RESUMO
Two related series of selective norepinephrine reuptake inhibitors were synthesized based on 3,4-dihydro-1H-2,1,3-benzothiadiazine 2,2-dioxide or 3,4-dihydrosulfostyril cores, and screened for monoamine reuptake inhibition. Structure-activity relationships were determined for the series' in vitro potency and selectivity versus serotonin or dopamine transporter inhibition, and analogs based on both cores were identified as potent and selective NRIs. The 3,4-dihydrosulfostyril series was further tested for microsome stability, and compound 16j, which was optimized for both potency and stability, showed efficacy in an in vivo model of thermoregulatory dysfunction.
Assuntos
Inibidores da Captação Adrenérgica/química , Benzotiadiazinas/química , Óxidos S-Cíclicos/química , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/química , Norepinefrina/metabolismo , Tiazinas/química , Inibidores da Captação Adrenérgica/síntese química , Inibidores da Captação Adrenérgica/farmacologia , Animais , Transporte Biológico , Óxidos S-Cíclicos/síntese química , Óxidos S-Cíclicos/farmacologia , Humanos , Microssomos Hepáticos/metabolismo , Modelos Animais , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/metabolismo , Ratos , Relação Estrutura-Atividade , Tiazinas/síntese química , Tiazinas/farmacologiaRESUMO
Canonical Wnt signaling has been demonstrated to increase bone formation, and Wnt pathway components are being pursued as potential drug targets for osteoporosis and other metabolic bone diseases. Deletion of the Wnt antagonist secreted frizzled-related protein (sFRP)-1 in mice activates canonical signaling in bone and increases trabecular bone formation in aged animals. We have developed small molecules that bind to and inhibit sFRP-1 in vitro and demonstrate robust anabolic activity in an ex vivo organ culture assay. A library of over 440,000 drug-like compounds was screened for inhibitors of human sFRP-1 using a cell-based functional assay that measured activation of canonical Wnt signaling with an optimized T-cell factor (TCF)-luciferase reporter gene assay. One of the hits in this screen, a diarylsulfone sulfonamide, bound to sFRP-1 with a K(D) of 0.35 microM in a tryptophan fluorescence quenching assay. This compound also selectively inhibited sFRP-1 with an EC(50) of 3.9 microM in the cell-based functional assay. Optimization of this high throughput screening hit for binding and functional potency as well as metabolic stability and other pharmaceutical properties led to improved lead compounds. One of these leads (WAY-316606) bound to sFRP-1 with a K(D) of 0.08 microM and inhibited it with an EC(50) of 0.65 microM. Moreover, this compound increased total bone area in a murine calvarial organ culture assay at concentrations as low as 0.0001 microM. This work demonstrates the feasibility of developing small molecules that inhibit sFRP-1 and stimulate canonical Wnt signaling to increase bone formation.
