Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Cell ; 170(3): 443-456.e14, 2017 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-28753424

RESUMO

Alzheimer's disease (AD)-linked mutations in Presenilins (PSEN) and the amyloid precursor protein (APP) lead to production of longer amyloidogenic Aß peptides. The shift in Aß length is fundamental to the disease; however, the underlying mechanism remains elusive. Here, we show that substrate shortening progressively destabilizes the consecutive enzyme-substrate (E-S) complexes that characterize the sequential γ-secretase processing of APP. Remarkably, pathogenic PSEN or APP mutations further destabilize labile E-S complexes and thereby promote generation of longer Aß peptides. Similarly, destabilization of wild-type E-S complexes by temperature, compounds, or detergent promotes release of amyloidogenic Aß. In contrast, E-Aßn stabilizers increase γ-secretase processivity. Our work presents a unifying model for how PSEN or APP mutations enhance amyloidogenic Aß production, suggests that environmental factors may increase AD risk, and provides the theoretical basis for the development of γ-secretase/substrate stabilizing compounds for the prevention of AD.


Assuntos
Doença de Alzheimer/enzimologia , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/metabolismo , Proteínas de Membrana/metabolismo , Peptídeo Hidrolases/metabolismo , Presenilina-1/metabolismo , Precursor de Proteína beta-Amiloide/química , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Endopeptidases , Estabilidade Enzimática , Feminino , Células HEK293 , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Modelos Moleculares , Mutação , Peptídeo Hidrolases/química , Peptídeo Hidrolases/genética , Presenilina-1/química , Presenilina-1/genética
3.
EMBO J ; 38(12)2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31109937

RESUMO

γ-Secretase complexes (GSECs) are multimeric membrane proteases involved in a variety of physiological processes and linked to Alzheimer's disease (AD). Presenilin (PSEN, catalytic subunit), Nicastrin (NCT), Presenilin Enhancer 2 (PEN-2), and Anterior Pharynx Defective 1 (APH1) are the essential subunits of GSECs. Mutations in PSEN and the Amyloid Precursor Protein (APP) cause early-onset AD GSECs successively cut APP to generate amyloid-ß (Aß) peptides of various lengths. AD-causing mutations destabilize GSEC-APP/Aßn interactions and thus enhance the production of longer Aßs, which elicit neurotoxic events underlying pathogenesis. Here, we investigated the molecular strategies that anchor GSEC and APP/Aßn during the sequential proteolysis. Our studies reveal that a direct interaction between NCT ectodomain and APPC99 influences the stability of GSEC-Aßn assemblies and thereby modulates Aß length. The data suggest a potential link between single-nucleotide variants in NCSTN and AD risk. Furthermore, our work indicates that an extracellular interface between the protease (NCT, PSEN) and the substrate (APP) represents the target for compounds (GSMs) modulating Aß length. Our findings may guide future rationale-based drug discovery efforts.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Glicoproteínas de Membrana/metabolismo , Domínios e Motivos de Interação entre Proteínas/fisiologia , Secretases da Proteína Precursora do Amiloide/química , Precursor de Proteína beta-Amiloide/química , Animais , Células Cultivadas , Ativação Enzimática , Espaço Extracelular , Células HEK293 , Humanos , Glicoproteínas de Membrana/química , Camundongos , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Quaternária de Proteína , Proteólise , Relação Estrutura-Atividade
4.
Neurobiol Dis ; 154: 105365, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33848635

RESUMO

The imbalance between production and clearance of amyloid ß (Aß) peptides and their resulting accumulation in the brain is an early and crucial step in the pathogenesis of Alzheimer's disease (AD). Therefore, Aß is strongly positioned as a promising and extensively validated therapeutic target for AD. Investigational disease-modifying approaches aiming at reducing cerebral Aß concentrations include prevention of de novo production of Aß through inhibition of ß-site amyloid precursor protein cleaving enzyme 1 (BACE1), and clearance of Aß deposits via passive Aß immunotherapy. We have developed a novel, high affinity antibody against Aß peptides bearing a pyroglutamate residue at amino acid position 3 (3pE), an Aß species abundantly present in plaque deposits in AD brains. Here, we describe the preclinical characterization of this antibody, and demonstrate a significant reduction in amyloid burden in the absence of microhemorrhages in different mouse models with established plaque deposition. Moreover, we combined antibody treatment with chronic BACE1 inhibitor treatment and demonstrate significant clearance of pre-existing amyloid deposits in transgenic mouse brain, without induction of microhemorrhages and other histopathological findings. Together, these data confirm significant potential for the 3pE-specific antibody to be developed as a passive immunotherapy approach that balances efficacy and safety. Moreover, our studies suggest further enhanced treatment efficacy and favorable safety after combination of the 3pE-specific antibody with BACE1 inhibitor treatment.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Anticorpos Monoclonais/administração & dosagem , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Imunização Passiva/métodos , Fragmentos de Peptídeos/antagonistas & inibidores , Placa Amiloide/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/imunologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/imunologia , Peptídeos beta-Amiloides/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Ácido Aspártico Endopeptidases/imunologia , Ácido Aspártico Endopeptidases/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Placa Amiloide/imunologia , Placa Amiloide/metabolismo , Resultado do Tratamento
5.
Bioorg Med Chem Lett ; 29(14): 1737-1745, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122869

RESUMO

The discovery, design and synthesis of a new series of GSMs is described. The classical imidazole heterocycle has been replaced by a cyano group attached to an indole nucleus. The exploration of this series has led to compound 26-S which combined high in vitro and in vivo potency with an acceptable drug-like profile.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Indóis/síntese química , Desenho de Fármacos , Humanos , Relação Estrutura-Atividade
6.
Artigo em Inglês | MEDLINE | ID: mdl-29943865

RESUMO

RATIONALE: Immuno-PET imaging may prove to be a diagnostic and progression/intervention biomarker for Alzheimer's disease (AD) with improved sensitivity and specificity. Immuno-PET imaging is based on the coupling of an antibody with a chelator that captures a radioisotope thus serving as an in-vivo PET ligand. A robust and quality controlled process for linking the chelator to the-antibody is fundamental for the success of this approach. METHODS: The structural integrities of two monoclonal antibodies (trastuzumab and JRF/AßN/25) and the quantity of desferal-based chelator attached following modification of the antibodies were assessed by online desalting and intact mass analysis. Enzymatic steps for the deglycosylation and removal of C-terminal lysine was performed sequentially and in a single tube to improve intact mass data. RESULTS: Intact mass analysis demonstrated that inclusion of enzymatic processing was critical to correctly derive the quantity of chelator linked to the monoclonal antibodies. For trastuzumab, enzymatic cleaving of the glycans was sufficient, whilst additional removal of the C-terminal lysine was necessary for JRF/AßN/25 to ensure reproducible assessment of the relatively low amount of attached chelator. CONCLUSIONS: An efficient intact mass analysis-based process was developed to reproducibly determine the integrity of monoclonal antibodies and the quantity of attached chelator. This technique could serve as an essential quality control approach for the development and production of immuno-PET tracers.

8.
Proteins ; 84(4): 427-34, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26800003

RESUMO

Microtubule-associated protein tau becomes abnormally phosphorylated in Alzheimer's disease and other tauopathies and forms aggregates of paired helical filaments (PHF-tau). AT8 is a PHF-tau-specific monoclonal antibody that is a commonly used marker of neuropathology because of its recognition of abnormally phosphorylated tau. Previous reports described the AT8 epitope to include pS202/pT205. Our studies support and extend previous findings by also identifying pS208 as part of the binding epitope. We characterized the phosphoepitope of AT8 through both peptide binding studies and costructures with phosphopeptides. From the cocrystal structure of AT8 Fab with the diphosphorylated (pS202/pT205) peptide, it appeared that an additional phosphorylation at S208 would also be accommodated by AT8. Phosphopeptide binding studies showed that AT8 bound to the triply phosphorylated tau peptide (pS202/pT205/pS208) 30-fold stronger than to the pS202/pT205 peptide, supporting the role of pS208 in AT8 recognition. We also show that the binding kinetics of the triply phosphorylated peptide pS202/pT205/pS208 was remarkably similar to that of PHF-tau. The costructure of AT8 Fab with a pS202/pT205/pS208 peptide shows that the interaction interface involves all six CDRs and tau residues 202-209. All three phosphorylation sites are recognized by AT8, with pT205 acting as the anchor. Crystallization of the Fab/peptide complex under acidic conditions shows that CDR-L2 is prone to unfolding and precludes peptide binding, and may suggest a general instability in the antibody.


Assuntos
Anticorpos Monoclonais/química , Epitopos/química , Fragmentos Fab das Imunoglobulinas/química , Fosfopeptídeos/química , Proteínas tau/química , Sequência de Aminoácidos , Anticorpos Monoclonais/biossíntese , Sítios de Ligação de Anticorpos , Cristalografia por Raios X , Mapeamento de Epitopos , Epitopos/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Fragmentos Fab das Imunoglobulinas/biossíntese , Modelos Moleculares , Fosfopeptídeos/síntese química , Fosforilação , Ligação Proteica , Dobramento de Proteína , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Serina/química , Serina/metabolismo , Treonina/química , Treonina/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo
9.
J Neurochem ; 135(5): 1049-58, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26332787

RESUMO

The 42-amino acid fragment of amyloid ß (Aß1-42) in cerebrospinal fluid has continued to be important for detecting cerebral ß-amyloidosis in Alzheimer's disease (AD). However, there are impediments to our ability to fully understand this measurement, including matrix interference and changes linked to apolipoprotein E (APOE) ε4 genotype. This study investigated matrix interference as a contributing factor for detecting AD in APOE ε4-negative patients by comparing total extractable Aß1-42 to free Aß1-42. It also examined the ratio of total Aß1-42 to Aß1-40, since changes relative to other Aß peptides may provide a measurement of cerebral ß-amyloidosis that is neutral to changes in APP metabolism. Total Aß1-42 lost the diagnostic power for detecting AD, confirming a role for matrix in the diagnostic. However, when total Aß1-42/Aß1-40 was examined, the separation between groups was reestablished. This result was confirmed in a second sample set of unknown APOE status. These results confirmed that matrix interference in some cerebrospinal fluid samples appears to contribute to identifying AD patients and this can be compensated by using a total extracted Aß1-42/Aß1-40 ratio when matrix interference is small. It may be preferable to employ a total Aß1-42/Aß1-40 measurement, since this could minimize variability because of matrix and compensate for across patient differences. Aß1-42 measurement in CSF has provided an important tool for early detection of AD. However, it appears that most assays measure a free fraction of Aß1-42. This study examined total extracted Aß1-42, since this would provide a more accurate assessment of Aß1-42 in AD CSF. Total Aß1-42 measurements alone were not good for detecting AD but total Aß1-42/Aß1-40 performed well.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Fragmentos de Peptídeos/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Cromatografia Líquida de Alta Pressão , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Proteínas tau/líquido cefalorraquidiano
10.
Neurobiol Dis ; 73: 83-95, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25220759

RESUMO

Neurofibrillary tangles composed of hyperphosphorylated fibrillized tau are found in numerous tauopathies including Alzheimer's disease. Increasing evidence suggests that tau pathology can be transmitted from cell-to-cell; however the mechanisms involved in the initiation of tau fibrillization and spreading of disease linked to progression of tau pathology are poorly understood. We show here that intracerebral injections of preformed synthetic tau fibrils into the hippocampus or frontal cortex of young tau transgenic mice expressing mutant human P301L tau induces tau hyperphosphorylation and aggregation around the site of injection, as well as a time-dependent propagation of tau pathology to interconnected brain areas distant from the injection site. Furthermore, we show that the tau pathology as a consequence of injection of tau preformed fibrils into the hippocampus induces selective loss of CA1 neurons. Together, our data confirm previous studies on the seeded induction and the spreading of tau pathology in a different tau transgenic mouse model and reveals neuronal loss associated with seeded tau pathology in tau transgenic mouse brain. These results further validate the utility of the tau seeding model in studying disease transmission, and provide a more complete in vivo tauopathy model with associated neurodegeneration which can be used to investigate the mechanisms involved in tau aggregation and spreading, as well as aid in the search for disease modifying treatments for Alzheimer's disease and related tauopathies.


Assuntos
Tauopatias , Proteínas tau/administração & dosagem , Proteínas tau/genética , Fatores Etários , Análise de Variância , Animais , Modelos Animais de Doenças , Progressão da Doença , Lateralidade Funcional , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Camundongos , Camundongos Transgênicos , Mutação/genética , Emaranhados Neurofibrilares/metabolismo , Tauopatias/induzido quimicamente , Tauopatias/genética , Tauopatias/patologia , Proteínas tau/química
11.
Acta Neuropathol ; 129(1): 21-37, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25432317

RESUMO

The key role of APP in the pathogenesis of Alzheimer disease is well established. However, postnatal lethality of double knockout mice has so far precluded the analysis of the physiological functions of APP and the APLPs in the brain. Previously, APP family proteins have been implicated in synaptic adhesion, and analysis of the neuromuscular junction of constitutive APP/APLP2 mutant mice showed deficits in synaptic morphology and neuromuscular transmission. Here, we generated animals with a conditional APP/APLP2 double knockout (cDKO) in excitatory forebrain neurons using NexCre mice. Electrophysiological recordings of adult NexCre cDKOs indicated a strong synaptic phenotype with pronounced deficits in the induction and maintenance of hippocampal LTP and impairments in paired pulse facilitation, indicating a possible presynaptic deficit. These deficits were also reflected in impairments in nesting behavior and hippocampus-dependent learning and memory tasks, including deficits in Morris water maze and radial maze performance. Moreover, while no gross alterations of brain morphology were detectable in NexCre cDKO mice, quantitative analysis of adult hippocampal CA1 neurons revealed prominent reductions in total neurite length, dendritic branching, reduced spine density and reduced spine head volume. Strikingly, the impairment of LTP could be selectively rescued by acute application of exogenous recombinant APPsα, but not APPsß, indicating a crucial role for APPsα to support synaptic plasticity of mature hippocampal synapses on a rapid time scale. Collectively, our analysis reveals an essential role of APP family proteins in excitatory principal neurons for mediating normal dendritic architecture, spine density and morphology, synaptic plasticity and cognition.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Hipocampo/fisiopatologia , Plasticidade Neuronal/fisiologia , Fragmentos de Peptídeos/metabolismo , Sinapses/fisiologia , Precursor de Proteína beta-Amiloide/genética , Animais , Dendritos/patologia , Dendritos/fisiologia , Feminino , Hipocampo/patologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos Knockout , Atividade Motora/fisiologia , Neuritos/patologia , Neuritos/fisiologia , Fragmentos de Peptídeos/genética , Proteínas Recombinantes/metabolismo , Memória Espacial/fisiologia , Sinapses/patologia
13.
J Biol Chem ; 287(31): 25927-40, 2012 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-22692213

RESUMO

The ß-site amyloid precursor protein-cleaving enzyme BACE1 is a prime drug target for Alzheimer disease. However, the function and the physiological substrates of BACE1 remain largely unknown. In this work, we took a quantitative proteomic approach to analyze the secretome of primary neurons after acute BACE1 inhibition, and we identified several novel substrate candidates for BACE1. Many of these molecules are involved in neuronal network formation in the developing nervous system. We selected the adhesion molecules L1 and CHL1, which are crucial for axonal guidance and maintenance of neural circuits, for further validation as BACE1 substrates. Using both genetic BACE1 knock-out and acute pharmacological BACE1 inhibition in mice and cell cultures, we show that L1 and CHL1 are cleaved by BACE1 under physiological conditions. The BACE1 cleavage sites at the membrane-proximal regions of L1 (between Tyr(1086) and Glu(1087)) and CHL1 (between Gln(1061) and Asp(1062)) were determined by mass spectrometry. This work provides molecular insights into the function and the pathways in which BACE1 is involved, and it will help to predict or interpret possible side effects of BACE1 inhibitor drugs in current clinical trials.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Moléculas de Adesão Celular/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Neurônios/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/metabolismo , Células COS , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Células Cultivadas , Chlorocebus aethiops , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Molécula L1 de Adesão de Célula Nervosa/química , Molécula L1 de Adesão de Célula Nervosa/genética , Neurônios/enzimologia , Fragmentos de Peptídeos/química , Cultura Primária de Células , Inibidores de Proteases/farmacologia , Proteólise , Proteoma/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/enzimologia , Sinapses/metabolismo
15.
J Alzheimers Dis ; 93(1): 151-167, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36970909

RESUMO

BACKGROUND: Clearance of tau seeds by immunization with tau antibodies is currently evaluated as therapeutic strategy to block the spreading of tau pathology in Alzheimer's disease and other tauopathies. Preclinical evaluation of passive immunotherapy is performed in different cellular culture systems and in wild-type and human tau transgenic mouse models. Depending on the preclinical model used, tau seeds or induced aggregates can either be of mouse, human or mixed origin. OBJECTIVE: We aimed to develop human and mouse tau-specific antibodies to discriminate between the endogenous tau and the introduced form in preclinical models. METHODS: Using hybridoma technology, we developed human and mouse tau-specific antibodies that were then used to develop several assays to specifically detect mouse tau. RESULTS: Four antibodies, mTau3, mTau5, mTau8, and mTau9, with a high degree of specificity for mouse tau were identified. Additionally, their potential application in highly sensitive immunoassays to measure tau in mouse brain homogenate and cerebrospinal fluid is illustrated, as well as their application for specific endogenous mouse tau aggregation detection. CONCLUSION: The antibodies reported here can be very important tools to better interpret the results obtained from different model systems as well as to study the role of endogenous tau in tau aggregation and pathology observed in the diverse mouse models available.


Assuntos
Doença de Alzheimer , Tauopatias , Camundongos , Humanos , Animais , Proteínas tau/metabolismo , Tauopatias/patologia , Doença de Alzheimer/patologia , Camundongos Transgênicos , Modelos Animais de Doenças , Anticorpos Monoclonais , Encéfalo/patologia
16.
Mol Ther Methods Clin Dev ; 31: 101158, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38074413

RESUMO

Over the last decade, there has been a growing interest in intrabodies and their therapeutic potential. Intrabodies are antibody fragments that are expressed inside a cell to target intracellular antigens. In the context of intracellular protein misfolding and aggregation, such as tau pathology in Alzheimer's disease, intrabodies have become an interesting approach as there is the possibility to target early stages of aggregation. As such, we engineered three anti-tau monoclonal antibodies into single-chain variable fragments for cytoplasmic expression and activity: PT51, PT77, and hTau21. Due to the reducing environment of the cytoplasm, single-chain variable fragment (scFv) aggregation is commonly observed. Therefore, we also performed complementarity-determining region (CDR) grafting into three different stable frameworks to rescue solubility and intracellular binding. All three scFvs retained binding to tau after cytoplasmic expression in HEK293 cells, in at least one of the frameworks. Subsequently, we show their capacity to interfere with either mouse or mutant human tau aggregation in two different primary mouse neuron models and organotypic hippocampal slice cultures. Collectively, our work extends the current knowledge on intracellular tau targeting with intrabodies, providing three scFv intrabodies that can be used as immunological tools to target tau inside cells.

17.
Ann Neurol ; 69(5): 819-30, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21472769

RESUMO

OBJECTIVE: The goal of this study was to investigate the role of endogenous amyloid-ß peptide (Aß) in healthy brain. METHODS: Long-term potentiation (LTP), a type of synaptic plasticity that is thought to be associated with learning and memory, was examined through extracellular field recordings from the CA1 region of hippocampal slices, whereas behavioral techniques were used to assess contextual fear memory and reference memory. Amyloid precursor protein (APP) expression was reduced through small interfering RNA (siRNA) technique. RESULTS: We found that both antirodent Aß antibody and siRNA against murine APP reduced LTP as well as contextual fear memory and reference memory. These effects were rescued by the addition of human Aß42, suggesting that endogenously produced Aß is needed for normal LTP and memory. Furthermore, the effect of endogenous Aß on plasticity and memory was likely due to regulation of transmitter release, activation of α7-containing nicotinic acetylcholine receptors, and Aß42 production. INTERPRETATION: Endogenous Aß42 is a critical player in synaptic plasticity and memory within the normal central nervous system. This needs to be taken into consideration when designing therapies aiming at reducing Aß levels to treat Alzheimer disease.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Hipocampo/fisiologia , Potenciação de Longa Duração/fisiologia , Memória/fisiologia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/imunologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Anticorpos/farmacologia , Comportamento Animal/efeitos dos fármacos , Biofísica/métodos , Estimulação Elétrica/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Regulação da Expressão Gênica/fisiologia , Hipocampo/efeitos dos fármacos , Humanos , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/metabolismo , RNA Interferente Pequeno/farmacologia
18.
Bioorg Med Chem Lett ; 22(2): 797-800, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22222037

RESUMO

The transient receptor potential A1 (TRPA1) channel has been implicated in a number of inflammatory and nociceptive processes, and antagonists of the TRPA1 receptor could offer a potential treatment for conditions such as inflammatory or neuropathic pain, airway disorders, and itch. In a high throughput screen aimed at the identification of TRPA1 antagonists, 4-phenyl-2-thioxo-1,2,3,4-tetrahydro-indeno[1,2-d]pyrimidin-5-one (1) was identified as a potent TRPA1 receptor antagonist. A series of analogous tricyclic 3,4-dihydropyrimidine-2-thiones has been prepared via the multi-component Biginelli reaction and subsequent derivatization. This has led to TRPA1 antagonists with potencies around 10nM for both rat and human derived TRPA1 receptors. The activity was shown to reside exclusively in the 4R-enantiomers.


Assuntos
Proteínas do Tecido Nervoso/antagonistas & inibidores , Pirimidinas/farmacologia , Canais de Cátion TRPC/antagonistas & inibidores , Tionas/farmacologia , Canais de Potencial de Receptor Transitório/antagonistas & inibidores , Animais , Canais de Cálcio , Humanos , Estrutura Molecular , Pirimidinas/síntese química , Pirimidinas/química , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Canal de Cátion TRPA1 , Tionas/síntese química , Tionas/química
19.
Alzheimers Dement ; 7(4): 386-395.e6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21784349

RESUMO

BACKGROUND: The cerebrospinal fluid (CSF) biomarkers amyloid ß (Aß)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program. METHODS: The program is open for laboratories using commercially available kits for Aß, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples. RESULTS: Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure Aß-(1-42), P-tau(181P), and T-tau), and 5 used Meso Scale Discovery with the Aß triplex (AßN-42, AßN-40, and AßN-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories. CONCLUSIONS: Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquidiano , Controle de Qualidade , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Bioensaio/métodos , Ensaio de Imunoadsorção Enzimática , Humanos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Fosforilação , Reprodutibilidade dos Testes , Suécia , Fatores de Tempo , Proteínas tau/líquido cefalorraquidiano
20.
Alzheimers Dement (Amst) ; 13(1): e12204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34095436

RESUMO

INTRODUCTION: Diagnosis of Alzheimer's disease (AD) based on amyloid beta (A), pathologic tau (T), and neurodegeneration (N) biomarkers in peripheral fluids promises to accelerate clinical trials and intercept disease earlier. METHODS: Qualification of a Simoa plasma p217+tau assay was performed, followed by clinical utility evaluation in a cohort of 227 subjects with broad A and T spectrum. RESULTS: The p217+tau plasma assay was accurate, precise, dilution linear, and highly sensitive. All measured samples were within linear range of the assay, presented higher concentration in AD versus healthy controls (P < .0001), and plasma and cerebrospinal fluid levels correlated (r2 = 0.35). The plasma p217+tau results were predictive of central T and A status (area under the curve = 0.90 and 0.90, respectively) with low false +/- rates. DISCUSSION: The assay described here exhibits good technical performance and shows potential as a highly accurate peripheral biomarker for A or T status in AD and cognitively normal subjects.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA