RESUMO
As a result of a high-throughput compound screening campaign using Mycobacterium tuberculosis-infected macrophages, a new drug candidate for the treatment of tuberculosis has been identified. GSK2556286 inhibits growth within human macrophages (50% inhibitory concentration [IC50] = 0.07 µM), is active against extracellular bacteria in cholesterol-containing culture medium, and exhibits no cross-resistance with known antitubercular drugs. In addition, it has shown efficacy in different mouse models of tuberculosis (TB) and has an adequate safety profile in two preclinical species. These features indicate a compound with a novel mode of action, although still not fully defined, that is effective against both multidrug-resistant (MDR) or extensively drug-resistant (XDR) and drug-sensitive (DS) M. tuberculosis with the potential to shorten the duration of treatment in novel combination drug regimens. (This study has been registered at ClinicalTrials.gov under identifier NCT04472897).
Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Animais , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Macrófagos , Camundongos , Testes de Sensibilidade Microbiana , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológicoRESUMO
Previous work established a coumarin scaffold as a starting point for inhibition of Mycobacterium tuberculosis (Mtb) FadD32 enzymatic activity. After further profiling of the coumarin inhibitor 4 revealed chemical instability, we discovered that a quinoline ring circumvented this instability and had the advantage of offering additional substitution vectors to further optimize. Ensuing SAR studies gave rise to quinoline-2-carboxamides with potent anti-tubercular activity. Further optimization of ADME/PK properties culminated in 21b that exhibited compelling in vivo efficacy in a mouse model of Mtb infection.
Assuntos
Antituberculosos/química , Proteínas de Bactérias/antagonistas & inibidores , Cumarínicos/química , Animais , Antituberculosos/metabolismo , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Proteínas de Bactérias/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Camundongos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/metabolismo , Quinolinas/química , Relação Estrutura-Atividade , Tuberculose/tratamento farmacológico , Tuberculose/microbiologiaRESUMO
The identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Descoberta de Drogas/métodos , Biblioteca Gênica , Mycobacterium tuberculosis/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas , Staphylococcus aureus/efeitos dos fármacos , Acinetobacter baumannii/metabolismo , Avaliação Pré-Clínica de Medicamentos , Terapia de Alvo Molecular , Mycobacterium tuberculosis/metabolismo , Staphylococcus aureus/metabolismoRESUMO
The translational value of zebrafish high-throughput screens can be improved when more knowledge is available on uptake characteristics of potential drugs. We investigated reference antibiotics and 15 preclinical compounds in a translational zebrafish-rodent screening system for tuberculosis. As a major advance, we have developed a new tool for testing drug uptake in the zebrafish model. This is important, because despite the many applications of assessing drug efficacy in zebrafish research, the current methods for measuring uptake using mass spectrometry do not take into account the possible adherence of drugs to the larval surface. Our approach combines nanoliter sampling from the yolk using a microneedle, followed by mass spectrometric analysis. To date, no single physicochemical property has been identified to accurately predict compound uptake; our method offers a great possibility to monitor how any novel compound behaves within the system. We have correlated the uptake data with high-throughput drug-screening data from Mycobacterium marinum-infected zebrafish larvae. As a result, we present an improved zebrafish larva drug-screening platform which offers new insights into drug efficacy and identifies potential false negatives and drugs that are effective in zebrafish and rodents. We demonstrate that this improved zebrafish drug-screening platform can complement conventional models of in vivo Mycobacterium tuberculosis-infected rodent assays. The detailed comparison of two vertebrate systems, fish and rodent, may give more predictive value for efficacy of drugs in humans.