RESUMO
SAM-760 [(2-methyl-1-(phenylsulfonyl)-4-(piperazin-1-yl)-1H-benzo[d]imidazole)], a 5HT6 antagonist, was investigated in humans for the treatment of Alzheimer's disease. In liver microsomes and recombinant cytochrome P450 (P450) isozymes, SAM-760 was predominantly metabolized by CYP3A (â¼85%). Based on these observations and an expectation of a 5-fold magnitude of interaction with moderate to strong CYP3A inhibitors, a clinical DDI study was performed. In the presence of ketoconazole, the mean Cmax and area under the plasma concentration-time curve from time zero extrapolated to infinite time values of SAM-760 showed only a modest increase by 30% and 38%, respectively. In vitro investigation of this unexpectedly low interaction was undertaken using [14C]SAM-760. Radiometric profiling in human hepatocytes confirmed all oxidative metabolites previously observed with unlabeled SAM-760; however, the predominant radiometric peak was an unexpected polar metabolite that was insensitive to the pan-P450 inhibitor 1-aminobenzotriazole. In human hepatocytes, radiometric integration attributed 43% of the total metabolism of SAM-760 to this non-P450 pathway. Using an authentic standard, this predominant metabolite was confirmed as benzenesulfinic acid. Additional investigation revealed that the benzenesulfinic acid metabolite may be a novel, nonenzymatic, thiol-mediated reductive cleavage of an aryl sulfonamide group of SAM-760. We also determined the relative contribution of P450 to the metabolism of SAM-760 in human hepatocytes by following the rate of formation of oxidative metabolites in the presence and absence of P450 isoform-specific inhibitors. The P450-mediated oxidative metabolism of SAM-760 was still primarily attributed to CYP3A (33%), with minor contributions from P450 isoforms CYP2C19 and CYP2D6. Thus, the disposition of [14C]SAM-760 in human hepatocytes via novel sulfonamide metabolism and CYP3A verified the lower than expected clinical DDI when SAM-760 was coadministered with ketoconazole.
Assuntos
Interações Medicamentosas/fisiologia , Imidazóis/metabolismo , Cetoconazol/metabolismo , Piperazinas/metabolismo , Receptores de Serotonina/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/metabolismo , Sulfonamidas/metabolismo , Citocromo P-450 CYP2C19/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Inibidores do Citocromo P-450 CYP3A/metabolismo , Hepatócitos/metabolismo , Humanos , Isoenzimas/metabolismo , Microssomos Hepáticos/metabolismo , PiperazinaRESUMO
α7 nicotinic acetylcholine receptor agonists are promising therapeutic candidates for the treatment of cognitive impairment. As a follow up of our internal medicinal chemistry program we investigated a novel series of α7 nAChR agonists. Starting from molecular docking studies on two series of molecules recently developed in our laboratories, an alternative scaffold was designed attempting to combine the optimal features of these previously identified urea and pyrazole compounds. Based on our previous SAR knowledge and on predicted drug-like properties, a small library was synthesized in parallel manner, affording compounds with excellent α7 nAChR activity, selectivity and preliminary ADME profile.
Assuntos
Desenho de Fármacos , Pirazóis/farmacologia , Ureia/farmacologia , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Humanos , Masculino , Modelos Moleculares , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/síntese químicaRESUMO
Precompetitive collaborations have been successful in several disease areas and industries. Such collaborations are critical to address the gaps and challenges in therapeutic development for chronic neurodegenerative diseases. On November 5, 2012, members of the scientific community, advocates, regulators, industry, and government officials met at the US Food and Drug Administration to develop tools to expedite drug development and maximize the potential for success in future drug trials for Alzheimer disease and Parkinson disease. The meeting established that multiple collaborative approaches are essential for accelerating drug development. Such approaches include precompetitive data sharing, regulatory qualification of biomarkers and clinical outcome assessments, implementation of data standards, and development of quantitative drug disease trial models. While challenges to collaboration among industry partners are formidable, they are not insurmountable. The Coalition Against Major Diseases (CAMD) has several positive examples to highlight. This review represents proceedings from CAMD's annual conference and discusses the key themes that are being advanced by the Critical Path Institute.
RESUMO
α7 Nicotinic acetylcholine receptors (α7 nAChR) represent promising therapeutic candidates for the treatment of cognitive impairment associated with Alzheimer's disease (AD) and schizophrenia. A medicinal chemistry effort around previously reported compound 1 (SEN15924, WAY-361789) led to the identification of 12 (SEN78702, WYE-308775) a potent and selective full agonist of the α7 nAChR that demonstrated improved plasma stability, brain levels, and efficacy in behavioral cognition models.
Assuntos
Encéfalo/efeitos dos fármacos , Cognição/efeitos dos fármacos , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Agonistas Nicotínicos/farmacologia , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptores Nicotínicos/química , Animais , Células CHO , Cálcio/metabolismo , Química Farmacêutica , Cricetinae , Canal de Potássio ERG1 , Humanos , Modelos Moleculares , Agonistas Nicotínicos/síntese química , Piperidinas/síntese química , Pirazóis/síntese química , Ratos , Receptores Nicotínicos/metabolismo , Relação Estrutura-Atividade , Receptor Nicotínico de Acetilcolina alfa7RESUMO
The 5-HT(2C) receptor is a highly complex, highly regulated receptor which is widely distributed throughout the brain. The 5-HT(2C) receptor couples to multiple signal transduction pathways leading to engagement of a number of intracellular signaling molecules. Moreover, there are multiple allelic variants of the 5-HT(2C) receptor and the receptor is subject to RNA editing in the coding regions. The complexity of this receptor is further emphasized by the studies suggesting the utility of either agonists or antagonists in the treatment of schizophrenia. While several 5-HT(2C) agonists have demonstrated clinical efficacy in obesity (lorcaserin, PRX-000933), the focus of this review is on the therapeutic potential of 5-HT(2C) agonists in schizophrenia. To this end, the preclinical profile of 5-HT(2C) agonists from a neurochemical, electrophysiological, and a behavioral perspective is indicative of antipsychotic-like efficacy without extrapyramidal symptoms or weight gain. Recently, the selective 5-HT(2C) agonist vabicaserin demonstrated clinical efficacy in a Phase II trial in schizophrenia patients without weight gain and with low EPS liability. These data are highly encouraging and suggest that 5-HT(2C) agonists are potential therapeutics for the treatment of psychiatric disorders.
Assuntos
Esquizofrenia/tratamento farmacológico , Agonistas do Receptor 5-HT2 de Serotonina/uso terapêutico , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Humanos , Edição de RNA , Pesquisa Translacional BiomédicaRESUMO
On the basis of the previously reported benzimidazole 1,3'-bipyrrolidine benzamides (1), a new class of 2-(pyrrolidin-1-yl)ethyl-3,4-dihydroisoquinolin-1(2H)-one derivatives (3-50) were synthesized and evaluated as potent H(3) receptor antagonists. In particular, compound 39 exhibited potent in vitro binding and functional activities at the H(3) receptor, good selectivities against other neurotransmitter receptors and ion channels, acceptable pharmacokinetic properties, and a favorable in vivo profile.
Assuntos
Benzamidas/síntese química , Antagonistas dos Receptores Histamínicos H3/síntese química , Isoquinolinas/síntese química , Pirrolidinas/síntese química , Receptores Histamínicos H3/metabolismo , Animais , Benzamidas/farmacocinética , Benzamidas/farmacologia , Proteínas Sanguíneas/metabolismo , Linhagem Celular , Inibidores das Enzimas do Citocromo P-450 , Cães , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Agonismo Inverso de Drogas , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Cobaias , Agonistas dos Receptores Histamínicos/síntese química , Agonistas dos Receptores Histamínicos/farmacocinética , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos H3/química , Antagonistas dos Receptores Histamínicos H3/farmacologia , Humanos , Técnicas In Vitro , Isoquinolinas/farmacocinética , Isoquinolinas/farmacologia , Macaca fascicularis , Masculino , Microssomos Hepáticos/metabolismo , Permeabilidade , Ligação Proteica , Pirrolidinas/farmacocinética , Pirrolidinas/farmacologia , Ensaio Radioligante , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Reconhecimento Psicológico/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Several anti-amyloid ß (Aß) antibodies are under evaluation for the treatment of Alzheimer's disease (AD). Clinical studies using the N-terminal-directed anti-Aß antibody bapineuzumab have demonstrated reduced brain PET-Pittsburg-B signals, suggesting the reduction of Aß plaques, and reduced levels of total and phosphorylated tau protein in the CSF of treated AD patients. Preclinical studies using 3D6 (the murine form of bapineuzumab) have demonstrated resolution of Aß plaque and vascular burdens, neuritic dystrophy, and preservation of synaptic density in the transgenic APP mouse models. In contrast, few studies have evaluated the direct interaction of this antibody with synaptotoxic soluble Aß species. In the current report, we demonstrated that 3D6 binds to soluble, synaptotoxic assemblies of Aß(1-42) and prevents multiple downstream functional consequences in rat hippocampal neurons including changes in glutamate AMPA receptor trafficking, AD-type tau phosphorylation, and loss of dendritic spines. In vivo, we further demonstrated that 3D6 prevents synaptic loss and acutely reverses the behavioral deficit in the contextual fear conditioning task in transgenic mouse models of AD, two endpoints thought to be linked to synaptotoxic soluble Aß moieties. Importantly C-terminal anti-Aß antibodies were ineffective on these endpoints. These results, taken with prior studies, suggest that N-terminal anti-Aß antibodies effectively interact with both soluble and insoluble forms of Aß and therefore appear particularly well suited for testing the Aß hypothesis of AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/imunologia , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Epitopos/imunologia , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Doença de Alzheimer/imunologia , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Análise de Variância , Animais , Anticorpos Neutralizantes , Sintomas Comportamentais/tratamento farmacológico , Sintomas Comportamentais/etiologia , Sintomas Comportamentais/imunologia , Biotina/metabolismo , Células Cultivadas , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Espinhas Dendríticas/efeitos dos fármacos , Modelos Animais de Doenças , Embrião de Mamíferos , Epitopos/metabolismo , Medo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Hipocampo/citologia , Humanos , Camundongos , Camundongos Transgênicos , Proteínas dos Microfilamentos/imunologia , Proteínas dos Microfilamentos/metabolismo , Proteínas Associadas aos Microtúbulos/imunologia , Proteínas Associadas aos Microtúbulos/metabolismo , Mutação/genética , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neuropeptídeos/imunologia , Neuropeptídeos/metabolismo , Fragmentos de Peptídeos/imunologia , Fosforilação , Ligação Proteica/imunologia , Estrutura Secundária de Proteína , Transporte Proteico/efeitos dos fármacos , Ratos , Receptores de AMPA/metabolismo , Solubilidade , Proteína Vesicular 1 de Transporte de Glutamato/imunologia , Proteína Vesicular 1 de Transporte de Glutamato/metabolismoRESUMO
On the basis of the previously reported benzimidazole 1,3'-bipyrrolidine benzamides (1), a series of related pyrrolidin-3-yl-N-methylbenzamides were synthesized and evaluated as H(3) receptor antagonists. In particular, compound 32 exhibits potent H(3) receptor binding affinity, improved pharmaceutical properties and a favorable in vivo profile.
Assuntos
Benzamidas/síntese química , Benzamidas/farmacologia , Desenho de Fármacos , Antagonistas dos Receptores Histamínicos H3/síntese química , Antagonistas dos Receptores Histamínicos H3/farmacologia , Pirrolidinas/síntese química , Pirrolidinas/farmacologia , Animais , Benzamidas/química , Benzamidas/farmacocinética , Encéfalo/metabolismo , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/fisiopatologia , Diabetes Insípido/tratamento farmacológico , Diabetes Insípido/metabolismo , Modelos Animais de Doenças , Antagonistas dos Receptores Histamínicos H3/química , Antagonistas dos Receptores Histamínicos H3/farmacocinética , Antígenos de Histocompatibilidade/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Microssomos Hepáticos/metabolismo , Terapia de Alvo Molecular , Ligação Proteica , Pirrolidinas/química , Pirrolidinas/farmacocinética , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Proteínas com Motivo TripartidoRESUMO
RATIONALE: α7 nicotinic acetylcholine receptor (nAChR) agonists are proposed as candidate agents for the adjunctive treatment of cognitive deficits associated with schizophrenia. Despite the pursuit of such an approach clinically, it is surprising that the preclinical profile of pro-cognitive agents in conjunction with antipsychotic drugs is currently unexplored. OBJECTIVES: We determined if the memory-enhancing effects of the selective α7 nAChR agonist WYE-103914 were preserved in the presence of the atypical antipsychotic drug risperidone, and if the antipsychotic-like profile of risperidone was preserved in the presence of WYE-103914. METHODS: Using the rat novel object recognition (NOR) paradigm, the maintenance of memory-enhancing activity of the α7 nAChR agonist WYE-103914 in the presence of risperidone was examined. Similarly, in the standard tests of antipsychotic-like activity, apomorphine-induced climbing (AIC) in mice and conditioned avoidance responding (CAR) in rats, the preservation of antipsychotic-like activity of risperidone was evaluated in the presence of WYE-103914. RESULTS: WYE-103914 exhibited memory-enhancing activity in rat NOR, and this effect of WYE-103914 was retained in the presence of risperidone. In AIC, the atypical antipsychotic profile of risperidone was not significantly altered by WYE-103914. In contrast, WYE-103914 moderately potentiated the efficacy profile of risperidone in CAR, an effect that did not appear to be convincingly linked to a pharmacokinetic interaction. CONCLUSIONS: These data underscore the value of a preclinical evaluation of the adjunctive profile of a memory-enhancing agent in combination with antipsychotics and provide further support to augmentation with α7 nAChR agonists to address the cognitive deficits associated with schizophrenia.
Assuntos
Transtornos Cognitivos/tratamento farmacológico , Piridinas/farmacologia , Risperidona/farmacologia , Esquizofrenia/tratamento farmacológico , Ureia/análogos & derivados , Animais , Antipsicóticos/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Transtornos Cognitivos/etiologia , Avaliação Pré-Clínica de Medicamentos , Interações Medicamentosas , Quimioterapia Combinada , Masculino , Memória/efeitos dos fármacos , Camundongos , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/metabolismo , Esquizofrenia/fisiopatologia , Ureia/farmacologia , Receptor Nicotínico de Acetilcolina alfa7RESUMO
As part of our efforts to develop agents for cognitive enhancement, we have been focused on the 5-HT(6) receptor in order to identify potent and selective ligands for this purpose. Herein we report the identification of a novel series of 3-sulfonylindazole derivatives with acyclic amino side chains as potent and selective 5-HT(6) antagonists. The synthesis and detailed SAR of this class of compounds are reported.
Assuntos
Indazóis/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Células HeLa , Humanos , Indazóis/química , Espectroscopia de Ressonância Magnética , Nootrópicos/química , Nootrópicos/farmacologia , Antagonistas da Serotonina/química , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-AtividadeRESUMO
As part of our efforts to develop agents for CNS diseases, we have been focused on the 5-HT(6) receptor in order to identify potent and selective ligands for cognitive enhancement. Herein we report the identification of a novel series of 5-piperazinyl-3-sulfonylindazoles as potent and selective 5-HT(6) antagonists. The synthesis, SAR, and pharmacokinetic and pharmacological activities of some of the compounds including 3-(naphthalen-1-ylsulfonyl)-5-(piperazin-1-yl)-1H-indazole (WAY-255315 or SAM-315) will be described.
Assuntos
Indazóis/síntese química , Nootrópicos/síntese química , Piperazinas/síntese química , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Sulfonas/síntese química , Acetilcolina/metabolismo , Animais , Disponibilidade Biológica , Encéfalo/metabolismo , Ácido Glutâmico/metabolismo , Células HeLa , Humanos , Indazóis/farmacocinética , Indazóis/farmacologia , Ligantes , Nootrópicos/farmacocinética , Nootrópicos/farmacologia , Piperazinas/farmacocinética , Piperazinas/farmacologia , Ratos , Antagonistas da Serotonina/farmacocinética , Antagonistas da Serotonina/farmacologia , Relação Estrutura-Atividade , Sulfonas/farmacocinética , Sulfonas/farmacologiaRESUMO
As part of an effort to identify 5-HT(1A) antagonists that did not possess typical arylalkylamine or keto/amido-alkyl aryl piperazine scaffolds, prototype compound 10a was identified from earlier work in a combined 5-HT(1A) antagonist/SSRI program. This quinolyl-piperazinyl piperidine analogue displayed potent, selective 5-HT(1A) antagonism but suffered from poor oxidative metabolic stability, resulting in low exposure following oral administration. SAR studies, driven primarily by in vitro liver microsomal stability assessment, identified compound 10b, which displayed improved oral bioavailability and lower intrinsic clearance. Further changes to the scaffold (e.g., 10r) resulted in a loss in potency. Compound 10b displayed cognitive enhancing effects in a number of animal models of learning and memory, enhanced the antidepressant-like effects of the SSRI fluoxetine, and reversed the sexual dysfunction induced by chronic fluoxetine treatment.
Assuntos
Piperazinas/síntese química , Piperidinas/síntese química , Quinolinas/síntese química , Antagonistas do Receptor 5-HT1 de Serotonina , Acetilcolina/metabolismo , Administração Oral , Precursor de Proteína beta-Amiloide/genética , Animais , Antidepressivos/síntese química , Antidepressivos/química , Antidepressivos/farmacologia , Disponibilidade Biológica , Células CHO , Córtex Cerebral/metabolismo , Cognição/efeitos dos fármacos , Cricetinae , Cricetulus , Fluoxetina/farmacologia , Hipocampo/metabolismo , Técnicas In Vitro , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Microssomos Hepáticos/metabolismo , Nootrópicos/síntese química , Nootrópicos/química , Nootrópicos/farmacologia , Ereção Peniana/efeitos dos fármacos , Piperazinas/química , Piperazinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Quinolinas/química , Quinolinas/farmacologia , Ratos , Serotonina/metabolismo , Relação Estrutura-AtividadeRESUMO
Alpha-7 nicotinic acetylcholine receptor (alpha7 nAChR) agonists are promising therapeutic candidates for the treatment of cognitive impairment. We report a series of novel, potent small molecule agonists (4-18) of the alpha7 nAChR deriving from our continuing efforts in the areas of Alzheimer's disease and schizophrenia. One of the compounds of the series containing a urea moiety (16) was further shown to be a selective agonist of the alpha7 nAChR with excellent in vitro and in vivo profiles, brain penetration, and oral bioavailability and demonstrated in vivo efficacy in multiple behavioral cognition models. Structural modifications leading to the improved selectivity profile and the biological evaluation of this series of compounds are discussed.
Assuntos
Agonistas Nicotínicos/síntese química , Agonistas Nicotínicos/farmacologia , Piridinas/síntese química , Piridinas/farmacologia , Receptores Nicotínicos/metabolismo , Ureia/análogos & derivados , Ureia/síntese química , Ureia/farmacologia , Administração Oral , Animais , Humanos , Concentração Inibidora 50 , Masculino , Modelos Moleculares , Agonistas Nicotínicos/administração & dosagem , Agonistas Nicotínicos/farmacocinética , Conformação Proteica , Piridinas/administração & dosagem , Piridinas/farmacocinética , Ratos , Receptores Nicotínicos/química , Relação Estrutura-Atividade , Especificidade por Substrato , Ureia/administração & dosagem , Ureia/farmacocinética , Receptor Nicotínico de Acetilcolina alfa7RESUMO
Phosphodiesterase 11A (PDE11A) is the most recently identified family of phosphodiesterases (PDEs), the only known enzymes to break down cyclic nucleotides. The tissue expression profile of this dual specificity PDE is controversial, and little is understood of its biological function, particularly in the brain. We seek here to determine if PDE11A is expressed in the brain and to understand its function, using PDE11A(-/-) knockout (KO) mice. We show that PDE11A mRNA and protein are largely restricted to hippocampus CA1, subiculum, and the amygdalohippocampal area, with a two- to threefold enrichment in the ventral vs. dorsal hippocampus, equal distribution between cytosolic and membrane fractions, and increasing levels of protein expression from postnatal day 7 through adulthood. Interestingly, PDE11A KO mice show subtle psychiatric-disease-related deficits, including hyperactivity in an open field, increased sensitivity to the glutamate N-methyl-D-aspartate receptor antagonist MK-801, as well as deficits in social behaviors (social odor recognition memory and social avoidance). In addition, PDE11A KO mice show enlarged lateral ventricles and increased activity in CA1 (as per increased Arc mRNA), phenotypes associated with psychiatric disease. The increased sensitivity to MK-801 exhibited by PDE11A KO mice may be explained by the biochemical dysregulation observed around the glutamate alpha-amino-3-hydroxy-5-methyl-4-isozazolepropionic (AMPA) receptor, including decreased levels of phosphorylated-GluR1 at Ser845 and the prototypical transmembrane AMPA-receptor-associated proteins stargazin (gamma2) and gamma8. Together, our data provide convincing evidence that PDE11A expression is restricted in the brain but plays a significant role in regulating brain function.
Assuntos
3',5'-GMP Cíclico Fosfodiesterases/metabolismo , Hipocampo/enzimologia , Transtornos Mentais/enzimologia , 3',5'-GMP Cíclico Fosfodiesterases/deficiência , 3',5'-GMP Cíclico Fosfodiesterases/genética , Animais , Comportamento Animal , Feminino , Regulação Enzimológica da Expressão Gênica , Glutamina/metabolismo , Hipocampo/patologia , Masculino , Transtornos Mentais/genética , Transtornos Mentais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , RNA Mensageiro/genética , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais , Comportamento SocialRESUMO
BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative condition characterized by an increasing loss of dopaminergic neurons resulting in motor dysfunction. However, cognitive impairments in PD patients are a common clinical feature that has gained increased attention. OBJECTIVE: The purpose of the current study was to evaluate the effects of an MPTP-induced dopaminergic lesion in mice on social odor recognition (SOR) memory. METHODS: Mice were acutely treated with MPTP and evaluated for memory impairments in the SOR assay and characterized using biochemical and immunohistochemical methods approximately 2 weeks later. RESULTS: Here we demonstrate that SOR memory is sensitive to MPTP treatment and that it correlates with multiple measures of nigrostriatal integrity. MPTP treatment of C57BL/6N mice produced a profound decrease in dopamine levels, dopamine transporter binding and tyrosine hydroxylase immunoreactivity in the striatum. These impairments in stratial dopaminergic function were blocked by pretreatment with the MAO-B inhibitor deprenyl. Changes in the dopaminergic system parallel those observed in SOR with MPTP treatment impairing recognition memory in the absence of a deficit in odor discrimination during learning. Deprenyl pretreatment blocked the MPTP-induced impairment of SOR memory. CONCLUSION: The use of the SOR memory model may provide a preclinical method for evaluating cognitive therapies for PD.
Assuntos
Intoxicação por MPTP/complicações , Intoxicação por MPTP/psicologia , Transtornos da Memória/etiologia , Reconhecimento Psicológico/fisiologia , Predomínio Social , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Análise de Variância , Animais , Modelos Animais de Doenças , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Intoxicação por MPTP/induzido quimicamente , Intoxicação por MPTP/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Substância Negra/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Novel 5-cyclic amine-3-arylsulfonylindazoles were prepared, and several analogues within this class have been identified as high-affinity 5-HT(6) receptor ligands with improved pharmacokinetic and pharmacological properties. One selected example, 18b, showed good brain penetrability and a generally favorable pharmacokinetic profile with procognitive efficacy in the rat novel object recognition assay. The synthesis and structure-activity relationship of this potent class are discussed.
Assuntos
Indazóis/metabolismo , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/metabolismo , Sulfonas/metabolismo , Animais , Ligação Competitiva , Encéfalo/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Habituação Psicofisiológica/efeitos dos fármacos , Humanos , Indazóis/química , Indazóis/farmacologia , Modelos Químicos , Estrutura Molecular , Ratos , Receptor 5-HT2B de Serotonina/química , Receptor 5-HT2B de Serotonina/metabolismo , Receptores de Serotonina/química , Reconhecimento Psicológico/efeitos dos fármacos , Antagonistas do Receptor 5-HT2 de Serotonina , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacocinética , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologiaRESUMO
Using a focused screen of biogenic amine compounds we identified a novel series of H(3)R antagonists. A preliminary SAR study led to reduction of MW while increasing binding affinity and potency. Optimization of the physical properties of the series led to (S)-6n, with improved brain to plasma exposure and efficacy in both water intake and novel object recognition models.
Assuntos
Benzamidas/química , Benzimidazóis/química , Antagonistas dos Receptores Histamínicos H3/química , Pirrolidinas/química , Receptores Histamínicos H3 , Animais , Benzamidas/sangue , Benzamidas/metabolismo , Benzimidazóis/sangue , Benzimidazóis/metabolismo , Células CACO-2 , Linhagem Celular , Antagonistas dos Receptores Histamínicos H3/sangue , Antagonistas dos Receptores Histamínicos H3/metabolismo , Humanos , Indóis/sangue , Indóis/química , Indóis/metabolismo , Ligação Proteica , Pirrolidinas/sangue , Pirrolidinas/metabolismo , Ratos , Receptores Histamínicos H3/sangue , Receptores Histamínicos H3/metabolismoRESUMO
Immunotherapy targeting of amyloid beta (Abeta) peptide in transgenic mouse models of Alzheimer disease (AD) has been widely demonstrated to resolve amyloid deposition as well as associated neuronal, glial, and inflammatory pathologies. These successes have provided the basis for ongoing clinical trials of immunotherapy for treatment of AD in humans. Acute as well as chronic Abeta-targeted immunotherapy has also been demonstrated to reverse Abeta-related behavioral deficits assessing memory in AD transgenic mouse models. We observe that three antibodies targeting the same linear epitope of Abeta, Abeta(3-7), differ in their ability to reverse contextual fear deficits in Tg2576 mice in an acute testing paradigm. Reversal of contextual fear deficit by the antibodies does not correlate with in vitro recognition of Abeta in a consistent or correlative manner. To better define differences in antigen recognition at the atomic level, we determined crystal structures of Fab fragments in complex with Abeta. The conformation of the Abeta peptide recognized by all three antibodies was highly related and is also remarkably similar to that observed in independently reported Abeta:antibody crystal structures. Sequence and structural differences between the antibodies, particularly in CDR3 of the heavy chain variable region, are proposed to account for differing in vivo properties of the antibodies under study. These findings provide a structural basis for immunotherapeutic strategies targeting Abeta species postulated to underlie cognitive deficits in AD.
Assuntos
Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/química , Animais , Comportamento Animal , Reagentes de Ligações Cruzadas/farmacologia , Cristalografia por Raios X/métodos , Modelos Animais de Doenças , Epitopos/química , Heterozigoto , Humanos , Cinética , Masculino , Camundongos , Conformação Molecular , Proteínas Recombinantes/químicaRESUMO
Following several recent reports that suggest that dual cAMP and cGMP phosphodiesterase 10A (PDE10A) inhibitors may present a novel mechanism to treat positive symptoms of schizophrenia, we sought to extend the preclinical characterization of two such compounds, papaverine [1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline] and MP-10 [2-{[4-(1-methyl-4-pyridin-4-yl-1H-pyrazol-3-yl)phenoxy]methyl}quinoline], in a variety of in vivo and in vitro assays. Both of these compounds were active in a range of antipsychotic models, antagonizing apomorphine-induced climbing in mice, inhibiting conditioned avoidance responding in both rats and mice, and blocking N-methyl-D-aspartate antagonist-induced deficits in prepulse inhibition of acoustic startle response in rats, while improving baseline sensory gating in mice, all of which strengthen previously reported observations. These compounds also demonstrated activity in several assays intended to probe negative symptoms and cognitive deficits, two disease domains that are underserved by current treatments, with both compounds showing an ability to increase sociality in BALB/cJ mice in the social approach/social avoidance assay, enhance social odor recognition in mice and, in the case of papaverine, improve novel object recognition in rats. Biochemical characterization of these compounds has shown that PDE10A inhibitors modulate both the dopamine D1-direct and D2-indirect striatal pathways and regulate the phosphorylation status of a panel of glutamate receptor subunits in the striatum. It is striking that PDE10A inhibition increased the phosphorylation of the (+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor GluR1 subunit at residue serine 845 at the cell surface. Together, our results suggest that PDE10A inhibitors alleviate both dopaminergic and glutamatergic dysfunction thought to underlie schizophrenia, which may contribute to the broad-spectrum efficacy.
Assuntos
Antipsicóticos , Cognição/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Pirazóis/farmacologia , Quinolinas/farmacologia , Psicologia do Esquizofrênico , Animais , Apomorfina/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Catalepsia/induzido quimicamente , Catalepsia/prevenção & controle , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Ratos , Ratos Sprague-Dawley , Reflexo de Sobressalto/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Comportamento Social , Comportamento Estereotipado/efeitos dos fármacosRESUMO
Alpha 7 nicotinic acetylcholine receptor (alpha(7) nAChR) agonists are promising therapeutic candidates for the treatment of cognitive impairment associated with a variety of disorders including Alzheimer's disease and schizophrenia. Alpha 7 nAChRs are expressed in brain regions associated with cognitive function, regulate cholinergic neurotransmission and have been shown to be down regulated in both schizophrenia and Alzheimer's disease. Herein we report a novel, potent small molecule agonist of the alpha 7 nAChR, SEN12333/WAY-317538. This compound is a selective agonist of the alpha(7) nAChR with excellent in vitro and in vivo profiles, excellent brain penetration and oral bioavailability, and demonstrates in vivo efficacy in multiple behavioural cognition models. The SAR and biological evaluation of this series of compounds are discussed.