of Alzheimer's disease (AD) and individuals with sporadic (early and late onset) AD (sEOAD and sLOAD, respectively). The aim of this was to elucidate important group differences and to provide mechanistic insights related to clinical and neuropathological phenotypes. Since lipid and cholesterol metabolism is implicated in AD as well as vascular disease, we additionally aimed to explore the role of APOE genotype in CAA severity and subtypes. Plaque formation was greater in DS and missense APP mutations than in APPdup, sEOAD and sLOAD cases. Conversely, CAA was more severe in APPdup and missense APP mutations, and in DS, compared to sEOAD and sLOAD. When stratified by CAA subtype from 1 to 4, there were no differences in plaque scores between the groups, though in patients with APPdup, APP mutations and sEOAD, types 2 and 3 CAA were more common than type 1. Conversely, in DS, sLOAD and controls, type 1 CAA was more common than types 2 and 3. APOE ε4 allele frequency was greater in sEOAD and sLOAD compared to APPdup, missense APP mutations, DS and controls, and varied between each of the CAA phenotypes with APOE ε4 homozygosity being more commonly associated with type 3 CAA than types 1 and 2 CAA in sLOAD and sEOAD. The differing patterns in CAA within individuals of each group could be a reflection of variations in the efficiency of perivascular drainage, this being less effective in types 2 and 3 CAA leading to a greater burden of CAA in parenchymal arteries and capillaries. Alternatively, as suggested by immunostaining using carboxy-terminal specific antibodies, it may relate to the relative tissue burdens of the two major forms of Aβ, with higher levels of Aβ40 promoting a more 'aggressive' form of CAA, and higher levels of Aβ42(3) favouring a greater plaque burden. Possession of APOE ε4 allele, especially ε4 homozygosity, favours development of CAA generally, and as type 3 particularly, in sEOAD and sLOAD.
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Affiliation(s)
- David M A Mann
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK.
| | - Yvonne S Davidson
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK
| | - Andrew C Robinson
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK
| | - Nancy Allen
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK
| | - Tadafumi Hashimoto
- Department of Neuropathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Anna Richardson
- Cerebral Function Unit, Greater Manchester Neurosciences Centre, Salford Royal Hospital, Stott Lane, Salford, UK
| | - Matthew Jones
- Cerebral Function Unit, Greater Manchester Neurosciences Centre, Salford Royal Hospital, Stott Lane, Salford, UK
| | - Julie S Snowden
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK
- Cerebral Function Unit, Greater Manchester Neurosciences Centre, Salford Royal Hospital, Stott Lane, Salford, UK
| | - Neil Pendleton
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, Salford Royal Hospital, University of Manchester, Salford, UK
| | - Marie-Claude Potier
- ICM Institut du Cerveau et de la Moelle épinière, CNRS UMR7225, INSERM U1127, UPMC, Hôpital de la Pitié-Salpêtrière, 47 Bd de l'Hôpital, Paris, France
| | - Annie Laquerrière
- Department of Pathology, Rouen University Hospital, Rouen, France
- Normandie Univ, UNIROUEN, CHU Rouen, INSERM U1245, Team 4, Neovasc, 76000, Rouen, France
| | - Vee Prasher
- Birmingham Community NHS Trust, The Greenfields, 30 Brookfield Road, Birmingham, B30 3QY, UK
| | - Takeshi Iwatsubo
- Department of Neuropathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Andre Strydom
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, 16 De Crespigny Park, London, UK
- Division of Psychiatry, University College London, 147 Tottenham Court Road, London, UK
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16
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Herault Y, Delabar JM, Fisher EMC, Tybulewicz VLJ, Yu E, Brault V. Rodent models in Down syndrome research: impact and future opportunities. Dis Model Mech 2018; 10:1165-1186. [PMID: 28993310 PMCID: PMC5665454 DOI: 10.1242/dmm.029728] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Down syndrome is caused by trisomy of chromosome 21. To date, a multiplicity of mouse models with Down-syndrome-related features has been developed to understand this complex human chromosomal disorder. These mouse models have been important for determining genotype-phenotype relationships and identification of dosage-sensitive genes involved in the pathophysiology of the condition, and in exploring the impact of the additional chromosome on the whole genome. Mouse models of Down syndrome have also been used to test therapeutic strategies. Here, we provide an overview of research in the last 15 years dedicated to the development and application of rodent models for Down syndrome. We also speculate on possible and probable future directions of research in this fast-moving field. As our understanding of the syndrome improves and genome engineering technologies evolve, it is necessary to coordinate efforts to make all Down syndrome models available to the community, to test therapeutics in models that replicate the whole trisomy and design new animal models to promote further discovery of potential therapeutic targets. Summary: Mouse models have boosted therapeutic options for Down syndrome, and improved models are being developed to better understand the pathophysiology of this genetic condition.
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Affiliation(s)
- Yann Herault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France.,T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris
| | - Jean M Delabar
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, UMR8251, CNRS, 75205 Paris, France.,INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et la Moelle épinière, ICM, 75013 Paris, France.,Brain and Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, 75013 Paris, France
| | - Elizabeth M C Fisher
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, WC1N 3BG, UK.,LonDownS Consortium, London, W1T 7NF UK
| | - Victor L J Tybulewicz
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,LonDownS Consortium, London, W1T 7NF UK.,The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,Department of Medicine, Imperial College, London, SW7 2AZ, UK
| | - Eugene Yu
- T21 Research Society, Brain and Spine Institute (ICM), 75013 Paris.,The Children's Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genetics Program, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.,Department of Cellular and Molecular Biology, Roswell Park Division of Graduate School, Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY 14263, USA
| | - Veronique Brault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 1 rue Laurent Fries, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
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17
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Ovchinnikov DA, Korn O, Virshup I, Wells CA, Wolvetang EJ. The Impact of APP on Alzheimer-like Pathogenesis and Gene Expression in Down Syndrome iPSC-Derived Neurons. Stem Cell Reports 2018; 11:32-42. [PMID: 29861166 PMCID: PMC6066957 DOI: 10.1016/j.stemcr.2018.05.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 05/03/2018] [Accepted: 05/04/2018] [Indexed: 12/17/2022] Open
Abstract
Early-onset Alzheimer disease (AD)-like pathology in Down syndrome is commonly attributed to an increased dosage of the amyloid precursor protein (APP) gene. To test this in an isogenic human model, we deleted the supernumerary copy of the APP gene in trisomic Down syndrome induced pluripotent stem cells or upregulated APP expression in euploid human pluripotent stem cells using CRISPRa. Cortical neuronal differentiation shows that an increased APP gene dosage is responsible for increased β-amyloid production, altered Aβ42/40 ratio, and deposition of the pyroglutamate (E3)-containing amyloid aggregates, but not for several tau-related AD phenotypes or increased apoptosis. Transcriptome comparisons demonstrate that APP has a widespread and temporally modulated impact on neuronal gene expression. Collectively, these data reveal an important role for APP in the amyloidogenic aspects of AD but challenge the idea that increased APP levels are solely responsible for increasing specific phosphorylated forms of tau or enhanced neuronal cell death in Down syndrome-associated AD pathogenesis.
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Affiliation(s)
- Dmitry A Ovchinnikov
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD 4072, Australia
| | - Othmar Korn
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD 4072, Australia
| | - Isaac Virshup
- Centre for Stem Cell Systems, MDHS, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Christine A Wells
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD 4072, Australia; Centre for Stem Cell Systems, MDHS, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD 4072, Australia.
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18
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Zhou ZD, Tan EK. Iron regulatory protein (IRP)-iron responsive element (IRE) signaling pathway in human neurodegenerative diseases. Mol Neurodegener 2017; 12:75. [PMID: 29061112 PMCID: PMC5654065 DOI: 10.1186/s13024-017-0218-4] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/17/2017] [Indexed: 12/13/2022] Open
Abstract
The homeostasis of iron is vital to human health, and iron dyshomeostasis can lead to various disorders. Iron homeostasis is maintained by iron regulatory proteins (IRP1 and IRP2) and the iron-responsive element (IRE) signaling pathway. IRPs can bind to RNA stem-loops containing an IRE in the untranslated region (UTR) to manipulate translation of target mRNA. However, iron can bind to IRPs, leading to the dissociation of IRPs from the IRE and altered translation of target transcripts. Recently an IRE is found in the 5′-UTR of amyloid precursor protein (APP) and α-synuclein (α-Syn) transcripts. The levels of α-Syn, APP and amyloid β-peptide (Aβ) as well as protein aggregation can be down-regulated by IRPs but are up-regulated in the presence of iron accumulation. Therefore, inhibition of the IRE-modulated expression of APP and α-Syn or chelation of iron in patient’s brains has therapeutic significance to human neurodegenerative diseases. Currently, new pre-drug IRE inhibitors with therapeutic effects have been identified and are at different stages of clinical trials for human neurodegenerative diseases. Although some promising drug candidates of chemical IRE inhibitors and iron-chelating agents have been identified and are being validated in clinical trials for neurodegenerative diseases, future studies are expected to further establish the clinical efficacy and safety of IRE inhibitors and iron-chelating agents in patients with neurodegenerative diseases.
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Affiliation(s)
- Zhi Dong Zhou
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. .,Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, 169857, Singapore.
| | - Eng-King Tan
- National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.,Department of Neurology, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore.,Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore, 169857, Singapore
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19
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Wang X, Zhou X, Li G, Zhang Y, Wu Y, Song W. Modifications and Trafficking of APP in the Pathogenesis of Alzheimer's Disease. Front Mol Neurosci 2017; 10:294. [PMID: 28966576 PMCID: PMC5605621 DOI: 10.3389/fnmol.2017.00294] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/31/2017] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD), the most common neurodegenerative disorder, is the leading cause of dementia. Neuritic plaque, one of the major characteristics of AD neuropathology, mainly consists of amyloid β (Aβ) protein. Aβ is derived from amyloid precursor protein (APP) by sequential cleavages of β- and γ-secretase. Although APP upregulation can promote AD pathogenesis by facilitating Aβ production, growing evidence indicates that aberrant post-translational modifications and trafficking of APP play a pivotal role in AD pathogenesis by dysregulating APP processing and Aβ generation. In this report, we reviewed the current knowledge of APP modifications and trafficking as well as their role in APP processing. More importantly, we discussed the effect of aberrant APP modifications and trafficking on Aβ generation and the underlying mechanisms, which may provide novel strategies for drug development in AD.
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Affiliation(s)
- Xin Wang
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China
| | - Xuan Zhou
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China
| | - Gongying Li
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical UniversityJining, China
| | - Yun Zhang
- Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
| | - Yili Wu
- Department of Psychiatry, Jining Medical UniversityJining, China.,Shandong Key Laboratory of Behavioral Medicine, Jining Medical UniversityJining, China.,Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical UniversityJining, China.,Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
| | - Weihong Song
- Townsend Family Laboratories, Department of Psychiatry, The University of British ColumbiaVancouver, BC, Canada
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20
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Doran E, Keator D, Head E, Phelan MJ, Kim R, Totoiu M, Barrio JR, Small GW, Potkin SG, Lott IT. Down Syndrome, Partial Trisomy 21, and Absence of Alzheimer's Disease: The Role of APP. J Alzheimers Dis 2017; 56:459-470. [PMID: 27983553 PMCID: PMC5662115 DOI: 10.3233/jad-160836] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Overexpression of the amyloid precursor protein (APP) gene on chromosome 21 in Down syndrome (DS) has been linked to increased brain amyloid levels and early-onset Alzheimer's disease (AD). An elderly man with phenotypic DS and partial trisomy of chromosome 21 (PT21) lacked triplication of APP affording an opportunity to study the role of this gene in the pathogenesis of dementia. Multidisciplinary studies between ages 66-72 years comprised neuropsychological testing, independent neurological exams, amyloid PET imaging with 11C-Pittsburgh compound-B (PiB), plasma amyloid-β (Aβ) measurements, and a brain autopsy examination. The clinical phenotype was typical for DS and his intellectual disability was mild in severity. His serial neuropsychological test scores showed less than a 3% decline as compared to high functioning individuals with DS who developed dementia wherein the scores declined 17-28% per year. No dementia was detected on neurological examinations. On PiB-PET scans, the patient with PT21 had lower PiB standard uptake values than controls with typical DS or sporadic AD. Plasma Aβ42 was lower than values for demented or non-demented adults with DS. Neuropathological findings showed only a single neuritic plaque and neurofibrillary degeneration consistent with normal aging but not AD. Taken together the findings in this rare patient with PT21 confirm the obligatory role of APP in the clinical, biochemical, and neuropathological findings of AD in DS.
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Affiliation(s)
- Eric Doran
- Department of Pediatrics, University of California, Irvine, Orange, CA, USA
| | - David Keator
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA, USA
| | - Elizabeth Head
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Michael J. Phelan
- Department of Statistics, University of California, Irvine, Irvine, CA, USA
| | - Ron Kim
- Department of Pathology, University of California, Irvine, Orange, CA, USA
| | - Minodora Totoiu
- Department of Pediatrics, University of California, Irvine, Orange, CA, USA
| | - Jorge R. Barrio
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at University of California, Los Angeles, CA, USA
| | - Gary W. Small
- Department of Psychiatry and Biobehavioral Sciences and the Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at the University of California, Los Angeles, CA, USA
| | - Steven G. Potkin
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA, USA
| | - Ira T. Lott
- Department of Pediatrics, University of California, Irvine, Orange, CA, USA,Corresponding author: Ira T. Lott, MD, Address: University of California, Irvine Medical Center, 101 The City Drive South, ZC 4482, Orange, CA 92868, Phone: 714-456-5333, Fax: 714-456-8466,
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21
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Palop JJ, Mucke L. Network abnormalities and interneuron dysfunction in Alzheimer disease. Nat Rev Neurosci 2016; 17:777-792. [PMID: 27829687 DOI: 10.1038/nrn.2016.141] [Citation(s) in RCA: 608] [Impact Index Per Article: 76.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The function of neural circuits and networks can be controlled, in part, by modulating the synchrony of their components' activities. Network hypersynchrony and altered oscillatory rhythmic activity may contribute to cognitive abnormalities in Alzheimer disease (AD). In this condition, network activities that support cognition are altered decades before clinical disease onset, and these alterations predict future pathology and brain atrophy. Although the precise causes and pathophysiological consequences of these network alterations remain to be defined, interneuron dysfunction and network abnormalities have emerged as potential mechanisms of cognitive dysfunction in AD and related disorders. Here, we explore the concept that modulating these mechanisms may help to improve brain function in these conditions.
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Affiliation(s)
- Jorge J Palop
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California 94158, USA.,Department of Neurology, University of California, San Francisco, 1650 Owens Street, San Francisco, California 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California 94158, USA.,Department of Neurology, University of California, San Francisco, 1650 Owens Street, San Francisco, California 94158, USA
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22
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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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23
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Regulation of global gene expression and cell proliferation by APP. Sci Rep 2016; 6:22460. [PMID: 26936520 PMCID: PMC4776145 DOI: 10.1038/srep22460] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/15/2016] [Indexed: 01/12/2023] Open
Abstract
Down syndrome (DS), caused by trisomy of chromosome 21, is one of the most common genetic disorders. Patients with DS display growth retardation and inevitably develop characteristic Alzheimer’s disease (AD) neuropathology, including neurofibrillary tangles and neuritic plaques. The expression of amyloid precursor protein (APP) is increased in both DS and AD patients. To reveal the function of APP and elucidate the pathogenic role of increased APP expression in DS and AD, we performed gene expression profiling using microarray method in human cells overexpressing APP. A set of genes are significantly altered, which are involved in cell cycle, cell proliferation and p53 signaling. We found that overexpression of APP inhibits cell proliferation. Furthermore, we confirmed that the downregulation of two validated genes, PSMA5 and PSMB7, inhibits cell proliferation, suggesting that the downregulation of PSMA5 and PSMB7 is involved in APP-induced cell proliferation impairment. Taken together, this study suggests that APP regulates global gene expression and increased APP expression inhibits cell proliferation. Our study provides a novel insight that APP overexpression may contribute to the growth impairment in DS patients and promote AD pathogenesis by inhibiting cell proliferation including neural stem cell proliferation and neurogenesis.
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Nizetic D, Chen CL, Hong W, Koo EH. Inter-Dependent Mechanisms Behind Cognitive Dysfunction, Vascular Biology and Alzheimer's Dementia in Down Syndrome: Multi-Faceted Roles of APP. Front Behav Neurosci 2015; 9:299. [PMID: 26648852 PMCID: PMC4664698 DOI: 10.3389/fnbeh.2015.00299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 10/27/2015] [Indexed: 01/05/2023] Open
Abstract
People with Down syndrome (DS) virtually all develop intellectual disability (ID) of varying degree of severity, and also have a high risk of early Alzheimer's disease (AD). ID prior to the onset of dementia, and its relationship to the onset of dementia in DS is a complex phenomenon influenced by many factors, and scarcely understood. Unraveling the causative factors and modulators of these processes remains a challenge, with potential to be informative for both ID and AD, for the development of early biomarkers and/or therapeutic approaches. We review the potential relative and inter-connected roles of the chromosome 21 gene for amyloid precursor protein (APP), in both pathological conditions. Rare non-DS people with duplication of APP (dupAPP) get familial early onset AD (FEOAD) with virtually 100% penetrance and prominent cerebrovascular pathology, but don't suffer from ID before dementia onset. All of these features appear to be radically different in DS. On the other hand, rare individuals with partial trisomy 21 (T21) (with APP, but not DS-critical region in trisomy) have been described having ID. Likewise, partial T21 DS (without APP trisomy) show a range of ID, but no AD pathology. We review the multi-faceted roles of APP that might affect cognitive functioning. Given the fact that both Aβ secretion and synaptic maturation/plasticity are dependent on neuronal activity, we explore how this conflicting inter-dependency might affect cognitive pathogenesis in a dynamic way in DS, throughout the lifespan of an individual.
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Affiliation(s)
- Dean Nizetic
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore Singapore ; The LonDownS Consortium, Wellcome Trust London, UK ; The Blizard Institute, Barts and The London School of Medicine, Queen Mary University of London London, UK
| | - Christopher L Chen
- Department of Psychological Medicine and Memory Aging and Cognition Centre, National University Health System, Singapore Singapore ; Department of Pharmacology, National University of Singapore, Singapore Singapore
| | - Wanjin Hong
- Agency for Science, Technology and Research (AStar), Institute of Molecular Cell Biology, Singapore Singapore
| | - Edward H Koo
- Departments of Medicine and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Singapore ; Department of Neurosciences, University of California, San Diego San Diego, CA, USA
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Choong XY, Tosh JL, Pulford LJ, Fisher EMC. Dissecting Alzheimer disease in Down syndrome using mouse models. Front Behav Neurosci 2015; 9:268. [PMID: 26528151 PMCID: PMC4602094 DOI: 10.3389/fnbeh.2015.00268] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/21/2015] [Indexed: 11/13/2022] Open
Abstract
Down syndrome (DS) is a common genetic condition caused by the presence of three copies of chromosome 21 (trisomy 21). This greatly increases the risk of Alzheimer disease (AD), but although virtually all people with DS have AD neuropathology by 40 years of age, not all develop dementia. To dissect the genetic contribution of trisomy 21 to DS phenotypes including those relevant to AD, a range of DS mouse models has been generated which are trisomic for chromosome segments syntenic to human chromosome 21. Here, we consider key characteristics of human AD in DS (AD-DS), and our current state of knowledge on related phenotypes in AD and DS mouse models. We go on to review important features needed in future models of AD-DS, to understand this type of dementia and so highlight pathogenic mechanisms relevant to all populations at risk of AD.
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Affiliation(s)
- Xun Yu Choong
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Justin L Tosh
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Laura J Pulford
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
| | - Elizabeth M C Fisher
- Department of Neurodegenerative Disease, Institute of Neurology, University College London London, UK ; The LonDownS Consortium London, UK
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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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Svedružić ŽM, Popović K, Šendula-Jengić V. Decrease in catalytic capacity of γ-secretase can facilitate pathogenesis in sporadic and Familial Alzheimer's disease. Mol Cell Neurosci 2015; 67:55-65. [PMID: 26051801 DOI: 10.1016/j.mcn.2015.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 05/13/2015] [Accepted: 06/01/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Alzheimer's disease can be a result of an age-induced disparity between increase in cellular metabolism of Aβ peptides and decrease in maximal activity of a membrane-embedded protease γ-secretase. RESULTS We compared activity of WT γ-secretase with the activity of 6 FAD mutants in its presenilin-1 component and 5 FAD mutants in Aβ-part of its APP substrate (Familial Alzheimer's disease). All 11 FAD mutations show linear correlation between the decrease in maximal activity and the clinically observed age-of-onset and age-of-death. Biphasic-inhibitors showed that a higher ratio between physiological Aβ-production and the maximal activity of γ-secretase can be observed in cells that can facilitate pathogenic changes in Aβ-products. For example, Aβ production in cells with WT γ-secretase is at 11% of its maximal activity, with delta-exon-9 mutant at 26%, while with M139V mutant is at 28% of the maximal activity. In the same conditions, G384A mutant is fully saturated and at its maximal activity. Similarly, Aβ production in cells with γ-secretase complex carrying Aph1AL component is 12% of its maximal activity, while in cells with Aph1B complex is 26% of its maximal activity. Similar to the cell-based studies, clinical studies of biphasic dose-response in plasma samples of 54 healthy individuals showed variable ratios between physiological Aβ production and the maximal activity of γ-secretase. CONCLUSIONS The increase in the ratio between physiological Aβ production and maximal activity of γ-secretase can be an early sign of pathogenic processes in enzyme-based, cell-based, and clinical studies of sporadic and Familiar Alzheimer's disease.
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Affiliation(s)
- Željko M Svedružić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia; Department of Biotechnology, University of Rijeka, Rijeka, Croatia.
| | - Katarina Popović
- Neurology and Geriatrics, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia
| | - Vesna Šendula-Jengić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia; Neurology and Geriatrics, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia
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Extracellular association of APP and tau fibrils induces intracellular aggregate formation of tau. Acta Neuropathol 2015; 129:895-907. [PMID: 25869641 PMCID: PMC4436700 DOI: 10.1007/s00401-015-1415-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 12/18/2022]
Abstract
Alzheimer’s disease (AD) is characterized by extracellular amyloid β (Aβ) deposition and intracellular tau aggregation. Many studies have indicated some association between these processes, but it remains unknown how the two pathologies are linked. In this study, we investigated whether expression of amyloid precursor protein (APP) influences extracellular seed-dependent intracellular tau accumulation in cultured cells. Treatment of tau-expressing SH-SY5Y cells with Aβ fibrils did not induce intracellular tau aggregation. On the other hand, in cells expressing both tau and APP, treatment with tau fibrils or Sarkosyl-insoluble tau from AD brains induced intracellular tau aggregation. The seed-dependent intracellular tau aggregation was not induced by expression of APP lacking the extracellular domain. The amount of phosphorylated tau aggregates in cultured cells was dose dependently elevated in response to increased levels of APP on the cell membrane. Our results indicate that the extracellular region of APP is involved in uptake of tau fibrils into cells, raising the possibility that APP, but not Aβ, influences cell-to-cell spreading of tau pathologies in AD by serving as a receptor of abnormal tau aggregates.
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Sala Frigerio C, Lau P, Troakes C, Deramecourt V, Gele P, Van Loo P, Voet T, De Strooper B. On the identification of low allele frequency mosaic mutations in the brains of Alzheimer's disease patients. Alzheimers Dement 2015; 11:1265-76. [PMID: 25937274 DOI: 10.1016/j.jalz.2015.02.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/11/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The cause of sporadic Alzheimer's disease (AD) remains unclear. Given the growing evidence that protein aggregates can spread in a "prion-like" fashion, we reasoned that a small population of brain cells producing such "prion-like" particles due to a postzygotic acquired mutation would be sufficient to trigger the disease. Deep DNA sequencing technology should in principle allow the detection of such mosaics. METHODS To detect the somatic mutations of genes causing AD present in a small number of cells, we developed a targeted deep sequencing approach to scrutinize the genomic loci of APP, PSEN1, and PSEN2 genes in DNA extracted from the entorhinal cortex, one of the brain regions showing the earliest signs of AD pathology. We also included the analysis of the MAPT gene because mutations may promote tangle formation. We validated candidate mutations with an independent targeted ultradeep amplicon sequencing technique. RESULTS We demonstrate that our approach can detect single-nucleotide mosaic variants with a 1% allele frequency and copy number mosaic variants present in as few as 10% of cells. We screened 72 AD and 58 control brain samples and identified three mosaic variants with low allelic frequency (∼1%): two novel MAPT variants in sporadic AD patients and a known PSEN2 variant in a Braak II control subject. Moreover, we detected both novel and known pathogenic nonmosaic heterozygous variants in PSEN1 and PSEN2 in this cohort of sporadic AD patients. DISCUSSION Our results show that mosaic mutations with low allelic frequencies in AD-relevant genes can be detected in brain-derived DNA, but larger samples need to be investigated before a more definitive conclusion with regard to the pathogenicity of such mosaics can be made.
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Affiliation(s)
- Carlo Sala Frigerio
- VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Pierre Lau
- VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Claire Troakes
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | - Patrick Gele
- Université Lille Nord de France, UDSL, Lille, France
| | - Peter Van Loo
- Center for Human Genetics, KU Leuven, Leuven, Belgium; The Francis Crick Institute, London, UK; Wellcome Trust Sanger Institute, Hinxton, UK
| | - Thierry Voet
- Wellcome Trust Sanger Institute, Hinxton, UK; Department of Human Genetics, Laboratory of Reproductive Genomics, KU Leuven, Leuven, Belgium.
| | - Bart De Strooper
- VIB Center for the Biology of Disease, KU Leuven, Leuven, Belgium; Center for Human Genetics, KU Leuven, Leuven, Belgium; Department of Molecular Neuroscience, University College London (UCL) Institute of Neurology, London, UK.
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Nasica-Labouze J, Nguyen PH, Sterpone F, Berthoumieu O, Buchete NV, Coté S, De Simone A, Doig AJ, Faller P, Garcia A, Laio A, Li MS, Melchionna S, Mousseau N, Mu Y, Paravastu A, Pasquali S, Rosenman DJ, Strodel B, Tarus B, Viles JH, Zhang T, Wang C, Derreumaux P. Amyloid β Protein and Alzheimer's Disease: When Computer Simulations Complement Experimental Studies. Chem Rev 2015; 115:3518-63. [PMID: 25789869 DOI: 10.1021/cr500638n] [Citation(s) in RCA: 478] [Impact Index Per Article: 53.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jessica Nasica-Labouze
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Phuong H Nguyen
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Fabio Sterpone
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Olivia Berthoumieu
- ‡LCC (Laboratoire de Chimie de Coordination), CNRS, Université de Toulouse, Université Paul Sabatier (UPS), Institut National Polytechnique de Toulouse (INPT), 205 route de Narbonne, BP 44099, Toulouse F-31077 Cedex 4, France
| | | | - Sébastien Coté
- ∥Département de Physique and Groupe de recherche sur les protéines membranaires (GEPROM), Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3T5, Canada
| | - Alfonso De Simone
- ⊥Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andrew J Doig
- #Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Peter Faller
- ‡LCC (Laboratoire de Chimie de Coordination), CNRS, Université de Toulouse, Université Paul Sabatier (UPS), Institut National Polytechnique de Toulouse (INPT), 205 route de Narbonne, BP 44099, Toulouse F-31077 Cedex 4, France
| | | | - Alessandro Laio
- ○The International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Mai Suan Li
- ◆Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.,¶Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Simone Melchionna
- ⬠Instituto Processi Chimico-Fisici, CNR-IPCF, Consiglio Nazionale delle Ricerche, 00185 Roma, Italy
| | | | - Yuguang Mu
- ▲School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | - Anant Paravastu
- ⊕National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Samuela Pasquali
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | | | - Birgit Strodel
- △Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Bogdan Tarus
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - John H Viles
- ▼School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Tong Zhang
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France.,▲School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | | | - Philippe Derreumaux
- †Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique (IBPC), UPR9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France.,□Institut Universitaire de France, 75005 Paris, France
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Abstract
Alzheimer's disease (AD), the most common form of dementia in western societies, is a pathologically and clinically heterogeneous disease with a strong genetic component. The recent advances in high-throughput genome technologies allowing for the rapid analysis of millions of polymorphisms in thousands of subjects has significantly advanced our understanding of the genomic underpinnings of AD susceptibility. During the last 5 years, genome-wide association and whole-exome- and whole-genome sequencing studies have mapped more than 20 disease-associated loci, providing insights into the molecular pathways involved in AD pathogenesis and hinting at potential novel therapeutic targets. This review article summarizes the challenges and opportunities of when using genomic information for the diagnosis and prognosis of AD.
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Affiliation(s)
- Christiane Reitz
- Sergievsly Center/Taub Institute/Dept. of Neurology, Columbia University, 630 W 168th Street, Rm 19-308, New York, NY 10032, phone: (212) 305-0865, fax: (212) 305-2391
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Firoz C, Jabir NR, Khan MS, Mahmoud M, Shakil S, Damanhouri GA, Zaidi SK, Tabrez S, Kamal MA. An overview on the correlation of neurological disorders with cardiovascular disease. Saudi J Biol Sci 2015; 22:19-23. [PMID: 25561878 PMCID: PMC4281592 DOI: 10.1016/j.sjbs.2014.09.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/30/2014] [Accepted: 09/01/2014] [Indexed: 01/20/2023] Open
Abstract
Neurological disorders (NDs) are one of the leading causes of death especially in the developed countries. Among those NDs, Alzheimer's disease (AD) and Parkinson disease (PD) are heading the table. There have been several reports in the scientific literatures which suggest the linkage between cardiovascular disorders (CVDs) and NDs. In the present communication, we have tried to compile NDs (AD and PD) association with CVDs reported in the literature. Based on the available scientific literature, we believe that further comprehensive study needs to be done to elucidate the molecular linking points associated with the above mentioned disorders.
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Affiliation(s)
- C.K. Firoz
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Nasimudeen R. Jabir
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Mohd Shahnawaz Khan
- Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Maged Mahmoud
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Shazi Shakil
- Department of Bioengineering, Integral University, Kursi Road, Lucknow, UP 226026, India
| | - Ghazi A. Damanhouri
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Syed Kashif Zaidi
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Shams Tabrez
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Mohammad A. Kamal
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia
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Opportunities and Limitations of Modelling Alzheimer's Disease with Induced Pluripotent Stem Cells. J Clin Med 2014; 3:1357-72. [PMID: 26237606 PMCID: PMC4470188 DOI: 10.3390/jcm3041357] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/31/2014] [Accepted: 11/12/2014] [Indexed: 01/16/2023] Open
Abstract
Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) has opened the way for patient-specific disease modelling. Following their differentiation into neuronal cell types, iPSC have enabled the investigation of human neurodegenerative diseases, such as Alzheimer's disease (AD). While human iPSCs certainly provide great opportunities to repeatedly interrogate specific human brain cell types of individuals with familial and sporadic forms of the disease, the complex aetiology and timescale over which AD develops in humans poses particular challenges to iPSC-based AD models. Here, we discuss the current state-of-play in the context of these and other iPSC model-related challenges and elaborate on likely future developments in this field of research.
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Wu Y, Deng Y, Zhang S, Luo Y, Cai F, Zhang Z, Zhou W, Li T, Song W. Amyloid-β precursor protein facilitates the regulator of calcineurin 1-mediated apoptosis by downregulating proteasome subunit α type-5 and proteasome subunit β type-7. Neurobiol Aging 2014; 36:169-77. [PMID: 25194880 DOI: 10.1016/j.neurobiolaging.2014.07.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 11/28/2022]
Abstract
Individuals with Down syndrome (DS), caused by trisomy of chromosome 21, inevitably develop characteristic Alzheimer's disease (AD) neuropathology, including neuritic plaques, neurofibrillary tangles, and neuronal loss. Amyloid-β protein, the major component of neuritic plaques, is the proteolytic product of amyloid-β precursor protein (APP). APP and the regulator of calcineurin 1 (RCAN1) genes on chromosome 21 play a pivotal role in promoting plaque formation and neuronal apoptosis. However, the mechanism underlying AD pathogenesis in DS is not well defined. In this study, we demonstrated that APP significantly increased RCAN1 level in both cells and transgenic mice. Overexpression of APP significantly reduced the expression of 2 proteasome subunits, proteasome subunit α type-5 and proteasome subunit β type-7, leading to the inhibition of proteasomal degradation of RCAN1. Furthermore, knockdown of RCAN1 expression attenuated APP-induced neuronal apoptosis. Taken together, the results clearly showed that APP has a previously unknown function in regulating RCAN1-mediated neuronal apoptosis through the proteasome pathway. Our study demonstrates a novel mechanism by which overexpression of APP and RCAN1 causes neurodegeneration and AD pathogenesis in DS, and it provides new insights into the potential of targeting APP-induced proteasomal impairment and RCAN1 accumulation for AD and DS treatment.
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Affiliation(s)
- Yili Wu
- Chongqing City Key Lab of Translational Medical Research in Cognitive Development and Learning and Memory Disorders and Ministry of Education Key Lab of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China; Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Yu Deng
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Shuting Zhang
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Yawen Luo
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Fang Cai
- Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Zhuohua Zhang
- State Key Laboratory of Medical Genetics of China, Central South University, Changsha, Hunan, China
| | - Weihui Zhou
- Chongqing City Key Lab of Translational Medical Research in Cognitive Development and Learning and Memory Disorders and Ministry of Education Key Lab of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Tingyu Li
- Chongqing City Key Lab of Translational Medical Research in Cognitive Development and Learning and Memory Disorders and Ministry of Education Key Lab of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
| | - Weihong Song
- Chongqing City Key Lab of Translational Medical Research in Cognitive Development and Learning and Memory Disorders and Ministry of Education Key Lab of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China; Townsend Family Laboratories, Department of Psychiatry, Brain Research Center, The University of British Columbia, Vancouver, British Columbia, Canada.
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Zou Z, Liu C, Che C, Huang H. Clinical genetics of Alzheimer's disease. BIOMED RESEARCH INTERNATIONAL 2014; 2014:291862. [PMID: 24955352 PMCID: PMC4052685 DOI: 10.1155/2014/291862] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/21/2014] [Indexed: 11/25/2022]
Abstract
Alzheimer's disease (AD) is the most common progressive neurodegenerative disease and the most common form of dementia in the elderly. It is a complex disorder with environmental and genetic components. There are two major types of AD, early onset and the more common late onset. The genetics of early-onset AD are largely understood with mutations in three different genes leading to the disease. In contrast, while susceptibility loci and alleles associated with late-onset AD have been identified using genetic association studies, the genetics of late-onset Alzheimer's disease are not fully understood. Here we review the known genetics of early- and late-onset AD, the clinical features of EOAD according to genotypes, and the clinical implications of the genetics of AD.
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Affiliation(s)
- Zhangyu Zou
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou 350001, China
| | - Changyun Liu
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou 350001, China
| | - Chunhui Che
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou 350001, China
| | - Huapin Huang
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou 350001, China
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Alzheimer's disease therapeutics targeted to the control of amyloid precursor protein translation: maintenance of brain iron homeostasis. Biochem Pharmacol 2014; 88:486-94. [PMID: 24513321 DOI: 10.1016/j.bcp.2014.01.032] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/16/2014] [Accepted: 01/22/2014] [Indexed: 11/20/2022]
Abstract
The neurotoxicity of amyloid beta (Aβ), a major cleavage product of the amyloid precursor protein (APP), is enhanced by iron, as found in the amyloid plaques of Alzheimer's disease (AD) patients. By contrast, the long-known neuroprotective activity of APP is evident after α-secretase cleavage of the precursor to release sAPPα, and depends on the iron export actions of APP itself. The latter underlie its neurotrophic and protective effects in facilitating the homeostatic actions of ferroportin mediated-iron export. Thus APP-dependent iron export may alleviate oxidative stress by minimizing labile iron thus protecting neurons from iron overload during stroke and hemorrhage. Consistent with this, altered phosphorylation of iron-regulatory protein-1 (IRP1) and its signaling processes play a critical role in modulating APP translation via the 5' untranslated region (5'UTR) of its transcript. The APP 5'UTR region encodes a functional iron-responsive element (IRE) RNA stem loop that represents a potential target for modulating APP production. Targeted regulation of APP gene expression via the modulation of 5'UTR sequence function represents a novel approach for the potential treatment of AD since altering APP translation can be used to improve both the protective brain iron balance and provide anti-amyloid efficacy. Approved drugs including paroxetine and desferrioxamine and several novel compounds have been identified that suppress abnormal metal-promoted Aβ accumulation with a subset of these acting via APP 5'UTR-dependent mechanisms to modulate APP translation and cleavage to generate the non-toxic sAPPα.
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Chen Y, Neve RN, Zheng H, Griffin WTS, Barger SW, Mrak RE. Cycle on Wheels: Is APP Key to the AppBp1 Pathway? AUSTIN ALZHEIMER'S AND PARKINSON'S DISEASE 2014; 1:id1008. [PMID: 25568892 PMCID: PMC4283775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Alzheimer's disease (AD) is the gradual loss of the cognitive function due to neuronal death. Currently no therapy is available to slow down, reverse or prevent the disease. Here we analyze the existing data in literature and hypothesize that the physiological function of the Amyloid Precursor Protein (APP) is activating the AppBp1 pathway and this function is gradually lost during the progression of AD pathogenesis. The AppBp1 pathway, also known as the neddylation pathway, activates the small ubiquitin-like protein nedd8, which covalently modifies and switches on Cullin ubiquitin ligases, which are essential in the turnover of cell cycle proteins. Here we discuss how APP may activate the AppBp1 pathway, which downregulates cell cycle markers and protects genome integrity. More investigation of this mechanism-driven hypothesis may provide insights into disease treatment and prevention strategies.
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Affiliation(s)
- Y Chen
- Department of Geriatrics, University of Arkansas for Medical Sciences, USA
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, USA
| | - RN Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, USA
| | - H Zheng
- Huffington Center on Aging, Baylor College of Medicine, USA
| | - WTS Griffin
- Department of Geriatrics, University of Arkansas for Medical Sciences, USA
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, USA
| | - SW Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences, USA
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, USA
| | - RE Mrak
- Department of Pathology, University of Toledo Health Sciences Campus, USA
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Wang W, Mutka AL, Zmrzljak UP, Rozman D, Tanila H, Gylling H, Remes AM, Huttunen HJ, Ikonen E. Amyloid precursor protein α- and β-cleaved ectodomains exert opposing control of cholesterol homeostasis via SREBP2. FASEB J 2013; 28:849-60. [PMID: 24249638 DOI: 10.1096/fj.13-239301] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Amyloid precursor protein (APP) is ubiquitously expressed. Studies in neuronal cells have implicated APP or its fragments as negative regulators of cholesterol metabolism. In the current study, APP acted, via its α-cleavage, as a positive regulator of sterol regulatory element-binding protein-2 (SREBP2) signaling in human astrocytic cells (U251MG), hepatic cells (HepG2), and primary fibroblasts, leading to an approximate 30% increase in SRE-dependent gene expression and, consequently, enhanced cholesterol biosynthesis and LDL receptor levels. This effect was mediated via the secretory ectodomain APPsα. The β-cleaved ectodomain, in turn, repressed SRE-dependent gene expression by up to ∼ 30%. This resulted in decreased cholesterol synthesis and LDL receptor content, establishing a physiological feedback loop in cholesterol-loaded cells, where APP undergoes preferential β-cleavage. Patients with familial Alzheimer's disease had decreased circulating lathosterol, reflecting hepatic cholesterol synthesis, and their fibroblasts had reduced LDL receptor content, which was alleviated by decreasing β-cleavage. These results show that APP regulates cholesterol metabolism in cells relevant for whole-body cholesterol balance and reveal that APP α- and β-cleavages produce opposing paracrine regulators of SREBP2 signaling.
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Affiliation(s)
- Wei Wang
- 2Institute of Biomedicine, Haartmaninkatu 8, FI-00014 University of Helsinki, Finland.
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39
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Yuan SH, Shaner M. Bioengineered stem cells in neural development and neurodegeneration research. Ageing Res Rev 2013; 12:739-48. [PMID: 23651546 DOI: 10.1016/j.arr.2013.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 04/05/2013] [Accepted: 04/09/2013] [Indexed: 01/26/2023]
Abstract
The recent discovery of a simple method for making induced pluripotent stem cells (iPSC) from human somatic cells was a major scientific advancement that opened the way for many promising new developments in the study of developmental and degenerative diseases. iPSC have already been used to model many different types of neurological diseases, including autism, schizophrenia, Alzheimer's disease and Parkinson's disease. Because of their pluripotent property, iPSC offer the possibility of modeling human development in vitro. Their differentiation seems to follow the developmental timeline and obeys environmental cues. Clinically relevant phenotypes of neurodegenerative pathologies have also been observed using iPSC derived human neuronal cultures. Options for treatment are still some way off. Although some early research in mouse models has been encouraging, major obstacles remain for neural stem cell (NSC) transplantation therapy. However, iPSC now offer the prospect of an unlimited amount of human neurons or astrocytes for drug testing. The aim of this review is to summarize the recent progress in modeling neural development and neurological diseases using iPSC and to describe their applications for aging research and personalized medicine.
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Affiliation(s)
- Shauna H Yuan
- University of California, San Diego, Department of Neurosciences, 9500 Gilman Dr. MC 0624, MTF Room 151, La Jolla, CA 92093-0624, USA.
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Hunter S, Arendt T, Brayne C. The senescence hypothesis of disease progression in Alzheimer disease: an integrated matrix of disease pathways for FAD and SAD. Mol Neurobiol 2013; 48:556-70. [PMID: 23546742 DOI: 10.1007/s12035-013-8445-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/13/2013] [Indexed: 12/24/2022]
Abstract
Alzheimer disease (AD) is a progressive, neurodegenerative disease characterised in life by cognitive decline and behavioural symptoms and post-mortem by the neuropathological hallmarks including the microtubule-associated protein tau-reactive tangles and neuritic plaques and amyloid-beta-protein-reactive senile plaques. Greater than 95 % of AD cases are sporadic (SAD) with a late onset and <5 % of AD cases are familial (FAD) with an early onset. FAD is associated with various genetic mutations in the amyloid precursor protein (APP) and the presenilins (PS)1 and PS2. As yet, no disease pathway has been fully accepted and there are no treatments that prevent, stop or reverse the cognitive decline associated with AD. Here, we review and integrate available environmental and genetic evidence associated with all forms of AD. We present the senescence hypothesis of AD progression, suggesting that factors associated with AD can be seen as partial stressors within the matrix of signalling pathways that underlie cell survival and function. Senescence pathways are triggered when stressors exceed the cells ability to compensate for them. The APP proteolytic system has many interactions with pathways involved in programmed senescence and APP proteolysis can both respond to and be driven by senescence-associated signalling. Disease pathways associated with sporadic disease may be different to those involving familial genetic mutations. The interpretation we provide strongly points to senescence as an additional underlying causal process in dementia progression in both SAD and FAD via multiple disease pathways.
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Affiliation(s)
- Sally Hunter
- Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Forvie Site, Robinson Way, Cambridge, CB2 0SR, UK,
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Cohen AD, Rabinovici GD, Mathis CA, Jagust WJ, Klunk WE, Ikonomovic MD. Using Pittsburgh Compound B for in vivo PET imaging of fibrillar amyloid-beta. ADVANCES IN PHARMACOLOGY 2013; 64:27-81. [PMID: 22840744 DOI: 10.1016/b978-0-12-394816-8.00002-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The development of Aβ-PET imaging agents has allowed for detection of fibrillar Aβ deposition in vivo and marks a major advancement in understanding the role of Aβ in Alzheimer's disease (AD). Imaging Aβ thus has many potential clinical benefits: early or perhaps preclinical detection of disease and accurately distinguishing AD from dementias of other non-Aβ causes in patients presenting with mild or atypical symptoms or confounding comorbidities (in which the distinction is difficult to make clinically). From a research perspective, imaging Aβ allows us to study relationships between amyloid pathology and changes in cognition, brain structure, and function across the continuum from normal aging to mild cognitive impairment (MCI) to AD; and to monitor the effectiveness of anti-Aβ drugs and relate them to neurodegeneration and clinical symptoms. Here, we will discuss the application of one of the most broadly studied and widely used Aβ imaging agents, Pittsburgh Compound-B (PiB).
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Affiliation(s)
- Ann D Cohen
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Chapman J, Rees E, Harold D, Ivanov D, Gerrish A, Sims R, Hollingworth P, Stretton A, Holmans P, Owen MJ, O'Donovan MC, Williams J, Kirov G. A genome-wide study shows a limited contribution of rare copy number variants to Alzheimer's disease risk. Hum Mol Genet 2013; 22:816-24. [PMID: 23148125 PMCID: PMC3554198 DOI: 10.1093/hmg/dds476] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/25/2012] [Accepted: 10/31/2012] [Indexed: 01/29/2023] Open
Abstract
We assessed the role of rare copy number variants (CNVs) in Alzheimer's disease (AD) using intensity data from 3260 AD cases and 1290 age-matched controls from the genome-wide association study (GWAS) conducted by the Genetic and Environmental Risk for Alzheimer's disease Consortium (GERAD). We did not observe a significant excess of rare CNVs in cases, although we did identify duplications overlapping APP and CR1 which may be pathogenic. We looked for an excess of CNVs in loci which have been highlighted in previous AD CNV studies, but did not replicate previous findings. Through pathway analyses, we observed suggestive evidence for biological overlap between single nucleotide polymorphisms and CNVs in AD susceptibility. We also identified that our sample of elderly controls harbours significantly fewer deletions >1 Mb than younger control sets in previous CNV studies on schizophrenia and bipolar disorder (P = 8.9 × 10(-4) and 0.024, respectively), raising the possibility that healthy elderly individuals have a reduced rate of large deletions. Thus, in contrast to diseases such as schizophrenia, autism and attention deficit/hyperactivity disorder, CNVs do not appear to make a significant contribution to the development of AD.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Julie Williams
- MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
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Abstract
In the search for new genes in Alzheimer's disease, classic linkage-based and candidate-gene-based association studies have been supplanted by exome sequencing, genome-wide sequencing (for mendelian forms of Alzheimer's disease), and genome-wide association studies (for non-mendelian forms). The identification of new susceptibility genes has opened new avenues for exploration of the underlying disease mechanisms. In addition to detecting novel risk factors in large samples, next-generation sequencing approaches can deliver novel insights with even small numbers of patients. The shift in focus towards translational studies and sequencing of individual patients places each patient's biomaterials as the central unit of genetic studies. The notional shift needed to make the patient central to genetic studies will necessitate strong collaboration and input from clinical neurologists.
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Affiliation(s)
- Karolien Bettens
- Neurodegenerative Brain Diseases Group, VIB Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
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Svedružić ŽM, Popović K, Šendula-Jengić V. Modulators of γ-secretase activity can facilitate the toxic side-effects and pathogenesis of Alzheimer's disease. PLoS One 2013; 8:e50759. [PMID: 23308095 PMCID: PMC3538728 DOI: 10.1371/journal.pone.0050759] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 10/25/2012] [Indexed: 11/18/2022] Open
Abstract
Background Selective modulation of different Aβ products of an intramembrane protease γ-secretase, could be the most promising strategy for development of effective therapies for Alzheimer's disease. We describe how different drug-candidates can modulate γ-secretase activity in cells, by studying how DAPT affects changes in γ-secretase activity caused by gradual increase in Aβ metabolism. Results Aβ 1–40 secretion in the presence of DAPT shows biphasic activation-inhibition dose-response curves. The biphasic mechanism is a result of modulation of γ-secretase activity by multiple substrate and inhibitor molecules that can bind to the enzyme simultaneously. The activation is due to an increase in γ-secretase's kinetic affinity for its substrate, which can make the enzyme increasingly more saturated with otherwise sub-saturating substrate. The noncompetitive inhibition that prevails at the saturating substrate can decrease the maximal activity. The synergistic activation-inhibition effects can drastically reduce γ-secretase's capacity to process its physiological substrates. This reduction makes the biphasic inhibitors exceptionally prone to the toxic side-effects and potentially pathogenic. Without the modulation, γ-secretase activity on it physiological substrate in cells is only 14% of its maximal activity, and far below the saturation. Significance Presented mechanism can explain why moderate inhibition of γ-secretase cannot lead to effective therapies, the pharmacodynamics of Aβ-rebound phenomenon, and recent failures of the major drug-candidates such as semagacestat. Novel improved drug-candidates can be prepared from competitive inhibitors that can bind to different sites on γ-secretase simultaneously. Our quantitative analysis of the catalytic capacity can facilitate the future studies of the therapeutic potential of γ-secretase and the pathogenic changes in Aβ metabolism.
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Affiliation(s)
- Željko M Svedružić
- Medical Biochemistry, PB Rab, Faculty of Medicine, University of Rijeka, Rab, Croatia.
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Molecular Genetic Analysis of the APP, PSEN1, and PSEN2 Genes in Finnish Patients With Early-onset Alzheimer Disease and Frontotemporal Lobar Degeneration. Alzheimer Dis Assoc Disord 2012; 26:272-6. [DOI: 10.1097/wad.0b013e318231e6c7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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46
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Hooli BV, Mohapatra G, Mattheisen M, Parrado AR, Roehr JT, Shen Y, Gusella JF, Moir R, Saunders AJ, Lange C, Tanzi RE, Bertram L. Role of common and rare APP DNA sequence variants in Alzheimer disease. Neurology 2012; 78:1250-7. [PMID: 22491860 DOI: 10.1212/wnl.0b013e3182515972] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES More than 30 different rare mutations, including copy number variants (CNVs), in the amyloid precursor protein gene (APP) cause early-onset familial Alzheimer disease (EOFAD), whereas the contribution of common APP variants to disease risk remains controversial. In this study we systematically assessed the role of both rare and common APP DNA variants in Alzheimer disease (AD) families. METHODS Families with EOFAD genetically linked to the APP region were screened for missense mutations and locus duplications of APP. Further, using genome-wide DNA microarray data, we examined the APP locus for CNVs in a total of 797 additional early- and late-onset AD pedigrees. Finally, 423 single nucleotide polymorphisms (SNPs) in the APP locus, including 2 promoter polymorphisms previously associated with AD risk, were tested in up to 4,200 individuals from multiplex AD families. RESULTS Analyses of 8 21q21-linked families revealed one family carrying a nonsynonymous mutation in exon 17 (Val717Leu) and another family with a partially penetrant 3.5-Mb locus duplication encompassing APP. CNV analysis in the APP locus revealed an additional family carrying a fully penetrant 380-kb duplication, merely spanning APP. Last, contrary to previous reports, association analyses of more than 400 different SNPs in or near APP failed to show significant effects on AD risk. CONCLUSION Our study shows that APP mutations and locus duplications are a very rare cause of EOFAD and that the contribution of common APP variants to AD susceptibility is insignificant. Furthermore, duplications of APP may not be fully penetrant, possibly indicating the existence of hitherto unknown protective genetic factors.
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Affiliation(s)
- B V Hooli
- Genetics and Aging Research Unit, Massachusetts General Hospital, Charlestown, MA, USA
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47
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Svedružić ZM, Popović K, Smoljan I, Sendula-Jengić V. Modulation of γ-secretase activity by multiple enzyme-substrate interactions: implications in pathogenesis of Alzheimer's disease. PLoS One 2012; 7:e32293. [PMID: 22479317 PMCID: PMC3316526 DOI: 10.1371/journal.pone.0032293] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 01/24/2012] [Indexed: 11/19/2022] Open
Abstract
Background We describe molecular processes that can facilitate pathogenesis of Alzheimer's disease (AD) by analyzing the catalytic cycle of a membrane-imbedded protease γ-secretase, from the initial interaction with its C99 substrate to the final release of toxic Aβ peptides. Results The C-terminal AICD fragment is cleaved first in a pre-steady-state burst. The lowest Aβ42/Aβ40 ratio is observed in pre-steady-state when Aβ40 is the dominant product. Aβ42 is produced after Aβ40, and therefore Aβ42 is not a precursor for Aβ40. The longer more hydrophobic Aβ products gradually accumulate with multiple catalytic turnovers as a result of interrupted catalytic cycles. Saturation of γ-secretase with its C99 substrate leads to 30% decrease in Aβ40 with concomitant increase in the longer Aβ products and Aβ42/Aβ40 ratio. To different degree the same changes in Aβ products can be observed with two mutations that lead to an early onset of AD, ΔE9 and G384A. Four different lines of evidence show that γ-secretase can bind and cleave multiple substrate molecules in one catalytic turnover. Consequently depending on its concentration, NotchΔE substrate can activate or inhibit γ-secretase activity on C99 substrate. Multiple C99 molecules bound to γ-secretase can affect processive cleavages of the nascent Aβ catalytic intermediates and facilitate their premature release as the toxic membrane-imbedded Aβ-bundles. Conclusions Gradual saturation of γ-secretase with its substrate can be the pathogenic process in different alleged causes of AD. Thus, competitive inhibitors of γ-secretase offer the best chance for a successful therapy, while the noncompetitive inhibitors could even facilitate development of the disease by inducing enzyme saturation at otherwise sub-saturating substrate. Membrane-imbedded Aβ-bundles generated by γ-secretase could be neurotoxic and thus crucial for our understanding of the amyloid hypothesis and AD pathogenesis.
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Affiliation(s)
- Zeljko M Svedružić
- Medical Biochemistry, Faculty of Medicine, University of Rijeka, Rab, Croatia.
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Lockrow JP, Fortress AM, Granholm ACE. Age-related neurodegeneration and memory loss in down syndrome. Curr Gerontol Geriatr Res 2012; 2012:463909. [PMID: 22545043 PMCID: PMC3318235 DOI: 10.1155/2012/463909] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 11/21/2011] [Indexed: 01/10/2023] Open
Abstract
Down syndrome (DS) is a condition where a complete or segmental chromosome 21 trisomy causes variable intellectual disability, and progressive memory loss and neurodegeneration with age. Many research groups have examined development of the brain in DS individuals, but studies on age-related changes should also be considered, with the increased lifespan observed in DS. DS leads to pathological hallmarks of Alzheimer's disease (AD) by 40 or 50 years of age. Progressive age-related memory deficits occurring in both AD and in DS have been connected to degeneration of several neuronal populations, but mechanisms are not fully elucidated. Inflammation and oxidative stress are early events in DS pathology, and focusing on these pathways may lead to development of successful intervention strategies for AD associated with DS. Here we discuss recent findings and potential treatment avenues regarding development of AD neuropathology and memory loss in DS.
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Affiliation(s)
- Jason P. Lockrow
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | - Ashley M. Fortress
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | - Ann-Charlotte E. Granholm
- Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
- Center on Aging, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
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Guerreiro RJ, Gustafson DR, Hardy J. The genetic architecture of Alzheimer's disease: beyond APP, PSENs and APOE. Neurobiol Aging 2012; 33:437-56. [PMID: 20594621 PMCID: PMC2980860 DOI: 10.1016/j.neurobiolaging.2010.03.025] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 03/01/2010] [Accepted: 03/11/2010] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a complex disorder with a clear genetic component. Three genes have been identified as the cause of early onset familial AD (EOAD). The most common form of the disease, late onset Alzheimer's disease (LOAD), is, however, a sporadic one presenting itself in later stages of life. The genetic component of this late onset form of AD has been the target of a large number of studies, because only one genetic risk factor (APOE4) has been consistently associated with the disease. However, technological advances allow new approaches in the study of complex disorders. In this review, we discuss the new results produced by genome wide association studies, in light of the current knowledge of the complexity of AD genetics.
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Affiliation(s)
- Rita J Guerreiro
- Laboratory of Neurogenetics, National Institute of Aging, National Institutes of Health, Bethesda, MD, USA.
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50
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McNaughton D, Knight W, Guerreiro R, Ryan N, Lowe J, Poulter M, Nicholl DJ, Hardy J, Revesz T, Lowe J, Rossor M, Collinge J, Mead S. Duplication of amyloid precursor protein (APP), but not prion protein (PRNP) gene is a significant cause of early onset dementia in a large UK series. Neurobiol Aging 2012; 33:426.e13-21. [PMID: 21193246 PMCID: PMC3657692 DOI: 10.1016/j.neurobiolaging.2010.10.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/12/2010] [Accepted: 10/12/2010] [Indexed: 10/27/2022]
Abstract
Amyloid precursor protein gene (APP) duplications have been identified in screens of selected probands with early onset familial Alzheimer's disease (FAD). A causal role for copy number variation (CNV) in the prion protein gene (PRNP) in prion dementias is not known. We aimed to determine the prevalence of copy number variation in APP and PRNP in a large referral series, test a screening method for detection of the same, and expand knowledge of clinical phenotype. We used a 3-tiered screening assay for APP and PRNP duplication (exonic real-time quantitative polymerase chain reaction [exon-qPCR], fluorescent microsatellite quantitative PCR [fm-q-PCR], and Illumina array [Illumina Inc., San Diego, CA, USA]) for analysis of a heterogeneous referral series comprising 1531 probands. Five of 1531 probands screened showed APP duplication, a similar prevalence to APP missense mutation. Real-time quantitative PCR and fluorescent microsatellite quantitative PCR were similar individually but are theoretically complementary; we used Illumina arrays as our reference assay. Two of 5 probands were from an autosomal dominant early onset Alzheimer's disease (familial Alzheimer's disease) pedigree. One extensive, noncontiguous duplication on chromosome 21 was consistent with an unbalanced translocation not including the Down's syndrome critical region. Seizures were prominent in the other typical APP duplications. A range of imaging, neuropsychological, cerebrospinal fluid, and pathological findings are reported that extend the known phenotype. APP but not PRNP duplication is a significant cause of early onset dementia in the UK. The recognized phenotype may be expanded to include the possibility of early seizures and apparently sporadic disease which, in part, may be due to different mutational mechanisms. The pros and cons of our screening method are discussed.
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Affiliation(s)
- Daniel McNaughton
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - William Knight
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
- University Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Rita Guerreiro
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
- Laboratory of Neurogenetics, National Institute of Aging, National Institutes of Health, Bethesda, MD, USA
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Natalie Ryan
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Jessica Lowe
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - Mark Poulter
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | | | - John Hardy
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Tamas Revesz
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - James Lowe
- School of Molecular Medical Sciences, University of Nottingham, Nottingham, UK
| | - Martin Rossor
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, Queen Square, London, UK
| | - Simon Mead
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- National Prion Clinic, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, Queen Square, London, UK
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