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1.
Neurobiol Aging ; 101: 123-129, 2021 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-33610961

RESUMO

KLOTHO∗VS heterozygosity (KL∗VSHET+) was recently shown to be associated with reduced risk of Alzheimer's disease (AD) in APOE∗4 carriers. Additional studies suggest that KL∗VSHET+ protects against amyloid burden in cognitively normal older subjects, but sample sizes were too small to draw definitive conclusions. We performed a well-powered meta-analysis across 5 independent studies, comprising 3581 pre-clinical participants ages 60-80, to investigate whether KL∗VSHET+ reduces the risk of having an amyloid-positive positron emission tomography scan. Analyses were stratified by APOE∗4 status. KL∗VSHET+ reduced the risk of amyloid positivity in APOE∗4 carriers (odds ratio = 0.67 [0.52-0.88]; p = 3.5 × 10-3), but not in APOE∗4 non-carriers (odds ratio = 0.94 [0.73-1.21]; p = 0.63). The combination of APOE∗4 and KL∗VS genotypes should help enrich AD clinical trials for pre-symptomatic subjects at increased risk of developing amyloid aggregation and AD. KL-related pathways may help elucidate protective mechanisms against amyloid accumulation and merit exploration for novel AD drug targets. Future investigation of the biological mechanisms by which KL interacts with APOE∗4 and AD are warranted.

2.
Nat Commun ; 11(1): 6024, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33247134

RESUMO

The availability of blood-based assays detecting Alzheimer's disease (AD) pathology should greatly accelerate AD therapeutic development and improve clinical care. This is especially true for markers that capture the risk of decline in pre-symptomatic stages of AD, as this would allow one to focus interventions on participants maximally at risk and at a stage prior to widespread synapse loss and neurodegeneration. Here we quantify plasma concentrations of an N-terminal fragment of tau (NT1) in a large, well-characterized cohort of clinically normal elderly who were followed longitudinally. Plasma NT1 levels at study entry (when all participants were unimpaired) were highly predictive of future cognitive decline, pathological tau accumulation, neurodegeneration, and transition to a diagnosis of MCI/AD. These predictive effects were particularly strong in participants with even modestly elevated brain ß-amyloid burden at study entry, suggesting plasma NT1 levels capture very early cognitive, pathologic and neurodegenerative changes along the AD trajectory.

3.
Cell Rep ; 32(9): 108091, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877673

RESUMO

Genetic mechanisms underlying age-related cognitive decline and dementia remain poorly understood. Here, we take advantage of the Diversity Outbred mouse population to utilize quantitative trait loci mapping and identify Dlgap2 as a positional candidate responsible for modifying working memory decline. To evaluate the translational relevance of this finding, we utilize longitudinal cognitive measures from human patients, RNA expression from post-mortem brain tissue, data from a genome-wide association study (GWAS) of Alzheimer's dementia (AD), and GWAS results in African Americans. We find an association between Dlgap2 and AD phenotypes at the variant, gene and protein expression, and methylation levels. Lower cortical DLGAP2 expression is observed in AD and is associated with more plaques and tangles at autopsy and faster cognitive decline. Results will inform future studies aimed at investigating the cross-species role of Dlgap2 in regulating cognitive decline and highlight the benefit of using genetically diverse mice to prioritize novel candidates.

4.
Brain ; 143(8): 2561-2575, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32844198

RESUMO

Approximately 30% of older adults exhibit the neuropathological features of Alzheimer's disease without signs of cognitive impairment. Yet, little is known about the genetic factors that allow these potentially resilient individuals to remain cognitively unimpaired in the face of substantial neuropathology. We performed a large, genome-wide association study (GWAS) of two previously validated metrics of cognitive resilience quantified using a latent variable modelling approach and representing better-than-predicted cognitive performance for a given level of neuropathology. Data were harmonized across 5108 participants from a clinical trial of Alzheimer's disease and three longitudinal cohort studies of cognitive ageing. All analyses were run across all participants and repeated restricting the sample to individuals with unimpaired cognition to identify variants at the earliest stages of disease. As expected, all resilience metrics were genetically correlated with cognitive performance and education attainment traits (P-values < 2.5 × 10-20), and we observed novel correlations with neuropsychiatric conditions (P-values < 7.9 × 10-4). Notably, neither resilience metric was genetically correlated with clinical Alzheimer's disease (P-values > 0.42) nor associated with APOE (P-values > 0.13). In single variant analyses, we observed a genome-wide significant locus among participants with unimpaired cognition on chromosome 18 upstream of ATP8B1 (index single nucleotide polymorphism rs2571244, minor allele frequency = 0.08, P = 2.3 × 10-8). The top variant at this locus (rs2571244) was significantly associated with methylation in prefrontal cortex tissue at multiple CpG sites, including one just upstream of ATPB81 (cg19596477; P = 2 × 10-13). Overall, this comprehensive genetic analysis of resilience implicates a putative role of vascular risk, metabolism, and mental health in protection from the cognitive consequences of neuropathology, while also providing evidence for a novel resilience gene along the bile acid metabolism pathway. Furthermore, the genetic architecture of resilience appears to be distinct from that of clinical Alzheimer's disease, suggesting that a shift in focus to molecular contributors to resilience may identify novel pathways for therapeutic targets.

5.
Neuron ; 107(3): 496-508.e6, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32526197

RESUMO

Here, we perform a genome-wide screen for variants that regulate the expression of gene co-expression modules in the aging human brain; we discover and replicate such variants in the TMEM106B and RBFOX1 loci. The TMEM106B haplotype is known to influence the accumulation of TAR DNA-binding protein 43 kDa (TDP-43) proteinopathy, and the haplotype's large-scale transcriptomic effects include the dysregulation of lysosomal genes and alterations in synaptic gene splicing that are also seen in the pathophysiology of TDP-43 proteinopathy. Further, a variant near GRN, another TDP-43 proteinopathy susceptibility gene, shows concordant effects with the TMEM106B haplotype. Leveraging neuropathology data from the same participants, we also show that TMEM106B and APOE-amyloid-ß effects converge to alter myelination and lysosomal gene expression, which then contributes to TDP-43 accumulation. These results advance our mechanistic understanding of the TMEM106B TDP-43 risk haplotype and uncover a transcriptional program that mediates the converging effects of APOE-amyloid-ß and TMEM106B on TDP-43 aggregation in older adults.


Assuntos
Envelhecimento/genética , Encéfalo/metabolismo , Regulação da Expressão Gênica/genética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Progranulinas/genética , Fatores de Processamento de RNA/genética , Proteinopatias TDP-43/genética , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/psicologia , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Apolipoproteínas E/genética , Encéfalo/patologia , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Feminino , Haplótipos , Humanos , Lisossomos , Masculino , Bainha de Mielina , Locos de Características Quantitativas , Proteinopatias TDP-43/psicologia
6.
JAMA Neurol ; 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32568366

RESUMO

Importance: Genetic studies of Alzheimer disease have focused on the clinical or pathologic diagnosis as the primary outcome, but little is known about the genetic basis of the preclinical phase of the disease. Objective: To examine the underlying genetic basis for brain amyloidosis in the preclinical phase of Alzheimer disease. Design, Setting, and Participants: In the first stage of this genetic association study, a meta-analysis was conducted using genetic and imaging data acquired from 6 multicenter cohort studies of healthy older individuals between 1994 and 2019: the Anti-Amyloid Treatment in Asymptomatic Alzheimer Disease Study, the Berkeley Aging Cohort Study, the Wisconsin Registry for Alzheimer's Prevention, the Biomarkers of Cognitive Decline Among Normal Individuals cohort, the Baltimore Longitudinal Study of Aging, and the Alzheimer Disease Neuroimaging Initiative, which included Alzheimer disease and mild cognitive impairment. The second stage was designed to validate genetic observations using pathologic and clinical data from the Religious Orders Study and Rush Memory and Aging Project. Participants older than 50 years with amyloid positron emission tomographic (PET) imaging data and DNA from the 6 cohorts were included. The largest cohort, the Anti-Amyloid Treatment in Asymptomatic Alzheimer Disease Study (n = 3154), was the PET screening cohort used for a secondary prevention trial designed to slow cognitive decline associated with brain amyloidosis. Six smaller, longitudinal cohort studies (n = 1160) provided additional amyloid PET imaging data with existing genetic data. The present study was conducted from March 29, 2019, to February 19, 2020. Main Outcomes and Measures: A genome-wide association study of PET imaging amyloid levels. Results: From the 4314 analyzed participants (age, 52-96 years; 2478 participants [57%] were women), a novel locus for amyloidosis was noted within RBFOX1 (ß = 0.61, P = 3 × 10-9) in addition to APOE. The RBFOX1 protein localized around plaques, and reduced expression of RBFOX1 was correlated with higher amyloid-ß burden (ß = -0.008, P = .002) and worse cognition (ß = 0.007, P = .006) during life in the Religious Orders Study and Rush Memory and Aging Project cohort. Conclusions and Relevance: RBFOX1 encodes a neuronal RNA-binding protein known to be expressed in neuronal tissues and may play a role in neuronal development. The findings of this study suggest that RBFOX1 is a novel locus that may be involved in the pathogenesis of Alzheimer disease.

7.
Neurobiol Aging ; 93: 124-130, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32249013

RESUMO

In the present study, we tested the hypothesis that higher amyloid-beta (Aß) burden at baseline is associated with greater longitudinal decline in body mass index (BMI) in clinically normal adults. Participants from the Harvard Aging Brain Study (n = 312) and the Alzheimer's Disease Neuroimaging Initiative (n = 336) underwent Aß positron emission tomography at baseline. BMI was assessed longitudinally over a median of >4 years. Linear mixed models showed that higher baseline Aß burden was significantly associated with greater decline in BMI in both the Harvard Aging Brain Study (t = -1.93; p = 0.05) and Alzheimer's Disease Neuroimaging Initiative cohorts (t = -2.54; p = 0.01), after adjusting for covariates, including cognitive performance and depressive symptoms. In addition, the association of Aß burden with longitudinal decline in BMI persisted in both cohorts after excluding participants with diabetes/endocrine disturbances and participants classified as underweight or obese (BMI <18.5 or >30). These findings suggest that decline in BMI in clinically normal adults may be an early manifestation related to cerebral amyloidosis that precedes objective cognitive impairment. Therefore, unintentional BMI decline in otherwise healthy individuals might alert clinicians to increased risk of Alzheimer's disease.

8.
Neuroimage Clin ; 26: 102052, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31711955

RESUMO

Resting-state functional connectivity MRI (rs-fcMRI) is a non-invasive imaging technique that has come into increasing use to understand disrupted neural network function in neuropsychiatric disease. However, despite extensive study over the past 15 years, the development of rs-fcMRI as a biomarker has been impeded by a lack of reliable longitudinal rs-fcMRI measures. Here we focus on longitudinal change along the Alzheimer's disease (AD) trajectory and demonstrate the utility of Template Based Rotation (TBR) in detecting differential longitudinal rs-fcMRI change between higher and lower amyloid burden individuals with mildly impaired cognition. Specifically, we examine a small (N = 24), but densely sampled (~5 observations over ~3 years), cohort of symptomatic individuals with serial rs-fcMRI imaging and PiB-PET imaging for ß-amyloid pathology. We observed longitudinal decline of the Default Mode and Salience network axis (DMN/SAL) among impaired individuals with high amyloid burden. No other networks showed differential change in high vs. low amyloid individuals over time. The standardized effect size of AD related DMN/SAL change is comparable to the standardized effect size of amyloid-related change on the mini-mental state exam (MMSE) and hippocampal volume (HV). Last, we show that the AD-related change in DMN/SAL connectivity is almost completely independent of change on MMSE or HV, suggesting that rs-fcMRI is sensitive to an aspect of AD progression that is not captured by these other measures. Together these analyses demonstrate that longitudinal rs-fcMRI using TBR can capture disease-relevant network disruption in a clinical population.

9.
JAMA Netw Open ; 2(8): e198964, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-31397865

RESUMO

Importance: Depressive symptoms are prevalent among older adults and may be early manifestations of Alzheimer disease (AD) before onset of mild cognitive impairment. However, it remains unclear whether worsening depressive symptoms in the presence of AD pathology are associated with cognitive decline in older adults. Objective: To determine the longitudinal association between depressive symptoms, cognition, and cortical amyloid in community-dwelling older adults. Design, Setting, and Participants: Participants from the Harvard Aging Brain Study, a cohort study, underwent annual assessments of depression and cognition and baseline cortical amyloid measurement (mean, 4.42 years; range, 2-7 years). Data collection was from September 2010 to August 2017 in a convenience sample of community-dwelling adults (276 participants, all cognitively unimpaired) with at most mild depression at entry. Main Outcomes and Measures: Depression (Geriatric Depression Scale [GDS]), cognition (Preclinical Alzheimer Cognitive Composite [PACC]), and a continuous measure of cortical amyloid (Pittsburgh Compound-B positron emission tomography imaging). Change in GDS and baseline amyloid were examined as interactive predictors of PACC decline in a linear mixed model with backward elimination, adjusting for age, sex, and education. Results: Participants were 164 women and 112 men (mean [SD] age, 73.5 [6.0] years). At baseline, the mean (SD) GDS score was 3.0 (2.8) (range, 0-12), the mean (SD) PACC score was -0.004 (0.67) (range, -2.32 to 1.88), and the mean (SD) amyloid positron emission tomography distribution volume ratio was 1.16 (0.20) (range, 0.92-1.94). At last follow-up, the mean (SD) GDS score was 3.9 (2.9) (range, 0-12), and the mean (SD) PACC score was -0.09 (1.27) (range, -5.66 to 1.67). The interaction between cortical amyloid and increasing GDS was associated with declining cognition (ß = -0.19; 95% CI, -0.27 to -0.12; P < .001). Conclusions and Relevance: In this study, cortical amyloid moderated the association between worsening depressive symptoms and declining cognition in older adults. While future work is needed to better understand causal associations, these findings may enhance early detection and prevention of AD clinical symptoms.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Disfunção Cognitiva/complicações , Depressão/complicações , Idoso , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico , Depressão/diagnóstico , Feminino , Humanos , Vida Independente/estatística & dados numéricos , Estudos Longitudinais , Masculino , Testes de Estado Mental e Demência
10.
JAMA Neurol ; 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31312836

RESUMO

Importance: In the absence of disease-modifying therapies for Alzheimer disease, there is a critical need to identify modifiable risk factors that may delay the progression of Alzheimer disease. Objective: To examine whether physical activity moderates the association of ß-amyloid (Aß) burden with longitudinal cognitive decline and neurodegeneration in clinically normal individuals and to examine whether these associations are independent of vascular risk. Design, Setting, and Participants: This longitudinal observational study included clinically normal participants from the Harvard Aging Brain Study. Participants were required to have baseline Aß positron emission tomography data, baseline medical data to quantify vascular risk, and longitudinal neuropsychological and structural magnetic resonance imaging data. Data were collected from April 2010 to June 2018. Data were analyzed from August to December 2018. Main Outcomes and Measures: Baseline physical activity was quantified with a pedometer (mean steps per day). Baseline Aß burden was measured with carbon 11-labeled Pittsburgh Compound B positron emission tomography. Cognition was measured annually with the Preclinical Alzheimer Cognitive Composite (PACC; median [interquartile range] follow-up, 6.0 [4.3-6.3] years). Neurodegeneration was assessed with longitudinal structural magnetic resonance imaging (2 to 5 scans per participant; median [interquartile range] follow-up, 4.5 [3.0-5.0] years), with a focus on total gray matter volume and regional cortical thickness. Physical activity and Aß burden were examined as interactive predictors of PACC decline and volume loss in separate linear mixed models, adjusting for age, sex, education, apolipoprotein E ε4 status, and, where appropriate, intracranial volume. Secondary models adjusted for vascular risk and its interaction with Aß burden. Results: Of the 182 included participants, 103 (56.6%) were female, and the mean (SD) age was 73.4 (6.2) years. In models examining PACC decline and volume loss, there was a significant interaction of physical activity with Aß burden, such that greater physical activity was associated with slower Aß-related cognitive decline (ß, 0.03; 95% CI, 0.02-0.05; P < .001) and volume loss (ß, 482.07; 95% CI, 189.40-774.74; P = .002). Adjusting for vascular risk did not alter these associations. In these models, lower vascular risk was independently associated with slower Aß-related PACC decline (ß, -0.04; 95% CI, -0.06 to -0.02; P < .001) and volume loss (ß, -483.41; 95% CI, -855.63 to -111.20; P = .01). Conclusions and Relevance: Greater physical activity and lower vascular risk independently attenuated the negative association of Aß burden with cognitive decline and neurodegeneration in asymptomatic individuals. These findings suggest that engaging in physical activity and lowering vascular risk may have additive protective effects on delaying the progression of Alzheimer disease.

11.
J Alzheimers Dis ; 68(3): 1161-1170, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30883345

RESUMO

BACKGROUND: The UNC5C rs3846455G allele has been linked to poor cognitive resilience against age-related neuropathologies, but this association remains to be replicated, and the allele's effect on hippocampal neurodegeneration needs to be examined. OBJECTIVE: To further validate the association between rs3846455G and faster cognitive decline, especially among cognitively normal older adults, and to assess whether rs3846455G predicts accelerated hippocampal volume loss in older adults. METHODS: We assessed participants in the Harvard Aging Brain Study (HABS), a longitudinal cohort study of older adults who were clinically normal at baseline. To avoid bias from population admixture, analyses were limited to participants of European descent with longitudinal neuroimaging data (n = 174). Linear mixed effect models were used to examine the effect of rs3846455G on longitudinal change of the Preclinical Alzheimer Cognitive Composite (PACC) and MRI-measured bilateral hippocampal volume, adjusting for baseline amyloid-ß (Aß) measured by the cortical Pittsburgh Compound B PET distributed volume ratio. We also tested whether hippocampal atrophy mediates the association between rs3846455G and greater PACC decline through a mediation analysis. RESULTS: rs3846455G was associated with greater PACC decline (ß= -0.087/year, 95% CI -0.169 to -0.005, p = 0.039) after controlling for baseline Aß. Further, rs3846455G predicted accelerated hippocampal atrophy after controlling for baseline Aß (ß= -57.3 mm3/year, 95% CI -102.8 to -11.9, p = 0.014). The association between rs3846455G and greater PACC decline was partially mediated by accelerated hippocampal atrophy (mediated effect (relative scale) = -0.014, 95% CI -0.032 to -6.0×10-4, p = 0.039). CONCLUSION: UNC5C rs3846455G predicts greater cognitive decline and accelerated hippocampal atrophy in clinically normal older adults.


Assuntos
Alelos , Disfunção Cognitiva/genética , Predisposição Genética para Doença/genética , Hipocampo/patologia , Receptores de Netrina/genética , Idoso , Doenças Assintomáticas , Atrofia , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Feminino , Técnicas de Genotipagem , Hipocampo/diagnóstico por imagem , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética , Masculino , Testes de Estado Mental e Demência , Neuroimagem , Polimorfismo de Nucleotídeo Único/genética , Tomografia por Emissão de Pósitrons
12.
Ann Neurol ; 85(2): 181-193, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30549303

RESUMO

OBJECTIVES: Amyloid-beta (Aß) and tau pathologies are commonly observed among clinically normal older individuals at postmortem and can now be detected with in vivo neuroimaging. The association and interaction of these proteinopathies with prospective cognitive decline in normal aging and preclinical Alzheimer's disease (AD) remains to be fully elucidated. METHODS: One hundred thirty-seven older individuals (age = 76.3 ± 6.22 years) participating in the Harvard Aging Brain Study underwent Aß (11 C-Pittsburgh compound B) and tau (18 F-flortaucipir) positron emission tomography (PET) with prospective neuropsychological assessments following PET imaging (mean number of cognitive visits = 2.8 ± 1.1). Tau and Aß PET measures were assessed in regions of interest (ROIs) as well as vertex-wise map analyses. Cognitive change was evaluated with Memory and Executive Function composites. RESULTS: Higher levels of Aß and tau were both associated with greater memory decline, but not with change in executive function. Higher cortical Aß was associated with higher tau levels in all ROIs, independent of age, and very elevated levels of tau were observed primarily in clinically normal with elevated Aß. A significant interaction between tau and Aß was observed in both ROI and map-level analyses, such that rapid prospective memory decline was observed in participants who had high levels of both pathologies. INTERPRETATION: Our results are consistent with the supposition that both Aß and tau are necessary for memory decline in the preclinical stages of AD. These findings may be relevant for disambiguating aging and early cognitive manifestations of AD, and to inform secondary prevention trials in preclinical AD. Ann Neurol 2019;00:1-3 ANN NEUROL 2019;85:181-193.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/metabolismo , Memória Episódica , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estudos Longitudinais , Masculino , Tomografia por Emissão de Pósitrons/métodos
13.
Ann Neurol ; 85(2): 272-279, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30565287

RESUMO

OBJECTIVE: Neuropathological studies have demonstrated that cerebrovascular disease and Alzheimer disease (AD) pathology frequently co-occur in older adults. The extent to which cerebrovascular disease influences the progression of AD pathology remains unclear. Leveraging newly available positron emission tomography (PET) imaging, we examined whether a well-validated measure of systemic vascular risk and ß-amyloid (Aß) burden have an interactive association with regional tau burden. METHODS: Vascular risk was quantified at baseline in 152 clinically normal older adults (mean age = 73.5 ± 6.1 years) with the office-based Framingham Heart Study cardiovascular disease risk algorithm (FHS-CVD). We acquired Aß (11 C-Pittsburgh compound B) and tau (18 F-flortaucipir) PET imaging on the same participants. Aß PET was performed at baseline; tau PET was acquired on average 2.98 ± 1.1 years later. Tau was measured in the entorhinal cortex (EC), an early site of tau deposition, and in the inferior temporal cortex (ITC), an early site of neocortical tau accumulation associated with AD. Linear regression models examined FHS-CVD and Aß as interactive predictors of tau deposition, adjusting for age, sex, APOE ε4 status, and the time interval between baseline and the tau PET scan. RESULTS: We observed a significant interaction between FHS-CVD and Aß burden on subsequently measured ITC tau (p < 0.001), whereby combined higher FHS-CVD and elevated Aß burden was associated with increased tau. The interaction was not significant for EC tau (p = 0.16). INTERPRETATION: Elevated vascular risk may influence tau burden when coupled with high Aß burden. These results suggest a potential link between vascular risk and tau pathology in preclinical AD. Ann Neurol 2019; 1-8 ANN NEUROL 2019;85:272-279.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Doenças Cardiovasculares/epidemiologia , Proteínas tau/metabolismo , Idoso , Compostos de Anilina , Encéfalo/diagnóstico por imagem , Carbolinas , Meios de Contraste , Córtex Entorrinal , Feminino , Voluntários Saudáveis , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Tomografia por Emissão de Pósitrons , Risco , Medição de Risco , Lobo Temporal , Tiazóis
14.
Nat Med ; 24(12): 1910-1918, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30374196

RESUMO

Tau and amyloid beta (Aß) proteins accumulate along neuronal circuits in Alzheimer's disease. Unraveling the genetic background for the regional vulnerability of these proteinopathies can help in understanding the mechanisms of pathology progression. To that end, we developed a novel graph theory approach and used it to investigate the intersection of longitudinal Aß and tau positron emission tomography imaging of healthy adult individuals and the genetic transcriptome of the Allen Human Brain Atlas. We identified distinctive pathways for tau and Aß accumulation, of which the tau pathways correlated with cognitive levels. We found that tau propagation and Aß propagation patterns were associated with a common genetic profile related to lipid metabolism, in which APOE played a central role, whereas the tau-specific genetic profile was classified as 'axon related' and the Aß profile as 'dendrite related'. This study reveals distinct genetic profiles that may confer vulnerability to tau and Aß in vivo propagation in the human brain.


Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Tomografia por Emissão de Pósitrons , Proteínas tau/genética , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Feminino , Humanos , Metabolismo dos Lipídeos/genética , Masculino , Agregação Patológica de Proteínas/diagnóstico por imagem , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/patologia , Transcriptoma/genética , Proteínas tau/metabolismo
15.
Nat Neurosci ; 21(10): 1310-1317, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30258235

RESUMO

The field of neurodegenerative disease research has seen tremendous advances over the last two decades as new technologies and analytic methods have enabled well-powered human genomic studies. Driven first by genetic studies and more recently by transcriptomic and epigenomic studies of proper size, we have uncovered a large repertoire of loci, genes, and molecular features that are implicated in discrete, syndromically defined neurodegenerative conditions, such as Alzheimer's disease, amyotrophic lateral sclerosis, frontotemporal dementia, multiple sclerosis, and Parkinson's disease. As we begin to understand the impact of these genomic features in each disease, we also appreciate that many aging individuals accumulate each of these pathologies without fulfilling criteria for syndromic diagnoses, that other pathologies are common in individuals with a given diagnosis, and that there may be shared protective factors against central nervous system injury. Thus, we now need to bring these disparate observations together into a person-centered approach that considers all neurodegenerative and protective processes simultaneously to modulate the trajectory of cognitive and functional decline that comes with brain aging.


Assuntos
Predisposição Genética para Doença/genética , Genômica , Doenças Neurodegenerativas/genética , Humanos
16.
Lancet Neurol ; 17(9): 773-781, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30093249

RESUMO

BACKGROUND: Transactive response DNA-binding protein of 43 kDa (TDP-43) proteinopathy in older adults frequently coexists with Alzheimer's disease pathology and hippocampal sclerosis. It is unclear whether there is a link between APOE ε4 and TDP-43 proteinopathy, and the role of APOE ε4 in the association of TDP-43 proteinopathy with hippocampal sclerosis remains to be examined. We investigated the relationships of TDP-43 proteinopathy and hippocampal sclerosis with APOE ε4. METHODS: We used data from two community-based cohort studies of ageing and dementia: the Religious Orders Study (ROS) and the Rush Memory and Aging Project (MAP). A battery of cognitive tests examining multiple cognitive domains is given to ROS-MAP participants each year, and a measure of annual global cognitive function for each participant is derived by averaging Z scores of these tests. The final clinical diagnosis is assigned after death by a neurologist using all available clinical data without access to post-mortem pathology. Amyloid-ß, paired helical filament tau, Lewy bodies, TDP-43, and hippocampal sclerosis were microscopically evaluated in the midbrain, medial temporal, and neocortical regions that capture the progression of each neuropathology. TDP-43 proteinopathy topographic stage was recorded as an ordinal variable, and TDP-43 burden was defined by averaging a semi-quantitative six-point scale across six brain regions. The relationships among APOE ε4, TDP-43 proteinopathy, and hippocampal sclerosis were tested with regression models controlled for sex and age at death, and they were further explored with a mediation analysis using the quasi-Bayesian Monte Carlo method. FINDINGS: ROS began data collection in 1994, and MAP began data collection in 1997. The data included in this study were analysed from Jan 16, 2017, to July 12, 2017. When analysis began in January, 2017, a total of 1059 ROS-MAP participants who were deceased had APOE genotype and complete pathological measures for amyloid-ß, paired helical filament tau, and TDP-43 proteinopathy stage. After excluding 15 participants with other pathological diagnoses, 1044 participants, 1042 of whom also had measures of Lewy body pathology, were included in this study (470 from ROS and 574 from MAP). APOE ε4 count was associated with higher TDP-43 proteinopathy stage (odds ratio [OR] 2·0, 95% CI 1·6-2·6; p=1·9 × 10-9) and TDP-43 burden (0·40, 0·28-0·52; p=1·2 × 10-10). Amyloid-ß, paired helical filament tau, or Lewy body pathology did not fully explain this association. APOE ε4 increased the odds of hippocampal sclerosis (OR 2·1, 95% CI 1·4-3·0; p=1·7 × 10-4); this effect was largely mediated by TDP-43 burden (mediated effect p<1·0 × 10-4) but not directly by APOE ε4 (direct effect p=0·40). APOE ε4 was associated with worse global cognition proximate to death even after adjusting for amyloid-ß and paired helical filament tau (estimated effect -0·18, 95% CI -0·31 to -0·04; p=0·010), but this association was attenuated by additionally adjusting for TDP-43 burden (-0·09, -0·22 to 0·04; p=0·18). INTERPRETATION: APOE ε4 seems to increase TDP-43 burden, and this effect in turn was associated with higher odds of hippocampal sclerosis, a pathology potentially downstream of TDP-43 proteinopathy. TDP-43 proteinopathy contributes to the detrimental effect of APOE ε4 on late-life cognition through mechanisms independent of Alzheimer's disease pathology, and future research should consider that TDP-43 proteinopathy might be an integral component of APOE-related neurodegeneration. FUNDING: US National Institute on Aging and Alzheimer's Association.


Assuntos
Apolipoproteína E4/genética , Hipocampo/patologia , Proteinopatias TDP-43/genética , Proteinopatias TDP-43/patologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Haplótipos , Humanos , Corpos de Lewy/patologia , Modelos Logísticos , Masculino , Quinases de Proteína Quinase Ativadas por Mitógeno , Espécies Reativas de Oxigênio/metabolismo , Características de Residência , Esclerose/complicações , Esclerose/genética , Esclerose/patologia , Proteinopatias TDP-43/complicações
17.
Interv Neurol ; 7(5): 256-264, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29765395

RESUMO

Intracranial dural arteriovenous fistulae (DAVF) within the deep cerebral vasculature are diagnostically challenging because of their variable clinical presentation and typical bilateral neuroimaging findings mimicking inflammatory, infectious, and metabolic processes. Increasingly, reports have emerged highlighting the diagnostic and treatment challenges of these lesions and their associated high morbidity and rapid clinical deterioration when untreated. We describe here a case series of 4 patients with deep cerebral DAVF who presented with impaired arousal or memory and behavioral changes. In all patients, the initial differential diagnosis included metabolic, inflammatory, infectious, or neoplastic disease, with an eventual correct diagnosis obtained after catheter angiography had demonstrated arterialization of the deep venous structures, including the vein of Galen. All patients were successfully treated with endovascular embolization, with 1 patient requiring additional surgical treatment. We review the contemporary diagnostic evaluation and management of DAVF within the deep cerebral vasculature. With rapid diagnosis and treatment, a favorable outcome is possible.

18.
JAMA Neurol ; 75(9): 1124-1131, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29799986

RESUMO

Importance: Identifying asymptomatic individuals at high risk of impending cognitive decline because of Alzheimer disease is crucial for successful prevention of dementia. Vascular risk and ß-amyloid (Aß) pathology commonly co-occur in older adults and are significant causes of cognitive impairment. Objective: To determine whether vascular risk and Aß burden act additively or synergistically to promote cognitive decline in clinically normal older adults; and, secondarily, to evaluate the unique influence of vascular risk on prospective cognitive decline beyond that of commonly used imaging biomarkers, including Aß burden, hippocampal volume, fludeoxyglucose F18-labeled (FDG) positron emission tomography (PET), and white matter hyperintensities, a marker of cerebrovascular disease. Design, Setting, and Participants: In this longitudinal observational study, we examined clinically normal older adults from the Harvard Aging Brain Study. Participants were required to have baseline imaging data (FDG-PET, Aß-PET, and magnetic resonance imaging), baseline medical data to quantify vascular risk, and at least 1 follow-up neuropsychological visit. Data collection began in 2010 and is ongoing. Data analysis was performed on data collected between 2010 and 2017. Main Outcomes and Measures: Vascular risk was quantified using the Framingham Heart Study general cardiovascular disease (FHS-CVD) risk score. We measured Aß burden with Pittsburgh Compound-B PET. Cognition was measured annually with the Preclinical Alzheimer Cognitive Composite. Models were corrected for baseline age, sex, years of education, and apolipoprotein E ε4 status. Results: Of the 223 participants, 130 (58.3%) were women. The mean (SD) age was 73.7 (6.0) years, and the mean (SD) follow-up time was 3.7 (1.2) years. Faster cognitive decline was associated with both a higher FHS-CVD risk score (ß = -0.064; 95% CI, -0.094 to -0.033; P < .001) and higher Aß burden (ß = -0.058; 95% CI, -0.079 to -0.037; P < .001). The interaction of the FHS-CVD risk score and Aß burden with time was significant (ß = -0.040, 95% CI, -0.062 to -0.018; P < .001), suggesting a synergistic effect. The FHS-CVD risk score remained robustly associated with prospective cognitive decline (ß = -0.055; 95% CI, -0.086 to -0.024; P < .001), even after adjustment for Aß burden, hippocampal volume, FDG-PET uptake, and white matter hyperintensities. Conclusions and Relevance: In this study, vascular risk was associated with prospective cognitive decline in clinically normal older adults, both alone and synergistically with Aß burden. Vascular risk may complement imaging biomarkers in assessing risk of prospective cognitive decline in preclinical Alzheimer disease.


Assuntos
Envelhecimento , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/epidemiologia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/epidemiologia , Idoso , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/metabolismo , Feminino , Humanos , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Fatores de Risco
19.
J Fam Pract ; 66(8): 507-509, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28783770

RESUMO

A 46-year-old man presented to the emergency department with sudden-onset right-sided visual loss. He had a history of asthma, but no family history of hypercoagulability, deep vein thrombosis, or stroke. The patient had an active lifestyle that included scuba diving, mountain biking, and hockey (coaching and playing). The physical examination revealed a right homonymous upper quadrantanopia. The neurologic examination was within normal limits, except for the visual deficit and unequal pupil size. A computerized tomography scan of the patient's head did not reveal any lesions.


Assuntos
Forame Oval Patente/complicações , Forame Oval Patente/cirurgia , Acidente Vascular Cerebral/etiologia , Transtornos da Visão/etiologia , Forame Oval Patente/diagnóstico , Forame Oval Patente/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Campo Visual
20.
Neurol Genet ; 3(4): e176, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28761931

RESUMO

OBJECTIVE: To determine whether common genetic variants in UNC5C, a recently identified late-onset Alzheimer disease (LOAD) dementia susceptibility gene, are associated with AD susceptibility or AD-related clinical/pathologic phenotypes. METHODS: We used data from deceased individuals of European descent who participated in the Religious Orders Study or the Rush Memory and Aging Project (n = 1,288). We examined whether there were associations between single nucleotide polymorphisms (SNPs) within ±100 kb of the UNC5C gene and a diagnosis of AD dementia, global cognitive decline, a pathologic diagnosis of AD, ß-amyloid load, neuritic plaque count, diffuse plaque count, paired helical filament tau density, neurofibrillary tangle count, and cerebral amyloid angiopathy (CAA) score. We also evaluated the relation of the CAA-associated variant and dorsolateral prefrontal cortex (DLPFC) UNC5C RNA expression. Secondary analyses were performed to examine the interaction of the CAA-associated SNP and known genetic risk factors of CAA as well as the association of the SNP with other cerebrovascular pathologies. RESULTS: A set of UNC5C SNPs tagged by rs28660566T was associated with a higher CAA score (p = 2.3 × 10-6): each additional rs28660566T allele was associated with a 0.60 point higher CAA score, which is equivalent to approximately 75% of the higher CAA score associated with each allele of APOE ε4. rs28660566T was weakly associated with lower UNC5C expression in the human DLPFC (p = 0.036). Moreover, rs28660566T had a synergistic interaction with APOE ε4 on their association with higher CAA severity (p = 0.027) and was associated with more severe arteriolosclerosis (p = 0.0065). CONCLUSIONS: Targeted analysis of the UNC5C region uncovered a set of SNPs associated with CAA.

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