RESUMO
MicroRNA (miRNA) homeostasis is crucial for the posttranscriptional regulation of their target genes during development and in disease states. miRNAs are derived from primary transcripts and are processed from a hairpin precursor intermediary to a mature 22-nucleotide duplex RNA. Loading of the duplex into the Argonaute (AGO) protein family is pivotal to miRNA abundance and its posttranscriptional function. The Integrator complex plays a key role in protein coding and noncoding RNA maturation, RNA polymerase II pause-release, and premature transcriptional termination. Here, we report that loss of Integrator results in global destabilization of mature miRNAs. Enhanced ultraviolet cross-linking and immunoprecipitation of Integrator uncovered an association with duplex miRNAs before their loading onto AGOs. Tracing miRNA fate from biogenesis to stabilization by incorporating 4-thiouridine in nascent transcripts pinpointed a critical role for Integrator in miRNA assembly into AGOs.
Assuntos
MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Regulação da Expressão Gênica , Núcleo Celular/metabolismoRESUMO
Elaboration of our previously disclosed spiropiperidine template led to the development of a series of novel CCR5 antagonists. Results of SAR exploration and preliminary lead characterization are described.
Assuntos
Antagonistas dos Receptores CCR5 , Imidazolidinas/síntese química , Imidazolidinas/farmacologia , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Humanos , Imidazolidinas/química , Imidazolidinas/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
Replacement of the cyclic carbamate in our previously disclosed 1-oxa-3,9-diazaspiro[5.5]undecan-2-one template led to the discovery of two novel series of 3,9-diazaspiro[5.5]undecane and undeca-2-one CCR5 antagonists. The synthesis, SAR, and antiviral activities of these two series are described. One compound (32) was found to have attractive combination of antiviral potency, selectivity, and pharmacokinetic profile. The asymmetric synthesis of 32 was also accomplished and both enantiomers were equally potent.
Assuntos
Alcanos/síntese química , Antivirais/síntese química , Antagonistas dos Receptores CCR5 , Compostos de Espiro/síntese química , Administração Oral , Alcanos/farmacologia , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Disponibilidade Biológica , Descoberta de Drogas , Compostos de Espiro/farmacologia , Relação Estrutura-AtividadeRESUMO
A novel series of CCR5 antagonists has been identified, utilizing leads from high-throughput screening which were further modified based on insights from competitor molecules. Lead optimization was pursued by balancing opposing trends of metabolic stability and potency. Selective and potent analogs with good pharmacokinetic properties were successfully developed.
Assuntos
Antagonistas dos Receptores CCR5 , Piperidinas/química , Piperidinas/farmacologia , Receptores CCR5/metabolismo , Animais , Células CACO-2 , Cães , Haplorrinos , Humanos , Piperidinas/farmacocinética , Ratos , Compostos de Espiro/química , Compostos de Espiro/farmacocinética , Compostos de Espiro/farmacologia , Relação Estrutura-AtividadeRESUMO
Organic impurities in compound libraries are known to often cause false-positive signals in screening campaigns for new leads, but organic impurities do not fully account for all false-positive results. We discovered inorganic impurities in our screening library that can also cause positive signals for a variety of targets and/or readout systems, including biochemical and biosensor assays. We investigated in depth the example of zinc for a specific project and in retrospect in various HTS screens at Roche and propose a straightforward counter screen using the chelator TPEN to rule out inhibition caused by zinc.
RESUMO
Lysophosphatidic acid is a class of bioactive phospholipid that mediates most of its biological effects through LPA receptors, of which six isoforms have been identified. The recent results from LPA1 knockout mice suggested that blocking LPA1 signaling could provide a potential novel approach for the treatment of idiopathic pulmonary fibrosis. Here, we report the design and synthesis of pyrazole- and triazole-derived carbamates as LPA1-selective and LPA1/3 dual antagonists. In particular, compound 2, the most selective LPA1 antagonist reported, inhibited proliferation and contraction of normal human lung fibroblasts (NHLF) following LPA stimulation. Oral dosing of compound 2 to mice resulted in a dose-dependent reduction of plasma histamine levels in a murine LPA challenge model. Furthermore, we applied our novel antagonists as chemistry probes and investigated the contribution of LPA1/2/3 in mediating the pro-fibrotic responses. Our results suggest LPA1 as the major receptor subtype mediating LPA-induced proliferation and contraction of NHLF.