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Farley SJ, Grishok A, Zeldich E. Shaking up the silence: consequences of HMGN1 antagonizing PRC2 in the Down syndrome brain. Epigenetics Chromatin 2022; 15:39. [PMID: 36463299 PMCID: PMC9719135 DOI: 10.1186/s13072-022-00471-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/11/2022] [Indexed: 12/04/2022] Open
Abstract
Intellectual disability is a well-known hallmark of Down Syndrome (DS) that results from the triplication of the critical region of human chromosome 21 (HSA21). Major studies were conducted in recent years to gain an understanding about the contribution of individual triplicated genes to DS-related brain pathology. Global transcriptomic alterations and widespread changes in the establishment of neural lineages, as well as their differentiation and functional maturity, suggest genome-wide chromatin organization alterations in trisomy. High Mobility Group Nucleosome Binding Domain 1 (HMGN1), expressed from HSA21, is a chromatin remodeling protein that facilitates chromatin decompaction and is associated with acetylated lysine 27 on histone H3 (H3K27ac), a mark correlated with active transcription. Recent studies causatively linked overexpression of HMGN1 in trisomy and the development of DS-associated B cell acute lymphoblastic leukemia (B-ALL). HMGN1 has been shown to antagonize the activity of the Polycomb Repressive Complex 2 (PRC2) and prevent the deposition of histone H3 lysine 27 trimethylation mark (H3K27me3), which is associated with transcriptional repression and gene silencing. However, the possible ramifications of the increased levels of HMGN1 through the derepression of PRC2 target genes on brain cell pathology have not gained attention. In this review, we discuss the functional significance of HMGN1 in brain development and summarize accumulating reports about the essential role of PRC2 in the development of the neural system. Mechanistic understanding of how overexpression of HMGN1 may contribute to aberrant brain cell phenotypes in DS, such as altered proliferation of neural progenitors, abnormal cortical architecture, diminished myelination, neurodegeneration, and Alzheimer's disease-related pathology in trisomy 21, will facilitate the development of DS therapeutic approaches targeting chromatin.
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Affiliation(s)
- Sean J. Farley
- grid.189504.10000 0004 1936 7558Department of Anatomy and Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA USA
| | - Alla Grishok
- grid.189504.10000 0004 1936 7558Department of Biochemistry, Boston University Chobanian & Avedisian School of Medicine, Boston, MA USA ,grid.189504.10000 0004 1936 7558Boston University Genome Science Institute, Boston University Chobanian & Avedisian School of Medicine, Boston, MA USA
| | - Ella Zeldich
- Department of Anatomy and Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
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2
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Andrews EJ, Martini AC, Head E. Exploring the role of sex differences in Alzheimer's disease pathogenesis in Down syndrome. Front Neurosci 2022; 16:954999. [PMID: 36033603 PMCID: PMC9411995 DOI: 10.3389/fnins.2022.954999] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 07/25/2022] [Indexed: 11/14/2022] Open
Abstract
Women are disproportionately affected by Alzheimer's disease (AD), yet little is known about sex-specific effects on the development of AD in the Down syndrome (DS) population. DS is caused by a full or partial triplication of chromosome 21, which harbors the amyloid precursor protein (APP) gene, among others. The majority of people with DS in their early- to mid-40s will accumulate sufficient amyloid-beta (Aβ) in their brains along with neurofibrillary tangles (NFT) for a neuropathological diagnosis of AD, and the triplication of the APP gene is regarded as the main cause. Studies addressing sex differences with age and impact on dementia in people with DS are inconsistent. However, women with DS experience earlier age of onset of menopause, marked by a drop in estrogen, than women without DS. This review focuses on key sex differences observed with age and AD in people with DS and a discussion of possible underlying mechanisms that could be driving or protecting from AD development in DS. Understanding how biological sex influences the brain will lead to development of dedicated therapeutics and interventions to improve the quality of life for people with DS and AD.
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Affiliation(s)
- Elizabeth J. Andrews
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, United States
| | - Alessandra C. Martini
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, United States
| | - Elizabeth Head
- Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
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3
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Salwierz P, Davenport C, Sumra V, Iulita MF, Ferretti MT, Tartaglia MC. Sex and gender differences in dementia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 164:179-233. [PMID: 36038204 DOI: 10.1016/bs.irn.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The dementia landscape has undergone a striking paradigm shift. The advances in understanding of neurodegeneration and proteinopathies has changed our approach to patients with cognitive impairment. Firstly, it has recently been shown that the various proteinopathies that are the cause of the dementia begin to build up long before the appearance of any obvious symptoms. This has cemented the idea that there is an urgency in diagnosis as it occurs very late in the pathophysiology of these diseases. Secondly, that accurate diagnosis is required to deliver targeted therapies, that is precision medicine. With this latter point, the realization that various factors of a person need to be considered as they may impact the presentation and progression of disease has risen to the forefront. Two of these factors aside from race and age are biological sex and gender (social construct), as both can have tremendous impact on manifestation of disease. This chapter will cover what is known and remains to be known on the interaction of sex and gender with some of the major causes of dementia.
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Affiliation(s)
- Patrick Salwierz
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Carly Davenport
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Vishaal Sumra
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - M Florencia Iulita
- Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain; Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED), Madrid, Spain; Women's Brain Project, Guntershausen, Switzerland
| | | | - Maria Carmela Tartaglia
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada; Memory Clinic, Krembil Brain Institute, University Health Network, Toronto, ON, Canada.
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4
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Hines CB, Simmons SA. Down Syndrome: A Review of Key Perioperative Implications. AORN J 2022; 116:4-20. [PMID: 35758744 DOI: 10.1002/aorn.13712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/22/2021] [Accepted: 12/12/2021] [Indexed: 11/11/2022]
Abstract
Down syndrome (DS) is the most common chromosomal abnormality in humans that is compatible with life. This syndrome occurs when there is an extra copy of the 21st chromosome. Down syndrome is associated with numerous comorbidities that can pose challenges for the perioperative nurse caring for a patient with DS undergoing surgery. These challenges can affect the patient assessment, communication with the patient, and patient safety (eg, preventing complications). As the life expectancy of people with DS has increased, so too have the chances that perioperative nurses will care for a patient with this disorder. This article reviews the pathophysiology of DS, discusses common comorbidities that may directly affect perioperative care, and reviews an exemplar case study that demonstrates how personnel with knowledge of DS can positively influence surgical team decision making for these patients in the perioperative setting.
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Hamadelseed O, Elkhidir IH, Skutella T. Psychosocial Risk Factors for Alzheimer's Disease in Patients with Down Syndrome and Their Association with Brain Changes: A Narrative Review. Neurol Ther 2022; 11:931-953. [PMID: 35596914 PMCID: PMC9338203 DOI: 10.1007/s40120-022-00361-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/28/2022] [Indexed: 12/02/2022] Open
Abstract
Several recent epidemiological studies attempted to identify risk factors for Alzheimer’s disease. Age, family history, genetic factors (APOE genotype, trisomy 21), physical activity, and a low level of schooling are significant risk factors. In this review, we summarize the known psychosocial risk factors for the development of Alzheimer’s disease in patients with Down syndrome and their association with neuroanatomical changes in the brains of people with Down syndrome. We completed a comprehensive review of the literature on PubMed, Google Scholar, and Web of Science about psychosocial risk factors for Alzheimer’s disease, for Alzheimer’s disease in Down syndrome, and Alzheimer’s disease in Down syndrome and their association with neuroanatomical changes in the brains of people with Down syndrome. Alzheimer’s disease causes early pathological changes in individuals with Down syndrome, especially in the hippocampus and corpus callosum. People with Down syndrome living with dementia showed reduced volumes of brain areas affected by Alzheimer’s disease as the hippocampus and corpus callosum in association with cognitive decline. These changes occur with increasing age, and the presence or absence of psychosocial risk factors impacts the degree of cognitive function. Correlating Alzheimer’s disease biomarkers in Down syndrome and cognitive function scores while considering the effect of psychosocial risk factors helps us identify the mechanisms leading to Alzheimer’s disease at an early age. Also, this approach enables us to create more sensitive and relevant clinical, memory, and reasoning assessments for people with Down syndrome.
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Affiliation(s)
- Osama Hamadelseed
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany.
| | - Ibrahim H Elkhidir
- Faculty of Medicine, University of Khartoum, Alqasr St., Khartoum, Sudan
| | - Thomas Skutella
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
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Association between Hypothyroidism Onset and Alzheimer Disease Onset in Adults with Down Syndrome. Brain Sci 2021; 11:brainsci11091223. [PMID: 34573243 PMCID: PMC8468431 DOI: 10.3390/brainsci11091223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/04/2021] [Accepted: 09/08/2021] [Indexed: 01/11/2023] Open
Abstract
Adults with Down syndrome (DS) have an exceptionally high frequency of Alzheimer disease (AD) with a wide variability in onset, from 40 to 70 years of age. Equally prevalent in DS is hypothyroidism. In this study, we sought to quantify the relationship between the two. A total of 232 adults with DS and AD were stratified into three AD onset age groups: early (<47 years), typical (48–59), and late (>59). Among patients with available data, differences in the distributions of demographics, hypothyroidism variables (presence, age of onset), thyroid function tests, thyroid autoantibodies, and APOE genotypes were assessed (e.g., chi-squared, Mann–Whitney tests). Spearman and partial Spearman correlations and ordinal logistic regression models were constructed to quantify the association between ages of AD and hypothyroidism onset with and without covariate adjustments. We observed a positive association between the ages of AD and hypothyroidism onset after accounting for APOE-Ɛ4 (correlation: 0.44, 0.24, 0.60; odds ratio: 1.09, 1.05–1.14). However, an early age of hypothyroidism onset and the presence of the APOE-Ɛ4 allele were independently associated with the early age of AD onset. Similar findings were observed when accounting for other factors. Our study provides evidence for the importance of hypothyroidism and associated pathological mechanisms for risk of AD in DS.
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The Association between Sex and Risk of Alzheimer's Disease in Adults with Down Syndrome. J Clin Med 2021; 10:jcm10132966. [PMID: 34279450 PMCID: PMC8268850 DOI: 10.3390/jcm10132966] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Sex differences in the risk of Alzheimer’s Disease (AD) in adults with Down Syndrome (DS) have not been extensively investigated, and existing studies have found conflicting results. This study examined the effect of sex on the risk of AD in adults with DS, adjusted for covariates. Methods: Adults with DS were assessed longitudinally for the development of AD. Competing risk survival analyses were used to determine the effect of sex alone and after adjustment for APOE-ε4 status, ethnicity, and level of intellectual disability (ID). Results: Sex differences were significant only in adults over 60 years of age, where men with DS were 6.32 (95% CI: 2.11–18.96, p < 0.001) times more likely to develop AD compared with age-matched women with DS. Conclusions: There is an age-associated effect of sex on the risk of AD, with men over 60 years old having six times the risk of AD compared with age-matched women, independent of APOE-ε4 status, ethnicity, and level of ID.
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Silverman W, Krinsky‐McHale S. Alzheimer's risk and quality of life: History of Down syndrome as a case in point. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12171. [PMID: 33816756 PMCID: PMC8010478 DOI: 10.1002/dad2.12171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/15/2021] [Indexed: 11/11/2022]
Affiliation(s)
- Wayne Silverman
- Department of PediatricsUniversity of California, IrvineInglewoodCaliforniaUSA
| | - Sharon Krinsky‐McHale
- Department of PsychologyNew York State Institute for Basic Research in Developmental DisabilitiesNew YorkNew YorkUSA
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9
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Lao PJ, Gutierrez J, Keator D, Rizvi B, Banerjee A, Igwe KC, Laing KK, Sathishkumar M, Moni F, Andrews H, Krinsky-McHale S, Head E, Lee JH, Lai F, Yassa MA, Rosas HD, Silverman W, Lott IT, Schupf N, Brickman AM. Alzheimer-Related Cerebrovascular Disease in Down Syndrome. Ann Neurol 2020; 88:1165-1177. [PMID: 32944999 PMCID: PMC7729262 DOI: 10.1002/ana.25905] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Adults with Down syndrome (DS) develop Alzheimer disease (AD) pathology by their 5th decade. Compared with the general population, traditional vascular risks in adults with DS are rare, allowing examination of cerebrovascular disease in this population and insight into its role in AD without the confound of vascular risk factors. We examined in vivo magnetic resonance imaging (MRI)-based biomarkers of cerebrovascular pathology in adults with DS, and determined their cross-sectional relationship with age, beta-amyloid pathology, and mild cognitive impairment or clinical AD diagnostic status. METHODS Participants from the Biomarkers of Alzheimer's Disease in Down Syndrome study (n = 138, 50 ± 7 years, 39% women) with MRI data and a subset (n = 90) with amyloid positron emission tomography (PET) were included. We derived MRI-based biomarkers of cerebrovascular pathology, including white matter hyperintensities (WMH), infarcts, cerebral microbleeds, and enlarged perivascular spaces (PVS), as well as PET-based biomarkers of amyloid burden. Participants were characterized as cognitively stable (CS), mild cognitive impairment-DS (MCI-DS), possible AD dementia, or definite AD dementia based on in-depth assessments of cognition, function, and health status. RESULTS There were detectable WMH, enlarged PVS, infarcts, and microbleeds as early as the 5th decade of life. There was a monotonic increase in WMH volume, enlarged PVS, and presence of infarcts across diagnostic groups (CS < MCI-DS < possible AD dementia < definite AD dementia). Higher amyloid burden was associated with a higher likelihood of an infarct. INTERPRETATION The findings highlight the prevalence of cerebrovascular disease in adults with DS and add to a growing body of evidence that implicates cerebrovascular disease as a core feature of AD and not simply a comorbidity. ANN NEUROL 2020;88:1165-1177.
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Affiliation(s)
- Patrick J. Lao
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - José Gutierrez
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY
| | - David Keator
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA
| | - Batool Rizvi
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Arit Banerjee
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Kay C. Igwe
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Krystal K. Laing
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Mithra Sathishkumar
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA
| | - Fahmida Moni
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Howard Andrews
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY
| | - Sharon Krinsky-McHale
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY
| | - Elizabeth Head
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA
| | - Joseph H. Lee
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY
| | - Florence Lai
- Department of Neurology, Massachusetts General Hospital, Harvard University, Boston, MA
| | - Michael A. Yassa
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA
| | - H. Diana Rosas
- Department of Neurology, Massachusetts General Hospital, Harvard University, Boston, MA;,Department of Radiology, Athinoula Martinos Center, Massachusetts General Hospital, Harvard University, Charlestown, MA
| | - Wayne Silverman
- Department of Pediatrics, University of California, Irvine, Irvine, CA
| | - Ira T. Lott
- Department of Pediatrics, University of California, Irvine, Irvine, CA
| | - Nicole Schupf
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Adam M. Brickman
- Gertrude H. Sergievsky Center and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY;,Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY
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10
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Hartley SL, Handen BL, Devenny D, Tudorascu D, Piro-Gambetti B, Zammit MD, Laymon CM, Klunk WE, Zaman S, Cohen A, Christian BT. Cognitive indicators of transition to preclinical and prodromal stages of Alzheimer's disease in Down syndrome. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12096. [PMID: 32995465 PMCID: PMC7507534 DOI: 10.1002/dad2.12096] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 11/09/2022]
Abstract
INTRODUCTION There is a critical need to identify measures of cognitive functioning sensitive to early Alzheimer's disease (AD) pathophysiology in Down syndrome to advance clinical trial research in this at-risk population. The objective of the study was to longitudinally track performance on cognitive measures in relation to neocortical and striatal amyloid beta (Aβ) in non-demented Down syndrome. METHODS The study included 118 non-demented adults with Down syndrome who participated in two to five points of data collection, spanning 1.5 to 8 years. Episodic memory, visual attention and executive functioning, and motor planning and coordination were assessed. Aβ was measured via [C-11] Pittsburgh Compound-B (PiB) PET. RESULTS PiB was associated with level and rate of decline in cognitive performance in episodic memory, visual attention, executive functioning, and visuospatial ability in models controlling for chronological age. DISCUSSION The Cued Recall Test emerged as a promising indicator of transition from preclinical to prodromal AD.
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Affiliation(s)
- Sigan L Hartley
- Waisman Center University of Wisconsin-Madison Madison Wisconsin USA
- Department of Human Development & Family Studies University of Wisconsin-Madison Madison Wisconsin USA
| | - Benjamin L Handen
- Department of Psychiatry University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Darlynne Devenny
- New York State Institute for Basic Research in Developmental Disabilities Albany New York USA
| | - Dana Tudorascu
- Department of Psychiatry University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Brianna Piro-Gambetti
- Waisman Center University of Wisconsin-Madison Madison Wisconsin USA
- Department of Human Development & Family Studies University of Wisconsin-Madison Madison Wisconsin USA
| | - Matthew D Zammit
- Waisman Center University of Wisconsin-Madison Madison Wisconsin USA
- Department of Medical Physics University of Wisconsin-Madison Madison Wisconsin USA
| | - Charles M Laymon
- Department of Psychiatry University of Pittsburgh Pittsburgh Pennsylvania USA
| | - William E Klunk
- Department of Psychiatry University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Shahid Zaman
- Department of Psychiatry University of Cambridge Cambridge UK
| | - Annie Cohen
- Department of Psychiatry University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Bradley T Christian
- Waisman Center University of Wisconsin-Madison Madison Wisconsin USA
- Department of Medical Physics University of Wisconsin-Madison Madison Wisconsin USA
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Lai F, Mhatre PG, Yang Y, Wang M, Schupf N, Rosas HD. Sex differences in risk of Alzheimer's disease in adults with Down syndrome. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2020; 12:e12084. [PMID: 32995462 PMCID: PMC7507514 DOI: 10.1002/dad2.12084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Adults with Down syndrome (DS) older than 40 have Alzheimer's disease (AD) neuropathology and high risk for dementia, but little is known about the relationship of sex to AD risk in this population. METHODS Using nonparametric methods and Cox proportional hazards models we analyzed differences in incidence of dementia, by sex, presence of an apolipoprotein E (APOE) ε4 or ε2 allele, and dementia duration and decline in 246 adults over 40 with DS. RESULTS There was no significant sex difference in risk of AD or rate of cognitive decline. APOE ε4 allele significantly increased risk of AD irrespective of sex. No significant interactions were found between sex and APOE status on AD risk. Among those who died, dementia duration was significantly longer in women. DISCUSSION This study showed no effect of sex nor interaction between sex and APOE for risk of AD in adults with DS; however, women had longer dementia duration.
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Affiliation(s)
- Florence Lai
- Department of NeurologyMassachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMcLean HospitalBelmontMassachusettsUSA
| | - Pooja G. Mhatre
- Department of EpidemiologyMailman School of Public HealthColumbia UniversityNew YorkNew YorkUSA
| | - Yuchen Yang
- Department of BiostatisticsBloomberg School of Public HealthJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Mei‐Cheng Wang
- Department of BiostatisticsBloomberg School of Public HealthJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain and G.H. Sergievsky CenterColumbia UniversityNew YorkNew YorkUSA
- Departments of Neurology and PsychiatryColumbia University Medical CenterNew YorkNew YorkUSA
| | - H. Diana Rosas
- Department of NeurologyMassachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMcLean HospitalBelmontMassachusettsUSA
- Department of RadiologyAthinoula A. Martinos Center for Biomedical ImagingCharlestownMassachusettsUSA
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Sun J, Martin JM, Vanderpoel V, Sumbria RK. The Promises and Challenges of Erythropoietin for Treatment of Alzheimer's Disease. Neuromolecular Med 2019; 21:12-24. [PMID: 30656553 DOI: 10.1007/s12017-019-08524-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/08/2019] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in the world, and intracellular neurofibrillary tangles and extracellular amyloid-beta protein deposits represent the major pathological hallmarks of the disease. Currently available treatments provide some symptomatic relief but fail to modify primary pathological processes that underlie the disease. Erythropoietin (EPO), a hematopoietic growth factor, acts primarily to stimulate erythroid cell production, and is clinically used to treat anemia. EPO has evolved as a therapeutic agent for neurodegeneration and has improved neurological outcomes and AD pathology in rodents. However, penetration of the blood-brain barrier (BBB) and negative hematopoietic effects are the two major challenges for the therapeutic development of EPO for chronic neurodegenerative diseases like AD. The transferrin receptors at the BBB, which are responsible for transporting transferrin-bound iron from the blood into the brain parenchyma, can be used to shuttle therapeutic molecules across the BBB. In this review, we discuss the role of EPO as a potential neurotherapeutic for AD, challenges associated with EPO development for AD, and targeting the BBB transferrin receptor for EPO brain delivery.
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Affiliation(s)
- Jiahong Sun
- Department of Biopharmaceutical Sciences, School of Pharmacy and Health Sciences, Keck Graduate Institute, 535 Watson Dr, Claremont, CA, 91711, USA
| | - Jan Michelle Martin
- College of Medicine, California Northstate University, Elk Grove, CA, 95757, USA
| | | | - Rachita K Sumbria
- Department of Biopharmaceutical Sciences, School of Pharmacy and Health Sciences, Keck Graduate Institute, 535 Watson Dr, Claremont, CA, 91711, USA. .,Department of Neurology, University of California, Irvine, CA, 92868, USA.
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13
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Sinai A, Mokrysz C, Bernal J, Bohnen I, Bonell S, Courtenay K, Dodd K, Gazizova D, Hassiotis A, Hillier R, McBrien J, McCarthy J, Mukherji K, Naeem A, Perez-Achiaga N, Rantell K, Sharma V, Thomas D, Walker Z, Whitham S, Strydom A. Predictors of Age of Diagnosis and Survival of Alzheimer's Disease in Down Syndrome. J Alzheimers Dis 2019; 61:717-728. [PMID: 29226868 PMCID: PMC6004911 DOI: 10.3233/jad-170624] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Background: People with Down syndrome (DS) are an ultra-high risk population for Alzheimer’s disease (AD). Understanding the factors associated with age of onset and survival in this population could highlight factors associated with modulation of the amyloid cascade. Objective: This study aimed to establish the typical age at diagnosis and survival associated with AD in DS and the risk factors associated with these. Methods: Data was obtained from the Aging with Down Syndrome and Intellectual Disabilities (ADSID) research database, consisting of data extracted from clinical records of patients seen by Community Intellectual Disability Services (CIDS) in England. Survival times when considering different risk factors were calculated. Results: The mean age of diagnosis was 55.80 years, SD 6.29. Median survival time after diagnosis was 3.78 years, and median age at death was approximately 60 years. Survival time was associated with age of diagnosis, severity of intellectual disability, living status, anti-dementia medication status, and history of epilepsy. Age at diagnosis and treatment status remained predictive of survival time following adjustment. Conclusion: This study provides the best estimate of survival in dementia within the DS population to date, and is in keeping with previous estimates from smaller studies in the DS population. This study provides important estimates and insights into possible predictors of survival and age of diagnosis of AD in adults with DS, which will inform selection of participants for treatment trials in the future.
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Affiliation(s)
- Amanda Sinai
- Division of Psychiatry, University College London, London, UK.,Sheba Medical Center, Tel Hashomer, Israel
| | - Claire Mokrysz
- Division of Psychiatry, University College London, London, UK
| | - Jane Bernal
- Cornwall Partnership Foundation NHS Trust, UK
| | - Ingrid Bohnen
- Westminster Learning Disability Partnership, Central and North West London NHS Foundation Trust, London, UK
| | - Simon Bonell
- Livewell SouthWest (CIC), Plymouth, UK (data from South London and Maudsley NHS Foundation Trust, Maudsley Hospital, London, UK).,Plymouth University Peninsula School of Medicine and Dentistry, Plymouth, UK
| | - Ken Courtenay
- Division of Psychiatry, University College London, London, UK.,Barnet Enfield and Haringey Mental Health NHS Trust, UK
| | - Karen Dodd
- Surrey and Borders Partnership NHS Foundation Trust, Epsom, UK
| | - Dina Gazizova
- Enfield Integrated Learning Disabilities Service, Enfield, UK
| | - Angela Hassiotis
- Division of Psychiatry, University College London, London, UK.,Camden and Islington NHS Foundation Trust, London, UK
| | | | - Judith McBrien
- Plymouth Teaching Primary Care Trust (now known as Livewell Southwest CIC), UK
| | - Jane McCarthy
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | - Asim Naeem
- Sutton MHLD Team, SW London and St George's Mental Health NHS Trust, Surrey, UK.,St George's University of London, UK
| | | | - Khadija Rantell
- Institute of Neurology, Queen Square, Education Unit, London, UK
| | - Vijaya Sharma
- Hertfordshire Partnership University NHS Foundation Trust, UK
| | - David Thomas
- Department of Community Mental Health, RAF Marham, Norfolk, UK (data from East London NHS Foundation Trust, UK)
| | - Zuzana Walker
- Division of Psychiatry, University College London, London, UK.,Essex Partnership University NHS Foundation Trust, UK
| | | | - Andre Strydom
- Division of Psychiatry, University College London, London, UK.,Camden and Islington NHS Foundation Trust, London, UK.,Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,The LonDownS Consortium
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14
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Lee JH, Lee AJ, Dang LH, Pang D, Kisselev S, Krinsky-McHale SJ, Zigman WB, Luchsinger JA, Silverman W, Tycko B, Clark LN, Schupf N. Candidate gene analysis for Alzheimer's disease in adults with Down syndrome. Neurobiol Aging 2017; 56:150-158. [PMID: 28554490 DOI: 10.1016/j.neurobiolaging.2017.04.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 03/17/2017] [Accepted: 04/21/2017] [Indexed: 11/16/2022]
Abstract
Individuals with Down syndrome (DS) overexpress many genes on chromosome 21 due to trisomy and have high risk of dementia due to the Alzheimer's disease (AD) neuropathology. However, there is a wide range of phenotypic differences (e.g., age at onset of AD, amyloid β levels) among adults with DS, suggesting the importance of factors that modify risk within this particularly vulnerable population, including genotypic variability. Previous genetic studies in the general population have identified multiple genes that are associated with AD. This study examined the contribution of polymorphisms in these genes to the risk of AD in adults with DS ranging from 30 to 78 years of age at study entry (N = 320). We used multiple logistic regressions to estimate the likelihood of AD using single-nucleotide polymorphisms (SNPs) in candidate genes, adjusting for age, sex, race/ethnicity, level of intellectual disability and APOE genotype. This study identified multiple SNPs in APP and CST3 that were associated with AD at a gene-wise level empirical p-value of 0.05, with odds ratios in the range of 1.5-2. SNPs in MARK4 were marginally associated with AD. CST3 and MARK4 may contribute to our understanding of potential mechanisms where CST3 may contribute to the amyloid pathway by inhibiting plaque formation, and MARK4 may contribute to the regulation of the transition between stable and dynamic microtubules.
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Affiliation(s)
- Joseph H Lee
- Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Taub Institute, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, School of Public Health, Columbia University, New York, NY, USA.
| | - Annie J Lee
- Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Lam-Ha Dang
- Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, School of Public Health, Columbia University, New York, NY, USA
| | - Deborah Pang
- Department of Psychology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Sergey Kisselev
- Department of Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Sharon J Krinsky-McHale
- Department of Psychology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Warren B Zigman
- Department of Psychology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - José A Luchsinger
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Wayne Silverman
- Kennedy Krieger Institute and Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Benjamin Tycko
- Department of Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Lorraine N Clark
- Taub Institute, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Nicole Schupf
- Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Taub Institute, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, School of Public Health, Columbia University, New York, NY, USA
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15
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Do C, Xing Z, Yu YE, Tycko B. Trans-acting epigenetic effects of chromosomal aneuploidies: lessons from Down syndrome and mouse models. Epigenomics 2016; 9:189-207. [PMID: 27911079 PMCID: PMC5549717 DOI: 10.2217/epi-2016-0138] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
An important line of postgenomic research seeks to understand how genetic factors can influence epigenetic patterning. Here we review epigenetic effects of chromosomal aneuploidies, focusing on findings in Down syndrome (DS, trisomy 21). Recent work in human DS and mouse models has shown that the extra chromosome 21 acts in trans to produce epigenetic changes, including differential CpG methylation (DS-DM), in specific sets of downstream target genes, mostly on other chromosomes. Mechanistic hypotheses emerging from these data include roles of chromosome 21-linked methylation pathway genes (DNMT3L and others) and transcription factor genes (RUNX1, OLIG2, GABPA, ERG and ETS2) in shaping the patterns of DS-DM. The findings may have broader implications for trans-acting epigenetic effects of chromosomal and subchromosomal aneuploidies in other human developmental and neuropsychiatric disorders, and in cancers.
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Affiliation(s)
- Catherine Do
- Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA
| | - Zhuo Xing
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program & Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Y Eugene Yu
- The Children's Guild Foundation Down Syndrome Research Program, Genetics Program & Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Benjamin Tycko
- Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA.,Taub Institute for Research on Alzheimer's disease & the Aging Brain, Columbia University, New York, NY 10032, USA.,Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA.,Department of Pathology & Cell Biology, Columbia University, New York, NY 10032, USA
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16
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Ringenbach SDR, Holzapfel SD, Mulvey GM, Jimenez A, Benson A, Richter M. The effects of assisted cycling therapy (ACT) and voluntary cycling on reaction time and measures of executive function in adolescents with Down syndrome. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2016; 60:1073-1085. [PMID: 27018305 DOI: 10.1111/jir.12275] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/19/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Reports of positive effects of aerobic exercise on cognitive function in persons with Down syndrome are extremely limited. However, a novel exercise intervention, termed assisted cycling therapy (ACT), has resulted in acutely improved cognitive planning ability and reaction times as well as improved cognitive planning after 8 weeks of ACT in adolescents and young adults with Down syndrome. Here, we report the effects of 8 weeks of ACT on reaction time, set-shifting, inhibition and language fluency in adolescents with Down syndrome. METHODS Adolescents with Down syndrome (age: ~18 years) were randomly assigned to 8 weeks of ACT (n = 17) or voluntary cycling (VC: n = 16), and a convenience sample (n = 11) was assigned to be an inactive comparison group (NC: n = 11). During ACT, the cycling cadence of the participants was augmented to an average cadence that was 80% faster than the voluntary cadence of the VC group. The increase in cadence was achieved with an electric motor in the stationary bicycle. Reaction time, set-shifting, inhibition and language fluency were assessed before and after 8 weeks of intervention. RESULTS Power output and heart rates of the ACT and VC groups were almost identical, but the ACT cadence was significantly faster. The ACT group, but not the VC or NC groups, showed significantly improved reactions times (Hedges' g = -0.42) and inhibitory control (g = 0.18). Only the VC group showed improved set-shifting ability (g = 0.57). The ACT and VC groups displayed improved semantic language fluency (g = 0.25, g = 0.22, respectively). DISCUSSIONS These and previous results support the hypothesis of increased neuroplasticity and prefrontal cortex function following ACT and, to a smaller extent, following VC. Both ACT and VC appear to be associated with cortical benefits, but based on current and previous results, ACT seems to maximize the benefits.
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Affiliation(s)
- S D R Ringenbach
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA
| | - S D Holzapfel
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA.
| | - G M Mulvey
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA
| | - A Jimenez
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA
| | - A Benson
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA
| | - M Richter
- School of Nutrition and Health Promotion, College of Health Solutions, Arizona State University, Tempe, AZ, USA
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17
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Romano E, Cosentino L, Laviola G, De Filippis B. Genes and sex hormones interaction in neurodevelopmental disorders. Neurosci Biobehav Rev 2016; 67:9-24. [DOI: 10.1016/j.neubiorev.2016.02.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/01/2016] [Indexed: 12/14/2022]
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18
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Abstract
Alzheimer disease (AD) is a slow progressive neurodegenerative disease that affects more elderly women than elderly men. It impairs memory, typically progresses into multidomain cognitive decline that destroys the quality of life, and ultimately leads to death. About 5.3 million older Americans are now living with this disease, and this number is projected to rise to 14 million by 2050. Annual health-care costs in the United States alone are projected to increase to about US$1.1 trillion by 2050. The initial theory that decreasing estrogen levels leads to AD development in postmenopausal women has been proven inconclusive. For example, Women's Health Research Initiative Memory Study and the population-based nested case-control study have failed to demonstrate that estrogen/progesterone (hormone replacement therapy [HRT]) or estrogen replacement therapy could prevent the cognitive decline or reduce the risk of AD. This led to the realization that AD development could be due to a progressive increase in luteinizing hormone (LH) levels in postmenopausal women. Accordingly, a large number of studies have demonstrated that an increase in LH levels is positively correlated with neuropathological, behavioral, and cognitive changes in AD. In addition, LH has been shown to promote amyloidogenic pathway of precursor protein metabolism and deposition of amyloid β plaques in the hippocampus, a region involved in AD. Cognate receptors that mediate LH effects are abundantly expressed in the hippocampus. Reducing the LH levels by treatment with gonadotropin-releasing hormone agonists could provide therapeutic benefits. Despite these advances, many questions remain and require further research.
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Affiliation(s)
- C V Rao
- 1 Department of Cellular Biology and Pharmacology, Reproduction and Development Program, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,2 Department of Molecular and Human Genetics, Reproduction and Development Program, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,3 Department of Obstetrics and Gynecology, Reproduction and Development Program, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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19
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Patel A, Yamashita N, Ascaño M, Bodmer D, Boehm E, Bodkin-Clarke C, Ryu YK, Kuruvilla R. RCAN1 links impaired neurotrophin trafficking to aberrant development of the sympathetic nervous system in Down syndrome. Nat Commun 2015; 6:10119. [PMID: 26658127 PMCID: PMC4682116 DOI: 10.1038/ncomms10119] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/05/2015] [Indexed: 02/08/2023] Open
Abstract
Down syndrome is the most common chromosomal disorder affecting the nervous system in humans. To date, investigations of neural anomalies in Down syndrome have focused on the central nervous system, although dysfunction of the peripheral nervous system is a common manifestation. The molecular and cellular bases underlying peripheral abnormalities have remained undefined. Here, we report the developmental loss of sympathetic innervation in human Down syndrome organs and in a mouse model. We show that excess regulator of calcineurin 1 (RCAN1), an endogenous inhibitor of the calcineurin phosphatase that is triplicated in Down syndrome, impairs neurotrophic support of sympathetic neurons by inhibiting endocytosis of the nerve growth factor (NGF) receptor, TrkA. Genetically correcting RCAN1 levels in Down syndrome mice markedly improves NGF-dependent receptor trafficking, neuronal survival and innervation. These results uncover a critical link between calcineurin signalling, impaired neurotrophin trafficking and neurodevelopmental deficits in the peripheral nervous system in Down syndrome.
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Affiliation(s)
- Ami Patel
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Naoya Yamashita
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Maria Ascaño
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Daniel Bodmer
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Erica Boehm
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Chantal Bodkin-Clarke
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Yun Kyoung Ryu
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
| | - Rejji Kuruvilla
- Department of Biology, Johns Hopkins University, 3400N. Charles Street, 224 Mudd Hall, Baltimore, Maryland 21218, USA
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20
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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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21
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Burnham VL, Thornton JE. Luteinizing hormone as a key player in the cognitive decline of Alzheimer's disease. Horm Behav 2015; 76:48-56. [PMID: 26031357 DOI: 10.1016/j.yhbeh.2015.05.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/10/2015] [Accepted: 05/25/2015] [Indexed: 12/30/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Alzheimer's disease is one of the most prevalent and costly neurological diseases in the world. Although decades of research have focused on understanding Alzheimer's disease pathology and progression, there is still a great lack of clinical treatments for those who suffer from it. One of the factors most commonly associated with the onset of Alzheimer's disease is a decrease in levels of gonadal hormones, such as estrogens and androgens. Despite the correlational and experimental data which support the role of these hormones in the etiology of Alzheimer's disease, clinical trials involving their reintroduction through hormone therapy have had varied results and these gonadal hormones often have accompanying health risks. More recently, investigation has turned toward other hormones in the hypothalamic-pituitary-gonadal axis that are disrupted by age-related decreases in gonadal hormones. Specifically, luteinizing hormone, which is increased with age in both men and women (in response to removal of negative feedback), has surfaced as a potentially powerful player in the risk and onset of Alzheimer's disease. Mounting evidence in basic research and epidemiological studies supports the role of elevated luteinizing hormone in exacerbating age-related cognitive decline in both males and females. This review summarizes the recent developments involving luteinizing hormone in increasing the cognitive deficits and molecular pathology characteristic of Alzheimer's disease.
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Affiliation(s)
- Veronica L Burnham
- Department of Neuroscience, Oberlin College, 119 Woodland St, Oberlin, OH 44074, USA
| | - Janice E Thornton
- Department of Neuroscience, Oberlin College, 119 Woodland St, Oberlin, OH 44074, USA.
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22
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Holzapfel SD, Ringenbach SDR, Mulvey GM, Sandoval-Menendez AM, Cook MR, Ganger RO, Bennett K. Improvements in manual dexterity relate to improvements in cognitive planning after assisted cycling therapy (ACT) in adolescents with down syndrome. RESEARCH IN DEVELOPMENTAL DISABILITIES 2015; 45-46:261-270. [PMID: 26280691 DOI: 10.1016/j.ridd.2015.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 06/19/2015] [Accepted: 08/04/2015] [Indexed: 06/04/2023]
Abstract
We have previously reported beneficial effects of acute (i.e., single session) Assisted Cycling Therapy (ACT) on manual dexterity and cognitive planning ability in adolescents with Down syndrome (DS). In the present study, we report the chronic effects of eight weeks of ACT, voluntary cycling (VC), and no cycling (NC), on the same measures in adolescents with DS. Participants completed 8 weeks of ACT, VC, or NC. Those in the ACT and VC groups completed 30min sessions three times per week on a stationary bicycle. During ACT, the mechanical motor of the bicycle augmented the cadence to a rate which was on average 79% faster than the voluntary cadence. During VC, the participants pedaled at a self-selected rate. Unimanual dexterity scores as measured with the Purdue Pegboard test (PPT) improved significantly more for the ACT and VC groups compared to the NC group. ACT lead to greater improvements than VC and NC in the assembly sub-test, which is a task that requires more advanced temporal and spatial processing. The ACT group improved significantly more than the VC group and non-significantly more than the NC group in cognitive planning ability as measured by the Tower of London test (ToL). There were also significant correlations between the assembly subtest of the PPT and all measures of the ToL. These correlations were stronger during post-testing than pre-testing. Pre-post changes in the combined PPT score and ToL number of correct moves correlated positively in the ACT group. These results support the efficacy of the salutary effects of ACT on global fine motor function and executive function in DS. Additionally, the performance on complex bimanual dexterity tasks appears to be related to the capacity of cognitive planning ability. This research has important implications for persons with movement deficits that affect activities of daily living.
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Affiliation(s)
- Simon D Holzapfel
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Shannon D R Ringenbach
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Genna M Mulvey
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Amber M Sandoval-Menendez
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Megan R Cook
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Rachel O Ganger
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
| | - Kristen Bennett
- Arizona State University, School of Nutrition and Health Promotion, 425N. 5th Street, Phoenix, AZ 85004, United States.
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23
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Weitzdoerfer R, Toran N, Subramaniyan S, Pollak A, Dierssen M, Lubec G. A cluster of protein kinases and phosphatases modulated in fetal Down syndrome (trisomy 21) brain. Amino Acids 2015; 47:1127-34. [PMID: 25740605 DOI: 10.1007/s00726-015-1941-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 02/13/2015] [Indexed: 01/29/2023]
Abstract
Down syndrome (DS; trisomy 21) is the most frequent cause of mental retardation with major cognitive and behavioral deficits. Although a series of aberrant biochemical pathways has been reported, work on signaling proteins is limited. It was, therefore, the aim of the study to test a selection of protein kinases and phosphatases known to be essential for memory and learning mechanisms in fetal DS brain. 12 frontal cortices from DS brain were compared to 12 frontal cortices from controls obtained at legal abortions. Proteins were extracted from brains and western blotting with specific antibodies was carried out. Primary results were used for networking (IntAct Molecular Interaction Database) and individual predicted pathway components were subsequently quantified by western blotting. Levels of calcium-calmodulin kinase II alpha, transforming growth factor beta-activated kinase 1 as well as phosphatase and tensin homolog (PTEN) were reduced in cortex of DS subjects and network generation pointed to interaction between PTEN and the dendritic spine protein drebrin that was subsequently determined and reduced levels were observed. The findings of reduced levels of cognitive-function-related protein kinases and the phosphatase may be relevant for interpretation of previous work and may be useful for the design of future studies on signaling in DS brain. Moreover, decreased drebrin levels may point to dendritic spine abnormalities.
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Affiliation(s)
- Rachel Weitzdoerfer
- Department of Pediatrics, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
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24
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Romano A, Moraschi M, Cornia R, Bozzao A, Gagliardo O, Chiacchiararelli L, Iani C, Stella G, Albertini G, Pierallini A. Age effects on cortical thickness in young Down's syndrome subjects: a cross-sectional gender study. Neuroradiology 2015; 57:401-11. [PMID: 25560246 DOI: 10.1007/s00234-014-1482-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The aim of this study was to determine differences in the characteristic pattern of age-related cortical thinning in men and women with Down's syndrome (DS) by means of MRI and automatic cortical thickness measurements and a cross-sectional design, in a large cohort of young subjects. METHODS Eighty-four subjects with DS, 30 females (11-35 years, mean age ± SD = 22.8 ± 5.9) and 54 males (11-35 years, mean age ± SD = 21.5 ± 6.5), were examined using a 1.5-T scanner. MRI-based quantification of cortical thickness was performed using FreeSurfer software package. For all subjects participating in the study, the Pearson product-moment correlation coefficient between age and mean cortical thickness values has been evaluated. RESULTS A significant negative correlation between cortical thickness and age was found in female DS subjects, predominantly in frontal and parietal lobes, bilaterally. In male DS subjects, a significant negative correlation between cortical thickness and age was found in the right fronto-temporal lobes and cingulate regions. Whole brain mean cortical thickness values were significantly negative correlated with age only in female DS subjects. CONCLUSIONS Females with Down's syndrome showed a strong correlation between cortical thickness and age, already in early age. We suggest that the cognitive impairment due to hormonal deficit in the postmenopausal period could be emphasized by the early structural decline of gray matter in female DS subjects.
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Affiliation(s)
- Andrea Romano
- San Raffaele Foundation Rome, Rehabilitation Facility Ceglie Messapica, Merit Project RBNE08E8CZ, Via di Grottarossa 1035, 00189, Rome, Italy,
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Carmeli E, Coleman R. The Clinical Characteristics of Aging Adults with Mental Retardation. PHYSICAL THERAPY REVIEWS 2013. [DOI: 10.1179/ptr.2001.6.4.267] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Zigman WB. Atypical aging in down syndrome. ACTA ACUST UNITED AC 2013; 18:51-67. [DOI: 10.1002/ddrr.1128] [Citation(s) in RCA: 176] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 11/14/2012] [Accepted: 11/29/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Warren B. Zigman
- Department of Psychology, Laboratory of Community Psychology, NYS Institute for Basic Research in Developmental Disabilities; Staten Island; New York
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Human chorionic gonadotropin increases β-cleavage of amyloid precursor protein in SH-SY5Y cells. Cell Mol Neurobiol 2013; 33:747-51. [PMID: 23812658 DOI: 10.1007/s10571-013-9954-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/18/2013] [Indexed: 01/02/2023]
Abstract
Elevated levels of amyloid-β (Aβ) peptides, the main component of amyloid plaques in Alzheimer's disease, are the result of excessive β- and γ-cleavage of the amyloid precursor protein (APP) and/or impaired Aβ clearance in the brain. It has been suggested that high concentrations of luteinizing hormone (LH) in women contribute to increased Aβ generation after menopause, but the mechanism for this is incompletely understood. We investigated the effect of human chorionic gonadotropin (hCG), an LH receptor agonist, on APP β-cleavage in the SH-SY5Y neuroblastoma cell line. Treatment of these cells with hCG-induced elevated β-cleavage in a dose-dependent manner: administration of 30 mIU but not 10 mIU/ml of hCG significantly increased sAPPβ levels in the cell medium 1.7-fold as measured by ELISA. These results support the notion that LH contributes to elevated Aβ levels at least in part by increasing β-cleavage of APP by β-site APP cleaving enzyme.
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Handen BL, Cohen AD, Channamalappa U, Bulova P, Cannon SA, Cohen WI, Mathis CA, Price JC, Klunk WE. Imaging brain amyloid in nondemented young adults with Down syndrome using Pittsburgh compound B. Alzheimers Dement 2013; 8:496-501. [PMID: 23102120 DOI: 10.1016/j.jalz.2011.09.229] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 08/17/2011] [Accepted: 09/14/2011] [Indexed: 11/19/2022]
Abstract
Down syndrome (DS) is one of the most common causes of intellectual disability. Although DS accounts for only 15% of all individuals with intellectual disabilities, adults with DS account for approximately 60% of individuals with intellectual disabilities and Alzheimer's disease. This is thought to be because of overproduction of the β-amyloid (Aβ) protein due to trisomy for the Aβ precursor protein gene on chromosome 21. Pittsburgh compound B (PiB) is a noninvasive in vivo positron emission tomography tracer used to image amyloid deposition in living humans. Studies using PiB have shown an age-dependent asymptomatic amyloid deposition in more than 20% of the cognitively normal elderly population. Presymptomatic carriers of presenilin (PS-1) and Aβ precursor protein gene mutations who are destined to develop Alzheimer's disease also show preclinical amyloid deposition. This report describes a pilot study involving the use of PiB in seven adults with DS (age: 20-44 years). Compared with objective cutoffs for amyloid positivity in older non-DS cognitively normal control subjects, only two of the seven DS subjects (age: 38 and 44 years) showed increased PiB retention. The remaining five subjects aged between 20 and 35 years showed no detectable increase in PiB retention. Interestingly, the two subjects who showed elevated PiB retention showed a striatal-predominant pattern similar to that previously reported for PS-1 mutation carriers. These results demonstrate the feasibility of conducting PiB positron emission tomography scanning in this special population, and suggest a link between Aβ overproduction and early striatal deposition of fibrillar Aβ.
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Affiliation(s)
- Benjamin L Handen
- Department of Psychiatry, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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Pan-neuronal expression of APL-1, an APP-related protein, disrupts olfactory, gustatory, and touch plasticity in Caenorhabditis elegans. J Neurosci 2012; 32:10156-69. [PMID: 22836251 DOI: 10.1523/jneurosci.0495-12.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Patients with Alzheimer's disease show age-related cognitive decline. Postmortem autopsy of their brains shows the presence of large numbers of senile plaques, whose major component is the β-amyloid peptide. The β-amyloid peptide is a cleavage product of the amyloid precursor protein (APP). In addition to the neurodegeneration associated with β-amyloid aggregation in Alzheimer's disease patients, mutations in APP in mammalian model organisms have also been shown to disrupt several behaviors independent of visible amyloid plaque formation. However, the pathways in which APP function are unknown and difficult to unravel in mammals. Here we show that pan-neuronal expression of APL-1, the Caenorhabditis elegans ortholog of APP, disrupts several behaviors, such as olfactory and gustatory learning behavior and touch habituation. These behaviors are mediated by distinct neural circuits, suggesting a broad impact of APL-1 on sensory plasticity in C. elegans. Furthermore, we found that disruption of these three behaviors requires activity of the TGFβ pathway and reduced activity of the insulin pathway. These results suggest pathways and molecular components that may underlie behavioral plasticity in mammals and in patients with Alzheimer's disease.
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Caenorhabditis elegans as a model organism to study APP function. Exp Brain Res 2011; 217:397-411. [PMID: 22038715 DOI: 10.1007/s00221-011-2905-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 10/05/2011] [Indexed: 12/20/2022]
Abstract
The brains of Alzheimer's disease patients show an increased number of senile plaques compared with normal patients. The major component of the plaques is the β-amyloid peptide, a cleavage product of the amyloid precursor protein (APP). Although the processing of APP has been well-described, the physiological functions of APP and its cleavage products remain unclear. This article reviews the multifunctional roles of an APP orthologue, the C. elegans APL-1. Understanding the function of APL-1 may provide insights into the functions and signaling pathways of human APP. In addition, the physiological effects of introducing human β-amyloid peptide into C. elegans are also reviewed. The C. elegans system provides a powerful genetic model to identify genes regulating the molecular mechanisms underlying intracellular β-amyloid peptide accumulation.
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Lamar M, Foy CM, Beacher F, Daly E, Poppe M, Archer N, Prasher V, Murphy KC, Morris RG, Simmons A, Lovestone S, Murphy DG. Down syndrome with and without dementia: An in vivo proton Magnetic Resonance Spectroscopy study with implications for Alzheimer's disease. Neuroimage 2011; 57:63-68. [DOI: 10.1016/j.neuroimage.2011.03.073] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 03/24/2011] [Accepted: 03/29/2011] [Indexed: 11/26/2022] Open
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Apolipoprotein E: Implications for AD neurobiology, epidemiology and risk assessment. Neurobiol Aging 2011; 32:778-90. [DOI: 10.1016/j.neurobiolaging.2009.04.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 04/20/2009] [Accepted: 04/29/2009] [Indexed: 11/18/2022]
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Casadesus G, Puig ER, Webber KM, Atwood CS, Escuer MC, Bowen RL, Perry G, Smith MA. Targeting gonadotropins: an alternative option for Alzheimer disease treatment. J Biomed Biotechnol 2010; 2006:39508. [PMID: 17047306 PMCID: PMC1559918 DOI: 10.1155/jbb/2006/39508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Recent evidence indicates that, alongside oxidative stress, dysregulation of the cell cycle in neurons susceptible to degeneration in Alzheimer disease may play a crucial role in the initiation of the disease. As such, the role of reproductive hormones, which are closely associated with the cell cycle both during development and after birth, may be of key import. While estrogen has been the primary focus, the protective effects of hormone replacement therapy on cognition and dementia only during a “crucial period” led us to expand the study of hormonal influences to other members of the hypothalamic pituitary axis. Specifically, in this review, we focus on luteinizing hormone, which is not only increased in the sera of patients with Alzheimer disease but, like estrogen, is modulated by hormone replacement therapy and also influences cognitive behavior and pathogenic processing in animal models of the disease. Targeting gonadotropins may be a useful treatment strategy for disease targeting multiple pleiotropic downstream consequences.
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Affiliation(s)
- Gemma Casadesus
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Emma Ramiro Puig
- Departament de Fisiologia, Facultat de Farmacia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Kate M. Webber
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Craig S. Atwood
- School of Medicine, University of Wisconsin and William S. Middleton Memorial Veterans Administration, Madison, WI 53705,
USA
| | - Margarida Castell Escuer
- Departament de Fisiologia, Facultat de Farmacia, Universitat de Barcelona, Barcelona 08028, Spain
| | | | - George Perry
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Mark A. Smith
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
- *Mark A. Smith:
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Bartzokis G, Lu PH, Mintz J. Human brain myelination and amyloid beta deposition in Alzheimer's disease. Alzheimers Dement 2009; 3:122-5. [PMID: 18596894 DOI: 10.1016/j.jalz.2007.01.019] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We hypothesized that myelin breakdown in vulnerable late-myelinating regions releases oligodendrocyte- and myelin-associated iron that promotes amyloid beta (A beta) oligomerization, its associated toxicity, and the deposition of oligomerized A beta and iron in neuritic plaques observed in Alzheimer's disease (AD). The model was tested by using published maps of cortical myelination from 1901 and recent in vivo imaging maps of A beta deposits in humans. The data show that in AD, radiolabeled ligands detect A beta deposition in a distribution that matches the map of late-myelinating regions. Furthermore, the strikingly lower ability of this imaging ligand to bind A beta in animal models is consistent with the much lower levels of myelin and associated iron levels in rodents when compared with humans. The hypotheses derived from the "myelin model" are testable with current imaging methods and have important implications for therapeutic interventions that should be expanded to include novel targets such as oligodendrocytes, myelin, and brain iron.
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Affiliation(s)
- George Bartzokis
- Department of Neurology, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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Gill CJ, Brown AA. Overview of Health Issues of Older Women with Intellectual Disabilities. PHYSICAL & OCCUPATIONAL THERAPY IN GERIATRICS 2009. [DOI: 10.1080/j148v18n01_03] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Prasher VP, Schupf N, Sajith SG, Zigman WB, Rees S, Patel A, Tewari S. Significant effect of APOE epsilon 4 genotype on the risk of dementia in Alzheimer's disease and mortality in persons with Down syndrome. Int J Geriatr Psychiatry 2008; 23:1134-40. [PMID: 18464295 PMCID: PMC2714805 DOI: 10.1002/gps.2039] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Virtually all adults with Down syndrome (DS) have neuropathological manifestations of Dementia in Alzheimer's disease (DAD) but not all develop clinical psychopathology. The effect of allelic variants of Apolipoprotein (APOE) gene in development and progression of DAD and mortality in persons with DS is examined. METHODS Recruited participants with DS underwent two to 14 sequential assessments over a follow up period of 6 years on average and their APOE genotype determined. Dementia status was confirmed as recommended by the Working Group for the Establishment of Criteria for the Diagnosis of Dementia in Individuals with Intellectual Disability. RESULTS APOE genotype results were available for 252 individuals. Participants with APOE epsilon 4 allele had significantly higher risk of developing DAD (HR = 1.8, 95% CI: 1.12-2.79), had an earlier onset of DAD (55.0 vs 57.0 years; p = 0.0027) and a more rapid progression to death compared with participants with epsilon 3 allele (4.2 years vs. 5.4 years, respectively, p = 0.048). In non-demented persons with DS, epsilon 4 allele was associated with earlier death by 17 years (mean survival age, 55.7 vs. 72.7 years; HR = 5.9, 95% CI: 1.7-21.3). CONCLUSIONS This study highlights the relationship of APOE genotype to morbidity and mortality in persons with DS which has important clinical implications. We recommend screening for APOE genotype in persons with DS to identify those at risk of DAD and premature death. Further research is required to investigate the underlying reasons for the early mortality in non-demented DS persons with an epsilon 4 allele.
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Affiliation(s)
- V P Prasher
- The Greenfields, Monyhull Hospital, Birmingham, UK.
| | - Nicole Schupf
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Medical Center, New York
| | - S G. Sajith
- The Greenfields, Monyhull Hospital, Birmingham UK
| | - Warren B. Zigman
- Department of Psychology, NYS Institute for Basic Research in Developmental Disabilities, New York
| | - Simon Rees
- University of Birmingham, Birmingham, UK
| | | | - S Tewari
- Lea Castle Centre, Kidderminster, UK
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Casadesus G, Rolston RK, Webber KM, Atwood CS, Bowen RL, Perry G, Smith MA. Menopause, estrogen, and gonadotropins in Alzheimer's disease. Adv Clin Chem 2008; 45:139-53. [PMID: 18429496 DOI: 10.1016/s0065-2423(07)00006-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
For decades, Alzheimer's disease (AD) has been linked to aging, gender, and menopause. Not surprisingly, this led most investigators to focus on the role of estrogen. While undoubtedly important, estrogen is unlikely the key determinant of disease pathogenesis. Rather, it appears that estrogen may work in conjunction with a novel determinant of disease pathogenesis, namely gonadotropins. The fact that gonadotropins, specifically luteinizing hormone, play a pivotal role in disease is apparent from significant etiological, epidemiological, and pathological evidences. Moreover, targeting gonadotropins appears to have beneficial actions as a therapeutic regimen.
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Affiliation(s)
- Gemma Casadesus
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Krinsky-McHale SJ, Devenny DA, Gu H, Jenkins EC, Kittler P, Murty VV, Schupf N, Scotto L, Tycko B, Urv TK, Ye L, Zigman WB, Silverman W. Successful aging in a 70-year-old man with down syndrome: a case study. INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2008; 46:215-228. [PMID: 18578579 DOI: 10.1352/2008.46:215-228] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The authors present a case study of a 70-year-old man with Down syndrome ("Mr. C.") who they followed for 16 years and who does not exhibit declines in cognitive or functional capacities indicative of dementia, despite having well-documented, complete trisomy 21. The authors describe the age-associated changes that occurred over 16 years as well as provide detailed information regarding Mr. C.'s health and genetic status. To further emphasize Mr. C.'s successful aging, the authors compared his longitudinal performance profile with that of 2 peers of comparable level of intellectual functioning: 1 similar-aged man with clinical Alzheimer's disease and a younger man who was healthy. The authors present potential explanations for the phenotypic variability observed in individuals with Down syndrome.
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Affiliation(s)
- Sharon J Krinsky-McHale
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.
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Abstract
Down syndrome (DS) is characterized by increased mortality rates, both during early and later stages of life, and age-specific mortality risk remains higher in adults with DS compared with the overall population of people with mental retardation and with typically developing populations. Causes of increased mortality rates early in life are primarily due to the increased incidence of congenital heart disease and leukemia, while causes of higher mortality rates later in life may be due to a number of factors, two of which are an increased risk for Alzheimer's disease (AD) and an apparent tendency toward premature aging. In this article, we describe the increase in lifespan for people with DS that has occurred over the past 100 years, as well as advances in the understanding of the occurrence of AD in adults with DS. Aspects of the neurobiology of AD, including the role of amyloid, oxidative stress, Cu/ZN dismutase (SOD-1), as well as advances in neuroimaging are presented. The function of risk factors in the observed heterogeneity in the expression of AD dementia in adults with DS, as well as the need for sensitive and specific biomarkers of the clinical and pathological progressing of AD in adults with DS is considered.
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Affiliation(s)
- Warren B Zigman
- Department of Psychology, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
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Zigman WB, Devenny DA, Krinsky-McHale SJ, Jenkins EC, Urv TK, Wegiel J, Schupf N, Silverman W. Alzheimer's Disease in Adults with Down Syndrome. INTERNATIONAL REVIEW OF RESEARCH IN MENTAL RETARDATION 2008; 36:103-145. [PMID: 19633729 PMCID: PMC2714652 DOI: 10.1016/s0074-7750(08)00004-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Warren B. Zigman
- Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
| | - Darlynne A. Devenny
- Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
| | - Sharon J. Krinsky-McHale
- Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
| | - Edmund C. Jenkins
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
| | - Tiina K. Urv
- Mental Retardation & Developmental Disabilities Branch, National Institute of Child Health and Human Development, Bethesda, MD 20892
| | - Jerzy Wegiel
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
| | - Nicole Schupf
- Department of Psychology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, N.Y. 10032
- Departments of Epidemiology and Psychiatry, Columbia University Medical Center, New York, NY 10032
| | - Wayne Silverman
- Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD 21205
- Department of Psychiatry and Behavioral Medicine, Johns Hopkins University Medical School, Baltimore, MD 21205
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Downes EC, Robson J, Grailly E, Abdel-All Z, Xuereb J, Brayne C, Holland A, Honer WG, Mukaetova-Ladinska EB. Loss of synaptophysin and synaptosomal-associated protein 25-kDa (SNAP-25) in elderly Down syndrome individuals. Neuropathol Appl Neurobiol 2007; 34:12-22. [PMID: 18005332 DOI: 10.1111/j.1365-2990.2007.00899.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS This study quantified the density of the synaptic proteins synaptophysin and synaptosomal-associated protein 25-kDa (SNAP-25) in brains from elderly Down's syndrome individuals. METHODS Six areas (frontal, occipital, parietal and temporal lobes, cerebellum and hippocampus) of post mortem brains from elderly Down's syndrome (DS) individuals (with reported functional memory problems and pathologically established Alzheimer's disease) and elderly controls were studied. RESULTS Collectively in the six brain areas studied, there were significantly lower levels of both synaptophysin and SNAP-25 immunostaining in the DS group compared with controls. The elderly control group displayed a significant decrease in the densities of synaptophysin and SNAP-25 as a function of age at death (AAD; P < or = 0.001), whereas the DS group only showed a significant decrease as a function of AAD for synaptophysin. Assessing synaptic density as a function of Braak stage (BST) revealed a significant decrease in synaptophysin density for both groups. SNAP-25 was only significantly decreased as a function of BST in the DS group. Synaptic protein density was also shown to vary according to gender. Thus, both DS and control female subjects had a higher synaptic density of SNAP-25 than their male counterparts. In contrast, male DS and control individuals had a significantly greater density of synaptophysin than females. CONCLUSIONS These results indicate that elderly DS individuals have lower synaptic densities of both analysed proteins than cognitively intact elderly individuals. Although AAD and BST show varying significance to decreases in protein density for both DS and control groups, results suggest that gender differences also play a role in the type of synaptic protein lost in elderly DS individuals.
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Affiliation(s)
- E C Downes
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
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Abstract
Several hypotheses have been proposed that attempt to explain the pathogenesis of Alzheimer Disease (AD) including theories involving senile plaque and neurofibrillary tangle formation, increased oxidative stress, and cell cycle abnormalities, since evidence for each of these pathological phenomena have been well documented in AD. Recent epidemiological and experimental data also support a role for the gonadotropin luteinizing hormone in AD. Paralleling the female predominance for developing AD, luteinizing hormone levels are significantly higher in females as compared to males, and furthermore, luteinizing hormone levels are higher still in individuals who succumb to AD. Luteinizing hormone, which is capable of modulating cognitive behavior, is not only present in the brain, but also has the highest receptor levels in the hippocampus, a key processor of cognition that is severely deteriorated in AD. Furthermore, we recently examined cognitive performance in a well-characterized transgenic mouse that over-expresses luteinizing hormone and found that these animals show decreased cognitive performance when compared to controls. We have also found that abolishing luteinizing hormone in amyloid-beta protein precursor transgenic mice (Tg2576) using a potent gonadotropin-lowering gonadotropin-releasing hormone agonist, leuprolide acetate, resulted in improved hippocampally-related cognitive performance and decreased amyloid-beta deposition. These findings, together with data indicating that luteinizing hormone modulates amyloid-beta protein precursor processing in vivo and in vitro, suggest that luteinizing hormone may contribute to AD pathology through an amyloid-dependent mechanism. These promising findings support the importance of luteinizing hormone in AD and bring to the forefront an alternative, and much needed, therapeutic avenue for the treatment of this insidious disease.
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Affiliation(s)
- Kate M Webber
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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Zana M, Janka Z, Kálmán J. Oxidative stress: A bridge between Down's syndrome and Alzheimer's disease. Neurobiol Aging 2007; 28:648-76. [PMID: 16624449 DOI: 10.1016/j.neurobiolaging.2006.03.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 02/23/2006] [Accepted: 03/16/2006] [Indexed: 12/20/2022]
Abstract
Besides the genetic, biochemical and neuropathological analogies between Down's syndrome (DS) and Alzheimer's disease (AD), there is ample evidence of the involvement of oxidative stress (OS) in the pathogenesis of both disorders. The present paper reviews the publications on DS and AD in the past 10 years in light of the "gene dosage" and "two-hit" hypotheses, with regard to the alterations caused by OS in both the central nervous system and the periphery, and the main pipeline of antioxidant therapeutic strategies. OS occurs decades prior to the signature pathology and manifests as lipid, protein and DNA oxidation, and mitochondrial abnormalities. In clinical settings, the assessment of OS has traditionally been hampered by the use of assays that suffer from inherent problems related to specificity and/or sensitivity, which explains some of the conflicting results presented in this work. For DS, no scientifically proven diet or drug is yet available, and AD trials have not provided a satisfactory approach for the prevention of and therapy against OS, although most of them still need evidence-based confirmation. In the future, a balanced up-regulation of endogenous antioxidants, together with multiple exogenous antioxidant supplementation, may be expected to be one of the most promising treatment methods.
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Affiliation(s)
- Marianna Zana
- Department of Psychiatry, Faculty of Medicine, Albert Szent-Györgyi Center for Medical and Pharmaceutical Sciences, University of Szeged, 6 Semmelweis St, Szeged H-6725, Hungary.
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Coppus AMW, Evenhuis HM, Verberne GJ, Visser FE, Arias-Vasquez A, Sayed-Tabatabaei FA, Vergeer-Drop J, Eikelenboom P, van Gool WA, van Duijn CM. The impact of apolipoprotein E on dementia in persons with Down's syndrome. Neurobiol Aging 2007; 29:828-35. [PMID: 17250929 DOI: 10.1016/j.neurobiolaging.2006.12.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 11/15/2006] [Accepted: 12/11/2006] [Indexed: 11/16/2022]
Abstract
Apolipoprotein E (APOE) is consistently associated with dementia in the general population. Findings on the role of this gene in persons with Down's syndrome (DS) are inconclusive. We studied the effects of APOE on mortality and dementia in a longitudinal prospective study of a large population-based sample of persons with DS (n=425), demented and non-demented. There was evidence that APOE epsilon4 is correlated with the rate of decline in the social competence rating scale (SRZ) (p=0.04). In our population, we found overall a modest but not statistical significant effect on the prevalence of dementia (OR=1.57, 95%CI: 0.87-2.82). We did observed a significant long-term effect on the incidence of dementia (HR=4.66, 95%CI: 1.35-16.14), but for those with a follow-up less than 3 years the risk was not significantly increased: HR=0.83 (95%CI 0.35-1.94). When pooling our data in a meta-analysis, the APOE epsilon4 allele shows a 1.59-fold (95%CI: 1.19-2.12) increase in risk of dementia in persons with DS. We conclude that APOE is influencing the risk of dementia in persons with DS.
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Affiliation(s)
- A M W Coppus
- Department of Epidemiology & Biostatistics, Erasmus MC, Rotterdam, The Netherlands
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Yoo JH, Valdovinos MG, Williams DC. Relevance of Donepezil in Enhancing Learning and Memory in Special Populations: A Review of the Literature. J Autism Dev Disord 2007; 37:1883-901. [PMID: 17221321 DOI: 10.1007/s10803-006-0322-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Accepted: 11/06/2006] [Indexed: 12/12/2022]
Abstract
This review discusses the laboratory and clinical research supporting the rationale for the efficacy of donepezil (Aricept USA) in enhancing cognition in autism, Alzheimer disease, Down syndrome, traumatic brain injury, Attention Deficit Hyperactivity Disorder (ADHD), and schizophrenia. While preliminary animal models have shown effective, human studies exclusive of Alzheimer disease are sparse. Although attention and memory are unlikely a sole operation of the cholinergic system, evidence indicates a promising direction for further examination of this hypothesis in autism. Studies that examine changes in operationally defined behaviors and reliable and valid measure of changes in attention and memory are needed.
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Affiliation(s)
- J Helen Yoo
- Center for Autism and Related Disorders, 3001 Bee Caves Road, Austin, TX 78746, USA.
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Nistor M, Don M, Parekh M, Sarsoza F, Goodus M, Lopez G, Kawas C, Leverenz J, Doran E, Lott I, Hill M, Head E. Alpha- and beta-secretase activity as a function of age and beta-amyloid in Down syndrome and normal brain. Neurobiol Aging 2006; 28:1493-506. [PMID: 16904243 PMCID: PMC3375834 DOI: 10.1016/j.neurobiolaging.2006.06.023] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 05/09/2006] [Accepted: 06/21/2006] [Indexed: 11/22/2022]
Abstract
Aged individuals with Down syndrome (DS) develop Alzheimer's disease (AD) neuropathology by the age of 40 years. The purpose of the current study was to measure age-associated changes in APP processing in 36 individuals with DS (5 months-69 years) and in 26 controls (5 months-100 years). Alpha-secretase significantly decreased with age in DS, particularly in cases over the age of 40 years and was stable in controls. The levels of C-terminal fragments of APP reflecting alpha-secretase processing (CTF-alpha) decreased with age in both groups. In both groups, there was significant increase in beta-secretase activity with age. CTF-beta remained constant with age in controls suggesting compensatory increases in turnover/clearance mechanisms. In DS, young individuals had the lowest CTF-beta levels that may reflect rapid conversion of beta-amyloid (Abeta) to soluble pools or efficient CTF-beta clearance mechanisms. Treatments to slow or prevent AD in the general population targeting secretase activity may be more efficacious in adults with DS if combined with approaches that enhance Abeta degradation and clearance.
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Affiliation(s)
- M. Nistor
- Institute for Brain Aging & Dementia, CA, United States
| | - M. Don
- Institute for Brain Aging & Dementia, CA, United States
| | - M. Parekh
- Institute for Brain Aging & Dementia, CA, United States
| | - F. Sarsoza
- Institute for Brain Aging & Dementia, CA, United States
| | - M. Goodus
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
| | - G.E. Lopez
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
| | - C. Kawas
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
| | - J. Leverenz
- Neurology and Psychiatry and Behavioral Sciences, University of Washington Seattle, WA 98108, United States
| | - E. Doran
- Institute for Brain Aging & Dementia, CA, United States
| | - I.T. Lott
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
| | - M. Hill
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
| | - E. Head
- Institute for Brain Aging & Dementia, CA, United States
- Department of Neurology, University of California, 1259 Gillespie NRF, Irvine, CA 92697-4540, United States
- Corresponding author. Tel.: +1 949 824 8700; fax: +1 949 824 2071. (E. Head)
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Casadesus G, Garrett MR, Webber KM, Hartzler AW, Atwood CS, Perry G, Bowen RL, Smith MA. The estrogen myth: potential use of gonadotropin-releasing hormone agonists for the treatment of Alzheimer's disease. Drugs R D 2006; 7:187-93. [PMID: 16752944 DOI: 10.2165/00126839-200607030-00004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Estrogen and other sex hormones have received a great deal of attention for their speculative role in Alzheimer's disease (AD), but at present a direct connection between estrogen and the pathogenesis of AD remains elusive and somewhat contradictory. For example, on one hand there is a large body of evidence suggesting that estrogen is neuroprotective and improves cognition, and that hormone replacement therapy (HRT) at the onset of menopause reduces the risk of developing AD decades later. However, on the other hand, studies such as the Women's Health Initiative demonstrate that HRT initiated in elderly women increases the risk of dementia. While estrogen continues to be investigated, the disparity of findings involving HRT has led many researchers to examine other hormones of the hypothalamic-pituitary-gonadal axis such as luteinising hormone (LH) and follicle-stimulating hormone. In this review, we propose that LH, rather than estrogen, is the paramount player in the pathogenesis of AD. Notably, both men and women experience a 3- to 4-fold increase in LH with aging, and LH receptors are found throughout the brain following a regional pattern remarkably similar to those neuron populations affected in AD. With respect to disease, serum LH level is increased in women with AD relative to non-diseased controls, and levels of LH in the brain are also elevated in AD. Mechanistically, we propose that elevated levels of LH may be a fundamental instigator responsible for the aberrant reactivation of the cell cycle that is seen in AD. Based on these aforementioned aspects, clinical trials underway with leuprolide acetate, a gonadotropin-releasing hormone agonist that ablates serum LH levels, hold great promise as a ready means of treatment in individuals afflicted with AD.
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Affiliation(s)
- Gemma Casadesus
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Webber KM, Casadesus G, Marlatt MW, Perry G, Hamlin CR, Atwood CS, Bowen RL, Smith MA. Estrogen bows to a new master: the role of gonadotropins in Alzheimer pathogenesis. Ann N Y Acad Sci 2006; 1052:201-9. [PMID: 16024763 DOI: 10.1196/annals.1347.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Epidemiological data showing a predisposition of women to develop Alzheimer disease (AD) led many researchers to investigate the role of sex steroids, namely estrogen, in disease pathogenesis. Although there is circumstantial support for the role of estrogen, the unexpected results of the Women's Health Initiative (WHI) Memory Study, which reported an increase in the risk for probable dementia and impaired cognitive performance in postmenopausal women treated with a combination of estrogen and progestin, have raised serious questions regarding the protective effects of estrogen. Although explanations for these surprising results vary greatly, the WHI Memory Study cannot be correctly interpreted without a complete investigation of the effects of the other hormones of the hypothalamic-pituitary-gonadal (HPG) axis on the aging brain. Certain hormones of the HPG axis, namely, the gonadotropins (luteinizing hormone and follicle-stimulating hormone), are not only involved in regulating reproductive function via a complex feedback loop but are also known to cross the blood-brain barrier. We propose that the increase in gonadotropin concentrations, and not the decrease in steroid hormone (e.g., estrogen) production following menopause/andropause, is a potentially primary causative factor for the development of AD. In this review, we examine how the gonadotropins may play a central and determining role in modulating the susceptibility to, and progression of, AD. On this basis, we suggest that the results of the WHI Memory Study are not only predictable but also avoidable by therapeutically targeting the gonadotropins instead of the sex steroids.
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Affiliation(s)
- Kate M Webber
- Institute of Pathology, Case Western Reserve University, 2085 Adelbert Rd., Cleveland, OH 44106, USA
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Casadesus G, Webber KM, Atwood CS, Pappolla MA, Perry G, Bowen RL, Smith MA. Luteinizing hormone modulates cognition and amyloid-beta deposition in Alzheimer APP transgenic mice. Biochim Biophys Acta Mol Basis Dis 2006; 1762:447-52. [PMID: 16503402 DOI: 10.1016/j.bbadis.2006.01.008] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 01/17/2006] [Accepted: 01/18/2006] [Indexed: 11/17/2022]
Abstract
Until recently, the study of hormonal influences in Alzheimer disease was limited to the role of sex steroids. Despite numerous epidemiological studies supporting a protective role for estrogen in Alzheimer disease, recent studies show that estrogen administration in elderly women increases the risk of disease. Reconciling these contradictory reports, we previously hypothesized that other hormones of the hypothalamic-pituitary-gonadal axis, such as luteinizing hormone, may be involved in the onset and development of the disease. In this regard, luteinizing hormone is elevated in Alzheimer disease and is known to modulate amyloidogenic processing of amyloid-beta protein precursor. Therefore, in this study, to evaluate the therapeutic potential of luteinizing hormone ablation, we administered a gonadotropin-releasing hormone analogue, leuprolide acetate, to an aged transgenic mouse model of Alzheimer disease (Tg 2576) and measured cognitive Y-maze performance and amyloid-beta deposition after 3 months of treatment. Our data indicate that luteinizing hormone ablation significantly attenuated cognitive decline and decreased amyloid-beta deposition as compared to placebo-treated animals. Importantly, leuprolide acetate-mediated reduction of amyloid-beta correlated with improved cognition. Since both cognitive loss and amyloid-beta deposition are features of Alzheimer disease, leuprolide acetate treatment may prove to be a useful therapeutic strategy for this disease.
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Affiliation(s)
- Gemma Casadesus
- Institute of Pathology, Case Western Reserve University, 2085 Adelbert Road, Cleveland, OH 44106, USA
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Webber KM, Casadesus G, Perry G, Atwood CS, Bowen R, Smith MA. Gender differences in Alzheimer disease: the role of luteinizing hormone in disease pathogenesis. Alzheimer Dis Assoc Disord 2006; 19:95-9. [PMID: 15942328 DOI: 10.1097/01.wad.0000165512.90864.3f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Epidemiological data reporting the predisposition of women to Alzheimer disease has provided researchers with an important clue as to the identity of the driving pathogenic force and lead many to question the potential role of sex steroids, namely estrogen, in disease pathogenesis. However, while estrogen has become the primary focus of research in the field, inconclusive data regarding estrogen replacement therapy has lead some researchers to begin investigating the effects of the other hormones of the hypothalamic-pituitary-gonadal (HPG) axis on the aging brain. Certain hormones of the HPG axis, namely the gonadotropins (luteinizing hormone and follicle-stimulating hormone), are not only involved in regulating reproductive function via a complex feedback loop but are also known to cross the blood-brain barrier. Recently, we proposed that an increase in gonadotropin concentrations, not the decrease in steroid hormone (eg, estrogen) production following menopause/andropause, is a potentially primary causative factor for the development of Alzheimer disease. In this review, we examine how the gonadotropins may play a central and determining role in modulating the susceptibility to, and progression of, Alzheimer disease. Based on this, we suggest that therapeutic interventions targeted at gonadotropins may both prevent disease in those patients currently asymptomatic or may halt, and even reverse, disease in those currently afflicted.
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Affiliation(s)
- Kate M Webber
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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