RESUMO
Disruption of interleukin-13 (IL-13) signaling with large molecule antibody therapies has shown promise in diseases of allergic inflammation. Given that IL-13 recruits several members of the Janus Kinase family (JAK1, JAK2, and TYK2) to its receptor complex, JAK inhibition may offer an alternate small molecule approach to disrupting IL-13 signaling. Herein we demonstrate that JAK1 is likely the isoform most important to IL-13 signaling. Structure-based design was then used to improve the JAK1 potency of a series of previously reported JAK2 inhibitors. The ability to impede IL-13 signaling was thereby significantly improved, with the best compounds exhibiting single digit nM IC50's in cell-based assays dependent upon IL-13 signaling. Appropriate substitution was further found to influence inhibition of a key off-target, LRRK2. Finally, the most potent compounds were found to be metabolically labile, which makes them ideal scaffolds for further development as topical agents for IL-13 mediated diseases of the lungs and skin (for example asthma and atopic dermatitis, respectively).
Assuntos
Dermatite Atópica/genética , Interleucina-13/metabolismo , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 2/antagonistas & inibidores , Humanos , Transdução de SinaisRESUMO
Preclinical and clinical evidence indicates that a subset of asthma is driven by type 2 cytokines such as interleukin-4 (IL-4), IL-5, IL-9, and IL-13. Additional evidence predicts pathogenic roles for IL-6 and type I and type II interferons. Because each of these cytokines depends on Janus kinase 1 (JAK1) for signal transduction, and because many of the asthma-related effects of these cytokines manifest in the lung, we hypothesized that lung-restricted JAK1 inhibition may confer therapeutic benefit. To test this idea, we synthesized iJak-381, an inhalable small molecule specifically designed for local JAK1 inhibition in the lung. In pharmacodynamic models, iJak-381 suppressed signal transducer and activator of transcription 6 activation by IL-13. Furthermore, iJak-381 suppressed ovalbumin-induced lung inflammation in both murine and guinea pig asthma models and improved allergen-induced airway hyperresponsiveness in mice. In a model driven by human allergens, iJak-381 had a more potent suppressive effect on neutrophil-driven inflammation compared to systemic corticosteroid administration. The inhibitor iJak-381 reduced lung pathology, without affecting systemic Jak1 activity in rodents. Our data show that local inhibition of Jak1 in the lung can suppress lung inflammation without systemic Jak inhibition in rodents, suggesting that this strategy might be effective for treating asthma.
Assuntos
Asma/tratamento farmacológico , Asma/enzimologia , Janus Quinase 1/antagonistas & inibidores , Pulmão/enzimologia , Inibidores de Proteínas Quinases/uso terapêutico , Administração por Inalação , Alérgenos , Animais , Asma/patologia , Dexametasona/farmacologia , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Eosinófilos/patologia , Cobaias , Inflamação/patologia , Janus Quinase 1/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Ovalbumina , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacocinética , Transdução de Sinais , Resultado do TratamentoRESUMO
Amalgamation of the structure-activity relationship of two series of GlyT1 inhibitors developed at Merck led to the discovery of a clinical candidate, compound 16 (DCCCyB), which demonstrated excellent in vivo occupancy of GlyT1 transporters in rhesus monkey as determined by displacement of a PET tracer ligand.
RESUMO
A series of heterocyclic sulfonamides have been developed which are potent and selective inhibitors of hGlyT1. SAR studies to optimise the in vitro and in vivo properties are described. Optimisation of the central scaffold resulted in cyclohexane sulfones 28 and 29, which have good PK properties and show promise for further development.
Assuntos
Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Sulfonamidas/administração & dosagem , Sulfonamidas/química , Administração Oral , Animais , Disponibilidade Biológica , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Humanos , Masculino , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Ratos , Ratos Sprague-Dawley , Sulfonamidas/metabolismo , Triazóis/administração & dosagem , Triazóis/síntese químicaRESUMO
Non-selective benzodiazepines, such as diazepam, interact with equivalent affinity and agonist efficacy at GABA(A) receptors containing either an alpha1, alpha2, alpha3 or alpha5 subunit. However, which of these particular subtypes are responsible for the anticonvulsant effects of diazepam remains uncertain. In the present study, we examined the ability of diazepam to reduce pentylenetetrazoLe (PTZ)-induced and maximal electroshock (MES)-induced seizures in mice containing point mutations in single (alpha1H101R, alpha2H101R or alpha5H105R) or multiple (alpha125H-->R) alpha subunits that render the resulting GABA(A) receptors diazepam-insensitive. Furthermore, the anticonvulsant properties of diazepam, the alpha1- and alpha3-selective compounds zolpidem and TP003, respectively, and the alpha2/alpha3 preferring compound TP13 were studied against PTZ-induced seizures. In the transgenic mice, no single subtype was responsible for the anticonvulsant effects of diazepam in either the PTZ or MES assay and neither the alpha3 nor alpha5 subtypes appeared to confer anticonvulsant activity. Moreover, whereas the alpha1 and alpha2 subtypes played a modest role with respect to the PTZ assay, they had a negligible role in the MES assay. With respect to subtype-selective compounds, zolpidem and TP003 had much reduced anticonvulsant efficacy relative to diazepam in both the PTZ and MES assays whereas TP13 had high anticonvulsant efficacy in the PTZ but not the MES assay. Taken together, these data not only indicate a role for alpha2-containing GABA(A) receptors in mediating PTZ and MES anticonvulsant activity but also suggest that efficacy at more than one subtype is required and that these subtypes act synergistically.
Assuntos
Anticonvulsivantes/farmacologia , Benzodiazepinas/farmacologia , Receptores de GABA-A/fisiologia , Convulsões/prevenção & controle , Animais , Sítios de Ligação , Convulsivantes , Diazepam/farmacologia , Eletrochoque , Agonistas de Receptores de GABA-A , Ligantes , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Pentilenotetrazol , Mutação Puntual , Subunidades Proteicas/agonistas , Subunidades Proteicas/genética , Subunidades Proteicas/fisiologia , Piridinas/farmacologia , Receptores de GABA-A/genética , Convulsões/etiologia , ZolpidemRESUMO
The cyclopyrrolone pagoclone binds with roughly equivalent high affinity (0.7-9.1nM) to the benzodiazepine binding site of human recombinant GABA(A) receptors containing either an alpha1, alpha2, alpha3 or alpha5 subunit. However, whereas it was a partial agonist at alpha1-, alpha2- and alpha5-containing GABA(A) receptors, pagoclone was a full agonist at receptors containing an alpha3 subunit. In the rat elevated plus maze assay pagoclone (3mg/kg) had significant anxiolytic-like activity but at all three doses tested (0.3, 1 and 3mg/kg p.o.) it produced a significant reduction in the total distance travelled. This sedative-like effect was confirmed in rat chain-pulling and spontaneous locomotor assays. Surprisingly, in the plasma and brain samples derived from the elevated plus maze assay, the major metabolite of pagoclone, 5'-hydroxy pagoclone, was present at 10-20-fold higher concentrations relative to the parent compound. In order to establish whether this metabolite might have pharmacological activity, we measured its affinity and efficacy profile and found that both were comparable to those of pagoclone with the exception that efficacy at the alpha1 subtype was considerably greater for 5'-hydroxy pagoclone compared with the parent. This metabolite had significant anxiolytic-like activity in the elevated plus maze but at these same doses (0.3-3mg/kg p.o.) also produced sedation. It is therefore likely that in rats 5'-hydroxy pagoclone mediates the majority of the pharmacological actions following pagoclone administration.
Assuntos
Comportamento Animal/efeitos dos fármacos , Naftiridinas/farmacologia , Animais , Sítios de Ligação/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular , Relação Dose-Resposta a Droga , Fibroblastos , Flumazenil/farmacologia , Moduladores GABAérgicos/farmacologia , Humanos , Indóis/farmacocinética , Isoindóis , Isomerismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos dos fármacos , Naftiridinas/sangue , Naftiridinas/química , Naftiridinas/farmacocinética , Subunidades Proteicas/metabolismo , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/química , Receptores de GABA-A/efeitos dos fármacos , Fatores de Tempo , Trítio/farmacocinéticaRESUMO
A series of high-affinity GABA(A) agonists with good oral bioavailability in rat and dog and functional selectivity for the GABA(A)alpha2 and -alpha3 subtypes is reported. The 7-trifluoromethylimidazopyrimidine 14g and the 7-propan-2-olimidazopyrimidine 14k are anxiolytic in both conditioned and unconditioned animal models of anxiety with minimal sedation observed at full BZ binding site occupancy.
Assuntos
Transtornos de Ansiedade/tratamento farmacológico , Agonistas de Receptores de GABA-A , Pirimidinas/farmacologia , Administração Oral , Animais , Sítios de Ligação , Disponibilidade Biológica , Linhagem Celular , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular , Técnicas de Patch-Clamp , Pirimidinas/síntese química , Pirimidinas/farmacocinética , Ratos , Receptores de GABA-A , Relação Estrutura-AtividadeRESUMO
Imidazo[1,2-a]pyrimidines are GABA(A) receptor benzodiazepine binding site ligands which can exhibit functional selectivity for the alpha(3) subtype over the alpha(1) subtype. SAR studies to optimize this functional selectivity are described.
Assuntos
Imidazóis/química , Imidazóis/metabolismo , Pirimidinas/química , Pirimidinas/metabolismo , Receptores de GABA-A/metabolismo , Ligantes , Estrutura Molecular , Pirimidinas/síntese química , Sensibilidade e Especificidade , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
Imidazo[1,2-a]pyrazin-8-ones, imidazo[1,2-d][1,2,4]triazin-8-ones and imidazo[2,1-f][1,2,4]triazin-8-ones are high affinity GABA(A) agonists. Compound 16d has good oral bioavailability in rat, functional selectivity for the GABA(A)alpha2 and alpha3-subtypes and is anxiolytic in a conditioned animal model of anxiety with minimal sedation observed at full BZ binding site occupancy.