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Krzyżanowska DM, Jabłońska M, Kaczyński Z, Czerwicka-Pach M, Macur K, Jafra S. Host-adaptive traits in the plant-colonizing Pseudomonas donghuensis P482 revealed by transcriptomic responses to exudates of tomato and maize. Sci Rep 2023; 13:9445. [PMID: 37296159 PMCID: PMC10256816 DOI: 10.1038/s41598-023-36494-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/05/2023] [Indexed: 06/12/2023] Open
Abstract
Pseudomonads are metabolically flexible and can thrive on different plant hosts. However, the metabolic adaptations required for host promiscuity are unknown. Here, we addressed this knowledge gap by employing RNAseq and comparing transcriptomic responses of Pseudomonas donghuensis P482 to root exudates of two plant hosts: tomato and maize. Our main goal was to identify the differences and the common points between these two responses. Pathways upregulated only by tomato exudates included nitric oxide detoxification, repair of iron-sulfur clusters, respiration through the cyanide-insensitive cytochrome bd, and catabolism of amino and/or fatty acids. The first two indicate the presence of NO donors in the exudates of the test plants. Maize specifically induced the activity of MexE RND-type efflux pump and copper tolerance. Genes associated with motility were induced by maize but repressed by tomato. The shared response to exudates seemed to be affected both by compounds originating from the plants and those from their growth environment: arsenic resistance and bacterioferritin synthesis were upregulated, while sulfur assimilation, sensing of ferric citrate and/or other iron carriers, heme acquisition, and transport of polar amino acids were downregulated. Our results provide directions to explore mechanisms of host adaptation in plant-associated microorganisms.
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Affiliation(s)
- Dorota M Krzyżanowska
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdańsk, ul. A. Abrahama 58, 80-307, Gdańsk, Poland
| | - Magdalena Jabłońska
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdańsk, ul. A. Abrahama 58, 80-307, Gdańsk, Poland
| | - Zbigniew Kaczyński
- Laboratory of Structural Biochemistry, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308, Gdańsk, Poland
| | - Małgorzata Czerwicka-Pach
- Laboratory of Structural Biochemistry, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308, Gdańsk, Poland
| | - Katarzyna Macur
- Laboratory of Mass Spectrometry, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdańsk, ul. A. Abrahama 58, 80-307, Gdańsk, Poland
| | - Sylwia Jafra
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdańsk, ul. A. Abrahama 58, 80-307, Gdańsk, Poland.
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Smitten K, Southam HM, Fairbanks S, Graf A, Chauvet A, Thomas JA. Clearing an ESKAPE Pathogen in a Model Organism; A Polypyridyl Ruthenium(II) Complex Theranostic that Treats a Resistant Acinetobacter baumannii Infection in Galleria mellonella. Chemistry 2023; 29:e202203555. [PMID: 36420820 PMCID: PMC10946903 DOI: 10.1002/chem.202203555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
In previous studies we have described the therapeutic action of luminescent dinuclear ruthenium(II) complexes based on the tetrapyridylphenazine, tpphz, bridging ligand on pathogenic strains of Escherichia coli and Enterococcus faecalis. Herein, the antimicrobial activity of the complex against pernicious Gram-negative ESKAPE pathogenic strains of Acinetobacter baumannii (AB12, AB16, AB184 and AB210) and Pseudomonas aeruginosa (PA2017, PA_ 007_ IMP and PA_ 004_ CRCN) are reported. Estimated minimum inhibitory concentrations and minimum bactericidal concentrations for the complexes revealed the complex shows potent activity against all A. baumannii strains, in both glucose defined minimal media and standard nutrient rich Mueller-Hinton-II. Although the activity was lower in P. aureginosa, a moderately high potency was observed and retained in carbapenem-resistant strains. Optical microscopy showed that the compound is rapidly internalized by A. baumannii. As previous reports had revealed the complex exhibited no toxicity in Galleria Mellonella up to concentrations of 80 mg/kg, the ability to clear pathogenic infection within this model was explored. The pathogenic concentrations to the larvae for each bacterium were determined to be≥105 for AB184 and≥103 CFU/mL for PA2017. It was found a single dose of the compound totally cleared a pathogenic A. baumannii infection from all treated G. mellonella within 96 h. Uniquely, in these conditions thanks to the imaging properties of the complex the clearance of the bacteria within the hemolymph of G. mellonella could be directly visualized through both optical and transmission electron microscopy.
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Affiliation(s)
- Kirsty Smitten
- Department of ChemistryUniversity of SheffieldSheffieldS3 7HFUK
| | | | - Simon Fairbanks
- Department of ChemistryUniversity of SheffieldSheffieldS3 7HFUK
| | - Arthur Graf
- Department of ChemistryUniversity of SheffieldSheffieldS3 7HFUK
| | - Adrien Chauvet
- Department of ChemistryUniversity of SheffieldSheffieldS3 7HFUK
| | - Jim A Thomas
- Department of ChemistryUniversity of SheffieldSheffieldS3 7HFUK
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Jing Y, Mu C, Wang H, Shen J, Zoetendal EG, Zhu W. Amino acid utilization allows intestinal dominance of Lactobacillus amylovorus. THE ISME JOURNAL 2022; 16:2491-2502. [PMID: 35896730 PMCID: PMC9561148 DOI: 10.1038/s41396-022-01287-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 06/25/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
The mammalian intestine harbors heterogeneous distribution of microbes among which specific taxa (e.g. Lactobacillus) dominate across mammals. Deterministic factors such as nutrient availability and utilization may affect microbial distributions. Due to physiological complexity, mechanisms linking nutrient utilization and the dominance of key taxa remain unclear. Lactobacillus amylovorus is a predominant species in the small intestine of pigs. Employing a pig model, we found that the small intestine was dominated by Lactobacillus and particularly L. amylovorus, and enriched with peptide-bound amino acids (PBAAs), all of which were further boosted after a peptide-rich diet. To investigate the bacterial growth dominance mechanism, a representative strain L. amylovorus S1 was isolated from the small intestine and anaerobically cultured in media with free amino acids or peptides as sole nitrogen sources. L. amylovorus S1 grew preferentially with peptide-rich rather than amino acid-rich substrates, as reflected by enhanced growth and PBAA utilization, and peptide transporter upregulations. Utilization of free amino acids (e.g. methionine, valine, lysine) and expressions of transporters and metabolic enzymes were enhanced simultaneously in peptide-rich substrate. Additionally, lactate was elevated in peptide-rich substrates while acetate in amino acid-rich substrates, indicating distinct metabolic patterns depending on substrate forms. These results suggest that an increased capability of utilizing PBAAs contributes to the dominance of L. amylovorus, indicating amino acid utilization as a deterministic factor affecting intestinal microbial distribution. These findings may provide new insights into the microbe-gut nutrition interplay and guidelines for dietary manipulations toward gut health especially small intestine health.
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Affiliation(s)
- Yujia Jing
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chunlong Mu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huisong Wang
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Junhua Shen
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Erwin G Zoetendal
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
- National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China.
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Huang H, Feng G, Wang M, Liu C, Wu Y, Dong L, Feng L, Zheng X, Chen Y. Nitric Oxide: A Neglected Driver for the Conjugative Transfer of Antibiotic Resistance Genes among Wastewater Microbiota. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6466-6478. [PMID: 35512279 DOI: 10.1021/acs.est.2c01889] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The dissemination of plasmid-borne antibiotic resistance genes (ARGs) in wastewater is becoming an urgent concern. Previous studies mainly focused on the effects of coexisting contaminants on plasmid conjugation, but ignored the potential contribution of some byproducts inevitably released from wastewater treatment processes. Herein, we demonstrate for the first time that nitric oxide (NO), an intermediate of the wastewater nitrogen cycle, can significantly boost the conjugative transfer of plasmid RP4 from Escherichia coli K12 to different recipients (E. coli HB101, Salmonella typhimurium, and wastewater microbiota). Phenotypic and genotypic tests confirmed that NO-induced promotion was not attributed to the SOS response, a well-recognized driver for horizontal gene transfer. Instead, NO exposure increased the outer membrane permeability of both the donor and recipient by inhibiting the expression of key genes involved in lipopolysaccharide biosynthesis (such as waaJ), thereby lowering the membrane barrier for conjugation. On the other hand, NO exposure not only resulted in the accumulation of intracellular tryptophan but also triggered the deficiency of intracellular methionine, both of which were validated to play key roles in regulating the global regulatory genes (korA, korB, and trbA) of plasmid RP4, activating its encoding transfer apparatus (represented by trfAp and trbBp). Overall, our findings highlighted the risks of NO in spreading ARGs among wastewater microbiota and updated the regulation mechanism of plasmid conjugation.
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Affiliation(s)
- Haining Huang
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Guanqun Feng
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Meng Wang
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Chao Liu
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yang Wu
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lei Dong
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Shanghai Municipal Engn Design Inst Grp Co. Ltd., 901 Zhongshan North Second Road, Shanghai 200092, P. R. China
| | - Leiyu Feng
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xiong Zheng
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yinguang Chen
- State key laboratory of pollution control and Resource reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Defenses of multidrug resistant pathogens against reactive nitrogen species produced in infected hosts. Adv Microb Physiol 2022; 80:85-155. [PMID: 35489794 DOI: 10.1016/bs.ampbs.2022.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacterial pathogens have sophisticated systems that allow them to survive in hosts in which innate immunity is the frontline of defense. One of the substances produced by infected hosts is nitric oxide (NO) that together with its derived species leads to the so-called nitrosative stress, which has antimicrobial properties. In this review, we summarize the current knowledge on targets and protective systems that bacteria have to survive host-generated nitrosative stress. We focus on bacterial pathogens that pose serious health concerns due to the growing increase in resistance to currently available antimicrobials. We describe the role of nitrosative stress as a weapon for pathogen eradication, the detoxification enzymes, protein/DNA repair systems and metabolic strategies that contribute to limiting NO damage and ultimately allow survival of the pathogen in the host. Additionally, this systematization highlights the lack of available data for some of the most important human pathogens, a gap that urgently needs to be addressed.
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Proton motive force underpins respiration-mediated potentiation of aminoglycoside lethality in pathogenic Escherichia coli. Arch Microbiol 2022; 204:120. [PMID: 34989857 PMCID: PMC8739286 DOI: 10.1007/s00203-021-02710-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022]
Abstract
It is well known that loss of aerobic respiration in Gram-negative bacteria can diminish the efficacy of a variety of bactericidal antibiotics, which has lead to subsequent demonstrations that the formation of reactive oxygen species (ROS) and the proton motive force (PMF) can both play a role in antibiotic toxicity. The susceptibility of Gram-negative bacteria to aminoglycoside antibiotics, particularly gentamicin, has previously been linked to both the production of ROS and the rate of antibiotic uptake that is mediated by the PMF, although the relative contributions of ROS and PMF to aminoglycoside toxicity has remained poorly understood. Herein, gentamicin was shown to elicit a very modest increase in ROS levels in an aerobically grown Escherichia coli clinical isolate. The well-characterised uncoupler 2,4-dinitrophenol (DNP) was used to disrupt the PMF, which resulted in a significant decrease in gentamicin lethality towards E. coli. DNP did not significantly alter respiratory oxygen consumption, supporting the hypothesis that this uncoupler does not increase ROS production via elevated respiratory oxidase activity. These observations support the hypothesis that maintenance of PMF rather than induction of ROS production underpins the mechanism for how the respiratory chain potentiates the toxicity of aminoglycosides. This was further supported by the demonstration that the uncoupler DNP elicits a dramatic decrease in gentamicin lethality under anaerobic conditions. Together, these data strongly suggest that maintenance of the PMF is the dominant mechanism for the respiratory chain in potentiating the toxic effects of aminoglycosides.
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Southam HM, Williamson MP, Chapman JA, Lyon RL, Trevitt CR, Henderson PJF, Poole RK. 'Carbon-Monoxide-Releasing Molecule-2 (CORM-2)' Is a Misnomer: Ruthenium Toxicity, Not CO Release, Accounts for Its Antimicrobial Effects. Antioxidants (Basel) 2021; 10:antiox10060915. [PMID: 34198746 PMCID: PMC8227206 DOI: 10.3390/antiox10060915] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023] Open
Abstract
Carbon monoxide (CO)-releasing molecules (CORMs) are used to deliver CO, a biological ‘gasotransmitter’, in biological chemistry and biomedicine. CORMs kill bacteria in culture and in animal models, but are reportedly benign towards mammalian cells. CORM-2 (tricarbonyldichlororuthenium(II) dimer, Ru2Cl4(CO)6), the first widely used and commercially available CORM, displays numerous pharmacological, biochemical and microbiological activities, generally attributed to CO release. Here, we investigate the basis of its potent antibacterial activity against Escherichia coli and demonstrate, using three globin CO sensors, that CORM-2 releases negligible CO (<0.1 mol CO per mol CORM-2). A strong negative correlation between viability and cellular ruthenium accumulation implies that ruthenium toxicity underlies biocidal activity. Exogenous amino acids and thiols (especially cysteine, glutathione and N-acetyl cysteine) protected bacteria against inhibition of growth by CORM-2. Bacteria treated with 30 μM CORM-2, with added cysteine and histidine, exhibited no significant loss of viability, but were killed in the absence of these amino acids. Their prevention of toxicity correlates with their CORM-2-binding affinities (Cys, Kd 3 μM; His, Kd 130 μM) as determined by 1H-NMR. Glutathione is proposed to be an important intracellular target of CORM-2, with CORM-2 having a much higher affinity for reduced glutathione (GSH) than oxidised glutathione (GSSG) (GSH, Kd 2 μM; GSSG, Kd 25,000 μM). The toxicity of low, but potent, levels (15 μM) of CORM-2 was accompanied by cell lysis, as judged by the release of cytoplasmic ATP pools. The biological effects of CORM-2 and related CORMs, and the design of biological experiments, must be re-examined in the light of these data.
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Affiliation(s)
- Hannah M. Southam
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
| | - Michael P. Williamson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
| | - Jonathan A. Chapman
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
- Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Rhiannon L. Lyon
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
| | - Clare R. Trevitt
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
| | - Peter J. F. Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK;
| | - Robert K. Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK; (H.M.S.); (M.P.W.); (J.A.C.); (R.L.L.); (C.R.T.)
- Correspondence:
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Cole JA. Anaerobic bacterial response to nitric oxide stress: Widespread misconceptions and physiologically relevant responses. Mol Microbiol 2021; 116:29-40. [PMID: 33706420 DOI: 10.1111/mmi.14713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 11/27/2022]
Abstract
How anaerobic bacteria protect themselves against nitric oxide-induced stress is controversial, not least because far higher levels of stress were used in the experiments on which most of the literature is based than bacteria experience in their natural environments. This results in chemical damage to enzymes that inactivates their physiological function. This review illustrates how transcription control mechanisms reveal physiological roles of the encoded gene products. Evidence that the hybrid cluster protein, Hcp, is a major high affinity NO reductase in anaerobic bacteria is reviewed: if so, its trans-nitrosation activity is a nonspecific secondary consequence of chemical inactivation. Whether the flavorubredoxin, NorV, is equally effective at such low [NO] is unknown. YtfE is proposed to be an enzyme rather than a source of iron for the repair of iron-sulfur proteins damaged by nitrosative stress. Any reaction catalyzed by YtfE needs to be revealed. The concentration of NO that accumulates in the cytoplasm of anaerobic bacteria is unknown, but indirect evidence indicates that it is in the pM to low nM range. Also unknown are the functions of the NO-inducible cytoplasmic proteins YgbA, YeaR, or YoaG. Experiments to resolve some of these questions are proposed.
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Affiliation(s)
- J A Cole
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
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Varney AM, Smitten KL, Thomas JA, McLean S. Transcriptomic Analysis of the Activity and Mechanism of Action of a Ruthenium(II)-Based Antimicrobial That Induces Minimal Evolution of Pathogen Resistance. ACS Pharmacol Transl Sci 2020; 4:168-178. [PMID: 33615170 DOI: 10.1021/acsptsci.0c00159] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Indexed: 01/30/2023]
Abstract
Increasing concern over rising levels of antibiotic resistance among pathogenic bacteria has prompted significant research into developing efficacious alternatives to antibiotic treatment. Previously, we have reported on the therapeutic activity of a dinuclear ruthenium(II) complex against pathogenic, multi-drug-resistant bacterial pathogens. Herein, we report that the solubility properties of this lead are comparable to those exhibited by orally available therapeutics that in comparison to clinically relevant antibiotics it induces very slow evolution of resistance in the uropathogenic, therapeutically resistant, E. coli strain EC958, and this resistance was lost when exposure to the compound was temporarily removed. With the aim of further investigating the mechanism of action of this compound, the regulation of nine target genes relating to the membrane, DNA damage, and other stress responses provoked by exposure to the compound was also studied. This analysis confirmed that the compound causes a significant transcriptional downregulation of genes involved in membrane transport and the tricarboxylic acid cycle. By contrast, expression of the chaperone protein-coding gene, spy, was significantly increased suggesting a requirement for repair of damaged proteins in the region of the outer membrane. The complex was also found to display activity comparable to that in E. coli in a range of other therapeutically relevant Gram-negative pathogens.
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Affiliation(s)
- Adam M Varney
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
| | - Kirsty L Smitten
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, United Kingdom
| | - Jim A Thomas
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, United Kingdom
| | - Samantha McLean
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
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10
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Smitten KL, Scattergood PA, Kiker C, Thomas JA, Elliott PIP. Triazole-based osmium(ii) complexes displaying red/near-IR luminescence: antimicrobial activity and super-resolution imaging. Chem Sci 2020; 11:8928-8935. [PMID: 34123147 PMCID: PMC8163367 DOI: 10.1039/d0sc03563g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 08/06/2020] [Indexed: 12/15/2022] Open
Abstract
Cellular uptake, luminescence imaging and antimicrobial activity against clinically relevant methicillin-resistant S. aureus (MRSA) bacteria are reported. The osmium(ii) complexes [Os(N^N)3]2+ (N^N = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (1 2+); 1-benzyl-4-(pyrimidin-2-yl)-1,2,3-triazole (2 2+); 1-benzyl-4-(pyrazin-2-yl)-1,2,3-triazole (3 2+)) were prepared and isolated as the chloride salts of their meridional and facial isomers. The complexes display prominent spin-forbidden ground state to triplet metal-to-ligand charge transfer (3MLCT) state absorption bands enabling excitation as low as 600 nm for fac/mer-3 2+ and observation of emission in aqueous solution in the deep-red/near-IR regions of the spectrum. Cellular uptake studies within MRSA cells show antimicrobial activity for 1 2+ and 2 2+ with greater toxicity for the meridional isomers in each case and mer-1 2+ showing the greatest potency (32 μg mL-1 in defined minimal media). Super-resolution imaging experiments demonstrate binding of mer- and fac-1 2+ to bacterial DNA with high Pearson's colocalisation coefficients (up to 0.95 using DAPI). Phototoxicity studies showed the complexes exhibited a higher antimicrobial activity upon irradiation with light.
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Affiliation(s)
- Kirsty L Smitten
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Paul A Scattergood
- Department of Chemistry & Centre for Functional Materials, University of Huddersfield Queensgate Huddersfield HD1 3DH UK
| | - Charlotte Kiker
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Jim A Thomas
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Paul I P Elliott
- Department of Chemistry & Centre for Functional Materials, University of Huddersfield Queensgate Huddersfield HD1 3DH UK
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LysR-Type Transcriptional Regulator MetR Controls Prodigiosin Production, Methionine Biosynthesis, Cell Motility, H 2O 2 Tolerance, Heat Tolerance, and Exopolysaccharide Synthesis in Serratia marcescens. Appl Environ Microbiol 2020; 86:AEM.02241-19. [PMID: 31791952 DOI: 10.1128/aem.02241-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/23/2019] [Indexed: 12/31/2022] Open
Abstract
Prodigiosin, a secondary metabolite produced by Serratia marcescens, has attracted attention due to its immunosuppressive, antimicrobial, and anticancer properties. However, information on the regulatory mechanism behind prodigiosin biosynthesis in S. marcescens remains limited. In this work, a prodigiosin-hyperproducing strain with the BVG90_22495 gene disrupted (ZK66) was selected from a collection of Tn5G transposon insertion mutants. Using real-time quantitative PCR (RT-qPCR) analysis, β-galactosidase assays, transcriptomics analysis, and electrophoretic mobility shift assays (EMSAs), the LysR-type regulator MetR encoded by the BVG90_22495 gene was found to affect prodigiosin synthesis, and this correlated with MetR directly binding to the promoter region of the prodigiosin-synthesis positive regulator PigP and hence negatively regulated the expression of the prodigiosin-associated pig operon. More analyses revealed that MetR regulated some other important cellular processes, including methionine biosynthesis, cell motility, H2O2 tolerance, heat tolerance, exopolysaccharide synthesis, and biofilm formation in S. marcescens Although MetR protein is highly conserved in many bacteria, we report here on the LysR-type regulator MetR exhibiting novel roles in negatively regulating prodigiosin synthesis and positively regulating heat tolerance, exopolysaccharide synthesis, and biofilm formation.IMPORTANCE Serratia marcescens, a Gram-negative bacterium, is found in a wide range of ecological niches and can produce several secondary metabolites, including prodigiosin, althiomycin, and serratamolide. Among them, prodigiosin shows diverse functions as an immunosuppressant, antimicrobial, and anticancer agent. However, the regulatory mechanisms behind prodigiosin synthesis in S. marcescens are not completely understood. Here, we adapted a transposon mutant library to identify the genes related to prodigiosin synthesis, and the BVG90_22495 gene encoding the LysR-type regulator MetR was found to negatively regulate prodigiosin synthesis. The molecular mechanism of the metR mutant hyperproducing prodigiosin was investigated. Additionally, we provided evidence supporting new roles for MetR in regulating methionine biosynthesis, cell motility, heat tolerance, H2O2 tolerance, and exopolysaccharide synthesis in S. marcescens Collectively, this work provides novel insight into regulatory mechanisms of prodigiosin synthesis and uncovers novel roles for the highly conserved MetR protein in regulating prodigiosin synthesis, heat tolerance, exopolysaccharide (EPS) synthesis, and biofilm formation.
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Abstract
Flavohaemoglobins were first described in yeast as early as the 1970s but their functions were unclear. The surge in interest in nitric oxide biology and both serendipitous and hypothesis-driven discoveries in bacterial systems have transformed our understanding of this unusual two-domain globin into a comprehensive, yet undoubtedly incomplete, appreciation of its pre-eminent role in nitric oxide detoxification. Here, I focus on research on the flavohaemoglobins of microorganisms, especially of bacteria, and update several earlier and more comprehensive reviews, emphasising advances over the past 5 to 10 years and some controversies that have arisen. Inevitably, in light of space restrictions, details of nitric oxide metabolism and globins in higher organisms are brief.
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Affiliation(s)
- Robert K. Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Sheffield, S10 2TN, UK
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13
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Smitten KL, Fairbanks SD, Robertson CC, Bernardino de la Serna J, Foster SJ, Thomas JA. Ruthenium based antimicrobial theranostics - using nanoscopy to identify therapeutic targets and resistance mechanisms in Staphylococcus aureus. Chem Sci 2020; 11:70-79. [PMID: 32110358 PMCID: PMC7012045 DOI: 10.1039/c9sc04710g] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 10/28/2019] [Indexed: 12/13/2022] Open
Abstract
In previous studies we reported that specific dinuclear RuII complexes are particularly active against pathogenic Gram-negative bacteria and, unusually for this class of compounds, appeared to display lowered activity against Gram-positive bacteria. With the aim of identifying resistance mechanisms specific to Gram-positive bacteria, the uptake and antimicrobial activity of the lead complex against Staphylococcus aureus SH1000 and other isolates, including MRSA was investigated. This revealed differential, strain specific, sensitivity to the complex. Exploiting the inherent luminescent properties of the RuII complex, super-resolution STED nanoscopy was used to image its initial interaction with S. aureus and confirm its cellular internalization. Membrane damage assays and transmission electron microscopy confirm that the complex disrupts the bacterial membrane structure before internalization, which ultimately results in a small amount of DNA damage. A known resistance mechanism against cationic antimicrobials in Gram-positive bacteria involves increased expression of the mprF gene as this results in an accumulation of positively charged lysyl-phosphatidylglycerol on the outer leaflet of the cytoplasmic membrane that electrostatically repel cationic species. Consistent with this model, it was found that an mprF deficient strain was particularly susceptible to treatment with the lead complex. More detailed co-staining studies also revealed that the complex was more active in S. aureus strains missing, or with altered, wall teichoic acids.
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Affiliation(s)
- Kirsty L Smitten
- Department of Chemistry , University of Sheffield , Sheffield S10 2TN , UK . ;
- The Florey Institute and Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN , UK
| | - Simon D Fairbanks
- Department of Chemistry , University of Sheffield , Sheffield S10 2TN , UK . ;
| | - Craig C Robertson
- Department of Chemistry , University of Sheffield , Sheffield S10 2TN , UK . ;
| | - Jorge Bernardino de la Serna
- National Heart and Lung Institute , Faculty of Medicine , Imperial College London , South Kensington Campus , London SW7 2AZ , UK
- Research Complex at Harwell , Rutherford Appleton Laboratory , Central Laser Facility , United Kingdom Research and Innovation , OX11 0FA , UK
| | - Simon J Foster
- The Florey Institute and Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN , UK
| | - Jim A Thomas
- Department of Chemistry , University of Sheffield , Sheffield S10 2TN , UK . ;
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14
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Smitten KL, Southam HM, de la Serna JB, Gill MR, Jarman PJ, Smythe CGW, Poole RK, Thomas JA. Using Nanoscopy To Probe the Biological Activity of Antimicrobial Leads That Display Potent Activity against Pathogenic, Multidrug Resistant, Gram-Negative Bacteria. ACS NANO 2019; 13:5133-5146. [PMID: 30964642 DOI: 10.1021/acsnano.8b08440] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Medicinal leads that are also compatible with imaging technologies are attractive, as they facilitate the development of therapeutics through direct mechanistic observations at the molecular level. In this context, the uptake and antimicrobial activities of several luminescent dinuclear RuII complexes against E. coli were assessed and compared to results obtained for another ESKAPE pathogen, the Gram-positive major opportunistic pathogen Enterococcus faecalis, V583. The most promising lead displays potent activity, particularly against the Gram-negative bacteria, and potency is retained in the uropathogenic multidrug resistant EC958 ST131 strain. Exploiting the inherent luminescent properties of this complex, super-resolution STED nanoscopy was used to image its initial localization at/in cellular membranes and its subsequent transfer to the cell poles. Membrane damage assays confirm that the complex disrupts the bacterial membrane structure before internalization. Mammalian cell culture and animal model studies indicate that the complex is not toxic to eukaryotes, even at concentrations that are several orders of magnitude higher than its minimum inhibitory concentration (MIC). Taken together, these results have identified a lead molecular architecture for hard-to-treat, multiresistant, Gram-negative bacteria, which displays activities that are already comparable to optimized natural product-based leads.
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Affiliation(s)
- Kirsty L Smitten
- Department of Chemistry , The University of Sheffield , Western Bank , Sheffield S3 7HF , U.K
| | - Hannah M Southam
- Department of Molecular Biology and Biotechnology , The University of Sheffield , Western Bank , Sheffield S10 2TN , U.K
| | - Jorge Bernardino de la Serna
- Central Laser Facility, Rutherford Appleton Laboratory, Research Complex at Harwell , Science and Technology Facilities Council , Harwell-Oxford , Didcot OX11 0QX , U.K
- Department of Physics , King's College London , London WC2R 2LS , U.K
| | - Martin R Gill
- Department of Chemistry , The University of Sheffield , Western Bank , Sheffield S3 7HF , U.K
| | - Paul J Jarman
- Department of Biomedical Science , The University of Sheffield , Western Bank , Sheffield S10 2TN , U.K
| | - Carl G W Smythe
- Department of Biomedical Science , The University of Sheffield , Western Bank , Sheffield S10 2TN , U.K
| | - Robert K Poole
- Department of Molecular Biology and Biotechnology , The University of Sheffield , Western Bank , Sheffield S10 2TN , U.K
| | - Jim A Thomas
- Department of Chemistry , The University of Sheffield , Western Bank , Sheffield S3 7HF , U.K
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15
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Abstract
SIGNIFICANCE Iron-sulfur cluster proteins carry out multiple functions, including as regulators of gene transcription/translation in response to environmental stimuli. In all known cases, the cluster acts as the sensory module, where the inherent reactivity/fragility of iron-sulfur clusters with small/redox-active molecules is exploited to effect conformational changes that modulate binding to DNA regulatory sequences. This promotes an often substantial reprogramming of the cellular proteome that enables the organism or cell to adapt to, or counteract, its changing circumstances. Recent Advances: Significant progress has been made recently in the structural and mechanistic characterization of iron-sulfur cluster regulators and, in particular, the O2 and NO sensor FNR, the NO sensor NsrR, and WhiB-like proteins of Actinobacteria. These are the main focus of this review. CRITICAL ISSUES Striking examples of how the local environment controls the cluster sensitivity and reactivity are now emerging, but the basis for this is not yet fully understood for any regulatory family. FUTURE DIRECTIONS Characterization of iron-sulfur cluster regulators has long been hampered by a lack of high-resolution structural data. Although this still presents a major future challenge, recent advances now provide a firm foundation for detailed understanding of how a signal is transduced to effect gene regulation. This requires the identification of often unstable intermediate species, which are difficult to detect and may be hard to distinguish using traditional techniques. Novel approaches will be required to solve these problems.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia , Norwich Research Park, Norwich, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia , Norwich Research Park, Norwich, United Kingdom
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16
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Southam HM, Smith TW, Lyon RL, Liao C, Trevitt CR, Middlemiss LA, Cox FL, Chapman JA, El-Khamisy SF, Hippler M, Williamson MP, Henderson PJF, Poole RK. A thiol-reactive Ru(II) ion, not CO release, underlies the potent antimicrobial and cytotoxic properties of CO-releasing molecule-3. Redox Biol 2018; 18:114-123. [PMID: 30007887 PMCID: PMC6067063 DOI: 10.1016/j.redox.2018.06.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/23/2018] [Indexed: 12/25/2022] Open
Abstract
Carbon monoxide (CO)-releasing molecules (CORMs), mostly metal carbonyl compounds, are extensively used as experimental tools to deliver CO, a biological ‘gasotransmitter’, in mammalian systems. CORMs are also explored as potential novel antimicrobial drugs, effectively and rapidly killing bacteria in vitro and in animal models, but are reportedly benign towards mammalian cells. Ru-carbonyl CORMs, exemplified by CORM-3 (Ru(CO)3Cl(glycinate)), exhibit the most potent antimicrobial effects against Escherichia coli. We demonstrate that CORM-3 releases little CO in buffers and cell culture media and that the active antimicrobial agent is Ru(II), which binds tightly to thiols. Thus, thiols and amino acids in complex growth media – such as histidine, methionine and oxidised glutathione, but most pertinently cysteine and reduced glutathione (GSH) – protect both bacterial and mammalian cells against CORM-3 by binding and sequestering Ru(II). No other amino acids exert significant protective effects. NMR reveals that CORM-3 binds cysteine and GSH in a 1:1 stoichiometry with dissociation constants, Kd, of about 5 μM, while histidine, GSSG and methionine are bound less tightly, with Kd values ranging between 800 and 9000 μM. There is a direct positive correlation between protection and amino acid affinity for CORM-3. Intracellular targets of CORM-3 in both bacterial and mammalian cells are therefore expected to include GSH, free Cys, His and Met residues and any molecules that contain these surface-exposed amino acids. These results necessitate a major reappraisal of the biological effects of CORM-3 and related CORMs. Carbon monoxide-releasing molecules (CORMs) are used for experimental CO delivery. CORM-3 is a potent antimicrobial, but is reportedly beneficial to mammalian cells. We demonstrate CORM-3 releases little CO in buffers and cell culture media. Redox-active Ru2+ is the biological agent, binding tightly to metabolites e.g. thiol. These results necessitate a major reappraisal of the biological effects of CORMs.
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Affiliation(s)
- Hannah M Southam
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Thomas W Smith
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, UK
| | - Rhiannon L Lyon
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Chunyan Liao
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Clare R Trevitt
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Laurence A Middlemiss
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, UK
| | - Francesca L Cox
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, UK
| | - Jonathan A Chapman
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, UK
| | - Sherif F El-Khamisy
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Michael Hippler
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, UK
| | - Michael P Williamson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| | - Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Robert K Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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17
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Abstract
This chapter provides an overview of current knowledge of how anaerobic bacteria protect themselves against nitrosative stress. Nitric oxide (NO) is the primary source of this stress. Aerobically its removal is an oxidative process, whereas reduction is required anaerobically. Mechanisms required to protect aerobic and anaerobic bacteria are therefore different. Several themes recur in the review. First, how gene expression is regulated often provides clues to the physiological function of the gene products. Second, the physiological significance of reports based upon experiments under extreme conditions that bacteria do not encounter in their natural environment requires reassessment. Third, responses to the primary source of stress need to be distinguished from secondary consequences of chemical damage due to failure of repair mechanisms to cope with extreme conditions. NO is generated by many mechanisms, some of which remain undefined. An example is the recent demonstration that the hybrid cluster protein combines with YtfE (or RIC protein, for repair of iron centres damaged by nitrosative stress) in a new pathway to repair key iron-sulphur proteins damaged by nitrosative stress. The functions of many genes expressed in response to nitrosative stress remain either controversial or are completely unknown. The concentration of NO that accumulates in the bacterial cytoplasm is essentially unknown, so dogmatic statements cannot be made that damage to transcription factors (Fur, FNR, SoxRS, MelR, OxyR) occurs naturally as part of a physiologically relevant signalling mechanism. Such doubts can be resolved by simple experiments to meet six proposed criteria.
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18
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Abstract
SIGNIFICANCE Iron-sulfur cluster proteins carry out a wide range of functions, including as regulators of gene transcription/translation in response to environmental stimuli. In all known cases, the cluster acts as the sensory module, where the inherent reactivity/fragility of iron-sulfur clusters towards small/redox active molecules is exploited to effect conformational changes that modulate binding to DNA regulatory sequences. This promotes an often substantial re-programming of the cellular proteome that enables the organism or cell to adapt to, or counteract, its changing circumstances. Recent Advances. Significant progress has been made recently in the structural and mechanistic characterization of iron-sulfur cluster regulators and, in particular, the O2 and NO sensor FNR, the NO sensor NsrR, and WhiB-like proteins of Actinobacteria. These are the main focus of this review. CRITICAL ISSUES Striking examples of how the local environment controls the cluster sensitivity and reactivity are now emerging, but the basis for this is not yet fully understood for any regulatory family. FUTURE DIRECTIONS Characterization of iron-sulfur cluster regulators has long been hampered by a lack of high resolution structural data. Though this still presents a major future challenge, recent advances now provide a firm foundation for detailed understanding of how a signal is transduced to effect gene regulation. This requires the identification of often unstable intermediate species, which are difficult to detect and may be hard to distinguish using traditional techniques. Novel approaches will be required to solve these problems.
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Affiliation(s)
- Jason C Crack
- School of Chemistry , University of East Anglia , Norwich, United Kingdom of Great Britain and Northern Ireland , NR4 7TJ ;
| | - Nick E Le Brun
- University of East Anglia, School of Chemistry , University plain , Norwich, United Kingdom of Great Britain and Northern Ireland , NR4 7TJ ;
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19
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Rana N, Jesse HE, Tinajero-Trejo M, Butler JA, Tarlit JD, von Und Zur Muhlen ML, Nagel C, Schatzschneider U, Poole RK. A manganese photosensitive tricarbonyl molecule [Mn(CO)3(tpa-κ 3N)]Br enhances antibiotic efficacy in a multi-drug-resistant Escherichia coli. MICROBIOLOGY-SGM 2017; 163:1477-1489. [PMID: 28954688 PMCID: PMC5845575 DOI: 10.1099/mic.0.000526] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Carbon monoxide-releasing molecules (CORMs) are a promising class of new antimicrobials, with multiple modes of action that are distinct from those of standard antibiotics. The relentless increase in antimicrobial resistance, exacerbated by a lack of new antibiotics, necessitates a better understanding of how such novel agents act and might be used synergistically with established antibiotics. This work aimed to understand the mechanism(s) underlying synergy between a manganese-based photoactivated carbon monoxide-releasing molecule (PhotoCORM), [Mn(CO)3(tpa-κ3N)]Br [tpa=tris(2-pyridylmethyl)amine], and various classes of antibiotics in their activities towards Escherichia coli EC958, a multi-drug-resistant uropathogen. The title compound acts synergistically with polymyxins [polymyxin B and colistin (polymyxin E)] by damaging the bacterial cytoplasmic membrane. [Mn(CO)3(tpa-κ3N)]Br also potentiates the action of doxycycline, resulting in reduced expression of tetA, which encodes a tetracycline efflux pump. We show that, like tetracyclines, the breakdown products of [Mn(CO)3(tpa-κ3N)]Br activation chelate iron and trigger an iron starvation response, which we propose to be a further basis for the synergies observed. Conversely, media supplemented with excess iron abrogated the inhibition of growth by doxycycline and the title compound. In conclusion, multiple factors contribute to the ability of this PhotoCORM to increase the efficacy of antibiotics in the polymyxin and tetracycline families. We propose that light-activated carbon monoxide release is not the sole basis of the antimicrobial activities of [Mn(CO)3(tpa-κ3N)]Br.
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Affiliation(s)
- Namrata Rana
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK
| | - Helen E Jesse
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK
| | - Mariana Tinajero-Trejo
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK.,Present address: Cell Biology Program, The Hospital for Sick Children, Toronto, Canada
| | - Jonathan A Butler
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK.,Present address: School of Healthcare Science, Manchester Metropolitan University, UK
| | - John D Tarlit
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK
| | | | - Christoph Nagel
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Ulrich Schatzschneider
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Robert K Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK
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20
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Galia W, Leriche F, Cruveiller S, Garnier C, Navratil V, Dubost A, Blanquet-Diot S, Thevenot-Sergentet D. Strand-specific transcriptomes of Enterohemorrhagic Escherichia coli in response to interactions with ground beef microbiota: interactions between microorganisms in raw meat. BMC Genomics 2017; 18:574. [PMID: 28774270 PMCID: PMC5543532 DOI: 10.1186/s12864-017-3957-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/24/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Enterohemorrhagic Escherichia coli (EHEC) are zoonotic agents associated with outbreaks worldwide. Growth of EHEC strains in ground beef could be inhibited by background microbiota that is present initially at levels greater than that of the pathogen E. coli. However, how the microbiota outcompetes the pathogenic bacteria is unknown. Our objective was to identify metabolic pathways of EHEC that were altered by natural microbiota in order to improve our understanding of the mechanisms controlling the growth and survival of EHECs in ground beef. RESULTS Based on 16S metagenomics analysis, we identified the microbial community structure in our beef samples which was an essential preliminary for subtractively analyzing the gene expression of the EHEC strains. Then, we applied strand-specific RNA-seq to investigate the effects of this microbiota on the global gene expression of EHEC O2621765 and O157EDL933 strains by comparison with their behavior in beef meat without microbiota. In strain O2621765, the expression of genes connected with nitrate metabolism and nitrite detoxification, DNA repair, iron and nickel acquisition and carbohydrate metabolism, and numerous genes involved in amino acid metabolism were down-regulated. Further, the observed repression of ftsL and murF, involved respectively in building the cytokinetic ring apparatus and in synthesizing the cytoplasmic precursor of cell wall peptidoglycan, might help to explain the microbiota's inhibitory effect on EHECs. For strain O157EDL933, the induced expression of the genes implicated in detoxification and the general stress response and the repressed expression of the peR gene, a gene negatively associated with the virulence phenotype, might be linked to the survival and virulence of O157:H7 in ground beef with microbiota. CONCLUSION In the present study, we show how RNA-Seq coupled with a 16S metagenomics analysis can be used to identify the effects of a complex microbial community on relevant functions of an individual microbe within it. These findings add to our understanding of the behavior of EHECs in ground beef. By measuring transcriptional responses of EHEC, we could identify putative targets which may be useful to develop new strategies to limit their shedding in ground meat thus reducing the risk of human illnesses.
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Affiliation(s)
- Wessam Galia
- UMR 5557 Ecologie Microbienne, Research Group on Bacterial Opportunistic Pathogens and Environment, CNRS, VetAgro Sup and Université de Lyon, Lyon, France.
- Université Clermont Auvergne, INRA, UMRF, F-15000, Aurillac, France.
- UMR UCA INRA 454 MEDIS Microbiota Digestive environment and Health, Université Clermont Auvergne, 63000, Clermont-Ferrand, France.
- VetAgro Sup, Campus Agronomique de Lempdes, Lempdes, France.
| | - Francoise Leriche
- Université Clermont Auvergne, INRA, UMRF, F-15000, Aurillac, France
- VetAgro Sup, Campus Agronomique de Lempdes, Lempdes, France
| | - Stéphane Cruveiller
- Alternative Energies and Atomic Energy Commission (CEA), Genomic Institute Genoscope & CNRS-UMR8030 & Evry University, Laboratory of Bioinformatics Analysis in Genomics and Metabolism, Evry, France
| | - Cindy Garnier
- UMR 5557 Ecologie Microbienne, Research Group on Bacterial Opportunistic Pathogens and Environment, CNRS, VetAgro Sup and Université de Lyon, Lyon, France
| | - Vincent Navratil
- PRABI, Rhône Alpes Bioinformatics Center, UCBL, Lyon1, Université de Lyon, Lyon, France
| | - Audrey Dubost
- UMR 5557 Ecologie Microbienne, CNRS, Université de Lyon, Lyon, France
| | - Stéphanie Blanquet-Diot
- UMR UCA INRA 454 MEDIS Microbiota Digestive environment and Health, Université Clermont Auvergne, 63000, Clermont-Ferrand, France
| | - Delphine Thevenot-Sergentet
- UMR 5557 Ecologie Microbienne, Research Group on Bacterial Opportunistic Pathogens and Environment, CNRS, VetAgro Sup and Université de Lyon, Lyon, France
- Reference Laboratory for Escherichia coli including Shiga Toxin-Producing E. coli, VetAgro Sup, Campus Vétérinaire de Lyon, Université de Lyon, Marcy l'Etoile, Lyon, France
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21
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Shepherd M, Achard MES, Idris A, Totsika M, Phan MD, Peters KM, Sarkar S, Ribeiro CA, Holyoake LV, Ladakis D, Ulett GC, Sweet MJ, Poole RK, McEwan AG, Schembri MA. The cytochrome bd-I respiratory oxidase augments survival of multidrug-resistant Escherichia coli during infection. Sci Rep 2016; 6:35285. [PMID: 27767067 PMCID: PMC5073308 DOI: 10.1038/srep35285] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/13/2016] [Indexed: 12/30/2022] Open
Abstract
Nitric oxide (NO) is a toxic free radical produced by neutrophils and macrophages in response to infection. Uropathogenic Escherichia coli (UPEC) induces a variety of defence mechanisms in response to NO, including direct NO detoxification (Hmp, NorVW, NrfA), iron-sulphur cluster repair (YtfE), and the expression of the NO-tolerant cytochrome bd-I respiratory oxidase (CydAB). The current study quantifies the relative contribution of these systems to UPEC growth and survival during infection. Loss of the flavohemoglobin Hmp and cytochrome bd-I elicit the greatest sensitivity to NO-mediated growth inhibition, whereas all but the periplasmic nitrite reductase NrfA provide protection against neutrophil killing and promote survival within activated macrophages. Intriguingly, the cytochrome bd-I respiratory oxidase was the only system that augmented UPEC survival in a mouse model after 2 days, suggesting that maintaining aerobic respiration under conditions of nitrosative stress is a key factor for host colonisation. These findings suggest that while UPEC have acquired a host of specialized mechanisms to evade nitrosative stresses, the cytochrome bd-I respiratory oxidase is the main contributor to NO tolerance and host colonisation under microaerobic conditions. This respiratory complex is therefore of major importance for the accumulation of high bacterial loads during infection of the urinary tract.
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Affiliation(s)
- Mark Shepherd
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Maud E S Achard
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Adi Idris
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Makrina Totsika
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kate M Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sohinee Sarkar
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Cláudia A Ribeiro
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Louise V Holyoake
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Dimitrios Ladakis
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Glen C Ulett
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert K Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
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22
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Oliver P, Peralta-Gil M, Tabche ML, Merino E. Molecular and structural considerations of TF-DNA binding for the generation of biologically meaningful and accurate phylogenetic footprinting analysis: the LysR-type transcriptional regulator family as a study model. BMC Genomics 2016; 17:686. [PMID: 27567672 PMCID: PMC5002191 DOI: 10.1186/s12864-016-3025-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/18/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The goal of most programs developed to find transcription factor binding sites (TFBSs) is the identification of discrete sequence motifs that are significantly over-represented in a given set of sequences where a transcription factor (TF) is expected to bind. These programs assume that the nucleotide conservation of a specific motif is indicative of a selective pressure required for the recognition of a TF for its corresponding TFBS. Despite their extensive use, the accuracies reached with these programs remain low. In many cases, true TFBSs are excluded from the identification process, especially when they correspond to low-affinity but important binding sites of regulatory systems. RESULTS We developed a computational protocol based on molecular and structural criteria to perform biologically meaningful and accurate phylogenetic footprinting analyses. Our protocol considers fundamental aspects of the TF-DNA binding process, such as: i) the active homodimeric conformations of TFs that impose symmetric structures on the TFBSs, ii) the cooperative binding of TFs, iii) the effects of the presence or absence of co-inducers, iv) the proximity between two TFBSs or one TFBS and a promoter that leads to very long spurious motifs, v) the presence of AT-rich sequences not recognized by the TF but that are required for DNA flexibility, and vi) the dynamic order in which the different binding events take place to determine a regulatory response (i.e., activation or repression). In our protocol, the abovementioned criteria were used to analyze a profile of consensus motifs generated from canonical Phylogenetic Footprinting Analyses using a set of analysis windows of incremental sizes. To evaluate the performance of our protocol, we analyzed six members of the LysR-type TF family in Gammaproteobacteria. CONCLUSIONS The identification of TFBSs based exclusively on the significance of the over-representation of motifs in a set of sequences might lead to inaccurate results. The consideration of different molecular and structural properties of the regulatory systems benefits the identification of TFBSs and enables the development of elaborate, biologically meaningful and precise regulatory models that offer a more integrated view of the dynamics of the regulatory process of transcription.
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Affiliation(s)
- Patricia Oliver
- Departmento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Martín Peralta-Gil
- Escuela Superior de Apan de la Universidad Autónoma del Estado de Hidalgo, Carretera Apan-Calpulalpan, Km 8, Chimalpa Tlalayote s/n, Colonia Chimalpa, Apan, Hidalgo, México
| | - María-Luisa Tabche
- Departmento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Enrique Merino
- Departmento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
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Punekar AS, Porter J, Carr SB, Phillips SEV. Structural basis for DNA recognition by the transcription regulator MetR. Acta Crystallogr F Struct Biol Commun 2016; 72:417-26. [PMID: 27303893 PMCID: PMC4909240 DOI: 10.1107/s2053230x16006828] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/22/2016] [Indexed: 11/10/2022] Open
Abstract
MetR, a LysR-type transcriptional regulator (LTTR), has been extensively studied owing to its role in the control of methionine biosynthesis in proteobacteria. A MetR homodimer binds to a 24-base-pair operator region of the met genes and specifically recognizes the interrupted palindromic sequence 5'-TGAA-N5-TTCA-3'. Mechanistic details underlying the interaction of MetR with its target DNA at the molecular level remain unknown. In this work, the crystal structure of the DNA-binding domain (DBD) of MetR was determined at 2.16 Å resolution. MetR-DBD adopts a winged-helix-turn-helix (wHTH) motif and shares significant fold similarity with the DBD of the LTTR protein BenM. Furthermore, a data-driven macromolecular-docking strategy was used to model the structure of MetR-DBD bound to DNA, which revealed that a bent conformation of DNA is required for the recognition helix α3 and the wing loop of the wHTH motif to interact with the major and minor grooves, respectively. Comparison of the MetR-DBD-DNA complex with the crystal structures of other LTTR-DBD-DNA complexes revealed residues that may confer operator-sequence binding specificity for MetR. Taken together, the results show that MetR-DBD uses a combination of direct base-specific interactions and indirect shape recognition of the promoter to regulate the transcription of met genes.
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Affiliation(s)
- Avinash S. Punekar
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, England
| | | | - Stephen B. Carr
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, England
| | - Simon E. V. Phillips
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, England
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24
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Tinajero-Trejo M, Rana N, Nagel C, Jesse HE, Smith TW, Wareham LK, Hippler M, Schatzschneider U, Poole RK. Antimicrobial Activity of the Manganese Photoactivated Carbon Monoxide-Releasing Molecule [Mn(CO)3(tpa-κ(3)N)](+) Against a Pathogenic Escherichia coli that Causes Urinary Infections. Antioxid Redox Signal 2016; 24:765-80. [PMID: 26842766 PMCID: PMC4876522 DOI: 10.1089/ars.2015.6484] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIMS We set out to investigate the antibacterial activity of a new Mn-based photoactivated carbon monoxide-releasing molecule (PhotoCORM, [Mn(CO)3(tpa-κ(3)N)](+)) against an antibiotic-resistant uropathogenic strain (EC958) of Escherichia coli. RESULTS Activated PhotoCORM inhibits growth and decreases viability of E. coli EC958, but non-illuminated carbon monoxide-releasing molecule (CORM) is without effect. NADH-supported respiration rates are significantly decreased by activated PhotoCORM, mimicking the effect of dissolved CO gas. CO from the PhotoCORM binds to intracellular targets, namely respiratory oxidases in strain EC958 and a bacterial globin heterologously expressed in strain K-12. However, unlike previously characterized CORMs, the PhotoCORM is not significantly accumulated in cells, as deduced from the cellular manganese content. Activated PhotoCORM reacts avidly with hydrogen peroxide producing hydroxyl radicals; the observed peroxide-enhanced toxicity of the PhotoCORM is ameliorated by thiourea. The PhotoCORM also potentiates the effect of the antibiotic, doxycycline. INNOVATION The present work investigates for the first time the antimicrobial activity of a light-activated PhotoCORM against an antibiotic-resistant pathogen. A comprehensive study of the effects of the PhotoCORM and its derivative molecules upon illumination is performed and mechanisms of toxicity of the activated PhotoCORM are investigated. CONCLUSION The PhotoCORM allows a site-specific and time-controlled release of CO in bacterial cultures and has the potential to provide much needed information on the generality of CORM activities in biology. Understanding the mechanism(s) of activated PhotoCORM toxicity will be key in exploring the potential of this and similar compounds as antimicrobial agents, perhaps in combinatorial therapies with other agents. Antioxid. Redox Signal. 24, 765-780.
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Affiliation(s)
- Mariana Tinajero-Trejo
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Namrata Rana
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Christoph Nagel
- 2 Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg, Germany
| | - Helen E Jesse
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Thomas W Smith
- 3 Department of Chemistry, The University of Sheffield , Sheffield, United Kingdom
| | - Lauren K Wareham
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Michael Hippler
- 3 Department of Chemistry, The University of Sheffield , Sheffield, United Kingdom
| | - Ulrich Schatzschneider
- 2 Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg , Würzburg, Germany
| | - Robert K Poole
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
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Runkel S, Wells HC, Rowley G. Living with Stress: A Lesson from the Enteric Pathogen Salmonella enterica. ADVANCES IN APPLIED MICROBIOLOGY 2016; 83:87-144. [PMID: 23651595 DOI: 10.1016/b978-0-12-407678-5.00003-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The ability to sense and respond to the environment is essential for the survival of all living organisms. Bacterial pathogens such as Salmonella enterica are of particular interest due to their ability to sense and adapt to the diverse range of conditions they encounter, both in vivo and in environmental reservoirs. During this cycling from host to non-host environments, Salmonella encounter a variety of environmental insults ranging from temperature fluctuations, nutrient availability and changes in osmolarity, to the presence of antimicrobial peptides and reactive oxygen/nitrogen species. Such fluctuating conditions impact on various areas of bacterial physiology including virulence, growth and antimicrobial resistance. A key component of the success of any bacterial pathogen is the ability to recognize and mount a suitable response to the discrete chemical and physical stresses elicited by the host. Such responses occur through a coordinated and complex programme of gene expression and protein activity, involving a range of transcriptional regulators, sigma factors and two component regulatory systems. This review briefly outlines the various stresses encountered throughout the Salmonella life cycle and the repertoire of regulatory responses with which Salmonella counters. In particular, how these Gram-negative bacteria are able to alleviate disruption in periplasmic envelope homeostasis through a group of stress responses, known collectively as the Envelope Stress Responses, alongside the mechanisms used to overcome nitrosative stress, will be examined in more detail.
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Affiliation(s)
- Sebastian Runkel
- School of Biological Sciences, University of East Anglia, Norwich, UK
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26
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Kondakova T, Catovic C, Barreau M, Nusser M, Brenner-Weiss G, Chevalier S, Dionnet F, Orange N, Poc CD. Response to Gaseous NO2 Air Pollutant of P. fluorescens Airborne Strain MFAF76a and Clinical Strain MFN1032. Front Microbiol 2016; 7:379. [PMID: 27065229 PMCID: PMC4814523 DOI: 10.3389/fmicb.2016.00379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 03/09/2016] [Indexed: 01/22/2023] Open
Abstract
Human exposure to nitrogen dioxide (NO2), an air pollutant of increasing interest in biology, results in several toxic effects to human health and also to the air microbiota. The aim of this study was to investigate the bacterial response to gaseous NO2. Two Pseudomonas fluorescens strains, namely the airborne strain MFAF76a and the clinical strain MFN1032 were exposed to 0.1, 5, or 45 ppm concentrations of NO2, and their effects on bacteria were evaluated in terms of motility, biofilm formation, antibiotic resistance, as well as expression of several chosen target genes. While 0.1 and 5 ppm of NO2did not lead to any detectable modification in the studied phenotypes of the two bacteria, several alterations were observed when the bacteria were exposed to 45 ppm of gaseous NO2. We thus chose to focus on this high concentration. NO2-exposed P. fluorescens strains showed reduced swimming motility, and decreased swarming in case of the strain MFN1032. Biofilm formed by NO2-treated airborne strain MFAF76a showed increased maximum thickness compared to non-treated cells, while NO2 had no apparent effect on the clinical MFN1032 biofilm structure. It is well known that biofilm and motility are inversely regulated by intracellular c-di-GMP level. The c-di-GMP level was however not affected in response to NO2 treatment. Finally, NO2-exposed P. fluorescens strains were found to be more resistant to ciprofloxacin and chloramphenicol. Accordingly, the resistance nodulation cell division (RND) MexEF-OprN efflux pump encoding genes were highly upregulated in the two P. fluorescens strains. Noticeably, similar phenotypes had been previously observed following a NO treatment. Interestingly, an hmp-homolog gene in P. fluorescens strains MFAF76a and MFN1032 encodes a NO dioxygenase that is involved in NO detoxification into nitrites. Its expression was upregulated in response to NO2, suggesting a possible common pathway between NO and NO2 detoxification. Taken together, our study provides evidences for the bacterial response to NO2 toxicity.
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Affiliation(s)
- Tatiana Kondakova
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIBEvreux, France; Aerothermic and Internal Combustion Engine Technological Research CentreSaint Etienne du Rouvray, France
| | - Chloé Catovic
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIB Evreux, France
| | - Magalie Barreau
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIB Evreux, France
| | - Michael Nusser
- Institute of Functional Interfaces, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Gerald Brenner-Weiss
- Institute of Functional Interfaces, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIB Evreux, France
| | - Frédéric Dionnet
- Aerothermic and Internal Combustion Engine Technological Research Centre Saint Etienne du Rouvray, France
| | - Nicole Orange
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIB Evreux, France
| | - Cécile Duclairoir Poc
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Normandy University, University of Rouen, SéSa, IRIB Evreux, France
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Wang J, Vine CE, Balasiny BK, Rizk J, Bradley CL, Tinajero-Trejo M, Poole RK, Bergaust LL, Bakken LR, Cole JA. The roles of the hybrid cluster protein, Hcp and its reductase, Hcr, in high affinity nitric oxide reduction that protects anaerobic cultures ofEscherichia coliagainst nitrosative stress. Mol Microbiol 2016; 100:877-92. [DOI: 10.1111/mmi.13356] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2016] [Indexed: 01/24/2023]
Affiliation(s)
- Jing Wang
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
| | - Claire E. Vine
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
| | - Basema K. Balasiny
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
| | - John Rizk
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
| | - Charlene L. Bradley
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
| | - Mariana Tinajero-Trejo
- Department of Molecular Biology & Biotechnology; University of Sheffield, Firth Court, Western Bank; Sheffield S10 2TN UK
| | - Robert K. Poole
- Department of Molecular Biology & Biotechnology; University of Sheffield, Firth Court, Western Bank; Sheffield S10 2TN UK
| | | | - Lars R. Bakken
- Norwegian University of Life Science; PO box 5003 N-1432 Ås Norway
| | - Jeffrey A. Cole
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham; Birmingham B15 2TT UK
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28
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Holyoake LV, Hunt S, Sanguinetti G, Cook GM, Howard MJ, Rowe ML, Poole RK, Shepherd M. CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress. Biochem J 2016; 473:693-701. [PMID: 26699904 PMCID: PMC4785604 DOI: 10.1042/bj20150536] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 12/18/2015] [Accepted: 12/21/2015] [Indexed: 01/04/2023]
Abstract
The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli. A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homoeostasis and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content. Transcriptomic analysis revealed a dramatic up-regulation of protein chaperones, protein degradation (via phenylpropionate/phenylacetate catabolism), β-oxidation of fatty acids and genes involved in nitrate/nitrite reduction. (1)H NMR metabolomics revealed elevated methionine and betaine and diminished acetate and NAD(+) in cydD cells, which was consistent with the transcriptomics-based metabolic model. The growth rate and ΔpH, however, were unaffected, although the cydD strain did exhibit sensitivity to the NO-releasing compound NOC-12. These observations are consistent with the hypothesis that the loss of CydDC-mediated reductant export promotes protein misfolding, adaptations to energy metabolism and sensitivity to NO. The addition of both glutathione and cysteine to the medium was found to complement the loss of bd-type cytochrome synthesis in a cydD strain (a key component of the pleiotropic cydDC phenotype), providing the first direct evidence that CydDC substrates are able to restore the correct assembly of this respiratory oxidase. These data provide an insight into the metabolic flexibility of E. coli, highlight the importance of bacterial redox homoeostasis during nitrosative stress, and report for the first time the ability of periplasmic low molecular weight thiols to restore haem incorporation into a cytochrome complex.
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Affiliation(s)
| | - Stuart Hunt
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, U.K
| | - Guido Sanguinetti
- School of Informatics, The University of Edinburgh, Informatics Forum, 10 Crichton Street, Edinburgh EH8 9AB, U.K
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, 720 Cumberland Street, Dunedin 9054, New Zealand
| | - Mark J Howard
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, U.K
| | - Michelle L Rowe
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, U.K
| | - Robert K Poole
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, U.K
| | - Mark Shepherd
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, U.K.
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29
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Saulou-Bérion C, Gonzalez I, Enjalbert B, Audinot JN, Fourquaux I, Jamme F, Cocaign-Bousquet M, Mercier-Bonin M, Girbal L. Escherichia coli under Ionic Silver Stress: An Integrative Approach to Explore Transcriptional, Physiological and Biochemical Responses. PLoS One 2015; 10:e0145748. [PMID: 26696268 PMCID: PMC4699211 DOI: 10.1371/journal.pone.0145748] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 12/08/2015] [Indexed: 11/19/2022] Open
Abstract
For a better understanding of the systemic effect of sub-lethal micromolar concentrations of ionic silver on Escherichia coli, we performed a multi-level characterization of cells under Ag+-mediated stress using an integrative biology approach combining physiological, biochemical and transcriptomic data. Physiological parameters, namely bacterial growth and survival after Ag+ exposure, were first quantified and related to the accumulation of intracellular silver, probed for the first time by nano secondary ion mass spectroscopy at sub-micrometer lateral resolution. Modifications in E. coli biochemical composition were evaluated under Ag+-mediated stress by in situ synchrotron Fourier-transform infrared microspectroscopy and a comprehensive transcriptome response was also determined. Using multivariate statistics, correlations between the physiological parameters, the extracellular concentration of AgNO3 and the intracellular silver content, gene expression profiles and micro-spectroscopic data were investigated. We identified Ag+-dependent regulation of gene expression required for growth (e.g. transporter genes, transcriptional regulators, ribosomal proteins), for ionic silver transport and detoxification (e.g. copA, cueO, mgtA, nhaR) and for coping with various types of stress (dnaK, pspA, metA,R, oxidoreductase genes). The silver-induced shortening of the acyl chain of fatty acids, mostly encountered in cell membrane, was highlighted by microspectroscopy and correlated with the down-regulated expression of genes involved in fatty acid transport (fadL) and synthesis/modification of lipid A (lpxA and arnA). The increase in the disordered secondary structure of proteins in the presence of Ag+ was assessed through the conformational shift shown for amides I and II, and further correlated with the up-regulated expression of peptidase (hfq) and chaperone (dnaJ), and regulation of transpeptidase expression (ycfS and ycbB). Interestingly, as these transpeptidases act on the structural integrity of the cell wall, regulation of their expression may explain the morphological damage reported under Ag+-mediated stress. This result clearly demonstrates that the cell membrane is a key target of ionic silver.
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Affiliation(s)
- Claire Saulou-Bérion
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
| | - Ignacio Gonzalez
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
| | - Brice Enjalbert
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
| | - Jean-Nicolas Audinot
- Luxembourg Institute of Science and Technology (LIST), Material Research & Technology Department (MRT), Belvaux, Luxembourg
| | - Isabelle Fourquaux
- Faculté de Médecine Rangueil, Centre de Microscopie Electronique Appliquée à la Biologie (CMEAB), Toulouse Cedex, France
| | - Frédéric Jamme
- INRA, UAR1008, CEPIA, Nantes, France
- Synchrotron SOLEIL, Gif-sur-Yvette, France
| | - Muriel Cocaign-Bousquet
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
| | - Muriel Mercier-Bonin
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
| | - Laurence Girbal
- Université de Toulouse, INSA, UPS, INPT, LISBP, Toulouse, France
- INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France
- CNRS, UMR5504, Toulouse, France
- * E-mail:
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30
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Abstract
This review focuses on the steps unique to methionine biosynthesis, namely the conversion of homoserine to methionine. The past decade has provided a wealth of information concerning the details of methionine metabolism and the review focuses on providing a comprehensive overview of the field, emphasizing more recent findings. Details of methionine biosynthesis are addressed along with key cellular aspects, including regulation, uptake, utilization, AdoMet, the methyl cycle, and growing evidence that inhibition of methionine biosynthesis occurs under stressful cellular conditions. The first unique step in methionine biosynthesis is catalyzed by the metA gene product, homoserine transsuccinylase (HTS, or homoserine O-succinyltransferase). Recent experiments suggest that transcription of these genes is indeed regulated by MetJ, although the repressor-binding sites have not yet been verified. Methionine also serves as the precursor of S-adenosylmethionine, which is an essential molecule employed in numerous biological processes. S-adenosylhomocysteine is produced as a consequence of the numerous AdoMet-dependent methyl transfer reactions that occur within the cell. In E. coli and Salmonella, this molecule is recycled in two discrete steps to complete the methyl cycle. Cultures challenged by oxidative stress appear to experience a growth limitation that depends on methionine levels. E. coli that are deficient for the manganese and iron superoxide dismutases (the sodA and sodB gene products, respectively) require the addition of methionine or cysteine for aerobic growth. Modulation of methionine levels in response to stressful conditions further increases the complexity of its regulation.
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31
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Abstract
Nitrate reduction to ammonia via nitrite occurs widely as an anabolic process through which bacteria, archaea, and plants can assimilate nitrate into cellular biomass. Escherichia coli and related enteric bacteria can couple the eight-electron reduction of nitrate to ammonium to growth by coupling the nitrate and nitrite reductases involved to energy-conserving respiratory electron transport systems. In global terms, the respiratory reduction of nitrate to ammonium dominates nitrate and nitrite reduction in many electron-rich environments such as anoxic marine sediments and sulfide-rich thermal vents, the human gastrointestinal tract, and the bodies of warm-blooded animals. This review reviews the regulation and enzymology of this process in E. coli and, where relevant detail is available, also in Salmonella and draws comparisons with and implications for the process in other bacteria where it is pertinent to do so. Fatty acids may be present in high levels in many of the natural environments of E. coli and Salmonella in which oxygen is limited but nitrate is available to support respiration. In E. coli, nitrate reduction in the periplasm involves the products of two seven-gene operons, napFDAGHBC, encoding the periplasmic nitrate reductase, and nrfABCDEFG, encoding the periplasmic nitrite reductase. No bacterium has yet been shown to couple a periplasmic nitrate reductase solely to the cytoplasmic nitrite reductase NirB. The cytoplasmic pathway for nitrate reduction to ammonia is restricted almost exclusively to a few groups of facultative anaerobic bacteria that encounter high concentrations of environmental nitrate.
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32
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Wilson JL, Wareham LK, McLean S, Begg R, Greaves S, Mann BE, Sanguinetti G, Poole RK. CO-Releasing Molecules Have Nonheme Targets in Bacteria: Transcriptomic, Mathematical Modeling and Biochemical Analyses of CORM-3 [Ru(CO)3Cl(glycinate)] Actions on a Heme-Deficient Mutant of Escherichia coli. Antioxid Redox Signal 2015; 23:148-62. [PMID: 25811604 PMCID: PMC4492677 DOI: 10.1089/ars.2014.6151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AIMS Carbon monoxide-releasing molecules (CORMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically, including applications in antimicrobial therapy. Hemes are generally considered the prime targets of CO and CORMs, so we tested this hypothesis using heme-deficient bacteria, applying cellular, transcriptomic, and biochemical tools. RESULTS CORM-3 [Ru(CO)3Cl(glycinate)] readily penetrated Escherichia coli hemA bacteria and was inhibitory to these and Lactococcus lactis, even though they lack all detectable hemes. Transcriptomic analyses, coupled with mathematical modeling of transcription factor activities, revealed that the response to CORM-3 in hemA bacteria is multifaceted but characterized by markedly elevated expression of iron acquisition and utilization mechanisms, global stress responses, and zinc management processes. Cell membranes are disturbed by CORM-3. INNOVATION This work has demonstrated for the first time that CORM-3 (and to a lesser extent its inactivated counterpart) has multiple cellular targets other than hemes. A full understanding of the actions of CORMs is vital to understand their toxic effects. CONCLUSION This work has furthered our understanding of the key targets of CORM-3 in bacteria and raises the possibility that the widely reported antimicrobial effects cannot be attributed to classical biochemical targets of CO. This is a vital step in exploiting the potential, already demonstrated, for using optimized CORMs in antimicrobial therapy.
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Affiliation(s)
- Jayne Louise Wilson
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Lauren K Wareham
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Samantha McLean
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Ronald Begg
- 2 School of Informatics, The University of Edinburgh , Edinburgh, United Kingdom
| | - Sarah Greaves
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
| | - Brian E Mann
- 3 Department of Chemistry, The University of Sheffield , Sheffield, United Kingdom
| | - Guido Sanguinetti
- 2 School of Informatics, The University of Edinburgh , Edinburgh, United Kingdom
| | - Robert K Poole
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
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Wareham LK, Poole RK, Tinajero-Trejo M. CO-releasing Metal Carbonyl Compounds as Antimicrobial Agents in the Post-antibiotic Era. J Biol Chem 2015; 290:18999-9007. [PMID: 26055702 PMCID: PMC4521022 DOI: 10.1074/jbc.r115.642926] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The possibility of a “post-antibiotic era” in the 21st century, in which common infections may kill, has prompted research into radically new antimicrobials. CO-releasing molecules (CORMs), mostly metal carbonyl compounds, originally developed for therapeutic CO delivery in animals, are potent antimicrobial agents. Certain CORMs inhibit growth and respiration, reduce viability, and release CO to intracellular hemes, as predicted, but their actions are more complex, as revealed by transcriptomic datasets and modeling. Progress is hindered by difficulties in detecting CO release intracellularly, limited understanding of the biological chemistry of CO reactions with non-heme targets, and the cytotoxicity of some CORMs to mammalian cells.
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Affiliation(s)
- Lauren K Wareham
- From the Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Robert K Poole
- From the Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Mariana Tinajero-Trejo
- From the Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, United Kingdom
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34
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Frederick RE, Caranto JD, Masitas CA, Gebhardt LL, MacGowan CE, Limberger RJ, Kurtz DM. Dioxygen and nitric oxide scavenging by Treponema denticola flavodiiron protein: a mechanistic paradigm for catalysis. J Biol Inorg Chem 2015; 20:603-13. [PMID: 25700637 PMCID: PMC4768905 DOI: 10.1007/s00775-015-1248-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/13/2015] [Indexed: 10/24/2022]
Abstract
Flavodiiron proteins (FDPs) contain a unique active site consisting of a non-heme diiron carboxylate site proximal to a flavin mononucleotide (FMN). FDPs serve as the terminal components for reductive scavenging of dioxygen (to water) or nitric oxide (to nitrous oxide), which combats oxidative or nitrosative stress in many bacteria. Characterizations of FDPs from spirochetes or from any oral microbes have not been previously reported. Here, we report characterization of an FDP from the anaerobic spirochete, Treponema (T.) denticola, which is associated with chronic periodontitis. The isolated T. denticola FDP exhibited efficient four-electron dioxygen reductase activity and lower but significant anaerobic nitric oxide reductase activity. A mutant T. denticola strain containing the inactivated FDP-encoding gene was significantly more air-sensitive than the wild-type strain. Single turnover reactions of the four-electron-reduced FDP (FMNH2-Fe(II)Fe(II)) (FDPred) with O2 monitored on the milliseconds to seconds time scale indicated initial rapid formation of a spectral feature consistent with a cis-μ-1,2-peroxo-diferric intermediate, which triggered two-electron oxidation of FMNH2. Reaction of FDPred with NO showed apparent cooperativity between binding of the first and second NO to the diferrous site. The resulting diferrous dinitrosyl complex triggered two-electron oxidation of the FMNH2. Our cumulative results on this and other FDPs indicate that smooth two-electron FMNH2 oxidation triggered by the FDPred/substrate complex and overall four-electron oxidation of FDPred to FDPox constitutes a mechanistic paradigm for both dioxygen and nitric oxide reductase activities of FDPs. Four-electron reductive O2 scavenging by FDPs could contribute to oxidative stress protection in many other oral bacteria.
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Affiliation(s)
- Rosanne E. Frederick
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jonathan D. Caranto
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Cesar A. Masitas
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Linda L. Gebhardt
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Charles E. MacGowan
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Ronald J. Limberger
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | - Donald M. Kurtz
- Department of Chemistry, University of Texas at San Antonio, San Antonio, TX 78249, USA
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Safar R, Ronzani C, Diab R, Chevrier J, Bensoussan D, Grandemange S, Le Faou A, Rihn BH, Joubert O. Human Monocyte Response to S-Nitrosoglutathione-Loaded Nanoparticles: Uptake, Viability, and Transcriptome. Mol Pharm 2015; 12:554-61. [DOI: 10.1021/mp5006382] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Ramia Safar
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
| | - Carole Ronzani
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
| | - Roudayna Diab
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
| | - Jérôme Chevrier
- Faculté
de Médecine, Service Commun de Microscopie, Université de Lorraine, France
| | - Danièle Bensoussan
- Unité
de Thérapie Cellulaire et tissus, CHU de Nancy, Vandœuvre-lès-Nancy, France
| | | | - Alain Le Faou
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
- Faculté
de Médecine de Nancy, Université de Lorraine, France
| | - Bertrand H. Rihn
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
| | - Olivier Joubert
- Faculté
de Pharmacie de Nancy, EA 3452 Cithéfor, Université de Lorraine, France
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Mordorski B, Pelgrift R, Adler B, Krausz A, da Costa Neto AB, Liang H, Gunther L, Clendaniel A, Harper S, Friedman JM, Nosanchuk JD, Nacharaju P, Friedman AJ. S-nitrosocaptopril nanoparticles as nitric oxide-liberating and transnitrosylating anti-infective technology. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2014; 11:283-91. [PMID: 25461287 DOI: 10.1016/j.nano.2014.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 09/06/2014] [Accepted: 09/30/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED Nitric oxide (NO), an essential agent of the innate immune system, exhibits multi-mechanistic antimicrobial activity. Previously, NO-releasing nanoparticles (NO-np) demonstrated increased antimicrobial activity when combined with glutathione (GSH) due to formation of S-nitrosoglutathione (GSNO), a transnitrosylating agent. To capitalize on this finding, we incorporated the thiol-containing ACE-inhibitor, captopril, with NO-np to form SNO-CAP-np, nanoparticles that both release NO and form S-nitrosocaptopril. In the presence of GSH, SNO-CAP-np demonstrated increased transnitrosylation activity compared to NO-np, as exhibited by increased GSNO formation. Escherichia coli and methicillin-resistant Staphylococcus aureus were highly susceptible to SNO-CAP-np in a dose-dependent fashion, with E. coli being most susceptible, and SNO-CAP-np were nontoxic in zebrafish embryos at translatable concentrations. Given SNO-CAP-np's increased transnitrosylation activity and increased E. coli susceptibility compared to NO-np, transnitrosylation rather than free NO is likely responsible for overcoming E. coli's resistance mechanisms and ultimately killing the pathogen. FROM THE CLINICAL EDITOR This team of authors incorporated the thiol-containing ACE-inhibitor, captopril, into a nitric oxide releasing nanoparticle system, generating nanoparticles that both release NO and form S-nitrosocaptopril, with pronounced toxic effects on MRSA and E. coli in the presented model system.
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Affiliation(s)
- Breanne Mordorski
- Division of Dermatology, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA
| | - Robert Pelgrift
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Brandon Adler
- Division of Dermatology, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA
| | - Aimee Krausz
- Division of Dermatology, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA
| | | | - Hongying Liang
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Leslie Gunther
- Analytical Imaging Facility, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alicea Clendaniel
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA
| | - Stacey Harper
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, USA; School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, USA
| | - Joel M Friedman
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Joshua D Nosanchuk
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA; Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Parimala Nacharaju
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Adam J Friedman
- Division of Dermatology, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA; Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY, USA.
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Tinajero-Trejo M, Denby KJ, Sedelnikova SE, Hassoubah SA, Mann BE, Poole RK. Carbon monoxide-releasing molecule-3 (CORM-3; Ru(CO)3Cl(glycinate)) as a tool to study the concerted effects of carbon monoxide and nitric oxide on bacterial flavohemoglobin Hmp: applications and pitfalls. J Biol Chem 2014; 289:29471-82. [PMID: 25193663 PMCID: PMC4207967 DOI: 10.1074/jbc.m114.573444] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 09/01/2014] [Indexed: 11/06/2022] Open
Abstract
CO and NO are small toxic gaseous molecules that play pivotal roles in biology as gasotransmitters. During bacterial infection, NO, produced by the host via the inducible NO synthase, exerts critical antibacterial effects while CO, generated by heme oxygenases, enhances phagocytosis of macrophages. In Escherichia coli, other bacteria and fungi, the flavohemoglobin Hmp is the most important detoxification mechanism converting NO and O2 to the ion nitrate (NO3(-)). The protoheme of Hmp binds not only O2 and NO, but also CO so that this ligand is expected to be an inhibitor of NO detoxification in vivo and in vitro. CORM-3 (Ru(CO)(3)Cl(glycinate)) is a metal carbonyl compound extensively used and recently shown to have potent antibacterial properties. In this study, attenuation of the NO resistance of E. coli by CORM-3 is demonstrated in vivo. However, polarographic measurements showed that CO gas, but not CORM-3, produced inhibition of the NO detoxification activity of Hmp in vitro. Nevertheless, CO release from CORM-3 in the presence of soluble cellular compounds is demonstrated by formation of carboxy-Hmp. We show that the inability of CORM-3 to inhibit the activity of purified Hmp is due to slow release of CO in protein solutions alone i.e. when sodium dithionite, widely used in previous studies of CO release from CORM-3, is excluded. Finally, we measure intracellular CO released from CORM-3 by following the formation of carboxy-Hmp in respiring cells. CORM-3 is a tool to explore the concerted effects of CO and NO in vivo.
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Affiliation(s)
| | - Katie J Denby
- From the Departments of Molecular Biology & Biotechnology and
| | | | | | - Brian E Mann
- Chemistry, The University of Sheffield, S10 2TN United Kingdom
| | - Robert K Poole
- From the Departments of Molecular Biology & Biotechnology and
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Stress response of Salmonella enterica serovar typhimurium to acidified nitrite. Appl Environ Microbiol 2014; 80:6373-82. [PMID: 25107963 DOI: 10.1128/aem.01696-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The antimicrobial action of the curing agent sodium nitrite (NaNO2), which is added as a preservative to raw meat products, depends on its conversion to nitric oxide and other reactive nitrogen species under acidic conditions. In this study, we used RNA sequencing to analyze the acidified-NaNO2 shock and adaptive responses of Salmonella enterica serovar Typhimurium, a frequent contaminant in raw meat, considering parameters relevant for the production of raw-cured sausages. Upon a 10-min exposure to 150 mg/liter NaNO2 in LB (pH 5.5) acidified with lactic acid, genes involved in nitrosative-stress protection, together with several other stress-related genes, were induced. In contrast, genes involved in translation, transcription, replication, and motility were downregulated. The induction of stress tolerance and the reduction of cell proliferation obviously promote survival under harsh acidified-NaNO2 stress. The subsequent adaptive response was characterized by upregulation of NsrR-regulated genes and iron uptake systems and by downregulation of genes involved in anaerobic respiratory pathways. Strikingly, amino acid decarboxylase systems, which contribute to acid tolerance, displayed increased transcript levels in response to acidified NaNO2. The induction of systems known to be involved in acid resistance indicates a nitrite-mediated increase in the level of acid stress. Deletion of cadA, which encodes lysine decarboxylase, resulted in increased sensitivity to acidified NaNO2. Intracellular pH measurements using a pH-sensitive green fluorescent protein (GFP) variant showed that the cytoplasmic pH of S. Typhimurium in LB medium (pH 5.5) is decreased upon the addition of NaNO2. This study provides the first evidence that intracellular acidification is an additional antibacterial mode of action of acidified NaNO2.
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Correcting direct effects of ethanol on translation and transcription machinery confers ethanol tolerance in bacteria. Proc Natl Acad Sci U S A 2014; 111:E2576-85. [PMID: 24927582 DOI: 10.1073/pnas.1401853111] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The molecular mechanisms of ethanol toxicity and tolerance in bacteria, although important for biotechnology and bioenergy applications, remain incompletely understood. Genetic studies have identified potential cellular targets for ethanol and have revealed multiple mechanisms of tolerance, but it remains difficult to separate the direct and indirect effects of ethanol. We used adaptive evolution to generate spontaneous ethanol-tolerant strains of Escherichia coli, and then characterized mechanisms of toxicity and resistance using genome-scale DNAseq, RNAseq, and ribosome profiling coupled with specific assays of ribosome and RNA polymerase function. Evolved alleles of metJ, rho, and rpsQ recapitulated most of the observed ethanol tolerance, implicating translation and transcription as key processes affected by ethanol. Ethanol induced miscoding errors during protein synthesis, from which the evolved rpsQ allele protected cells by increasing ribosome accuracy. Ribosome profiling and RNAseq analyses established that ethanol negatively affects transcriptional and translational processivity. Ethanol-stressed cells exhibited ribosomal stalling at internal AUG codons, which may be ameliorated by the adaptive inactivation of the MetJ repressor of methionine biosynthesis genes. Ethanol also caused aberrant intragenic transcription termination for mRNAs with low ribosome density, which was reduced in a strain with the adaptive rho mutation. Furthermore, ethanol inhibited transcript elongation by RNA polymerase in vitro. We propose that ethanol-induced inhibition and uncoupling of mRNA and protein synthesis through direct effects on ribosomes and RNA polymerase conformations are major contributors to ethanol toxicity in E. coli, and that adaptive mutations in metJ, rho, and rpsQ help protect these central dogma processes in the presence of ethanol.
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Begara-Morales JC, Sánchez-Calvo B, Luque F, Leyva-Pérez MO, Leterrier M, Corpas FJ, Barroso JB. Differential transcriptomic analysis by RNA-Seq of GSNO-responsive genes between Arabidopsis roots and leaves. PLANT & CELL PHYSIOLOGY 2014; 55:1080-95. [PMID: 24599390 DOI: 10.1093/pcp/pcu044] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
S-Nitrosoglutathione (GSNO) is a nitric oxide-derived molecule that can regulate protein function by a post-translational modification designated S-nitrosylation. GSNO has also been detected in different plant organs under physiological and stress conditions, and it can also modulate gene expression. Thirty-day-old Arabidopsis plants were grown under hydroponic conditions, and exogenous 1 mM GSNO was applied to the root systems for 3 h. Differential gene expression analyses were carried out both in roots and in leaves by RNA sequencing (RNA-seq). A total of 3,263 genes were identified as being modulated by GSNO. Most of the genes identified were associated with the mechanism of protection against stress situations, many of these having previously been identified as target genes of GSNO by array-based methods. However, new genes were identified, such as that for methionine sulfoxide reductase (MSR) in leaves or different miscellaneous RNA (miscRNA) genes in Arabidopsis roots. As a result, 1,945 GSNO-responsive genes expressed differently in leaves and roots were identified, and 114 of these corresponded exclusively to one of these organs. In summary, it is demonstrated that RNA-seq extends our knowledge of GSNO as a signaling molecule which differentially modulates gene expression in roots and leaves under non-stress conditions.
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Affiliation(s)
- Juan C Begara-Morales
- Group of Biochemistry and Cell Signalling in Nitric Oxide, Área de Bioquímica y Biología Molecular, Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Universitario 'Las Lagunillas' s/n, Universidad de Jaén, E-23071 Jaén, Spain
| | - Beatriz Sánchez-Calvo
- Group of Biochemistry and Cell Signalling in Nitric Oxide, Área de Bioquímica y Biología Molecular, Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Universitario 'Las Lagunillas' s/n, Universidad de Jaén, E-23071 Jaén, Spain
| | - Francisco Luque
- Group of Biochemistry and Cell Signalling in Nitric Oxide, Área de Bioquímica y Biología Molecular, Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Universitario 'Las Lagunillas' s/n, Universidad de Jaén, E-23071 Jaén, Spain
| | - María O Leyva-Pérez
- Group of Biochemistry and Cell Signalling in Nitric Oxide, Área de Bioquímica y Biología Molecular, Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Universitario 'Las Lagunillas' s/n, Universidad de Jaén, E-23071 Jaén, Spain
| | - Marina Leterrier
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (EEZ), Consejo Superior de Investigaciones Científicas, E-18080 Granada, Spain
| | - Francisco J Corpas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (EEZ), Consejo Superior de Investigaciones Científicas, E-18080 Granada, Spain
| | - Juan B Barroso
- Group of Biochemistry and Cell Signalling in Nitric Oxide, Área de Bioquímica y Biología Molecular, Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Campus Universitario 'Las Lagunillas' s/n, Universidad de Jaén, E-23071 Jaén, Spain
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Transcriptome Response to Nitrosative Stress inRhodobacter sphaeroides2.4.1. Biosci Biotechnol Biochem 2014; 77:111-8. [DOI: 10.1271/bbb.120601] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nobre LS, Garcia-Serres R, Todorovic S, Hildebrandt P, Teixeira M, Latour JM, Saraiva LM. Escherichia coli RIC is able to donate iron to iron-sulfur clusters. PLoS One 2014; 9:e95222. [PMID: 24740378 PMCID: PMC3989283 DOI: 10.1371/journal.pone.0095222] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/24/2014] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli RIC (Repair of Iron Centers) is a diiron protein previously reported to be involved in the repair of iron-sulfur proteins damaged by oxidative or nitrosative stresses, and proposed to act as an iron donor. This possible role of RIC was now examined specifically by evaluating its ability to donate iron ions to apo-iron-sulfur proteins, determining the iron binding constants and assessing the lability of its iron ions. We show, by UV-visible, EPR and resonance Raman spectroscopies that RIC may participate in the synthesis of an iron-sulfur cluster in the apo-forms of the spinach ferredoxin and IscU when in the presence of the sulfide donating system IscS and L-cysteine. Iron binding assays allowed determining the as-isolated and fully reduced RIC dissociation constants for the ferric and ferrous iron of 10-27 M and 10-13 M, respectively. Mössbauer studies revealed that the RIC iron ions are labile, namely when the center is in the mixed-valence redox form as compared with the (μ-oxo) diferric one. Altogether, these results suggest that RIC is capable of delivering iron for the formation of iron-sulfur clusters.
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Affiliation(s)
- Lígia S. Nobre
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República (EAN), Oeiras, Portugal
| | - Ricardo Garcia-Serres
- DSV/iRTSV/CBM, UMR 5249 CEA-Université Grenoble I-CNRS/Equipe de Physicochimie des Métaux en Biologie, CEA-Grenoble, France
| | - Smilja Todorovic
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República (EAN), Oeiras, Portugal
| | - Peter Hildebrandt
- Technische Universität Berlin, Institut für Chemie, FG Biophysikalische Chemie, Berlin, Germany
| | - Miguel Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República (EAN), Oeiras, Portugal
- * E-mail: (LMS); (MT)
| | - Jean-Marc Latour
- DSV/iRTSV/CBM, UMR 5249 CEA-Université Grenoble I-CNRS/Equipe de Physicochimie des Métaux en Biologie, CEA-Grenoble, France
| | - Lígia M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República (EAN), Oeiras, Portugal
- * E-mail: (LMS); (MT)
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McLean S, Begg R, Jesse HE, Mann BE, Sanguinetti G, Poole RK. Analysis of the bacterial response to Ru(CO)3Cl(Glycinate) (CORM-3) and the inactivated compound identifies the role played by the ruthenium compound and reveals sulfur-containing species as a major target of CORM-3 action. Antioxid Redox Signal 2013; 19:1999-2012. [PMID: 23472713 PMCID: PMC3869425 DOI: 10.1089/ars.2012.5103] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AIMS Carbon monoxide (CO)-releasing molecules (CO-RMs) are being developed with the ultimate goal of safely utilizing the therapeutic potential of CO clinically. One such application is antimicrobial activity; therefore, we aimed to characterize and compare the effects of the CO-RM, CORM-3, and its inactivated counterpart, where all labile CO has been removed, at the transcriptomic and cellular level. RESULTS We found that both compounds are able to penetrate the cell, but the inactive form is not inhibitory to bacterial growth under conditions where CORM-3 is. Transcriptomic analyses revealed that the bacterial response to inactivated CORM-3 (iCORM-3) is much lower than to the active compound and that a wide range of processes appear to be affected by CORM-3 and to a lesser extent iCORM-3, including energy metabolism, membrane transport, motility, and the metabolism of many sulfur-containing species, including cysteine and methionine. INNOVATION This work has demonstrated that both CORM-3 and its inactivated counterpart react with cellular functions to yield a complex response at the transcriptomic level. A full understanding of the actions of both compounds is vital to understand the toxic effects of CO-RMs. CONCLUSION This work has furthered our understanding of how CORM-3 behaves at the cellular level and identifies the responses that occur when the host is exposed to the Ru compound as well as those that result from the released CO. This is a vital step in laying the groundwork for future development of optimized CO-RMs for eventual use in antimicrobial therapy.
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Affiliation(s)
- Samantha McLean
- 1 Department of Molecular Biology and Biotechnology, The University of Sheffield , Sheffield, United Kingdom
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Zhou S, Narukami T, Masuo S, Shimizu M, Fujita T, Doi Y, Kamimura Y, Takaya N. NO-inducible nitrosothionein mediates NO removal in tandem with thioredoxin. Nat Chem Biol 2013; 9:657-63. [DOI: 10.1038/nchembio.1316] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/08/2013] [Indexed: 11/09/2022]
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Kutner AJ, Friedman AJ. Use of nitric oxide nanoparticulate platform for the treatment of skin and soft tissue infections. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2013; 5:502-14. [PMID: 23661566 PMCID: PMC7169754 DOI: 10.1002/wnan.1230] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/08/2013] [Accepted: 04/18/2013] [Indexed: 12/24/2022]
Abstract
The incidence of skin and soft tissue infections (SSTI) due to multi‐drug resistant pathogens is increasing. The concomitant increase in antibiotic use along with the ease with which organisms develop mechanisms of resistance have together become a medical crisis, underscoring the importance of developing innovative and effective antimicrobial strategies. Nitric oxide (NO) is an endogenously produced molecule with many physiologic functions, including broad spectrum antimicrobial activity and immunomodulatory properties. The risk of resistance to NO is minimized because NO has multiple mechanisms of antimicrobial action. NO's clinical utility has been limited largely because it is highly reactive and lacks appropriate vehicles for storage and delivery. To harness NO's antimicrobial potential, a variety exogenous NO delivery platforms have been developed and evaluated, yet limitations preclude their use in the clinical setting. Nanotechnology represents a paradigm through which these limitations can be overcome, allowing for the encapsulation, controlled release, and focused delivery of NO for the treatment of SSTI. WIREs Nanomed Nanobiotechnol 2013. doi: 10.1002/wnan.1230 This article is categorized under:
Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
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Affiliation(s)
- Allison J Kutner
- Division of Dermatology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
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46
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Nobre LS, Saraiva LM. Effect of combined oxidative and nitrosative stresses on Staphylococcus aureus transcriptome. Appl Microbiol Biotechnol 2013; 97:2563-73. [PMID: 23389340 DOI: 10.1007/s00253-013-4730-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/13/2013] [Accepted: 01/15/2013] [Indexed: 12/28/2022]
Abstract
Staphylococcus aureus is a pathogen responsible for severe community- and nosocomially acquired infections. To fight pathogen intrusion, the innate immune system uses a plethora of weapons, with the generation of oxidative and nitrosative stresses among the most efficient. In this work, the S. aureus genome-wide transcriptional responses to oxidative stress generated by hydrogen peroxide, to nitrosative stress imposed by S-nitrosoglutathione (GSNO), and to the combination of the two were investigated using microarray analysis. The results showed that these stresses have a significant impact on the transcriptome of S. aureus. Hydrogen peroxide modified mainly the mRNA abundance of genes involved in oxidative detoxification and DNA metabolism, which together represent 14 % of the total number of upregulated genes. GSNO caused significant alteration of the expression of gene products with regulatory function. However, the simultaneous addition of GSNO and hydrogen peroxide was found to cause the more significant transcriptomic alteration, affecting ∼10 % of the total transcriptome. In particular, exposure of S. aureus to GSNO plus hydrogen peroxide modified the transcription of genes associated with cell envelope and iron metabolism, including induction of ftnA and dps genes that encode iron-storage and oxidative-protecting proteins. Further studies revealed that when exposed to combined GSNO-hydrogen peroxide stresses, S. aureus has decreased viability, which is enhanced in the presence of iron, and low siderophore activity. Altogether, this study revealed, for the first time, how the combined oxidative and nitrosative stresses inflicted during phagocytosis interfere at the transcriptional level with the S. aureus cellular metabolism.
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Affiliation(s)
- Lígia S Nobre
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República (EAN), 2780-157 Oeiras, Portugal
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Laver JR, McLean S, Bowman LAH, Harrison LJ, Read RC, Poole RK. Nitrosothiols in bacterial pathogens and pathogenesis. Antioxid Redox Signal 2013; 18:309-22. [PMID: 22768799 DOI: 10.1089/ars.2012.4767] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE The formation and degradation of S-nitrosothiols (SNOs) are important mechanisms of post-translational protein modification and appear to be ubiquitous in biology. These processes play well-characterized roles in eukaryotic cells, including a variety of pathologies and in relation to chronic conditions. We know little of the roles of these processes in pathogenic and other bacteria. RECENT ADVANCES It is clear, mostly from growth and transcriptional studies, that bacteria sense and respond to exogenous SNOs. These responses are phenotypically and mechanistically distinct from the responses of bacteria to nitric oxide (NO) and NO-releasing agents, as well as peroxynitrite. Small SNOs, such as S-nitrosoglutathione (GSNO), are accumulated by bacteria with the result that intracellular S-nitrosoproteins (the 'S-nitrosoproteome') are detectable. Recently, conditions for endogenous SNO formation in enterobacteria have been described. CRITICAL ISSUES The propensity of intracellular proteins to form SNOs is presumably constrained by the same rules of selectivity that have been discovered in eukaryotic systems, but is also influenced by uniquely bacterial NO detoxification systems, exemplified by the flavohemoglobin Hmp in enterobacteria and NO reductase of meningococci. Furthermore, the bacterial expression of such proteins impacts upon the formation of SNOs in mammalian hosts. FUTURE DIRECTIONS The impairment during bacterial infections of specific SNO events in the mammalian host is of considerable interest in the context of proteins involved in innate immunity and intracellular signalling. In bacteria, numerous mechanisms of S-nitrosothiol degradation have been reported (e.g., GSNO reductase); others are thought to operate, based on consideration of their mammalian counterparts. The nitrosothiols of bacteria and particularly of pathogens warrant more intensive investigation.
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Affiliation(s)
- Jay R Laver
- Department of Infection and Immunity, The University of Sheffield, Sheffield, United Kingdom.
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Vinella D, Loiseau L, de Choudens SO, Fontecave M, Barras F. In vivo[Fe-S] cluster acquisition by IscR and NsrR, two stress regulators inEscherichia coli. Mol Microbiol 2013; 87:493-508. [DOI: 10.1111/mmi.12135] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel Vinella
- Laboratoire de Chimie Bactérienne; UMR 7283 (Aix-Marseille Université-CNRS); Institut de Microbiologie de la Méditerranée; 31 Chemin Joseph Aiguier; 13009; Marseille; France
| | - Laurent Loiseau
- Laboratoire de Chimie Bactérienne; UMR 7283 (Aix-Marseille Université-CNRS); Institut de Microbiologie de la Méditerranée; 31 Chemin Joseph Aiguier; 13009; Marseille; France
| | - Sandrine Ollagnier de Choudens
- Laboratoire de Chimie et Biologie des Métaux; UMR 5249 (CEA-Université Grenoble I-CNRS); 17 Rue des Martyrs; 38054; Grenoble Cedex; France
| | | | - Frédéric Barras
- Laboratoire de Chimie Bactérienne; UMR 7283 (Aix-Marseille Université-CNRS); Institut de Microbiologie de la Méditerranée; 31 Chemin Joseph Aiguier; 13009; Marseille; France
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Abstract
Campylobacter jejuni is a zoonotic Gram-negative bacterial pathogen that is exposed to reactive nitrogen species, such as nitric oxide, from a variety of sources. To combat the toxic effects of this nitrosative stress, C. jejuni upregulates a small regulon under the control of the transcriptional activator NssR, which positively regulates the expression of a single-domain globin protein (Cgb) and a truncated globin protein (Ctb). Cgb has previously been shown to detoxify nitric oxide, but the role of Ctb remains contentious. As C. jejuni is amenable to genetic manipulation, and its globin proteins are easily expressed and purified, a combination of mutagenesis, complementation, transcriptomics, spectroscopic characterisation and structural analyses has been used to probe the regulation, function and structure of Cgb and Ctb. This ability to study Cgb and Ctb with such a multi-pronged approach is a valuable asset, especially since only a small fraction of known globin proteins have been functionally characterised.
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Abstract
SIGNIFICANCE In bacteria, transcriptional responses to reactive oxygen and nitrogen species (ROS and RNS, respectively) are typically coordinated by regulatory proteins that employ metal centers or reactive thiols to detect the presence of those species. This review is focused on the structure, function and mechanism of three regulatory proteins (Fur, PerR, and NorR) that contain non-heme iron and regulate the transcription of target genes in response to ROS and/or RNS. The targets for regulation include genes encoding detoxification activities, and genes encoding proteins involved in the repair of the damage caused by ROS and RNS. RECENT ADVANCES Three-dimensional structures of several Fur proteins and of PerR are revealing important details of the metal binding sites of these proteins, showing a surprising degree of structural diversity in the Fur family. CRITICAL ISSUES Discussion of the interaction of Fur with ROS and RNS will illustrate the difficulty that sometimes exists in distinguishing between true physiological responses and adventitious reactions of a regulatory protein with a reactive ligand. FUTURE DIRECTIONS Consideration of these three sensor proteins illuminates some of the key questions that remain unanswered, for example, the nature of the biochemical determinants that dictate the sensitivity and specificity of the interaction of the sensor proteins with their cognate signals.
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Affiliation(s)
- Stephen Spiro
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas 75080, USA.
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