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Islam A, Shaukat Z, Hussain R, Ricos MG, Dibbens LM, Gregory SL. Aneuploidy is Linked to Neurological Phenotypes Through Oxidative Stress. J Mol Neurosci 2024; 74:50. [PMID: 38693434 PMCID: PMC11062972 DOI: 10.1007/s12031-024-02227-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/19/2024] [Indexed: 05/03/2024]
Abstract
Aneuploidy, having an aberrant genome, is gaining increasing attention in neurodegenerative diseases. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift which makes these cells sensitive to internal and environmental stresses. A growing body of research from numerous laboratories suggests that many neurodegenerative disorders, especially Alzheimer's disease and frontotemporal dementia, are characterised by neuronal aneuploidy and the ensuing apoptosis, which may contribute to neuronal loss. Using Drosophila as a model, we investigated the effect of induced aneuploidy in GABAergic neurons. We found an increased proportion of aneuploidy due to Mad2 depletion in the third-instar larval brain and increased cell death. Depletion of Mad2 in GABAergic neurons also gave a defective climbing and seizure phenotype. Feeding animals an antioxidant rescued the climbing and seizure phenotype. These findings suggest that increased aneuploidy leads to higher oxidative stress in GABAergic neurons which causes cell death, climbing defects, and seizure phenotype. Antioxidant feeding represents a potential therapy to reduce the aneuploidy-driven neurological phenotype.
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Affiliation(s)
- Anowarul Islam
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Zeeshan Shaukat
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Rashid Hussain
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Michael G Ricos
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Leanne M Dibbens
- Epilepsy Research Group, Australian Centre for Precision Health, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stephen L Gregory
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia.
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2
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Lucero EM, Freund RK, Smith A, Johnson NR, Dooling B, Sullivan E, Prikhodko O, Ahmed MM, Bennett DA, Hohman TJ, Dell’Acqua ML, Chial HJ, Potter H. Increased KIF11/ kinesin-5 expression offsets Alzheimer Aβ-mediated toxicity and cognitive dysfunction. iScience 2022; 25:105288. [PMID: 36304124 PMCID: PMC9593841 DOI: 10.1016/j.isci.2022.105288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 08/08/2022] [Accepted: 10/04/2022] [Indexed: 11/28/2022] Open
Abstract
Previously, we found that amyloid-beta (Aβ) competitively inhibits the kinesin motor protein KIF11 (Kinesin-5/Eg5), leading to defects in the microtubule network and in neurotransmitter and neurotrophin receptor localization and function. These biochemical and cell biological mechanisms for Aβ-induced neuronal dysfunction may underlie learning and memory defects in Alzheimer's disease (AD). Here, we show that KIF11 overexpression rescues Aβ-mediated decreases in dendritic spine density in cultured neurons and in long-term potentiation in hippocampal slices. Furthermore, Kif11 overexpression from a transgene prevented spatial learning deficits in the 5xFAD mouse model of AD. Finally, increased KIF11 expression in neuritic plaque-positive AD patients' brains was associated with better cognitive performance and higher expression of synaptic protein mRNAs. Taken together, these mechanistic biochemical, cell biological, electrophysiological, animal model, and human data identify KIF11 as a key target of Aβ-mediated toxicity in AD, which damages synaptic structures and functions critical for learning and memory in AD.
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Affiliation(s)
- Esteban M. Lucero
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Program for Human Medical Genetics and Genomics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Ronald K. Freund
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Alexandra Smith
- Vanderbilt Memory and Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Noah R. Johnson
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Breanna Dooling
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Program for Human Medical Genetics and Genomics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Emily Sullivan
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Olga Prikhodko
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Md. Mahiuddin Ahmed
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Timothy J. Hohman
- Vanderbilt Memory and Alzheimer’s Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mark L. Dell’Acqua
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Heidi J. Chial
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Huntington Potter
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- University of Colorado Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Baker NE, Montagna C. Reducing the aneuploid cell burden - cell competition and the ribosome connection. Dis Model Mech 2022; 15:dmm049673. [PMID: 36444717 PMCID: PMC10621665 DOI: 10.1242/dmm.049673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Aneuploidy, the gain or loss of chromosomes, is the cause of birth defects and miscarriage and is almost ubiquitous in cancer cells. Mosaic aneuploidy causes cancer predisposition, as well as age-related disorders. Despite the cell-intrinsic mechanisms that prevent aneuploidy, sporadic aneuploid cells do arise in otherwise normal tissues. These aneuploid cells can differ from normal cells in the copy number of specific dose-sensitive genes, and may also experience proteotoxic stress associated with mismatched expression levels of many proteins. These differences may mark aneuploid cells for recognition and elimination. The ribosomal protein gene dose in aneuploid cells could be important because, in Drosophila, haploinsufficiency for these genes leads to elimination by the process of cell competition. Constitutive haploinsufficiency for human ribosomal protein genes causes Diamond Blackfan anemia, but it is not yet known whether ribosomal protein gene dose contributes to aneuploid cell elimination in mammals. In this Review, we discuss whether cell competition on the basis of ribosomal protein gene dose is a tumor suppressor mechanism, reducing the accumulation of aneuploid cells. We also discuss how this might relate to the tumor suppressor function of p53 and the p53-mediated elimination of aneuploid cells from murine embryos, and how cell competition defects could contribute to the cancer predisposition of Diamond Blackfan anemia.
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Affiliation(s)
- Nicholas E. Baker
- Departments of Genetics, Developmental and Molecular Biology, and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Cristina Montagna
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
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4
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Genomic Mosaicism Formed by Somatic Variation in the Aging and Diseased Brain. Genes (Basel) 2021; 12:genes12071071. [PMID: 34356087 PMCID: PMC8305509 DOI: 10.3390/genes12071071] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 12/22/2022] Open
Abstract
Over the past 20 years, analyses of single brain cell genomes have revealed that the brain is composed of cells with myriad distinct genomes: the brain is a genomic mosaic, generated by a host of DNA sequence-altering processes that occur somatically and do not affect the germline. As such, these sequence changes are not heritable. Some processes appear to occur during neurogenesis, when cells are mitotic, whereas others may also function in post-mitotic cells. Here, we review multiple forms of DNA sequence alterations that have now been documented: aneuploidies and aneusomies, smaller copy number variations (CNVs), somatic repeat expansions, retrotransposons, genomic cDNAs (gencDNAs) associated with somatic gene recombination (SGR), and single nucleotide variations (SNVs). A catch-all term of DNA content variation (DCV) has also been used to describe the overall phenomenon, which can include multiple forms within a single cell’s genome. A requisite step in the analyses of genomic mosaicism is ongoing technology development, which is also discussed. Genomic mosaicism alters one of the most stable biological molecules, DNA, which may have many repercussions, ranging from normal functions including effects of aging, to creating dysfunction that occurs in neurodegenerative and other brain diseases, most of which show sporadic presentation, unlinked to causal, heritable genes.
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5
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Dai X, Guo X. Decoding and rejuvenating human ageing genomes: Lessons from mosaic chromosomal alterations. Ageing Res Rev 2021; 68:101342. [PMID: 33866012 DOI: 10.1016/j.arr.2021.101342] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 01/10/2023]
Abstract
One of the most curious findings emerged from genome-wide studies over the last decade was that genetic mosaicism is a dominant feature of human ageing genomes. The clonal dominance of genetic mosaicism occurs preceding the physiological and physical ageing and associates with propensity for diseases including cancer, Alzheimer's disease, cardiovascular disease and diabetes. These findings are revolutionizing the ways biologists thinking about health and disease pathogenesis. Among all mosaic mutations in ageing genomes, mosaic chromosomal alterations (mCAs) have the most significant functional consequences because they can produce intercellular genomic variations simultaneously involving dozens to hundreds or even thousands genes, and therefore have most profound effects in human ageing and disease etiology. Here, we provide a comprehensive picture of the landscapes, causes, consequences and rejuvenation of mCAs at multiple scales, from cell to human population, by reviewing data from cytogenetic, genetic and genomic studies in cells, animal models (fly and mouse) and, more frequently, large-cohort populations. A detailed decoding of ageing genomes with a focus on mCAs may yield important insights into the genomic architecture of human ageing, accelerate the risk stratification of age-related diseases (particularly cancers) and development of novel targets and strategies for delaying or rejuvenating human (genome) ageing.
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Affiliation(s)
- Xueqin Dai
- School of Life Sciences, Yunnan Normal University, Kunming, Yunnan, 650500, China
| | - Xihan Guo
- School of Life Sciences, Yunnan Normal University, Kunming, Yunnan, 650500, China; The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, Yunnan, 650500, China; Yunnan Environmental Mutagen Society, Kunming, Yunnan, 650500, China.
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6
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Abstract
Somatic mutations arise postzygotically, producing genetic differences between cells in an organism. Well established as a driver of cancer, somatic mutations also exist in nonneoplastic cells, including in the brain. Technological advances in nucleic acid sequencing have enabled recent break-throughs that illuminate the roles of somatic mutations in aging and degenerative diseases of the brain. Somatic mutations accumulate during aging in human neurons, a process termed genosenium. A number of recent studies have examined somatic mutations in Alzheimer’s disease (AD), primarily from the perspective of genes causing familial AD. We have also gained new information on genome-wide mutations, providing insights into the cellular events driving somatic mutation and cellular dysfunction. This review highlights recent concepts, methods, and findings in the progress to understand the role of brain somatic mutation in aging and AD.
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Affiliation(s)
- Michael B Miller
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Division of Neuropathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Hannah C Reed
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Allegheny College, Meadville, Pennsylvania 16335, USA;
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.,Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, USA
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7
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McDonald WS, Miyamoto K, Rivera R, Kennedy G, Almeida BSV, Kingsbury MA, Chun J. Altered cleavage plane orientation with increased genomic aneuploidy produced by receptor-mediated lysophosphatidic acid (LPA) signaling in mouse cerebral cortical neural progenitor cells. Mol Brain 2020; 13:169. [PMID: 33317583 PMCID: PMC7734743 DOI: 10.1186/s13041-020-00709-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/02/2020] [Indexed: 01/03/2023] Open
Abstract
The brain is composed of cells having distinct genomic DNA sequences that arise post-zygotically, known as somatic genomic mosaicism (SGM). One form of SGM is aneuploidy-the gain and/or loss of chromosomes-which is associated with mitotic spindle defects. The mitotic spindle orientation determines cleavage plane positioning and, therefore, neural progenitor cell (NPC) fate during cerebral cortical development. Here we report receptor-mediated signaling by lysophosphatidic acid (LPA) as a novel extracellular signal that influences cleavage plane orientation and produces alterations in SGM by inducing aneuploidy during murine cortical neurogenesis. LPA is a bioactive lipid whose actions are mediated by six G protein-coupled receptors, LPA1-LPA6. RNAscope and qPCR assessment of all six LPA receptor genes, and exogenous LPA exposure in LPA receptor (Lpar)-null mice, revealed involvement of Lpar1 and Lpar2 in the orientation of the mitotic spindle. Lpar1 signaling increased non-vertical cleavage in vivo by disrupting cell-cell adhesion, leading to breakdown of the ependymal cell layer. In addition, genomic alterations were significantly increased after LPA exposure, through production of chromosomal aneuploidy in NPCs. These results identify LPA as a receptor-mediated signal that alters both NPC fate and genomes during cortical neurogenesis, thus representing an extracellular signaling mechanism that can produce stable genomic changes in NPCs and their progeny. Normal LPA signaling in early life could therefore influence both the developing and adult brain, whereas its pathological disruption could contribute to a range of neurological and psychiatric diseases, via long-lasting somatic genomic alterations.
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Affiliation(s)
- Whitney S McDonald
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA, 92037, USA.,The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Kyoko Miyamoto
- The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Richard Rivera
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA, 92037, USA.,The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Grace Kennedy
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA, 92037, USA.,The Scripps Research Institute, La Jolla, CA, 92037, USA
| | | | | | - Jerold Chun
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N Torrey Pines Rd, La Jolla, CA, 92037, USA. .,The Scripps Research Institute, La Jolla, CA, 92037, USA.
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8
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Andreychuk YV, Zadorsky SP, Zhuk AS, Stepchenkova EI, Inge-Vechtomov SG. Relationship between Type I and Type II Template Processes: Amyloids and Genome Stability. Mol Biol 2020. [DOI: 10.1134/s0026893320050027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Iron-responsive-like elements and neurodegenerative ferroptosis. ACTA ACUST UNITED AC 2020; 27:395-413. [PMID: 32817306 PMCID: PMC7433652 DOI: 10.1101/lm.052282.120] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/26/2022]
Abstract
A set of common-acting iron-responsive 5′untranslated region (5′UTR) motifs can fold into RNA stem loops that appear significant to the biology of cognitive declines of Parkinson's disease dementia (PDD), Lewy body dementia (LDD), and Alzheimer's disease (AD). Neurodegenerative diseases exhibit perturbations of iron homeostasis in defined brain subregions over characteristic time intervals of progression. While misfolding of Aβ from the amyloid-precursor-protein (APP), alpha-synuclein, prion protein (PrP) each cause neuropathic protein inclusions in the brain subregions, iron-responsive-like element (IRE-like) RNA stem–loops reside in their transcripts. APP and αsyn have a role in iron transport while gene duplications elevate the expression of their products to cause rare familial cases of AD and PDD. Of note, IRE-like sequences are responsive to excesses of brain iron in a potential feedback loop to accelerate neuronal ferroptosis and cognitive declines as well as amyloidosis. This pathogenic feedback is consistent with the translational control of the iron storage protein ferritin. We discuss how the IRE-like RNA motifs in the 5′UTRs of APP, alpha-synuclein and PrP mRNAs represent uniquely folded drug targets for therapies to prevent perturbed iron homeostasis that accelerates AD, PD, PD dementia (PDD) and Lewy body dementia, thus preventing cognitive deficits. Inhibition of alpha-synuclein translation is an option to block manganese toxicity associated with early childhood cognitive problems and manganism while Pb toxicity is epigenetically associated with attention deficit and later-stage AD. Pathologies of heavy metal toxicity centered on an embargo of iron export may be treated with activators of APP and ferritin and inhibitors of alpha-synuclein translation.
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Snyder HM, Bain LJ, Brickman AM, Carrillo MC, Esbensen AJ, Espinosa JM, Fernandez F, Fortea J, Hartley SL, Head E, Hendrix J, Kishnani PS, Lai F, Lao P, Lemere C, Mobley W, Mufson EJ, Potter H, Zaman SH, Granholm AC, Rosas HD, Strydom A, Whitten MS, Rafii MS. Further understanding the connection between Alzheimer's disease and Down syndrome. Alzheimers Dement 2020; 16:1065-1077. [PMID: 32544310 PMCID: PMC8865308 DOI: 10.1002/alz.12112] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/25/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
Improved medical care of individuals with Down syndrome (DS) has led to an increase in life expectancy to over the age of 60 years. In conjunction, there has been an increase in age-related co-occurring conditions including Alzheimer's disease (AD). Understanding the factors that underlie symptom and age of clinical presentation of dementia in people with DS may provide insights into the mechanisms of sporadic and DS-associated AD (DS-AD). In March 2019, the Alzheimer's Association, Global Down Syndrome Foundation and the LuMind IDSC Foundation partnered to convene a workshop to explore the state of the research on the intersection of AD and DS research; to identify research gaps and unmet needs; and to consider how best to advance the field. This article provides a summary of discussions, including noting areas of emerging science and discovery, considerations for future studies, and identifying open gaps in our understanding for future focus.
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Affiliation(s)
- Heather M. Snyder
- Alzheimer’s Association, Medical & Scientific Relations, Chicago, Illinois, USA
| | - Lisa J. Bain
- Independent Science Writer, Elverson, Pennsylvania, USA
| | - Adam M. Brickman
- Department of Neurology, College of Physicians and Surgeons, Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, New York, USA
| | - Maria C. Carrillo
- Alzheimer’s Association, Medical & Scientific Relations, Chicago, Illinois, USA
| | - Anna J. Esbensen
- Division of Developmental and Behavioral Pediatrics, Cincinnati Children’s Hospital Medical Center & University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Joaquin M. Espinosa
- Department of Pharmacology, Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Fabian Fernandez
- Departments of Psychology and Neurology, BIO5 Institute, and The Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, USA
| | - Juan Fortea
- Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute Sant Pau, Universitat Autonoma de Barcelona, CIBERNED, Barcelona, Spain
- Down Medical Center, Catalan Down Syndrome Foundation, Barcelona, Spain
| | - Sigan L. Hartley
- Department of Human Development and Family Studies, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, University of California, Irvine, Irvine, California, USA
| | - James Hendrix
- LuMind IDSC Foundation, Burlington, Massachusetts, USA
| | - Priya S. Kishnani
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Florence Lai
- Department of Neurology, Harvard University/Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Patrick Lao
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Cynthia Lemere
- Department of Neurology, Brigham & Women’s Hospital and Harvard University, Boston, Massachusetts, USA
| | - William Mobley
- Department of Neurosciences, University of California, San Diego, San Diego, California, USA
| | | | - Huntington Potter
- Rocky Mountain Alzheimer’s Disease Center and Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Shahid H. Zaman
- Cambridge Intellectual & Developmental Disability Research Group, Department of Psychiatry University of Cambridge, Cambridgeshire & Peterborough NHS Foundation Trust, Cambridge, UK
| | - Ann-Charlotte Granholm
- Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado, USA
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden
| | - H. Diana Rosas
- Departments of Neurology and Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Andre Strydom
- Department of Forensic and Neurodevelopmental Sciences, Psychology and Neuroscience, King’s College London, South London and the Maudsley NHS Foundation Trust, LonDowns Consortium, Institute of Psychiatry, London, UK
| | | | - Michael S. Rafii
- Alzheimer’s Therapeutics Research Institute and Department of Neurology, University of Southern California, Los Angeles, California, USA
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11
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Ueberham U, Arendt T. Genomic Indexing by Somatic Gene Recombination of mRNA/ncRNA - Does It Play a Role in Genomic Mosaicism, Memory Formation, and Alzheimer's Disease? Front Genet 2020; 11:370. [PMID: 32411177 PMCID: PMC7200996 DOI: 10.3389/fgene.2020.00370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022] Open
Abstract
Recent evidence indicates that genomic individuality of neurons, characterized by DNA-content variation, is a common if not universal phenomenon in the human brain that occurs naturally but can also show aberrancies that have been linked to the pathomechanism of Alzheimer’s disease and related neurodegenerative disorders. Etiologically, this genomic mosaic has been suggested to arise from defects of cell cycle regulation that may occur either during brain development or in the mature brain after terminal differentiation of neurons. Here, we aim to draw attention towards another mechanism that can give rise to genomic individuality of neurons, with far-reaching consequences. This mechanism has its origin in the transcriptome rather than in replication defects of the genome, i.e., somatic gene recombination of RNA. We continue to develop the concept that somatic gene recombination of RNA provides a physiological process that, through integration of intronless mRNA/ncRNA into the genome, allows a particular functional state at the level of the individual neuron to be indexed. By insertion of defined RNAs in a somatic recombination process, the presence of specific mRNA transcripts within a definite temporal context can be “frozen” and can serve as an index that can be recalled at any later point in time. This allows information related to a specific neuronal state of differentiation and/or activity relevant to a memory trace to be fixed. We suggest that this process is used throughout the lifetime of each neuron and might have both advantageous and deleterious consequences.
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Affiliation(s)
- Uwe Ueberham
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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12
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Contributions of DNA Damage to Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21051666. [PMID: 32121304 PMCID: PMC7084447 DOI: 10.3390/ijms21051666] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common type of neurodegenerative disease. Its typical pathology consists of extracellular amyloid-β (Aβ) plaques and intracellular tau neurofibrillary tangles. Mutations in the APP, PSEN1, and PSEN2 genes increase Aβ production and aggregation, and thus cause early onset or familial AD. Even with this strong genetic evidence, recent studies support AD to result from complex etiological alterations. Among them, aging is the strongest risk factor for the vast majority of AD cases: Sporadic late onset AD (LOAD). Accumulation of DNA damage is a well-established aging factor. In this regard, a large amount of evidence reveals DNA damage as a critical pathological cause of AD. Clinically, DNA damage is accumulated in brains of AD patients. Genetically, defects in DNA damage repair resulted from mutations in the BRAC1 and other DNA damage repair genes occur in AD brain and facilitate the pathogenesis. Abnormalities in DNA damage repair can be used as diagnostic biomarkers for AD. In this review, we discuss the association, the causative potential, and the biomarker values of DNA damage in AD pathogenesis.
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Bajic VP, Essack M, Zivkovic L, Stewart A, Zafirovic S, Bajic VB, Gojobori T, Isenovic E, Spremo-Potparevic B. The X Files: "The Mystery of X Chromosome Instability in Alzheimer's Disease". Front Genet 2020; 10:1368. [PMID: 32047510 PMCID: PMC6997486 DOI: 10.3389/fgene.2019.01368] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/13/2019] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that affects millions of individuals worldwide and can occur relatively early or later in life. It is well known that genetic components, such as the amyloid precursor protein gene on chromosome 21, are fundamental in early-onset AD (EOAD). To date, however, only the apolipoprotein E4 (ApoE4) gene has been proved to be a genetic risk factor for late-onset AD (LOAD). In recent years, despite the hypothesis that many additional unidentified genes are likely to play a role in AD development, it is surprising that additional gene polymorphisms associated with LOAD have failed to come to light. In this review, we examine the role of X chromosome epigenetics and, based upon GWAS studies, the PCDHX11 gene. Furthermore, we explore other genetic risk factors of AD that involve X-chromosome epigenetics.
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Affiliation(s)
- Vladan P Bajic
- Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Magbubah Essack
- Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Lada Zivkovic
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Alan Stewart
- School of Medicine, University of St Andrews, St Andrews, United Kingdom
| | - Sonja Zafirovic
- Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Vladimir B Bajic
- Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Takashi Gojobori
- Computational Bioscience Research Center (CBRC), Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Esma Isenovic
- Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
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14
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Nunes KM, Benzaquem DC, Carvalho NDM, Vianez TN, Fernandes ERDQGDSE, Fantin C. Investigation of chromosomal alterations in patients with Alzheimer's disease in the state of Amazonas, Brazil. ARQUIVOS DE NEURO-PSIQUIATRIA 2020; 77:855-859. [PMID: 31939582 DOI: 10.1590/0004-282x20190163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 08/05/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Alzheimer's disease (AD) has as its main characteristic the deterioration of cerebral functions. Its etiology is still complex and undefined despite the progress made in understanding its neurological, infectious, biochemical, genetic and cytogenetic mechanisms. METHODS Considering this, the aim of this study was to investigate the presence of chromosomal alterations in the peripheral blood lymphocytes, and to verify if there was a high frequency of these alterations in patients diagnosed with AD at the University Hospital GetúLio Vargas Outpatient Clinic Araújo Lima in Manaus, Amazonas, Brazil. RESULTS Among the nine patients in the AD group, only one patient did not have metaphases with chromosomal alterations (2n = 46,XX), while eight patients with AD showed numerical chromosomal alterations, classified as X chromosome aneupLoidy (2n = 45,X) and double aneupLoidy (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 and 2n = 44,X,-X,-21). CONCLUSION In the control group, no chromosomal changes were found in the karyotypes of these individuals. Therefore, the karyotypes of patients with AD undergo chromosomal alterations at different levels. These findings are being described for the first time in the population of Amazonas, and they highlight the importance of the inclusion of cytogenetic investigations in the routine management of patients with AD.
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Affiliation(s)
- Kledson Moraes Nunes
- Universidade do Estado do Amazonas, Escola Superior de Ciências da Saúde, Laboratório de Citogenética, Manaus AM, Brasil
| | - Denise Corrêa Benzaquem
- Universidade do Estado do Amazonas, Escola Superior de Ciências da Saúde, Laboratório de Citogenética, Manaus AM, Brasil
| | - Natalia Dayane Moura Carvalho
- Universidade do Estado do Amazonas, Escola Superior de Ciências da Saúde, Laboratório de Citogenética, Manaus AM, Brasil
| | - Talísia Nascimento Vianez
- Universidade Federal do Amazonas, Hospital Universitário Getúlio Vargas, Departamento de Neurologia, Manaus AM, Brasil
| | | | - Cleiton Fantin
- Universidade do Estado do Amazonas, Escola Superior de Ciências da Saúde, Laboratório de Citogenética, Manaus AM, Brasil
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15
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Gong M, Wang Z, Liu Y, Li W, Ye S, Zhu J, Zhang H, Wang J, He K. A transcriptomic analysis of Nsmce1 overexpression in mouse hippocampal neuronal cell by RNA sequencing. Funct Integr Genomics 2019; 20:459-470. [PMID: 31792732 DOI: 10.1007/s10142-019-00728-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 10/10/2019] [Accepted: 11/06/2019] [Indexed: 02/07/2023]
Abstract
Mouse Nsmce1 gene is the homolog of non-structural maintenance of chromosomes element 1 (NSE1) that is mainly involved in maintenance of genome integrity, DNA damage response, and DNA repair. Defective DNA repair may cause neurological disorders such as Alzheimer's disease (AD). So far, there is no direct evidence for the correlation between Nsmce1 and AD. In order to explore the function of Nsmce1 in the regulation of nervous system, we have overexpressed or knocked down Nsmce1 in the mouse hippocampal neuronal cells (MHNCs) HT-22 and detected its regulation of AD marker genes as well as cell proliferation. The results showed that the expression of App, Bace2, and Mapt could be inhibited by Nsmce1 overexpression and activated by the knockdown of Nsmce1. Moreover, the HT-22 cell proliferation ability could be promoted by Nsmce1 overexpression and inhibited by knockdown of Nsmce1. Furthermore, we performed a transcriptomics study by RNA sequencing (RNA-seq) to evaluate and quantify the gene expression profiles in response to the overexpression of Nsmce1 in HT-22 cells. As a result, 224 significantly dysregulated genes including 83 upregulated and 141 downregulated genes were identified by the comparison of Nsmce1 /+ to WT cells, which were significantly enriched in several Gene Ontology (GO) terms and pathways. In addition, the complexity of the alternative splicing (AS) landscape was increased by Nsmce1 overexpression in HT-22 cells. Thousands of AS events were identified to be mainly involved in the pathway of ubiquitin-mediated proteolysis (UMP) as well as 3 neurodegenerative diseases including AD. The protein-protein interaction network was reconstructed to show top 10 essential genes regulated by Nsmce1. Our sequencing data is available in the Gene Expression Omnibus (GEO) database with accession number as GSE113436. These results may provide some evidence of molecular and cellular functions of Nsmce1 in MHNCs.
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Affiliation(s)
- Mengting Gong
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, 230601, Anhui, China
| | - Zhen Wang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yanjun Liu
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Wenxing Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
| | - Shoudong Ye
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, 230601, Anhui, China
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Jie Zhu
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Hui Zhang
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Jing Wang
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China
| | - Kan He
- Center for Stem Cell and Translational Medicine, School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, 230601, Anhui, China.
- Department of Biostatistics, School of Life Sciences, Anhui University, Hefei, 230601, Anhui, China.
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16
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Gronek P, Balko S, Gronek J, Zajac A, Maszczyk A, Celka R, Doberska A, Czarny W, Podstawski R, Clark CCT, Yu F. Physical Activity and Alzheimer's Disease: A Narrative Review. Aging Dis 2019; 10:1282-1292. [PMID: 31788339 PMCID: PMC6844593 DOI: 10.14336/ad.2019.0226] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/26/2019] [Indexed: 12/12/2022] Open
Abstract
Although age is a dominant risk factor for Alzheimer’s disease (AD), epidemiological studies have shown that physical activity may significantly decrease age-related risks for AD, and indeed mitigate the impact in existing diagnosis. The aim of this study was to perform a narrative review on the preventative, and mitigating, effects of physical activity on AD onset, including genetic factors, mechanism of action and physical activity typology. In this article, we conducted a narrative review of the influence physical activity and exercise have on AD, utilising key terms related to AD, physical activity, mechanism and prevention, searching the online databases; Web of Science, PubMed and Google Scholar, and, subsequently, discuss possible mechanisms of this action. On the basis of this review, it is evident that physical activity and exercise may be incorporated in AD, notwithstanding, a greater number of high-quality randomised controlled trials are needed, moreover, physical activity typology must be acutely considered, primarily due to a dearth of research on the efficacy of physical activity types other than aerobic.
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Affiliation(s)
- Piotr Gronek
- 1Faculty of Physical Education, Sport and Rehabilitation, Poznan University of Physical Education, Poland
| | - Stefan Balko
- 2Department of Physical Education and Sport, Faculty of Education, Jan Evangelista Purkyne University in Usti nad Labem, Czech Republic
| | - Joanna Gronek
- 1Faculty of Physical Education, Sport and Rehabilitation, Poznan University of Physical Education, Poland
| | - Adam Zajac
- 3Department of Physical Education, University of Physical Education and Sport, Gdansk, Poland
| | - Adam Maszczyk
- 4Department of Methodology and Statistics, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
| | - Roman Celka
- 1Faculty of Physical Education, Sport and Rehabilitation, Poznan University of Physical Education, Poland
| | - Agnieszka Doberska
- 1Faculty of Physical Education, Sport and Rehabilitation, Poznan University of Physical Education, Poland
| | - Wojciech Czarny
- 5Faculty of Physical Education, Department of Human Sciences, University of Rzeszow, ul. Towarnickiego 3, 35-959 Rzeszów, Poland
| | - Robert Podstawski
- 6Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Cain C T Clark
- 7Faculty of Health and Life Sciences, Coventry University, Coventry, CV1 5FB, United Kingdom
| | - Fang Yu
- 8School of Nursing, University of Minnesota, Minneapolis, MN 55455, USA
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17
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Potter H, Chial HJ, Caneus J, Elos M, Elder N, Borysov S, Granic A. Chromosome Instability and Mosaic Aneuploidy in Neurodegenerative and Neurodevelopmental Disorders. Front Genet 2019; 10:1092. [PMID: 31788001 PMCID: PMC6855267 DOI: 10.3389/fgene.2019.01092] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/09/2019] [Indexed: 12/15/2022] Open
Abstract
Evidence from multiple laboratories has accumulated to show that mosaic neuronal aneuploidy and consequent apoptosis characterizes and may underlie neuronal loss in many neurodegenerative diseases, particularly Alzheimer’s disease and frontotemporal dementia. Furthermore, several neurodevelopmental disorders, including Seckel syndrome, ataxia telangiectasia, Nijmegen breakage syndrome, Niemann–Pick type C, and Down syndrome, have been shown to also exhibit mosaic aneuploidy in neurons in the brain and in other cells throughout the body. Together, these results indicate that both neurodegenerative and neurodevelopmental disorders with apparently different pathogenic causes share a cell cycle defect that leads to mosaic aneuploidy in many cell types. When such mosaic aneuploidy arises in neurons in the brain, it promotes apoptosis and may at least partly underlie the cognitive deficits that characterize the neurological symptoms of these disorders. These findings have implications for both diagnosis and treatment/prevention.
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Affiliation(s)
- Huntington Potter
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Heidi J Chial
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Julbert Caneus
- NanoScience Technology Center, University of Central Florida, Orlando, FL, United States
| | - Mihret Elos
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Nina Elder
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado, Aurora, CO, United States.,Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, United States
| | - Sergiy Borysov
- Department of Math and Science, Saint Leo University, Saint Leo, FL, United States
| | - Antoneta Granic
- AGE Research Group, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle University Institute for Ageing, NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, United Kingdom.,Newcastle upon Tyne Hospitals, NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
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18
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Graham EJ, Vermeulen M, Vardarajan B, Bennett D, De Jager P, Pearse RV, Young-Pearse TL, Mostafavi S. Somatic mosaicism of sex chromosomes in the blood and brain. Brain Res 2019; 1721:146345. [PMID: 31348909 PMCID: PMC6717667 DOI: 10.1016/j.brainres.2019.146345] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 07/19/2019] [Accepted: 07/21/2019] [Indexed: 12/26/2022]
Abstract
In the blood, mosaic somatic aneuploidy (mSA) of all chromosomes has been found to be associated with adverse health outcomes, including hematological cancer. Sex chromosome mSA in the blood has been found to occur at a higher rate than autosomal mSA. Mosaic loss of the Y chromosome is the most common copy number alteration in males, and has been found to be associated with Alzheimer's disease (AD) in blood lymphocytes. mSA of the sex chromosomes has also been identified in the brain; however, little is known about its frequency across individuals. Using WGS data from 362 males and 719 females from the ROSMAP cohort, we quantified the relative rate of sex chromosome mSA in the dorsolateral prefrontal cortex (DLPFC), cerebellum and whole blood. To ascertain the functionality of observed sex chromosome mosaicism in the DLPFC, we examined its correlation with chromosome X and Y gene expression as well as neuropathological and clinical characteristics of AD and cognitive ageing. In males, we found that mSA of the Y chromosome occurs more frequently in blood than in the DLPFC or cerebellum. In the DLPFC, the presence of at least one APOE4 allele was associated with a reduction in read depth of the Y chromosome (p = 1.9e-02). In the female DLPFC, a reduction in chromosome X read depth was associated with reduced cognition at the last clinical visit and faster rate of cognitive decline (p = 7.8e-03; p = 1.9e-02). mSA of all sex chromosomes in the DLPFC were associated with aggregate measures of gene expression, implying functional impact. Our results provide insight into the relative rate of mSA between tissues and suggest that Y and female X chromosome read depth in the DLPFC is modestly associated with late AD risk factors and cognitive pathologies.
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Affiliation(s)
- Emma J Graham
- Department of Bioinformatics, University of British Columbia, Vancouver, BC, Canada; BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Michael Vermeulen
- BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Badri Vardarajan
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York City, NY, United States
| | - David Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States
| | - Phil De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Medical Center, New York City, NY, United States; Cell Circuits Program, Broad Institute, Cambridge, MA, United States; Neurodegeneration Program, New York Genome Center, New York, NY, United States
| | - Richard V Pearse
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Tracy L Young-Pearse
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Sara Mostafavi
- BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada; Department of Statistics, University of British Columbia, Vancouver, BC, Canada.
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19
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Targeting the Iron-Response Elements of the mRNAs for the Alzheimer's Amyloid Precursor Protein and Ferritin to Treat Acute Lead and Manganese Neurotoxicity. Int J Mol Sci 2019; 20:ijms20040994. [PMID: 30823541 PMCID: PMC6412244 DOI: 10.3390/ijms20040994] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 02/08/2019] [Accepted: 02/10/2019] [Indexed: 12/29/2022] Open
Abstract
The therapeutic value of inhibiting translation of the amyloid precursor protein (APP) offers the possibility to reduce neurotoxic amyloid formation, particularly in cases of familial Alzheimer’s disease (AD) caused by APP gene duplications (Dup–APP) and in aging Down syndrome individuals. APP mRNA translation inhibitors such as the anticholinesterase phenserine, and high throughput screened molecules, selectively inhibited the uniquely folded iron-response element (IRE) sequences in the 5’untranslated region (5’UTR) of APP mRNA and this class of drug continues to be tested in a clinical trial as an anti-amyloid treatment for AD. By contrast, in younger age groups, APP expression is not associated with amyloidosis, instead it acts solely as a neuroprotectant while facilitating cellular ferroportin-dependent iron efflux. We have reported that the environmental metallotoxins Lead (Pb) and manganese (Mn) cause neuronal death by interfering with IRE dependent translation of APP and ferritin. The loss of these iron homeostatic neuroprotectants thereby caused an embargo of iron (Fe) export from neurons as associated with excess unstored intracellular iron and the formation of toxic reactive oxidative species (ROS). We propose that APP 5’UTR directed translation activators can be employed therapeutically to protect neurons exposed to high acute Pb and/or Mn exposure. Certainly, high potency APP translation activators, exemplified by the Food and Drug Administration (FDA) pre-approved M1 muscarinic agonist AF102B and high throughput-screened APP 5’UTR translation activators, are available for drug development to treat acute toxicity caused by Pb/Mn exposure to neurons. We conclude that APP translation activators can be predicted to prevent acute metal toxicity to neurons by a mechanism related to the 5’UTR specific yohimbine which binds and targets the canonical IRE RNA stem loop as an H-ferritin translation activator.
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20
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Verheijen BM, Vermulst M, van Leeuwen FW. Somatic mutations in neurons during aging and neurodegeneration. Acta Neuropathol 2018; 135:811-826. [PMID: 29705908 PMCID: PMC5954077 DOI: 10.1007/s00401-018-1850-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 12/22/2022]
Abstract
The nervous system is composed of a large variety of neurons with a diverse array of morphological and functional properties. This heterogeneity is essential for the construction and maintenance of a distinct set of neural networks with unique characteristics. Accumulating evidence now indicates that neurons do not only differ at a functional level, but also at the genomic level. These genomic discrepancies seem to be the result of somatic mutations that emerge in nervous tissue during development and aging. Ultimately, these mutations bring about a genetically heterogeneous population of neurons, a phenomenon that is commonly referred to as "somatic brain mosaicism". Improved understanding of the development and consequences of somatic brain mosaicism is crucial to understand the impact of somatic mutations on neuronal function in human aging and disease. Here, we highlight a number of topics related to somatic brain mosaicism, including some early experimental evidence for somatic mutations in post-mitotic neurons of the hypothalamo-neurohypophyseal system. We propose that age-related somatic mutations are particularly interesting, because aging is a major risk factor for a variety of neuronal diseases, including Alzheimer's disease. We highlight potential links between somatic mutations and the development of these diseases and argue that recent advances in single-cell genomics and in vivo physiology have now finally made it possible to dissect the origins and consequences of neuronal mutations in unprecedented detail.
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Affiliation(s)
- Bert M Verheijen
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG, Utrecht, The Netherlands.
- Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3508 GA, Utrecht, The Netherlands.
| | - Marc Vermulst
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Fred W van Leeuwen
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6229 ER, Maastricht, The Netherlands
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21
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Garcia A, Mathur S, Kalaw MC, McAvoy E, Anderson J, Luedke A, Itorralba J, Mai S. Quantitative 3D Telomeric Imaging of Buccal Cells Reveals Alzheimer's Disease-Specific Signatures. J Alzheimers Dis 2018; 58:139-145. [PMID: 28387668 PMCID: PMC5438476 DOI: 10.3233/jad-161169] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study validates and expands on our previous work that assessed three-dimensional (3D) nuclear telomere profiling in buccal cells of Alzheimer’s disease (AD) patients and non-AD controls (Mathur et al., J Alzheimers Dis 39, 35–48, 2014). While the previous study used age- and gender-matched caregiver controls, the current study consented a new cohort of 44 age- and gender-matched healthy non-caregiver controls and 44 AD study participants. 3D telomeric profiles of buccal cells of AD patients and their non-AD controls were examined with participant information blinded to the analysis. In agreement with our previous study, we demonstrate that 3D telomeric profiles allow for the distinction between AD and non-AD individuals. This validation cohort provides an indication that the total number of 3D telomeric signals and their telomere lengths may be a suitable biomarker to differentiate between AD and non-AD and between mild, moderate, and severe AD. Further studies with larger sample sizes are required to move this technology further toward the clinic.
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Affiliation(s)
- Angeles Garcia
- Department of Medicine (Geriatrics) and Neuroscience Centre, Queen's University, Kingston, ON, Canada
| | - Shubha Mathur
- Manitoba Institute of Cell Biology, The University of Manitoba, CancerCare Manitoba, Winnipeg, MB, Canada
| | - Maria Carmela Kalaw
- Manitoba Institute of Cell Biology, The University of Manitoba, CancerCare Manitoba, Winnipeg, MB, Canada
| | - Elizabeth McAvoy
- Department of Medicine (Geriatrics) and Neuroscience Centre, Queen's University, Kingston, ON, Canada
| | - James Anderson
- Department of Medicine (Geriatrics) and Neuroscience Centre, Queen's University, Kingston, ON, Canada
| | - Angela Luedke
- Department of Medicine (Geriatrics) and Neuroscience Centre, Queen's University, Kingston, ON, Canada
| | - Justine Itorralba
- Department of Medicine (Geriatrics) and Neuroscience Centre, Queen's University, Kingston, ON, Canada
| | - Sabine Mai
- Manitoba Institute of Cell Biology, The University of Manitoba, CancerCare Manitoba, Winnipeg, MB, Canada
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22
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Shepherd CE, Yang Y, Halliday GM. Region- and Cell-specific Aneuploidy in Brain Aging and Neurodegeneration. Neuroscience 2018; 374:326-334. [PMID: 29432756 DOI: 10.1016/j.neuroscience.2018.01.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 01/02/2018] [Accepted: 01/23/2018] [Indexed: 12/13/2022]
Abstract
Variations in genomic DNA content, or aneuploidy, are a well-recognized feature of normal human brain development. Whether changes in the levels of aneuploidy are a factor in Alzheimer's disease (AD) is less clear, as the data reported to date vary substantially in the levels of aneuploidy detected (0.7-11.5%), possibly due to methodological limitations, but also influenced by individual, regional and cellular heterogeneity as well as variations in cell subtypes. These issues have not been adequately addressed to date. While it is known that the DNA damage response increases with age, the limited human studies investigating aneuploidy in normal aging also show variable results, potentially due to susceptibility to age-related neurodegenerative processes. Neuronal aneuploidy has recently been reported in multiple brain regions in Lewy body disease, but similar genomic changes are not a feature of all synucleinopathies and aneuploidy does not appear to be related to alpha-synuclein aggregation. Rather, aneuploidy was associated with Alzheimer's pathology in the hippocampus and anterior cingulate cortex and neuronal degeneration in the substantia nigra. The association between Alzheimer's pathology and aneuploidy in regions with limited neurodegeneration is supported by a growing body of in vitro and in vivo data on aneuploidy and beta-amyloid and tau abnormalities. Large-scale studies using high-resolution techniques alongside other sensitive and specific methodologies are now required to assess the true extent of cell- and region-specific aneuploidy in aging and neurodegeneration, and to determine any associations with pathologies.
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Affiliation(s)
- C E Shepherd
- Neuroscience Research Australia, Margarete Ainsworth Building, Barker Street, Randwick, Sydney 2031, Australia; School of Medical Sciences, University of New South Wales, Sydney 2031, Australia.
| | - Y Yang
- Neuroscience Research Australia, Margarete Ainsworth Building, Barker Street, Randwick, Sydney 2031, Australia; School of Medical Sciences, University of New South Wales, Sydney 2031, Australia; Brain and Mind Centre, Sydney Medical School, The University of Sydney, Australia.
| | - G M Halliday
- Neuroscience Research Australia, Margarete Ainsworth Building, Barker Street, Randwick, Sydney 2031, Australia; School of Medical Sciences, University of New South Wales, Sydney 2031, Australia; Brain and Mind Centre, Sydney Medical School, The University of Sydney, Australia.
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23
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Caneus J, Granic A, Rademakers R, Dickson DW, Coughlan CM, Chial HJ, Potter H. Mitotic defects lead to neuronal aneuploidy and apoptosis in frontotemporal lobar degeneration caused by MAPT mutations. Mol Biol Cell 2017; 29:575-586. [PMID: 29282277 PMCID: PMC6004587 DOI: 10.1091/mbc.e17-01-0031] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 12/08/2017] [Accepted: 12/22/2017] [Indexed: 01/01/2023] Open
Abstract
Mutant Tau (MAPT) can lead to frontotemporal lobar degeneration (FTLD). Previous studies associated MAPT mutations and altered function with aneuploidy and chromosome instability in human lymphocytes and in Drosophila development. Here we examine whether FTLD-causing mutations in human MAPT induce aneuploidy and apoptosis in the mammalian brain. First, aneuploidy was found in brain cells from MAPT mutant transgenic mice expressing FTLD mutant human MAPT. Then brain neurons from mice homozygous or heterozygous for the Tau (Mapt) null allele were found to exhibit increasing levels of aneuploidy with decreasing Tau gene dosage. To determine whether aneuploidy leads to neurodegeneration in FTLD, we measured aneuploidy and apoptosis in brain cells from patients with MAPT mutations and identified both increased aneuploidy and apoptosis in the same brain neurons and glia. To determine whether there is a direct relationship between MAPT-induced aneuploidy and apoptosis, we expressed FTLD-causing mutant forms of MAPT in karyotypically normal human cells and found that they cause aneuploidy and mitotic spindle defects that then result in apoptosis. Collectively, our findings reveal a neurodegenerative pathway in FTLD-MAPT in which neurons and glia exhibit mitotic spindle abnormalities, chromosome mis-segregation, and aneuploidy, which then lead to apoptosis.
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Affiliation(s)
- Julbert Caneus
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045.,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045.,Neuroscience Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Antoneta Granic
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045.,Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045.,AGE Research Group, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom.,Campus for Ageing and Vitality, Biomedical Research Building, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom.,NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom
| | - Rosa Rademakers
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224
| | | | - Christina M Coughlan
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045.,Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045
| | - Heidi J Chial
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045.,Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045
| | - Huntington Potter
- Department of Neurology, Rocky Mountain Alzheimer's Disease Center, University of Colorado School of Medicine, Aurora, CO 80045 .,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045.,Neuroscience Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
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24
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Bhaumik P, Ghosh P, Ghosh S, Feingold E, Ozbek U, Sarkar B, Dey SK. Combined association of Presenilin-1 and Apolipoprotein E polymorphisms with maternal meiosis II error in Down syndrome births. Genet Mol Biol 2017; 40:577-585. [PMID: 28767121 PMCID: PMC5596362 DOI: 10.1590/1678-4685-gmb-2016-0138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 02/27/2017] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease and Down syndrome often exhibit close association and predictively share common genetic risk-factors. Presenilin-1 (PSEN-1) and Apolipoprotein E (APOE) genes are associated with early and late onset of Alzheimer's disease, respectively. Presenilin -1 is involved in faithful chromosomal segregation. A higher frequency of the APOE ε4 allele has been reported among young mothers giving birth to Down syndrome children. In this study, 170 Down syndrome patients, grouped according to maternal meiotic stage of nondisjunction and maternal age at conception, and their parents were genotyped for PSEN-1 intron-8 and APOE polymorphisms. The control group consisted of 186 mothers of karyotypically normal children. The frequencies of the PSEN-1 T allele and TT genotype, in the presence of the APOE ε4 allele, were significantly higher among young mothers (< 35 years) with meiosis II nondisjunction than in young control mothers (96.43% vs. 65.91% P = 0.0002 and 92.86% vs. 45.45% P < 0.0001 respectively) but not among mothers with meiosis I nondisjunction. We infer that the co-occurrence of the PSEN-1 T allele and the APOE ε4 allele associatively increases the risk of meiotic segregation error II among young women.
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Affiliation(s)
- Pranami Bhaumik
- Department of Biotechnology, School of Biotechnology and Biological
Sciences. Maulana Abul Kalam Azad University of Technology, West Bengal, India
| | - Priyanka Ghosh
- Department of Biotechnology, School of Biotechnology and Biological
Sciences. Maulana Abul Kalam Azad University of Technology, West Bengal, India
| | - Sujay Ghosh
- Department of Zoology, University of Calcutta, Ballygunge Science
college campus, Kolkata, West Bengal, India
| | - Eleanor Feingold
- Department of Human Genetics, Graduate School of Public Health,
University of Pittsburgh, PA, USA
- Department of Biostatistics, Graduate School of Public Health,
University of Pittsburgh, Pittsburgh, PA, USA
| | - Umut Ozbek
- Department of Biostatistics, Graduate School of Public Health,
University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Subrata Kumar Dey
- Department of Biotechnology, School of Biotechnology and Biological
Sciences. Maulana Abul Kalam Azad University of Technology, West Bengal, India
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25
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Andriani GA, Vijg J, Montagna C. Mechanisms and consequences of aneuploidy and chromosome instability in the aging brain. Mech Ageing Dev 2017; 161:19-36. [PMID: 27013377 PMCID: PMC5490080 DOI: 10.1016/j.mad.2016.03.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/17/2016] [Accepted: 03/19/2016] [Indexed: 01/31/2023]
Abstract
Aneuploidy and polyploidy are a form of Genomic Instability (GIN) known as Chromosomal Instability (CIN) characterized by sporadic abnormalities in chromosome copy numbers. Aneuploidy is commonly linked to pathological states. It is a hallmark of spontaneous abortions and birth defects and it is observed virtually in every human tumor, therefore being generally regarded as detrimental for the development or the maturation of tissues under physiological conditions. Polyploidy however, occurs as part of normal physiological processes during maturation and differentiation of some mammalian cell types. Surprisingly, high levels of aneuploidy are present in the brain, and their frequency increases with age suggesting that the brain is able to maintain its functionality in the presence of high levels of mosaic aneuploidy. Because somatic aneuploidy with age can reach exceptionally high levels, it is likely to have long-term adverse effects in this organ. We describe the mechanisms accountable for an abnormal DNA content with a particular emphasis on the CNS where cell division is limited. Next, we briefly summarize the types of GIN known to date and discuss how they interconnect with CIN. Lastly we highlight how several forms of CIN may contribute to genetic variation, tissue degeneration and disease in the CNS.
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Affiliation(s)
- Grasiella A Andriani
- Department of Genetics, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA
| | - Jan Vijg
- Department of Genetics, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA; Department Ophthalmology and Visual Science, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA; Department of Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA
| | - Cristina Montagna
- Department of Genetics, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA; Department of Pathology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.
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26
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Hou Y, Song H, Croteau DL, Akbari M, Bohr VA. Genome instability in Alzheimer disease. Mech Ageing Dev 2017; 161:83-94. [PMID: 27105872 PMCID: PMC5195918 DOI: 10.1016/j.mad.2016.04.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/05/2016] [Accepted: 04/15/2016] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common form of dementia. Autosomal dominant, familial AD (fAD) is very rare and caused by mutations in amyloid precursor protein (APP), presenilin-1 (PSEN-1), and presenilin-2 (PSEN-2) genes. The pathogenesis of sporadic AD (sAD) is more complex and variants of several genes are associated with an increased lifetime risk of AD. Nuclear and mitochondrial DNA integrity is pivotal during neuronal development, maintenance and function. DNA damage and alterations in cellular DNA repair capacity have been implicated in the aging process and in age-associated neurodegenerative diseases, including AD. These findings are supported by research using animal models of AD and in DNA repair deficient animal models. In recent years, novel mechanisms linking DNA damage to neuronal dysfunction have been identified and have led to the development of noninvasive treatment strategies. Further investigations into the molecular mechanisms connecting DNA damage to AD pathology may help to develop novel treatment strategies for this debilitating disease. Here we provide an overview of the role of genome instability and DNA repair deficiency in AD pathology and discuss research strategies that include genome instability as a component.
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Affiliation(s)
- Yujun Hou
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Hyundong Song
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Mansour Akbari
- Center for Healthy Aging, SUND, University of Copenhagen, Denmark
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA.
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27
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Rasheed MZ, Tabassum H, Parvez S. Mitochondrial permeability transition pore: a promising target for the treatment of Parkinson's disease. PROTOPLASMA 2017; 254:33-42. [PMID: 26825389 DOI: 10.1007/s00709-015-0930-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 12/10/2015] [Indexed: 06/05/2023]
Abstract
Among the neurodegenerative diseases (ND), Parkinson's disease affects 6.3 million people worldwide characterized by the progressive loss of dopaminergic neurons in substantia nigra. The mitochondrial permeability transition pore (mtPTP) is a non-selective voltage-dependent mitochondrial channel whose opening modifies the permeability properties of the mitochondrial inner membrane. It is recognized as a potent pharmacological target for diseases associated with mitochondrial dysfunction and excessive cell death including ND such as Parkinson's disease (PD). Imbalance in Ca2+ concentration, change in mitochondrial membrane potential, overproduction of reactive oxygen species (ROS), or mutation in mitochondrial genome has been implicated in the pathophysiology of the opening of the mtPTP. Different proteins are released by permeability transition including cytochrome c which is responsible for apoptosis. This review aims to discuss the importance of PTP in the pathophysiology of PD and puts together different positive as well as negative aspects of drugs such as pramipexole, ropinirole, minocyclin, rasagilin, and safinamide which act as a blocker or modifier for mtPTP. Some of them may be detrimental in their neuroprotective nature.
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Affiliation(s)
- Md Zeeshan Rasheed
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi, 110 062, India
| | - Heena Tabassum
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi, 110 062, India
- Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, 110 062, India
| | - Suhel Parvez
- Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi, 110 062, India.
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28
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Atwood CS, Bowen RL. A Unified Hypothesis of Early- and Late-Onset Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2016; 47:33-47. [PMID: 26402752 DOI: 10.3233/jad-143210] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Early-onset familial Alzheimer's disease (EOFAD) and late-onset sporadic AD (LOSAD) both follow a similar pathological and biochemical course that includes: neuron and synapse loss and dysfunction, microvascular damage, microgliosis, extracellular amyloid-β deposition, tau phosphorylation, formation of intracellular neurofibrillary tangles, endoreduplication and related cell cycle events in affected brain regions. Any mechanistic explanation of AD must accommodate these biochemical and neuropathological features for both forms of the disease. In this insight paper we provide a unifying hypothesis for EOFAD and LOSAD that proposes that the aberrant re-entry of terminally differentiated, post-mitotic neurons into the cell division cycle is a common pathway that explains both early and late-onset forms of AD. Cell cycle abnormalities appear very early in the disease process, prior to the appearance of plaques and tangles, and explain the biochemical (e.g. tau phosphorylation), neuropathological (e.g. neuron hypertrophy; polypoidy) and cognitive changes observed in EOFAD and LOSAD. Genetic mutations in AβPP, PSEN1, and PSEN2 that alter amyloid-β precursor protein and Notch processing drive reactivation of the cell cycle in EOFAD, while age-related reproductive endocrine dyscrasia that upregulates mitogenic TNF signaling and AβPP processing toward the amyloidogenic pathway drives reactivation of the cell cycle in LOSAD. In essence, AβPP and presenilin mutations initiate early, what endocrine dyscrasia initiates later: aberrant cell cycle re-entry of post-mitotic neurons leading to neurodegeneration and cognitive decline in AD. Inhibition of cell cycle re-entry in post-mitotic neurons may be a useful therapeutic strategy to prevent, slow or halt disease progression.
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Affiliation(s)
- Craig S Atwood
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.,Geriatric Research, Education and Clinical Center, Veterans Administration Hospital, Madison, WI, USA.,School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
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29
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Potter H. Beyond Trisomy 21: Phenotypic Variability in People with Down Syndrome Explained by Further Chromosome Mis-segregation and Mosaic Aneuploidy. ACTA ACUST UNITED AC 2016. [PMID: 29516054 PMCID: PMC5837063 DOI: 10.4172/2472-1115.1000109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Phenotypic variability is a fundamental feature of the human population and is particularly evident among people with Down syndrome and/or Alzheimer’s disease. Herein, we review current theories of the potential origins of this phenotypic variability and propose a novel mechanism based on our finding that the Alzheimer’s disease-associated Aβ peptide, encoded on chromosome 21, disrupts the mitotic spindle, induces abnormal chromosome segregation, and produces mosaic populations of aneuploid cells in all tissues of people with Alzheimer’s disease and in mouse and cell models thereof. Thus, individuals exposed to increased levels of the Aβ peptide should accumulate mosaic populations of aneuploid cells, with different chromosomes affected in different tissues and in different individuals. Specifically, people with Down syndrome, who express elevated levels of Aβ peptide throughout their lifetimes, would be predicted to accumulate additional types of aneuploidy, beyond trisomy 21 and including changes in their trisomy 21 status, in mosaic cell populations. Such mosaic aneuploidy would introduce a novel form of genetic variability that could potentially underlie much of the observed phenotypic variability among people with Down syndrome, and possibly also among people with Alzheimer’s disease. This mosaic aneuploidy theory of phenotypic variability in Down syndrome is supported by several observations, makes several testable predictions, and identifies a potential approach to reducing the frequency of some of the most debilitating features of Down syndrome, including Alzheimer’s disease.
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Affiliation(s)
- Huntington Potter
- Department of Neurology, and Linda Crnic Institute for Down Syndrome, Rocky Mountain Alzheimer's Disease Center, University of Colorado Anschutz Medical Center, USA
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30
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Potter H, Granic A, Caneus J. Role of Trisomy 21 Mosaicism in Sporadic and Familial Alzheimer's Disease. Curr Alzheimer Res 2016; 13:7-17. [PMID: 26651340 PMCID: PMC5570437 DOI: 10.2174/156720501301151207100616] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/13/2015] [Accepted: 08/30/2015] [Indexed: 02/07/2023]
Abstract
Trisomy 21 and the consequent extra copy of the amyloid precursor protein (APP) gene and increased beta-amyloid (Aβ) peptide production underlie the universal development of Alzheimer's disease (AD) pathology and high risk of AD dementia in people with Down syndrome (DS). Trisomy 21 and other forms of aneuploidy also arise among neurons and peripheral cells in both sporadic and familial AD and in mouse and cell models thereof, reinforcing the conclusion that AD and DS are two sides of the same coin. The demonstration that 90% of the neurodegeneration in AD can be attributed to the selective loss of aneuploid neurons generated over the course of the disease indicates that aneuploidy is an essential feature of the pathogenic pathway leading to the depletion of neuronal cell populations. Trisomy 21 mosaicism also occurs in neurons and other cells from patients with Niemann-Pick C1 disease and from patients with familial or sporadic frontotemporal lobar degeneration (FTLD), as well as in their corresponding mouse and cell models. Biochemical studies have shown that Aβ induces mitotic spindle defects, chromosome mis-segregation, and aneuploidy in cultured cells by inhibiting specific microtubule motors required for mitosis. These data indicate that neuronal trisomy 21 and other types of aneuploidy characterize and likely contribute to multiple neurodegenerative diseases and are a valid target for therapeutic intervention. For example, reducing extracellular calcium or treating cells with lithium chloride (LiCl) blocks the induction of trisomy 21 by Aβ. The latter finding is relevant in light of recent reports of a lowered risk of dementia in bipolar patients treated with LiCl and in the stabilization of cognition in AD patients treated with LiCl.
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Affiliation(s)
- Huntington Potter
- Department of Neurology and Linda Crnic Institute for Down Syndrome, 12700 E. 19th Ave room 4010, mail stop 8608, Aurora CO 80045, USA.
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31
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Atwood CS, Bowen RL. The endocrine dyscrasia that accompanies menopause and andropause induces aberrant cell cycle signaling that triggers re-entry of post-mitotic neurons into the cell cycle, neurodysfunction, neurodegeneration and cognitive disease. Horm Behav 2015; 76:63-80. [PMID: 26188949 PMCID: PMC4807861 DOI: 10.1016/j.yhbeh.2015.06.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 06/23/2015] [Accepted: 06/23/2015] [Indexed: 12/26/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Sex hormones are physiological factors that promote neurogenesis during embryonic and fetal development. During childhood and adulthood these hormones support the maintenance of brain structure and function via neurogenesis and the formation of dendritic spines, axons and synapses required for the capture, processing and retrieval of information (memories). Not surprisingly, changes in these reproductive hormones that occur with menopause and during andropause are strongly correlated with neurodegeneration and cognitive decline. In this connection, much evidence now indicates that Alzheimer's disease (AD) involves aberrant re-entry of post-mitotic neurons into the cell cycle. Cell cycle abnormalities appear very early in the disease, prior to the appearance of plaques and tangles, and explain the biochemical, neuropathological and cognitive changes observed with disease progression. Intriguingly, a recent animal study has demonstrated that induction of adult neurogenesis results in the loss of previously encoded memories while decreasing neurogenesis after memory formation during infancy mitigated forgetting. Here we review the biochemical, epidemiological and clinical evidence that alterations in sex hormone signaling associated with menopause and andropause drive the aberrant re-entry of post-mitotic neurons into an abortive cell cycle that leads to neurite retraction, neuron dysfunction and neuron death. When the reproductive axis is in balance, gonadotropins such as luteinizing hormone (LH), and its fetal homolog, human chorionic gonadotropin (hCG), promote pluripotent human and totipotent murine embryonic stem cell and neuron proliferation. However, strong evidence supports menopausal/andropausal elevations in the LH:sex steroid ratio as driving aberrant mitotic events. These include the upregulation of tumor necrosis factor; amyloid-β precursor protein processing towards the production of mitogenic Aβ; and the activation of Cdk5, a key regulator of cell cycle progression and tau phosphorylation (a cardinal feature of both neurogenesis and neurodegeneration). Cognitive and biochemical studies confirm the negative consequences of a high LH:sex steroid ratio on dendritic spine density and human cognitive performance. Prospective epidemiological and clinical evidence in humans supports the premise that rebalancing the ratio of circulating gonadotropins:sex steroids reduces the incidence of AD. Together, these data support endocrine dyscrasia and the subsequent loss of cell cycle control as an important etiological event in the development of neurodegenerative diseases including AD, stroke and Parkinson's disease.
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Affiliation(s)
- Craig S Atwood
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA; Geriatric Research, Education and Clinical Center, Veterans Administration Hospital, Madison, WI 53705, USA; School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, 6027 WA, Australia.
| | - Richard L Bowen
- OTB Research, 217 Calhoun St, Unit 1, Charleston, SC 29401, USA
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32
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Arendt T, Brückner MK, Lösche A. Regional mosaic genomic heterogeneity in the elderly and in Alzheimer's disease as a correlate of neuronal vulnerability. Acta Neuropathol 2015; 130:501-10. [PMID: 26298468 DOI: 10.1007/s00401-015-1465-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/31/2015] [Accepted: 07/31/2015] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by fibrillary aggregates of Aβ peptide and tau protein. The distribution of these pathological hallmarks throughout the brain is not random; it follows a predictive pattern that is used for pathological staging. However, most etiopathogenetic concepts, irrespective of whether they focus on Aβ or tau pathology, leave a key question unanswered: what is the explanation for the different vulnerabilities of brain regions in AD? The pattern of regional progression of neurofibrillary degeneration in AD to some extent inversely recapitulates ontogenetic and phylogenetic brain development. Accordingly, degeneration preferentially affects brain areas that have recently been acquired or restructured during anthropoid evolution, which means that the involvement of a neurodevelopmental mechanism is highly likely. Since evolutionary expansion of the neocortex is based on a substantial extension of the mitotic activity of progenitor cells, we propose a conceptual link between neurogenesis in anthropoid primates and a higher risk of accumulating mitotic errors that give rise to genomic aberrations commonly referred to as DNA content variation (DCV). If increased rates of DCV make neurons more vulnerable to AD-related pathology, one might expect there to be a higher rate of DCV in areas that are affected very early during the course of AD, as compared to areas which are hardly affected or are affected only during the most advanced stages. Therefore, in the present study, we comparatively analyzed the DCV in five different cortical areas that are affected during the early stage (entorhinal cortex), the intermediate stage (temporal, frontal, and parietal association cortex), and the late stage (primary sensory occipital cortex) of AD in both normal elderly subjects and AD patients. On average, we observed about 10 % neuronal mosaic DCV in the normal elderly and a two- to threefold increase in DCV in AD patients. We were able to demonstrate, moreover, that the neuronal DCV in the cerebral cortex of the normal elderly as well as the increased neuronal DCV in AD patients are not randomly distributed but instead show systematic regional differences which correspond to differences in vulnerability. These findings provide additional evidence that mosaic genomic heterogeneity may play a key role in AD pathology.
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Affiliation(s)
- Thomas Arendt
- Department of Molecular and Cellular Mechanism of Neurodegeneration, Paul Flechsig Institute for Brain Research, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany.
| | - Martina K Brückner
- Department of Molecular and Cellular Mechanism of Neurodegeneration, Paul Flechsig Institute for Brain Research, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
| | - Andreas Lösche
- Core Unit Fluorescence Technologies of the Medical Faculty, Universität Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
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33
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Bajic V, Spremo-Potparevic B, Zivkovic L, Isenovic ER, Arendt T. Cohesion and the aneuploid phenotype in Alzheimer's disease: A tale of genome instability. Neurosci Biobehav Rev 2015; 55:365-74. [PMID: 26003528 DOI: 10.1016/j.neubiorev.2015.05.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 03/26/2015] [Accepted: 05/12/2015] [Indexed: 12/20/2022]
Abstract
Neurons are postmitotic cells that are in permanent cell cycle arrest. However, components of the cell cycle machinery that are expressed in Alzheimer's disease (AD) neurons are showing features of a cycling cell and those attributed to a postmitotic cell as well. Furthermore, the unique physiological operations taking place in neurons, ascribed to "core cell cycle regulators" are also key regulators in cell division. Functions of these cell cycle regulators include neuronal migration, axonal elongation, axon pruning, dendrite morphogenesis and synaptic maturation and plasticity. In this review, we focus on cohesion and cohesion related proteins in reference to their neuronal functions and how impaired centromere/cohesion dynamics may connect cell cycle dysfunction to aneuploidy in AD.
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Affiliation(s)
- Vladan Bajic
- Institute for Nuclear Research "Vinca", Laboratory for Radiobiology and Molecular Genetics, University of Belgrade, P.O. 522, 11001 Belgrade, Serbia.
| | - Biljana Spremo-Potparevic
- Faculty of Pharmacy, Institute of Physiology, Department of Biology and Human Genetics, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia.
| | - Lada Zivkovic
- Faculty of Pharmacy, Institute of Physiology, Department of Biology and Human Genetics, University of Belgrade, Vojvode Stepe 450, 11000 Belgrade, Serbia.
| | - Esma R Isenovic
- Institute for Nuclear Research "Vinca", Laboratory for Radiobiology and Molecular Genetics, University of Belgrade, P.O. 522, 11001 Belgrade, Serbia.
| | - Thomas Arendt
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, School of Medicine, Leipzig, Germany.
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34
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Coppedè F, Migliore L. DNA damage in neurodegenerative diseases. Mutat Res 2015; 776:84-97. [PMID: 26255941 DOI: 10.1016/j.mrfmmm.2014.11.010] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/27/2014] [Accepted: 11/30/2014] [Indexed: 06/04/2023]
Abstract
Following the observation of increased oxidative DNA damage in nuclear and mitochondrial DNA extracted from post-mortem brain regions of patients affected by neurodegenerative diseases, the last years of the previous century and the first decade of the present one have been largely dedicated to the search of markers of DNA damage in neuronal samples and peripheral tissues of patients in early, intermediate or late stages of neurodegeneration. Those studies allowed to demonstrate that oxidative DNA damage is one of the earliest detectable events in neurodegeneration, but also revealed cytogenetic damage in neurodegenerative conditions, such as for example a tendency towards chromosome 21 malsegregation in Alzheimer's disease. As it happens for many neurodegenerative risk factors the question of whether DNA damage is cause or consequence of the neurodegenerative process is still open, and probably both is true. The research interest in markers of oxidative stress was shifted, in recent years, towards the search of epigenetic biomarkers of neurodegenerative disorders, following the accumulating evidence of a substantial contribution of epigenetic mechanisms to learning, memory processes, behavioural disorders and neurodegeneration. Increasing evidence is however linking DNA damage and repair with epigenetic phenomena, thereby opening the way to a very attractive and timely research topic in neurodegenerative diseases. We will address those issues in the context of Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis, which represent three of the most common neurodegenerative pathologies in humans.
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Affiliation(s)
- Fabio Coppedè
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
| | - Lucia Migliore
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
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François M, Leifert W, Martins R, Thomas P, Fenech M. Biomarkers of Alzheimer's disease risk in peripheral tissues; focus on buccal cells. Curr Alzheimer Res 2015; 11:519-31. [PMID: 24938500 PMCID: PMC4166904 DOI: 10.2174/1567205011666140618103827] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/26/2014] [Accepted: 06/16/2014] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is a progressive degenerative disorder of the brain and is the most common form of dementia. To-date no simple, inexpensive and minimally invasive procedure is available to confirm with certainty the early diagnosis of AD prior to the manifestations of symptoms characteristic of the disease. Therefore, if population screening of individuals is to be performed, more suitable, easily accessible tissues would need to be used for a diagnostic test that would identify those who exhibit cellular pathology indicative of mild cognitive impairment (MCI) and AD risk so that they can be prioritized for primary prevention. This need for minimally invasive tests could be achieved by targeting surrogate tissues, since it is now well recognized that AD is not only a disorder restricted to pathology and biomarkers within the brain. Human buccal cells for instance are accessible in a minimally invasive manner, and exhibit cytological and nuclear morphologies that may be indicative of accelerated ageing or neurodegenerative disorders such as AD. However, to our knowledge there is no review available in the literature covering the biology of buccal cells and their applications in AD biomarker research. Therefore, the aim of this review is to summarize some of the main findings of biomarkers reported for AD in peripheral tissues, with a further focus on the rationale for the use of the buccal mucosa (BM) for biomarkers of AD and the evidence to date of changes exhibited in buccal cells with AD.
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Affiliation(s)
| | | | | | | | - Michael Fenech
- CSIRO Animal, Food and Health Sciences, Gate 13, Kintore Ave, Adelaide, South Australia, 5000, Australia.
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Bushman DM, Kaeser GE, Siddoway B, Westra JW, Rivera RR, Rehen SK, Yung YC, Chun J. Genomic mosaicism with increased amyloid precursor protein (APP) gene copy number in single neurons from sporadic Alzheimer's disease brains. eLife 2015; 4. [PMID: 25650802 PMCID: PMC4337608 DOI: 10.7554/elife.05116] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/14/2015] [Indexed: 12/31/2022] Open
Abstract
Previous reports have shown that individual neurons of the brain can display somatic genomic mosaicism of unknown function. In this study, we report altered genomic mosaicism in single, sporadic Alzheimer's disease (AD) neurons characterized by increases in DNA content and amyloid precursor protein (APP) gene copy number. AD cortical nuclei displayed large variability with average DNA content increases of ∼8% over non-diseased controls that were unrelated to trisomy 21. Two independent single-cell copy number analyses identified amplifications at the APP locus. The use of single-cell qPCR identified up to 12 copies of APP in sampled neurons. Peptide nucleic acid (PNA) probes targeting APP, combined with super-resolution microscopy detected primarily single fluorescent signals of variable intensity that paralleled single-cell qPCR analyses. These data identify somatic genomic changes in single neurons, affecting known and unknown loci, which are increased in sporadic AD, and further indicate functionality for genomic mosaicism in the CNS. DOI:http://dx.doi.org/10.7554/eLife.05116.001 The instructions for living cells are contained in certain stretches of DNA, called genes, and these instructions have been largely considered to be invariant, such that every cell in the body has the same DNA. However, research has revealed that many neurons in the human brain can contain different amounts of DNA compared to other cells. When cells with varied DNA are present in the same person, it is referred to as mosaicism. The effects of this mosaicism are unknown, although by altering the instructions in brain cells, it is suspected to influence both the normal and diseased brain. The brains of patients with Alzheimer's disease often contain deposits of proteins called amyloids. The precursor of the protein that makes up most of these deposits is produced from a gene called the amyloid precursor protein gene, or APP. Having an extra copy of the APP gene can cause rare ‘familial’ Alzheimer's disease, wherein the APP duplication can be passed on genetically and is present in all the cells of a patient's body. By contrast, ‘sporadic’ Alzheimer's disease, which constitutes around 95% of cases, does not show any difference in the number of APP genes found in tissue samples, including whole brain. The early studies that discovered this were conducted before an appreciation of brain mosaicism, and thus single neurons were not investigated. This raises the possibility that the number of APP genes may be mosaically increased, which would not be detected by examining non-brain or bulk brain tissue. Bushman, Kaeser et al. used five different types of experiments to examine the DNA content of single neurons and investigate whether mosaicism could explain the discrepancy in the results of the previous studies. The neurons from people with Alzheimer's disease contained more DNA—on average, hundreds of millions of DNA base pairs more—and more copies of the APP gene, with some neurons containing up to 12 copies. Bushman, Kaeser et al.'s findings present evidence of a way that mosaicism can affect how the brain works by altering the number of gene copies, and how this impacts the most common form of Alzheimer's disease. Many questions arise from the work, including when does mosaicism arise, and what promotes its formation? How does this relate to age? What parts of the genome are changed, what genes are affected, and how do these changes alter neuronal function? Furthermore, Bushman, Kaeser et al.'s work suggests that mosaicism may also play a role in other brain diseases, and could also provide new insights into the normal, complex functions of the brain. In the future, this knowledge could help to identify new treatments for brain diseases; for example, by identifying new molecular targets for therapy hidden in the extra DNA or by understanding how to alter mosaicism. DOI:http://dx.doi.org/10.7554/eLife.05116.002
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Affiliation(s)
- Diane M Bushman
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Gwendolyn E Kaeser
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Benjamin Siddoway
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Jurgen W Westra
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Richard R Rivera
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Stevens K Rehen
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Yun C Yung
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Jerold Chun
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
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Hartley D, Blumenthal T, Carrillo M, DiPaolo G, Esralew L, Gardiner K, Granholm AC, Iqbal K, Krams M, Lemere C, Lott I, Mobley W, Ness S, Nixon R, Potter H, Reeves R, Sabbagh M, Silverman W, Tycko B, Whitten M, Wisniewski T. Down syndrome and Alzheimer's disease: Common pathways, common goals. Alzheimers Dement 2014; 11:700-9. [PMID: 25510383 DOI: 10.1016/j.jalz.2014.10.007] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 08/26/2014] [Accepted: 10/02/2014] [Indexed: 12/17/2022]
Abstract
In the United States, estimates indicate there are between 250,000 and 400,000 individuals with Down syndrome (DS), and nearly all will develop Alzheimer's disease (AD) pathology starting in their 30s. With the current lifespan being 55 to 60 years, approximately 70% will develop dementia, and if their life expectancy continues to increase, the number of individuals developing AD will concomitantly increase. Pathogenic and mechanistic links between DS and Alzheimer's prompted the Alzheimer's Association to partner with the Linda Crnic Institute for Down Syndrome and the Global Down Syndrome Foundation at a workshop of AD and DS experts to discuss similarities and differences, challenges, and future directions for this field. The workshop articulated a set of research priorities: (1) target identification and drug development, (2) clinical and pathological staging, (3) cognitive assessment and clinical trials, and (4) partnerships and collaborations with the ultimate goal to deliver effective disease-modifying treatments.
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Affiliation(s)
- Dean Hartley
- Medical and Scientific Relations, Alzheimer's Association, Chicago, IL, USA.
| | - Thomas Blumenthal
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Maria Carrillo
- Medical and Scientific Relations, Alzheimer's Association, Chicago, IL, USA
| | - Gilbert DiPaolo
- Department of Pathology and Cell Biology, Columbia University Medical Center and The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, New York, NY, USA
| | - Lucille Esralew
- Department of Behavioral Health, Trinitas Regional Medical Center, Elizabeth, NJ, USA
| | - Katheleen Gardiner
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado, Denver, CO, USA
| | - Ann-Charlotte Granholm
- Department of Neuroscience and the Center on Aging, Medical University of South Carolina, Columbia, SC, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, New York, NY, USA
| | | | - Cynthia Lemere
- Department of Neurology and the Anne Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ira Lott
- Department of Pediatrics, University of California, Irvine, CA, USA
| | - William Mobley
- Department of Neurosciences, University of California, San Diego, CA, USA
| | - Seth Ness
- Janssen Research & Development, Raritan, NJ, USA
| | - Ralph Nixon
- Department of Psychiatry and Cell Biology, New York University, Langone Medical Center, New York, NY, USA
| | - Huntington Potter
- Linda Crnic Institute for Down Syndrome, University of Colorado, Aurora, CO, USA; Department of Neurology, University of Colorado, Denver, CO, USA
| | - Roger Reeves
- Department of Physiology, McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marwan Sabbagh
- Banner Sun Health Research Institute, Banner Health, Sun City, AZ, USA
| | - Wayne Silverman
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Benjamin Tycko
- Department of Pathology and Cell Biology, Columbia University Medical Center and The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, New York, NY, USA
| | | | - Thomas Wisniewski
- Department of Neurology, Pathology, and Psychiatry, New York University, Langone Medical Center, New York, NY, USA
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Ari C, Borysov SI, Wu J, Padmanabhan J, Potter H. Alzheimer amyloid beta inhibition of Eg5/kinesin 5 reduces neurotrophin and/or transmitter receptor function. Neurobiol Aging 2014; 35:1839-49. [PMID: 24636920 DOI: 10.1016/j.neurobiolaging.2014.02.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 12/23/2013] [Accepted: 02/05/2014] [Indexed: 12/29/2022]
Abstract
The mechanism by which amyloid beta (Aβ) causes neuronal dysfunction and/or death in Alzheimer's disease (AD) is unclear. Previously, we showed that Aβ inhibits several microtubule-dependent kinesin motors essential for mitosis and also present in mature neurons. Here, we show that inhibition of kinesin 5 (Eg5) by Aβ blocks neuronal function by reducing transport of neurotrophin and neurotransmitter receptors to the cell surface. Specifically, cell-surface NGF/NTR(p75) and NMDA receptors decline in cells treated with Aβ or the kinesin 5 inhibitor monastrol, or expressing APP. Aβ and monastrol also inhibit NGF-dependent neurite outgrowth from PC12 cells and glutamate-dependent Ca++ entry into primary neurons. Like Aβ, monastrol inhibits long-term potentiation, a cellular model of NMDA-dependent learning and memory, and kinesin 5 activity is absent from APP/PS transgenic mice brain or neurons treated with Aβ. These data imply that cognitive deficits in AD may derive in part from inhibition of neuronal Eg5 by Aβ, resulting in impaired neuronal function and/or survival through receptor mislocalization. Preventing inhibition of Eg5 or other motors by Aβ may represent a novel approach to AD therapy.
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Affiliation(s)
- Csilla Ari
- USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL, USA
| | - Sergiy I Borysov
- USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL, USA; Eric Pfeiffer Suncoast Alzheimer's Center, University of South Florida, Tampa, FL, USA; Department of Oncology, H. Lee Moffitt Cancer and Research Center, Tampa, FL, USA
| | - Jiashin Wu
- Department of Molecular Pharmacology and Physiology, College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jaya Padmanabhan
- USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL, USA
| | - Huntington Potter
- USF Health Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, USA; Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL, USA; Eric Pfeiffer Suncoast Alzheimer's Center, University of South Florida, Tampa, FL, USA; Department of Neurology and Linda Crnic Institute for Down Syndrome, Anschutz Medical Campus, University of Colorado, Denver, Aurora, CO, USA.
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Genetics of Alzheimer's disease. BIOMED RESEARCH INTERNATIONAL 2013; 2013:254954. [PMID: 23984328 PMCID: PMC3741956 DOI: 10.1155/2013/254954] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/08/2013] [Accepted: 07/08/2013] [Indexed: 01/18/2023]
Abstract
Alzheimer's disease is the most common form of dementia and is the only top 10 cause of death in the United States that lacks disease-altering treatments. It is a complex disorder with environmental and genetic components. There are two major types of Alzheimer's disease, early onset and the more common late onset. The genetics of early-onset Alzheimer's disease are largely understood with variants in three different genes leading to disease. In contrast, while several common alleles associated with late-onset Alzheimer's disease, including APOE, have been identified using 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 Alzheimer's disease.
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40
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Granic A, Potter H. Mitotic spindle defects and chromosome mis-segregation induced by LDL/cholesterol-implications for Niemann-Pick C1, Alzheimer's disease, and atherosclerosis. PLoS One 2013; 8:e60718. [PMID: 23593294 PMCID: PMC3625184 DOI: 10.1371/journal.pone.0060718] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 03/01/2013] [Indexed: 12/17/2022] Open
Abstract
Elevated low-density lipoprotein (LDL)-cholesterol is a risk factor for both Alzheimer's disease (AD) and Atherosclerosis (CVD), suggesting a common lipid-sensitive step in their pathogenesis. Previous results show that AD and CVD also share a cell cycle defect: chromosome instability and up to 30% aneuploidy-in neurons and other cells in AD and in smooth muscle cells in atherosclerotic plaques in CVD. Indeed, specific degeneration of aneuploid neurons accounts for 90% of neuronal loss in AD brain, indicating that aneuploidy underlies AD neurodegeneration. Cell/mouse models of AD develop similar aneuploidy through amyloid-beta (Aß) inhibition of specific microtubule motors and consequent disruption of mitotic spindles. Here we tested the hypothesis that, like upregulated Aß, elevated LDL/cholesterol and altered intracellular cholesterol homeostasis also causes chromosomal instability. Specifically we found that: 1) high dietary cholesterol induces aneuploidy in mice, satisfying the hypothesis' first prediction, 2) Niemann-Pick C1 patients accumulate aneuploid fibroblasts, neurons, and glia, demonstrating a similar aneugenic effect of intracellular cholesterol accumulation in humans 3) oxidized LDL, LDL, and cholesterol, but not high-density lipoprotein (HDL), induce chromosome mis-segregation and aneuploidy in cultured cells, including neuronal precursors, indicating that LDL/cholesterol directly affects the cell cycle, 4) LDL-induced aneuploidy requires the LDL receptor, but not Aß, showing that LDL works differently than Aß, with the same end result, 5) cholesterol treatment disrupts the structure of the mitotic spindle, providing a cell biological mechanism for its aneugenic activity, and 6) ethanol or calcium chelation attenuates lipoprotein-induced chromosome mis-segregation, providing molecular insights into cholesterol's aneugenic mechanism, specifically through its rigidifying effect on the cell membrane, and potentially explaining why ethanol consumption reduces the risk of developing atherosclerosis or AD. These results suggest a novel, cell cycle mechanism by which aberrant cholesterol homeostasis promotes neurodegeneration and atherosclerosis by disrupting chromosome segregation and potentially other aspects of microtubule physiology.
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Affiliation(s)
- Antoneta Granic
- Department of Neurology and Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- Institute for Ageing and Health, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Huntington Potter
- Department of Neurology and Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, Colorado, United States of America
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Bushman DM, Chun J. The genomically mosaic brain: aneuploidy and more in neural diversity and disease. Semin Cell Dev Biol 2013; 24:357-69. [PMID: 23466288 PMCID: PMC3637860 DOI: 10.1016/j.semcdb.2013.02.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/25/2013] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
Genomically identical cells have long been assumed to comprise the human brain, with post-genomic mechanisms giving rise to its enormous diversity, complexity, and disease susceptibility. However, the identification of neural cells containing somatically generated mosaic aneuploidy - loss and/or gain of chromosomes from a euploid complement - and other genomic variations including LINE1 retrotransposons and regional patterns of DNA content variation (DCV), demonstrate that the brain is genomically heterogeneous. The precise phenotypes and functions produced by genomic mosaicism are not well understood, although the effects of constitutive aberrations, as observed in Down syndrome, implicate roles for defined mosaic genomes relevant to cellular survival, differentiation potential, stem cell biology, and brain organization. Here we discuss genomic mosaicism as a feature of the normal brain as well as a possible factor in the weak or complex genetic linkages observed for many of the most common forms of neurological and psychiatric diseases.
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Affiliation(s)
- Diane M. Bushman
- Molecular and Cellular Neuroscience Department, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
- Biomedical Sciences Graduate Program, School of Medicine, University of California San Diego, La Jolla, California, USA
| | - Jerold Chun
- Molecular and Cellular Neuroscience Department, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
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Iourov IY, Vorsanova SG, Yurov YB. Somatic cell genomics of brain disorders: a new opportunity to clarify genetic-environmental interactions. Cytogenet Genome Res 2013; 139:181-8. [PMID: 23428498 DOI: 10.1159/000347053] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recent genomic advances have exacerbated the problem of interpreting genome-wide association studies aimed at uncovering genetic basis of brain disorders. Despite of a plethora of data on candidate genes determining the susceptibility to neuropsychiatric diseases, no consensus is reached on their intrinsic contribution to the pathogenesis, and the influence of the environment on these genes is incompletely understood. Alternatively, single-cell analyses of the normal and diseased human brain have shown that somatic genome/epigenome variations (somatic mosaicism) do affect neuronal cell populations and are likely to mediate pathogenic processes associated with brain dysfunctions. Such (epi-)genomic changes are likely to arise from disturbances in genome maintenance and cell cycle regulation pathways as well as from environmental exposures. Therefore, one can suggest that, at least in a proportion of cases, inter- and intragenic variations (copy number variations (CNVs) or single nucleotide polymorphisms (SNPs)) associated with major brain disorders (i.e. schizophrenia, Alzheimer's disease, autism) lead to genetic dysregulation resulting in somatic genetic and epigenetic mosaicism. In addition, environmental influences on malfunctioning cellular machinery could trigger a cascade of abnormal processes producing genomic/chromosomal instability (i.e. brain-specific aneuploidy). Here, a brief analysis of a genome-wide association database has allowed us to support these speculations. Accordingly, an ontogenetic 2-/multiple-hit mechanism of brain diseases was hypothesized. Finally, we speculate that somatic cell genomics approach considering both genome-wide associations and somatic (epi-)genomic variations is likely to have bright perspectives for disease-oriented genome research.
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Affiliation(s)
- I Y Iourov
- Research Center of Mental Health, Russian Academy of Medical Sciences, RU–119152 Moscow, Russia.
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Iourov IY, Vorsanova SG, Yurov YB. Single cell genomics of the brain: focus on neuronal diversity and neuropsychiatric diseases. Curr Genomics 2012; 13:477-88. [PMID: 23449087 PMCID: PMC3426782 DOI: 10.2174/138920212802510439] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 01/30/2012] [Accepted: 06/12/2012] [Indexed: 12/21/2022] Open
Abstract
Single cell genomics has made increasingly significant contributions to our understanding of the role that somatic genome variations play in human neuronal diversity and brain diseases. Studying intercellular genome and epigenome variations has provided new clues to the delineation of molecular mechanisms that regulate development, function and plasticity of the human central nervous system (CNS). It has been shown that changes of genomic content and epigenetic profiling at single cell level are involved in the pathogenesis of neuropsychiatric diseases (schizophrenia, mental retardation (intellectual/leaning disability), autism, Alzheimer's disease etc.). Additionally, several brain diseases were found to be associated with genome and chromosome instability (copy number variations, aneuploidy) variably affecting cell populations of the human CNS. The present review focuses on the latest advances of single cell genomics, which have led to a better understanding of molecular mechanisms of neuronal diversity and neuropsychiatric diseases, in the light of dynamically developing fields of systems biology and "omics".
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Affiliation(s)
- Ivan Y Iourov
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow, Russia
- Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
| | - Svetlana G Vorsanova
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow, Russia
- Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
- Center for Neurobiological Diagnosis of Genetic Psychiatric Disorders, Moscow City University of Psychology and Education, Russia
| | - Yuri B Yurov
- National Research Center of Mental Health, Russian Academy of Medical Sciences, Moscow, Russia
- Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
- Center for Neurobiological Diagnosis of Genetic Psychiatric Disorders, Moscow City University of Psychology and Education, Russia
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Fischer HG, Morawski M, Brückner MK, Mittag A, Tarnok A, Arendt T. Changes in neuronal DNA content variation in the human brain during aging. Aging Cell 2012; 11:628-33. [PMID: 22510449 DOI: 10.1111/j.1474-9726.2012.00826.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The human brain has been proposed to represent a genetic mosaic, containing a small but constant number of neurons with an amount of DNA exceeding the diploid level that appear to be generated through various chromosome segregation defects initially. While a portion of these cells apparently die during development, neurons with abnormal chromosomal copy number have been identified in the mature brain. This genomic alteration might to lead to chromosomal instability affecting neuronal viability and could thus contribute to age-related mental disorders. Changes in the frequency of neurons with such structural genomic variation in the adult and aging brain, however, are unknown. Here, we quantified the frequency of neurons with a more than diploid DNA content in the cerebral cortex of normal human brain and analyzed its changes between the fourth and ninth decades of life. We applied a protocol of slide-based cytometry optimized for DNA quantification of single identified neurons, which allowed to analyze the DNA content of about 500 000 neurons for each brain. On average, 11.5% of cortical neurons showed DNA content above the diploid level. The frequency of neurons with this genomic alteration was highest at younger age and declined with age. Our results indicate that the genomic variation associated with DNA content exceeding the diploid level might compromise viability of these neurons in the aging brain and might thus contribute to susceptibilities for age-related CNS disorders. Alternatively, a potential selection bias of "healthy aging brains" needs to be considered, assuming that DNA content variation above a certain threshold associates with Alzheimer's disease.
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Affiliation(s)
- Hans-Georg Fischer
- Paul Flechsig Institute for Brain Research, Universität Leipzig, Germany
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45
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Massone S, Ciarlo E, Vella S, Nizzari M, Florio T, Russo C, Cancedda R, Pagano A. NDM29, a RNA polymerase III-dependent non coding RNA, promotes amyloidogenic processing of APP and amyloid β secretion. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1170-7. [DOI: 10.1016/j.bbamcr.2012.05.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/29/2012] [Accepted: 05/02/2012] [Indexed: 10/28/2022]
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Down-regulation of replication factor C-40 (RFC40) causes chromosomal missegregation in neonatal and hypertrophic adult rat cardiac myocytes. PLoS One 2012; 7:e39009. [PMID: 22720015 PMCID: PMC3375256 DOI: 10.1371/journal.pone.0039009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 05/15/2012] [Indexed: 11/25/2022] Open
Abstract
Background Adult mammalian cardiac myocytes are generally assumed to be terminally differentiated; nonetheless, a small fraction of cardiac myocytes have been shown to replicate during ventricular remodeling. However, the expression of Replication Factor C (RFC; RFC140/40/38/37/36) and DNA polymerase δ (Pol δ) proteins, which are required for DNA synthesis and cell proliferation, in the adult normal and hypertrophied hearts has been rarely studied. Methods We performed qRT-PCR and Western blot analysis to determine the levels of RFC and Pol δ message and proteins in the adult normal cardiac myocytes and cardiac fibroblasts, as well as in adult normal and pulmonary arterial hypertension induced right ventricular hypertrophied hearts. Immunohistochemical analyses were performed to determine the localization of the re-expressed DNA replication and cell cycle proteins in adult normal (control) and hypertrophied right ventricle. We determined right ventricular cardiac myocyte polyploidy and chromosomal missegregation/aneuploidy using Fluorescent in situ hybridization (FISH) for rat chromosome 12. Results RFC40-mRNA and protein was undetectable, whereas Pol δ message was detectable in the cardiac myocytes isolated from control adult hearts. Although RFC40 and Pol δ message and protein significantly increased in hypertrophied hearts as compared to the control hearts; however, this increase was marginal as compared to the fetal hearts. Immunohistochemical analyses revealed that in addition to RFC40, proliferative and mitotic markers such as cyclin A, phospho-Aurora A/B/C kinase and phospho-histone 3 were also re-expressed/up-regulated simultaneously in the cardiac myocytes. Interestingly, FISH analyses demonstrated cardiac myocytes polyploidy and chromosomal missegregation/aneuploidy in these hearts. Knock-down of endogenous RFC40 caused chromosomal missegregation/aneuploidy and decrease in the rat neonatal cardiac myocyte numbers. Conclusion Our novel findings suggest that transcription of RFC40 is suppressed in the normal adult cardiac myocytes and its insufficient re-expression may be responsible for causing chromosomal missegregation/aneuploidy and in cardiac myocytes during right ventricular hypertrophy.
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47
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Cell cycle activation and aneuploid neurons in Alzheimer's disease. Mol Neurobiol 2012; 46:125-35. [PMID: 22528601 DOI: 10.1007/s12035-012-8262-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 03/20/2012] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder, characterized by synaptic degeneration associated with fibrillar aggregates of the amyloid-ß peptide and the microtubule-associated protein tau. The progression of neurofibrillary degeneration throughout the brain during AD follows a predictive pattern which provides the basis for the neuropathological staging of the disease. This pattern of selective neuronal vulnerability against neurofibrillary degeneration matches the regional degree of neuronal plasticity and inversely recapitulates ontogenetic and phylogenetic brain development which links neurodegenerative cell death to neuroplasticity and brain development. Here, we summarize recent evidence for a loss of neuronal differentiation control as a critical pathogenetic event in AD, associated with a reactivation of the cell cycle and a partial or full replication of DNA giving rise to neurons with a content of DNA above the diploid level. Neurons with an aneuploid set of chromosomes are also present at a low frequency in the normal brain where they appear to be well tolerated. In AD, however, where the number of aneuploid neurons is highly increased, a rather selective cell death of neurons with this chromosomal aberrancy occurs. This finding add aneuploidy to the list of critical molecular events that are shared between neurodegeneration and oncogenesis. It defines a molecular signature for neuronal vulnerability and directs our attention to a failure of neuronal differentiation control as a critical pathogenetic event and potential therapeutic target in AD.
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Yurov YB, Vorsanova SG, Iourov IY. The DNA replication stress hypothesis of Alzheimer's disease. ScientificWorldJournal 2012; 11:2602-12. [PMID: 22262948 PMCID: PMC3254013 DOI: 10.1100/2011/625690] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 12/18/2011] [Indexed: 12/25/2022] Open
Abstract
A well-recognized theory of Alzheimer's disease (AD) pathogenesis suggests ectopic cell cycle events to mediate neurodegeneration. Vulnerable neurons of the AD brain exhibit biomarkers of cell cycle progression and DNA replication suggesting a reentry into the cell cycle. Chromosome reduplication without proper cell cycle completion and mitotic division probably causes neuronal cell dysfunction and death. However, this theory seems to require some inputs in accordance with the generally recognized amyloid cascade theory as well as to explain causes and consequences of genomic instability (aneuploidy) in the AD brain. We propose that unscheduled and incomplete DNA replication (replication stress) destabilizes (epi)genomic landscape in the brain and leads to DNA replication "catastrophe" causing cell death during the S phase (replicative cell death). DNA replication stress can be a key element of the pathogenetic cascade explaining the interplay between ectopic cell cycle events and genetic instabilities in the AD brain. Abnormal cell cycle reentry and somatic genome variations can be used for updating the cell cycle theory introducing replication stress as a missing link between cell genetics and neurobiology of AD.
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Affiliation(s)
- Yuri B. Yurov
- Laboratory of Cytogenetics and Genomics of Psychiatric Disorders, Mental Health Research Center, Russian Academy of Medical Sciences, Moscow 119152, Russia
- Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
- Center for Neurobiological Diagnosis of Genetic Psychiatric Disorders, Moscow State University of Psychology and Education, Moscow, Russia
| | - Svetlana G. Vorsanova
- Laboratory of Cytogenetics and Genomics of Psychiatric Disorders, Mental Health Research Center, Russian Academy of Medical Sciences, Moscow 119152, Russia
- Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
- Center for Neurobiological Diagnosis of Genetic Psychiatric Disorders, Moscow State University of Psychology and Education, Moscow, Russia
| | - Ivan Y. Iourov
- Laboratory of Cytogenetics and Genomics of Psychiatric Disorders, Mental Health Research Center, Russian Academy of Medical Sciences, Moscow 119152, Russia
- Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Institute of Pediatrics and Children Surgery, Minzdravsotsrazvitia, Moscow, Russia
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Judge M, Hornbeck L, Potter H, Padmanabhan J. Mitosis-specific phosphorylation of amyloid precursor protein at threonine 668 leads to its altered processing and association with centrosomes. Mol Neurodegener 2011; 6:80. [PMID: 22112898 PMCID: PMC3284477 DOI: 10.1186/1750-1326-6-80] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 11/23/2011] [Indexed: 11/29/2022] Open
Abstract
Background Atypical expression of cell cycle regulatory proteins has been implicated in Alzheimer's disease (AD), but the molecular mechanisms by which they induce neurodegeneration are not well understood. We examined transgenic mice expressing human amyloid precursor protein (APP) and presenilin 1 (PS1) for changes in cell cycle regulatory proteins to determine whether there is a correlation between cell cycle activation and pathology development in AD. Results Our studies in the AD transgenic mice show significantly higher levels of cyclin E, cyclin D1, E2F1, and P-cdc2 in the cells in the vicinity of the plaques where maximum levels of Threonine 668 (Thr668)-phosphorylated APP accumulation was observed. This suggests that the cell cycle regulatory proteins might be influencing plaque pathology by affecting APP phosphorylation. Using neuroglioma cells overexpressing APP we demonstrate that phosphorylation of APP at Thr668 is mitosis-specific. Cells undergoing mitosis show altered cellular distribution and localization of P-APP at the centrosomes. Also, Thr668 phosphorylation in mitosis correlates with increased processing of APP to generate Aβ and the C-terminal fragment of APP, which is prevented by pharmacological inhibitors of the G1/S transition. Conclusions The data presented here suggests that cell cycle-dependent phosphorylation of APP may affect its normal cellular function. For example, association of P-APP with the centrosome may affect spindle assembly and cell cycle progression, further contributing to the development of pathology in AD. The experiments with G1/S inhibitors suggest that cell cycle inhibition may impede the development of Alzheimer's pathology by suppressing modification of βAPP, and thus may represent a novel approach to AD treatment. Finally, the cell cycle regulated phosphorylation and processing of APP into Aβ and the C-terminal fragment suggest that these proteins may have a normal function during mitosis.
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Affiliation(s)
- Monique Judge
- Department of Molecular Medicine, University of South Florida, 12901 Bruce B, Downs Blvd,, Tampa, FL 33612, USA
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Maes A, Verschaeve L. Can cytogenetics explain the possible association between exposure to extreme low-frequency magnetic fields and Alzheimer's disease? J Appl Toxicol 2011; 32:81-7. [PMID: 21935970 DOI: 10.1002/jat.1724] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 07/11/2011] [Accepted: 07/11/2011] [Indexed: 01/08/2023]
Abstract
Recently, a number of epidemiological studies have suggested that occupational as well as residential exposure to extreme low-frequency electromagnetic fields (ELF-EMFs) may be a risk factor for Alzheimer's disease. This is not proven yet and there are no known biological mechanisms to explain this alleged association. Alzheimer's disease is characterized by a number of events that have, at least partially, a genetic origin. In particular, trisomy of chromosomes 17 and 21 seems to be involved. Overall ELF-EMFs have not been identified as genotoxic agents, but there are some papers in the scientific literature that indicate that they may enhance the effects of agents that are known to induce mutations or tumors. There are also some indications that ELF-EMFs may induce aneuploïdy. This opens some perspectives for investigating the alleged association between ELF-EMFs and Alzheimer's. This paper reviews the possibility of a cytogenetic association between the electromagnetic fields and Alzheimer's disease.
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Affiliation(s)
- Annemarie Maes
- Scientific Institute of Public Health, Laboratory of Toxicology, J. Wytsmanstreet 14, B-1050, Brussels, Belgium
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