RESUMO
An in vitro screening protocol was used to transform a systemically-distributed SCD inhibitor into a liver-targeted compound. Incorporation of a key nicotinic acid moiety enables molecular recognition by OATP transporters, as demonstrated by uptake studies in transfected cell lines, and likely serves as a critical component of the observed liver-targeted tissue distribution profile. Preclinical anti-diabetic oGTT efficacy is demonstrated with nicotinic acid-based, liver-targeting SCD inhibitor 10, and studies with a close-structural analog devoid of SCD1 activity, suggest this efficacy is a result of on-target activity.
Assuntos
Inibidores Enzimáticos/química , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Ácidos Nicotínicos/química , Estearoil-CoA Dessaturase/antagonistas & inibidores , Administração Oral , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacocinética , Fígado/efeitos dos fármacos , Fígado/enzimologia , Camundongos , Camundongos Endogâmicos C57BL , Ácidos Nicotínicos/síntese química , Ácidos Nicotínicos/farmacocinética , Ácidos Nicotínicos/farmacologia , Ratos , Estearoil-CoA Dessaturase/metabolismo , Relação Estrutura-Atividade , Distribuição TecidualRESUMO
Optimization of a lead thiazole amide MF-152 led to the identification of potent bicyclic heteroaryl SCD1 inhibitors with good mouse pharmacokinetic profiles. In a view to target the liver for efficacy and to avoid SCD1 inhibition in the skin and eyes where adverse effects were previously observed in rodents, representative systemically-distributed SCD1 inhibitors were converted into liver-targeting SCD1 inhibitors.
Assuntos
Desenho de Fármacos , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Piperazinas/síntese química , Piperazinas/farmacologia , Estearoil-CoA Dessaturase/antagonistas & inibidores , Tiazóis/síntese química , Tiazóis/farmacologia , Amidas , Animais , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/toxicidade , Fígado/efeitos dos fármacos , Camundongos , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Piperazinas/farmacocinética , Piperazinas/toxicidade , Ratos , Relação Estrutura-Atividade , Tiazóis/farmacocinética , Tiazóis/toxicidadeRESUMO
Potent and orally bioavailable SCD inhibitors built on an azetidinyl pyridazine scaffold were identified. In a one-month gDIO mouse model of obesity, we demonstrated that there was no therapeutic index even at low doses; efficacy in preventing weight gain tracked closely with skin and eye adverse events. This was attributed to the local SCD inhibition in these tissues as a consequence of the broad tissue distribution observed in mice for this class of compounds. The search for new structural scaffolds which may display a different tissue distribution was initiated. In preparation for an HTS campaign, a radiolabeled azetidinyl pyridazine displaying low non-specific binding in the scintillation proximity assay was prepared.
Assuntos
Azetidinas/química , Inibidores Enzimáticos/química , Piridazinas/química , Estearoil-CoA Dessaturase/antagonistas & inibidores , Animais , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Ensaios de Triagem em Larga Escala , Camundongos , Ligação Proteica , Piridazinas/síntese química , Piridazinas/farmacologia , Estearoil-CoA Dessaturase/metabolismoRESUMO
Prostaglandin E2 synthase (mPGES-1), the enzyme which catalyzes the synthesis of PGE2, is induced during the inflammatory response. For this reason, mPGES-1 could be a potential therapeutic target. A high-throughput screening assay was developed to identify potential inhibitors of mPGES-1. The assay consisted of a 30-s mPGES-1 enzymatic reaction followed by the detection of PGE2 by enzyme immunoassay (EIA). The enzymatic reaction was performed in a batch mode because the instability of the substrate (10 min) limited the number of plates assayed within a working day. The detection of the product by EIA was performed on 3 instruments requiring 14 different steps for complete automation. The authors describe here the optimization and implementation of a 2-part assay on a Thermo CRS robotic system. More than 315,000 compounds were tested, and a hit rate of 0.84% was obtained for this assay. Although the entire assay required multiple steps, the assay was successfully miniaturized and automated for a high-throughput screening campaign.
Assuntos
Indústria Farmacêutica/métodos , Oxirredutases Intramoleculares/antagonistas & inibidores , Animais , Automação , Bovinos , Química Farmacêutica/métodos , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Técnicas Imunoenzimáticas , Prostaglandina-E Sintases , Albumina Sérica/metabolismo , Fatores de TempoRESUMO
To better define the role of the various prostanoid synthases in the adjuvant-induced arthritis (AIA) model, we have determined the temporal expression of the inducible PGE synthase (mPGES-1), mPGES-2, the cytosolic PGES (cPGES/p23), and prostacyclin synthase, and compared with that of cyclooxygenase-1 (COX-1) and COX-2. The profile of induction of mPGES-1 (50- to 80-fold) in the primary paw was similar to that of COX-2 by both RNA and protein analysis. Quantitative PCR analysis indicated that induction of mPGES-1 at day 15 was within 2-fold that of COX-2. Increased PGES activity was measurable in membrane preparations of inflamed paws, and the activity was inhibitable by MK-886 to >or=90% with a potency similar to that of recombinant rat mPGES-1 (IC(50) = 2.4 microM). The RNA of the newly described mPGES-2 decreased by 2- to 3-fold in primary paws between days 1 and 15 postadjuvant. The cPGES/p23 and COX-1 were induced during AIA, but at much lower levels (2- to 6-fold) than mPGES-1, with the peak of cPGES/p23 expression occurring later than that of COX-2 and PGE(2) production. Prostacyclin (measured as 6-keto-PGF(1alpha)) was transiently elevated on day 1, and prostacyclin synthase was down-regulated at the RNA level after day 3, suggesting a diminished role of prostacyclin during the maintenance of chronic inflammation in the rat AIA. These results show that mPGES-1 is up-regulated throughout the development of AIA and suggest that it plays a major role in the elevated production of PGE(2) in this model.