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Fettucciari K, Dini F, Marconi P, Bassotti G. Role of the Alteration in Calcium Homeostasis in Cell Death Induced by Clostridioides difficile Toxin A and Toxin B. BIOLOGY 2023; 12:1117. [PMID: 37627001 PMCID: PMC10452684 DOI: 10.3390/biology12081117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 08/05/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
Clostridioides difficile (C. difficile), responsible for 15-25% of gastrointestinal infections, causes health problems mainly due to the toxic activity of toxins A and B (Tcds). These are responsible for its clinical manifestations, including diarrhea, pseudomembranous colitis, toxic megacolon and death, with a mortality of 5-30% in primary infection, that increase following relapses. Studies on Tcd-induced cell death have highlighted a key role of caspases, calpains, and cathepsins, with involvement of mitochondria and reactive oxygen species (ROS) in a complex signaling pathway network. The complex response in the execution of various types of cell death (apoptosis, necrosis, pyroptosis and pyknosis) depends on the amount of Tcd, cell types, and Tcd receptors involved, and could have as initial/precocious event the alterations in calcium homeostasis. The entities, peculiarities and cell types involved in these alterations will decide the signaling pathways activated and cell death type. Calcium homeostasis alterations can be caused by calcium influx through calcium channel activation, transient intracellular calcium oscillations, and leakage of calcium from intracellular stores. These increases in cytoplasmic calcium have important effects on all calcium-regulated molecules, which may play a direct role in several cell death types and/or activate other cell death effectors, such as caspases, calpains, ROS and proapoptotic Bcl-2 family members. Furthermore, some support for the possible role of the calcium homeostasis alteration in Tcd-induced cell death originates from the similarity with cytotoxic effects that cause pore-forming toxins, based mainly on calcium influx through plasma membrane pores.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Fabrizio Dini
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy;
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy;
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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Fettucciari K, Fruganti A, Stracci F, Spaterna A, Marconi P, Bassotti G. Clostridioides difficile Toxin B Induced Senescence: A New Pathologic Player for Colorectal Cancer? Int J Mol Sci 2023; 24:ijms24098155. [PMID: 37175861 PMCID: PMC10179142 DOI: 10.3390/ijms24098155] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
Clostridioides difficile (C. difficile) is responsible for a high percentage of gastrointestinal infections and its pathological activity is due to toxins A and B. C. difficile infection (CDI) is increasing worldwide due to the unstoppable spread of C. difficile in the anthropized environment and the progressive human colonization. The ability of C. difficile toxin B to induce senescent cells and the direct correlation between CDI, irritable bowel syndrome (IBS), and inflammatory bowel diseases (IBD) could cause an accumulation of senescent cells with important functional consequences. Furthermore, these senescent cells characterized by long survival could push pre-neoplastic cells originating in the colon towards the complete neoplastic transformation in colorectal cancer (CRC) by the senescence-associated secretory phenotype (SASP). Pre-neoplastic cells could appear as a result of various pro-carcinogenic events, among which, are infections with bacteria that produce genotoxins that generate cells with high genetic instability. Therefore, subjects who develop IBS and/or IBD after CDI should be monitored, especially if they then have further CDI relapses, waiting for the availability of senolytic and anti-SASP therapies to resolve the pro-carcinogenic risk due to accumulation of senescent cells after CDI followed by IBS and/or IBD.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy
| | - Fabrizio Stracci
- Public Health Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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Bassotti G, Fruganti A, Stracci F, Marconi P, Fettucciari K. Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases. World J Gastroenterol 2023; 29:582-596. [PMID: 36742168 PMCID: PMC9896618 DOI: 10.3748/wjg.v29.i4.582] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/03/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023] Open
Abstract
Clostridioides difficile (C. difficile) is progressively colonizing humans and animals living with humans. During this process, hypervirulent strains and mutated toxin A and B of C. difficile (TcdA and TcdB) are originating and developing. While in healthy subjects colonization by C. difficile becomes a risk after the use of antibiotics that alter the microbiome, other categories of people are more susceptible to infection and at risk of relapse, such as those with inflammatory bowel disease (IBD). Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma (CKs). Therefore, in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C. difficile infection and its progression and relapses. TcdB is internalized in the cell via three receptors: chondroitin sulphate proteoglycan 4; poliovirus receptor-like 3; and Wnt receptor frizzled family. Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types, while poliovirus receptor-like 3 induces only necrosis. It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis. Therefore, in subjects with IBD there are the conditions: (1) For greater susceptibility to C. difficile infection, such as the inflammatory state, and abnormalities of the microbiome and of the immune system; (2) for the enhancement of the cytotoxic activity of TcdB +Cks; and (3) for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis. The only therapeutic approach currently possible in IBD patients is monitoring of C. difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins. The future perspective is to generate bacteriophages against C. difficile for targeted therapy.
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Affiliation(s)
- Gabrio Bassotti
- Department of Medicine and Surgery, Gastroenterology, Hepatology & Digestive Endoscopy Section University of Perugia Medical School, Piazza Lucio Severi, Perugia 06132, Italy, and Santa Maria della Misericordia Hospital, Gastroenterology & Hepatology Unit Perugia 06156, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Matelica 62024, Italy
| | - Fabrizio Stracci
- Medicine and Surgery, Hygiene and Public Health Section, University of Perugia, Perugia 06123, Italy
| | - Pierfrancesco Marconi
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
| | - Katia Fettucciari
- Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Perugia 06132, Italy
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Fettucciari K, Marconi P, Marchegiani A, Fruganti A, Spaterna A, Bassotti G. Invisible steps for a global endemy: molecular strategies adopted by Clostridioides difficile. Therap Adv Gastroenterol 2021; 14:17562848211032797. [PMID: 34413901 PMCID: PMC8369858 DOI: 10.1177/17562848211032797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/26/2021] [Indexed: 02/06/2023] Open
Abstract
Clostridioides difficile infection (CDI) is on the rise worldwide and is associated with an increase in deaths and socio-health burden. C. difficile has become ubiquitous in anthropized environments because of the extreme resistance of its spores. Based on the epidemiological data and knowledge of molecular pathogenesis of C. difficile, it is possible to predict its progressive colonization of the human population for the following reasons: first, its global spread is unstoppable; second, the toxins (Tcds) produced by C. difficile, TcdA and TcdB, mainly cause cell death by apoptosis, but the surviving cells acquire a senescence state that favours persistence of C. difficile in the intestine; third, proinflammatory cytokines, tumour necrosis factor-α and interferon-γ, induced during CDI, enhance the cytotoxicity of Tcds and can increase the survival of senescent cells; fourth, Tcds block mobility and induce apoptosis in immune cells recruited at the infection site; and finally, after remission from primary infection or relapse, C. difficile causes functional abnormalities in the enteric glial cell (EGC) network that can result in irritable bowel syndrome, characterized by a latent inflammatory response that contributes to C. difficile survival and enhances the cytotoxic activity of low doses of TcdB, thus favouring further relapses. Since a 'global endemy' of C. difficile seems inevitable, it is necessary to develop an effective vaccine against Tcds for at-risk individuals, and to perform a prophylaxis/selective therapy with bacteriophages highly specific for C. difficile. We must be aware that CDI will become a global health problem in the forthcoming years, and we must be prepared to face this menace.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Medical School -Piazza Lucio Severi 1, Edificio B - IV piano; Sant’Andrea delle Fratte, Perugia, 06132, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Andrea Marchegiani
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria della Misericordia Hospital, Perugia, Italy
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Fettucciari K, Fruganti A, Marchegiani A, Brancorsini S, Marconi P, Bassotti G. Proinflammatory Cytokines: Possible Accomplices for the Systemic Effects of Clostridioides difficile Toxin B. J Inflamm Res 2021; 14:57-62. [PMID: 33469335 PMCID: PMC7810702 DOI: 10.2147/jir.s287096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
Clostridioides difficile infection (CDI) has a serious impact on the healthcare system, and most of its pathogenic effects are mainly due to the activity of toxins A and B (TcdA and TcdB, respectively). The molecular mechanisms of their cytotoxic activity are well known, especially in the colon, where the infection occurs and normally remains localized. However, the mechanisms causing toxic effects on various systemic organs (extraintestinal manifestations) with frequent lethal outcomes in some patients affected by CDI are still poorly understood. Few studies are available that demonstrate low serum levels of Tcds in both experimental animal models and patients with CDI. Until now, it has remained unclear how low levels of circulating Tcds could lead to serious toxic effects. On the basis of our previous in vitro studies, in which the proinflammatory cytokines TNF-alpha and IFN-gamma strongly potentiated the toxic activity of low doses of TcdB, we hypothesize that the presence of both TcdB in the circulation and a systemic proinflammatory cytokine storm may be responsible for the selective severe effects of TcdB in some patients. This may occur in patients with severe CDI and systemic Tcds, in whom proinflammatory cytokines such as TNF-alpha and IFN-gamma reach a significant concentration in the circulation. This hypothesis could identify therapeutic interventions based on the reduction or neutralization of the indirect toxic action of these cytokines.
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Affiliation(s)
- Katia Fettucciari
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
- Correspondence: Katia Fettucciari Department of Experimental Medicine, University of Perugia Medical School, Piazza Lucio Severi 1, Edificio B IV Piano, Sant’Andrea delle Fratte, Perugia06132, ItalyTel +39755858124 Email
| | - Alessandro Fruganti
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Andrea Marchegiani
- School of Biosciences and Veterinary Medicine, University of Camerino, Macerata, Italy
| | - Stefano Brancorsini
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
| | - Pierfrancesco Marconi
- Department of Experimental Medicine, University of Perugia Medical School, Perugia, Italy
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine, University of Perugia Medical School, Perugia, Italy
- Gastroenterology & Hepatology Unit, Santa Maria della Misericordia Hospital, Perugia, Italy
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Díaz JM, Dozois CM, Avelar-González FJ, Hernández-Cuellar E, Pokharel P, de Santiago AS, Guerrero-Barrera AL. The Vacuolating Autotransporter Toxin (Vat) of Escherichia coli Causes Cell Cytoskeleton Changes and Produces Non-lysosomal Vacuole Formation in Bladder Epithelial Cells. Front Cell Infect Microbiol 2020; 10:299. [PMID: 32670893 PMCID: PMC7332727 DOI: 10.3389/fcimb.2020.00299] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Urinary tract infections (UTIs) affect more than 150 million people, with a cost of over 3.5 billion dollars, each year. Escherichia coli is associated with 70–80% of UTIs. Uropathogenic E. coli (UPEC) has virulence factors including adhesins, siderophores, and toxins that damage host cells. Vacuolating autotransporter toxin (Vat) is a member of serine protease autotransporter proteins of Enterobacteriaceae (SPATEs) present in some uropathogenic E. coli (UPEC) strains. Vat has been identified in 20–36% of UPEC and is present in almost 68% of urosepsis isolates. However, the mechanism of action of Vat on host cells is not well-known. Thus, in this study the effect of Vat in a urothelium model of bladder cells was investigated. Several toxin concentrations were tested for different time periods, resulting in 15–47% of cellular damage as measured by the LDH assay. Vat induced vacuole formation on the urothelium model in a time-dependent manner. Vat treatment showed loss of the intercellular contacts on the bladder cell monolayer, observed by Scanning Electron Microscopy. This was also shown using antibodies against ZO-1 and occludin by immunofluorescence. Additionally, changes in permeability of the epithelial monolayer was demonstrated with a fluorescence-based permeability assay. Cellular damage was also evaluated by the identification of cytoskeletal changes produced by Vat. Thus, after Vat treatment, cells presented F-actin distribution changes and loss of stress fibers in comparison with control cells. Vat also modified tubulin, but it was not found to affect Arp3 distribution. In order to find the nature of the vacuoles generated by Vat, the Lysotracker deep red fluorescent dye for the detection of acidic organelles was used. Cells treated with Vat showed generation of some vacuoles without acidic content. An ex vivo experiment with mouse bladder exposed to Vat demonstrated loss of integrity of the urothelium. In conclusion, Vat induced cellular damage, vacuole formation, and urothelial barrier dysregulation of bladder epithelial cells. Further studies are needed to elucidate the role of these vacuoles induced by Vat and their relationship with the pathogenesis of urinary tract infection.
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Affiliation(s)
- Juan Manuel Díaz
- Departamento de Morfología, Universidad Autónoma de Aguascalientes (UAA), Aguascalientes, Mexico
| | - Charles M Dozois
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Fappier Santé Biotechnologie, Laval, QC, Canada
| | | | | | - Pravil Pokharel
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Fappier Santé Biotechnologie, Laval, QC, Canada
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Cassady-Cain RL, Blackburn EA, Alsarraf H, Dedic E, Bease AG, Böttcher B, Jørgensen R, Wear M, Stevens MP. Biophysical Characterization and Activity of Lymphostatin, a Multifunctional Virulence Factor of Attaching and Effacing Escherichia coli. J Biol Chem 2016; 291:5803-5816. [PMID: 26786100 PMCID: PMC4786716 DOI: 10.1074/jbc.m115.709600] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/11/2016] [Indexed: 12/20/2022] Open
Abstract
Attaching and effacing Escherichia coli cause diarrhea and typically produce lymphostatin (LifA), an inhibitor of mitogen-activated proliferation of lymphocytes and pro-inflammatory cytokine synthesis. A near-identical factor (Efa1) has been reported to mediate adherence of E. coli to epithelial cells. An amino-terminal region of LifA shares homology with the catalytic domain of the large clostridial toxins, which are retaining glycosyltransferases with a DXD motif involved in binding of a metal ion. Understanding the mode(s) of action of lymphostatin has been constrained by difficulties obtaining a stably transformed plasmid expression clone. We constructed a tightly inducible clone of enteropathogenic E. coli O127:H6 lifA for affinity purification of lymphostatin. The purified protein inhibited mitogen-activated proliferation of bovine T lymphocytes in the femtomolar range. It is a monomer in solution and the molecular envelope was determined using both transmission electron microscopy and small-angle x-ray scattering. Domain architecture was further studied by limited proteolysis. The largest proteolytic fragment containing the putative glycosyltransferase domain was tested in isolation for activity against T cells, and was not sufficient for activity. Tryptophan fluorescence studies indicated thatlymphostatin binds uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) but not UDP-glucose (UDP-Glc). Substitution of the predicted DXD glycosyltransferase motif with alanine residues abolished UDP-GlcNAc binding and lymphostatin activity, although other biophysical properties were unchanged. The data indicate that lymphostatin has UDP-sugar binding potential that is critical for activity, and is a major leap toward identifying the nature and consequences of modifications of host cell factors.
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Affiliation(s)
- Robin L Cassady-Cain
- From the Roslin Institute, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | - Elizabeth A Blackburn
- the Centre for Translational and Chemical Biology (CTCB), University of Edinburgh, Michael Swann Building, King's Buildings, Edinburgh EH9 3BF, United Kingdom, and
| | - Husam Alsarraf
- the Department of Microbiology & Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| | - Emil Dedic
- the Department of Microbiology & Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| | - Andrew G Bease
- From the Roslin Institute, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | - Bettina Böttcher
- the Centre for Translational and Chemical Biology (CTCB), University of Edinburgh, Michael Swann Building, King's Buildings, Edinburgh EH9 3BF, United Kingdom, and
| | - René Jørgensen
- the Department of Microbiology & Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
| | - Martin Wear
- the Centre for Translational and Chemical Biology (CTCB), University of Edinburgh, Michael Swann Building, King's Buildings, Edinburgh EH9 3BF, United Kingdom, and
| | - Mark P Stevens
- From the Roslin Institute, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom,.
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Yu H, Chen K, Wu J, Yang Z, Shi L, Barlow LL, Aronoff DM, Garey KW, Savidge TC, von Rosenvinge EC, Kelly CP, Feng H. Identification of toxemia in patients with Clostridium difficile infection. PLoS One 2015; 10:e0124235. [PMID: 25885671 PMCID: PMC4401762 DOI: 10.1371/journal.pone.0124235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/27/2015] [Indexed: 01/05/2023] Open
Abstract
Toxemia can develop in Clostridium difficile-infected animals, and correlates with severe and fulminant disease outcomes. Circumstantial evidence suggests that toxemia may occur in patients with C. difficile infection (CDI), but positive diagnosis is extremely rare. We analyzed the potential for C. difficile toxemia in patients, determined its characteristics, and assessed challenges. C. difficile toxins in serum from patients were tested using an ultrasensitive cell-based assay and further confirmed by Rac1 glucosylation assay. The factors that hinder a diagnosis of toxemia were assessed, including investigation of toxin stability, the level of toxins-specific neutralizing antibodies in sera and its effect on diagnosis limits. CDI patients develop detectable toxemia in some cases (2.3%). Toxins were relatively stable in stored sera. Neutralizing anti-toxin antibodies were present during infection and positively correlated with the diagnosis limits. Thus, the masking effect of toxin-specific neutralizing antibodies is the major obstacle in diagnosing C. difficile toxemia using cell-based bioassays.
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Affiliation(s)
- Hua Yu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Jianguo Wu
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Zhiyong Yang
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lianfa Shi
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
| | - Lydia L. Barlow
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David M. Aronoff
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America; Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Kevin W. Garey
- University of Houston College of Pharmacy, Houston, Texas, United States of America; Baylor St. Luke's Medical Center, Houston, Texas, United States of America; University of Texas School of Public Health, Houston, Texas, United States of America
| | - Tor C. Savidge
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, United States of America; Texas Children's Microbiome Center, Texas Children's Hospital, Houston, Texas, United States of America
| | - Erik C. von Rosenvinge
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Maryland, Baltimore, Maryland, United States of America; VA Maryland Health Care System, Baltimore, Maryland, United States of America
| | - Ciaran P. Kelly
- Department of Medicine, Harvard Medical School and Celiac Center, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America; Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, Maryland, United States of America
- * E-mail:
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D'Auria KM, Bloom MJ, Reyes Y, Gray MC, van Opstal EJ, Papin JA, Hewlett EL. High temporal resolution of glucosyltransferase dependent and independent effects of Clostridium difficile toxins across multiple cell types. BMC Microbiol 2015; 15:7. [PMID: 25648517 PMCID: PMC4323251 DOI: 10.1186/s12866-015-0361-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 01/22/2015] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Clostridium difficile toxins A and B (TcdA and TcdB), considered to be essential for C. difficile infection, affect the morphology of several cell types with different potencies and timing. However, morphological changes over various time scales are poorly characterized. The toxins' glucosyltransferase domains are critical to their deleterious effects, and cell responses to glucosyltransferase-independent activities are incompletely understood. By tracking morphological changes of multiple cell types to C. difficile toxins with high temporal resolution, cellular responses to TcdA, TcdB, and a glucosyltransferase-deficient TcdB (gdTcdB) are elucidated. RESULTS Human umbilical vein endothelial cells, J774 macrophage-like cells, and four epithelial cell lines (HCT8, T84, CHO, and immortalized mouse cecal epithelial cells) were treated with TcdA, TcdB, gdTcdB. Impedance across cell cultures was measured to track changes in cell morphology. Metrics from impedance data, developed to quantify rapid and long-lasting responses, produced standard curves with wide dynamic ranges that defined cell line sensitivities. Except for T84 cells, all cell lines were most sensitive to TcdB. J774 macrophages stretched and increased in size in response to TcdA and TcdB but not gdTcdB. High concentrations of TcdB and gdTcdB (>10 ng/ml) greatly reduced macrophage viability. In HCT8 cells, gdTcdB did not induce a rapid cytopathic effect, yet it delayed TcdA and TcdB's rapid effects. gdTcdB did not clearly delay TcdA or TcdB's toxin-induced effects on macrophages. CONCLUSIONS Epithelial and endothelial cells have similar responses to toxins yet differ in timing and degree. Relative potencies of TcdA and TcdB in mouse epithelial cells in vitro do not correlate with potencies in vivo. TcdB requires glucosyltransferase activity to cause macrophages to spread, but cell death from high TcdB concentrations is glucosyltransferase-independent. Competition experiments with gdTcdB in epithelial cells confirm common TcdA and TcdB mechanisms, yet different responses of macrophages to TcdA and TcdB suggest different, additional mechanisms or targets in these cells. This first-time, precise quantification of the response of multiple cell lines to TcdA and TcdB provides a comparative framework for delineating the roles of different cell types and toxin-host interactions.
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Affiliation(s)
- Kevin M D'Auria
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA, 22908, USA.
| | - Meghan J Bloom
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA, 22908, USA. .,Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, PO Box 801340, Charlottesville, VA, 22908, USA.
| | - Yesenia Reyes
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, PO Box 801340, Charlottesville, VA, 22908, USA.
| | - Mary C Gray
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, PO Box 801340, Charlottesville, VA, 22908, USA.
| | - Edward J van Opstal
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, PO Box 801340, Charlottesville, VA, 22908, USA. .,Current address: Vanderbilt University School of Medicine, 340 Light Hall, Nashville, TN, 27232, USA.
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, PO Box 800759, Charlottesville, VA, 22908, USA.
| | - Erik L Hewlett
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, PO Box 801340, Charlottesville, VA, 22908, USA.
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Abstract
Clostridium difficile infection (CDI) is becoming more common worldwide. The morbidity and mortality associated with C difficile is also increasing at an alarming rate. Critically ill patients are at particularly high risk for CDI because of the prevalence of multiple risk factors in this patient population. Treatment of C difficile continues to be a difficult problem in patients with severe or recurrent disease. This article seeks to provide a broad understanding of CDI in the intensive care unit, with special emphasis on risk factor identification, treatment options, and disease prevention.
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Meneses-Lorente G, Watt A, Salim K, Gaskell SJ, Muniappa N, Lawrence J, Guest PC. Identification of early proteomic markers for hepatic steatosis. Chem Res Toxicol 2006; 19:986-98. [PMID: 16918237 DOI: 10.1021/tx060007f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The identification of biomarkers for disease state, drug efficacy, and toxicity is becoming increasingly important for drug discovery and development. We have used two-dimensional differential in-gel electrophoresis and mass spectrometry to identify proteomic markers associated with hepatocellular steatosis in rats after dosing with a compound (CDA) in preclinical development. Rats were dosed daily for up to 5 days with CDA for measurement of blood biochemical parameters, histological, and proteomic analysis. Alterations in plasma glucose and liver transaminases were detected from dosing day 3 onward, and livers showed trace levels of hepatocellular vacuolation from 6 h which increased in extent and severity over the 5 day time course. The number of significantly altered protein spots increased over the 5 day time course, and Ingenuity Pathway Analysis showed that the predominant functions altered by CDA treatment were cell death and cellular assembly and organization. This included alterations in secreted proteins, endoplasmic reticulum and mitochondrial chaperones, antioxidant proteins, and enzymes involved in fatty acid biosynthesis. Comparative in vitro dosing studies showed similar alterations to the proteome, neutral lipid accumulation, and mitochondrial dehydrogenase activity in response to CDA treatment of cultured rat hepatocytes. The finding that several proteins showed significant changes in abundance before the onset of overt toxicity in vivo suggested that these could serve as predictive biomarkers of compounds with a propensity to induce liver steatosis. These markers underwent further direct analysis in the in vitro hepatocyte toxicity model to determine their utility in the development of high throughput assays for drug-induced steatosis.
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Affiliation(s)
- G Meneses-Lorente
- Merck Sharp & Dohme Neuroscience Research Centre, Terlings Park, Harlow, Essex, CM20 2QR, United Kingdom.
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Deng XK, Nesbit LA, Morrow KJ. Recombinant single-chain variable fragment antibodies directed against Clostridium difficile toxin B produced by use of an optimized phage display system. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2003; 10:587-95. [PMID: 12853390 PMCID: PMC164272 DOI: 10.1128/cdli.10.4.587-595.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recombinant antibody cloning and phage display technologies were used to produce single-chain antibodies (scFv) against Clostridium difficile toxin B. The starting material was the mouse B cell hybridoma line 5A8, which generates a monoclonal antibody against the toxin. The integrated cloning, screening, and phage display system of Krebber et al. (J. Immunol. Methods 201:35-55, 1997) allowed us to rapidly obtain toxin B-binding scFv sequences derived from the hybridoma cell line. The best candidate scFv sequences, based on preliminary enzyme-linked immunosorbent assay (ELISA) screening data were then subcloned into the compatible expression vector. Recombinant single-chain antibodies were expressed in Escherichia coli. A 29-kDa band was observed on polyacrylamide gel electrophoresis as predicted. The expressed product was characterized by immunoblotting and detection with an anti-FLAG antibody. The toxin B-binding function of the single-chain antibody was shown by a sandwich ELISA. The antibody was highly specific for toxin B and did not cross-react with material isolated from a toxin B-negative C. difficile strain. The sensitivity of the soluble single-chain antibody is significantly higher than the original monoclonal antibody based on ELISA data and could detect a minimum of 10 ng of toxin B/well. Competitive ELISAs established that the affinity of the 5A8 parent antibody and the best representative (clone 10) of the single-chain antibodies were similar and in the range of 10(-8) M. We propose that recombinant antibody technology is a rapid and effective approach to the development of the next generation of immunodiagnostic reagents.
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Affiliation(s)
- Xiao K Deng
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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Sautin YY, Crawford JM, Svetlov SI. Enhancement of survival by LPA via Erk1/Erk2 and PI 3-kinase/Akt pathways in a murine hepatocyte cell line. Am J Physiol Cell Physiol 2001; 281:C2010-9. [PMID: 11698260 DOI: 10.1152/ajpcell.00077.2001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
First published September 5, 2001; 10.1152/ajpcell.00077.2001.-Protective mechanisms for lysophosphatidic acid (LPA) against cell death caused by Clostridium difficile toxin, or tumor necrosis factor-alpha (TNF-alpha) plus D-galactosamine, were investigated in a murine hepatocyte cell line AML12 expressing Edg2 LPA receptor. In these models of hepatocellular injury, LPA prevented hepatocyte damage, suppressed apoptosis, and enhanced cell survival in a dose-dependent fashion. The protective effects of LPA were abolished by wortmannin and LY-294002, specific inhibitors of phosphatidylinositol 3-phosphate kinase (PI 3-kinase), and by PD-98059 and U-0126, inhibitors of MEK1/MEK2. In nontreated hepatocytes, LPA elicited a gradual and sustained increase in phosphorylation of Erk1/Erk2 over 180 min of stimulation and downstream phosphorylation of p90RSK and transcription factor Elk-1. In C. difficile toxin-treated cells, LPA-induced phosphorylation of Erk1/Erk2 was rapid but transient, while p90RSK and Elk-1 phosphorylation did not change significantly. LPA stimulated phosphorylation of Akt in a time-dependent manner in both intact and toxin-treated AML12 hepatocytes. Wortmannin and LY-294002 abolished phosphorylation of Akt, further supporting activation of PI 3-kinase/Akt as a signaling pathway, which mediates hepatocyte protection by LPA. Taken together, these results demonstrate that LPA prevents cell apoptosis induced by C. difficile toxin and TNF-alpha/D-galactosamine in the AML12 murine hepatocyte cell line. Cell protection by LPA involves activation of the mitogen-activated protein kinase Erk1/Erk2 cascade and PI 3-kinase-dependent phosphorylation of Akt.
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Affiliation(s)
- Y Y Sautin
- Department of Pathology, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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