RESUMO
High throughput screening identified the pyridothienopyrimidinone 1 as a ligand for the metabotropic glutamate receptor 1 (mGluR1=10 nM). Compound 1 has an excellent in vivo profile; however, it displays unfavorable pharmacokinetic issues and metabolic stability. Therefore, using 1 as a template, novel analogues (10i) were prepared. These analogues displayed improved oral exposure and activity in the Spinal Nerve Ligation (SNL) pain model.
Assuntos
Compostos Heterocíclicos com 3 Anéis/química , Pirimidinonas/química , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Tiofenos/química , Administração Oral , Animais , Dor Crônica/tratamento farmacológico , Modelos Animais de Doenças , Compostos Heterocíclicos com 3 Anéis/síntese química , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Humanos , Pirimidinonas/síntese química , Pirimidinonas/uso terapêutico , Ratos , Receptores de Glutamato Metabotrópico/metabolismo , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/uso terapêuticoRESUMO
A series of fused tricyclic mGluR1 antagonists containing a pyridone ring were synthesized. In vitro, these antagonists were potent against both human and rat isozymes, as well as selective for inhibiting mGluR1 over mGluR5. When dosed orally, several examples were active in vivo in a rat SNL test.
Assuntos
Piridonas/síntese química , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Administração Oral , Analgésicos/farmacologia , Animais , Células Cultivadas , Ciclização , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Neuralgia/tratamento farmacológico , Ligação Proteica/efeitos dos fármacos , Piridonas/química , Piridonas/farmacologia , RatosRESUMO
Recently, new technologies based on biosensors and called label free have been developed. These technologies eliminate the need for using markers and dyes. The authors applied one of these technologies, based on measurement of cell impedance variation, to study the pharmacological profiles of ligands for the cannabinoid receptor 2 (CB2), a Gi-coupled receptor, and for the metabopotropic glutamate receptor 1 (mGluR1), a Gq-coupled receptor. Reference agonists and antagonists/inverse agonists for the 2 receptors were applied to recombinant cell lines and impedance monitored over time. Agonists (JWH133 and CP55940 for CB2; quisqualate, glutamate, 1S-3R-ACPD, and S-3,5-DHPG for mGluR1) triggered a variation of impedance consistent in both potency and efficacy with data obtained using classical assays measuring cAMP or Ca(2+) levels. This effect was not present in the parental nontransfected cell line, confirming specific receptor-mediated response. Application of antagonists (AM630 for CB2; YM298198, SCH1014222, J&J16259685, and CPCCOEt for mGluR1) reduced agonist-induced impedance changes. The only exception was the mGluR1 antagonist BAY367620 that, while active in the Ca(2+) assay, was inactive in the impedance assay. Overall, these results confirm the possibility of using cell impedance-based technology to study the pharmacological profile of ligands acting at G-protein-coupled receptors coupled to different downstream signaling pathways.
Assuntos
Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Analgésicos/farmacologia , Animais , Benzimidazóis/farmacologia , Bioensaio , Células CHO , Cálcio/metabolismo , Canabinoides/farmacologia , Cromonas , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Cicloexanóis/farmacologia , Cicloleucina/análogos & derivados , Cicloleucina/farmacologia , Impedância Elétrica , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/metabolismo , Ácido Glutâmico/farmacologia , Glicina/análogos & derivados , Glicina/farmacologia , Indóis/farmacologia , Naftalenos/farmacologia , Fármacos Neuroprotetores/farmacologia , Quinolinas/farmacologia , Ácido Quisquálico/farmacologia , Receptor CB2 de Canabinoide/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Resorcinóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Tiazóis/farmacologiaRESUMO
A-ring modifications on the triazafluorenone core structure were investigated. Five membered heterocycles such as pyrazoles and isothiazoles are not tolerated. It has been found that the pyrimidine nucleus was very well tolerated on the left hand side. Amino pyrimidine compounds 24 and 27 showed acceptable PK profile with significant brain penetration. Compound 9 served as a versatile intermediate for a number of chemical transformations.
Assuntos
Compostos Aza/química , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Humanos , Estrutura MolecularRESUMO
Introduction of small unsaturated alkylamino groups at the 4-position of the A-ring of the tricyclic framework (triazafluorenone) afforded extremely potent and selective mGluR1 antagonists with desirable properties. Compounds 11q and 11s are active in the SNL pain model with ED(50)s 3.3 and 6.4 mg/kg respectively. Metabolic outcome of propargyl amino moiety was studied.
Assuntos
Neuralgia/tratamento farmacológico , Piridinas/química , Pirimidinas/química , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Administração Oral , Animais , Relação Dose-Resposta a Droga , Compostos Heterocíclicos com 3 Anéis/química , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Concentração Inibidora 50 , Piridinas/farmacologia , Pirimidinas/farmacologia , Ratos , Relação Estrutura-AtividadeRESUMO
mGluR1 receptors are believed to play major roles in the pathophysiology of diseases such as anxiety and chronic pain and are being actively investigated as targets for drug development. Sequence polymorphisms can potentially influence the efficacy of drugs in patient populations and are therefore an important consideration in the drug development process. To identify DNA sequence variants of the mGluR1 receptor, comparative DNA sequencing was performed on DNA samples (n=186) from apparently healthy subjects representing two ethnic groups. In total, eight non-synonymous single nucleotide polymorphisms (SNPs) were identified and one SNP (c2977>T) was found to be particularly common, this SNP results in a proline to serine substitution at residue 993 (P993S). The WT (P993) and S993 variants were expressed in an inducible system which allowed us to titrate gene expression to equivalent levels and were pharmacologically characterized. We determined the potency and affinity of standard antagonist compounds as well as the potency and efficacy of the endogenous ligand glutamate and other agonist compounds at both receptor variants. Agonist evoked increases in intracellular Ca(2+) were measured by fluorometric imaging plate reader (FLIPR). The potency of mGluR1 antagonists was evaluated by their ability to inhibit quisqualate induced increases in intracellular Ca(2+), while their affinities were determined by radio-ligand binding studies. This study demonstrates that the Pro993Ser amino acid exchange is highly frequent in the human mGluR1 gene. This polymorphism however, does not appear to affect the potency of agonist compounds or the potencies or affinities of small molecule antagonist compounds.
Assuntos
Substituição de Aminoácidos/genética , Antagonistas de Aminoácidos Excitatórios/farmacologia , Variação Genética/genética , Ácido Glutâmico/farmacologia , Polimorfismo de Nucleotídeo Único/genética , Receptores de Glutamato Metabotrópico/genética , Linhagem Celular , Ácido Glutâmico/análogos & derivados , Humanos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/antagonistas & inibidoresRESUMO
Metabotropic glutamate receptor 1 (mGluR1) plays important roles in the neurotransmission and pathogenesis of several neurological disorders, including chronic pain. Antagonists of mGlur1 are suggested to be useful for the treatment of pain. Herein, we report the discovery of a novel series of tetracyclic mGluR1 antagonists, such as 23c and 23e, with oral efficacy of ED50 of 8 and 5.1 mg/kg, respectively, in rat spinal nerve ligation neuropathic pain model.
Assuntos
Analgésicos/síntese química , Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Dor/tratamento farmacológico , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Analgésicos/química , Analgésicos/farmacologia , Animais , Área Sob a Curva , Doença Crônica , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Indazóis/síntese química , Indazóis/química , Indazóis/farmacologia , Morfolinas/síntese química , Morfolinas/química , Morfolinas/farmacologia , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Pirróis/síntese química , Pirróis/química , Pirróis/farmacologia , Ratos , Relação Estrutura-AtividadeRESUMO
Stable and inducible expression of human metabotropic glutamate receptor types 2, 5, and 8 was achieved in HEK293 cells using the ecdysone inducible system. Treatment of the respective cell lines with ponasterone A resulted in time and concentration-dependent induction of receptor expression. In all cases, the functional activation of receptors was determined by measuring increases in intracellular calcium. The physiologically GalphaI-coupled receptors mGluR2 and mGluR8 were successfully coupled to phospholipase C activation using the chimeric G protein Galphaq/o. The pharmacological properties of recombinant receptors were characterized and proved to be similar to native receptors. Our data suggest that the ecdysone system has a number of characteristics that make it well suited for expressing mGluRs and that the combined use of this system and chimeric G proteins allows receptors to be characterized using a rapid and straightforward Ca2+ assay.
Assuntos
Ecdisona/farmacologia , Receptores de Glutamato Metabotrópico/biossíntese , Cálcio/metabolismo , Linhagem Celular/metabolismo , Clonagem Molecular , Ecdisterona/análogos & derivados , Ecdisterona/farmacologia , Subunidades alfa de Proteínas de Ligação ao GTP/fisiologia , Expressão Gênica , Humanos , Receptor de Glutamato Metabotrópico 5 , Transcrição Gênica/efeitos dos fármacosRESUMO
Patients with Alzheimer's disease suffer from progressive cognitive impairments and show distinct post-mortem neuropathology, including beta-amyloid plaques. Transgenic (Tg) CRND8 mice carry a mutated human amyloid precursor protein gene and show age-related increases in beta-amyloid production and plaque deposition. It was previously reported that during the early stages of plaque deposition, Tg CRND8 mice demonstrated Morris maze impairments. However, it is unknown if Tg mice would be impaired at an earlier age prior to plaque deposition or more impaired at a later age with more extensive plaque deposition. In the current study, we describe Tg CRND8 age-progressing beta-amyloid neuropathology and cognitive abilities in greater detail. At all ages, Tg mice showed normal short-term memory in the Y-maze. Pre-plaque Tg and age-matched Non-Tg mice did not differ in learning the spatial Morris water maze. However, both early and late plaque Tg mice showed impairments during acquisition. In addition, although early plaque Tg mice performed well in the probe trial, late plaque Tg mice demonstrated impaired probe trial performance. Therefore compared to their Non-Tg littermates, Tg CRND8 mice demonstrate cognitive impairments that progressed with age and seemed to coincide with the onset of beta-amyloid plaque deposition.
Assuntos
Envelhecimento/fisiologia , Precursor de Proteína beta-Amiloide/genética , Transtornos Cognitivos , Fatores Etários , Peptídeos beta-Amiloides/metabolismo , Análise de Variância , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Transtornos Cognitivos/genética , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Diagnóstico por Imagem/métodos , Feminino , Imuno-Histoquímica/métodos , Masculino , Aprendizagem em Labirinto/fisiologia , Memória de Curto Prazo/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/fisiologia , Placa Amiloide/metabolismo , Desempenho Psicomotor/fisiologia , Comportamento Espacial/fisiologiaRESUMO
Notch proteins are involved in cell fate specification during development in tissues including brain. Little is known about their function in adulthood. Recently, Notch receptors have been hypothesized to play a role in neurodegeneration and in particular in Alzheimer's disease (Notch1) and CADASIL (Notch3). Here we show that another family member (Notch2) is constitutively expressed in adult mouse hippocampus in DG and not in CA1 and CA3 neurons. Treatment with kainic acid resulted in marked Notch2 induction in pyramidal neurons of CA1 and in a subpopulation of CA3 neurons surviving the lesion and protein expression was still detectable 6 weeks after drug treatment. These results suggest Notch2 involvement in the response of postmitotic neurons to excitotoxic stimuli.