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1.
EMBO J ; 40(17): e105603, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34254352

RESUMEN

Variants identified in genome-wide association studies have implicated immune pathways in the development of Alzheimer's disease (AD). Here, we investigated the mechanistic basis for protection from AD associated with PLCγ2 R522, a rare coding variant of the PLCG2 gene. We studied the variant's role in macrophages and microglia of newly generated PLCG2-R522-expressing human induced pluripotent cell lines (hiPSC) and knockin mice, which exhibit normal endogenous PLCG2 expression. In all models, cells expressing the R522 mutation show a consistent non-redundant hyperfunctionality in the context of normal expression of other PLC isoforms. This manifests as enhanced release of cellular calcium ion stores in response to physiologically relevant stimuli like Fc-receptor ligation or exposure to Aß oligomers. Expression of the PLCγ2-R522 variant resulted in increased stimulus-dependent PIP2 depletion and reduced basal PIP2 levels in vivo. Furthermore, it was associated with impaired phagocytosis and enhanced endocytosis. PLCγ2 acts downstream of other AD-related factors, such as TREM2 and CSF1R, and alterations in its activity directly impact cell function. The inherent druggability of enzymes such as PLCγ2 raises the prospect of PLCγ2 manipulation as a future therapeutic approach in AD.


Asunto(s)
Enfermedad de Alzheimer/genética , Endocitosis , Fosfatidilinositol 4,5-Difosfato/metabolismo , Proteína Quinasa C/genética , Péptidos beta-Amiloides/metabolismo , Animales , Línea Celular , Células Cultivadas , Humanos , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Mutación Missense , Neuroglía/metabolismo , Proteína Quinasa C/metabolismo
2.
J Cell Sci ; 136(6)2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36825945

RESUMEN

Abnormalities in the endosomal-autophagic-lysosomal (EAL) system are an early event in Alzheimer's disease (AD) pathogenesis. However, the mechanisms underlying these abnormalities are unclear. The transient receptor potential channel mucolipin 1(TRPML1, also known as MCOLN1), a vital endosomal-lysosomal Ca2+ channel whose loss of function leads to neurodegeneration, has not been investigated with respect to EAL pathogenesis in late-onset AD (LOAD). Here, we identify pathological hallmarks of TRPML1 dysregulation in LOAD neurons, including increased perinuclear clustering and vacuolation of endolysosomes. We reveal that induced pluripotent stem cell (iPSC)-derived human cortical neurons expressing APOE ε4, the strongest genetic risk factor for LOAD, have significantly diminished TRPML1-induced endolysosomal Ca2+ release. Furthermore, we found that blocking TRPML1 function in primary neurons by depleting the TRPML1 agonist PI(3,5)P2 via PIKfyve inhibition, recreated multiple features of EAL neuropathology evident in LOAD. This included increased endolysosomal Ca2+ content, enlargement and perinuclear clustering of endolysosomes, autophagic vesicle accumulation and early endosomal enlargement. Strikingly, these AD-like neuronal EAL defects were rescued by TRPML1 reactivation using its synthetic agonist ML-SA1. These findings implicate defects in TRPML1 in LOAD EAL pathogenesis and present TRPML1 as a potential therapeutic target.


Asunto(s)
Enfermedad de Alzheimer , Canales de Potencial de Receptor Transitorio , Humanos , Calcio/metabolismo , Enfermedad de Alzheimer/patología , Canales de Potencial de Receptor Transitorio/genética , Lisosomas/metabolismo , Autofagia
3.
Brain ; 146(2): 690-699, 2023 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-35383826

RESUMEN

Plasma biomarkers for Alzheimer's disease-related pathologies have undergone rapid developments during the past few years, and there are now well-validated blood tests for amyloid and tau pathology, as well as neurodegeneration and astrocytic activation. To define Alzheimer's disease with biomarkers rather than clinical assessment, we assessed prediction of research-diagnosed disease status using these biomarkers and tested genetic variants associated with the biomarkers that may reflect more accurately the risk of biochemically defined Alzheimer's disease instead of the risk of dementia. In a cohort of Alzheimer's disease cases [n = 1439, mean age 68 years (standard deviation = 8.2)] and screened controls [n = 508, mean age 82 years (standard deviation = 6.8)], we measured plasma concentrations of the 40 and 42 amino acid-long amyloid-ß (Aß) fragments (Aß40 and Aß42, respectively), tau phosphorylated at amino acid 181 (P-tau181), neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) using state-of-the-art Single molecule array (Simoa) technology. We tested the relationships between the biomarkers and Alzheimer's disease genetic risk, age at onset and disease duration. We also conducted a genome-wide association study for association of disease risk genes with these biomarkers. The prediction accuracy of Alzheimer's disease clinical diagnosis by the combination of all biomarkers, APOE and polygenic risk score reached area under receiver operating characteristic curve (AUC) = 0.81, with the most significant contributors being ε4, Aß40 or Aß42, GFAP and NfL. All biomarkers were significantly associated with age in cases and controls (P < 4.3 × 10-5). Concentrations of the Aß-related biomarkers in plasma were significantly lower in cases compared with controls, whereas other biomarker levels were significantly higher in cases. In the case-control genome-wide analyses, APOE-ε4 was associated with all biomarkers (P = 0.011-4.78 × 10-8), except NfL. No novel genome-wide significant single nucleotide polymorphisms were found in the case-control design; however, in a case-only analysis, we found two independent genome-wide significant associations between the Aß42/Aß40 ratio and WWOX and COPG2 genes. Disease prediction modelling by the combination of all biomarkers indicates that the variance attributed to P-tau181 is mostly captured by APOE-ε4, whereas Aß40, Aß42, GFAP and NfL biomarkers explain additional variation over and above APOE. We identified novel plausible genome wide-significant genes associated with Aß42/Aß40 ratio in a sample which is 50 times smaller than current genome-wide association studies in Alzheimer's disease.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/genética , Estudio de Asociación del Genoma Completo , Péptidos beta-Amiloides , Biomarcadores , Aminoácidos/genética , Apolipoproteínas E/genética , Proteínas tau/genética , Fragmentos de Péptidos
4.
J Neuroinflammation ; 20(1): 169, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37480051

RESUMEN

BACKGROUND: Alzheimer's disease (AD) has been associated with immune dysregulation in biomarker and genome-wide association studies (GWAS). GWAS hits include the genes encoding complement regulators clusterin (CLU) and complement receptor 1 (CR1), recognised as key players in AD pathology, and complement proteins have been proposed as biomarkers. MAIN BODY: To address whether changes in plasma complement protein levels in AD relate to AD-associated complement gene variants we first measured relevant plasma complement proteins (clusterin, C1q, C1s, CR1, factor H) in a large cohort comprising early onset AD (EOAD; n = 912), late onset AD (LOAD; n = 492) and control (n = 504) donors. Clusterin and C1q were significantly increased (p < 0.001) and sCR1 and factor H reduced (p < 0.01) in AD plasma versus controls. ROC analyses were performed to assess utility of the measured complement biomarkers, alone or in combination with amyloid beta, in predicting AD. C1q was the most predictive single complement biomarker (AUC 0.655 LOAD, 0.601 EOAD); combining C1q with other complement or neurodegeneration makers through stepAIC-informed models improved predictive values slightly. Effects of GWS SNPs (rs6656401, rs6691117 in CR1; rs11136000, rs9331888 in CLU; rs3919533 in C1S) on protein concentrations were assessed by comparing protein levels in carriers of the minor vs major allele. To identify new associations between SNPs and changes in plasma protein levels, we performed a GWAS combining genotyping data in the cohort with complement protein levels as endophenotype. SNPs in CR1 (rs6656401), C1S (rs3919533) and CFH (rs6664877) reached significance and influenced plasma levels of the corresponding protein, whereas SNPs in CLU did not influence clusterin levels. CONCLUSION: Complement dysregulation is evident in AD and may contribute to pathology. AD-associated SNPs in CR1, C1S and CFH impact plasma levels of the encoded proteins, suggesting a mechanism for impact on disease risk.


Asunto(s)
Enfermedad de Alzheimer , Factor H de Complemento , Humanos , Factor H de Complemento/genética , Enfermedad de Alzheimer/genética , Clusterina/genética , Péptidos beta-Amiloides , Complemento C1q , Estudio de Asociación del Genoma Completo , Proteínas del Sistema Complemento/genética
5.
Alzheimers Dement ; 19(9): 4187-4195, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37390458

RESUMEN

INTRODUCTION: Sequencing efforts to identify genetic variants and pathways underlying Alzheimer's disease (AD) have largely focused on late-onset AD although early-onset AD (EOAD), accounting for ∼10% of cases, is largely unexplained by known mutations, resulting in a lack of understanding of its molecular etiology. METHODS: Whole-genome sequencing and harmonization of clinical, neuropathological, and biomarker data of over 5000 EOAD cases of diverse ancestries. RESULTS: A publicly available genomics resource for EOAD with extensive harmonized phenotypes. Primary analysis will (1) identify novel EOAD risk loci and druggable targets; (2) assess local-ancestry effects; (3) create EOAD prediction models; and (4) assess genetic overlap with cardiovascular and other traits. DISCUSSION: This novel resource complements over 50,000 control and late-onset AD samples generated through the Alzheimer's Disease Sequencing Project (ADSP). The harmonized EOAD/ADSP joint call will be available through upcoming ADSP data releases and will allow for additional analyses across the full onset range. HIGHLIGHTS: Sequencing efforts to identify genetic variants and pathways underlying Alzheimer's disease (AD) have largely focused on late-onset AD although early-onset AD (EOAD), accounting for ∼10% of cases, is largely unexplained by known mutations. This results in a significant lack of understanding of the molecular etiology of this devastating form of the disease. The Early-Onset Alzheimer's Disease Whole-genome Sequencing Project is a collaborative initiative to generate a large-scale genomics resource for early-onset Alzheimer's disease with extensive harmonized phenotype data. Primary analyses are designed to (1) identify novel EOAD risk and protective loci and druggable targets; (2) assess local-ancestry effects; (3) create EOAD prediction models; and (4) assess genetic overlap with cardiovascular and other traits. The harmonized genomic and phenotypic data from this initiative will be available through NIAGADS.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/genética , Mutación/genética , Edad de Inicio
6.
Psychol Med ; 52(14): 2852-2860, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35959559

RESUMEN

Ensuring continuity of care for patients with major depressive disorders poses multiple challenges. We conducted a systematic review and meta-analysis of randomised controlled trials comparing real-time telehealth to face-to-face therapy for individuals with depression. We searched Medline, Embase, and Cochrane Central (to November 2020), conducted a citation analysis (January 2021), and searched clinical trial registries (March 2021). We included randomised controlled trials comparing similar or identical care, delivered via real-time telehealth (phone, video) to face-to-face. Outcomes included: depression severity, quality of life, therapeutic alliance, and care satisfaction. Where data were sufficient, mean differences were calculated. Nine trials (1268 patients) were included. There were no differences between telehealth and face-to-face care for depression severity at post-treatment (SMD -0.04, 95% CI -0.21 to 0.13, p = 0.67) or at other time points, except at 9 months post-treatment (SMD -0.39, 95% CI -0.75 to -0.02, p = 0.04). One trial reported no differences in quality-of-life scores at 3- or 12-months post-treatment. One trial found no differences in therapeutic alliance at weeks 4 and 14 of treatment. There were no differences in treatment satisfaction between telehealth and face-to-face immediately post-treatment (SMD -0.14, 95% CI -0.56 to 0.28, p = 0.51) or at 3 or 12-months. Evidence suggests that for patients with depression or depression symptoms, the provision of care via telehealth may be a viable alternative to the provision of care face-to-face. However, additional trials are needed with longer follow-up, conducted in a wider range of settings, and with younger patients.


Asunto(s)
Trastorno Depresivo Mayor , Telemedicina , Humanos , Depresión/terapia , Calidad de Vida , Trastorno Depresivo Mayor/terapia
7.
Mol Psychiatry ; 26(10): 5797-5811, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34112972

RESUMEN

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.


Asunto(s)
Enfermedad de Alzheimer , Trastornos Psicóticos , Esquizofrenia , Enfermedad de Alzheimer/genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Alucinaciones , Humanos , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro , Polimorfismo de Nucleótido Simple/genética , Trastornos Psicóticos/genética , Esquizofrenia/genética
8.
Health Expect ; 24(4): 1450-1458, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34153150

RESUMEN

BACKGROUND: Current guidelines recommend that patients attending general practice should be screened for excess weight, and provided with weight management advice. OBJECTIVE: This study sought to elicit the views of people with overweight and obesity about the role of GPs in initiating conversations about weight management. METHODS: Participants with a body mass index ≥25 were recruited from a region in Australia to take part in a Community Jury. Over 2 days, participants (n = 11) deliberated on two interconnected questions: 'Should GPs initiate discussions about weight management?' And 'if so, when: (a) opportunistically, (b) in the context of disease prevention, (c) in the context of disease management or (d) other?' The jury deliberations were analysed qualitatively to elicit their views and recommendations. RESULTS: The jury concluded GPs should be discussing weight management, but within the broader context of general health. The jury were divided about the utility of screening. Jurors felt GPs should initiate the conversation if directly relevant for disease prevention or management, otherwise GPs should provide opportunities for patients to consent to the issue being raised. CONCLUSION: The jury's verdict suggests informed people affected by overweight and obesity believe GPs should discuss weight management with their patients. GPs should feel reassured that discussions are likely to be welcomed by patients, particularly if embedded within a more holistic focus on person-centred care. PUBLIC CONTRIBUTION: Members of the public took part in the conduct of this study as jurors, but were not involved in the design, analysis or write-up.


Asunto(s)
Medicina General , Atención Primaria de Salud , Humanos , Tamizaje Masivo , Obesidad/prevención & control , Sobrepeso/terapia
9.
Ann Neurol ; 86(3): 427-435, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31199530

RESUMEN

OBJECTIVE: Alzheimer disease (AD) is the most common form of dementia and is responsible for a huge and growing health care burden in the developed and developing world. The polygenic risk score (PRS) approach has shown 75 to 84% prediction accuracy of identifying individuals with AD risk. METHODS: In this study, we tested the prediction accuracy of AD, mild cognitive impairment (MCI), and amyloid deposition risks with PRS, including and excluding APOE genotypes in a large publicly available dataset with extensive phenotypic data, the Alzheimer's Disease Neuroimaging Initiative cohort. Among MCI individuals with amyloid-positive status, we examined PRS prediction accuracy in those who converted to AD. In addition, we divided polygenic risk score by biological pathways and tested them independently for distinguishing between AD, MCI, and amyloid deposition. RESULTS: We found that AD and MCI are predicted by both APOE genotype and PRS (area under the curve [AUC] = 0.82% and 68%, respectively). Amyloid deposition is predicted by APOE only (AUC = 79%). Further progression to AD of individuals with MCI and amyloid-positive status is predicted by PRS over and above APOE (AUC = 67%). In pathway-specific PRS analyses, the protein-lipid complex has the strongest association with AD and amyloid deposition even when genes in the APOE region were removed (p = 0.0055 and p = 0.0079, respectively). INTERPRETATION: The results showed different pattern of APOE contribution in PRS risk predictions of AD/MCI and amyloid deposition. Our study suggests that APOE mostly contributes to amyloid accumulation and the PRS affects risk of further conversion to AD. ANN NEUROL 2019;86:427-435.


Asunto(s)
Enfermedad de Alzheimer/genética , Apolipoproteínas E/genética , Encéfalo/metabolismo , Disfunción Cognitiva/genética , Placa Amiloide/genética , Anciano , Anciano de 80 o más Años , Bases de Datos Genéticas , Progresión de la Enfermedad , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Herencia Multifactorial/genética , Placa Amiloide/metabolismo , Factores de Riesgo
10.
BMC Pregnancy Childbirth ; 20(1): 76, 2020 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-32028931

RESUMEN

BACKGROUND: Gestational diabetes mellitus (GDM) - a transitory form of diabetes induced by pregnancy - has potentially important short and long-term health consequences for both the mother and her baby. There is no globally agreed definition of GDM, but definition changes have increased the incidence in some countries in recent years, with some research suggesting minimal clinical improvement in outcomes. The aim of this qualitative systematic review was to identify the psychosocial experiences a diagnosis of GDM has on women during pregnancy and the postpartum period. METHODS: We searched CINAHL, EMBASE, MEDLINE and PsycINFO databases for studies that provided qualitative data on the psychosocial experiences of a diagnosis of GDM on women across any stage of pregnancy and/or the postpartum period. We appraised the methodological quality of the included studies using the Critical Appraisal Skills Programme Checklist for Qualitative Studies and used thematic analysis to synthesis the data. RESULTS: Of 840 studies identified, 41 studies of diverse populations met the selection criteria. The synthesis revealed eight key themes: initial psychological impact; communicating the diagnosis; knowledge of GDM; risk perception; management of GDM; burden of GDM; social support; and gaining control. The identified benefits of a GDM diagnosis were largely behavioural and included an opportunity to make healthy eating changes. The identified harms were emotional, financial and cultural. Women commented about the added responsibility (eating regimens, appointments), financial constraints (expensive food, medical bills) and conflicts with their cultural practices (alternative eating, lack of information about traditional food). Some women reported living in fear of risking the health of their baby and conducted extreme behaviours such as purging and starving themselves. CONCLUSION: A diagnosis of GDM has wide reaching consequences that are common to a diverse group of women. Threshold cut-offs for blood glucose levels have been determined using the risk of physiological harms to mother and baby. It may also be advantageous to consider the harms and benefits from a psychosocial and a physiological perspective. This may avoid unnecessary burden to an already vulnerable population.


Asunto(s)
Diabetes Gestacional/diagnóstico , Diabetes Gestacional/psicología , Conocimientos, Actitudes y Práctica en Salud , Periodo Posparto/psicología , Atención Prenatal/psicología , Comunicación , Ajuste Emocional , Femenino , Humanos , Estilo de Vida , Embarazo , Apoyo Social
11.
Health Expect ; 23(3): 593-602, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32090415

RESUMEN

BACKGROUND: There is no international diagnostic agreement for gestational diabetes mellitus (GDM). In 2014, Australia adopted a new definition and testing procedure. Since then, significantly more women have been diagnosed with GDM but with little difference in health outcomes. We explored the priorities and preferences of women potentially impacted by a GDM diagnosis. METHOD: We recruited 15 women from the Gold Coast, Australia, to participate in a pilot community jury (CJ). Over two days, the women deliberated on the following: (a) which important consequences of a diagnosis of GDM should be considered when defining GDM?; (b) what should Australian health practitioners call the condition known as GDM? RESULTS: Eight women attended the pilot CJ, and their recommendations were a consensus. Women were surprised that the level of risk for physical harms was low but emotional harms were high. The final ranking of important consequences (high to low) was as follows: women's negative emotions; management burden of GDM; overmedicalized pregnancy; minimizing infant risks; improving lifestyle; and macrosomia. To describe the four different clinical states of GDM, the women chose three different labels. One was GDM. CONCLUSIONS: The women from this pilot CJ prioritized the consequences of a diagnosis of GDM differently from clinicians. The current glucose threshold for GDM in Australia is set at a cut-point for adverse risks including macrosomia and neonatal hyperinsulinaemia. Definitions and guideline panels often fail to ask the affected public about their values and preferences. Community voices impacted by health policies should be embedded in the decision-making process.


Asunto(s)
Diabetes Gestacional , Complicaciones del Embarazo , Australia , Diabetes Gestacional/diagnóstico , Femenino , Macrosomía Fetal , Humanos , Recién Nacido , Estilo de Vida , Embarazo
12.
Genet Epidemiol ; 42(4): 366-377, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29532500

RESUMEN

Polygenic risk scores (PRSs) are a method to summarize the additive trait variance captured by a set of SNPs, and can increase the power of set-based analyses by leveraging public genome-wide association study (GWAS) datasets. PRS aims to assess the genetic liability to some phenotype on the basis of polygenic risk for the same or different phenotype estimated from independent data. We propose the application of PRSs as a set-based method with an additional component of adjustment for linkage disequilibrium (LD), with potential extension of the PRS approach to analyze biologically meaningful SNP sets. We call this method POLARIS: POlygenic Ld-Adjusted RIsk Score. POLARIS identifies the LD structure of SNPs using spectral decomposition of the SNP correlation matrix and replaces the individuals' SNP allele counts with LD-adjusted dosages. Using a raw genotype dataset together with SNP effect sizes from a second independent dataset, POLARIS can be used for set-based analysis. MAGMA is an alternative set-based approach employing principal component analysis to account for LD between markers in a raw genotype dataset. We used simulations, both with simple constructed and real LD-structure, to compare the power of these methods. POLARIS shows more power than MAGMA applied to the raw genotype dataset only, but less or comparable power to combined analysis of both datasets. POLARIS has the advantages that it produces a risk score per person per set using all available SNPs, and aims to increase power by leveraging the effect sizes from the discovery set in a self-contained test of association in the test dataset.


Asunto(s)
Estudio de Asociación del Genoma Completo , Desequilibrio de Ligamiento/genética , Herencia Multifactorial/genética , Alelos , Simulación por Computador , Humanos , Modelos Genéticos , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Análisis de Componente Principal , Factores de Riesgo
13.
Neuroimage ; 189: 793-803, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30735826

RESUMEN

Midlife obesity is a risk factor of late onset Alzheimer's disease (LOAD) but why this is the case remains unknown. As systemic inflammation is involved in both conditions, obesity-related neuroinflammation may contribute to damage in limbic structures important in LOAD. Here, we investigated the hypothesis that systemic inflammation would mediate central obesity related effects on limbic tissue microstructure in 166 asymptomatic individuals (38-71 years old). We employed MRI indices sensitive to myelin and neuroinflammation [macromolecular proton fraction (MPF) and kf] from quantitative magnetization transfer (qMT) together with indices from neurite orientation dispersion and density imaging (NODDI) to investigate the effects of central adiposity on the fornix, parahippocampal cingulum, uncinate fasciculus (compared with whole brain white matter and corticospinal tract) and the hippocampus. Central obesity was assessed with the Waist Hip Ratio (WHR) and abdominal visceral and subcutaneous fat area fractions (VFF, SFF), and systemic inflammation with blood plasma concentrations of leptin, adiponectin, C-reactive protein and interleukin 8. Men were significantly more centrally obese and had higher VFF than women. Individual differences in WHR and in VFF were negatively correlated with differences in fornix MPF and kf, but not with any differences in neurite microstructure. In women, age mediated the effects of VFF on fornix MPF and kf, whilst in men differences in the leptin and adiponectin ratio fully mediated the effect of WHR on fornix MPF. These results suggest that visceral fat related systemic inflammation may damage myelin-related properties of the fornix, a key limbic structure known to be involved in LOAD.


Asunto(s)
Adiposidad , Giro del Cíngulo/patología , Hipocampo/patología , Inflamación/complicaciones , Grasa Intraabdominal , Obesidad Abdominal/complicaciones , Caracteres Sexuales , Sustancia Blanca/patología , Adulto , Factores de Edad , Anciano , Femenino , Fórnix/diagnóstico por imagen , Fórnix/patología , Giro del Cíngulo/diagnóstico por imagen , Hipocampo/diagnóstico por imagen , Humanos , Inflamación/sangre , Inflamación/etiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Factores Sexuales , Sustancia Blanca/diagnóstico por imagen
14.
Health Expect ; 22(3): 537-546, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30864216

RESUMEN

BACKGROUND: Public participation in health policy decision making is thought to improve the quality of the decisions and enhance their legitimacy. Citizen/Community Juries (CJs) are a form of public participation that aims to elicit an informed community perspective on controversial topics. Reporting standards for CJ processes have already been proposed. However, less clarity exists about the standards for what constitutes a good quality CJ deliberation-we aim to begin to address this gap here. METHODS: We identified the goals that underlie CJs and searched the literature to identify existing frameworks assessing the quality of CJ deliberations. We then mapped the items constituting these frameworks onto the CJ goals; where none of the frameworks addressed one of the CJ goals, we generated additional items that did map onto the goal. RESULTS: This yielded a single operationalized deductive coding framework, consisting of four deliberation elements and four recommendation elements. The deliberation elements focus on the following: jurors' preferences and values, engagement with each other, referencing expert information and enrichment of the deliberation. The recommendation elements focus on the following: reaching a clear and identifiable recommendation, whether the recommendation directly addresses the CJ question, justification for the recommendation and adoption of societal (rather than individual) perspective. To explore the alignment between this framework and the goals underlying CJs, we mapped the operationalized framework onto the transcripts of a CJ. CONCLUSION: Results suggest that framework items map well onto what transpires in an actual CJ deliberation. Further testing of the validity, generalizability and reliability of the framework is planned.


Asunto(s)
Participación de la Comunidad/métodos , Toma de Decisiones , Objetivos , Política de Salud , Humanos
15.
Health Expect ; 22(3): 475-484, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30714290

RESUMEN

BACKGROUND: Case-finding for dementia is practised by general practitioners (GPs) in Australia but without an awareness of community preferences. We explored the values and preferences of informed community members around case-finding for dementia in Australian general practice. DESIGN, SETTING AND PARTICIPANTS: A before and after, mixed-methods study in Gold Coast, Australia, with ten community members aged 50-70. INTERVENTION: A 2-day citizen/community jury. Participants were informed by experts about dementia, the potential harms and benefits of case-finding, and ethical considerations. PRIMARY AND SECONDARY OUTCOMES: We asked participants, "Should the health system encourage GPs to practice 'case-finding' of dementia in people older than 50?" Case-finding was defined as a GP initiating testing for dementia when the patient is unaware of symptoms. We also assessed changes in participant comprehension/knowledge, attitudes towards dementia and participants' own intentions to undergo case-finding for dementia if it were suggested. RESULTS: Participants voted unanimously against case-finding for dementia, citing a lack of effective treatments, potential for harm to patients and potential financial incentives. However, they recognized that case-finding was currently practised by Australian GPs and recommended specific changes to the guidelines. Participants increased their comprehension/knowledge of dementia, their attitude towards case-finding became less positive, and their intentions to be tested themselves decreased. CONCLUSION: Once informed, community jury participants did not agree case-finding for dementia should be conducted by GPs. Yet their personal intentions to accept case-finding varied. If case-finding for dementia is recommended in the guidelines, then shared decision making is essential.


Asunto(s)
Demencia/diagnóstico , Medicina General/normas , Tamizaje Masivo/normas , Guías de Práctica Clínica como Asunto , Opinión Pública , Factores de Edad , Anciano , Australia , Femenino , Humanos , Masculino , Persona de Mediana Edad
16.
PLoS Genet ; 12(10): e1006327, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27764101

RESUMEN

We performed an exome-wide association analysis in 1393 late-onset Alzheimer's disease (LOAD) cases and 8141 controls from the CHARGE consortium. We found that a rare variant (P155L) in TM2D3 was enriched in Icelanders (~0.5% versus <0.05% in other European populations). In 433 LOAD cases and 3903 controls from the Icelandic AGES sub-study, P155L was associated with increased risk and earlier onset of LOAD [odds ratio (95% CI) = 7.5 (3.5-15.9), p = 6.6x10-9]. Mutation in the Drosophila TM2D3 homolog, almondex, causes a phenotype similar to loss of Notch/Presenilin signaling. Human TM2D3 is capable of rescuing these phenotypes, but this activity is abolished by P155L, establishing it as a functionally damaging allele. Our results establish a rare TM2D3 variant in association with LOAD susceptibility, and together with prior work suggests possible links to the ß-amyloid cascade.


Asunto(s)
Enfermedad de Alzheimer/genética , Proteínas de Drosophila/genética , Proteínas de la Membrana/genética , Receptores Notch/genética , Tropomiosina/genética , Edad de Inicio , Anciano , Alelos , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/genética , Animales , Apolipoproteínas E/genética , Drosophila melanogaster/genética , Exoma/genética , Femenino , Estudio de Asociación del Genoma Completo , Genómica , Humanos , Islandia , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Mutación , Fenotipo , Población Blanca
18.
Alzheimers Dement ; 14(7): 848-857, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29494809

RESUMEN

INTRODUCTION: Exploring the role of Alzheimer's disease (AD) implicated pathways in the predementia phase may provide new insight for preventive and clinical trials targeting disease specific pathways. METHODS: We constructed weighted Genetic risk scores, first based on 20 genome-wide significant AD risk variants and second clustering these variants within pathways. Risk scores were investigated for their association with AD, mild cognitive impairment, and brain magnetic resonance imaging phenotypes including white matter lesions, hippocampal volume, and brain volume. RESULTS: The risk score capturing endocytosis pathway was significantly associated with mild cognitive impairment (P = 1.44 × 10-4). Immune response (P = .016) and clathrin/AP2 adaptor complex pathway (P = 3.55 × 10-3) excluding apolipoprotein E also showed modest association with white matter lesions but did not sustain Bonferroni correction (P = 9.09 × 10-4). DISCUSSION: Our study suggests that the clinical spectrum of early AD pathology is explained by different biological pathways, in particular, the endocytosis, clathrin/AP2 adaptor complex, and immune response pathways, that are independent of apolipoprotein E (APOE).


Asunto(s)
Enfermedad de Alzheimer/genética , Disfunción Cognitiva/genética , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Encéfalo/patología , Disfunción Cognitiva/patología , Endocitosis/genética , Femenino , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Países Bajos , Estudios Prospectivos , Factores de Riesgo , Sustancia Blanca/patología
19.
Health Expect ; 20(4): 626-637, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-27704684

RESUMEN

BACKGROUND: Opportunities for community members to actively participate in policy development are increasing. Community/citizen's juries (CJs) are a deliberative democratic process aimed to illicit informed community perspectives on difficult topics. But how comprehensive these processes are reported in peer-reviewed literature is unknown. Adequate reporting of methodology enables others to judge process quality, compare outcomes, facilitate critical reflection and potentially repeat a process. We aimed to identify important elements for reporting CJs, to develop an initial checklist and to review published health and health policy CJs to examine reporting standards. DESIGN: Using the literature and expertise from CJ researchers and policy advisors, a list of important CJ reporting items was suggested and further refined. We then reviewed published CJs within the health literature and used the checklist to assess the comprehensiveness of reporting. RESULTS: CJCheck was developed and examined reporting of CJ planning, juror information, procedures and scheduling. We screened 1711 studies and extracted data from 38. No studies fully reported the checklist items. The item most consistently reported was juror numbers (92%, 35/38), while least reported was the availability of expert presentations (5%, 2/38). Recruitment strategies were described in 66% of studies (25/38); however, the frequency and timing of deliberations was inadequately described (29%, 11/38). CONCLUSIONS: Currently CJ publications in health and health policy literature are inadequately reported, hampering their use in policy making. We propose broadening the CJCheck by creating a reporting standards template in collaboration with international CJ researchers, policy advisors and consumer representatives to ensure standardized, systematic and transparent reporting.


Asunto(s)
Lista de Verificación/métodos , Participación de la Comunidad/psicología , Técnica Delphi , Formulación de Políticas , Política de Salud , Humanos
20.
Circulation ; 131(23): 2061-2069, 2015 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-25862742

RESUMEN

BACKGROUND: Epidemiological findings suggest a relationship between Alzheimer disease (AD), inflammation, and dyslipidemia, although the nature of this relationship is not well understood. We investigated whether this phenotypic association arises from a shared genetic basis. METHODS AND RESULTS: Using summary statistics (P values and odds ratios) from genome-wide association studies of >200 000 individuals, we investigated overlap in single-nucleotide polymorphisms associated with clinically diagnosed AD and C-reactive protein (CRP), triglycerides, and high- and low-density lipoprotein levels. We found up to 50-fold enrichment of AD single-nucleotide polymorphisms for different levels of association with C-reactive protein, low-density lipoprotein, high-density lipoprotein, and triglyceride single-nucleotide polymorphisms using a false discovery rate threshold <0.05. By conditioning on polymorphisms associated with the 4 phenotypes, we identified 55 loci associated with increased AD risk. We then conducted a meta-analysis of these 55 variants across 4 independent AD cohorts (total: n=29 054 AD cases and 114 824 healthy controls) and discovered 2 genome-wide significant variants on chromosome 4 (rs13113697; closest gene, HS3ST1; odds ratio=1.07; 95% confidence interval=1.05-1.11; P=2.86×10(-8)) and chromosome 10 (rs7920721; closest gene, ECHDC3; odds ratio=1.07; 95% confidence interval=1.04-1.11; P=3.38×10(-8)). We also found that gene expression of HS3ST1 and ECHDC3 was altered in AD brains compared with control brains. CONCLUSIONS: We demonstrate genetic overlap between AD, C-reactive protein, and plasma lipids. By conditioning on the genetic association with the cardiovascular phenotypes, we identify novel AD susceptibility loci, including 2 genome-wide significant variants conferring increased risk for AD.


Asunto(s)
Enfermedad de Alzheimer/genética , Proteína C-Reactiva/metabolismo , Dislipidemias/genética , Estudio de Asociación del Genoma Completo , Inflamación/genética , Lípidos/sangre , Herencia Multifactorial/genética , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/epidemiología , Biomarcadores/metabolismo , Encéfalo/metabolismo , Proteína C-Reactiva/genética , Dislipidemias/complicaciones , Femenino , Humanos , Inflamación/complicaciones , Lípidos/genética , Masculino , Enzima Bifuncional Peroxisomal/genética , Enzima Bifuncional Peroxisomal/metabolismo , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Factores de Riesgo , Sulfotransferasas/genética , Sulfotransferasas/metabolismo
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