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Mistry H, Richardson CD, Higginbottom A, Ashford B, Ahamed SU, Moore Z, Matthews FE, Brayne C, Simpson JE, Wharton SB. Relationships of brain cholesterol and cholesterol biosynthetic enzymes to Alzheimer's pathology and dementia in the CFAS population-derived neuropathology cohort. Neurosci Res 2024; 204:22-33. [PMID: 38278219 PMCID: PMC11192635 DOI: 10.1016/j.neures.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 01/05/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Altered cholesterol metabolism is implicated in brain ageing and Alzheimer's disease. We examined whether key genes regulating cholesterol metabolism and levels of brain cholesterol are altered in dementia and Alzheimer's disease neuropathological change (ADNC). Temporal cortex (n = 99) was obtained from the Cognitive Function and Ageing Study. Expression of the cholesterol biosynthesis rate-limiting enzyme HMG-CoA reductase (HMGCR) and its regulator, SREBP2, were detected using immunohistochemistry. Expression of HMGCR, SREBP2, CYP46A1 and ABCA1 were quantified by qPCR in samples enriched for astrocyte and neuronal RNA following laser-capture microdissection. Total cortical cholesterol was measured using the Amplex Red assay. HMGCR and SREBP2 proteins were predominantly expressed in pyramidal neurones, and in glia. Neuronal HMGCR did not vary with ADNC, oxidative stress, neuroinflammation or dementia status. Expression of HMGCR neuronal mRNA decreased with ADNC (p = 0.022) and increased with neuronal DNA damage (p = 0.049), whilst SREBP2 increased with ADNC (p = 0.005). High or moderate tertiles for cholesterol levels were associated with increased dementia risk (OR 1.44, 1.58). APOE ε4 allele was not associated with cortical cholesterol levels. ADNC is associated with gene expression changes that may impair cholesterol biosynthesis in neurones but not astrocytes, whilst levels of cortical cholesterol show a weak relationship to dementia status.
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Affiliation(s)
- Hemant Mistry
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Bridget Ashford
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Saif U Ahamed
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Zoe Moore
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Carol Brayne
- Cambridge Public Health, University of Cambridge, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK.
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Rajab MD, Taketa T, Wharton SB, Wang D. Ranking and filtering of neuropathology features in the machine learning evaluation of dementia studies. Brain Pathol 2024; 34:e13247. [PMID: 38374326 PMCID: PMC11189772 DOI: 10.1111/bpa.13247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Early diagnosis of dementia diseases, such as Alzheimer's disease, is difficult because of the time and resources needed to perform neuropsychological and pathological assessments. Given the increasing use of machine learning methods to evaluate neuropathology features in the brains of dementia patients, it is important to investigate how the selection of features may be impacted and which features are most important for the classification of dementia. We objectively assessed neuropathology features using machine learning techniques for filtering features in two independent ageing cohorts, the Cognitive Function and Aging Studies (CFAS) and Alzheimer's Disease Neuroimaging Initiative (ADNI). The reliefF and least loss methods were most consistent with their rankings between ADNI and CFAS; however, reliefF was most biassed by feature-feature correlations. Braak stage was consistently the highest ranked feature and its ranking was not correlated with other features, highlighting its unique importance. Using a smaller set of highly ranked features, rather than all features, can achieve a similar or better dementia classification performance in CFAS (60%-70% accuracy with Naïve Bayes). This study showed that specific neuropathology features can be prioritised by feature filtering methods, but they are impacted by feature-feature correlations and their results can vary between cohort studies. By understanding these biases, we can reduce discrepancies in feature ranking and identify a minimal set of features needed for accurate classification of dementia.
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Affiliation(s)
- Mohammed D. Rajab
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
- Department of Computer ScienceUniversity of SheffieldSheffieldUK
| | - Teruka Taketa
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - Stephen B. Wharton
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - Dennis Wang
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
- Department of Computer ScienceUniversity of SheffieldSheffieldUK
- Singapore Institute Clinical SciencesAgency for Science Technology and Research (A*STAR)SingaporeSingapore
- Bioinformatics InstituteAgency for Science Technology and Research (A*STAR)SingaporeSingapore
- National Heart and Lung InstituteImperial College LondonLondonUK
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Almansouri T, Waller R, Wharton SB, Heath PR, Matthews FE, Brayne C, van Eeden F, Simpson JE. The Microglial Transcriptome of Age-Associated Deep Subcortical White Matter Lesions Suggests a Neuroprotective Response to Blood-Brain Barrier Dysfunction. Int J Mol Sci 2024; 25:4445. [PMID: 38674030 PMCID: PMC11050386 DOI: 10.3390/ijms25084445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Age-associated deep-subcortical white matter lesions (DSCLs) are an independent risk factor for dementia, displaying high levels of CD68+ microglia. This study aimed to characterize the transcriptomic profile of microglia in DSCLs and surrounding radiologically normal-appearing white matter (NAWM) compared to non-lesional control white matter. CD68+ microglia were isolated from white matter groups (n = 4 cases per group) from the Cognitive Function and Ageing Study neuropathology cohort using immuno-laser capture microdissection. Microarray gene expression profiling, but not RNA-sequencing, was found to be compatible with immuno-LCM-ed post-mortem material in the CFAS cohort and identified significantly differentially expressed genes (DEGs). Functional grouping and pathway analysis were assessed using the Database for Annotation Visualization and Integrated Discovery (DAVID) software, and immunohistochemistry was performed to validate gene expression changes at the protein level. Transcriptomic profiling of microglia in DSCLs compared to non-lesional control white matter identified 181 significant DEGs (93 upregulated and 88 downregulated). Functional clustering analysis in DAVID revealed dysregulation of haptoglobin-haemoglobin binding (Enrichment score 2.5, p = 0.017), confirmed using CD163 immunostaining, suggesting a neuroprotective microglial response to blood-brain barrier dysfunction in DSCLs. In NAWM versus control white matter, microglia exhibited 347 DEGs (209 upregulated, 138 downregulated), with significant dysregulation of protein de-ubiquitination (Enrichment score 5.14, p < 0.001), implying an inability to maintain protein homeostasis in NAWM that may contribute to lesion spread. These findings enhance understanding of microglial transcriptomic changes in ageing white matter pathology, highlighting a neuroprotective adaptation in DSCLs microglia and a potentially lesion-promoting phenotype in NAWM microglia.
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Affiliation(s)
- Taghreed Almansouri
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK; (T.A.); (R.W.); (S.B.W.); (P.R.H.)
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Rachel Waller
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK; (T.A.); (R.W.); (S.B.W.); (P.R.H.)
| | - Stephen B. Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK; (T.A.); (R.W.); (S.B.W.); (P.R.H.)
| | - Paul R. Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK; (T.A.); (R.W.); (S.B.W.); (P.R.H.)
| | - Fiona E. Matthews
- Institute for Clinical and Applied Health Research, University of Hull, Hull HU6 7RX, UK;
| | - Carol Brayne
- Department of Psychiatry, University of Cambridge, Cambridge CB2 3EG, UK;
| | | | - Julie E. Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK; (T.A.); (R.W.); (S.B.W.); (P.R.H.)
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Wharton SB, Simpson JE, Ince PG, Richardson CD, Merrick R, Matthews FE, Brayne C. Insights into the pathological basis of dementia from population-based neuropathology studies. Neuropathol Appl Neurobiol 2023; 49:e12923. [PMID: 37462105 PMCID: PMC10946587 DOI: 10.1111/nan.12923] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/29/2023] [Indexed: 08/17/2023]
Abstract
The epidemiological neuropathology perspective of population and community-based studies allows unbiased assessment of the prevalence of various pathologies and their relationships to late-life dementia. In addition, this approach provides complementary insights to conventional case-control studies, which tend to be more representative of a younger clinical cohort. The Cognitive Function and Ageing Study (CFAS) is a longitudinal study of cognitive impairment and frailty in the general United Kingdom population. In this review, we provide an overview of the major findings from CFAS, alongside other studies, which have demonstrated a high prevalence of pathology in the ageing brain, particularly Alzheimer's disease neuropathological change and vascular pathology. Increasing burdens of these pathologies are the major correlates of dementia, especially neurofibrillary tangles, but there is substantial overlap in pathology between those with and without dementia, particularly at intermediate burdens of pathology and also at the oldest ages. Furthermore, additional pathologies such as limbic-predominant age-related TDP-43 encephalopathy, ageing-related tau astrogliopathy and primary age-related tauopathies contribute to late-life dementia. Findings from ageing population-representative studies have implications for the understanding of dementia pathology in the community. The high prevalence of pathology and variable relationship to dementia status has implications for disease definition and indicate a role for modulating factors on cognitive outcome. The complexity of late-life dementia, with mixed pathologies, indicates a need for a better understanding of these processes across the life-course to direct the best research for reducing risk in later life of avoidable clinical dementia syndromes.
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Affiliation(s)
- Stephen B. Wharton
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - Julie E. Simpson
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | - Paul G. Ince
- Sheffield Institute for Translational NeuroscienceUniversity of SheffieldSheffieldUK
| | | | - Richard Merrick
- Cambridge Public Health, School of Clinical MedicineUniversity of CambridgeSheffieldUK
| | | | - Carol Brayne
- Cambridge Public Health, School of Clinical MedicineUniversity of CambridgeSheffieldUK
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Rajab MD, Jammeh E, Taketa T, Brayne C, Matthews FE, Su L, Ince PG, Wharton SB, Wang D. Assessment of Alzheimer-related pathologies of dementia using machine learning feature selection. Alzheimers Res Ther 2023; 15:47. [PMID: 36895019 PMCID: PMC9999590 DOI: 10.1186/s13195-023-01195-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 02/20/2023] [Indexed: 03/11/2023]
Abstract
Although a variety of brain lesions may contribute to the pathological assessment of dementia, the relationship of these lesions to dementia, how they interact and how to quantify them remains uncertain. Systematically assessing neuropathological measures by their degree of association with dementia may lead to better diagnostic systems and treatment targets. This study aims to apply machine learning approaches to feature selection in order to identify critical features of Alzheimer-related pathologies associated with dementia. We applied machine learning techniques for feature ranking and classification to objectively compare neuropathological features and their relationship to dementia status during life using a cohort (n=186) from the Cognitive Function and Ageing Study (CFAS). We first tested Alzheimer's Disease and tau markers and then other neuropathologies associated with dementia. Seven feature ranking methods using different information criteria consistently ranked 22 out of the 34 neuropathology features for importance to dementia classification. Although highly correlated, Braak neurofibrillary tangle stage, beta-amyloid and cerebral amyloid angiopathy features were ranked the highest. The best-performing dementia classifier using the top eight neuropathological features achieved 79% sensitivity, 69% specificity and 75% precision. However, when assessing all seven classifiers and the 22 ranked features, a substantial proportion (40.4%) of dementia cases was consistently misclassified. These results highlight the benefits of using machine learning to identify critical indices of plaque, tangle and cerebral amyloid angiopathy burdens that may be useful for classifying dementia.
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Affiliation(s)
- Mohammed D Rajab
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
- Department of Computer Science, University of Sheffield, Sheffield, S1 4DP, UK
| | - Emmanuel Jammeh
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Teruka Taketa
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | | | - Fiona E Matthews
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Li Su
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SP, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
| | - Dennis Wang
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK.
- Department of Computer Science, University of Sheffield, Sheffield, S1 4DP, UK.
- Singapore Institute for Clinical Sciences, A*STAR, Singapore, 117609, Singapore.
- National Heart and Lung Institute, Imperial College London, London, SW3 6LY, UK.
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6
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Nichols E, Merrick R, Hay SI, Himali D, Himali JJ, Hunter S, Keage HAD, Latimer CS, Scott MR, Steinmetz JD, Walker JM, Wharton SB, Wiedner CD, Crane PK, Keene CD, Launer LJ, Matthews FE, Schneider J, Seshadri S, White L, Brayne C, Vos T. The prevalence, correlation, and co-occurrence of neuropathology in old age: harmonisation of 12 measures across six community-based autopsy studies of dementia. THE LANCET. HEALTHY LONGEVITY 2023; 4:e115-e125. [PMID: 36870337 PMCID: PMC9977689 DOI: 10.1016/s2666-7568(23)00019-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND Population-based autopsy studies provide valuable insights into the causes of dementia but are limited by sample size and restriction to specific populations. Harmonisation across studies increases statistical power and allows meaningful comparisons between studies. We aimed to harmonise neuropathology measures across studies and assess the prevalence, correlation, and co-occurrence of neuropathologies in the ageing population. METHODS We combined data from six community-based autopsy cohorts in the US and the UK in a coordinated cross-sectional analysis. Among all decedents aged 80 years or older, we assessed 12 neuropathologies known to be associated with dementia: arteriolosclerosis, atherosclerosis, macroinfarcts, microinfarcts, lacunes, cerebral amyloid angiopathy, Braak neurofibrillary tangle stage, Consortium to Establish a Registry for Alzheimer's disease (CERAD) diffuse plaque score, CERAD neuritic plaque score, hippocampal sclerosis, limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and Lewy body pathology. We divided measures into three groups describing level of confidence (low, moderate, and high) in harmonisation. We described the prevalence, correlations, and co-occurrence of neuropathologies. FINDINGS The cohorts included 4354 decedents aged 80 years or older with autopsy data. All cohorts included more women than men, with the exception of one study that only included men, and all cohorts included decedents at older ages (range of mean age at death across cohorts 88·0-91·6 years). Measures of Alzheimer's disease neuropathological change, Braak stage and CERAD scores, were in the high confidence category, whereas measures of vascular neuropathologies were in the low (arterioloscerosis, atherosclerosis, cerebral amyloid angiopathy, and lacunes) or moderate (macroinfarcts and microinfarcts) categories. Neuropathology prevalence and co-occurrence was high (2443 [91%] of 2695 participants had more than one of six key neuropathologies and 1106 [41%] of 2695 had three or more). Co-occurrence was strongly but not deterministically associated with dementia status. Vascular and Alzheimer's disease features clustered separately in correlation analyses, and LATE-NC had moderate associations with Alzheimer's disease measures (eg, Braak stage ρ=0·31 [95% CI 0·20-0·42]). INTERPRETATION Higher variability and more inconsistency in the measurement of vascular neuropathologies compared with the measurement of Alzheimer's disease neuropathological change suggests the development of new frameworks for the measurement of vascular neuropathologies might be helpful. Results highlight the complexity and multi-morbidity of the brain pathologies that underlie dementia in older adults and suggest that prevention efforts and treatments should be multifaceted. FUNDING Gates Ventures.
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Affiliation(s)
- Emma Nichols
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
| | - Richard Merrick
- Cambridge Public Health, University of Cambridge, Cambridge, UK
| | - Simon I Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Jayandra J Himali
- Framingham Heart Study, Framingham, MA, USA; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, UT Health San Antonio, San Antonio, TX, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Sally Hunter
- Cambridge Public Health, University of Cambridge, Cambridge, UK
| | - Hannah A D Keage
- Cognitive Ageing and Impairment Neurosciences Lab, Justice and Society, University of South Australia, Adelaide, SA, Australia
| | - Caitlin S Latimer
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, USA
| | - Matthew R Scott
- Framingham Heart Study, Framingham, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Jaimie D Steinmetz
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | - Jamie M Walker
- Department of Pathology, Molecular and Cell Based Medicine, Icahn School of Medicine at Mt Sinai, New York, NY, USA
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Crystal D Wiedner
- Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, UT Health San Antonio, San Antonio, TX, USA
| | - Paul K Crane
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - C Dirk Keene
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, USA
| | - Lenore J Launer
- Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA
| | - Fiona E Matthews
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Julie Schneider
- Rush Alzheimer's Disease Center, Chicago, IL, USA; Rush University Medical Center, Chicago, IL, USA
| | - Sudha Seshadri
- Framingham Heart Study, Framingham, MA, USA; Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, UT Health San Antonio, San Antonio, TX, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Lon White
- Pacific Health Research and Education Institute, Honolulu, HI, USA
| | - Carol Brayne
- Cambridge Public Health, University of Cambridge, Cambridge, UK
| | - Theo Vos
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
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Lehmann DJ, Elshorbagy A, Hurley MJ. Many Paths to Alzheimer's Disease: A Unifying Hypothesis Integrating Biological, Chemical, and Physical Risk Factors. J Alzheimers Dis 2023; 95:1371-1382. [PMID: 37694367 DOI: 10.3233/jad-230295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Sporadic Alzheimer's disease (AD) is a complex, multifactorial disease. We should therefore expect to find many factors involved in its causation. The known neuropathology seen at autopsy in patients dying with AD is not consistently seen in all patients with AD and is sometimes seen in patients without dementia. This suggests that patients follow different paths to AD, with different people having slightly different combinations of predisposing physical, chemical and biologic risk factors, and varying neuropathology. This review summarizes what is known of the biologic and chemical predisposing factors and features in AD. We postulate that, underlying the neuropathology of AD is a progressive failure of neurons, with advancing age or other morbidity, to rid themselves of entropy, i.e., the disordered state resulting from brain metabolism. Understanding the diverse causes of AD may allow the development of new therapies targeted at blocking the paths that lead to dementia in each subset of patients.
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Affiliation(s)
- Donald J Lehmann
- Oxford Project to Investigate Memory and Ageing (OPTIMA), Department of Pharmacology, University of Oxford, Oxford, UK
| | - Amany Elshorbagy
- Department of Pharmacology, University of Oxford, Oxford, UK
- Department of Physiology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Michael J Hurley
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
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Nelson PT, Brayne C, Flanagan ME, Abner EL, Agrawal S, Attems J, Castellani RJ, Corrada MM, Cykowski MD, Di J, Dickson DW, Dugger BN, Ervin JF, Fleming J, Graff-Radford J, Grinberg LT, Hokkanen SRK, Hunter S, Kapasi A, Kawas CH, Keage HAD, Keene CD, Kero M, Knopman DS, Kouri N, Kovacs GG, Labuzan SA, Larson EB, Latimer CS, Leite REP, Matchett BJ, Matthews FE, Merrick R, Montine TJ, Murray ME, Myllykangas L, Nag S, Nelson RS, Neltner JH, Nguyen AT, Petersen RC, Polvikoski T, Reichard RR, Rodriguez RD, Suemoto CK, Wang SHJ, Wharton SB, White L, Schneider JA. Frequency of LATE neuropathologic change across the spectrum of Alzheimer's disease neuropathology: combined data from 13 community-based or population-based autopsy cohorts. Acta Neuropathol 2022; 144:27-44. [PMID: 35697880 PMCID: PMC9552938 DOI: 10.1007/s00401-022-02444-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/04/2022] [Accepted: 05/22/2022] [Indexed: 02/02/2023]
Abstract
Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) and Alzheimer's disease neuropathologic change (ADNC) are each associated with substantial cognitive impairment in aging populations. However, the prevalence of LATE-NC across the full range of ADNC remains uncertain. To address this knowledge gap, neuropathologic, genetic, and clinical data were compiled from 13 high-quality community- and population-based longitudinal studies. Participants were recruited from United States (8 cohorts, including one focusing on Japanese-American men), United Kingdom (2 cohorts), Brazil, Austria, and Finland. The total number of participants included was 6196, and the average age of death was 88.1 years. Not all data were available on each individual and there were differences between the cohorts in study designs and the amount of missing data. Among those with known cognitive status before death (n = 5665), 43.0% were cognitively normal, 14.9% had MCI, and 42.4% had dementia-broadly consistent with epidemiologic data in this age group. Approximately 99% of participants (n = 6125) had available CERAD neuritic amyloid plaque score data. In this subsample, 39.4% had autopsy-confirmed LATE-NC of any stage. Among brains with "frequent" neuritic amyloid plaques, 54.9% had comorbid LATE-NC, whereas in brains with no detected neuritic amyloid plaques, 27.0% had LATE-NC. Data on LATE-NC stages were available for 3803 participants, of which 25% had LATE-NC stage > 1 (associated with cognitive impairment). In the subset of individuals with Thal Aβ phase = 0 (lacking detectable Aβ plaques), the brains with LATE-NC had relatively more severe primary age-related tauopathy (PART). A total of 3267 participants had available clinical data relevant to frontotemporal dementia (FTD), and none were given the clinical diagnosis of definite FTD nor the pathological diagnosis of frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). In the 10 cohorts with detailed neurocognitive assessments proximal to death, cognition tended to be worse with LATE-NC across the full spectrum of ADNC severity. This study provided a credible estimate of the current prevalence of LATE-NC in advanced age. LATE-NC was seen in almost 40% of participants and often, but not always, coexisted with Alzheimer's disease neuropathology.
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Affiliation(s)
- Peter T Nelson
- University of Kentucky, Rm 311 Sanders-Brown Center on Aging, Lexington, KY, USA.
| | | | | | - Erin L Abner
- University of Kentucky, Rm 311 Sanders-Brown Center on Aging, Lexington, KY, USA
| | | | | | | | | | | | - Jing Di
- University of Kentucky, Rm 311 Sanders-Brown Center on Aging, Lexington, KY, USA
| | | | | | | | | | | | - Lea T Grinberg
- University of California, San Francisco, CA, USA
- University of Sao Paulo Medical School, Sao Paulo, Brazil
| | | | | | | | | | | | | | - Mia Kero
- University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | | | - Gabor G Kovacs
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Laboratory Medicine Program, University Health Network, Toronto, ON, Canada
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | | | - Eric B Larson
- Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
| | | | | | | | | | | | | | | | - Liisa Myllykangas
- University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sukriti Nag
- Rush University Medical Center, Chicago, IL, USA
| | | | - Janna H Neltner
- University of Kentucky, Rm 311 Sanders-Brown Center on Aging, Lexington, KY, USA
| | | | | | | | | | | | | | | | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - Lon White
- Pacific Health Research and Education Institute, Honolulu, HI, USA
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Romero K, Ladyka-Wojcik N, Heir A, Bellana B, Leach L, Proulx GB. The Influence of Cerebrovascular Pathology on Cluster Analysis of Neuropsychological Scores in Patients With Mild Cognitive Impairment. Arch Clin Neuropsychol 2022; 37:1480-1492. [PMID: 35772970 DOI: 10.1093/arclin/acac043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The diagnostic entity of mild cognitive impairment (MCI) is heterogeneous, highlighting the need for data-driven classification approaches to identify patient subgroups. However, these approaches can be strongly determined by sample characteristics and selected measures. Here, we applied a cluster analysis to an MCI patient database from a neuropsychology clinic to determine whether the inclusion of patients with MCI with vascular pathology would result in a different classification of subgroups. METHODS Participants diagnosed with MCI (n = 166), vascular cognitive impairment-no dementia (n = 26), and a group of older adults with subjective cognitive concerns but no objective impairment (n = 144) were assessed using a full neuropsychological battery and other clinical measures. Cognitive measures were analyzed using a hierarchical cluster analysis and then a k-means approach, with resulting clusters compared on a range of demographic and clinical variables. RESULTS We found a 4-factor solution: a cognitively intact cluster, a globally impaired cluster, an amnestic/visuospatial impairment cluster, and a mild, mixed-domain cluster. Interestingly, group differences in self-reported multilingualism emerged in the derived clusters that were not observed when comparing diagnostic groups. CONCLUSIONS Our results were generally consistent with previous studies using cluster analysis in MCI. Including patients with primarily cerebrovascular disease resulted in subtle differences in the derived clusters and revealed new insights into shared cognitive profiles of patients beyond diagnostic categories. These profiles should be further explored to develop individualized assessment and treatment approaches.
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Affiliation(s)
| | | | - Arjan Heir
- Department of Psychology, York University Glendon Campus
| | | | - Larry Leach
- Department of Psychology, York University Glendon Campus
| | - Guy B Proulx
- Department of Psychology, York University Glendon Campus
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10
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Brayne C, Wu YT. Population-Based Studies in Dementia and Ageing Research: A Local and National Experience in Cambridgeshire and the UK. Am J Alzheimers Dis Other Demen 2022; 37:15333175221104347. [PMID: 36000966 PMCID: PMC10581148 DOI: 10.1177/15333175221104347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Dementia has been recognised as a key challenge in many ageing societies across the world. Several population-based studies have been developed to investigate dementia and cognitive ageing from perspectives of biology, health, psychology and social sciences. However, there is a need to provide a better understanding of 'contexts', the circumstance where these ageing populations existed, and heterogeneity within and across the populations in different time and places. In this article, we summarise some examples of earlier population-based studies undertaken by our research groups in England and Wales and their contribution to the epidemiology of dementia, neuropathology, cognitive and mental health in older age. We also describe how these studies illustrated variation among ageing populations and changes in their health conditions across time and place. These findings highlight the contribution that population-based studies can make, along with the vital to incorporate contexts in ageing research. A lifecourse approach within social context is needed to integrate life experiences, social circumstances, and multiple dimensions of cognition, functioning, physical health and wellbeing over the ageing process. We also discuss how evidence from population-based studies can support various international initiatives on dementia, healthy ageing and Sustainable Development Goals and facilitate tailored approaches for diverse populations across global societies.
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Affiliation(s)
- Carol Brayne
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Yu-Tzu Wu
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, UK
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11
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Griffa A, Legdeur N, Badissi M, van den Heuvel MP, Stam CJ, Visser PJ, Hillebrand A. Magnetoencephalography Brain Signatures Relate to Cognition and Cognitive Reserve in the Oldest-Old: The EMIF-AD 90 + Study. Front Aging Neurosci 2021; 13:746373. [PMID: 34899269 PMCID: PMC8656941 DOI: 10.3389/fnagi.2021.746373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/01/2021] [Indexed: 11/25/2022] Open
Abstract
The oldest-old subjects represent the fastest growing segment of society and are at high risk for dementia with a prevalence of up to 40%. Lifestyle factors, such as lifelong participation in cognitive and leisure activities, may contribute to individual cognitive reserve and reduce the risk for cognitive impairments. However, the neural bases underlying cognitive functioning and cognitive reserve in this age range are still poorly understood. Here, we investigate spectral and functional connectivity features obtained from resting-state MEG recordings in a cohort of 35 cognitively normal (92.2 ± 1.8 years old, 19 women) and 11 cognitively impaired (90.9 ± 1.9 years old, 1 woman) oldest-old participants, in relation to cognitive traits and cognitive reserve. The latter was approximated with a self-reported scale on lifelong engagement in cognitively demanding activities. Cognitively impaired oldest-old participants had slower cortical rhythms in frontal, parietal and default mode network regions compared to the cognitively normal subjects. These alterations mainly concerned the theta and beta band and partially explained inter-subject variability of episodic memory scores. Moreover, a distinct spectral pattern characterized by higher relative power in the alpha band was specifically associated with higher cognitive reserve while taking into account the effect of age and education level. Finally, stronger functional connectivity in the alpha and beta band were weakly associated with better cognitive performances in the whole group of subjects, although functional connectivity effects were less prominent than the spectral ones. Our results shed new light on the neural underpinnings of cognitive functioning in the oldest-old population and indicate that cognitive performance and cognitive reserve may have distinct spectral electrophysiological substrates.
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Affiliation(s)
- Alessandra Griffa
- Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals and Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Center of Neuroprosthetics, Institute of Bioengineering, École Polytechnique Fédérale De Lausanne (EPFL), Geneva, Switzerland.,Department of Clinical Neurophysiology and MEG Center, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Nienke Legdeur
- Department of Neurology, Amsterdam Neuroscience, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Maryam Badissi
- Department of Neurology, Amsterdam Neuroscience, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Martijn P van den Heuvel
- Dutch Connectome Lab, Department of Complex Trait Genetics, Center for Neuroscience and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Cornelis J Stam
- Department of Clinical Neurophysiology and MEG Center, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Pieter Jelle Visser
- Department of Neurology, Amsterdam Neuroscience, Alzheimer Center Amsterdam, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands.,Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Arjan Hillebrand
- Department of Clinical Neurophysiology and MEG Center, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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12
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Peng S, Roth AR, Perry BL. A latent variable approach to measuring bridging social capital and examining its association to older adults' cognitive health. Soc Neurosci 2021; 16:684-694. [PMID: 34727017 DOI: 10.1080/17470919.2021.2001368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Access to cognitive stimulation through social interactions is a key mechanism used to explain the association between personal networks, cognitive health, and brain structure in older adults. However, little research has assessed how best to operationalize access to novel or diverse social stimuli using social network measures, many of which were designed to study information diffusion within large whole networks (e.g., structural holes and bridging social capital). Using data from 277 adults in the Social Networks and Alzheimer Disease (SNAD) study, we aimed to evaluate such measures for use in research on cognitive aging using personal social networks. We found a positive association between individual measures of structural holes and cognitive health, but not with brain structure. Further, we extracted a latent measure of bridging social capital using multiple individual measures (i.e., structural holes, network diversity, weak ties, and network size) and found it was significantly associated with cognitive health and brain structure, supporting the utility of this concept and related measures in the study of cognitive aging. Finally, individual measures may underestimate the effects of multidimensional bridging social capital on cognitive health and brain structure compared to a latent measure that combines them.
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Affiliation(s)
- Siyun Peng
- Department of Sociology, Indiana University, Bloomington, IN, USA
| | - Adam R Roth
- Department of Sociology & Network Science Institute, Indiana University
| | - Brea L Perry
- Department of Sociology & Network Science Institute, Indiana University
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13
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Ellmerich S, Taylor GW, Richardson CD, Minett T, Schmidt AF, Brayne C, Matthews FE, Ince PG, Wharton SB, Pepys MB. Dementia in the older population is associated with neocortex content of serum amyloid P component. Brain Commun 2021; 3:fcab225. [PMID: 34671726 PMCID: PMC8523881 DOI: 10.1093/braincomms/fcab225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/10/2021] [Accepted: 07/15/2021] [Indexed: 11/30/2022] Open
Abstract
Despite many reported associations, the direct cause of neurodegeneration responsible for cognitive loss in Alzheimer’s disease and some other common dementias is not known. The normal human plasma protein, serum amyloid P component, a constituent of all human fibrillar amyloid deposits and present on most neurofibrillary tangles, is cytotoxic for cerebral neurones in vitro and in experimental animals in vivo. The neocortical content of serum amyloid P component was immunoassayed in 157 subjects aged 65 or more with known dementia status at death, in the large scale, population-representative, brain donor cohort of the Cognitive Function and Ageing Study, which avoids the biases inherent in studies of predefined clinico-pathological groups. The serum amyloid P component values were significantly higher in individuals with dementia, independent of serum albumin content measured as a control for plasma in the cortex samples. The odds ratio for dementia at death in the high serum amyloid P component tertile was 5.24 (95% confidence interval 1.79–15.29) and was independent of Braak tangle stages and Thal amyloid-β phases of neuropathological severity. The strong and specific association of higher brain content of serum amyloid P component with dementia, independent of neuropathology, is consistent with a pathogenetic role in dementia.
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Affiliation(s)
- Stephan Ellmerich
- Wolfson Drug Discovery Unit, UCL Royal Free Campus, London NW3 2PF, UK
| | - Graham W Taylor
- Wolfson Drug Discovery Unit, UCL Royal Free Campus, London NW3 2PF, UK
| | - Connor D Richardson
- Population Health Sciences Institute; Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Thais Minett
- Department of Radiology, Cambridge Biomedical Research Centre, University of Cambridge, Cambridge CB2 0QQ, UK
| | | | | | - Fiona E Matthews
- Population Health Sciences Institute; Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Mark B Pepys
- Wolfson Drug Discovery Unit, UCL Royal Free Campus, London NW3 2PF, UK
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14
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Hussain B, Fang C, Chang J. Blood-Brain Barrier Breakdown: An Emerging Biomarker of Cognitive Impairment in Normal Aging and Dementia. Front Neurosci 2021; 15:688090. [PMID: 34489623 PMCID: PMC8418300 DOI: 10.3389/fnins.2021.688090] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/14/2021] [Indexed: 12/11/2022] Open
Abstract
The blood–brain barrier (BBB) plays a vital role in maintaining the specialized microenvironment of the neural tissue. It separates the peripheral circulatory system from the brain parenchyma while facilitating communication. Alterations in the distinct physiological properties of the BBB lead to BBB breakdown associated with normal aging and various neurodegenerative diseases. In this review, we first briefly discuss the aging process, then review the phenotypes and mechanisms of BBB breakdown associated with normal aging that further cause neurodegeneration and cognitive impairments. We also summarize dementia such as Alzheimer's disease (AD) and vascular dementia (VaD) and subsequently discuss the phenotypes and mechanisms of BBB disruption in dementia correlated with cognition decline. Overlaps between AD and VaD are also discussed. Techniques that could identify biomarkers associated with BBB breakdown are briefly summarized. Finally, we concluded that BBB breakdown could be used as an emerging biomarker to assist to diagnose cognitive impairment associated with normal aging and dementia.
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Affiliation(s)
- Basharat Hussain
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cheng Fang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Junlei Chang
- Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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15
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Leaston J, Ferris CF, Kulkarni P, Chandramohan D, van de Ven AL, Qiao J, Timms L, Sepulcre J, El Fakhri G, Ma C, Normandin MD, Gharagouzloo C. Neurovascular imaging with QUTE-CE MRI in APOE4 rats reveals early vascular abnormalities. PLoS One 2021; 16:e0256749. [PMID: 34449808 PMCID: PMC8396782 DOI: 10.1371/journal.pone.0256749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/13/2021] [Indexed: 11/19/2022] Open
Abstract
Cerebrovascular abnormality is linked to Alzheimer's disease and related dementias (ADRDs). ApoE-Ɛ4 (APOE4) is known to play a critical role in neurovascular dysfunction, however current medical imaging technologies are limited in quantification. This cross-sectional study tested the feasibility of a recently established imaging modality, quantitative ultra-short time-to-echo contrast-enhanced magnetic resonance imaging (QUTE-CE MRI), to identify small vessel abnormality early in development of human APOE4 knock-in female rat (TGRA8960) animal model. At 8 months, 48.3% of the brain volume was found to have significant signal increase (75/173 anatomically segmented regions; q<0.05 for multiple comparisons). Notably, vascular abnormality was detected in the tri-synaptic circuit, cerebellum, and amygdala, all of which are known to functionally decline throughout AD pathology and have implications in learning and memory. The detected abnormality quantified with QUTE-CE MRI is likely a result of hyper-vascularization, but may also be partly, or wholly, due to contributions from blood-brain-barrier leakage. Further exploration with histological validation is warranted to verify the pathological cause. Regardless, these results indicate that QUTE-CE MRI can detect neurovascular dysfunction with high sensitivity with APOE4 and may be helpful to provide new insights into health and disease.
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Affiliation(s)
- Joshua Leaston
- Imaginostics, Inc., Cambridge, Massachusetts, United States of America
| | - Craig F. Ferris
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
| | - Praveen Kulkarni
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
| | | | - Anne L. van de Ven
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Ju Qiao
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Liam Timms
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
- Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts, United States of America
| | - Jorge Sepulcre
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chao Ma
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marc D. Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Codi Gharagouzloo
- Imaginostics, Inc., Cambridge, Massachusetts, United States of America
- Department of Psychology, Northeastern University, Boston, Massachusetts, United States of America
- Center for Translational Neuroimaging, Northeastern University, Boston, Massachusetts, United States of America
- Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
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16
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Emrani S, Lamar M, Price CC, Wasserman V, Matusz E, Au R, Swenson R, Nagele R, Heilman KM, Libon DJ. Alzheimer's/Vascular Spectrum Dementia: Classification in Addition to Diagnosis. J Alzheimers Dis 2021; 73:63-71. [PMID: 31815693 DOI: 10.3233/jad-190654] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) and vascular dementia (VaD) are the two most common types of dementia. Although the combination of these disorders, called 'mixed' dementia, is recognized, the prevailing clinical and research perspective continues to consider AD and VaD as independent disorders. A review of recent neuropathological and neuropsychological literature reveals that these two disorders frequently co-occur and so-called 'pure' AD or VaD is comparatively rare. In addition, recent research shows that vascular dysfunction not only potentiates AD pathology, but that pathological changes in AD may subsequently induce vascular disorders. On the basis of these data, we propose that the neurobiological underpinnings underlying AD/VaD dementia and their neuropsychological phenotypes are best understood as existing along a clinical/pathological continuum or spectrum. We further propose that in conjunction with current diagnostic criteria, statistical modeling techniques using neuropsychological test performance should be leveraged to construct a system to classify AD/VaD spectrum dementia in order to test hypotheses regarding how mechanisms related to AD and VaD pathology interact and influence each other.
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Affiliation(s)
- Sheina Emrani
- Department of Psychology, Rowan University, Glassboro, NJ, USA
| | - Melissa Lamar
- Department of Behavioral Sciences and the Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Catherine C Price
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | | | - Emily Matusz
- New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
| | - Rhoda Au
- Department of Anatomy and Neurobiology, Neurology, Epidemiology, Boston University Schools of Medicine & Public Health, Boston, MA, USA
| | - Rodney Swenson
- Clinical Professor in the Department of Psychiatry and Behavioral Science at the University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Robert Nagele
- New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
| | - Kenneth M Heilman
- Department of Neurology, Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Center for Cognitive Aging and Memory - Clinical Translational Research Program, and Center for Neuropsychological Studies, University of Florida, Gainseville, FL, USA
| | - David J Libon
- Department of Psychology, Rowan University, Glassboro, NJ, USA.,New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
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17
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Chambers A, Bury JJ, Minett T, Richardson CD, Brayne C, Ince PG, Shaw PJ, Garwood CJ, Heath PR, Simpson JE, Matthews FE, Wharton SB. Advanced Glycation End Product Formation in Human Cerebral Cortex Increases With Alzheimer-Type Neuropathologic Changes but Is Not Independently Associated With Dementia in a Population-Derived Aging Brain Cohort. J Neuropathol Exp Neurol 2021; 79:950-958. [PMID: 32766675 DOI: 10.1093/jnen/nlaa064] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/12/2020] [Accepted: 06/09/2020] [Indexed: 12/11/2022] Open
Abstract
Diabetes mellitus is a risk factor for dementia, and nonenzymatic glycosylation of macromolecules results in formation of advanced glycation end-products (AGEs). We determined the variation in AGE formation in brains from the Cognitive Function and Ageing Study population-representative neuropathology cohort. AGEs were measured on temporal neocortex by enzyme-linked immunosorbent assay (ELISA) and cell-type specific expression on neurons, astrocytes and endothelium was detected by immunohistochemistry and assessed semiquantitatively. Fifteen percent of the cohort had self-reported diabetes, which was not significantly associated with dementia status at death or neuropathology measures. AGEs were expressed on neurons, astrocytes and endothelium and overall expression showed a positively skewed distribution in the population. AGE measures were not significantly associated with dementia. AGE measured by ELISA increased with Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neurofibrillary tangle score (p = 0.03) and Thal Aβ phase (p = 0.04), while AGE expression on neurons (and astrocytes), detected immunohistochemically, increased with increasing Braak tangle stage (p < 0.001), CERAD tangle score (p = 0.002), and neuritic plaques (p = 0.01). Measures of AGE did not show significant associations with cerebral amyloid angiopathy, microinfarcts or neuroinflammation. In conclusion, AGE expression increases with Alzheimer's neuropathology, particular later stages but is not independently associated with dementia. AGE formation is likely to be important for impaired brain cell function in aging and Alzheimer's.
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Affiliation(s)
- Annabelle Chambers
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Joanna J Bury
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Thais Minett
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Connor D Richardson
- Population Health Sciences Institute, University of Newcastle, Newcastle, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Fiona E Matthews
- Population Health Sciences Institute, University of Newcastle, Newcastle, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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18
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Waller R, Narramore R, Simpson JE, Heath PR, Verma N, Tinsley M, Barnes JR, Haris HT, Henderson FE, Matthews FE, Richardson CD, Brayne C, Ince PG, Kalaria RN, Wharton SB. Heterogeneity of cellular inflammatory responses in ageing white matter and relationship to Alzheimer's and small vessel disease pathologies. Brain Pathol 2021; 31:e12928. [PMID: 33336479 PMCID: PMC8412112 DOI: 10.1111/bpa.12928] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/18/2022] Open
Abstract
White matter lesions (WML) are common in the ageing brain, often arising in a field effect of diffuse white matter abnormality. Although WML are associated with cerebral small vessel disease (SVD) and Alzheimer’s disease (AD), their cause and pathogenesis remain unclear. The current study tested the hypothesis that different patterns of neuroinflammation are associated with SVD compared to AD neuropathology by assessing the immunoreactive profile of the microglial (CD68, IBA1 and MHC‐II) and astrocyte (GFAP) markers in ageing parietal white matter (PARWM) obtained from the Cognitive Function and Ageing Study (CFAS), an ageing population‐representative neuropathology cohort. Glial responses varied extensively across the PARWM with microglial markers significantly higher in the subventricular region compared to either the middle‐zone (CD68 p = 0.028, IBA1 p < 0.001, MHC‐II p < 0.001) or subcortical region (CD68 p = 0.002, IBA1 p < 0.001, MHC‐II p < 0.001). Clasmatodendritic (CD) GFAP+ astrocytes significantly increased from the subcortical to the subventricular region (p < 0.001), whilst GFAP+ stellate astrocytes significantly decreased (p < 0.001). Cellular reactions could be grouped into two distinct patterns: an immune response associated with MHC‐II/IBA1 expression and CD astrocytes; and a more innate response characterised by CD68 expression associated with WML. White matter neuroinflammation showed weak relationships to the measures of SVD, but not to the measures of AD neuropathology. In conclusion, glial responses vary extensively across the PARWM with diverse patterns of white matter neuroinflammation. Although these findings support a role for vascular factors in the pathogenesis of age‐related white matter neuroinflammation, additional factors other than SVD and AD pathology may drive this. Understanding the heterogeneity in white matter neuroinflammation will be important for the therapeutic targeting of age‐associated white matter damage.
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Affiliation(s)
- Rachel Waller
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Ruth Narramore
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Nikita Verma
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Megan Tinsley
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Jordan R Barnes
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Hanna T Haris
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Frances E Henderson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Fiona E Matthews
- Translational and Clinical Research Institute, University of Newcastle, Newcastle upon Tyne, UK
| | - Connor D Richardson
- Translational and Clinical Research Institute, University of Newcastle, Newcastle upon Tyne, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Raj N Kalaria
- Translational and Clinical Research Institute, University of Newcastle, Newcastle upon Tyne, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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19
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Bury JJ, Chambers A, Heath PR, Ince PG, Shaw PJ, Matthews FE, Brayne C, Simpson JE, Wharton SB. Type 2 diabetes mellitus-associated transcriptome alterations in cortical neurones and associated neurovascular unit cells in the ageing brain. Acta Neuropathol Commun 2021; 9:5. [PMID: 33407907 PMCID: PMC7788898 DOI: 10.1186/s40478-020-01109-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022] Open
Abstract
Type 2 diabetes mellitus (T2D), characterised by peripheral insulin resistance, is a risk factor for dementia. In addition to its contribution to small and large vessel disease, T2D may directly damage cells of the brain neurovascular unit. In this study, we investigated the transcriptomic changes in cortical neurones, and associated astrocytes and endothelial cells of the neurovascular unit, in the ageing brain. Neurone, astrocyte, and endothelial cell-enriched mRNA, obtained by immuno-laser capture microdissection of temporal cortex (Brodmann area 21/22) from 6 cases with self-reported T2D in the Cognitive Function and Ageing Study neuropathology cohort, and an equal number of age and sex-matched controls, was assessed by microarray analysis. Integrated Molecular Pathway Level Analysis was performed using the Kyoto Encyclopaedia of Genes and Genomes database on significantly differentially expressed genes, defined as P < 0.05 and fold-change ± 1.2. Hub genes identified from Weighted Gene Co-expression Network Analysis were validated in neurones using the NanoString nCounter platform. The expression and cellular localisation of proteins encoded by selected candidate genes were confirmed by immunohistochemistry. 912, 2202, and 1227 genes were significantly differentially expressed between cases with self-reported T2D and controls in neurones, astrocytes, and endothelial cells respectively. Changes in cortical neurones included alterations in insulin and other signalling pathways, cell cycle, cellular senescence, inflammatory mediators, and components of the mitochondrial respiratory electron transport chain. Impaired insulin signalling was shared by neurovascular unit cells with, additionally, apoptotic pathway changes in astrocytes and dysregulation of advanced glycation end-product signalling in endothelial cells. Transcriptomic analysis identified changes in key cellular pathways associated with T2D that may contribute to neuronal damage and dysfunction. These effects on brain cells potentially contribute to a diabetic dementia, and may provide novel approaches for therapeutic intervention.
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Affiliation(s)
- Joanna J Bury
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Annabelle Chambers
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Fiona E Matthews
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK.
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20
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Evans IEM, Martyr A, Collins R, Brayne C, Clare L. Social Isolation and Cognitive Function in Later Life: A Systematic Review and Meta-Analysis. J Alzheimers Dis 2020; 70:S119-S144. [PMID: 30372678 PMCID: PMC6700717 DOI: 10.3233/jad-180501] [Citation(s) in RCA: 237] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND There is some evidence to suggest that social isolation may be associated with poor cognitive function in later life. However, findings are inconsistent and there is wide variation in the measures used to assess social isolation. OBJECTIVE We conducted a systematic review and meta-analysis to investigate the association between social isolation and cognitive function in later life. METHODS A search for longitudinal studies assessing the relationship between aspects of social isolation (including social activity and social networks) and cognitive function (including global measures of cognition, memory, and executive function) was conducted in PsycInfo, CINAHL, PubMed, and AgeLine. A random effects meta-analysis was conducted to assess the overall association between measures of social isolation and cognitive function. Sub-analyses investigated the association between different aspects of social isolation and each of the measures of cognitive function. RESULTS Sixty-five articles were identified by the systematic review and 51 articles were included in the meta-analysis. Low levels of social isolation characterized by high engagement in social activity and large social networks were associated with better late-life cognitive function (r = 0.054, 95% CI: 0.043, 0.065). Sub-analyses suggested that the association between social isolation and measures of global cognitive function, memory, and executive function were similar and there was no difference according to gender or number of years follow-up. CONCLUSIONS Aspects of social isolation are associated with cognitive function in later life. There is wide variation in approaches to measuring social activity and social networks across studies which may contribute to inconsistencies in reported findings.
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Affiliation(s)
- Isobel E M Evans
- Centre for Research in Ageing and Cognitive Health (REACH), School of Psychology, University of Exeter, Exeter, UK
| | - Anthony Martyr
- Centre for Research in Ageing and Cognitive Health (REACH), School of Psychology, University of Exeter, Exeter, UK
| | - Rachel Collins
- Centre for Research in Ageing and Cognitive Health (REACH), School of Psychology, University of Exeter, Exeter, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Linda Clare
- Centre for Research in Ageing and Cognitive Health (REACH), School of Psychology, University of Exeter, Exeter, UK.,University of Exeter Medical School, Exeter, UK.,Wellcome Centre for Cultures and Environments of Health, University of Exeter, Exeter, UK.,Centre for Research Excellence in Promoting Cognitive Health, University of New South Wales, Sydney, Australia
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21
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Scheifele HM, Ulbrich P, Garz C, Carare RO, Heinze HJ, Schreiber S, Jandke S. Retinal Vascular Pathology in a Rat Model of Cerebral Small Vessel Disease. Front Neurol 2020; 11:533. [PMID: 32695061 PMCID: PMC7338761 DOI: 10.3389/fneur.2020.00533] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/13/2020] [Indexed: 01/26/2023] Open
Abstract
Introduction: The initial disease stages of hypertensive arteriopathy (HA) and cerebral amyloid angiopathy (CAA), the two main forms of sporadic human cerebral small vessel diseases (CSVD), are too subtle to be detectable on clinical routine imaging. Small vessel disease (SVD) is a systemic condition, affecting not only the brain, but also other organs. The retina appears as an ideal marker for the early detection of incipient CSVD. We therefore investigated the retinal microvasculature of the spontaneously hypertensive stroke-prone rat (SHRSP), an animal model of sporadic CSVD. Materials and Methods: The brains and retinas of 26 male SHRSP (18–44 weeks) were examined histologically and immunohistochemically for the presence of HA phenomena (erythrocyte thrombi, small perivascular bleeds) and amyloid angiopathy (AA). Results: CAA and AA in the retina showed a significant correlation with age (CAA: rho = 0.55, p = 0.005; AA: rho = 0.89, p < 0.001). The number of erythrocyte thrombi in the brain correlated with the severity of retinal erythrocyte thrombi (rho = 0.46, p = 0.023), while the occurrence of CAA correlated with the appearance of AA in the retina (rho = 0.51, p = 0.012). Retinal SVD markers predicted CSVD markers with good sensitivity. Conclusions: These results indicate that SVD also occurs in the retinal microvasculature of SHRSP and the prediction of cerebral erythrocyte thrombi and CAA might be possible using retinal biomarkers. This underlines the important role of the investigation of the retina in the early diagnosis of CSVD.
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Affiliation(s)
- Heinrich Maximilian Scheifele
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany
| | - Philipp Ulbrich
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany
| | - Cornelia Garz
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | | | - Hans-Jochen Heinze
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany.,Department of Behavioral Neurology, Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | - Stefanie Schreiber
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany
| | - Solveig Jandke
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases (DZNE) Within the Helmholtz Association, Magdeburg, Germany
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22
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Abstract
SUMMARYThis is an overview of epidemiology relevant to mental health problems in old age. We start by reviewing some basic terminology: the definitions of prevalence and incidence; the difference between descriptive and analytical epidemiology; the differences between study designs, including cross-sectional, case–control and cohort studies. We then cover the main epidemiological features of the major psychiatric diseases that affect older people (dementia and its different types, depression, late-onset schizophrenia, bipolar affective disorder, delirium, anxiety-related disorders, eating disorders, alcohol and substance misuse, personality disorders) and suicide.We end with some descriptive statistics regarding quality of life in older people.
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23
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NDRG2 Expression Correlates with Neurofibrillary Tangles and Microglial Pathology in the Ageing Brain. Int J Mol Sci 2020; 21:ijms21010340. [PMID: 31947996 PMCID: PMC6982267 DOI: 10.3390/ijms21010340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/02/2020] [Indexed: 11/17/2022] Open
Abstract
Astrocytes play a major role in the pathogenesis of a range of neurodegenerative diseases, including Alzheimer’s disease (AD), undergoing dramatic morphological and molecular changes that can cause potentially both beneficial and detrimental effects. They comprise a heterogeneous population, requiring a panel of specific phenotype markers to identify astrocyte subtypes, changes in function and their relation to pathology. This study aimed to characterise expression of the astrocyte marker N-myc downstream regulated gene 2 (NDRG2) in the ageing brain, investigate the relationship between NDRG2 and a panel of astrocyte markers, and relate NDRG2 expression to pathology. NDRG2 specifically immunolabelled the cell body and radiating processes of astrocytes in the temporal cortex of the Cognitive Function and Ageing Study (CFAS) neuropathology cohort. Expression of NDRG2 did not correlate with other astrocyte markers, including glial fibrillary acidic protein (GFAP), excitatory amino acid transporter 2 (EAAT2) and glutamine synthetase (GS). NDRG2 showed a relationship to AT8+ neurofibrillary tangles (p = 0.001) and CD68+ microglia (p = 0.047), but not β-amyloid plaques or astrocyte nuclear γH2AX immunoreactivity, a marker of DNA damage response. These findings provide new insight into the astrocyte response to pathology in the ageing brain, and suggest NDRG2 may be a potential target to modulate this response.
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24
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Wharton SB, Wang D, Parikh C, Matthews FE, Brayne C, Ince PG. Epidemiological pathology of Aβ deposition in the ageing brain in CFAS: addition of multiple Aβ-derived measures does not improve dementia assessment using logistic regression and machine learning approaches. Acta Neuropathol Commun 2019; 7:198. [PMID: 31806014 PMCID: PMC6896261 DOI: 10.1186/s40478-019-0858-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 02/03/2023] Open
Abstract
Aβ-amyloid deposition is a key feature of Alzheimer’s disease, but Consortium to Establish a Registry for Alzheimer's Disease (CERAD) assessment, based on neuritic plaque density, shows a limited relationships to dementia. Thal phase is based on a neuroanatomical hierarchy of Aβ-deposition, and in combination with Braak neurofibrillary tangle staging also allows derivation of primary age-related tauopathy (PART). We sought to determine whether Thal Aβ phase predicts dementia better than CERAD in a population-representative cohort (n = 186) derived from the Cognitive Function and Ageing Study (CFAS). Cerebral amyloid angiopathy (CAA) was quantitied as the number of neuroanatomical areas involved and cases meeting criteria for PART were defined to determine if they are a distinct pathological group within the ageing population. Agreement with the Thal scheme was excellent. In univariate analysis Thal phase performed less well as a predictor of dementia than CERAD, Braak or CAA. Logistic regression, decision tree and linear discriminant analysis were performed for multivariable analysis, with similar results. Thal phase did not provide a better explanation of dementia than CERAD, and there was no additional benefit to including more than one assessment of Aβ in the model. Number of areas involved by CAA was highly correlated with assessment based on a severity score (p < 0.001). The presence of capillary involvement (CAA type I) was associated with higher Thal phase and Braak stage (p < 0.001). CAA was not associated with microinfarcts (p = 0.1). Cases satisfying pathological criteria for PART were present at a frequency of 10.2% but were not older and did not have a higher likelihood of dementia than a comparison group of individuals with similar Braak stage but with more Aβ. They also did not have higher hippocampal-tau stage, although PART was weakly associated with increased presence of thorn-shaped astrocytes (p = 0.048), suggesting common age-related mechanisms. Thal phase is highly applicable in a population-representative setting and allows definition of pathological subgroups, such as PART. Thal phase, plaque density, and extent and type of CAA measure different aspects of Aβ pathology, but addition of more than one Aβ measure does not improve dementia prediction, probably because these variables are highly correlated. Machine learning predictions reveal the importance of combining neuropathological measurements for the assessment of dementia.
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25
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Waller R, Murphy M, Garwood CJ, Jennings L, Heath PR, Chambers A, Matthews FE, Brayne C, Ince PG, Wharton SB, Simpson JE. Metallothionein‐I/II expression associates with the astrocyte DNA damage response and not Alzheimer‐type pathology in the aging brain. Glia 2018; 66:2316-2323. [DOI: 10.1002/glia.23465] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/11/2018] [Accepted: 05/15/2018] [Indexed: 01/13/2023]
Affiliation(s)
- Rachel Waller
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Mark Murphy
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Claire J Garwood
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Luke Jennings
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Paul R Heath
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Annabelle Chambers
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Fiona E Matthews
- MRC Biostatistics UnitUniversity of Cambridge Cambridge United Kingdom
- Institute of Health and SocietyUniversity of Newcastle Newcastle United Kingdom
| | - Carol Brayne
- Institute of Public HealthUniversity of Cambridge Cambridge United Kingdom
| | - Paul G Ince
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Stephen B Wharton
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
| | - Julie E Simpson
- Sheffield Institute for Translational NeuroscienceUniversity of Sheffield Sheffield United Kingdom
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26
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Hunter S, Smailagic N, Brayne C. Dementia Research: Populations, Progress, Problems, and Predictions. J Alzheimers Dis 2018; 64:S119-S143. [DOI: 10.3233/jad-179927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sally Hunter
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Nadja Smailagic
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
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27
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Garwood CJ, Ratcliffe LE, Simpson JE, Heath PR, Ince PG, Wharton SB. Review: Astrocytes in Alzheimer's disease and other age-associated dementias: a supporting player with a central role. Neuropathol Appl Neurobiol 2018; 43:281-298. [PMID: 27442752 DOI: 10.1111/nan.12338] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 07/15/2016] [Accepted: 07/21/2016] [Indexed: 12/12/2022]
Abstract
Astrocytes have essential roles in the central nervous system and are also implicated in the pathogenesis of neurodegenerative disease. Forming non-overlapping domains, astrocytes are highly complex cells. Immunohistochemistry to a variety of proteins can be used to study astrocytes in tissue, labelling different cellular components and sub-populations, including glial fibrillary acidic protein, ALDH1L1, CD44, NDRG2 and amino acid transporters, but none of these labels the entire astrocyte population. Increasing heterogeneity is recognized in the astrocyte population, a complexity that is relevant both to their normal function and pathogenic roles. They are involved in neuronal support, as active components of the tripartite synapse and in cell interactions within the neurovascular unit (NVU), where they are essential for blood-brain barrier maintenance and neurovascular coupling. Astrocytes change with age, and their responses may modulate the cellular effects of neurodegenerative pathologies, which alone do not explain all of the variance in statistical models of neurodegenerative dementias. Astrocytes respond to both the neurofibrillary tangles and plaques of Alzheimer's disease, to hyperphosphorylated tau and Aβ, eliciting an effect which may be neuroprotective or deleterious. Not only astrocyte hypertrophy, in the form of gliosis, occurs, but also astrocyte injury and atrophy. Loss of normal astrocyte functions may contribute to reduced support for neurones and dysfunction of the NVU. Understanding how astrocytes contribute to dementia requires an understanding of the underlying heterogeneity of astrocyte populations, and the complexity of their responses to pathology. Enhancing the supportive and neuroprotective components of the astrocyte response has potential translational applications in therapeutic approaches to dementia.
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Affiliation(s)
- C J Garwood
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - L E Ratcliffe
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - J E Simpson
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - P R Heath
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - P G Ince
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
| | - S B Wharton
- Sheffield Institute for Translational Neuroscience, Sheffield, UK
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28
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Tariq S, Barber PA. Dementia risk and prevention by targeting modifiable vascular risk factors. J Neurochem 2017; 144:565-581. [PMID: 28734089 DOI: 10.1111/jnc.14132] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/23/2017] [Accepted: 07/15/2017] [Indexed: 01/04/2023]
Abstract
The incidence of dementia is expected to double in the next 20 years and will contribute to heavy social and economic burden. Dementia is caused by neuronal loss that leads to brain atrophy years before symptoms manifest. Currently, no cure exists and extensive efforts are being made to mitigate cognitive impairment in late life in order to reduce the burden on patients, caregivers, and society. The most common type of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) often co-exists in the brain and shares common, modifiable risk factors, which are targeted in numerous secondary prevention trials. There is a growing need for non-pharmacological interventions and infrastructural support from governments to encourage psychosocial and behavioral interventions. Secondary prevention trials need to be redesigned based on the risk profile of individual subjects, which require the use of validated and standardized clinical, biological, and neuroimaging biomarkers. Multi-domain approaches have been proposed in high-risk populations that target optimal treatment; clinical trials need to recruit individuals at the highest risk of dementia before symptoms develop, thereby identifying an enriched disease group to test preventative and disease modifying strategies. The underlying aim should be to reduce microscopic brain tissue loss by modifying vascular and lifestyle risk factors over a relatively short period of time, thus optimizing the opportunity for preventing dementia in the future. Collaboration between international research groups is of key importance to the optimal use and allocation of existing resources, and the development of new techniques in preventing dementia. This article is part of the Special Issue "Vascular Dementia".
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Affiliation(s)
- Sana Tariq
- Seaman Family MR Center, Foothills Medical Centre, Calgary, AB, Canada.,Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, Calgary, AB, Canada
| | - Philip A Barber
- Hotchkiss Brain Institute, Foothills Medical Center, Room 1A10 Health Research Innovation Center, Calgary, AB, Canada.,Calgary Stroke Program, Department of Clinical Neurosciences, Foothills Medical Centre, Calgary, AB, Canada
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29
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Carvalho C, Moreira PI. Isolation of Rodent Brain Vessels. Bio Protoc 2017; 7:e2535. [PMID: 34541191 PMCID: PMC8413598 DOI: 10.21769/bioprotoc.2535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/02/2017] [Accepted: 08/21/2017] [Indexed: 11/02/2022] Open
Abstract
The prevalence of neurodegenerative diseases is increasing worldwide. Cerebrovascular disorders and/or conditions known to affect brain vasculature, such as diabetes, are well-known risk factors for neurodegenerative diseases. Thus, the evaluation of the brain vasculature is of great importance to better understand the mechanisms underlying brain damage. We established a protocol for the isolation of brain vessels from rodents. This is a simple, non-enzymatic isolation protocol that allows us to perform comparative studies in different animal models of disease, helping understand the impact of several pathological conditions on brain vasculature and how those alterations predispose to neurodegenerative conditions.
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Affiliation(s)
- Cristina Carvalho
- CNC–Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Paula I. Moreira
- CNC–Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Laboratory of Physiology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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30
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Davey DA. Prevention of Alzheimer's disease, cerebrovascular disease and dementia in women: the case for menopause hormone therapy. Neurodegener Dis Manag 2017; 7:85-94. [PMID: 28074678 DOI: 10.2217/nmt-2016-0044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease, cerebrovascular disease and aging-related cognitive impairment and dementia (ARCID) increase in prevalence in women with advancing age. The development of Alzheimer's disease, cerebrovascular disease and ARCID may be postponed or prevented by protective measures including the active treatment of vascular risk factors and continuing exercise and healthy lifestyle from early- and mid-life onward. Bilateral oophorectomy before the natural menopause is associated with an increased incidence of ARCID and the increased risk is significantly reduced by estrogen therapy. Recent advances in menopause hormone therapy including transdermal estrogen therapy have favorably influenced the balance of benefits and risks. A case can be made for menopause hormone therapy in healthy postmenopausal women for 5-10 years starting during the menopausal transition (the 'window of opportunity'), together with all other protective measures, to delay or prevent the development of ARCID in later life.
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Affiliation(s)
- Dennis A Davey
- Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Western Cape 7925, South Africa
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31
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Zhou W, Baughman BD, Soman S, Wintermark M, Lazzeroni LC, Hitchner E, Bhat J, Rosen A. Volume of subclinical embolic infarct correlates to long-term cognitive changes after carotid revascularization. J Vasc Surg 2016; 65:686-694. [PMID: 28024850 DOI: 10.1016/j.jvs.2016.09.057] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/22/2016] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Carotid intervention is safe and effective in stroke prevention in appropriately selected patients. Despite minimal neurologic complications, procedure-related subclinical microemboli are common and their cognitive effects are largely unknown. In this prospective longitudinal study, we sought to determine long-term cognitive effects of embolic infarcts. METHODS The study recruited 119 patients including 46% symptomatic patients who underwent carotid revascularization. Neuropsychological testing was administered preoperatively and at 1 month, 6 months, and 12 months postoperatively. Rey Auditory Verbal Learning Test (RAVLT) was the primary cognitive measure with parallel forms to avoid practice effect. All patients also received 3T brain magnetic resonance imaging with a diffusion-weighted imaging (DWI) sequence preoperatively and within 48 hours postoperatively to identify procedure-related new embolic lesions. Each DWI lesion was manually traced and input into a neuroimaging program to define volume. Embolic infarct volumes were correlated with cognitive measures. Regression models were used to identify relationships between infarct volumes and cognitive measures. RESULTS A total of 587 DWI lesions were identified on 3T magnetic resonance imaging in 81.7% of carotid artery stenting (CAS) and 36.4% of carotid endarterectomy patients with a total volume of 29,327 mm3. Among them, 54 DWI lesions were found in carotid endarterectomy patients and 533 in the CAS patients. Four patients had transient postoperative neurologic symptoms and one had a stroke. CAS was an independent predictor of embolic infarction (odds ratio, 6.6 [2.1-20.4]; P < .01) and infarct volume (P = .004). Diabetes and contralateral carotid severe stenosis or occlusion had a trend of positive association with infarct volume, whereas systolic blood pressure ≥140 mm Hg had a negative association (P = .1, .09, and .1, respectively). There was a trend of improved RAVLT scores overall after carotid revascularization. Significantly higher infarct volumes were observed among those with RAVLT decline. Within the CAS cohort, infarct volume was negatively correlated with short- and long-term RAVLT changes (P < .05). CONCLUSIONS Cognitive assessment of procedure-related subclinical microemboli is challenging. Volumes of embolic infarct correlate with long-term cognitive changes, suggesting that microembolization should be considered a surrogate measure for carotid disease management.
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Affiliation(s)
- Wei Zhou
- Vascular Surgery, VA Palo Alto Health Care System, Palo Alto, Calif; Department of Surgery, Stanford University, Stanford, Calif.
| | | | - Salil Soman
- Department of Radiology, Harvard Medical School, Cambridge, Mass
| | - Max Wintermark
- Department of Radiology, Stanford University, Stanford, Calif
| | - Laura C Lazzeroni
- Department of Psychiatry and Behavior Science, Stanford University, Stanford, Calif
| | | | - Jyoti Bhat
- Department of Psychiatry, VA Palo Alto Health Care System, Palo Alto, Calif
| | - Allyson Rosen
- Department of Psychiatry and Behavior Science, Stanford University, Stanford, Calif; Department of Psychiatry, VA Palo Alto Health Care System, Palo Alto, Calif
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32
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Harrison JK, Van Der Wardt V, Conroy SP, Stott DJ, Dening T, Gordon AL, Logan P, Welsh TJ, Taggar J, Harwood R, Gladman JRF. New horizons: the management of hypertension in people with dementia. Age Ageing 2016; 45:740-746. [PMID: 27836926 DOI: 10.1093/ageing/afw155] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/03/2016] [Indexed: 12/13/2022] Open
Abstract
The optimal management of hypertension in people with dementia is uncertain. This review explores if people with dementia experience greater adverse effects from antihypertensive medications, if cognitive function is protected or worsened by controlling blood pressure (BP) and if there are subgroups of people with dementia for whom antihypertensive therapy is more likely to be harmful. Robust evidence is scant, trials of antihypertensive medications have generally excluded those with dementia. Observational data show changes in risk association over the life course, with high BP being a risk factor for cognitive decline in mid-life, while low BP is predictive in later life. It is therefore possible that excessive BP lowering in older people with dementia might harm cognition. From the existing literature, there is no direct evidence of benefit or harm from treating hypertension in people with dementia. So what practical steps can the clinician take? Assess capacity, establish patient preferences when making treatment decisions, use ambulatory monitoring to thoroughly assess BP, individualise and consider deprescribing where side effects (e.g. hypotension) outweigh the benefits. Future research might include pragmatic randomised trials of targeted deprescribing, which include patient-centred outcome measures to help support decision-making and studies to address mechanistic uncertainties.
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Affiliation(s)
- Jennifer Kirsty Harrison
- The Alzheimer Scotland Dementia Research Centre, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
| | | | - Simon Paul Conroy
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - David J Stott
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Tom Dening
- Division of Psychiatry and Applied Psychology, University of Nottingham, Nottingham, UK
| | - Adam Lee Gordon
- University of Nottingham - Division of Medical Sciences and Graduate Entry Medicine, Nottingham, UK
| | - Pip Logan
- Division of Rehabilitation & Ageing, University of Nottingham, Nottingham, UK
| | - Tomas James Welsh
- Division of Rehabilitation & Ageing, University of Nottingham, Nottingham, UK
| | - Jaspal Taggar
- Division of Primary Care, University of Nottingham, Nottingham, UK
| | - Rowan Harwood
- Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - John R F Gladman
- Division of Rehabilitation & Ageing, University of Nottingham, Nottingham, UK
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33
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Wolz R, Schwarz AJ, Gray KR, Yu P, Hill DLG. Enrichment of clinical trials in MCI due to AD using markers of amyloid and neurodegeneration. Neurology 2016; 87:1235-41. [PMID: 27558378 PMCID: PMC5035986 DOI: 10.1212/wnl.0000000000003126] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/07/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate the effect of enriching mild cognitive impairment (MCI) clinical trials using combined markers of amyloid pathology and neurodegeneration. METHODS We evaluate an implementation of the recent National Institute for Aging-Alzheimer's Association (NIA-AA) diagnostic criteria for MCI due to Alzheimer disease (AD) as inclusion criteria in clinical trials and assess the effect of enrichment with amyloid (A+), neurodegeneration (N+), and their combination (A+N+) on the rate of clinical progression, required sample sizes, and estimates of trial time and cost. RESULTS Enrichment based on an individual marker (A+ or N+) substantially improves all assessed trial characteristics. Combined enrichment (A+N+) further improves these results with a reduction in required sample sizes by 45% to 60%, depending on the endpoint. CONCLUSIONS Operationalizing the NIA-AA diagnostic criteria for clinical trial screening has the potential to substantially improve the statistical power of trials in MCI due to AD by identifying a more rapidly progressing patient population.
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Affiliation(s)
- Robin Wolz
- From IXICO Plc (R.W., K.R.G., D.L.G.H.), London, UK; Department of Computing (R.W., K.R.G.,), Imperial College London, UK; Eli Lilly and Company (A.J.S., P.Y.), Indianapolis, IN; Department of Psychology and Brain Sciences (A.J.S.), Indiana University, Bloomington; and Department of Radiology and Imaging Sciences (A.J.S.), Indiana University School of Medicine, Indianapolis.
| | - Adam J Schwarz
- From IXICO Plc (R.W., K.R.G., D.L.G.H.), London, UK; Department of Computing (R.W., K.R.G.,), Imperial College London, UK; Eli Lilly and Company (A.J.S., P.Y.), Indianapolis, IN; Department of Psychology and Brain Sciences (A.J.S.), Indiana University, Bloomington; and Department of Radiology and Imaging Sciences (A.J.S.), Indiana University School of Medicine, Indianapolis
| | - Katherine R Gray
- From IXICO Plc (R.W., K.R.G., D.L.G.H.), London, UK; Department of Computing (R.W., K.R.G.,), Imperial College London, UK; Eli Lilly and Company (A.J.S., P.Y.), Indianapolis, IN; Department of Psychology and Brain Sciences (A.J.S.), Indiana University, Bloomington; and Department of Radiology and Imaging Sciences (A.J.S.), Indiana University School of Medicine, Indianapolis
| | - Peng Yu
- From IXICO Plc (R.W., K.R.G., D.L.G.H.), London, UK; Department of Computing (R.W., K.R.G.,), Imperial College London, UK; Eli Lilly and Company (A.J.S., P.Y.), Indianapolis, IN; Department of Psychology and Brain Sciences (A.J.S.), Indiana University, Bloomington; and Department of Radiology and Imaging Sciences (A.J.S.), Indiana University School of Medicine, Indianapolis
| | - Derek L G Hill
- From IXICO Plc (R.W., K.R.G., D.L.G.H.), London, UK; Department of Computing (R.W., K.R.G.,), Imperial College London, UK; Eli Lilly and Company (A.J.S., P.Y.), Indianapolis, IN; Department of Psychology and Brain Sciences (A.J.S.), Indiana University, Bloomington; and Department of Radiology and Imaging Sciences (A.J.S.), Indiana University School of Medicine, Indianapolis
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Price CC, Tanner JJ, Schmalfuss IM, Brumback B, Heilman KM, Libon DJ. Dissociating Statistically-Determined Alzheimer's Disease/Vascular Dementia Neuropsychological Syndromes Using White and Gray Neuroradiological Parameters. J Alzheimers Dis 2016; 48:833-47. [PMID: 26402109 DOI: 10.3233/jad-150407] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND There is remarkable heterogeneity in clinical Alzheimer's disease (AD) or vascular dementia (VaD). OBJECTIVES 1) To statistically examine neuropsychological data to determine dementia subgroups for individuals clinically diagnosed with AD or VaD and then 2) examine group differences in specific gray/white matter regions of interest. METHODS A k-means cluster analysis requested a 3-group solution from neuropsychological data acquired from individuals diagnosed clinically with AD/VaD. MRI measures of hippocampal, caudate, ventricular, subcortical lacunar infarction, whole brain volume, and leukoaraiosis (LA) were analyzed. Three regions of LA volumes were quantified and these included the periventricular (5 mm around the ventricles), infracortical (5 mm beneath the gray matter), and deep (between periventricular and infracortical) regions. RESULTS Cluster analysis sorted AD/VaD patients into single domain amnestic (n = 41), single-domain dysexecutive (n = 26), and multi-domain (n = 26) phenotypes. Multi-domain patients exhibited worst performance on language tests; however, multi-domain patients were equally impaired on memory tests when compared to amnestic patients. Statistically-determined groups dissociated using neuroradiological parameters: amnestic and multi-domain groups presented with smaller hippocampal volume while the dysexecutive group presented with greater deep, periventricular, and whole brain LA. Neither caudate nor lacunae volume differed by group. Caudate nucleus volume negatively correlated with total LA in the dysexecutive and multi-domain groups. CONCLUSIONS There are at least three distinct subtypes embedded within patients diagnosed clinically with AD/VaD spectrum dementia. We encourage future research to assess a) the neuroradiological substrates underlying statistically-determined AD/VaD spectrum dementia and b) how statistical modeling can be integrated into existing diagnostic criteria.
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Affiliation(s)
- Catherine C Price
- Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA
| | - Jared J Tanner
- Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA
| | - Ilona M Schmalfuss
- Department of Radiology, University of Florida, Gainesville, Florida, USA.,Department of Radiology, North Florida/South Georgia Veteran Administration, Gainesville, Florida, USA
| | - Babette Brumback
- Department of Biostatistics, University of Florida, Gainesville, Florida, USA
| | - Kenneth M Heilman
- Department of Neurology, University of Florida, Gainesville, Florida, USA
| | - David J Libon
- Drexel Neuroscience Institute, Drexel University, College of Medicine, Philadelphia, PA, USA
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Van der Linden M, Juillerat Van der Linden AC. A life-course and multifactorial approach to Alzheimer's disease: Implications for research, clinical assessment and intervention practices. DEMENTIA 2016; 17:880-895. [PMID: 27353414 DOI: 10.1177/1471301216657270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
According to the dominant biomedical view, Alzheimer's disease (AD) has a precise, necessary and unifying neurobiological cause, which distinguishes it from other neurodegenerative diseases and normal ageing. However, different types of evidence specifically lead to questioning the foundations of this essentialist and category-based approach to AD. It seems more and more evident that AD represents a heterogeneous state, determined by multiple factors and mechanisms that interact and intervene throughout life. This other way of conceiving AD not only requires a change of research objectives, but also a profound modification of clinical assessment and intervention practices. It also appeals to follow the path of prevention.
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Wharton SB, Minett T, Drew D, Forster G, Matthews F, Brayne C, Ince PG. Epidemiological pathology of Tau in the ageing brain: application of staging for neuropil threads (BrainNet Europe protocol) to the MRC cognitive function and ageing brain study. Acta Neuropathol Commun 2016; 4:11. [PMID: 26857919 PMCID: PMC4746919 DOI: 10.1186/s40478-016-0275-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 01/14/2016] [Indexed: 02/04/2023] Open
Abstract
Introduction Deposition of abnormally phosphorylated tau (phospho-tau) occurs in Alzheimer’sdisease but also with brain ageing. The Braak staging scheme focused on neurofibrillary tangles, butabundant p-tau is also present in neuropil threads, and a recent scheme has been proposed by theBrainNet Europe consortium for staging tau pathology based on neuropil threads. We determined therelationship of threads to tangles, and the value of staging for threads in an unselected population-representative ageing brain cohort. We also determined the prevalence of astroglial tau pathologies, and their relationship to neuronal tau. Phospho-tau pathology was determined by immunohistochemistry (AT8 antibody) in the MRC-CFAS neuropathology cohort. Neuropil threads were staged using the BrainNet Europe protocol for tau pathology, and compared with Braak tangle stages. Astroglial tau pathology was assessed in neo-cortical, mesial temporal and subcortical areas. Results Cases conformed well to the hierarchical neuropil threads staging of the BrainNet Europe protocol and correlated strongly with Braak staging (r=0.84, p < 0.001). Based on the areas under the receiver operator curves (AUC), incorporating either threads or tangle staging significantly improved dementia case identification to a similar degree over age alone (Braak stage X2(1)=10.1, p=0.002; BNE stage X2(1)=9.7, p=0.002). Thorn-shaped astrocytes, present in 40 % of cases, were most common in mesial temporal lobe, then brainstem, and were associated with subpial tau-positive neurites (mesial temporal: X2(1)=61.3, p < 0.001; brainstem: X2(1)=47.9, p < 0.001). Adding thorn astrocytes did not improve dementia prediction (AUC: X2(1)=0.77, p=0.381), but there was a weak relationship between numbers of areas involved and staging for threads or tangles (r=0.17, p=0.023). Neuropil threads develop hierarchically in parallel with neurofibrillary tangles. Conclusions The BrainNet Europe staging protocol is straightforward to apply, and offers similar predictive value for dementia to Braak tangle staging. Astroglial tauopathy, particularly thorn shaped astrocyte formation, does not relate to dementia status, but the association with phospho-tau neurites may suggest a pathogenic relationship to neuronal tau pathology.
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Banerjee G, Wilson D, Jäger HR, Werring DJ. Novel imaging techniques in cerebral small vessel diseases and vascular cognitive impairment. Biochim Biophys Acta Mol Basis Dis 2015; 1862:926-38. [PMID: 26687324 DOI: 10.1016/j.bbadis.2015.12.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/07/2015] [Accepted: 12/08/2015] [Indexed: 11/27/2022]
Abstract
Dementia is a global growing concern, affecting over 35 million people with a global economic impact of over $604 billion US. With an ageing population the number of people affected is expected double over the next two decades. Vascular cognitive impairment can be caused by various types of cerebrovascular disease, including cortical and subcortical infarcts, and the more diffuse white matter injury due to cerebral small vessel disease. Although this type of cognitive impairment is usually considered the second most common form of dementia after Alzheimer's disease, there is increasing recognition of the vascular contribution to neurodegeneration, with both pathologies frequently coexisting. The aim of this review is to highlight the recent advances in the understanding of vascular cognitive impairment, with a focus on small vessel diseases of the brain. We discuss recently identified small vessel imaging markers that have been associated with cognitive impairment, namely cerebral microbleeds, enlarged perivascular spaces, cortical superficial siderosis, and microinfarcts. We will also consider quantitative techniques including diffusion tensor imaging, magnetic resonance perfusion imaging with arterial spin labelling, functional magnetic resonance imaging and positron emission tomography. As well as potentially shedding light on the mechanism by which cerebral small vessel diseases cause dementia, these novel imaging biomarkers are also of increasing relevance given their ability to guide diagnosis and reflect disease progression, which may in the future be useful for therapeutic interventions. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.
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Affiliation(s)
- Gargi Banerjee
- UCL Stroke Research Centre, Department of Brain Repair & Rehabilitation, UCL Institute of Neurology, 10-12 Russell Square, London WC1B 3EE, UK
| | - Duncan Wilson
- UCL Stroke Research Centre, Department of Brain Repair & Rehabilitation, UCL Institute of Neurology, 10-12 Russell Square, London WC1B 3EE, UK
| | - Hans R Jäger
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology and the National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - David J Werring
- UCL Stroke Research Centre, Department of Brain Repair & Rehabilitation, UCL Institute of Neurology, 10-12 Russell Square, London WC1B 3EE, UK
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Garwood CJ, Simpson JE, Al Mashhadi S, Axe C, Wilson S, Heath PR, Shaw PJ, Matthews FE, Brayne C, Ince PG, Wharton SB. DNA damage response and senescence in endothelial cells of human cerebral cortex and relation to Alzheimer's neuropathology progression: a population-based study in the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS) cohort. Neuropathol Appl Neurobiol 2015; 40:802-14. [PMID: 24861546 DOI: 10.1111/nan.12156] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 04/27/2014] [Indexed: 12/15/2022]
Abstract
AIMS Abnormalities of the brain microvasculature in Alzheimer's disease have led to the vascular hypothesis of the disease, which predicts that vascular changes precede neuronal dysfunction and degeneration. To determine the spectrum of endothelial injury in the elderly and its relation to Alzheimer-type neuropathology we investigated DNA damage in a population-based sample derived from the Medical Research Council Cognitive Function and Ageing Study. METHODS We examined endothelial damage in frontal and temporal cortex (n = 97) using immunohistochemistry for γH2AX and DNA-protein kinase (DNA-PKcs). To determine the effects of endothelial DNA damage at the earliest stages of Alzheimer's pathology we further focused our analysis on cases classified as Braak 0-II and examined endothelial senescence using histochemistry for β-galactosidase and the expression of genes related to DNA damage and senescence using quantitative polymerase chain reaction (qPCR). RESULTS We demonstrated large variation in endothelial DNA damage which was not associated with Alzheimer's neuropathology. Endothelial DNA-PKcs correlated with neuronal and glial DNA-PKcs counts. Focusing our further analysis on Braak 0-II cases, qPCR analysis demonstrated a trend to increased TP53 (P = 0.064) in cases with high compared with low endothelial DNA damage which was supported by immunohistochemical analysis of p53. Endothelial β-galactosidase expression was associated with increased neuronal (P = 0.033) and glial (P = 0.038), but not endothelial DNA-PKcs expression. CONCLUSIONS Damage to brain endothelial cells occurs early in relation to, or independently of, Alzheimer pathology, and parallels that in neurones and glia. Endothelial DNA damage and senescence are a brain ageing process that may contribute to dysfunction of the neurovascular unit in some elderly individuals.
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Affiliation(s)
- Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield
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Kämäläinen A, Herukka SK, Hartikainen P, Helisalmi S, Moilanen V, Knuuttila A, Jansson L, Tienari PJ, Remes AM. Cerebrospinal fluid biomarkers for Alzheimer's disease in patients with frontotemporal lobar degeneration and amyotrophic lateral sclerosis with the C9ORF72 repeat expansion. Dement Geriatr Cogn Disord 2015; 39:287-93. [PMID: 25791939 DOI: 10.1159/000371704] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/16/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The C9ORF72 expansion is one of the most common causes of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). The C9ORF72 expansion is associated with TDP-43 and p62 neuropathology, and amyloid plaques and neurofibrillary tangles are not common in patients with the C9ORF72 expansion. Therefore, we hypothesized that cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease [AD; Aβ1-42, total tau (T-tau) and phospho-tau] are normal in these patients. METHODS The CSF Aβ1-42, T-tau and phospho-tau levels were measured in 40 Finnish patients with the C9ORF72 expansion (29 FTLD, 10 ALS and 1 FTLD-ALS) using ELISA. RESULTS A decreased Aβ1-42 level was found in 25% of cases, while there were only single cases with changes in the t-Tau or phospho-tau level. The patients with abnormal biomarkers fulfilled the clinical criteria of the behavioral variant frontotemporal dementia and expressed no clinical signs of AD. CONCLUSIONS In clinical diagnostics, a decreased CSF Aβ1-42 level does not exclude the C9ORF72 expansion associated with FTLD.
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Affiliation(s)
- Anna Kämäläinen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland
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40
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Fluteau A, Ince PG, Minett T, Matthews FE, Brayne C, Garwood CJ, Ratcliffe LE, Morgan S, Heath PR, Shaw PJ, Wharton SB, Simpson JE. The nuclear retention of transcription factor FOXO3a correlates with a DNA damage response and increased glutamine synthetase expression by astrocytes suggesting a neuroprotective role in the ageing brain. Neurosci Lett 2015; 609:11-7. [PMID: 26455863 PMCID: PMC4674771 DOI: 10.1016/j.neulet.2015.10.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/01/2015] [Accepted: 10/01/2015] [Indexed: 01/14/2023]
Abstract
The accumulation of reactive oxygen species leading to oxidative damage and cell death plays an important role in a number of neurodegenerative disorders. FOXO3a, the main isoform of FOXO transcription factors, mediates the cellular response to oxidative stress by regulating the expression of genes involved in DNA repair and glutamine metabolism, including glutamine synthetase (GS). Immunohistochemical investigation of the population-based neuropathology cohort of the Medical Research Council's Cognitive Function and Ageing Study (MRC CFAS) demonstrates that nuclear retention of FOXO3a significantly correlates with a DNA damage response and with GS expression by astrocytes. Furthermore, we show that GS expression correlates with increasing Alzheimer-type pathology in this ageing cohort. Our findings suggest that in response to oxidative stress, the nuclear retention of FOXO3a in astrocytes upregulates expression of GS as a neuroprotective mechanism. However, the activity of GS may be compromised by increasing levels of oxidative stress in the ageing brain resulting in dysfunctional enzyme activity, neuronal excitotoxic damage and cognitive impairment.
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Affiliation(s)
- Adeline Fluteau
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom; MRC Human Genetics Unit, University of Edinburgh, United Kingdom
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Thais Minett
- Institute of Public Health, University of Cambridge, United Kingdom; Department of Radiology, University of Cambridge, United Kingdom
| | - Fiona E Matthews
- MRC Biostatistics Unit, Cambridge, United Kingdom; Institute of Health and Society, University of Newcastle, United Kingdom; Faculty of Life Sciences, University of Manchester, United Kingdom
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, United Kingdom
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Laura E Ratcliffe
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Sarah Morgan
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom.
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
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Garwood CJ, Ratcliffe LE, Morgan SV, Simpson JE, Owens H, Vazquez-Villaseñor I, Heath PR, Romero IA, Ince PG, Wharton SB. Insulin and IGF1 signalling pathways in human astrocytes in vitro and in vivo; characterisation, subcellular localisation and modulation of the receptors. Mol Brain 2015; 8:51. [PMID: 26297026 PMCID: PMC4546315 DOI: 10.1186/s13041-015-0138-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/02/2015] [Indexed: 12/20/2022] Open
Abstract
Background The insulin/IGF1 signalling (IIS) pathways are involved in longevity regulation and are dysregulated in neurons in Alzheimer’s disease (AD). We previously showed downregulation in IIS gene expression in astrocytes with AD-neuropathology progression, but IIS in astrocytes remains poorly understood. We therefore examined the IIS pathway in human astrocytes and developed models to reduce IIS at the level of the insulin or the IGF1 receptor (IGF1R). Results We determined IIS was present and functional in human astrocytes by immunoblotting and showed astrocytes express the insulin receptor (IR)-B isoform of Ir. Immunocytochemistry and cell fractionation followed by western blotting revealed the phosphorylation status of insulin receptor substrate (IRS1) affects its subcellular localisation. To validate IRS1 expression patterns observed in culture, expression of key pathway components was assessed on post-mortem AD and control tissue using immunohistochemistry. Insulin signalling was impaired in cultured astrocytes by treatment with insulin + fructose and resulted in decreased IR and Akt phosphorylation (pAkt S473). A monoclonal antibody against IGF1R (MAB391) induced degradation of IGF1R receptor with an associated decrease in downstream pAkt S473. Neither treatment affected cell growth or viability as measured by MTT and Cyquant® assays or GFAP immunoreactivity. Discussion IIS is functional in astrocytes. IR-B is expressed in astrocytes which differs from the pattern in neurons, and may be important in differential susceptibility of astrocytes and neurons to insulin resistance. The variable presence of IRS1 in the nucleus, dependent on phosphorylation pattern, suggests the function of signalling molecules is not confined to cytoplasmic cascades. Down-regulation of IR and IGF1R, achieved by insulin + fructose and monoclonal antibody treatments, results in decreased downstream signalling, though the lack of effect on viability suggests that astrocytes can compensate for changes in single pathways. Changes in signalling in astrocytes, as well as in neurons, may be important in ageing and neurodegeneration. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0138-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Claire J Garwood
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Laura E Ratcliffe
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Sarah V Morgan
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Helen Owens
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Irina Vazquez-Villaseñor
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Ignacio A Romero
- Biomedical Research Network, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK.
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Wharton SB, Simpson JE, Brayne C, Ince PG. Age-associated white matter lesions: the MRC Cognitive Function and Ageing Study. Brain Pathol 2015; 25:35-43. [PMID: 25521175 DOI: 10.1111/bpa.12219] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/08/2014] [Indexed: 12/11/2022] Open
Abstract
Cerebral white matter lesions (WML) are common in the aging brain and are associated with dementia and depression. They are associated with vascular risk factors and small vessel disease, suggesting an ischemic origin, but recent pathology studies suggest a more complex pathogenesis. Studies using samples from the population-representative Medical Research Council Cognitive Function and Ageing Study neuropathology cohort used post-mortem magnetic resonance imaging to identify WML for further study. Expression of hypoxia-related molecules and other injury and protective cellular pathways in candidate immunohistochemical and gene expression microarray studies support a role for hypoxia/ischemia. However, these approaches also suggest that immune activation, blood-brain barrier dysfunction, altered cell metabolic pathways and glial cell injury contribute to pathogenesis. These abnormalities are not confined to WML, but are also found in apparently normal white matter in brains with lesions, suggesting a field effect of white matter abnormality within which lesions arise. WML are an active pathology with a complex pathogenesis that may potentially offer a number of primary and secondary intervention targets.
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Affiliation(s)
- Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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Simpson JE, Ince PG, Minett T, Matthews FE, Heath PR, Shaw PJ, Goodall E, Garwood CJ, Ratcliffe LE, Brayne C, Rattray M, Wharton SB. Neuronal DNA damage response-associated dysregulation of signalling pathways and cholesterol metabolism at the earliest stages of Alzheimer-type pathology. Neuropathol Appl Neurobiol 2015; 42:167-79. [PMID: 26095650 PMCID: PMC5102584 DOI: 10.1111/nan.12252] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/02/2015] [Indexed: 12/21/2022]
Abstract
Aims Oxidative damage and an associated DNA damage response (DDR) are evident in mild cognitive impairment and early Alzheimer's disease, suggesting that neuronal dysfunction resulting from oxidative DNA damage may account for some of the cognitive impairment not fully explained by Alzheimer‐type pathology. Methods Frontal cortex (Braak stage 0–II) was obtained from the Medical Research Council's Cognitive Function and Ageing Study cohort. Neurones were isolated from eight cases (four high and four low DDR) by laser capture microdissection and changes in the transcriptome identified by microarray analysis. Results Two thousand three hundred seventy‐eight genes were significantly differentially expressed (1690 up‐regulated, 688 down‐regulated, P < 0.001) in cases with a high neuronal DDR. Functional grouping identified dysregulation of cholesterol biosynthesis, insulin and Wnt signalling, and up‐regulation of glycogen synthase kinase 3β. Candidate genes were validated by quantitative real‐time polymerase chain reaction. Cerebrospinal fluid levels of 24(S)‐hydroxycholesterol associated with neuronal DDR across all Braak stages (rs = 0.30, P = 0.03). Conclusions A persistent neuronal DDR may result in increased cholesterol biosynthesis, impaired insulin and Wnt signalling, and increased GSK3β, thereby contributing to neuronal dysfunction independent of Alzheimer‐type pathology in the ageing brain.
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Affiliation(s)
- Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Thais Minett
- Institute of Public Health, University of Cambridge, Cambridge, UK.,Department of Radiology, University of Cambridge, Cambridge, UK
| | - Fiona E Matthews
- MRC Biostatistics Unit, Institute of Public Health, Cambridge, UK.,Institute of Health and Society, University of Newcastle, Newcastle, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily Goodall
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Laura E Ratcliffe
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Magnus Rattray
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK.,Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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Simpson JE, Ince PG, Matthews FE, Shaw PJ, Heath PR, Brayne C, Garwood C, Higginbottom A, Wharton SB. A neuronal DNA damage response is detected at the earliest stages of Alzheimer's neuropathology and correlates with cognitive impairment in the Medical Research Council's Cognitive Function and Ageing Study ageing brain cohort. Neuropathol Appl Neurobiol 2015; 41:483-96. [PMID: 25443110 PMCID: PMC4861215 DOI: 10.1111/nan.12202] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 11/27/2014] [Indexed: 01/03/2023]
Abstract
AIMS Population-based studies have shown that approximately 20% of the ageing population (aged 65 years and over) with dementia have little or no classical Alzheimer-type neuropathology. Cumulative DNA damage and a reduced capacity of DNA repair may result in neuronal dysfunction and contribute to cognitive impairment independent of Alzheimer-type pathology in the ageing brain. METHODS We investigated expression of the DNA damage response (DDR)-associated molecules γH2AX and DNA-PKcs using immunohistochemistry and western blotting, and senescence-associated β-galactosidase in the frontal association neocortex of cases with low levels of Alzheimer-type pathology (Braak & Braak stage 0-II), and explored their relationship to cognitive impairment in a population-representative sample from the Medical Research Council's Cognitive Function and Ageing Study cohort. RESULTS Increases in both γH2AX(+) (r(s) = -0.36, P = 0.025) and DNA-PKcs(+) (r(s) = -0.39, P = 0.01) neuronal counts were associated with a lower Mini-Mental State Examination score. Increasing levels of senescence associated-β-gal(+) pyramidal neurones were weakly associated with the total number of DNA-PKcs(+) neurones (P = 0.08), but not with traditional senescence-associated signalling molecules, including p53 and p16. CONCLUSION The association between the neuronal DDR and cognitive impairment, independent of AD pathology in the ageing brain, may be suggestive of a causal link via neuronal dysfunction.
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Affiliation(s)
- Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Claire Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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Davey DA. Alzheimer's disease and vascular dementia: one potentially preventable and modifiable disease. Part I: Pathology, diagnosis and screening. Neurodegener Dis Manag 2015; 4:253-9. [PMID: 25095819 DOI: 10.2217/nmt.14.13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) and vascular dementia (VaD) frequently coexist and their separation may well be a false dichotomy. The neurodegenerative and cerebrovascular changes vary from the extremes of 'pure AD' to 'pure VaD' and a combination of changes is the most frequent. Both changes have a preclinical phase of decades. The clinical presentation is often out of proportion to the neuropathology to a lesser or greater degree. The diagnosis of dementia or mild cognitive impairment is based on clinical assessment and diagnostic criteria have been published. Neuropsychological testing and specialist evaluation may be required. The UK and US governments propose screening of all older adults. The value of routine screening has been questioned. Consent for testing and counseling are essential.
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Mathur R, Ince PG, Minett T, Garwood CJ, Shaw PJ, Matthews FE, Brayne C, Simpson JE, Wharton SB. A reduced astrocyte response to β-amyloid plaques in the ageing brain associates with cognitive impairment. PLoS One 2015; 10:e0118463. [PMID: 25707004 PMCID: PMC4338046 DOI: 10.1371/journal.pone.0118463] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/18/2014] [Indexed: 12/18/2022] Open
Abstract
Aims β-amyloid (Aβ) plaques are a key feature of Alzheimer’s disease pathology but correlate poorly with dementia. They are associated with astrocytes which may modulate the effect of Aβ-deposition on the neuropil. This study characterised the astrocyte response to Aβ plaque subtypes, and investigated their association with cognitive impairment. Methods Aβ plaque subtypes were identified in the cingulate gyrus using dual labelling immunohistochemistry to Aβ and GFAP+ astrocytes, and quantitated in two cortical areas: the area of densest plaque burden and the deep cortex near the white matter border (layer VI). Three subtypes were defined for both diffuse and compact plaques (also known as classical or core-plaques): Aβ plaque with (1) no associated astrocytes, (2) focal astrogliosis or (3) circumferential astrogliosis. Results In the area of densest burden, diffuse plaques with no astrogliosis (β = -0.05, p = 0.001) and with focal astrogliosis (β = -0.27, p = 0.009) significantly associated with lower MMSE scores when controlling for sex and age at death. In the deep cortex (layer VI), both diffuse and compact plaques without astrogliosis associated with lower MMSE scores (β = -0.15, p = 0.017 and β = -0.81, p = 0.03, respectively). Diffuse plaques with no astrogliosis in layer VI related to dementia status (OR = 1.05, p = 0.025). In the area of densest burden, diffuse plaques with no astrogliosis or with focal astrogliosis associated with increasing Braak stage (β = 0.01, p<0.001 and β = 0.07, p<0.001, respectively), and ApoEε4 genotype (OR = 1.02, p = 0.001 and OR = 1.10, p = 0.016, respectively). In layer VI all plaque subtypes associated with Braak stage, and compact amyloid plaques with little and no associated astrogliosis associated with ApoEε4 genotype (OR = 1.50, p = 0.014 and OR = 0.10, p = 0.003, respectively). Conclusions Reactive astrocytes in close proximity to either diffuse or compact plaques may have a neuroprotective role in the ageing brain, and possession of at least one copy of the ApoEε4 allele impacts the astroglial response to Aβ plaques.
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Affiliation(s)
- Ryan Mathur
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Paul G. Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Thais Minett
- Institute of Public Health, University of Cambridge, Cambridge, England, United Kingdom
| | - Claire J. Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | - Pamela J. Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
| | | | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, England, United Kingdom
| | - Julie E. Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
- * E-mail:
| | - Stephen B. Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, England, United Kingdom
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Abstract
The spectrum of mixed brain pathologies expands beyond accompanying vascular pathology in brains with Alzheimer's disease-related pathology. Co-occurrence of neurodegenerative non-Alzheimer's disease-type proteinopathies is increasingly recognized to be a frequent event in the brains of symptomatic and asymptomatic patients, particularly in older people. Owing to the evolving concept of neurodegenerative diseases, clinical and neuropathological diagnostic criteria have changed during the last decades. Autopsy-based studies differ in the selection criteria and also in the applied staining methods used. The present review summarizes the prevalence of mixed brain pathologies reported in recent community-based studies. In these cohorts, irrespective of the clinical symptoms, the frequency of Alzheimer's disease-related pathology is between 19 and 67%, of Lewy body pathology is between 6 and 39%, of vascular pathologies is between 28 and 70%, of TDP-43 proteinopathy is between 13 and 46%, of hippocampal sclerosis is between 3 and 13% and, finally, of mixed pathologies is between 10 and 74%. Some studies also mention tauopathies. White-matter pathologies are not discussed specifically in all studies, although these lesions may be present in more than 80% of the aging brains. In summary, community-based neuropathology studies have shown that complex constellations of underlying pathologies may lead to cognitive decline, and that the number of possible combinations increases in the aging brain. These observations have implications for the prediction of the prognosis, for the development of biomarkers or therapy targets, or for the stratification of patient cohorts for genome-wide studies or, eventually, for therapy trials.
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Affiliation(s)
- Jasmin Rahimi
- Institute of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Gabor G Kovacs
- Institute of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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Al-Mashhadi S, Simpson JE, Heath PR, Dickman M, Forster G, Matthews FE, Brayne C, Ince PG, Wharton SB. Oxidative Glial Cell Damage Associated with White Matter Lesions in the Aging Human Brain. Brain Pathol 2014; 25:565-74. [PMID: 25311358 PMCID: PMC4861214 DOI: 10.1111/bpa.12216] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/07/2014] [Indexed: 01/04/2023] Open
Abstract
White matter lesions (WML) are common in brain aging and are associated with dementia. We aimed to investigate whether oxidative DNA damage and occur in WML and in apparently normal white matter in cases with lesions. Tissue from WML and control white matter from brains with lesions (controls lesional) and without lesions (controls non‐lesional) were obtained, using post‐mortem magnetic resonance imaging‐guided sampling, from the Medical Research Council Cognitive Function and Ageing Study. Oxidative damage was assessed by immunohistochemistry to 8‐hydroxy‐2′‐deoxoguanosine (8‐OHdG) and Western blotting for malondialdehyde. DNA response was assessed by phosphorylated histone H2AX (γH2AX), p53, senescence markers and by quantitative Reverse transcription polymerase chain reaction (RT‐PCR) panel for candidate DNA damage‐associated genes. 8‐OHdG was expressed in glia and endothelium, with increased expression in both WML and controls lesional compared with controls non‐lesional (P < 0.001). γH2Ax showed a similar, although attenuated difference among groups (P = 0.03). Expression of senescence‐associated β‐galactosidase and p16 suggested induction of senescence mechanisms in glia. Oxidative DNA damage and a DNA damage response are features of WML pathogenesis and suggest candidate mechanisms for glial dysfunction. Their expression in apparently normal white matter in cases with WML suggests that white matter dysfunction is not restricted to lesions. The role of this field‐effect lesion pathogenesis and cognitive impairment are areas to be defined.
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Affiliation(s)
- Sufana Al-Mashhadi
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK.,King Fahad Medical City, Riyadh, Saudi Arabia
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Mark Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - Gillian Forster
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Fiona E Matthews
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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Garwood C, Faizullabhoy A, Wharton SB, Ince PG, Heath PR, Shaw PJ, Baxter L, Gelsthorpe C, Forster G, Matthews FE, Brayne C, Simpson JE. Calcium dysregulation in relation to Alzheimer-type pathology in the ageing brain. Neuropathol Appl Neurobiol 2014; 39:788-99. [PMID: 23421725 DOI: 10.1111/nan.12033] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/23/2013] [Indexed: 01/14/2023]
Abstract
AIMS Calcium dyshomeostasis is implicated in the pathogenesis of several neurodegenerative disorders including Alzheimer's disease. However, much of the previous research has focused on changes in neuronal calcium signalling. In a recent microarray study we identified dysregulation of several key signalling pathways including the Ca(2+) signalling pathway in astrocytes as Alzheimer-type pathology developed. In this study we sought to determine the expression of calpain-10 and calcium/calmodulin-dependent kinase alpha (CamKIIα) in relation to Alzheimer-type pathology in a population-based study. METHODS Using post mortem temporal cortex samples derived from the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS) ageing brain cohort we examined calpain-10 and CamKIIα gene and protein expression using quantitative polymerase chain reaction and immunohistochemistry. RESULTS We demonstrate that astrocytic expression of calpain-10 is up-regulated, and CamKIIα down-regulated with increasing Braak stage. Using immunohistochemistry we confirm protein expression of calpain-10 in astrocytes throughout the temporal cortex and demonstrate that calpain-10 immunoreactivity is correlated with both local and global measures of Alzheimer-type pathology. In addition, we identify a subpopulation of calpain-10 immunoreactive interlaminar astrocytes that extend processes deep into the cortex. CamKIIα is predominantly neuronal in localization and is associated with the presence of diffuse plaques in the ageing brain. DISCUSSION Dysregulated expression of key calcium signalling molecules occurs with progression of Alzheimer-type pathology in the ageing brain, highlighting the need for further functional studies of astrocytic calcium signalling with respect to disease progression.
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Affiliation(s)
- C Garwood
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield, UK
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Janaway BM, Simpson JE, Hoggard N, Highley JR, Forster G, Drew D, Gebril OH, Matthews FE, Brayne C, Wharton SB, Ince PG. Brain haemosiderin in older people: pathological evidence for an ischaemic origin of magnetic resonance imaging (MRI) microbleeds. Neuropathol Appl Neurobiol 2014; 40:258-69. [PMID: 23678850 PMCID: PMC4282337 DOI: 10.1111/nan.12062] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 05/10/2013] [Indexed: 01/03/2023]
Abstract
Introduction Magnetic resonance imaging (MRI) cerebral microbleeds (CMB) arise from ferromagnetic haemosiderin iron assumed to derive from extravasation of erythrocytes. Light microscopy of ageing brain frequently reveals foci of haemosiderin from single crystalloids to larger, predominantly perivascular, aggregates. The pathological and radiological relationship between these findings is not resolved. Methods Haemosiderin deposition and vascular pathology in the putamen were quantified in 200 brains donated to the population-representative Medical Research Council Cognitive Function and Ageing Study. Molecular markers of gliosis and tissue integrity were assessed by immunohistochemistry in brains with highest (n = 20) and lowest (n = 20) levels of putamen haemosiderin. The association between haemosiderin counts and degenerative and vascular brain pathology, clinical data, and the haemochromatosis (HFE) gene H63D genotype were analysed. The frequency of MRI CMB in 10 cases with highest and lowest burden of putamen haemosiderin, was compared using post mortem 3T MRI. Results Greater putamen haemosiderin was significantly associated with putaminal indices of small vessel ischaemia (microinfarcts, P < 0.05; arteriolosclerosis, P < 0.05; perivascular attenuation, P < 0.001) and with lacunes in any brain region (P < 0.023) but not large vessel disease, or whole brain measures of neurodegenerative pathology. Higher levels of putamen haemosiderin correlated with more CMB (P < 0.003). Conclusions The MRI-CMB concept should take account of brain iron homeostasis, and small vessel ischaemic change in later life, rather than only as a marker for minor episodes of cerebrovascular extravasation. These data are of clinical relevance, suggesting that basal ganglia MRI microbleeds may be a surrogate for ischaemic small vessel disease rather than exclusively a haemorrhagic diathesis.
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Affiliation(s)
- B M Janaway
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
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