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Fang Y, Fu M, Li X, Zhang B, Wan C. Enterohemorrhagic Escherichia coli effector EspF triggers oxidative DNA lesions in intestinal epithelial cells. Infect Immun 2024; 92:e0000124. [PMID: 38415639 PMCID: PMC11003234 DOI: 10.1128/iai.00001-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 02/29/2024] Open
Abstract
Attaching/effacing (A/E) pathogens induce DNA damage and colorectal cancer by injecting effector proteins into host cells via the type III secretion system (T3SS). EspF is one of the T3SS-dependent effector proteins exclusive to A/E pathogens, which include enterohemorrhagic Escherichia coli. The role of EspF in the induction of double-strand breaks (DSBs) and the phosphorylation of the repair protein SMC1 has been demonstrated previously. However, the process of damage accumulation and DSB formation has remained enigmatic, and the damage response is not well understood. Here, we first showed a compensatory increase in the mismatch repair proteins MutS homolog 2 (MSH2) and MSH6, as well as poly(ADP-ribose) polymerase 1, followed by a dramatic decrease, threatening cell survival in the presence of EspF. Flow cytometry revealed that EspF arrested the cell cycle at the G2/M phase to facilitate DNA repair. Subsequently, 8-oxoguanine (8-oxoG) lesions, a marker of oxidative damage, were assayed by ELISA and immunofluorescence, which revealed the accumulation of 8-oxoG from the cytosol to the nucleus. Furthermore, the status of single-stranded DNA (ssDNA) and DSBs was confirmed. We observed that EspF accelerated the course of DNA lesions, including 8-oxoG and unrepaired ssDNA, which were converted into DSBs; this was accompanied by the phosphorylation of replication protein A 32 in repair-defective cells. Collectively, these findings reveal that EspF triggers various types of oxidative DNA lesions with impairment of the DNA damage response and may result in genomic instability and cell death, offering novel insight into the tumorigenic potential of EspF.IMPORTANCEOxidative DNA lesions play causative roles in colitis-associated colon cancer. Accumulating evidence shows strong links between attaching/effacing (A/E) pathogens and colorectal cancer (CRC). EspF is one of many effector proteins exclusive to A/E pathogens with defined roles in the induction of oxidative stress, double-strand breaks (DSBs), and repair dysregulation. Here, we found that EspF promotes reactive oxygen species generation and 8-oxoguanine (8-oxoG) lesions when the repair system is activated, contributing to sustained cell survival. However, infected cells exposed to EspF presented 8-oxoG, which results in DSBs and ssDNA accumulation when the cell cycle is arrested at the G2/M phase and the repair system is defective or saturated by DNA lesions. In addition, we found that EspF could intensify the accumulation of nuclear DNA lesions through oxidative and replication stress. Overall, our work highlights the involvement of EspF in DNA lesions and DNA damage response, providing a novel avenue by which A/E pathogens may contribute to CRC.
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Affiliation(s)
- Yuting Fang
- BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Muqing Fu
- Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Xinyue Li
- BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Bao Zhang
- BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
| | - Chengsong Wan
- BSL-3 Laboratory, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China
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Joon A, Chandel S, Ghosh S. Enteroaggregative Escherichia coli induced activation of epidermal growth factor receptor contributes to IL-8 secretion by cultured human intestinal epithelial cells. Microbes Infect 2023; 25:105166. [PMID: 37290638 DOI: 10.1016/j.micinf.2023.105166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 04/19/2023] [Accepted: 05/30/2023] [Indexed: 06/10/2023]
Abstract
Enteroaggregative Escherichia coli (EAEC) has been identified as a new enteropathogen that causes acute and chronic diarrhea in children and travelers. One defining aspect of EAEC-pathogenesis is the induction of an inflammatory response in intestinal epithelium. In this study, we have found that EAEC-induced EGFR activation in human small intestinal and colonic epithelial was attenuated in the presence of a specific inhibitor of EGFR (Tyrphostin AG1478). Further, the aggregative stacked-brick type of adherence of this organism to both the cell lines and this pathogen-induced cytoskeletal rearrangement of these cells was also reduced in the presence of Tyrphostin AG1478. Moreover, EAEC-induced activation of downstream effectors (ERK-1/2, PI3K and Akt) of EGFR mediated cell signaling pathways were found to be suppressed in the presence of EGFR inhibitor. A decrease in IL-8 response in EAEC infected both the cell types were also noted in the presence of specific inhibitors of these downstream effectors, transcription factors and Tyrphostin AG1478. We propose that EAEC-induced activation of EGFR is quintessential for stacked-brick adherence of EAEC to human intestinal epithelial cells, their cytoskeletal rearrangements and stimulation of ERK-1/2 and PI3K/Akt mediated signal transduction pathways, resulting in the activation of NF-κB, AP-1, STAT-3 and finally IL-8 secretion by these cells.
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Affiliation(s)
- Archana Joon
- Department of Experimental Medicine and Biotechnology; Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - Shipra Chandel
- Department of Experimental Medicine and Biotechnology; Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - Sujata Ghosh
- Department of Experimental Medicine and Biotechnology; Post Graduate Institute of Medical Education & Research, Chandigarh, India.
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3
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Roxas JL, Ramamurthy S, Cocchi K, Rutins I, Harishankar A, Agellon A, Wilbur JS, Sylejmani G, Vedantam G, Viswanathan V. Enteropathogenic Escherichia coli regulates host-cell mitochondrial morphology. Gut Microbes 2022; 14:2143224. [PMID: 36476073 PMCID: PMC9733699 DOI: 10.1080/19490976.2022.2143224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The diarrheagenic pathogen enteropathogenic Escherichia coli is responsible for significant childhood mortality and morbidity. EPEC and related attaching-and-effacing (A/E) pathogens use a type III secretion system to hierarchically deliver effector proteins into host cells and manipulate epithelial structure and function. Subversion of host mitochondrial biology is a key aspect of A/E pathogen virulence strategy, but the mechanisms remain poorly defined. We demonstrate that the early-secreted effector EspZ and the late-secreted effector EspH have contrasting effects on host mitochondrial structure and function. EspZ interacts with FIS1, a protein that induces mitochondrial fragmentation and mitophagy. Infection of epithelial cells with either wildtype EPEC or an isogenic espZ deletion mutant (ΔespZ) robustly upregulated FIS1 abundance, but a marked increase in mitochondrial fragmentation and mitophagy was seen only in ΔespZ-infected cells. FIS1-depleted cells were protected against ΔespZ-induced fission, and EspZ-expressing transfected epithelial cells were protected against pharmacologically induced mitochondrial fission and membrane potential disruption. Thus, EspZ interacts with FIS1 and blocks mitochondrial fragmentation and mitophagy. In contrast to WT EPEC, ΔespH-infected epithelial cells had minimal FIS1 upregulation and exhibited hyperfused mitochondria. Consistent with the contrasting impacts on organelle shape, mitochondrial membrane potential was preserved in ΔespH-infected cells, but profoundly disrupted in ΔespZ-infected cells. Collectively, our studies reveal hitherto unappreciated roles for two essential EPEC virulence factors in the temporal and dynamic regulation of host mitochondrial biology.
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Affiliation(s)
- Jennifer Lising Roxas
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Shylaja Ramamurthy
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Katie Cocchi
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Ilga Rutins
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Anusha Harishankar
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Al Agellon
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - John Scott Wilbur
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Gresa Sylejmani
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA,Department of Immunobiology, University of Arizona, Tucson, AZ, USA,BIO5 Institute for Collaborative Research, University of Arizona, Tucson, AZ, USA,Research Service, Southern Arizona VA Healthcare System, Tucson, AZ, USA
| | - V.K. Viswanathan
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA,Department of Immunobiology, University of Arizona, Tucson, AZ, USA,BIO5 Institute for Collaborative Research, University of Arizona, Tucson, AZ, USA,CONTACT V.K. Viswanathan School of Animal & Comparative Biomedical Sciences, the University of Arizona, Room 227, 1117 E. Lowell Street, Tucson, AZ85721, USA
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The Four Horsemen in Colon Cancer. JOURNAL OF ONCOLOGY 2019; 2019:5636272. [PMID: 31662752 PMCID: PMC6791268 DOI: 10.1155/2019/5636272] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 08/26/2019] [Indexed: 02/06/2023]
Abstract
Worldwide, neoplasms of the gastrointestinal tract have a very high incidence and mortality. Among these, colorectal cancer, which includes colon and rectum malignancies, representing both highest incidence and mortality. While gallbladder cancer, another neoplasm associated to gastrointestinal tract occurs less frequently. Genetic factors, inflammation and nutrition are important risk factors associated with colorectal cancer development. Likewise, pathogenic microorganisms inducing intestinal dysbiosis have become an important scope to determine the role of bacterial infection on tumorigenesis. Interestingly, in human biopsies of different types of gastrointestinal tract cancer, the presence of different bacterial strains, such as Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis and Salmonella enterica have been detected, and it has been considered as a high-risk factor to cancer development. Therefore, pathogens infection could contribute to neoplastic development through different mechanisms; including intestinal dysbiosis, inflammation, evasion of tumoral immune response and activation of pro-tumoral signaling pathways, such as β catenin. Here, we have reviewed the suggested bacterial molecular mechanisms and their possible role on development and progression of gastrointestinal neoplasms, focusing mainly on colon neoplasms, where the bacteria Fusobacterium nucleatum, Escherichia coli, Bacteroides fragilis and Salmonella enterica infect.
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Hua Y, Yan K, Wan C. Clever Cooperation: Interactions Between EspF and Host Proteins. Front Microbiol 2018; 9:2831. [PMID: 30524410 PMCID: PMC6262023 DOI: 10.3389/fmicb.2018.02831] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/05/2018] [Indexed: 12/12/2022] Open
Abstract
EspF is a central effector protein of enterohemorrhagic Escherichia coli (EHEC), enteropathogenic E. coli (EPEC), and Citrobacter rodentium (CR) that is secreted through the type III secretion system to host cells. The interaction between EspF and host proteins plays an important role in bacterial pathogenesis. EspF protein binds to host SNX9 and N-WASP proteins to promote the colonization of pathogenic bacteria in intestinal epithelial cells; combines with cytokeratin 18, actin, 14-3-3ζ, Arp2/3, profilin, and ZO-1 proteins to intervene in the redistribution of intermediate filaments, the rearrangement of actin, and the disruption of tight junctions; acts together with Abcf2 to boost host cell intrinsic apoptosis; and collaborates with Anxa6 protein to inhibit phagocytosis. The interaction between EspF and host proteins is key to the pathogenic mechanism of EHEC and EPEC. Here, we review how EspF protein functions through interactions with these 10 host proteins and contributes to the pathogenicity of EHEC/EPEC.
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Affiliation(s)
- Ying Hua
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, China.,Key Laboratory of Tropical Disease Research of Guangdong Province, Guangzhou, China
| | - Kaina Yan
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, China.,Key Laboratory of Tropical Disease Research of Guangdong Province, Guangzhou, China
| | - Chengsong Wan
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, China.,Key Laboratory of Tropical Disease Research of Guangdong Province, Guangzhou, China
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Vedantam G, Kochanowsky J, Lindsey J, Mallozzi M, Roxas JL, Adamson C, Anwar F, Clark A, Claus-Walker R, Mansoor A, McQuade R, Monasky RC, Ramamurthy S, Roxas B, Viswanathan VK. An Engineered Synthetic Biologic Protects Against Clostridium difficile Infection. Front Microbiol 2018; 9:2080. [PMID: 30233548 PMCID: PMC6134020 DOI: 10.3389/fmicb.2018.02080] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/14/2018] [Indexed: 12/18/2022] Open
Abstract
Morbidity and mortality attributed to Clostridium difficile infection (CDI) have increased over the past 20 years. Currently, antibiotics are the only US FDA-approved treatment for primary C. difficile infection, and these are, ironically, associated with disease relapse and the threat of burgeoning drug resistance. We previously showed that non-toxin virulence factors play key roles in CDI, and that colonization factors are critical for disease. Specifically, a C. difficile adhesin, Surface Layer Protein A (SlpA) is a major contributor to host cell attachment. In this work, we engineered Syn-LAB 2.0 and Syn-LAB 2.1, two synthetic biologic agents derived from lactic acid bacteria, to stably and constitutively express a host-cell binding fragment of the C. difficile adhesin SlpA on their cell-surface. Both agents harbor conditional suicide plasmids expressing a codon-optimized chimera of the lactic acid bacterium's cell-wall anchoring surface-protein domain, fused to the conserved, highly adherent, host-cell-binding domain of C. difficile SlpA. Both agents also incorporate engineered biocontrol, obviating the need for any antibiotic selection. Syn-LAB 2.0 and Syn-LAB 2.1 possess positive biophysical and in vivo properties compared with their parental antecedents in that they robustly and constitutively display the SlpA chimera on their cell surface, potentiate human intestinal epithelial barrier function in vitro, are safe, tolerable and palatable to Golden Syrian hamsters and neonatal piglets at high daily doses, and are detectable in animal feces within 24 h of dosing, confirming robust colonization. In combination, the engineered strains also delay (in fixed doses) or prevent (when continuously administered) death of infected hamsters upon challenge with high doses of virulent C. difficile. Finally, fixed-dose Syn-LAB ameliorates diarrhea in a non-lethal model of neonatal piglet enteritis. Taken together, our findings suggest that the two synthetic biologics may be effectively employed as non-antibiotic interventions for CDI.
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Affiliation(s)
- Gayatri Vedantam
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
- Department of Immunobiology, The University of Arizona, Tucson, AZ, United States
- Bio5 Institute for Collaborative Research, The University of Arizona, Tucson, AZ, United States
- Southern Arizona VA Health Care System, Tucson, AZ, United States
| | - Joshua Kochanowsky
- Department of Immunobiology, The University of Arizona, Tucson, AZ, United States
| | - Jason Lindsey
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Michael Mallozzi
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Jennifer Lising Roxas
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Chelsea Adamson
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Farhan Anwar
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Andrew Clark
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Rachel Claus-Walker
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Asad Mansoor
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Rebecca McQuade
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Ross Calvin Monasky
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Shylaja Ramamurthy
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - Bryan Roxas
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
| | - V. K. Viswanathan
- School of Animal and Comparative Biomedical Sciences, The University of Arizona, Tucson, AZ, United States
- Department of Immunobiology, The University of Arizona, Tucson, AZ, United States
- Bio5 Institute for Collaborative Research, The University of Arizona, Tucson, AZ, United States
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Kim WJ, Shea AE, Kim JH, Daaka Y. Uropathogenic Escherichia coli invades bladder epithelial cells by activating kinase networks in host cells. J Biol Chem 2018; 293:16518-16527. [PMID: 30166343 DOI: 10.1074/jbc.ra118.003499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/23/2018] [Indexed: 12/16/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is the causative bacterium in most urinary tract infections (UTIs). UPEC cells adhere to and invade bladder epithelial cells (BECs) and cause uropathogenicity. Invading UPEC cells may encounter one of several fates, including degradation in the lysosome, expulsion to the extracellular milieu for clearance, or survival as an intracellular bacterial community and quiescent intracellular reservoir that can cause later infections. Here we considered the possibility that UPEC cells secrete factors that activate specific host cell signaling networks to facilitate the UPEC invasion of BECs. Using GFP-based reporters and Western blot analysis, we found that the representative human cystitis isolate E. coli UTI89 and its derivative UTI89ΔFimH, which does not bind to BECs, equally activate phosphatidylinositol 4,5-bisphosphate 3-OH kinase (PI3K), Akt kinase, and mTOR complex (mTORC) 1 and 2 in BECs. We also found that conditioned medium taken from UTI89 and UTI89ΔFimH cultures similarly activates epidermal growth factor receptor (EGFR), PI3K, Akt, and mTORC and that inhibition of EGFR and mTORC2, but not mTORC1, abrogates UTI89 invasion in vitro and in animal models of UTI. Our results reveal a key molecular mechanism of UPEC invasion and the host cells it targets, insights that may have therapeutic utility for managing the ever-increasing number of persistent and chronic UTIs.
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Affiliation(s)
- Wan-Ju Kim
- From the Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Allyson E Shea
- From the Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Joon-Hyung Kim
- From the Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Yehia Daaka
- From the Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, Florida 32610
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8
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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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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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10
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Pearson JS, Giogha C, Wong Fok Lung T, Hartland EL. The Genetics of EnteropathogenicEscherichia coliVirulence. Annu Rev Genet 2016; 50:493-513. [DOI: 10.1146/annurev-genet-120215-035138] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jaclyn S. Pearson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Cristina Giogha
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Tania Wong Fok Lung
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
| | - Elizabeth L. Hartland
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia; , , ,
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Serapio-Palacios A, Navarro-Garcia F. EspC, an Autotransporter Protein Secreted by Enteropathogenic Escherichia coli, Causes Apoptosis and Necrosis through Caspase and Calpain Activation, Including Direct Procaspase-3 Cleavage. mBio 2016; 7:e00479-16. [PMID: 27329750 PMCID: PMC4916375 DOI: 10.1128/mbio.00479-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/12/2016] [Indexed: 01/30/2023] Open
Abstract
UNLABELLED Enteropathogenic Escherichia coli (EPEC) has the ability to antagonize host apoptosis during infection through promotion and inhibition of effectors injected by the type III secretion system (T3SS), but the total number of these effectors and the overall functional relationships between these effectors during infection are poorly understood. EspC produced by EPEC cleaves fodrin, paxillin, and focal adhesion kinase (FAK), which are also cleaved by caspases and calpains during apoptosis. Here we show the role of EspC in cell death induced by EPEC. EspC is involved in EPEC-mediated cell death and induces both apoptosis and necrosis in epithelial cells. EspC induces apoptosis through the mitochondrial apoptotic pathway by provoking (i) a decrease in the expression levels of antiapoptotic protein Bcl-2, (ii) translocation of the proapoptotic protein Bax from cytosol to mitochondria, (iii) cytochrome c release from mitochondria to the cytoplasm, (iv) loss of mitochondrial membrane potential, (v) caspase-9 activation, (vi) cleavage of procaspase-3 and (vii) an increase in caspase-3 activity, (viii) PARP proteolysis, and (ix) nuclear fragmentation and an increase in the sub-G1 population. Interestingly, EspC-induced apoptosis was triggered through a dual mechanism involving both independent and dependent functions of its EspC serine protease motif, the direct cleavage of procaspase-3 being dependent on this motif. This is the first report showing a shortcut for induction of apoptosis by the catalytic activity of an EPEC protein. Furthermore, this atypical intrinsic apoptosis appeared to induce necrosis through the activation of calpain and through the increase of intracellular calcium induced by EspC. Our data indicate that EspC plays a relevant role in cell death induced by EPEC. IMPORTANCE EspC, an autotransporter protein with serine protease activity, has cytotoxic effects on epithelial cells during EPEC infection. EspC causes cytotoxicity by cleaving fodrin, a cytoskeletal actin-associated protein, and focal adhesion proteins (i.e., FAK); interestingly, these proteins are also cleaved during apoptosis and necrosis. Here we show that EspC is able to cause cell death, which is characterized by apoptosis: by dissecting the apoptotic pathway and considering that EspC is translocated by an injectisome, we found that EspC induces the mitochondrial apoptotic pathway. Remarkably, EspC activates this pathway by two distinct mechanisms-either by using or not using its serine protease motif. Thus, we show for the first time that this serine protease motif is able to cleave procaspase-3, thereby reaching the terminal stages of caspase cascade activation leading to apoptosis. Furthermore, this overlapped apoptosis appears to potentiate cell death through necrosis, where EspC induces calpain activation and increases intracellular calcium.
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Affiliation(s)
- Antonio Serapio-Palacios
- 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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Santos AS, Finlay BB. Bringing down the host: enteropathogenic and enterohaemorrhagic Escherichia coli effector-mediated subversion of host innate immune pathways. Cell Microbiol 2015; 17:318-32. [PMID: 25588886 DOI: 10.1111/cmi.12412] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/17/2014] [Accepted: 12/22/2014] [Indexed: 12/14/2022]
Abstract
Enteric bacterial pathogens commonly use a type III secretion system (T3SS) to successfully infect intestinal epithelial cells and survive and proliferate in the host. Enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC; EHEC) colonize the human intestinal mucosa, form characteristic histological lesions on the infected epithelium and require the T3SS for full virulence. T3SS effectors injected into host cells subvert cellular pathways to execute a variety of functions within infected host cells. The EPEC and EHEC effectors that subvert innate immune pathways--specifically those involved in phagocytosis, host cell survival, apoptotic cell death and inflammatory signalling--are all required to cause disease. These processes are reviewed within, with a focus on recent work that has provided insights into the functions and host cell targets of these effectors.
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Affiliation(s)
- Andrew S Santos
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada; Michael Smith Laboratories, The University of British Columbia, Vancouver, BC, Canada
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The secreted effector protein EspZ is essential for virulence of rabbit enteropathogenic Escherichia coli. Infect Immun 2015; 83:1139-49. [PMID: 25561713 DOI: 10.1128/iai.02876-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Attaching and effacing (A/E) pathogens adhere intimately to intestinal enterocytes and efface brush border microvilli. A key virulence strategy of A/E pathogens is the type III secretion system (T3SS)-mediated delivery of effector proteins into host cells. The secreted protein EspZ is postulated to promote enterocyte survival by regulating the T3SS and/or by modulating epithelial signaling pathways. To explore the role of EspZ in A/E pathogen virulence, we generated an isogenic espZ deletion strain (ΔespZ) and corresponding cis-complemented derivatives of rabbit enteropathogenic Escherichia coli and compared their abilities to regulate the T3SS and influence host cell survival in vitro. For virulence studies, rabbits infected with these strains were monitored for bacterial colonization, clinical signs, and intestinal tissue alterations. Consistent with data from previous reports, espZ-transfected epithelial cells were refractory to infection-dependent effector translocation. Also, the ΔespZ strain induced greater host cell death than did the parent and complemented strains. In rabbit infections, fecal ΔespZ strain levels were 10-fold lower than those of the parent strain at 1 day postinfection, while the complemented strain was recovered at intermediate levels. In contrast to the parent and complemented mutants, ΔespZ mutant fecal carriage progressively decreased on subsequent days. ΔespZ mutant-infected animals gained weight steadily over the infection period, failed to show characteristic disease symptoms, and displayed minimal infection-induced histological alterations. Terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) staining of intestinal sections revealed increased epithelial cell apoptosis on day 1 after infection with the ΔespZ strain compared to animals infected with the parent or complemented strains. Thus, EspZ-dependent host cell cytoprotection likely prevents epithelial cell death and sloughing and thereby promotes bacterial colonization.
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