RESUMO
INTRODUCTION: Treatment options against Mycobacterium abscessus infections are very limited. New compounds are needed to cure M. abscessus pulmonary diseases. While the mycolic acid biosynthetic pathway has been largely exploited for the treatment of tuberculosis, this metabolic process has been overlooked in M. abscessus, although it offers many potential drug targets for the treatment of this opportunistic pathogen. AREAS COVERED: Herein, the authors review the role of the MmpL3 membrane protein and the enoyl-ACP reductase InhA involved in the transport and synthesis of mycolic acids, respectively. They discuss their importance as two major vulnerable drug targets in M. abscessus and report the activity of MmpL3 and InhA inhibitors. In particular, they focus on NITD-916, a direct InhA inhibitor against M. abscessus, particularly warranted in the context of multidrug resistance. EXPERT OPINION: There is an increasing body of evidence validating the mycolic acid pathway as an attractive drug target to be further exploited for M. abscessus lung disease treatments. The NITD-916 studies provide a proof-of-concept that direct inhibitors of InhA are efficient in vitro, in macrophages and in zebrafish. Future work is now required to improve the activity and pharmacological properties of these inhibitors and their evaluation in pre-clinical models.
Assuntos
Pneumopatias , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Mycobacterium tuberculosis , Animais , Humanos , Mycobacterium abscessus/metabolismo , Ácidos Micólicos/metabolismo , Ácidos Micólicos/uso terapêutico , Peixe-Zebra/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Pneumopatias/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: The recent lockdown due to the COVID-19 pandemic has been linked to a higher incidence of psychiatric manifestations and substance abuse. The recreative use of nitrous oxide is more and more widespread and neurological complications are frequent. METHODS: We report clinical characteristics and biological findings of five consecutive patients presenting to our tertiary care center between April 2020 and February 2021 with various neurological symptoms occurring after recent nitrous oxide abuse. RESULTS: Our patients presented with subacute combined degeneration of the spinal cord (4/5 patients) or with acute inflammatory demyelinating polyneuropathy (1/5 patients). No patient had reduced vitamin B-12 titer, but all had elevated blood levels of homocysteine and methylmalonic acid. This reflects the functional deficit in vitamin B-12 that can be linked to nitrous oxide consumption. After vitamin B-12 supplementation, clinical signs regressed at least partially in all 5 patients. CONCLUSION: We report an elevated incidence of neurological complications of nitrous oxide abuse occurring during the recent COVID-19 lockdown. Nitrous oxide abuse should be tracked down in patients presenting with compatible neurological symptoms and elevated homocysteinemia. Vitamin B-12 should be supplemented as soon as the diagnosis is made.
Assuntos
COVID-19 , Deficiência de Vitamina B 12 , Controle de Doenças Transmissíveis , Humanos , Óxido Nitroso/efeitos adversos , Pandemias , SARS-CoV-2 , Vitamina B 12 , Deficiência de Vitamina B 12/induzido quimicamente , Deficiência de Vitamina B 12/epidemiologiaAssuntos
Desenvolvimento de Medicamentos/tendências , Terapia de Alvo Molecular/tendências , Infecções por Mycobacterium não Tuberculosas/terapia , Terapias em Estudo/tendências , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/uso terapêutico , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/imunologia , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Desenvolvimento de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos , Humanos , Proteínas de Membrana Transportadoras/efeitos dos fármacos , Proteínas de Membrana Transportadoras/imunologia , Terapia de Alvo Molecular/métodos , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Mycobacterium abscessus/fisiologia , Terapias em Estudo/métodosRESUMO
In this study, we screen three heterocyclic structures as potential inhibitors of UDP-galactopyranose mutase (UGM), an enzyme involved in the biosynthesis of the cell wall of Mycobacterium tuberculosis. In order to understand the binding mode, docking simulations are performed on the best inhibitors. Their activity on Mycobacterium tuberculosis is also evaluated. This study made it possible to highlight an "oxazepino-indole" structure as a new inhibitor of UGM and of M. tuberculosis growth in vitro.
Assuntos
4-Butirolactona/análogos & derivados , Antituberculosos/síntese química , Inibidores Enzimáticos/síntese química , Indóis/síntese química , Transferases Intramoleculares/antagonistas & inibidores , Tuberculose/tratamento farmacológico , 4-Butirolactona/síntese química , 4-Butirolactona/farmacologia , Antituberculosos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Humanos , Indóis/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , Ligação ProteicaRESUMO
Mycobacterium tuberculosis (M.tb), the etiologic agent of tuberculosis, remains the leading cause of death from a single infectious agent worldwide. The emergence of drug-resistant M.tb strains stresses the need for drugs acting on new targets. Mycolic acids are very long chain fatty acids playing an essential role in the architecture and permeability of the mycobacterial cell wall. Their biosynthesis involves two fatty acid synthase (FAS) systems. Among the four enzymes (MabA, HadAB/BC, InhA and KasA/B) of the FAS-II cycle, MabA (FabG1) remains the only one for which specific inhibitors have not been reported yet. The development of a new LC-MS/MS based enzymatic assay allowed the screening of a 1280 fragment-library and led to the discovery of the first small molecules that inhibit MabA activity. A fragment from the anthranilic acid series was optimized into more potent inhibitors and their binding to MabA was confirmed by 19F ligand-observed NMR experiments.
Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Ácido Graxo Sintases/antagonistas & inibidores , Mycobacterium tuberculosis/enzimologia , ortoaminobenzoatos/farmacologia , Proteínas de Bactérias/metabolismo , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Ácido Graxo Sintases/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade , ortoaminobenzoatos/químicaRESUMO
The progression of mycobacterial diseases requires the development of new therapeutics. This study evaluated the efficacy and selectivity of a panel of Cyclophostin and Cyclipostins analogues (CyCs) against various bacteria and mycobacteria. The activity 26 CyCs was first assayed by the agar plate method. Compounds exhibiting 50-100% growth inhibition were then selected to determine their minimum inhibitory concentrations (MICs) by the resazurin microtiter assay (REMA). The best drug candidate was further tested against clinical mycobacterial isolates and bacteria responsible for nosocomial infections, including 6 Gram-negative bacteria, 5 Gram-positive bacteria, 29 rapid-growing mycobacteria belonging to the Mycobacterium chelonae-abscessus clade and 3 slow-growing mycobacteria (Mycobacterium marinum, Mycobacterium bovis BCG and Mycobacterium tuberculosis). Among the 26 CyCs tested, 10 were active and their inhibitory activity was exclusively restricted to mycobacteria. The best candidate (CyC17) was further tested against 26 clinical strains and showed high selectivity for mycobacteria, with MICs (<2-40 µg/mL) comparable with those of most classical antimicrobials used to treat M. abscessus infections. Together, these results support the fact that such CyCs represent a new family of potent and selective inhibitors against mycobacteria. This is of particular interest for future chemotherapeutic developments against mycobacterial-associated infections, especially against M. abscessus, the most drug-resistant mycobacterial species.
Assuntos
Antibacterianos/uso terapêutico , Infecções por Mycobacterium/tratamento farmacológico , Mycobacterium abscessus/efeitos dos fármacos , Mycobacterium bovis/efeitos dos fármacos , Mycobacterium marinum/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Compostos Organofosforados/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium/microbiologia , Mycobacterium abscessus/isolamento & purificação , Mycobacterium bovis/isolamento & purificação , Mycobacterium marinum/isolamento & purificação , Mycobacterium tuberculosis/isolamento & purificaçãoRESUMO
Mycobacterium abscessus is a fast-growing, multidrug-resistant organism that has emerged as a clinically significant pathogen in cystic fibrosis (CF) patients. The intrinsic resistance of M. abscessus to most commonly available antibiotics seriously restricts chemotherapeutic options. Herein, we report the potent activity of a series of indolecarboxamides against M. abscessus. The lead compounds, 6 and 12, exhibited strong activity in vitro against a wide panel of M. abscessus isolates and in infected macrophages. High resistance levels to the indolecarboxamides appear to be associated with an A309P mutation in the mycolic acid transporter MmpL3. Biochemical analyses demonstrated that while de novo mycolic acid synthesis remained unaffected, the indolecarboxamides strongly inhibited the transport of trehalose monomycolate, resulting in the loss of trehalose dimycolate production and abrogating mycolylation of arabinogalactan. Our data introduce a hereto unexploited chemical structure class active against M. abscessus infections with promising translational development possibilities for the treatment of CF patients.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Indóis/química , Indóis/farmacologia , Mycobacterium/efeitos dos fármacos , Ácidos Micólicos/metabolismo , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Fatores Corda/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium/metabolismo , Infecções por Mycobacterium/tratamento farmacológico , Infecções por Mycobacterium/microbiologiaRESUMO
This study reports a novel class of inhibitors of uridine 5'-diphosphate (UDP) galactopyranose mutase (UGM) derived from a screening of natural products. This enzyme is an essential biocatalyst involved in the cell wall biosynthesis of Mycobacterium tuberculosis. Flavonoids are potent inhibitors of UGM. The synthesis of novel methylated flavonoids allowed a structure-activity relationship analysis to be performed and which functional groups and structural elements were required for UGM inhibition could be determined. The binding mode of one of the best inhibitors was found to be noncompetitive. Docking simulations indicated that this molecule was likely to bind UGM in its open conformation, in a cavity recently identified as a "druggable" pocket. Importantly, two of the best inhibitors of the M. tuberculosis UGM displayed moderate activity against whole M. tuberculosis cells. This study reports the first natural products that act as inhibitor of UGM. Given the importance of natural products in medicinal chemistry, these results create new opportunities for the discovery of new antitubercular agents.
Assuntos
Antituberculosos/química , Flavonoides/química , Transferases Intramoleculares/antagonistas & inibidores , Mycobacterium tuberculosis/metabolismo , Antituberculosos/síntese química , Antituberculosos/farmacologia , Sítios de Ligação , Linhagem Celular , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/síntese química , Flavonoides/farmacologia , Humanos , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular/métodos , Estrutura Molecular , Extratos Vegetais/química , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
Mycobacterium abscessus is responsible for a wide spectrum of clinical syndromes and is one of the most intrinsically drug-resistant mycobacterial species. Recent evaluation of the in vivo therapeutic efficacy of the few potentially active antibiotics against M. abscessus was essentially performed using immunocompromised mice. Herein, we assessed the feasibility and sensitivity of fluorescence imaging for monitoring the in vivo activity of drugs against acute M. abscessus infection using zebrafish embryos. A protocol was developed where clarithromycin and imipenem were directly added to water containing fluorescent M. abscessus-infected embryos in a 96-well plate format. The status of the infection with increasing drug concentrations was visualized on a spatiotemporal level. Drug efficacy was assessed quantitatively by measuring the index of protection, the bacterial burden (CFU), and the number of abscesses through fluorescence measurements. Both drugs were active in infected embryos and were capable of significantly increasing embryo survival in a dose-dependent manner. Protection from bacterial killing correlated with restricted mycobacterial growth in the drug-treated larvae and with reduced pathophysiological symptoms, such as the number of abscesses within the brain. In conclusion, we present here a new and efficient method for testing and compare the in vivo activity of two clinically relevant drugs based on a fluorescent reporter strain in zebrafish embryos. This approach could be used for rapid determination of the in vivo drug susceptibility profile of clinical isolates and to assess the preclinical efficacy of new compounds against M. abscessus.
Assuntos
Claritromicina/uso terapêutico , Imipenem/uso terapêutico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Micobactérias não Tuberculosas/efeitos dos fármacos , Imagem Óptica/métodos , Animais , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/microbiologia , Farmacorresistência Bacteriana Múltipla , Quimioterapia Combinada , Larva/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/microbiologia , Peixe-Zebra/microbiologiaRESUMO
A library of quinoline-ß-lactam-based hybrids was synthesized and tested for their antimalarial and antitubercular activities. The present antimalarial data showed the dependence of activity on the nature of linker, N-1 substituent of the ß-lactam ring as well as the length of alkyl chain. Most of the compounds are not as efficient as chloroquine in inhibiting the culture growth of Plasmodium falciparum W2 strain. Nevertheless, the synthesized hybrids showed better antitubercular activities (up to five times) compared with cephalexin (up to three times) and ethionamide.