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1.
Chem Commun (Camb) ; 55(70): 10424-10427, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31407744

RESUMO

The development of sensitive and reliable fluorescent probes for the early diagnosis of Alzheimer's disease (AD) is highly challenging and plays an important role in achieving effective treatments. Herein, we designed and synthesized an indole-based fluorophore for TTR in human plasma, an important hallmark of AD pathogenesis. This robust and simple fluorescent method allows quantification of TTR in the complex biological matrix.


Assuntos
Doença de Alzheimer/diagnóstico , Corantes Fluorescentes/química , Pré-Albumina/metabolismo , Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/metabolismo , Humanos , Limite de Detecção , Espectrometria de Fluorescência
2.
Cell Physiol Biochem ; 53(2): 413-428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31415717

RESUMO

BACKGROUND/AIMS: Amyloid plaques, generated during the progression of Alzheimer's disease, cause major neurological deficits due to substantial cell toxicity and death. The underlying cause of plaque generation stems from cleavage of the amyloid precursor protein (APP) by ß-secretase (BACE1). A resulting amyloid-ß (Aß) fragment forms aggregates to produce the main constituent of a plaque. METHODS: Phage display and biopanning techniques were used to identify a 12-mer peptide that had a natural affinity for the BACE1 enzyme. The peptide was translated from phage DNA and synthetically produced. The peptide, at concentrations of 1nM, 10nM and 100nM, was used to confirm binding by direct assay. Non-specific binding to BACE2, renin and cathepsin D was tested by direct binding assay. A BACE1 activity assay was used to determine the peptide effect on cleavage of an APP substrate. Treatment of SY5Y cells with the peptide was used to determine toxicity and prevention of Aß40 and Aß42 production. RESULTS: After identification and synthetic production, the peptide exhibited a strong affinity for BACE1 at nanomolar concentrations in the direct assay. In case of non-specific binding to homologous BACE2, renin and cathepsin D, the peptide showed minor binding but was nullified when in solution with BACE1. The peptide addition to a BACE1 activity assay was able to significantly reduce the amount of substrate cleavage. SY5Y cells, when treated with the peptide, did not show any detrimental morphological changes while being able to reduce the production of natural Aß40 and Aß42. Even under stressed conditions (H2O2 treatment) where the Aß production was higher, the peptide was still able to significantly reduce the effect of BACE1 while not effecting cell viability. CONCLUSION: The identified peptide exhibited strong binding to BACE1 in vitro and was able to reduce production of Aß, suggesting a favourable BACE1 inhibitor for future refining and characterisation.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Peptídeos/farmacologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Linhagem Celular , Descoberta de Drogas , Inibidores Enzimáticos/metabolismo , Humanos , Fragmentos de Peptídeos/metabolismo , Peptídeos/metabolismo
4.
Chem Commun (Camb) ; 55(59): 8595-8598, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31276123

RESUMO

The amino acid sequence plays an essential role in amyloid formation. Here, using the central core recognition module of the Aß peptide and its reverse sequence, we show that although both peptides assemble into ß-sheets, their morphologies, kinetics and cell toxicities display marked differences. In addition, the native peptide, but not the reverse one, shows notable affinity towards bilayer lipid model membranes that modulates the aggregation pathways to stabilize the oligomeric intermediate states and function as the toxic agent responsible for neuronal dysfunction.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Peptídeos beta-Amiloides/toxicidade , Animais , Linhagem Celular Tumoral , Colesterol/química , Humanos , Cinética , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Fragmentos de Peptídeos/toxicidade , Fosfatidilcolinas/química , Conformação Proteica em Folha beta , Multimerização Proteica , Ratos , Esfingomielinas/química
5.
Adv Exp Med Biol ; 1140: 401-415, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31347061

RESUMO

Mass spectrometry is a powerful analytical technique becoming increasingly important in different biomedical research area. Mass spectrometric based methods were developed and applied to detect and identify multiple metal ion complexes of peptides and proteins with high sensitivity and high mass accuracy. Aggregation of amyloid-ß (Aß) peptides is one of the main pathological features of Alzheimer's disease (AD), and some metal ions seem to play a key role in AD pathogenesis. Consequently, mass spectrometry was used to investigate heavy metal binding to AD-related peptides. Therefore, the purpose of this chapter is to review the methodology and application of identifying coordination chemistry and binding properties of several metal ion-binding sites to synthetic ß-amyloid (Aß) and anti-amyloid model peptides. The selective metal-amyloid-ß peptide interaction studies using (a) Matrix-assisted laser desorption/ionization mass spectrometry (MALDI); (b) Electrospray ionization mass spectrometry (ESI-MS), and (c) Tandem mass spectrometry (MS/MSn) will be reported.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/metabolismo , Metais Pesados/metabolismo , Humanos , Modelos Moleculares , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
6.
Nervenarzt ; 90(9): 891-897, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31332452

RESUMO

Alzheimer's disease is histopathologically characterized by aggregation of two proteins, namely amyloid-beta peptide and tau protein. Whereas former intervention trials focused particularly on the amyloid pathology, recent therapeutic approaches are directed against the tau pathology. This article summarizes recent progress in anti-tau therapies, especially therapies based on anti-tau immunization and antisense oligonucleotides (ASO).


Assuntos
Doença de Alzheimer , Proteínas tau , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/metabolismo , Humanos , Imunoterapia , Oligonucleotídeos Antissenso/uso terapêutico , Proteínas tau/antagonistas & inibidores , Proteínas tau/metabolismo
7.
Clin Interv Aging ; 14: 817-826, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190768

RESUMO

Background: Alzheimer's disease (AD) is the most common neurodegenerative disorder that also involves neuroinflammation in addition to many other features. Icariin (ICA) as one of the active ingredients of Chinese herbal medicine has the immunomodulating function. This study aimed to investigate the immunotherapeutic potential of ICA on AD. Methods: APP/PS1 mice and wild type C57BL/6 mice were subjected to orally ICA administration (60 mg/kg/d) for 8 months. Then, the ethological and biochemical experiments, such as Morris water maze assay, Aß ELISA, blood T cell flow cytometry, and plasma and brain cytokines array, were conducted to evaluate the effects of ICA administration. Results: ICA significantly improved spatial learning and memory retention in APP/PS1 mice. Long-term application of ICA could also reduce hippocampus Aß deposition, modulate the differentiation of CD4+ T cells, and modulate the release of inflammatory cytokines in plasma and brain tissue. Conclusion: ICA shows the neuroprotective effects via modulating the CD4+ T lymphocyte-related immuno-inflammatory responses in APP/PS1 mice and may be a promising drug against AD progression.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Flavonoides/farmacologia , Memória/efeitos dos fármacos , Aprendizagem Espacial/efeitos dos fármacos , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Cognição/fisiologia , Citocinas/metabolismo , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Presenilina-1
8.
Chem Biol Interact ; 309: 108707, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31194956

RESUMO

Alzheimer's disease (AD) is a slow but progressive neurodegenerative disease. One of the pathological hallmarks of AD is the progressive accumulation of ß-amyloid (Aß) in the form of senile plaques, and Aß insult to neuronal cells has been identified as one of the major causes of AD onset. In the present study, we investigated the anti-AD potential of four flavonoids, naringenin, didymin, prunin, and poncirin, by evaluating their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1). All four flavonoids displayed promising inhibitory activity against AChE, BChE, and BACE1. Structure-activity relationships suggested that glycosylation of naringenin at sugar moieties, and at different positions of the glycosidic linkage, might be closely associated with anti-AD potential. Kinetic and docking studies showed the lowest binding energy and highest affinity for the mixed, competitive, and non-competitive type inhibitors didymin, prunin, and poncirin. Hydrophobic interactions and the number of hydrogen bonds determined the strength of the protein-inhibitor interaction. We also examined the neuroprotective mechanisms by which flavonoids act against Aß25-35-induced toxicity in PC12 cells. Exposure of PC12 cells to 10 µM Aß25-35 for 24 h resulted in a significant decrease in cell viability. In addition, pretreatment of PC12 cells with different concentrations of flavonoids for 1 h significantly reversed the effects of Aß. Furthermore, treatment with the most active flavonoid, didymin, significantly reduced BACE1, APPsß, and C99 expression levels in a dose-dependent manner, without affecting amyloid precursor protein (APP) levels in the amyloidogenic pathway. Together, our results indicate that flavonoids, and in particular didymin, exhibit inhibitory activity in vitro, and may be useful in the development of therapeutic modalities for the treatment of AD.


Assuntos
Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Butirilcolinesterase/metabolismo , Flavanonas/química , Glicosídeos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Acetilcolinesterase/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/farmacologia , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Sítios de Ligação , Butirilcolinesterase/química , Domínio Catalítico , Sobrevivência Celular/efeitos dos fármacos , Glicosídeos/química , Cinética , Simulação de Acoplamento Molecular , Células PC12 , Fragmentos de Peptídeos/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Ratos , Relação Estrutura-Atividade
9.
Cell Mol Life Sci ; 76(16): 3167-3191, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31197405

RESUMO

As life expectancy increases worldwide, age-related neurodegenerative diseases will increase in parallel. The lack of effective treatment strategies may soon lead to an unprecedented health, social and economic crisis. Any attempt to halt the progression of these diseases requires a thorough knowledge of the pathophysiological mechanisms involved to facilitate the identification of new targets and the application of innovative therapeutic strategies. The metzincin superfamily of metalloproteinases includes matrix metalloproteinases (MMP), a disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS). These multigenic and multifunctional proteinase families regulate the functions of an increasing number of signalling and scaffolding molecules involved in neuroinflammation, blood-brain barrier disruption, protein misfolding, synaptic dysfunction or neuronal death. Metalloproteinases and their physiological inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), are therefore, at the crossroads of molecular and cellular mechanisms that support neurodegenerative processes, and emerge as potential new therapeutic targets. We provide an overview of current knowledge on the role and regulation of metalloproteinases and TIMPs in four major neurodegenerative diseases: Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and Huntington's disease.


Assuntos
Doença de Alzheimer/patologia , Metaloproteinases da Matriz/metabolismo , Doenças Neurodegenerativas/patologia , Inibidores Teciduais de Metaloproteinases/metabolismo , Proteínas ADAM/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Humanos , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Doenças Neurodegenerativas/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia
10.
Cell Mol Life Sci ; 76(16): 3193-3206, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201463

RESUMO

Alzheimer's Disease (AD) is the sixth-leading cause of death in industrialized countries. Neurotoxic amyloid-ß (Aß) plaques are one of the pathological hallmarks in AD patient brains. Aß accumulates in the brain upon sequential, proteolytic processing of the amyloid precursor protein (APP) by ß- and γ-secretases. However, so far disease-modifying drugs targeting ß- and γ-secretase pathways seeking a decrease in the production of toxic Aß peptides have failed in clinics. It has been demonstrated that the metalloproteinase meprin ß acts as an alternative ß-secretase, capable of generating truncated Aß2-x peptides that have been described to be increased in AD patients. This indicates an important ß-site cleaving enzyme 1 (BACE-1)-independent contribution of the metalloprotease meprin ß within the amyloidogenic pathway and may lead to novel drug targeting avenues. However, meprin ß itself is embedded in a complex regulatory network. Remarkably, the anti-amyloidogenic α-secretase a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is a direct competitor for APP at the cell surface, but also a sheddase of inactive pro-meprin ß. Overall, we highlight the current cellular, molecular and structural understanding of meprin ß as alternative ß-secretase within the complex protease web, regulating APP processing in health and disease.


Assuntos
Proteína ADAM10/metabolismo , Metaloendopeptidases/metabolismo , Proteína ADAM10/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Metaloendopeptidases/química , Presenilina-1/metabolismo , Proteólise , Serina Endopeptidases/metabolismo
11.
Eur J Med Chem ; 177: 291-301, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158745

RESUMO

Based on our previous research on the fluorinated phenylquinoxaline scaffold, in this study, different positions of N,N-dimethyl amino group, and alkyl linkers with various lengths were introduced into this scaffold to regulate their lipophilicity and binding affinity to Tau. Four novel 99mTc/Re complexes with diethyl iminodiacetate chelator were synthesized and evaluated as Tau imaging tracers in the brain of Alzheimer's disease. Their specific binding to neurofibrillary tangles was verified by in vitro fluorescence staining and further confirmed by the results of immunofluorescence staining on the same brain sections from AD patient and Tg-tau mice. From in vitro binding assay using recombinant Tau aggregates, complex 4.2 with 6-N(CH3)2 and longer carbon chain (n = 4) displayed the highest affinity (Kd = 59.95 nM). [99mTc]4.2 was achieved by the ligand exchange reaction between dicarboxylic precursor and [99mTc(CO)3(H2O)3]+ intermediate with radiochemical yield over 45%. Ex vivo biodistribution studies on normal ICR mice revealed that [99mTc]4.2 exhibited moderate initial brain uptake (0.61% ID/g) and more structure optimizations are still required to improve the blood-brain barrier permeability.


Assuntos
Doença de Alzheimer/diagnóstico , Complexos de Coordenação/química , Corantes Fluorescentes/química , Compostos de Organotecnécio/química , Quinoxalinas/química , Proteínas tau/metabolismo , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Quelantes/síntese química , Quelantes/química , Quelantes/metabolismo , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Feminino , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Humanos , Iminoácidos/síntese química , Iminoácidos/química , Iminoácidos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Estrutura Molecular , Emaranhados Neurofibrilares/metabolismo , Emaranhados Neurofibrilares/patologia , Compostos de Organotecnécio/síntese química , Compostos de Organotecnécio/metabolismo , Fragmentos de Peptídeos/metabolismo , Quinoxalinas/síntese química , Quinoxalinas/metabolismo , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/metabolismo , Rênio/química , Distribuição Tecidual
12.
Eur J Med Chem ; 177: 414-424, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158754

RESUMO

Due to the role of butyrylcholinesterase (BChE) in acetylcholine hydrolysis in the late stages of the Alzheimer's disease (AD), inhibitors of butyrylcholinesterase (BChE) have been recently envisaged, besides acetylcholinesterase (AChE) inhibitors, as candidates for treating mild-to-moderate AD. Herein, synthesis and AChE/BChE inhibition activity of some twenty derivatives of 1,2,3,4,5,6-hexahydroazepino[4,3-b]indole (HHAI) is reported. Most of the newly synthesized HHAI derivatives achieved the inhibition of both ChE isoforms with IC50s in the micromolar range, with a structure-dependent selectivity toward BChE. Apparently, molecular volume and lipophilicity do increase selectivity toward BChE, and indeed the N2-(4-phenylbutyl) HHAI derivative 15d, which behaves as a mixed-type inhibitor, resulted the most potent (IC50 0.17 µM) and selective (>100-fold) inhibitor toward either horse serum and human BChE. Moreover, 15d inhibited in vitro self-induced aggregation of neurotoxic amyloid-ß (Aß) peptide and displayed neuroprotective effects in neuroblastoma SH-SY5Y cell line, significantly recovering (P < 0.001) cell viability when impaired by Aß1-42 and hydrogen peroxide insults. Overall, this study highlighted HHAI as useful and versatile scaffold for developing new small molecules targeting some enzymes and biochemical pathways involved in the pathogenesis of AD.


Assuntos
Azepinas/farmacologia , Inibidores da Colinesterase/farmacologia , Indóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Peptídeos beta-Amiloides/metabolismo , Azepinas/síntese química , Azepinas/química , Azepinas/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Relação Dose-Resposta a Droga , Desenho de Drogas , Depuradores de Radicais Livres/síntese química , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Humanos , Indóis/síntese química , Indóis/química , Indóis/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Relação Estrutura-Atividade
13.
Life Sci ; 231: 116537, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31176774

RESUMO

AIMS: Renal dysfunction has been reported in individuals with Down syndrome (DS); however, the causes and mechanisms involved remain unknown. Here, we present a proposal for how the triplication of the amyloid beta precursor protein (APP) and, mainly the amyloid ß peptide 1-42 (Aß42) can favor the development of renal abnormalities in DS. We evaluated the effects of vitamin D3 (VD3) supplementation on morphofunctional aspects and the repercussions on the presence and localization of Aß42, methylenetetrahydrofolate reductase (MTHFR), caspase-3 p12, and P-glycoprotein (Pgp) in the renal tissue of DS mouse model. MAIN METHODS: Twenty female mice (14-week-old) belonging to the B6EiC3Sn-Rb(12.Ts171665Dn)2Cje/CjeDnJ lineage were divided into four experimental groups (n = 5/group): common diet; trisomy (Ts) and wild-type (Wt); and high doses VD3, Ts(VD3), and Wt(VD3). All the groups were treated for 10 weeks. At 24 weeks, the protocol experimental was interrupted. The kidney was weighed, collected, and processed for immunochemical analysis for Aß42, Caspase-3 p12, MTHFR, and Pgp proteins. All data were analyzed statistically. KEY FINDINGS: Our results showed that VD3 promoted an increase in caspase-3 p12, MTHFR, and Pgp, and consequently contributed to reduced Aß42 in the renal tissue of a mouse model of DS. Furthermore, VD3 treatment affected the plasma creatinine and urea levels and contributed to the attenuation of the dilation of Bowman's space observed in trisomic mice. SIGNIFICANCE: Finally, the results showed that VD3 may activate specific mechanisms involved in reduced Aß42 and tissue repair in the kidneys of a mouse model for Down syndrome.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Colecalciferol/farmacologia , Síndrome de Down/tratamento farmacológico , Síndrome de Down/metabolismo , Rim/efeitos dos fármacos , Fragmentos de Peptídeos/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/fisiologia , Animais , Caspase 3/metabolismo , Suplementos Nutricionais , Modelos Animais de Doenças , Síndrome de Down/patologia , Feminino , Rim/metabolismo , Rim/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Endogâmicos BALB C
14.
Nat Commun ; 10(1): 2353, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164641

RESUMO

The link between brain amyloid-ß (Aß), metabolism, and dementia symptoms remains a pressing question in Alzheimer's disease. Here, using positron emission tomography ([18F]florbetapir tracer for Aß and [18F]FDG tracer for glucose metabolism) with a novel analytical framework, we found that Aß aggregation within the brain's default mode network leads to regional hypometabolism in distant but functionally connected brain regions. Moreover, we found that an interaction between this hypometabolism with overlapping Aß aggregation is associated with subsequent cognitive decline. These results were also observed in transgenic Aß rats that do not form neurofibrillary tangles, which support these findings as an independent mechanism of cognitive deterioration. These results suggest a model in which distant Aß induces regional metabolic vulnerability, whereas the interaction between local Aß with a vulnerable environment drives the clinical progression of dementia.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Emaranhados Neurofibrilares/metabolismo , Doença de Alzheimer/diagnóstico por imagem , Compostos de Anilina , Animais , Animais Geneticamente Modificados , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Etilenoglicóis , Fluordesoxiglucose F18 , Humanos , Imagem por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Vias Neurais/metabolismo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Ratos
15.
JAMA ; 321(23): 2316-2325, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31211344

RESUMO

Importance: A National Institute on Aging and Alzheimer's Association workgroup proposed a research framework for Alzheimer disease in which biomarker classification of research participants is labeled AT(N) for amyloid, tau, and neurodegeneration biomarkers. Objective: To determine the associations between AT(N) biomarker profiles and memory decline in a population-based cohort of individuals without dementia age 60 years or older, and to determine whether biomarkers provide incremental prognostic value beyond more readily available clinical and genetic information. Design, Setting, and Participants: Population-based cohort study of cognitive aging in Olmsted County, Minnesota, that included 480 nondemented Mayo Clinic Study of Aging participants who had a clinical evaluation and amyloid positron emission tomography (PET) (A), tau PET (T), and magnetic resonance imaging (MRI) cortical thickness (N) measures between April 16, 2015, and November 1, 2017, and at least 1 clinical evaluation follow-up by November 12, 2018. Exposures: Age, sex, education, cardiovascular and metabolic conditions score, APOE genotype, and AT(N) biomarker profiles. Each of A, T, or (N) can be abnormal (+) or normal (-), resulting in 8 AT(N) profiles. Main Outcomes and Measures: Primary outcome was a composite memory score measured longitudinally at 15-month intervals. Analyses measured the associations between predictor variables and the memory score, and whether AT(N) biomarker profiles significantly improved prediction of memory z score rates of change beyond a model with clinical and genetic variables only. Results: Participants were followed up for a median of 4.8 years (interquartile range [IQR], 3.8-5.1) and 44% were women (211/480). Median (IQR) ages ranged from 67 years (65-73) in the A-T-(N)- group to 83 years (76-87) in the A+T+(N)+ group. Of the participants, 92% (441/480) were cognitively unimpaired but the A+T+(N)+ group had the largest proportion of mild cognitive impairment (30%). AT(N) biomarkers improved the prediction of memory performance over a clinical model from an R2 of 0.26 to 0.31 (P < .001). Memory declined fastest in the A+T+(N)+, A+T+(N)-, and A+T-(N)+ groups compared with the other 5 AT(N) groups (P = .002). Estimated rates of decline in the 3 fastest declining groups were -0.13 (95% CI, -0.17 to -0.09), -0.10 (95% CI, -0.16 to -0.05), and -0.10 (95% CI, -0.13 to -0.06) z score units per year, respectively, for an 85-year-old APOE ε4 noncarrier. Conclusions and Relevance: Among older persons without baseline dementia followed for a median of 4.8 years, a prediction model that included amyloid PET, tau PET, and MRI cortical thickness resulted in a small but statistically significant improvement in predicting memory decline over a model with more readily available clinical and genetic variables. The clinical importance of this difference is uncertain.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Apolipoproteínas E/genética , Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Imagem por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Estudos de Coortes , Demência , Progressão da Doença , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
16.
J Agric Food Chem ; 67(27): 7684-7693, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31203623

RESUMO

This study investigated the alleviative effect of caffeic acid (CA) on Alzheimer's disease (AD) pathogenesis and associated mechanisms in high-fat (HF) diet-induced hyperinsulinemic rats. The results of a Morris water maze indicated that, by administrating CA (30 mg/kg b.w./day) for 30 weeks, the memory and learning impairments in HF-induced hyperinsulinemic rats were significantly ameliorated. CA also enhanced superoxide dismutase and glutathione free radical scavenger activity in hyperinsulinemic rats. The Western blot data further confirmed that protein expressions of phosphorylated-glycogen synthase kinase 3ß (GSK3ß) were significantly increased, whereas the expression of phosphorylated-tau protein decreased in the hippocampus of rats administered with CA in comparison with the HF group. Moreover, the expression of amyloid precursor protein (APP) and ß-site APP cleaving enzyme were attenuated, subsequently lowering the level of ß-amyloid 1-42 (Aß 1-42) in the hippocampus of CA-treated hyperinsulinemic rats. CA also significantly increased the expression of synaptic proteins in HF rats.


Assuntos
Doença de Alzheimer/prevenção & controle , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Ácidos Cafeicos/administração & dosagem , Insulina/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Doença de Alzheimer/metabolismo , Animais , Antioxidantes/química , Córtex Cerebral/química , Córtex Cerebral/enzimologia , Córtex Cerebral/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Glutationa/metabolismo , Glicogênio Sintase Quinase 3 beta/análise , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/química , Hipocampo/enzimologia , Hipocampo/metabolismo , Hiperinsulinismo/etiologia , Hiperinsulinismo/metabolismo , Masculino , Fosforilação , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Proteínas tau/análise , Proteínas tau/metabolismo
17.
Nervenarzt ; 90(9): 884-890, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31243509

RESUMO

Numerous amyloid-based clinical studies have recently failed. Does this mean that the mechanisms of Alzheimer's disease have to be reinvestigated and that amyloid is not the trigger of the disease? Strong genetic evidence from familial Alzheimer's disease contradicts this fatalistic opinion. Mutations in all genes associated with familial Alzheimer's disease affect amyloid metabolism and aggregation. Moreover, a protective mutation reduces amyloid production by 20-30% throughout the lifetime. Clinical studies rather failed because secretase inhibitors block cleavage of numerous other physiologically important substrates of secretases. Moreover, the disease is initiated decades before symptoms occur. Successful treatment attempts with anti-amyloid medication based on other prototype amyloidoses are described. Finally, new therapeutic target molecules expressed in microglia cells are discussed.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Humanos , Mutação , Pesquisa/normas
18.
Nanoscale ; 11(18): 9185-9193, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31038146

RESUMO

Recent advances in nanotechnology have developed a lot of opportunities for biological applications. In this work, multifunctional MoS2/AuNR nanocomposites with unique high NIR absorption were designed via combining MoS2 nanosheets and gold nanorods (AuNRs). The nanocomposites were synthesized through electrostatic self-assembly and showed high stability and good biocompatibility. Then they were used to modulate the aggregation of amyloid-ß peptides, destabilize mature fibrils under NIR irradiation, and eliminate Aß-induced ROS against neurotoxicity. The inhibition and destabilization effects were confirmed by Thioflavin T (ThT) fluorescence assay and transmission electron microscopy (TEM). Cell viability assay and ROS assay revealed that MoS2/AuNR nanocomposites could alleviate Aß-induced oxidative stress and cell toxicity. More importantly, both MoS2 nanosheets and AuNRs can be used as NIR photothermal agents, MoS2/AuNR nanocomposites have enhanced ability of disrupting Aß fibrils and improved cell viability by generating local heat under low power NIR irradiation. Our results provide new insights into the design of new multifunctional systems for the treatment of amyloid-related diseases.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Raios Infravermelhos , Nanocompostos/química , Fragmentos de Peptídeos/metabolismo , Amiloide/química , Amiloide/toxicidade , Peptídeos beta-Amiloides/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Dissulfetos/química , Ouro/química , Humanos , Molibdênio/química , Nanocompostos/toxicidade , Nanotubos/química , Fragmentos de Peptídeos/química , Espécies Reativas de Oxigênio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Eur J Med Chem ; 177: 198-211, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31136894

RESUMO

A series of 3-amino-substituted rutacecarpine derivatives were synthesized to identify novel multitarget-directed ligands (MTDLs) for the treatment of Alzheimer's disease (AD). Biological evaluation showed that most of the synthesized compounds inhibited butyrylcholinesterase (BuChE) and exerted antioxidant effects. Among the synthesized compounds, 6n was subjected to further biological evaluation. Lineweaver-Burk plotting and molecular modeling illustrated that 6n bound simultaneously to the peripheral anionic site (PAS) and catalytic sites (CAS) of BuChE. Furthermore, 6n modulated Aß aggregation; chelated biometals; presented good absorption, distribution, metabolism, excretion, and toxicity properties; and showed remarkable neuroprotective activity. Previous research has shown that the optimized compound 6n has considerable potential for development as an MTDL for the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Substâncias Protetoras/farmacologia , Sulfonamidas/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Linhagem Celular Tumoral , Quelantes/síntese química , Quelantes/química , Quelantes/farmacocinética , Quelantes/farmacologia , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacocinética , Desenho de Drogas , Humanos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Substâncias Protetoras/síntese química , Substâncias Protetoras/química , Substâncias Protetoras/farmacocinética , Multimerização Proteica/efeitos dos fármacos , Ratos , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Sulfonamidas/farmacocinética
20.
Expert Opin Investig Drugs ; 28(6): 545-554, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094578

RESUMO

INTRODUCTION: Alzheimer's dementia (AD) is the most common form of dementia in the World. Pathologically, it is characterized by extracellular ß-amyloid plaques and intraneuronal neurofibrillary tangles (NFTs). The latter is composed of irregular, pathological forms of the tau protein. Currently, FDA-approved symptomatic treatments are limited to the targeting of cholinergic deficits and glutamatergic dysfunctions. However, as understanding of ß-amyloid plaques and NFTs expands, these dysfunctional proteins represent potential therapeutic interventions. The present review article evaluates active and passive immunotherapies in clinical development for AD to date and their potential to significantly improve the treatment of AD going forward. AREAS COVERED: All clinical trials that have targeted ß-amyloid to date have produced somewhat disappointing results, leading to a shift in intervention focus to targeting tau protein. A key component in understanding the value of targeting tau in therapeutic paradigms has come from the conceptualization of prion-like pathological spread of tau isoforms from neuron to neuron, and referred to as 'tauons'. Immunotherapies currently under investigation include approaches aiming at preventing pathological tau aggregation, stabilizing microtubules, and blocking of tauons. EXPERT OPINION: A multi-targeted approach that would use biologics targeting tau offers great promise to the development of effective AD therapeutic interventions.


Assuntos
Doença de Alzheimer/terapia , Imunoterapia/métodos , Proteínas tau/imunologia , Doença de Alzheimer/imunologia , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Produtos Biológicos/farmacologia , Humanos , Terapia de Alvo Molecular , Emaranhados Neurofibrilares/metabolismo , Proteínas tau/metabolismo
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