RESUMEN
Impaired glycogen synthesis and turnover are common in insulin resistance and type 2 diabetes. As glycogen synthase (GS) is a key enzyme involved in the synthetic process, it presents a promising therapeutic target for the treatment of type 2 diabetes. In the present study, we identified a novel, potent and orally available GS activator AJS1669 {sodium 2-[[5-[[4-(4,5-difluoro-2-methylsulfanyl-phenyl)phenoxy] methyl]furan-2-carbonyl]-(2-furylmethyl)amino] acetate}. In vitro, we performed a glycogen synthase 1 (GYS1) activation assay for screening GS activators and identified that the activity of AJS1669 was further potentiated in the presence of glucose-6-phosphate (G6P). In vivo, we used ob/ob mice to evaluate the novel anti-diabetic effects of AJS1669 by measuring basal blood glucose levels, glucose tolerance and body fat mass index. Repeated administration of AJS1669 over 4 weeks reduced blood glucose and hemoglobin A1c (HbA1c) levels in ob/ob mice. AJS1669 also improved glucose tolerance in a dose-dependent manner, and decreased body fat mass. The mRNA levels of genes involved in mitochondrial fatty acid oxidation and mitochondrial biogenesis were elevated in skeletal muscle tissue following AJS1669 treatment. Hepatic tissue of treated mice also exhibited elevated expression of genes associated with fatty acid oxidation. In contrast to ob/ob mice, in C57Bl/6 mice AJS1669 administration did not alter body weight or reduce glucose levels. These results demonstrate that pharmacological agents that activate GYS1, the main GS subtype found in skeletal muscle, have potential for use as novel treatments for diabetes that improve glucose metabolism in skeletal muscle.
Asunto(s)
Adiposidad/efectos de los fármacos , Activadores de Enzimas/farmacología , Glucosa-6-Fosfato/metabolismo , Glucógeno Sintasa/metabolismo , Músculo Esquelético/enzimología , Administración Oral , Animales , Activadores de Enzimas/química , Prueba de Tolerancia a la Glucosa , Hígado/enzimología , Ratones , Ratones ObesosRESUMEN
X-ray crystal structural determination of FABP4 in complex with four inhibitors revealed the complex binding modes, and the resulting observations led to improvement of the inhibitory potency of FABP4 inhibitors. However, the detailed structure-activity relationship (SAR) could not be explained from these structural observations. For a more detailed understanding of the interactions between FABP4 and inhibitors, fragment molecular orbital analyses were performed. These analyses revealed that the total interfragment interaction energies of FABP4 and each inhibitor correlated with the ranking of the K i value for the four inhibitors. Furthermore, interactions between each inhibitor and amino acid residues in FABP4 were identified. The oxygen atom of Lys58 in FABP4 was found to be very important for strong interactions with FABP4. These results might provide useful information for the development of novel potent FABP4 inhibitors.
RESUMEN
Interleukin-12 (IL-12) and IL-23 are proinflammatory cytokines and therapeutic targets for inflammatory and autoimmune diseases, including inflammatory bowel diseases, psoriasis, rheumatoid arthritis, and multiple sclerosis. We describe the discovery of APY0201, a unique small molecular IL-12/23 production inhibitor, from activated macrophages and monocytes, and demonstrate ameliorated inflammation in an experimental model of colitis. Through a chemical proteomics approach using a highly sensitive direct nanoflow LC-MS/MS system and bait compounds equipped with the FLAG epitope associated regulator of PIKfyve (ArPIKfyve) was detected. Further study identified its associated protein phosphoinositide kinase, FYVE finger-containing (PIKfyve), as the target protein of APY0201, which was characterized as a potent, highly selective, ATP-competitive PIKfyve inhibitor that interrupts the conversion of phosphatidylinositol 3-phosphate (PtdIns3P) to PtdIns(3,5)P2. These results elucidate the function of PIKfyve kinase in the IL-12/23 production pathway and in IL-12/23-driven inflammatory disease pathologies to provide a compelling rationale for targeting PIKfyve kinase in inflammatory and autoimmune diseases.
Asunto(s)
Interleucina-12/antagonistas & inhibidores , Interleucina-23/antagonistas & inhibidores , Pirazoles/farmacología , Pirimidinas/farmacología , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Línea Celular , Colitis/tratamiento farmacológico , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Descubrimiento de Drogas , Femenino , Humanos , Inflamación/tratamiento farmacológico , Interleucina-10/deficiencia , Leucocitos Mononucleares/efectos de los fármacos , Macrófagos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones SCID , Modelos Moleculares , Estructura Molecular , Pirazoles/química , Pirimidinas/química , Bibliotecas de Moléculas Pequeñas/química , Relación Estructura-ActividadRESUMEN
By human sensory analyses, we found that various extracellular calcium-sensing receptor (CaSR) agonists enhance sweet, salty, and umami tastes, although they have no taste themselves. These characteristics are known as "kokumi taste" and often appear in traditional Japanese cuisine. Although GSH is a typical kokumi taste substance (taste enhancer), its mode of action is poorly understood. Here, we demonstrate how the kokumi taste is enhanced by the CaSR, a close relative of the class C G-protein-coupled receptors T1R1, T1R2, and T1R3 (sweet and umami receptors). We identified a large number of CaSR agonist gamma-glutamyl peptides, including GSH (gamma-Glu-Cys-Gly) and gamma-Glu-Val-Gly, and showed that these peptides elicit the kokumi taste. Further analyses revealed that some known CaSR agonists such as Ca(2+), protamine, polylysine, L-histidine, and cinacalcet (a calcium-mimetic drug) also elicit the kokumi taste and that the CaSR-specific antagonist, NPS-2143, significantly suppresses the kokumi taste. This is the first report indicating a distinct function of the CaSR in human taste perception.
Asunto(s)
Receptores Sensibles al Calcio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Gusto/fisiología , Animales , Calcio/metabolismo , Calcio/farmacología , Línea Celular , Cinacalcet , Femenino , Antagonistas de Heparina/farmacología , Histidina/farmacología , Humanos , Japón , Masculino , Naftalenos/farmacología , Oligopéptidos/farmacología , Protaminas/farmacología , Receptores Sensibles al Calcio/agonistas , Receptores Sensibles al Calcio/antagonistas & inhibidores , Receptores Sensibles al Calcio/genética , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/genética , Gusto/efectos de los fármacos , Percepción del Gusto/efectos de los fármacos , Percepción del Gusto/fisiología , Xenopus laevisRESUMEN
A 3(')-terminal fragment of a splice variant of KIAA0641, a human homologue of apoptosis-associated tyrosine kinase (AATYK), was screened from human brain cDNA libraries by a yeast two-hybrid system using a Cdk5 activator p35 as a bait. The cloned cDNA encoded 477 amino acids, composed of internal 458 amino acids of KIAA0641 and 19 amino acids unique to this variant after splicing, then referred to this clone as hAATYKs-p35BP (human AATYK short isoform-p35 binding polypeptide). Using GST-fusion protein, hAATYKs-p35BP was shown to bind to Cdk5/p35 in a rat brain extract. hAATYKs made by fusing the kinase domain of KIAA0641 to the N-terminus of hAATYKs-p35BP was used for binding to Cdk5/p35 in HEK293 cells. Both hAATYKs and KIAA0641 bound to and were phosphorylated by Cdk5/p35. These results suggest that both isoforms of hAATYK are novel Cdk5/p35-binding and substrate proteins.