101
|
Prosser G, Brandenburg J, Reiling N, Barry CE, Wilkinson RJ, Wilkinson KA. The bacillary and macrophage response to hypoxia in tuberculosis and the consequences for T cell antigen recognition. Microbes Infect 2016; 19:177-192. [PMID: 27780773 PMCID: PMC5335906 DOI: 10.1016/j.micinf.2016.10.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/06/2016] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis is a facultative anaerobe and its characteristic pathological hallmark, the granuloma, exhibits hypoxia in humans and in most experimental models. Thus the host and bacillary adaptation to hypoxia is of central importance in understanding pathogenesis and thereby to derive new drug treatments and vaccines.
Collapse
Affiliation(s)
- Gareth Prosser
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, United States
| | - Julius Brandenburg
- Microbial Interface Biology, Priority Research Area Infections, Forschungszentrum Borstel, Leibniz Center for Medicine and Biosciences, Parkallee 1-40, D-23845, Borstel, Germany
| | - Norbert Reiling
- Microbial Interface Biology, Priority Research Area Infections, Forschungszentrum Borstel, Leibniz Center for Medicine and Biosciences, Parkallee 1-40, D-23845, Borstel, Germany; German Center for Infection Research (DZIF), Partner Site Hamburg-Borstel-Lübeck, Borstel, Germany
| | - Clifton Earl Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, United States; Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, South Africa
| | - Robert J Wilkinson
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, South Africa; The Francis Crick Institute, London, NW1 2AT, United Kingdom; Department of Medicine, Imperial College, London, W2 1PG, United Kingdom.
| | - Katalin A Wilkinson
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, 7925, South Africa; The Francis Crick Institute, London, NW1 2AT, United Kingdom
| |
Collapse
|
102
|
Selective small molecule inhibitor of the Mycobacterium tuberculosis fumarate hydratase reveals an allosteric regulatory site. Proc Natl Acad Sci U S A 2016; 113:7503-8. [PMID: 27325754 DOI: 10.1073/pnas.1600630113] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Enzymes in essential metabolic pathways are attractive targets for the treatment of bacterial diseases, but in many cases, the presence of homologous human enzymes makes them impractical candidates for drug development. Fumarate hydratase, an essential enzyme in the tricarboxylic acid (TCA) cycle, has been identified as one such potential therapeutic target in tuberculosis. We report the discovery of the first small molecule inhibitor, to our knowledge, of the Mycobacterium tuberculosis fumarate hydratase. A crystal structure at 2.0-Å resolution of the compound in complex with the protein establishes the existence of a previously unidentified allosteric regulatory site. This allosteric site allows for selective inhibition with respect to the homologous human enzyme. We observe a unique binding mode in which two inhibitor molecules interact within the allosteric site, driving significant conformational changes that preclude simultaneous substrate and inhibitor binding. Our results demonstrate the selective inhibition of a highly conserved metabolic enzyme that contains identical active site residues in both the host and the pathogen.
Collapse
|
103
|
McDaniel MM, Krishna N, Handagama WG, Eda S, Ganusov VV. Quantifying Limits on Replication, Death, and Quiescence of Mycobacterium tuberculosis in Mice. Front Microbiol 2016; 7:862. [PMID: 27379030 PMCID: PMC4906525 DOI: 10.3389/fmicb.2016.00862] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/23/2016] [Indexed: 02/02/2023] Open
Abstract
When an individual is exposed to Mycobacterium tuberculosis (Mtb) three outcomes are possible: bacterial clearance, active disease, or latent infection. It is generally believed that most individuals exposed to Mtb become latently infected and carry the mycobacteria for life. How Mtb is maintained during this latent infection remains largely unknown. During an Mtb infection in mice, there is a phase of rapid increase in bacterial numbers in the murine lungs within the first 3 weeks, and then bacterial numbers either stabilize or increase slowly over the period of many months. It has been debated whether the relatively constant numbers of bacteria in the chronic infection result from latent (dormant, quiescent), non-replicating bacteria, or whether the observed Mtb cell numbers are due to balance between rapid replication and death. A recent study of mice, infected with a Mtb strain carrying an unstable plasmid, showed that during the chronic phase, Mtb was replicating at significant rates. Using experimental data from this study and mathematical modeling we investigated the limits of the rates of bacterial replication, death, and quiescence during Mtb infection of mice. First, we found that to explain the data the rates of bacterial replication and death could not be constant and had to decrease with time since infection unless there were large changes in plasmid segregation probability over time. While a decrease in the rate of Mtb replication with time since infection was expected due to depletion of host's resources, a decrease in the Mtb death rate was counterintuitive since Mtb-specific immune response, appearing in the lungs 3–4 weeks after infection, should increase removal of bacteria. Interestingly, we found no significant correlation between estimated rates of Mtb replication and death suggesting the decline in these rates was driven by independent mechanisms. Second, we found that the data could not be explained by assuming that bacteria do not die, suggesting that some removal of bacteria from lungs of these mice had to occur even though the total bacterial counts in these mice always increased over time. Third and finally, we showed that to explain the data the majority of bacterial cells (at least ~60%) must be replicating in the chronic phase of infection further challenging widespread belief of nonreplicating Mtb in latency. Our predictions were robust to some changes in the structure of the model, for example, when the loss of plasmid-bearing cells was mainly due to high fitness cost of the plasmid. Further studies should determine if more mechanistic models for Mtb dynamics are also able to accurately explain these data.
Collapse
Affiliation(s)
- Margaret M McDaniel
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Biochemistry, Cellular and Molecular Biology, University of TennesseeKnoxville, TN, USA; Department of Mathematics, University of TennesseeKnoxville, TN, USA
| | - Nitin Krishna
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; The College at the University of ChicagoChicago, IL, USA
| | - Winode G Handagama
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Departments of Chemistry and Mathematics, Maryville CollegeMaryville, TN, USA
| | - Shigetoshi Eda
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Forestry, Wildlife and Fisheries, University of TennesseeKnoxville, TN, USA
| | - Vitaly V Ganusov
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Mathematics, University of TennesseeKnoxville, TN, USA; Department of Microbiology, University of TennesseeKnoxville, TN, USA
| |
Collapse
|
104
|
Benard EL, Rougeot J, Racz PI, Spaink HP, Meijer AH. Transcriptomic Approaches in the Zebrafish Model for Tuberculosis-Insights Into Host- and Pathogen-specific Determinants of the Innate Immune Response. ADVANCES IN GENETICS 2016; 95:217-51. [PMID: 27503359 DOI: 10.1016/bs.adgen.2016.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mycobacterium marinum infection in zebrafish has become a well-established model of tuberculosis. Both embryonic and adult zebrafish infection studies have contributed to our knowledge of the development and function of tuberculous granulomas, which are typical of mycobacterial pathogenesis. In this review we discuss how transcriptome profiling studies have helped to characterize this infection process. We illustrate this using new RNA sequencing (RNA-Seq) data that reveals three main phases in the host response to M. marinum during the early stages of granuloma development in zebrafish embryos and larvae. The early phase shows induction of complement and transcription factors, followed by a relatively minor induction of pro-inflammatory cytokines within hours following phagocytosis of M. marinum. A minimal response is observed in the mid-phase, between 6 hours and 1day post infection, when the tissue dissemination of M. marinum begins. During subsequent larval development the granulomas expand and a late-phase response is apparent, which is characterized by progressively increasing induction of complement, transcription factors, pro-inflammatory cytokines, matrix metalloproteinases, and other defense and inflammation-related gene groups. This late-phase response shares common components with the strong and acute host transcriptome response that has previously been reported for Salmonella typhimurium infection in zebrafish embryos. In contrast, the early/mid-phase response to M. marinum infection, characterized by suppressed pro-inflammatory signaling, is strikingly different from the acute response to S. typhimurium infection. Furthermore, M. marinum infection shows a collective and strongly fluctuating regulation of lipoproteins, while S. typhimurium infection has pronounced effects on amino acid metabolism and glycolysis.
Collapse
Affiliation(s)
- E L Benard
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - J Rougeot
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - P I Racz
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - H P Spaink
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - A H Meijer
- Institute of Biology, Leiden University, Leiden, The Netherlands
| |
Collapse
|
105
|
Ang MLT, Pethe K. Contribution of high-content imaging technologies to the development of anti-infective drugs. Cytometry A 2016; 89:755-60. [PMID: 27272127 PMCID: PMC5089693 DOI: 10.1002/cyto.a.22885] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/17/2016] [Accepted: 05/06/2016] [Indexed: 12/18/2022]
Abstract
Originally developed to study fundamental aspects of cellular biology, high‐content imaging (HCI) was rapidly adapted to study host–pathogen interactions at the cellular level and adopted as a technology of choice to unravel disease biology. HCI platforms allow for the visualization and quantification of discrete phenotypes that cannot be captured using classical screening approaches. A key advantage of high‐content screening technologies lies in the possibility to develop and interrogate physiologically significant, predictive ex vivo disease models that reproduce complex conditions relevant for infection. Here we review and discuss recent advances in HCI technologies and chemical biology approaches that are contributing to an increased understanding of the intricate host–pathogen interrelationship on the cellular level, and which will foster the development of novel therapeutic approaches for the treatment of human bacterial and protozoan infections. © 2016 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of ISAC
Collapse
Affiliation(s)
- Michelle Lay Teng Ang
- Lee Kong Chian School of Medicine and School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kevin Pethe
- Lee Kong Chian School of Medicine and School of Biological Sciences, Nanyang Technological University, Singapore
| |
Collapse
|
106
|
Giffin MM, Shi L, Gennaro ML, Sohaskey CD. Role of Alanine Dehydrogenase of Mycobacterium tuberculosis during Recovery from Hypoxic Nonreplicating Persistence. PLoS One 2016; 11:e0155522. [PMID: 27203084 PMCID: PMC4874671 DOI: 10.1371/journal.pone.0155522] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/29/2016] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis can maintain a nonreplicating persistent state in the host for decades, but must maintain the ability to efficiently reactivate and produce active disease to survive and spread in a population. Among the enzymes expressed during this dormancy is alanine dehydrogenase, which converts pyruvate to alanine, and glyoxylate to glycine concurrent with the oxidation of NADH to NAD. It is involved in the metabolic remodeling of M. tuberculosis through its possible interactions with both the glyoxylate and methylcitrate cycle. Both mRNA levels and enzymatic activities of isocitrate lyase, the first enzyme of the glyoxylate cycle, and alanine dehydrogenase increased during entry into nonreplicating persistence, while the gene and activity for the second enzyme of the glyoxylate cycle, malate synthase were not. This could suggest a shift in carbon flow away from the glyoxylate cycle and instead through alanine dehydrogenase. Expression of ald was also induced in vitro by other persistence-inducing stresses such as nitric oxide, and was expressed at high levels in vivo during the initial lung infection in mice. Enzyme activity was maintained during extended hypoxia even after transcription levels decreased. An ald knockout mutant of M. tuberculosis showed no reduction in anaerobic survival in vitro, but resulted in a significant lag in the resumption of growth after reoxygenation. During reactivation the ald mutant had an altered NADH/NAD ratio, and alanine dehydrogenase is proposed to maintain the optimal NADH/NAD ratio during anaerobiosis in preparation of eventual regrowth, and during the initial response during reoxygenation.
Collapse
Affiliation(s)
- Michelle M. Giffin
- Department of Veterans Affairs Medical Center, Long Beach, CA, United States of America
| | - Lanbo Shi
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America
| | - Maria L. Gennaro
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, NJ, United States of America
| | - Charles D. Sohaskey
- Department of Veterans Affairs Medical Center, Long Beach, CA, United States of America
- * E-mail:
| |
Collapse
|
107
|
Thakur P, Gantasala NP, Choudhary E, Singh N, Abdin MZ, Agarwal N. The preprotein translocase YidC controls respiratory metabolism in Mycobacterium tuberculosis. Sci Rep 2016; 6:24998. [PMID: 27166092 PMCID: PMC4863248 DOI: 10.1038/srep24998] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/08/2016] [Indexed: 12/02/2022] Open
Abstract
The YidC–Oxa1–Alb3 preprotein translocases play a vital role in membrane insertion of proteins in eukaryotes and bacteria. In a recent study we observed that Rv3921c, which encodes putative YidC translocase in Mycobacterium tuberculosis (Mtb), is essential for in vitro growth of bacteria. However, the exact function of this particular protein remains to identify in mycobacterial pathogens. By performing a systematic study here we show that YidC of Mtb is an envelope protein, which is required for production of ATP and maintenance of cellular redox balance. Drastic effects of depletion of Rv3921c on the expression of hypoxic genes, ATP synthases, and many proteins of central metabolic and respiratory pathways shed a significant light on the function of YidC towards controlling respiratory metabolism in Mtb. Association of YidC with proteins such as succinate dehydrogenases and ubiquinol-cytochrome C reductase further confirms its role in respiration. Finally we demonstrate that YidC is required for the intracellular survival of Mtb in human macrophages.
Collapse
Affiliation(s)
- Preeti Thakur
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001 India.,Faculty of Science, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India
| | - Nagavara Prasad Gantasala
- Regional Center for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad- 121001 India
| | - Eira Choudhary
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001 India.,Symbiosis School of Biomedical Sciences, Symbiosis International University, Lavale, Pune- 412115 (Maharashtra) India
| | - Nirpendra Singh
- Regional Center for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad- 121001 India
| | - Malik Zainul Abdin
- Faculty of Science, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India
| | - Nisheeth Agarwal
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001 India
| |
Collapse
|
108
|
Physiology, Biochemistry, and Applications of F420- and Fo-Dependent Redox Reactions. Microbiol Mol Biol Rev 2016; 80:451-93. [PMID: 27122598 DOI: 10.1128/mmbr.00070-15] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
5-Deazaflavin cofactors enhance the metabolic flexibility of microorganisms by catalyzing a wide range of challenging enzymatic redox reactions. While structurally similar to riboflavin, 5-deazaflavins have distinctive and biologically useful electrochemical and photochemical properties as a result of the substitution of N-5 of the isoalloxazine ring for a carbon. 8-Hydroxy-5-deazaflavin (Fo) appears to be used for a single function: as a light-harvesting chromophore for DNA photolyases across the three domains of life. In contrast, its oligoglutamyl derivative F420 is a taxonomically restricted but functionally versatile cofactor that facilitates many low-potential two-electron redox reactions. It serves as an essential catabolic cofactor in methanogenic, sulfate-reducing, and likely methanotrophic archaea. It also transforms a wide range of exogenous substrates and endogenous metabolites in aerobic actinobacteria, for example mycobacteria and streptomycetes. In this review, we discuss the physiological roles of F420 in microorganisms and the biochemistry of the various oxidoreductases that mediate these roles. Particular focus is placed on the central roles of F420 in methanogenic archaea in processes such as substrate oxidation, C1 pathways, respiration, and oxygen detoxification. We also describe how two F420-dependent oxidoreductase superfamilies mediate many environmentally and medically important reactions in bacteria, including biosynthesis of tetracycline and pyrrolobenzodiazepine antibiotics by streptomycetes, activation of the prodrugs pretomanid and delamanid by Mycobacterium tuberculosis, and degradation of environmental contaminants such as picrate, aflatoxin, and malachite green. The biosynthesis pathways of Fo and F420 are also detailed. We conclude by considering opportunities to exploit deazaflavin-dependent processes in tuberculosis treatment, methane mitigation, bioremediation, and industrial biocatalysis.
Collapse
|
109
|
Zhou M, Xie L, Yang Z, Zhou J, Xie J. Lysine succinylation of Mycobacterium tuberculosis isocitrate lyase (ICL) fine-tunes the microbial resistance to antibiotics. J Biomol Struct Dyn 2016; 35:1030-1041. [PMID: 27023679 DOI: 10.1080/07391102.2016.1169219] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lysine succinylation (Ksucc) is a newly identified protein posttranslational modification (PTM), which may play an important role in cellular physiology. However, the role of lysine succinylation in antibiotic resistance remains elusive. Isocitrate lyase (ICL) is crucial for broad-spectrum antibiotics tolerance in Mycobacterium tuberculosis (Mtb). We previously found that MtbICL (Rv0467) has at least three succinylated lysine residues, namely K189, K322, and K334.To explore the effect of succinylation on the activity of MtbICL, mutants' mimicry of the lysine succinylation were generated by site-directed mutagenesis. ICL-K189E mutant strain is more sensitive than the wild-type to rifampicin and streptomycin, but not isoniazid. For the in vitro activity of the purified isocitrate lyase, only K189E mutant showed significantly decreased activity. Crystal structure analysis showed that Lys189 Glu dramatically increased the pKa of Glu188 and decreased the pKa of Lys190, whereas had negligible effect on other residues within 5 Å as well as disruption of the electrostatic interaction between Lys189 and Glu182, which might prevent the closure of the active site loop and cause severe reduction of the enzyme activity. Considering the genetic, biochemical, and crystallographical evidences together, the succinylation of specific ICL residue can fine-tune the bacterial resistance to selected antibiotics. The decreased enzymatic activity resulting from the succinylation-changed electrostatic interaction might underlie this phenotype. This study provided the first insight into the link between lysine succinylation and antibiotic resistance.
Collapse
Affiliation(s)
- Mingliang Zhou
- a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China
| | - Longxiang Xie
- a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China
| | - Zhaozhen Yang
- b State Key Laboratory of Bioorganic and Natural Products Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032 , China
| | - Jiahai Zhou
- b State Key Laboratory of Bioorganic and Natural Products Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032 , China
| | - Jianping Xie
- a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 400715 , China
| |
Collapse
|
110
|
Sawers RG, Falke D, Fischer M. Oxygen and Nitrate Respiration in Streptomyces coelicolor A3(2). Adv Microb Physiol 2016; 68:1-40. [PMID: 27134020 DOI: 10.1016/bs.ampbs.2016.02.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Streptomyces species belong to the phylum Actinobacteria and can only grow with oxygen as a terminal electron acceptor. Like other members of this phylum, such as corynebacteria and mycobacteria, the aerobic respiratory chain lacks a soluble cytochrome c. It is therefore implicit that direct electron transfer between the cytochrome bc1 and the cytochrome aa3 oxidase complexes occurs. The complex developmental cycle of streptomycetes manifests itself in the production of spores, which germinate in the presence of oxygen into a substrate mycelium that greatly facilitates acquisition of nutrients necessary to support their saprophytic lifestyle in soils. Due to the highly variable oxygen levels in soils, streptomycetes have developed means of surviving long periods of hypoxia or even anaerobiosis but they fail to grow under these conditions. Little to nothing is understood about how they maintain viability under conditions of oxygen limitation. It is assumed that they can utilise a number of different electron acceptors to help them maintain a membrane potential, one of which is nitrate. The model streptomycete remains Streptomyces coelicolor A3(2), and it synthesises three nonredundant respiratory nitrate reductases (Nar). These Nar enzymes are synthesised during different phases of the developmental cycle and they are functional only under oxygen-limiting (<5% oxygen in air) conditions. Nevertheless, the regulation of their synthesis does not appear to be responsive to nitrate and in the case of Nar1, it appears to be developmentally regulated. This review highlights some of the novel aspects of our current, but somewhat limited, knowledge of respiration in these fascinating bacteria.
Collapse
Affiliation(s)
- R G Sawers
- Institute for Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany.
| | - D Falke
- Institute for Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - M Fischer
- Institute for Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| |
Collapse
|
111
|
Abstract
Mycobacteria inhabit a wide range of intracellular and extracellular environments. Many of these environments are highly dynamic and therefore mycobacteria are faced with the constant challenge of redirecting their metabolic activity to be commensurate with either replicative growth or a non-replicative quiescence. A fundamental feature in this adaptation is the ability of mycobacteria to respire, regenerate reducing equivalents and generate ATP via oxidative phosphorylation. Mycobacteria harbor multiple primary dehydrogenases to fuel the electron transport chain and two terminal respiratory oxidases, an aa3 -type cytochrome c oxidase and cytochrome bd-type menaquinol oxidase, are present for dioxygen reduction coupled to the generation of a protonmotive force. Hypoxia leads to the downregulation of key respiratory complexes, but the molecular mechanisms regulating this expression are unknown. Despite being obligate aerobes, mycobacteria have the ability to metabolize in the absence of oxygen and a number of reductases are present to facilitate the turnover of reducing equivalents under these conditions (e.g. nitrate reductase, succinate dehydrogenase/fumarate reductase). Hydrogenases and ferredoxins are also present in the genomes of mycobacteria suggesting the ability of these bacteria to adapt to an anaerobic-type of metabolism in the absence of oxygen. ATP synthesis by the membrane-bound F1FO-ATP synthase is essential for growing and non-growing mycobacteria and the enzyme is able to function over a wide range of protonmotive force values (aerobic to hypoxic). The discovery of lead compounds that target respiration and oxidative phosphorylation in Mycobacterium tuberculosis highlights the importance of this area for the generation of new front line drugs to combat tuberculosis.
Collapse
|
112
|
Noy T, Vergnolle O, Hartman TE, Rhee KY, Jacobs WR, Berney M, Blanchard JS. Central Role of Pyruvate Kinase in Carbon Co-catabolism of Mycobacterium tuberculosis. J Biol Chem 2016; 291:7060-9. [PMID: 26858255 DOI: 10.1074/jbc.m115.707430] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Indexed: 11/06/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) displays a high degree of metabolic plasticity to adapt to challenging host environments. Genetic evidence suggests thatMtbrelies mainly on fatty acid catabolism in the host. However,Mtbalso maintains a functional glycolytic pathway and its role in the cellular metabolism ofMtbhas yet to be understood. Pyruvate kinase catalyzes the last and rate-limiting step in glycolysis and theMtbgenome harbors one putative pyruvate kinase (pykA, Rv1617). Here we show thatpykAencodes an active pyruvate kinase that is allosterically activated by glucose 6-phosphate (Glc-6-P) and adenosine monophosphate (AMP). Deletion ofpykApreventsMtbgrowth in the presence of fermentable carbon sources and has a cidal effect in the presence of glucose that correlates with elevated levels of the toxic catabolite methylglyoxal. Growth attenuation was also observed in media containing a combination of short chain fatty acids and glucose and surprisingly, in media containing odd and even chain fatty acids alone. Untargeted high sensitivity metabolomics revealed that inactivation of pyruvate kinase leads to accumulation of phosphoenolpyruvate (P-enolpyruvate), citrate, and aconitate, which was consistent with allosteric inhibition of isocitrate dehydrogenase by P-enolpyruvate. This metabolic block could be relieved by addition of the α-ketoglutarate precursor glutamate. Taken together, our study identifies an essential role of pyruvate kinase in preventing metabolic block during carbon co-catabolism inMtb.
Collapse
Affiliation(s)
- Tahel Noy
- From the Departments of Biochemistry and
| | | | - Travis E Hartman
- the Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York 10021
| | - Kyu Y Rhee
- the Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York 10021
| | - William R Jacobs
- the Department of Microbiology and Immunology, Howard Hughes Medical Institute at Albert Einstein College of Medicine, New York, New York 10461, and Microbiology and Immunology, Albert Einstein College of Medicine, New York, New York 10461
| | - Michael Berney
- Microbiology and Immunology, Albert Einstein College of Medicine, New York, New York 10461,
| | | |
Collapse
|
113
|
Evangelopoulos D, da Fonseca JD, Waddell SJ. Understanding anti-tuberculosis drug efficacy: rethinking bacterial populations and how we model them. Int J Infect Dis 2016; 32:76-80. [PMID: 25809760 DOI: 10.1016/j.ijid.2014.11.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/23/2014] [Indexed: 01/04/2023] Open
Abstract
Tuberculosis still remains a global health emergency, claiming 1.5 million lives in 2013. The bacterium responsible for this disease, Mycobacterium tuberculosis (M.tb), has successfully survived within hostile host environments, adapting to immune defence mechanisms, for centuries. This has resulted in a disease that is challenging to treat, requiring lengthy chemotherapy with multi-drug regimens. One explanation for this difficulty in eliminating M.tb bacilli in vivo is the disparate action of antimicrobials on heterogeneous populations of M.tb, where mycobacterial physiological state may influence drug efficacy. In order to develop improved drug combinations that effectively target diverse mycobacterial phenotypes, it is important to understand how such subpopulations of M.tb are formed during human infection. We review here the in vitro and in vivo systems used to model M.tb subpopulations that may persist during drug therapy, and offer aspirations for future research in this field.
Collapse
Affiliation(s)
| | | | - Simon J Waddell
- Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX, UK
| |
Collapse
|
114
|
Lockwood SY, Meisel JE, Monsma FJ, Spence DM. A Diffusion-Based and Dynamic 3D-Printed Device That Enables Parallel in Vitro Pharmacokinetic Profiling of Molecules. Anal Chem 2016; 88:1864-70. [PMID: 26727249 PMCID: PMC5296943 DOI: 10.1021/acs.analchem.5b04270] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The process of bringing a drug to market involves many steps, including the preclinical stage, where various properties of the drug candidate molecule are determined. These properties, which include drug absorption, distribution, metabolism, and excretion, are often displayed in a pharmacokinetic (PK) profile. While PK profiles are determined in animal models, in vitro systems that model in vivo processes are available, although each possesses shortcomings. Here, we present a 3D-printed, diffusion-based, and dynamic in vitro PK device. The device contains six flow channels, each with integrated porous membrane-based insert wells. The pores of these membranes enable drugs to freely diffuse back and forth between the flow channels and the inserts, thus enabling both loading and clearance portions of a standard PK curve to be generated. The device is designed to work with 96-well plate technology and consumes single-digit milliliter volumes to generate multiple PK profiles, simultaneously. Generation of PK profiles by use of the device was initially performed with fluorescein as a test molecule. Effects of such parameters as flow rate, loading time, volume in the insert well, and initial concentration of the test molecule were investigated. A prediction model was generated from this data, enabling the user to predict the concentration of the test molecule at any point along the PK profile within a coefficient of variation of ∼ 5%. Depletion of the analyte from the well was characterized and was determined to follow first-order rate kinetics, indicated by statistically equivalent (p > 0.05) depletion half-lives that were independent of the starting concentration. A PK curve for an approved antibiotic, levofloxacin, was generated to show utility beyond the fluorescein test molecule.
Collapse
Affiliation(s)
- Sarah Y. Lockwood
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jayda E. Meisel
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | | | - Dana M. Spence
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| |
Collapse
|
115
|
Ascensao JA, Datta P, Hancioglu B, Sontag E, Gennaro ML, Igoshin OA. Non-monotonic Response to Monotonic Stimulus: Regulation of Glyoxylate Shunt Gene-Expression Dynamics in Mycobacterium tuberculosis. PLoS Comput Biol 2016; 12:e1004741. [PMID: 26900694 PMCID: PMC4762938 DOI: 10.1371/journal.pcbi.1004741] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 01/07/2016] [Indexed: 01/27/2023] Open
Abstract
Understanding how dynamical responses of biological networks are constrained by underlying network topology is one of the fundamental goals of systems biology. Here we employ monotone systems theory to formulate a theorem stating necessary conditions for non-monotonic time-response of a biochemical network to a monotonic stimulus. We apply this theorem to analyze the non-monotonic dynamics of the σB-regulated glyoxylate shunt gene expression in Mycobacterium tuberculosis cells exposed to hypoxia. We first demonstrate that the known network structure is inconsistent with observed dynamics. To resolve this inconsistency we employ the formulated theorem, modeling simulations and optimization along with follow-up dynamic experimental measurements. We show a requirement for post-translational modulation of σB activity in order to reconcile the network dynamics with its topology. The results of this analysis make testable experimental predictions and demonstrate wider applicability of the developed methodology to a wide class of biological systems.
Collapse
Affiliation(s)
- Joao A. Ascensao
- Department of Bioengineering and Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| | - Pratik Datta
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Baris Hancioglu
- Department of Bioengineering and Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| | - Eduardo Sontag
- Department of Mathematics and Center for Quantitative Biology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Maria L. Gennaro
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey, United States of America
| | - Oleg A. Igoshin
- Department of Bioengineering and Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| |
Collapse
|
116
|
Devasundaram S, Raja A. Variable transcriptional adaptation between the laboratory (H37Rv) and clinical strains (S7 and S10) of Mycobacterium tuberculosis under hypoxia. INFECTION GENETICS AND EVOLUTION 2016; 40:21-28. [PMID: 26780642 DOI: 10.1016/j.meegid.2016.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/12/2015] [Accepted: 01/07/2016] [Indexed: 11/28/2022]
Abstract
Tuberculosis continues to be a major public health problem in many parts of the world, despite intensified efforts taken to control the disease. The remarkable success of M. tuberculosis as a pathogen is largely due to its ability to persist within the host for long periods. To develop the effective intervention strategies, understanding the biology of persistence is highly required. Accumulating evidences showed oxygen deprivation (hypoxia) as a potential stimulus for triggering the transition of M. tuberculosis to a non-replicating persistent state analogous to latency in vivo. To date, in vitro hypoxia experimental models used the laboratory adapted isolate H37Rv and very little is known about the behavior of clinical isolates that are involved during disease outbreaks. Hence, we compared the transcription profiles of H37Rv and two south Indian clinical isolates (S7 and S10) under hypoxia to find differences in gene expression pattern. The main objective of this current work is to find "differentially regulated genes" (genes that are down regulated in H37Rv but upregulated in both the clinical isolates) under hypoxia. Microarray results showed, a total of 502 genes were down regulated in H37Rv under hypoxia and 10 out of 502 genes were upregulated in both the clinical isolates. Thus, giving less importance to down regulated genes based on H37Rv model strain might exclude the true representative gene candidates in clinical isolates. Our study suggests the use of most prevalent clinical isolates for in vitro experimental model to minimize the variation in understanding the adaptation mechanisms of the strains.
Collapse
Affiliation(s)
- Santhi Devasundaram
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) (Formerly Tuberculosis Research Centre), No.1, Mayor Sathiyamoorthy Road, Chetpet, Chennai 600 031, India
| | - Alamelu Raja
- Department of Immunology, National Institute for Research in Tuberculosis (ICMR) (Formerly Tuberculosis Research Centre), No.1, Mayor Sathiyamoorthy Road, Chetpet, Chennai 600 031, India.
| |
Collapse
|
117
|
Ehrt S, Rhee K, Schnappinger D. Mycobacterial genes essential for the pathogen's survival in the host. Immunol Rev 2015; 264:319-26. [PMID: 25703569 DOI: 10.1111/imr.12256] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mycobacterium tuberculosis (Mtb) has evolved within the human immune system as both host and reservoir. The study of genes required for its growth and persistence in vivo thus offers linked insights into its pathogenicity and host immunity. Studies of Mtb mutants have implicated metabolic adaptation (consisting of carbon, nitrogen, vitamin, and cofactor metabolism), intrabacterial pH homeostasis, and defense against reactive oxygen and reactive nitrogen species, as key determinants of its pathogenicity. However, the mechanisms of host immunity are complex and often combinatorial. Growing evidence has thus begun to reveal that the determinants of Mtb's pathogenicity may serve a broader and more complex array of functions than the isolated experimental settings in which they were initially found. Here, we review select examples, which exemplify this complexity, highlighting the distinct phases of Mtb's life cycle and the diverse microenvironments encountered therein.
Collapse
Affiliation(s)
- Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA
| | | | | |
Collapse
|
118
|
Neyrolles O, Wolschendorf F, Mitra A, Niederweis M. Mycobacteria, metals, and the macrophage. Immunol Rev 2015; 264:249-63. [PMID: 25703564 DOI: 10.1111/imr.12265] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mycobacterium tuberculosis is a facultative intracellular pathogen that thrives inside host macrophages. A key trait of M. tuberculosis is to exploit and manipulate metal cation trafficking inside infected macrophages to ensure survival and replication inside the phagosome. Here, we describe the recent fascinating discoveries that the mammalian immune system responds to infections with M. tuberculosis by overloading the phagosome with copper and zinc, two metals which are essential nutrients in small quantities but are toxic in excess. M. tuberculosis has developed multi-faceted resistance mechanisms to protect itself from metal toxicity including control of uptake, sequestration inside the cell, oxidation, and efflux. The host response to infections combines this metal poisoning strategy with nutritional immunity mechanisms that deprive M. tuberculosis from metals such as iron and manganese to prevent bacterial replication. Both immune mechanisms rely on the translocation of metal transporter proteins to the phagosomal membrane during the maturation process of the phagosome. This review summarizes these recent findings and discusses how metal-targeted approaches might complement existing TB chemotherapeutic regimens with novel anti-infective therapies.
Collapse
Affiliation(s)
- Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, Toulouse, France; Institut de Pharmacologie et de Biologie Structurale, Univer-sité Paul Sabatier, Université de Toulouse, Toulouse, France
| | | | | | | |
Collapse
|
119
|
Anand A, Verma P, Singh AK, Kaushik S, Pandey R, Shi C, Kaur H, Chawla M, Elechalawar CK, Kumar D, Yang Y, Bhavesh NS, Banerjee R, Dash D, Singh A, Natarajan VT, Ojha AK, Aldrich CC, Gokhale RS. Polyketide Quinones Are Alternate Intermediate Electron Carriers during Mycobacterial Respiration in Oxygen-Deficient Niches. Mol Cell 2015; 60:637-50. [PMID: 26585386 DOI: 10.1016/j.molcel.2015.10.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/24/2015] [Accepted: 10/08/2015] [Indexed: 11/16/2022]
Abstract
Mycobacterium tuberculosis (Mtb) adaptation to hypoxia is considered crucial to its prolonged latent persistence in humans. Mtb lesions are known to contain physiologically heterogeneous microenvironments that bring about differential responses from bacteria. Here we exploit metabolic variability within biofilm cells to identify alternate respiratory polyketide quinones (PkQs) from both Mycobacterium smegmatis (Msmeg) and Mtb. PkQs are specifically expressed in biofilms and other oxygen-deficient niches to maintain cellular bioenergetics. Under such conditions, these metabolites function as mobile electron carriers in the respiratory electron transport chain. In the absence of PkQs, mycobacteria escape from the hypoxic core of biofilms and prefer oxygen-rich conditions. Unlike the ubiquitous isoprenoid pathway for the biosynthesis of respiratory quinones, PkQs are produced by type III polyketide synthases using fatty acyl-CoA precursors. The biosynthetic pathway is conserved in several other bacterial genomes, and our study reveals a redox-balancing chemicocellular process in microbial physiology.
Collapse
Affiliation(s)
- Amitesh Anand
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India; Academy of Scientific and Innovative Research, Rafi Marg, New Delhi 110001, India
| | - Priyanka Verma
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Anil Kumar Singh
- CSIR-North East Institute of Science and Technology, Jorhat 785006, India
| | - Sandeep Kaushik
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India
| | - Rajesh Pandey
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India
| | - Ce Shi
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Harneet Kaur
- Center for Drug Design, University of Minnesota, Minneapolis, MN 55455, USA
| | - Manbeena Chawla
- Department of Microbiology and Cell Biology, Centre for Infectious Disease and Research, Indian Institute of Science, Bangalore 560012, India
| | - Chandra Kumar Elechalawar
- Academy of Scientific and Innovative Research, Rafi Marg, New Delhi 110001, India; CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
| | - Dhirendra Kumar
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India
| | - Yong Yang
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Neel S Bhavesh
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Rajkumar Banerjee
- Academy of Scientific and Innovative Research, Rafi Marg, New Delhi 110001, India; CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
| | - Debasis Dash
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Centre for Infectious Disease and Research, Indian Institute of Science, Bangalore 560012, India
| | - Vivek T Natarajan
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India
| | - Anil K Ojha
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA; Center for Drug Design, University of Minnesota, Minneapolis, MN 55455, USA
| | - Rajesh S Gokhale
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi 110020, India; Academy of Scientific and Innovative Research, Rafi Marg, New Delhi 110001, India; National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India.
| |
Collapse
|
120
|
Magalon A, Alberge F. Distribution and dynamics of OXPHOS complexes in the bacterial cytoplasmic membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:198-213. [PMID: 26545610 DOI: 10.1016/j.bbabio.2015.10.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 12/23/2022]
Abstract
Oxidative phosphorylation (OXPHOS) is an essential process for most living organisms mostly sustained by protein complexes embedded in the cell membrane. In order to thrive, cells need to quickly respond to changes in the metabolic demand or in their environment. An overview of the strategies that can be employed by bacterial cells to adjust the OXPHOS outcome is provided. Regulation at the level of gene expression can only provide a means to adjust the OXPHOS outcome to long-term trends in the environment. In addition, the actual view is that bioenergetic membranes are highly compartmentalized structures. This review discusses what is known about the spatial organization of OXPHOS complexes and the timescales at which they occur. As exemplified with the commensal gut bacterium Escherichia coli, three levels of spatial organization are at play: supercomplexes, membrane microdomains and polar assemblies. This review provides a particular focus on whether dynamic spatial organization can fine-tune the OXPHOS through the definition of specialized functional membrane microdomains. Putative mechanisms responsible for spatio-temporal regulation of the OXPHOS complexes are discussed. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.
Collapse
Affiliation(s)
- Axel Magalon
- CNRS, Laboratoire de Chimie Bactérienne (UMR 7283), Institut de Microbiologie de la Méditerranée, 13009 Marseille, France; Aix-Marseille University, UMR 7283, 13009 Marseille, France.
| | - François Alberge
- CNRS, Laboratoire de Chimie Bactérienne (UMR 7283), Institut de Microbiologie de la Méditerranée, 13009 Marseille, France; Aix-Marseille University, UMR 7283, 13009 Marseille, France
| |
Collapse
|
121
|
Singh KS, Singh SK. The Mycobacterium tuberculosis H37Ra gene MRA_1916 causes growth defects upon down-regulation. Sci Rep 2015; 5:16131. [PMID: 26531045 PMCID: PMC4632087 DOI: 10.1038/srep16131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 10/08/2015] [Indexed: 11/09/2022] Open
Abstract
D-amino acid oxidases play an important role in converting D-amino acids to their corresponding α-keto acids. MRA_1916 of Mycobacterium tuberculosis H37Ra (Mtb-Ra) is annotated to be a D-amino acid oxidase (DAO). However, not much information is available about its physiological role during Mtb-Ra growth and survival. The present study was taken-up to understand the role of DAO during different stages of growth and effect of its down-regulation on growth. Recombinant Mtb-Ra strains with DAO and GlcB (malate synthase: MRA_1848) gene knockdown were developed and their growth was studied using Microtiter Alamar Blue Assay (MABA) with glycerol, acetate and glycine as a carbon source. Ethyl bromopyruvate (BrP) was used as an inhibitor of GlcB. MABA study showed inhibition of wild-type (WT) and knockdowns in the presence of BrP (2.5mM). However, growth inhibition of WT was less noticeable at lower concentrations of BrP. Mtb-Ra with DAO knockdown showed poor utilization of glycine in the presence of BrP. The DAO localization study showed its prominent distribution in cytosolic fraction and to some extent in cell wall and membrane fractions. Growth profile of WT under oxygen and nutritional stress showed changes in expression of DAO, GlcB, PckA (phosphoenolpyruvate carboxykinase: MRA_0219) and GlyA1 (serine hydroxymethyltransferase: MRA_1104).
Collapse
Affiliation(s)
- Kumar Sachin Singh
- Microbiology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, U.P., India, Pin: 226031
| | - Sudheer Kumar Singh
- Microbiology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, U.P., India, Pin: 226031
| |
Collapse
|
122
|
Zimmermann M, Kuehne A, Boshoff HI, Barry CE, Zamboni N, Sauer U. Dynamic exometabolome analysis reveals active metabolic pathways in non-replicating mycobacteria. Environ Microbiol 2015; 17:4802-15. [PMID: 26373870 PMCID: PMC10500702 DOI: 10.1111/1462-2920.13056] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/13/2015] [Accepted: 09/13/2015] [Indexed: 01/01/2023]
Abstract
An organism's metabolic activity leaves an extracellular footprint and dynamic changes in this exometabolome inform about nutrient uptake, waste disposal and signalling activities. Using non-targeted mass spectrometry, we report exometabolome dynamics of hypoxia-induced, non-replicating mycobacteria that are thought to play a role in latent tuberculosis. Despite evidence of active metabolism, little is known about the mechanisms enabling obligate aerobic mycobacteria to cope with hypoxia, resulting in long-term survival and increased chemotherapeutic tolerance. The dynamics of 379 extracellular compounds of Mycobacterium smegmatis were deconvoluted with a genome-scale metabolic reaction-pair network to generate hypotheses about intracellular pathway usage. Time-resolved (13) C-tracing and mutant experiments then demonstrated a crucial, energy-generating role of asparagine utilization and non-generic usage of the glyoxylate shunt for hypoxic fitness. Experiments with M. bovis and M. tuberculosis revealed the general relevance of asparagine fermentation and a variable contribution of the glyoxylate shunt to non-replicative, hypoxic survival between the three species.
Collapse
Affiliation(s)
- Michael Zimmermann
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- PhD Program Systems Biology, Life Science Zurich Graduate School, Zurich, Switzerland
| | - Andreas Kuehne
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- PhD Program Systems Biology, Life Science Zurich Graduate School, Zurich, Switzerland
| | - Helena I. Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
123
|
Kiran D, Podell BK, Chambers M, Basaraba RJ. Host-directed therapy targeting the Mycobacterium tuberculosis granuloma: a review. Semin Immunopathol 2015; 38:167-83. [PMID: 26510950 PMCID: PMC4779125 DOI: 10.1007/s00281-015-0537-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/13/2015] [Indexed: 12/16/2022]
Abstract
Infection by the intracellular bacterial pathogen Mycobacterium tuberculosis (Mtb) is a major cause of morbidity and mortality worldwide. Slow progress has been made in lessening the impact of tuberculosis (TB) on human health, especially in parts of the world where Mtb is endemic. Due to the complexity of TB disease, there is still an urgent need to improve diagnosis, prevention, and treatment strategies to control global spread of disease. Active research targeting avenues to prevent infection or transmission through vaccination, to diagnose asymptomatic carriers of Mtb, and to improve antimicrobial drug treatment responses is ongoing. However, this research is hampered by a relatively poor understanding of the pathogenesis of early infection and the factors that contribute to host susceptibility, protection, and the development of active disease. There is increasing interest in the development of adjunctive therapy that will aid the host in responding to Mtb infection appropriately thereby improving the effectiveness of current and future drug treatments. In this review, we summarize what is known about the host response to Mtb infection in humans and animal models and highlight potential therapeutic targets involved in TB granuloma formation and resolution. Strategies designed to shift the balance of TB granuloma formation toward protective rather than destructive processes are discussed based on our current knowledge. These therapeutic strategies are based on the assumption that granuloma formation, although thought to prevent the spread of the tubercle bacillus within and between individuals contributes to manifestations of active TB disease in human patients when left unchecked. This effect of granuloma formation favors the spread of infection and impairs antimicrobial drug treatment. By gaining a better understanding of the mechanisms by which Mtb infection contributes to irreversible tissue damage, down regulates protective immune responses, and delays tissue healing, new treatment strategies can be rationally designed. Granuloma-targeted therapy is advantageous because it allows for the repurpose of existing drugs used to treat other communicable and non-communicable diseases as adjunctive therapies combined with existing and future anti-TB drugs. Thus, the development of adjunctive, granuloma-targeted therapy, like other host-directed therapies, may benefit from the availability of approved drugs to aid in treatment and prevention of TB. In this review, we have attempted to summarize the results of published studies in the context of new innovative approaches to host-directed therapy that need to be more thoroughly explored in pre-clinical animal studies and in human clinical trials.
Collapse
Affiliation(s)
- Dilara Kiran
- Department of Microbiology, Immunology and Pathology, Metabolism of Infectious Diseases Laboratory and Mycobacteria Research Laboratories, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 200 West Lake Street, 1619 Campus Delivery, Fort Collins, CO, 80523-1619, USA
| | - Brendan K Podell
- Department of Microbiology, Immunology and Pathology, Metabolism of Infectious Diseases Laboratory and Mycobacteria Research Laboratories, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 200 West Lake Street, 1619 Campus Delivery, Fort Collins, CO, 80523-1619, USA
| | - Mark Chambers
- Department of Bacteriology, Animal and Plant Health Agency (APHA), Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, UK.,School of Veterinary Medicine Faculty of Health and Medical Sciences, University of Surrey, Vet School Main Building, Daphne Jackson Road, Guildford, GU2 7AL, UK
| | - Randall J Basaraba
- Department of Microbiology, Immunology and Pathology, Metabolism of Infectious Diseases Laboratory and Mycobacteria Research Laboratories, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 200 West Lake Street, 1619 Campus Delivery, Fort Collins, CO, 80523-1619, USA.
| |
Collapse
|
124
|
Gutka HJ, Wang Y, Franzblau SG, Movahedzadeh F. glpx Gene in Mycobacterium tuberculosis Is Required for In Vitro Gluconeogenic Growth and In Vivo Survival. PLoS One 2015; 10:e0138436. [PMID: 26397812 PMCID: PMC4580611 DOI: 10.1371/journal.pone.0138436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/31/2015] [Indexed: 11/18/2022] Open
Abstract
Several enzymes involved in central carbon metabolism and gluconeogenesis play a critical role in survival and pathogenesis of Mycobacterium tuberculosis (Mtb). The only known functional fructose 1,6-bisphosphatase (FBPase) in Mtb is encoded by the glpX gene and belongs to the Class II sub-family of FBPase. We describe herein the generation of a ΔglpX strain using homologous recombination. Although the growth profile of ΔglpX is comparable to that of wild type Mtb when grown on the standard enrichment media, its growth is dysgonic with individual gluconeogenic substrates such as oleic acid, glycerol and acetate. In mice lung CFU titers of ΔglpX were 2-3 log10 lower than the wild-type Mtb strain. The results indicate that glpX gene encodes a functional FBPase and is essential for both in vitro and in vivo growth and survival of Mtb. Loss of glpX results in significant reduction of FBPase activity but not complete abolition. These findings verify that the glpX encoded FBPase II in Mtb can be a potential target for drug discovery.
Collapse
Affiliation(s)
- Hiten J. Gutka
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yuehong Wang
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Farahnaz Movahedzadeh
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
125
|
Hampel A, Huber C, Geffers R, Spona-Friedl M, Eisenreich W, Bange FC. Mycobacterium tuberculosis Is a Natural Ornithine Aminotransferase (rocD) Mutant and Depends on Rv2323c for Growth on Arginine. PLoS One 2015; 10:e0136914. [PMID: 26368558 PMCID: PMC4569260 DOI: 10.1371/journal.pone.0136914] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) possesses a genetic repertoire for metabolic pathways, which are specific and fit to its intracellular life style. Under in vitro conditions, Mtb is known to use arginine as a nitrogen source, but the metabolic pathways for arginine utilization have not been identified. Here we show that, in the presence of arginine, Mtb upregulates a gene cluster which includes an ornithine aminotransferase (rocD) and Rv2323c, a gene of unknown function. Isotopologue analysis by using 13C- or 15N-arginine revealed that in Mtb arginine is not only used as nitrogen source but also as carbon source for the formation of amino acids, in particular of proline. Surprisingly, rocD, which is widespread in other bacteria and is part of the classical arginase pathway turned out to be naturally deleted in Mtb, but not in non-tuberculous mycobacteria. Mtb lacking Rv2323c showed a growth defect on arginine, did not produce proline from arginine, and incorporated less nitrogen derived from arginine in its core nitrogen metabolism. We conclude that the highly induced pathway for arginine utilization in Mtb differs from that of other bacteria including non-tuberculous mycobacteria, probably reflecting a specific metabolic feature of intracellular Mtb.
Collapse
Affiliation(s)
- Annegret Hampel
- Department of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hanover, Germany
| | - Claudia Huber
- Lehrstuhl für Biochemie, Technische Universität München, Garching, Germany
| | - Robert Geffers
- Research Group Genome Analytics, Helmholtz Center for Infection Research, 38124 Braunschweig, Germany
| | | | | | - Franz-Christoph Bange
- Department of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hanover, Germany
- * E-mail:
| |
Collapse
|
126
|
Hollinshead WD, Henson WR, Abernathy M, Moon TS, Tang YJ. Rapid metabolic analysis of
Rhodococcus opacus
PD630 via parallel
13
C‐metabolite fingerprinting. Biotechnol Bioeng 2015; 113:91-100. [DOI: 10.1002/bit.25702] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 07/04/2015] [Accepted: 07/07/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Whitney D. Hollinshead
- Department of Energy, Environmental and Chemical EngineeringWashington University in St. LouisSt. LouisMissouri63130
| | - William R. Henson
- Department of Energy, Environmental and Chemical EngineeringWashington University in St. LouisSt. LouisMissouri63130
| | - Mary Abernathy
- Department of Energy, Environmental and Chemical EngineeringWashington University in St. LouisSt. LouisMissouri63130
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical EngineeringWashington University in St. LouisSt. LouisMissouri63130
| | - Yinjie J. Tang
- Department of Energy, Environmental and Chemical EngineeringWashington University in St. LouisSt. LouisMissouri63130
| |
Collapse
|
127
|
Paritala H, Suzuki Y, Carroll KS. Design, synthesis and evaluation of Fe-S targeted adenosine 5'-phosphosulfate reductase inhibitors. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2015; 34:199-220. [PMID: 25710356 DOI: 10.1080/15257770.2014.978012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Adenosine 5'-phosphosulfate reductase (APR) is an iron-sulfur enzyme that is vital for survival of Mycobacterium tuberculosis during dormancy and is an attractive target for the treatment of latent tuberculosis (TB) infection. The 4Fe-4S cluster is coordinated to APR by sulfur atoms of four cysteine residues, is proximal to substrate, adenosine 5'-phopsphosulfate (APS), and is essential for catalytic activity. Herein, we present an approach for the development of a new class of APR inhibitors. As an initial step, we have employed an improved solid-phase chemistry method to prepare a series of N(6)-substituted adenosine analogues and their 5'-phosphates as well as adenosine 5'-phosphate diesters bearing different Fe and S binding groups, such as thiols or carboxylic and hydroxamic acid moieties. Evaluation of the resulting compounds indicates a clearly defined spacing requirement between the Fe-S targeting group and adenosine scaffold and that smaller Fe-S targeting groups are better tolerated. Molecular docking analysis suggests that the S atom of the most potent inhibitor may establish a favorable interaction with an S atom in the cluster. In summary, this study showcases an improved solid-phase method that expedites the preparation of adenosine and related 5'-phosphate derivatives and presents a unique Fe-S targeting strategy for the development of APR inhibitors.
Collapse
|
128
|
Abstract
The dramatic rise in microbial drug resistance in recent years has led to ongoing searches for novel drugs to add to the armory against infectious disease. Nevertheless, a paucity of new antibacterial drugs in discovery and development pipelines using traditional approaches has prompted a variety of unconventional and disruptive strategies for antibacterial drug discovery. Herein, we review recent nontraditional approaches that have been piloted for early drug discovery efforts. These unique methodologies open new avenues for finding the next generation of antimicrobials.
Collapse
Affiliation(s)
- Maya A Farha
- M.G. DeGroote Institute for Infectious Disease Research, and Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada
| | - Eric D Brown
- M.G. DeGroote Institute for Infectious Disease Research, and Department of Biochemistry and Biomedical Sciences, McMaster University, Ontario, Canada
| |
Collapse
|
129
|
Schubert OT, Ludwig C, Kogadeeva M, Zimmermann M, Rosenberger G, Gengenbacher M, Gillet LC, Collins BC, Röst HL, Kaufmann SHE, Sauer U, Aebersold R. Absolute Proteome Composition and Dynamics during Dormancy and Resuscitation of Mycobacterium tuberculosis. Cell Host Microbe 2015; 18:96-108. [PMID: 26094805 DOI: 10.1016/j.chom.2015.06.001] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 04/20/2015] [Accepted: 05/18/2015] [Indexed: 10/23/2022]
Abstract
Mycobacterium tuberculosis remains a health concern due to its ability to enter a non-replicative dormant state linked to drug resistance. Understanding transitions into and out of dormancy will inform therapeutic strategies. We implemented a universally applicable, label-free approach to estimate absolute cellular protein concentrations on a proteome-wide scale based on SWATH mass spectrometry. We applied this approach to examine proteomic reorganization of M. tuberculosis during exponential growth, hypoxia-induced dormancy, and resuscitation. The resulting data set covering >2,000 proteins reveals how protein biomass is distributed among cellular functions during these states. The stress-induced DosR regulon contributes 20% to cellular protein content during dormancy, whereas ribosomal proteins remain largely unchanged at 5%-7%. Absolute protein concentrations furthermore allow protein alterations to be translated into changes in maximal enzymatic reaction velocities, enhancing understanding of metabolic adaptations. Thus, global absolute protein measurements provide a quantitative description of microbial states, which can support the development of therapeutic interventions.
Collapse
Affiliation(s)
- Olga T Schubert
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Christina Ludwig
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Maria Kogadeeva
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Michael Zimmermann
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - George Rosenberger
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Martin Gengenbacher
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, D-10117, Germany; Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore SG-117545, Singapore
| | - Ludovic C Gillet
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Ben C Collins
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Hannes L Röst
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Stefan H E Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, D-10117, Germany
| | - Uwe Sauer
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, CH-8093, Switzerland; Faculty of Science, University of Zurich, Zurich CH-8057, Switzerland.
| |
Collapse
|
130
|
Nguta JM, Appiah-Opong R, Nyarko AK, Yeboah-Manu D, Addo PGA. Current perspectives in drug discovery against tuberculosis from natural products. Int J Mycobacteriol 2015; 4:165-83. [PMID: 27649863 DOI: 10.1016/j.ijmyco.2015.05.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 05/03/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022] Open
Abstract
Currently, one third of the world's population is latently infected with Mycobacterium tuberculosis (MTB), while 8.9-9.9 million new and relapse cases of tuberculosis (TB) are reported yearly. The renewed research interests in natural products in the hope of discovering new and novel antitubercular leads have been driven partly by the increased incidence of multidrug-resistant strains of MTB and the adverse effects associated with the first- and second-line antitubercular drugs. Natural products have been, and will continue to be a rich source of new drugs against many diseases. The depth and breadth of therapeutic agents that have their origins in the secondary metabolites produced by living organisms cannot be compared with any other source of therapeutic agents. Discovery of new chemical molecules against active and latent TB from natural products requires an interdisciplinary approach, which is a major challenge facing scientists in this field. In order to overcome this challenge, cutting edge techniques in mycobacteriology and innovative natural product chemistry tools need to be developed and used in tandem. The present review provides a cross-linkage to the most recent literature in both fields and their potential to impact the early phase of drug discovery against TB if seamlessly combined.
Collapse
Affiliation(s)
- Joseph Mwanzia Nguta
- Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana; Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, Kenya
| | - Regina Appiah-Opong
- Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
| | - Alexander K Nyarko
- Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
| | - Dorothy Yeboah-Manu
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
| | - Phyllis G A Addo
- Department of Animal Experimentation, Noguchi Memorial Institute for Medical Research, University of Ghana, Ghana
| |
Collapse
|
131
|
Gopinath V, Raghunandanan S, Gomez RL, Jose L, Surendran A, Ramachandran R, Pushparajan AR, Mundayoor S, Jaleel A, Kumar RA. Profiling the Proteome of Mycobacterium tuberculosis during Dormancy and Reactivation. Mol Cell Proteomics 2015; 14:2160-76. [PMID: 26025969 DOI: 10.1074/mcp.m115.051151] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Indexed: 11/06/2022] Open
Abstract
Tuberculosis, caused by Mycobacterium tuberculosis, still remains a major global health problem. The main obstacle in eradicating this disease is the ability of this pathogen to remain dormant in macrophages, and then reactivate later under immuno-compromised conditions. The physiology of hypoxic nonreplicating M. tuberculosis is well-studied using many in vitro dormancy models. However, the physiological changes that take place during the shift from dormancy to aerobic growth (reactivation) have rarely been subjected to a detailed investigation. In this study, we developed an in vitro reactivation system by re-aerating the virulent laboratory strain of M. tuberculosis that was made dormant employing Wayne's dormancy model, and compared the proteome profiles of dormant and reactivated bacteria using label-free one-dimensional LC/MS/MS analysis. The proteome of dormant bacteria was analyzed at nonreplicating persistent stage 1 (NRP1) and stage 2 (NRP2), whereas that of reactivated bacteria was analyzed at 6 and 24 h post re-aeration. Proteome of normoxially grown bacteria served as the reference. In total, 1871 proteins comprising 47% of the M. tuberculosis proteome were identified, and many of them were observed to be expressed differentially or uniquely during dormancy and reactivation. The number of proteins detected at different stages of dormancy (764 at NRP1, 691 at NRP2) and reactivation (768 at R6 and 983 at R24) was very low compared with that of the control (1663). The number of unique proteins identified during normoxia, NRP1, NRP2, R6, and R24 were 597, 66, 56, 73, and 94, respectively. We analyzed various biological functions during these conditions. Fluctuation in the relative quantities of proteins involved in energy metabolism during dormancy and reactivation was the most significant observation we made in this study. Proteins that are up-regulated or uniquely expressed during reactivation from dormancy offer to be attractive targets for therapeutic intervention to prevent reactivation of latent tuberculosis.
Collapse
Affiliation(s)
- Vipin Gopinath
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Sajith Raghunandanan
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Roshna Lawrence Gomez
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Leny Jose
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Arun Surendran
- §Mass Spectrometry and Proteomic Core Facility, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Ranjit Ramachandran
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Akhil Raj Pushparajan
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Sathish Mundayoor
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Abdul Jaleel
- §Mass Spectrometry and Proteomic Core Facility, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India
| | - Ramakrishnan Ajay Kumar
- From the ‡Mycobacterium Research Group, Rajiv Gandhi Centre for Biotechnology, Thycaud P.O., Thiruvananthapuram 695014, India;
| |
Collapse
|
132
|
Bioluminescence for assessing drug potency against nonreplicating Mycobacterium tuberculosis. Antimicrob Agents Chemother 2015; 59:4012-9. [PMID: 25896710 DOI: 10.1128/aac.00528-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 04/16/2015] [Indexed: 12/17/2022] Open
Abstract
Targeting dormant Mycobacterium tuberculosis represents a challenge to antituberculosis drug discovery programs. We previously reported and validated the use of the streptomycin (STR)-dependent M. tuberculosis 18b strain as a tool for assessing drug potency against nonreplicating bacteria both in vitro and in vivo. In this study, we generated a luminescent 18b strain, named 18b-Lux, by transforming the bacteria with a vector expressing the luxCDABE operon from Photorhabdus luminescens. Luciferase expression was demonstrated under replicating conditions, and, more importantly, luminescence levels significantly above background were detected following STR removal. The sensitivity of STR-starved 18b-Lux to approved and candidate antituberculosis therapeutic agents was evaluated by means of a luciferase assay in a 96-well format. Results mirrored the data obtained with the standard resazurin reduction microplate assay, and the luminescence readout allowed time course assessments of drug efficacy in vitro. Specifically, we proved that bedaquiline, the rifamycins, and sutezolid displayed time-dependent activity against dormant bacteria, while pyrazinamide and SQ109 showed bactericidal effects at the highest concentrations tested. Overall, we established the optimal conditions for an inexpensive, simple, and very sensitive assay with great potential for future applications.
Collapse
|
133
|
Drain PK, Gounder L, Grobler A, Sahid F, Bassett IV, Moosa MYS. Urine lipoarabinomannan to monitor antituberculosis therapy response and predict mortality in an HIV-endemic region: a prospective cohort study. BMJ Open 2015; 5:e006833. [PMID: 25877271 PMCID: PMC4401837 DOI: 10.1136/bmjopen-2014-006833] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE To determine if urinary lipoarabinomannan (LAM) may serve as a biomarker to monitor antituberculosis (TB) therapy response, and whether LAM results before and after treatment are predictive of patient outcomes. DESIGN Prospective cohort. SETTING Outpatient referral clinic and tertiary hospital in South Africa. PARTICIPANTS Adults (≥18 years) with ≥2 TB-related symptoms (cough, fever, weight loss, night sweats) for ≥2 weeks being initiated on anti-TB therapy. INTERVENTIONS On enrolment, we obtained urine and nebulised sputum specimens, offered HIV testing and started participants on anti-TB therapy for ≥6 months. We collected urine samples after the 2-month intensive treatment phase and at the completion of anti-TB therapy. Positive LAM results were graded from 1 (low) to 5 (high). Participants were followed for >3 years. OUTCOME MEASURES The primary outcome was change in urine LAM results during anti-TB therapy. The secondary outcome was all-cause mortality. RESULTS Among 90 participants, 57 (63%) had culture-confirmed pulmonary TB. Among the 88 participants tested, 82 (93%) were HIV-infected with median CD4 168/mm(3) (IQR 89-256/mm(3)). During anti-TB therapy, the percentage of LAM-positive participants decreased from baseline to 2 months (32% to 16%), and from baseline to 6-months (32% to 10%) (p values <0.005). In multivariate longitudinal analyses, urine LAM positivity and grade decreased among those with culture-confirmed pulmonary TB (p<0.0001), and had no change in sputum culture-negative participants. At the 2-month visit, participants with positive laboratory-based LAM or rapid LAM with ≥2+ grade had a significantly greater risk of mortality. In analyses adjusted for age, sex, baseline Karnofsky score and HIV status, participants with a rapid LAM ≥2+ grade after 2 months of anti-TB therapy had a 5.6-fold (95% CI 1.2 to 25.2) greater risk of mortality. CONCLUSIONS Rapid urine LAM testing may be a valuable tool to monitor anti-TB therapy response and to assess prognosis of patients being treated for pulmonary TB in HIV-endemic regions.
Collapse
Affiliation(s)
- Paul K Drain
- Medical Practice Evaluation Center, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Lilishia Gounder
- Department of Virology, National Health Laboratory Service, Inkosi Albert Luthuli Central Hospital, Durban, South Africa
| | - Anneke Grobler
- Centre for the AIDS Programme of Research in South Africa, Durban, South Africa
| | - Faieza Sahid
- University of Witwatersrand, Johannesburg, South Africa
| | - Ingrid V Bassett
- Medical Practice Evaluation Center, Boston, Massachusetts, USA
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Mahomed-Yunus S Moosa
- Department of Infectious Diseases, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
134
|
Mohanty S, Jagannathan L, Ganguli G, Padhi A, Roy D, Alaridah N, Saha P, Nongthomba U, Godaly G, Gopal RK, Banerjee S, Sonawane A. A mycobacterial phosphoribosyltransferase promotes bacillary survival by inhibiting oxidative stress and autophagy pathways in macrophages and zebrafish. J Biol Chem 2015; 290:13321-43. [PMID: 25825498 DOI: 10.1074/jbc.m114.598482] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The M. tuberculosis cell wall contains numerous glycoproteins with unknown roles in pathogenesis. Here, by using Concanavalin A and LC-MS analysis, we identified a novel mannosylated glycoprotein phosphoribosyltransferase, encoded by Rv3242c from M. tuberculosis cell walls. Homology modeling, bioinformatic analyses, and an assay of phosphoribosyltransferase activity in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that the M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild type and the complemented ΔmimG:Rv3242c M. marinum strains showed prominent pathological features, such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared with wild type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c- and mimG-mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species, and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB, and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factor, suggesting that it may constitute a novel target for antimycobacterial drugs.
Collapse
Affiliation(s)
- Soumitra Mohanty
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Lakshmanan Jagannathan
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India, the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India
| | - Geetanjali Ganguli
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Avinash Padhi
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India
| | - Debasish Roy
- the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Nader Alaridah
- the Department of Microbiology, Immunology, and Glycobiology, Institute of Laboratory Medicine, Lund University, 221 00 Lund, Sweden
| | - Pratip Saha
- the Bioinformatics Center, Indian Institute of Science, Bangalore, Karnataka 560012, India, and
| | - Upendra Nongthomba
- the Department of Molecular Reproduction, Development, and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Gabriela Godaly
- the Department of Microbiology, Immunology, and Glycobiology, Institute of Laboratory Medicine, Lund University, 221 00 Lund, Sweden
| | - Ramesh Kumar Gopal
- the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India
| | - Sulagna Banerjee
- the AU-KBC Research Center, MIT Campus, Anna University, Chromepet, Chennai, Tamil Nadu 600025, India, the Department of Surgery, University of Minnesota, Minneapolis, Minnesota 55455
| | - Avinash Sonawane
- From the School of Biotechnology, Campus-11, KIIT University, Bhubaneswar, Orissa-751024, India,
| |
Collapse
|
135
|
Walter ND, Dolganov GM, Garcia BJ, Worodria W, Andama A, Musisi E, Ayakaka I, Van TT, Voskuil MI, de Jong BC, Davidson RM, Fingerlin TE, Kechris K, Palmer C, Nahid P, Daley CL, Geraci M, Huang L, Cattamanchi A, Strong M, Schoolnik GK, Davis JL. Transcriptional Adaptation of Drug-tolerant Mycobacterium tuberculosis During Treatment of Human Tuberculosis. J Infect Dis 2015; 212:990-8. [PMID: 25762787 DOI: 10.1093/infdis/jiv149] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/02/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Treatment initiation rapidly kills most drug-susceptible Mycobacterium tuberculosis, but a bacterial subpopulation tolerates prolonged drug exposure. We evaluated drug-tolerant bacilli in human sputum by comparing messenger RNA (mRNA) expression of drug-tolerant bacilli that survive the early bactericidal phase with treatment-naive bacilli. METHODS M. tuberculosis gene expression was quantified via reverse-transcription polymerase chain reaction in serial sputa from 17 Ugandans treated for drug-susceptible pulmonary tuberculosis. RESULTS Within 4 days, bacterial mRNA abundance declined >98%, indicating rapid killing. Thereafter, the rate of decline slowed >94%, indicating drug tolerance. After 14 days, 16S ribosomal RNA transcripts/genome declined 96%, indicating slow growth. Drug-tolerant bacilli displayed marked downregulation of genes associated with growth, metabolism, and lipid synthesis and upregulation in stress responses and key regulatory categories-including stress-associated sigma factors, transcription factors, and toxin-antitoxin genes. Drug efflux pumps were upregulated. The isoniazid stress signature was induced by initial drug exposure, then disappeared after 4 days. CONCLUSIONS Transcriptional patterns suggest that drug-tolerant bacilli in sputum are in a slow-growing, metabolically and synthetically downregulated state. Absence of the isoniazid stress signature in drug-tolerant bacilli indicates that physiological state influences drug responsiveness in vivo. These results identify novel drug targets that should aid in development of novel shorter tuberculosis treatment regimens.
Collapse
Affiliation(s)
- Nicholas D Walter
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora Pulmonary Division, Denver Veterans Administration Medical Center, Colorado
| | - Gregory M Dolganov
- Department of Microbiology and Immunology, Stanford University, California
| | - Benjamin J Garcia
- Integrated Center for Genes, Environment, and Health, National Jewish Health, Denver Computational Bioscience Program, University of Colorado Denver, Aurora
| | - William Worodria
- Makerere University-University of California, San Francisco Research Collaboration, Kampala, Uganda
| | - Alfred Andama
- Makerere University-University of California, San Francisco Research Collaboration, Kampala, Uganda
| | - Emmanuel Musisi
- Makerere University-University of California, San Francisco Research Collaboration, Kampala, Uganda
| | - Irene Ayakaka
- Makerere University-University of California, San Francisco Research Collaboration, Kampala, Uganda
| | - Tran T Van
- Department of Microbiology and Immunology, Stanford University, California
| | - Martin I Voskuil
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora
| | | | - Rebecca M Davidson
- Integrated Center for Genes, Environment, and Health, National Jewish Health, Denver
| | - Tasha E Fingerlin
- Department of Epidemiology and Biostatistics Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora
| | - Katerina Kechris
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora
| | - Claire Palmer
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora
| | - Payam Nahid
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco
| | - Charles L Daley
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora Division of Mycobacterial and Respiratory Infections, National Jewish Health, Denver, Colorado
| | - Mark Geraci
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora
| | - Laurence Huang
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco HIV/AIDS Division, University of California San Francisco
| | - Adithya Cattamanchi
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco
| | - Michael Strong
- Integrated Center for Genes, Environment, and Health, National Jewish Health, Denver
| | - Gary K Schoolnik
- Department of Microbiology and Immunology, Stanford University, California
| | - John Lucian Davis
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco
| |
Collapse
|
136
|
Abhale YK, Deshmukh KK, Sasane AV, Chavan AP, Mhaske PC. Fused Heterocycles: Synthesis and Antitubercular Activity of Novel 6-Substituted-2-(4-methyl-2-substituted phenylthiazol-5-yl)H-imidazo[1,2-a]pyridine. J Heterocycl Chem 2015. [DOI: 10.1002/jhet.2409] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Yogita K. Abhale
- Post-Graduate and Research, Department of Chemistry; S. N. Arts, D. J. M. Commerce and B. N. S. Science College; Sangamner 422 005 District Ahmednagar India (Affiliated to University of Pune)
| | - Keshav K. Deshmukh
- Post-Graduate and Research, Department of Chemistry; S. N. Arts, D. J. M. Commerce and B. N. S. Science College; Sangamner 422 005 District Ahmednagar India (Affiliated to University of Pune)
| | - Amit V. Sasane
- Post Graduate Department of Chemistry; S. P. Mandali's, Sir Parashurambhau College; Tilak Road Pune 411 030 India (Affiliated to University of Pune)
| | - Abhijit P. Chavan
- Post Graduate Department of Chemistry; S. P. Mandali's, Sir Parashurambhau College; Tilak Road Pune 411 030 India (Affiliated to University of Pune)
| | - Pravin C. Mhaske
- Post Graduate Department of Chemistry; S. P. Mandali's, Sir Parashurambhau College; Tilak Road Pune 411 030 India (Affiliated to University of Pune)
| |
Collapse
|
137
|
Mashalidis EH, Gittis AG, Tomczak A, Abell C, Barry CE, Garboczi DN. Molecular insights into the binding of coenzyme F420 to the conserved protein Rv1155 from Mycobacterium tuberculosis. Protein Sci 2015; 24:729-40. [PMID: 25644473 DOI: 10.1002/pro.2645] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 01/17/2015] [Accepted: 01/20/2015] [Indexed: 01/01/2023]
Abstract
Coenzyme F420 is a deazaflavin hydride carrier with a lower reduction potential than most flavins. In Mycobacterium tuberculosis (Mtb), F420 plays an important role in activating PA-824, an antituberculosis drug currently used in clinical trials. Although F420 is important to Mtb redox metabolism, little is known about the enzymes that bind F420 and the reactions that they catalyze. We have identified a novel F420 -binding protein, Rv1155, which is annotated in the Mtb genome sequence as a putative flavin mononucleotide (FMN)-binding protein. Using biophysical techniques, we have demonstrated that instead of binding FMN or other flavins, Rv1155 binds coenzyme F420 . The crystal structure of the complex of Rv1155 and F420 reveals one F420 molecule bound to each monomer of the Rv1155 dimer. Structural, biophysical, and bioinformatic analyses of the Rv1155-F420 complex provide clues about its role in the bacterium.
Collapse
Affiliation(s)
- Ellene H Mashalidis
- Tuberculosis Research Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, 20892; Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, United Kingdom
| | | | | | | | | | | |
Collapse
|
138
|
Abhale YK, Sasane AV, Chavan AP, Deshmukh KK, Kotapalli SS, Ummanni R, Sayyad SF, Mhaske PC. Synthesis and biological screening of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyls as possible anti-tubercular and antimicrobial agents. Eur J Med Chem 2015; 94:340-7. [PMID: 25778990 DOI: 10.1016/j.ejmech.2015.03.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 03/05/2015] [Accepted: 03/06/2015] [Indexed: 12/21/2022]
Abstract
A series of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyl derivatives, 25-64 were synthesized and evaluated for inhibitory activity against Mycobacterium smegmatis MC(2) 155 strain and antimicrobial activities against four pathogenic bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Among them, compounds 40, 49, 50, and 54 exhibited moderate to good inhibition on the growth of the bacteria Mycobacterium smegmatis at the concentration of 30 μM. Compounds 26, 40, 44, 54 and 56 exhibited moderate to good antibacterial activity. Compound 5-(2'-(4-fluorobenzyl)thiazol-4'-yl)-2-(4-fluorophenyl)-4-methyl-thiazole (54) exhibited both antitubercular as well as antimicrobial activity against all tested strains.
Collapse
Affiliation(s)
- Yogita K Abhale
- Post-Graduate Department of Chemistry and Research Centre, S. N. Arts, D. J. M. Commerce and B. N. S. Science College, College Road, District Ahmednagar, Sangamner 422 605, India
| | - Amit V Sasane
- Post Graduate Department of Chemistry, S. P. Mandali's Sir Parashurambhau College, Tilak Road, 411 030 Pune, India
| | - Abhijit P Chavan
- Post Graduate Department of Chemistry, S. P. Mandali's Sir Parashurambhau College, Tilak Road, 411 030 Pune, India
| | - Keshav K Deshmukh
- Post-Graduate Department of Chemistry and Research Centre, S. N. Arts, D. J. M. Commerce and B. N. S. Science College, College Road, District Ahmednagar, Sangamner 422 605, India
| | - Sudha Sravanti Kotapalli
- Center for Chemical Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Ramesh Ummanni
- Center for Chemical Biology, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Sadikali F Sayyad
- Amrutvahini College of Pharmacy, Amrutnagar, P. O. Sangamner (S.K.), Tal. Dist. Ahmednagar, 422 608 Sangamner, Maharashtra, India
| | - Pravin C Mhaske
- Post Graduate Department of Chemistry, S. P. Mandali's Sir Parashurambhau College, Tilak Road, 411 030 Pune, India.
| |
Collapse
|
139
|
Lewis AH, Falkinham JO. Microaerobic growth and anaerobic survival of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum. Int J Mycobacteriol 2015; 4:25-30. [PMID: 26655194 DOI: 10.1016/j.ijmyco.2014.11.066] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/17/2014] [Indexed: 11/19/2022] Open
Abstract
Representative strains of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS) grew at equal rates in laboratory medium at 21% (air) and 12% oxygen. Growth in 6% oxygen proceeded at a 1.4-1.8-fold lower rate. Colony formation was the same at 21% (air) and 6% oxygen. The MAIS strains survived rapid shifts from aerobic to anaerobic conditions as measured by two experimental approaches (Falkinham (1996) [1]). MAIS cells grown aerobically to log phase in broth were diluted, spread on agar medium, and incubated anaerobically for up to 20 days at 37°C. Although no colonies formed anaerobically, upon transfer to aerobic conditions, greater than 25% of the colony forming units (CFU) survived after 20 days of anaerobic incubation (Prince et al. (1989) [2]). MAIS cells grown in broth aerobically to log phase were sealed and vigorous agitation led to oxygen depletion (Wayne model). After 12 days anaerobic incubation, M. avium and M. scrofulaceum survival were high (>50%), while M. intracellulare survival was lower (22%). M. avium cells shifted to anaerobiosis in broth had increased levels of glycine dehydrogenase and isocitrate lyase. Growth of MAIS strains at low oxygen levels and their survival following a rapid shift to anaerobiosis is consistent with their presence in environments with fluctuating oxygen levels.
Collapse
Affiliation(s)
- Amy Herndon Lewis
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0406, USA
| | - Joseph O Falkinham
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0406, USA.
| |
Collapse
|
140
|
Yang M, Wang Y, Chen Y, Cheng Z, Gu J, Deng J, Bi L, Chen C, Mo R, Wang X, Ge F. Succinylome analysis reveals the involvement of lysine succinylation in metabolism in pathogenic Mycobacterium tuberculosis. Mol Cell Proteomics 2015; 14:796-811. [PMID: 25605462 DOI: 10.1074/mcp.m114.045922] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis, remains one of the most prevalent human pathogens and a major cause of mortality worldwide. Metabolic network is a central mediator and defining feature of the pathogenicity of Mtb. Increasing evidence suggests that lysine succinylation dynamically regulates enzymes in carbon metabolism in both bacteria and human cells; however, its extent and function in Mtb remain unexplored. Here, we performed a global succinylome analysis of the virulent Mtb strain H37Rv by using high accuracy nano-LC-MS/MS in combination with the enrichment of succinylated peptides from digested cell lysates and subsequent peptide identification. In total, 1545 lysine succinylation sites on 626 proteins were identified in this pathogen. The identified succinylated proteins are involved in various biological processes and a large proportion of the succinylation sites are present on proteins in the central metabolism pathway. Site-specific mutations showed that succinylation is a negative regulatory modification on the enzymatic activity of acetyl-CoA synthetase. Molecular dynamics simulations demonstrated that succinylation affects the conformational stability of acetyl-CoA synthetase, which is critical for its enzymatic activity. Further functional studies showed that CobB, a sirtuin-like deacetylase in Mtb, functions as a desuccinylase of acetyl-CoA synthetase in in vitro assays. Together, our findings reveal widespread roles for lysine succinylation in regulating metabolism and diverse processes in Mtb. Our data provide a rich resource for functional analyses of lysine succinylation and facilitate the dissection of metabolic networks in this life-threatening pathogen.
Collapse
Affiliation(s)
- Mingkun Yang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yan Wang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Ying Chen
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhongyi Cheng
- §Advanced Institute of Translational Medicine, Tongji University, Shanghai 200092, China
| | - Jing Gu
- ¶Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jiaoyu Deng
- ¶Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Lijun Bi
- ‖Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chuangbin Chen
- **Jingjie PTM Biolabs (Hangzhou) Co. Ltd, Hangzhou 310018, China
| | - Ran Mo
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xude Wang
- ¶Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Feng Ge
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
| |
Collapse
|
141
|
Ferraris DM, Spallek R, Oehlmann W, Singh M, Rizzi M. Structures of citrate synthase and malate dehydrogenase of M
ycobacterium tuberculosis. Proteins 2015; 83:389-94. [DOI: 10.1002/prot.24743] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/20/2014] [Accepted: 11/26/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Davide M. Ferraris
- Department of Pharmaceutical Sciences; Università del Piemonte Orientale “A. Avogadro”, Largo Donegani 2; 28100 Novara Italy
| | - Ralf Spallek
- Lionex Diagnostics and Therapeutic GmbH; D-38126 Braunschweig Germany
| | - Wulf Oehlmann
- Lionex Diagnostics and Therapeutic GmbH; D-38126 Braunschweig Germany
| | - Mahavir Singh
- Lionex Diagnostics and Therapeutic GmbH; D-38126 Braunschweig Germany
| | - Menico Rizzi
- Department of Pharmaceutical Sciences; Università del Piemonte Orientale “A. Avogadro”, Largo Donegani 2; 28100 Novara Italy
| |
Collapse
|
142
|
Shukla H, Kumar V, Singh AK, Singh N, Kashif M, Siddiqi MI, Yasoda Krishnan M, Sohail Akhtar M. Insight into the structural flexibility and function of Mycobacterium tuberculosis isocitrate lyase. Biochimie 2015; 110:73-80. [PMID: 25576828 DOI: 10.1016/j.biochi.2014.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 12/26/2014] [Indexed: 10/24/2022]
Abstract
Isocitrate lyase (ICL), is a key enzyme of the glyoxylate shunt crucial for the survival of Mycobacterium tuberculosis (Mtb) in macrophages during persistent infection. MtbICL catalyses the first step of this carbon anaplerosis cycle and is considered as a potential anti-tubercular drug target. The MtbICL is a tetramer with 222 symmetry, and each subunit of the enzymeis composed of 14 α-helices and 14 β-strands. We studied the conformational flexibility of the enzyme to get a deeper insight into its stability and function. Our studies show that the mutation of His180, close to the MtbICL signature sequence (K193KCGH197) completely abolishes the oligomeric conformation and function of the enzyme. Molecular dynamics studies suggest that the loss of interaction between His180 and Tyr89 most likely alters the orientation of Tyr89 side chain, thereby causing the movement of helices α6, α12, α13 and α14 in the vicinity and affecting the tetrameric assembly. We further show that the oligomerization of MtbICL is primarily mediated by the inter subunit interactions, and strengthened by the helix swapping of α12-α13 between adjacent subunits. Furthermore, the enzyme activity is influenced by the interactions between the residues of lid region (P411NSSTTALTGSTEEGQFH428) and the loop region (T391KHQREV397). Mutation of glutamates of the lid region to non homologous residues (E423A or E424A) or basic residues (E423K or E424K) inactivates the enzyme, whereas the activity is not much compromised in case of homologous mutations (E423D or E424D).
Collapse
Affiliation(s)
- Harish Shukla
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Vikash Kumar
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Amit Kumar Singh
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Neha Singh
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Md Kashif
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Manju Yasoda Krishnan
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India
| | - Md Sohail Akhtar
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Lucknow, PIN 226 031, India.
| |
Collapse
|
143
|
Xia K, Shen GB, Zhu XQ. Thermodynamics of various F420 coenzyme models as sources of electrons, hydride ions, hydrogen atoms and protons in acetonitrile. Org Biomol Chem 2015; 13:6255-68. [DOI: 10.1039/c5ob00538h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
32 F420 coenzyme model were designed and synthesized; their thermodynamic driving forces to release electrons, hydride ions, hydrogen atoms and protons in acetonitrile were determined. The difference between F420 coenzyme and NADH coenzyme as sources of electrons, hydride ions, hydrogen atoms and protons was examined.
Collapse
Affiliation(s)
- Ke Xia
- The State Key Laboratory of Elemento-Organic Chemistry
- Department of Chemistry
- Collaborative Innovation Center of Chemical Science and Engineering
- Nankai University
- Tianjin 300071
| | - Guang-Bin Shen
- The State Key Laboratory of Elemento-Organic Chemistry
- Department of Chemistry
- Collaborative Innovation Center of Chemical Science and Engineering
- Nankai University
- Tianjin 300071
| | - Xiao-Qing Zhu
- The State Key Laboratory of Elemento-Organic Chemistry
- Department of Chemistry
- Collaborative Innovation Center of Chemical Science and Engineering
- Nankai University
- Tianjin 300071
| |
Collapse
|
144
|
Cho S, Lee HS, Franzblau S. Microplate Alamar Blue Assay (MABA) and Low Oxygen Recovery Assay (LORA) for Mycobacterium tuberculosis. Methods Mol Biol 2015; 1285:281-292. [PMID: 25779323 DOI: 10.1007/978-1-4939-2450-9_17] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Throughput in tuberculosis drug discovery was extremely limited prior to the introduction of microplate-based susceptibility assays. The 96-well Microplate Alamar Blue Assay (MABA) allows for the quantitative determination of drug susceptibility against any strain of replicating Mycobacterium tuberculosis to be completed within a week at minimal cost. The Low-Oxygen Recovery Assay (LORA) uses a recombinant M. tuberculosis expressing luciferase and provides results of drug activity against non-replicating M. tuberculosis surviving under hypoxic conditions. Determining activity against non-replicating M. tuberculosis is an important factor when developing drug candidates against M. tuberculosis. Here we describe a step-by-step procedure for both the MABA and LORA.
Collapse
Affiliation(s)
- Sanghyun Cho
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street (M/C 964), Chicago, IL, 60612, USA
| | | | | |
Collapse
|
145
|
Eniyan K, Bajpai U. Cloning, expression, purification and bioinformatic analysis of 2–methylcitrate synthase from Mycobacterium tuberculosis. ASIAN PAC J TROP MED 2015; 8:19-23. [DOI: 10.1016/s1995-7645(14)60181-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 11/10/2014] [Accepted: 12/22/2014] [Indexed: 10/23/2022] Open
|
146
|
Abstract
Metabolism underpins the physiology and pathogenesis of Mycobacterium tuberculosis. However, although experimental mycobacteriology has provided key insights into the metabolic pathways that are essential for survival and pathogenesis, determining the metabolic status of bacilli during different stages of infection and in different cellular compartments remains challenging. Recent advances-in particular, the development of systems biology tools such as metabolomics-have enabled key insights into the biochemical state of M. tuberculosis in experimental models of infection. In addition, their use to elucidate mechanisms of action of new and existing antituberculosis drugs is critical for the development of improved interventions to counter tuberculosis. This review provides a broad summary of mycobacterial metabolism, highlighting the adaptation of M. tuberculosis as specialist human pathogen, and discusses recent insights into the strategies used by the host and infecting bacillus to influence the outcomes of the host-pathogen interaction through modulation of metabolic functions.
Collapse
Affiliation(s)
- Digby F Warner
- Medical Research Council/National Health Laboratory Services/University of Cape Town Molecular Mycobacteriology Research Unit and Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical TB Research, Institute of Infectious Disease and Molecular Medicine and Division of Medical Microbiology, University of Cape Town, Rondebosch 7700, South Africa
| |
Collapse
|
147
|
Pienaar E, Cilfone NA, Lin PL, Dartois V, Mattila JT, Butler JR, Flynn JL, Kirschner DE, Linderman JJ. A computational tool integrating host immunity with antibiotic dynamics to study tuberculosis treatment. J Theor Biol 2014; 367:166-179. [PMID: 25497475 DOI: 10.1016/j.jtbi.2014.11.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/17/2014] [Accepted: 11/20/2014] [Indexed: 12/31/2022]
Abstract
While active tuberculosis (TB) is a treatable disease, many complex factors prevent its global elimination. Part of the difficulty in developing optimal therapies is the large design space of antibiotic doses, regimens and combinations. Computational models that capture the spatial and temporal dynamics of antibiotics at the site of infection can aid in reducing the design space of costly and time-consuming animal pre-clinical and human clinical trials. The site of infection in TB is the granuloma, a collection of immune cells and bacteria that form in the lung, and new data suggest that penetration of drugs throughout granulomas is problematic. Here we integrate our computational model of granuloma formation and function with models for plasma pharmacokinetics, lung tissue pharmacokinetics and pharmacodynamics for two first line anti-TB antibiotics. The integrated model is calibrated to animal data. We make four predictions. First, antibiotics are frequently below effective concentrations inside granulomas, leading to bacterial growth between doses and contributing to the long treatment periods required for TB. Second, antibiotic concentration gradients form within granulomas, with lower concentrations toward their centers. Third, during antibiotic treatment, bacterial subpopulations are similar for INH and RIF treatment: mostly intracellular with extracellular bacteria located in areas non-permissive for replication (hypoxic areas), presenting a slowly increasing target population over time. Finally, we find that on an individual granuloma basis, pre-treatment infection severity (including bacterial burden, host cell activation and host cell death) is predictive of treatment outcome.
Collapse
Affiliation(s)
- Elsje Pienaar
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Nicholas A Cilfone
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Philana Ling Lin
- Department of Pediatrics, Children׳s Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Véronique Dartois
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Joshua T Mattila
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Russell Butler
- Department of Health and Biomedical Sciences, Adventist University of Health Sciences, Orlando, FL, USA
| | - JoAnne L Flynn
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Denise E Kirschner
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | | |
Collapse
|
148
|
Yongyat C, Ruchirawat S, Boonyarattanakalin S. Controlled ring-opening polymerization of 1,2,6-tricyclic orthoesters of mannose toward size–controlled α-d-mannopyranan. E-POLYMERS 2014. [DOI: 10.1515/epoly-2014-0129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractLipomannan (LM), one of the major components of glycans found on the cell wall of Mycobacterium tuberculosis, plays a critical role in interacting with host cells and moderating immune response. The backbone of LM is composed of α(1–6) mannopyranan, consisting of approximately 10–15 repeating mannose residues. Rapid synthesis of α(1–6) mannopyranan has been accomplished by ring-opening polymerization using 3,4-O-benzyl-β-d-mannopyranose 1,2,6-orthobenzoate (1) as a starting monomer. Here, we report the progress on attempts to control the size of α(1–6) mannopyranan polymer products. It is possible to prepare α-d-mannopyranan polymer products in different sizes by varying the monomer concentration.
Collapse
Affiliation(s)
| | | | - Siwarutt Boonyarattanakalin
- 1School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, Pathum Thani 12121, Thailand
| |
Collapse
|
149
|
Zheng Y, Jiang X, Gao F, Song J, Sun J, Wang L, Sun X, Lu Z, Zhang H. Identification of plant-derived natural products as potential inhibitors of the Mycobacterium tuberculosis proteasome. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 14:400. [PMID: 25315519 PMCID: PMC4203866 DOI: 10.1186/1472-6882-14-400] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 10/07/2014] [Indexed: 01/22/2023]
Abstract
Background The Mycobacterium tuberculosis (Mtb) proteasome has been established as a viable target for the development of anti-tuberculosis agents. In this study, the inhibitory activities of 100 plant-derived natural products on the Mtb proteasome were analyzed to identify novel potential inhibitors. Methods The fluorescent substrate Suc-Leu-Leu-Val-Tyr-AMC can be hydrolyzed by the proteasome to release free AMC, the fluorescence of which is proportional to the proteasome activity. The inhibitory activities of 100 natural products (each at a final concentration of 200 μM) were detected by this method using MG132 as a positive control. Results Twelve of these natural products (10 of which were flavonoids) inhibited the activity of the Mtb proteasome by more than 65%. Comparison of the structural differences between the flavonoids with good inhibitory activity and those without inhibitory activity revealed that the hydroxyl at the flavonoid C ring C-3 or the hydroxyl/methoxyl at the flavonoid A ring C-6 were critical for the inhibition of proteasomal activity. Conclusions These data indicate that flavonoids represent a basis for rational structural design in the process of novel anti-tuberculosis drug discovery.
Collapse
|
150
|
Siricilla S, Mitachi K, Wan B, Franzblau SG, Kurosu M. Discovery of a capuramycin analog that kills nonreplicating Mycobacterium tuberculosis and its synergistic effects with translocase I inhibitors. J Antibiot (Tokyo) 2014; 68:271-8. [PMID: 25269459 PMCID: PMC4382465 DOI: 10.1038/ja.2014.133] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/02/2014] [Accepted: 09/07/2014] [Indexed: 11/20/2022]
Abstract
Capuramycin (1) and its analogs are strong translocase I (MurX/MraY) inhibitors. In our SAR studies of capuramycin analogs against M. tuberculosis (Mtb), we observed for the first time that a capuramycin analog, UT-01320 (3) killed non-replicating (dormant) Mtb at low concentrations under low-oxygen conditions, whereas selective MurX inhibitors killed only replicating Mtb under aerobic conditions. Interestingly, 3 did not exhibit MurX enzyme inhibitory activity even at high concentrations, however, 3 inhibited bacterial RNA polymerases with the IC50 values of 100-150 nM range. A new RNA polymerase inhibitor 3 displayed strong synergistic effects with a MurX inhibitor SQ 641 (2), a promising preclinical TB drug.
Collapse
Affiliation(s)
- Shajila Siricilla
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Katsuhiko Mitachi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bajoie Wan
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Scott G Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Michio Kurosu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|