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1.
Nat Immunol ; 24(11): 1854-1866, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37857825

RESUMO

Microglial involvement in Alzheimer's disease (AD) pathology has emerged as a risk-determining pathogenic event. While apolipoprotein E (APOE) is known to modify AD risk, it remains unclear how microglial apoE impacts brain cognition and AD pathology. Here, using conditional mouse models expressing apoE isoforms in microglia and central nervous system-associated macrophages (CAMs), we demonstrate a cell-autonomous effect of apoE3-mediated microglial activation and function, which are negated by apoE4. Expression of apoE3 in microglia/CAMs improves cognitive function, increases microglia surrounding amyloid plaque and reduces amyloid pathology and associated toxicity, whereas apoE4 expression either compromises or has no effects on these outcomes by impairing lipid metabolism. Single-cell transcriptomic profiling reveals increased antigen presentation and interferon pathways upon apoE3 expression. In contrast, apoE4 expression downregulates complement and lysosomal pathways, and promotes stress-related responses. Moreover, in the presence of mouse endogenous apoE, microglial apoE4 exacerbates amyloid pathology. Finally, we observed a reduction in Lgals3-positive responsive microglia surrounding amyloid plaque and an increased accumulation of lipid droplets in APOE4 human brains and induced pluripotent stem cell-derived microglia. Our findings establish critical isoform-dependent effects of microglia/CAM-expressed apoE in brain function and the development of amyloid pathology, providing new insight into how apoE4 vastly increases AD risk.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Microglia/metabolismo , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Encéfalo , Homeostase , Camundongos Transgênicos
2.
Mol Psychiatry ; 29(3): 809-819, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38135757

RESUMO

ABCA7 loss-of-function variants are associated with increased risk of Alzheimer's disease (AD). Using ABCA7 knockout human iPSC models generated with CRISPR/Cas9, we investigated the impacts of ABCA7 deficiency on neuronal metabolism and function. Lipidomics revealed that mitochondria-related phospholipids, such as phosphatidylglycerol and cardiolipin were reduced in the ABCA7-deficient iPSC-derived cortical organoids. Consistently, ABCA7 deficiency-induced alterations of mitochondrial morphology accompanied by reduced ATP synthase activity and exacerbated oxidative damage in the organoids. Furthermore, ABCA7-deficient iPSC-derived neurons showed compromised mitochondrial respiration and excess ROS generation, as well as enlarged mitochondrial morphology compared to the isogenic controls. ABCA7 deficiency also decreased spontaneous synaptic firing and network formation in iPSC-derived neurons, in which the effects were rescued by supplementation with phosphatidylglycerol or NAD+ precursor, nicotinamide mononucleotide. Importantly, effects of ABCA7 deficiency on mitochondria morphology and synapses were recapitulated in synaptosomes isolated from the brain of neuron-specific Abca7 knockout mice. Together, our results provide evidence that ABCA7 loss-of-function contributes to AD risk by modulating mitochondria lipid metabolism.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Células-Tronco Pluripotentes Induzidas , Metabolismo dos Lipídeos , Camundongos Knockout , Mitocôndrias , Neurônios , Mitocôndrias/metabolismo , Neurônios/metabolismo , Humanos , Animais , Metabolismo dos Lipídeos/fisiologia , Camundongos , Células-Tronco Pluripotentes Induzidas/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Encéfalo/metabolismo
3.
Ann Neurol ; 93(4): 830-843, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36546684

RESUMO

OBJECTIVE: Recent evidence supports a link between increased TDP-43 burden and the presence of an APOE4 gene allele in Alzheimer's disease (AD); however, it is difficult to conclude the direct effect of APOE on TDP-43 pathology due to the presence of mixed AD pathologies. The goal of this study is to address how APOE isoforms impact TDP-43 pathology and related neurodegeneration in the absence of typical AD pathologies. METHODS: We overexpressed human TDP-43 via viral transduction in humanized APOE2, APOE3, APOE4 mice, and murine Apoe-knockout (Apoe-KO) mice. Behavior tests were performed across ages. Animals were harvested at 11 months of age and TDP-43 overexpression-related neurodegeneration and gliosis were assessed. To further address the human relevance, we analyzed the association of APOE with TDP-43 pathology in 160 postmortem brains from autopsy-confirmed amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with motor neuron disease (FTLD-MND) in the Mayo Clinic Brain Bank. RESULTS: We found that TDP-43 overexpression induced motor function deficits, neuronal loss, and gliosis in the motor cortex, especially in APOE2 mice, with much milder or absent effects in APOE3, APOE4, or Apoe-KO mice. In the motor cortex of the ALS and FTLD-MND postmortem human brains, we found that the APOE2 allele was associated with more severe TDP-43-positive dystrophic neurites. INTERPRETATION: Our data suggest a genotype-specific effect of APOE on TDP-43 proteinopathy and neurodegeneration in the absence of AD pathology, with the strongest association seen with APOE2. ANN NEUROL 2023;93:830-843.


Assuntos
Doença de Alzheimer , Esclerose Lateral Amiotrófica , Demência Frontotemporal , Degeneração Lobar Frontotemporal , Doença dos Neurônios Motores , Humanos , Animais , Camundongos , Esclerose Lateral Amiotrófica/genética , Apolipoproteína E2/genética , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Apolipoproteína E4/genética , Apolipoproteína E3 , Gliose/genética , Proteínas de Ligação a DNA/genética , Apolipoproteínas E/genética , Degeneração Lobar Frontotemporal/patologia
4.
Acta Neuropathol ; 143(6): 641-662, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35471463

RESUMO

Approximately half of Alzheimer's disease (AD) brains have concomitant Lewy pathology at autopsy, suggesting that α-synuclein (α-SYN) aggregation is a regulated event in the pathogenesis of AD. Genome-wide association studies revealed that the ε4 allele of the apolipoprotein E (APOE4) gene, the strongest genetic risk factor for AD, is also the most replicated genetic risk factor for Lewy body dementia (LBD), signifying an important role of APOE4 in both amyloid-ß (Aß) and α-SYN pathogenesis. How APOE4 modulates α-SYN aggregation in AD is unclear. In this study, we aimed to determine how α-SYN is associated with AD-related pathology and how APOE4 impacts α-SYN seeding and toxicity. We measured α-SYN levels and their association with other established AD-related markers in brain samples from autopsy-confirmed AD patients (N = 469), where 54% had concomitant LB pathology (AD + LB). We found significant correlations between the levels of α-SYN and those of Aß40, Aß42, tau and APOE, particularly in insoluble fractions of AD + LB. Using a real-time quaking-induced conversion (RT-QuIC) assay, we measured the seeding activity of soluble α-SYN and found that α-SYN seeding was exacerbated by APOE4 in the AD cohort, as well as a small cohort of autopsy-confirmed LBD brains with minimal Alzheimer type pathology. We further fractionated the soluble AD brain lysates by size exclusion chromatography (SEC) ran on fast protein liquid chromatography (FPLC) and identified the α-SYN species (~ 96 kDa) that showed the strongest seeding activity. Finally, using human induced pluripotent stem cell (iPSC)-derived neurons, we showed that amplified α-SYN aggregates from AD + LB brain of patients with APOE4 were highly toxic to neurons, whereas the same amount of α-SYN monomer was not toxic. Our findings suggest that the presence of LB pathology correlates with AD-related pathologies and that APOE4 exacerbates α-SYN seeding activity and neurotoxicity, providing mechanistic insight into how APOE4 affects α-SYN pathogenesis in AD.


Assuntos
Doença de Alzheimer , Apolipoproteína E4 , Células-Tronco Pluripotentes Induzidas , Doença por Corpos de Lewy , Síndromes Neurotóxicas , Doença de Alzheimer/patologia , Apolipoproteína E4/genética , Apolipoproteínas E , Estudo de Associação Genômica Ampla , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Corpos de Lewy/patologia , Doença por Corpos de Lewy/patologia , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo
5.
BMC Cancer ; 22(1): 1262, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36471255

RESUMO

BACKGROUND: This retrospective study was performed to determine the prognostic potential of smoking and its combination with pre-treatment plasma Epstein-Barr virus (EBV) DNA levels in patients with nasopharyngeal carcinoma (NPC). METHODS: Medical records of 1080 non-metastatic NPC patients who received intensity-modulated radiotherapy were reviewed. Male patients were categorized as never and ever smokers, and the smoking amount, duration, and cumulative consumption were used to evaluate dose-dependent effects. Survival outcomes were assessed using Kaplan-Meier survival analysis and the multivariate Cox regression analysis. Propensity score matching (PSM) was constructed. RESULTS: The 5-year overall survival (OS) was worse for ever smokers than never smokers, and significantly decreased with the increase of smoking amount, duration, and cumulative consumption. Compared with never smokers, the multivariate-adjusted hazard ratio (HR) of death was higher in ever smokers (HR = 1.361, P = 0.049), those smoked ≥20 cigarettes/day (HR = 1.473, P = 0.017), those smoked for ≥30 years (HR = 1.523, P = 0.023), and those cumulative smoked for ≥30 pack-years (HR = 1.649, P = 0.005). The poor prognostic effects of smoking was also confirmed in the PSM analysis. The combination of cumulative smoking consumption and pre-treatment EBV DNA levels was proven to be an independent poor prognostic factor for male NPC, and the risk of death, progression, and distant metastases gradually increased with both factors (P < 0.001). CONCLUSIONS: Combination of smoking and pre-treatment EBV DNA levels as a predictor of poor prognosis could further improve the risk stratification and prognostication for NPC.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias Nasofaríngeas , Humanos , Masculino , Carcinoma Nasofaríngeo/patologia , Herpesvirus Humano 4/genética , Estudos Retrospectivos , Neoplasias Nasofaríngeas/patologia , Fumar/efeitos adversos , Seguimentos , DNA Viral , Prognóstico
6.
J Proteome Res ; 17(4): 1474-1484, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29558158

RESUMO

Influenza A virus infections can result in severe respiratory diseases. The H7N9 subtype of avian influenza A virus has been transmitted to humans and caused severe disease and death. Nonstructural protein 1 (NS1) of influenza A virus is a virulence determinant during viral infection. To elucidate the functions of the NS1 encoded by influenza A H7N9 virus (H7N9 NS1), interaction partners of H7N9 NS1 in human cells were identified with immunoprecipitation followed by SDS-PAGE coupled with liquid chromatography-tandem mass spectrometry (GeLC-MS/MS). We identified 36 cellular proteins as the interacting partners of the H7N9 NS1, and they are involved in RNA processing, mRNA splicing via spliceosome, and the mRNA surveillance pathway. Two of the interacting partners, cleavage and polyadenylation specificity factor subunit 2 (CPSF2) and CPSF7, were confirmed to interact with H7N9 NS1 using coimmunoprecipitation and immunoblotting based on the previous finding that the two proteins are involved in pre-mRNA polyadenylation machinery. Furthermore, we illustrate that overexpression of H7N9 NS1, as well as infection by the influenza A H7N9 virus, interfered with pre-mRNA polyadenylation in host cells. This study comprehensively profiled the interactome of H7N9 NS1 in host cells, and the results demonstrate a novel endotype for H7N9 NS1 in inhibiting host mRNA maturation.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/química , RNA Mensageiro/antagonistas & inibidores , Proteínas não Estruturais Virais/farmacologia , Animais , Fator de Especificidade de Clivagem e Poliadenilação , Interações entre Hospedeiro e Microrganismos , Humanos , Immunoblotting , Imunoprecipitação , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Ligação Proteica , Fatores de Poliadenilação e Clivagem de mRNA
7.
J Virol ; 90(9): 4696-4705, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26912617

RESUMO

UNLABELLED: The NS1 protein encoded by influenza A virus antagonizes the interferon response through various mechanisms, including blocking cellular mRNA maturation by binding the cellular CPSF30 3' end processing factor and/or suppressing the activation of interferon regulatory factor 3 (IRF3). In the present study, we identified two truncated NS1 proteins that are translated from internal AUGs at positions 235 and 241 of the NS1 open reading frame. We analyzed the cellular localization and function of the N-truncated NS1 proteins encoded by two influenza A virus strains, Udorn/72/H3N2 (Ud) and Puerto Rico/8/34/H1N1 (PR8). The NS1 protein of PR8, but not Ud, inhibits the activation of IRF3, whereas the NS1 protein of Ud, but not PR8, binds CPSF30. The truncated PR8 NS1 proteins are localized in the cytoplasm, whereas the full-length PR8 NS1 protein is localized in the nucleus. The infection of cells with a PR8 virus expressing an NS1 protein containing mutations of the two in-frame AUGs results in both the absence of truncated NS1 proteins and the reduced inhibition of activation of IRF3 and beta interferon (IFN-ß) transcription. The expression of the truncated PR8 NS1 protein by itself enhances the inhibition of the activation of IRF3 and IFN-ß transcription in Ud virus-infected cells. These results demonstrate that truncated PR8 NS1 proteins contribute to the inhibition of activation of this innate immune response. In contrast, the N-truncated NS1 proteins of the Ud strain, like the full-length NS1 protein, are localized in the nucleus, and mutation of the two in-frame AUGs has no effect on the activation of IRF3 and IFN-ß transcription. IMPORTANCE: Influenza A virus causes pandemics and annual epidemics in the human population. The viral NS1 protein plays a critical role in suppressing type I interferon expression. In the present study, we identified two novel truncated NS1 proteins that are translated from the second and third in-frame AUG codons in the NS1 open reading frame. The N-terminally truncated NS1 encoded by the H1N1 PR8 strain of influenza virus that suppresses IRF3 activation is localized primarily in the cytoplasm. We demonstrate that this truncated NS1 protein by itself enhances this suppression, demonstrating that some strains of influenza A virus express truncated forms of the NS1 protein that function in the inhibition of cytoplasmic antiviral events.


Assuntos
Vírus da Influenza A/fisiologia , Fator Regulador 3 de Interferon/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Códon de Iniciação , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Humanos , Influenza Humana/metabolismo , Influenza Humana/virologia , Interferon beta/genética , Camundongos , Mutação , Fases de Leitura Aberta , Biossíntese de Proteínas , Transporte Proteico , Transcrição Gênica , Proteínas não Estruturais Virais/química
8.
J Proteome Res ; 15(5): 1639-48, 2016 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-27096427

RESUMO

Influenza A virus, which can cause severe respiratory illnesses in infected individuals, is responsible for worldwide human pandemics. The NS1 protein encoded by this virus plays a crucial role in regulating the host antiviral response through various mechanisms. In addition, it has been reported that NS1 can modulate cellular pre-mRNA splicing events. To investigate the biological processes potentially affected by the NS1 protein in host cells, NS1-associated protein complexes in human cells were identified using coimmunoprecipitation combined with GeLC-MS/MS. By employing software to build biological process and protein-protein interaction networks, NS1-interacting cellular proteins were found to be related to RNA splicing/processing, cell cycle, and protein folding/targeting cellular processes. By monitoring spliced and unspliced RNAs of a reporter plasmid, we further validated that NS1 can interfere with cellular pre-mRNA splicing. One of the identified proteins, pre-mRNA-processing factor 19 (PRP19), was confirmed to interact with the NS1 protein in influenza A virus-infected cells. Importantly, depletion of PRP19 in host cells reduced replication of influenza A virus. In summary, the interactome of influenza A virus NS1 in host cells was comprehensively profiled, and our findings reveal a novel regulatory role for PRP19 in viral replication.


Assuntos
Enzimas Reparadoras do DNA/fisiologia , Interações Hospedeiro-Patógeno , Vírus da Influenza A Subtipo H1N1/química , Proteínas Nucleares/fisiologia , Proteômica/métodos , Fatores de Processamento de RNA/fisiologia , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Cromatografia Líquida , Humanos , Imunoprecipitação , Vírus da Influenza A Subtipo H1N1/fisiologia , Espectrometria de Massas em Tandem , Proteínas não Estruturais Virais/análise
9.
Acta Neuropathol Commun ; 12(1): 25, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336940

RESUMO

Alzheimer's disease (AD), characterized by the deposition of amyloid-ß (Aß) in senile plaques and neurofibrillary tangles of phosphorylated tau (pTau), is increasingly recognized as a complex disease with multiple pathologies. AD sometimes pathologically overlaps with age-related tauopathies such as four repeat (4R)-tau predominant argyrophilic grain disease (AGD). While AGD is often detected with AD pathology, the contribution of APOE4 to AGD risk is not clear despite its robust effects on AD pathogenesis. Specifically, how APOE genotype influences Aß and tau pathology in co-occurring AGD and AD has not been fully understood. Using postmortem brain samples (N = 353) from a neuropathologically defined cohort comprising of cases with AD and/or AGD pathology built to best represent different APOE genotypes, we measured the amounts of major AD-related molecules, including Aß40, Aß42, apolipoprotein E (apoE), total tau (tTau), and pTau181, in the temporal cortex. The presence of tau lesions characteristic of AD (AD-tau) was correlated with cognitive decline based on Mini-Mental State Examination (MMSE) scores, while the presence of AGD tau lesions (AGD-tau) was not. Interestingly, while APOE4 increased the risk of AD-tau pathology, it did not increase the risk of AGD-tau pathology. Although APOE4 was significantly associated with higher levels of insoluble Aß40, Aß42, apoE, and pTau181, the APOE4 effect was no longer detected in the presence of AGD-tau. We also found that co-occurrence of AGD with AD was associated with lower insoluble Aß42 and pTau181 levels. Overall, our findings suggest that different patterns of Aß, tau, and apoE accumulation mediate the development of AD-tau and AGD-tau pathology, which is affected by APOE genotype.


Assuntos
Doença de Alzheimer , Apolipoproteínas E , Tauopatias , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Amiloide , Peptídeos beta-Amiloides , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Proteínas tau , Tauopatias/patologia
10.
STAR Protoc ; 4(2): 102271, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37289593

RESUMO

The apolipoprotein E protein (apoE) confers differential risk for Alzheimer's disease depending on which isoforms are expressed. Here, we present a 2-day immunoprecipitation protocol using the HJ15.4 monoclonal apoE antibody for the pull-down of native apoE particles. We describe major steps for apoE production via immortalized astrocyte culture and HJ15.4 antibody bead coupling for apoE particle pull-down, elution, and characterization. This protocol could be used to isolate native apoE particles from multiple model systems or human biospecimens.

11.
Neurology ; 98(20): e2036-e2045, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35314499

RESUMO

BACKGROUND AND OBJECTIVES: To identify clinicopathologic factors contributing to mild cognitive impairment (MCI) reversion to normal cognition. METHODS: We analyzed 3 longitudinal cohorts in this study: the Mayo Clinic Study of Aging (MCSA), the Religious Orders Study and Memory and Aging Project (ROSMAP), and the National Alzheimer's Coordinating Center (NACC). Demographic characteristics and clinical outcomes were compared between patients with MCI with or without an experience of reversion to normal cognition (referred to as reverters and nonreverters, respectively). We also compared longitudinal changes in cortical thickness, glucose metabolism, and amyloid and tau load in a subcohort of reverters and nonreverters in MCSA with MRI or PET imaging information from multiple visits. RESULTS: We identified 164 (56.4%) individuals in MCSA, 508 (66.8%) individuals in ROSMAP, and 280 (34.1%) individuals in NACC who experienced MCI reversion to normal cognition. Cox proportional hazards regression models showed that MCI reverters had an increased chance of being cognitively normal at the last visit in MCSA (HR 3.31, 95% CI 2.14-5.12), ROSMAP (HR 3.72, 95% CI 2.50-5.56), and NACC (HR 9.29, 95% CI 6.45-13.40) and a reduced risk of progression to dementia (HR 0.12, 95% CI 0.05-0.29 in MCSA; HR 0.41, 95% CI 0.32-0.53 in ROSMAP; and HR 0.29, 95% CI 0.21-0.40 in NACC). Compared with MCI nonreverters, reverters had better-preserved cortical thickness (ß = 0.082, p <0.001) and glucose metabolism (ß = 0.119, p = 0.001) and lower levels of amyloid, albeit statistically nonsignificant (ß = -0.172, p = 0.090). However, no difference in tau load was found between reverters and nonreverters (ß = 0.073, p = 0.24). DISCUSSION: MCI reversion to normal cognition is likely attributed to better-preserved cortical structure and glucose metabolism.


Assuntos
Doença de Alzheimer , Amiloidose , Disfunção Cognitiva , Envelhecimento , Doença de Alzheimer/patologia , Amiloide , Cognição , Disfunção Cognitiva/psicologia , Progressão da Doença , Glucose , Humanos , Testes Neuropsicológicos
12.
Nat Neurosci ; 25(8): 1020-1033, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35915180

RESUMO

The ε4 allele of the apolipoprotein E (APOE) gene, a genetic risk factor for Alzheimer's disease, is abundantly expressed in both the brain and periphery. Here, we present evidence that peripheral apoE isoforms, separated from those in the brain by the blood-brain barrier, differentially impact Alzheimer's disease pathogenesis and cognition. To evaluate the function of peripheral apoE, we developed conditional mouse models expressing human APOE3 or APOE4 in the liver with no detectable apoE in the brain. Liver-expressed apoE4 compromised synaptic plasticity and cognition by impairing cerebrovascular functions. Plasma proteome profiling revealed apoE isoform-dependent functional pathways highlighting cell adhesion, lipoprotein metabolism and complement activation. ApoE3 plasma from young mice improved cognition and reduced vessel-associated gliosis when transfused into aged mice, whereas apoE4 compromised the beneficial effects of young plasma. A human induced pluripotent stem cell-derived endothelial cell model recapitulated the plasma apoE isoform-specific effect on endothelial integrity, further supporting a vascular-related mechanism. Upon breeding with amyloid model mice, liver-expressed apoE4 exacerbated brain amyloid pathology, whereas apoE3 reduced it. Our findings demonstrate pathogenic effects of peripheral apoE4, providing a strong rationale for targeting peripheral apoE to treat Alzheimer's disease.


Assuntos
Doença de Alzheimer , Células-Tronco Pluripotentes Induzidas , Doença de Alzheimer/metabolismo , Animais , Apolipoproteína E3/genética , Apolipoproteína E3/metabolismo , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Apolipoproteínas E/genética , Encéfalo/metabolismo , Cognição , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Camundongos Transgênicos , Isoformas de Proteínas/metabolismo
13.
J Exp Med ; 219(12)2022 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-36107206

RESUMO

TREM2 is exclusively expressed by microglia in the brain and is strongly linked to the risk for Alzheimer's disease (AD). As microglial responses modulated by TREM2 are central to AD pathogenesis, enhancing TREM2 signaling has been explored as an AD therapeutic strategy. However, the effective therapeutic window targeting TREM2 is unclear. Here, by using microglia-specific inducible mouse models overexpressing human wild-type TREM2 (TREM2-WT) or R47H risk variant (TREM2-R47H), we show that TREM2-WT expression reduces amyloid deposition and neuritic dystrophy only during the early amyloid seeding stage, whereas TREM2-R47H exacerbates amyloid burden during the middle amyloid rapid growth stage. Single-cell RNA sequencing reveals suppressed disease-associated microglia (DAM) signature and reduced DAM population upon TREM2-WT expression in the early stage, whereas upregulated antigen presentation pathway is detected with TREM2-R47H expression in the middle stage. Together, our findings highlight the dynamic effects of TREM2 in modulating AD pathogenesis and emphasize the beneficial effect of enhancing TREM2 function in the early stage of AD development.


Assuntos
Doença de Alzheimer , Amiloidose , Doença de Alzheimer/patologia , Amiloide/metabolismo , Amiloidose/patologia , Animais , Encéfalo/patologia , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Microglia/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo
14.
BMC Public Health ; 11: 445, 2011 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-21649930

RESUMO

BACKGROUND: Hearing impairment negatively impacts students' development of academic, language and social skills. Even minimal unilateral hearing loss can hinder educational performance. We investigated the prevalence of ear diseases among secondary school students in the city of Xi'an, China in order to provide a foundation for evidence-based hearing healthcare. METHODS: A stratified random sampling survey was conducted in 29 secondary schools. Demographics and medical histories were collected, and otologic examinations were performed. Questionnaires were administered to assess insomnia, academic stress and use of portable audio devices. Logistic regression analysis was used to identify factors associated with hearing impairment, and the association of sensorineural hearing loss with insomnia, academic stress and the use of portable audio devices was analyzed with the chi-square test. RESULTS: The percentage of students with some form of ear disease was 3.32%. External ear disease, middle ear disease and sensorineural hearing loss occurred in 1.21%, 0.64% and 1.47% of the students, respectively. Boys had a relatively higher prevalence of ear disease than girls. According to our survey, the prevalence of sensorineural hearing loss increased significantly among the students with insomnia and extended use of portable audio devices, but not among those with elevated levels of academic stress. Hearing aids and surgical treatment were needed in 1.47% and 0.89% of the students, respectively. CONCLUSIONS: There is a high prevalence of ear disease among secondary school students, and this should be given more attention. Insomnia and the excessive use of portable audio devices may be related to adolescent sensorineural hearing loss. It is important to establish and comply with an evidence-based preventive strategy.


Assuntos
Otopatias/epidemiologia , Ruído/efeitos adversos , Distúrbios do Início e da Manutenção do Sono/complicações , Estresse Psicológico/complicações , Adolescente , Audiometria , Criança , China/epidemiologia , Estudos Transversais , Otopatias/etiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Adulto Jovem
15.
PLoS One ; 16(7): e0253199, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197469

RESUMO

The effects of cement dosage, compaction coefficient, molding method (vertical vibration method and static pressure method), and dry-wet and freeze-thaw cycles on the mechanical strength of cement-improved loess (CIL) were studied to reveal its strength degradation law under dry-wet and freeze-thaw cycles. Results show that when using the vertical vibration molding method, the strength degradation effect of CIL can be improved by increasing the cement dosage and compaction coefficient; however, it is not obvious. Under the action of dry-wet cycle, damages, such as voids and cracks of CIL, develop continuously. Further, the strength deteriorates continuously and does not decrease after more than 15 dry-wet cycles. Therefore, the dry-wet cycle degradation system is selected by considering the most unfavorable conditions. In the process of freeze-thaw alternation, the pores and fissures of CIL develop and evolve continuously and the strength deteriorates continuously under the joint influence of water and low temperature. The strength tends to become stable after more than 12 freeze-thaw cycles. According to the safety principle, the deterioration coefficient of the freeze-thaw cycles is 0.3.


Assuntos
Cinza de Carvão/química , Materiais de Construção/análise , Congelamento , Sedimentos Geológicos/química , Vibração , Resistência ao Cisalhamento , Solo
16.
Cancer Med ; 10(3): 883-894, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33378109

RESUMO

BACKGROUND: This study was performed to investigate whether long-term monitoring of dynamic changes in plasma Epstein-Barr virus (EBV) DNA could improve prognosis prediction of nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: About 1077 nonmetastatic NPC patients were recruited to retrospectively analyze the prognostic value of plasma EBV DNA load pretreatment and 3, 12, 24, and 36 months posttreatment. We also examined the prognostic value of dynamic changes in plasma EBV DNA at various time points. RESULTS: Patients with plasma EBV DNA load above optimal pre- and posttreatment cut-offs had significantly worse five-year progression-free survival, distant metastasis-free survival, locoregional relapse-free survival, and overall survival (OS) at all-time points, excluding only OS at 36 months posttreatment due to limited mortalities. Patients with persistently undetectable plasma EBV DNA at the first four time points had the best prognosis, followed by those with positive detection pretreatment and consistently negative detection posttreatment, those with negative detection pretreatment and positive detection at one time point posttreatment, and those with positive detection pretreatment and at one time point posttreatment, whereas patients with positive detection at ≥2 time points posttreatment had the worst prognosis. Cox proportional hazard models identified the dynamic change pattern as an independent prognostic factor, and receiver operating characteristic curve analysis demonstrated that the dynamic change at four time point was more valuable than any single time point for predicting disease progression, distant metastasis, locoregional relapse, and mortality. CONCLUSIONS: Dynamic changes in plasma EBV DNA pre- and posttreatment could predict the long-term survival outcome and provide accurate risk stratification in NPC.


Assuntos
DNA Viral/genética , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/secundário , Recidiva Local de Neoplasia/patologia , Quimiorradioterapia , DNA Viral/análise , Infecções por Vírus Epstein-Barr/virologia , Feminino , Seguimentos , Herpesvirus Humano 4/isolamento & purificação , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/terapia , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/terapia , Neoplasias Nasofaríngeas/virologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/terapia , Recidiva Local de Neoplasia/virologia , Prognóstico , Curva ROC , Estudos Retrospectivos , Taxa de Sobrevida
17.
J Cancer ; 12(9): 2715-2722, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33854631

RESUMO

Background: Pre- and post-treatment plasma Epstein-Barr virus (EBV) DNA are important biomarkers for the prognosis of nasopharyngeal carcinoma (NPC). This study was performed to determine the prognostic potential of integrating EBV DNA levels in plasma measured pre-treatment (pre-EBV) and 3 months post-treatment (3 m-EBV). Materials and methods: A total of 543 incident non-metastatic NPC patients treated with intensity-modulated radiotherapy, with or without chemotherapy, were reviewed. Patients were divided into four subgroups based on pre-EBV and 3 m-EBV status. The data for pre-EBV and 3 m-EBV samples were integrated, and the predictability of the survival of patients with NPC was analyzed. Results: There were significant differences in the 5-year progression-free survival, distant metastasis-free survival, locoregional relapse-free survival, and overall survival among the four patient subgroups (P<0.001). Patients who tested negative for both pre-EBV and 3 m-EBV had the best prognosis, followed by patients who tested positive for pre-EBV and negative for 3 m-EBV, and those who tested negative for pre-EBV and positive for 3 m-EBV; however, patients who tested positive for both pre-EBV and 3 m-EBV had the poorest chances of survival. Multivariate analyses demonstrated that integration of pre-EBV and 3 m-EBV data was an independent predictor of NPC progression in patients. Receiver operating characteristic curve analysis further confirmed that the combination of pre-EBV and 3 m-EBV had a greater prognostic value than pre-EBV or 3 m-EBV alone. Conclusions: Integrating pre-EBV and 3 m-EBV data could provide more accurate risk stratification and better prognostic prediction in NPC.

18.
Mol Neurodegener ; 15(1): 63, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-33148290

RESUMO

Investigations of apolipoprotein E (APOE) gene, the major genetic risk modifier for Alzheimer's disease (AD), have yielded significant insights into the pathogenic mechanism. Among the three common coding variants, APOE*ε4 increases, whereas APOE*ε2 decreases the risk of late-onset AD compared with APOE*ε3. Despite increased understanding of the detrimental effect of APOE*ε4, it remains unclear how APOE*ε2 confers protection against AD. Accumulating evidence suggests that APOE*ε2 protects against AD through both amyloid-ß (Aß)-dependent and independent mechanisms. In addition, APOE*ε2 has been identified as a longevity gene, suggesting a systemic effect of APOE*ε2 on the aging process. However, APOE*ε2 is not entirely benign; APOE*ε2 carriers exhibit increased risk of certain cerebrovascular diseases and neurological disorders. Here, we review evidence from both human and animal studies demonstrating the protective effect of APOE*ε2 against AD and propose a working model depicting potential underlying mechanisms. Finally, we discuss potential therapeutic strategies designed to leverage the protective effect of APOE2 to treat AD.


Assuntos
Doença de Alzheimer/genética , Apolipoproteína E2/genética , Animais , Humanos
19.
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
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