RESUMEN
In the present study, we developed a high-throughput screening system for small molecule-inhibitors of the basic helix-loop-helix (bHLH) transcriptional repressor factor Hes1. Successful dimerization of Hes1 immobilized on a microplate and fluorophore (Cy3)-labelled Hes1 was confirmed. Using this system, several natural products were identified as the first Hes1 dimer inhibitors. Of these, two compounds which were isolated from myxomycetes (true slime molds) inhibited Hes1 from N box-dependent suppression of the gene expression in C3H10T1/2 cells.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/antagonistas & inhibidores , Productos Biológicos/química , Ácidos Dicarboxílicos/química , Proteínas de Homeodominio/antagonistas & inhibidores , Naftoquinonas/química , Pirroles/química , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Línea Celular , Ácidos Dicarboxílicos/aislamiento & purificación , Ácidos Dicarboxílicos/farmacología , Dimerización , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Proteínas Inmovilizadas/antagonistas & inhibidores , Proteínas Inmovilizadas/metabolismo , Ratones , Mixomicetos/química , Naftoquinonas/aislamiento & purificación , Naftoquinonas/farmacología , Pirroles/aislamiento & purificación , Pirroles/farmacología , Proteínas Recombinantes/antagonistas & inhibidores , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Factor de Transcripción HES-1RESUMEN
We previously reported attenuation of autoimmune disease by low-dose gamma-ray irradiation in MRL-lpr/lpr mice. Here, we studied the effect of low-dose gamma-ray irradiation on collagen-induced arthritis (CIA) in DBA/1J mice. Mice were immunized with type II collagen, and exposed to low-dose gamma-rays (0.5 Gy per week for 5 weeks). Paw swelling, redness, and bone degradation were suppressed by irradiation, which also delayed the onset of pathological change and reduced the severity of the arthritis. Production of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6, which play important roles in the onset of CIA, was suppressed by the irradiation. The level of anti-type II collagen antibody, which is essential for the onset of CIA, was also lower in irradiated CIA mice. The population of plasma cells was increased in CIA mice, but irradiation blocked this increase. Since regulatory T cells are known to be involved in suppression of autoimmune disease, the population of CD4(+)CD25(+)Foxp3(+) regulatory T cells was measured. Intriguingly, a significant increase of these regulatory T cells was found in irradiated CIA mice. Overall, our data suggest that low-dose gamma-ray irradiation could attenuate CIA through suppression of pro-inflammatory cytokines and autoantibody production, and induction of regulatory T cells.