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1.
J Stroke Cerebrovasc Dis ; 32(12): 107417, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37924779

RESUMO

AIM: Evidence for an association between Internal carotid artery (ICA) kinking and ischemic stroke has been controversial. We aimed to examine the association between ICA tortuosity and risk of ischemic stroke and specific ischemic stroke subtypes (large artery atherosclerosis, LAA; small artery occlusion, SAO). METHODS: A total of 419 outpatients were included in this cross-sectional study. ICA kinking was objectively assessed by head and neck computed tomography angiography (CTA). The risk of ischemic stroke for each patient was evaluated according to the Essen Stroke Risk Score (ESRS). Ischemic stroke subtypes (LAA and SAO) were measure with head magnetic resonance imaging (MRI). RESULTS: The average age of patients was 59.1 years (SD = 13.25) and 264 (63.0 %) were males. The prevalence of ICA kinking in this sample was 31.5 % (132 out of 419). Individuals with ICA kinking was associated with 0.55-points increase in ESRS score than those without ICA kinking (95 % CI, 0.28-0.81, p < 0.001) among patients over 50 years. In addition, right ICA kinking or left ICA kinking were associated with 0.35-points (95 % CI, 0.08-0.63) and 0.49-points (95 % CI, 0.23-0.76) increase in ESRS score, respectively. For specific ischemic stroke subtypes, individuals with ICA kinking had a 10.34-fold increased risk of SAO compared to those without ICA kinking (95 % CI, 6.22-20.68). Individuals with right ICA kinking had a 4.51-fold risk of SAO than those without kinking (95 % CI, 2.64-7.71), and had an 8.86-fold risk of SAO than those without kinking in the left ICA kinking (95 % CI, 4.97-15.79). CONCLUSION: Our findings support the role of ICA kinking on ischemic stroke. Early screening and proper treatment of carotid artery tortuosity could be a potential intervention strategy for the prevention of ischemic stroke later on.


Assuntos
Estenose das Carótidas , AVC Isquêmico , Acidente Vascular Cerebral , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , AVC Isquêmico/complicações , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/patologia , Estenose das Carótidas/complicações , Estudos Transversais , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia
2.
Mol Psychiatry ; 26(10): 5568-5577, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32681097

RESUMO

It is traditionally believed that cerebral amyloid-beta (Aß) deposits are derived from the brain itself in Alzheimer's disease (AD). Peripheral cells such as blood cells also produce Aß. The role of peripherally produced Aß in the pathogenesis of AD remains unknown. In this study, we established a bone marrow transplantation model to investigate the contribution of blood cell-produced Aß to AD pathogenesis. We found that bone marrow cells (BMCs) transplanted from APPswe/PS1dE9 transgenic mice into wild-type (Wt) mice at 3 months of age continuously expressed human Aß in the blood, and caused AD phenotypes including Aß plaques, cerebral amyloid angiopathy (CAA), tau hyperphosphorylation, neuronal degeneration, neuroinflammation, and behavioral deficits in the Wt recipient mice at 12 months after transplantation. Bone marrow reconstitution in APPswe/PS1dE9 mice with Wt-BMCs at 3 months of age reduced blood Aß levels, and alleviated brain Aß burden, neuronal degeneration, neuroinflammation, and behavioral deficits in the AD model mice at 12 months after transplantation. Our study demonstrated that blood cell-produced Aß plays a significant role in AD pathogenesis, and the elimination of peripheral production of Aß can decrease brain Aß deposition and represents a novel therapeutic approach for AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Células Sanguíneas/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos
3.
Mol Psychiatry ; 23(8): 1813-1824, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29867188

RESUMO

Tau pathology is characterized as a form of frontotemporal lobar degeneration (FTLD) known as FTLD-tau. The underlying pathogenic mechanisms are not known and no therapeutic interventions are currently available. Here, we report that the neurotrophin receptor p75NTR plays a critical role in the pathogenesis of FTLD-tau. The expression of p75NTR and the precursor of nerve growth factor (proNGF) were increased in the brains of FTLD-tau patients and mice (P301L transgenic). ProNGF-induced tau phosphorylation via p75NTR in vitro, which was associated with the AKT/glycogen synthase kinase (GSK)3ß pathway. Genetic reduction of p75NTR in P301L mice rescued the memory deficits, alleviated tau hyperphosphorylation and restored the activity of the AKT/GSK3ß pathway. Treatment of the P301L mice with the soluble p75NTR extracellular domain (p75ECD-Fc), which can antagonize neurotoxic ligands of p75NTR, effectively improved memory behavior and suppressed tau pathology. This suggests that p75NTR plays a crucial role in tau paGSKthology and represents a potential druggable target for FTLD-tau and related tauopathies.


Assuntos
Degeneração Lobar Frontotemporal/metabolismo , Fator de Crescimento Neural/metabolismo , Precursores de Proteínas/metabolismo , Receptores de Fator de Crescimento Neural/metabolismo , Proteínas tau/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Feminino , Degeneração Lobar Frontotemporal/patologia , Degeneração Lobar Frontotemporal/terapia , Glicogênio Sintase Quinase 3 beta/metabolismo , Masculino , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Transtornos da Memória/terapia , Camundongos Transgênicos , Neurônios/metabolismo , Neurônios/patologia , Fosforilação/fisiologia , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
4.
Acta Neuropathol ; 136(4): 525-536, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30074071

RESUMO

Accumulation of pathological tau is the hallmark of Alzheimer's disease and other tauopathies and is closely correlated with cognitive decline. Clearance of pathological tau from the brain is a major therapeutic strategy for tauopathies. The physiological capacity of the periphery to clear brain-derived tau and its therapeutic potential remain largely unknown. Here, we found that cisterna magna injected 131I-labelled synthetic tau dynamically effluxed from the brain and was mainly cleared from the kidney, blood, and liver in mice; we also found that plasma tau levels in inferior vena cava were lower than those in femoral artery in humans. These findings suggest that tau proteins can efflux out of the brain and be cleared in the periphery under physiological conditions. Next, we showed that lowering blood tau levels via peritoneal dialysis could reduce interstitial fluid (ISF) tau levels in the brain, and tau levels in the blood and ISF were dynamically correlated; furthermore, tau efflux from the brain was accelerated after the addition of another set of peripheral system in a parabiosis model. Finally, we established parabiosis mouse models using tau transgenic mice and their wild-type littermates and found that brain tau levels and related pathologies in parabiotic transgenic mice were significantly reduced after parabiosis, suggesting that chronic enhancement of peripheral tau clearance alleviates pathological tau accumulation and neurodegeneration in the brain. Our study provides the first evidence of physiological clearance of brain-derived pathological tau in the periphery, suggesting that enhancing peripheral tau clearance is a potential therapeutic strategy for tauopathies.


Assuntos
Sistema Nervoso Periférico/metabolismo , Tauopatias/metabolismo , Tauopatias/terapia , Proteínas tau/metabolismo , Adulto , Idoso , Animais , Química Encefálica , Cisterna Magna/metabolismo , Líquido Extracelular/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Parabiose , Diálise Peritoneal , Distribuição Tecidual , Veia Cava Inferior/metabolismo , Proteínas tau/genética
5.
Proc Natl Acad Sci U S A ; 112(16): 5225-30, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25847999

RESUMO

Alzheimer's disease (AD) is one of most devastating diseases affecting elderly people. Amyloid-ß (Aß) accumulation and the downstream pathological events such as oxidative stress play critical roles in pathogenesis of AD. Lessons from failures of current clinical trials suggest that targeting multiple key pathways of the AD pathogenesis is necessary to halt the disease progression. Here we show that Edaravone, a free radical scavenger that is marketed for acute ischemic stroke, has a potent capacity of inhibiting Aß aggregation and attenuating Aß-induced oxidation in vitro. When given before or after the onset of Aß deposition via i.p. injection, Edaravone substantially reduces Aß deposition, alleviates oxidative stress, attenuates the downstream pathologies including Tau hyperphosphorylation, glial activation, neuroinflammation, neuronal loss, synaptic dysfunction, and rescues the behavioral deficits of APPswe/PS1 mice. Oral administration of Edaravone also ameliorates the AD-like pathologies and memory deficits of the mice. These findings suggest that Edaravone holds a promise as a therapeutic agent for AD by targeting multiple key pathways of the disease pathogenesis.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Antipirina/análogos & derivados , Transtornos Cognitivos/tratamento farmacológico , Administração Oral , Doença de Alzheimer/complicações , Doença de Alzheimer/patologia , Amiloide/metabolismo , Peptídeos beta-Amiloides/toxicidade , Animais , Antipirina/administração & dosagem , Antipirina/química , Antipirina/farmacologia , Antipirina/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Linhagem Celular , Transtornos Cognitivos/complicações , Transtornos Cognitivos/patologia , Dendritos/efeitos dos fármacos , Dendritos/patologia , Edaravone , Humanos , Inflamação/patologia , Camundongos Transgênicos , Neurotoxinas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Presenilina-1/metabolismo , Agregação Patológica de Proteínas/complicações , Agregação Patológica de Proteínas/tratamento farmacológico , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas tau/metabolismo
6.
J Stroke Cerebrovasc Dis ; 27(2): 479-485, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29056405

RESUMO

BACKGROUND: In the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial, 19.1% of ischemic strokes occurred out of the territory of previously symptomatic stenosis during the mean follow-up period of 23.4 months. However, it is unknown how many ischemic strokes were due to a previously asymptomatic intracranial atherosclerotic stenosis (ICAS). The objective of this study was to investigate whether the concomitant asymptomatic ICAS influences the outcome of patients undergoing symptomatic ICAS stenting. METHODS: We retrospectively reviewed 576 consecutive patients with nondisabling ischemic stroke (modified Rankin scale score of ≤3) who were treated with symptomatic ICAS (≥70% stenosis) stenting with or without concomitant asymptomatic ICAS. The baseline characteristics and the 30-day primary end points (stroke or death after stenting) were compared by bivariate and multivariable logistic analyses. RESULTS: The 30-day rate of primary end points was 5.2%, which was higher in patients with concomitant asymptomatic ICAS (≥50% stenosis) than in those without asymptomatic ICAS (no stenosis or <50% stenosis) (8.9% versus 3.8%, P = .014). In patients with concomitant asymptomatic ICAS, 25% of ischemic strokes occurred out of the territory of the stented artery, whereas in patients without asymptomatic ICAS, no ischemic stroke occurred out of the territory of the stented artery. Multivariable analysis showed that concomitant asymptomatic ICAS was an independent risk factor for 30-day stroke (odds ratio = 2.37, 95% confidence interval, 1.14-5.63; P = .023). CONCLUSIONS: Concomitant asymptomatic ICAS (≥50% stenosis) might increase the 30-day risk of stroke in patients undergoing symptomatic ICAS stenting.


Assuntos
Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Arteriosclerose Intracraniana/terapia , Stents , Acidente Vascular Cerebral/etiologia , Doenças Assintomáticas , Distribuição de Qui-Quadrado , China , Feminino , Humanos , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/diagnóstico por imagem , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico , Fatores de Tempo , Resultado do Tratamento
7.
Acta Neuropathol ; 134(2): 207-220, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28477083

RESUMO

Clearance of amyloid-beta (Aß) from the brain is an important therapeutic strategy for Alzheimer's disease (AD). Current studies mainly focus on the central approach of Aß clearance by introducing therapeutic agents into the brain. In a previous study, we found that peripheral tissues and organs play important roles in clearing brain-derived Aß, suggesting that the peripheral approach of removing Aß from the blood may also be effective for AD therapy. Here, we investigated whether peritoneal dialysis, a clinically available therapeutic method for chronic kidney disease (CKD), reduces brain Aß burden and attenuates AD-type pathologies and cognitive impairments. Thirty patients with newly diagnosed CKD were enrolled. The plasma Aß concentrations of the patients were measured before and after peritoneal dialysis. APP/PS1 mice were subjected to peritoneal dialysis once a day for 1 month from 6 months of age (prevention study) or 9 months of age (treatment study). The Aß in the interstitial fluid (ISF) was collected using microdialysis. Behavioural performance, long-term potentiation (LTP), Aß burden and other AD-type pathologies were measured after 1 month of peritoneal dialysis. Peritoneal dialysis significantly reduced plasma Aß levels in both CKD patients and APP/PS1 mice. Aß levels in the brain ISF of APP/PS1 mice immediately decreased after reduction of Aß in the blood during peritoneal dialysis. In both prevention and treatment studies, peritoneal dialysis substantially reduced Aß deposition, attenuated other AD-type pathologies, including Tau hyperphosphorylation, glial activation, neuroinflammation, neuronal loss, and synaptic dysfunction, and rescued the behavioural deficits of APPswe/PS1 mice. Importantly, the Aß phagocytosis function of microglia was enhanced in APP/PS1 mice after peritoneal dialysis. Our study suggests that peritoneal dialysis is a promising therapeutic method for AD, and Aß clearance using a peripheral approach could be a desirable therapeutic strategy for AD.


Assuntos
Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/sangue , Diálise Peritoneal/métodos , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/sangue , Precursor de Proteína beta-Amiloide/genética , Animais , Apoptose/fisiologia , Ácido Aspártico Endopeptidases/sangue , Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio , Estudos de Casos e Controles , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Potenciais Pós-Sinápticos Excitadores , Humanos , Camundongos , Camundongos Transgênicos , Proteínas dos Microfilamentos , Proteínas do Tecido Nervoso/metabolismo , Fenótipo , Presenilina-1/genética , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/terapia
8.
J Neurochem ; 138(1): 163-73, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26991827

RESUMO

The neurotrophin receptor p75 (p75NTR) is a receptor for amyloid-beta (Aß) and mediates Aß-induced neurodegenerative signals. The ectodomain of p75NTR (p75ECD) is a physiological protective factor against Aß in Alzheimer's disease (AD). We have previously demonstrated that the shedding of p75ECD from the cell surface is down-regulated in AD brains and restoration of the p75ECD level in the brain, through intracranial administration of p75ECD by adeno-associated virus vectors, attenuates AD-like pathologies in an AD mouse model. In this study, we further investigated the feasibility and efficacy of peripheral administration of AAV-p75ECD on brain amyloid burden and associated pathogenesis. We found that intramuscular delivery of AAV-p75ECD increased the level of p75ECD in the blood, significantly improved the behavioral phenotype of amyloid precursor protein/PS1 transgenic mice, and reduced brain amyloid burden, attenuated Tau hyperphosphorylation, and neuroinflammation. Furthermore, intramuscular delivery of AAV-p75ECD was well tolerated. Our results indicate that peripheral delivery of p75ECD represents a safe and effective therapeutic strategy for AD. The ectodomain of p75NTR (p75ECD) is a physiological protective factor against amyloid-beta (Aß) in Alzheimer's disease (AD). Intramuscular delivery of AAV-p75ECD increased the p75ECD levels in the blood, reduced brain amyloid burden through a 'peripheral sink' mechanism and alleviates AD-type pathologies. Peripheral delivery of p75ECD represents a promising therapeutic strategy for AD.


Assuntos
Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Transtornos Cognitivos/terapia , Receptor de Fator de Crescimento Neural/química , Receptor de Fator de Crescimento Neural/metabolismo , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Transtornos Cognitivos/genética , Dependovirus/genética , Modelos Animais de Doenças , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Injeções Intramusculares , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Presenilina-1/genética , Receptor de Fator de Crescimento Neural/genética , Transdução Genética
9.
J Neuroinflammation ; 12: 153, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26311039

RESUMO

BACKGROUND: Senile plaques consisting of amyloid-beta (Aß) are the major pathological hallmark of Alzheimer's disease (AD) and have been the primary therapeutic target. Immunotherapies, which are designed to remove brain Aß deposits, increased levels of soluble Aß and accelerated brain atrophy in some clinical trials, suggesting that the solubilization of Aß deposition might facilitate the formation of more toxic Aß oligomers and enhance neurotoxicity. METHODS: The capacity of antibodies against different epitopes of Aß to disaggregate preformed Aß fibrils was investigated. The co-incubation of antibodies and Aß fibrils was then tested for neurotoxicity both in vitro and in vivo. RESULTS: After the incubation of preformed Aß fibrils with the N-terminal antibody 6E10, the fibrils were decreased, while the oligomers, mostly dimers and trimers, were significantly increased. However, no such effects were observed for antibodies targeting the middle domain (4G8) and C-terminus of Aß (8G7). The co-incubates of preformed Aß fibrils with 6E10 were more neurotoxic, both in vitro and in vivo, than the co-incubates with 4G8 and 8G7. CONCLUSIONS: Our results indicate that the antibody targeting the N-terminus of Aß promoted the transformation of Aß from fibrils into oligomers and increased neurotoxicity. Immunotherapies should take into consideration the enhanced neurotoxicity associated with the solubilization of Aß deposits by antibodies against the Nterminus of Aß.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Anticorpos/efeitos adversos , Apoptose/efeitos dos fármacos , Síndromes Neurotóxicas , Fragmentos de Peptídeos/imunologia , Peptídeos beta-Amiloides/imunologia , Análise de Variância , Animais , Anticorpos/uso terapêutico , Caspase 3/metabolismo , Modelos Animais de Doenças , Humanos , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Neuritos/efeitos dos fármacos , Neuritos/patologia , Neuritos/ultraestrutura , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Fragmentos de Peptídeos/metabolismo , Fosfopiruvato Hidratase/metabolismo , Placa Amiloide/patologia
10.
Acta Neuropathol ; 130(4): 487-99, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26363791

RESUMO

Amyloid-beta (Aß) plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). The physiological capacity of peripheral tissues and organs in clearing brain-derived Aß and its therapeutic potential for AD remains largely unknown. Here, we measured blood Aß levels in different locations of the circulation in humans and mice, and used a parabiosis model to investigate the effect of peripheral Aß catabolism on AD pathogenesis. We found that blood Aß levels in the inferior/posterior vena cava were lower than that in the superior vena cava in both humans and mice. In addition, injected (125)I labeled Aß40 was located mostly in the liver, kidney, gastrointestinal tract, and skin but very little in the brain; suggesting that Aß derived from the brain can be cleared in the periphery. Parabiosis before and after Aß deposition in the brain significantly reduced brain Aß burden without alterations in the expression of amyloid precursor protein, Aß generating and degrading enzymes, Aß transport receptors, and AD-type pathologies including hyperphosphorylated tau, neuroinflammation, as well as neuronal degeneration and loss in the brains of parabiotic AD mice. Our study revealed that the peripheral system is potent in clearing brain Aß and preventing AD pathogenesis. The present work suggests that peripheral Aß clearance is a valid therapeutic approach for AD, and implies that deficits in the Aß clearance in the periphery might also contribute to AD pathogenesis.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/metabolismo , Adulto , Idoso , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Radioisótopos do Iodo , Masculino , Camundongos Transgênicos , Pessoa de Meia-Idade , Presenilina-1/genética , Presenilina-1/metabolismo , Adulto Jovem
11.
Curr Alzheimer Res ; 18(5): 428-442, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34488598

RESUMO

BACKGROUND: High cholesterol aggravates the risk development of Alzheimer's disease (AD). AD is closely related to the transport impairment of Amyloid-ß (Aß) in the blood-brain barrier. It is unclear whether high cholesterol affects the risk of cognitive impairment in AD by affecting Aß transport. The purpose of the study is to investigate whether high cholesterol regulates Aß transport through low-density Lipoprotein Receptor-Related Protein 1 (LRP1) and Receptor for Advanced Glycation End products (RAGE) in the risk development of AD. METHODS: We established high cholesterol AD mice model. The learning and memory functions were evaluated by Morris Water Maze (MWM). Cerebral microvascular endothelial cells were isolated, cultured, and observed. The expression levels of LRP1 and RAGE of endothelial cells and their effect on Aß transport in vivo were observed. The expression level of LRP1 and RAGE was detected in cultured microvessels after using Wnt inhibitor DKK-1 and ß-catenin inhibitor XAV-939. RESULTS: Hypercholesterolemia exacerbated spatial learning and memory impairment. Hypercholesterolemia increased serum Aß40 level, while serum Aß42 level did not change significantly. Hypercholesterolemia decreased LRP1 expression and increased RAGE expression in cerebral microvascular endothelial cells. Hypercholesterolemia increased brain apoptosis in AD mice. In in vitro experiment, high cholesterol decreased LRP1 expression and increased RAGE expression, increased Aß40 expression in cerebral microvascular endothelial cells. High cholesterol regulated the expressions of LRP1 and RAGE and transcriptional activity of LRP1 and RAGE promoters by the Wnt/ß-catenin signaling pathway. CONCLUSION: High cholesterol decreased LRP1 expression and increased RAGE expression in cerebral microvascular endothelial cells, which led to Aß transport disorder in the blood-brain barrier. Increased Aß deposition in the brain aggravated apoptosis in the brain, resulting to cognitive impairment of AD mice.


Assuntos
Doença de Alzheimer/metabolismo , Barreira Hematoencefálica/metabolismo , Colesterol , Modelos Animais de Doenças , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/metabolismo , Colesterol/farmacologia , Células Endoteliais/metabolismo , Humanos , Hipercolesterolemia , Camundongos , Fragmentos de Peptídeos
12.
Sci Adv ; 7(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33523832

RESUMO

The pathological relevance of naturally occurring antibodies to ß-amyloid (NAbs-Aß) in Alzheimer's disease (AD) remains unclear. We aimed to investigate their levels and associations with Aß burden and cognitive decline in AD in a cross-sectional cohort from China and a longitudinal cohort from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. NAbs-Aß levels in plasma and cerebrospinal fluid (CSF) were tested according to their epitopes. Levels of NAbs targeting the amino terminus of Aß increased, and those targeting the mid-domain of Aß decreased in both CSF and plasma in AD patients. Higher plasma levels of NAbs targeting the amino terminus of Aß and lower plasma levels of NAbs targeting the mid-domain of Aß were associated with higher brain amyloidosis at baseline and faster cognitive decline during follow-up. Our findings suggest a dynamic response of the adaptive immune system in the progression of AD and are relevant to current passive immunotherapeutic strategies.


Assuntos
Doença de Alzheimer , Amiloidose , Disfunção Cognitiva , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Amiloidose/complicações , Anticorpos , Austrália , Biomarcadores , Disfunção Cognitiva/etiologia , Estudos Transversais , Progressão da Doença , Humanos , Proteínas tau
13.
Brain Behav Immun ; 24(8): 1281-93, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20595065

RESUMO

Anti-beta-amyloid (Aß) immunotherapy is effective in removing brain Aß, but has shown to be associated with detrimental effects. We have demonstrated that Adeno-associated virus (AAV)-mediated delivery of an anti-Aß single chain antibody (scFv) gene was effective in clearing brain Aß without eliciting any inflammatory side effects in old APP(Swe)/PS1dE9 transgenic mice. In the present study, we tested the efficacy and safety of intramuscular delivery of the scFv gene in preventing brain Aß deposition. The scFv gene was intramuscularly delivered to APP(Swe)/PS1dE9 transgenic mice at 3 months of age, prior to Aß deposition in the brain. Six months later, we found that the transgenes were expressed in a stable form at the delivered sites, with a small amount of ectopic expression in the liver and olfactory bulb. Brain Aß plaque formation, Aß accumulation, AD-type pathologies and cognitive impairment were significantly attenuated in scFv-treated APP(Swe)/PS1dE9 transgenic mice relative to EGFP-treated mice. Intramuscular delivery of scFv gene was well tolerated by the animals, did not cause inflammation or microhemorrhage at the gene expression site and in the brain, and did not induce neutralizing antibodies in the animals. These findings suggest that peripheral application of scFv is effective and safe in preventing the development of Alzheimer's disease (AD), and would be a promising non-inflammatory immunological modality for prevention and treatment of AD.


Assuntos
Vacinas contra Alzheimer/uso terapêutico , Peptídeos beta-Amiloides/imunologia , Química Encefálica/efeitos dos fármacos , Transtornos Cognitivos/imunologia , Transtornos Cognitivos/prevenção & controle , Anticorpos de Cadeia Única/farmacologia , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Transtornos Cognitivos/psicologia , Citocinas/sangue , Citocinas/metabolismo , Dependovirus/genética , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Humanos , Processamento de Imagem Assistida por Computador , Injeções Intramusculares , Camundongos , Camundongos Transgênicos , Presenilinas/genética , Anticorpos de Cadeia Única/administração & dosagem
14.
Zhonghua Yi Xue Za Zhi ; 90(19): 1353-6, 2010 May 18.
Artigo em Zh | MEDLINE | ID: mdl-20646587

RESUMO

OBJECTIVE: To explore the effects of proBDNF on cell proliferation and differentiation in hippocampal dentate gyrus in Alzheimer' disease (AD) rat model. METHODS: The AD rat model was established. Alzet osmotic minipumps were connected to right hippocampus of AD rat and filled with proBDNF, sheep antibody to proBDNF or normal sheep serum respectively. Rats received the injection for 14 days at the speed of 0.5 microl/h. 5-bromo-2'-deoxyuridine (BrdU, 50 mg/kg, ip) was injected twice daily for 14 days. BrdU immunohistochemistry was processed to determine the number of newly generated cells. To examine the phenotype of newly generated cells, immunofluorescent triple labeling was conducted to colocalize BrdU-positive cells with rabbit anti-doublecortin (DCX) or mouse anti-glial fibrillary acid protein (GFAP). RESULTS: proBDNF group had fewer BrdU positive cells in dentate gyrus (P < 0.01), while anti-proBDNF group had more BrdU positive cells (P < 0.01) as compared with control group respectively. Immunofluorescent triple labeling showed that there was no phenotypic difference of BrdU positive cells between each group. CONCLUSION: proBDNF can suppress the proliferation of hippocampal neuron in dentate gyrus in AD rats while anti-proBDNF has the opposite effect. These findings suggest that promoting the hippocampal neurogenesis by blocking the functions of endogenous proBDNF may be a potential therapeutic strategy for AD.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/farmacologia , Neurônios/citologia , Precursores de Proteínas/farmacologia , Doença de Alzheimer/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Giro Denteado/citologia , Giro Denteado/metabolismo , Modelos Animais de Doenças , Proteína Duplacortina , Hipocampo/citologia , Camundongos , Neurônios/metabolismo , Neurônios/fisiologia , Coelhos , Ratos , Proteínas Recombinantes/farmacologia , Ovinos
15.
Transl Psychiatry ; 10(1): 230, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661266

RESUMO

Alzheimer's disease (AD) is the most common cause of age-related dementia and is currently incurable. The failures of current clinical trials and the establishment of modifiable risk factors have shifted the AD intervention from treatment to prevention in the at-risk population. Previous studies suggest that there is a geographic overlap between AD incidence and spicy food consumption. We previously reported that capsaicin-rich diet consumption was associated with better cognition and lower serum Amyloid-beta (Aß) levels in people aged 40 years and over. In the present study, we found that intake of capsaicin, the pungent ingredient in chili peppers, reduced brain Aß burden and rescued cognitive decline in APP/PS1 mice. Our in vivo and in vitro studies revealed that capsaicin shifted Amyloid precursor protein (APP) processing towards α-cleavage and precluded Aß generation by promoting the maturation of a disintegrin and metalloproteinase 10 (ADAM10). We also found that capsaicin alleviated other AD-type pathologies, such as tau hyperphosphorylation, neuroinflammation and neurodegeneration. The present study suggests that capsaicin is a potential therapeutic candidate for AD and warrants clinical trials on chili peppers or capsaicin as dietary supplementation for the prevention and treatment of AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/prevenção & controle , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Capsaicina/farmacologia , Cognição , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/prevenção & controle , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Presenilina-1/metabolismo
16.
Front Aging Neurosci ; 11: 381, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32038226

RESUMO

Polymorphism of the cholesterol-24S-hydroxylase (CYP46A1) gene is thought to be a risk factor for Alzheimer's disease (AD). A single nucleotide polymorphism (T/C) in intron 2, rs754203, has been confirmed to be implicated in AD. Rs754203 is located in the long intronic non-coding RNA (LincRNA) sequence, which has previously been shown to be involved in the pathology of many diseases. Thus, the present study aimed to investigate the role of LincRNA in the CYP46A1 gene expression and related AD pathology. SH-SY5Y cells with overexpressed TT or CC genotype CYP46A1 were used. Through RT-PCR, Western blot and ELISA assays, we found that LincRNA can affect the CYP46A1 gene expression and the production of 24-OHC and Aß. Overexpression of LincRNA can significantly inhibit CYP46A1 expression and 24-OHC production, as well as increasing the Aß expression level. Silencing of LincRNA confirmed the role that it plays in the regulation of CYP46A1, as well as the production of 24-OHC and Aß. In addition, this effect was stronger in the A type LincRNA than in the G type LincRNA. Results from dual luciferase assays show that LincRNA inhibited the activity of the CYP46A1 gene promoter. This study indicates a possible novel role of LincRNA and provides a new way to look into the relationship between CYP46A1 polymorphism and AD pathology. This may identify a novel pathway through which to explore AD therapy.

17.
J Alzheimers Dis ; 69(1): 169-178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30958377

RESUMO

Brain amyloid-ß (Aß) deposition is a hallmark to define Alzheimer's disease (AD). We investigated the positive rate of brain amyloid deposition assessed with 11C-Pittsburgh compound (PiB)-PET and blood Aß levels in a cohort of probable AD patients who were diagnosed according to the 1984 NINCDS-ADRDA criteria. Eighty-four subjects with a clinical diagnosis of probable AD dementia, amnestic mild cognitive impairment (MCI), and cognitively normal (CN) status were subjected to PiB-PET and 18F-fluorodeoxyglucose (FDG)-PET scans. Plasma biomarkers of Aß42, Aß40, and T-tau were measured using single molecule array technology. The positive rate of PiB-PET, the associations between PiB-PET status and FDG-PET, plasma biomarkers, and clinical manifestations were analyzed. PiB-PET was positive in 77.36% of probable AD patients, 31.80% of MCI patients, and 0 of NC. Plasma Aß42/Aß40 ratio was associated with PiB-PET, the ROC curve analysis revealing an AUC of 0.77 (95% CI: 0.66-0.87), with a sensitivity of 82% and specificity of 64%. Some clinical manifestations were associated with PiB-PET imaging. Our findings indicate that only three-fourths of patients diagnosed with probable AD fit the pathological criteria, suggesting that we should be cautious regarding the accuracy of AD diagnosis when no biomarker evidence is available in our clinical practice.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Fragmentos de Peptídeos/metabolismo , Proteínas tau/metabolismo , Idoso , Doença de Alzheimer/sangue , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/sangue , Biomarcadores/sangue , Encéfalo/patologia , Disfunção Cognitiva/sangue , Disfunção Cognitiva/patologia , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/sangue , Tomografia por Emissão de Pósitrons , Proteínas tau/sangue
18.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 20(11): 660-2, 2008 Nov.
Artigo em Zh | MEDLINE | ID: mdl-19000420

RESUMO

OBJECTIVE: To characterize relation between changes in serum soluble intercellular adhesion molecule (sICAM) and infarction volume in patients with acute cerebral infarction (ACI). METHODS: The levels of serum sICAM-1 of 165 patients with ACI were measured with enzyme linked immunosorbent assay (ELISA), and compared the results with that of 58 patients suffering from cerebral hemorrhage and 87 normal controls. RESULTS: sICAM-1 in patients with ACI 24 hours after the onset [(4.73+/-0.26) mg/L] was higher than that in patients with cerebral hemorrhage [(2.81+/-0.18) mg/L] and normal controls [(2.64+/-0.25) mg/L, both P<0.01]. It was still higher than that in patients with cerebral hemorrhage and normal controls at the 14 days after the onset (both P<0.01). The levels of serum sICAM-1 were significantly higher in the patients with large cerebral infarction group [infarction volume was >10 cm(3), (5.14+/-0.34) mg/L] than in patients with medium [infarction volume was 4-10 cm(3), (4.47+/-0.20) mg/L] and small cerebral infarction groups [infarction volume was <4 cm(3), (4.12+/-0.28) mg/L, both P<0.01]. The levels of sICAM-1 were higher in patients complicated with infection compared with those without in 14 days (P<0.05 or P<0.01). CONCLUSION: Serum sICAM-1 was closely related to cerebral infarction volume in patients with ACI.


Assuntos
Encéfalo/patologia , Infarto Cerebral/sangue , Molécula 1 de Adesão Intercelular/sangue , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Infarto Cerebral/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Mol Neurobiol ; 55(10): 8179-8187, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29516283

RESUMO

Polymorphisms of the cholesterol-24S-hydroxylase (CYP46A1) and apolipoprotein E (APOE) genes are risk factors for Alzheimer's disease (AD). Plasma level of 24S-hydroxcholesterol (24-OHC), the metabolite of cholesterol, is thought to correlate with AD. The present study investigated the correlation between these genetic factors and blood 24-OHC and amyloid-beta (Aß) levels in AD patients. Association analysis, logistic regression, and linear regression were used to analyze the correlation of CYP46A1 and APOE genotypes with blood 24-OHC and Aß levels and AD risk. We found that the APOEε4 alleles were significantly higher in patients with AD and there was a potential synergistic interaction between the CYP46A1 C allele and APOEε4 allele in AD. Blood 24-OHC level and Aß level were significantly higher in AD patients than controls, indicating 24-OHC could be a marker in AD diagnosis. However, AD patients with the CYP46A1 TT, but not CC, genotype had higher 24-OHC levels, which indicated that there may be other mechanisms in the relationship between CYP46A1 polymorphisms and AD.


Assuntos
Alelos , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Colesterol 24-Hidroxilase/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Idoso , Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/sangue , Estudos de Casos e Controles , Demografia , Feminino , Estudos de Associação Genética , Humanos , Hidroxicolesteróis/sangue , Masculino , Fatores de Risco , Índice de Gravidade de Doença
20.
J Alzheimers Dis ; 63(4): 1337-1346, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29758946

RESUMO

Previous studies suggest that gut microbiota is associated with neuropsychiatric disorders, such as Parkinson's disease, amyotrophic lateral sclerosis, and depression. However, whether the composition and diversity of gut microbiota is altered in patients with Alzheimer's disease (AD) remains largely unknown. In the present study, we collected fecal samples from 43 AD patients and 43 age- and gender-matched cognitively normal controls. 16S ribosomal RNA sequencing technique was used to analyze the microbiota composition in feces. The composition of gut microbiota was different between the two groups. Several bacteria taxa in AD patients were different from those in controls at taxonomic levels, such as Bacteroides, Actinobacteria, Ruminococcus, Lachnospiraceae, and Selenomonadales. Our findings suggest that gut microbiota is altered in AD patients and may be involved in the pathogenesis of AD.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Microbioma Gastrointestinal , Trato Gastrointestinal/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Trato Gastrointestinal/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , RNA Ribossômico 16S/genética
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