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Fillenbaum GG, Mohs R. CERAD (Consortium to Establish a Registry for Alzheimer's Disease) Neuropsychology Assessment Battery: 35 Years and Counting. J Alzheimers Dis 2023; 93:1-27. [PMID: 36938738 PMCID: PMC10175144 DOI: 10.3233/jad-230026] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
BACKGROUND In 1986, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) was mandated to develop a brief neuropsychological assessment battery (CERAD-NAB) for AD, for uniform neuropsychological assessment, and information aggregation. Initially used across the National Institutes of Aging-funded Alzheimer's Disease Research Centers, it has become widely adopted wherever information is desired on cognitive status and change therein, particularly in older populations. OBJECTIVE Our purpose is to provide information on the multiple uses of the CERAD-NAB since its inception, and possible further developments. METHODS Since searching on "CERAD neuropsychological assessment battery" or similar terms missed important information, "CERAD" alone was entered into PubMed and SCOPUS, and CERAD-NAB use identified from the resulting studies. Use was sorted into major categories, e.g., psychometric information, norms, dementia/differential dementia diagnosis, epidemiology, intervention evaluation, genetics, etc., also translations, country of use, and alternative data gathering approaches. RESULTS CERAD-NAB is available in ∼20 languages. In addition to its initial purpose assessing AD severity, CERAD-NAB can identify mild cognitive impairment, facilitate differential dementia diagnosis, determine cognitive effects of naturally occurring and experimental interventions (e.g., air pollution, selenium in soil, exercise), has helped to clarify cognition/brain physiology-neuroanatomy, and assess cognitive status in dementia-risk conditions. Surveys of primary and tertiary care patients, and of population-based samples in multiple countries have provided information on prevalent and incident dementia, and cross-sectional and longitudinal norms for ages 35-100 years. CONCLUSION CERAD-NAB has fulfilled its original mandate, while its uses have expanded, keeping up with advances in the area of dementia.
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Affiliation(s)
- Gerda G Fillenbaum
- Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, NC, USA
| | - Richard Mohs
- Global Alzheimer's Platform Foundation, Washington, DC, USA
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Coley N, Giulioli C, Aisen PS, Vellas B, Andrieu S. Randomised controlled trials for the prevention of cognitive decline or dementia: A systematic review. Ageing Res Rev 2022; 82:101777. [PMID: 36336171 DOI: 10.1016/j.arr.2022.101777] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 09/02/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022]
Abstract
Dementia prevention research has progressed rapidly in recent years, with publication of several large lifestyle intervention trials, and renewed interest in pharmacological interventions, notably for individuals with Alzheimer's disease biomarkers, warranting an updated review of results and methodology. We identified 112 completed trials testing the efficacy of single-domain pharmacological (n = 33, 29%), nutritional (n = 27, 24%), physical activity (n = 18, 16%) and cognitive stimulation (n = 13, 12%), or multidomain (n = 22, 20%) interventions on incident dementia, or a relevant intermediate marker (e.g. cognitive function, biomarkers or dementia risk scores) in people without dementia. The earliest trials tested pharmacological interventions or nutritional supplements, but lifestyle interventions predominated in the last decade. In total, 21 (19%) trials demonstrated a clear beneficial effect on the pre-specified primary outcome (or all co-primary outcomes), but only two (10%) were large-scale (testing blood pressure lowering (Syst-Eur) or multidomain (FINGER) interventions on incident dementia and cognitive change in cognitive function, respectively). Of the 116 ongoing trials, 40% (n = 46) are testing multidomain interventions. Recent methodological shifts concern target populations, primary outcome measures, and intervention design, but study design remains constant (parallel group randomised controlled trial). Future trials may consider using adaptive trials or interventions, and more targeted approaches, since certain interventions may be more effective in certain subgroups of the population, and at specific times in the life-course. Efforts should also be made to increase the representativeness and diversity of prevention trial populations.
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Affiliation(s)
- Nicola Coley
- Center for Epidemiology and Research in Population Health (CERPOP), University of Toulouse, INSERM UMR1295, UPS, Toulouse, France; Department of Epidemiology and Public Health, Toulouse University Hospital, Toulouse, France.
| | - Caroline Giulioli
- Center for Epidemiology and Research in Population Health (CERPOP), University of Toulouse, INSERM UMR1295, UPS, Toulouse, France; Department of Epidemiology and Public Health, Toulouse University Hospital, Toulouse, France
| | - Paul S Aisen
- Alzheimer's Therapeutic Research Institute, University of Southern California, San Diego, CA, USA
| | - Bruno Vellas
- Center for Epidemiology and Research in Population Health (CERPOP), University of Toulouse, INSERM UMR1295, UPS, Toulouse, France; Department of Epidemiology and Public Health, Toulouse University Hospital, Toulouse, France; Gerontopole of Toulouse, Institute of Ageing, Toulouse University Hospital, France
| | - Sandrine Andrieu
- Center for Epidemiology and Research in Population Health (CERPOP), University of Toulouse, INSERM UMR1295, UPS, Toulouse, France; Department of Epidemiology and Public Health, Toulouse University Hospital, Toulouse, France; Department of Internal Medicine, Division of General Internal and Geriatric Medicine, University of New Mexico, USA
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3
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Vinceti M, Filippini T, Jablonska E, Saito Y, Wise LA. Safety of selenium exposure and limitations of selenoprotein maximization: Molecular and epidemiologic perspectives. ENVIRONMENTAL RESEARCH 2022; 211:113092. [PMID: 35259406 DOI: 10.1016/j.envres.2022.113092] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 02/08/2023]
Abstract
Recent evidence from laboratory and epidemiologic studies has shed a different light on selenium health effects and its recommended range of environmental exposure, compared with earlier research. Specifically, epidemiologic studies in Western populations have shown adverse effects of selenium exposure at low levels, sometimes below or slightly above selenium intakes needed to maximize selenoprotein expression and activity. In addition, three recent lines of evidence in molecular and biochemical studies suggest some potential drawbacks associated with selenoprotein maximization: 1) the possibility that selenoprotein upregulation is a compensatory response to oxidative challenge, induced by selenium itself or other oxidants; 2) the capacity of selenoproteins to trigger tumor growth in some circumstances; and 3) the deleterious metabolic effects of selenoproteins and particularly of selenoprotein P. The last observation provides a toxicological basis to explain why in humans selenium intake levels as low as 60 μg/day, still in the range of selenium exposure upregulating selenoprotein expression, might start to increase risk of type 2 diabetes. Overall, these new pieces of evidence from the literature call into question the purported benefit of selenoprotein maximization, and indicate the need to reassess selenium dietary reference values and upper intake level. This reassessment should clarify which range of selenoprotein upregulation follows restoration of adequate selenium availability and which range is driven by a compensatory response to selenium toxicity and oxidative stress.
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Affiliation(s)
- Marco Vinceti
- CREAGEN Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
| | - Tommaso Filippini
- CREAGEN Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Ewa Jablonska
- Department of Translational Research, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Yoshiro Saito
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Lauren A Wise
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
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4
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Lei P, Ayton S, Bush AI. The essential elements of Alzheimer's disease. J Biol Chem 2020; 296:100105. [PMID: 33219130 PMCID: PMC7948403 DOI: 10.1074/jbc.rev120.008207] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 02/05/2023] Open
Abstract
Treatments for Alzheimer’s disease (AD) directed against the prominent amyloid plaque neuropathology are yet to be proved effective despite many phase 3 clinical trials. There are several other neurochemical abnormalities that occur in the AD brain that warrant renewed emphasis as potential therapeutic targets for this disease. Among those are the elementomic signatures of iron, copper, zinc, and selenium. Here, we review these essential elements of AD for their broad potential to contribute to Alzheimer’s pathophysiology, and we also highlight more recent attempts to translate these findings into therapeutics. A reinspection of large bodies of discovery in the AD field, such as this, may inspire new thinking about pathogenesis and therapeutic targets.
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Affiliation(s)
- Peng Lei
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, P.R. China; Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.
| | - Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
| | - Ashley I Bush
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.
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Farahzadi R, Fathi E, Vietor I. Mesenchymal Stem Cells Could Be Considered as a Candidate for Further Studies in Cell-Based Therapy of Alzheimer's Disease via Targeting the Signaling Pathways. ACS Chem Neurosci 2020; 11:1424-1435. [PMID: 32310632 DOI: 10.1021/acschemneuro.0c00052] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are of particular interest because of their potential in regenerative medicine. Stem cell-based therapies cast a new hope for neurodegenerative disease treatment as a regeneration strategy, including treatment for Alzheimer's disease (AD). A multitude of cytokines and factors secreted from MSCs are known to give such multifunctional properties, but associated mechanisms of these factors have yet to be entirely understood. To better understand the in vitro effect of MSCs on a neurodegenerative disorder, we treated primary cortical and hippocampal neural cells with amyloid β (Aβ) as an in vitro cell line model for AD. For this purpose, bone marrow-derived MSCs (BMSCs) were cocultured with Aβ-treated neural cells, collected at day 3, and subjected to absolute telomere length measurement and telomerase activity assay. Next, the gene and protein expression levels of mTOR, p-mTOR, AMPK, p-AMPK, GSK-3β, p-GSK-3β, Wnt3, and β-catenin were investigated. Also, after 3 days of coculture treatment, the supernatant was collected from both groups for cytokine measurement. It was found that telomere length as a biomarker in neurodegenerative disorder as well as telomerase activity had significantly increased in the experimental group, and the presence of IL-6, IL-10, and TGF-β was obviously significant in the cocultured media. Also, BMSCs significantly changed the gene and protein expression of mTOR, AMPK, GSK-3β, and Wnt3/β-catenin signaling pathways components. It was concluded that the mentioned effects of MSCs on neural cells as an in vitro cell line model for AD as a therapeutic agent can be related to the signaling network.
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Affiliation(s)
- Raheleh Farahzadi
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz 516615731, Iran
| | - Ezzatollah Fathi
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz 5166616471, Iran
| | - Ilja Vietor
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
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Rutjes AWS, Denton DA, Di Nisio M, Chong L, Abraham RP, Al‐Assaf AS, Anderson JL, Malik MA, Vernooij RWM, Martínez G, Tabet N, McCleery J. Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life. Cochrane Database Syst Rev 2018; 12:CD011906. [PMID: 30556597 PMCID: PMC6353240 DOI: 10.1002/14651858.cd011906.pub2] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning. Supplementation of the diet with various vitamins and minerals has been suggested as a means of maintaining cognitive function, or even of preventing dementia, in later life. OBJECTIVES To evaluate the effects of vitamin and mineral supplementation on cognitive function in cognitively healthy people aged 40 years or more. SEARCH METHODS We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov and the WHO Portal/ICTRP from inception to 26th January 2018. SELECTION CRITERIA We included randomised controlled trials that evaluated the cognitive effects on people aged 40 years or more of any vitamin or mineral supplements taken by mouth for at least three months. DATA COLLECTION AND ANALYSIS Study selection, data extraction, and quality assessments were done in duplicate. Vitamins were considered broadly in the categories of B vitamins, antioxidant vitamins, and combinations of both. Minerals were considered separately, where possible. If interventions and outcomes were considered sufficiently similar, then data were pooled. In order to separate short-term cognitive effects from possible longer-term effects on the trajectory of cognitive decline, data were pooled for various treatment durations from 3 months to 12 months and up to 10 years or more. MAIN RESULTS In total, we included 28 studies with more than 83,000 participants. There were some general limitations of the evidence. Most participants were enrolled in studies which were not designed primarily to assess cognition. These studies often had no baseline cognitive assessment and used only brief cognitive assessments at follow-up. Very few studies assessed the incidence of dementia. Most study reports did not mention adverse events or made only very general statements about them. Only 10 studies had a mean follow-up > 5 years. Only two studies had participants whose mean age was < 60 years at baseline. The risk of bias in the included studies was generally low, other than a risk of attrition bias for longer-term outcomes. We considered the certainty of the evidence behind almost all results to be moderate or low.We included 14 studies with 27,882 participants which compared folic acid, vitamin B12, vitamin B6, or a combination of these to placebo. The majority of participants were aged over 60 years and had a history of cardio- or cerebrovascular disease. We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01). There were very sparse data on adverse effects or on incidence of cognitive impairment or dementia.We included 8 studies with 47,840 participants in which the active intervention was one or more of the antioxidant vitamins: ß-carotene, vitamin C or vitamin E. Results were mixed. For overall cognitive function, there was low-certainty evidence of benefit associated with ß-carotene after a mean of 18 years of treatment (MD 0.18 TICS points, 95% CI 0.01 to 0.35) and of vitamin C after 5 years to 10 years (MD 0.46 TICS points, 95% CI 0.14 to 0.78), but not at earlier time points. From two studies which reported on dementia incidence, there was low-certainty evidence of no effect of an antioxidant vitamin combination or of vitamin E, either alone or combined with selenium. One of the included studies had been designed to look for effects on the incidence of prostate cancer; it found a statistically significant increase in prostate cancer diagnoses among men taking vitamin E.One trial with 4143 participants compared vitamin D3 (400 IU/day) and calcium supplements to placebo. We found low- to moderate-certainty evidence of no effect of vitamin D3 and calcium supplements at any time-point up to 10 years on overall cognitive function (MD after a mean of 7.8 years -0.1 MMSE points, 95% CI -0.81 to 0.61) or the incidence of dementia (HR 0.94, 95% CI 0.72 to 1.24). A pilot study with 60 participants used a higher dose of vitamin D3 (4000 IU on alternate days) and found preliminary evidence that this dose probably has no effect on cognitive function over six months.We included data from one trial of zinc and copper supplementation with 1072 participants. There was moderate-certainty evidence of little or no effect on overall cognitive function (MD 0.6 MMSE points, 95% CI -0.19 to 1.39) or on the incidence of cognitive impairment after 5 years to 10 years. A second smaller trial provided no usable data, but reported no cognitive effects of six months of supplementation with zinc gluconate.From one study with 3711 participants, there was low-certainty evidence of no effect of approximately five years of selenium supplementation on the incidence of dementia (HR 0.83, 95% CI 0.61 to 1.13).Finally, we included three trials of complex supplements (combinations of B vitamins, antioxidant vitamins, and minerals) with 6306 participants. From the one trial which assessed overall cognitive function, there was low-certainty evidence of little or no effect on the TICS (MD after a mean of 8.5 years 0.12, 95% CI -0.14 to 0.38). AUTHORS' CONCLUSIONS We did not find evidence that any vitamin or mineral supplementation strategy for cognitively healthy adults in mid or late life has a meaningful effect on cognitive decline or dementia, although the evidence does not permit definitive conclusions. There were very few data on supplementation starting in midlife (< 60 years); studies designed to assess cognitive outcomes tended to be too short to assess maintenance of cognitive function; longer studies often had other primary outcomes and used cognitive measures which may have lacked sensitivity. The only positive signals of effect came from studies of long-term supplementation with antioxidant vitamins. These may be the most promising for further research.
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Affiliation(s)
- Anne WS Rutjes
- University of BernInstitute of Social and Preventive Medicine (ISPM)Mittelstrasse 43BernBernSwitzerland3012
- University of BernInstitute of Primary Health Care (BIHAM)Mittelstrasse 43BernBernSwitzerland3012
| | - David A Denton
- Sussex Partnership NHS Foundation TrustSpecialist Older People's ServicesUckfield Community HosptialFramfield RoadUckfieldUKTN22 5AW
| | - Marcello Di Nisio
- University "G. D'Annunzio" of Chieti‐PescaraDepartment of Medicine and Ageing SciencesVia dei Vestini 31Chieti ScaloItaly66013
| | | | - Rajesh P Abraham
- Surrey and Borders Partnership NHS Foundation TrustCommunity Mental Health Team for Older People:Waverley11‐13 Ockford RoadGuildfordUKGU7 1QU
| | - Aalya S Al‐Assaf
- Newcastle UniversityNIHR Innovation ObservatorySuite A, 4th Floor, Time CentralGallowgateNewcastle Upon TyneUKNE1 4BF
| | - John L Anderson
- Brighton and Sussex Medical School, University of BrightonDepartment of Medical EducationWatson BuildingFalmerUKBN1 9PH
| | - Muzaffar A Malik
- Brighton and Sussex Medical School, University of BrightonDepartment of Medical Education (Postgraduate)Room 341, Mayfield HouseFalmerUKBN1 9PH
| | - Robin WM Vernooij
- Iberoamerican Cochrane CentreC/ Sant Antoni Maria Claret 167BarcelonaBarcelonaSpain08025
| | - Gabriel Martínez
- Universidad de AntofagastaFaculty of Medicine and DentistryAvenida Argentina 2000AntofagastaChile127001
| | - Naji Tabet
- Brighton and Sussex Medical SchoolCentre for Dementia StudiesMayfield House, University of BrightonFalmerBrightonUKBN1 9PH
| | - Jenny McCleery
- Oxford Health NHS Foundation TrustElms CentreOxford RoadBanburyOxfordshireUKOX16 9AL
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Solovyev N, Drobyshev E, Bjørklund G, Dubrovskii Y, Lysiuk R, Rayman MP. Selenium, selenoprotein P, and Alzheimer's disease: is there a link? Free Radic Biol Med 2018; 127:124-133. [PMID: 29481840 DOI: 10.1016/j.freeradbiomed.2018.02.030] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/18/2018] [Accepted: 02/22/2018] [Indexed: 12/13/2022]
Abstract
The essential trace element, selenium (Se), is crucial to the brain but it may be potentially neurotoxic, depending on dosage and speciation; Se has been discussed for decades in relation to Alzheimer's disease (AD). Selenoprotein P (SELENOP) is a secreted heparin-binding glycoprotein which serves as the main Se transport protein in mammals. In vivo studies showed that this protein might have additional functions such as a contribution to redox regulation. The current review focuses on recent research on the possible role of SELENOP in AD pathology, based on model and human studies. The review also briefly summarizes results of epidemiological studies on Se supplementation in relation to brain diseases, including PREADViSE, EVA, and AIBL. Although mainly positive effects of Se are assessed in this review, possible detrimental effects of Se supplementation or exposure, including potential neurotoxicity, are also mentioned. In relation to AD, various roles of SELENOP are discussed, i.e. as the means of Se delivery to neurons, as an antioxidant, in cytoskeleton assembly, in interaction with redox-active metals (copper, iron, and mercury) and with misfolded proteins (amyloid-beta and hyperphosphorylated tau-protein).
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Affiliation(s)
- Nikolay Solovyev
- St. Petersburg State University, Institute of Chemistry, St. Petersburg, Russian Federation.
| | - Evgenii Drobyshev
- Universität Potsdam, Institut für Ernährungswissenschaft, Potsdam, Germany
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway.
| | - Yaroslav Dubrovskii
- St. Petersburg State University, Institute of Chemistry, St. Petersburg, Russian Federation
| | - Roman Lysiuk
- Department of Pharmacognosy and Botany, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Margaret P Rayman
- Department of Nutritional Sciences, University of Surrey, Guildford, UK
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8
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Ford WP, Westgate PM. A comparison of bias-corrected empirical covariance estimators with generalized estimating equations in small-sample longitudinal study settings. Stat Med 2018; 37:4318-4329. [DOI: 10.1002/sim.7917] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/01/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Whitney P. Ford
- Department of Biostatistics, College of Public Health; University of Kentucky; Lexington Kentucky
| | - Philip M. Westgate
- Department of Biostatistics, College of Public Health; University of Kentucky; Lexington Kentucky
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9
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Reversal of memory and neuropsychiatric symptoms and reduced tau pathology by selenium in 3xTg-AD mice. Sci Rep 2018; 8:6431. [PMID: 29691439 PMCID: PMC5915484 DOI: 10.1038/s41598-018-24741-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/05/2018] [Indexed: 12/03/2022] Open
Abstract
Accumulation of amyloid-β plaques and tau contribute to the pathogenesis of Alzheimer’s disease (AD), but it is unclear whether targeting tau pathology by antioxidants independently of amyloid-β causes beneficial effects on memory and neuropsychiatric symptoms. Selenium, an essential antioxidant element reduced in the aging brain, prevents development of neuropathology in AD transgenic mice at early disease stages. The therapeutic potential of selenium for ameliorating or reversing neuropsychiatric and cognitive behavioral symptoms at late AD stages is largely unknown. Here, we evaluated the effects of chronic dietary sodium selenate supplementation for 4 months in female 3xTg-AD mice at 12–14 months of age. Chronic sodium selenate treatment efficiently reversed hippocampal-dependent learning and memory impairments, and behavior- and neuropsychiatric-like symptoms in old female 3xTg-AD mice. Selenium significantly decreased the number of aggregated tau-positive neurons and astrogliosis, without globally affecting amyloid plaques, in the hippocampus of 3xTg-AD mice. These results indicate that selenium treatment reverses AD-like memory and neuropsychiatric symptoms by a mechanism involving reduction of aggregated tau and/or reactive astrocytes but not amyloid pathology. These results suggest that sodium selenate could be part of a combined therapeutic approach for the treatment of memory and neuropsychiatric symptoms in advanced AD stages.
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10
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Kwak KA, Lee SP, Yang JY, Park YS. Current Perspectives regarding Stem Cell-Based Therapy for Alzheimer's Disease. Stem Cells Int 2018; 2018:6392986. [PMID: 29686714 PMCID: PMC5852851 DOI: 10.1155/2018/6392986] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 01/15/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder featuring memory loss and cognitive impairment, is caused by synaptic failure and the excessive accumulation of misfolded proteins. Many unsuccessful attempts have been made to develop new small molecules or antibodies to intervene in the disease's pathogenesis. Stem cell-based therapies cast a new hope for AD treatment as a replacement or regeneration strategy. The results from recent preclinical studies regarding stem cell-based therapies are promising. Human clinical trials are now underway. However, a number of questions remain to be answered prior to safe and effective clinical translation. This review explores the pathophysiology of AD and summarizes the relevant stem cell research according to cell type. We also briefly summarize related clinical trials. Finally, future perspectives are discussed with regard to their clinical applications.
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Affiliation(s)
- Kyeong-Ah Kwak
- Department of Oral Anatomy, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Seung-Pyo Lee
- Department of Oral Anatomy, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Jin-Young Yang
- Department of Dental Hygiene, Daejeon Institute of Science and Technology, Daejeon, Republic of Korea
| | - Young-Seok Park
- Department of Oral Anatomy, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder without a cure. Most AD cases are sporadic where age represents the greatest risk factor. Lack of understanding of the disease mechanism hinders the development of efficacious therapeutic approaches. The loss of synapses in the affected brain regions correlates best with cognitive impairment in AD patients and has been considered as the early mechanism that precedes neuronal loss. Oxidative stress has been recognized as a contributing factor in aging and in the progression of multiple neurodegenerative diseases including AD. Increased production of reactive oxygen species (ROS) associated with age- and disease-dependent loss of mitochondrial function, altered metal homeostasis, and reduced antioxidant defense directly affect synaptic activity and neurotransmission in neurons leading to cognitive dysfunction. In addition, molecular targets affected by ROS include nuclear and mitochondrial DNA, lipids, proteins, calcium homeostasis, mitochondrial dynamics and function, cellular architecture, receptor trafficking and endocytosis, and energy homeostasis. Abnormal cellular metabolism in turn could affect the production and accumulation of amyloid-β (Aβ) and hyperphosphorylated Tau protein, which independently could exacerbate mitochondrial dysfunction and ROS production, thereby contributing to a vicious cycle. While mounting evidence implicates ROS in the AD etiology, clinical trials with antioxidant therapies have not produced consistent results. In this review, we will discuss the role of oxidative stress in synaptic dysfunction in AD, innovative therapeutic strategies evolved based on a better understanding of the complexity of molecular mechanisms of AD, and the dual role ROS play in health and disease.
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Affiliation(s)
- Eric Tönnies
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Eugenia Trushina
- Department of Neurology, Mayo Clinic, Rochester, MN, USA.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA
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Kang JM, Yeon BK, Cho SJ, Suh YH. Stem Cell Therapy for Alzheimer's Disease: A Review of Recent Clinical Trials. J Alzheimers Dis 2018; 54:879-889. [PMID: 27567851 DOI: 10.3233/jad-160406] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Stem cell therapy has been noted to be a disease-modifying treatment for Alzheimer's disease (AD). After the failure to develop new drugs for AD, the number of studies on stem cells, such as mesenchymal stem cells (MSCs) and neural stem cells (NSCs), has increased from the early 2000 s. Issues pertaining to stem cells have been investigated in many animal studies in terms of stem cell origin, differentiation potency, method of culture, tumor formation, injection route, and mobility. Since 2010, mainly in East Asia, researchers began clinical trials investigating the use of stem cells for AD. Two phase I trials on moderate AD have been completed; though they revealed no severe acute or long-term side effects, no significant clinical efficacy was observed. Several studies, which involve more sophisticated study designs using different injection routes, well-established scales, and biomarkers such as amyloid positron emission tomography, are planned for mild to moderate AD patients. Here, we review the concept of stem cell therapy for AD and the progress of recent clinical trials.
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Affiliation(s)
- Jae Myeong Kang
- Department of Psychiatry, Gil Medical Center, Gachon University, College of Medicine, Incheon, Korea
| | - Byeong Kil Yeon
- Department of Psychiatry, Gil Medical Center, Gachon University, College of Medicine, Incheon, Korea.,Incheon Metropolitan Dementia Center, Incheon, Korea
| | - Seong-Jin Cho
- Department of Psychiatry, Gil Medical Center, Gachon University, College of Medicine, Incheon, Korea
| | - Yoo-Hun Suh
- Neuroscience Research Institute, Gachon University, College of Medicine, Incheon, Korea
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Fougère B, Morley JE, Little MO, De Souto Barreto P, Cesari M, Vellas B. Interventions Against Disability in Frail Older Adults: Lessons Learned from Clinical Trials. J Nutr Health Aging 2018; 22:676-688. [PMID: 29806856 DOI: 10.1007/s12603-017-0987-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
As the population ages, the number of older people with frailty is expected to increase worldwide with consequent rising of expenditures for healthcare and long-term care. Effective methods for preventing or delaying the onset of disability are urgently required. Frailty is a common and important geriatric condition characterized by age-associated declines in multiple physiological mechanisms, leading to increased vulnerability to stressors and higher risk for adverse health outcomes. Significant advancements have been made in the understanding of the frailty pathophysiological background. Given its multidimensional nature, reversing frailty requires a comprehensive approach. In this context, several studies testing the effects of pharmacological approach, physical activity, nutritional intervention, or cognitive training showed evidence of efficacy in frail older adults. Important innovations in ongoing trials include the development of multidomain interventions. Challenges include the use of trial designs, the development of standardized, sensitive outcome measures, and the need for interventions that can be implemented in resource-poor settings. In this viewpoint paper, based on recent literature, our aim was to identify relevant studies performed to reverse or delay disability in frail older adults.
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Affiliation(s)
- B Fougère
- Bertrand Fougère, Institut du Vieillissement, Gérontopôle, Université Toulouse III Paul Sabatier, 37 Allées Jules Guesde, 31000 Toulouse, France. Tel: +33561145657 ; fax: +33561145640. E-mail:
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Grimm MOW, Michaelson DM, Hartmann T. Omega-3 fatty acids, lipids, and apoE lipidation in Alzheimer's disease: a rationale for multi-nutrient dementia prevention. J Lipid Res 2017; 58:2083-2101. [PMID: 28528321 DOI: 10.1194/jlr.r076331] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/09/2017] [Indexed: 12/14/2022] Open
Abstract
In the last decade, it has become obvious that Alzheimer's disease (AD) is closely linked to changes in lipids or lipid metabolism. One of the main pathological hallmarks of AD is amyloid-β (Aβ) deposition. Aβ is derived from sequential proteolytic processing of the amyloid precursor protein (APP). Interestingly, both, the APP and all APP secretases are transmembrane proteins that cleave APP close to and in the lipid bilayer. Moreover, apoE4 has been identified as the most prevalent genetic risk factor for AD. ApoE is the main lipoprotein in the brain, which has an abundant role in the transport of lipids and brain lipid metabolism. Several lipidomic approaches revealed changes in the lipid levels of cerebrospinal fluid or in post mortem AD brains. Here, we review the impact of apoE and lipids in AD, focusing on the major brain lipid classes, sphingomyelin, plasmalogens, gangliosides, sulfatides, DHA, and EPA, as well as on lipid signaling molecules, like ceramide and sphingosine-1-phosphate. As nutritional approaches showed limited beneficial effects in clinical studies, the opportunities of combining different supplements in multi-nutritional approaches are discussed and summarized.
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Affiliation(s)
- Marcus O W Grimm
- Department of Experimental Neurology and Department of Neurodegeneration and Neurobiology, and Deutsches Institut für DemenzPrävention (DIDP), Saarland University, Homburg/Saar, Germany
| | - Daniel M Michaelson
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tobias Hartmann
- Department of Experimental Neurology and Department of Neurodegeneration and Neurobiology, and Deutsches Institut für DemenzPrävention (DIDP), Saarland University, Homburg/Saar, Germany
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Farina N, Llewellyn D, Isaac MGEKN, Tabet N. Vitamin E for Alzheimer's dementia and mild cognitive impairment. Cochrane Database Syst Rev 2017; 4:CD002854. [PMID: 28418065 PMCID: PMC6478142 DOI: 10.1002/14651858.cd002854.pub5] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Vitamin E occurs naturally in the diet. It has several biological activities, including functioning as an antioxidant to scavenge toxic free radicals. Evidence that free radicals may contribute to the pathological processes behind cognitive impairment has led to interest in the use of vitamin E supplements to treat mild cognitive impairment (MCI) and Alzheimer's disease (AD). This is an update of a Cochrane Review first published in 2000, and previously updated in 2006 and 2012. OBJECTIVES To assess the efficacy of vitamin E in the treatment of MCI and dementia due to AD. SEARCH METHODS We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources on 22 April 2016 using the terms: "Vitamin E", vitamin-E, alpha-tocopherol. SELECTION CRITERIA We included all double-blind, randomised trials in which treatment with any dose of vitamin E was compared with placebo in people with AD or MCI. DATA COLLECTION AND ANALYSIS We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. Where appropriate we attempted to contact authors to obtain missing information. MAIN RESULTS Four trials met the inclusion criteria, but we could only extract outcome data in accordance with our protocol from two trials, one in an AD population (n = 304) and one in an MCI population (n = 516). Both trials had an overall low to unclear risk of bias. It was not possible to pool data across studies owing to a lack of comparable outcome measures.In people with AD, we found no evidence of any clinically important effect of vitamin E on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) over six to 48 months (mean difference (MD) -1.81, 95% confidence interval (CI) -3.75 to 0.13, P = 0.07, 1 study, n = 272; moderate quality evidence). There was no evidence of a difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event over six to 48 months (risk ratio (RR) 0.86, 95% CI 0.71 to 1.05, P = 0.13, 1 study, n = 304; moderate quality evidence), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34, P = 0.46, 1 study, n = 304; moderate quality evidence). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at six to 48 months (mean difference (MD) 3.15, 95% CI 0.07 to 6.23, P = 0.04, 1 study, n = 280; moderate quality evidence). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD -1.47, 95% CI -4.26 to 1.32, P = 0.30, 1 study, n = 280; moderate quality evidence).We found no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35, P = 0.81, 1 study, n = 516; moderate quality evidence). Five deaths occurred in each of the vitamin E and placebo groups over the 36 months (RR 1.01, 95% CI 0.30 to 3.44, P = 0.99, 1 study, n = 516; moderate quality evidence). We were unable to extract data in accordance with the review protocol for other outcomes. However, the study authors found no evidence that vitamin E differed from placebo in its effect on cognitive function, global severity or activities of daily living . There was also no evidence of a difference between groups in the more commonly reported adverse events. AUTHORS' CONCLUSIONS We found no evidence that the alpha-tocopherol form of vitamin E given to people with MCI prevents progression to dementia, or that it improves cognitive function in people with MCI or dementia due to AD. However, there is moderate quality evidence from a single study that it may slow functional decline in AD. Vitamin E was not associated with an increased risk of serious adverse events or mortality in the trials in this review. These conclusions have changed since the previous update, however they are still based on small numbers of trials and participants and further research is quite likely to affect the results.
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Affiliation(s)
- Nicolas Farina
- Brighton and Sussex Medical SchoolCentre for Dementia StudiesBrightonUKBN1 9QH
| | - David Llewellyn
- University of ExeterMedical SchoolExeterUK+44 (0) 1392 726018
| | | | - Naji Tabet
- Brighton and Sussex Medical SchoolCentre for Dementia StudiesBrightonUKBN1 9QH
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Westgate PM, Burchett WW. On the analysis of very small samples of Gaussian repeated measurements: an alternative approach. Stat Med 2017; 36:958-970. [PMID: 28064473 PMCID: PMC5291809 DOI: 10.1002/sim.7199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/13/2016] [Accepted: 11/21/2016] [Indexed: 11/06/2022]
Abstract
The analysis of very small samples of Gaussian repeated measurements can be challenging. First, due to a very small number of independent subjects contributing outcomes over time, statistical power can be quite small. Second, nuisance covariance parameters must be appropriately accounted for in the analysis in order to maintain the nominal test size. However, available statistical strategies that ensure valid statistical inference may lack power, whereas more powerful methods may have the potential for inflated test sizes. Therefore, we explore an alternative approach to the analysis of very small samples of Gaussian repeated measurements, with the goal of maintaining valid inference while also improving statistical power relative to other valid methods. This approach uses generalized estimating equations with a bias-corrected empirical covariance matrix that accounts for all small-sample aspects of nuisance correlation parameter estimation in order to maintain valid inference. Furthermore, the approach utilizes correlation selection strategies with the goal of choosing the working structure that will result in the greatest power. In our study, we show that when accurate modeling of the nuisance correlation structure impacts the efficiency of regression parameter estimation, this method can improve power relative to existing methods that yield valid inference. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Philip M Westgate
- Department of Biostatistics, College of Public Health, University of Kentucky, Lexington, 40536, KY, U.S.A
| | - Woodrow W Burchett
- Department of Statistics, College of Arts and Sciences, University of Kentucky, Lexington, 40536, KY, U.S.A
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17
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Abstract
BACKGROUND Vitamin E occurs naturally in the diet. It has several biological activities, including functioning as an antioxidant to scavenge toxic free radicals. Evidence that free radicals may contribute to the pathological processes behind cognitive impairment has led to interest in the use of vitamin E supplements to treat mild cognitive impairment (MCI) and Alzheimer's disease (AD). This is an update of a Cochrane Review first published in 2000, and previously updated in 2006 and 2012. OBJECTIVES To assess the efficacy of vitamin E in the treatment of MCI and dementia due to AD. SEARCH METHODS We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources on 22 April 2016 using the terms: "Vitamin E", vitamin-E, alpha-tocopherol. SELECTION CRITERIA We included all double-blind, randomised trials in which treatment with any dose of vitamin E was compared with placebo in people with AD or MCI. DATA COLLECTION AND ANALYSIS We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. Where appropriate we attempted to contact authors to obtain missing information. MAIN RESULTS Four trials met the inclusion criteria, but we could only extract outcome data in accordance with our protocol from two trials, one in an AD population (n = 304) and one in an MCI population (n = 516). Both trials had an overall low to unclear risk of bias. It was not possible to pool data across studies owing to a lack of comparable outcome measures.In people with AD, we found no evidence of any clinically important effect of vitamin E on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) over six to 48 months (mean difference (MD) -1.81, 95% confidence interval (CI) -3.75 to 0.13, P = 0.07, 1 study, n = 272; moderate quality evidence). There was no evidence of a difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event over six to 48 months (risk ratio (RR) 0.86, 95% CI 0.71 to 1.05, P = 0.13, 1 study, n = 304; moderate quality evidence), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34, P = 0.46, 1 study, n = 304; moderate quality evidence). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at six to 48 months (mean difference (MD) 3.15, 95% CI 0.07 to 6.23, P = 0.04, 1 study, n = 280; moderate quality evidence). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD -1.47, 95% CI -4.26 to 1.32, P = 0.30, 1 study, n = 280; moderate quality evidence).We found no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35, P = 0.81, 1 study, n = 516; moderate quality evidence). Five deaths occurred in each of the vitamin E and placebo groups over the 36 months (RR 1.01, 95% CI 0.30 to 3.44, P = 0.99, 1 study, n = 516; moderate quality evidence). We were unable to extract data in accordance with the review protocol for other outcomes. However, the study authors found no evidence that vitamin E differed from placebo in its effect on cognitive function, global severity or activities of daily living . There was also no evidence of a difference between groups in the more commonly reported adverse events. AUTHORS' CONCLUSIONS We found no evidence that the alpha-tocopherol form of vitamin E given to people with MCI prevents progression to dementia, or that it improves cognitive function in people with MCI or dementia due to AD. However, there is moderate quality evidence from a single study that it may slow functional decline in AD. Vitamin E was not associated with an increased risk of serious adverse events or mortality in the trials in this review. These conclusions have changed since the previous update, however they are still based on small numbers of trials and participants and further research is quite likely to affect the results.
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Affiliation(s)
- Nicolas Farina
- Brighton and Sussex Medical SchoolCentre for Dementia StudiesBrightonUKBN1 9QH
| | - David Llewellyn
- University of ExeterMedical SchoolExeterUK+44 (0) 1392 726018
| | | | - Naji Tabet
- Brighton and Sussex Medical SchoolCentre for Dementia StudiesBrightonUKBN1 9QH
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Wang J, Tan L, Yu JT. Prevention Trials in Alzheimer's Disease: Current Status and Future Perspectives. J Alzheimers Dis 2016; 50:927-45. [PMID: 26836177 DOI: 10.3233/jad-150826] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly. Over the past 20 years, both pharmacological and lifestyle interventions have been studied for AD prevention, but the overall results have been disappointing. The majority of disappointing results have raised questions and great challenges for the future of AD prevention trials. Ongoing advances in the knowledge of pathogenesis, in the identification of novel targets, in improved outcome measures, and in identification and validation of biomarkers may lead to effective strategies for AD prevention. In this paper, we review the selection of participants and interventions, trial design, outcome assessments, and promising biomarkers in prevention trials, and summarize the lessons learned from completed trials and perspectives from ongoing trials in AD prevention. Selection of optimal participants and interventions, coupled with more refined outcomes and more efficient trial design, may have the capacity to deliver a new era of preventive discovery in this challenging area.
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Affiliation(s)
- Jun Wang
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China.,Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Yuzhong District, Chongqing, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China
| | - Jin-Tai Yu
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, USA
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Ding X, Kryscio RJ, Turner J, Jicha GA, Cooper G, Caban-Holt A, Schmitt FA, Abner EL. Self-Reported Sleep Apnea and Dementia Risk: Findings from the Prevention of Alzheimer's Disease with Vitamin E and Selenium Trial. J Am Geriatr Soc 2016; 64:2472-2478. [PMID: 27801937 DOI: 10.1111/jgs.14393] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To investigate the association between baseline sleep apnea and risk of incident dementia in the Prevention of Alzheimer's Disease with Vitamin E and Selenium (PREADViSE) study and to explore whether the association depends on apolipoprotein E (APOE) ɛ4 allele status. DESIGN Secondary analysis based on data collected during PREADViSE. SETTING Participants were assessed at 128 local clinical study sites during the clinical trial phase and later were followed by telephone from a centralized location. PARTICIPANTS Men enrolled in PREADViSE (without dementia or other active neurological conditions that affect cognition such as major psychiatric disorders, including depression; N = 7,547). MEASUREMENTS Participants were interviewed at baseline for sleep apnea. The Memory Impairment Screen (MIS) was administered to each participant annually. Subjects who failed this initial screen were tested with secondary screening tests. Medical history and medication use were determined, and the AD8 dementia screening instrument was used. RESULTS The effect of self-reported sleep apnea on dementia risk depended on APOE ɛ4 status. When the allele was absent, baseline self-reported sleep apnea was associated with a 66% higher risk of developing dementia (95% confidence interval = 2-170%), whereas self-reported sleep apnea conferred no additional risk for participants with an ɛ4 allele. CONCLUSION Sleep apnea may increase risk of dementia in the absence of APOE ɛ4. This may help inform prevention strategies for dementia or AD in older men with sleep apnea. Registration: PREADViSE is registered at ClinicalTrials.gov: NCT00040378.
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Affiliation(s)
- Xiuhua Ding
- College of Public Health, University of Kentucky, Lexington, Kentucky
| | - Richard J Kryscio
- College of Public Health, University of Kentucky, Lexington, Kentucky.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky.,Department of Statistics, University of Kentucky, Lexington, Kentucky.,Department of Biostatistics, University of Kentucky, Lexington, Kentucky
| | - Joshua Turner
- Department of Counseling Psychology, New Mexico State University, Las Cruces, New Mexico
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky.,Department of Neurology, University of Kentucky, Lexington, Kentucky
| | - Gregory Cooper
- Baptist Health Medical Group, Neurology, Lexington, Kentucky
| | - Allison Caban-Holt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky.,Department of Neurology, University of Kentucky, Lexington, Kentucky
| | - Erin L Abner
- College of Public Health, University of Kentucky, Lexington, Kentucky.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky.,Department of Epidemiology, University of Kentucky, Lexington, Kentucky
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20
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Killin LOJ, Starr JM, Shiue IJ, Russ TC. Environmental risk factors for dementia: a systematic review. BMC Geriatr 2016; 16:175. [PMID: 27729011 PMCID: PMC5059894 DOI: 10.1186/s12877-016-0342-y] [Citation(s) in RCA: 204] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 09/19/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Dementia risk reduction is a major and growing public health priority. While certain modifiable risk factors for dementia have been identified, there remains a substantial proportion of unexplained risk. There is evidence that environmental risk factors may explain some of this risk. Thus, we present the first comprehensive systematic review of environmental risk factors for dementia. METHODS We searched the PubMed and Web of Science databases from their inception to January 2016, bibliographies of review articles, and articles related to publically available environmental data. Articles were included if they examined the association between an environmental risk factor and dementia. Studies with another outcome (for example, cognition), a physiological measure of the exposure, case studies, animal studies, and studies of nutrition were excluded. Data were extracted from individual studies which were, in turn, appraised for methodological quality. The strength and consistency of the overall evidence for each risk factor identified was assessed. RESULTS We screened 4784 studies and included 60 in the review. Risk factors were considered in six categories: air quality, toxic heavy metals, other metals, other trace elements, occupational-related exposures, and miscellaneous environmental factors. Few studies took a life course approach. There is at least moderate evidence implicating the following risk factors: air pollution; aluminium; silicon; selenium; pesticides; vitamin D deficiency; and electric and magnetic fields. CONCLUSIONS Studies varied widely in size and quality and therefore we must be circumspect in our conclusions. Nevertheless, this extensive review suggests that future research could focus on a short list of environmental risk factors for dementia. Furthermore, further robust, longitudinal studies with repeated measures of environmental exposures are required to confirm these associations.
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Affiliation(s)
- Lewis O. J. Killin
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing & Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
- Scottish Dementia Clinical Research Network, NHS Scotland, Perth, UK
| | - John M. Starr
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing & Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | - Ivy J. Shiue
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
- Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, UK
| | - Tom C. Russ
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, UK
- Centre for Cognitive Ageing & Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
- Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK
- Division of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
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Sonet J, Bulteau AL, Chavatte L, García-Barrera T, Gómez-Ariza JL, Callejón-Leblic B, Nischwitz V, Theiner S, Galvez L, Koellensperger G, Keppler BK, Roman M, Barbante C, Neth K, Bornhorst J, Michalke B. Biomedical and Pharmaceutical Applications. Metallomics 2016. [DOI: 10.1002/9783527694907.ch13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Jordan Sonet
- Centre National de Recherche Scientifique (CNRS)/Université de Pau et des Pays de l'Adour (UPPA), Unité Mixte de Recherche (UMR) 5254; Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE); Technopôle Hélioparc Pau Pyrénées, 2 Avenue du Président Pierre Angot 64000 Pau France
| | - Anne-Laure Bulteau
- Centre National de Recherche Scientifique (CNRS)/Université de Pau et des Pays de l'Adour (UPPA), Unité Mixte de Recherche (UMR) 5254; Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE); Technopôle Hélioparc Pau Pyrénées, 2 Avenue du Président Pierre Angot 64000 Pau France
| | - Laurent Chavatte
- Centre National de Recherche Scientifique (CNRS)/Université de Pau et des Pays de l'Adour (UPPA), Unité Mixte de Recherche (UMR) 5254; Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE); Technopôle Hélioparc Pau Pyrénées, 2 Avenue du Président Pierre Angot 64000 Pau France
| | - Tamara García-Barrera
- University of Huelva; Department of Chemistry, Campus El Carmen; Fuerzas Armadas Ave 21007 Huelva Spain
| | - José Luis Gómez-Ariza
- University of Huelva, Research Center of Health and Environment (CYSMA); Campus El Carmen; Fuerzas Armadas Ave 21007 Huelva Spain
| | - Belén Callejón-Leblic
- University of Huelva; Department of Chemistry, Campus El Carmen; Fuerzas Armadas Ave 21007 Huelva Spain
| | - Volker Nischwitz
- Forschungszentrum Jülich; Central Institute for Engineering, Electronics and Analytics; Analytics (ZEA-3), Wilhelm-Johnen-Straße 52428 Jülich Germany
| | - Sarah Theiner
- University of Vienna; Department of Inorganic Chemistry; Waehringer Strasse 42 1090 Vienna Austria
| | - Luis Galvez
- University of Vienna, Research Platform ‘Translational Cancer Therapy Research’; Waehringer Strasse 42 1090 Vienna Austria
| | - Gunda Koellensperger
- University of Vienna, Department of Analytical Chemistry; Waehringer Strasse 38 1090 Vienna Austria
| | - Bernhard K. Keppler
- University of Vienna; Department of Inorganic Chemistry; Waehringer Strasse 42 1090 Vienna Austria
| | - Marco Roman
- Ca' Foscari University of Venice; Department of Environmental Sciences, Informatics and Statistics (DAIS); Via Torino 155 30172 Venice Italy
| | - Carlo Barbante
- National Research Council; Institute for the Dynamics of Environmental Processes (IDPA-CNR); Via Torino 155 30172 Venice Italy
| | - Katharina Neth
- Helmholtz Center Munich, German Research Center for Environmental Health GmbH; Research Unit: Analytical BioGeoChemistry; Ingolstädter Landstraße 1 85764 Neuherberg Germany
| | - Julia Bornhorst
- University of Potsdam; Department of Food Chemistry, Institute of Nutritional Science; Arthur-Scheunert-Allee 114-116 14558 Nuthetal Germany
| | - Bernhard Michalke
- Helmholtz Center Munich, German Research Center for Environmental Health GmbH; Research Unit: Analytical BioGeoChemistry; Ingolstädter Landstraße 1 85764 Neuherberg Germany
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Opportunities and challenges in incorporating ancillary studies into a cancer prevention randomized clinical trial. Trials 2016; 17:400. [PMID: 27519183 PMCID: PMC4983010 DOI: 10.1186/s13063-016-1524-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/26/2016] [Indexed: 11/15/2022] Open
Abstract
Background The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a randomized, double-blind, placebo-controlled, prostate cancer prevention study funded by the National Cancer Institute and conducted by SWOG (Southwest Oncology Group). A total of 35,533 men were assigned randomly to one of four treatment groups (vitamin E + placebo, selenium + placebo, vitamin E + selenium, placebo + placebo). At the time of the trial’s development, NIH had invested substantial resources in evaluating the potential benefits of these antioxidants. To capitalize on the knowledge gained from following a large cohort of healthy, aging males on the effects of selenium and/or vitamin E, ancillary studies with other disease endpoints were solicited. Methods Four ancillary studies were added. Each drew from the same population but had independent objectives and an endpoint other than prostate cancer. These studies fell into two categories: those prospectively enrolling and following participants (studies of Alzheimer’s disease and respiratory function) and those requiring a retrospective medical record review after a reported event (cataracts/age-related macular degeneration and colorectal screening). An examination of the challenges and opportunities of adding ancillary studies is provided. The impact of the ancillary studies on adherence to SELECT was evaluated using a Cox proportional hazards model. Results While the addition of ancillary studies appears to have improved participant adherence to the primary trial, this did not come without added complexity. Activation of the ancillary studies happened after the SELECT randomizations had begun resulting in accrual problems to some of the studies. Study site participation in the ancillary trials varied greatly and depended on the interest of the study site principal investigator. Procedures for each were integrated into the primary trial and all monitoring was done by the SELECT Data and Safety Monitoring Committee. The impact of the early closure of the primary trial was different for each of the ancillary trials. Conclusions The ancillary studies allowed study sites to broaden the research opportunities for their participants. Their implementation was efficient because of the established infrastructure of the primary trial. Implementation of these ancillary trials took substantial planning and coordination but enriched the overall primary trial. Trial registration NCT00006392-S0000: Selenium and Vitamin E in Preventing Prostate Cancer (SELECT) (4 October 2000). NCT00780689-S0000A: Prevention of Alzheimer’s Disease by Vitamin E and Selenium (PREADVISE) (25 June 2002). NCT00784225-S0000B: Vitamin E and/or Selenium in Preventing Cataract and Age-Related Macular Degeneration in Men on SELECT SWOG-S0000 (SEE) (31 October 2008). NCT00706121-S0000D: Effect of Vitamin E and/or Selenium on Colorectal Polyps in Men Enrolled on SELECT Trial SWOG-S0000 (ACP) (26 June 2008). NCT00063453-S0000C: Vitamin E and/or Selenium in Preventing Loss of Lung Function in Older Men Enrolled on SELECT Clinical Trial SWOG-S0000 (26 June 2003). Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1524-9) contains supplementary material, which is available to authorized users.
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Coley N, Gallini A, Ousset PJ, Vellas B, Andrieu S. Evaluating the clinical relevance of a cognitive composite outcome measure: An analysis of 1414 participants from the 5-year GuidAge Alzheimer's prevention trial. Alzheimers Dement 2016; 12:1216-1225. [PMID: 27423962 DOI: 10.1016/j.jalz.2016.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/02/2016] [Accepted: 06/06/2016] [Indexed: 01/30/2023]
Abstract
INTRODUCTION Composite cognitive scores have been developed as primary outcome measures for preclinical/prevention trials for Alzheimer's disease (AD), mainly using observational data and with little consideration of clinical relevance. METHODS Secondary analysis of placebo group data from a 5-year AD prevention trial. The composite score was the average of the following z scores: MMSE orientation items, Free and Cued Selective Reminding Test, Category Fluency, Trail Making Test-part B. RESULTS Composite score change from baseline differed significantly by age, APOE genotype, and CDR progression and AD dementia status. A 1 point decrease in baseline score was highly predictive of 5-year AD dementia risk (HR = 3.51, 95% CI, 2.62-4.71, P < .001). The 1 year minimum clinically important difference was estimated at -0.3 points and predicted AD dementia. DISCUSSION We explored the clinical relevance of a composite score in a prevention trial setting. This type of analysis facilitates the interpretation of composite scores and informs power calculations.
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Affiliation(s)
- Nicola Coley
- INSERM-University of Toulouse, UMR1027, Toulouse, France; Department of Epidemiology and Public Health, CHU Toulouse, Toulouse, France.
| | - Adeline Gallini
- INSERM-University of Toulouse, UMR1027, Toulouse, France; Department of Epidemiology and Public Health, CHU Toulouse, Toulouse, France
| | - Pierre-Jean Ousset
- INSERM-University of Toulouse, UMR1027, Toulouse, France; Department of Geriatric Medicine, CHU Toulouse, Gerontopole, Toulouse, France
| | - Bruno Vellas
- INSERM-University of Toulouse, UMR1027, Toulouse, France; Department of Geriatric Medicine, CHU Toulouse, Gerontopole, Toulouse, France
| | - Sandrine Andrieu
- INSERM-University of Toulouse, UMR1027, Toulouse, France; Department of Epidemiology and Public Health, CHU Toulouse, Toulouse, France
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Solovyev ND. Importance of selenium and selenoprotein for brain function: From antioxidant protection to neuronal signalling. J Inorg Biochem 2015; 153:1-12. [PMID: 26398431 DOI: 10.1016/j.jinorgbio.2015.09.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
Multiple biological functions of selenium manifest themselves mainly via 25 selenoproteins that have selenocysteine at their active centre. Selenium is vital for the brain and seems to participate in the pathology of disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and epilepsy. Since selenium was shown to be involved in diverse functions of the central nervous system, such as motor performance, coordination, memory and cognition, a possible role of selenium and selenoproteins in brain signalling pathways may be assumed. The aim of the present review is to analyse possible relations between selenium and neurotransmission. Selenoproteins seem to be of special importance in the development and functioning of GABAergic (GABA, γ-aminobutyric acid) parvalbumin positive interneurons of the cerebral cortex and hippocampus. Dopamine pathway might be also selenium dependent as selenium shows neuroprotection in the nigrostriatal pathway and also exerts toxicity towards dopaminergic neurons under higher concentrations. Recent findings also point to acetylcholine neurotransmission involvement. The role of selenium and selenoproteins in neurotransmission might not only be limited to their antioxidant properties but also to inflammation, influencing protein phosphorylation and ion channels, alteration of calcium homeostasis and brain cholesterol metabolism. Moreover, a direct signalling function was proposed for selenoprotein P through interaction with post-synaptic apoliprotein E receptors 2 (ApoER2).
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Affiliation(s)
- Nikolay D Solovyev
- Institute of Chemistry, St. Petersburg State University, St. Petersburg 198504, Russian Federation.
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Andrieu S, Coley N, Lovestone S, Aisen PS, Vellas B. Prevention of sporadic Alzheimer's disease: lessons learned from clinical trials and future directions. Lancet Neurol 2015. [PMID: 26213339 DOI: 10.1016/s1474-4422(15)00153-2] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Interventions that have even quite modest effects at the individual level could drastically reduce the future burden of dementia associated with Alzheimer's disease at the population level. In the past three decades, both pharmacological and lifestyle interventions have been studied for the prevention of cognitive decline or dementia in randomised controlled trials of individuals mostly aged older than 50-55 years with or without risk factors for Alzheimer's disease. Several trials testing the effects of physical activity, cognitive training, or antihypertensive interventions showed some evidence of efficacy on a primary cognitive endpoint. However, most of these trials had short follow-up periods, and further evidence is needed to confirm effectiveness and establish the optimum design or dose of interventions and ideal target populations. Important innovations in ongoing trials include the development of multidomain interventions, and the use of biomarker or genetic inclusion criteria. Challenges include the use of adaptive trial designs, the development of standardised, sensitive outcome measures, and the need for interventions that can be implemented in resource-poor settings.
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Affiliation(s)
- Sandrine Andrieu
- Inserm UMR1027, F-31073, Toulouse, France; University Toulouse III, Toulouse, France; Department of Epidemiology and Public Health, CHU Toulouse, Toulouse, France.
| | - Nicola Coley
- Inserm UMR1027, F-31073, Toulouse, France; University Toulouse III, Toulouse, France; Department of Epidemiology and Public Health, CHU Toulouse, Toulouse, France
| | | | - Paul S Aisen
- Alzheimer's Therapeutic Research Institute, University of Southern California, San Diego, CA, USA
| | - Bruno Vellas
- Inserm UMR1027, F-31073, Toulouse, France; University Toulouse III, Toulouse, France; Department of Geriatric Medicine, CHU Toulouse, Toulouse, France
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Grimm MOW, Stahlmann CP, Mett J, Haupenthal VJ, Zimmer VC, Lehmann J, Hundsdörfer B, Endres K, Grimm HS, Hartmann T. Vitamin E: Curse or Benefit in Alzheimer's Disease? A Systematic Investigation of the Impact of α-, γ- and δ-Tocopherol on Aß Generation and Degradation in Neuroblastoma Cells. J Nutr Health Aging 2015; 19:646-56. [PMID: 26054501 DOI: 10.1007/s12603-015-0506-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES The E vitamins are a class of lipophilic compounds including tocopherols, which have high antioxidative properties. Because of the elevated lipid peroxidation and increased reactive oxidative species in Alzheimer's disease (AD) many attempts have been made to slow down the progression of AD by utilizing the antioxidative action of vitamin E. Beside the mixed results of these studies nothing is known about the impact of vitamin E on the mechanisms leading to amyloid-β production and degradation being responsible for the plaque formation, one of the characteristic pathological hallmarks in AD. Here we systematically investigate the influence of different tocopherols on Aβ production and degradation in neuronal cell lines. MEASUREMENTS Beside amyloid-β level the mechanisms leading to Aβ production and degradation are examined. RESULTS Surprisingly, all tocopherols have shown to increase Aβ level by enhancing the Aβ production and decreasing the Aβ degradation. Aβ production is enhanced by an elevated activity of the involved enzymes, the β- and γ-secretase. These secretases are not directly affected, but tocopherols increase their protein level and expression. We could identify significant differences between the single tocopherols; whereas α-tocopherol had only minor effects on Aβ production, δ-tocopherol showed the highest potency to increase Aβ generation. Beside Aβ production, Aβ clearance was decreased by affecting IDE, one of the major Aβ degrading enzymes. CONCLUSIONS Our results suggest that beside the beneficial antioxidative effects of vitamin E, tocopherol has in respect to AD also a potency to increase the amyloid-β level, which differ for the analysed tocopherols. We therefore recommend that further studies are needed to clarify the potential role of these various vitamin E species in respect to AD and to identify the form which comprises an antioxidative property without having an amyloidogenic potential.
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Affiliation(s)
- M O W Grimm
- Marcus Grimm, Kirrberger Str.1, Building 90.1, 66421 Homburg/Saar, Germany; Tel: +49-6841-1647919; Fax: +49-6841-1624137; E-mail:
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Jablonska E, Vinceti M. Selenium and Human Health: Witnessing a Copernican Revolution? JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2015; 33:328-68. [PMID: 26074278 DOI: 10.1080/10590501.2015.1055163] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.
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Affiliation(s)
- Ewa Jablonska
- a Department of Toxicology and Carcinogenesis , Nofer Institute of Occupational Medicine , Lodz , Poland
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Mechanism of Oxidative Stress and Synapse Dysfunction in the Pathogenesis of Alzheimer's Disease: Understanding the Therapeutics Strategies. Mol Neurobiol 2014; 53:648-661. [PMID: 25511446 DOI: 10.1007/s12035-014-9053-6] [Citation(s) in RCA: 311] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/28/2014] [Indexed: 10/24/2022]
Abstract
Synapses are formed by interneuronal connections that permit a neuronal cell to pass an electrical or chemical signal to another cell. This passage usually gets damaged or lost in most of the neurodegenerative diseases. It is widely believed that the synaptic dysfunction and synapse loss contribute to the cognitive deficits in patients with Alzheimer's disease (AD). Although pathological hallmarks of AD are senile plaques, neurofibrillary tangles, and neuronal degeneration which are associated with increased oxidative stress, synaptic loss is an early event in the pathogenesis of AD. The involvement of major kinases such as mitogen-activated protein kinase (MAPK), extracellular receptor kinase (ERK), calmodulin-dependent protein kinase (CaMKII), glycogen synthase-3β (GSK-3β), cAMP response element-binding protein (CREB), and calcineurin is dynamically associated with oxidative stress-mediated abnormal hyperphosphorylation of tau and suggests that alteration of these kinases could exclusively be involved in the pathogenesis of AD. N-methyl-D-aspartate (NMDA) receptor (NMDAR) activation and beta amyloid (Aβ) toxicity alter the synapse function, which is also associated with protein phosphatase (PP) inhibition and tau hyperphosphorylation (two main events of AD). However, the involvement of oxidative stress in synapse dysfunction is poorly understood. Oxidative stress and free radical generation in the brain along with excitotoxicity leads to neuronal cell death. It is inferred from several studies that excitotoxicity, free radical generation, and altered synaptic function encouraged by oxidative stress are associated with AD pathology. NMDARs maintain neuronal excitability, Ca(2+) influx, and memory formation through mechanisms of synaptic plasticity. Recently, we have reported the mechanism of the synapse redox stress associated with NMDARs altered expression. We suggest that oxidative stress mediated through NMDAR and their interaction with other molecules might be a driving force for tau hyperphosphorylation and synapse dysfunction. Thus, understanding the oxidative stress mechanism and degenerating synapses is crucial for the development of therapeutic strategies designed to prevent AD pathogenesis.
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Swaminathan A, Jicha GA. Nutrition and prevention of Alzheimer's dementia. Front Aging Neurosci 2014; 6:282. [PMID: 25368575 PMCID: PMC4202787 DOI: 10.3389/fnagi.2014.00282] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/25/2014] [Indexed: 11/13/2022] Open
Abstract
A nutritional approach to prevent, slow, or halt the progression of disease is a promising strategy that has been widely investigated. Much epidemiologic data suggests that nutritional intake may influence the development and progression of Alzheimer’s dementia (AD). Modifiable, environmental causes of AD include potential metabolic derangements caused by dietary insufficiency and or excess that may be corrected by nutritional supplementation and or dietary modification. Many nutritional supplements contain a myriad of health promoting constituents (anti-oxidants, vitamins, trace minerals, flavonoids, lipids, …etc.) that may have novel mechanisms of action affecting cellular health and regeneration, the aging process itself, or may specifically disrupt pathogenic pathways in the development of AD. Nutritional modifications have the advantage of being cost effective, easy to implement, socially acceptable and generally safe and devoid of significant adverse events in most cases. Many nutritional interventions have been studied and continue to be evaluated in hopes of finding a successful agent, combination of agents, or dietary modifications that can be used for the prevention and or treatment of AD. The current review focuses on several key nutritional compounds and dietary modifications that have been studied in humans, and further discusses the rationale underlying their potential utility for the prevention and treatment of AD.
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Affiliation(s)
- Arun Swaminathan
- Department of Neurology and Sanders-Brown Center on Aging, College of Medicine, University of Kentucky Lexington, KY, USA
| | - Gregory A Jicha
- Department of Neurology and Sanders-Brown Center on Aging, College of Medicine, University of Kentucky Lexington, KY, USA
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Di Domenico F, Barone E, Perluigi M, Butterfield DA. Strategy to reduce free radical species in Alzheimer’s disease: an update of selected antioxidants. Expert Rev Neurother 2014; 15:19-40. [DOI: 10.1586/14737175.2015.955853] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Solomon A, Mangialasche F, Richard E, Andrieu S, Bennett DA, Breteler M, Fratiglioni L, Hooshmand B, Khachaturian AS, Schneider LS, Skoog I, Kivipelto M. Advances in the prevention of Alzheimer's disease and dementia. J Intern Med 2014; 275:229-50. [PMID: 24605807 PMCID: PMC4390027 DOI: 10.1111/joim.12178] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Definitions and diagnostic criteria for all medical conditions are regularly subjected to reviews and revisions as knowledge advances. In the field of Alzheimer's disease (AD) research, it has taken almost three decades for diagnostic nomenclature to undergo major re-examination. The shift towards presymptomatic and pre-dementia stages of AD has brought prevention and treatment trials much closer to each other than before. METHODS Here we discuss: (i) the impact of diagnostic reliability on the possibilities for developing preventive strategies for AD; (ii) the scientific evidence to support moving from observation to action; (iii) ongoing intervention studies; and (iv) the methodological issues and prospects for balancing strategies for high-risk individuals with those for broad population-based prevention. RESULTS The associations between neuropathology and cognition are still not entirely clear. In addition, the risk factors for AD dementia and the neuropathological hallmarks of AD may not necessarily be the same. Cognitive impairment has a clearer clinical significance and should therefore remain the main focus of prevention. Risk/protective factors for dementia/AD need to be studied from a life-course perspective. New approaches in prevention trials include enrichment strategies based on genetic risk factors or beta-amyloid biomarkers (at least four ongoing pharmacological trials), and multidomain interventions simultaneously targeting various vascular and lifestyle-related risk factors (at least three ongoing trials). Experience from prevention programmes in other chronic diseases can provide additional methodological improvements. CONCLUSIONS Building infrastructures for international collaborations is necessary for managing the worldwide public health problem of AD and dementia. The International Database on Aging and Dementia (IDAD) and the European Dementia Prevention Initiative (EDPI) are examples of ongoing international efforts aiming to improve the methodology of preventive studies and provide the basis for larger intervention trials.
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Affiliation(s)
- Alina Solomon
- Karolinska Institutet Alzheimer Disease Research Center (KI-ADRC), Stockholm, Sweden
- Department of Neurology, University of Eastern Finland, Kuopio, Finland
| | - Francesca Mangialasche
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Edo Richard
- Department of Neurology, Academic Medical Centre, University of Amsterdam, The Netherlands
| | - Sandrine Andrieu
- Department of Epidemiology and Public Health, Toulouse University Hospital, Toulouse, France
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Monique Breteler
- German Center for Neurodegenerative Diseases (DZNE) and University of Bonn, Bonn, Germany
| | - Laura Fratiglioni
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Babak Hooshmand
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Ara S. Khachaturian
- Campaign to Prevent Alzheimer’s Disease by 2020 (PAD2020), Rockville, MD, USA
| | - Lon S. Schneider
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Ingmar Skoog
- Neuropsychiatric Epidemiology Research Unit, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
| | - Miia Kivipelto
- Karolinska Institutet Alzheimer Disease Research Center (KI-ADRC), Stockholm, Sweden
- Department of Neurology, University of Eastern Finland, Kuopio, Finland
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
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Schneider LS, Mangialasche F, Andreasen N, Feldman H, Giacobini E, Jones R, Mantua V, Mecocci P, Pani L, Winblad B, Kivipelto M. Clinical trials and late-stage drug development for Alzheimer's disease: an appraisal from 1984 to 2014. J Intern Med 2014; 275:251-83. [PMID: 24605808 PMCID: PMC3956752 DOI: 10.1111/joim.12191] [Citation(s) in RCA: 465] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The modern era of drug development for Alzheimer's disease began with the proposal of the cholinergic hypothesis of memory impairment and the 1984 research criteria for Alzheimer's disease. Since then, despite the evaluation of numerous potential treatments in clinical trials, only four cholinesterase inhibitors and memantine have shown sufficient safety and efficacy to allow marketing approval at an international level. Although this is probably because the other drugs tested were ineffective, inadequate clinical development methods have also been blamed for the failures. Here, we review the development of treatments for Alzheimer's disease during the past 30 years, considering the drugs, potential targets, late-stage clinical trials, development methods, emerging use of biomarkers and evolution of regulatory considerations in order to summarize advances and anticipate future developments. We have considered late-stage Alzheimer's disease drug development from 1984 to 2013, including individual clinical trials, systematic and qualitative reviews, meta-analyses, methods, commentaries, position papers and guidelines. We then review the evolution of drugs in late clinical development, methods, biomarkers and regulatory issues. Although a range of small molecules and biological products against many targets have been investigated in clinical trials, the predominant drug targets have been the cholinergic system and the amyloid cascade. Trial methods have evolved incrementally: inclusion criteria have largely remained focused on mild-to-moderate Alzheimer's disease criteria, recently extending to early or prodromal Alzheimer disease or 'mild cognitive impairment due to Alzheimer's disease', for drugs considered to be disease modifying. The duration of trials has remained at 6-12 months for drugs intended to improve symptoms; 18- to 24-month trials have been established for drugs expected to attenuate clinical course. Cognitive performance, activities of daily living, global change and severity ratings have persisted as the primary clinically relevant outcomes. Regulatory guidance and oversight have evolved to allow for enrichment of early-stage Alzheimer's disease trial samples using biomarkers and phase-specific outcomes. In conclusion, validated drug targets for Alzheimer's disease remain to be developed. Only drugs that affect an aspect of cholinergic function have shown consistent, but modest, clinical effects in late-phase trials. There is opportunity for substantial improvements in drug discovery and clinical development methods.
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Affiliation(s)
- Lon S. Schneider
- Departments of Psychiatry and the Behavioral Sciences, and Neurology, Keck School of Medicine, and the Leonard Davis School of Gerontology of the University of Southern California, Los Angeles, CA, USA
| | - Francesca Mangialasche
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Section of Gerontology and Geriatrics, University of Perugia, Perugia, Italy
| | - Niels Andreasen
- Department of Geriatric Medicine, Karolinska University Hospital, Huddinge, Sweden
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Howard Feldman
- Division of Neurology, University of British Columbia, Vancouver, Canada
| | - Ezio Giacobini
- Departments of Internal Medicine, Rehabilitation and Geriatrics, University of Geneva Hospitals, Geneva, Switzerland
| | - Roy Jones
- The Research Institute for the Care of Older People (RICE) and University of Bath, Bath, UK
| | - Valentina Mantua
- European Assessment Office, Italian Medicines Agency (AIFA), Rome, Italy
| | - Patrizia Mecocci
- Section of Gerontology and Geriatrics, University of Perugia, Perugia, Italy
| | - Luca Pani
- European Assessment Office, Italian Medicines Agency (AIFA), Rome, Italy
| | - Bengt Winblad
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Miia Kivipelto
- Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Alzheimer Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- Department of Neurology, University of Eastern Finland, Kuopio, Finland
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Oxidative stress in Alzheimer's disease: why did antioxidant therapy fail? OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:427318. [PMID: 24669288 PMCID: PMC3941783 DOI: 10.1155/2014/427318] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 12/06/2013] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly, with increasing prevalence and no disease-modifying treatment available yet. A remarkable amount of data supports the hypothesis that oxidative stress is an early and important pathogenic operator in AD. However, all clinical studies conducted to date did not prove a clear beneficial effect of antioxidant treatment in AD patients. In the current work, we review the current knowledge about oxidative stress in AD pathogeny and we suggest future paths that are worth to be explored in animal models and clinical studies, in order to get a better approach of oxidative imbalance in this inexorable neurodegenerative disease.
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Barberger-Gateau P, Samieri C, Feart C, Cunnane SC. Nutrition and Cognitive Decline in Older Persons: Bridging the Gap Between Epidemiology and Intervention Studies. PHARMA-NUTRITION 2014. [DOI: 10.1007/978-3-319-06151-1_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Ferry M, Coley N, Andrieu S, Bonhomme C, Caubère JP, Cesari M, Gautry J, Garcia Sanchez I, Hugonot L, Mansuy L, Pahor M, Pariente J, Ritz P, Salva A, Sijben J, Wieggers R, Ythier-Moury P, Zaïm M, Zetlaoui J, Vellas B. How to design nutritional intervention trials to slow cognitive decline in apparently healthy populations and apply for efficacy claims: a statement from the International Academy on Nutrition and Aging Task Force. J Nutr Health Aging 2013; 17:619-23. [PMID: 23933873 PMCID: PMC4312656 DOI: 10.1007/s12603-013-0350-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Interventions are crucial as they offer simple and inexpensive public health solutions that will be useful over the long term use. A Task Force on designing trials of nutritional interventions to slow cognitive decline in older adults was held in Toulouse in September 2012. The aim of the Task Force was to bring together leading experts from academia, the food industry and regulatory agencies to determine the best trial designs that would enable us to reach our goal of maintaining or improving cognitive function in apparently healthy aging people. An associated challenge for this Task Force was to determine the type of trials required by the Public Food Agencies for assessing the impact of nutritional compounds in comparison to well established requirements for drug trials. Although the required quality of the study design, rationale and statistical analysis remains the same, the studies designed to show reduction of cognitive decline require a long duration and the objectives of this task force was to determine best design for these trials. Two specific needs were identified to support trials of nutritional interventions: 1- Risk- reduction strategies are needed to tackle the growing burden of cognitive decline that may lead to dementia, 2- Innovative study designs are needed to improve the quality of these studies.
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Affiliation(s)
- M Ferry
- Nutritional Epidemiology Unit, Human Nutrition Research Center of Ile de France, UFR SMBH Paris 13, 75 rue Marcel Cachin, F-93017 Bobigny cedex, France.
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Weekley CM, Harris HH. Which form is that? The importance of selenium speciation and metabolism in the prevention and treatment of disease. Chem Soc Rev 2013; 42:8870-94. [DOI: 10.1039/c3cs60272a] [Citation(s) in RCA: 371] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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