RESUMO
We have recently reported the discovery of a novel class of glucocorticoid receptor (GR) antagonists, exemplified by 3, containing a 1,2-dihydroquinoline molecular scaffold. Further SAR studies of these antagonists uncovered chemical modifications conveying agonist functional activity to this series. These agonists exhibit good GR binding affinity and are selective against other nuclear hormone receptors.
Assuntos
Quinolinas/química , Quinolinas/farmacologia , Receptores de Glucocorticoides/agonistas , Quinolinas/metabolismo , Receptores de Glucocorticoides/metabolismo , Relação Estrutura-AtividadeRESUMO
We report the discovery of a novel class of glucocorticoid receptor (GR) ligands based on 1,2-dihydroquinoline molecular scaffold. The compounds exhibit good GR binding affinity and selectivity profile against other nuclear hormone receptors.
Assuntos
Quinolinas/síntese química , Quinolinas/farmacologia , Receptores de Glucocorticoides/antagonistas & inibidores , Receptores de Glucocorticoides/metabolismo , Anti-Inflamatórios/farmacologia , Dexametasona/farmacologia , Células HeLa , Humanos , Interleucina-1/farmacologia , Interleucina-6/metabolismo , Ligantes , Vírus do Tumor Mamário do Camundongo/genética , Modelos Moleculares , Estrutura Molecular , Regiões Promotoras Genéticas/efeitos dos fármacos , Quinolinas/química , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Receptores de Mineralocorticoides/efeitos dos fármacos , Receptores de Mineralocorticoides/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Relação Estrutura-Atividade , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genéticaRESUMO
Major histocompatibility complex (MHC) class II genes are regulated at the transcriptional level by coordinate action of a limited number of transcription factors that include regulatory factor X (RFX), class II transcriptional activator (CIITA), nuclear factor Y (NF-Y), and cyclic AMP-response element binding protein (CREB). Here, the MHC class-II-specific transcription factors and CREB were expressed in insect cells with recombinant baculoviruses, isolated, and characterized by biochemical and biophysical methods. Analytical ultracentrifugation (AUC) has demonstrated that RFX is a heterotrimer. A heterodimer of RFX5 and RFX-AP was also observed. A high-affinity interaction (K(d) = 25 nM) between RFX5 and RFX-AP was measured by isothermal titration calorimetry (ITC), while the interaction between RFX-AP and RFX-ANK is at least an order of magnitude weaker. The biophysical data show that the interaction between RFX-AP and RFX5 is a key event in the assembly of the heterotrimer. Fluorescence anisotropy was used to determine protein-nucleic acid binding affinities for the RFX subunits and complexes binding to duplex DNA. The RFX5 subunit was found to drive recognition of the promoter, while the auxiliary RFX-AP and RFX-ANK subunits were shown to contribute to the specificity of binding for the overall complex. AUC experiments demonstrate that in the absence of additional subunits, monomeric RFX5 binds to X-box DNA with a 1:1 stoichiometry. Interactions between CREB, CIITA, and RFX in the absence of DNA were demonstrated using bead-based immunoprecipitation assays, confirming that preassociation with DNA is not required for forming the macromolecular assemblies that drive MHC class II gene expression.
