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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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2
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Li H, Liu Y, Liu Y, Xu L, Sun Z, Zheng D, Liu X, Song C, Zhang Y, Liang H, Yang B, Tian X, Luo J, Chang Q. Tumor-associated astrocytes promote tumor progression of Sonic Hedgehog medulloblastoma by secreting lipocalin-2. Brain Pathol 2024; 34:e13212. [PMID: 37721122 PMCID: PMC10711256 DOI: 10.1111/bpa.13212] [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: 03/19/2023] [Accepted: 08/28/2023] [Indexed: 09/19/2023] Open
Abstract
Sonic Hedgehog (SHH) subgroup of medulloblastoma (MB) accounts for about 25% of all subgroups of MB. Tumor microenvironment (TME) may play a key role in the tumor progression and therapeutic resistance. Tumor-associated astrocytes (TAAs) are reshaped to drive tumor progression through multiple paracrine signals. However, the mechanism by which TAAs modulate MB cells remains elusive. Here, we illuminated that TAAs showed a specific and dynamic pattern during SHH-MB development. Most TAAs gathered to the tumor margin during the tumor progression, rather than evenly distributed in the early-stage tumors. We further demonstrated that lipocalin-2 (LCN2) secreted by TAAs could promote the tumor growth and was correlated with the poor prognosis of MB patients. Knocking down LCN2 in TAAs in vitro impeded the proliferation and migration abilities of MB cells. In addition, we identified that TAAs accelerated the tumor growth by secreting LCN2 via STAT3 signaling pathway. Accordingly, blockade of STAT3 signaling by its inhibitor WP1066 and AAV-Lcn2 shRNA, respectively, in TAAs abrogated the effects of LCN2 on tumor progression in vitro and in vivo. In summary, we for the first time clarified that LCN2, secreted by TAAs, could promote MB tumor progression via STAT3 pathway and has potential prognostic value. Our findings unveiled a new sight in reprogramming the TME of SHH-MB and provided a potential therapeutic strategy targeting TAAs.
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Affiliation(s)
- Haishuang Li
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
- Department of Neuropathology, Beijing Neurosurgical Institute, Tiantan HospitalCapital Medical UniversityBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Yuqing Liu
- Department of Neuropathology, Beijing Neurosurgical Institute, Tiantan HospitalCapital Medical UniversityBeijingChina
| | - Yantao Liu
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
- Department of Neuropathology, Beijing Neurosurgical Institute, Tiantan HospitalCapital Medical UniversityBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Luzheng Xu
- Department of Medical and Health Analysis CenterPeking University Health Science CenterBeijingChina
| | - Ziwen Sun
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
- Department of Neuropathology, Beijing Neurosurgical Institute, Tiantan HospitalCapital Medical UniversityBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Danfeng Zheng
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Xiaodan Liu
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Chen Song
- Department of Medical Genetics, Center for Medical GeneticsPeking University Health Science CenterBeijingChina
| | - Yu Zhang
- Department of Medical Genetics, Center for Medical GeneticsPeking University Health Science CenterBeijingChina
| | - Hui Liang
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Bao Yang
- Department of Neurosurgery, Tiantan HospitalCapital Medical UniversityBeijingChina
| | - Xinxia Tian
- Department of Pathology, School of Basic Medical Sciences, Peking University Third HospitalPeking University Health Science CenterBeijingChina
| | - Jianyuan Luo
- Department of Medical Genetics, Center for Medical GeneticsPeking University Health Science CenterBeijingChina
- Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular BiologyPeking University Health Science CenterBeijingChina
| | - Qing Chang
- Department of Neuropathology, Beijing Neurosurgical Institute, Tiantan HospitalCapital Medical UniversityBeijingChina
- Beijing Key Laboratory of Research and Transformation of Biomarkers for Neurodegenerative Diseases, Peking University Third HospitalPeking University Health Science CenterBeijingChina
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3
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Chen Z, Guan D, Wang Z, Li X, Dong S, Huang J, Zhou W. Microbiota in cancer: molecular mechanisms and therapeutic interventions. MedComm (Beijing) 2023; 4:e417. [PMID: 37937304 PMCID: PMC10626288 DOI: 10.1002/mco2.417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/04/2023] [Accepted: 10/12/2023] [Indexed: 11/09/2023] Open
Abstract
The diverse bacterial populations within the symbiotic microbiota play a pivotal role in both health and disease. Microbiota modulates critical aspects of tumor biology including cell proliferation, invasion, and metastasis. This regulation occurs through mechanisms like enhancing genomic damage, hindering gene repair, activating aberrant cell signaling pathways, influencing tumor cell metabolism, promoting revascularization, and remodeling the tumor immune microenvironment. These microbiota-mediated effects significantly impact overall survival and the recurrence of tumors after surgery by affecting the efficacy of chemoradiotherapy. Moreover, leveraging the microbiota for the development of biovectors, probiotics, prebiotics, and synbiotics, in addition to utilizing antibiotics, dietary adjustments, defensins, oncolytic virotherapy, and fecal microbiota transplantation, offers promising alternatives for cancer treatment. Nonetheless, due to the extensive and diverse nature of the microbiota, along with tumor heterogeneity, the molecular mechanisms underlying the role of microbiota in cancer remain a subject of intense debate. In this context, we refocus on various cancers, delving into the molecular signaling pathways associated with the microbiota and its derivatives, the reshaping of the tumor microenvironmental matrix, and the impact on tolerance to tumor treatments such as chemotherapy and radiotherapy. This exploration aims to shed light on novel perspectives and potential applications in the field.
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Affiliation(s)
- Zhou Chen
- The First Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The First Hospital of Lanzhou UniversityLanzhouGansuChina
| | - Defeng Guan
- The First Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The First Hospital of Lanzhou UniversityLanzhouGansuChina
| | - Zhengfeng Wang
- The First Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The First Hospital of Lanzhou UniversityLanzhouGansuChina
| | - Xin Li
- The Second Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The Department of General SurgeryLanzhou University Second HospitalLanzhouGansuChina
| | - Shi Dong
- The Second Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The Department of General SurgeryLanzhou University Second HospitalLanzhouGansuChina
| | - Junjun Huang
- The First Hospital of Lanzhou UniversityLanzhouGansuChina
| | - Wence Zhou
- The First Clinical Medical CollegeLanzhou UniversityLanzhouGansuChina
- The Department of General SurgeryLanzhou University Second HospitalLanzhouGansuChina
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4
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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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5
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Blagodarov SV, Zheltukhina GA, Nebolsin VE. Iron metabolism in the cell as a target in the development of potential antimicrobial and antiviral agents. BIOMEDITSINSKAIA KHIMIIA 2023; 69:199-218. [PMID: 37705481 DOI: 10.18097/pbmc20236904199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
The search and creation of innovative antimicrobial drugs, acting against resistant and multiresistant strains of bacteria and fungi, are one of the most important tasks of modern bioorganic chemistry and pharmaceuticals. Since iron is essential for the vital activity of almost all organisms, including mammals and bacteria, the proteins involved in its metabolism can serve as potential targets in the development of new promising antimicrobial agents. Such targets include endogenous mammalian biomolecules, heme oxygenases, siderophores, protein 24p3, as well as bacterial heme oxygenases and siderophores. Other proteins that are responsible for the delivery of iron to cells and its balance between bacteria and the host organism also attract certain particular interest. The review summarizes data on the development of inhibitors and inducers (activators) of heme oxygenases, selective for mammals and bacteria, and considers the characteristic features of their mechanisms of action and structure. Based on the reviewed literature data, it was concluded that the use of hemin, the most powerful hemooxygenase inducer, and its derivatives as potential antimicrobial and antiviral agents, in particular against COVID-19 and other dangerous infections, would be a promising approach. In this case, an important role is attributed to the products of hemin degradation formed by heme oxygenases in vitro and in vivo. Certain attention has been paid to the data on the antimicrobial action of iron-free protoporphyrinates, namely complexes with Co, Ga, Zn, Mn, their advantages and disadvantages compared to hemin. Modification of the well-known antibiotic ceftazidime with a siderophore molecule increased its effectiveness against resistant bacteria.
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Affiliation(s)
- S V Blagodarov
- MIREA - Russian Technological University (MITHT), Moscow, Russia; LLC "Pharmenterprises", Moscow, Russia
| | - G A Zheltukhina
- MIREA - Russian Technological University (MITHT), Moscow, Russia; LLC "Pharmenterprises", Moscow, Russia
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Jati AP, Sola-Campoy PJ, Bosch T, Schouls LM, Hendrickx APA, Bautista V, Lara N, Raangs E, Aracil B, Rossen JWA, Friedrich AW, Navarro Riaza AM, Cañada-García JE, Ramírez de Arellano E, Oteo-Iglesias J, Pérez-Vázquez M, García-Cobos S. Widespread Detection of Yersiniabactin Gene Cluster and Its Encoding Integrative Conjugative Elements (ICE Kp) among Nonoutbreak OXA-48-Producing Klebsiella pneumoniae Clinical Isolates from Spain and the Netherlands. Microbiol Spectr 2023; 11:e0471622. [PMID: 37310221 PMCID: PMC10434048 DOI: 10.1128/spectrum.04716-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 05/22/2023] [Indexed: 06/14/2023] Open
Abstract
In this study, we determined the presence of virulence factors in nonoutbreak, high-risk clones and other isolates belonging to less common sequence types associated with the spread of OXA-48-producing Klebsiella pneumoniae clinical isolates from The Netherlands (n = 61) and Spain (n = 53). Most isolates shared a chromosomally encoded core of virulence factors, including the enterobactin gene cluster, fimbrial fim and mrk gene clusters, and urea metabolism genes (ureAD). We observed a high diversity of K-Locus and K/O loci combinations, KL17 and KL24 (both 16%), and the O1/O2v1 locus (51%) being the most prevalent in our study. The most prevalent accessory virulence factor was the yersiniabactin gene cluster (66.7%). We found seven yersiniabactin lineages-ybt 9, ybt 10, ybt 13, ybt 14, ybt 16, ybt 17, and ybt 27-which were chromosomally embedded in seven integrative conjugative elements (ICEKp): ICEKp3, ICEKp4, ICEKp2, ICEKp5, ICEKp12, ICEKp10, and ICEKp22, respectively. Multidrug-resistant lineages-ST11, ST101, and ST405-were associated with ybt 10/ICEKp4, ybt 9/ICEKp3, and ybt 27/ICEKp22, respectively. The fimbrial adhesin kpi operon (kpiABCDEFG) was predominant among ST14, ST15, and ST405 isolates, as well as the ferric uptake system kfuABC, which was also predominant among ST101 isolates. No convergence of hypervirulence and resistance was observed in this collection of OXA-48-producing K. pneumoniae clinical isolates. Nevertheless, two isolates, ST133 and ST792, were positive for the genotoxin colibactin gene cluster (ICEKp10). In this study, the integrative conjugative element, ICEKp, was the major vehicle for yersiniabactin and colibactin gene clusters spreading. IMPORTANCE Convergence of multidrug resistance and hypervirulence in Klebsiella pneumoniae isolates has been reported mostly related to sporadic cases or small outbreaks. Nevertheless, little is known about the real prevalence of carbapenem-resistant hypervirulent K. pneumoniae since these two phenomena are often separately studied. In this study, we gathered information on the virulent content of nonoutbreak, high-risk clones (i.e., ST11, ST15, and ST405) and other less common STs associated with the spread of OXA-48-producing K. pneumoniae clinical isolates. The study of virulence content in nonoutbreak isolates can help us to expand information on the genomic landscape of virulence factors in K. pneumoniae population by identifying virulence markers and their mechanisms of spread. Surveillance should focus not only on antimicrobial resistance but also on virulence characteristics to avoid the spread of multidrug and (hyper)virulent K. pneumoniae that may cause untreatable and more severe infections.
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Affiliation(s)
- Afif P. Jati
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
- Indonesian Society of Bioinformatics and Biodiversity, Indonesia
| | - Pedro J. Sola-Campoy
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Thijs Bosch
- Infectious Diseases Research, Diagnostics and Laboratory Surveillance, Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Leo M. Schouls
- Infectious Diseases Research, Diagnostics and Laboratory Surveillance, Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Antoni P. A. Hendrickx
- Infectious Diseases Research, Diagnostics and Laboratory Surveillance, Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Verónica Bautista
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Noelia Lara
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Erwin Raangs
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
| | - Belén Aracil
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas, Spanish Network for Research in Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - John W. A. Rossen
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
- Laboratory of Medical Microbiology and Infectious Diseases, Isala Hospital, Zwolle, The Netherlands
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Alex W. Friedrich
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
- University Hospital Münster, Institute of European Prevention Networks in Infection Control, Münster, Germany
| | - Ana M. Navarro Riaza
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Javier E. Cañada-García
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Eva Ramírez de Arellano
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas, Spanish Network for Research in Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Oteo-Iglesias
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas, Spanish Network for Research in Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - María Pérez-Vázquez
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas, Spanish Network for Research in Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
| | - Silvia García-Cobos
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - The Dutch and Spanish Collaborative Working Groups on Surveillance on Carbapenemase-Producing Enterobacterales
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, The Netherlands
- Indonesian Society of Bioinformatics and Biodiversity, Indonesia
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- Infectious Diseases Research, Diagnostics and Laboratory Surveillance, Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- CIBER de Enfermedades Infecciosas, Spanish Network for Research in Infectious Diseases, Instituto de Salud Carlos III, Madrid, Spain
- Laboratory of Medical Microbiology and Infectious Diseases, Isala Hospital, Zwolle, The Netherlands
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA
- University Hospital Münster, Institute of European Prevention Networks in Infection Control, Münster, Germany
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7
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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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8
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Chen Z, Han F, Du Y, Shi H, Zhou W. Hypoxic microenvironment in cancer: molecular mechanisms and therapeutic interventions. Signal Transduct Target Ther 2023; 8:70. [PMID: 36797231 PMCID: PMC9935926 DOI: 10.1038/s41392-023-01332-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 102.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/20/2022] [Accepted: 01/18/2023] [Indexed: 02/18/2023] Open
Abstract
Having a hypoxic microenvironment is a common and salient feature of most solid tumors. Hypoxia has a profound effect on the biological behavior and malignant phenotype of cancer cells, mediates the effects of cancer chemotherapy, radiotherapy, and immunotherapy through complex mechanisms, and is closely associated with poor prognosis in various cancer patients. Accumulating studies have demonstrated that through normalization of the tumor vasculature, nanoparticle carriers and biocarriers can effectively increase the oxygen concentration in the tumor microenvironment, improve drug delivery and the efficacy of radiotherapy. They also increase infiltration of innate and adaptive anti-tumor immune cells to enhance the efficacy of immunotherapy. Furthermore, drugs targeting key genes associated with hypoxia, including hypoxia tracers, hypoxia-activated prodrugs, and drugs targeting hypoxia-inducible factors and downstream targets, can be used for visualization and quantitative analysis of tumor hypoxia and antitumor activity. However, the relationship between hypoxia and cancer is an area of research that requires further exploration. Here, we investigated the potential factors in the development of hypoxia in cancer, changes in signaling pathways that occur in cancer cells to adapt to hypoxic environments, the mechanisms of hypoxia-induced cancer immune tolerance, chemotherapeutic tolerance, and enhanced radiation tolerance, as well as the insights and applications of hypoxia in cancer therapy.
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Affiliation(s)
- Zhou Chen
- The First Clinical Medical College, Lanzhou University, Lanzhou, Gansu, China.,The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - Fangfang Han
- The First Clinical Medical College, Lanzhou University, Lanzhou, Gansu, China.,The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - Yan Du
- The Second Clinical Medical College, Lanzhou University, Lanzhou, Gansu, China
| | - Huaqing Shi
- The Second Clinical Medical College, Lanzhou University, Lanzhou, Gansu, China
| | - Wence Zhou
- The First Clinical Medical College, Lanzhou University, Lanzhou, Gansu, China. .,Lanzhou University Sencond Hospital, Lanzhou, Gansu, China.
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9
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Ghio C, Soukup JM, Dailey LA, Ghio AJ, Schreinemachers DM, Koppes RA, Koppes AN. Lactate Production can Function to Increase Human Epithelial Cell Iron Concentration. Cell Mol Bioeng 2022; 15:571-585. [PMID: 36531860 PMCID: PMC9751240 DOI: 10.1007/s12195-022-00741-z] [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: 03/26/2022] [Accepted: 09/21/2022] [Indexed: 11/28/2022] Open
Abstract
Introduction Under conditions of limited iron availability, plants and microbes have evolved mechanisms to acquire iron. For example, metal deficiency stimulates reprogramming of carbon metabolism, increasing activity of enzymes involved in the Krebs cycle and the glycolytic pathway. Resultant carboxylates/hydroxycarboxylates then function as ligands to complex iron and facilitate solubilization and uptake, reversing the metal deficiency. Similarly, human intestinal epithelial cells may produce lactate, a hydroxycarboxylate, during absolute and functional iron deficiency to import metal to reverse limited availability. Methods Here we investigate (1) if lactate can increase cell metal import of epithelial cells in vitro, (2) if lactate dehydrogenase (LDH) activity in and lactate production by epithelial cells correspond to metal availability, and (3) if blood concentrations of LDH in a human cohort correlate with indices of iron homeostasis. Results Results show that exposures of human epithelial cells, Caco-2, to both sodium lactate and ferric ammonium citrate (FAC) increase metal import relative to FAC alone. Similarly, fumaric, isocitric, malic, and succinic acid coincubation with FAC increase iron import relative to FAC alone. Increased iron import following exposures to sodium lactate and FAC elevated both ferritin and metal associated with mitochondria. LDH did not change after exposure to deferoxamine but decreased with 24 h exposure to FAC. Lactate levels revealed decreased levels with FAC incubation. Review of the National Health and Nutrition Examination Survey demonstrated significant negative relationships between LDH concentrations and serum iron in human cohorts. Conclusions Therefore, we conclude that iron import in human epithelial cells can involve lactate, LDH activity can reflect the availability of this metal, and blood LDH concentrations can correlate with indices of iron homeostasis.
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Affiliation(s)
- Caroline Ghio
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | | | - Lisa A. Dailey
- US Environmental Protection Agency, Chapel Hill, NC 27514 USA
| | - Andrew J. Ghio
- US Environmental Protection Agency, Chapel Hill, NC 27514 USA
| | | | - Ryan A. Koppes
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
| | - Abigail N. Koppes
- Department of Chemical Engineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
- Department of Biology, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
- Department of Bioengineering, Northeastern University, 360 Huntington Ave., 313 Snell Engineering, Boston, MA 02115 USA
- Northeastern University, 360 Huntington Ave., 332 Mugar Life Science Building, Boston, MA 02115 USA
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10
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Zhang J, Wang Z, Zhang H, Li S, Li J, Liu H, Cheng Q. The role of lipocalin 2 in brain injury and recovery after ischemic and hemorrhagic stroke. Front Mol Neurosci 2022; 15:930526. [PMID: 36187347 PMCID: PMC9520288 DOI: 10.3389/fnmol.2022.930526] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/02/2022] [Indexed: 12/03/2022] Open
Abstract
Ischemic and hemorrhagic stroke (including intracerebral hemorrhage, intraventricular hemorrhage, and subarachnoid hemorrhage) is the dominating cause of disability and death worldwide. Neuroinflammation, blood–brain barrier (BBB) disruption, neuronal death are the main pathological progress, which eventually causes brain injury. Increasing evidence indicated that lipocalin 2 (LCN2), a 25k-Da acute phase protein from the lipocalin superfamily, significantly increased immediately after the stroke and played a vital role in these events. Meanwhile, there exists a close relationship between LCN2 levels and the worse clinical outcome of patients with stroke. Further research revealed that LCN2 elimination is associated with reduced immune infiltrates, infarct volume, brain edema, BBB leakage, neuronal death, and neurological deficits. However, some studies revealed that LCN2 might also act as a beneficial factor in ischemic stroke. Nevertheless, the specific mechanism of LCN2 and its primary receptors (24p3R and megalin) involving in brain injury remains unclear. Therefore, it is necessary to investigate the mechanism of LCN2 induced brain damage after stroke. This review focuses on the role of LCN2 and its receptors in brain injury and aiming to find out possible therapeutic targets to reduce brain damage following stroke.
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Affiliation(s)
- Jingwei Zhang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Changsha, China
| | - Zeyu Wang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Changsha, China
| | - Hao Zhang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Changsha, China
| | - Shuwang Li
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Li
- Department of Rehabilitation, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hongwei Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Changsha, China
- Hongwei Liu,
| | - Quan Cheng
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Changsha, China
- Clinical Diagnosis and Therapy Center for Glioma of Xiangya Hospital, Central South University, Changsha, China
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Quan Cheng,
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11
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Lopez LR, Ahn JH, Alves T, Arthur JC. Microenvironmental Factors that Shape Bacterial Metabolites in Inflammatory Bowel Disease. Front Cell Infect Microbiol 2022; 12:934619. [PMID: 35959366 PMCID: PMC9362432 DOI: 10.3389/fcimb.2022.934619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022] Open
Abstract
Inflammatory bowel disease (IBD) is a significant global health problem that involves chronic intestinal inflammation and can involve severe comorbidities, including intestinal fibrosis and inflammation-associated colorectal cancer (CRC). Disease-associated alterations to the intestinal microbiota often include fecal enrichment of Enterobacteriaceae, which are strongly implicated in IBD development. This dysbiosis of intestinal flora accompanies changes in microbial metabolites, shaping host:microbe interactions and disease risk. While there have been numerous studies linking specific bacterial taxa with IBD development, our understanding of microbial function in the context of IBD is limited. Several classes of microbial metabolites have been directly implicated in IBD disease progression, including bacterial siderophores and genotoxins. Yet, our microbiota still harbors thousands of uncharacterized microbial products. In-depth discovery and characterization of disease-associated microbial metabolites is necessary to target these products in IBD treatment strategies. Towards improving our understanding of microbiota metabolites in IBD, it is important to recognize how host relevant factors influence microbiota function. For example, changes in host inflammation status, metal availability, interbacterial community structure, and xenobiotics all play an important role in shaping gut microbial ecology. In this minireview, we outline how each of these factors influences gut microbial function, with a specific focus on IBD-associated Enterobacteriaceae metabolites. Importantly, we discuss how altering the intestinal microenvironment could improve the treatment of intestinal inflammation and associated disorders, like intestinal fibrosis and CRC.
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Affiliation(s)
- Lacey R. Lopez
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ju-Hyun Ahn
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Tomaz Alves
- Division of Comprehensive Oral Health, Adams School of Dentistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Janelle C. Arthur
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Center for Gastrointestinal Biology and Disease, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- *Correspondence: Janelle C. Arthur,
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12
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Genomic and Immunological Characterization of Hypermucoviscous Carbapenem-Resistant Klebsiella pneumoniae ST25 Isolates from Northwest Argentina. Int J Mol Sci 2022; 23:ijms23137361. [PMID: 35806365 PMCID: PMC9266295 DOI: 10.3390/ijms23137361] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/14/2022] [Accepted: 06/27/2022] [Indexed: 02/05/2023] Open
Abstract
In recent years, an increase in the prevalence hypermucoviscous carbapenem-resistant Klebsiella pneumoniae with sequence type 25 (ST25) was detected in hospitals of Tucuman (Northwest Argentina). In this work, the virulence and the innate immune response to two K. pneumoniae ST25 strains (LABACER 01 and LABACER 27) were evaluated in a murine model after a respiratory challenge. In addition, comparative genomics was performed with K. pneumoniae LABACER01 and LABACER27 to analyze genes associated with virulence. Both LABACER01 and LABACER27 were detected in the lungs of infected mice two days after the nasal challenge, with LABACER01 counts significantly higher than those of LABACER27. Only LABACER01 was detected in hemocultures. Lactate dehydrogenase (LDH) and albumin levels in bronchoalveolar lavage (BAL) samples were significantly higher in mice challenged with LABACER01 than in LABACER27-infected animals, indicating greater lung tissue damage. Both strains increased the levels of neutrophils, macrophages, TNF-α, IL-1β, IL-6, KC, MCP-1, IFN-γ, and IL-17 in the respiratory tract and blood, with the effect of LABACER01 more marked than that of LABACER27. In contrast, LABACER27 induced higher levels of IL-10 in the respiratory tract than LABACER01. Genomic analysis revealed that K. pneumoniae LABACER01 and LABACER27 possess virulence factors found in other strains that have been shown to be hypervirulent, including genes required for enterobactin (entABCDEF) and salmochelin (iroDE) biosynthesis. In both strains, the genes of toxin–antitoxin systems, as well as regulators of the expression of virulence factors and adhesion genes were also detected. Studies on the genetic potential of multiresistant K. pneumoniae strains as well as their cellular and molecular interactions with the host are of fundamental importance to assess the association of certain virulence factors with the intensity of the inflammatory response. In this sense, this work explored the virulence profile based on genomic and in vivo studies of hypermucoviscous carbapenem-resistant K. pneumoniae ST25 strains, expanding the knowledge of the biology of the emerging ST25 clone in Argentina.
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13
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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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14
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Wellawa DH, Lam PKS, White AP, Gomis S, Allan B, Köster W. High Affinity Iron Acquisition Systems Facilitate but Are Not Essential for Colonization of Chickens by Salmonella Enteritidis. Front Microbiol 2022; 13:824052. [PMID: 35308377 PMCID: PMC8928163 DOI: 10.3389/fmicb.2022.824052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/24/2022] [Indexed: 01/02/2023] Open
Abstract
The roles of TonB mediated Fe3+ (ferric iron) uptake via enterobactin (involving biosynthesis genes entABCDEF) and Fe2+ (ferrous iron) uptake through the FeoABC transporter are poorly defined in the context of chicken-Salmonella interactions. Both uptake systems are believed to be the major contributors of iron supply in the Salmonella life cycle. Current evidence suggests that these iron uptake systems play a major role in pathogenesis in mammals and as such, they represent promising antibacterial targets with therapeutic potential. We investigated the role of these iron uptake mechanisms regarding the ability of Salmonella Enteritidis (SEn) strains to colonize in a chicken infection model. Further we constructed a bioluminescent reporter to sense iron limitation during gastrointestinal colonization of Salmonella in chicken via ex vivo imaging. Our data indicated that there is some redundancy between the ferric and ferrous iron uptake mechanisms regarding iron acquisition during SEn pathogenesis in chicken. We believe that this redundancy of iron acquisition in the host reservoir may be the consequence of adaptation to unique avian environments, and thus warrants further investigation. To our knowledge, this the first report providing direct evidence that both enterobactin synthesis and FeoABC mediated iron uptake contribute to the virulence of SEn in chickens.
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Affiliation(s)
- Dinesh H Wellawa
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Po-King S Lam
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada
| | - Aaron P White
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Susantha Gomis
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Brenda Allan
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Wolfgang Köster
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.,Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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15
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Multilocus Sequence Typing for Molecular Epidemiology of Stenotrophomonas maltophilia Clinical and Environmental Isolates from a Tertiary Hospital in West of Iran. IRANIAN BIOMEDICAL JOURNAL 2022; 26:142-52. [PMID: 35032967 PMCID: PMC8987417 DOI: 10.52547/ibj.26.2.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Background Stenotrophomonas maltophilia is an opportunistic bacterium, contributing to different hospital-acquired infections and can be acquired from different hospital setting sources. Epidemiological study of S. maltophilia in the hospital also demonstrates the intrahospital distribution of certain strains of bacteria in healthcare facilities. The aim of the current study was to identify the molecular epidemiology of S. maltophilia isolates from clinical and environmental sources within a hospital. Methods A total of 400 samples (clinical and environmental) were collected from the different settings of hospital. Following the standard biochemical testing and 23S rRNA genotyping, the molecular typing of S. maltophilia isolates was determined using the multilocus sequence typing (MLST) technique. Also, the frequencies of zot and entF virulence genes among S. maltophilia isolates were examined by PCR technique. Results Based on the biochemical testes and PCRs targeting 23S rRNA gene, 22 S. maltophilia isolates were identified. The MLST analysis demonstrated that these isolates were assigned to 14 ST, and 6 out of 14 STs were common among clinical and environmental samples. All 22 isolates were identified in the PubMLST database. The PCR screening demonstrated that none of 22 S. maltophilia isolates had zot virulence gene, while the entF gene with the 59% frequency was observed in 13 out of 22 isolates. Among these 13 isolates, 6 STs were common in clinical and environmental isolates. Conclusion Our study showed the clonal relatedness between clinical and environmental sources of the S. maltophilia isolates in a hospital. Further studies are required to understand the epidemic situation of this pathogen in the clinic and the environment.
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16
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Das S, Saqib M, Meng RC, Chittur SV, Guan Z, Wan F, Sun W. Hemochromatosis drives acute lethal intestinal responses to hyperyersiniabactin-producing Yersinia pseudotuberculosis. Proc Natl Acad Sci U S A 2022; 119:e2110166119. [PMID: 34969677 PMCID: PMC8764673 DOI: 10.1073/pnas.2110166119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 12/19/2022] Open
Abstract
Hemachromatosis (iron-overload) increases host susceptibility to siderophilic bacterial infections that cause serious complications, but the underlying mechanisms remain elusive. The present study demonstrates that oral infection with hyperyersiniabactin (Ybt) producing Yersinia pseudotuberculosis Δfur mutant (termed Δfur) results in severe systemic infection and acute mortality to hemochromatotic mice due to rapid disruption of the intestinal barrier. Transcriptome analysis of Δfur-infected intestine revealed up-regulation in cytokine-cytokine receptor interactions, the complement and coagulation cascade, the NF-κB signaling pathway, and chemokine signaling pathways, and down-regulation in cell-adhesion molecules and Toll-like receptor signaling pathways. Further studies indicate that dysregulated interleukin (IL)-1β signaling triggered in hemachromatotic mice infected with Δfur damages the intestinal barrier by activation of myosin light-chain kinases (MLCK) and excessive neutrophilia. Inhibiting MLCK activity or depleting neutrophil infiltration reduces barrier disruption, largely ameliorates immunopathology, and substantially rescues hemochromatotic mice from lethal Δfur infection. Moreover, early intervention of IL-1β overproduction can completely rescue hemochromatotic mice from the lethal infection.
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Affiliation(s)
- Shreya Das
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208
| | - Mohd Saqib
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208
| | - Ryan C Meng
- Center for Functional Genomics, University at Albany-State University of New York, Rensselaer, NY 12144
| | - Sridar V Chittur
- Center for Functional Genomics, University at Albany-State University of New York, Rensselaer, NY 12144
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710
| | - Fengyi Wan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205
| | - Wei Sun
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208;
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17
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Yu Y, Singh H, Tsitrin T, Bekele S, Lin YH, Sikorski P, Moncera KJ, Torralba MG, Morrow L, Wolcott R, Nelson KE, Pieper R. Urethral Catheter Biofilms Reveal Plasticity in Bacterial Composition and Metabolism and Withstand Host Immune Defenses in Hypoxic Environment. Front Med (Lausanne) 2021; 8:667462. [PMID: 34249966 PMCID: PMC8260951 DOI: 10.3389/fmed.2021.667462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 05/06/2021] [Indexed: 11/18/2022] Open
Abstract
Biofilms composed of multiple microorganisms colonize the surfaces of indwelling urethral catheters that are used serially by neurogenic bladder patients and cause chronic infections. Well-adapted pathogens in this niche are Escherichia coli, Proteus, and Enterococcus spp., species that cycle through adhesion and multilayered cell growth, trigger host immune responses, are starved off nutrients, and then disperse. Viable microbial foci retained in the urinary tract recolonize catheter surfaces. The molecular adaptations of bacteria in catheter biofilms (CBs) are not well-understood, promising new insights into this pathology based on host and microbial meta-omics analyses from clinical specimens. We examined catheters from nine neurogenic bladder patients longitudinally over up to 6 months. Taxonomic analyses from 16S rRNA gene sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics revealed that 95% of all catheter and corresponding urinary pellet (UP) samples contained bacteria. CB biomasses were dominated by Enterobacteriaceae spp. and often accompanied by lactic acid and anaerobic bacteria. Systemic antibiotic drug treatments of patients resulted in either transient or lasting microbial community perturbations. Neutrophil effector proteins were abundant not only in UP but also CB samples, indicating their penetration of biofilm surfaces. In the context of one patient who advanced to a kidney infection, Proteus mirabilis proteomic data suggested a combination of factors associated with this disease complication: CB biomasses were high; the bacteria produced urease alkalinizing the pH and triggering urinary salt deposition on luminal catheter surfaces; P. mirabilis utilized energy-producing respiratory systems more than in CBs from other patients. The NADH:quinone oxidoreductase II (Nqr), a Na+ translocating enzyme not operating as a proton pump, and the nitrate reductase A (Nar) equipped the pathogen with electron transport chains promoting growth under hypoxic conditions. Both P. mirabilis and E. coli featured repertoires of transition metal ion acquisition systems in response to human host-mediated iron and zinc sequestration. We discovered a new drug target, the Nqr respiratory system, whose deactivation may compromise P. mirabilis growth in a basic pH milieu. Animal models would not allow such molecular-level insights into polymicrobial biofilm metabolism and interactions because the complexity cannot be replicated.
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Affiliation(s)
- Yanbao Yu
- J. Craig Venter Institute, Rockville, MD, United States
| | | | | | | | - Yi-Han Lin
- J. Craig Venter Institute, Rockville, MD, United States
| | | | | | | | - Lisa Morrow
- Southwest Regional Wound Care Center, Lubbock, TX, United States
| | - Randall Wolcott
- Southwest Regional Wound Care Center, Lubbock, TX, United States
| | - Karen E. Nelson
- J. Craig Venter Institute, Rockville, MD, United States
- J. Craig Venter Institute, La Jolla, CA, United States
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18
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Botta A, Barra NG, Lam NH, Chow S, Pantopoulos K, Schertzer JD, Sweeney G. Iron Reshapes the Gut Microbiome and Host Metabolism. J Lipid Atheroscler 2021; 10:160-183. [PMID: 34095010 PMCID: PMC8159756 DOI: 10.12997/jla.2021.10.2.160] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/12/2021] [Accepted: 02/21/2021] [Indexed: 12/12/2022] Open
Abstract
Compelling studies have established that the gut microbiome is a modifier of metabolic health. Changes in the composition of the gut microbiome are influenced by genetics and the environment, including diet. Iron is a potential node of crosstalk between the host-microbe relationship and metabolic disease. Although iron is well characterized as a frequent traveling companion of metabolic disease, the role of iron is underappreciated because the mechanisms of iron's influence on host metabolism are poorly characterized. Both iron deficiency and excessive amounts leading to iron overload can have detrimental effects on cardiometabolic health. Optimal iron homeostasis is critical for regulation of host immunity and metabolism in addition to regulation of commensal and pathogenic enteric bacteria. In this article we review evidence to support the notion that altering composition of the gut microbiome may be an important route via which iron impacts cardiometabolic health. We discuss reshaping of the microbiome by iron, the physiological significance and the potential for therapeutic interventions.
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Affiliation(s)
- Amy Botta
- Department of Biology, York University, Toronto, ON, Canada
| | - Nicole G. Barra
- Department of Biochemistry and Biomedical Sciences, Farncombe Family Digestive Health Research Institute, Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, ON, Canada
| | - Nhat Hung Lam
- Department of Biology, York University, Toronto, ON, Canada
| | - Samantha Chow
- Department of Biology, York University, Toronto, ON, Canada
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC, Canada
| | - Jonathan D. Schertzer
- Department of Biochemistry and Biomedical Sciences, Farncombe Family Digestive Health Research Institute, Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, ON, Canada
| | - Gary Sweeney
- Department of Biology, York University, Toronto, ON, Canada
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19
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Zhu J, Wang T, Chen L, Du H. Virulence Factors in Hypervirulent Klebsiella pneumoniae. Front Microbiol 2021; 12:642484. [PMID: 33897652 PMCID: PMC8060575 DOI: 10.3389/fmicb.2021.642484] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/11/2021] [Indexed: 12/25/2022] Open
Abstract
Hypervirulent Klebsiella pneumoniae (hvKP) has spread globally since first described in the Asian Pacific Rim. It is an invasive variant that differs from the classical K. pneumoniae (cKP), with hypermucoviscosity and hypervirulence, causing community-acquired infections, including pyogenic liver abscess, pneumonia, meningitis, and endophthalmitis. It utilizes a battery of virulence factors for survival and pathogenesis, such as capsule, siderophores, lipopolysaccharide, fimbriae, outer membrane proteins, and type 6 secretion system, of which the former two are dominant. This review summarizes these hvKP-associated virulence factors in order to understand its molecular pathogenesis and shed light on new strategies to improve the prevention, diagnosis, and treatment of hvKP-causing infection.
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Affiliation(s)
- Jie Zhu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Tao Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Liang Chen
- Hackensack Meridian Health Center for Discovery and Innovation, Nutley, NJ, United States.,Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, United States
| | - Hong Du
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
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20
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Modification of the Pulmonary MyD88 Inflammatory Response Underlies the Role of the Yersinia pestis Pigmentation Locus in Primary Pneumonic Plague. Infect Immun 2021; 89:IAI.00595-20. [PMID: 33257532 DOI: 10.1128/iai.00595-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/17/2020] [Indexed: 01/28/2023] Open
Abstract
Pneumonic plague, caused by Yersinia pestis, is a rapidly progressing bronchopneumonia involving focal bacterial growth, neutrophilic congestion, and alveolar necrosis. Within a short time after inhalation of Y. pestis, inflammatory cytokines are expressed via the Toll/interleukin-1 (IL-1) adaptor myeloid differentiation primary response 88 (MyD88), which facilitates the primary lung infection. We previously showed that Y. pestis lacking the 102-kb chromosomal pigmentation locus (pgm) is unable to cause inflammatory damage in the lungs, whereas the wild-type (WT) strain induces the toxic MyD88 pulmonary inflammatory response. In this work, we investigated the involvement of the pgm in skewing the inflammatory response during pneumonic plague. We show that the early MyD88-dependent and -independent cytokine responses to pgm- Y. pestis infection of the lungs are similar yet distinct from those that occur during pgm+ infection. Furthermore, we found that MyD88 was necessary to prevent growth of the iron-starved pgm- Y. pestis despite the presence of iron chelators lactoferrin and transferrin. However, while this induced neutrophil recruitment, there was no hyperinflammatory response, and pulmonary disease was mild without MyD88. In contrast, growth in blood and tissues progressed rapidly in the absence of MyD88, due to an almost total loss of serum interferon gamma (IFN-γ). We further show that the expression of MyD88 by myeloid cells is important to control bacteremia but not the primary lung infection. The combined data indicate distinct roles for myeloid and nonmyeloid MyD88 and suggest that expression of the pgm is necessary to skew the inflammatory response in the lungs to cause pneumonic plague.
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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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Wellawa DH, Allan B, White AP, Köster W. Iron-Uptake Systems of Chicken-Associated Salmonella Serovars and Their Role in Colonizing the Avian Host. Microorganisms 2020; 8:E1203. [PMID: 32784620 PMCID: PMC7465098 DOI: 10.3390/microorganisms8081203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 01/09/2023] Open
Abstract
Iron is an essential micronutrient for most bacteria. Salmonella enterica strains, representing human and animal pathogens, have adopted several mechanisms to sequester iron from the environment depending on availability and source. Chickens act as a major reservoir for Salmonella enterica strains which can lead to outbreaks of human salmonellosis. In this review article we summarize the current understanding of the contribution of iron-uptake systems to the virulence of non-typhoidal S. enterica strains in colonizing chickens. We aim to address the gap in knowledge in this field, to help understand and define the interactions between S. enterica and these important hosts, in comparison to mammalian models.
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Affiliation(s)
- Dinesh H. Wellawa
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Brenda Allan
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
| | - Aaron P. White
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Wolfgang Köster
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
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Carvalho EM, Ridnour LA, Júnior FSG, Cabral PHB, do Nascimento NRF, Wink DA, Franco DW, de Medeiros MJC, de Lima Pontes D, Longhinotti E, de Freitas Paulo T, Bernardes-Génisson V, Chauvin R, Sousa EHS, Lopes LGDF. A divergent mode of activation of a nitrosyl iron complex with unusual antiangiogenic activity. J Inorg Biochem 2020; 210:111133. [PMID: 32619898 DOI: 10.1016/j.jinorgbio.2020.111133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/03/2020] [Accepted: 06/07/2020] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) and nitroxyl (HNO) have gained broad attention due to their roles in several physiological and pathophysiological processes. Remarkably, these sibling species can exhibit opposing effects including the promotion of angiogenic activity by NO compared to HNO, which blocks neovascularization. While many NO donors have been developed over the years, interest in HNO has led to the recent emergence of new donors. However, in both cases there is an expressive lack of iron-based compounds. Herein, we explored the novel chemical reactivity and stability of the trans-[Fe(cyclam)(NO)Cl]Cl2 (cyclam = 1,4,8,11-tetraazacyclotetradecane) complex. Interestingly, the half-life (t1/2) for NO release was 1.8 min upon light irradiation, vs 5.4 h upon thermal activation at 37 °C. Importantly, spectroscopic evidence supported the generation of HNO rather than NO induced by glutathione. Moreover, we observed significant inhibition of NO donor- or hypoxia-induced HIF-1α (hypoxia-inducible factor 1α) accumulation in breast cancer cells, as well as reduced vascular tube formation by endothelial cells pretreated with the trans-[Fe(cyclam)(NO)Cl]Cl2 complex. Together, these studies provide the first example of an iron-nitrosyl complex with anti-angiogenic activity as well as the potential dual activity of this compound as a NO/HNO releasing agent, which warrants further pharmacological investigation.
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Affiliation(s)
- Edinilton Muniz Carvalho
- Departamento de Química Orgânica e Inorgânica, Grupo de Bioinorgânica, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil; CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, BP 44099, F-31077 Toulouse, Cedex 4, France; Université de Toulouse, UPS, INPT, F-31077 Toulouse, Cedex 4, France
| | - Lisa A Ridnour
- National Cancer Institute, Cancer and Inflammation Program, Frederick, MD 21702, United States
| | - Florêncio Sousa Gouveia Júnior
- Departamento de Química Orgânica e Inorgânica, Grupo de Bioinorgânica, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil
| | - Pedro Henrique Bezerra Cabral
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará-UECE, Paranjana Av, 1700, Fortaleza, Ceará 60740-00, Brazil
| | | | - David A Wink
- National Cancer Institute, Cancer and Inflammation Program, Frederick, MD 21702, United States
| | - Douglas W Franco
- Instituto de Química de São Carlos, Universidade de São Paulo-USP, P.O. Box 780, São Carlos, SP CEP 13566-590, Brazil
| | - Mayara Jane Campos de Medeiros
- Laboratório de Química de Coordenação e Polímeros (LQCPol), Instituto de Química, Universidade Federal do Rio Grande do Norte (UFRN), Natal CEP 59078-970, Brazil
| | - Daniel de Lima Pontes
- Laboratório de Química de Coordenação e Polímeros (LQCPol), Instituto de Química, Universidade Federal do Rio Grande do Norte (UFRN), Natal CEP 59078-970, Brazil
| | - Elisane Longhinotti
- Departamento de Química Analítica e Físico-Química, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil
| | - Tércio de Freitas Paulo
- Departamento de Química Orgânica e Inorgânica, Grupo de Bioinorgânica, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil
| | - Vania Bernardes-Génisson
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, BP 44099, F-31077 Toulouse, Cedex 4, France; Université de Toulouse, UPS, INPT, F-31077 Toulouse, Cedex 4, France
| | - Remi Chauvin
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, BP 44099, F-31077 Toulouse, Cedex 4, France; Université de Toulouse, UPS, INPT, F-31077 Toulouse, Cedex 4, France
| | - Eduardo Henrique Silva Sousa
- Departamento de Química Orgânica e Inorgânica, Grupo de Bioinorgânica, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil.
| | - Luiz Gonzaga de França Lopes
- Departamento de Química Orgânica e Inorgânica, Grupo de Bioinorgânica, Universidade Federal do Ceará-UFC, P.O Box 6021, Fortaleza, CE CEP 60440-900, Brazil.
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Wang W, Lu Y, Wang Y, Zhang Y, Xia B, Cao J. Siderophores induce mitophagy-dependent apoptosis in platelets. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:879. [PMID: 32793723 DOI: 10.21037/atm-20-4861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background Siderophores are major virulent factors of K. pneumoniae, and their roles are iron chelators in the host. Several studies have shown that iron chelation could result in mitochondrial dysfunction and increase the production of reactive oxygen species (ROS), which further induces cell mitophagy and apoptosis. However, the impacts of siderophores on platelets are still unknown. Methods We obtained platelets of healthy volunteers to perform in vitro experiments in our study and treated platelets with different siderophores. Mitophagy related proteins (TOMM20, TIMM23, LC3, and p62), signal proteins (PINK1/Parkin and BNIP3), and apoptosis protein (caspase3) in platelets were analyzed by western blot. The co-localization of mitotracker with LC3-II was analyzed by immunofluorescence assays. The flow cytometer was used to evaluate ROS levels. Results All four kinds of siderophores (10 μM) secreted by K. pneumoniae increased the expression of LC3 II and reduced the expression of mitochondrial membrane protein, TOMM20, and TIMM23. Immunofluorescence assays revealed that the treatment of enterobactin significantly increased the co-localization of mitotracker with LC3-II. All four kinds of siderophores increased the ROS level in platelets. Mitophagy of platelets was activated through several pathways, including PINK1/Parkin- and BNIP3-dependent pathways. We also proved that siderophores increased the expression of caspase3 in platelets, and the expression of caspase3 significantly decreased after the pathways of mitophagy were blocked. Conclusions K. pneumoniae siderophores lead to mitophagy in platelets, and mitophagy further induces apoptosis, which may be a potential treatment of thrombocytopenia in infections.
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Affiliation(s)
- Wenyuan Wang
- Department of Gastroenterology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Yufeng Lu
- Department of Gastroenterology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Yulin Wang
- Clinical Medicine, Xuzhou Medical University, Xuzhou, China
| | - Yan Zhang
- Department of Hematology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Beilei Xia
- Department of Gastroenterology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Juan Cao
- Department of Infectious Diseases, the Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
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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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Abstract
Recent years have witnessed an emergence of interest in understanding metabolic changes associated with immune responses, termed immunometabolism. As oxygen is central to all aerobic metabolism, hypoxia is now recognized to contribute fundamentally to inflammatory and immune responses. Studies from a number of groups have implicated a prominent role for oxygen metabolism and hypoxia in innate immunity of healthy tissue (physiologic hypoxia) and during active inflammation (inflammatory hypoxia). This inflammatory hypoxia emanates from a combination of recruited inflammatory cells (e.g., neutrophils, eosinophils, and monocytes), high rates of oxidative metabolism, and the activation of multiple oxygen-consuming enzymes during inflammation. These localized shifts toward hypoxia have identified a prominent role for the transcription factor hypoxia-inducible factor (HIF) in the regulation of innate immunity. Such studies have provided new and enlightening insight into our basic understanding of immune mechanisms, and extensions of these findings have identified potential therapeutic targets. In this review, we summarize recent literature around the topic of innate immunity and mucosal hypoxia with a focus on transcriptional responses mediated by HIF.
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Affiliation(s)
- Sean P Colgan
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado 80045, USA;
- Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Glenn T Furuta
- Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Cormac T Taylor
- UCD Conway Institute, Systems Biology Ireland and School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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Yersiniabactin-Producing Adherent/Invasive Escherichia coli Promotes Inflammation-Associated Fibrosis in Gnotobiotic Il10-/- Mice. Infect Immun 2019; 87:IAI.00587-19. [PMID: 31481410 PMCID: PMC6803345 DOI: 10.1128/iai.00587-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/22/2019] [Indexed: 12/16/2022] Open
Abstract
Fibrosis is a significant complication of intestinal disorders associated with microbial dysbiosis and pathobiont expansion, notably Crohn’s disease (CD). Mechanisms that favor fibrosis are not well understood, and therapeutic strategies are limited. Here we demonstrate that colitis-susceptible Il10-deficient mice develop inflammation-associated fibrosis when monoassociated with adherent/invasive Escherichia coli (AIEC) that harbors the yersiniabactin (Ybt) pathogenicity island. Fibrosis is a significant complication of intestinal disorders associated with microbial dysbiosis and pathobiont expansion, notably Crohn’s disease (CD). Mechanisms that favor fibrosis are not well understood, and therapeutic strategies are limited. Here we demonstrate that colitis-susceptible Il10-deficient mice develop inflammation-associated fibrosis when monoassociated with adherent/invasive Escherichia coli (AIEC) that harbors the yersiniabactin (Ybt) pathogenicity island. Inactivation of Ybt siderophore production in AIEC nearly abrogated fibrosis development in inflamed mice. In contrast, inactivation of Ybt import through its cognate receptor FyuA enhanced fibrosis severity. This corresponded with increased colonic expression of profibrogenic genes prior to the development of histological disease, therefore suggesting causality. fyuA-deficient AIEC also exhibited greater localization within subepithelial tissues and fibrotic lesions that was dependent on Ybt biosynthesis and corresponded with increased fibroblast activation in vitro. Together, these findings suggest that Ybt establishes a profibrotic environment in the host in the absence of binding to its cognate receptor and indicate a direct link between intestinal AIEC and the induction of inflammation-associated fibrosis.
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Vornhagen J, Sun Y, Breen P, Forsyth V, Zhao L, Mobley HLT, Bachman MA. The Klebsiella pneumoniae citrate synthase gene, gltA, influences site specific fitness during infection. PLoS Pathog 2019; 15:e1008010. [PMID: 31449551 PMCID: PMC6730947 DOI: 10.1371/journal.ppat.1008010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/06/2019] [Accepted: 07/29/2019] [Indexed: 01/09/2023] Open
Abstract
Klebsiella pneumoniae (Kp), one of the most common causes of healthcare-associated infections, increases patient morbidity, mortality, and hospitalization costs. Kp must acquire nutrients from the host for successful infection; however, the host is able to prevent bacterial nutrient acquisition through multiple systems. This includes the innate immune protein lipocalin 2 (Lcn2), which prevents Kp iron acquisition. To identify novel Lcn2-dependent Kp factors that mediate evasion of nutritional immunity during lung infection, we undertook an InSeq study using a pool of >20,000 transposon mutants administered to Lcn2+/+ and Lcn2-/- mice. Comparing transposon mutant frequencies between mouse genotypes, we identified the Kp citrate synthase, GltA, as potentially interacting with Lcn2, and this novel finding was independently validated. Interestingly, in vitro studies suggest that this interaction is not direct. Given that GltA is involved in oxidative metabolism, we screened the ability of this mutant to use a variety of carbon and nitrogen sources. The results indicated that the gltA mutant has a distinct amino acid auxotrophy rendering it reliant upon glutamate family amino acids for growth. Deletion of Lcn2 from the host leads to increased amino acid levels in bronchioloalveolar lavage fluid, corresponding to increased fitness of the gltA mutant in vivo and ex vivo. Accordingly, addition of glutamate family amino acids to Lcn2+/+ bronchioloalveolar lavage fluid rescued growth of the gltA mutant. Using a variety of mouse models of infection, we show that GltA is an organ-specific fitness factor required for complete fitness in the spleen, liver, and gut, but dispensable in the bloodstream. Similar to bronchioloalveolar lavage fluid, addition of glutamate family amino acids to Lcn2+/+ organ lysates was sufficient to rescue the loss of gltA. Together, this study describes a critical role for GltA in Kp infection and provides unique insight into how metabolic flexibility impacts bacterial fitness during infection. The bacteria Klebsiella pneumoniae (Kp) is an important cause of infection in healthcare settings. These infections can be difficult to treat, as they frequently occur in chronically ill patients and the bacteria have the ability to acquire multiple antibiotic resistance markers. Kp is a common colonizer of the intestinal tract in hospitalized patients, and can progress to infections of the bloodstream, respiratory, and urinary tract. However, the bacterial factors that allow Kp to replicate in these different body sites are unclear. In this study, we found that the Kp citrate synthase, GltA, enables bacterial replication in the lung and intestine by enhancing the ability of Kp to use diverse nutrients in a mechanism known as metabolic flexibility. Kp lacking GltA require specific amino acids that are abundant in blood, but not other body sites. The work in this study provides novel insight into why Kp is a successful hospital pathogen that can colonize and infect multiple body sites.
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Affiliation(s)
- Jay Vornhagen
- Department of Pathology, University of Michigan, Ann Arbor, United States of America
| | - Yuang Sun
- Department of Pathology, University of Michigan, Ann Arbor, United States of America
| | - Paul Breen
- Department of Pathology, University of Michigan, Ann Arbor, United States of America
| | - Valerie Forsyth
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, United States of America
| | - Lili Zhao
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, United States of America
| | - Harry L T Mobley
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, United States of America
| | - Michael A Bachman
- Department of Pathology, University of Michigan, Ann Arbor, United States of America
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Liu Z, Cominelli F, Di Martino L, Liu R, Devireddy N, Devireddy LR, Wald DN. Lipocalin 24p3 Induction in Colitis Adversely Affects Inflammation and Contributes to Mortality. Front Immunol 2019; 10:812. [PMID: 31057545 PMCID: PMC6478753 DOI: 10.3389/fimmu.2019.00812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 03/27/2019] [Indexed: 12/12/2022] Open
Abstract
Recognition of microorganism associated molecular patterns by epithelial cells elicits signaling cascades resulting in the production of host defense proteins. Lipocalin 24p3 is purported to be one such protein. 24p3 binds prokaryotic and eukaryotic siderophores and by sequestering iron laden bacterial siderophores it was believed to restrict bacterial replication. As such mice deficient for 24p3 are susceptible to systemic infections. However, it is not clear whether deficiency of 24p3 on the gut mucosa contributes to inflammation. In line with 24p3's function as a bacteriostat, it would be reasonable to assume that deficiencies in the control of intestinal flora from 24p3 absence play a role in inflammatory intestinal diseases. Surprisingly, we show 24p3 is a contributor of inflammation and 24p3 deficiency protects mice from dextran sodium sulfate (DSS)-induced colitis. 24p3 was found to be a negative regulator of platelet-derived growth factor (PDGF), which helps maintain the integrity of the gut mucosa. Neutralization of PDGF-BB abrogated resistance of 24p3 null mice to DSS confirming the direct link between 24p3 and PDGF-BB. Finally, iron handling in wild-type and 24p3-null mice upon DSS treatment also differed. In summary, differential iron levels and enhanced expression of PDGF-BB in 24p3 null mice confers resistance to DSS.
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Affiliation(s)
- Zhuoming Liu
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Fabio Cominelli
- Department of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Luca Di Martino
- Department of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Ruifu Liu
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | | | - Lax R Devireddy
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - David N Wald
- Department of Pathology, Case Western Reserve University, Cleveland, OH, United States.,Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, United States
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30
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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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Iron Acquisition and Siderophore Release by Carbapenem-Resistant Sequence Type 258 Klebsiella pneumoniae. mSphere 2018; 3:3/2/e00125-18. [PMID: 29669884 PMCID: PMC5907654 DOI: 10.1128/msphere.00125-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/24/2018] [Indexed: 11/20/2022] Open
Abstract
Carbapenem-resistant Enterobacteriaceae, including K. pneumoniae, are a major health care concern worldwide because they cause a wide range of infection and are resistant to all or nearly all antibiotics. To cause infection, these bacteria must acquire iron, and a major mechanism of acquiring iron is by secreting a molecule called enterobactin that strips iron from host proteins. However, a subset of carbapenem-resistant K. pneumoniae strains that lack a portion of the entS gene that is required for enterobactin secretion was recently discovered. To understand how these mutant strains obtain iron, we studied their transcriptional responses, bacterial growth, and enterobactin secretion under iron-limited conditions. We found that strains both with mutated and intact entS genes grow under iron-limiting conditions, secrete enterobactin, and utilize an alternate iron source, hemin, for growth. Our data indicate that carbapenem-resistant K. pneumoniae can use varied methods for iron uptake during infection. Klebsiella pneumoniae is rapidly acquiring resistance to all known antibiotics, including carbapenems. Multilocus sequence type ST258 (sequence type 258), carrying a gene encoding the K. pneumoniae carbapenemase (blaKPC) on a transmissible plasmid, is the most prevalent carbapenem-resistant Enterobacteriaceae (CRE) in the United States and has disseminated worldwide. Previously, whole-genome sequencing identified core genome single nucleotide variants that divide ST258 into two distinct clades, ST258a and ST258b. Furthermore, a subset of ST258b strains have a 347-base deletion within the enterobactin (Ent) exporter gene entS. Despite the predicted inability of these strains to secrete the siderophore Ent, this clade is prevalent among clinical isolates, indicating that a full-length entS gene is not necessary for infection. To compare the transcriptional responses of ST258 subtypes to iron limitation, we performed transcriptome sequencing (RNA-Seq) in minimal medium alone or supplemented with iron or human serum and measured gene expression patterns. Iron limitation induced differential expression of distinct iron acquisition pathways when comparing ST258a and ST258b strains, including the upregulation of the hemin transport operon in entS partial deletion isolates. To measure how K. pneumoniae strains vary in iron chelation and siderophore production, we performed in vitro chrome azurol S (CAS) and Arnow assays as well as mass spectrometry. We determined that both ST258a and ST258b strains grow under iron-depleted conditions, can utilize hemin for growth, and secrete Ent, despite the partial entS deletion in a subset of ST258b strains. All carbapenem-resistant (CR) K. pneumoniae strains tested were susceptible to growth inhibition by the Ent-sequestering innate immune protein lipocalin 2. IMPORTANCE Carbapenem-resistant Enterobacteriaceae, including K. pneumoniae, are a major health care concern worldwide because they cause a wide range of infection and are resistant to all or nearly all antibiotics. To cause infection, these bacteria must acquire iron, and a major mechanism of acquiring iron is by secreting a molecule called enterobactin that strips iron from host proteins. However, a subset of carbapenem-resistant K. pneumoniae strains that lack a portion of the entS gene that is required for enterobactin secretion was recently discovered. To understand how these mutant strains obtain iron, we studied their transcriptional responses, bacterial growth, and enterobactin secretion under iron-limited conditions. We found that strains both with mutated and intact entS genes grow under iron-limiting conditions, secrete enterobactin, and utilize an alternate iron source, hemin, for growth. Our data indicate that carbapenem-resistant K. pneumoniae can use varied methods for iron uptake during infection.
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Abstract
Mucosal tissues represent surfaces that are exposed to the outside world and provide a conduit for internal and external communication. Tissues such as the intestine and the lung are lined by layer(s) of epithelial cells that, when organized in three dimensions, provide a critical barrier to the flux of luminal contents. This selective barrier is provided through the regulated expression of junctional proteins and mucins. Tissue oxygen metabolism is central to the maintenance of homeostasis in the mucosa. In some organs (e.g., the colon), low baseline Po2 determines tissue metabolism and results in basal expression of the transcription factor, hypoxia-inducible factor (HIF), which is enhanced after ischemia/inflammation. Recent studies have indicated that HIF contributes fundamentally to the expression of barrier-related genes and in the regulation of barrier-adaptive responses within the mucosa. Here, we briefly review recent literature on the topic of hypoxia and HIF regulation of barrier in mucosal health and during disease.
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Holo-lipocalin-2-derived siderophores increase mitochondrial ROS and impair oxidative phosphorylation in rat cardiomyocytes. Proc Natl Acad Sci U S A 2018; 115:1576-1581. [PMID: 29378951 DOI: 10.1073/pnas.1720570115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lipocalin-2 (Lcn2), a critical component of the innate immune response which binds siderophores and limits bacterial iron acquisition, can elicit spillover adverse proinflammatory effects. Here we show that holo-Lcn2 (Lcn2-siderophore-iron, 1:3:1) increases mitochondrial reactive oxygen species (ROS) generation and attenuates mitochondrial oxidative phosphorylation in adult rat primary cardiomyocytes in a manner blocked by N-acetyl-cysteine or the mitochondria-specific antioxidant SkQ1. We further demonstrate using siderophores 2,3-DHBA (2,3-dihydroxybenzoic acid) and 2,5-DHBA that increased ROS and reduction in oxidative phosphorylation are direct effects of the siderophore component of holo-Lcn2 and not due to apo-Lcn2 alone. Extracellular apo-Lcn2 enhanced the potency of 2,3-DHBA and 2,5-DHBA to increase ROS production and decrease mitochondrial respiratory capacity, whereas intracellular apo-Lcn2 attenuated these effects. These actions of holo-Lcn2 required an intact plasma membrane and were decreased by inhibition of endocytosis. The hearts, but not serum, of Lcn2 knockout (LKO) mice contained lower levels of 2,5-DHBA compared with wild-type hearts. Furthermore, LKO mice were protected from ischemia/reperfusion-induced cardiac mitochondrial dysfunction. Our study identifies the siderophore moiety of holo-Lcn2 as a regulator of cardiomyocyte mitochondrial bioenergetics.
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Krismer B, Weidenmaier C, Zipperer A, Peschel A. The commensal lifestyle of Staphylococcus aureus and its interactions with the nasal microbiota. Nat Rev Microbiol 2017; 15:675-687. [PMID: 29021598 DOI: 10.1038/nrmicro.2017.104] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although human colonization by facultative bacterial pathogens, such as Staphylococcus aureus, represents a major risk factor for invasive infections, the commensal lifestyle of such pathogens has remained a neglected area of research. S. aureus colonizes the nares of approximately 30% of the human population and recent studies suggest that the composition of highly variable nasal microbiota has a major role in promoting or inhibiting S. aureus colonization. Competition for epithelial attachment sites or limited nutrients, different susceptibilities to host defence molecules and the production of antimicrobial molecules may determine whether nasal bacteria outcompete each other. In this Review, we discuss recent insights into mechanisms that are used by S. aureus to prevail in the human nose and the counter-strategies that are used by other nasal bacteria to interfere with its colonization. Understanding such mechanisms will be crucial for the development of new strategies for the eradication of endogenous facultative pathogens.
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Affiliation(s)
- Bernhard Krismer
- Interfaculty Institute of Microbiology and Infection Medicine, Infection Biology, University of Tübingen, 72076 Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany
| | - Christopher Weidenmaier
- German Centre for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany.,Interfaculty Institute of Microbiology and Infection Medicine, Medical Microbiology and Hygiene, University of Tübingen, 72076 Tübingen, Germany
| | - Alexander Zipperer
- Interfaculty Institute of Microbiology and Infection Medicine, Infection Biology, University of Tübingen, 72076 Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, Infection Biology, University of Tübingen, 72076 Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, 72076 Tübingen, Germany
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Future Directions and Molecular Basis of Ventilator Associated Pneumonia. Can Respir J 2017; 2017:2614602. [PMID: 29162982 PMCID: PMC5661065 DOI: 10.1155/2017/2614602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/14/2017] [Indexed: 12/26/2022] Open
Abstract
Mechanical ventilation is a lifesaving treatment and has complications such as ventilator associated pneumonia (VAP) that lead to high morbidity and mortality. Moreover VAP is the second most common hospital-acquired infection in pediatric intensive care units. Although it is still not well understood, understanding molecular pathogenesis is essential for preventing and treating pneumonia. A lot of microbes are detected as a causative agent of VAP. The most common isolated VAP pathogens in pediatric patients are Staphylococcus aureus, Pseudomonas aeruginosa, and other gram negative bacteria. All of the bacteria have different pathogenesis due to their different virulence factors and host reactions. This review article focused on mechanisms of VAP with molecular pathogenesis of the causative bacteria one by one from the literature. We hope that we know more about molecular pathogenesis of VAP and we can investigate and focus on the management of the disease in near future.
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Nas MY, Cianciotto NP. Stenotrophomonas maltophilia produces an EntC-dependent catecholate siderophore that is distinct from enterobactin. MICROBIOLOGY-SGM 2017; 163:1590-1603. [PMID: 28984234 DOI: 10.1099/mic.0.000545] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stenotrophomonas maltophilia, a Gram-negative, multi-drug-resistant bacterium, is increasingly recognized as a key opportunistic pathogen. Thus, we embarked upon an investigation of S. maltophilia iron acquisition. To begin, we determined that the genome of strain K279a is predicted to encode a complete siderophore system, including a biosynthesis pathway, an outer-membrane receptor for ferrisiderophore, and other import and export machinery. Compatible with these data, K279a and other clinical isolates of S. maltophilia secreted a siderophore-like activity when grown at 25-37 °C in low-iron media, as demonstrated by a chrome azurol S assay, which detects iron chelation, and Arnow and Rioux assays, which detect catecholate structures. Importantly, these supernatants rescued the growth of iron-starved S. maltophilia, documenting the presence of a biologically active siderophore. A mutation in one of the predicted biosynthesis genes (entC) abolished production of the siderophore and impaired bacterial growth in low-iron conditions. Inactivation of the putative receptor gene (fepA) prevented the utilization of siderophore-containing supernatants for growth in low-iron conditions. Although the biosynthesis and import loci showed some similarity to those of enterobactin, a well-known catecholate made by enteric bacteria, the siderophore of K279a was unable to rescue the growth of an enterobactin-utilizing indicator strain, and conversely iron-starved S. maltophilia could not use purified enterobactin. Furthermore, the S. maltophilia siderophore displayed patterns of solubility in organic compounds and mobility upon thin-layer chromatography that were distinct from those of enterobactin and its derivative, salmochelin. Together, these data demonstrate that S. maltophilia secretes a novel catecholate siderophore.
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Affiliation(s)
- Megan Y Nas
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
| | - Nicholas P Cianciotto
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
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Ali MK, Kim RY, Karim R, Mayall JR, Martin KL, Shahandeh A, Abbasian F, Starkey MR, Loustaud-Ratti V, Johnstone D, Milward EA, Hansbro PM, Horvat JC. Role of iron in the pathogenesis of respiratory disease. Int J Biochem Cell Biol 2017; 88:181-195. [PMID: 28495571 DOI: 10.1016/j.biocel.2017.05.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/01/2017] [Accepted: 05/03/2017] [Indexed: 12/13/2022]
Abstract
Iron is essential for many biological processes, however, too much or too little iron can result in a wide variety of pathological consequences, depending on the organ system, tissue or cell type affected. In order to reduce pathogenesis, iron levels are tightly controlled in throughout the body by regulatory systems that control iron absorption, systemic transport and cellular uptake and storage. Altered iron levels and/or dysregulated homeostasis have been associated with several lung diseases, including chronic obstructive pulmonary disease, lung cancer, cystic fibrosis, idiopathic pulmonary fibrosis and asthma. However, the mechanisms that underpin these associations and whether iron plays a key role in the pathogenesis of lung disease are yet to be fully elucidated. Furthermore, in order to survive and replicate, pathogenic micro-organisms have evolved strategies to source host iron, including freeing iron from cells and proteins that store and transport iron. To counter these microbial strategies, mammals have evolved immune-mediated defence mechanisms that reduce iron availability to pathogens. This interplay between iron, infection and immunity has important ramifications for the pathogenesis and management of human respiratory infections and diseases. An increased understanding of the role that iron plays in the pathogenesis of lung disease and respiratory infections may help inform novel therapeutic strategies. Here we review the clinical and experimental evidence that highlights the potential importance of iron in respiratory diseases and infections.
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Affiliation(s)
- Md Khadem Ali
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Richard Y Kim
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Rafia Karim
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Jemma R Mayall
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Kristy L Martin
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Ali Shahandeh
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Firouz Abbasian
- Global Centre for Environmental Remediation, Faculty of Science, the University of Newcastle, Callaghan, NSW 2308, Australia
| | - Malcolm R Starkey
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | | | - Daniel Johnstone
- Bosch Institute and Discipline of Physiology, The University of Sydney, Sydney NSW 2000, Australia
| | - Elizabeth A Milward
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Philip M Hansbro
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia
| | - Jay C Horvat
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, The University of Newcastle, Callaghan NSW 2308, Australia.
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Shan K, Pang R, Zhao C, Liu X, Gao W, Zhang J, Zhao D, Wang Y, Qiu W. IL-17-triggered downregulation of miR-497 results in high HIF-1α expression and consequent IL-1β and IL-6 production by astrocytes in EAE mice. Cell Mol Immunol 2017; 14:cmi201712. [PMID: 28458392 PMCID: PMC5675954 DOI: 10.1038/cmi.2017.12] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 01/16/2017] [Accepted: 01/31/2017] [Indexed: 01/14/2023] Open
Abstract
Interleukin 17 (IL-17) is increasingly recognized as a key factor that contributes to the pathogenesis of multiple sclerosis (MS) and its experimental mouse autoimmune encephalomyelitis (EAE) model. However, the roles and regulatory mechanisms of IL-17-induced pro-inflammatory cytokine production in EAE mice remain largely unclear. In this study, the expression of IL-17, hypoxia inducible factor-1α (HIF-1α), IL-1β, IL-6 and microRNA-497 (miR-497), as well as their intrinsic associations, was investigated using EAE model mice and cultured astrocytes exposed to IL-17 in vitro. We observed markedly increased production of IL-17, HIF-1α, IL-1β and IL-6 in the brain tissues of EAE mice, while the expression and secretion of HIF-1α, IL-1β and IL-6 were also significantly increased when cultured primary astrocytes from mice were stimulated with IL-17. Meanwhile, the expression of miR-497 was downregulated both in vivo and in vitro. Subsequent in vitro experiments revealed that IL-17 induced the production of IL-1β and IL-6 in astrocytes through the upregulation of HIF-1α as a transcriptional factor, indicating that IL-17-mediated downregulation of miR-497 enhanced HIF-1α expression. Furthermore, astrocyte-specific knockdown of IL-17RA and HIF-1α or astrocyte-specific overexpression of miR-497 by infection with different lentiviral vectors containing an astrocyte-specific promotor markedly decreased IL-1β and IL-6 production in brain tissues and alleviated the pathological changes and score of EAE mice. Collectively, these findings indicate that decreased miR-497 expression is responsible for IL-17-triggered high HIF-1α expression and consequent IL-1β and IL-6 production by astrocytes in EAE mice.Cellular & Molecular Immunology advance online publication, 1 May 2017; doi:10.1038/cmi.2017.12.
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Affiliation(s)
- Kai Shan
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Rongrong Pang
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Chenhui Zhao
- Department of Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiaomei Liu
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Department of Pathogen Biology and Immunology and Laboratory of Infection and Immunity, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Wenxing Gao
- Basic Medical Science of Basic Medical College, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Jing Zhang
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Dan Zhao
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Yingwei Wang
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Wen Qiu
- Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
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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: 86] [Impact Index Per Article: 12.3] [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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40
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Sassone-Corsi M, Chairatana P, Zheng T, Perez-Lopez A, Edwards RA, George MD, Nolan EM, Raffatellu M. Siderophore-based immunization strategy to inhibit growth of enteric pathogens. Proc Natl Acad Sci U S A 2016; 113:13462-13467. [PMID: 27821741 PMCID: PMC5127304 DOI: 10.1073/pnas.1606290113] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Infections with Gram-negative pathogens pose a serious threat to public health. This scenario is exacerbated by increases in antibiotic resistance and the limited availability of vaccines and therapeutic tools to combat these infections. Here, we report an immunization approach that targets siderophores, which are small molecules exported by enteric Gram-negative pathogens to acquire iron, an essential nutrient, in the host. Because siderophores are nonimmunogenic, we designed and synthesized conjugates of a native siderophore and the immunogenic carrier protein cholera toxin subunit B (CTB). Mice immunized with the CTB-siderophore conjugate developed anti-siderophore antibodies in the gut mucosa, and when mice were infected with the enteric pathogen Salmonella, they exhibited reduced intestinal colonization and reduced systemic dissemination of the pathogen. Moreover, analysis of the gut microbiota revealed that reduction of Salmonella colonization in the inflamed gut was accompanied by expansion of Lactobacillus spp., which are beneficial commensal organisms that thrive in similar locales as Enterobacteriaceae. Collectively, our results demonstrate that anti-siderophore antibodies inhibit Salmonella colonization. Because siderophore-mediated iron acquisition is a virulence trait shared by many bacterial and fungal pathogens, blocking microbial iron acquisition by siderophore-based immunization or other siderophore-targeted approaches may represent a novel strategy to prevent and ameliorate a broad range of infections.
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Affiliation(s)
- Martina Sassone-Corsi
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697
- Institute for Immunology, University of California, Irvine, CA 92697
| | - Phoom Chairatana
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Tengfei Zheng
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Araceli Perez-Lopez
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697
- Institute for Immunology, University of California, Irvine, CA 92697
| | - Robert A Edwards
- Department of Pathology and Laboratory Medicine, University of California, Irvine, CA 92697
| | - Michael D George
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139;
| | - Manuela Raffatellu
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697;
- Institute for Immunology, University of California, Irvine, CA 92697
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Abstract
Siderophores are small molecular iron chelators that are produced by microbes and whose most notable function is to sequester iron from the host and provide this essential metal nutrient to microbes. Recent studies have proposed additional, noncanonical roles for siderophores, including the acquisition of noniron metals and modulation of host functions. Recently, Holden et al. (V. I. Holden, P. Breen, S. Houle, C. M. Dozois, and M. A. Bachman, mBio 7:e01397-16, 2016, http://dx.doi.org/10.1128/mBio.01397-16) showed that siderophores secreted by Klebsiella pneumoniae during lung infection induce stabilization of the transcription factor HIF-1α, increase the expression of proinflammatory cytokines in the lung, and promote dissemination of K. pneumoniae to the spleen. Thus, their study demonstrated novel roles for siderophores in vivo, beyond iron sequestration. The interaction of siderophores with host cells further promotes the pathogenicity of K. pneumoniae and is likely relevant for other pathogens that also secrete siderophores in the host.
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Wilson BR, Bogdan AR, Miyazawa M, Hashimoto K, Tsuji Y. Siderophores in Iron Metabolism: From Mechanism to Therapy Potential. Trends Mol Med 2016; 22:1077-1090. [PMID: 27825668 DOI: 10.1016/j.molmed.2016.10.005] [Citation(s) in RCA: 262] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/10/2016] [Accepted: 10/12/2016] [Indexed: 12/28/2022]
Abstract
Iron is an essential nutrient for life. During infection, a fierce battle of iron acquisition occurs between the host and bacterial pathogens. Bacteria acquire iron by secreting siderophores, small ferric iron-binding molecules. In response, host immune cells secrete lipocalin 2 (also known as siderocalin), a siderophore-binding protein, to prevent bacterial reuptake of iron-loaded siderophores. To counter this threat, some bacteria can produce lipocalin 2-resistant siderophores. This review discusses the recently described molecular mechanisms of siderophore iron trafficking between host and bacteria, highlighting the therapeutic potential of exploiting pathogen siderophore machinery for the treatment of antibiotic-resistant bacterial infections. Because the latter reflect a persistent problem in hospital settings, siderophore-targeting or siderophore-based compounds represent a promising avenue to combat such infections.
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Affiliation(s)
- Briana R Wilson
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7633, USA
| | - Alexander R Bogdan
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7633, USA
| | - Masaki Miyazawa
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7633, USA
| | - Kazunori Hashimoto
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7633, USA
| | - Yoshiaki Tsuji
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695-7633, USA.
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Klebsiella pneumoniae Siderophores Induce Inflammation, Bacterial Dissemination, and HIF-1α Stabilization during Pneumonia. mBio 2016; 7:mBio.01397-16. [PMID: 27624128 PMCID: PMC5021805 DOI: 10.1128/mbio.01397-16] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Klebsiella pneumoniae is a Gram-negative pathogen responsible for a wide range of infections, including pneumonia and bacteremia, and is rapidly acquiring antibiotic resistance. K. pneumoniae requires secretion of siderophores, low-molecular-weight, high-affinity iron chelators, for bacterial replication and full virulence. The specific combination of siderophores secreted by K. pneumoniae during infection can impact tissue localization, systemic dissemination, and host survival. However, the effect of these potent iron chelators on the host during infection is unknown. In vitro, siderophores deplete epithelial cell iron, induce cytokine secretion, and activate the master transcription factor hypoxia inducible factor-1α (HIF-1α) protein that controls vascular permeability and inflammatory gene expression. Therefore, we hypothesized that siderophore secretion by K. pneumoniae directly contributes to inflammation and bacterial dissemination during pneumonia. To examine the effects of siderophore secretion independently of bacterial growth, we performed infections with tonB mutants that persist in vivo but are deficient in siderophore import. Using a murine model of pneumonia, we found that siderophore secretion by K. pneumoniae induces the secretion of interleukin-6 (IL-6), CXCL1, and CXCL2, as well as bacterial dissemination to the spleen, compared to siderophore-negative mutants at an equivalent bacterial number. Furthermore, we determined that siderophore-secreting K. pneumoniae stabilized HIF-1α in vivo and that bacterial dissemination to the spleen required alveolar epithelial HIF-1α. Our results indicate that siderophores act directly on the host to induce inflammatory cytokines and bacterial dissemination and that HIF-1α is a susceptibility factor for bacterial invasion during pneumonia. Klebsiella pneumoniae causes a wide range of bacterial diseases, including pneumonia, urinary tract infections, and sepsis. To cause infection, K. pneumoniae steals iron from its host by secreting siderophores, small iron-chelating molecules. Classically, siderophores are thought to worsen infections by promoting bacterial growth. In this study, we determined that siderophore-secreting K. pneumoniae causes lung inflammation and bacterial dissemination to the bloodstream independently of bacterial growth. Furthermore, we determined that siderophore-secreting K. pneumoniae activates a host protein, hypoxia inducible factor (HIF)-1α, and requires it for siderophore-dependent bacterial dissemination. Although HIF-1α can protect against some infections, it appears to worsen infection with K. pneumoniae. Together, these results indicate that bacterial siderophores directly alter the host response to pneumonia in addition to providing iron for bacterial growth. Therapies that disrupt production of siderophores could provide a two-pronged attack against K. pneumoniae infection by preventing bacterial growth and preventing bacterial dissemination to the blood.
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Glover LE, Lee JS, Colgan SP. Oxygen metabolism and barrier regulation in the intestinal mucosa. J Clin Invest 2016; 126:3680-3688. [PMID: 27500494 DOI: 10.1172/jci84429] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mucosal surfaces are lined by epithelial cells and provide an important barrier to the flux of antigens from the outside. This barrier is provided at a number of levels, including epithelial junctional complexes, mucus production, and mucosa-derived antimicrobials. Tissue metabolism is central to the maintenance of homeostasis in the mucosa. In the intestine, for example, baseline pO2 levels are uniquely low due to counter-current blood flow and the presence of large numbers of bacteria. As such, hypoxia and HIF signaling predominates normal intestinal metabolism and barrier regulation during both homeostasis and active inflammation. Contributing factors that elicit important adaptive responses within the mucosa include the transcriptional regulation of tight junction proteins, metabolic regulation of barrier components, and changes in autophagic flux. Here, we review recent literature around the topic of hypoxia and barrier function in health and during disease.
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Singh V, Yeoh BS, Chassaing B, Zhang B, Saha P, Xiao X, Awasthi D, Shashidharamurthy R, Dikshit M, Gewirtz A, Vijay-Kumar M. Microbiota-inducible Innate Immune, Siderophore Binding Protein Lipocalin 2 is Critical for Intestinal Homeostasis. Cell Mol Gastroenterol Hepatol 2016; 2:482-498.e6. [PMID: 27458605 PMCID: PMC4957954 DOI: 10.1016/j.jcmgh.2016.03.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Lipocalin 2 (Lcn2) is a multifunctional innate immune protein whose expression closely correlates with extent of intestinal inflammation. However, whether Lcn2 plays a role in the pathogenesis of gut inflammation is unknown. Herein, we investigated the extent to which Lcn2 regulates inflammation and gut bacterial dysbiosis in mouse models of IBD. METHODS Lcn2 expression was monitored in murine colitis models and upon microbiota ablation/restoration. WT and Lcn2 knockout (Lcn2KO) mice were analyzed for gut bacterial load, composition by 16S rRNA gene pyrosequencing and, their colitogenic potential by co-housing with Il-10KO mice. Acute (dextran sodium sulfate) and chronic (IL-10R neutralization and T-cell adoptive transfer) colitis was induced in WT and Lcn2KO mice with or without antibiotics. RESULTS Lcn2 expression was dramatically induced upon inflammation and was dependent upon presence of a gut microbiota and MyD88 signaling. Use of bone-marrow chimeric mice revealed non-immune cells are the major contributors of circulating Lcn2. Lcn2KO mice exhibited elevated levels of entA-expressing gut bacteria burden and, moreover, a broadly distinct bacterial community relative to WT littermates. Lcn2KO mice developed highly colitogenic T-cells and exhibited exacerbated colitis upon exposure to DSS or neutralization of IL-10. Such exacerbated colitis could be prevented by antibiotic treatment. Moreover, exposure to the microbiota of Lcn2KO mice, via cohousing, resulted in severe colitis in Il-10KO mice. CONCLUSION Lcn2 is a bacterially-induced, MyD88-dependent, protein that play an important role in gut homeostasis and a pivotal role upon challenge. Hence, therapeutic manipulation of Lcn2 levels may provide a strategy to help manage diseases driven by alteration of the gut microbiota.
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Affiliation(s)
- Vishal Singh
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Beng San Yeoh
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Benoit Chassaing
- Center for Inflammation, Immunity and Infection, Institute of Biomedical Sciences, Georgia State University, Atlanta, Georgia
| | - Benyue Zhang
- Center for Inflammation, Immunity and Infection, Institute of Biomedical Sciences, Georgia State University, Atlanta, Georgia
| | - Piu Saha
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Xia Xiao
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Deepika Awasthi
- Pharmacology Division, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | | | - Madhu Dikshit
- Pharmacology Division, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow, India
| | - Andrew Gewirtz
- Center for Inflammation, Immunity and Infection, Institute of Biomedical Sciences, Georgia State University, Atlanta, Georgia
| | - 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,Correspondence Address correspondence to: Matam Vijay-Kumar, PhD, Department of Nutritional Sciences 222, Chandlee Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802. fax: (814) 863-6103.Department of Nutritional Sciences 222Chandlee LaboratoryThe Pennsylvania State UniversityUniversity ParkPennsylvania 16802
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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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Jensen-Jarolim E, Pacios LF, Bianchini R, Hofstetter G, Roth-Walter F. Structural similarities of human and mammalian lipocalins, and their function in innate immunity and allergy. Allergy 2016; 71:286-94. [PMID: 26497994 PMCID: PMC4949658 DOI: 10.1111/all.12797] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2015] [Indexed: 01/08/2023]
Abstract
Owners and their domestic animals via skin shedding and secretions, mutually exchange microbiomes, potential pathogens and innate immune molecules. Among the latter especially lipocalins are multifaceted: they may have an immunomodulatory function and, furthermore, they represent one of the most important animal allergen families. The amino acid identities, as well as their structures by superposition modeling were compared among human lipocalins, hLCN1 and hLCN2, and most important animal lipocalin allergens, such as Can f 1, Can f 2 and Can f 4 from dog, Fel d 4 from cats, Bos d 5 from cow's milk, Equ c 1 from horses, and Mus m 1 from mice, all of them representing major allergens. The β-barrel fold with a central molecular pocket is similar among human and animal lipocalins. Thereby, lipocalins are able to transport a variety of biological ligands in their highly conserved calyx-like cavity, among them siderophores with the strongest known capability to complex iron (Fe(3+) ). Levels of human lipocalins are elevated in nonallergic inflammation and cancer, associated with innate immunoregulatory functions that critically depend on ligand load. Accordingly, deficient loading of lipocalin allergens establishes their capacity to induce Th2 hypersensitivity. Our similarity analysis of human and mammalian lipocalins highlights their function in innate immunity and allergy.
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Affiliation(s)
- E Jensen-Jarolim
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
- Institute of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University Vienna, Vienna, Austria
| | - L F Pacios
- Biotechnology Department, Center for Plant Biotechnology and Genomics, ETSI Montes, Technical University of Madrid, Madrid, Spain
- Department of Natural Systems and Resources, ETSI Montes, Technical University of Madrid, Madrid, Spain
| | - R Bianchini
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
| | - G Hofstetter
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
| | - F Roth-Walter
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
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Abstract
Ancient bacteria originated from metal-rich environments. Billions of years of evolution directed these tiny single cell creatures to exploit the versatile properties of metals in catalyzing chemical reactions and biological responses. The result is an entire metallome of proteins that use metal co-factors to facilitate key cellular process that range from the production of energy to the replication of DNA. Two key metals in this regard are iron and zinc, both abundant on Earth but not readily accessible in a human host. Instead, pathogenic bacteria must employ clever ways to acquire these metals. In this review we describe the many elegant ways these bacteria mine, regulate, and craft the use of two key metals (iron and zinc) to build a virulence arsenal that challenges even the most sophisticated immune response.
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Affiliation(s)
- Li Ma
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77459, USA.
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