Publications by authors named "Véronique Dartois"

142 Publications

Comparative Analysis of Pharmacodynamics in the C3HeB/FeJ Mouse Tuberculosis Model for DprE1 inhibitors TBA-7371, PBTZ169 and OPC-167832.

Antimicrob Agents Chemother 2021 Aug 9:AAC0058321. Epub 2021 Aug 9.

Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America.

Multiple drug discovery initiatives for tuberculosis are currently ongoing to identify and develop new potent drugs with novel targets in order to shorten treatment duration. One of the drug classes with a new mode of action are DprE1 inhibitors targeting an essential process in cell wall synthesis of . In this investigation, three DprE1 inhibitors currently in clinical trials, TBA-7371, PBTZ169 and OPC-167832, were evaluated side-by-side as single agents in the C3HeB/FeJ mouse model presenting with caseous necrotic pulmonary lesions upon tuberculosis infection. The goal was to confirm the efficacy of the DprE1 inhibitors in a mouse tuberculosis model with advanced pulmonary pathology, and perform comprehensive analysis of plasma, lung and lesion-centric drug levels to establish pharmacokinetic-pharmacodynamic (PK-PD) parameters predicting efficacy at the site of infection. Results showed significant efficacy for all three DprE1 inhibitors in the C3HeB/FeJ mouse model after two months of treatment. Superior efficacy was observed for OPC-167832 even at low dose levels, which can be attributed to its low MIC, favorable distribution and sustained retention above the MIC throughout the dosing interval in caseous necrotic lesions where the majority of bacteria reside in C3HeB/FeJ mice. These results support further progression of the three drug candidates through clinical development for tuberculosis treatment.
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http://dx.doi.org/10.1128/AAC.00583-21DOI Listing
August 2021

Bayesian Modeling and Intrabacterial Drug Metabolism Applied to Drug-Resistant .

ACS Infect Dis 2021 08 3;7(8):2508-2521. Epub 2021 Aug 3.

Department of Pharmacology, Physiology, and Neuroscience, Rutgers University - New Jersey Medical School, 185 South Orange Ave, Newark, New Jersey 07103, United States.

We present the application of Bayesian modeling to identify chemical tools and/or drug discovery entities pertinent to drug-resistant infections. The quinoline JSF-3151 was predicted by modeling and then empirically demonstrated to be active against cultured clinical methicillin- and vancomycin-resistant strains while also exhibiting efficacy in a mouse peritonitis model of methicillin-resistant infection. We highlight the utility of an intrabacterial drug metabolism (IBDM) approach to probe the mechanism by which JSF-3151 is transformed within the bacteria. We also identify and then validate two mechanisms of resistance in : one mechanism involves increased expression of a lipocalin protein, and the other arises from the loss of function of an azoreductase. The computational and experimental approaches, discovery of an antibacterial agent, and elucidated resistance mechanisms collectively hold promise to advance our understanding of therapeutic regimens for drug-resistant .
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http://dx.doi.org/10.1021/acsinfecdis.1c00265DOI Listing
August 2021

Structure, Detection, and Antibacterial Activity of Metabolites of SQ109, an Anti-Infective Drug Candidate.

ACS Infect Dis 2021 08 19;7(8):2492-2507. Epub 2021 Jul 19.

Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.

SQ109 is a drug candidate for the treatment of tuberculosis (TB). It is thought to target primarily the protein MmpL3 in , but it also inhibits the growth of some other bacteria. SQ109 is metabolized by the liver, and it has been proposed that some of its metabolites might be responsible for its activity against TB. Here, we synthesized six potential P450 metabolites of SQ109 and used these as well as 10 other likely metabolites as standards in a mass spectrometry study of -infected rabbits treated with SQ109, in addition to testing all 16 putative metabolites for antibacterial activity. We found that there were just two major metabolites in lung tissue: a hydroxy-adamantyl analog of SQ109 and '-adamantylethylenediamine. Neither of these, or the other potential metabolites tested, inhibited the growth of or of , , or , making it unlikely that an SQ109 metabolite contributes to its antibacterial activity. In the rabbit TB model, it is thus the gradual accumulation of nonmetabolized SQ109 in tissues to therapeutic levels that leads to good efficacy. Our results also provide new insights into how SQ109 binds to its target MmpL3, based on our mass spectroscopy results which indicate that the charge in SQ109 is primarily localized on the geranyl nitrogen, explaining the very short distance to a key Asp found in the X-ray structure of SQ109 bound to MmpL3.
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http://dx.doi.org/10.1021/acsinfecdis.1c00259DOI Listing
August 2021

Lesion penetration and activity limit the utility of second-line injectable agents in pulmonary tuberculosis.

Antimicrob Agents Chemother 2021 Jul 12:AAC0050621. Epub 2021 Jul 12.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA.

Amikacin and kanamycin are second line injectables used in the treatment of multidrug resistant tuberculosis (MDR-TB), based on the clinical utility of streptomycin, another aminoglycoside and first line anti-TB drug. While streptomycin was tested as a single agent in the first controlled TB clinical trial, introduction of amikacin and kanamycin into MDR-TB regimens was not preceded by randomized controlled trials. A recent large retrospective meta-analysis revealed that compared with regimens without any injectable drug, amikacin provided modest benefits, and kanamycin was associated with worse outcomes. Although their long-term use can cause irreversible ototoxicity, they remain part of MDR-TB regimens because they have a role in preventing emergence of resistance to other drugs. To quantify the contribution of amikacin and kanamycin to second-line regimens, we applied 2-dimensional MALDI mass spectrometry imaging in large lung lesions, quantified drug exposure in lung and lesions of rabbits with active TB, and measured the concentrations required to kill or inhibit growth of the resident bacterial populations. Using these metrics, we applied site-of-action pharmacokinetic and pharmacodynamic (PK-PD) concepts and simulated drug coverage in patients' lung lesions. The results provide a pharmacological explanation for the limited clinical utility of both agents and reveal better PK-PD lesion coverage for amikacin than kanamycin, consistent with retrospective data of contribution to treatment success. Together with recent mechanistic studies dissecting antibacterial activity from aminoglycoside ototoxicity, the limited but rapid penetration of streptomycin, amikacin and kanamycin to the sites of TB disease supports the development of analogs with improved efficacy and tolerability.
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http://dx.doi.org/10.1128/AAC.00506-21DOI Listing
July 2021

Drug Sensitivity Testing of Mycobacterium tuberculosis Growing in a Hollow Fiber Bioreactor.

Methods Mol Biol 2021 ;2314:715-731

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA.

Hollow fiber systems (HFSs) have been widely applied to study pharmacokinetic-pharmacodynamic (PK-PD) relationships in antibiotic research and development. The system comprises a bundle of high-density hollow capillary fibers that conduct a flow of medium with or without drug and an extra-capillary space (ECS) inoculated with the pathogen of interest. The semipermeable membrane of the hollow fibers allows for rapid exchange of small molecule drugs and solutes, while the pathogen is restricted to the ECS. The unique properties of the HFS are (1) the ability to simulate any PK profile within the fibers and ECS, including plasma or site-of-disease PK profiles, (2) the ability to simultaneously input several drugs with different half-lives, (3) the ability to manipulate growth conditions such as medium composition, carbon source, and pH, and (4) the ability to sample in both compartments in order to monitor drug concentrations and bacterial growth kinetics over time. The system is particularly suited for Mycobacterium tuberculosis research in a biosafety level 3 (BSL3) environment since pathogenic bacteria are sequestered in an isolated compartment. The HFS was qualified by the European Medicines Agency for antituberculosis drug development in 2015. Here, we describe the standard procedures used to study the growth kinetics of M. tuberculosis in the HFS and the killing effect of first-line antituberculous drugs applied under simulated human PK conditions. This animal-sparing and economical tool can be applied to optimize dosing schedules that minimize emergence of resistance and to prioritize drug regimens that accelerate sterilization.
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http://dx.doi.org/10.1007/978-1-0716-1460-0_31DOI Listing
August 2021

Blocking Bacterial Naphthohydroquinone Oxidation and ADP-Ribosylation Improves Activity of Rifamycins against Mycobacterium abscessus.

Antimicrob Agents Chemother 2021 08 17;65(9):e0097821. Epub 2021 Aug 17.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA.

Rifampicin is an effective drug for treating tuberculosis (TB) but is not used to treat Mycobacterium abscessus infections due to poor activity. While rifabutin, another rifamycin, has better anti-M. abscessus activity, its activity is far from the nanomolar potencies of rifamycins against Mycobacterium tuberculosis. Here, we asked (i) why is rifabutin more active against M. abscessus than rifampicin, and (ii) why is rifabutin's anti-M. abscessus activity poorer than its anti-TB activity? Comparative analysis of naphthoquinone- versus naphthohydroquinone-containing rifamycins suggested that the improved activity of rifabutin over rifampicin is linked to its less readily oxidizable naphthoquinone core. Although rifabutin is resistant to bacterial oxidation, metabolite and genetic analyses showed that this rifamycin is metabolized by the ADP-ribosyltransferase Arr like rifampicin, preventing it from achieving the nanomolar activity that it displays against M. tuberculosis. Based on the identified dual mechanism of intrinsic rifamycin resistance, we hypothesized that rifamycins more potent than rifabutin should contain the molecule's naphthoquinone core plus a modification that blocks ADP-ribosylation at its C-23. To test these predictions, we performed a blinded screen of a diverse collection of 189 rifamycins and identified two molecules more potent than rifabutin. As predicted, these compounds contained both a more oxidatively resistant naphthoquinone core and C-25 modifications that blocked ADP-ribosylation. Together, this work revealed dual bacterial metabolism as the mechanism of intrinsic resistance of M. abscessus to rifamycins and provides proof of concept for the repositioning of rifamycins for M. abscessus disease by developing derivatives that resist both bacterial oxidation and ADP-ribosylation.
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http://dx.doi.org/10.1128/AAC.00978-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8370238PMC
August 2021

Pharmacokinetics and Target Attainment of SQ109 in Plasma and Human-Like Tuberculosis Lesions in Rabbits.

Antimicrob Agents Chemother 2021 08 17;65(9):e0002421. Epub 2021 Aug 17.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA.

SQ109 is a novel well-tolerated drug candidate in clinical development for the treatment of drug-resistant tuberculosis (TB). It is the only inhibitor of the MmpL3 mycolic acid transporter in clinical development. No SQ109-resistant mutant has been directly isolated thus far , in mice, or in patients, which is tentatively attributed to its multiple targets. It is considered a potential replacement for poorly tolerated components of multidrug-resistant TB regimens. To prioritize SQ109-containing combinations with the best potential for cure and treatment shortening, one must understand its contribution against different bacterial populations in pulmonary lesions. Here, we have characterized the pharmacokinetics of SQ109 in the rabbit model of active TB and its penetration at the sites of disease-lung tissue, cellular and necrotic lesions, and caseum. A two-compartment model with first-order absorption and elimination described the plasma pharmacokinetics. At the human-equivalent dose, parameter estimates fell within the ranges published for preclinical species. Tissue concentrations were modeled using an "effect" compartment, showing high accumulation in lung and cellular lesion areas with penetration coefficients in excess of 1,000 and lower passive diffusion in caseum after 7 daily doses. These results, together with the hydrophobic nature and high nonspecific caseum binding of SQ109, suggest that multiweek dosing would be required to reach steady state in caseum and poorly vascularized compartments, similar to bedaquiline. Linking lesion pharmacokinetics to SQ109 potency in assays against replicating, nonreplicating, and intracellular M. tuberculosis showed SQ109 concentrations markedly above pharmacokinetic-pharmacodynamic targets in lung and cellular lesions throughout the dosing interval.
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http://dx.doi.org/10.1128/AAC.00024-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8370215PMC
August 2021

FATTY ACID SYNTHESIS IS REQUIRED FOR BREAST CANCER BRAIN METASTASIS.

Nat Cancer 2021 Apr 1;2(4):414-428. Epub 2021 Apr 1.

Division of Signal Transduction, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

Brain metastases are refractory to therapies that control systemic disease in patients with human epidermal growth factor receptor 2 (HER2+) breast cancer, and the brain microenvironment contributes to this therapy resistance. Nutrient availability can vary across tissues, therefore metabolic adaptations required for brain metastatic breast cancer growth may introduce liabilities that can be exploited for therapy. Here, we assessed how metabolism differs between breast tumors in brain versus extracranial sites and found that fatty acid synthesis is elevated in breast tumors growing in brain. We determine that this phenotype is an adaptation to decreased lipid availability in brain relative to other tissues, resulting in a site-specific dependency on fatty acid synthesis for breast tumors growing at this site. Genetic or pharmacological inhibition of fatty acid synthase (FASN) reduces HER2+ breast tumor growth in the brain, demonstrating that differences in nutrient availability across metastatic sites can result in targetable metabolic dependencies.
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http://dx.doi.org/10.1038/s43018-021-00183-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8223728PMC
April 2021

Potency boost of a dihydrofolate reductase inhibitor by multienzyme FH-dependent reduction.

Proc Natl Acad Sci U S A 2021 Jun;118(25)

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110;

Triaza-coumarin (TA-C) is a (Mtb) dihydrofolate reductase (DHFR) inhibitor with an IC (half maximal inhibitory concentration) of ∼1 µM against the enzyme. Despite this moderate target inhibition, TA-C shows exquisite antimycobacterial activity (MIC, concentration inhibiting growth by 50% = 10 to 20 nM). Here, we investigated the mechanism underlying this potency disconnect. To confirm that TA-C targets DHFR and investigate its unusual potency pattern, we focused on resistance mechanisms. In Mtb, resistance to DHFR inhibitors is frequently associated with mutations in thymidylate synthase , which sensitizes Mtb to DHFR inhibition, rather than in DHFR itself. We observed mutations, consistent with TA-C interfering with the folate pathway. A second resistance mechanism involved biosynthesis of the redox coenzyme F Thus, we hypothesized that TA-C may be metabolized by Mtb F-dependent oxidoreductases (FDORs). By chemically blocking the putative site of FDOR-mediated reduction in TA-C, we reproduced the F-dependent resistance phenotype, suggesting that FH-dependent reduction is required for TA-C to exert its potent antibacterial activity. Indeed, chemically synthesized TA-C-Acid, the putative product of TA-C reduction, displayed a 100-fold lower IC against DHFR. Screening seven recombinant Mtb FDORs revealed that at least two of these enzymes reduce TA-C. This redundancy in activation explains why no mutations in the activating enzymes were identified in the resistance screen. Analysis of the reaction products confirmed that FDORs reduce TA-C at the predicted site, yielding TA-C-Acid. This work demonstrates that intrabacterial metabolism converts TA-C, a moderately active "prodrug," into a 100-fold-more-potent DHFR inhibitor, thus explaining the disconnect between enzymatic and whole-cell activity.
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http://dx.doi.org/10.1073/pnas.2025172118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8237569PMC
June 2021

A Ginger Root or Plum Model for the Tuberculosis "Granuloma"?

Am J Respir Crit Care Med 2021 09;204(5):505-507

Center for Discovery and Innovation Hackensack Meridian Health Nutley, New Jersey.

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http://dx.doi.org/10.1164/rccm.202104-1052EDDOI Listing
September 2021

Piperidine-4-Carboxamides Target DNA Gyrase in Mycobacterium abscessus.

Antimicrob Agents Chemother 2021 07 16;65(8):e0067621. Epub 2021 Jul 16.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA.

New, more-effective drugs for the treatment of lung disease caused by nontuberculous mycobacteria (NTM) are needed. Among NTM opportunistic pathogens, Mycobacterium abscessus is the most difficult to cure and intrinsically multidrug resistant. In a whole-cell screen of a compound collection active against Mycobacterium tuberculosis, we previously identified the piperidine-4-carboxamide (P4C) MMV688844 (844) as a hit against M. abscessus. Here, we identified a more potent analog of 844 and showed that both the parent and improved analog retain activity against strains representing all three subspecies of the M. abscessus complex. Furthermore, P4Cs showed bactericidal and antibiofilm activity. Spontaneous resistance against the P4Cs emerged at a frequency of 10/CFU and mapped to and encoding the subunits of DNA gyrase. Biochemical studies with recombinant M. abscessus DNA gyrase showed that P4Cs inhibit the wild-type enzyme but not the P4C-resistant mutant. P4C-resistant strains showed limited cross-resistance to the fluoroquinolone moxifloxacin, which is in clinical use for the treatment of macrolide-resistant M. abscessus disease, and no cross-resistance to the benzimidazole SPR719, a novel DNA gyrase inhibitor in clinical development for the treatment of mycobacterial diseases. Analyses of P4Cs in promoter-based DNA damage reporter strains showed induction of promoter activity in the wild type but not in the P4C-resistant mutant background. This indicates that P4Cs, similar to fluoroquinolones, cause DNA gyrase-mediated DNA damage. Together, our results show that P4Cs present a novel class of mycobacterial DNA gyrase inhibitors with attractive antimicrobial activities against the M. abscessus complex.
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http://dx.doi.org/10.1128/AAC.00676-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8284461PMC
July 2021

An optimized method for the detection and spatial distribution of aminoglycoside and vancomycin antibiotics in tissue sections by mass spectrometry imaging.

J Mass Spectrom 2021 Mar;56(3):e4708

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA.

Suboptimal antibiotic dosing has been identified as one of the key drivers in the development of multidrug-resistant (MDR) bacteria that have become a global health concern. Aminoglycosides and vancomycin are broad-spectrum antibiotics used to treat critically ill patients infected by a variety of MDR bacterial species. Resistance to these antibiotics is becoming more prevalent. In order to design proper antibiotic regimens that maximize efficacy and minimize the development of resistance, it is pivotal to obtain the in situ pharmacokinetic-pharmacodynamic profiles at the sites of infection. Mass spectrometry imaging (MSI) is the ideal technique to achieve this. Aminoglycosides, due to their structure, suffer from poor ionization efficiency. Additionally, ion suppression effects by endogenous molecules greatly inhibit the detection of aminoglycosides and vancomycin at therapeutic levels. In the current study, an optimized method was developed that enabled the detection of these antibiotics by MSI. Tissue spotting experiments demonstrated a 5-, 15-, 35-, and 54-fold increase in detection sensitivity in the washed samples for kanamycin, amikacin, streptomycin, and vancomycin, respectively. Tissue mimetic models were utilized to optimize the washing time and matrix additive concentration. These studies determined the improved limit of detection was 40 to 5 μg/g of tissue for vancomycin and streptomycin, and 40 to 10 μg/g of tissue for kanamycin and amikacin. The optimized protocol was applied to lung sections from mice dosed with therapeutic levels of kanamycin and vancomycin. The washing protocol enabled the first drug distribution investigations of aminoglycosides and vancomycin by MSI, paving the way for site-of-disease antibiotic penetration studies.
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http://dx.doi.org/10.1002/jms.4708DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8032321PMC
March 2021

A Leucyl-tRNA Synthetase Inhibitor with Broad-Spectrum Anti-Mycobacterial Activity.

Antimicrob Agents Chemother 2021 Feb 8. Epub 2021 Feb 8.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

Global infections by non-tuberculous mycobacteria (NTM) are steadily rising. New drugs are needed to treat NTM infections, but the NTM drug pipeline remains poorly populated and focused on repurposing or reformulating approved antibiotics. We sought to accelerate NTM drug discovery by testing advanced compounds with established activity against 3-aminomethyl 4-halogen benzoxaboroles, a novel class of leucyl-tRNA synthetase inhibitors, were recently discovered as active against Here, we report that the benzoxaborole EC/11770 is not only a potent anti-tubercular agent but is active against the and complexes. Focusing on , which causes the most difficult-to-cure NTM disease, we show that EC/11770 retained potency against drug-tolerant biofilms and was effective in a mouse lung infection model. Resistant mutant selection experiments showed a low frequency of resistance and confirmed leucyl-tRNA synthetase as the target. This work establishes the benzoxaborole EC/11770 as a novel preclinical candidate for the treatment of NTM lung disease and tuberculosis and validates leucyl-tRNA synthetase as an attractive target for the development of broad-spectrum anti-mycobacterials.
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http://dx.doi.org/10.1128/AAC.02420-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8092876PMC
February 2021

Therapeutic Potential of Fosmanogepix (APX001) for Intra-abdominal Candidiasis: from Lesion Penetration to Efficacy in a Mouse Model.

Antimicrob Agents Chemother 2021 03 18;65(4). Epub 2021 Mar 18.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

Intra-abdominal candidiasis (IAC) is one of the most common yet underappreciated forms of invasive candidiasis. IAC is difficult to treat, and therapeutic failure and drug-resistant breakthrough infections are common in some institutions despite the use of echinocandins as first-line agents. Fosmanogepix (FMGX, formerly APX001) is a first-in-class antifungal prodrug that can be administered both intravenously and orally. FMGX is currently in phase 2 clinical development for the treatment of life-threatening invasive fungal infections. To explore the pharmacological properties and therapeutic potential of FMGX for IAC, we evaluated both drug penetration and efficacy of the active moiety manogepix (MGX, formerly APX001A) in liver tissues in a clinically relevant IAC mouse model infected with Matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) and laser capture microdissection (LCM)-directed absolute drug quantitation were employed to evaluate drug penetration into liver abscess lesions both spatially and quantitatively. The partitioning of MGX into lesions occurred slowly after a single dose; however, robust accumulation in the lesion was achieved after 3 days of repeated dosing. Associated with this drug penetration pattern, reduction in fungal burden and clearance in the liver were observed in mice receiving the multiday FMGX regimen. In comparison, administration of micafungin resulted in marginal reduction in fungal burden at the end of 4 days of treatment. These results suggest that FMGX is a promising candidate for the treatment of IAC.
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http://dx.doi.org/10.1128/AAC.02476-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8097442PMC
March 2021

Indole Propionic Acid, an Unusual Antibiotic Produced by the Gut Microbiota, With Anti-inflammatory and Antioxidant Properties.

Front Microbiol 2020 27;11:575586. Epub 2020 Oct 27.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States.

Most antibiotics are produced by soil microbes and typically interfere with macromolecular synthesis processes as their antibacterial mechanism of action. These natural products are often large and suffer from poor chemical tractability. Here, we discuss discovery, mechanism of action, and the therapeutic potentials of an unusual antibiotic, indole propionic acid (IPA). IPA is produced by the human gut microbiota. The molecule is small, chemically tractable, and targets amino acid biosynthesis. IPA is active against a broad spectrum of mycobacteria, including drug resistant and non-tuberculous mycobacteria (NTM). Interestingly, the microbiota-produced metabolite is detectable in the serum of healthy individuals, tuberculosis (TB) patients, and several animal models. Thus, the microbiota in our gut may influence susceptibility to mycobacterial diseases. If a gut-lung microbiome axis can be demonstrated, IPA may have potential as a biomarker of disease progression, and development of microbiota-based therapies could be explored. In addition to its antimycobacterial activity, the molecule displays anti-inflammatory and antioxidant properties. This raises the possibility that IPA has therapeutic potential as both antibiotic and add-on host-directed drug for the treatment of TB in patient populations where disease morbidity and mortality is driven by excessive inflammation and tissue damage, such as TB-associated immune reconstitution inflammatory syndrome, TB-meningitis, and TB-diabetes.
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http://dx.doi.org/10.3389/fmicb.2020.575586DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652848PMC
October 2020

Development of New Tuberculosis Drugs: Translation to Regimen Composition for Drug-Sensitive and Multidrug-Resistant Tuberculosis.

Annu Rev Pharmacol Toxicol 2021 01 17;61:495-516. Epub 2020 Aug 17.

Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, USA; email:

Tuberculosis (TB) kills more people than any other infectious disease. Challenges for developing better treatments include the complex pathology due to within-host immune dynamics, interpatient variability in disease severity and drug pharmacokinetics-pharmacodynamics (PK-PD), and the growing emergence of resistance. Model-informed drug development using quantitative and translational pharmacology has become increasingly recognized as a method capable of drug prioritization and regimen optimization to efficiently progress compounds through TB drug development phases. In this review, we examine translational models and tools, including plasma PK scaling, site-of-disease lesion PK, host-immune and bacteria interplay, combination PK-PD models of multidrug regimens, resistance formation, and integration of data across nonclinical and clinical phases.We propose a workflow that integrates these tools with computational platforms to identify drug combinations that have the potential to accelerate sterilization, reduce relapse rates, and limit the emergence of resistance.
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http://dx.doi.org/10.1146/annurev-pharmtox-030920-011143DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7790895PMC
January 2021

Inhibition of Fatty Acid Oxidation Promotes Macrophage Control of Mycobacterium tuberculosis.

mBio 2020 07 7;11(4). Epub 2020 Jul 7.

Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA

Macrophage activation involves metabolic reprogramming to support antimicrobial cellular functions. How these metabolic shifts influence the outcome of infection by intracellular pathogens remains incompletely understood. (Mtb) modulates host metabolic pathways and utilizes host nutrients, including cholesterol and fatty acids, to survive within macrophages. We found that intracellular growth of Mtb depends on host fatty acid catabolism: when host fatty acid β-oxidation (FAO) was blocked chemically with trimetazidine, a compound in clinical use, or genetically by deletion of the mitochondrial fatty acid transporter carnitine palmitoyltransferase 2 (CPT2), Mtb failed to grow in macrophages, and its growth was attenuated in mice. Mechanistic studies support a model in which inhibition of FAO generates mitochondrial reactive oxygen species, which enhance macrophage NADPH oxidase and xenophagy activity to better control Mtb infection. Thus, FAO inhibition promotes key antimicrobial functions of macrophages and overcomes immune evasion mechanisms of Mtb. (Mtb) is the leading infectious disease killer worldwide. We discovered that intracellular Mtb fails to grow in macrophages in which fatty acid β-oxidation (FAO) is blocked. Macrophages treated with FAO inhibitors rapidly generate a burst of mitochondria-derived reactive oxygen species, which promotes NADPH oxidase recruitment and autophagy to limit the growth of Mtb. Furthermore, we demonstrate the ability of trimetazidine to reduce pathogen burden in mice infected with Mtb. These studies will add to the knowledge of how host metabolism modulates Mtb infection outcomes.
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http://dx.doi.org/10.1128/mBio.01139-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7343992PMC
July 2020

Potentiation of rifampin activity in a mouse model of tuberculosis by activation of host transcription factor EB.

PLoS Pathog 2020 06 23;16(6):e1008567. Epub 2020 Jun 23.

Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York, United States of America.

Efforts at host-directed therapy of tuberculosis have produced little control of the disease in experimental animals to date. This is not surprising, given that few specific host targets have been validated, and reciprocally, many of the compounds tested potentially impact multiple targets with both beneficial and detrimental consequences. This puts a premium on identifying appropriate molecular targets and subjecting them to more selective modulation. We discovered an aminopyrimidine small molecule, 2062, that had no direct antimycobacterial activity, but synergized with rifampin to reduce bacterial burden in Mtb infected macrophages and mice and also dampened lung immunopathology. We used 2062 and its inactive congeners as tool compounds to identify host targets. By biochemical, pharmacologic, transcriptomic and genetic approaches, we found that 2062's beneficial effects on Mtb control and clearance in macrophages and in mice are associated with activation of transcription factor EB via an organellar stress response. 2062-dependent TFEB activation led to improved autophagy, lysosomal acidification and lysosomal degradation, promoting bacterial clearance in macrophages. Deletion of TFEB resulted in the loss of IFNγ-dependent control of Mtb replication in macrophages. 2062 also targeted multiple kinases, such as PIKfyve, VPS34, JAKs and Tyk2, whose inhibition likely limited 2062's efficacy in vivo. These findings support a search for selective activators of TFEB for HDT of TB.
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http://dx.doi.org/10.1371/journal.ppat.1008567DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7337396PMC
June 2020

Pharmacokinetics of tedizolid, sutezolid, and sutezolid-M1 in non-human primates.

Eur J Pharm Sci 2020 Aug 9;151:105421. Epub 2020 Jun 9.

Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, United States of America.

Non-human primates (NHP) are thought to be a good preclinical animal model for tuberculosis because they develop disease characteristics that are similar to humans. The objective of the current study was to determine if NHPs can also be used to reliably predict the exposure of tedizolid, sutezolid, and its biologically active metabolite sutezolid-M1 in humans. The prodrug tedizolid phosphate and sutezolid were administered orally to NHPs either once or twice daily for up to eight days. The active moieties, tedizolid, and sutezolid showed linear pharmacokinetics and respective concentration-time profiles could be described by one-compartment body models with first-order elimination. One additional metabolite compartment with first-order elimination was found appropriate to capture the pharmacokinetics of sutezolid-M1. Once allometrically scaled to humans with a fixed exponent of 0.75 for apparent clearance and 1 for apparent volume of distribution, the AUCs of tedizolid and sutezolid were predicted reasonably well, whereas C was under-predicted for sutezolid. Both NHP and humanized concentration-time profiles will now be used in vitro hollow-fiber pharmacodynamic experiments to determine if differences in drug exposures result in differences in Mycobacterium tuberculosis kill and emergence of resistance.
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http://dx.doi.org/10.1016/j.ejps.2020.105421DOI Listing
August 2020

Evaluation of IL-1 Blockade as an Adjunct to Linezolid Therapy for Tuberculosis in Mice and Macaques.

Front Immunol 2020 12;11:891. Epub 2020 May 12.

Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.

In 2017 over 550,000 estimated new cases of multi-drug/rifampicin resistant tuberculosis (MDR/RR-TB) occurred, emphasizing a need for new treatment strategies. Linezolid (LZD) is a potent antibiotic for drug-resistant Gram-positive infections and is an effective treatment for TB. However, extended LZD use can lead to LZD-associated host toxicities, most commonly bone marrow suppression. LZD toxicities may be mediated by IL-1, an inflammatory pathway important for early immunity during infection. However, IL-1 can contribute to pathology and disease severity late in TB progression. Since IL-1 may contribute to LZD toxicity and does influence TB pathology, we targeted this pathway with a potential host-directed therapy (HDT). We hypothesized LZD efficacy could be enhanced by modulation of IL-1 pathway to reduce bone marrow toxicity and TB associated-inflammation. We used two animal models of TB to test our hypothesis, a TB-susceptible mouse model and clinically relevant cynomolgus macaques. Antagonizing IL-1 in mice with established infection reduced lung neutrophil numbers and partially restored the erythroid progenitor populations that are depleted by LZD. In macaques, we found no conclusive evidence of bone marrow suppression associated with LZD, indicating our treatment time may have been short enough to avoid the toxicities observed in humans. Though treatment was only 4 weeks (the FDA approved regimen at the time of study), we observed sterilization of the majority of granulomas regardless of co-administration of the FDA-approved IL-1 receptor antagonist (IL-1Rn), also known as Anakinra. However, total lung inflammation was significantly reduced in macaques treated with IL-1Rn and LZD compared to LZD alone. Importantly, IL-1Rn administration did not impair the host response against Mtb or LZD efficacy in either animal model. Together, our data support that inhibition of IL-1 in combination with LZD has potential to be an effective HDT for TB and the need for further research in this area.
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http://dx.doi.org/10.3389/fimmu.2020.00891DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235418PMC
April 2021

Both Pharmacokinetic Variability and Granuloma Heterogeneity Impact the Ability of the First-Line Antibiotics to Sterilize Tuberculosis Granulomas.

Front Pharmacol 2020 24;11:333. Epub 2020 Mar 24.

Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, United States.

Tuberculosis (TB) remains as one of the world's deadliest infectious diseases despite the use of standardized antibiotic therapies. Recommended therapy for drug-susceptible TB is up to 6 months of antibiotics. Factors that contribute to lengthy regimens include antibiotic underexposure in lesions due to poor pharmacokinetics (PK) and complex granuloma compositions, but it is difficult to quantify how individual antibiotics are affected by these factors and to what extent these impact treatments. We use our next-generation multi-scale computational model to simulate granuloma formation and function together with antibiotic pharmacokinetics and pharmacodynamics, allowing us to predict conditions leading to granuloma sterilization. In this work, we focus on how PK variability, determined from human PK data, and granuloma heterogeneity each quantitatively impact granuloma sterilization. We focus on treatment with the standard regimen for TB of four first-line antibiotics: isoniazid, rifampin, ethambutol, and pyrazinamide. We find that low levels of antibiotic concentration due to naturally occurring PK variability and complex granulomas leads to longer granuloma sterilization times. Additionally, the ability of antibiotics to distribute in granulomas and kill different subpopulations of bacteria contributes to their specialization in the more efficacious combination therapy. These results can inform strategies to improve antibiotic therapy for TB.
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http://dx.doi.org/10.3389/fphar.2020.00333DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105635PMC
March 2020

Caseum: a Niche for Mycobacterium tuberculosis Drug-Tolerant Persisters.

Clin Microbiol Rev 2020 06 1;33(3). Epub 2020 Apr 1.

Center for Discovery and Innovation, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey, USA.

Caseum, the central necrotic material of tuberculous lesions, is a reservoir of drug-recalcitrant persisting mycobacteria. Caseum is found in closed nodules and in open cavities connecting with an airway. Several commonly accepted characteristics of caseum were established during the preantibiotic era, when autopsies of deceased tuberculosis (TB) patients were common but methodologies were limited. These pioneering studies generated concepts such as acidic pH, low oxygen tension, and paucity of nutrients being the drivers of nonreplication and persistence in caseum. Here we review widely accepted beliefs about the caseum-specific stress factors thought to trigger the shift of to drug tolerance. Our current state of knowledge reveals that is faced with a lipid-rich diet rather than nutrient deprivation in caseum. Variable caseum pH is seen across lesions, possibly transiently acidic in young lesions but overall near neutral in most mature lesions. Oxygen tension is low in the avascular caseum of closed nodules and high at the cavity surface, and a gradient of decreasing oxygen tension likely forms toward the cavity wall. Since caseum is largely made of infected and necrotized macrophages filled with lipid droplets, the microenvironmental conditions encountered by in foamy macrophages and in caseum bear many similarities. While there remain a few knowledge gaps, these findings constitute a solid starting point to develop high-throughput drug discovery assays that combine the right balance of oxygen tension, pH, lipid abundance, and lipid species to model the profound drug tolerance of in caseum.
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http://dx.doi.org/10.1128/CMR.00159-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7117546PMC
June 2020

A Preclinical Candidate Targeting Mycobacterium tuberculosis KasA.

Cell Chem Biol 2020 05 19;27(5):560-570.e10. Epub 2020 Mar 19.

Department of Pharmacology, Physiology, and Neuroscience, Rutgers University - New Jersey Medical School, Newark, NJ, USA; Division of Infectious Disease, Department of Medicine and the Ruy V. Lourenco Center for the Study of Emerging and Re-emerging Pathogens, Rutgers University - New Jersey Medical School, Newark, NJ, USA. Electronic address:

Published Mycobacterium tuberculosis β-ketoacyl-ACP synthase KasA inhibitors lack sufficient potency and/or pharmacokinetic properties. A structure-based approach was used to optimize existing KasA inhibitor DG167. This afforded indazole JSF-3285 with a 30-fold increase in mouse plasma exposure. Biochemical, genetic, and X-ray studies confirmed JSF-3285 targets KasA. JSF-3285 offers substantial activity in an acute mouse model of infection and in the corresponding chronic infection model, with efficacious reductions in colony-forming units at doses as low as 5 mg/kg once daily orally and improvement of the efficacy of front-line drugs isoniazid or rifampicin. JSF-3285 is a promising preclinical candidate for tuberculosis.
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http://dx.doi.org/10.1016/j.chembiol.2020.02.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245553PMC
May 2020

Antitubercular nanocarrier monotherapy: Study of In Vivo efficacy and pharmacokinetics for rifampicin.

J Control Release 2020 05 14;321:312-323. Epub 2020 Feb 14.

Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského náměstí 2, 162 00 Prague 6, Czechia. Electronic address:

Tuberculosis represents a major global health problem for which improved approaches are needed to shorten the course of treatment and to combat the emergence of resistant strains. The development of effective and safe nanobead-based interventions can be particularly relevant for increasing the concentrations of antitubercular agents within the infected site and reducing the concentrations in the general circulation, thereby avoiding off-target toxic effects. In this work, rifampicin, a first-line antitubercular agent, was encapsulated into biocompatible and biodegradable polyester-based nanoparticles. In a well-established BALB/c mouse model of pulmonary tuberculosis, the nanoparticles provided improved pharmacokinetics and pharmacodynamics. The nanoparticles were well tolerated and much more efficient than an equivalent amount of free rifampicin.
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http://dx.doi.org/10.1016/j.jconrel.2020.02.026DOI Listing
May 2020

Tissue Distribution of Doxycycline in Animal Models of Tuberculosis.

Antimicrob Agents Chemother 2020 04 21;64(5). Epub 2020 Apr 21.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

Doxycycline, an FDA-approved tetracycline, is used in tuberculosis models for the temporal control of mycobacterial gene expression. In these models, animals are infected with recombinant carrying genes of interest under transcriptional control of the doxycycline-responsive TetR- unit. To minimize fluctuations of plasma levels, doxycycline is usually administered in the diet. However, tissue penetration studies to identify the minimum doxycycline content in food achieving complete repression of TetR-controlled genes in tuberculosis (TB)-infected organs and lesions have not been conducted. Here, we first determined the tetracycline concentrations required to achieve silencing of target genes Next, we measured doxycycline concentrations in plasma, major organs, and lung lesions in TB-infected mice and rabbits and compared these values to silencing concentrations measured We found that 2,000 ppm doxycycline supplemented in mouse and rabbit feed is sufficient to reach target concentrations in TB lesions. In rabbit chow, the calcium content had to be reduced 5-fold to minimize chelation of doxycycline and deliver adequate oral bioavailability. Clearance kinetics from major organs and lung lesions revealed that doxycycline levels fall below concentrations that repress promoters within 7 to 14 days after doxycycline is removed from the diet. In summary, we have shown that 2,000 ppm doxycycline supplemented in standard mouse diet and in low-calcium rabbit diet delivers concentrations adequate to achieve full repression of promoters in infected tissues of mice and rabbits.
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http://dx.doi.org/10.1128/AAC.02479-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7179585PMC
April 2020

TBAJ-876, a 3,5-Dialkoxypyridine Analogue of Bedaquiline, Is Active against Mycobacterium abscessus.

Antimicrob Agents Chemother 2020 03 24;64(4). Epub 2020 Mar 24.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

Lung disease caused by is very difficult to cure, and treatment failure rates are high. The antituberculosis drug bedaquiline (BDQ) is used as salvage therapy against this dreadful disease. However, BDQ is highly lipophilic, displays a long terminal half-life, and presents a cardiotoxicity liability associated with QT interval prolongation. Recent medicinal chemistry campaigns resulted in the discovery of 3,5-dialkoxypyridine analogues of BDQ which are less lipophilic, have higher clearance, and display lower cardiotoxic potential. TBAJ-876, a clinical development candidate of this series, shows attractive antitubercular activity and efficacy in a murine tuberculosis model. Here, we asked whether TBAJ-876 is active against TBAJ-876 displayed submicromolar activity against reference strains representing the three subspecies of and against a collection of clinical isolates. Drug-drug potency interaction studies with commonly used anti- antibiotics showed no antagonistic effects, suggesting that TBAJ-876 could be coadministered with currently used drugs. Efficacy studies, employing a mouse model of infection, demonstrated potent activity In summary, we demonstrate that TBAJ-876 shows attractive and activities against , similar to its BDQ parent. This suggests that next-generation BDQ, with improved tolerability and pharmacological profiles, may be useful for the treatment of lung disease in addition to the treatment of tuberculosis.
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http://dx.doi.org/10.1128/AAC.02404-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7179298PMC
March 2020

Penetration of Ibrexafungerp (Formerly SCY-078) at the Site of Infection in an Intra-abdominal Candidiasis Mouse Model.

Antimicrob Agents Chemother 2020 02 21;64(3). Epub 2020 Feb 21.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

Ibrexafungerp (IBX), formerly SCY-078, is a novel, oral and intravenous, semisynthetic triterpenoid glucan synthase inhibitor in clinical development for treating multiple fungal infections, including invasive candidiasis. Intra-abdominal candidiasis (IAC) is one of the most common types of invasive candidiasis associated with high mortality largely due to poor drug exposure in infected lesions. To better understand the potential of IBX to treat such infections, we investigated its penetration at the site of infection. Using matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) and laser capture microdissection (LCM)-directed high-pressure liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), we investigated tissue distribution and lesion-specific drug exposure of IBX in a clinically relevant IAC mouse model. After a single-dose treatment, IBX quickly distributed into tissues and efficiently accumulated within lesions. Drug concentrations of IBX within the liver abscesses were almost 100-fold higher than the serum concentration. In addition, drug penetration after repeated treatment of IBX was compared with micafungin. IBX exhibited robust and long-lasting lesion penetration after repeated treatment. These data indicate that IBX penetrates into intra-abdominal abscesses highly efficiently and holds promise as a potential therapeutic option for IAC patients.
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http://dx.doi.org/10.1128/AAC.02268-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7038262PMC
February 2020

Rifabutin Is Active against Mycobacterium abscessus in Mice.

Antimicrob Agents Chemother 2020 01 27;64(2). Epub 2020 Jan 27.

Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA

There is no reliable cure for lung disease. Rifampin is not used clinically due to poor potency. In contrast, we have shown that rifabutin, another approved rifamycin used to treat tuberculosis, is potent against Here, we report that rifabutin is as active as clarithromycin against K21 in NOD.CB17-Prkdc/NCrCrl mice. This suggests that rifabutin should be considered a repurposing candidate for patients with disease.
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http://dx.doi.org/10.1128/AAC.01943-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985736PMC
January 2020

Antitubercular Triazines: Optimization and Intrabacterial Metabolism.

Cell Chem Biol 2020 02 8;27(2):172-185.e11. Epub 2019 Nov 8.

Department of Pharmacology, Physiology and Neuroscience, Rutgers University - New Jersey Medical School, Newark, NJ 07103, USA; Division of Infectious Disease, Department of Medicine and the Ruy V. Lourenço Center for the Study of Emerging and Re-emerging Pathogens, Rutgers University - New Jersey Medical School, Newark, NJ 07103, USA. Electronic address:

The triazine antitubercular JSF-2019 was of interest due to its in vitro efficacy and the nitro group shared with the clinically relevant delamanid and pretomanid. JSF-2019 undergoes activation requiring FH and one or more nitroreductases in addition to Ddn. An intrabacterial drug metabolism (IBDM) platform was leveraged to demonstrate the system kinetics, evidencing formation of NO and a des-nitro metabolite. Structure-activity relationship studies focused on improving the solubility and mouse pharmacokinetic profile of JSF-2019 and culminated in JSF-2513, relying on the key introduction of a morpholine. Mechanistic studies with JSF-2019, JSF-2513, and other triazines stressed the significance of achieving potent in vitro efficacy via release of intrabacterial NO along with inhibition of InhA and, more generally, the FAS-II pathway. This study highlights the importance of probing IBDM and its potential to clarify mechanism of action, which in this case is a combination of NO release and InhA inhibition.
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http://dx.doi.org/10.1016/j.chembiol.2019.10.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035970PMC
February 2020
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