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Kang D, Xu Q, Kirienko NV. In vitro lung epithelial cell model reveals novel roles for Pseudomonas aeruginosa siderophores. Microbiol Spectr 2024; 12:e0369323. [PMID: 38311809 PMCID: PMC10913452 DOI: 10.1128/spectrum.03693-23] [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: 10/18/2023] [Accepted: 12/21/2023] [Indexed: 02/06/2024] Open
Abstract
The multidrug-resistant pathogen Pseudomonas aeruginosa is a common nosocomial respiratory pathogen that continues to threaten the lives of patients with mechanical ventilation in intensive care units and those with underlying comorbidities such as cystic fibrosis or chronic obstructive pulmonary disease. For over 20 years, studies have repeatedly demonstrated that the major siderophore pyoverdine is an important virulence factor for P. aeruginosa in invertebrate and mammalian hosts in vivo. Despite its physiological significance, an in vitro, mammalian cell culture model that can be used to characterize the impact and molecular mechanisms of pyoverdine-mediated virulence has only been developed very recently. In this study, we adapt a previously-established, murine macrophage-based model to use human bronchial epithelial (16HBE) cells. We demonstrate that conditioned medium from P. aeruginosa induced rapid 16HBE cell death through the pyoverdine-dependent secretion of cytotoxic rhamnolipids. Genetic or chemical disruption of pyoverdine biosynthesis decreased rhamnolipid production and mitigated cell death. Consistent with these observations, chemical depletion of lipids or genetic disruption of rhamnolipid biosynthesis abrogated the toxicity of the conditioned medium. Furthermore, we also examine the effects of exposure to purified pyoverdine on 16HBE cells. While pyoverdine accumulated within cells, it was largely sequestered within early endosomes, resulting in minimal cytotoxicity. More membrane-permeable iron chelators, such as the siderophore pyochelin, decreased epithelial cell viability and upregulated several pro-inflammatory genes. However, pyoverdine potentiated these iron chelators in activating pro-inflammatory pathways. Altogether, these findings suggest that the siderophores pyoverdine and pyochelin play distinct roles in virulence during acute P. aeruginosa lung infection. IMPORTANCE Multidrug-resistant Pseudomonas aeruginosa is a versatile bacterium that frequently causes lung infections. This pathogen is life-threatening to mechanically-ventilated patients in intensive care units and is a debilitating burden for individuals with cystic fibrosis. However, the role of P. aeruginosa virulence factors and their regulation during infection are not fully understood. Previous murine lung infection studies have demonstrated that the production of siderophores (e.g., pyoverdine and pyochelin) is necessary for full P. aeruginosa virulence. In this report, we provide further mechanistic insight into this phenomenon. We characterize distinct and novel ways these siderophores contribute to virulence using an in vitro human lung epithelial cell culture model.
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Affiliation(s)
- Donghoon Kang
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Qi Xu
- Department of BioSciences, Rice University, Houston, Texas, USA
- Department of Bioengineering, Rice University, Houston, Texas, USA
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Kang D, Xu Q, Kirienko NV. In vitro Lung Epithelial Cell Model Reveals Novel Roles for Pseudomonas aeruginosa Siderophores. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525796. [PMID: 36747656 PMCID: PMC9901015 DOI: 10.1101/2023.01.26.525796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Multidrug-resistant Pseudomonas aeruginosa is a common nosocomial respiratory pathogen that continues to threaten the lives of patients with mechanical ventilation in intensive care units and those with underlying comorbidities such as cystic fibrosis or chronic obstructive pulmonary disease. For over 20 years, studies have repeatedly demonstrated that the major siderophore pyoverdine is an important virulence factor for P. aeruginosa in invertebrate and mammalian hosts in vivo. Despite its physiological significance, an in vitro, mammalian cell culture model to characterize the impact and molecular mechanism of pyoverdine-mediated virulence has only been developed very recently. In this study, we adapt a previously-established, murine macrophage-based model for human bronchial epithelial cells (16HBE). We demonstrate that conditioned medium from P. aeruginosa induced rapid 16HBE cell death through the pyoverdine-dependent secretion of cytotoxic rhamnolipids. Genetic or chemical disruption of pyoverdine biosynthesis decreased rhamnolipid production and mitigated cell death. Consistent with these observations, chemical depletion of lipid factors or genetic disruption of rhamnolipid biosynthesis was sufficient to abrogate conditioned medium toxicity. Furthermore, we also examine the effects of purified pyoverdine exposure on 16HBE cells. While pyoverdine accumulated within cells, the siderophore was largely sequestered within early endosomes, showing minimal cytotoxicity. More membrane-permeable iron chelators, such as the siderophore pyochelin, decreased epithelial cell viability and upregulated several proinflammatory genes. However, pyoverdine potentiated these iron chelators in activating proinflammatory pathways. Altogether, these findings suggest that the siderophores pyoverdine and pyochelin play distinct roles in virulence during acute P. aeruginosa lung infection.
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Affiliation(s)
- Donghoon Kang
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Qi Xu
- Department of BioSciences, Rice University, Houston, TX, USA
- Department of Bioengineering, Rice University, Houston, TX, USA
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3
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Hollifield IE, Motyka NI, Fernando KA, Bitoun JP. Heat-Labile Enterotoxin Decreases Macrophage Phagocytosis of Enterotoxigenic Escherichia coli. Microorganisms 2023; 11:2121. [PMID: 37630681 PMCID: PMC10459231 DOI: 10.3390/microorganisms11082121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Enterotoxigenic E. coli (ETEC) are endemic in low-resource settings and cause robust secretory diarrheal disease in children less than five years of age. ETEC cause secretory diarrhea by producing the heat-stable (ST) and/or heat-labile (LT) enterotoxins. Recent studies have shown that ETEC can be carried asymptomatically in children and adults, but how ETEC subvert mucosal immunity to establish intestinal residency remains unclear. Macrophages are innate immune cells that can be exploited by enteric pathogens to evade mucosal immunity, so we interrogated the ability of ETEC and other E. coli pathovars to survive within macrophages. Using gentamicin protection assays, we show that ETEC H10407 is phagocytosed more readily than other ETEC and non-ETEC isolates. Furthermore, we demonstrate that ETEC H10407, at high bacterial burdens, causes nitrite accumulation in macrophages, which is indicative of a proinflammatory macrophage nitric oxide killing response. However, at low bacterial burdens, ETEC H10407 remains viable within macrophages for an extended period without nitrite accumulation. We demonstrate that LT, but not ST, intoxication decreases the number of ETEC phagocytosed by macrophages. Furthermore, we now show that macrophages exposed simultaneously to LPS and LT produce IL-33, which is a cytokine implicated in promoting macrophage alternative activation, iron recycling, and intestinal repair. Lastly, iron restriction using deferoxamine induces IL-33 receptor (IL-33R) expression and allows ETEC to escape macrophages. Altogether, these data demonstrate that LT provides ETEC with the ability to decrease the perceived ETEC burden and suppresses the initiation of inflammation. Furthermore, these data suggest that host IL-33/IL-33R signaling may augment pathways that promote iron restriction to facilitate ETEC escape from macrophages. These data could help explain novel mechanisms of immune subversion that may contribute to asymptomatic ETEC carriage.
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Affiliation(s)
| | | | | | - Jacob P. Bitoun
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, #8638, New Orleans, LA 70112, USA; (I.E.H.); (N.I.M.); (K.A.F.)
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Fahoum L, Belisowski S, Ghatpande N, Guttmann-Raviv N, Zhang W, Li K, Tong WH, Nyska A, Waterman M, Weisshof R, Zuckerman A, Meyron-Holtz E. Iron Regulatory Protein 1 is Required for the Propagation of Inflammation in Inflammatory Bowel Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525690. [PMID: 36789413 PMCID: PMC9928023 DOI: 10.1101/2023.01.27.525690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Objective Inflammatory bowel diseases (IBD) are complex disorders. Iron accumulates in the inflamed tissue of IBD patients, yet neither a mechanism for the accumulation nor its implication on the course of inflammation are known. We hypothesized that the inflammation modifies iron homeostasis, affects tissue iron distribution and that this in turn perpetuates the inflammation. Design This study analyzed human biopsies, animal models and cellular systems to decipher the role of iron homeostasis in IBD. Results We found inflammation-mediated modifications of iron distribution, and iron-decoupled activation of the iron regulatory protein (IRP)1. To understand the role of IRP1 in the course of this inflammation-associated iron pattern, a novel cellular co-culture model was established, that replicated the iron-pattern observed in vivo, and supported involvement of nitric oxide in the activation of IRP1 and the typical iron pattern in inflammation. Importantly, deletion of IRP1 from an IBD mouse model completely abolished both, the misdistribution of iron and intestinal inflammation. Conclusion These findings suggest that IRP1 plays a central role in the coordination of the inflammatory response in the intestinal mucosa and that it is a viable candidate for therapeutic intervention in IBD.
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Affiliation(s)
- L. Fahoum
- Laboratory of Molecular Nutrition, Department of Biotechnology and Food Engineering, Technion– Israel Institute of Technology, Haifa, Israel
| | - S. Belisowski
- Laboratory of Molecular Nutrition, Department of Biotechnology and Food Engineering, Technion– Israel Institute of Technology, Haifa, Israel
| | - N. Ghatpande
- Laboratory of Molecular Nutrition, Department of Biotechnology and Food Engineering, Technion– Israel Institute of Technology, Haifa, Israel
| | - N. Guttmann-Raviv
- Laboratory of Molecular Nutrition, Department of Biotechnology and Food Engineering, Technion– Israel Institute of Technology, Haifa, Israel
| | - W. Zhang
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing 210093, China
| | - K. Li
- Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing 210093, China
| | - W-H. Tong
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - A. Nyska
- Tel Aviv University and Consultant in Toxicologic Pathology, Tel Aviv, Israel
| | - M. Waterman
- Rambam / Technion– Israel Institute of Technology, Haifa, Israel
| | - R. Weisshof
- Rambam / Technion– Israel Institute of Technology, Haifa, Israel
| | | | - E.G. Meyron-Holtz
- Laboratory of Molecular Nutrition, Department of Biotechnology and Food Engineering, Technion– Israel Institute of Technology, Haifa, Israel
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Lopez AE, Grigoryeva LS, Barajas A, Cianciotto NP. Legionella pneumophila Rhizoferrin Promotes Bacterial Biofilm Formation and Growth within Amoebae and Macrophages. Infect Immun 2023; 91:e0007223. [PMID: 37428036 PMCID: PMC10429650 DOI: 10.1128/iai.00072-23] [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: 02/15/2023] [Accepted: 06/20/2023] [Indexed: 07/11/2023] Open
Abstract
Previously, we showed that Legionella pneumophila secretes rhizoferrin, a polycarboxylate siderophore that promotes bacterial growth in iron-deplete media and the murine lung. Yet, past studies failed to identify a role for the rhizoferrin biosynthetic gene (lbtA) in L. pneumophila infection of host cells, suggesting the siderophore's importance was solely linked to extracellular survival. To test the possibility that rhizoferrin's relevance to intracellular infection was missed due to functional redundancy with the ferrous iron transport (FeoB) pathway, we characterized a new mutant lacking both lbtA and feoB. This mutant was highly impaired for growth on bacteriological media that were only modestly depleted of iron, confirming that rhizoferrin-mediated ferric iron uptake and FeoB-mediated ferrous iron uptake are critical for iron acquisition. The lbtA feoB mutant, but not its lbtA-containing complement, was also highly defective for biofilm formation on plastic surfaces, demonstrating a new role for the L. pneumophila siderophore in extracellular survival. Finally, the lbtA feoB mutant, but not its complement containing lbtA, proved to be greatly impaired for growth in Acanthamoeba castellanii, Vermamoeba vermiformis, and human U937 cell macrophages, revealing that rhizoferrin does promote intracellular infection by L. pneumophila. Moreover, the application of purified rhizoferrin triggered cytokine production from the U937 cells. Rhizoferrin-associated genes were fully conserved across the many sequenced strains of L. pneumophila examined but were variably present among strains from the other species of Legionella. Outside of Legionella, the closest match to the L. pneumophila rhizoferrin genes was in Aquicella siphonis, another facultative intracellular parasite of amoebae.
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Affiliation(s)
- Alberto E. Lopez
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Lubov S. Grigoryeva
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Armando Barajas
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Nicholas P. Cianciotto
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
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Heat-Stable Enterotoxin Secretions Assessed via ICP-MS Reveal Iron-Mediated Regulation of Virulence in CFA/I- and CS6-Expressing ETEC Isolates. Cells 2023; 12:cells12040567. [PMID: 36831233 PMCID: PMC9954033 DOI: 10.3390/cells12040567] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/11/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are a significant cause of childhood diarrhea in low-resource settings. ETEC are defined by the production of heat-stable enterotoxin (ST) and/or heat-labile enterotoxin (LT), which alter intracellular cyclic nucleotide signaling and cause the secretion of water and electrolytes into the intestinal lumen. ETEC take cues from chemicals (e.g., glycans, bile salts, and solutes) that may be liberated following enterotoxin activity to recognize entrance into the host. ETEC then alter the expression of surface adhesins called colonization factors (CFs) to attach to the intestinal epithelium, proliferate, and cause disease. Here, we used an in vivo model of oral ST intoxication to determine its impact on luminal ion concentrations via ICP-MS. We also used functional assays, including Western blots, qPCR, and toxin activity assays, to assess the impact of luminal ion flux on CF and toxin expression. Finally, we assessed ETEC strains with CFs CFA/I or CS6 in a streptomycin mouse model of ETEC colonization. ST causes rapid and significant increases in luminal chloride but significant decreases in luminal magnesium and iron. We confirmed that increased sodium chloride suppresses CFA/I production in ETEC H10407 but does not affect CS6 production in ETEC 214-4. CFA/I production in ETEC H10407 is increased when magnesium becomes limiting, although it does not affect CS6 production in ETEC 214-4. Iron restriction via deferoxamine induces CFA/I expression in ETEC H10407 but not CS6 expression in ETEC 214-4. We demonstrate that ST production is suppressed via iron restriction in H10407, 214-4, and over 50 other ETEC clinical isolates. Lastly, we demonstrate that the iron restriction of mice using oral deferoxamine pre-treatment extends the duration of ETEC H10407 (CFA/I+) fecal shedding while accelerating ETEC 214-4 (CS6+) fecal shedding. Combined, these data suggest that enterotoxins modulate luminal ion flux to influence ETEC virulence including toxin and CF production.
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Natural statin derivatives as potential therapy to reduce intestinal fluid loss in cholera. PLoS Negl Trop Dis 2022; 16:e0010989. [PMID: 36490300 PMCID: PMC9770395 DOI: 10.1371/journal.pntd.0010989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/21/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
As a leading cause of death in children under 5 years old, secretory diarrheas including cholera are characterized by excessive intestinal fluid secretion driven by enterotoxin-induced cAMP-dependent intestinal chloride transport. This study aimed to identify fungal bioactive metabolites possessing anti-secretory effects against cAMP-dependent chloride secretion in intestinal epithelial cells. Using electrophysiological analyses in human intestinal epithelial (T84) cells, five fungus-derived statin derivatives including α,β-dehydrolovastatin (DHLV), α,β-dehydrodihydromonacolin K, lovastatin, mevastatin and simvastatin were found to inhibit the cAMP-dependent chloride secretion with IC50 values of 1.8, 8.9, 11.9, 11.4 and 5 μM, respectively. Being the most potent statin derivatives, DHLV was evaluated for its pharmacological properties including cellular toxicity, mechanism of action, target specificity and in vivo efficacy. DHLV at concentrations up to 20 μM did not affect cell viability and barrier integrity of T84 cells. Electrophysiological analyses indicated that DHLV inhibited cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent apical chloride channel, via mechanisms not involving alteration of intracellular cAMP levels or its negative regulators including AMP-activated protein kinases and protein phosphatases. DHLV had no effect on Na+-K+ ATPase activities but inhibited Ca2+-dependent chloride secretion without affecting intracellular Ca2+ levels. Importantly, intraperitoneal (2 mg/kg) and intraluminal (20 μM) injections of DHLV reduced cholera toxin-induced intestinal fluid secretion in mice by 59% and 65%, respectively without affecting baseline intestinal fluid transport. This study identifies natural statin derivatives as novel natural product-derived CFTR inhibitors, which may be beneficial in the treatment of enterotoxin-induced secretory diarrheas including cholera.
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Pita-Grisanti V, Chasser K, Sobol T, Cruz-Monserrate Z. Understanding the Potential and Risk of Bacterial Siderophores in Cancer. Front Oncol 2022; 12:867271. [PMID: 35785195 PMCID: PMC9248441 DOI: 10.3389/fonc.2022.867271] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/06/2022] [Indexed: 01/19/2023] Open
Abstract
Siderophores are iron chelating molecules produced by nearly all organisms, most notably by bacteria, to efficiently sequester the limited iron that is available in the environment. Siderophores are an essential component of mammalian iron homeostasis and the ongoing interspecies competition for iron. Bacteria produce a broad repertoire of siderophores with a canonical role in iron chelation and the capacity to perform versatile functions such as interacting with other microbes and the host immune system. Siderophores are a vast area of untapped potential in the field of cancer research because cancer cells demand increased iron concentrations to sustain rapid proliferation. Studies investigating siderophores as therapeutics in cancer generally focused on the role of a few siderophores as iron chelators; however, these studies are limited and some show conflicting results. Moreover, siderophores are biologically conserved, structurally diverse molecules that perform additional functions related to iron chelation. Siderophores also have a role in inflammation due to their iron acquisition and chelation properties. These diverse functions may contribute to both risks and benefits as therapeutic agents in cancer. The potential of siderophore-mediated iron and bacterial modulation to be used in the treatment of cancer warrants further investigation. This review discusses the wide range of bacterial siderophore functions and their utilization in cancer treatment to further expand their functional relevance in cancer detection and treatment.
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Affiliation(s)
- Valentina Pita-Grisanti
- The Ohio State University Interdisciplinary Nutrition Program, The Ohio State University, Columbus, OH, United States
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Kaylin Chasser
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Trevor Sobol
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Zobeida Cruz-Monserrate
- Division of Gastroenterology, Hepatology, and Nutrition, Division of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Comprehensive Cancer Center–Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH, United States
- *Correspondence: Zobeida Cruz-Monserrate,
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Ghio AJ, Pavlisko EN, Roggli VL, Todd NW, Sangani RG. Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis. Int J Chron Obstruct Pulmon Dis 2022; 17:117-140. [PMID: 35046648 PMCID: PMC8763205 DOI: 10.2147/copd.s337354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/06/2021] [Indexed: 11/23/2022] Open
Abstract
It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).
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Affiliation(s)
- Andrew J Ghio
- Human Studies Facility, US Environmental Protection Agency, Chapel Hill, NC, 27514, USA
- Correspondence: Andrew J Ghio Human Studies Facility, US Environmental Protection Agency, 104 Mason Farm Road, Chapel Hill, NC, USA Email
| | | | | | - Nevins W Todd
- Department of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Rahul G Sangani
- Department of Medicine, West Virginia University, Morgantown, WV, USA
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McQueen CF, Groves JT. Toxicity of the iron siderophore mycobactin J in mouse macrophages: Evidence for a hypoxia response. J Inorg Biochem 2021; 227:111669. [PMID: 34864292 DOI: 10.1016/j.jinorgbio.2021.111669] [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: 08/03/2021] [Revised: 11/07/2021] [Accepted: 11/07/2021] [Indexed: 11/25/2022]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is an obligate intracellular pathogen that lives within the phagosome of macrophages. Here we demonstrate that the siderophore mycobactin J, produced by the closely related intracellular pathogen Mycobacterium paratuberculosis, is toxic to murine macrophage cells. Its median lethal dose, 10 μM, is lower than that of the iron chelators desferrioxamine B and TrenCAM, an enterobactin analog. To determine the source of this toxicity, we conducted microarray, ELISA, and metabolite profiling experiments. The primary response is hypoxia-like, which implies iron starvation as the underlying cause of the toxicity. This observation is consistent with our recent finding that mycobactin J is a stronger iron chelator than had been inferred from previous studies. Mycobactin J is known to partition into cell membranes and hydrophobic organelles indicating that enhanced membrane penetration is also a likely factor. Thus, mycobactin J is shown to be toxic, eliciting a hypoxia-like response under physiological conditions.
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Affiliation(s)
| | - John T Groves
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
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Saha P, Yeoh BS, Xiao X, Golonka RM, Abokor AA, Wenceslau CF, Shah YM, Joe B, Vijay-Kumar M. Enterobactin induces the chemokine, interleukin-8, from intestinal epithelia by chelating intracellular iron. Gut Microbes 2020; 12:1-18. [PMID: 33171063 PMCID: PMC7671005 DOI: 10.1080/19490976.2020.1841548] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Iron is an indispensable nutrient for both mammals and microbes. Bacteria synthesize siderophores to sequester host iron, whereas lipocalin 2 (Lcn2) is the host defense protein that prevent this iron thievery. Enterobactin (Ent) is a catecholate-type siderophore that has one of the strongest known affinities for iron. Intestinal epithelial cells (IECs) are adjacent to large microbial population and are in contact with microbial products, including Ent. We undertook this study to investigate whether a single stimulus of Ent could affect IEC functions. Using three human IEC cell-lines with differential basal levels of Lcn2 (i.e. HT29 < DLD-1 < Caco-2/BBe), we demonstrated that iron-free Ent could induce a dose-dependent secretion of the pro-inflammatory chemokine, interleukin 8 (IL-8), in HT29 and DLD-1 IECs, but not in Caco-2/BBe. Ent-induced IL-8 secretion was dependent on chelation of the labile iron pool and on the levels of intracellular Lcn2. Accordingly, IL-8 secretion by Ent-treated HT29 cells could be substantially inhibited by either saturating Ent with iron or by adding exogenous Lcn2 to the cells. IL-8 production by Ent could be further potentiated when co-stimulated with other microbial products (i.e. flagellin, lipopolysaccharide). Water-soluble microbial siderophores did not induce IL-8 production, which signifies that IECs are specifically responding to the lipid-soluble Ent. Intriguingly, formyl peptide receptor (FPR) antagonists (i.e. Boc2, cyclosporine H) abrogated Ent-induced IL-8, implicating that such IEC response could be, in part, dependent on FPR. Taken together, these results demonstrate that IECs sense Ent as a danger signal, where its recognition results in IL-8 secretion.
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Affiliation(s)
- Piu Saha
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Beng San Yeoh
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Xia Xiao
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Rachel M. Golonka
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Ahmed A. Abokor
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Camilla F. Wenceslau
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Yatrik M. Shah
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA,Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA,Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Bina Joe
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Matam Vijay-Kumar
- UT Microbiome Consortium, Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA,CONTACT Matam Vijay-Kumar Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH43614, USA
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Wongkrasant P, Pongkorpsakol P, Ariyadamrongkwan J, Meesomboon R, Satitsri S, Pichyangkura R, Barrett KE, Muanprasat C. A prebiotic fructo-oligosaccharide promotes tight junction assembly in intestinal epithelial cells via an AMPK-dependent pathway. Biomed Pharmacother 2020; 129:110415. [PMID: 32603892 DOI: 10.1016/j.biopha.2020.110415] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/04/2020] [Accepted: 06/13/2020] [Indexed: 12/14/2022] Open
Abstract
Tight junctions play an important role in maintaining barrier integrity of intestinal epithelia. Activation of AMP-activated protein kinase (AMPK) promotes tight junction assembly in intestinal epithelial cells (IEC). Fructo-oligosaccharides (FOS), well-known prebiotics, have previously been shown to alleviate inflammation-associated intestinal epithelial disruption although the mechanisms were unclear. This study aimed to investigate any effect of FOS on AMPK activity and tight junction assembly under non-inflammatory and inflammatory conditions using T84 cells as an IEC model. As analyzed by western blot, FOS induced AMPK activation through a calcium sensing receptor (CaSR)-phospholipase C (PLC)- Ca2+/calmodulin-dependent protein kinase kinase-β (CaMKKβ) pathway. Calcium switch assays and immunofluorescence staining of zonula occludens-1 (ZO-1) revealed that FOS induced tight junction assembly via an CaMKKβ-AMPK-dependent mechanism in IEC. Interestingly, FOS reversed the suppressive effect of lipopolysaccharide (LPS) on AMPK activity and tight junction assembly via a CaMKKβ pathway. Taken together, these findings uncover a prebiotic-independent effect of FOS in promoting intestinal epithelial tight junction assembly through AMPK activation, which may have implications for the treatment of diseases whose pathogenesis involves impaired intestinal barrier function.
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Affiliation(s)
- Preedajit Wongkrasant
- Department of Physiology, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok, 10400, Thailand; Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA; Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangpla, Bangpli, Samutprakarn, 10540, Thailand
| | - Pawin Pongkorpsakol
- Translational Medicine Graduate Program, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Rama VI Road, Rajathevi, Bangkok, 10400, Thailand
| | - Jutharat Ariyadamrongkwan
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangpla, Bangpli, Samutprakarn, 10540, Thailand
| | - Roojanaat Meesomboon
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangpla, Bangpli, Samutprakarn, 10540, Thailand
| | - Saravut Satitsri
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangpla, Bangpli, Samutprakarn, 10540, Thailand
| | - Rath Pichyangkura
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Payathai Road, Patumwan, Bangkok, 10330, Thailand
| | - Kim E Barrett
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Chatchai Muanprasat
- Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangpla, Bangpli, Samutprakarn, 10540, Thailand.
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13
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Potor L, Sikura KÉ, Hegedűs H, Pethő D, Szabó Z, Szigeti ZM, Pócsi I, Trencsényi G, Szikra D, Garai I, Gáll T, Combi Z, Kappelmayer J, Balla G, Balla J. The Fungal Iron Chelator Desferricoprogen Inhibits Atherosclerotic Plaque Formation. Int J Mol Sci 2020; 21:ijms21134746. [PMID: 32635347 PMCID: PMC7369830 DOI: 10.3390/ijms21134746] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 12/14/2022] Open
Abstract
Hemoglobin, heme and iron are implicated in the progression of atherosclerosis. Therefore, we investigated whether the hydrophobic fungal iron chelator siderophore, desferricoprogen (DFC) inhibits atherosclerosis. DFC reduced atherosclerotic plaque formation in ApoE-/- mice on an atherogenic diet. It lowered the plasma level of oxidized LDL (oxLDL) and inhibited lipid peroxidation in aortic roots. The elevated collagen/elastin content and enhanced expression of adhesion molecule VCAM-1 were decreased. DFC diminished oxidation of Low-density Lipoprotein (LDL) and plaque lipids catalyzed by heme or hemoglobin. Formation of foam cells, uptake of oxLDL by macrophages, upregulation of CD36 and increased expression of TNF-α were reduced by DFC in macrophages. TNF-triggered endothelial cell activation (vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecules (ICAMs), E-selectin) and increased adhesion of monocytes to endothelium were attenuated. The increased endothelial permeability and intracellular gap formation provoked by TNF-α was also prevented by DFC. DFC acted as a cytoprotectant in endothelial cells and macrophages challenged with a lethal dose of oxLDL and lowered the expression of stress-responsive heme oxygenase-1 as sublethal dose was employed. Saturation of desferrisiderophore with iron led to the loss of the beneficial effects. We demonstrated that DFC accumulated within the atheromas of the aorta in ApoE-/- mice. DFC represents a novel therapeutic approach to control the progression of atherosclerosis.
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Affiliation(s)
- László Potor
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Katalin Éva Sikura
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Hajnalka Hegedűs
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Dávid Pethő
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Zsuzsa Szabó
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - Zsuzsa M Szigeti
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Technology, Faculty of Science and Technology, University of Debrecen, 4012 Debrecen, Hungary; (Z.S.); (Z.M.S.); (I.P.)
| | - György Trencsényi
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Dezső Szikra
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Ildikó Garai
- Scanomed Ltd., University of Debrecen, 4012 Debrecen, Hungary; (G.T.); (D.S.); (I.G.)
| | - Tamás Gáll
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - Zsolt Combi
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
| | - János Kappelmayer
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary;
| | - György Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary
- Correspondence: (G.B.); (J.B.)
| | - József Balla
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, University of Debrecen, 4012 Debrecen, Hungary; (L.P.); (K.É.S.); (T.G.)
- Division of Nephrology, Department of Medicine, Faculty of Medicine, University of Debrecen, 4012 Debrecen, Hungary; (H.H.); (D.P.); (Z.C.)
- Correspondence: (G.B.); (J.B.)
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14
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Sato K, Inoue S, Igarashi A, Tokairin Y, Yamauchi K, Kimura T, Nishiwaki M, Nemoto T, Nakano H, Sato M, Machida H, Yang S, Minegishi Y, Furuyama K, Watanabe M, Shibata Y. Effect of Iron Deficiency on a Murine Model of Smoke-induced Emphysema. Am J Respir Cell Mol Biol 2020; 62:588-597. [DOI: 10.1165/rcmb.2018-0239oc] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Kento Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Sumito Inoue
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Akira Igarashi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Yoshikane Tokairin
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Keiko Yamauchi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Tomomi Kimura
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Michiko Nishiwaki
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Takako Nemoto
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Hiroshi Nakano
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Masamichi Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Hiroyoshi Machida
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Sujeong Yang
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Yukihiro Minegishi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Kodai Furuyama
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Masafumi Watanabe
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan; and
| | - Yoko Shibata
- Department of Pulmonary Medicine, Fukushima Medical University, Fukushima, Japan
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15
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Ghio AJ, Soukup JM, Dailey LA, Madden MC. Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury. Free Radic Biol Med 2020; 151:38-55. [PMID: 32092410 PMCID: PMC8274387 DOI: 10.1016/j.freeradbiomed.2020.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.
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Affiliation(s)
- Andrew J Ghio
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA.
| | - Joleen M Soukup
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Lisa A Dailey
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Michael C Madden
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
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16
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McCarville JL, Chen GY, Cuevas VD, Troha K, Ayres JS. Microbiota Metabolites in Health and Disease. Annu Rev Immunol 2020; 38:147-170. [DOI: 10.1146/annurev-immunol-071219-125715] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metabolism is one of the strongest drivers of interkingdom interactions—including those between microorganisms and their multicellular hosts. Traditionally thought to fuel energy requirements and provide building blocks for biosynthetic pathways, metabolism is now appreciated for its role in providing metabolites, small-molecule intermediates generated from metabolic processes, to perform various regulatory functions to mediate symbiotic relationships between microbes and their hosts. Here, we review recent advances in our mechanistic understanding of how microbiota-derived metabolites orchestrate and support physiological responses in the host, including immunity, inflammation, defense against infections, and metabolism. Understanding how microbes metabolically communicate with their hosts will provide us an opportunity to better describe how a host interacts with all microbes—beneficial, pathogenic, and commensal—and an opportunity to discover new ways to treat microbial-driven diseases.
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Affiliation(s)
- Justin L. McCarville
- Molecular and Systems Physiology Laboratory, Gene Expression Laboratory, NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Grischa Y. Chen
- Molecular and Systems Physiology Laboratory, Gene Expression Laboratory, NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Víctor D. Cuevas
- Molecular and Systems Physiology Laboratory, Gene Expression Laboratory, NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Katia Troha
- Molecular and Systems Physiology Laboratory, Gene Expression Laboratory, NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Janelle S. Ayres
- Molecular and Systems Physiology Laboratory, Gene Expression Laboratory, NOMIS Center for Immunobiology and Microbial Pathogenesis, Salk Institute for Biological Studies, La Jolla, California 92037, USA
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17
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Kiefer MC, Motyka NI, Clements JD, Bitoun JP. Enterotoxigenic Escherichia coli Heat-Stable Toxin Increases the Rate of Zinc Release from Metallothionein and Is a Zinc- and Iron-Binding Peptide. mSphere 2020; 5:e00146-20. [PMID: 32238569 PMCID: PMC7113584 DOI: 10.1128/msphere.00146-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/12/2020] [Indexed: 12/16/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major diarrheal pathogen in children in low- to middle-income countries. Previous studies have identified heat-stable enterotoxin (ST)-producing ETEC as one of the major diarrhea-causing pathogens in children younger than five years. In this study, we examined iron and zinc binding by both human and porcine ST variants and determined how host metallothionein could detoxify ST. We found that ST purified from ETEC culture supernatants eluted as a doublet during C18 reverse-phase chromatography. Leading edge fractions of the ST doublet were found to be devoid of iron, while trailing edge fractions of the ST doublet were found to contain measurable iron. Next, we found that purified ST could be reconstituted with iron under reducing and anaerobic conditions, and iron-bound ST attenuated the induction of cGMP in T84 epithelial cells. Moreover, we demonstrated that supernatants of ETEC 214-4 grown under increasing iron concentrations were only able to induce cGMP at iron concentrations greater than 5 μM. In vitro studies also demonstrated that ST binds zinc, and once bound, zinc removal from ST required denaturing conditions. Zinc-bound ST also failed to induce cGMP. We found that ST contributes disulfide bonds to the perceived oxidized glutathione pool, increases the rate of zinc release from metallothionein, and can be detoxified by metallothionein. Lastly, we showed ST induces transcriptional changes in genes previously shown to be regulated by deferoxamine. These studies demonstrate ST ETEC pathogenesis may be tied intimately to host mucosal metal status.IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) is a major diarrheal pathogen in children in low- to middle-income countries, deployed military personnel, and travelers to regions of endemicity. The heat-stable toxin (ST) is a small nonimmunogenic secreted peptide with 3 disulfide bonds. It has been appreciated that dietary disulfides modulate intestinal redox potential and that ST could be detoxified using exogenous reductants. Using biochemical and spectroscopic approaches, we demonstrated that ST can separately bind iron and zinc under reducing conditions, thereby reducing ST toxicity. Moreover, we demonstrated that ST modulates the glutathione (GSH)/oxidized glutathione (GSSG) ratio and that ST should be considered a toxin oxidant. ST can be detoxified by oxidizing zinc-loaded metallothionine, causing free zinc to be released. These studies help lay a foundation to understand how diarrheal pathogens modulate intestinal redox potential and may impact how we design therapeutics and/or vaccines for the pathogens that produce them.
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Affiliation(s)
- Mallory C Kiefer
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Natalya I Motyka
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - John D Clements
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Jacob P Bitoun
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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18
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Abstract
Growing evidence indicates that the mammalian microbiome can affect behaviour, and several symbionts even produce neurotransmitters. One common explanation for these observations is that symbionts have evolved to manipulate host behaviour for their benefit. Here, we evaluate the manipulation hypothesis by applying evolutionary theory to recent work on the gut-brain axis. Although the theory predicts manipulation by symbionts under certain conditions, these appear rarely satisfied by the genetically diverse communities of the mammalian microbiome. Specifically, any symbiont investing its resources to manipulate host behaviour is expected to be outcompeted within the microbiome by strains that do not manipulate and redirect their resources into growth and survival. Moreover, current data provide no clear evidence for manipulation. Instead, we show how behavioural effects can readily arise as a by-product of natural selection on microorganisms to grow within the host and natural selection on hosts to depend upon their symbionts. We argue that understanding why the microbiome influences behaviour requires a focus on microbial ecology and local effects within the host.
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Affiliation(s)
| | - Kevin R Foster
- Department of Zoology, University of Oxford, Oxford, UK.
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19
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Wagner A, Alan B, Yilmaz D, Ahmad M, Liu P, Tangudu NK, Tuckermann JP, Vujic Spasic M. Despite Genetic Iron Overload, Hfe-Hemochromatosis Mice Do Not Show Bone Loss. JBMR Plus 2019; 3:e10206. [PMID: 31667458 PMCID: PMC6808227 DOI: 10.1002/jbm4.10206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/13/2019] [Accepted: 05/21/2019] [Indexed: 12/15/2022] Open
Abstract
One of the most prevalent genetic iron overload disorders in Caucasians is caused by mutations in the HFE gene. Both HFE patients and Hfe‐mouse models develop a progressive accumulation of iron in the parenchymal cells of various tissues, eventually resulting in liver cirrhosis, hepatocellular carcinoma, cardiomyopathies, hypogonadism, and other pathologies. Clinical data and preclinical models have brought considerable attention to the correlation between iron overload and the development of osteoporosis in HFE/Hfe hemochromatosis. Our study critically challenges this concept. We show that systemic iron overload, at the degree present in Hfe−/− mice, does not associate with the microarchitecture impairment of long bones, thus excluding a negative effect of iron overload on bone integrity. We further reveal that Hfe actions in osteoblasts and osteoclasts are dispensable for the maintenance of bone and iron homeostasis in mice under steady‐state conditions. We conclude that, despite systemic iron overload, Hfe−/− mice present normal physiological bone homeostasis. © 2019 The Authors. JBMR Plus in published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Alessa Wagner
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | - Betül Alan
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | - Dilay Yilmaz
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | - Mubashir Ahmad
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | - Peng Liu
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | | | - Jan P Tuckermann
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
| | - Maja Vujic Spasic
- Institute of Comparative Molecular Endocrinology, University of Ulm Ulm Germany
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20
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Golonka R, Yeoh BS, Vijay-Kumar M. The Iron Tug-of-War between Bacterial Siderophores and Innate Immunity. J Innate Immun 2019; 11:249-262. [PMID: 30605903 DOI: 10.1159/000494627] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/20/2018] [Indexed: 12/21/2022] Open
Abstract
Iron is necessary for the survival of almost all aerobic organisms. In the mammalian host, iron is a required cofactor for the assembly of functional iron-sulfur (Fe-S) cluster proteins, heme-binding proteins and ribonucleotide reductases that regulate various functions, including heme synthesis, oxygen transport and DNA synthesis. However, the bioavailability of iron is low due to its insolubility under aerobic conditions. Moreover, the host coordinates a nutritional immune response to restrict the accessibility of iron against potential pathogens. To counter nutritional immunity, most commensal and pathogenic bacteria synthesize and secrete small iron chelators termed siderophores. Siderophores have potent affinity for iron, which allows them to seize the essential metal from the host iron-binding proteins. To safeguard against iron thievery, the host relies upon the innate immune protein, lipocalin 2 (Lcn2), which could sequester catecholate-type siderophores and thus impede bacterial growth. However, certain bacteria are capable of outmaneuvering the host by either producing "stealth" siderophores or by expressing competitive antagonists that bind Lcn2 in lieu of siderophores. In this review, we summarize the mechanisms underlying the complex iron tug-of-war between host and bacteria with an emphasis on how host innate immunity responds to siderophores.
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Affiliation(s)
- Rachel Golonka
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Beng San Yeoh
- Graduate Program in Immunology and Infectious Disease, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Matam Vijay-Kumar
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA, .,Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA,
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21
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Zou Z, Cai J, Zhong A, Zhou Y, Wang Z, Wu Z, Yang Y, Li X, Cheng X, Tan J, Fan Y, Zhang X, Lu Y, Zhou Y, Yang L, Zhang C, Zhao Q, Fu D, Shen Q, Chen J, Bai S, Wu L, Chen Y, Chen X, Chen J, Zheng H, Wang H, Lou Y, Ding Y, Shen S, Ye Y, Chen L, Lin Y, Huang J, Zou K, Zhang J, Bian B, Huang C, Rong C, Dai L, Xu Y, Cheng L, Chen Y, Luo Y, Zhang S, Li L. Using the synthesized peptide HAYED (5) to protect the brain against iron catalyzed radical attack in a naturally senescence Kunming mouse model. Free Radic Biol Med 2019; 130:458-470. [PMID: 30448512 DOI: 10.1016/j.freeradbiomed.2018.11.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/27/2018] [Accepted: 11/13/2018] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease of the brain. It cannot be cured currently, and those suffering from AD place a great burden on their caregivers and society. AD is characterized by high levels of iron ions in the brain, which catalyze radicals that damage the neurons. Knowing that the Aβ42 peptide precipitates iron by binding iron ions at amino acid residues D1, E3, H11, H13, and H14, we synthesized a 5-repeat (HAYED) sequence peptide. By treating iron-stressed SH-SY5Y cells with it and injecting it into the cerebrospinal fluid (CSF) of naturally senescence Kunming mouse, which displaying AD-similar symptoms such as learning and memory dysfunction, neuron degeneration and high level of iron in brain, we found that HAYED (5) decreased the iron and radical levels in the cell culture medium and in the CSF. Specially, the synthesized peptide prevented cell and brain damage. Furthermore, functional magnetic resonance imaging (fMRI), Morris water maze and passive avoidance tests demonstrated that the peptide ameliorated brain blood-oxygen metabolism and slowed cognitive loss in the experimental senescence mice, and clinical and blood tests showed that HAYED (5) was innoxious to the kidney, the liver and blood and offset the AD-associated inflammation and anemia.
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Affiliation(s)
- Zhenyou Zou
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, GX 541199, China; Medical School of Taizhou University, Taizhou, ZJ 318000, China; Biochemistry Department, Purdue University, West Lafayette, IN 47906, USA.
| | - Jing Cai
- Genetic Department of Nanjing Medical University, Nanjing, JS 210000, China
| | - Aiguo Zhong
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yong Zhou
- Clinical Laboratory of Affiliated Hospital of Taizhou University, Taizhou, ZJ 318000, China.
| | - Zengxian Wang
- Medical Image Center of Affiliated Hospital of Taizhou University, Taizhou, ZJ 318000, China.
| | - Zhongmin Wu
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yue Yang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Xin Li
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Xiaoying Cheng
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Jie Tan
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, GX 541199, China
| | - Yihao Fan
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Xiaotong Zhang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yuxiang Lu
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yaping Zhou
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Liu Yang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | | | - Qiang Zhao
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Derong Fu
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Qiqiong Shen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Jie Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Shi Bai
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Lijuan Wu
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yongfeng Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Xin Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Jiaren Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Hongjie Zheng
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Hongdian Wang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yingjie Lou
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yarong Ding
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Shiyi Shen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Ying Ye
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Lifen Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yukai Lin
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Jue Huang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Kechun Zou
- Shangli Teacher Training School, Pingxiang, JX 337009, China
| | - Jianxing Zhang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Baohua Bian
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Chengbo Huang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Cuiping Rong
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, GX 541199, China
| | - Limiao Dai
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yali Xu
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Lin Cheng
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Ye Chen
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Yewen Luo
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Shanshan Zhang
- Medical School of Taizhou University, Taizhou, ZJ 318000, China
| | - Liangxian Li
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical University, Guilin, GX 541199, China
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Intracellular Iron Chelation by a Novel Compound, C7, Reactivates Epstein⁻Barr Virus (EBV) Lytic Cycle via the ERK-Autophagy Axis in EBV-Positive Epithelial Cancers. Cancers (Basel) 2018; 10:cancers10120505. [PMID: 30544928 PMCID: PMC6316324 DOI: 10.3390/cancers10120505] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/01/2018] [Accepted: 12/06/2018] [Indexed: 12/21/2022] Open
Abstract
Pharmaceutical reactivation of lytic cycle of Epstein–Barr virus (EBV) represents a potential therapeutic strategy against EBV-associated epithelial malignancies, e.g., gastric carcinoma (GC) and nasopharyngeal carcinoma (NPC). A novel lytic-inducing compound, C7, which exhibits structural similarity to Di-2-Pyridyl Ketone 4, 4-Dimethyl-3-Thiosemicarbazone (Dp44mT), a known chelator of intracellular iron, is found to reactivate EBV lytic cycle in GC and NPC. This study aims to investigate the role of intracellular iron chelation by C7 and other iron chelators in lytic reactivation of EBV in GC and NPC. Testing of six structural analogs of C7 revealed only those which have high affinity towards transition metals could induce EBV lytic cycle. Precomplexing C7 and iron chelators to iron prior to treatment of the cells abolished EBV lytic reactivation. Though hypoxia signaling pathway was activated, it was not the only pathway associated with EBV reactivation. Specifically, C7 and iron chelators initiated autophagy by activating extracellular signal-regulated kinase (ERK1/2) to reactivate EBV lytic cycle since autophagy and EBV lytic reactivation were abolished in cells treated with ERK1/2 blockers whilst inhibition of autophagy by 3-Methyladenine (3-MA) and atg5 knockdown significantly abolished EBV lytic reactivation. In summary, we discovered a novel mechanism of reactivation of the EBV lytic cycle through intracellular iron chelation and induction of ERK-autophagy axis in EBV-positive epithelial malignancies, raising the question whether clinically available iron chelators can be incorporated into existing therapeutic regimens to treat these cancers.
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Mattingly AJ, Laitano O, Clanton TL. Epinephrine stimulates CXCL1 IL-1 α, IL-6 secretion in isolated mouse limb muscle. Physiol Rep 2018; 5. [PMID: 29192066 PMCID: PMC5727277 DOI: 10.14814/phy2.13519] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 10/27/2017] [Indexed: 12/21/2022] Open
Abstract
Catecholamines stimulate interleukin‐6 (IL‐6) secretion in skeletal muscles. However, whether other cytokines are secreted is currently unknown. Skeletal muscle ex vivo preparations commonly used to study cytokine secretion have dealt with limitations including auto‐oxidation of catecholamines. The use of metal chelators could be an alternative to avoid auto‐oxidation and allow catecholamines to be used at physiological doses. We exposed isolated soleus muscles to 1 or 100 ng/mL epinephrine (EPI) and collected bath samples at 1 and 2 h for multiplex cytokine analysis. Keratinocyte chemoattractant (CXCL1), IL‐6, and IL‐1α were significantly elevated by 100 ng/mL exposure, but not by 1 ng/mL (median [CXCL1] (2 h) = 83 pg/mL; [IL‐6] = 19 pg/mL; IL‐1α = 7.5 pg/mL). CXCL1 and IL‐6 were highly correlated in each sample (P = 0.0001). A second experiment combined the metal chelator, deferoxamine mesylate (DFO), to prevent EPI autoxidation, with 2 ng/mL EPI and 10.5 ng/mL norepinephrine (NOREPI) to mimic peak exercise. Unexpectedly, DFO alone stimulated both IL‐6 and CXCL1 secretion, but together with EPI and NOREPI had no additional effects. Stimulation of cytokine secretory responses from skeletal muscle cells in response to DFO thus precludes its use as a chelating agent in ex vivo models. In conclusion, 100 ng/mL EPI stimulates a robust secretory CXCL1 response, which together with IL‐6 and IL‐1α, may constitute an adrenal‐muscle endocrine response system.
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Affiliation(s)
- Alex J Mattingly
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, Florida
| | - Orlando Laitano
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, Florida
| | - Thomas L Clanton
- Department of Applied Physiology & Kinesiology, University of Florida, College of Health and Human Performance, Gainesville, Florida
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Ellermann M, Arthur JC. Siderophore-mediated iron acquisition and modulation of host-bacterial interactions. Free Radic Biol Med 2017; 105:68-78. [PMID: 27780750 PMCID: PMC5401654 DOI: 10.1016/j.freeradbiomed.2016.10.489] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/11/2016] [Accepted: 10/19/2016] [Indexed: 02/07/2023]
Abstract
Iron is an essential micronutrient for most life forms including the majority of resident bacteria of the microbiota and their mammalian hosts. Bacteria have evolved numerous mechanisms to competitively acquire iron within host environments, such as the secretion of small molecules known as siderophores that can solubilize iron for bacterial use. However, siderophore biosynthesis and acquisition is not a capability equally harbored by all resident bacteria. Moreover, the structural diversity of siderophores creates variability in the susceptibility to host mechanisms that serve to counteract siderophore-mediated iron acquisition and limit bacterial growth. As a result, the differential capabilities to acquire iron among members of a complex microbial community carry important implications for the growth and function of resident bacteria. Siderophores can also directly influence host function by modulating cellular iron homeostasis, further providing a mechanism by which resident bacteria may influence their local environment at the host-microbial interface. This review will explore the putative mechanisms by which siderophore production by resident bacteria in the intestines may influence microbial community dynamics and host-bacterial interactions with important implications for pathogen- and microbiota-driven diseases including infection, inflammatory bowel diseases and colorectal cancer.
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Affiliation(s)
- Melissa Ellermann
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, USA
| | - Janelle C Arthur
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, USA; Center for Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.
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25
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Cabezas-Cruz A, Alberdi P, Valdés JJ, Villar M, de la Fuente J. Anaplasma phagocytophilum Infection Subverts Carbohydrate Metabolic Pathways in the Tick Vector, Ixodes scapularis. Front Cell Infect Microbiol 2017; 7:23. [PMID: 28229048 PMCID: PMC5293764 DOI: 10.3389/fcimb.2017.00023] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
The obligate intracellular pathogen, Anaplasma phagocytophilum, is the causative agent of human, equine, and canine granulocytic anaplasmosis and tick-borne fever (TBF) in ruminants. A. phagocytophilum has become an emerging tick-borne pathogen in the United States, Europe, Africa, and Asia, with increasing numbers of infected people and animals every year. It has been recognized that intracellular pathogens manipulate host cell metabolic pathways to increase infection and transmission in both vertebrate and invertebrate hosts. However, our current knowledge on how A. phagocytophilum affect these processes in the tick vector, Ixodes scapularis is limited. In this study, a genome-wide search for components of major carbohydrate metabolic pathways was performed in I. scapularis ticks for which the genome was recently published. The enzymes involved in the seven major carbohydrate metabolic pathways glycolysis, gluconeogenesis, pentose phosphate, tricarboxylic acid cycle (TCA), glyceroneogenesis, and mitochondrial oxidative phosphorylation and β-oxidation were identified. Then, the available transcriptomics and proteomics data was used to characterize the mRNA and protein levels of I. scapularis major carbohydrate metabolic pathway components in response to A. phagocytophilum infection of tick tissues and cultured cells. The results showed that major carbohydrate metabolic pathways are conserved in ticks. A. phagocytophilum infection inhibits gluconeogenesis and mitochondrial metabolism, but increases the expression of glycolytic genes. A model was proposed to explain how A. phagocytophilum could simultaneously control tick cell glucose metabolism and cytoskeleton organization, which may be achieved in part by up-regulating and stabilizing hypoxia inducible factor 1 alpha in a hypoxia-independent manner. The present work provides a more comprehensive view of the major carbohydrate metabolic pathways involved in the response to A. phagocytophilum infection in ticks, and provides the basis for further studies to develop novel strategies for the control of granulocytic anaplasmosis.
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Affiliation(s)
- Alejandro Cabezas-Cruz
- Institute of Parasitology, Biology Center, Czech Academy of SciencesCeské Budejovice, Czechia
- Faculty of Science, University of South BohemiaCeské Budejovice, Czechia
| | - Pilar Alberdi
- SaBio. Instituto de Investigación en Recursos Cinegéticos (CSIC-UCLM-JCCM)Ciudad Real, Spain
| | - James J. Valdés
- Institute of Parasitology, Biology Center, Czech Academy of SciencesCeské Budejovice, Czechia
- Department of Virology, Veterinary Research InstituteBrno, Czechia
| | - Margarita Villar
- SaBio. Instituto de Investigación en Recursos Cinegéticos (CSIC-UCLM-JCCM)Ciudad Real, Spain
| | - José de la Fuente
- SaBio. Instituto de Investigación en Recursos Cinegéticos (CSIC-UCLM-JCCM)Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State UniversityStillwater, OK, USA
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26
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Air pollution particles and iron homeostasis. Biochim Biophys Acta Gen Subj 2016; 1860:2816-25. [PMID: 27217087 DOI: 10.1016/j.bbagen.2016.05.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 05/04/2016] [Accepted: 05/19/2016] [Indexed: 12/26/2022]
Abstract
BACKGROUND The mechanism underlying biological effects, including pro-inflammatory outcomes, of particles deposited in the lung has not been defined. MAJOR CONCLUSIONS A disruption in iron homeostasis follows exposure of cells to all particulate matter including air pollution particles. Following endocytosis, functional groups at the surface of retained particle complex iron available in the cell. In response to a reduction in concentrations of requisite iron, a functional deficiency can result intracellularly. Superoxide production by the cell exposed to a particle increases ferrireduction which facilitates import of iron with the objective being the reversal of the metal deficiency. Failure to resolve the functional iron deficiency following cell exposure to particles activates kinases and transcription factors resulting in a release of inflammatory mediators and inflammation. Tissue injury is the end product of this disruption in iron homeostasis initiated by the particle exposure. Elevation of available iron to the cell precludes deficiency of the metal and either diminishes or eliminates biological effects. GENERAL SIGNIFICANCE Recognition of the pathway for biological effects after particle exposure to involve a functional deficiency of iron suggests novel therapies such as metal supplementation (e.g. inhaled and oral). In addition, the demonstration of a shared mechanism of biological effects allows understanding the common clinical, physiological, and pathological presentation following exposure to disparate particles. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu.
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Yeoh BS, Aguilera Olvera R, Singh V, Xiao X, Kennett MJ, Joe B, Lambert JD, Vijay-Kumar M. Epigallocatechin-3-Gallate Inhibition of Myeloperoxidase and Its Counter-Regulation by Dietary Iron and Lipocalin 2 in Murine Model of Gut Inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:912-26. [PMID: 26968114 PMCID: PMC5848242 DOI: 10.1016/j.ajpath.2015.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 11/05/2015] [Accepted: 12/03/2015] [Indexed: 12/19/2022]
Abstract
Green tea-derived polyphenol (-)-epigallocatechin-3-gallate (EGCG) has been extensively studied for its antioxidant and anti-inflammatory properties in models of inflammatory bowel disease, yet the underlying molecular mechanism is not completely understood. Herein, we demonstrate that EGCG can potently inhibit the proinflammatory enzyme myeloperoxidase in vitro in a dose-dependent manner over a range of physiologic temperatures and pH values. The ability of EGCG to mediate its inhibitory activity is counter-regulated by the presence of iron and lipocalin 2. Spectral analysis indicated that EGCG prevents the peroxidase-catalyzed reaction by reverting the reactive peroxidase heme (compound I:oxoiron) back to its native inactive ferric state, possibly via the exchange of electrons. Further, administration of EGCG to dextran sodium sulfate-induced colitic mice significantly reduced the colonic myeloperoxidase activity and alleviated proinflammatory mediators associated with gut inflammation. However, the efficacy of EGCG against gut inflammation is diminished when orally coadministered with iron. These findings indicate that the ability of EGCG to inhibit myeloperoxidase activity is one of the mechanisms by which it exerts mucoprotective effects and that counter-regulatory factors such as dietary iron and luminal lipocalin 2 should be taken into consideration for optimizing clinical management strategies for inflammatory bowel disease with the use of EGCG treatment.
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Affiliation(s)
- Beng San Yeoh
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Rodrigo Aguilera Olvera
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Vishal Singh
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Xia Xiao
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Mary J Kennett
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Bina Joe
- Department of Physiology and Pharmacology, Center for Hypertension and Personalized Medicine, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Joshua D Lambert
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania
| | - Matam Vijay-Kumar
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania; Department of Medicine, The Pennsylvania State University Medical Center, Hershey, Pennsylvania.
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28
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Abstract
Siderophores are low molecular weight, high affinity iron chelating molecules that are essential virulence factors in many Gram-negative bacterial pathogens. Whereas the chemical structure of siderophores is extremely variable, the function of siderophores has been narrowly defined as the chelation and delivery of iron to bacteria for proliferation. The discovery of the host protein Lipocalin 2, capable of specifically sequestering the siderophore Enterobactin but not its glycosylated-derivative Salmochelin, indicated that diversity in structure could be an immune evasion mechanism that provides functional redundancy during infection. However, there is growing evidence that siderophores are specialized in their iron-acquisition functions, can perturb iron homeostasis in their hosts, and even bind non-iron metals to promote bacterial fitness. The combination of siderophores produced by a pathogen can enable inter-bacterial competition, modulate host cellular pathways, and determine the bacterial "replicative niche" during infection. This review will examine both classical and novel functions of siderophores to address the concept that siderophores are non-redundant virulence factors used to enhance bacterial pathogenesis.
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Affiliation(s)
- Victoria I Holden
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
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29
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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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30
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El Sayed SM, Baghdadi H, Abou-Taleb A, Mahmoud HS, Maria RA, Ahmed NS, Helmy Nabo MM. Al-hijamah and oral honey for treating thalassemia, conditions of iron overload, and hyperferremia: toward improving the therapeutic outcomes. J Blood Med 2014; 5:219-37. [PMID: 25382989 PMCID: PMC4222535 DOI: 10.2147/jbm.s65042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Iron overload causes iron deposition and accumulation in the liver, heart, skin, and other tissues resulting in serious tissue damages. Significant blood clearance from iron and ferritin using wet cupping therapy (WCT) has been reported. WCT is an excretory form of treatment that needs more research efforts. WCT is an available, safe, simple, economic, and time-saving outpatient modality of treatment that has no serious side effects. There are no serious limitations or precautions to discontinue WCT. Interestingly, WCT has solid scientific and medical bases (Taibah mechanism) that explain its effectiveness in treating many disease conditions differing in etiology and pathogenesis. WCT utilizes an excretory physiological principle (pressure-dependent excretion) that resembles excretion through renal glomerular filtration and abscess evacuation. WCT exhibits a percutaneous excretory function that clears blood (through fenestrated skin capillaries) and interstitial fluids from pathological substances without adding a metabolic or detoxification burden on the liver and the kidneys. Interestingly, WCT was reported to decrease serum ferritin (circulating iron stores) significantly by about 22.25% in healthy subjects (in one session) and to decrease serum iron significantly to the level of causing iron deficiency (in multiple sessions). WCT was reported to clear blood significantly of triglycerides, low-density lipoprotein (LDL) cholesterol, total cholesterol, uric acid, inflammatory mediators, and immunoglobulin antibodies (rheumatoid factor). Moreover, WCT was reported to enhance the natural immunity, potentiate pharmacological treatments, and to treat many different disease conditions. There are two distinct methods of WCT: traditional WCT and Al-hijamah (WCT of prophetic medicine). Both start and end with skin sterilization. In traditional WCT, there are two steps, skin scarification followed by suction using plastic cups (double S technique); Al-hijamah is a three-step procedure that includes skin suction using cups, scarification (shartat mihjam in Arabic), and second skin suction (triple S technique). Al-hijamah is a more comprehensive technique and does better than traditional WCT, as Al-hijamah includes two pressure-dependent filtration steps versus one step in traditional WCT. Whenever blood plasma is to be cleared of an excess pathological substance, Al-hijamah is indicated. We will discuss here some reported hematological and therapeutic benefits of Al-hijamah, its medical bases, methodologies, precautions, side effects, contraindications, quantitative evaluation, malpractice, combination with oral honey treatment, and to what extent it may be helpful when treating thalassemia and other conditions of iron overload and hyperferremia.
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Affiliation(s)
- Salah Mohamed El Sayed
- Department of Medical Biochemistry, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt ; Department of Clinical Biochemistry and Molecular Medicine, Taibah Faculty of Medicine, Taibah University, Al-Madinah Al-Munawwarah, Kingdom of Saudi Arabia
| | - Hussam Baghdadi
- Department of Clinical Biochemistry and Molecular Medicine, Taibah Faculty of Medicine, Taibah University, Al-Madinah Al-Munawwarah, Kingdom of Saudi Arabia
| | - Ashraf Abou-Taleb
- Department of Pediatrics, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Hany Salah Mahmoud
- World Federation of Alternative and Complementary Medicine, Cairo Regional Headquarter, Cairo, Egypt
| | - Reham A Maria
- Department of Clinical Biochemistry and Molecular Medicine, Taibah Faculty of Medicine, Taibah University, Al-Madinah Al-Munawwarah, Kingdom of Saudi Arabia ; Department of Medical Biochemistry, Tanta Faulty of Medicine, Tanta University, Tanta, Egypt
| | - Nagwa S Ahmed
- Department of Medical Biochemistry, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Manal Mohamed Helmy Nabo
- Department of Pediatrics, Sohag Teaching Hospital, Sohag, Egypt ; Division of Pediatric Cardiology, Department of Pediatrics, Maternity and Children Hospital, King Abdullah Medical City, Al-Madinah Al-Munawwarah, Kingdom of Saudi Arabia
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Bacterial siderophores that evade or overwhelm lipocalin 2 induce hypoxia inducible factor 1α and proinflammatory cytokine secretion in cultured respiratory epithelial cells. Infect Immun 2014; 82:3826-36. [PMID: 24980968 DOI: 10.1128/iai.01849-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Iron is essential for many cellular processes and is required by bacteria for replication. To acquire iron from the host, pathogenic Gram-negative bacteria secrete siderophores, including enterobactin (Ent). However, Ent is bound by the host protein lipocalin 2 (Lcn2), preventing bacterial reuptake of aferric or ferric Ent. Furthermore, the combination of Ent and Lcn2 (Ent+Lcn2) leads to enhanced secretion of interleukin-8 (IL-8) compared to that induced by either stimulus alone. Modified or structurally distinct siderophores, including yersiniabactin (Ybt) and glycosylated Ent (GlyEnt, or salmochelin), deliver iron to bacteria despite the presence of Lcn2. We hypothesized that the robust immune response to Ent and Lcn2 requires iron chelation rather than the Ent+Lcn2 complex itself and also can be stimulated by Lcn2-evasive siderophores. To test this hypothesis, cultured respiratory epithelial cells were stimulated with combinations of purified siderophores and Lcn2 and analyzed by gene expression microarrays, quantitative PCR, and cytokine immunoassays. Ent caused HIF-1α protein stabilization, induced the expression of genes regulated by hypoxia-inducible factor 1α (HIF-1α), and repressed genes involved in cell cycle and DNA replication, whereas Lcn2 induced expression of proinflammatory cytokines. Iron chelation by excess Ent or Ybt significantly increased Lcn2-induced secretion of IL-8, IL-6, and CCL20. Stabilization of HIF-1α was sufficient to enhance Lcn2-induced IL-6 secretion. These data indicate that respiratory epithelial cells can respond to bacterial siderophores that evade or overwhelm Lcn2 binding by increasing proinflammatory cytokine production.
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32
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Aznar A, Chen NW, Rigault M, Riache N, Joseph D, Desmaële D, Mouille G, Boutet S, Soubigou-Taconnat L, Renou JP, Thomine S, Expert D, Dellagi A. Scavenging iron: a novel mechanism of plant immunity activation by microbial siderophores. PLANT PHYSIOLOGY 2014; 164:2167-83. [PMID: 24501001 PMCID: PMC3982770 DOI: 10.1104/pp.113.233585] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H₂O₂ staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity.
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Ghio AJ, Tong H, Soukup JM, Dailey LA, Cheng WY, Samet JM, Kesic MJ, Bromberg PA, Turi JL, Upadhyay D, Scott Budinger GR, Mutlu GM. Sequestration of mitochondrial iron by silica particle initiates a biological effect. Am J Physiol Lung Cell Mol Physiol 2013; 305:L712-24. [DOI: 10.1152/ajplung.00099.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Inhalation of particulate matter has presented a challenge to human health for thousands of years. The underlying mechanism for biological effect following particle exposure is incompletely understood. We tested the postulate that particle sequestration of cell and mitochondrial iron is a pivotal event mediating oxidant generation and biological effect. In vitro exposure of human bronchial epithelial cells to silica reduced intracellular iron, which resulted in increases in both the importer divalent metal transporter 1 expression and metal uptake. Diminished mitochondrial 57Fe concentrations following silica exposure confirmed particle sequestration of cell iron. Preincubation of cells with excess ferric ammonium citrate increased cell, nuclear, and mitochondrial metal concentrations and prevented significant iron loss from mitochondria following silica exposure. Cell and mitochondrial oxidant generation increased after silica incubation, but pretreatment with iron diminished this generation of reactive oxygen species. Silica exposure activated MAP kinases (ERK and p38) and altered the expression of transcription factors (nF-κB and NF-E2-related factor 2), proinflammatory cytokines (interleukin-8 and -6), and apoptotic proteins. All of these changes in indexes of biological effect were either diminished or inhibited by cell pretreatment with iron. Finally, percentage of neutrophils and total protein concentrations in an animal model instilled with silica were decreased by concurrent exposure to iron. We conclude that an initiating event in the response to particulate matter is a sequestration of cell and mitochondrial iron by endocytosed particle. The resultant oxidative stress and biological response after particle exposure are either diminished or inhibited by increasing the cell iron concentration.
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Affiliation(s)
- Andrew J. Ghio
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Chapel Hill, North Carolina
| | - Haiyan Tong
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Chapel Hill, North Carolina
| | - Joleen M. Soukup
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Chapel Hill, North Carolina
| | - Lisa A. Dailey
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Chapel Hill, North Carolina
| | - Wan-Yun Cheng
- Department of Environmental Sciences and Engineering, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | - James M. Samet
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Chapel Hill, North Carolina
| | - Matthew J. Kesic
- Center for Environmental Medicine, Asthma, and Lung Biology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | | | - Jennifer L. Turi
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina
| | - Daya Upadhyay
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Stanford University Medical Center, Stanford, California; and
| | - G. R. Scott Budinger
- Division of Pulmonary and Critical Care Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Gökhan M. Mutlu
- Division of Pulmonary and Critical Care Medicine, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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Yousef M, Pichyangkura R, Soodvilai S, Chatsudthipong V, Muanprasat C. Chitosan oligosaccharide as potential therapy of inflammatory bowel disease: therapeutic efficacy and possible mechanisms of action. Pharmacol Res 2012; 66:66-79. [PMID: 22475725 DOI: 10.1016/j.phrs.2012.03.013] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/08/2012] [Accepted: 03/19/2012] [Indexed: 12/31/2022]
Abstract
Inflammatory bowel disease (IBD) results from intestinal epithelial barrier defect and dysregulated mucosal immune response. This study aimed to evaluate the therapeutic potential of chitosan oligosaccharide (COS), a biodegradation product of dietary fiber chitosan, in the treatment of IBD and to elucidate its possible mechanisms of action. Oral administration of COS protected against mortality and intestinal inflammation in a mouse model of acute colitis induced by 5% dextran sulfate sodium (DSS). The most effective dose range of COS was 10-20 mg/kg/day. In addition, nuclear factor kappa B (NF-κB) activation, and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in colonic tissues were suppressed in mice receiving COS. Similar protective effect of COS against mortality and intestinal inflammation was observed in another mouse model of acute colitis induced by rectal instillation of 4% acetic acid. Importantly, COS administration after colitis induction was effective in ameliorating intestinal inflammation in both acute colitis models induced by 5% DSS and chronic colitis models induced by cycles of 2.5% DSS. In human colonic epithelial cells (T84 cells), COS treatment prevented NF-κB activation, production of TNF-α and IL-6, and loss of epithelial barrier integrity under both lipopolysaccharide (LPS) and TNF-α-stimulated conditions. Furthermore, binding of LPS to T84 cells, and TNF-α and oxidative stress-induced apoptosis of T84 cells were prevented by treatment with COS. These results suggest that COS may be effective in the treatment of IBD through inhibition of NF-κB signaling and apoptosis of intestinal epithelial cells.
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Affiliation(s)
- Mohammad Yousef
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
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Percy ME, Kruck TPA, Pogue AI, Lukiw WJ. Towards the prevention of potential aluminum toxic effects and an effective treatment for Alzheimer's disease. J Inorg Biochem 2011; 105:1505-12. [PMID: 22099160 PMCID: PMC3714848 DOI: 10.1016/j.jinorgbio.2011.08.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 07/31/2011] [Accepted: 08/01/2011] [Indexed: 01/19/2023]
Abstract
In 1991, treatment with low dose intramuscular desferrioxamine (DFO), a trivalent chelator that can remove excessive iron and/or aluminum from the body, was reported to slow the progression of Alzheimer's disease (AD) by a factor of two. Twenty years later this promising trial has not been followed up and why this treatment worked still is not clear. In this critical interdisciplinary review, we provide an overview of the complexities of AD and involvement of metal ions, and revisit the neglected DFO trial. We discuss research done by us and others that is helping to explain involvement of metal ion catalyzed production of reactive oxygen species in the pathogenesis of AD, and emerging strategies for inhibition of metal-ion toxicity. Highlighted are insights to be considered in the quests to prevent potentially toxic effects of aluminum toxicity and prevention and intervention in AD.
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Affiliation(s)
- Maire E Percy
- Neurogenetics Laboratory, Surrey Place Centre, Toronto, ON, Canada M5S 2C2.
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Fan Y, Wang J, Wei L, He B, Wang C, Wang B. Iron deficiency activates pro-inflammatory signaling in macrophages and foam cells via the p38 MAPK-NF-κB pathway. Int J Cardiol 2011; 152:49-55. [DOI: 10.1016/j.ijcard.2010.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 05/18/2010] [Accepted: 07/02/2010] [Indexed: 01/19/2023]
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Abstract
The divalent metal ion transporter DMT1 is critical for nonheme iron import. We have previously shown that DMT1 is regulated in vitro by ubiquitination that is facilitated by the adaptor proteins Ndfip1 and Ndfip2. Here we report that in Ndfip1(-/-) mice fed a low- iron diet, DMT1 expression and activity in duodenal enterocytes are significant higher than in the wild-type animals. This correlates with an increase in serum iron levels and transferrin saturation. Liver and spleen iron stores were also increased in Ndfip1(-/-) mice fed a normal diet. Counterintuitive to the increase in iron uptake, Ndfip1(-/-) mice fed a low iron diet develop severe microcytic, hypochromic anemia. We demonstrate that this is due to a combination of iron deficiency and inflammatory disease in Ndfip1(-/-) mice, because Ndfip1(-/-)/Rag1(-/-) immunodeficient mice fed a low iron diet did not develop anemia and showed an iron overload phenotype. These data demonstrate that Ndfip1 is a critical mediator of DMT1 regulation in vivo, particularly under iron restricted conditions.
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Fetherston JD, Kirillina O, Bobrov AG, Paulley JT, Perry RD. The yersiniabactin transport system is critical for the pathogenesis of bubonic and pneumonic plague. Infect Immun 2010; 78:2045-52. [PMID: 20160020 PMCID: PMC2863531 DOI: 10.1128/iai.01236-09] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 11/30/2009] [Accepted: 02/04/2010] [Indexed: 01/18/2023] Open
Abstract
Iron acquisition from the host is an important step in the pathogenic process. While Yersinia pestis has multiple iron transporters, the yersiniabactin (Ybt) siderophore-dependent system plays a major role in iron acquisition in vitro and in vivo. In this study, we determined that the Ybt system is required for the use of iron bound by transferrin and lactoferrin and examined the importance of the Ybt system for virulence in mouse models of bubonic and pneumonic plague. Y. pestis mutants unable to either transport Ybt or synthesize the siderophore were both essentially avirulent via subcutaneous injection (bubonic plague model). Surprisingly, via intranasal instillation (pneumonic plague model), we saw a difference in the virulence of Ybt biosynthetic and transport mutants. Ybt biosynthetic mutants displayed an approximately 24-fold-higher 50% lethal dose (LD(50)) than transport mutants. In contrast, under iron-restricted conditions in vitro, a Ybt transport mutant had a more severe growth defect than the Ybt biosynthetic mutant. Finally, a Delta pgm mutant had a greater loss of virulence than the Ybt biosynthetic mutant, indicating that the 102-kb pgm locus encodes a virulence factor, in addition to Ybt, that plays a role in the pathogenesis of pneumonic plague.
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Affiliation(s)
- Jacqueline D. Fetherston
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0298
| | - Olga Kirillina
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0298
| | - Alexander G. Bobrov
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0298
| | - James T. Paulley
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0298
| | - Robert D. Perry
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536-0298
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Mukerji SS, Rainey RN, Rhodes JL, Hall AK. Delayed activin A administration attenuates tissue death after transient focal cerebral ischemia and is associated with decreased stress-responsive kinase activation. J Neurochem 2009; 111:1138-48. [PMID: 19780899 DOI: 10.1111/j.1471-4159.2009.06406.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Focal cerebral ischemia and reperfusion initiates complex cellular and molecular interactions that lead to either cell repair or destruction. In earlier work, we found that activin A is an early gene response to cerebral ischemia and supports cortical neuron survival in vitro. In this study, the ability of exogenous activin A to attenuate injury from transient middle cerebral artery occlusion was tested in adult mice. Intracerebroventricular administration of activin A prior to middle cerebral artery occlusion reduced infarct volume apparent 1 day after experimental stroke. A single activin A administration at 6 h following ischemia/reperfusion reduced lesion volumes at 1 and 3 days and led to improved neurobehavior. Moreover, activin A treatment spared neurons within the ischemic hemisphere and led to a concomitant reduction in microglial activation. Activation of the stress-responsive kinases p38 and c-jun N-terminal kinase implicated in neuronal apoptosis after stroke was reduced following activin A treatment. Together these findings suggest that activin A promotes tissue survival after focal cerebral ischemia/reperfusion with an extended therapeutic window.
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Affiliation(s)
- Shibani S Mukerji
- Department of Neuroscience, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA
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Persistently elevated level of IL-8 in Chlamydia trachomatis infected HeLa 229 cells is dependent on intracellular available iron. Mediators Inflamm 2009; 2009:417658. [PMID: 19503841 PMCID: PMC2686236 DOI: 10.1155/2009/417658] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 04/16/2009] [Indexed: 11/17/2022] Open
Abstract
Chlamydia trachomatis is a leading cause of sexually transmitted infection worldwide and responsible for myriad of immunopathological changes associated with reproductive health. Delayed secretion of proinflammatory chemokine interleukin (IL)-8 is a hallmark of chlamydial infection and is dependent on chlamydial growth. We examined the effect of iron chelators on IL-8 production in HeLa 229 (cervix epitheloid cell, CCL2) cells infected with C. trachomatis. IL-8 production was induced by Iron chelator DFO and Mimosine, however, synergy with chlamydial infection was obtained with DFO only. Temporal expression of proinflammatory secreted cytokines IL-1beta, TNF-alpha, and IL-8 did not show synchrony in Chlamydia trachomatis infected cells. Secretion of IL-8 from Hela cells infected with C. trachomatis was not dependent on IL-1 beta and TNF- alpha induction. These results indicate towards involvement of iron in chlamydia induced IL-8 production.
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Purification of Legiobactin and importance of this siderophore in lung infection by Legionella pneumophila. Infect Immun 2009; 77:2887-95. [PMID: 19398549 DOI: 10.1128/iai.00087-09] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When cultured in a low-iron medium, Legionella pneumophila secretes a siderophore (legiobactin) that is both reactive in the chrome azurol S (CAS) assay and capable of stimulating the growth of iron-starved legionellae. Using anion-exchange high-pressure liquid chromatography (HPLC), we purified legiobactin from culture supernatants of a virulent strain of L. pneumophila. In the process, we detected the ferrated form of legiobactin as well as other CAS-reactive substances. Purified legiobactin had a yellow-gold color and absorbed primarily from 220 nm and below. In accordance, nuclear magnetic resonance spectroscopy revealed that legiobactin lacks aromatic carbons, and among the 13 aliphatics present, there were 3 carbonyls. When examined by HPLC, supernatants from L. pneumophila mutants inactivated for lbtA and lbtB completely lacked legiobactin, indicating that the LbtA and LbtB proteins are absolutely required for siderophore activity. Independently derived lbtA mutants, but not a complemented derivative, displayed a reduced ability to infect the lungs of A/J mice after intratracheal inoculation, indicating that legiobactin is required for optimal intrapulmonary survival by L. pneumophila. This defect, however, was not evident when the lbtA mutant and its parental strain were coinoculated into the lung, indicating that legiobactin secreted by the wild type can promote growth of the mutant in trans. Legiobactin mutants grew normally in murine lung macrophages and alveolar epithelial cells, suggesting that legiobactin promotes something other than intracellular infection of resident lung cells. Overall, these data represent the first documentation of a role for siderophore expression in the virulence of L. pneumophila.
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Wang L, Cherayil BJ. Ironing out the wrinkles in host defense: interactions between iron homeostasis and innate immunity. J Innate Immun 2009; 1:455-64. [PMID: 20375603 DOI: 10.1159/000210016] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 01/16/2009] [Indexed: 12/15/2022] Open
Abstract
Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Recent advances in our understanding of the molecular regulation of iron metabolism have shed new light on how alterations in iron homeostasis both contribute to and influence innate immunity. In this article, we review what is currently known about the role of iron in the response to infection.
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Affiliation(s)
- Lijian Wang
- Mucosal Immunology Laboratory, Massachusetts General Hospital, Charlestown, MA, USA
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Potier E, Ferreira E, Dennler S, Mauviel A, Oudina K, Logeart-Avramoglou D, Petite H. Desferrioxamine-driven upregulation of angiogenic factor expression by human bone marrow stromal cells. J Tissue Eng Regen Med 2008; 2:272-8. [PMID: 18512268 DOI: 10.1002/term.92] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bone marrow stromal cells (BMSCs) are the subject of intense research because of their biological properties and potential use for the repair of damaged tissues. Success of BMSC-based therapies, however, relies on a number of methodological improvements, including the establishment of a vascular network providing nutrients and oxygen to the transplanted cells and ensuring their immediate survival and long-term functionality. We described a method to enhance the autocrine expression of angiogenic factors by BMSCs. For this purpose, human BMSCs were treated with desferrioxamine (DFX). No PDGF-BB, VEGF-R1 or -R2 mRNA expression was detected under any of the conditions tested. mRNA and protein expression levels of TGFbeta1 were similar in BMSCs, whether they were exposed to DFX (50 microM) or to control conditions under normoxia for 48 h. In comparison with the results obtained with control conditions under normoxia, exposure of BMSCs to DFX for 48 h resulted in upregulation of bFGF at the protein (26-fold) but not at the mRNA levels and VEGF at both the mRNA (1.5-fold) and protein levels (4.5-fold). In comparison with the results obtained with control conditions under hypoxia, DFX induced a 50% increase in VEGF secretion but led to the same level of hypoxia inducible factor-1alpha protein expression (a transduction factor involved in angiogenic factor expression and known to be activated by DFX). Exposure of BMSCs to DFX resulted in oversecretion of angiogenic factors, suggesting that DFX-treated BMSCs could be used to supply angiogenic factors.
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Affiliation(s)
- Esther Potier
- Université Denis Diderot Paris VII, Laboratoire de Recherches Orthopédiques (B2OA), UMR CNRS 7052, Paris, France.
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Lee SK, Lee J, Min SK, Won DH, Lee YM, Lim HD, Lee W, Pae HO, Chung HT, Jun CD, Lee SK, Kim EC. Iron chelator differentially activates macrophage inflammatory protein-3α/CCL20 in immortalized and malignant human oral keratinocytes. Arch Oral Biol 2008; 53:801-9. [DOI: 10.1016/j.archoralbio.2008.01.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 01/22/2008] [Accepted: 01/28/2008] [Indexed: 11/16/2022]
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Lee HJ, Lee J, Lee SK, Lee SK, Kim EC. Differential regulation of iron chelator-induced IL-8 synthesis via MAP kinase and NF-kappaB in immortalized and malignant oral keratinocytes. BMC Cancer 2007; 7:176. [PMID: 17850672 PMCID: PMC2078595 DOI: 10.1186/1471-2407-7-176] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Accepted: 09/13/2007] [Indexed: 11/24/2022] Open
Abstract
Background Interleukin-8 (IL-8) is a cytokine that plays an important role in tumor progression in a variety of cancer types; however, its regulation is not well understood in oral cancer cells. In the present study, we examined the expression and mechanism of IL-8 in which it is involved by treating immortalized (IHOK) and malignant human oral keratinocytes (HN12) cells with deferoxamine (DFO). Methods IL-8 production was measured by an enzyme-linked immunoabsorbent assay and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Electrophoretic mobility shift assays was used to determine NF-κB binding activity. Phosphorylation and degradation of the I-κB were analyized by Western blot. Results IHOK cells incubated with DFO showed increased expression of IL-8 mRNA, as well as higher release of the IL-8 protein. The up-regulation of DFO-induced IL-8 expression was higher in IHOK cells than in HN12 cells and was concentration-dependent. DFO acted additively with IL-1β to strongly up-regulate IL-8 in IHOK cells but not in HN12 cells. Accordingly, selective p38 and ERK1/2 inhibitors for both kinases abolished DFO-induced IL-8 expression in both IHOK and HN12 cells. Furthermore, DFO induced the degradation and phosphorylation of IκB, and activation of NF-κB. The IL-8 inducing effects of DFO were mediated by a nitric oxide donor (S-nitrosoglutathione), and by pyrrolidine dithiocarbamate, an inhibitor of NF-κB, as well as by wortmannin, which inhibits the phosphatidylinositol 3-kinase-dependent activation of NAD(P)H oxidase. Conclusion This results demonstrate that DFO-induced IL-8 acts via multiple signaling pathways in immortalized and malignant oral keratinocytes, and that the control of IL-8 may be an important target for immunotheraphy against human oral premalignant lesions.
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Affiliation(s)
- Hwa-Jeong Lee
- Department of Oral & Maxillofacial Pathology, College of Dentistry, Wonkwang University, Iksan, Republic of Korea
| | - Jun Lee
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Wonkwang University, Iksan, Republic of Korea
| | - Sun-Kyung Lee
- Department of Oral & Maxillofacial Pathology, College of Dentistry, Wonkwang University, Iksan, Republic of Korea
| | - Suk-Keun Lee
- Department of Oral Pathology, College of Dentistry, Kangnung National University, Gangneung, Republic of Korea
| | - Eun-Cheol Kim
- Department of Oral & Maxillofacial Pathology, College of Dentistry, Wonkwang University, Iksan, Republic of Korea
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Nelson AL, Ratner AJ, Barasch J, Weiser JN. Interleukin-8 secretion in response to aferric enterobactin is potentiated by siderocalin. Infect Immun 2007; 75:3160-8. [PMID: 17420239 PMCID: PMC1932857 DOI: 10.1128/iai.01719-06] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Siderophores are low-molecular-weight iron chelators secreted by microbes to obtain iron under deprivation. We hypothesized that the catecholate siderophore enterobactin, produced by Enterobacteriaceae, serves as a proinflammatory signal for respiratory epithelial cells. Respiratory tract responses were explored, since at this site siderocalin, an enterobactin-binding mammalian gene product, is expressed inducibly at high levels and enterobactin-secreting respiratory flora is rare, suggesting selection against a dependence on enterobactin. Addition of aferric, but not iron-saturated, enterobactin elicits a dose-dependent increase in secretion of the proinflammatory chemokine interleukin-8 by human respiratory epithelial cells in culture. This response to purified enterobactin is potentiated by recombinant siderocalin at physiologically relevant concentrations. Conditioned media from genetically modified Escherichia coli strains expressing various levels of enterobactin induce an enterobactin-mediated proinflammatory response. Siderocalin has been shown to deliver enterobactin to other mammalian cell types, exogenously supplied siderocalin can be detected within epithelial cells, and siderocalin increases delivery of enterobactin to the intracellular compartment. Although many siderophores perturb labile cellular iron pools, only enterobactin elicits interleukin-8 secretion, suggesting that iron chelation is necessary but not sufficient. Thus, aferric enterobactin may be a proinflammatory signal for respiratory epithelial cells, permitting detection of microbial communities that have disturbed local iron homeostasis, and siderocalin expression by the host amplifies this signal. This may be a novel mechanism for the mucosa to respond to metabolic signals of expanding microbial communities.
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Affiliation(s)
- Aaron L Nelson
- Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104-6076, USA
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Markel TA, Crisostomo PR, Wang M, Herring CM, Lahm T, Meldrum KK, Lillemoe KD, Rescorla FJ, Meldrum DR. Iron chelation acutely stimulates fetal human intestinal cell production of IL-6 and VEGF while decreasing HGF: the roles of p38, ERK, and JNK MAPK signaling. Am J Physiol Gastrointest Liver Physiol 2007; 292:G958-63. [PMID: 17204543 DOI: 10.1152/ajpgi.00502.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Bacteria have developed mechanisms to sequester host iron via chelators such as deferoxamine (DFO). Interestingly, DFO has been shown to stimulate acute intestinal epithelial cell inflammatory cytokine production in the absence of bacteria; however, this mechanism has not been elucidated. Intestinal epithelial cell production of IL-6 and TNF-alpha is elevated in various gastrointestinal pathologies, including acute intestinal ischemia. Similarly, VEGF and HGF are essential to intestinal epithelial cell integrity. Therapeutic strategies that decrease IL-6 and TNF-alpha while increasing VEGF and HGF therefore have theoretical appeal. We hypothesized that 1) fetal human intestinal epithelial cells acutely produce increased IL-6, TNF-alpha, VEGF, and HGF during iron chelation and 2) the MAPK pathway mediates these effects. Fetal human intestinal epithelial cells were stimulated by iron chelation (1 mM DFO) with and without p38 MAPK, ERK, or JNK inhibition. Supernatants were harvested after 24 h of incubation, and IL-6, TNF-alpha, VEGF, and HGF levels were quantified by ELISA. Activation of MAPK pathways was confirmed by Western blot analysis. DFO stimulation resulted in a significant increase in epithelial cell IL-6 and VEGF production while yielding a decrease in HGF production (P<0.05). Unexpectedly, TNF-alpha was not detectable. p38 MAPK, ERK, and JNK inhibition significantly decreased IL-6, VEGF, and HGF production (P<0.05). In conclusion, DFO acutely increases fetal human intestinal epithelial cell IL-6 and VEGF expression while causing an unexpected decrease in HGF expression and no detectable TNF-alpha production. Furthermore, chelator-induced intestinal epithelial cell cytokine expression depends on p38, ERK, and JNK MAPK pathways.
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Affiliation(s)
- Troy A Markel
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Megías J, Busserolles J, Alcaraz MJ. The carbon monoxide-releasing molecule CORM-2 inhibits the inflammatory response induced by cytokines in Caco-2 cells. Br J Pharmacol 2007; 150:977-86. [PMID: 17339836 PMCID: PMC2013913 DOI: 10.1038/sj.bjp.0707184] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Recent evidence indicates that carbon monoxide-releasing molecules (CO-RMs) exhibit potential anti-inflammatory properties. In the present study, we have investigated whether tricarbonyl dichloro ruthenium(II) dimer (CORM-2) can control the inflammatory response induced by cytokines in a human colonic epithelial cell line, Caco-2. EXPERIMENTAL APPROACH Caco-2 cells were preincubated with CORM-2 for 30 minutes and then stimulated with interleukin (IL)-1beta, tumor necrosis factor-alpha and interferon-gamma for different times. Gene expression was analyzed by real-time PCR. Protein expression was investigated by Western blot and ELISA. Transcription factor activation was determined by the luciferase method. KEY RESULTS We have shown that CORM-2 significantly decreased the mRNA expression of nitric oxide synthase-2 (NOS-2) and the production of nitrite, in Caco-2 cells stimulated with cytokines. IL-8, IL-6 and metalloproteinase-7 (MMP-7) mRNA and protein were also significantly reduced by CORM-2. Time-course and small interfering RNA studies suggest that inhibition of IL-6 plays a role in the regulation of MMP-7 expression by CORM-2. These effects of CORM-2 can be dependent on the modulation of nuclear factor-kappaB (NF-kappaB), activator protein-1, CCAT/enhancer binding protein and the phosphorylated forms of NF-kappaB inhibitory protein-alpha, c-Jun N-terminal protein kinase 1/2, p38 and extracellular signal-regulated kinase 1/2. CONCLUSIONS AND IMPLICATIONS CORM-2 can regulate a number of genes relevant in intestinal inflammation and cancer progression. These findings provide new insights into the anti-inflammatory properties and potential applications of this class of compounds.
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Affiliation(s)
- J Megías
- Department of Pharmacology, University of Valencia, Burjasot, Valencia, Spain
| | - J Busserolles
- Department of Pharmacology, University of Valencia, Burjasot, Valencia, Spain
| | - M J Alcaraz
- Department of Pharmacology, University of Valencia, Burjasot, Valencia, Spain
- Author for correspondence:
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Markel TA, Crisostomo PR, Wang M, Herring CM, Meldrum KK, Lillemoe KD, Meldrum DR. The struggle for iron: gastrointestinal microbes modulate the host immune response during infection. J Leukoc Biol 2007; 81:393-400. [PMID: 17255516 DOI: 10.1189/jlb.0906579] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The gastrointestinal track is one source of potential bacterial entry into the host, and the local immune system at the mucosal border is paramount in establishing host immune tolerance and the immune response to invading organisms. Macrophages use iron for production of hydroxy-radical and superoxide reactions, which are necessary for microbial killing. Presumably, as a survival strategy, bacteria, which also require iron for survival, have adapted the ability to sequester iron from the host, thereby limiting the availability to macrophages. As current modes of antimicrobial therapy are evolving, examination of nontraditional therapies is emerging. One such potential therapy involves altering the bacterial micronutrient iron concentration. Necrotizing enterocolitis is a clinical condition where such a strategy makes intuitive sense. This review will describe the immune response to gastrointestinal infection, the mechanisms that the gastrointestinal system uses to absorb intraluminal iron, and the critical role iron plays in the infectious process.
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Affiliation(s)
- Troy A Markel
- Department of Surgery, Indiana University School of Medicine, Emerson Hall 215, Indianapolis, IN 46202, USA
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Liu G, Greenshields DL, Sammynaiken R, Hirji RN, Selvaraj G, Wei Y. Targeted alterations in iron homeostasis underlie plant defense responses. J Cell Sci 2007; 120:596-605. [PMID: 17244651 DOI: 10.1242/jcs.001362] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Iron (Fe) is a ubiquitous redox-active element essential for most life. The formation of localized cell wall appositions, the oxidative burst and the production of pathogenesis-related proteins are hallmarks of plant defense responses. Here, we report that iron is a central mediator linking these three phenomena. We show that in response to pathogen attack, reactive Fe3+, but not Fe2+, is deposited at cell wall appositions where it accumulates and mediates the oxidative burst. We provide evidence that the bulk secretion of Fe3+ provoked by pathogen attack leads to intracellular iron depletion, and that H2O2 itself induces ATP-dependent intracellular iron efflux. Finally, we demonstrate that this intracellular iron depletion promotes the transcription of pathogenesis-related genes in concert with H2O2. This work identifies iron as an underlying factor associated with the oxidative burst and regulating cereal defenses, and establishes links between disease-related iron homeostasis in plants and animals.
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Affiliation(s)
- Guosheng Liu
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada
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