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1.
Nat Commun ; 11(1): 5540, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33139712

RESUMO

APOE4 is the strongest genetic risk factor associated with late-onset Alzheimer's disease (AD). To address the underlying mechanism, we develop cerebral organoid models using induced pluripotent stem cells (iPSCs) with APOE ε3/ε3 or ε4/ε4 genotype from individuals with either normal cognition or AD dementia. Cerebral organoids from AD patients carrying APOE ε4/ε4 show greater apoptosis and decreased synaptic integrity. While AD patient-derived cerebral organoids have increased levels of Aß and phosphorylated tau compared to healthy subject-derived cerebral organoids, APOE4 exacerbates tau pathology in both healthy subject-derived and AD patient-derived organoids. Transcriptomics analysis by RNA-sequencing reveals that cerebral organoids from AD patients are associated with an enhancement of stress granules and disrupted RNA metabolism. Importantly, isogenic conversion of APOE4 to APOE3 attenuates the APOE4-related phenotypes in cerebral organoids from AD patients. Together, our study using human iPSC-organoids recapitulates APOE4-related phenotypes and suggests APOE4-related degenerative pathways contributing to AD pathogenesis.


Assuntos
Doença de Alzheimer/metabolismo , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Organoides/metabolismo , Sinapses/metabolismo , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Regulação da Expressão Gênica , Genótipo , Humanos , Organoides/patologia , RNA/metabolismo , Transcriptoma
2.
Nat Commun ; 11(1): 4727, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948752

RESUMO

The apolipoprotein E (APOE) gene contains both the major common risk variant for late onset Alzheimer's disease (AD), e4, and the major neuroprotective variant, e2. Here we examine the association of APOE e2 with multiple neurodegenerative pathologies, leveraging the NACC v. 10 database of 1557 brains that included 130 e2 carriers and 679 e4 carriers in order to examine potential neuroprotective effects. For AD-related pathologies of amyloid plaques and Braak stage, e2 had large and highly significant protective effects contrasted with e3/e3 and e4 carriers with odds ratios of about 0.50 for e3 contrasts and 0.10 for e4 contrasts. When we separately examined e2/e4 carriers, risk for AD pathologies was similar to that of e4 carriers, not e2 carriers. For multiple fronto-temporal lobar pathologies and tauopathies, e2 was not significantly associated with pathology. In sum, we found that e2 was associated with large but circumscribed protective effects.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Apolipoproteína E2/genética , Apolipoproteína E2/metabolismo , Genótipo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Encéfalo/metabolismo , Feminino , Degeneração Lobar Frontotemporal/metabolismo , Humanos , Modelos Logísticos , Masculino , Placa Amiloide/patologia , Tauopatias/metabolismo , alfa-Sinucleína/metabolismo
3.
PLoS Med ; 17(8): e1003289, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817639

RESUMO

BACKGROUND: The ε4 allele of apolipoprotein E (APOE) gene and increasing age are two of the most important known risk factors for developing Alzheimer disease (AD). The diagnosis of AD based on clinical symptoms alone is known to have poor specificity; recently developed diagnostic criteria based on biomarkers that reflect underlying AD neuropathology allow better assessment of the strength of the associations of risk factors with AD. Accordingly, we examined the global and age-specific association between APOE genotype and AD by using the A/T/N classification, relying on the cerebrospinal fluid (CSF) levels of ß-amyloid peptide (A, ß-amyloid deposition), phosphorylated tau (T, pathologic tau), and total tau (N, neurodegeneration) to identify patients with AD. METHODS AND FINDINGS: This case-control study included 1,593 white AD cases (55.4% women; mean age 72.8 [range = 44-96] years) with abnormal values of CSF biomarkers from nine European memory clinics and the American Alzheimer's Disease Neuroimaging Initiative (ADNI) study. A total of 11,723 dementia-free controls (47.1% women; mean age 65.6 [range = 44-94] years) were drawn from two longitudinal cohort studies (Whitehall II and Three-City), in which incident cases of dementia over the follow-up were excluded from the control population. Odds ratio (OR) and population attributable fraction (PAF) for AD associated with APOE genotypes were determined, overall and by 5-year age categories. In total, 63.4% of patients with AD and 22.6% of population controls carried at least one APOE ε4 allele. Compared with non-ε4 carriers, heterozygous ε4 carriers had a 4.6 (95% confidence interval 4.1-5.2; p < 0.001) and ε4/ε4 homozygotes a 25.4 (20.4-31.2; p < 0.001) higher OR of AD in unadjusted analysis. This association was modified by age (p for interaction < 0.001). The PAF associated with carrying at least one ε4 allele was greatest in the 65-70 age group (69.7%) and weaker before 55 years (14.2%) and after 85 years (22.6%). The protective effect of APOE ε2 allele for AD was unaffected by age. Main study limitations are that analyses were based on white individuals and AD cases were drawn from memory centers, which may not be representative of the general population of patients with AD. CONCLUSIONS: In this study, we found that AD diagnosis based on biomarkers was associated with APOE ε4 carrier status, with a higher OR than previously reported from studies based on only clinical AD criteria. This association differs according to age, with the strongest effect at 65-70 years. These findings highlight the need for early interventions for dementia prevention to mitigate the effect of APOE ε4 at the population level.


Assuntos
Envelhecimento/líquido cefalorraquidiano , Envelhecimento/genética , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/genética , Apolipoproteína E4/líquido cefalorraquidiano , Apolipoproteína E4/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquidiano , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
4.
Neurology ; 95(11): e1554-e1564, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32759192

RESUMO

OBJECTIVE: To determine whether years of education and the ε4 risk allele at APOE influence ß-amyloid (Aß) pathology similarly in asymptomatic individuals with a family history of sporadic Alzheimer disease (AD) and presymptomatic autosomal dominant AD mutation carriers. METHODS: We analyzed cross-sectional data from 106 asymptomatic individuals with a parental history of sporadic AD (PREVENT-AD cohort; age 67.28 ± 4.72 years) and 117 presymptomatic autosomal dominant AD mutation carriers (DIAN cohort; age 35.04 ± 9.43 years). All participants underwent structural MRI and Aß-PET imaging. In each cohort we investigated the influence of years of education, APOE ε4 status, and their interaction on Aß-PET. RESULTS: Asymptomatic individuals with a parental history of sporadic AD showed increased Aß burden associated with APOE ε4 carriage and lower level of education, but no interaction between these. Presymptomatic mutation carriers of autosomal dominant AD showed no relation between APOE ε4 and Aß burden, but increasing level of education was associated with reduced Aß burden. The association between educational attainment and Aß burden was similar in the 2 cohorts. CONCLUSIONS: While the APOE ε4 allele confers increased tendency toward Aß accumulation in sporadic AD only, protective environmental factors, like increased education, may promote brain resistance against Aß pathology in both sporadic and autosomal dominant AD.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Apolipoproteína E4/genética , Escolaridade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Curr Atheroscler Rep ; 22(9): 48, 2020 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-32710255

RESUMO

PURPOSE OF REVIEW: The COVID-19 pandemic has infected over > 11 million as of today people worldwide and is associated with significant cardiovascular manifestations, particularly in subjects with preexisting comorbidities and cardiovascular risk factors. Recently, a predisposition for arterial and venous thromboses has been reported in COVID-19 infection. We hypothesize that besides conventional risk factors, subjects with elevated lipoprotein(a) (Lp(a)) may have a particularly high risk of developing cardiovascular complications. RECENT FINDINGS: The Lp(a) molecule has the propensity for inhibiting endogenous fibrinolysis through its apolipoprotein(a) component and for enhancing proinflammatory effects such as through its content of oxidized phospholipids. The LPA gene contains an interleukin-6 (IL-6) response element that may induce an acute phase-type increase in Lp(a) levels following a cytokine storm from COVID-19. Thus, subjects with either baseline elevated Lp(a) or those who have an increase following COVID-19 infection, or both, may be at very high risk of developing thromboses. Elevated Lp(a) may also lead to acute destabilization of preexisting but quiescent atherosclerotic plaques, which might induce acute myocardial infarction and stroke. Ongoing studies with IL-6 antagonists may be informative in understanding this relationship, and registries are being initiated to measure Lp(a) in subjects infected with COVID-19. If indeed an association is suggestive of being causal, consideration can be given to systematic testing of Lp(a) and prophylactic systemic anticoagulation in infected inpatients. Therapeutic lipid apheresis and pharmacotherapy for the reduction of Lp(a) levels may minimize thrombogenic potential and proinflammatory effects. We propose studies to test the hypothesis that Lp(a) may contribute to cardiovascular complications of COVID-19.


Assuntos
Infecções por Coronavirus/sangue , Infecções por Coronavirus/complicações , Inflamação/etiologia , Lipoproteína(a)/sangue , Pneumonia Viral/sangue , Pneumonia Viral/complicações , Trombose/etiologia , Proteínas da Fase Aguda/análise , Proteínas da Fase Aguda/genética , Anticoagulantes/uso terapêutico , Apolipoproteína E4/genética , Aterosclerose/etiologia , Betacoronavirus , Biomarcadores/sangue , Pesquisa Biomédica , Remoção de Componentes Sanguíneos , Grupos de Populações Continentais/genética , Infecções por Coronavirus/epidemiologia , Genótipo , Humanos , Inflamação/prevenção & controle , Interleucina-6/antagonistas & inibidores , Interleucina-6/sangue , Lipoproteína(a)/genética , Pandemias , Pneumonia Viral/epidemiologia , Fatores Raciais , Fatores de Risco , Índice de Gravidade de Doença , Trombose/prevenção & controle
6.
Stroke ; 51(7): 2153-2160, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32517581

RESUMO

BACKGROUND AND PURPOSE: For survivors of oral anticoagulation therapy (OAT)-associated intracerebral hemorrhage (OAT-ICH) who are at high risk for thromboembolism, the benefits of OAT resumption must be weighed against increased risk of recurrent hemorrhagic stroke. The ε2/ε4 alleles of the apolipoprotein E (APOE) gene, MRI-defined cortical superficial siderosis, and cerebral microbleeds are the most potent risk factors for recurrent ICH. We sought to determine whether combining MRI markers and APOE genotype could have clinical impact by identifying ICH survivors in whom the risks of OAT resumption are highest. METHODS: Joint analysis of data from 2 longitudinal cohort studies of OAT-ICH survivors: (1) MGH-ICH study (Massachusetts General Hospital ICH) and (2) longitudinal component of the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage). We evaluated whether MRI markers and APOE genotype predict ICH recurrence. We then developed and validated a combined APOE-MRI classification scheme to predict ICH recurrence, using Classification and Regression Tree analysis. RESULTS: Cortical superficial siderosis, cerebral microbleed, and APOE ε2/ε4 variants were independently associated with ICH recurrence after OAT-ICH (all P<0.05). Combining APOE genotype and MRI data resulted in improved prediction of ICH recurrence (Harrell C: 0.79 versus 0.55 for clinical data alone, P=0.033). In the MGH (training) data set, CSS, cerebral microbleed, and APOE ε2/ε4 stratified likelihood of ICH recurrence into high-, medium-, and low-risk categories. In the ERICH (validation) data set, yearly ICH recurrence rates for high-, medium-, and low-risk individuals were 6.6%, 2.5%, and 0.9%, respectively, with overall area under the curve of 0.91 for prediction of recurrent ICH. CONCLUSIONS: Combining MRI and APOE genotype stratifies likelihood of ICH recurrence into high, medium, and low risk. If confirmed in prospective studies, this combined APOE-MRI classification scheme may prove useful for selecting individuals for OAT resumption after ICH.


Assuntos
Anticoagulantes/efeitos adversos , Apolipoproteína E4/genética , Hemorragia Cerebral/induzido quimicamente , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/genética , Idoso , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Recidiva
8.
Nat Med ; 26(6): 952-963, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32514169

RESUMO

In Alzheimer's disease, amyloid deposits along the brain vasculature lead to a condition known as cerebral amyloid angiopathy (CAA), which impairs blood-brain barrier (BBB) function and accelerates cognitive degeneration. Apolipoprotein (APOE4) is the strongest risk factor for CAA, yet the mechanisms underlying this genetic susceptibility are unknown. Here we developed an induced pluripotent stem cell-based three-dimensional model that recapitulates anatomical and physiological properties of the human BBB in vitro. Similarly to CAA, our in vitro BBB displayed significantly more amyloid accumulation in APOE4 compared to APOE3. Combinatorial experiments revealed that dysregulation of calcineurin-nuclear factor of activated T cells (NFAT) signaling and APOE in pericyte-like mural cells induces APOE4-associated CAA pathology. In the human brain, APOE and NFAT are selectively dysregulated in pericytes of APOE4 carriers, and inhibition of calcineurin-NFAT signaling reduces APOE4-associated CAA pathology in vitro and in vivo. Our study reveals the role of pericytes in APOE4-mediated CAA and highlights calcineurin-NFAT signaling as a therapeutic target in CAA and Alzheimer's disease.


Assuntos
Apolipoproteína E4/genética , Barreira Hematoencefálica/metabolismo , Calcineurina/metabolismo , Angiopatia Amiloide Cerebral/genética , Fatores de Transcrição NFATC/genética , Pericitos/metabolismo , Peptídeos beta-Amiloides/metabolismo , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Apolipoproteína E4/metabolismo , Barreira Hematoencefálica/citologia , Humanos , Técnicas In Vitro , Células-Tronco Pluripotentes Induzidas , Fatores de Transcrição NFATC/metabolismo , Permeabilidade , RNA-Seq , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Neurology ; 94(23): e2404-e2411, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32457210

RESUMO

OBJECTIVE: To test the hypothesis that ApoE isoforms affect mitochondrial structure and function that are related to cognitive impairment in Alzheimer disease (AD), we systematically investigated the effects of ApoE isoforms on mitochondrial biogenesis and dynamics, oxidative stress, synapses, and cognitive performance in AD. METHODS: We obtained postmortem human brain tissues and measured proteins that are responsible for mitochondrial biogenesis (peroxisome proliferator-activated receptor-gamma coactivator-1α [PGC-1α] and sirtuin 3 [SIRT3]), for mitochondrial dynamics (mitofusin 1 [MFN1], mitofusin 2 [MFN2], and dynamin-like protein 1 [DLP1]), for oxidative stress (superoxide dismutase 2 [SOD2] and forkhead-box protein O3a [Foxo3a]), and for synapses (postsynaptic density protein 95 [PSD95] and synapsin1 [Syn1]). A total of 46 cases were enrolled, including ApoE-ɛ4 carriers (n = 21) and noncarriers (n = 25). RESULTS: Levels of these proteins were compared between ApoE-ɛ4 carriers and noncarriers. ApoE-ɛ4 was associated with impaired mitochondrial structure and function, oxidative stress, and synaptic integrity in the human brain. Correlation analysis revealed that mitochondrial proteins and the synaptic protein were strongly associated with cognitive performance. CONCLUSION: ApoE isoforms influence mitochondrial structure and function, which likely leads to alteration in oxidative stress, synapses, and cognitive function. These mitochondria-related proteins may be a harbinger of cognitive decline in ApoE-ɛ4 carriers and provide novel therapeutic targets for prevention and treatment of AD.


Assuntos
Doença de Alzheimer/metabolismo , Apolipoproteínas E/fisiologia , Mitocôndrias/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Apolipoproteína E4/genética , Apolipoproteína E4/fisiologia , Química Encefálica , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência , Mitocôndrias/ultraestrutura , Dinâmica Mitocondrial , Proteínas Mitocondriais/análise , Proteínas do Tecido Nervoso/análise , Plasticidade Neuronal/genética , Biogênese de Organelas , Estresse Oxidativo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/análise , Isoformas de Proteínas/fisiologia , Sirtuína 3/análise , Aprendizagem Verbal
10.
Nature ; 581(7806): 71-76, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32376954

RESUMO

Vascular contributions to dementia and Alzheimer's disease are increasingly recognized1-6. Recent studies have suggested that breakdown of the blood-brain barrier (BBB) is an early biomarker of human cognitive dysfunction7, including the early clinical stages of Alzheimer's disease5,8-10. The E4 variant of apolipoprotein E (APOE4), the main susceptibility gene for Alzheimer's disease11-14, leads to accelerated breakdown of the BBB and degeneration of brain capillary pericytes15-19, which maintain BBB integrity20-22. It is unclear, however, whether the cerebrovascular effects of APOE4 contribute to cognitive impairment. Here we show that individuals bearing APOE4 (with the ε3/ε4 or ε4/ε4 alleles) are distinguished from those without APOE4 (ε3/ε3) by breakdown of the BBB in the hippocampus and medial temporal lobe. This finding is apparent in cognitively unimpaired APOE4 carriers and more severe in those with cognitive impairment, but is not related to amyloid-ß or tau pathology measured in cerebrospinal fluid or by positron emission tomography23. High baseline levels of the BBB pericyte injury biomarker soluble PDGFRß7,8 in the cerebrospinal fluid predicted future cognitive decline in APOE4 carriers but not in non-carriers, even after controlling for amyloid-ß and tau status, and were correlated with increased activity of the BBB-degrading cyclophilin A-matrix metalloproteinase-9 pathway19 in cerebrospinal fluid. Our findings suggest that breakdown of the BBB contributes to APOE4-associated cognitive decline independently of Alzheimer's disease pathology, and might be a therapeutic target in APOE4 carriers.


Assuntos
Apolipoproteína E4/genética , Barreira Hematoencefálica/patologia , Disfunção Cognitiva/genética , Disfunção Cognitiva/patologia , Alelos , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Peptídeos beta-Amiloides/metabolismo , Capilares/patologia , Ciclofilina A/líquido cefalorraquidiano , Ciclofilina A/metabolismo , Feminino , Heterozigoto , Hipocampo/irrigação sanguínea , Humanos , Masculino , Metaloproteinase 9 da Matriz/líquido cefalorraquidiano , Metaloproteinase 9 da Matriz/metabolismo , Giro Para-Hipocampal/irrigação sanguínea , Pericitos/patologia , Tomografia por Emissão de Pósitrons , Receptor beta de Fator de Crescimento Derivado de Plaquetas/líquido cefalorraquidiano , Lobo Temporal/irrigação sanguínea , Proteínas tau/líquido cefalorraquidiano , Proteínas tau/metabolismo
12.
Nat Med ; 26(7): 1048-1053, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32451497

RESUMO

Common germline variants of the APOE gene are major risk modifiers of neurodegenerative and atherosclerotic diseases1-3, but their effect on cancer outcome is poorly defined. Here we report that, in a reversal of their effect on Alzheimer's disease, the APOE4 and APOE2 variants confer favorable and poor outcomes in melanoma, respectively. Mice expressing the human APOE4 allele exhibited reduced melanoma progression and metastasis relative to APOE2 mice. APOE4 mice exhibited enhanced anti-tumor immune activation relative to APOE2 mice, and T cell depletion experiments showed that the effect of APOE genotype on melanoma progression was mediated by altered anti-tumor immunity. Consistently, patients with melanoma carrying the APOE4 variant experienced improved survival in comparison to carriers of APOE2. Notably, APOE4 mice also showed improved outcomes under PD1 immune checkpoint blockade relative to APOE2 mice, and patients carrying APOE4 experienced improved anti-PD1 immunotherapy survival after progression on frontline regimens. Finally, enhancing APOE expression via pharmacologic activation of liver X receptors, previously shown to boost anti-tumor immunity4, exhibited therapeutic efficacy in APOE4 mice but not in APOE2 mice. These findings demonstrate that pre-existing hereditary genetics can impact progression and survival outcomes of a future malignancy and warrant prospective investigation of APOE genotype as a biomarker for melanoma outcome and therapeutic response.


Assuntos
Apolipoproteína E2/genética , Apolipoproteína E3/genética , Apolipoproteína E4/genética , Melanoma/genética , Animais , Encéfalo/imunologia , Encéfalo/metabolismo , Encéfalo/patologia , Progressão da Doença , Intervalo Livre de Doença , Feminino , Genótipo , Mutação em Linhagem Germinativa/genética , Mutação em Linhagem Germinativa/imunologia , Humanos , Melanoma/imunologia , Melanoma/patologia , Camundongos , Camundongos Transgênicos/genética , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia
13.
Neurobiol Aging ; 92: 61-72, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32388179

RESUMO

In the Look AHEAD trial, randomization to Intensive Lifestyle Intervention (ILI) or Diabetes Support and Education (DSE) did not result in differences in cognitive outcomes. However, menopause and APOE genotype are factors that affect the response to this intervention. The effect of this intervention on a single cognitive assessment was examined in 3 groups of women: premenopausal or <5 years postmenopausal (N = 594), within 5-10 years (n = 388), and ≥10 years postmenopausal (n = 963), and as a function of continuous years since menopause. The late postmenopausal group in the ILI had worse composite z-scores compared to those in the DSE, whereas the younger premenopausal or early postmenopausal women in the ILI had better composite z-scores than the DSE. A significant interaction between years since menopause and intervention arm, but not baseline age, was observed on executive function domains. ILI appeared only to benefit cognitive function among non-APOE4 carriers during premenopause or early postmenopause. These findings emphasize the importance of assessing menopause and APOE status to understand how weight loss impacts cognition.


Assuntos
Apolipoproteína E4/genética , Cognição , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/psicologia , Genótipo , Estilo de Vida , Menopausa/genética , Menopausa/fisiologia , Perda de Peso/fisiologia , Idoso , Feminino , Heterozigoto , Humanos , Pessoa de Meia-Idade , Fatores de Tempo
14.
PLoS One ; 15(3): e0229240, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119690

RESUMO

Various brain injuries lead to the activation of adult neural stem/progenitor cells in the mammalian hippocampus. Subsequent injury-induced neurogenesis appears to be essential for at least some aspects of the innate recovery in cognitive function observed following traumatic brain injury (TBI). It has previously been established that Apolipoprotein E (ApoE) plays a regulatory role in adult hippocampal neurogenesis, which is of particular interest as the presence of the human ApoE isoform ApoE4 leads to significant risk for the development of late-onset Alzheimer's disease, where impaired neurogenesis has been linked with disease progression. Moreover, genetically modified mice lacking ApoE or expressing the ApoE4 human isoform have been shown to impair adult hippocampal neurogenesis under normal conditions. Here, we investigate how controlled cortical impact (CCI) injury affects dentate gyrus development using hippocampal stereotactic injections of GFP-expressing retroviruses in wild-type (WT), ApoE-deficient and humanized (ApoE3 and ApoE4) mice. Infected adult-born hippocampal neurons were morphologically analyzed once fully mature, revealing significant attenuation of dendritic complexity and spine density in mice lacking ApoE or expressing the human ApoE4 allele, which may help inform how ApoE influences neurological diseases where neurogenesis is defective.


Assuntos
Apolipoproteína E3/metabolismo , Apolipoproteína E4/metabolismo , Apolipoproteínas E/deficiência , Lesões Encefálicas Traumáticas/patologia , Hipocampo/crescimento & desenvolvimento , Retroviridae/genética , Animais , Apolipoproteína E3/genética , Apolipoproteína E4/genética , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/metabolismo , Modelos Animais de Doenças , Feminino , Vetores Genéticos/administração & dosagem , Hipocampo/metabolismo , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Neurogênese , Neurônios/metabolismo
15.
Nat Rev Neurol ; 16(4): 193-197, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32152461

RESUMO

The idea that infectious agents in the brain have a role in the pathogenesis of Alzheimer disease (AD) was proposed nearly 30 years ago. However, this theory failed to gain substantial traction and was largely disregarded by the AD research community for many years. Several recent discoveries have reignited interest in the infectious theory of AD, culminating in a debate on the topic at the Alzheimer's Association International Conference (AAIC) in July 2019. In this Viewpoint article, experts who participated in the AAIC debate weigh up the evidence for and against the infectious theory of AD and suggest avenues for future research and drug development.


Assuntos
Doença de Alzheimer/microbiologia , Encéfalo/microbiologia , Infecções/microbiologia , Doença de Alzheimer/etiologia , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Borrelia burgdorferi , Chlamydophila pneumoniae , Herpesvirus Humano 1 , Herpesvirus Humano 6 , Herpesvirus Humano 7 , Humanos , Infecções/complicações , Porphyromonas gingivalis
16.
Arch Clin Neuropsychol ; 35(6): 660-670, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32129455

RESUMO

OBJECTIVE: Mild cognitive impairment and dementia are clinically heterogeneous disorders influenced by diverse risk factors. Improved characterization of the effect of multiple risk factors influence on specific cognitive functions may improve understanding of mechanisms in early cognitive change and lead to more effective interventions. METHODS: Structural equation modeling (SEM) simultaneously examined the effects of modifiable (education, depression, and metabolic/vascular risk) and nonmodifiable risk factors (age, sex, and apolipoprotein E-ɛ4 allele [APOE-e4] status) on specific cognitive domains in 461 cognitively normal older adults. RESULTS: The hypothesized model(s) provided an adequate fit for the data. Sex differences in cognition, depression, and vascular risk were found. On average, men were higher in vascular risk with generally lower cognitive performance than women; women were more likely to have depression. APOE-e4 associated with depression but not age, sex, or metabolic/vascular risk. Depression associated with lower executive attention, memory, and language performance, whereas metabolic/vascular risk associated with lower executive attention, memory, and working memory. Older age and lower education are associated with worse performance across the cognitive domains. The combined risk factors accounted for 16%-47% of the variance in the cognitive domains. CONCLUSIONS: Results highlight the combined effect of risk factors on cognitive function. Future research is needed to determine whether the multifactorial risk effects on cognition vary by sex. Precision medicine approaches that integrate neuropsychological services may improve diagnostic accuracy and earlier identification of those at risk of cognitive decline.


Assuntos
Apolipoproteína E4 , Cognição , Depressão , Doenças Vasculares , Idoso , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Depressão/genética , Feminino , Humanos , Masculino , Memória , Testes Neuropsicológicos , Risco , Doenças Vasculares/genética
17.
Neuron ; 106(5): 727-742.e6, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32199103

RESUMO

Evidence suggests interplay among the three major risk factors for Alzheimer's disease (AD): age, APOE genotype, and sex. Here, we present comprehensive datasets and analyses of brain transcriptomes and blood metabolomes from human apoE2-, apoE3-, and apoE4-targeted replacement mice across young, middle, and old ages with both sexes. We found that age had the greatest impact on brain transcriptomes highlighted by an immune module led by Trem2 and Tyrobp, whereas APOE4 was associated with upregulation of multiple Serpina3 genes. Importantly, these networks and gene expression changes were mostly conserved in human brains. Finally, we observed a significant interaction between age, APOE genotype, and sex on unfolded protein response pathway. In the periphery, APOE2 drove distinct blood metabolome profile highlighted by the upregulation of lipid metabolites. Our work identifies unique and interactive molecular pathways underlying AD risk factors providing valuable resources for discovery and validation research in model systems and humans.


Assuntos
Envelhecimento/genética , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Encéfalo/metabolismo , Serpinas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Fatores Etários , Doença de Alzheimer/metabolismo , Animais , Apolipoproteína E2/genética , Apolipoproteína E3/genética , Apolipoproteína E4/genética , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Genótipo , Humanos , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Metaboloma , Camundongos , Camundongos Transgênicos , Fatores de Proteção , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Fatores de Risco , Fatores Sexuais , Resposta a Proteínas não Dobradas/genética
18.
Stroke ; 51(3): 751-758, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32070224

RESUMO

Background and Purpose- APOE-ε4 genotype is a risk factor for sporadic Alzheimer disease and reduced recovery from brain injury. Since data on APOE genotype and dementia associated with transient ischemic attack/stroke are sparse, we determined the associations in a longitudinal population-based cohort. Methods- All patients with transient ischemic attack or stroke (2002-2012) in a defined population of 92 728 OxVASC (Oxford Vascular Study) had follow-up to 5-years. Pre-event and incident postevent dementia were ascertained through direct patient assessment and follow-up, supplemented by review of hospital/primary care records. Associations between pre- and post-event dementia and APOE genotype (ε4/ε4-homozygous and ε4/ε3-heterozygous versus ε3/ε3) were examined using logistic regression and Cox regression models, respectively, adjusted for age, sex, education, cerebrovascular burden (stroke severity, prior stroke, white matter disease), diabetes mellitus, and dysphasia. Results- Among 1767 genotyped patients (mean/SD age, 73.0/13.0 years, 901 [51%] male, 602 [34%] transient ischemic attack), 1058 (59.9%) were APOE-ε3/ε3, 403 (22.8%) were ε4/ε3 and 30 (1.7%) were ε4-homozygous. Homozygosity was associated with both pre-event (adjusted odds ratio, 5.81 [95% CI, 1.93-17.48]; P=0.002) and postevent dementia (adjusted hazard ratio, 3.64 [95% CI, 1.90-7.00]; P<0.0001). Association with postevent dementia was maintained after further adjustment for baseline cognitive impairment (hazard ratio, 2.41 [95% CI, 1.19-4.89]; P=0.01). There were no associations overall between ε4/ε3 and pre-event dementia (adjusted odds ratio, 1.47 [95% CI, 0.88-2.45]; P=0.14) or postevent dementia (hazard ratio, 1.11 [95% CI, 0.84-1.48]; P=0.47). Conclusions- In patients with transient ischemic attack and stroke, APOE-ε4 homozygosity was associated with both pre- and post-event dementia. Associations were independent of cerebrovascular burden and may be mediated through increased neurodegenerative pathology or vulnerability to injury.


Assuntos
Apolipoproteína E4/genética , Demência/etiologia , Demência/genética , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/genética , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/genética , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Estudos de Coortes , Efeitos Psicossociais da Doença , Demência/epidemiologia , Feminino , Seguimentos , Genótipo , Homozigoto , Humanos , Ataque Isquêmico Transitório/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estudos Prospectivos , Acidente Vascular Cerebral/epidemiologia , Substância Branca/diagnóstico por imagem
20.
Brain ; 143(3): 976-992, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32091109

RESUMO

Research into hippocampal self-regulation abilities may help determine the clinical significance of hippocampal hyperactivity throughout the pathophysiological continuum of Alzheimer's disease. In this study, we aimed to identify the effects of amyloid-ß peptide 42 (amyloid-ß42) and phosphorylated tau on the patterns of functional connectomics involved in hippocampal downregulation. We identified 48 cognitively unimpaired participants (22 with elevated CSF amyloid-ß peptide 42 levels, 15 with elevated CSF phosphorylated tau levels, mean age of 62.705 ± 4.628 years), from the population-based 'Alzheimer's and Families' study, with baseline MRI, CSF biomarkers, APOE genotyping and neuropsychological evaluation. We developed a closed-loop, real-time functional MRI neurofeedback task with virtual reality and tailored it for training downregulation of hippocampal subfield cornu ammonis 1 (CA1). Neurofeedback performance score, cognitive reserve score, hippocampal volume, number of apolipoprotein ε4 alleles and sex were controlled for as confounds in all cross-sectional analyses. First, using voxel-wise multiple regression analysis and controlling for CSF biomarkers, we identified the effect of healthy ageing on eigenvector centrality, a measure of each voxel's overall influence based on iterative whole-brain connectomics, during hippocampal CA1 downregulation. Then, controlling for age, we identified the effects of abnormal CSF amyloid-ß42 and phosphorylated tau levels on eigenvector centrality during hippocampal CA1 downregulation. Across subjects, our main findings during hippocampal downregulation were: (i) in the absence of abnormal biomarkers, age correlated with eigenvector centrality negatively in the insula and midcingulate cortex, and positively in the inferior temporal gyrus; (ii) abnormal CSF amyloid-ß42 (<1098) correlated negatively with eigenvector centrality in the anterior cingulate cortex and primary motor cortex; and (iii) abnormal CSF phosphorylated tau levels (>19.2) correlated with eigenvector centrality positively in the ventral striatum, anterior cingulate and somatosensory cortex, and negatively in the precuneus and orbitofrontal cortex. During resting state functional MRI, similar eigenvector centrality patterns in the cingulate had previously been associated to CSF biomarkers in mild cognitive impairment and dementia patients. Using the developed closed-loop paradigm, we observed such patterns, which are characteristic of advanced disease stages, during a much earlier presymptomatic phase. In the absence of CSF biomarkers, our non-invasive, interactive, adaptive and gamified neuroimaging procedure may provide important information for clinical prognosis and monitoring of therapeutic efficacy. We have released the developed paradigm and analysis pipeline as open-source software to facilitate replication studies.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Região CA1 Hipocampal/metabolismo , Neurorretroalimentação/métodos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Fatores Etários , Idoso , Doença de Alzheimer/complicações , Apolipoproteína E4/genética , Biomarcadores/líquido cefalorraquidiano , Estudos de Casos e Controles , Disfunção Cognitiva/complicações , Disfunção Cognitiva/metabolismo , Conectoma , Estudos Transversais , Regulação para Baixo , Feminino , Genótipo , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Testes Neuropsicológicos , Fosforilação , Software , Realidade Virtual
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