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1.
Eur J Pharmacol ; 812: 104-112, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28690193

RESUMO

Alzheimer's disease is associated with the accumulation of amyloid-ß (Aß) in the brain. In particular, the 42-amino acid form, Aß1-42, is thought to play a key role in the disease. It is therefore of interest that diverse compounds, known as γ-secretase modulators (GSM), can selectively decrease Aß1-42 production without inhibiting the production of other forms of Aß. Here we describe the novel discovery of synergistic inhibition of Aß by certain combinations of GSMs. Cell cultures were treated with pairwise combinations of GSMs to determine how Aß peptide production was affected. Analysis of isobolograms and calculation of the combination index showed that BMS-869780 and GSM-2 were highly synergistic. Additional combinations of GSMs revealed that inhibition of Aß occurred only when one GSM was of the "acid GSM" structural class and the other was of the "non-acid GSM" class. A total of 15 representative acid/non-acid GSM combinations were shown to inhibit Aß production, whereas 10 pairwise combinations containing two acid GSMs or containing two non-acid GSMs did not inhibit Aß. We also discovered that lasalocid, a natural product, is a potent GSM. Lasalocid is unique in that it did not synergize with other GSMs. Synergism did not translate in vivo perhaps because of biochemical differences between the cell culture model and brain. These findings reinforce the pharmacological differences between different structural classes of GSMs, and may help to exploit the potential of γ-secretase as a drug target.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/biossíntese , Fragmentos de Peptídeos/biossíntese , Inibidores de Proteases/farmacologia , Acetatos/farmacologia , Animais , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Camundongos , Piperidinas/farmacologia
2.
Bioorg Med Chem Lett ; 26(23): 5729-5731, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27816517

RESUMO

This Letter describes the synthesis and structure-activity relationships of a series of furo[2,3-d][1,3]thiazinamine BACE1 inhibitors. The co-crystal structure of a representative thiazinamine 2e bound with the BACE1 active site displayed a binding mode driven by interactions with the catalytic aspartate dyad and engagement of the biaryl amide toward the S1 and S3 pockets. This work indicates that furo[2,3-d]thiazine can serve as a viable bioisostere of the known furo[3,4-d]thiazine.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Furanos/química , Furanos/farmacologia , Tiazinas/química , Tiazinas/farmacologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/química , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Domínio Catalítico , Humanos , Modelos Moleculares , Ligação Proteica
3.
J Med Chem ; 59(18): 8593-600, 2016 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-27559936

RESUMO

Truncation of the S3 substituent of the biaryl aminothiazine 2, a potent BACE1 inhibitor, led to a low molecular weight aminothiazine 5 with moderate activity. Despite its moderate activity, compound 5 demonstrated significant brain Aß reduction in rodents. The metabolic instability of 5 was overcome by the replacement of the 6-dimethylisoxazole, a metabolic soft spot, with a pyrimidine ring. Thus, truncation of the S3 substituent represents a viable approach to the discovery of orally bioavailable, brain-penetrant BACE1 inhibitors.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Tiazinas/química , Tiazinas/farmacologia , Aminação , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Inibidores Enzimáticos/sangue , Humanos , Camundongos , Simulação de Acoplamento Molecular , Ratos , Relação Estrutura-Atividade , Tiazinas/sangue
4.
J Pharmacol Exp Ther ; 358(1): 138-50, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27189973

RESUMO

The pharmacokinetics, pharmacodynamics, safety, and tolerability of BMS-932481, a γ-secretase modulator (GSM), were tested in healthy young and elderly volunteers after single and multiple doses. BMS-932481 was orally absorbed, showed dose proportionality after a single dose administration, and had approximately 3-fold accumulation after multiple dosing. High-fat/caloric meals doubled the Cmax and area under the curve and prolonged Tmax by 1.5 hours. Consistent with the preclinical pharmacology of GSMs, BMS-932481 decreased cerebrospinal fluid (CSF) Aß39, Aß40, and Aß42 while increasing Aß37 and Aß38, thereby providing evidence of γ-secretase enzyme modulation rather than inhibition. In plasma, reductions in Aß40 and Aß42 were observed with no change in total Aß; in CSF, modest decreases in total Aß were observed at higher dose levels. Increases in liver enzymes were observed at exposures associated with greater than 70% CSF Aß42 lowering after multiple dosing. Although further development was halted due to an insufficient safety margin to test the hypothesis for efficacy of Aß lowering in Alzheimer's disease, this study demonstrates that γ-secretase modulation is achievable in healthy human volunteers and supports further efforts to discover well tolerated GSMs for testing in Alzheimer's disease and other indications.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides , Compostos de Anilina/farmacologia , Compostos de Anilina/farmacocinética , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/farmacocinética , Pirimidinas/farmacologia , Pirimidinas/farmacocinética , Adolescente , Adulto , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/enzimologia , Peptídeos beta-Amiloides/sangue , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Compostos de Anilina/efeitos adversos , Compostos de Anilina/química , Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Inflamatórios não Esteroides/química , Área Sob a Curva , Cromatografia Líquida , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Limite de Detecção , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Pirimidinas/efeitos adversos , Pirimidinas/química , Adulto Jovem
5.
J Pharmacol Exp Ther ; 358(1): 125-37, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27189974

RESUMO

The amyloid-ß peptide (Aß)-in particular, the 42-amino acid form, Aß1-42-is thought to play a key role in the pathogenesis of Alzheimer's disease (AD). Thus, several therapeutic modalities aiming to inhibit Aß synthesis or increase the clearance of Aß have entered clinical trials, including γ-secretase inhibitors, anti-Aß antibodies, and amyloid-ß precursor protein cleaving enzyme inhibitors. A unique class of small molecules, γ-secretase modulators (GSMs), selectively reduce Aß1-42 production, and may also decrease Aß1-40 while simultaneously increasing one or more shorter Aß peptides, such as Aß1-38 and Aß1-37. GSMs are particularly attractive because they do not alter the total amount of Aß peptides produced by γ-secretase activity; they spare the processing of other γ-secretase substrates, such as Notch; and they do not cause accumulation of the potentially toxic processing intermediate, ß-C-terminal fragment. This report describes the translation of pharmacological activity across species for two novel GSMs, (S)-7-(4-fluorophenyl)-N2-(3-methoxy-4-(3-methyl-1H-1,2,4-triazol-1-yl)phenyl)-N4-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidine-2,4-diamine (BMS-932481) and (S,Z)-17-(4-chloro-2-fluorophenyl)-34-(3-methyl-1H-1,2,4-triazol-1-yl)-16,17-dihydro-15H-4-oxa-2,9-diaza-1(2,4)-cyclopenta[d]pyrimidina-3(1,3)-benzenacyclononaphan-6-ene (BMS-986133). These GSMs are highly potent in vitro, exhibit dose- and time-dependent activity in vivo, and have consistent levels of pharmacological effect across rats, dogs, monkeys, and human subjects. In rats, the two GSMs exhibit similar pharmacokinetics/pharmacodynamics between the brain and cerebrospinal fluid. In all species, GSM treatment decreased Aß1-42 and Aß1-40 levels while increasing Aß1-38 and Aß1-37 by a corresponding amount. Thus, the GSM mechanism and central activity translate across preclinical species and humans, thereby validating this therapeutic modality for potential utility in AD.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Compostos de Anilina/farmacologia , Compostos de Anilina/farmacocinética , Encéfalo/efeitos dos fármacos , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacocinética , Pirimidinas/farmacologia , Pirimidinas/farmacocinética , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Peptídeos beta-Amiloides/genética , Compostos de Anilina/química , Animais , Encéfalo/enzimologia , Encéfalo/metabolismo , Hidrocarbonetos Aromáticos com Pontes/química , Linhagem Celular , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Macaca fascicularis , Pirimidinas/química , Ratos Sprague-Dawley , Receptores Notch/metabolismo , Especificidade da Espécie , Distribuição Tecidual
6.
ACS Med Chem Lett ; 7(3): 271-6, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26985314

RESUMO

By targeting the flap backbone of the BACE1 active site, we discovered 6-dimethylisoxazole-substituted biaryl aminothiazine 18 with 34-fold improved BACE1 inhibitory activity over the lead compound 1. The cocrystal structure of 18 bound to the active site indicated two hydrogen-bond interactions between the dimethylisoxazole and threonine 72 and glutamine 73 of the flap. Incorporation of the dimethylisoxazole substitution onto the related aminothiazine carboxamide series led to pyrazine-carboxamide 26 as a very potent BACE1 inhibitor (IC50 < 1 nM). This compound demonstrated robust brain Aß reduction in rat dose-response studies. Thus, compound 26 may be useful in testing the amyloid hypothesis of Alzheimer's disease.

7.
Bioorg Med Chem Lett ; 26(6): 1554-1557, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26898338

RESUMO

This Letter describes an efficient ring-closing metathesis approach to 2-chloro-4-amino-pyrimido[4,5-c]azepines and 2-chloro-4-amino-pyrimido[4,5-c]oxepines. These chlorides were applied to the synthesis of several potent γ-secretase modulators (GSMs).


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Azepinas/farmacologia , Oxepinas/farmacologia , Pirimidinas/farmacologia , Azepinas/síntese química , Azepinas/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Oxepinas/síntese química , Oxepinas/química , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade
9.
Bioorg Med Chem Lett ; 25(22): 5040-7, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26497283

RESUMO

The synthesis, evaluation, and structure-activity relationships of a class of acyl guanidines which inhibit the BACE-1 enzyme are presented. The prolinyl acyl guanidine chemotype (7c), unlike compounds of the parent isothiazole chemotype (1), yielded compounds with good agreement between their enzymatic and cellular potency as well as a reduced susceptibility to P-gp efflux. Further improvements in potency and P-gp ratio were realized via a macrocyclization strategy. The in vivo profile in wild-type mice and P-gp effects for the macrocyclic analog 21c is presented.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Guanidinas/farmacologia , Compostos Macrocíclicos/farmacologia , Prolina/análogos & derivados , Prolina/farmacologia , Inibidores de Proteases/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Peptídeos beta-Amiloides/biossíntese , Animais , Células CACO-2 , Catepsina D/antagonistas & inibidores , Catepsina E/antagonistas & inibidores , Cães , Guanidinas/síntese química , Humanos , Compostos Macrocíclicos/síntese química , Células Madin Darby de Rim Canino , Masculino , Camundongos , Simulação de Acoplamento Molecular , Pepsina A/antagonistas & inibidores , Prolina/síntese química , Inibidores de Proteases/síntese química
10.
Int J Alzheimers Dis ; 2014: 431858, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25097793

RESUMO

Alzheimer's disease is the most prevalent cause of dementia and is associated with accumulation of amyloid-ß peptide (Aß), particularly the 42-amino acid Aß1-42, in the brain. Aß1-42 levels can be decreased by γ-secretase modulators (GSM), which are small molecules that modulate γ-secretase, an enzyme essential for Aß production. BMS-869780 is a potent GSM that decreased Aß1-42 and Aß1-40 and increased Aß1-37 and Aß1-38, without inhibiting overall levels of Aß peptides or other APP processing intermediates. BMS-869780 also did not inhibit Notch processing by γ-secretase and lowered brain Aß1-42 without evidence of Notch-related side effects in rats. Human pharmacokinetic (PK) parameters were predicted through allometric scaling of PK in rat, dog, and monkey and were combined with the rat pharmacodynamic (PD) parameters to predict the relationship between BMS-869780 dose, exposure and Aß1-42 levels in human. Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aß1-42 lowering. Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued. Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aß1-42 without Notch-related side effects.

11.
Alzheimers Res Ther ; 6(2): 14, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25031632

RESUMO

The failure of several potential Alzheimer's disease therapeutics in mid- to late-stage clinical development has provoked significant discussion regarding the validity of the amyloid hypothesis. In this review, we propose a minimum criterion of 25% for amyloid-ß (Aß) lowering to achieve clinically meaningful slowing of disease progression. This criterion is based on genetic, risk factor, clinical and preclinical studies. We then compare this minimum criterion with the degree of Aß lowering produced by the potential therapies that have failed in clinical trials. If the proposed minimum Aß lowering criterion is used, then the amyloid hypothesis has yet to be adequately tested in the clinic. Therefore, we believe that the amyloid hypothesis remains valid and remains to be confirmed or refuted in future clinical trials.

13.
J Pharmacol Exp Ther ; 344(3): 686-95, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23275065

RESUMO

A hallmark of Alzheimer's disease (AD) pathology is the accumulation of brain amyloid ß-peptide (Aß), generated by γ-secretase-mediated cleavage of the amyloid precursor protein (APP). Therefore, γ-secretase inhibitors (GSIs) may lower brain Aß and offer a potential new approach to treat AD. As γ-secretase also cleaves Notch proteins, GSIs can have undesirable effects due to interference with Notch signaling. Avagacestat (BMS-708163) is a GSI developed for selective inhibition of APP over Notch cleavage. Avagacestat inhibition of APP and Notch cleavage was evaluated in cell culture by measuring levels of Aß and human Notch proteins. In rats, dogs, and humans, selectivity was evaluated by measuring plasma blood concentrations in relation to effects on cerebrospinal fluid (CSF) Aß levels and Notch-related toxicities. Measurements of Notch-related toxicity included goblet cell metaplasia in the gut, marginal-zone depletion in the spleen, reductions in B cells, and changes in expression of the Notch-regulated hairy and enhancer of split homolog-1 from blood cells. In rats and dogs, acute administration of avagacestat robustly reduced CSF Aß40 and Aß42 levels similarly. Chronic administration in rats and dogs, and 28-day, single- and multiple-ascending-dose administration in healthy human subjects caused similar exposure-dependent reductions in CSF Aß40. Consistent with the 137-fold selectivity measured in cell culture, we identified doses of avagacestat that reduce CSF Aß levels without causing Notch-related toxicities. Our results demonstrate the selectivity of avagacestat for APP over Notch cleavage, supporting further evaluation of avagacestat for AD therapy.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Precursor de Proteína beta-Amiloide/antagonistas & inibidores , Oxidiazóis/farmacologia , Sulfonamidas/farmacologia , Adolescente , Adulto , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Células Cultivadas , Cães , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Sprague-Dawley , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adulto Jovem
14.
J Med Chem ; 55(21): 9208-23, 2012 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-23030502

RESUMO

This report describes the discovery and optimization of a BACE-1 inhibitor series containing an unusual acyl guanidine chemotype that was originally synthesized as part of a 6041-membered solid-phase library. The synthesis of multiple follow-up solid- and solution-phase libraries facilitated the optimization of the original micromolar hit into a single-digit nanomolar BACE-1 inhibitor in both radioligand binding and cell-based functional assay formats. The X-ray structure of representative inhibitors bound to BACE-1 revealed a number of key ligand:protein interactions, including a hydrogen bond between the side chain amide of flap residue Gln73 and the acyl guanidine carbonyl group, and a cation-π interaction between Arg235 and the isothiazole 4-methoxyphenyl substituent. Following subcutaneous administration in rats, an acyl guanidine inhibitor with single-digit nanomolar activity in cells afforded good plasma exposures and a dose-dependent reduction in plasma Aß levels, but poor brain exposure was observed (likely due to Pgp-mediated efflux), and significant reductions in brain Aß levels were not obtained.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Guanidinas/síntese química , Bibliotecas de Moléculas Pequenas , Secretases da Proteína Precursora do Amiloide/química , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/química , Encéfalo/metabolismo , Linhagem Celular , Cristalografia por Raios X , Guanidinas/farmacocinética , Guanidinas/farmacologia , Humanos , Isoxazóis/síntese química , Isoxazóis/farmacocinética , Isoxazóis/farmacologia , Modelos Moleculares , Estrutura Molecular , Mutação , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Ensaio Radioligante , Ratos , Técnicas de Síntese em Fase Sólida , Soluções , Relação Estrutura-Atividade
15.
Bioorg Med Chem Lett ; 21(22): 6909-15, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21974952
16.
Bioorg Med Chem Lett ; 21(22): 6916-24, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21782431

RESUMO

The synthesis, evaluation, and structure-activity relationships of a class of γ-lactam 1,3-diaminopropan-2-ol transition-state isostere inhibitors of BACE are discussed. Two strategies for optimizing lead compound 1a are presented. Reducing the overall size of the inhibitors resulted in the identification of γ-lactam 1i, whereas the introduction of conformational constraint on the prime-side of the inhibitor generated compounds such as the 3-hydroxypyrrolidine inhibitor 28n. The full in vivo profile of 1i in rats and 28n in Tg 2576 mice is presented.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Lactamas/química , Lactamas/farmacologia , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/enzimologia , Animais , Cristalografia por Raios X , Desenho de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Lactamas/síntese química , Lactamas/farmacocinética , Camundongos , Modelos Moleculares , Ratos , Relação Estrutura-Atividade
17.
Bioorg Med Chem Lett ; 21(1): 537-41, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21078556

RESUMO

Heterocyclic replacement of the isophthalamide phenyl ring in hydroxyethylamine (HEA) BACE-1 inhibitors was explored. A variety of indole-1,3-dicarboxamide HEAs exhibited potent BACE-1 enzyme inhibition, but displayed poor cellular activity. Improvements in cellular activity and aspartic protease selectivity were observed for 7-azaindole-1,3-dicarboxamide HEAs. A methylprolinol-bearing derivative (10n) demonstrated robust reductions in rat plasma Aß levels, but did not lower rat brain Aß due to poor central exposure. The same analog exhibited a high efflux ratio in a bidirectional Caco-2 assay and was likely a substrate of the efflux transporter P-glycoprotein. X-ray crystal structures are reported for two indole HEAs in complex with BACE-1.


Assuntos
Aminas/química , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Indóis/síntese química , Inibidores de Proteases/química , Piridinas/síntese química , Aminas/síntese química , Aminas/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/sangue , Animais , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Indóis/química , Indóis/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Estrutura Terciária de Proteína , Piridinas/química , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade
18.
BMC Neurosci ; 11: 143, 2010 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-21054826

RESUMO

BACKGROUND: Accumulation of amyloid-ß (Aß) peptide in the brain is thought to play a key pathological role in Alzheimer's disease. Many pharmacological targets have therefore been proposed based upon the biochemistry of Aß, but not all are equally tractable for drug discovery. RESULTS: To search for novel targets that affect brain Aß without causing toxicity, we screened mouse brain samples from 1930 novel gene knock-out (KO) strains, representing 1926 genes, using Aß ELISA assays. Although robust Aß lowering was readily apparent in brains from a BACE1 KO strain, none of the novel strains exhibited robust decreases in brain Aß, including a GPR3 KO strain, which had previously been proposed as an Aß target. However, significantly increased Aß was observed in brain samples from two KO strains, corresponding to genes encoding the glycosylphosphatidylinositol mannosyl transferase PIGZ and quinolinate phosphoribosyltransferase (QPRT). CONCLUSIONS: Thus, gene ablations that are permissive for mouse survival and that also have a robust effect on Aß levels in the brain are rare.


Assuntos
Secretases da Proteína Precursora do Amiloide/genética , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/genética , Técnicas de Inativação de Genes/métodos , Peptídeos beta-Amiloides/biossíntese , Precursor de Proteína beta-Amiloide/biossíntese , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Testes Genéticos/métodos , Manosiltransferases/genética , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pentosiltransferases/genética , Fragmentos de Peptídeos/biossíntese , Fragmentos de Peptídeos/metabolismo
19.
ACS Med Chem Lett ; 1(3): 120-4, 2010 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24900185

RESUMO

During the course of our research efforts to develop a potent and selective γ-secretase inhibitor for the treatment of Alzheimer's disease, we investigated a series of carboxamide-substituted sulfonamides. Optimization based on potency, Notch/amyloid-ß precursor protein selectivity, and brain efficacy after oral dosing led to the discovery of 4 (BMS-708163). Compound 4 is a potent inhibitor of γ-secretase (Aß40 IC50 = 0.30 nM), demonstrating a 193-fold selectivity against Notch. Oral administration of 4 significantly reduced Aß40 levels for sustained periods in brain, plasma, and cerebrospinal fluid in rats and dogs.

20.
J Neurosci Methods ; 180(2): 255-60, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19464516

RESUMO

An area of current research in Alzheimer's disease (AD) is the biosynthetic pathway of amyloid beta peptides (Abeta) via consecutive proteolytic cleavages of the amyloid beta precursor protein (APP) by BACE and gamma-secretase enzymes. APP is first cleaved by BACE to form a C-terminal fragment APP-betaCTF, or also called C99, which then undergoes further cleavage by gamma-secretase to form Abeta. Inhibitors of gamma-secretase have been observed to yield a so-called 'Abeta rise' phenomenon whereby low inhibitor concentrations result in an increase in Abeta levels while high inhibitor concentrations result in lower Abeta levels. A previous report from our labs indicated that this phenomenon was related to ratios of APP-betaCTF substrate relative to gamma-secretase enzyme. A quantitative Western blot analysis was used with a recombinant C100 protein as calibration standards to assess the relationship of APP-betaCTF, gamma-secretase enzyme and various inhibitors resulting in the 'Abeta rise'. An on-line liquid chromatography mass spectrometry (LC-MS) method employing the 'surrogate peptide' methodology was developed to accurately quantify the recombinant C100 used in the Western blot analyses. The surrogate peptide approach utilizes tryptic digestion of the protein to stoichiometrically yield a unique peptide fragment, in this case (C100)Abeta17-28 (LVFFAEDVGSNK) that can be readily detected by LC-MS. The absolute quantitative assessment of C100 was accomplished using synthetic Abeta17-28 to generate calibration curves over a 0.001-1 microM range and 15N isotopically labeled Abeta1-40 as the internal standard for enzymatic digestion and its proteolytic peptide [15N]-Abeta17-28 for the analysis.


Assuntos
Precursor de Proteína beta-Amiloide/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Fragmentos de Peptídeos/análise , Precursor de Proteína beta-Amiloide/química , Animais , Bioquímica/métodos , Humanos , Neuroquímica/métodos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Estrutura Terciária de Proteína/fisiologia , Proteômica/métodos
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