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Marques E, Gallazzini M. Lipocalins. Curr Biol 2024; 34:R670-R672. [PMID: 39043135 DOI: 10.1016/j.cub.2024.05.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Marques and Gallazzini introduce the lipocalin family of small extracellular proteins, discussing their structure, functions, and roles in disease.
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Affiliation(s)
- Eloïse Marques
- Mechanisms and Therapeutic Strategies of Chronic Kidney Disease, INSERM U1151-CNRS UMR 8253, Université Paris Cité, Institut Necker Enfants Malades, 160 Rue de Vaugirard, Paris 75015, France.
| | - Morgan Gallazzini
- Mechanisms and Therapeutic Strategies of Chronic Kidney Disease, INSERM U1151-CNRS UMR 8253, Université Paris Cité, Institut Necker Enfants Malades, 160 Rue de Vaugirard, Paris 75015, France.
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Henry M, Khemiri I, Tebbji F, Abu-Helu R, Vincent AT, Sellam A. Manganese homeostasis modulates fungal virulence and stress tolerance in Candida albicans. mSphere 2024; 9:e0080423. [PMID: 38380913 PMCID: PMC10964418 DOI: 10.1128/msphere.00804-23] [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: 12/21/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
Due to the scarcity of transition metals within the human host, fungal pathogens have evolved sophisticated mechanisms to uptake and utilize these micronutrients at the infection interface. While considerable attention was turned to iron and copper acquisition mechanisms and their importance in fungal fitness, less was done regarding either the role of manganese (Mn) in infectious processes or the cellular mechanism by which fungal cells achieve their Mn-homeostasis. Here, we undertook transcriptional profiling in the pathogenic fungus Candida albicans experiencing both Mn starvation and excess to capture biological processes that are modulated by this metal. We uncovered that Mn scarcity influences diverse processes associated with fungal fitness including invasion of host cells and antifungal sensitivity. We show that Mn levels influence the abundance of iron and zinc emphasizing the complex crosstalk between metals. The deletion of SMF12, a member of Mn Nramp transporters, confirmed its contribution to Mn uptake. smf12 was unable to form hyphae and damage host cells and exhibited sensitivity to azoles. We found that the unfolded protein response (UPR), likely activated by decreased glycosylation under Mn limitation, was required to recover growth when cells were shifted from an Mn-starved to an Mn-repleted medium. RNA-seq profiling of cells exposed to Mn excess revealed that UPR was also activated. Furthermore, the UPR signaling axis Ire1-Hac1 was required to bypass Mn toxicity. Collectively, this study underscores the importance of Mn homeostasis in fungal virulence and comprehensively provides a portrait of biological functions that are modulated by Mn in a fungal pathogen. IMPORTANCE Transition metals such as manganese provide considerable functionality across biological systems as they are used as cofactors for many catalytic enzymes. The availability of manganese is very limited inside the human body. Consequently, pathogenic microbes have evolved sophisticated mechanisms to uptake this micronutrient inside the human host to sustain their growth and cause infections. Here, we undertook a comprehensive approach to understand how manganese availability impacts the biology of the prevalent fungal pathogen, Candida albicans. We uncovered that manganese homeostasis in this pathogen modulates different biological processes that are essential for host infection which underscores the value of targeting fungal manganese homeostasis for potential antifungal therapeutics development.
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Affiliation(s)
- Manon Henry
- Montreal Heart Institute/Institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Inès Khemiri
- Montreal Heart Institute/Institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Faiza Tebbji
- Montreal Heart Institute/Institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Rasmi Abu-Helu
- Department of Medical Laboratory Sciences, Faculty of Health Professions, Al-Quds University, Jerusalem, Palestine
| | - Antony T. Vincent
- Department of Animal Sciences, Université Laval, Quebec City, Québec, Canada
| | - Adnane Sellam
- Montreal Heart Institute/Institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
- Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
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3
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Matějková T, Dodoková A, Kreisinger J, Stopka P, Stopková R. Microbial, proteomic, and metabolomic profiling of the estrous cycle in wild house mice. Microbiol Spectr 2024; 12:e0203723. [PMID: 38171017 PMCID: PMC10846187 DOI: 10.1128/spectrum.02037-23] [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: 05/15/2023] [Accepted: 11/20/2023] [Indexed: 01/05/2024] Open
Abstract
Symbiotic microbial communities affect the host immune system and produce molecules contributing to the odor of an individual. In many mammalian species, saliva and vaginal fluids are important sources of chemical signals that originate from bacterial metabolism and may act as honest signals of health and reproductive status. In this study, we aimed to define oral and vaginal microbiomes and their dynamics throughout the estrous cycle in wild house mice. In addition, we analyzed a subset of vaginal proteomes and metabolomes to detect potential interactions with microbiomes. 16S rRNA sequencing revealed that both saliva and vagina are dominated by Firmicutes and Proteobacteria but differ at the genus level. The oral microbiome is more stable during the estrous cycle and most abundant bacteria belong to the genera Gemella and Streptococcus, while the vaginal microbiome shows higher bacterial diversity and dynamics during the reproductive cycle and is characterized by the dominance of Muribacter and Rodentibacter. These two genera cover around 50% of the bacterial community during estrus. Proteomic profiling of vaginal fluids revealed specific protein patterns associated with different estrous phases. Highly expressed proteins in estrus involve the keratinization process thus providing estrus markers (e.g., Hrnr) while some proteins are downregulated such as immune-related proteins that limit bacterial growth (Camp, Clu, Elane, Lyz2, and Ngp). The vaginal metabolome contains volatile compounds potentially involved in chemical communication, for example, ketones, aldehydes, and esters of carboxylic acids. Data integration of all three OMICs data sets revealed high correlations, thus providing evidence that microbiomes, host proteomes, and metabolomes may interact.IMPORTANCEOur data revealed dynamic changes in vaginal, but not salivary, microbiome composition during the reproductive cycle of wild mice. With multiple OMICs platforms, we provide evidence that changes in microbiota in the vaginal environment are accompanied by changes in the proteomic and metabolomics profiles of the host. This study describes the natural microbiota of wild mice and may contribute to a better understanding of microbiome-host immune system interactions during the hormonal and cellular changes in the female reproductive tract. Moreover, analysis of volatiles in the vaginal fluid shows particular substances that can be involved in chemical communication and reproductive behavior.
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Affiliation(s)
- Tereza Matějková
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
| | - Alica Dodoková
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
| | - Jakub Kreisinger
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
| | - Pavel Stopka
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
| | - Romana Stopková
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
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Liu Z, Wang Q, Chai Z, Wang D. Recognition of Actinides by Siderocalin. Inorg Chem 2024; 63:923-927. [PMID: 38156893 DOI: 10.1021/acs.inorgchem.3c03040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Plain simulations and enhanced sampling unveil a novel siderocalin (Scn) recognition mode for An-Ent (where An = actinides and Ent = enterobactin) complexes and identify a "seesaw" relationship between actinide affinity to Ent and Scn recognition to an An-Ent complex. Electrostatic interactions predominantly govern competitive binding in both processes. Additionally, hydrolysis-induced negative charge, water expulsion-driven entropy, and Ent's conformational adaptability collectively enhance high-affinity recognition.
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Affiliation(s)
- Ziyi Liu
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory for Catalytic Conversion of Carbon Resources, School of Chemistry, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
- Multidisciplinary Initiative Center and CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences and the University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qin Wang
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory for Catalytic Conversion of Carbon Resources, School of Chemistry, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Zhifang Chai
- Multidisciplinary Initiative Center and CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences and the University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Radiation Medicine and Protection and School of Radiation Medicine and Interdisciplinary Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Dongqi Wang
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory for Catalytic Conversion of Carbon Resources, School of Chemistry, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
- Multidisciplinary Initiative Center and CAS-HKU Joint Laboratory of Metallomics on Health & Environment, Institute of High Energy Physics, Chinese Academy of Sciences and the University of Chinese Academy of Sciences, Beijing 100049, China
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5
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Nienaber A, Uyoga MA, Dolman-Macleod RC, Malan L. Iron Status and Supplementation during Tuberculosis. Microorganisms 2023; 11:microorganisms11030785. [PMID: 36985358 PMCID: PMC10055784 DOI: 10.3390/microorganisms11030785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Tuberculosis (TB) is characterised by chronic non-resolving inflammation. The effects of the host immune and inflammatory response to reduce iron acquisition by the bacteria, together with other contributing factors, predispose TB patients to anaemia of infection and iron deficiency anaemia (IDA). The presence of anaemia in TB patients has been linked to poor clinical outcomes. However, due to the reliance of the bacteria on iron, the management of anaemia in TB is complicated, and anaemia of infection is likely to resolve with correct TB drug treatment. On the other hand, IDA may require iron supplementation. This review aims to describe iron metabolism in TB and how this contributes to the development of iron deficiency and anaemia. Additionally, we summarise the evidence on the association between iron status and clinical outcomes as well as the available preclinical and clinical trials on iron supplementation in TB.
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Affiliation(s)
- Arista Nienaber
- Centre of Excellence for Nutrition, North-West University, Potchefstroom 2531, South Africa
| | - Mary A Uyoga
- Centre of Excellence for Nutrition, North-West University, Potchefstroom 2531, South Africa
| | - Robin C Dolman-Macleod
- Centre of Excellence for Nutrition, North-West University, Potchefstroom 2531, South Africa
| | - Linda Malan
- Centre of Excellence for Nutrition, North-West University, Potchefstroom 2531, South Africa
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The Role of the Yersiniachelin Siderophore in the Physiology of <i>Yersinia pestis</i>. PROBLEMS OF PARTICULARLY DANGEROUS INFECTIONS 2023. [DOI: 10.21055/0370-1069-2022-4-75-81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Pathogenic bacteria use low-molecular-weight iron chelators – siderophores – to assimilate iron in the host body. Being recognized as virulence factors, these molecules, differing in structural and functional properties, are the subject of the most intensive research in medical microbiology. The present study is devoted to the investigation of yersiniachelin siderophore (Ych) found in the causative agent of plague, Yersinia pestis. The aim of the work was to clarify the role of Ych in the physiology of Y. pestis by comparing the properties of three strains of the plague microbe, differing in Ych production. Materials and methods. Three variants of Y. pestis EV76 strain were used in the experiments: parent strain Y. pestis EV76, its mutant that does not produce Ych due to deletion of three siderophore biosynthesis genes (analogues of ypo1530–1532 in Y. pestis CO92 strain) and a complemented mutant that was transformed by a recombinant pSC-A-5EV plasmid containing Ych biosynthesis genes cloned into the high-copy plasmid vector pSC-A-amp/kan. Comparative analysis of the three strains was carried out in terms of colony morphology, siderophore activity, growth rate, and sensitivity to hydrogen peroxide. Results and discussion. The comparison of these strains has revealed that the secretion of Ych by bacteria at 26 °С ensures the assimilation of iron. At 37 °С, Ych is not secreted into the medium and protects bacteria from the bactericidal action of reactive oxygen compounds. Thus, the study shows that yersiniachelin is able to stimulate the assimilation of iron by bacteria under iron-deficit conditions and has antioxidant properties.
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Abstract
Living systems are built from a small subset of the atomic elements, including the bulk macronutrients (C,H,N,O,P,S) and ions (Mg,K,Na,Ca) together with a small but variable set of trace elements (micronutrients). Here, we provide a global survey of how chemical elements contribute to life. We define five classes of elements: those that are (i) essential for all life, (ii) essential for many organisms in all three domains of life, (iii) essential or beneficial for many organisms in at least one domain, (iv) beneficial to at least some species, and (v) of no known beneficial use. The ability of cells to sustain life when individual elements are absent or limiting relies on complex physiological and evolutionary mechanisms (elemental economy). This survey of elemental use across the tree of life is encapsulated in a web-based, interactive periodic table that summarizes the roles chemical elements in biology and highlights corresponding mechanisms of elemental economy.
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Affiliation(s)
- Kaleigh A Remick
- Department of Microbiology, Cornell University, New York, NY, United States
| | - John D Helmann
- Department of Microbiology, Cornell University, New York, NY, United States.
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Morina F, Küpper H. Trace metals at the frontline of pathogen defence responses in non-hyperaccumulating plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6516-6524. [PMID: 35876626 DOI: 10.1093/jxb/erac316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Metal hyperaccumulation is an exclusive evolutionary trait contributing to efficient plant defence against biotic stress. The defence can be based on direct metal toxicity or the joint effects of accumulated metal and organic compounds, the latter being based on integrated signalling networks. While the role of metals in biotic stress defence of hyperaccumulators has been intensively studied, their role in the pathogen immunity of non-accumulator plants is far less understood. New findings show that in metal non-hyperaccumulating plants, localized hot spots of zinc, manganese, and iron increase plant immunity, while manipulation of nutrient availability may be used for priming against subsequent pathogen attack. Recent findings on the role of metals in plant-pathogen interactions are discussed considering the narrow line between deficiency and toxicity, host-pathogen nutrient competition and synergistic effects of simultaneous metal and biotic stress. We discuss the suitability of the direct-defence and joint-effects hypotheses in non-hyperaccumulating plants, and the involvement of metals as active centres of immunity-related enzymes. We also consider future challenges in revealing the mechanisms underlying metal-mediated plant immunity.
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Affiliation(s)
- Filis Morina
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Department of Plant Biophysics & Biochemistry, Branišovská, České Budějovice, Czech Republic
| | - Hendrik Küpper
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Department of Plant Biophysics & Biochemistry, Branišovská, České Budějovice, Czech Republic
- University of South Bohemia, Department of Experimental Plant Biology, Branišovská, České Budějovice, Czech Republic
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Bacterial Siderophores: Structure, Functions, and Role in the Pathogenesis of Infections. PROBLEMS OF PARTICULARLY DANGEROUS INFECTIONS 2022. [DOI: 10.21055/0370-1069-2022-3-14-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This review systematizes and analyzes the data published over the past decade, devoted to the study of low-molecular-weight high affinity iron chelators – siderophores. Siderophores, which are found in bacteria, fungi and mammals, are able to extract iron from insoluble inorganic compounds, and in the host organism – from complexes with proteins that perform the function of nonspecific protection of mammals from infections. The extracted iron is delivered to cells through surface protein receptors specific for each siderophore, as well as various protein transport systems that make up membranes. Siderophores play an important role in virulence in pathogenic bacteria, performing many functions in the host organism, in addition to providing microbes with iron and other biological metals. They participate in the storage of excess iron, toxic to cells, protect bacteria from reactive oxygen compounds, compete for iron with phagocytes, and have a harmful effect on host cells, acting as secreted bacterial toxin in some cases. Bacterial siderophores perform a signaling function and regulate both, their own synthesis and the synthesis of other virulence factors. Many pathogenic bacteria produce several siderophores that are active under different conditions, against various sources of iron in the host organism and at different stages of infectious process. The review presents the results of the experimental studies aimed at elucidating the structure and diverse functions of bacterial siderophores, the mechanisms of their biosynthesis and regulation of expression, as well as the role of these molecules in the physiology and virulence of pathogenic bacteria. Special emphasis is put on siderophores of bacteria causing particularly dangerous infections.
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10
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Stoudenmire JL, Greenawalt AN, Cornelissen CN. Stealthy microbes: How Neisseria gonorrhoeae hijacks bulwarked iron during infection. Front Cell Infect Microbiol 2022; 12:1017348. [PMID: 36189345 PMCID: PMC9519893 DOI: 10.3389/fcimb.2022.1017348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Transition metals are essential for metalloprotein function among all domains of life. Humans utilize nutritional immunity to limit bacterial infections, employing metalloproteins such as hemoglobin, transferrin, and lactoferrin across a variety of physiological niches to sequester iron from invading bacteria. Consequently, some bacteria have evolved mechanisms to pirate the sequestered metals and thrive in these metal-restricted environments. Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, causes devastating disease worldwide and is an example of a bacterium capable of circumventing human nutritional immunity. Via production of specific outer-membrane metallotransporters, N. gonorrhoeae is capable of extracting iron directly from human innate immunity metalloproteins. This review focuses on the function and expression of each metalloprotein at gonococcal infection sites, as well as what is known about how the gonococcus accesses bound iron.
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Affiliation(s)
| | | | - Cynthia Nau Cornelissen
- Center for Translational Immunology, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA, United States
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Zhang Y, Martin JE, Edmonds KA, Winkler ME, Giedroc DP. SifR is an Rrf2-family quinone sensor associated with catechol iron uptake in Streptococcus pneumoniae D39. J Biol Chem 2022; 298:102046. [PMID: 35597283 PMCID: PMC9218516 DOI: 10.1016/j.jbc.2022.102046] [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: 02/10/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 01/15/2023] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a Gram-positive commensal and human respiratory pathogen. How this bacterium satisfies its nutritional iron (Fe) requirement in the context of endogenously produced hydrogen peroxide is not well understood. Here, we characterize a novel virulence-associated Rrf2-family transcriptional repressor that we term SifR (streptococcal IscR-like family transcriptional repressor) encoded by spd_1448 and conserved in Streptococci. Global transcriptomic analysis of a ΔsifR strain defines the SifR regulon as genes encoding a candidate catechol dioxygenase CatE, an uncharacterized oxidoreductase YwnB, a candidate flavin-dependent ferric reductase YhdA, a candidate heme-based ferric reductase domain-containing protein and the Piu (pneumococcus iron uptake) Fe transporter (piuBCDA). Previous work established that membrane-anchored PiuA binds FeIII-bis-catechol or monocatechol complexes with high affinity, including the human catecholamine stress hormone, norepinephrine. We demonstrate that SifR senses quinone via a single conserved cysteine that represses its regulon when in the reduced form. Upon reaction with catechol-derived quinones, we show that SifR dissociates from the DNA leading to regulon derepression, allowing the pneumococcus to access a catechol-derived source of Fe while minimizing reactive electrophile stress induced by quinones. Consistent with this model, we show that CatE is an FeII-dependent 2,3-catechol dioxygenase with broad substrate specificity, YwnB is an NAD(P)H-dependent quinone reductase capable of reducing the oxidized and cyclized norepinephrine, adrenochrome, and YhdA is capable of reducing a number of FeIII complexes, including PiuA-binding transport substrates. These findings are consistent with a model where FeIII-catechol complexes serve as significant nutritional Fe sources in the host.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA
| | - Julia E Martin
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Biological Sciences, Idaho State University, Pocatello, Idaho, USA
| | | | - Malcolm E Winkler
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA; Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA.
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Kumar A, Yang T, Chakravorty S, Majumdar A, Nairn BL, Six DA, Marcondes Dos Santos N, Price SL, Lawrenz MB, Actis LA, Marques M, Russo TA, Newton SM, Klebba PE. Fluorescent sensors of siderophores produced by bacterial pathogens. J Biol Chem 2022; 298:101651. [PMID: 35101443 PMCID: PMC8921320 DOI: 10.1016/j.jbc.2022.101651] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 11/25/2022] Open
Abstract
Siderophores are iron-chelating molecules that solubilize Fe3+ for microbial utilization and facilitate colonization or infection of eukaryotes by liberating host iron for bacterial uptake. By fluorescently labeling membrane receptors and binding proteins, we created 20 sensors that detect, discriminate, and quantify apo- and ferric siderophores. The sensor proteins originated from TonB-dependent ligand-gated porins (LGPs) of Escherichia coli (Fiu, FepA, Cir, FhuA, IutA, BtuB), Klebsiella pneumoniae (IroN, FepA, FyuA), Acinetobacter baumannii (PiuA, FepA, PirA, BauA), Pseudomonas aeruginosa (FepA, FpvA), and Caulobacter crescentus (HutA) from a periplasmic E. coli binding protein (FepB) and from a human serum binding protein (siderocalin). They detected ferric catecholates (enterobactin, degraded enterobactin, glucosylated enterobactin, dihydroxybenzoate, dihydroxybenzoyl serine, cefidericol, MB-1), ferric hydroxamates (ferrichromes, aerobactin), mixed iron complexes (yersiniabactin, acinetobactin, pyoverdine), and porphyrins (hemin, vitamin B12). The sensors defined the specificities and corresponding affinities of the LGPs and binding proteins and monitored ferric siderophore and porphyrin transport by microbial pathogens. We also quantified, for the first time, broad recognition of diverse ferric complexes by some LGPs, as well as monospecificity for a single metal chelate by others. In addition to their primary ferric siderophore ligands, most LGPs bound the corresponding aposiderophore with ∼100-fold lower affinity. These sensors provide insights into ferric siderophore biosynthesis and uptake pathways in free-living, commensal, and pathogenic Gram-negative bacteria.
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Affiliation(s)
- Ashish Kumar
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA
| | - Taihao Yang
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA
| | - Somnath Chakravorty
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA; Department of Medicine, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo School of Medicine, Buffalo, New York, USA
| | - Aritri Majumdar
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA
| | - Brittany L Nairn
- Department of Biological Sciences, Bethel University, St. Paul, Minnesota, USA
| | - David A Six
- Department of Biology, Venatorx Pharmaceuticals, Inc, Malvern, Pennsylvania, USA
| | - Naara Marcondes Dos Santos
- Departamento de Microbiologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, Brazil
| | - Sarah L Price
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Matthew B Lawrenz
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Luis A Actis
- Department of Microbiology, Miami University, Oxford, Ohio, USA
| | - Marilis Marques
- Departamento de Microbiologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, São Paulo, Brazil
| | - Thomas A Russo
- Department of Medicine, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo School of Medicine, Buffalo, New York, USA
| | - Salete M Newton
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA
| | - Phillip E Klebba
- Department of Biochemistry & Molecular Biophysics, Kansas State University, Manhattan, Kansas, USA.
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Extracellular haem utilization by the opportunistic pathogen Pseudomonas aeruginosa and its role in virulence and pathogenesis. Adv Microb Physiol 2021; 79:89-132. [PMID: 34836613 DOI: 10.1016/bs.ampbs.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Iron is an essential micronutrient for all bacteria but presents a significant challenge given its limited bioavailability. Furthermore, iron's toxicity combined with the need to maintain iron levels within a narrow physiological range requires integrated systems to sense, regulate and transport a variety of iron complexes. Most bacteria encode systems to chelate and transport ferric iron (Fe3+) via siderophore receptor mediated uptake or via cytoplasmic energy dependent transport systems. Pathogenic bacteria have further lowered the barrier to iron acquisition by employing systems to utilize haem as a source of iron. Haem, a lipophilic and toxic molecule, presents a significant challenge for transport into the cell. As such pathogenic bacteria have evolved sophisticated cell surface signaling (CSS) and transport systems to sense and obtain haem from the host. Once internalized haem is cleaved by both oxidative and non-oxidative mechanisms to release iron. Herein we summarize our current understanding of the mechanism of haem sensing, uptake and utilization in Pseudomonas aeruginosa, its role in pathogenesis and virulence, and the potential of these systems as antimicrobial targets.
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Samsonov SA, Zsila F, Maszota-Zieleniak M. Acute phase α 1-acid glycoprotein as a siderophore-capturing component of the human plasma: A molecular modeling study. J Mol Graph Model 2021; 105:107861. [PMID: 33640788 DOI: 10.1016/j.jmgm.2021.107861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/26/2022]
Abstract
Siderophores are ferric ion-specific organic compounds that are used by bacteria and fungi to secure their iron supply when infecting target organisms. There are a few proteins in the human body, named siderocalins, which bind these important virulence factors and so starve microorganisms of iron. In this study, we analyzed in silico if serum α1-acid glycoprotein (AAG), the major acute phase lipocalin component of the human plasma, could functionally belong to this group. The real biological function of AAG is elusive and its concentration substantially increases in response to pathological stimuli, including bacterial infections. We computationally evaluated the potential binding of nine microbial siderophores into the β-barrel cavity of AAG and compared the results with the corresponding experimental data reported for siderophore-neutrophil gelatinase-associated lipocalin complexes. According to the results, petrobactin and Fe-BisHaCam are putative candidates to be recognized by this protein. It is proposed that AAG may function as a siderophore capturing component of the innate immune system being able to neutralize bacterial iron chelators not recognized by other siderocalins.
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Affiliation(s)
- Sergey A Samsonov
- Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308, Gdańsk, Poland
| | - Ferenc Zsila
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, H-1117 Budapest, Magyar tudósok körútja 2, Hungary.
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15
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Crowther JM, Broadhurst M, Laue TM, Jameson GB, Hodgkinson AJ, Dobson RCJ. On the utility of fluorescence-detection analytical ultracentrifugation in probing biomolecular interactions in complex solutions: a case study in milk. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:677-685. [PMID: 33052462 DOI: 10.1007/s00249-020-01468-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/24/2022]
Abstract
β-Lactoglobulin is the most abundant protein in the whey fraction of ruminant milks, yet is absent in human milk. It has been studied intensively due to its impact on the processing and allergenic properties of ruminant milk products. However, the physiological function of β-lactoglobulin remains unclear. Using the fluorescence-detection system within the analytical ultracentrifuge, we observed an interaction involving fluorescently labelled β-lactoglobulin in its native environment, i.e. cow and goat milk, for the first time. Co-elution experiments support that these β-lactoglobulin interactions occur naturally in milk and provide evidence that the interacting partners are immunoglobulins, while further sedimentation velocity experiments confirm that an interaction occurs between these molecules. The identification of these interactions, made possible through the use of fluorescence-detected analytical ultracentrifugation, provides possible clues to the long debated physiological function of this abundant milk protein.
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Affiliation(s)
- Jennifer M Crowther
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- The Riddet Institute, Massey University, Palmerston North, New Zealand.
| | - Marita Broadhurst
- Food and Bio-Based Products, AgResearch Limited, Ruakura Research Centre, Hamilton, New Zealand
| | - Thomas M Laue
- Center To Advance Molecular Interaction Science, University of New Hampshire, Durham, NH, USA
| | - Geoffrey B Jameson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- The Riddet Institute, Massey University, Palmerston North, New Zealand
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Alison J Hodgkinson
- Food and Bio-Based Products, AgResearch Limited, Ruakura Research Centre, Hamilton, New Zealand.
- On-Farm R&D, Farm Source, Fonterra Co-Operative Group, Hamilton, 3200, New Zealand.
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- The Riddet Institute, Massey University, Palmerston North, New Zealand.
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia.
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16
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Luthra A, Montezuma-Rusca JM, La Vake CJ, LeDoyt M, Delgado KN, Davenport TC, Fiel-Gan M, Caimano MJ, Radolf JD, Hawley KL. Evidence that immunization with TP0751, a bipartite Treponema pallidum lipoprotein with an intrinsically disordered region and lipocalin fold, fails to protect in the rabbit model of experimental syphilis. PLoS Pathog 2020; 16:e1008871. [PMID: 32936831 PMCID: PMC7521688 DOI: 10.1371/journal.ppat.1008871] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/28/2020] [Accepted: 08/10/2020] [Indexed: 12/18/2022] Open
Abstract
Deconvolution of syphilis pathogenesis and selection of candidate syphilis vaccinogens requires detailed knowledge of the molecular architecture of the Treponema pallidum outer membrane (OM). The T. pallidum OM contains a low density of integral OM proteins, while the spirochete's many lipoprotein immunogens are periplasmic. TP0751, a lipoprotein with a lipocalin fold, is reportedly a surface-exposed protease/adhesin and protective antigen. The rapid expansion of calycin/lipocalin structures in the RCSB PDB database prompted a comprehensive reassessment of TP0751. Small angle X-ray scattering analysis of full-length protein revealed a bipartite topology consisting of an N-terminal, intrinsically disordered region (IDR) and the previously characterized C-terminal lipocalin domain. A DALI server query using the lipocalin domain yielded 97 hits, 52 belonging to the calycin superfamily, including 15 bacterial lipocalins, but no Gram-negative surface proteins. Surprisingly, Tpp17 (TP0435) was identified as a structural ortholog of TP0751. In silico docking predicted that TP0751 can bind diverse ligands along the rim of its eight-stranded β-barrel; high affinity binding of one predicted ligand, heme, to the lipocalin domain was demonstrated. qRT-PCR and immunoblotting revealed very low expression of TP0751 compared to other T. pallidum lipoproteins. Immunoblot analysis of immune rabbit serum failed to detect TP0751 antibodies, while only one of five patients with secondary syphilis mounted a discernible TP0751-specific antibody response. In opsonophagocytosis assays, neither TP0751 nor Tpp17 antibodies promoted uptake of T. pallidum by rabbit peritoneal macrophages. Rabbits immunized with intact, full-length TP0751 showed no protection against local or disseminated infection following intradermal challenge with T. pallidum. Our data argue that, like other lipoprotein lipocalins in dual-membrane bacteria, TP0751 is periplasmic and binds small molecules, and we propose that its IDR facilitates ligand binding by and offloading from the lipocalin domain. The inability of TP0751 to elicit opsonic or protective antibodies is consistent with a subsurface location.
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Affiliation(s)
- Amit Luthra
- Department of Medicine, UConn Health, Farmington, United States of America
| | - Jairo M. Montezuma-Rusca
- Department of Medicine, UConn Health, Farmington, United States of America
- Division of Infectious Diseases, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
| | - Carson J. La Vake
- Department of Pediatrics, UConn Health, Farmington, United States of America
| | - Morgan LeDoyt
- Department of Medicine, UConn Health, Farmington, United States of America
| | | | | | - Mary Fiel-Gan
- Department of Pathology, Hartford Hospital, Hartford, United States of America
| | - Melissa J. Caimano
- Department of Medicine, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, United States of America
| | - Justin D. Radolf
- Department of Medicine, UConn Health, Farmington, United States of America
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, United States of America
- Department of Genetics and Genome Sciences, UConn Health, Farmington, United States of America
- Department of Immunology, UConn Health, Farmington, United States of America
| | - Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, United States of America
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, United States of America
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17
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Zhang Y, Sen S, Giedroc DP. Iron Acquisition by Bacterial Pathogens: Beyond Tris-Catecholate Complexes. Chembiochem 2020; 21:1955-1967. [PMID: 32180318 PMCID: PMC7367709 DOI: 10.1002/cbic.201900778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/06/2020] [Indexed: 12/11/2022]
Abstract
Sequestration of the essential nutrient iron from bacterial invaders that colonize the vertebrate host is a central feature of nutritional immunity and the "fight over transition metals" at the host-pathogen interface. The iron quota for many bacterial pathogens is large, as iron enzymes often make up a significant share of the metalloproteome. Iron enzymes play critical roles in respiration, energy metabolism, and other cellular processes by catalyzing a wide range of oxidation-reduction, electron transfer, and oxygen activation reactions. In this Concept article, we discuss recent insights into the diverse ways that bacterial pathogens acquire this essential nutrient, beyond the well-characterized tris-catecholate FeIII complexes, in competition and cooperation with significant host efforts to cripple these processes. We also discuss pathogen strategies to adapt their metabolism to less-than-optimal iron concentrations, and briefly speculate on what might be an integrated adaptive response to the concurrent limitation of both iron and zinc in the infected host.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
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18
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Phagomimetic action of antibiotics: Revisited. How do antibiotics know where to go? Biochem Biophys Res Commun 2020; 521:721-724. [PMID: 31703841 DOI: 10.1016/j.bbrc.2019.10.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 11/20/2022]
Abstract
Phagocytic cells know exactly where an infection is by following chemotactic signals. The phagocytosis of bacteria results in a 'respiratory burst' in which superoxide radicals are released. We have previously compared the release of reactive oxygen species (ROS) by antibiotics, during electron transfer reactions, to this event. Antibiotics in their normal bacterial environment, and ROS, are both increasingly implicated in purposeful signalling functions, rather than their more widely known roles in bacterial killing and molecular damage. Here, we extend our comparison between antibiotics and phagocytic cells to propose that antibiotics actively accumulate at a site of pathogen infection or tumour growth. A common link being virulent cellular growth. When this occurs, new proteins are secreted, aberrant iron acquisition takes place, and lipocalins are released. Each provide a mechanism by which antibiotics can bind, and be retained, at an active site of pathogen infection or tumour growth.
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19
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Dauner M, Skerra A. Scavenging Bacterial Siderophores with Engineered Lipocalin Proteins as an Alternative Antimicrobial Strategy. Chembiochem 2019; 21:601-606. [PMID: 31613035 PMCID: PMC7079049 DOI: 10.1002/cbic.201900564] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Indexed: 12/30/2022]
Abstract
Iron acquisition mediated by siderophores, high-affinity chelators for which bacteria have evolved specific synthesis and uptake mechanisms, plays a crucial role in microbiology and in host-pathogen interactions. In the ongoing fight against bacterial infections, this area has attracted biomedical interest. Beyond several approaches to interfere with siderophore-mediated iron uptake from medicinal and immunochemistry, the development of high-affinity protein scavengers that tightly complex the siderophores produced by pathogenic bacteria has appeared as a novel strategy. Such binding proteins have been engineered based on siderocalin-also known as lipocalin 2-an endogenous human scavenger of enterobactin and bacillibactin that controls the systemic spreading of commensal bacteria such as Escherichia coli. By using combinatorial protein design, siderocalin was reshaped to bind several siderophores from Pseudomonas aeruginosa and, in particular, petrobactin from Bacillus anthracis, none of which is recognized by the natural protein. Such engineered versions of siderocalin effectively suppress the growth of corresponding pathogenic bacteria by depriving them of their iron supply and offer the potential to complement antibiotic therapy in situations of acute or persistent infection.
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Affiliation(s)
- Martin Dauner
- Institut für Biochemie und Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3a, 06120, Halle/Saale, Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
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20
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Page MGP. The Role of Iron and Siderophores in Infection, and the Development of Siderophore Antibiotics. Clin Infect Dis 2019; 69:S529-S537. [PMID: 31724044 PMCID: PMC6853763 DOI: 10.1093/cid/ciz825] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Iron is an essential nutrient for bacterial growth, replication, and metabolism. Humans store iron bound to various proteins such as hemoglobin, haptoglobin, transferrin, ferritin, and lactoferrin, limiting the availability of free iron for pathogenic bacteria. However, bacteria have developed various mechanisms to sequester or scavenge iron from the host environment. Iron can be taken up by means of active transport systems that consist of bacterial small molecule siderophores, outer membrane siderophore receptors, the TonB-ExbBD energy-transducing proteins coupling the outer and the inner membranes, and inner membrane transporters. Some bacteria also express outer membrane receptors for iron-binding proteins of the host and extract iron directly from these for uptake. Ultimately, iron is acquired and transported into the bacterial cytoplasm. The siderophores are small molecules produced and released by nearly all bacterial species and are classified according to the chemical nature of their iron-chelating group (ie, catechol, hydroxamate, α-hydroxyl-carboxylate, or mixed types). Siderophore-conjugated antibiotics that exploit such iron-transport systems are under development for the treatment of infections caused by gram-negative bacteria. Despite demonstrating high in vitro potency against pathogenic multidrug-resistant bacteria, further development of several candidates had stopped due to apparent adaptive resistance during exposure, lack of consistent in vivo efficacy, or emergence of side effects in the host. However, cefiderocol, with an optimized structure, has advanced and has been investigated in phase 1 to 3 clinical trials. This article discusses the mechanisms implicated in iron uptake and the challenges associated with the design and utilization of siderophore-mimicking antibiotics.
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Affiliation(s)
- Malcom G P Page
- Life Sciences and Chemistry, Jacobs University, Bremen gGmbh, Bremen, Germany
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21
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The anti-bacterial iron-restriction defence mechanisms of egg white; the potential role of three lipocalin-like proteins in resistance against Salmonella. Biometals 2019; 32:453-467. [PMID: 30810876 PMCID: PMC6584246 DOI: 10.1007/s10534-019-00180-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 01/25/2019] [Indexed: 11/26/2022]
Abstract
Salmonella enterica serovar Enteritidis (SE) is the most frequently-detected Salmonella in foodborne outbreaks in the European Union. Among such outbreaks, egg and egg products were identified as the most common vehicles of infection. Possibly, the major antibacterial property of egg white is iron restriction, which results from the presence of the iron-binding protein, ovotransferrin. To circumvent iron restriction, SE synthesise catecholate siderophores (i.e. enterobactin and salmochelin) that can chelate iron from host iron-binding proteins. Here, we highlight the role of lipocalin-like proteins found in egg white that could enhance egg-white iron restriction through sequestration of certain siderophores, including enterobactin. Indeed, it is now apparent that the egg-white lipocalin, Ex-FABP, can inhibit bacterial growth via its siderophore-binding capacity in vitro. However, it remains unclear whether Ex-FABP performs such a function in egg white or during bird infection. Regarding the two other lipocalins of egg white (Cal-γ and α-1-glycoprotein), there is currently no evidence to indicate that they sequester siderophores.
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22
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Wilde EJ, Blagova EV, Sanderson TJ, Raines DJ, Thomas RP, Routledge A, Duhme-Klair AK, Wilson KS. Mimicking salmochelin S1 and the interactions of its Fe(III) complex with periplasmic iron siderophore binding proteins CeuE and VctP. J Inorg Biochem 2018; 190:75-84. [PMID: 30384009 DOI: 10.1016/j.jinorgbio.2018.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/16/2022]
Abstract
A mimic of the tetradentate stealth siderophore salmochelin S1, was synthesised, characterised and shown to form Fe(III) complexes with ligand-to-metal ratios of 1:1 and 3:2. Circular dichroism spectroscopy confirmed that the periplasmic binding proteins CeuE and VctP of Campylobacter jejuni and Vibrio cholerae, respectively, bind the Fe(III) complex of the salmochelin mimic by preferentially selecting Λ-configured Fe(III) complexes. Intrinsic fluorescence quenching studies revealed that VctP binds Fe(III) complexes of the mimic and structurally-related catecholate ligands, such as enterobactin, bis(2, 3-dihydroxybenzoyl-l-serine) and bis(2, 3-dihydroxybenzoyl)-1, 5-pentanediamine with higher affinity than does CeuE. Both CeuE and VctP display a clear preference for the tetradentate bis(catecholates) over the tris(catecholate) siderophore enterobactin. These findings are consistent with reports that V. cholerae and C. jejuni utilise the enterobactin hydrolysis product bis(2, 3-dihydroxybenzoyl)-O-seryl serine for the acquisition of Fe(III) and suggest that the role of salmochelin S1 in the iron uptake of enteric pathogens merits further investigation.
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Affiliation(s)
- Ellis J Wilde
- Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK; Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Elena V Blagova
- Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Thomas J Sanderson
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Daniel J Raines
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Ross P Thomas
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Anne Routledge
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | | | - Keith S Wilson
- Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
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23
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Sun WY, Bai B, Luo C, Yang K, Li D, Wu D, Félétou M, Villeneuve N, Zhou Y, Yang J, Xu A, Vanhoutte PM, Wang Y. Lipocalin-2 derived from adipose tissue mediates aldosterone-induced renal injury. JCI Insight 2018; 3:120196. [PMID: 30185654 DOI: 10.1172/jci.insight.120196] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 07/24/2018] [Indexed: 12/14/2022] Open
Abstract
Lipocalin-2 is not only a sensitive biomarker, but it also contributes to the pathogenesis of renal injuries. The present study demonstrates that adipose tissue-derived lipocalin-2 plays a critical role in causing both chronic and acute renal injuries. Four-week treatment with aldosterone and high salt after uninephrectomy (ANS) significantly increased both circulating and urinary lipocalin-2, and it induced glomerular and tubular injuries in kidneys of WT mice. Despite increased renal expression of lcn2 and urinary excretion of lipocalin-2, mice with selective deletion of lcn2 alleles in adipose tissue (Adipo-LKO) are protected from ANS- or aldosterone-induced renal injuries. By contrast, selective deletion of lcn2 alleles in kidney did not prevent aldosterone- or ANS-induced renal injuries. Transplantation of fat pads from WT donors increased the sensitivity of mice with complete deletion of Lcn2 alleles (LKO) to aldosterone-induced renal injuries. Aldosterone promoted the urinary excretion of a human lipocalin-2 variant, R81E, in turn causing renal injuries in LKO mice. Chronic treatment with R81E triggered significant renal injuries in LKO, resembling those observed in WT mice following ANS challenge. Taken in conjunction, the present results demonstrate that lipocalin-2 derived from adipose tissue causes acute and chronic renal injuries, largely independent of local lcn2 expression in kidney.
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Affiliation(s)
- Wai Yan Sun
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Bo Bai
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Cuiting Luo
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Kangmin Yang
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Dahui Li
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Donghai Wu
- Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | | | | | - Yang Zhou
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, China
| | - Junwei Yang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, China
| | - Aimin Xu
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Paul M Vanhoutte
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Yu Wang
- The State Key Laboratory of Pharmaceutical Biotechnology and.,Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
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24
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Gutteridge JMC, Halliwell B. Mini-Review: Oxidative stress, redox stress or redox success? Biochem Biophys Res Commun 2018; 502:183-186. [PMID: 29752940 DOI: 10.1016/j.bbrc.2018.05.045] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/08/2018] [Indexed: 01/19/2023]
Abstract
The first life forms evolved in a highly reducing environment. This reduced state is still carried by cells today, which makes the concept of "reductive stress" somewhat redundant. When oxygen became abundant on the Earth, due to the evolution of photosynthesis, life forms had to adapt or become extinct. Living organisms did adapt, proliferated and an explosion of new life forms resulted, using reactive oxygen species (ROS) to drive their evolution. Adaptation to oxygen and its reduction intermediates necessitated the simultaneous evolution of select antioxidant defences, carefully regulated to allow ROS to perform their major roles. Clearly this "oxidative stress" did not cause a major problem to the evolution of complex life forms. Why not? Iron and oxygen share a close relationship in aerobic evolution. Iron is used in proteins to transport oxygen, promote electron transfers, and catalyse chemical reactions. In all of these functions, iron is carefully sequestered within proteins and restricted from reacting with ROS, this sequestration being one of our major antioxidant defences. Iron was abundant to life forms before the appearance of oxygen. However, oxygen caused its oxidative precipitation from solution and thereby decreased its bioavailability and thus the risk of iron-dependent oxidative damage. Micro-organisms had to adapt and develop strategies involving siderophores to acquire iron from the environment and eventually their host. This battle for iron between bacteria and animal hosts continues today, and is a much greater daily threat to our survival than "oxidative stress" and "redox stress".
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Affiliation(s)
| | - Barry Halliwell
- Department of Biochemistry and Centre for Life Sciences, National University of Singapore, #04-19, 28 Medical Drive, 117456, Singapore.
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25
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26
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Ectopic Expression of Innate Immune Protein, Lipocalin-2, in Lactococcus lactis Protects Against Gut and Environmental Stressors. Inflamm Bowel Dis 2017; 23:1120-1132. [PMID: 28445245 PMCID: PMC5469687 DOI: 10.1097/mib.0000000000001134] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Lipocalin-2 (Lcn2) is a multifunctional innate immune protein that exhibits antimicrobial activity by the sequestration of bacterial siderophores, regulates iron homeostasis, and augments cellular tolerance to oxidative stress. Studies in the murine model of colitis have demonstrated that Lcn2 deficiency exacerbates colitogenesis; however, the therapeutic potential of Lcn2 supplementation has yet to be elucidated. In light of its potential mucoprotective functions, we, herein, investigated whether expression of Lcn2 in the probiotic bacterium can be exploited to alleviate experimental colitis. METHODS Murine Lcn2 was cloned into the pT1NX plasmid and transformed into Lactococcus lactis to generate L. lactis-expressing Lcn2 (Lactis-Lcn2) or the empty plasmid (Lactis-Con). Lactis-Lcn2 was characterized by immunoblot and enzyme-linked immunosorbent assay and tested for its antimicrobial efficacy on Escherichia coli. The capacity of Lactis-Lcn2 and Lactis-Con to withstand adverse conditions was tested using in vitro viability assays. Dextran sodium sulfate colitis model was used to investigate the colonization ability and therapeutic potential of Lactis-Lcn2 and Lactis-Con. RESULTS Lcn2 derived from Lactis-Lcn2 inhibited the growth of E. coli and reduced the bioactivity of enterobactin (E. coli-derived siderophore) in vitro. Lactis-Lcn2 displayed enhanced tolerance to adverse pH, high concentration of bile acids, and oxidative stress in vitro and survived better in the inflamed gut than Lactis-Con. Consistent with these features, Lactis-Lcn2 displayed better mucoprotection against intestinal inflammation than Lactis-Con when administered into mice with dextran sulfate sodium-induced acute colitis. CONCLUSIONS Our findings suggest that Lcn2 expression can be exploited to enhance the survivability of probiotic bacteria during inflammation, which could further improve its efficacy to treat experimental colitis.
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27
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Abstract
Iron is essential for the survival of most bacteria but presents a significant challenge given its limited bioavailability. Furthermore, the toxicity of iron combined with the need to maintain physiological iron levels within a narrow concentration range requires sophisticated systems to sense, regulate, and transport iron. Most bacteria have evolved mechanisms to chelate and transport ferric iron (Fe3+) via siderophore receptor systems, and pathogenic bacteria have further lowered this barrier by employing mechanisms to utilize the host's hemoproteins. Once internalized, heme is cleaved by both oxidative and nonoxidative mechanisms to release iron. Heme, itself a lipophilic and toxic molecule, presents a significant challenge for transport into the cell. As such, pathogenic bacteria have evolved sophisticated cell surface signaling and transport systems to obtain heme from the host. In this review, we summarize the structure and function of the heme-sensing and transport systems of pathogenic bacteria and the potential of these systems as antimicrobial targets.
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Affiliation(s)
- Weiliang Huang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201;
| | - Angela Wilks
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201;
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Neumann W, Gulati A, Nolan EM. Metal homeostasis in infectious disease: recent advances in bacterial metallophores and the human metal-withholding response. Curr Opin Chem Biol 2016; 37:10-18. [PMID: 27992799 DOI: 10.1016/j.cbpa.2016.09.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 09/14/2016] [Indexed: 10/20/2022]
Abstract
A tug-of-war between the mammalian host and bacterial pathogen for nutrients, including first-row transition metals (e.g. Mn, Fe, Zn), occurs during infection. Here we present recent advances about three metal-chelating metabolites that bacterial pathogens deploy when invading the host: staphylopine, staphyloferrin B, and enterobactin. These highlights provide new insights into the mechanisms of bacterial metal acquisition and regulation, as well as the contributions of host-defense proteins during the human innate immune response. The studies also underscore that the chemical composition of the microenvironment at an infection site can influence bacterial pathogenesis and the innate immune system.
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Affiliation(s)
- Wilma Neumann
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anmol Gulati
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Szebesczyk A, Olshvang E, Shanzer A, Carver PL, Gumienna-Kontecka E. Harnessing the power of fungal siderophores for the imaging and treatment of human diseases. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Shields-Cutler RR, Crowley JR, Miller CD, Stapleton AE, Cui W, Henderson JP. Human Metabolome-derived Cofactors Are Required for the Antibacterial Activity of Siderocalin in Urine. J Biol Chem 2016; 291:25901-25910. [PMID: 27780864 PMCID: PMC5207064 DOI: 10.1074/jbc.m116.759183] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/18/2016] [Indexed: 01/07/2023] Open
Abstract
In human urinary tract infections, host cells release the antimicrobial protein siderocalin (SCN; also known as lipocalin-2, neutrophil gelatinase-associated lipocalin, or 24p3) into the urinary tract. By binding to ferric catechol complexes, SCN can sequester iron, a growth-limiting nutrient for most bacterial pathogens. Recent evidence links the antibacterial activity of SCN in human urine to iron sequestration and metabolomic variation between individuals. To determine whether these metabolomic associations correspond to functional Fe(III)-binding SCN ligands, we devised a biophysical protein binding screen to identify SCN ligands through direct analysis of human urine. This screen revealed a series of physiologic unconjugated urinary catechols that were able to function as SCN ligands of which pyrogallol in particular was positively associated with high urinary SCN activity. In a purified, defined culture system, these physiologic SCN ligands were sufficient to activate SCN antibacterial activity against Escherichia coli. In the presence of multiple SCN ligands, native mass spectrometry demonstrated that SCN may preferentially combine different ligands to coordinate iron, suggesting that availability of specific ligand combinations affects in vivo SCN antibacterial activity. These results support a mechanistic link between the human urinary metabolome and innate immune function.
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Affiliation(s)
- Robin R Shields-Cutler
- From the Division of Infectious Diseases, Department of Medicine.,the Center for Women's Infectious Diseases Research, and
| | - Jan R Crowley
- the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Connelly D Miller
- From the Division of Infectious Diseases, Department of Medicine.,the Center for Women's Infectious Diseases Research, and
| | - Ann E Stapleton
- the Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington 98195, and
| | - Weidong Cui
- the Department of Chemistry, Washington University, St. Louis, Missouri 63130
| | - Jeffrey P Henderson
- From the Division of Infectious Diseases, Department of Medicine, .,the Center for Women's Infectious Diseases Research, and
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Petrik M, Zhai C, Haas H, Decristoforo C. Siderophores for molecular imaging applications. Clin Transl Imaging 2016; 5:15-27. [PMID: 28138436 PMCID: PMC5269471 DOI: 10.1007/s40336-016-0211-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 09/30/2016] [Indexed: 01/21/2023]
Abstract
This review covers publications on siderophores applied for molecular imaging applications, mainly for radionuclide-based imaging. Siderophores are low molecular weight chelators produced by bacteria and fungi to scavenge essential iron. Research on these molecules has a continuing history over the past 50 years. Many biomedical applications have been developed, most prominently the use of the siderophore desferrioxamine (DFO) to tackle iron overload related diseases. Recent research described the upregulation of siderophore production and transport systems during infection. Replacing iron in siderophores by radionuclides, the most prominent Ga-68 for PET, opens approaches for targeted imaging of infection; the proof of principle has been reported for fungal infections using 68Ga-triacetylfusarinine C (TAFC). Additionally, fluorescent siderophores and therapeutic conjugates have been described and may be translated to optical imaging and theranostic applications. Siderophores have also been applied as bifunctional chelators, initially DFO as chelator for Ga-67 and more recently for Zr-89 where it has become the standard chelator in Immuno-PET. Improved DFO constructs and bifunctional chelators based on cyclic siderophores have recently been developed for Ga-68 and Zr-89 and show promising properties for radiopharmaceutical development in PET. A huge potential from basic biomedical research on siderophores still awaits to be utilized for clinical and translational imaging.
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Affiliation(s)
- Milos Petrik
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University, Olomouc, Czech Republic
| | - Chuangyan Zhai
- Universitätsklinik für Nuklearmedizin, Medizinische Universität Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
- Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong China
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - Clemens Decristoforo
- Universitätsklinik für Nuklearmedizin, Medizinische Universität Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
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Kell DB, Pretorius E. On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death. Integr Biol (Camb) 2016; 7:1339-77. [PMID: 26345428 DOI: 10.1039/c5ib00158g] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, 131, Princess St, Manchester M1 7DN, Lancs, UK.
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa.
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Fazary AE, Al-Shihri AS, Alfaifi MY, Saleh KA, Alshehri MA, Elbehairi SEI, Ju YH. Microbial production of four biodegradable siderophores under submerged fermentation. Int J Biol Macromol 2016; 88:527-41. [DOI: 10.1016/j.ijbiomac.2016.03.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 03/03/2016] [Accepted: 03/07/2016] [Indexed: 11/29/2022]
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Catecholamine-Directed Epithelial Cell Interactions with Bacteria in the Intestinal Mucosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 874:79-99. [DOI: 10.1007/978-3-319-20215-0_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Bao GH, Ho CT, Barasch J. The Ligands of Neutrophil Gelatinase-Associated Lipocalin. RSC Adv 2015; 5:104363-104374. [PMID: 27617081 DOI: 10.1039/c5ra18736b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Neutrophil gelatinase associated lipocalin (NGAL), was originally identified in neutrophil granules as a heterodimer complex with gelatinase B (matrix metalloproteinase 9, MMP9), but more recently has been found to be secreted by damaged epithelial cells. Ngal is a member of the lipocalin family and subsequently named as lipocalin 2 on the basis of structural similarity with other members of the lipocalin family and its potential association with hydrophobic retinol and cholesterol oleate more strongly than their hydrophilic counterparts. In 2002, a landmark paper suggested that Ngal is a bacteriostatic agent which blocks iron acquisition by interacting with a number of bacterial siderophores, especially enterobactin. Since then, more siderophore-carrying functions have been reported than the possibility of hydrophobic ligand transport. In this setting, Ngal was renamed Siderocalin. Functions of siderocalin include not only bacteriostatic activity but potentially as a mediator of cell growth and differentiation; some of these functions appear to be referable to the holo siderocalin:siderophore:iron complex and recent work suggests that metabolic products may act as mammalian siderophores bound by Ngal. While still speculative, it may be that the mammalian siderophores can establish the missing link between Ngal and a number of its functions in vivo. This review provides an overview of the discoveries of the different ligands of Ngal and consequently related functions. Hydrophobic ligands, bacterial siderophores as well as their modified structures (synthetic siderophores), and mammalian siderophores are summarized.
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Affiliation(s)
- Guan-Hu Bao
- State Key Laboratory of Tea Plant Biology and Utilization, Biotechnology Building 214, Anhui Agricultural University, China
| | - Chi-Tang Ho
- State Key Laboratory of Tea Plant Biology and Utilization, Biotechnology Building 214, Anhui Agricultural University, China; Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901-8520, United States
| | - Jonathan Barasch
- College of Physicians and Surgeons of Columbia University, New York, USA
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Abstract
This Account focuses on the coordination chemistry of the microbial iron chelators called siderophores. The initial research (early 1970s) focused on simple analogs of siderophores, which included hydroxamate, catecholate, or hydroxycarboxylate ligands. The subsequent work increasingly focused on the transport of siderophores and their microbial iron transport. Since these are pseudo-octahedral complexes often composed of bidentate ligands, there is chirality at the metal center that in principle is independent of the ligand chirality. It has been shown in many cases that chiral recognition of the complex occurs. Many techniques have been used to elucidate the iron uptake processes in both Gram-positive (single membrane) and Gram-negative (double membrane) bacteria. These have included the use of radioactive labels (of ligand, metal, or both), kinetically inert metal complexes, and Mössbauer spectroscopy. In general, siderophore recognition and transport involves receptors that recognize the metal chelate portion of the iron-siderophore complex. A second, to date less commonly found, mechanism called the siderophore shuttle involves the receptor binding an apo-siderophore. Since one of the primary ways that microbes compete with each other for iron stores is the strength of their competing siderophore complexes, it became important early on to characterize the solution thermodynamics of these species. Since the acidity of siderophores varies significantly, just the stability constant does not give a direct measure of the relative competitive strength of binding. For this reason, the pM value is compared. The pM, like pH, is a measure of the negative log of the free metal ion concentration, typically calculated at pH 7.4, and standard total concentrations of metal and ligand. The characterization of the electronic structure of ferric siderophores has done much to help explain the high stability of these complexes. A new chapter in siderophore science has emerged with the characterization of what are now called siderocalins. Initially found as a protein of the human innate immune system, these proteins bind both ferric and apo-siderophores to inactivate the siderophore transport system and hence deny iron to an invading pathogenic microbe. Siderocalins also can play a role in iron transport of the host, particularly in the early stages of fetal development. Finally, it is speculated that the molecular targets of siderocalins in different species differ based on the siderophore structures of the most important bacterial pathogens of those species.
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Affiliation(s)
- Kenneth N. Raymond
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Benjamin E. Allred
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Allyson K. Sia
- Department of Chemistry, University of California, Berkeley, California 94720-1460, United States
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Vaulont S, Schalk I. [Roles of bacterial and mammalian siderophores in host-pathogen interactions]. Med Sci (Paris) 2015; 31:756-63. [PMID: 26340835 DOI: 10.1051/medsci/20153108014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Iron is an essential nutriment for almost all forms of life, from bacteria to humans. Despite its key role in living organisms, iron becomes toxic at high concentrations. In the body, to circumvent this toxicity, almost all the intracellular iron is bound to proteins (especially to ferritin, a protein able to bind up to 4000 atoms of iron) and a small proportion (0.2% to 3%) to low molecular weight ligands (less than 2 kDa) constituting a free iron pool able to ensure the traffic of intracellular iron. A number of small molecules (citrate, phosphate, phospholipid, polypeptide) able to chelate iron, with variable affinities, have been known for a long time. In 2010, two teams have identified new mammal endogen chelators able to bind iron with similar chemical properties as bacterial siderophores. Recently, a few publications emphasized that most of the free iron present in the body cells is indeed linked to these siderophores, which play a key role in infected-host protection mechanisms during bacterial infections, through iron homeostasis and oxidative stress regulation.
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Affiliation(s)
- Sophie Vaulont
- Inserm U1016, institut Cochin, 24, rue du Faubourg Saint-Jacques, 75014 Paris, France - CNRS, UMR8104, Paris, France - Université Paris Descartes, Sorbonne Paris Cité, Paris, France - Laboratory of excellence GR-Ex
| | - Isabelle Schalk
- UMR 7242, université de Strasbourg-CNRS, ESBS, Strasbourg, France - CNRS, UMR 7242, ESBS, Illkirch, France
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A novel method of consensus pan-chromosome assembly and large-scale comparative analysis reveal the highly flexible pan-genome of Acinetobacter baumannii. Genome Biol 2015. [PMID: 26195261 PMCID: PMC4507327 DOI: 10.1186/s13059-015-0701-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background Infections by pan-drug resistant Acinetobacter baumannii plague military and civilian healthcare systems. Previous A. baumannii pan-genomic studies used modest sample sizes of low diversity and comparisons to a single reference genome, limiting our understanding of gene order and content. A consensus representation of multiple genomes will provide a better framework for comparison. A large-scale comparative study will identify genomic determinants associated with their diversity and adaptation as a successful pathogen. Results We determine draft-level genomic sequence of 50 diverse military isolates and conduct the largest bacterial pan-genome analysis of 249 genomes. The pan-genome of A. baumannii is open when the input genomes are normalized for diversity with 1867 core proteins and a paralog-collapsed pan-genome size of 11,694 proteins. We developed a novel graph-based algorithm and use it to assemble the first consensus pan-chromosome, identifying both the order and orientation of core genes and flexible genomic regions. Comparative genome analyses demonstrate the existence of novel resistance islands and isolates with increased numbers of resistance island insertions over time, from single insertions in the 1950s to triple insertions in 2011. Gene clusters responsible for carbon utilization, siderophore production, and pilus assembly demonstrate frequent gain or loss among isolates. Conclusions The highly variable and dynamic nature of the A. baumannii genome may be the result of its success in rapidly adapting to both abiotic and biotic environments through the gain and loss of gene clusters controlling fitness. Importantly, some archaic adaptation mechanisms appear to have reemerged among recent isolates. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0701-6) contains supplementary material, which is available to authorized users.
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Du ZP, Wu BL, Wu X, Lin XH, Qiu XY, Zhan XF, Wang SH, Shen JH, Zheng CP, Wu ZY, Xu LY, Wang D, Li EM. A systematic analysis of human lipocalin family and its expression in esophageal carcinoma. Sci Rep 2015; 5:12010. [PMID: 26131602 PMCID: PMC4487233 DOI: 10.1038/srep12010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/11/2015] [Indexed: 02/05/2023] Open
Abstract
The lipocalin proteins (lipocalins) are a large family of small proteins characterized by low sequence similarity and highly conserved crystal structures. Lipocalins have been found to play important roles in many human diseases. For this reason, a systemic analysis of the molecular properties of human lipocalins is essential. In this study, human lipocalins were found to contain four structurally conserved regions (SCRs) and could be divided into two subgroups. A human lipocalin protein-protein interaction network (PPIN) was constructed and integrated with their expression data in esophageal carcinoma. Many lipocalins showed obvious co-expression patterns in esophageal carcinoma. Their subcellular distributions also suggested these lipocalins may transfer signals from the extracellular space to the nucleus using the pathway-like paths. These analyses also expanded our knowledge about this human ancient protein family in the background of esophageal carcinoma.
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Affiliation(s)
- Ze-Peng Du
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Bing-Li Wu
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
| | - Xuan Wu
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Xuan-Hao Lin
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Xiao-Yang Qiu
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Xiao-Fen Zhan
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Shao-Hong Wang
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Jin-Hui Shen
- Department of Pathology, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Chun-Peng Zheng
- Department of Oncology Surgery, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Zhi-Yong Wu
- Department of Oncology Surgery, Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-sen University, Shantou 515041, China
| | - Li-Yan Xu
- Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, China
| | - Dong Wang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150000, China
| | - En-Min Li
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
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Aznar A, Dellagi A. New insights into the role of siderophores as triggers of plant immunity: what can we learn from animals? JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:3001-10. [PMID: 25934986 DOI: 10.1093/jxb/erv155] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Microorganisms use siderophores to obtain iron from the environment. In pathogenic interactions, siderophores are involved in iron acquisition from the host and are sometimes necessary for the expression of full virulence. This review summarizes the main data describing the role of these iron scavengers in animal and plant defence systems. To protect themselves against iron theft, mammalian hosts have developed a hypoferremia strategy that includes siderophore-binding molecules called siderocalins. In addition to microbial ferri-siderophore sequestration, siderocalins are involved in triggering immunity. In plants, no similar mechanisms have been described and many fewer data are available, although recent advances have shed light on the role of siderophores in plant-pathogen interactions. Siderophores can trigger immunity in plants in several contexts. The most frequently described situation involving siderophores is induced systemic resistance (ISR) triggered by plant-growth-promoting rhizobacteria. Although ISR responses have been observed after treating roots with certain siderophores, the underlying mechanisms are poorly understood. Immunity can also be triggered by siderophores in leaves. Siderophore perception in plants appears to be different from the well-known perception mechanisms of other microbial compounds, known as microbe-associated molecular patterns. Scavenging iron per se appears to be a novel mechanism of immunity activation, involving complex disturbance of metal homeostasis. Receptor-specific recognition of siderophores has been described in animals, but not in plants. The review closes with an overview of the possible mechanisms of defence activation, via iron scavenging by siderophores or specific siderophore recognition by the plant host.
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Affiliation(s)
- Aude Aznar
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Route de St Cyr (RD 10), F-78026 Versailles Cedex, France 2 AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France Université Paris 06, Case 156,4 Place Jussieu, F-75005 Paris, France
| | - Alia Dellagi
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Route de St Cyr (RD 10), F-78026 Versailles Cedex, France
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Potgieter M, Bester J, Kell DB, Pretorius E. The dormant blood microbiome in chronic, inflammatory diseases. FEMS Microbiol Rev 2015; 39:567-91. [PMID: 25940667 PMCID: PMC4487407 DOI: 10.1093/femsre/fuv013] [Citation(s) in RCA: 269] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 02/07/2023] Open
Abstract
Blood in healthy organisms is seen as a ‘sterile’ environment: it lacks proliferating microbes. Dormant or not-immediately-culturable forms are not absent, however, as intracellular dormancy is well established. We highlight here that a great many pathogens can survive in blood and inside erythrocytes. ‘Non-culturability’, reflected by discrepancies between plate counts and total counts, is commonplace in environmental microbiology. It is overcome by improved culturing methods, and we asked how common this would be in blood. A number of recent, sequence-based and ultramicroscopic studies have uncovered an authentic blood microbiome in a number of non-communicable diseases. The chief origin of these microbes is the gut microbiome (especially when it shifts composition to a pathogenic state, known as ‘dysbiosis’). Another source is microbes translocated from the oral cavity. ‘Dysbiosis’ is also used to describe translocation of cells into blood or other tissues. To avoid ambiguity, we here use the term ‘atopobiosis’ for microbes that appear in places other than their normal location. Atopobiosis may contribute to the dynamics of a variety of inflammatory diseases. Overall, it seems that many more chronic, non-communicable, inflammatory diseases may have a microbial component than are presently considered, and may be treatable using bactericidal antibiotics or vaccines. Atopobiosis of microbes (the term describing microbes that appear in places other than where they should be), as well as the products of their metabolism, seems to correlate with, and may contribute to, the dynamics of a variety of inflammatory diseases.
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Affiliation(s)
- Marnie Potgieter
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
| | - Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
| | - Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, 131, Princess St, Manchester M1 7DN, Lancs, UK
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia 0007, South Africa
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An Integrated In Silico Approach for the Structural and Functional Exploration of Lipocalin 2 and its Functional Insights with Metalloproteinase 9 and Lipoprotein Receptor-Related Protein 2. Appl Biochem Biotechnol 2015; 176:712-29. [DOI: 10.1007/s12010-015-1606-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 04/06/2015] [Indexed: 12/17/2022]
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Haas H, Petrik M, Decristoforo C. An iron-mimicking, Trojan horse-entering fungi--has the time come for molecular imaging of fungal infections? PLoS Pathog 2015; 11:e1004568. [PMID: 25634225 PMCID: PMC4310729 DOI: 10.1371/journal.ppat.1004568] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
- * E-mail: (HH); (CD)
| | - Milos Petrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic
| | - Clemens Decristoforo
- Clinical Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria
- * E-mail: (HH); (CD)
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Harrington JM, Duckworth OW, Haselwandter K. The fate of siderophores: antagonistic environmental interactions in exudate-mediated micronutrient uptake. Biometals 2015; 28:461-72. [DOI: 10.1007/s10534-015-9821-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/07/2015] [Indexed: 11/25/2022]
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45
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Mitophagy confers resistance to siderophore-mediated killing by Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2015; 112:1821-6. [PMID: 25624506 DOI: 10.1073/pnas.1424954112] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the arms race of bacterial pathogenesis, bacteria produce an array of toxins and virulence factors that disrupt core host processes. Hosts mitigate the ensuing damage by responding with immune countermeasures. The iron-binding siderophore pyoverdin is a key virulence mediator of the human pathogen Pseudomonas aeruginosa, but its pathogenic mechanism has not been established. Here we demonstrate that pyoverdin enters Caenorhabditis elegans and that it is sufficient to mediate host killing. Moreover, we show that iron chelation disrupts mitochondrial homeostasis and triggers mitophagy both in C. elegans and mammalian cells. Finally, we show that mitophagy provides protection both against the extracellular pathogen P. aeruginosa and to treatment with a xenobiotic chelator, phenanthroline, in C. elegans. Although autophagic machinery has been shown to target intracellular bacteria for degradation (a process known as xenophagy), our report establishes a role for authentic mitochondrial autophagy in the innate immune defense against P. aeruginosa.
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Bao GH, Barasch J, Xu J, Wang W, Hu FL, Deng SX. Purification and Structural Characterization of "Simple Catechol", the NGAL-Siderocalin Siderophore in Human Urine. RSC Adv 2015; 5:28527-28535. [PMID: 26257890 DOI: 10.1039/c5ra02509e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The identification of ligands that bind the protein Neutrophil Gelatinase-Associated Lipocalin (NGAL, Siderocalin, Lipocalin-2) have helped to elucidate its function. NGAL-Siderocalin binds and sequesters the iron loaded bacterial siderophore enterochelin (Ent), defining the protein as an innate immune effector. Simple metabolic catechols can also form tight complexes with NGAL-Siderocalin and ferric iron, suggesting that the protein may act as an iron scavenger even in the absence of Ent. While different catechols have been detected in human urine, they have not been directly purified from a biofluid and demonstrated to ligate iron with NGAL-Siderocalin. This paper describes a "natural products" approach to identify small molecules that mediate iron binding to NGAL-Siderocalin. A 10K filtrate of human urine was subjected to multiple steps of column chromatography and reverse-phase HPLC, guided by NGAL-Siderocalin-iron binding assays and LC-MS detection. The co-factor forming a ternary structure with iron and NGAL-Siderocalin was identified as authentic simple catechol (dihydroxybenze) by ESI-HR-Mass, UV, and NMR spectrometric analysis. Comparison of the binding strengths of different catechols demonstrated that the vicinal-dihydroxyl groups were the key functional groups and that steric compatibilities of the catechol ring have the strongest effect on binding. Although catechol was a known NGAL-Siderocalin co-factor, our purification directly confirmed its presence in urine as well as its capacity to serve as an iron trap with NGAL-Siderocalin.
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Affiliation(s)
- Guan-Hu Bao
- Anhui Agricultural University, 130 West Changjiang Road, Hefei, Anhui Province, 230036, China
| | - Jonathan Barasch
- College of Physicians and Surgeons of Columbia University, 630 West 168 St, New York, USA
| | - Jie Xu
- Anhui Agricultural University, 130 West Changjiang Road, Hefei, Anhui Province, 230036, China
| | - Wei Wang
- Anhui Agricultural University, 130 West Changjiang Road, Hefei, Anhui Province, 230036, China
| | - Feng-Lin Hu
- Anhui Agricultural University, 130 West Changjiang Road, Hefei, Anhui Province, 230036, China
| | - Shi-Xian Deng
- College of Physicians and Surgeons of Columbia University, 630 West 168 St, New York, USA
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Bergeron RJ, Wiegand J, McManis JS, Bharti N. Desferrithiocin: a search for clinically effective iron chelators. J Med Chem 2014; 57:9259-91. [PMID: 25207964 PMCID: PMC4255733 DOI: 10.1021/jm500828f] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Indexed: 01/19/2023]
Abstract
The successful search for orally active iron chelators to treat transfusional iron-overload diseases, e.g., thalassemia, is overviewed. The critical role of iron in nature as a redox engine is first described, as well as how primitive life forms and humans manage the metal. The problems that derive when iron homeostasis in humans is disrupted and the mechanism of the ensuing damage, uncontrolled Fenton chemistry, are discussed. The solution to the problem, chelator-mediated iron removal, is clear. Design options for the assembly of ligands that sequester and decorporate iron are reviewed, along with the shortcomings of the currently available therapeutics. The rationale for choosing desferrithiocin, a natural product iron chelator (a siderophore), as a platform for structure-activity relationship studies in the search for an orally active iron chelator is thoroughly developed. The study provides an excellent example of how to systematically reengineer a pharmacophore in order to overcome toxicological problems while maintaining iron clearing efficacy and has led to three ligands being evaluated in human clinical trials.
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Affiliation(s)
- Raymond J. Bergeron
- Department of Medicinal Chemistry, University of Florida, Box 100485 JHMHC, Gainesville, Florida 32610-0485, United States
| | - Jan Wiegand
- Department of Medicinal Chemistry, University of Florida, Box 100485 JHMHC, Gainesville, Florida 32610-0485, United States
| | - James S. McManis
- Department of Medicinal Chemistry, University of Florida, Box 100485 JHMHC, Gainesville, Florida 32610-0485, United States
| | - Neelam Bharti
- Department of Medicinal Chemistry, University of Florida, Box 100485 JHMHC, Gainesville, Florida 32610-0485, United States
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Lisher JP, Giedroc DP. Manganese acquisition and homeostasis at the host-pathogen interface. Front Cell Infect Microbiol 2013; 3:91. [PMID: 24367765 PMCID: PMC3851752 DOI: 10.3389/fcimb.2013.00091] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/18/2013] [Indexed: 11/21/2022] Open
Abstract
Pathogenic bacteria acquire transition metals for cell viability and persistence of infection in competition with host nutritional defenses. The human host employs a variety of mechanisms to stress the invading pathogen with both cytotoxic metal ions and oxidative and nitrosative insults while withholding essential transition metals from the bacterium. For example, the S100 family protein calprotectin (CP) found in neutrophils is a calcium-activated chelator of extracellular Mn and Zn and is found in tissue abscesses at sites of infection by Staphylococcus aureus. In an adaptive response, bacteria have evolved systems to acquire the metals in the face of this competition while effluxing excess or toxic metals to maintain a bioavailability of transition metals that is consistent with a particular inorganic "fingerprint" under the prevailing conditions. This review highlights recent biological, chemical and structural studies focused on manganese (Mn) acquisition and homeostasis and connects this process to oxidative stress resistance and iron (Fe) availability that operates at the human host-pathogen interface.
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Affiliation(s)
- John P. Lisher
- Graduate Program in Biochemistry, Indiana UniversityBloomington, IN, USA
| | - David P. Giedroc
- Graduate Program in Biochemistry, Indiana UniversityBloomington, IN, USA
- Department of Chemistry, Indiana UniversityBloomington, IN, USA
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