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Ansari I, Mandal A, Kansal K, Walling P, Khan S, Aijaz S. The C-terminal proline-rich repeats of Enteropathogenic E. coli effector EspF are sufficient for the depletion of tight junction membrane proteins and interactions with early and recycling endosomes. Gut Pathog 2024; 16:36. [PMID: 38972985 PMCID: PMC11229284 DOI: 10.1186/s13099-024-00626-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 06/28/2024] [Indexed: 07/09/2024] Open
Abstract
BACKGROUND Enteropathogenic E. coli (EPEC) causes acute infantile diarrhea accounting for significant morbidity and mortality in developing countries. EPEC uses a type three secretion system to translocate more than twenty effectors into the host intestinal cells. At least four of these effectors, namely EspF, Map, EspG1/G2 and NleA, are reported to disrupt the intestinal tight junction barrier. We have reported earlier that the expression of EspF and Map in MDCK cells causes the depletion of the TJ membrane proteins and compromises the integrity of the intestinal barrier. In the present study, we have examined the role of the proline-rich repeats (PRRs) within the C-terminus of EspF in the depletion of the tight junction membrane proteins and identified key endocytosis markers that interact with EspF via these repeats. RESULTS We generated mutant EspF proteins which lacked one or more proline-rich repeats (PRRs) from the N-terminus of EspF and examined the effect of their expression on the cellular localization of tight junction membrane proteins. In lysates derived from cells expressing the mutant EspF proteins, we found that the C-terminal PRRs of EspF are sufficient to cause the depletion of TJ membrane proteins. Pull-down assays revealed that the PRRs mediate interactions with the TJ adaptor proteins ZO-1 and ZO-2 as well as with the proteins involved in endocytosis such as caveolin-1, Rab5A and Rab11. CONCLUSIONS Our study demonstrates the direct role of the proline-rich repeats of EspF in the depletion of the TJ membrane proteins and a possible involvement of the PRRs in the endocytosis of host proteins. New therapeutic strategies can target these PRR domains to prevent intestinal barrier dysfunction in EPEC infections.
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Affiliation(s)
- Imran Ansari
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Anupam Mandal
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Kritika Kansal
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Pangertoshi Walling
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Sumbul Khan
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Saima Aijaz
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
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2
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Massier L, Musat N, Stumvoll M, Tremaroli V, Chakaroun R, Kovacs P. Tissue-resident bacteria in metabolic diseases: emerging evidence and challenges. Nat Metab 2024; 6:1209-1224. [PMID: 38898236 DOI: 10.1038/s42255-024-01065-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
Although the impact of the gut microbiome on health and disease is well established, there is controversy regarding the presence of microorganisms such as bacteria and their products in organs and tissues. However, recent contamination-aware findings of tissue-resident microbial signatures provide accumulating evidence in support of bacterial translocation in cardiometabolic disease. The latter provides a distinct paradigm for the link between microbial colonizers of mucosal surfaces and host metabolism. In this Perspective, we re-evaluate the concept of tissue-resident bacteria including their role in metabolic low-grade tissue and systemic inflammation. We examine the limitations and challenges associated with studying low bacterial biomass samples and propose experimental and analytical strategies to overcome these issues. Our Perspective aims to encourage further investigation of the mechanisms linking tissue-resident bacteria to host metabolism and their potentially actionable health implications for prevention and treatment.
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Affiliation(s)
- Lucas Massier
- Department of Medicine (H7), Karolinska Institutet, Stockholm, Sweden
| | - Niculina Musat
- Aarhus University, Department of Biology, Section for Microbiology, Århus, Denmark
| | - Michael Stumvoll
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Valentina Tremaroli
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Rima Chakaroun
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany.
- Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
| | - Peter Kovacs
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany.
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3
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Rogers AP, Mileto SJ, Lyras D. Impact of enteric bacterial infections at and beyond the epithelial barrier. Nat Rev Microbiol 2023; 21:260-274. [PMID: 36175770 DOI: 10.1038/s41579-022-00794-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2022] [Indexed: 11/09/2022]
Abstract
The mucosal lining of the gut has co-evolved with a diverse microbiota over millions of years, leading to the development of specialized mechanisms to actively limit the invasion of pathogens. However, some enteric microorganisms have adapted against these measures, developing ways to hijack or overcome epithelial micro-integrity mechanisms. This breach of the gut barrier not only enables the leakage of host factors out of circulation but can also initiate a cascade of detrimental systemic events as microbiota, pathogens and their affiliated secretions passively leak into extra-intestinal sites. Under normal circumstances, gut damage is rapidly repaired by intestinal stem cells. However, with substantial and deep perturbation to the gut lining and the systemic dissemination of gut contents, we now know that some enteric infections can cause the impairment of host regenerative processes. Although these local and systemic aspects of enteric disease are often studied in isolation, they heavily impact one another. In this Review, by examining the journey of enteric infections from initial establishment to systemic sequelae and how, or if, the host can successfully repair damage, we will tie together these complex interactions to provide a holistic overview of the impact of enteric infections at and beyond the epithelial barrier.
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Affiliation(s)
- Ashleigh P Rogers
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Steven J Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia. .,Department of Microbiology, Monash University, Melbourne, Victoria, Australia.
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4
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Achi SC, Karimilangi S, Lie D, Sayed IM, Das S. The WxxxE proteins in microbial pathogenesis. Crit Rev Microbiol 2023; 49:197-213. [PMID: 35287539 PMCID: PMC9737147 DOI: 10.1080/1040841x.2022.2046546] [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: 10/23/2021] [Revised: 02/10/2022] [Accepted: 02/19/2022] [Indexed: 12/14/2022]
Abstract
Effector proteins secreted by pathogens modulate various host cellular processes and help in bacterial pathogenesis. Some of these proteins, injected by enteric pathogens via Type Three Secretion System (T3SS) were grouped together based on a conserved signature motif (WxxxE) present in them. The presence of WxxxE motif is not limited to effectors released by enteric pathogens or the T3SS but has been detected in non-enteric pathogens, plant pathogens and in association with Type II and Type IV secretion systems. WxxxE effectors are involved in actin organization, inflammation regulation, vacuole or tubule formation, endolysosomal signalling regulation, tight junction disruption, and apoptosis. The WxxxE sequence has also been identified in TIR [Toll/interleukin-1 (IL-1) receptor] domains of bacteria and host. In the present review, we have focussed on the established and predicted functions of WxxxE effectors secreted by several pathogens, including enteric, non-enteric, and plant pathogens.
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Affiliation(s)
| | - Sareh Karimilangi
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Dominique Lie
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Ibrahim M. Sayed
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
| | - Soumita Das
- Department of Pathology, University of California San Diego, La Jolla, CA, USA
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5
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Kaur P, Dudeja PK. Pathophysiology of Enteropathogenic Escherichia coli-induced Diarrhea. NEWBORN (CLARKSVILLE, MD.) 2023; 2:102-113. [PMID: 37388762 PMCID: PMC10308259 DOI: 10.5005/jp-journals-11002-0056] [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: 07/01/2023]
Abstract
Enteropathogenic Escherichia coli (EPEC) are important diarrheal pathogens of infants and young children. Since the availability of molecular diagnosis methods, we now have new insights into the incidence and prevalence of these infections. Recent epidemiological studies indicate that atypical EPEC (aEPEC) are seen more frequently than typical EPEC (tEPEC) worldwide, including in both endemic diarrhea and diarrhea outbreaks. Therefore, it is important to further characterize the pathogenicity of these emerging strains. The virulence mechanisms and pathophysiology of the attaching and effacing lesion (A/E) and the type-three-secretion-system (T3SS) are complex but well-studied. A/E strains use their pool of locus of enterocyte effacement (LEE)-encoded and non-LEE-encoded effector proteins to subvert and modulate cellular and barrier properties of the host. However, the exact mechanisms of diarrhea in EPEC infection are not completely understood. From the clinical perspective, there is a need for fast, easy, and inexpensive diagnostic methods to define optimal treatment and prevention for children in endemic areas. In this article, we present a review of the classification of EPEC, epidemiology, pathogenesis of the disease caused by these bacteria, determinants of virulence, alterations in signaling, determinants of colonization vs. those of disease, and the limited information we have on the pathophysiology of EPEC-induced diarrhea. This article combines peer-reviewed evidence from our own studies and the results of an extensive literature search in the databases PubMed, EMBASE, and Scopus.
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Affiliation(s)
- Prabhdeep Kaur
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Illinois, United States of America
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
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6
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Clerbaux LA, Fillipovska J, Muñoz A, Petrillo M, Coecke S, Amorim MJ, Grenga L. Mechanisms Leading to Gut Dysbiosis in COVID-19: Current Evidence and Uncertainties Based on Adverse Outcome Pathways. J Clin Med 2022; 11:5400. [PMID: 36143044 PMCID: PMC9505288 DOI: 10.3390/jcm11185400] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/24/2022] [Accepted: 09/09/2022] [Indexed: 02/06/2023] Open
Abstract
Alteration in gut microbiota has been associated with COVID-19. However, the underlying mechanisms remain poorly understood. Here, we outlined three potential interconnected mechanistic pathways leading to gut dysbiosis as an adverse outcome following SARS-CoV-2 presence in the gastrointestinal tract. Evidence from the literature and current uncertainties are reported for each step of the different pathways. One pathway investigates evidence that intestinal infection by SARS-CoV-2 inducing intestinal inflammation alters the gut microbiota. Another pathway links the binding of viral S protein to angiotensin-converting enzyme 2 (ACE2) to the dysregulation of this receptor, essential in intestinal homeostasis-notably for amino acid metabolism-leading to gut dysbiosis. Additionally, SARS-CoV-2 could induce gut dysbiosis by infecting intestinal bacteria. Assessing current evidence within the Adverse Outcome Pathway framework justifies confidence in the proposed mechanisms to support disease management and permits the identification of inconsistencies and knowledge gaps to orient further research.
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Affiliation(s)
| | | | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | | | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
| | - Maria-Joao Amorim
- Instituto Gulbenkian de Ciência, 2780-156 Oerias, Portugal
- Católica Medical School, Católica Biomedical Research Centre, Universidade Católica Portuguesa, 1649-023 Lisbon, Portugal
| | - Lucia Grenga
- Département Médicaments et Technologies pour la Santé, Commissariat à l’Énergie Atomique et Aux Énergies Alternatives (CEA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Paris-Saclay, 30200 Bagnols-sur-Cèze, France
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7
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Clerbaux LA, Albertini MC, Amigó N, Beronius A, Bezemer GFG, Coecke S, Daskalopoulos EP, del Giudice G, Greco D, Grenga L, Mantovani A, Muñoz A, Omeragic E, Parissis N, Petrillo M, Saarimäki LA, Soares H, Sullivan K, Landesmann B. Factors Modulating COVID-19: A Mechanistic Understanding Based on the Adverse Outcome Pathway Framework. J Clin Med 2022; 11:4464. [PMID: 35956081 PMCID: PMC9369763 DOI: 10.3390/jcm11154464] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/10/2022] Open
Abstract
Addressing factors modulating COVID-19 is crucial since abundant clinical evidence shows that outcomes are markedly heterogeneous between patients. This requires identifying the factors and understanding how they mechanistically influence COVID-19. Here, we describe how eleven selected factors (age, sex, genetic factors, lipid disorders, heart failure, gut dysbiosis, diet, vitamin D deficiency, air pollution and exposure to chemicals) influence COVID-19 by applying the Adverse Outcome Pathway (AOP), which is well-established in regulatory toxicology. This framework aims to model the sequence of events leading to an adverse health outcome. Several linear AOPs depicting pathways from the binding of the virus to ACE2 up to clinical outcomes observed in COVID-19 have been developed and integrated into a network offering a unique overview of the mechanisms underlying the disease. As SARS-CoV-2 infectibility and ACE2 activity are the major starting points and inflammatory response is central in the development of COVID-19, we evaluated how those eleven intrinsic and extrinsic factors modulate those processes impacting clinical outcomes. Applying this AOP-aligned approach enables the identification of current knowledge gaps orientating for further research and allows to propose biomarkers to identify of high-risk patients. This approach also facilitates expertise synergy from different disciplines to address public health issues.
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Affiliation(s)
- Laure-Alix Clerbaux
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | | | - Núria Amigó
- Biosfer Teslab SL., 43204 Reus, Spain;
- Department of Basic Medical Sciences, Universitat Rovira i Virgili (URV), 23204 Reus, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
| | - Anna Beronius
- Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm, Sweden;
| | - Gillina F. G. Bezemer
- Impact Station, 1223 JR Hilversum, The Netherlands;
- Department of Pharmaceutical Sciences, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands
| | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Evangelos P. Daskalopoulos
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Giusy del Giudice
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Dario Greco
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Lucia Grenga
- Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, F-30200 Bagnols-sur-Ceze, France;
| | - Alberto Mantovani
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium;
| | - Elma Omeragic
- Faculty of Pharmacy, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Nikolaos Parissis
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Mauro Petrillo
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
| | - Laura A. Saarimäki
- Finnish Hub for Development and Validation of Integrated Approaches (FHAIVE), Faculty of Medicine and Health Technology, Tampere University, 33100 Tampere, Finland; (G.d.G.); (D.G.); (L.A.S.)
| | - Helena Soares
- Laboratory of Immunobiology and Pathogenesis, Chronic Diseases Research Centre, Faculdade de Ciências Médicas Medical School, University of Lisbon, 1649-004 Lisbon, Portugal;
| | - Kristie Sullivan
- Physicians Committee for Responsible Medicine, Washington, DC 20016, USA;
| | - Brigitte Landesmann
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy; (S.C.); (E.P.D.); (N.P.); (M.P.); (B.L.)
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Yu S, Sun Y, Shao X, Zhou Y, Yu Y, Kuai X, Zhou C. Leaky Gut in IBD: Intestinal Barrier-Gut Microbiota Interaction. J Microbiol Biotechnol 2022; 32:825-834. [PMID: 35791076 PMCID: PMC9628915 DOI: 10.4014/jmb.2203.03022] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/26/2022] [Accepted: 06/28/2022] [Indexed: 12/15/2022]
Abstract
Inflammatory bowel disease (IBD) is a global disease that is in increasing incidence. The gut, which contains the largest amount of lymphoid tissue in the human body, as well as a wide range of nervous system components, is integral in ensuring intestinal homeostasis and function. By interacting with gut microbiota, immune cells, and the enteric nervous system, the intestinal barrier, which is a solid barrier, protects the intestinal tract from the external environment, thereby maintaining homeostasis throughout the body. Destruction of the intestinal barrier is referred to as developing a "leaky gut," which causes a series of changes relating to the occurrence of IBD. Changes in the interactions between the intestinal barrier and gut microbiota are particularly crucial in the development of IBD. Exploring the leaky gut and its interaction with the gut microbiota, immune cells, and the neuroimmune system may help further explain the pathogenesis of IBD and provide potential therapeutic methods for future use.
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Affiliation(s)
- Shunying Yu
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China
| | - Yibin Sun
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China
| | - Xinyu Shao
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China
| | - Yuqing Zhou
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China
| | - Yang Yu
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China
| | - Xiaoyi Kuai
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China,
X. Kuai Phone: +86-13776084279 E-mail:
| | - Chunli Zhou
- Department of Gastroenterology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou 215001, Jiangsu, P.R. China,Corresponding authors C. Zhou Phone: +86-13962124345 E-mail:
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Sanchez-Garrido J, Ruano-Gallego D, Choudhary JS, Frankel G. The type III secretion system effector network hypothesis. Trends Microbiol 2022; 30:524-533. [PMID: 34840074 DOI: 10.1016/j.tim.2021.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 11/18/2022]
Abstract
Type III secretion system (T3SS) effectors are key virulence factors that underpin the infection strategy of many clinically important Gram-negative pathogens, including Salmonella enterica, Shigella spp., enteropathogenic and enterohemorrhagic Escherichia coli and their murine equivalent, Citrobacter rodentium. The cellular processes or proteins targeted by the effectors can be common to multiple pathogens or pathogen-specific. The main approach to understanding T3SS-mediated pathogenesis has been to determine the contribution of one effector at a time, with the aim of piecing together individual functions and unveiling infection mechanisms. However, in contrast to this prevailing approach, simultaneous deletion of multiple effectors revealed that they function as an interconnected network in vivo, uncovering effector codependency and context-dependent effector essentiality. This paradigm shift in T3SS biology is at the heart of this opinion article.
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Affiliation(s)
- Julia Sanchez-Garrido
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK.
| | - David Ruano-Gallego
- Department of Molecular Evolution, Centro de Astrobiología, Instituto Nacional de Técnica Aeroespacial-Consejo Superior de Investigaciones Científicas (INTA-CSIC), Madrid, Spain.
| | - Jyoti S Choudhary
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
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10
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Ngo PA, Neurath MF, López-Posadas R. Impact of Epithelial Cell Shedding on Intestinal Homeostasis. Int J Mol Sci 2022; 23:ijms23084160. [PMID: 35456978 PMCID: PMC9027054 DOI: 10.3390/ijms23084160] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 02/04/2023] Open
Abstract
The gut barrier acts as a first line of defense in the body, and plays a vital role in nutrition and immunoregulation. A layer of epithelial cells bound together via intercellular junction proteins maintains intestinal barrier integrity. Based on a tight equilibrium between cell extrusion and cell restitution, the renewal of the epithelium (epithelial turnover) permits the preservation of cell numbers. As the last step within the epithelial turnover, cell shedding occurs due to the pressure of cell division and migration from the base of the crypt. During this process, redistribution of tight junction proteins enables the sealing of the epithelial gap left by the extruded cell, and thereby maintains barrier function. Disturbance in cell shedding can create transient gaps (leaky gut) or cell accumulation in the epithelial layer. In fact, numerous studies have described the association between dysregulated cell shedding and infection, inflammation, and cancer; thus epithelial cell extrusion is considered a key defense mechanism. In the gastrointestinal tract, altered cell shedding has been observed in mouse models of intestinal inflammation and appears as a potential cause of barrier loss in human inflammatory bowel disease (IBD). Despite the relevance of this process, there are many unanswered questions regarding cell shedding. The investigation of those mechanisms controlling cell extrusion in the gut will definitely contribute to our understanding of intestinal homeostasis. In this review, we summarized the current knowledge about intestinal cell shedding under both physiological and pathological circumstances.
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Affiliation(s)
- Phuong A. Ngo
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; (P.A.N.); (M.F.N.)
- Deutsches Zentrum Immuntherapie (DZI), 91054 Erlangen, Germany
| | - Markus F. Neurath
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; (P.A.N.); (M.F.N.)
- Deutsches Zentrum Immuntherapie (DZI), 91054 Erlangen, Germany
| | - Rocío López-Posadas
- Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; (P.A.N.); (M.F.N.)
- Deutsches Zentrum Immuntherapie (DZI), 91054 Erlangen, Germany
- Correspondence:
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11
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Jiang L, Yang W, Jiang X, Yao T, Wang L, Yang B. Virulence-related O islands in enterohemorrhagic Escherichia coli O157:H7. Gut Microbes 2022; 13:1992237. [PMID: 34711138 PMCID: PMC8565820 DOI: 10.1080/19490976.2021.1992237] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a principally foodborne pathogen linked to serious diseases, including bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Comparative genomics analysis revealed that EHEC O157 contains 177 unique genomic islands, termed O islands, compared with the nonpathogenic E. coli K-12 laboratory strain. These O islands contribute largely to the pathogenicity of EHEC O157:H7 by providing numerous virulence factors, effectors, virulence regulatory proteins, and virulence regulatory sRNAs. The present review aimed to provide a comprehensive understanding of the research progress on the function of O islands, especially focusing on virulence-related O islands.
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Affiliation(s)
- Lingyan Jiang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Wen Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Xinlei Jiang
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, P. R. China
| | - Ting Yao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Lu Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China,CONTACT Bin Yang TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin300457, P. R. China
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12
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Xue Y, Zhu MJ. Unraveling enterohemorrhagic Escherichia coli infection: the promising role of dietary compounds and probiotics in bacterial elimination and host innate immunity boosting. Crit Rev Food Sci Nutr 2021; 63:1551-1563. [PMID: 34404306 DOI: 10.1080/10408398.2021.1965538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The innate immune system has developed sophisticated strategies to defense against infections. Host cells utilize the recognition machineries such as toll-like receptors and nucleotide binding and oligomerization domain-like receptors to identify the pathogens and alert immune system. However, some pathogens have developed tactics to evade host defenses, including manipulation of host inflammatory response, interference with cell death pathway, and highjack of phagocytosis signaling for a better survival and colonization in host. Enterohemorrhagic Escherichia coli (EHEC) is a notorious foodborne pathogen that causes severe tissue damages and gastrointestinal diseases, which has been reported to disturb host immune responses. Diverse bioactive compounds such as flavonoids, phenolic acids, alkaloids, saccharides, and terpenoids derived from food varieties and probiotics have been discovered and investigated for their capability of combating bacterial infections. Some of them serve as novel antimicrobial agents and act as immune boosters that harness host immune system. In this review, we will discuss how EHEC, specifically E. coli O157:H7, hijacks the host immune system and interferes with host signaling pathway; and highlight the promising role of food-derived bioactive compounds and probiotics in harnessing host innate immunity and eliminating E. coli O157:H7 infection with multiple strategies.
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Affiliation(s)
- Yansong Xue
- Key Laboratory of Functional Dairy, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA, USA
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13
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Nandi I, Aroeti L, Ramachandran RP, Kassa EG, Zlotkin-Rivkin E, Aroeti B. Type III secreted effectors that target mitochondria. Cell Microbiol 2021; 23:e13352. [PMID: 33960116 DOI: 10.1111/cmi.13352] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/22/2021] [Accepted: 04/29/2021] [Indexed: 01/05/2023]
Abstract
A type III secretion system (T3SS) is used by Gram-negative bacterial pathogens to secrete and translocate a battery of proteins, termed effectors, from the bacteria directly into the host cells. These effectors, which are thought to play a key role in bacterial virulence, hijack and modify the activity of diverse host cell organelles, including mitochondria. Mitochondria-the energy powerhouse of the cell-are important cell organelles that play role in numerous critical cellular processes, including the initiation of apoptosis and the induction of innate immunity. Therefore, it is not surprising that pathogenic bacteria use mitochondrially targeted effectors to control host cell death and immunity pathways. Surprisingly, however, we found that despite their importance, only a limited number of type III secreted effectors have been characterised to target host mitochondria, and the mechanisms underlying their mitochondrial activity have not been sufficiently analysed. These include effectors secreted by the enteric attaching and effacing (A/E), Salmonella and Shigella bacterial pathogens. Here we give an overview of key findings, present gaps in knowledge and hypotheses concerning the mode by which these type III secreted effectors control the host and the bacterial cell life (and death) through targeting mitochondria.
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Affiliation(s)
- Ipsita Nandi
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lior Aroeti
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachana Pattani Ramachandran
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ephrem G Kassa
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Efrat Zlotkin-Rivkin
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Benjamin Aroeti
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
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14
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Hajra D, Nair AV, Chakravortty D. An elegant nano-injection machinery for sabotaging the host: Role of Type III secretion system in virulence of different human and animal pathogenic bacteria. Phys Life Rev 2021; 38:25-54. [PMID: 34090822 DOI: 10.1016/j.plrev.2021.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 01/22/2023]
Abstract
Various Gram-negative bacteria possess a specialized membrane-bound protein secretion system known as the Type III secretion system (T3SS), which transports the bacterial effector proteins into the host cytosol thereby helping in bacterial pathogenesis. The T3SS has a special needle-like translocon that can sense the contact with the host cell membrane and translocate effectors. The export apparatus of T3SS recognizes these effector proteins bound to chaperones and translocates them into the host cell. Once in the host cell cytoplasm, these effector proteins result in modulation of the host system and promote bacterial localization and infection. Using molecular biology, bioinformatics, genetic techniques, electron microscopic studies, and mathematical modeling, the structure and function of the T3SS and the corresponding effector proteins in various bacteria have been studied. The strategies used by different human pathogenic bacteria to modulate the host system and thereby enhance their virulence mechanism using T3SS have also been well studied. Here we review the history, evolution, and general structure of the T3SS, highlighting the details of its comparison with the flagellar export machinery. Also, this article provides mechanistic details about the common role of T3SS in subversion and manipulation of host cellular processes. Additionally, this review describes specific T3SS apparatus and the role of their specific effectors in bacterial pathogenesis by considering several human and animal pathogenic bacteria.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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15
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Ruano-Gallego D, Sanchez-Garrido J, Kozik Z, Núñez-Berrueco E, Cepeda-Molero M, Mullineaux-Sanders C, Naemi Baghshomali Y, Slater SL, Wagner N, Glegola-Madejska I, Roumeliotis TI, Pupko T, Fernández LÁ, Rodríguez-Patón A, Choudhary JS, Frankel G. Type III secretion system effectors form robust and flexible intracellular virulence networks. Science 2021; 371:eabc9531. [PMID: 33707240 DOI: 10.1126/science.abc9531] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/15/2020] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
Infections with many Gram-negative pathogens, including Escherichia coli, Salmonella, Shigella, and Yersinia, rely on type III secretion system (T3SS) effectors. We hypothesized that while hijacking processes within mammalian cells, the effectors operate as a robust network that can tolerate substantial contractions. This was tested in vivo using the mouse pathogen Citrobacter rodentium (encoding 31 effectors). Sequential gene deletions showed that effector essentiality for infection was context dependent and that the network could tolerate 60% contraction while maintaining pathogenicity. Despite inducing very different colonic cytokine profiles (e.g., interleukin-22, interleukin-17, interferon-γ, or granulocyte-macrophage colony-stimulating factor), different networks induced protective immunity. Using data from >100 distinct mutant combinations, we built and trained a machine learning model able to predict colonization outcomes, which were confirmed experimentally. Furthermore, reproducing the human-restricted enteropathogenic E. coli effector repertoire in C. rodentium was not sufficient for efficient colonization, which implicates effector networks in host adaptation. These results unveil the extreme robustness of both T3SS effector networks and host responses.
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Affiliation(s)
- David Ruano-Gallego
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Julia Sanchez-Garrido
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Zuzanna Kozik
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Elena Núñez-Berrueco
- Laboratorio de Inteligencia Artificial, Departamento de Inteligencia Artificial, Universidad Politécnica de Madrid, Campus de Montegancedo, Boadilla del Monte, Madrid, Spain
| | - Massiel Cepeda-Molero
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | | | - Yasaman Naemi Baghshomali
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Sabrina L Slater
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Izabela Glegola-Madejska
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Theodoros I Roumeliotis
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Luis Ángel Fernández
- Centro Nacional de Biotecnología (CNB-CSIC), Department of Microbial Biotechnology, Madrid, Spain
| | - Alfonso Rodríguez-Patón
- Laboratorio de Inteligencia Artificial, Departamento de Inteligencia Artificial, Universidad Politécnica de Madrid, Campus de Montegancedo, Boadilla del Monte, Madrid, Spain
| | - Jyoti S Choudhary
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK.
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK.
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16
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Tight Junctions as a Key for Pathogens Invasion in Intestinal Epithelial Cells. Int J Mol Sci 2021; 22:ijms22052506. [PMID: 33801524 PMCID: PMC7958858 DOI: 10.3390/ijms22052506] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/21/2021] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
Tight junctions play a major role in maintaining the integrity and impermeability of the intestinal barrier. As such, they act as an ideal target for pathogens to promote their translocation through the intestinal mucosa and invade their host. Different strategies are used by pathogens, aimed at directly destabilizing the junctional network or modulating the different signaling pathways involved in the modulation of these junctions. After a brief presentation of the organization and modulation of tight junctions, we provide the state of the art of the molecular mechanisms leading to permeability breakdown of the gut barrier as a consequence of tight junctions’ attack by pathogens, including bacteria, viruses, fungi, and parasites.
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17
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Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens. Infect Immun 2021; 89:IAI.00619-20. [PMID: 33257534 DOI: 10.1128/iai.00619-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/11/2020] [Indexed: 12/12/2022] Open
Abstract
Typical enteropathogenic Escherichia coli (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death. The purposes of this study were to (i) determine the genomic similarity between kitten aEPEC and human aEPEC isolates and (ii) identify genotypic or phenotypic traits associated with virulence in kitten aEPEC. We observed no differences between kitten and human aEPEC in core genome content or gene cluster sequence identities, and no distinguishing genomic content was observed between aEPEC isolates from kittens with nonclinical colonization (NC) versus those with lethal infection (LI). Variation in adherence patterns and ability to aggregate actin in cultured cells mirrored descriptions of human aEPEC. The aEPEC isolated from kittens with LI were significantly more motile than isolates from kittens with NC. Kittens may serve as a reservoir for aEPEC that is indistinguishable from human aEPEC isolates and may provide a needed comparative animal model for the study of aEPEC pathogenesis. Motility seems to be an important factor in pathogenesis of LI associated with aEPEC in kittens.
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18
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Garcez ML, Tan VX, Heng B, Guillemin GJ. Sodium Butyrate and Indole-3-propionic Acid Prevent the Increase of Cytokines and Kynurenine Levels in LPS-induced Human Primary Astrocytes. Int J Tryptophan Res 2021; 13:1178646920978404. [PMID: 33447046 PMCID: PMC7780186 DOI: 10.1177/1178646920978404] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 11/10/2020] [Indexed: 12/14/2022] Open
Abstract
The crosstalk between central nervous system (CNS) and gut microbiota plays key roles in neuroinflammation and chronic immune activation that are common features of all neurodegenerative diseases. Imbalance in the microbiota can lead to an increase in the intestinal permeability allowing toxins to diffuse and reach the CNS, as well as impairing the production of neuroprotective metabolites such as sodium butyrate (SB) and indole-3-propionic acid (IPA). The aim of the present study was to evaluate the effect of SB and IPA on LPS-induced production of cytokines and tryptophan metabolites in human astrocytes. Primary cultures of human astrocytes were pre-incubated with SB or IPA for 1 hour before treatment with LPS. Cell viability was not affected at 24, 48 or 72 hours after pre-treatment with SB, IPA or LPS treatment. SB was able to significantly prevent the increase of GM-CSF, MCP-1, IL-6 IL-12, and IL-13 triggered by LPS. SB and IPA also prevented inflammation indicated by the increase in kynurenine and kynurenine/tryptophan ratio induced by LPS treatment. IPA pre-treatment prevented the LPS-induced increase in MCP-1, IL-12, IL-13, and TNF-α levels 24 hours after pre-treatment, but had no effect on tryptophan metabolites. The present study showed for the first time that bacterial metabolites SB and IPA have potential anti-inflammatory effect on primary human astrocytes with potential therapeutic benefit in neurodegenerative disease characterized by the presence of chronic low-grade inflammation.
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Affiliation(s)
- Michelle L Garcez
- Neurochemistry Laboratory, Department of Biochemistry, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.,Neurodegenerative diseases Research Group, Faculty of Medicine, Health and Human Sciences, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Vanessa X Tan
- Neurodegenerative diseases Research Group, Faculty of Medicine, Health and Human Sciences, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Benjamin Heng
- Neurodegenerative diseases Research Group, Faculty of Medicine, Health and Human Sciences, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Gilles J Guillemin
- Neurodegenerative diseases Research Group, Faculty of Medicine, Health and Human Sciences, Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,PANDIS.org, Little Collins St, Melbourne VIC, Australia
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19
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Massier L, Blüher M, Kovacs P, Chakaroun RM. Impaired Intestinal Barrier and Tissue Bacteria: Pathomechanisms for Metabolic Diseases. Front Endocrinol (Lausanne) 2021; 12:616506. [PMID: 33767669 PMCID: PMC7985551 DOI: 10.3389/fendo.2021.616506] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/02/2021] [Indexed: 02/06/2023] Open
Abstract
An intact intestinal barrier, representing the interface between inner and outer environments, is an integral regulator of health. Among several factors, bacteria and their products have been evidenced to contribute to gut barrier impairment and its increased permeability. Alterations of tight junction integrity - caused by both external factors and host metabolic state - are important for gut barrier, since they can lead to increased influx of bacteria or bacterial components (endotoxin, bacterial DNA, metabolites) into the host circulation. Increased systemic levels of bacterial endotoxins and DNA have been associated with an impaired metabolic host status, manifested in obesity, insulin resistance, and associated cardiovascular complications. Bacterial components and cells are distributed to peripheral tissues via the blood stream, possibly contributing to metabolic diseases by increasing chronic pro-inflammatory signals at both tissue and systemic levels. This response is, along with other yet unknown mechanisms, mediated by toll like receptor (TLR) transduction and increased expression of pro-inflammatory cytokines, which in turn can further increase intestinal permeability leading to a detrimental positive feedback loop. The modulation of gut barrier function through nutritional and other interventions, including manipulation of gut microbiota, may represent a potential prevention and treatment target for metabolic diseases.
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Affiliation(s)
- Lucas Massier
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- Department of Medicine (H7), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Matthias Blüher
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München, University Hospital Leipzig, University of Leipzig, Leipzig, Germany
| | - Peter Kovacs
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Rima M. Chakaroun
- Medical Department III – Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
- *Correspondence: Rima M. Chakaroun,
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20
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Abstract
The gastrointestinal microbiome plays a pivotal role in physiological homeostasis of the intestine as well as in the pathophysiology of diseases including inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Emerging evidence suggests that gut microbiota signal to the mitochondria of mucosal cells, including epithelial cells and immune cells. Gut microbiota signaling to mitochondria has been shown to alter mitochondrial metabolism, activate immune cells, induce inflammasome signaling, and alter epithelial barrier function. Both dysbiosis of the gut microbiota and mitochondrial dysfunction are associated with chronic intestinal inflammation and CRC. This review discusses mitochondrial metabolism of gut mucosal cells, mitochondrial dysfunction, and known gut microbiota-mediated mitochondrial alterations during IBD and CRC.
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Affiliation(s)
- Dakota N. Jackson
- Department of Internal Medicine, Division of Gastroenterology, Baylor Scott & White Research Institute, Baylor University Medical Center, Dallas, TX, USA
| | - Arianne L. Theiss
- Department of Internal Medicine, Division of Gastroenterology, Baylor Scott & White Research Institute, Baylor University Medical Center, Dallas, TX, USA,CONTACT Arianne L. Theiss Division of Gastroenterology, Baylor Research Institute, Baylor University Medical Center, 250 Hoblitzelle, 3500 Gaston Avenue, Dallas, TX75246, USA
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21
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Enteropathogenic Escherichia coli (EPEC) Recruitment of PAR Polarity Protein Atypical PKCζ to Pedestals and Cell-Cell Contacts Precedes Disruption of Tight Junctions in Intestinal Epithelial Cells. Int J Mol Sci 2020; 21:ijms21020527. [PMID: 31947656 PMCID: PMC7014222 DOI: 10.3390/ijms21020527] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/26/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) uses a type three secretion system to inject effector proteins into host intestinal epithelial cells, causing diarrhea. EPEC induces the formation of pedestals underlying attached bacteria, disrupts tight junction (TJ) structure and function, and alters apico-basal polarity by redistributing the polarity proteins Crb3 and Pals1, although the mechanisms are unknown. Here we investigate the temporal relationship of PAR polarity complex and TJ disruption following EPEC infection. EPEC recruits active aPKCζ, a PAR polarity protein, to actin within pedestals and at the plasma membrane prior to disrupting TJ. The EPEC effector EspF binds the endocytic protein sorting nexin 9 (SNX9). This interaction impacts actin pedestal organization, recruitment of active aPKCζ to actin at cell–cell borders, endocytosis of JAM-A S285 and occludin, and TJ barrier function. Collectively, data presented herein support the hypothesis that EPEC-induced perturbation of TJ is a downstream effect of disruption of the PAR complex and that EspF binding to SNX9 contributes to this phenotype. aPKCζ phosphorylates polarity and TJ proteins and participates in actin dynamics. Therefore, the early recruitment of aPKCζ to EPEC pedestals and increased interaction with actin at the membrane may destabilize polarity complexes ultimately resulting in perturbation of TJ.
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22
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O’Callaghan AA, Corr SC. Establishing Boundaries: The Relationship That Exists between Intestinal Epithelial Cells and Gut-Dwelling Bacteria. Microorganisms 2019; 7:microorganisms7120663. [PMID: 31818022 PMCID: PMC6956261 DOI: 10.3390/microorganisms7120663] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 12/16/2022] Open
Abstract
The human gastrointestinal (GI) tract is a highly complex organ in which various dynamic physiological processes are tightly coordinated while interacting with a complex community of microorganisms. Within the GI tract, intestinal epithelial cells (IECs) create a structural interface that separates the intestinal lumen from the underlying lamina propria. In the lumen, gut-dwelling microbes play an essential role in maintaining gut homeostasis and functionality. Whether commensal or pathogenic, their interaction with IECs is inevitable. IECs and myeloid immune cells express an array of pathogen recognition receptors (PRRs) that define the interaction of both pathogenic and beneficial bacteria with the intestinal mucosa and mount appropriate responses including induction of barrier-related factors which enhance the integrity of the epithelial barrier. Indeed, the integrity of this barrier and induction of appropriate immune responses is critical to health status, with defects in this barrier and over-activation of immune cells by invading microbes contributing to development of a range of inflammatory and infectious diseases. This review describes the complexity of the GI tract and its interactions with gut bacteria.
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23
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Ugalde-Silva P, Navarro-Garcia F. Coordinated transient interaction of ZO-1 and afadin is required for pedestal maturation induced by EspF from enteropathogenic Escherichia coli. Microbiologyopen 2019; 8:e931. [PMID: 31568664 PMCID: PMC6925160 DOI: 10.1002/mbo3.931] [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: 05/16/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 01/09/2023] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) infection causes a histopathological lesion including recruitment of F‐actin beneath the attached bacteria and formation of actin‐rich pedestal‐like structures. Another important target of EPEC is the tight junction (TJ), and EspF induces displacement of TJ proteins and increased intestinal permeability. Previously, we determined that an EPEC strain lacking EspF did not cause TJ disruption; meanwhile, pedestals were located on the TJ and smaller than those induced by the wild‐type strain. Therefore, EspF could be playing an important role in both phenotypes. Here, using different cell models, we found that EspF was essential for pedestal maturation through ZO‐1 disassembly from TJ, leading to (a) ZO‐1 recruitment to the pedestal structure; no other main TJ proteins were required. Recruited ZO‐1 allowed the afadin recruitment. (b) Afadin recruitment caused an afadin–ZO‐1 transient interaction, like during TJ formation. (c) Afadin and ZO‐1 were segregated to the tip and the stem of pedestal, respectively, causing pedestal maturation. Initiation of these three discrete phases for pedestal maturation functionally and physically required EspF expression. Pedestal maturation process could help coordinate the epithelial actomyosin function by maintaining the actin‐rich column composing the pedestal structure and could be important in the dynamics of the pedestal movement on epithelial cells.
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Affiliation(s)
- Paul Ugalde-Silva
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México City, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), México City, Mexico
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24
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Xia X, Liu Y, Hodgson A, Xu D, Guo W, Yu H, She W, Zhou C, Lan L, Fu K, Vallance BA, Wan F. EspF is crucial for Citrobacter rodentium-induced tight junction disruption and lethality in immunocompromised animals. PLoS Pathog 2019; 15:e1007898. [PMID: 31251784 PMCID: PMC6623547 DOI: 10.1371/journal.ppat.1007898] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 07/11/2019] [Accepted: 06/05/2019] [Indexed: 12/17/2022] Open
Abstract
Attaching/Effacing (A/E) bacteria include human pathogens enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and their murine equivalent Citrobacter rodentium (CR), of which EPEC and EHEC are important causative agents of foodborne diseases worldwide. While A/E pathogen infections cause mild symptoms in the immunocompetent hosts, an increasing number of studies show that they produce more severe morbidity and mortality in immunocompromised and/or immunodeficient hosts. However, the pathogenic mechanisms and crucial host-pathogen interactions during A/E pathogen infections under immunocompromised conditions remain elusive. We performed a functional screening by infecting interleukin-22 (IL-22) knockout (Il22-/-) mice with a library of randomly mutated CR strains. Our screen reveals that interruption of the espF gene, which encodes the Type III Secretion System effector EspF (E. coli secreted protein F) conserved among A/E pathogens, completely abolishes the high mortality rates in CR-infected Il22-/- mice. Chromosomal deletion of espF in CR recapitulates the avirulent phenotype without impacting colonization and proliferation of CR, and EspF complement in ΔespF strain fully restores the virulence in mice. Moreover, the expression levels of the espF gene are elevated during CR infection and CR induces disruption of the tight junction (TJ) strands in colonic epithelium in an EspF-dependent manner. Distinct from EspF, chromosomal deletion of other known TJ-damaging effector genes espG and map failed to impede CR virulence in Il22-/- mice. Hence our findings unveil a critical pathophysiological function for EspF during CR infection in the immunocompromised host and provide new insights into the complex pathogenic mechanisms of A/E pathogens.
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Affiliation(s)
- Xue Xia
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Yue Liu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Andrea Hodgson
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Dongqing Xu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Wenxuan Guo
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Hongbing Yu
- Division of Gastroenterology, Department of Pediatrics, BC's Children's Hospital and Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Weifeng She
- Eudowood Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Chenxing Zhou
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, PR China
| | - Lei Lan
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, PR China
| | - Kai Fu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Bruce A. Vallance
- Division of Gastroenterology, Department of Pediatrics, BC's Children's Hospital and Child and Family Research Institute, Vancouver, British Columbia, Canada
| | - Fengyi Wan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, United States of America
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Mohamed-Salem R, Rodríguez Fernández C, Nieto-Pelegrín E, Conde-Valentín B, Rumbero A, Martinez-Quiles N. Aqueous extract of Hibiscus sabdariffa inhibits pedestal induction by enteropathogenic E. coli and promotes bacterial filamentation in vitro. PLoS One 2019; 14:e0213580. [PMID: 30849110 PMCID: PMC6407759 DOI: 10.1371/journal.pone.0213580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 02/25/2019] [Indexed: 11/19/2022] Open
Abstract
Diarrheic diseases account for the annual death of approximately 1.9 million children under the age of 5 years, and it is a major cause of work absenteeism in developed countries. As diarrheagenic bacteria, enteropathogenic Escherichia coli (EPEC) attach to cells in the small intestine, causing local disappearance of microvilli and inducing the formation of actin-rich pedestals that disrupt the intestinal barrier and help EPEC adhere to and infect intestinal cells. Antibiotics and other bioactive compounds can often be found by analyzing traditional medicines. Here a crude aqueous extract of Hibiscus sabdariffa, which typically grows in subtropical and tropical areas and is a popular medicinal tisane in many countries, was analyzed for antibacterial activity against EPEC. In standard microdilution assays, the extract showed a minimum inhibitory concentration of 6.5 mg/ml against EPEC growth. Time-kill kinetics assays demonstrated significant 24 h bactericidal activity at 25 mg/ml. The extract is able to impede pedestal induction. Not only did the extract inhibit preformed pedestals but it prevented pedestal induction as well. Remarkably, it also promoted the formation of EPEC filaments, as observed with other antibiotics. Our results in vitro support the potential of Hibiscus sabdariffa as an antimicrobial agent against EPEC.
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Affiliation(s)
- Reda Mohamed-Salem
- Department of Microbiology and Parasitology, Pharmacy School, Complutense University, Madrid, Spain
| | | | - Elvira Nieto-Pelegrín
- Department of Microbiology and Parasitology, Pharmacy School, Complutense University, Madrid, Spain
| | - Beatriz Conde-Valentín
- Department of Microbiology and Parasitology, Pharmacy School, Complutense University, Madrid, Spain
- Pharmaceutics and Food Technology Department, Complutense University, Madrid, Spain
| | - Angel Rumbero
- Organic Chemistry Department, Autonóma University, Madrid, Spain
| | - Narcisa Martinez-Quiles
- Department of Microbiology and Parasitology, Pharmacy School, Complutense University, Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, School of Medicine, Complutense University and Gregorio Marañón Health Research Institute (IiSGM), Madrid, Spain
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26
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Roxas JL, Monasky RC, Roxas BAP, Agellon AB, Mansoor A, Kaper JB, Vedantam G, Viswanathan V. Enteropathogenic Escherichia coli EspH-Mediated Rho GTPase Inhibition Results in Desmosomal Perturbations. Cell Mol Gastroenterol Hepatol 2018; 6:163-180. [PMID: 30003123 PMCID: PMC6039986 DOI: 10.1016/j.jcmgh.2018.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 04/20/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND & AIMS The diarrheagenic pathogen, enteropathogenic Escherichia coli (EPEC), uses a type III secretion system to deliver effector molecules into intestinal epithelial cells (IECs). While exploring the basis for the lateral membrane separation of EPEC-infected IECs, we observed infection-induced loss of the desmosomal cadherin desmoglein-2 (DSG2). We sought to identify the molecule(s) involved in, and delineate the mechanisms and consequences of, EPEC-induced DSG2 loss. METHODS DSG2 abundance and localization was monitored via immunoblotting and immunofluorescence, respectively. Junctional perturbations were visualized by electron microscopy, and cell-cell adhesion was assessed using dispase assays. EspH alanine-scan mutants as well as pharmacologic agents were used to evaluate impacts on desmosomal alterations. EPEC-mediated DSG2 loss, and its impact on bacterial colonization in vivo, was assessed using a murine model. RESULTS The secreted virulence protein EspH mediates EPEC-induced DSG2 degradation, and contributes to desmosomal perturbation, loss of cell junction integrity, and barrier disruption in infected IECs. EspH sequesters Rho guanine nucleotide exchange factors and inhibits Rho guanosine triphosphatase signaling; EspH mutants impaired for Rho guanine nucleotide exchange factor interaction failed to inhibit RhoA or deplete DSG2. Cytotoxic necrotizing factor 1, which locks Rho guanosine triphosphatase in the active state, jasplakinolide, a molecule that promotes actin polymerization, and the lysosomal inhibitor bafilomycin A, respectively, rescued infected cells from EPEC-induced DSG2 loss. Wild-type EPEC, but not an espH-deficient strain, colonizes mouse intestines robustly, widens paracellular junctions, and induces DSG2 re-localization in vivo. CONCLUSIONS Our studies define the mechanism and consequences of EPEC-induced desmosomal alterations in IECs. These perturbations contribute to the colonization and virulence of EPEC, and likely related pathogens.
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Key Words
- A/E, attaching and effacing
- BSA, bovine serum albumin
- CM, calcium and magnesium
- DMEM, Dulbecco's modified Eagle medium
- DSC, desmocollin
- DSG, desmoglein
- DSG2
- Desmoglein
- EPEC
- EPEC, enteropathogenic Escherichia coli
- GEF, guanine nucleotide exchange factors
- GTPase, guanosine triphosphatase
- Host–Pathogen Interaction
- IEC, intestinal epithelial cell
- IF, intermediate filament
- PBS, phosphate-buffered saline
- T3SS, type 3 secretion system
- TER, transepithelial electrical resistance
- TJ, tight junction
- WT, wild-type
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Affiliation(s)
- Jennifer Lising Roxas
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Ross Calvin Monasky
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Bryan Angelo P. Roxas
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Al B. Agellon
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
- BIO5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona
| | - Asad Mansoor
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - James B. Kaper
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
- BIO5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona
- Department of Immunobiology, University of Arizona, Tucson, Arizona
- Southern Arizona VA Healthcare System, Tucson, Arizona
| | - V.K. Viswanathan
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
- BIO5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona
- Department of Immunobiology, University of Arizona, Tucson, Arizona
- Correspondence Address correspondence to: V. K. Viswanathan, PhD, School of Animal and Comparative Biomedical Sciences, 1006 E. Lowell, Building 106, Room 231, University of Arizona, Tucson, Arizona 85721. fax: (520) 621-6366.
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27
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Roxas JL, Viswanathan VK. Modulation of Intestinal Paracellular Transport by Bacterial Pathogens. Compr Physiol 2018; 8:823-842. [PMID: 29687905 DOI: 10.1002/cphy.c170034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The passive and regulated movement of ions, solutes, and water via spaces between cells of the epithelial monolayer plays a critical role in the normal intestinal functioning. This paracellular pathway displays a high level of structural and functional specialization, with the membrane-spanning complexes of the tight junctions, adherens junctions, and desmosomes ensuring its integrity. Tight junction proteins, like occludin, tricellulin, and the claudin family isoforms, play prominent roles as barriers to unrestricted paracellular transport. The past decade has witnessed major advances in our understanding of the architecture and function of epithelial tight junctions. While it has been long appreciated that microbes, notably bacterial and viral pathogens, target and disrupt junctional complexes and alter paracellular permeability, the precise mechanisms remain to be defined. Notably, renewed efforts will be required to interpret the available data on pathogen-mediated barrier disruption in the context of the most recent findings on tight junction structure and function. While much of the focus has been on pathogen-induced dysregulation of junctional complexes, commensal microbiota and their products may influence paracellular permeability and contribute to the normal physiology of the gut. Finally, microbes and their products have become important tools in exploring host systems, including the junctional properties of epithelial cells. © 2018 American Physiological Society. Compr Physiol 8:823-842, 2018.
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Affiliation(s)
- Jennifer Lising Roxas
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, USA
| | - V K Viswanathan
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, USA.,Department of Immunobiology, University of Arizona, Tucson, Arizona, USA.,BIO5 Institute for Collaborative Research, University of Arizona, Tucson, Arizona, USA
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28
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Singh AP, Sharma S, Pagarware K, Siraji RA, Ansari I, Mandal A, Walling P, Aijaz S. Enteropathogenic E. coli effectors EspF and Map independently disrupt tight junctions through distinct mechanisms involving transcriptional and post-transcriptional regulation. Sci Rep 2018; 8:3719. [PMID: 29487356 PMCID: PMC5829253 DOI: 10.1038/s41598-018-22017-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/14/2018] [Indexed: 01/05/2023] Open
Abstract
Enteropathogenic E. coli infection is characterized by rapid onset of diarrhea but the underlying mechanisms are not well defined. EPEC targets the tight junctions which selectively regulate the permeability of charged and uncharged molecules. Cooperative actions of the EPEC effectors EspF and Map have been reported to mediate tight junction disruption. To analyze the individual contributions of EspF and Map, we generated in vitro models where EspF and Map, derived from the EPEC strain E2348/69, were constitutively expressed in epithelial cells. Here we report that tight junction disruption by EspF and Map is caused by the inhibition of the junctional recruitment of proteins during tight junction assembly. Constitutive expression of EspF and Map depleted the levels of tight junction proteins. EspF down-regulated the transcript levels of claudin-1, occludin and ZO-1, while Map down-regulated only claudin-1 transcripts. Both effectors also caused lysosomal degradation of existing tight junction proteins. We also identified a novel interaction of Map with non-muscle myosin II. Consistent with earlier studies, EspF was found to interact with ZO-1 while actin was the common interacting partner for both effectors. Our data provides evidence for the distinct roles of Map and EspF in tight junction disruption through non-synergistic functions.
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Affiliation(s)
- Anand Prakash Singh
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Swati Sharma
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Kirti Pagarware
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rafay Anwar Siraji
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Imran Ansari
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Anupam Mandal
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Pangertoshi Walling
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Saima Aijaz
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
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29
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Shenoy AR, Furniss RCD, Goddard PJ, Clements A. Modulation of Host Cell Processes by T3SS Effectors. Curr Top Microbiol Immunol 2018; 416:73-115. [PMID: 30178263 DOI: 10.1007/82_2018_106] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Two of the enteric Escherichia coli pathotypes-enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC)-have a conserved type 3 secretion system which is essential for virulence. The T3SS is used to translocate between 25 and 50 bacterial proteins directly into the host cytosol where they manipulate a variety of host cell processes to establish a successful infection. In this chapter, we discuss effectors from EPEC/EHEC in the context of the host proteins and processes that they target-the actin cytoskeleton, small guanosine triphosphatases and innate immune signalling pathways that regulate inflammation and cell death. Many of these translocated proteins have been extensively characterised, which has helped obtain insights into the mechanisms of pathogenesis of these bacteria and also understand the host pathways they target in more detail. With increasing knowledge of the positive and negative regulation of host signalling pathways by different effectors, a future challenge is to investigate how the specific effector repertoire of each strain cooperates over the course of an infection.
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Affiliation(s)
- Avinash R Shenoy
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, SW7 2AZ, London, UK
| | - R Christopher D Furniss
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, SW7 2AZ, London, UK
| | - Philippa J Goddard
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, SW7 2AZ, London, UK
| | - Abigail Clements
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, SW7 2AZ, London, UK.
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30
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Hua Y, Ju J, Wang X, Zhang B, Zhao W, Zhang Q, Feng Y, Ma W, Wan C. Screening for host proteins interacting with Escherichia coli O157:H7 EspF using bimolecular fluorescence complementation. Future Microbiol 2017; 13:37-58. [PMID: 29227212 DOI: 10.2217/fmb-2017-0087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
AIM To screen host proteins that interact with enterohemorrhagic Escherichia coli O157:H7 EspF. MATERIALS & METHODS Flow cytometry and high-throughput sequencing were used to screen interacting proteins. Molecular function, biological processes and Kyoto Encyclopedia of Genes and Genomes pathways were studied using the DAVID online tool. Glutathione S-transferase pull down and dot blotting were used to verify the interactions. RESULTS 293 host proteins were identified to associate with EspF. They were mainly enriched in RNA splicing (p = 0.005), ribosome structure (p = 0.012), and involved in 109 types of signaling pathways. SNX9 and ANXA6 were confirmed to interact with EspF. CONCLUSION EspF interacts with ANXA6; they may form a complex to manipulate the process of phagocytosis; EspF plays a highlighted pathogenic role in enterohemorrhagic E. coli infection process.
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Affiliation(s)
- Ying Hua
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
| | - Jingwei Ju
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University, Guangzhou 510006, China
| | - Xiangyu Wang
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
| | - Bao Zhang
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
| | - Wei Zhao
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
| | - Qiwei Zhang
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
| | - Yingzhu Feng
- Guangzhou Institutes of Biomedicine & Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Wenbin Ma
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.,Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University, Guangzhou 510006, China
| | - Chengsong Wan
- Biosafety Level 3 Laboratory, School of Public Health, Southern Medical University, Guangzhou 510515, China.,Key Laboratory of Tropical Disease Research of Guangdong Provincial, Guangzhou 510515, China
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31
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Tapia R, Kralicek SE, Hecht GA. EPEC effector EspF promotes Crumbs3 endocytosis and disrupts epithelial cell polarity. Cell Microbiol 2017; 19. [PMID: 28618099 DOI: 10.1111/cmi.12757] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/19/2017] [Accepted: 06/09/2017] [Indexed: 12/12/2022]
Abstract
Enteropathogenic Escherichia coli (EPEC) uses a type III secretion system to inject effector proteins into host intestinal epithelial cells causing diarrhoea. EPEC infection redistributes basolateral proteins β1-integrin and Na+ /K+ ATPase to the apical membrane of host cells. The Crumbs (Crb) polarity complex (Crb3/Pals1/Patj) is essential for epithelial cell polarisation and tight junction (TJ) assembly. Here, we demonstrate that EPEC displaces Crb3 and Pals1 from the apical membrane to the cytoplasm of cultured intestinal epithelial cells and colonocytes of infected mice. In vitro studies show that EspF, but not Map, alters Crb3, whereas both effectors modulate Pals1. EspF perturbs polarity formation in cyst morphogenesis assays and induces endocytosis and apical redistribution of Na+ /K+ ATPase. EspF binds to sorting nexin 9 (SNX9) causing membrane remodelling in host cells. Infection with ΔespF/pespFD3, a mutant strain that ablates EspF binding to SNX9, or inhibition of dynamin, attenuates Crb3 endocytosis caused by EPEC. In addition, infection with ΔespF/pespFD3 has no impact on Na+ /K+ ATPase endocytosis. These data support the hypothesis that EPEC perturbs apical-basal polarity in an EspF-dependent manner, which would contribute to EPEC-associated diarrhoea by disruption of TJ and altering the crucial positioning of membrane transporters involved in the absorption of ions and solutes.
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Affiliation(s)
- Rocio Tapia
- Department of Medicine and Division of Gastroenterology and Nutrition, Loyola University Chicago, Chicago, IL, USA
| | - Sarah E Kralicek
- Department of Medicine and Division of Gastroenterology and Nutrition, Loyola University Chicago, Chicago, IL, USA
| | - Gail A Hecht
- Department of Medicine and Division of Gastroenterology and Nutrition, Loyola University Chicago, Chicago, IL, USA.,Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL, USA.,Edward Hines Jr. VA Hospital, Hines, IL, USA
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32
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Association of Atypical Enteropathogenic Escherichia coli with Diarrhea and Related Mortality in Kittens. J Clin Microbiol 2017; 55:2719-2735. [PMID: 28659315 DOI: 10.1128/jcm.00403-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/19/2017] [Indexed: 12/19/2022] Open
Abstract
Diarrhea is responsible for the death of approximately 900,000 children per year worldwide. In children, typical enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea and is associated with a higher hazard of death. Typical EPEC infection is rare in animals and poorly reproduced in experimental animal models. In contrast, atypical EPEC (aEPEC) infection is common in both children and animals, but its role in diarrhea is uncertain. Mortality in kittens is often attributed to diarrhea, and we previously identified enteroadherent EPEC in the intestines of deceased kittens. The purpose of this study was to determine the prevalence and type of EPEC in kittens and whether infection was associated with diarrhea, diarrhea-related mortality, gastrointestinal pathology, or other risk factors. Kittens with and without diarrhea were obtained from two shelter facilities and determined to shed atypical EPEC at a culture-based prevalence of 18%. In contrast, quantitative PCR detected the presence of the gene for intimin (eae) in feces from 42% of kittens. aEPEC was isolated from kittens with and without diarrhea. However, kittens with diarrhea harbored significantly larger quantities of aEPEC than kittens without diarrhea. Kittens with aEPEC had a significantly greater severity of small intestinal and colonic lesions and were significantly more likely to have required subcutaneous fluid administration. These findings identify aEPEC to be prevalent in kittens and a significant primary or contributing cause of intestinal inflammation, diarrhea, dehydration, and associated mortality in kittens.
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33
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Tapia R, Kralicek SE, Hecht GA. Modulation of epithelial cell polarity by bacterial pathogens. Ann N Y Acad Sci 2017. [PMID: 28628193 DOI: 10.1111/nyas.13388] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Epithelial cells constitute a physical barrier that aids in protecting the host from microbial pathogens. Polarized epithelial cells contain distinct apical and basolateral membrane domains separated by intercellular junctions, including tight junctions (TJs), which contribute to the maintenance of apical-basal polarity. Polarity complexes also contribute to the establishment of TJ formation. Several pathogens perturb epithelial TJ barrier function and structure in addition to causing a loss of apical-basal polarity. Here, we review the impact of pathogenic bacteria on the disruption of cell-cell junctions and epithelial polarity.
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Affiliation(s)
- Rocio Tapia
- Division of Gastroenterology and Nutrition, Department of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Sarah E Kralicek
- Division of Gastroenterology and Nutrition, Department of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Gail A Hecht
- Division of Gastroenterology and Nutrition, Department of Medicine, Loyola University Chicago, Maywood, Illinois.,Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois.,Edward Hines Jr. VA Hospital, Hines, Illinois
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Tricellular Tight Junction Protein Tricellulin Is Targeted by the Enteropathogenic Escherichia coli Effector EspG1, Leading to Epithelial Barrier Disruption. Infect Immun 2016; 85:IAI.00700-16. [PMID: 27795363 DOI: 10.1128/iai.00700-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/16/2016] [Indexed: 12/31/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC)-induced diarrhea is often associated with disruption of intestinal epithelial tight junctions. Although studies have shown alterations in the expression and localization of bicellular tight junction proteins during EPEC infections, little is known about whether tricellular tight junction proteins (tTJs) are affected. Using Caco-2 cell monolayers, we investigated if EPEC is capable of targeting the tTJ protein tricellulin. Our results demonstrated that at 4 h postinfection, EPEC induced a significant reduction in tricellulin levels, accompanied by a significant loss of transepithelial resistance (TEER) and a corresponding increase in paracellular permeability. Conversely, cells overexpressing tricellulin were highly resistant to EPEC-induced barrier disruption. Confocal microscopy revealed the distribution of tricellulin into the plasma membrane of infected epithelial cells and confirmed the localization of EPEC aggregates in close proximity to tTJs. Moreover, infections with EPEC strains lacking genes encoding specific type III secreted effector proteins demonstrated a crucial role for the effector EspG1 in modulating tricellulin expression. Complementation studies suggest that the EspG-induced depletion of tricellulin is microtubule dependent. Overall, our results show that EPEC-induced epithelial barrier dysfunction is mediated in part by EspG1-induced microtubule-dependent depletion of tricellulin.
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35
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Targeting and alteration of tight junctions by bacteria and their virulence factors such as Clostridium perfringens enterotoxin. Pflugers Arch 2016; 469:77-90. [DOI: 10.1007/s00424-016-1902-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/01/2016] [Accepted: 11/06/2016] [Indexed: 01/01/2023]
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36
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König J, Wells J, Cani PD, García-Ródenas CL, MacDonald T, Mercenier A, Whyte J, Troost F, Brummer RJ. Human Intestinal Barrier Function in Health and Disease. Clin Transl Gastroenterol 2016; 7:e196. [PMID: 27763627 PMCID: PMC5288588 DOI: 10.1038/ctg.2016.54] [Citation(s) in RCA: 525] [Impact Index Per Article: 65.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/14/2016] [Indexed: 02/07/2023] Open
Abstract
The gastrointestinal tract consists of an enormous surface area that is optimized to efficiently absorb nutrients, water, and electrolytes from food. At the same time, it needs to provide a tight barrier against the ingress of harmful substances, and protect against a reaction to omnipresent harmless compounds. A dysfunctional intestinal barrier is associated with various diseases and disorders. In this review, the role of intestinal permeability in common disorders such as infections with intestinal pathogens, inflammatory bowel disease, irritable bowel syndrome, obesity, celiac disease, non-celiac gluten sensitivity, and food allergies will be discussed. In addition, the effect of the frequently prescribed drugs proton pump inhibitors and non-steroidal anti-inflammatory drugs on intestinal permeability, as well as commonly used methods to assess barrier function will be reviewed.
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Affiliation(s)
- Julia König
- Nutrition-Gut-Brain Interactions Research Centre, Faculty of Health and Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden
| | - Jerry Wells
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Patrice D Cani
- Metabolism and Nutrition Research Group, WELBIO-Walloon Excellence in Life Sciences and BIOtechnology, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | | | - Tom MacDonald
- Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Annick Mercenier
- Nutrition and Health Research, Nestlé Research Center, Lausanne, Switzerland
| | - Jacqueline Whyte
- European Branch, The International Life Sciences Institute, Brussels, Belgium
| | - Freddy Troost
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, University Hospital Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Robert-Jan Brummer
- Nutrition-Gut-Brain Interactions Research Centre, Faculty of Health and Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden
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37
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Ugalde-Silva P, Gonzalez-Lugo O, Navarro-Garcia F. Tight Junction Disruption Induced by Type 3 Secretion System Effectors Injected by Enteropathogenic and Enterohemorrhagic Escherichia coli. Front Cell Infect Microbiol 2016; 6:87. [PMID: 27606286 PMCID: PMC4995211 DOI: 10.3389/fcimb.2016.00087] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/10/2016] [Indexed: 12/18/2022] Open
Abstract
The intestinal epithelium consists of a single cell layer, which is a critical selectively permeable barrier to both absorb nutrients and avoid the entry of potentially harmful entities, including microorganisms. Epithelial cells are held together by the apical junctional complexes, consisting of adherens junctions, and tight junctions (TJs), and by underlying desmosomes. TJs lay in the apical domain of epithelial cells and are mainly composed by transmembrane proteins such as occludin, claudins, JAMs, and tricellulin, that are associated with the cytoplasmic plaque formed by proteins from the MAGUK family, such as ZO-1/2/3, connecting TJ to the actin cytoskeleton, and cingulin and paracingulin connecting TJ to the microtubule network. Extracellular bacteria such as EPEC and EHEC living in the intestinal lumen inject effectors proteins directly from the bacterial cytoplasm to the host cell cytoplasm, where they play a relevant role in the manipulation of the eukaryotic cell functions by modifying or blocking cell signaling pathways. TJ integrity depends on various cell functions such as actin cytoskeleton, microtubule network for vesicular trafficking, membrane integrity, inflammation, and cell survival. EPEC and EHEC effectors target most of these functions. Effectors encoded inside or outside of locus of enterocyte effacement (LEE) disrupt the TJ strands. EPEC and EHEC exploit the TJ dynamics to open this structure, for causing diarrhea. EPEC and EHEC secrete effectors that mimic host proteins to manipulate the signaling pathways, including those related to TJ dynamics. In this review, we focus on the known mechanisms exploited by EPEC and EHEC effectors for causing TJ disruption.
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Affiliation(s)
- Paul Ugalde-Silva
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
| | - Octavio Gonzalez-Lugo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
| | - Fernando Navarro-Garcia
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México City, Mexico
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38
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Visualizing the Translocation and Localization of Bacterial Type III Effector Proteins by Using a Genetically Encoded Reporter System. Appl Environ Microbiol 2016; 82:2700-2708. [PMID: 26921426 PMCID: PMC4836418 DOI: 10.1128/aem.03418-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 02/19/2016] [Indexed: 12/25/2022] Open
Abstract
Bacterial type III secretion system (T3SS) effector proteins are critical determinants of infection for many animal and plant pathogens. However, monitoring of the translocation and delivery of these important virulence determinants has proved to be technically challenging. Here, we used a genetically engineered LOV (light-oxygen-voltage) sensing domain derivative to monitor the expression, translocation, and localization of bacterial T3SS effectors. We found the Escherichia coli O157:H7 bacterial effector fusion Tir-LOV was functional following its translocation and localized to the host cell membrane in discrete foci, demonstrating that LOV-based reporters can be used to visualize the effector translocation with minimal manipulation and interference. Further evidence for the versatility of the reporter was demonstrated by fusing LOV to the C terminus of the Shigella flexneri effector IpaB. IpaB-LOV localized preferentially at bacterial poles before translocation. We observed the rapid translocation of IpaB-LOV in a T3SS-dependent manner into host cells, where it localized at the bacterial entry site within membrane ruffles.
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39
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The Locus of Enterocyte Effacement and Associated Virulence Factors of Enterohemorrhagic Escherichia coli. Microbiol Spectr 2016; 2:EHEC-0007-2013. [PMID: 26104209 DOI: 10.1128/microbiolspec.ehec-0007-2013] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A subset of Shiga toxin-producing Escherichia coli strains, termed enterohemorrhagic E. coli (EHEC), is defined in part by the ability to produce attaching and effacing (A/E) lesions on intestinal epithelia. Such lesions are characterized by intimate bacterial attachment to the apical surface of enterocytes, cytoskeletal rearrangements beneath adherent bacteria, and destruction of proximal microvilli. A/E lesion formation requires the locus of enterocyte effacement (LEE), which encodes a Type III secretion system that injects bacterial proteins into host cells. The translocated proteins, termed effectors, subvert a plethora of cellular pathways to the benefit of the pathogen, for example, by recruiting cytoskeletal proteins, disrupting epithelial barrier integrity, and interfering with the induction of inflammation, phagocytosis, and apoptosis. The LEE and selected effectors play pivotal roles in intestinal persistence and virulence of EHEC, and it is becoming clear that effectors may act in redundant, synergistic, and antagonistic ways during infection. Vaccines that target the function of the Type III secretion system limit colonization of reservoir hosts by EHEC and may thus aid control of zoonotic infections. Here we review the features and functions of the LEE-encoded Type III secretion system and associated effectors of E. coli O157:H7 and other Shiga toxin-producing E. coli strains.
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40
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Ingle DJ, Tauschek M, Edwards DJ, Hocking DM, Pickard DJ, Azzopardi KI, Amarasena T, Bennett-Wood V, Pearson JS, Tamboura B, Antonio M, Ochieng JB, Oundo J, Mandomando I, Qureshi S, Ramamurthy T, Hossain A, Kotloff KL, Nataro JP, Dougan G, Levine MM, Robins-Browne RM, Holt KE. Evolution of atypical enteropathogenic E. coli by repeated acquisition of LEE pathogenicity island variants. Nat Microbiol 2016; 1:15010. [PMID: 27571974 DOI: 10.1038/nmicrobiol.2015.10] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/02/2015] [Indexed: 01/25/2023]
Abstract
Atypical enteropathogenic Escherichia coli (aEPEC) is an umbrella term given to E. coli that possess a type III secretion system encoded in the locus of enterocyte effacement (LEE), but lack the virulence factors (stx, bfpA) that characterize enterohaemorrhagic E. coli and typical EPEC, respectively. The burden of disease caused by aEPEC has recently increased in industrialized and developing nations, yet the population structure and virulence profile of this emerging pathogen are poorly understood. Here, we generated whole-genome sequences of 185 aEPEC isolates collected during the Global Enteric Multicenter Study from seven study sites in Asia and Africa, and compared them with publicly available E. coli genomes. Phylogenomic analysis revealed ten distinct widely distributed aEPEC clones. Analysis of genetic variation in the LEE pathogenicity island identified 30 distinct LEE subtypes divided into three major lineages. Each LEE lineage demonstrated a preferred chromosomal insertion site and different complements of non-LEE encoded effector genes, indicating distinct patterns of evolution of these lineages. This study provides the first detailed genomic framework for aEPEC in the context of the EPEC pathotype and will facilitate further studies into the epidemiology and pathogenicity of EPEC by enabling the detection and tracking of specific clones and LEE variants.
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Affiliation(s)
- Danielle J Ingle
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia.,Centre for Systems Genomics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marija Tauschek
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - David J Edwards
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia.,Centre for Systems Genomics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Dianna M Hocking
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Derek J Pickard
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Kristy I Azzopardi
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Thakshila Amarasena
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Vicki Bennett-Wood
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Jaclyn S Pearson
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia
| | - Boubou Tamboura
- Centre pour le Développement des Vaccins du Mali, Bamako, Mali
| | - Martin Antonio
- Medical Research Council Unit (United Kingdom), Fajara, The Gambia
| | - John B Ochieng
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Joseph Oundo
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Inácio Mandomando
- Centro de Investigação em Saúde de Manhiça, (CISM), CP 1929, Maputo, Mozambique.,Instituto Nacional de Saúde, Ministério da Saúde, Maputo, Mozambique
| | - Shahida Qureshi
- Department of Paediatrics and Child Health, The Aga Khan University, Karachi 74800, Pakistan
| | | | - Anowar Hossain
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Karen L Kotloff
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - James P Nataro
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Myron M Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Roy M Robins-Browne
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Victoria 3010, Australia.,Murdoch Childrens Research Institute, Royal Children's Hospital, Victoria 3052, Australia
| | - Kathryn E Holt
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia.,Centre for Systems Genomics, The University of Melbourne, Parkville, Victoria 3010, Australia
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41
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Stradal TEB, Costa SCP. Type III Secreted Virulence Factors Manipulating Signaling to Actin Dynamics. Curr Top Microbiol Immunol 2016; 399:175-199. [PMID: 27744505 DOI: 10.1007/82_2016_35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A key aspect of bacterial pathogenesis is the colonization and persistence within the host and, later on, its dissemination to new niches. During evolution, bacteria developed a myriad of virulence mechanisms to usurp the host's sophisticated defense mechanisms in order to establish their colonization niche. Elucidation of the highly dynamic and complex interactions between host and pathogens remains an important field of study. Here, we highlight the conserved manipulation of the actin cytoskeleton by some Gram-negative gastrointestinal pathogens, addressing the role of type III secreted bacterial GEFs at the different steps of pathogenesis. As a final topic, we review cytoskeleton dynamics induced by EPEC/EHEC strains for pedestal formation.
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Affiliation(s)
- Theresia E B Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany.
| | - Sonia C P Costa
- Department of Cell Biology, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124, Baunschweig, Germany
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42
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Cultured enterocytes internalise bacteria across their basolateral surface for, pathogen-inhibitable, trafficking to the apical compartment. Sci Rep 2015; 5:17359. [PMID: 26612456 PMCID: PMC4661573 DOI: 10.1038/srep17359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/23/2015] [Indexed: 01/13/2023] Open
Abstract
In vitro- and in vivo-polarised absorptive epithelia (enterocytes) are considered to be non-phagocytic towards bacteria with invasive pathogenic strains relying on virulence factors to 'force' entry. Here, we report a serendipitous discovery that questions these beliefs. Thus, we uncover in well-established models of human small (Caco-2; TC-7) and large (T84) intestinal enterocytes a polarization-dependent mechanism that can transfer millions of bacteria from the basal to apical compartment. Antibiotic-protection assays, confocal imaging and drug inhibitor data are consistent with a transcellular route in which internalized, basolateral-membrane enclosed bacteria are trafficked to and across the apical surface. Basal-to-apical transport of non-pathogenic bacteria (and inert beads) challenged the idea of pathogens relying on virulence factors to force entry. Indeed, studies with Salmonella demonstrated that it's entry-forcing virulence factor (SPI-I) was not required to enter via the basolateral surface but to promote another virulence-associated event (intra-enterocyte accumulation).
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43
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Deligianni DD. MWCNTs enhance hBMSCs spreading but delay their proliferation in the direction of differentiation acceleration. Cell Adh Migr 2015; 8:404-17. [PMID: 25482637 DOI: 10.4161/19336918.2014.969993] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Investigating the ability of films of pristine multiwalled nanotubes (MWCNTs) to influence human mesenchymal stem cells' proliferation, morphology, and differentiation into osteoblasts, we concluded to the following: A. MWCNTs delay the proliferation of hBMS cells but increase their differentiation. The enhancement of the differentiation markers could be a result of decreased proliferation and maturation of the extracellular matrix B. Cell spread on MWCNTs toward a polygonal shape with many thin filopodia to attach to the surfaces. Spreading may be critical in supporting osteogenic differentiation in pre-osteoblastic progenitors, being related with cytoskeletal tension. C. hBMS cells prefer MWCNTs than tissue plastic to attach and grow, being non-toxic to these cells. MWCNTs can be regarded as osteoinductive biomaterial topographies for bone regenerative engineering.
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Affiliation(s)
- Despina D Deligianni
- a Department of Mechanical Engineering & Aeronautics ; University of Patras ; Rion , Greece
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44
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Singh AP, Aijaz S. Generation of a MDCK cell line with constitutive expression of the Enteropathogenic E. coli effector protein Map as an in vitro model of pathogenesis. Bioengineered 2015; 6:335-41. [PMID: 26430918 DOI: 10.1080/21655979.2015.1096456] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Enteropathogenic E. coli (EPEC) cause diarrhea and are the major cause of mortality in developing countries. EPEC use a type III secretion system to deliver effector proteins into the host epithelial cells. To understand the functions of these effectors, majority of studies on EPEC pathogenesis have relied on infections of animals or cell lines with wild type strains of EPEC or mutant strains deficient in one or more effectors. While these studies have provided valuable data, it can be difficult to assess functions of an individual effector in the presence of other EPEC effectors. Recent studies have reported the use of transient transfections with plasmids encoding various EPEC effectors into different cell lines. However, variable transfection efficiencies and expression levels of the effector proteins coupled with their expression for relatively short periods of time pose a problem if the long term effects of these effectors need to be examined. We have generated a MDCK cell line with constitutive expression of the EPEC effector Map (Mitochondrial associated protein) for efficient stable expression of EGFP-tagged Map. We observed that the constitutive expression of Map increased the permeability of charged and non-charged molecules. We also generated polyclonal antibodies against Map and checked for their specificity in MDCK-Map expressing cells. Map has been reported to contribute to the onset of diarrhea but the underlying mechanism is yet to be identified. The MDCK-Map cell line and the anti-Map antibodies generated by us can be used for in vitro studies to examine the role of Map in EPEC pathogenesis.
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Affiliation(s)
- Anand Prakash Singh
- a Centre for Molecular Medicine; Jawaharlal Nehru University ; New Delhi, India
| | - Saima Aijaz
- a Centre for Molecular Medicine; Jawaharlal Nehru University ; New Delhi, India
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45
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Tran CD, Grice DM, Wade B, Kerr CA, Bauer DC, Li D, Hannan GN. Gut permeability, its interaction with gut microflora and effects on metabolic health are mediated by the lymphatics system, liver and bile acid. Future Microbiol 2015; 10:1339-53. [DOI: 10.2217/fmb.15.54] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There is evidence to link obesity (and metabolic syndrome) with alterations in gut permeability and microbiota. The underlying mechanisms have been questioned and have prompted this review. We propose that the gut barrier function is a primary driver in maintaining metabolic health with poor health being linked to ‘gut leakiness'. This review will highlight changes in intestinal permeability and how it may change gut microflora and subsequently affect metabolic health by influencing the functioning of major bodily organs/organ systems: the lymphatic system, liver and pancreas. We also discuss the likelihood that metabolic syndrome undergoes a cyclic worsening facilitated by an increase in intestinal permeability leading to gut dysbiosis, culminating in ongoing poor health leading to further exacerbated gut leakiness.
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Affiliation(s)
- Cuong D Tran
- CSIRO Food & Nutrition Flagship, Adelaide, SA 5000, Australia
| | - Desma M Grice
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Ben Wade
- CSIRO Biosecurity Flagship, Geelong, VIC 3219, Australia
| | - Caroline A Kerr
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Denis C Bauer
- CSIRO Digital Productivity & Services Flagship, North Ryde, NSW 1670, Australia
| | - Dongmei Li
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
| | - Garry N Hannan
- CSIRO Food & Nutrition Flagship, North Ryde, NSW 2113, Australia
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46
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Singh AP, Aijaz S. Enteropathogenic E. coli: breaking the intestinal tight junction barrier. F1000Res 2015; 4:231. [DOI: 10.12688/f1000research.6778.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/09/2015] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic E. coli (EPEC) causes acute intestinal infections in infants in the developing world. Infection typically spreads through contaminated food and water and leads to severe, watery diarrhea. EPEC attaches to the intestinal epithelial cells and directly injects virulence factors which modulate multiple signaling pathways leading to host cell dysfunction. However, the molecular mechanisms that regulate the onset of diarrhea are poorly defined. A major target of EPEC is the host cell tight junction complex which acts as a barrier and regulates the passage of water and solutes through the paracellular space. In this review, we focus on the EPEC effectors that target the epithelial barrier, alter its functions and contribute to leakage through the tight junctions.
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47
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Abstract
Enteropathogenic
E. coli (EPEC) causes acute intestinal infections in infants in the developing world. Infection typically spreads through contaminated food and water and leads to severe, watery diarrhea. EPEC attaches to the intestinal epithelial cells and directly injects virulence factors which modulate multiple signaling pathways leading to host cell dysfunction. However, the molecular mechanisms that regulate the onset of diarrhea are poorly defined. A major target of EPEC is the host cell tight junction complex which acts as a barrier and regulates the passage of water and solutes through the paracellular space. In this review, we focus on the EPEC effectors that target the epithelial barrier, alter its functions and contribute to leakage through the tight junctions.
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Affiliation(s)
- Anand Prakash Singh
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Saima Aijaz
- Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
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48
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Retrofitting the battlements: tight junction remodeling as a novel antimicrobial approach. Future Med Chem 2015; 7:9-13. [DOI: 10.4155/fmc.14.146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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49
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Wong Fok Lung T, Pearson JS, Schuelein R, Hartland EL. The cell death response to enteropathogenic Escherichia coli infection. Cell Microbiol 2014; 16:1736-45. [PMID: 25266336 DOI: 10.1111/cmi.12371] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/24/2014] [Accepted: 09/26/2014] [Indexed: 12/13/2022]
Abstract
Given the critical roles of inflammation and programmed cell death in fighting infection, it is not surprising that many bacterial pathogens have evolved strategies to inactivate these defences. The causative agent of infant diarrhoea, enteropathogenic Escherichia coli (EPEC), is an extracellular, intestinal pathogen that blocks both inflammation and programmed cell death. EPEC attaches to enterocytes, remains in the gut lumen and utilizes a type III secretion system (T3SS) to inject multiple virulence effector proteins directly into the infected cell, many of which subvert host antimicrobial processes through the disruption of signalling pathways. Recently, T3SS effector proteins from EPEC have been identified that inhibit death receptor-induced apoptosis. Here we review the mechanisms used by EPEC T3SS effectors to manipulate apoptosis and promote host cell survival and discuss the role of these activities during infection.
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Affiliation(s)
- Tania Wong Fok Lung
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Australia
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50
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Expression of enteropathogenic Escherichia coli map is significantly different than that of other type III secreted effectors in vivo. Infect Immun 2014; 83:130-7. [PMID: 25312947 DOI: 10.1128/iai.02467-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The enteropathogenic Escherichia coli (EPEC) locus of enterocyte effacement (LEE)-encoded effectors EspF and Map are multifunctional and have an impact on the tight junction barrier while the non-LEE-encoded proteins NleH1 and NleH2 possess significant anti-inflammatory activity. In order to address the temporal expression of these important genes in vivo, their promoters were cloned upstream of the luxCDABE operon, and luciferase expression was measured in EPEC-infected mice by bioluminescence using an in vivo imaging system (IVIS). Bioluminescent images of living mice, of excised whole intestines, and of whole intestines longitudinally opened and washed were assessed. The majority of bioluminescent bacteria localized in the cecum by 3 h postinfection, indicating that the cecum is not only a major colonization site of EPEC but also a site of EPEC effector gene expression in mice. espF, nleH1, and nleH2 were abundantly expressed over the course of infection. In contrast, map expression was suppressed at 2 days postinfection, and at 4 days postinfection it was totally abolished. After 2 to 4 days postinfection, when map is suppressed, EPEC colonization is significantly reduced, indicating that map may be one of the factors required to maintain EPEC colonization. This was confirmed in a competitive colonization study and in two models of chronic infection, repeated exposure to ketamine and Citrobacter rodentium infection. Our data suggest that map expression contributes to the maintenance of EPEC colonization.
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