Respiratory Flexibility in Response to Inhibition of Cytochrome
            <i>c</i>
            Oxidase in Mycobacterium tuberculosis

Arora, Kriti; Ochoa‐Montaño, Bernardo; Tsang, Patricia; Blundell, Tom L.; Dawes, Stephanie S.; Mizrahi, Valerie; Bayliss, Tracy; Mackenzie, Claire J.; Cleghorn, Laura A. T.; Ray, Peter C.; Wyatt, Paul G.; Uh, Eugene; Lee, Jun Young; Barry, Clifton E.; Boshoff, Helena I.

doi:10.1128/aac.03486-14

Cited by 115 publications

(178 citation statements)

References 19 publications

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“…7B). These computational results are consistent with recent experimental results obtained using small molecules to poison cytochrome bc1 activity, resulting in upregulation of cytochrome bd (101). Similarly, knockout of eno requires a bypass reaction for generation of 3-phosphoglycer- (Fig.…”

Section: Resultssupporting

confidence: 91%

Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions

et al. 2016

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cGranulomas are a hallmark of tuberculosis. Inside granulomas, the pathogen Mycobacterium tuberculosis may enter a metabolically inactive state that is less susceptible to antibiotics. Understanding M. tuberculosis metabolism within granulomas could contribute to reducing the lengthy treatment required for tuberculosis and provide additional targets for new drugs. Two key adaptations of M. tuberculosis are a nonreplicating phenotype and accumulation of lipid inclusions in response to hypoxic conditions. To explore how these adaptations influence granuloma-scale outcomes in vivo, we present a multiscale in silico model of granuloma formation in tuberculosis. The model comprises host immunity, M. tuberculosis metabolism, M. tuberculosis growth adaptation to hypoxia, and nutrient diffusion. We calibrated our model to in vivo data from nonhuman primates and rabbits and apply the model to predict M. tuberculosis population dynamics and heterogeneity within granulomas. We found that bacterial populations are highly dynamic throughout infection in response to changing oxygen levels and host immunity pressures. Our results indicate that a nonreplicating phenotype, but not lipid inclusion formation, is important for long-term M. tuberculosis survival in granulomas. We used virtual M. tuberculosis knockouts to predict the impact of both metabolic enzyme inhibitors and metabolic pathways exploited to overcome inhibition. Results indicate that knockouts whose growth rates are below ϳ66% of the wild-type growth rate in a culture medium featuring lipid as the only carbon source are unable to sustain infections in granulomas. By mapping metabolite-and gene-scale perturbations to granuloma-scale outcomes and predicting mechanisms of sterilization, our method provides a powerful tool for hypothesis testing and guiding experimental searches for novel antituberculosis interventions.T uberculosis (TB), caused by inhalation of the pathogen Mycobacterium tuberculosis, is a leading cause of death worldwide (1, 2). The main sites of infection during TB are lung granulomas, dense collections of immune cells and bacteria that develop following infection (3). Understanding M. tuberculosis dynamics within granulomas could aid in development of new antibiotic therapies, since M. tuberculosis growth rates, heterogeneity, and dynamics can affect antibiotic efficacy (3-7).Two in vitro-observed adaptations of M. tuberculosis, suspected to be important in the ability of M. tuberculosis to persist in the host lung, are (i) the adoption of a nonreplicating phenotype and (ii) the accumulation of lipid inclusions, aggregates of neutral lipids inside bacteria (8-13). Hypoxia is known to be a trigger for the transition to a nonreplicating phenotype and the formation of lipid inclusions (9,12,14,15).The in vivo role of the nonreplicating phenotype remains controversial. It has been suggested that M. tuberculosis acquires the nonreplicating phenotype in response to stresses present in the host (such as hypoxia) and that this phenotype allows M. tubercul...

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Section: Resultssupporting

confidence: 91%

Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions

et al. 2016

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“…The first of these limitations can be ameliorated through the use of different screening conditions (6)(7)(8), whereas counterscreening strategies can eliminate known (and promiscuous) targets (9,10). In contrast, establishing the MOA usually depends on the ability to raise-and then genotype-mutant bacteria with heritable resistance to the applied agent (11).…”

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confidence: 99%

Bioluminescent Reporters for Rapid Mechanism of Action Assessment in Tuberculosis Drug Discovery

Naran

Moosa

Barry

et al. 2016

Antimicrob Agents Chemother

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cThe tuberculosis (TB) drug discovery pipeline is fueled by compounds identified in whole-cell screens against the causative agent, Mycobacterium tuberculosis. Phenotypic screening enables the selection of molecules that inhibit essential cellular functions in live, intact bacilli grown under a chosen in vitro condition. However, deducing the mechanism of action (MOA), which is important to avoid promiscuous targets, often requires significant biological resources in a lengthy process that risks decoupling medicinal chemistry and biology efforts. Therefore, there is a need to develop methods enabling rapid MOA assessment of putative "actives" for triage decisions. Here, we describe a modified version of a bioluminescence reporter assay that allows nondestructive detection of compounds targeting either of two macromolecular processes in M. tuberculosis: cell wall biosynthesis or maintenance of DNA integrity. Coupling the luxCDABE operon from Photorhabdus luminescens to mycobacterial promoters driving expression of the iniBAC operon (PiniB-LUX) or the DNA damage-inducible genes, recA (PrecA-LUX) or radA (PradA-LUX), provided quantitative detection in real time of compounds triggering expression of any of these promoters over an extended 10-to 12-day incubation. Testing against known anti-TB agents confirmed the specificity of each reporter in registering the MOA of the applied antibiotic in M. tuberculosis, independent of bactericidal or bacteriostatic activity. Moreover, profiles obtained for experimental compounds indicated the potential to infer complex MOAs in which multiple cellular processes are disrupted. These results demonstrate the utility of the reporters for early triage of compounds based on the provisional MOA and suggest their application to investigate polypharmacology in known and experimental anti-TB agents.

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“…78 No entanto, já foi relatado que durante o crescimento aeróbio do MTB, a participação do citocromo bd oxidase pode compensar os efeitos inibitórios do complexo citocromo bc1. 79 A validação do QcrB como alvo foi descrita detalhadamente para o composto Q203 (25) (Figura 9). Este composto exibiu CIM 90 de 2,7 nmol L -1 contra MTB H 37 Rv.…”

Section: Alvos Envolvidos Com a Geração De Energiaunclassified

“…Além disso, os autores observaram uma redução drástica nos níveis de ATP produzidos pela micobacteria quando em contato com o lansoprazol (27). 81 Derivados ftalimídicos também foram reportados como inibidores do complexo bc1 com a valores de CIM 90 80,81,83,84 A NADH desidrogenase tipo-II (NDH-2) é uma enzima presente na mitocôndria do MTB e que participa do processo respiratório da micobactéria. 85 Curiosamente, a atividade antituberculose in vitro de derivados fenotiazínicos (como por exemplo alguns fármacos antipsicóticos) e clofazimina (anti-hansênico) tem sido relacionadas com a inibição da enzima micobacteriana NDH-2; no entanto, o uso desses fármacos na terapia é limitado devido a efeitos adversos.…”

Section: Alvos Envolvidos Com a Geração De Energiaunclassified

Potenciais alvos moleculares para o desenvolvimento de novos fármacos antituberculose

2017

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POTENTIAL MOLECULAR TARGETS FOR ANTITUBERCULOSIS DRUG DISCOVERY. Tuberculosis (TB) is an infectious disease caused by mycobacteria from the Mycobacterium genus, mainly by Mycobacterium tuberculosis (MTB). The World HealthOrganization (WHO) aims to reduce the number of TB cases worldwide in the coming years. Nevertheless, the increasing number of multidrug-resistant (MDR-TB) and extensive-drug resistance (XDR-TB) strains, and the ineffectiveness of the current treatment in latent tuberculosis are challenges to be overcome. In this review, we will demonstrate the recent advances in the tuberculosis drug discovery, focusing the research of new molecular targets in the Mycobacterium tuberculosis. Among the promising targets described herein, we highlight those, which act in different pathways in the mycobacteria, such as energy metabolism, cell wall biosynthesis, DNA synthesis, iron metabolism and transport through membranes. Furthermore, bioactive compounds discovered using phenotypic assays screening and validated through genetic approaches are also presented.Keywords: medicinal chemistry; tuberculosis; Mycobacterium tuberculosis; molecular targets; new drugs. INTRODUÇÃOA tuberculose (TB) é uma doença infecciosa causada por micobactérias do complexo Mycobacterium, no entanto, a espécie responsável pelo maior número de casos de morbidade e mortalidade é o Mycobacterium tuberculosis (MTB). 1 Ocupando o ranking mundial como a principal causa de mortes causadas por doenças infecciosas, nos últimos anos a tuberculose ultrapassou, em número de casos, a infecção causada pelo vírus da imunodeficiência humana (HIV). 2,3 O último levantamento realizado em 2015 pela Organização Mundial da Saúde (OMS) apontou 9.6 milhões de novos casos no mundo e 1.5 milhões de mortes causadas pela doença. 3 Somado a esses dados, o surgimento e aumento de cepas de M. tuberculosis multirresistente aos fármacos (MDR-TB) e extensivamente resistente aos fármacos (XDR-TB) vêm alarmando as autoridades de todo o mundo. Essas formas de tuberculose apresentam baixas taxas de cura e maiores taxas de mortalidade devido às dificuldades de tratamento. 4 Além disso, já foram relatados na clínica casos de tuberculose totalmente resistente aos fármacos (TDR-TB). 5,6 Ao longo dos últimos anos, é possível constatar algumas evoluções no desenvolvimento de compostos candidatos a fármacos que possam atuar contra a TB. 7 Após um intervalo de mais de 50 anos sem novos medicamentos para o tratamento da TB, a bedaquilina foi aprovada em 2012 pela agência norte-americana U.S. Food and Drug Administration (FDA) para o tratamento de MDR-TB. Atualmente, diversos candidatos a fármacos estão em estudos clínicos, [8][9][10][11][12] 39 Atualmente, diversos métodos e estratégias são utilizados para o desenvolvimento de novos fármacos contra a TB, como por exemplo: 1) abordagens genéticas para identificação de novos alvos; 2) ensaios de triagem em larga escala utilizando a micobactéria como plataforma; 3) ferramentas de biologia estrutural e triagem virtual e; 4) modificações ...

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Respiratory Flexibility in Response to Inhibition of Cytochrome c Oxidase in Mycobacterium tuberculosis

Cited by 115 publications

References 19 publications

Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions

Multiscale Model of Mycobacterium tuberculosis Infection Maps Metabolite and Gene Perturbations to Granuloma Sterilization Predictions

Bioluminescent Reporters for Rapid Mechanism of Action Assessment in Tuberculosis Drug Discovery

Potenciais alvos moleculares para o desenvolvimento de novos fármacos antituberculose

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