Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Br J Clin Pharmacol ; 88(12): 5238-5256, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35655123

RESUMO

AIMS: To improve the tolerability and therapeutic application of histone deacetylase inhibitors (HDACi), by application of an esterase-sensitive motif (ESM), to target pharmacological activity directly to mononuclear myeloid cells expressing the processing enzyme carboxylesterase-1 (CES1). METHODS: This first-in-human study comprised single and multiple ascending dose cohorts to determine safety and tolerability. Pharmacodynamic parameters included acetylation, cytokine inhibition and intracellular concentrations of processed acid metabolite in isolated monocytes. Mechanistic work was conducted in vitro and in a CES1/Es1elo mouse strain. RESULTS: ESM-HDAC391 showed transient systemic exposure (plasma half-life of 21-30 min) but selective retention of processed acid for at least 12 hours, resulting in robust targeted mechanistic engagement (increased acetylation in monocytes plus inhibition of ex vivo stimulated cytokine production). ESM-HDAC391 was well tolerated and clinical toxicities common to non-targeted HDACi were not observed. ESM-HDAC391 treatment was accompanied by the novel finding of a dose-dependent monocyte depletion that was transient and reversible and which plateaued at 0.06 × 109 monocytes/L after repeat dosing with 20 or 40 mg. Characterisation of monocyte depletion in transgenic mice (CES1/Es1elo ) suggested that colony stimulating factor 1 receptor loss on circulating cells contributed to ESM-HDAC-mediated depletion. Further mechanistic investigations using human monocytes in vitro demonstrated HDACi-mediated change in myeloid fate through modulation of colony stimulating factor 1 receptor and downstream effects on cell differentiation. CONCLUSION: These findings demonstrate selective targeting of monocytes in humans using the ESM approach and identify monocytopaenia as a novel outcome of ESM-HDACi treatment, with implications for potential benefit of these molecules in myeloid-driven diseases.


Assuntos
Esterases , Inibidores de Histona Desacetilases , Humanos , Animais , Camundongos , Inibidores de Histona Desacetilases/farmacologia , Fator Estimulador de Colônias de Macrófagos , Citocinas
2.
J Crohns Colitis ; 16(4): 668-681, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34633041

RESUMO

BACKGROUND AND AIMS: Histone deacetylase inhibitors [HDACi] exert potent anti-inflammatory effects. Because of the ubiquitous expression of HDACs, clinical utility of HDACi is limited by off-target effects. Esterase-sensitive motif [ESM] technology aims to deliver ESM-conjugated compounds to human mononuclear myeloid cells, based on their expression of carboxylesterase 1 [CES1]. This study aims to investigate utility of an ESM-tagged HDACi in inflammatory bowel disease [IBD]. METHODS: CES1 expression was assessed in human blood, in vitro differentiated macrophage and dendritic cells, and Crohn's disease [CD] colon mucosa, by mass cytometry, quantitative polymerase chain reaction [PCR], and immunofluorescence staining, respectively. ESM-HDAC528 intracellular retention was evaluated by mass spectrometry. Clinical efficacy of ESM-HDAC528 was tested in dextran sulphate sodium [DSS]-induced colitis and T cell transfer colitis models using transgenic mice expressing human CES1 under the CD68 promoter. RESULTS: CES1 mRNA was highly expressed in human blood CD14+ monocytes, in vitro differentiated and lipopolysaccharide [LPS]-stimulated macrophages, and dendritic cells. Specific hydrolysis and intracellular retention of ESM-HDAC528 in CES1+ cells was demonstrated. ESM-HDAC528 inhibited LPS-stimulated IL-6 and TNF-α production 1000 times more potently than its control, HDAC800, in CES1high monocytes. In healthy donor peripheral blood, CES1 expression was significantly higher in CD14++CD16- monocytes compared with CD14+CD16++ monocytes. In CD-inflamed colon, a higher number of mucosal CD68+ macrophages expressed CES1 compared with non-inflamed mucosa. In vivo, ESM-HDAC528 reduced monocyte differentiation in the colon and significantly improved colitis in a T cell transfer model, while having limited potential in ameliorating DSS-induced colitis. CONCLUSIONS: We demonstrate that monocytes and inflammatory macrophages specifically express CES1, and can be preferentially targeted by ESM-HDAC528 to achieve therapeutic benefit in IBD.


Assuntos
Hidrolases de Éster Carboxílico , Colite , Doença de Crohn , Inibidores de Histona Desacetilases , Doenças Inflamatórias Intestinais , Animais , Hidrolases de Éster Carboxílico/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Doença de Crohn/tratamento farmacológico , Doença de Crohn/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Lipopolissacarídeos , Camundongos , Monócitos , Células Mieloides
3.
Ann Rheum Dis ; 80(10): 1268-1277, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34380700

RESUMO

Increasingly earlier identification of individuals at high risk of rheumatoid arthritis (RA) (eg, with autoantibodies and mild symptoms) improves the feasibility of preventing or curing disease. The use of antigen-specific immunotherapies to reinstate immunological self-tolerance represent a highly attractive strategy due to their potential to induce disease resolution, in contrast to existing approaches that require long-term treatment of underlying symptoms.Preclinical animal models have been used to understand disease mechanisms and to evaluate novel immunotherapeutic approaches. However, models are required to understand critical processes supporting disease development such as the breach of self-tolerance that triggers autoimmunity and the progression from asymptomatic autoimmunity to joint pain and bone loss. These models would also be useful in evaluating the response to treatment in the pre-RA period.This review proposes that focusing on immune processes contributing to initial disease induction rather than end-stage pathological consequences is essential to allow development and evaluation of novel immunotherapies for early intervention. We will describe and critique existing models in arthritis and the broader field of autoimmunity that may fulfil these criteria. We will also identify key gaps in our ability to study these processes in animal models, to highlight where further research should be targeted.


Assuntos
Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Autoimunidade/imunologia , Imunoterapia , Tolerância a Antígenos Próprios/imunologia , Animais , Anticorpos Antiproteína Citrulinada/imunologia , Artrite Experimental/prevenção & controle , Artrite Experimental/terapia , Artrite Reumatoide/prevenção & controle , Artrite Reumatoide/terapia , Doenças Assintomáticas , Dessensibilização Imunológica , Modelos Animais de Doenças , Progressão da Doença , Tolerância Imunológica/imunologia , Camundongos , Ratos , Fator Reumatoide/imunologia
4.
Sci Adv ; 7(22)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34039605

RESUMO

The transcriptional coactivator BRD4 has a fundamental role in transcription regulation and thus became a promising epigenetic therapeutic candidate to target diverse pathologies. However, the regulation of BRD4 by posttranslational modifications has been largely unexplored. Here, we show that BRD4 is methylated on chromatin at lysine-99 by the protein lysine methyltransferase SETD6. BRD4 methylation negatively regulates the expression of genes that are involved in translation and inhibits total mRNA translation in cells. Mechanistically, we provide evidence that supports a model where BRD4 methylation by SETD6 does not have a direct role in the association with acetylated histone H4 at chromatin. However, this methylation specifically determines the recruitment of the transcription factor E2F1 to selected target genes that are involved in mRNA translation. Together, our findings reveal a previously unknown molecular mechanism for BRD4 methylation-dependent gene-specific targeting, which may serve as a new direction for the development of therapeutic applications.


Assuntos
Proteínas de Ciclo Celular , Proteínas Nucleares , Proteínas Metiltransferases , Fatores de Transcrição , Proteínas de Ciclo Celular/genética , Cromatina , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Metilação , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Biossíntese de Proteínas , Proteínas Metiltransferases/genética , Processamento de Proteína Pós-Traducional , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Front Immunol ; 12: 651475, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968050

RESUMO

In this study, we sought to characterize synovial tissue obtained from individuals with arthralgia and disease-specific auto-antibodies and patients with established rheumatoid arthritis (RA), by applying an integrative multi-omics approach where we investigated differences at the level of DNA methylation and gene expression in relation to disease pathogenesis. We performed concurrent whole-genome bisulphite sequencing and RNA-Sequencing on synovial tissue obtained from the knee and ankle from 4 auto-antibody positive arthralgia patients and thirteen RA patients. Through multi-omics factor analysis we observed that the latent factor explaining the variance in gene expression and DNA methylation was associated with Swollen Joint Count 66 (SJC66), with patients with SJC66 of 9 or more displaying separation from the rest. Interrogating these observed differences revealed activation of the immune response as well as dysregulation of cell adhesion pathways at the level of both DNA methylation and gene expression. We observed differences for 59 genes in particular at the level of both transcript expression and DNA methylation. Our results highlight the utility of genome-wide multi-omics profiling of synovial samples for improved understanding of changes associated with disease spread in arthralgia and RA patients, and point to novel candidate targets for the treatment of the disease.


Assuntos
Artralgia/imunologia , Artrite Reumatoide/complicações , Metilação de DNA/imunologia , Epigênese Genética/imunologia , Membrana Sinovial/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artralgia/genética , Artralgia/patologia , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Artroscopia , Biópsia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA-Seq , Índice de Gravidade de Doença , Membrana Sinovial/imunologia , Sequenciamento Completo do Genoma , Adulto Jovem
6.
Front Pharmacol ; 10: 1242, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31736752

RESUMO

Monocytes and macrophages are key drivers in the pathogenesis of inflammatory diseases. Epigenetic targets have been shown to control the transcriptional profile and phenotype of these cells. Since histone deacetylase protein inhibitors demonstrate profound anti-inflammatory activity, we wanted to test whether HDAC inhibition within monocytes and macrophages could be applied to suppress inflammation in vivo. ESM technology conjugates an esterase-sensitive motif (ESM) onto small molecules to allow targeting of cells that express carboxylesterase 1 (CES1), such as mononuclear myeloid cells. This study utilized an ESM-HDAC inhibitor to target monocytes and macrophages in mice in both an acute response model and an atherosclerosis model. We demonstrate that the molecule blocks the maturation of peritoneal macrophages and inhibits pro-inflammatory cytokine production in both models but to a lesser extent in the atherosclerosis model. Despite regulating the inflammatory response, ESM-HDAC528 did not significantly affect plaque size or phenotype, although histological classification of the plaques demonstrated a significant shift to a less severe phenotype. We hereby show that HDAC inhibition in myeloid cells impairs the maturation and activation of peritoneal macrophages but shows limited efficacy in a model of atherosclerosis.

7.
Bioorg Med Chem Lett ; 28(21): 3458-3462, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30249354

RESUMO

The discovery and lead optimisation of a novel series of SYK inhibitors is described. These were optimised for SYK potency and selectivity against Aurora B. Compounds were profiled in a human skin penetration study to identify a suitable candidate molecule for pre-clinical development. Compound 44 (GSK2646264) was selected for progression and is currently in Phase I clinical trials.


Assuntos
Anti-Inflamatórios/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Pele/efeitos dos fármacos , Quinase Syk/antagonistas & inibidores , Administração Tópica , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Domínio Catalítico , Linhagem Celular Tumoral , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Piridinas/administração & dosagem , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Quinase Syk/química
8.
Bioorg Med Chem Lett ; 26(19): 4606-4612, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27578246

RESUMO

The optimisation of the azanaphthyridine series of Spleen Tyrosine Kinase inhibitors is described. The medicinal chemistry strategy was focused on optimising the human whole blood activity whilst achieving a sufficient margin over hERG activity. A good pharmacokinetic profile was achieved by modification of the pKa. Morpholine compound 32 is a potent SYK inhibitor showing moderate selectivity, good oral bioavailability and good efficacy in the rat Arthus model but demonstrated a genotoxic potential in the Ames assay.


Assuntos
Naftiridinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Administração Oral , Animais , Disponibilidade Biológica , Cristalografia por Raios X , Humanos , Testes de Mutagenicidade , Naftiridinas/administração & dosagem , Naftiridinas/farmacocinética , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacocinética , Ratos , Relação Estrutura-Atividade
9.
Curr Opin Chem Biol ; 33: 169-78, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27372273

RESUMO

Over the last five years, a growing body of literature has strengthened the rationale for the involvement of PAD (protein arginine deiminase) enzymes in diverse diseases, through direct roles of citrullination in mechanisms such as neutrophil extracellular trap formation and immune complex formation. The recent development of inhibitors of the PAD family, coupled with the availability of mice genetically deficient in PAD2 or PAD4, has accelerated understanding of the role of these targets in varied disease models. This review surveys the recent literature to confirm the therapeutic potential of PAD inhibitors as a new class of drugs to treat human autoimmune disease.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Aterosclerose/tratamento farmacológico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Microcomputadores , Trombose/tratamento farmacológico , Animais , Camundongos , Camundongos Transgênicos
10.
J Exp Med ; 212(11): 1771-81, 2015 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-26392221

RESUMO

Studies investigating the causes of autism spectrum disorder (ASD) point to genetic, as well as epigenetic, mechanisms of the disease. Identification of epigenetic processes that contribute to ASD development and progression is of major importance and may lead to the development of novel therapeutic strategies. Here, we identify the bromodomain and extraterminal domain-containing proteins (BETs) as epigenetic regulators of genes involved in ASD-like behaviors in mice. We found that the pharmacological suppression of BET proteins in the brain of young mice, by the novel, highly specific, brain-permeable inhibitor I-BET858 leads to selective suppression of neuronal gene expression followed by the development of an autism-like syndrome. Many of the I-BET858-affected genes have been linked to ASD in humans, thus suggesting the key role of the BET-controlled gene network in the disorder. Our studies suggest that environmental factors controlling BET proteins or their target genes may contribute to the epigenetic mechanism of ASD.


Assuntos
Transtorno do Espectro Autista/etiologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Receptores de Superfície Celular/antagonistas & inibidores , Animais , Transtorno do Espectro Autista/genética , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Epigênese Genética , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
11.
Nat Chem Biol ; 11(3): 189-91, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25622091

RESUMO

PAD4 has been strongly implicated in the pathogenesis of autoimmune, cardiovascular and oncological diseases through clinical genetics and gene disruption in mice. New selective PAD4 inhibitors binding a calcium-deficient form of the PAD4 enzyme have validated the critical enzymatic role of human and mouse PAD4 in both histone citrullination and neutrophil extracellular trap formation for, to our knowledge, the first time. The therapeutic potential of PAD4 inhibitors can now be explored.


Assuntos
Benzimidazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Hidrolases/antagonistas & inibidores , Neutrófilos/efeitos dos fármacos , Animais , Benzimidazóis/síntese química , Ligação Competitiva , Cálcio/metabolismo , Citrulina/metabolismo , Inibidores Enzimáticos/síntese química , Células HEK293 , Histonas/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Modelos Moleculares , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas , Bibliotecas de Moléculas Pequenas , Especificidade por Substrato
12.
ACS Chem Biol ; 10(4): 1043-53, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25621824

RESUMO

Protein arginine deiminases (PADs) are calcium-dependent histone-modifying enzymes whose activity is dysregulated in inflammatory diseases and cancer. PAD2 functions as an Estrogen Receptor (ER) coactivator in breast cancer cells via the citrullination of histone tail arginine residues at ER binding sites. Although an attractive therapeutic target, the mechanisms that regulate PAD2 activity are largely unknown, especially the detailed role of how calcium facilitates enzyme activation. To gain insights into these regulatory processes, we determined the first structures of PAD2 (27 in total), and through calcium-titrations by X-ray crystallography, determined the order of binding and affinity for the six calcium ions that bind and activate this enzyme. These structures also identified several PAD2 regulatory elements, including a calcium switch that controls proper positioning of the catalytic cysteine residue, and a novel active site shielding mechanism. Additional biochemical and mass-spectrometry-based hydrogen/deuterium exchange studies support these structural findings. The identification of multiple intermediate calcium-bound structures along the PAD2 activation pathway provides critical insights that will aid the development of allosteric inhibitors targeting the PADs.


Assuntos
Cálcio/metabolismo , Hidrolases/química , Hidrolases/metabolismo , Sequência de Aminoácidos , Benzimidazóis/química , Benzimidazóis/farmacologia , Domínio Catalítico , Cristalografia por Raios X , Cisteína/química , Cisteína/metabolismo , Medição da Troca de Deutério , Ativação Enzimática , Inibidores Enzimáticos/química , Humanos , Hidrolases/antagonistas & inibidores , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Conformação Proteica , Proteína-Arginina Desiminase do Tipo 2 , Desiminases de Arginina em Proteínas
13.
Br J Pharmacol ; 171(22): 4981-5010, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25060293

RESUMO

The properties of a cell are determined both genetically by the DNA sequence of its genes and epigenetically through processes that regulate the pattern, timing and magnitude of expression of its genes. While the genetic basis of disease has been a topic of intense study for decades, recent years have seen a dramatic increase in the understanding of epigenetic regulatory mechanisms and a growing appreciation that epigenetic misregulation makes a significant contribution to human disease. Several large protein families have been identified that act in different ways to control the expression of genes through epigenetic mechanisms. Many of these protein families are finally proving tractable for the development of small molecules that modulate their function and represent new target classes for drug discovery. Here, we provide an overview of some of the key epigenetic regulatory proteins and discuss progress towards the development of pharmacological tools for use in research and therapy.


Assuntos
Descoberta de Drogas , Epigênese Genética , Histona Acetiltransferases/metabolismo , Histona Desacetilases/metabolismo , Histona Desmetilases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Hidrolases/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo
14.
Bioorg Med Chem Lett ; 21(20): 6188-94, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21903390
15.
Mol Brain ; 3(1): 21, 2010 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-20630068

RESUMO

Synaptic transmission and long-term potentiation (LTP) in the CA1 region of hippocampal slices have been studied during ageing of a double transgenic mouse strain relevant to early-onset familial Alzheimer's disease (AD). This strain, which over-expresses both the 695 amino acid isoform of human amyloid precursor protein (APP) with K670N and M671L mutations and presenilin 1 with the A246E mutation, has accelerated amyloidosis and plaque formation. There was a decrease in synaptic transmission in both wildtype and transgenic mice between 2 and 9 months of age. However, preparing slices from 14 month old animals in kynurenic acid (1 mM) counteracted this age-related deficit. Basal transmission and paired-pulse facilitation was similar between the two groups at all ages (2, 6, 9 and 14 months) tested. Similarly, at all ages LTP, induced either by theta burst stimulation or by multiple tetani, was normal. These data show that a prolonged, substantially elevated level of Abeta are not sufficient to cause deficits in the induction or expression of LTP in the CA1 hippocampal region.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Potenciação de Longa Duração/fisiologia , Proteínas Mutantes/metabolismo , Presenilina-1/metabolismo , Envelhecimento/patologia , Precursor de Proteína beta-Amiloide/genética , Animais , Região CA1 Hipocampal/fisiopatologia , Estimulação Elétrica , Potenciais Pós-Sinápticos Excitadores/fisiologia , Humanos , Camundongos , Camundongos Transgênicos , Proteínas Mutantes/genética , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Presenilina-1/genética , Transmissão Sináptica/fisiologia , Tetania/fisiopatologia
16.
Eur J Neurosci ; 29(7): 1335-47, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19519625

RESUMO

The mechanism by which aggregates of the beta-amyloid peptide (Abeta) mediate their toxicity is uncertain. We show here that the expression of the 42-amino-acid isoform of Abeta (Abeta(1-42)) changes the expression of genes involved in oxidative stress in a Drosophila model of Alzheimer's disease. A subsequent genetic screen confirmed the importance of oxidative stress and a molecular dissection of the steps in the cellular metabolism of reactive oxygen species revealed that the iron-binding protein ferritin and the H(2)O(2) scavenger catalase are the most potent suppressors of the toxicity of wild-type and Arctic (E22G) Abeta(1-42). Likewise, treatment with the iron-binding compound clioquinol increased the lifespan of flies expressing Arctic Abeta(1-42). The effect of iron appears to be mediated by oxidative stress as ferritin heavy chain co-expression reduced carbonyl levels in Abeta(1-42) flies by 65% and restored the survival and locomotion function to normal. This was achieved despite the presence of elevated levels of the Abeta(1-42). Taken together, our data show that oxidative stress, probably mediated by the hydroxyl radical and generated by the Fenton reaction, is essential for Abeta(1-42) toxicity in vivo and provide strong support for Alzheimer's disease therapies based on metal chelation.


Assuntos
Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/toxicidade , Ferro/metabolismo , Estresse Oxidativo/genética , Fragmentos de Peptídeos/toxicidade , Peptídeos beta-Amiloides/genética , Animais , Animais Geneticamente Modificados , Apoferritinas/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Clioquinol/farmacologia , Modelos Animais de Doenças , Drosophila , Quelantes de Ferro/farmacologia , Estimativa de Kaplan-Meier , Atividade Motora/fisiologia , Mutação , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo/efeitos dos fármacos , Fragmentos de Peptídeos/genética , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1
17.
J Med Chem ; 52(11): 3441-4, 2009 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-19432431

RESUMO

The development of potent gamma-secretase inhibitors having substituted heterocycles attached to a benzobicyclo[4.2.1]nonane core is described. This work led to the identification of [6S,9R,11R]-2',3',4',5,5',6,7,8,9,10-decahydro-2-(5-(4-fluorophenyl)-1-methylpyrazol-3-yl)-5'-(2,2,2-trifluoroethyl)spiro[6,9-methanobenzocyclooctene-11,3'-[1,2,5]thiadiazole] 1',1'-dioxide (16), which has excellent in vitro potency (0.06 nM) and which reduced amyloid-beta in APP-YAC mice with an ED(50) of 1 mg/kg (po). 16 had a good pharmacokinetic profile in three preclinical species.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Ciclo-Octanos/farmacologia , Inibidores de Proteases/farmacologia , Tiadiazóis/farmacologia , Administração Oral , Animais , Ciclo-Octanos/administração & dosagem , Ciclo-Octanos/síntese química , Ciclo-Octanos/farmacocinética , Concentração Inibidora 50 , Camundongos , Inibidores de Proteases/administração & dosagem , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacocinética , Tiadiazóis/administração & dosagem , Tiadiazóis/síntese química , Tiadiazóis/farmacocinética
18.
FASEB J ; 23(9): 2942-55, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19376818

RESUMO

gamma-Secretase cleaves amyloid precursor protein (APP) to generate amyloid-beta (Abeta) peptides, which aggregate in the brain in Alzheimer's disease (AD). gamma-Secretase also cleaves molecules that regulate osteoblast activity, such as Notch and ephrinB2. However, the role of APP in bone is unknown. In this study, the expression, cleavage, and function of APP were investigated during osteogenesis in vitro and in vivo. Expression of all gamma-secretase subunits was confirmed in human primary osteoprogenitors cells, and a significant increase in enzyme activity was observed during osteogenic differentiation using a specific fluorimetric assay. Application of selective inhibitors confirmed gamma-secretase-dependent cleavage of APP within osteogenic cells, and secretion of Abeta by mature osteoblasts was demonstrated with the use of a chemiluminescent immunoassay. Osteoprogenitors showed a selective and significant increase in adhesion to extracellular matrices containing aged Abeta plaques compared with nonaged Abeta peptide controls. Abeta on the endosteal and periosteal surfaces of adult rat ulnae were identified by immunohistochemistry. MicroCT analysis of vertebrae from an AD mouse model, Tg2576, identified a decrease in bone volume, surface area, and thickness compared with wild-type controls. These findings indicate that APP functions as a novel regulator of osteoblast activity and suggest that the mechanisms underlying the pathogenesis of AD may also influence bone.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Osteoblastos/citologia , Doença de Alzheimer/patologia , Animais , Adesão Celular , Diferenciação Celular , Células Cultivadas , Humanos , Hidrólise , Camundongos , Osteogênese , Ratos , Células-Tronco
19.
Inflamm Bowel Dis ; 15(4): 534-45, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19058230

RESUMO

BACKGROUND: A common feature of preclinical models of colitis is that the time-course, magnitude, and persistence of inflammation vary considerably within the experimental animal group. Accordingly, noninvasive, serial quantification of colonic inflammation could advantageously guide dosing regimens and assess drug efficacy, thus enhancing the value of colitis models in research. This investigation using magnetic resonance imaging (MRI) was therefore undertaken to objectively determine inflammatory progression, variability, and response to therapy associated with trinitrobenzene sulfonic acid (TNBS)-induced colitis in Wistar rats. METHODS: Rats underwent TNBS treatment on Day 0 and received sulfasalazine or vehicle (methylcellulose) orally, daily, from Day -1 (prophylactically) or Day 2 (therapeutically). T2-weighted and semidynamic T1-weighted contrast-enhanced MRI (CE-MRI) was repeated over 7-10 days to measure colon wall thickness and perfusion-related aspects of inflammation. Rectal bleeding, stool consistency, and disease activity were scored throughout and colon pathology determined terminally. RESULTS: Principal component analysis of the CE-MRI time-series highlighted colon wall and mesenteric inflammation, which increased by 6-8x naïve values. Peristaltic artifacts were distinguished from perfusion changes using the normalized temporal standard deviation. MRI correlated strongly with terminal colon weight (mean correlation r = 0.8), well with body weight change (r = -0.7), but little with conventional clinical scores. Sulfasalazine reduced inflammation administered prophylactically and therapeutically. CONCLUSIONS: Inflammation and therapeutic efficacy can be sensitively quantified noninvasively using MRI in TNBS-treated rats. This methodology provides unique and objective in vivo measures of inflammation that can guide dosing strategies, enhancing colitis research effectiveness and the assessment of potential IBD therapeutics.


Assuntos
Colite/patologia , Colo/imunologia , Colo/patologia , Imageamento por Ressonância Magnética/métodos , Anestésicos Inalatórios , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Meios de Contraste , Modelos Animais de Doenças , Progressão da Doença , Fármacos Gastrointestinais/farmacologia , Isoflurano , Masculino , Tamanho do Órgão , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Sulfassalazina/farmacologia , Ácido Trinitrobenzenossulfônico/toxicidade
20.
Chem Biol ; 14(2): 209-19, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17317574

RESUMO

In this report, inhibitors of the gamma-secretase enzyme have been exploited to characterize the antiproliferative relationship between target inhibition and cellular responses in Notch-dependent human T cell acute lymphoblastic leukemia (T-ALL) cell lines. Inhibition of gamma-secretase led to decreased Notch signaling, measured by endogenous NOTCH intracellular domain (NICD) formation, and was associated with decreased cell viability. Flow cytometry revealed that decreased cell viability resulted from a G(0)/G(1) cell cycle block, which correlated strongly to the induction of apoptosis. These effects associated with inhibitor treatment were rescued by exogenous expression of NICD and were not mirrored when a markedly less active enantiomer was used, demonstrating the gamma-secretase dependency and specificity of these responses. Together, these data strengthen the rationale for using gamma-secretase inhibitors therapeutically and suggest that programmed cell death may contribute to reduction of tumor burden in the clinic.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/patologia , Receptores Notch/antagonistas & inibidores , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Óxidos S-Cíclicos/farmacologia , Citometria de Fluxo , Humanos , Leucemia-Linfoma de Células T do Adulto/enzimologia , Leucemia-Linfoma de Células T do Adulto/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tiadiazóis/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...