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Buratta S, Urbanelli L, Pellegrino RM, Alabed HBR, Latella R, Cerrotti G, Emiliani C, Bassotti G, Spaterna A, Marconi P, Fettucciari K. PhosphoLipidome Alteration Induced by Clostridioides difficile Toxin B in Enteric Glial Cells. Cells 2024; 13:1103. [PMID: 38994956 PMCID: PMC11240607 DOI: 10.3390/cells13131103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/13/2024] Open
Abstract
Clostridioides difficile (C. difficile) is responsible for a spectrum of nosocomial/antibiotic-associated gastrointestinal diseases that are increasing in global incidence and mortality rates. The C. difficile pathogenesis is due to toxin A and B (TcdA/TcdB), both causing cytopathic and cytotoxic effects and inflammation. Recently, we demonstrated that TcdB induces cytopathic and cytotoxic (apoptosis and necrosis) effects in enteric glial cells (EGCs) in a dose/time-dependent manner and described the underlying signaling. Despite the role played by lipids in host processes activated by pathogens, to counter infection and/or induce cell death, to date no studies have investigated lipid changes induced by TcdB/TcdA. Here, we evaluated the modification of lipid composition in our in vitro model of TcdB infection. Apoptosis, cell cycle, cell viability, and lipidomic profiles were evaluated in EGCs treated for 24 h with two concentrations of TcdB (0.1 ng/mL; 10 ng/mL). In EGCs treated with the highest concentration of TcdB, not only an increased content of total lipids was observed, but also lipidome changes, allowing the separation of TcdB-treated cells and controls into different clusters. The statistical analyses also allowed us to ascertain which lipid classes and lipid molecular species determine the clusterization. Changes in lipid species containing inositol as polar head and plasmalogen phosphatidylethanolamine emerged as key indicators of altered lipid metabolism in TcdB-treated EGCs. These results not only provide a picture of the phospholipid profile changes but also give information regarding the lipid metabolism pathways altered by TcdB, and this might represent an important step for developing strategies against C. difficile infection.
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Affiliation(s)
- Sandra Buratta
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
- Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Lorena Urbanelli
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
- Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Roberto Maria Pellegrino
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
| | - Husam B. R. Alabed
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
| | - Raffaella Latella
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
| | - Giada Cerrotti
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
| | - Carla Emiliani
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via del Giochetto, 06123 Perugia, Italy; (S.B.); (L.U.); (R.M.P.); (H.B.R.A.); (R.L.); (G.C.); (C.E.)
- Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), University of Perugia, Via del Giochetto, 06123 Perugia, Italy
| | - Gabrio Bassotti
- Department of Medicine and Surgery, Gastroenterology, Hepatology & Digestive Endoscopy Section, University of Perugia, Piazzale Lucio Severi 1, 06132 Perugia, Italy;
- Santa Maria Della Misericordia Hospital, Gastroenterology & Hepatology Unit, Piazzale Menghini 1, 06129 Perugia, Italy
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Macerata, Italy
| | - Pierfrancesco Marconi
- Department of Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Piazzale Lucio Severi 1, 06132 Perugia, Italy;
| | - Katia Fettucciari
- Department of Medicine and Surgery, Biosciences & Medical Embryology Section, University of Perugia, Piazzale Lucio Severi 1, 06132 Perugia, Italy;
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Pourliotopoulou E, Karampatakis T, Kachrimanidou M. Exploring the Toxin-Mediated Mechanisms in Clostridioides difficile Infection. Microorganisms 2024; 12:1004. [PMID: 38792835 PMCID: PMC11124097 DOI: 10.3390/microorganisms12051004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains produce an additional toxin, the C. difficile transferase (CDT), which further enhances the virulence and pathogenicity of C. difficile. These toxins disrupt colonic epithelial barrier integrity, and induce inflammation and cellular damage, leading to CDI symptoms. Significant progress has been made in the past decade in elucidating the molecular mechanisms of TcdA, TcdB, and CDT, which provide insights into the management of CDI and the future development of novel treatment strategies based on anti-toxin therapies. While antibiotics are common treatments, high recurrence rates necessitate alternative therapies. Bezlotoxumab, targeting TcdB, is the only available anti-toxin, yet limitations persist, prompting ongoing research. This review highlights the current knowledge of the structure and mechanism of action of C. difficile toxins and their role in disease. By comprehensively describing the toxin-mediated mechanisms, this review provides insights for the future development of novel treatment strategies and the management of CDI.
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Affiliation(s)
- Evdokia Pourliotopoulou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | | | - Melania Kachrimanidou
- Department of Microbiology, Medical School, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
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3
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Fettucciari K, Spaterna A, Marconi P, Bassotti G. Pro-Inflammatory Cytokines Enhanced In Vitro Cytotoxic Activity of Clostridioides difficile Toxin B in Enteric Glial Cells: The Achilles Heel of Clostridioides difficile Infection? Int J Mol Sci 2024; 25:958. [PMID: 38256032 PMCID: PMC10815653 DOI: 10.3390/ijms25020958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Bacterial infections are characterized by an inflammatory response, which is essential for infection containment but is also responsible for negative effects on the host. The pathogen itself may have evolved molecular mechanisms to antagonize the antimicrobial effects of an inflammatory response and to enhance its pathogenicity using inflammatory response mediators, such as cytokines. Clostridioides difficile (C. difficile) infection (CDI) causes gastrointestinal diseases with markedly increasing global incidence and mortality rates. The main C. difficile virulence factors, toxin A and B (TcdA/TcdB), cause cytopathic/cytotoxic effects and inflammation. We previously demonstrated that TcdB induces enteric glial cell (EGC) apoptosis, which is enhanced by the pro-inflammatory cytokine tumor necrosis factor alpha plus interferon gamma (CKs). However, it is unknown whether CKs-enhanced TcdB cytotoxicity (apoptosis/necrosis) is affected by the timing of the appearance of the CKs. Thus, we simulated in vitro, in our experimental model with TcdB and EGCs, three main situations of possible interactions between TcdB and the timing of CK stimulation: before TcdB infection, concomitantly with infection, or at different times after infection and persisting over time. In these experimental conditions, which all represent situations of possible interactions between C. difficile and the timing of CK stimulation, we evaluated apoptosis, necrosis, and cell cycle phases. The CKs, in all of these conditions, enhanced TcdB cytotoxicity, which from apoptosis became necrosis when CK stimulation persisted over time, and was most relevant after 48 h of TcdB:EGCs interaction. Particularly, the enhancement of apoptosis by CKs was dependent on the TcdB dose and in a less relevant manner on the CK stimulation time, while the enhancement of necrosis occurred always independently of the TcdB dose and CK stimulation time. However, since in all conditions stimulation with CKs strongly enhanced the TcdB cytotoxicity, it always had a negative impact on C. difficile pathogenicity. This study might have important implications for the treatment of CDI.
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Affiliation(s)
- Katia Fettucciari
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy;
| | - Andrea Spaterna
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Macerata, Italy
| | - Pierfrancesco Marconi
- Biosciences & Medical Embryology Section, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy;
| | - Gabrio Bassotti
- Gastroenterology, Hepatology & Digestive Endoscopy Section, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy;
- Gastroenterology & Hepatology Unit, Santa Maria Della Misericordia Hospital, 06129 Perugia, Italy
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Papatheodorou P, Minton NP, Aktories K, Barth H. An Updated View on the Cellular Uptake and Mode-of-Action of Clostridioides difficile Toxins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1435:219-247. [PMID: 38175478 DOI: 10.1007/978-3-031-42108-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Research on the human gut pathogen Clostridioides (C.) difficile and its toxins continues to attract much attention as a consequence of the threat to human health posed by hypervirulent strains. Toxin A (TcdA) and Toxin B (TcdB) are the two major virulence determinants of C. difficile. Both are single-chain proteins with a similar multidomain architecture. Certain hypervirulent C. difficile strains also produce a third toxin, namely binary toxin CDT (C. difficile transferase). C. difficile toxins are the causative agents of C. difficile-associated diseases (CDADs), such as antibiotics-associated diarrhea and pseudomembranous colitis. For that reason, considerable efforts have been expended to unravel their molecular mode-of-action and the cellular mechanisms responsible for their uptake. Many of these studies have been conducted in European laboratories. Here, we provide an update on our previous review (Papatheodorou et al. Adv Exp Med Biol, 2018) on important advances in C. difficile toxins research.
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Affiliation(s)
- Panagiotis Papatheodorou
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany.
| | - Nigel P Minton
- BBSRC/EPSRC Synthetic Biology Research Centre, University of Nottingham, Nottingham, UK
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Holger Barth
- Institute of Experimental and Clinical Pharmacology, Toxicology and Pharmacology of Natural Products, Ulm University Medical Center, Ulm, Germany
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Abstract
Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community. However, only a few microorganisms have been identified that directly initiate tumorigenesis or skew the immune system to generate a tumour-permissive milieu. Over the past two decades, research on the human microbiome and its functionalities within and across individuals has revealed microbiota-focused strategies for health and disease. Here, we review the evolving understanding of the mechanisms by which the microbiota acts in cancer initiation, promotion and progression. We explore the roles of bacteria in gastrointestinal tract malignancies and cancers of the lung, breast and prostate. Finally, we discuss the promises and limitations of targeting or harnessing bacteria in personalized cancer prevention, diagnostics and treatment.
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Affiliation(s)
- Geniver El Tekle
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
- The Harvard T. H. Chan Microbiome in Public Health Center, Boston, MA, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Wendy S Garrett
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
- The Harvard T. H. Chan Microbiome in Public Health Center, Boston, MA, USA.
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
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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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Naz F, Petri WA. Host Immunity and Immunization Strategies for Clostridioides difficile Infection. Clin Microbiol Rev 2023; 36:e0015722. [PMID: 37162338 PMCID: PMC10283484 DOI: 10.1128/cmr.00157-22] [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] [Indexed: 05/11/2023] Open
Abstract
Clostridioides difficile infection (CDI) represents a significant challenge to public health. C. difficile-associated mortality and morbidity have led the U.S. CDC to designate it as an urgent threat. Moreover, recurrence or relapses can occur in up to a third of CDI patients, due in part to antibiotics being the primary treatment for CDI and the major cause of the disease. In this review, we summarize the current knowledge of innate immune responses, adaptive immune responses, and the link between innate and adaptive immune responses of the host against CDI. The other major determinants of CDI, such as C. difficile toxins, the host microbiota, and related treatments, are also described. Finally, we discuss the known therapeutic approaches and the current status of immunization strategies for CDI, which might help to bridge the knowledge gap in the generation of therapy against CDI.
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Affiliation(s)
- Farha Naz
- Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - William A. Petri
- Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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Dang Y, Ma C, Chen K, Chen Y, Jiang M, Hu K, Li L, Zeng Z, Zhang H. The Effects of a High-Fat Diet on Inflammatory Bowel Disease. Biomolecules 2023; 13:905. [PMID: 37371485 DOI: 10.3390/biom13060905] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/26/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
The interactions among diet, intestinal immunity, and microbiota are complex and play contradictory roles in inflammatory bowel disease (IBD). An increasing number of studies has shed light on this field. The intestinal immune balance is disrupted by a high-fat diet (HFD) in several ways, such as impairing the intestinal barrier, influencing immune cells, and altering the gut microbiota. In contrast, a rational diet is thought to maintain intestinal immunity by regulating gut microbiota. In this review, we emphasize the crucial contributions made by an HFD to the gut immune system and microbiota.
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Affiliation(s)
- Yuan Dang
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chunxiang Ma
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Kexin Chen
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yiding Chen
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Mingshan Jiang
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Kehan Hu
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lili Li
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zhen Zeng
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hu Zhang
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu 610041, China
- Centre for Inflammatory Bowel Disease, West China Hospital, Sichuan University, Chengdu 610041, China
- Laboratory of Inflammatory Bowel Disease, Institute of Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, China
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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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10
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Rosselot AE, Park M, Kim M, Matsu‐Ura T, Wu G, Flores DE, Subramanian KR, Lee S, Sundaram N, Broda TR, McCauley HA, Hawkins JA, Chetal K, Salomonis N, Shroyer NF, Helmrath MA, Wells JM, Hogenesch JB, Moore SR, Hong CI. Ontogeny and function of the circadian clock in intestinal organoids. EMBO J 2022; 41:e106973. [PMID: 34704277 PMCID: PMC8762567 DOI: 10.15252/embj.2020106973] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 09/30/2021] [Accepted: 10/11/2021] [Indexed: 12/19/2022] Open
Abstract
Circadian rhythms regulate diverse aspects of gastrointestinal physiology ranging from the composition of microbiota to motility. However, development of the intestinal circadian clock and detailed mechanisms regulating circadian physiology of the intestine remain largely unknown. In this report, we show that both pluripotent stem cell-derived human intestinal organoids engrafted into mice and patient-derived human intestinal enteroids possess circadian rhythms and demonstrate circadian phase-dependent necrotic cell death responses to Clostridium difficile toxin B (TcdB). Intriguingly, mouse and human enteroids demonstrate anti-phasic necrotic cell death responses to TcdB. RNA-Seq analysis shows that ~3-10% of the detectable transcripts are rhythmically expressed in mouse and human enteroids. Remarkably, we observe anti-phasic gene expression of Rac1, a small GTPase directly inactivated by TcdB, between mouse and human enteroids, and disruption of Rac1 abolishes clock-dependent necrotic cell death responses. Our findings uncover robust functions of circadian rhythms regulating clock-controlled genes in both mouse and human enteroids governing organism-specific, circadian phase-dependent necrotic cell death responses, and lay a foundation for human organ- and disease-specific investigation of clock functions using human organoids for translational applications.
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Affiliation(s)
- Andrew E Rosselot
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
| | - Miri Park
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
| | - Mari Kim
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
| | - Toru Matsu‐Ura
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
| | - Gang Wu
- Division of Human Genetics and ImmunobiologyCenter for ChronobiologyDepartment of PediatricsCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Danilo E Flores
- Division of Human Genetics and ImmunobiologyCenter for ChronobiologyDepartment of PediatricsCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | | | - Suengwon Lee
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
| | - Nambirajan Sundaram
- Department of Pediatric SurgeryCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Taylor R Broda
- Center for Stem Cell and Organoid MedicineDivision of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Heather A McCauley
- Center for Stem Cell and Organoid MedicineDivision of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Jennifer A Hawkins
- Department of Pediatric SurgeryCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Kashish Chetal
- Division of Biomedical InformaticsCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Nathan Salomonis
- Division of Biomedical InformaticsCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Noah F Shroyer
- Gastroenterology and HepatologyBaylor College of MedicineHoustonTXUSA
| | - Michael A Helmrath
- Department of Pediatric SurgeryCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
- Center for Stem Cell and Organoid MedicineDivision of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - James M Wells
- Center for Stem Cell and Organoid MedicineDivision of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
- Division of EndocrinologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - John B Hogenesch
- Division of Human Genetics and ImmunobiologyCenter for ChronobiologyDepartment of PediatricsCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
- Center for ChronobiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
| | - Sean R Moore
- Division of Pediatric Gastroenterology, Hepatology, and NutritionDepartment of PediatricsUniversity of Virginia School of MedicineCharlottesvilleVAUSA
| | - Christian I Hong
- Department of Pharmacology & Systems PhysiologyUniversity of CincinnatiCincinnatiOHUSA
- Center for Stem Cell and Organoid MedicineDivision of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
- Center for ChronobiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
- Division of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOHUSA
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11
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Plakoglobin and High-Mobility Group Box 1 Mediate Intestinal Epithelial Cell Apoptosis Induced by Clostridioides difficile TcdB. mBio 2022; 13:e0184922. [PMID: 36043787 DOI: 10.1128/mbio.01849-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of antibiotic-associated intestinal disease, resulting in severe diarrhea and fatal pseudomembranous colitis. TcdB, one of the essential virulence factors secreted by this bacterium, induces host cell apoptosis through a poorly understood mechanism. Here, we performed an RNA interference (RNAi) screen customized to Caco-2 cells, a cell line model of the intestinal epithelium, to discover host factors involved in TcdB-induced apoptosis. We identified plakoglobin, also known as junction plakoglobin (JUP) or γ-catenin, a member of the catenin family, as a novel host factor and a previously known cell death-related chromatin factor, high-mobility group box 1 (HMGB1). Disruption of those host factors by RNAi and CRISPR resulted in resistance of cells to TcdB-mediated and mitochondrion-dependent apoptosis. JUP was redistributed from adherens junctions to the mitochondria and colocalized with the antiapoptotic factor Bcl-XL. JUP proteins could permeabilize the mitochondrial membrane, resulting in the release of cytochrome c. Our results reveal a novel role of JUP in targeting the mitochondria to promote the mitochondrial apoptotic pathway. Treatment with glycyrrhizin, an HMGB1 inhibitor, resulted in significantly increased resistance to TcdB-induced epithelial damage in cultured cells and a mouse ligated colon loop model. These findings demonstrate the critical roles of JUP and HMGB1 in TcdB-induced epithelial cell apoptosis. IMPORTANCE Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea. Toxins, especially TcdB, cause epithelial cell apoptosis, but the underlying cell death mechanism is less clear. Through an apoptosis-focused RNAi screen using a bacterium-made small interfering (siRNA) library customized to a human colonic epithelial cell model, we found a novel host factor, plakoglobin (γ-catenin), as a key factor required for cell apoptosis induced by TcdB. Plakoglobin targets and permeabilizes mitochondria after stimulation by TcdB, demonstrating a hitherto underappreciated role of this catenin family member in the apoptosis of intestinal epithelial cells. We also found a previously known cell death-related chromatin factor, HMGB1, and explored the inhibition of HMGB1 for CDI therapy in vivo.
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12
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Kordus SL, Thomas AK, Lacy DB. Clostridioides difficile toxins: mechanisms of action and antitoxin therapeutics. Nat Rev Microbiol 2022; 20:285-298. [PMID: 34837014 PMCID: PMC9018519 DOI: 10.1038/s41579-021-00660-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 01/03/2023]
Abstract
Clostridioides difficile is a Gram-positive anaerobe that can cause a spectrum of disorders that range in severity from mild diarrhoea to fulminant colitis and/or death. The bacterium produces up to three toxins, which are considered the major virulence factors in C. difficile infection. These toxins promote inflammation, tissue damage and diarrhoea. In this Review, we highlight recent biochemical and structural advances in our understanding of the mechanisms that govern host-toxin interactions. Understanding how C. difficile toxins affect the host forms a foundation for developing novel strategies for treatment and prevention of C. difficile infection.
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Affiliation(s)
- Shannon L. Kordus
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,These authors contributed equally: Shannon L. Kordus, Audrey K. Thomas
| | - Audrey K. Thomas
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,These authors contributed equally: Shannon L. Kordus, Audrey K. Thomas
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA,Center for Structural Biology, Vanderbilt University, Nashville, TN, USA,The Veterans Affairs, Tennessee Valley Healthcare, System, Nashville, TN, USA,
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13
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Stieglitz F, Gerhard R, Hönig R, Giehl K, Pich A. TcdB of Clostridioides difficile Mediates RAS-Dependent Necrosis in Epithelial Cells. Int J Mol Sci 2022; 23:ijms23084258. [PMID: 35457076 PMCID: PMC9024770 DOI: 10.3390/ijms23084258] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
A Clostridioides difficile infection (CDI) is the most common nosocomial infection worldwide. The main virulence factors of pathogenic C. difficile are TcdA and TcdB, which inhibit small Rho-GTPases. The inhibition of small Rho-GTPases leads to the so-called cytopathic effect, a reorganization of the actin cytoskeleton, an impairment of the colon epithelium barrier function and inflammation. Additionally, TcdB induces a necrotic cell death termed pyknosis in vitro independently from its glucosyltransferases, which are characterized by chromatin condensation and ROS production. To understand the underlying mechanism of this pyknotic effect, we conducted a large-scale phosphoproteomic study. We included the analysis of alterations in the phosphoproteome after treatment with TcdA, which was investigated for the first time. TcdA exhibited no glucosyltransferase-independent necrotic effect and was, thus, a good control to elucidate the underlying mechanism of the glucosyltransferase-independent effect of TcdB. We found RAS to be a central upstream regulator of the glucosyltransferase-independent effect of TcdB. The inhibition of RAS led to a 68% reduction in necrosis. Further analysis revealed apolipoprotein C-III (APOC3) as a possible crucial factor of CDI-induced inflammation in vivo.
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Affiliation(s)
- Florian Stieglitz
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
- Core Facility Proteomics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
| | - Rabea Hönig
- Signal Transduction of Cellular Motility, Internal Medicine V, Justus Liebig University Giessen, Aulweg 128, 35392 Giessen, Germany; (R.H.); (K.G.)
| | - Klaudia Giehl
- Signal Transduction of Cellular Motility, Internal Medicine V, Justus Liebig University Giessen, Aulweg 128, 35392 Giessen, Germany; (R.H.); (K.G.)
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; (F.S.); (R.G.)
- Core Facility Proteomics, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
- Correspondence: ; Tel.: +49-511-532-2808; Fax: +49-511-532-2879
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14
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Chen J, Du Y, Lu Y, Wang H, Wu Q. Recent development of small-molecular inhibitors against Clostridioides difficile infection. Bioorg Chem 2022; 125:105843. [DOI: 10.1016/j.bioorg.2022.105843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 03/02/2022] [Accepted: 04/23/2022] [Indexed: 11/29/2022]
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15
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Petersen L, Stroh S, Schöttelndreier D, Grassl GA, Rottner K, Brakebusch C, Fahrer J, Genth H. The Essential Role of Rac1 Glucosylation in Clostridioides difficile Toxin B-Induced Arrest of G1-S Transition. Front Microbiol 2022; 13:846215. [PMID: 35321078 PMCID: PMC8937036 DOI: 10.3389/fmicb.2022.846215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/14/2022] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile infection (CDI) in humans causes pseudomembranous colitis (PMC), which is a severe pathology characterized by a loss of epithelial barrier function and massive colonic inflammation. PMC has been attributed to the action of two large protein toxins, Toxin A (TcdA) and Toxin B (TcdB). TcdA and TcdB mono-O-glucosylate and thereby inactivate a broad spectrum of Rho GTPases and (in the case of TcdA) also some Ras GTPases. Rho/Ras GTPases promote G1-S transition through the activation of components of the ERK, AKT, and WNT signaling pathways. With regard to CDI pathology, TcdB is regarded of being capable of inhibiting colonic stem cell proliferation and colonic regeneration, which is likely causative for PMC. In particular, it is still unclear, the glucosylation of which substrate Rho-GTPase is critical for TcdB-induced arrest of G1-S transition. Exploiting SV40-immortalized mouse embryonic fibroblasts (MEFs) with deleted Rho subtype GTPases, evidence is provided that Rac1 (not Cdc42) positively regulates Cyclin D1, an essential factor of G1-S transition. TcdB-catalyzed Rac1 glucosylation results in Cyclin D1 suppression and arrested G1-S transition in MEFs and in human colonic epithelial cells (HCEC), Remarkably, Rac1−/− MEFs are insensitive to TcdB-induced arrest of G1-S transition, suggesting that TcdB arrests G1-S transition in a Rac1 glucosylation-dependent manner. Human intestinal organoids (HIOs) specifically expressed Cyclin D1 (neither Cyclin D2 nor Cyclin D3), which expression was suppressed upon TcdB treatment. In sum, Cyclin D1 expression in colonic cells seems to be regulated by Rho GTPases (most likely Rac1) and in turn seems to be susceptible to TcdB-induced suppression. With regard to PMC, toxin-catalyzed Rac1 glucosylation and subsequent G1-S arrest of colonic stem cells seems to be causative for decreased repair capacity of the colonic epithelium and delayed epithelial renewal.
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Affiliation(s)
- Lara Petersen
- Institute for Toxicology, Hannover Medical School, Hannover, Germany
| | - Svenja Stroh
- Department of Toxicology, University Medical Center Mainz, Mainz, Germany
| | | | - Guntram A. Grassl
- Institute of Medical Microbiology and Hospital Epidemiology and DZIF partner site Hannover, Hannover Medical School, Hannover, Germany
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Cord Brakebusch
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Jörg Fahrer
- Department of Toxicology, University Medical Center Mainz, Mainz, Germany
- Rudolf-Buchheim-Institute of Pharmacology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Harald Genth
- Institute for Toxicology, Hannover Medical School, Hannover, Germany
- *Correspondence: Harald Genth,
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16
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Chaves-Cordero C, Quesada-Gómez C, Chaves-Olarte E, Barquero-Calvo E. Human neutrophils are resistant to Clostridioides difficile toxin B. Anaerobe 2022; 74:102553. [DOI: 10.1016/j.anaerobe.2022.102553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/08/2023]
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17
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Peritore-Galve FC, Shupe JA, Cave RJ, Childress KO, Washington MK, Kuehne SA, Lacy DB. Glucosyltransferase-dependent and independent effects of Clostridioides difficile toxins during infection. PLoS Pathog 2022; 18:e1010323. [PMID: 35176123 PMCID: PMC8890742 DOI: 10.1371/journal.ppat.1010323] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/02/2022] [Accepted: 01/30/2022] [Indexed: 11/17/2022] Open
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial diarrhea and pseudomembranous colitis in the USA. In addition to these symptoms, patients with CDI can develop severe inflammation and tissue damage, resulting in life-threatening toxic megacolon. CDI is mediated by two large homologous protein toxins, TcdA and TcdB, that bind and hijack receptors to enter host cells where they use glucosyltransferase (GT) enzymes to inactivate Rho family GTPases. GT-dependent intoxication elicits cytopathic changes, cytokine production, and apoptosis. At higher concentrations TcdB induces GT-independent necrosis in cells and tissue by stimulating production of reactive oxygen species via recruitment of the NADPH oxidase complex. Although GT-independent necrosis has been observed in vitro, the relevance of this mechanism during CDI has remained an outstanding question in the field. In this study we generated novel C. difficile toxin mutants in the hypervirulent BI/NAP1/PCR-ribotype 027 R20291 strain to test the hypothesis that GT-independent epithelial damage occurs during CDI. Using the mouse model of CDI, we observed that epithelial damage occurs through a GT-independent process that does not involve immune cell influx. The GT-activity of either toxin was sufficient to cause severe edema and inflammation, yet GT activity of both toxins was necessary to produce severe watery diarrhea. These results demonstrate that both TcdA and TcdB contribute to disease pathogenesis when present. Further, while inactivating GT activity of C. difficile toxins may suppress diarrhea and deleterious GT-dependent immune responses, the potential of severe GT-independent epithelial damage merits consideration when developing toxin-based therapeutics against CDI.
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Affiliation(s)
- F. Christopher Peritore-Galve
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - John A. Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Rory J. Cave
- School of Biomedical Sciences, University of West London, London, United Kingdom
| | - Kevin O. Childress
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - M. Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Sarah A. Kuehne
- Oral Microbiology Group, School of Dentistry and Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Veterans Affairs Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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18
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Nibbering B, Gerding DN, Kuijper EJ, Zwittink RD, Smits WK. Host Immune Responses to Clostridioides difficile: Toxins and Beyond. Front Microbiol 2022; 12:804949. [PMID: 34992590 PMCID: PMC8724541 DOI: 10.3389/fmicb.2021.804949] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile is often resistant to the actions of antibiotics to treat other bacterial infections and the resulting C. difficile infection (CDI) is among the leading causes of nosocomial infectious diarrhea worldwide. The primary virulence mechanism contributing to CDI is the production of toxins. Treatment failures and recurrence of CDI have urged the medical community to search for novel treatment options. Strains that do not produce toxins, so called non-toxigenic C. difficile, have been known to colonize the colon and protect the host against CDI. In this review, a comprehensive description and comparison of the immune responses to toxigenic C. difficile and non-toxigenic adherence, and colonization factors, here called non-toxin proteins, is provided. This revealed a number of similarities between the host immune responses to toxigenic C. difficile and non-toxin proteins, such as the influx of granulocytes and the type of T-cell response. Differences may reflect genuine variation between the responses to toxigenic or non-toxigenic C. difficile or gaps in the current knowledge with respect to the immune response toward non-toxigenic C. difficile. Toxin-based and non-toxin-based immunization studies have been evaluated to further explore the role of B cells and reveal that plasma cells are important in protection against CDI. Since the success of toxin-based interventions in humans to date is limited, it is vital that future research will focus on the immune responses to non-toxin proteins and in particular non-toxigenic strains.
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Affiliation(s)
- Britt Nibbering
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Dale N Gerding
- Department of Veterans Affairs, Research Service, Edward Hines Jr. VA Hospital, Hines, IL, United States
| | - Ed J Kuijper
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Romy D Zwittink
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - Wiep Klaas Smits
- Center for Microbiome Analyses and Therapeutics, Leiden University Medical Center, Leiden, Netherlands.,Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
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19
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Klepka C, Sandmann M, Tatge H, Mangan M, Arens A, Henkel D, Gerhard R. Impairment of lysosomal function by Clostridioides difficile TcdB. Mol Microbiol 2021; 117:493-507. [PMID: 34931374 DOI: 10.1111/mmi.14864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 11/30/2022]
Abstract
TcdB is a potent cytotoxin produced by pathogenic Clostridioides difficile that inhibits Rho GTPases by mono-glucosylation. TcdB enters cells via receptor-mediated endocytosis. The pathogenic glucosyltransferase domain (GTD) egresses endosomes by pH-mediated conformational changes, and is subsequently released in an autoproteolytic manner. We here investigated the uptake, localization and degradation of TcdB. TcdB colocalized with lysosomal marker protein LAMP1, verifying the endosomal-lysosomal route of the toxin. In pulse assays endocytosed TcdB declined to a limit of detection within 2 hr, whereas the released GTD accumulated for up to 8 hr. We observed that autoproteolytic deficient TcdB NXN C698S was degraded significantly faster than wildtype TcdB, suggesting interference of TcdB with lysosomal degradation process. In fact, TcdB reduced lysosomal degradation of endosome cargo as tested with DQ-Green BSA. Lysosomal dysfunction was accompanied by perinuclear accumulation of LAMP1 and a weaker detection in immunoblots. Galectin-8 or galectin-3 was not recruited to lysosomes speaking against lysosome membrane damage. Changes in the autophagosomal marker LC3B suggested additional indirect effect of lysosomal dysfunction on the autophagic flux. In contrast to necrotic signaling induced in by TcdB, lysosomal dysfunction was not abolished by calcium channel blocker nifedipin, indicating separate cytopathogenic effects induced by TcdB during endo-lysosomal trafficking.
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Affiliation(s)
- Carmen Klepka
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Moritz Sandmann
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Helma Tatge
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Matthew Mangan
- Institute of Innate Immunology, Biomedical Center, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Annabel Arens
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Daniel Henkel
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
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20
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Ikeda Y, Taniguchi K, Nagase N, Tsuji A, Kitagishi Y, Matsuda S. Reactive oxygen species may influence on the crossroads of stemness, senescence, and carcinogenesis in a cell via the roles of APRO family proteins. EXPLORATION OF MEDICINE 2021. [DOI: 10.37349/emed.2021.00062] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Excessive reactive oxygen species (ROS) may cause oxidative stress which is involved in aging and in the pathogenesis of various human diseases. Whereas unregulated levels of the ROS may be harmful, regulated basal level of ROS are even necessary to support cellular functions as a second messenger for homeostasis under physiological conditions. Therefore, redox medicine could develop as a new therapeutic concept for human health-benefits. Here, we introduce the involvement of ROS on the crossroads of stemness, senescence, and carcinogenesis in a stem cell and cancer cell biology. Amazingly, the anti-proliferative (APRO) family anti-proliferative proteins characterized by immediate early growth responsive genes may also be involved in the crossroads machinery. The biological functions of APRO proteins (APROs) seem to be quite intricate, however, which might be a key modulator of microRNAs (miRNAs). Given the crucial roles of ROS and APROs for pathophysiological functions, upcoming novel therapeutics should include vigilant modulation of the redox state. Next generation of medicine including regenerative medicine and/or cancer therapy will likely comprise strategies for altering the redox environment with the APROs via the modulation of miRNAs as well as with the regulation of ROS of cells in a sustainable manner.
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Affiliation(s)
- Yuka Ikeda
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
| | - Kurumi Taniguchi
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
| | - Nozomi Nagase
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
| | - Ai Tsuji
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
| | - Yasuko Kitagishi
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
| | - Satoru Matsuda
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
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21
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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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22
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Monaghan TM, Seekatz AM, Markham NO, Yau TO, Hatziapostolou M, Jilani T, Christodoulou N, Roach B, Birli E, Pomenya O, Louie T, Lacy DB, Kim P, Lee C, Kao D, Polytarchou C. Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection Associates With Functional Alterations in Circulating microRNAs. Gastroenterology 2021; 161:255-270.e4. [PMID: 33844988 PMCID: PMC8579492 DOI: 10.1053/j.gastro.2021.03.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 03/20/2021] [Accepted: 03/23/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS The molecular mechanisms underlying successful fecal microbiota transplantation (FMT) for recurrent Clostridioides difficile infection (rCDI) remain poorly understood. The primary objective of this study was to characterize alterations in microRNAs (miRs) following FMT for rCDI. METHODS Sera from 2 prospective multicenter randomized controlled trials were analyzed for miRNA levels with the use of the Nanostring nCounter platform and quantitative reverse-transcription (RT) polymerase chain reaction (PCR). In addition, rCDI-FMT and toxin-treated animals and ex vivo human colonoids were used to compare intestinal tissue and circulating miRs. miR inflammatory gene targets in colonic epithelial and peripheral blood mononuclear cells were evaluated by quantitative PCR (qPCR) and 3'UTR reporter assays. Colonic epithelial cells were used for mechanistic, cytoskeleton, cell growth, and apoptosis studies. RESULTS miRNA profiling revealed up-regulation of 64 circulating miRs 4 and 12 weeks after FMT compared with screening, of which the top 6 were validated in the discovery cohort by means of RT-qPCR. In a murine model of relapsing-CDI, RT-qPCR analyses of sera and cecal RNA extracts demonstrated suppression of these miRs, an effect reversed by FMT. In mouse colon and human colonoids, C difficile toxin B (TcdB) mediated the suppressive effects of CDI on miRs. CDI dysregulated DROSHA, an effect reversed by FMT. Correlation analyses, qPCR ,and 3'UTR reporter assays revealed that miR-23a, miR-150, miR-26b, and miR-28 target directly the 3'UTRs of IL12B, IL18, FGF21, and TNFRSF9, respectively. miR-23a and miR-150 demonstrated cytoprotective effects against TcdB. CONCLUSIONS These results provide novel and provocative evidence that modulation of the gut microbiome via FMT induces alterations in circulating and intestinal tissue miRs. These findings contribute to a greater understanding of the molecular mechanisms underlying FMT and identify new potential targets for therapeutic intervention in rCDI.
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Affiliation(s)
- Tanya M Monaghan
- National Institute for Health Research Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom; Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom.
| | - Anna M Seekatz
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
| | - Nicholas O Markham
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Tung On Yau
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Maria Hatziapostolou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Tahseen Jilani
- Advanced Data Analysis Centre, School of Computer Science, University of Nottingham, Nottingham, United Kingdom
| | - Niki Christodoulou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Brandi Roach
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Eleni Birli
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Odette Pomenya
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Thomas Louie
- Department of Microbiology and infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - D Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Peter Kim
- Department of Mathematics and Statistics, University of Guelph, Ontario, Canada
| | - Christine Lee
- Vancouver Island Health Authority, Victoria, British Columbia, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dina Kao
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
| | - Christos Polytarchou
- Department of Biosciences, John van Geest Cancer Research Centre, Centre for Health Aging and Understanding Disease, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom.
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Abstract
Large clostridial toxins (LCTs) are a family of bacterial exotoxins that infiltrate and destroy target cells. Members of the LCT family include Clostridioides difficile toxins TcdA and TcdB, Paeniclostridium sordellii toxins TcsL and TcsH, Clostridium novyi toxin TcnA, and Clostridium perfringens toxin TpeL. Since the 19th century, LCT-secreting bacteria have been isolated from the blood, organs, and wounds of diseased individuals, and LCTs have been implicated as the primary virulence factors in a variety of infections, including C. difficile infection and some cases of wound-associated gas gangrene. Clostridia express and secrete LCTs in response to various physiological signals. LCTs invade host cells by binding specific cell surface receptors, ultimately leading to internalization into acidified vesicles. Acidic pH promotes conformational changes within LCTs, which culminates in translocation of the N-terminal glycosyltransferase and cysteine protease domain across the endosomal membrane and into the cytosol, leading first to cytopathic effects and later to cytotoxic effects. The focus of this review is on the role of LCTs in infection and disease, the mechanism of LCT intoxication, with emphasis on recent structural work and toxin subtyping analysis, and the genomic discovery and characterization of LCT homologues. We provide a comprehensive review of these topics and offer our perspective on emerging questions and future research directions for this enigmatic family of toxins.
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24
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Markham NO, Bloch SC, Shupe JA, Laubacher EN, Thomas AK, Kroh HK, Childress KO, Peritore-Galve FC, Washington MK, Coffey RJ, Lacy DB. Murine Intrarectal Instillation of Purified Recombinant Clostridioides difficile Toxins Enables Mechanistic Studies of Pathogenesis. Infect Immun 2021; 89:e00543-20. [PMID: 33468584 PMCID: PMC8090962 DOI: 10.1128/iai.00543-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 01/09/2021] [Indexed: 12/15/2022] Open
Abstract
Clostridioides difficile is linked to nearly 225,000 antibiotic-associated diarrheal infections and almost 13,000 deaths per year in the United States. Pathogenic strains of C. difficile produce toxin A (TcdA) and toxin B (TcdB), which can directly kill cells and induce an inflammatory response in the colonic mucosa. Hirota et al. (S. A. Hirota et al., Infect Immun 80:4474-4484, 2012) first introduced the intrarectal instillation model of intoxication using TcdA and TcdB purified from VPI 10463 (VPI 10463 reference strain [ATCC 43255]) and 630 C. difficile strains. Here, we expand this technique by instilling purified, recombinant TcdA and TcdB, which allows for the interrogation of how specifically mutated toxins affect tissue. Mouse colons were processed and stained with hematoxylin and eosin for blinded evaluation and scoring by a board-certified gastrointestinal pathologist. The amount of TcdA or TcdB needed to produce damage was lower than previously reported in vivo and ex vivo Furthermore, TcdB mutants lacking either endosomal pore formation or glucosyltransferase activity resemble sham negative controls. Immunofluorescent staining revealed how TcdB initially damages colonic tissue by altering the epithelial architecture closest to the lumen. Tissue sections were also immunostained for markers of acute inflammatory infiltration. These staining patterns were compared to slides from a human C. difficile infection (CDI). The intrarectal instillation mouse model with purified recombinant TcdA and/or TcdB provides the flexibility needed to better understand structure/function relationships across different stages of CDI pathogenesis.
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Affiliation(s)
- Nicholas O Markham
- Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Sarah C Bloch
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John A Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Erin N Laubacher
- Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Audrey K Thomas
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Heather K Kroh
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kevin O Childress
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - F Christopher Peritore-Galve
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Robert J Coffey
- Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - D Borden Lacy
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Veterans Affairs Medical Center, Nashville, Tennessee, USA
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25
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Henkel D, Tatge H, Schöttelndreier D, Tao L, Dong M, Gerhard R. Receptor Binding Domains of TcdB from Clostridioides difficile for Chondroitin Sulfate Proteoglycan-4 and Frizzled Proteins Are Functionally Independent and Additive. Toxins (Basel) 2020; 12:toxins12120736. [PMID: 33255261 PMCID: PMC7759879 DOI: 10.3390/toxins12120736] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
Toxin B (TcdB) produced by Clostridioides difficile is a main pathogenicity factor that affects a variety of different cell types within the colonic mucosa. TcdB is known to utilize frizzled-1,2,7 and chondroitin sulfate proteoglycan-4 (CSPG4) as protein receptors. By using human cervical cancer cell line HeLa CSPG4 knockout (CSPG4−/−) cells as well as TcdB mutants which do not bind to either CSPG4 or frizzled-1,2,7, or both, we evaluated the impact of the individual receptors for cytopathic and cytotoxic effects of TcdB. We compared TcdB from the reference strain VPI10463 (TcdBVPI) and the endemic strain R20291 (TcdBR20) which does not interact with frizzled-1,2,7. TcdBVPI devoid of CSPG4 binding (TcdBVPI ΔCROP) shows identical cytopathic potency as full-length TcdB in HeLa CSPG4−/− cells, indicating that interaction with frizzled proteins is not affected in the presence of the C-terminal CROP domain. We validated CSPG4 as cellular receptor for both TcdB toxinotypes in HeLa and HEp-2 cells. By exchange of a single phenylalanine residue, 1597 with serine, we generated a mutated TcdBVPI variant (TcdBVPI F1597S) that in accordance with TcdBR20 lacks binding to frizzled-1,2,7 and showed identical potency as TcdBR20 on HeLa cells. This enabled us to estimate the respective share of CSPG4 and frizzled-1,2,7 in the cytotoxic and cytopathic effect induced by TcdB. Our data reveal that binding to frizzled-1,2,7 and to CSPG4 occurs independently and in an additive manner.
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Affiliation(s)
- Daniel Henkel
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany; (D.H.); (H.T.); (D.S.)
| | - Helma Tatge
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany; (D.H.); (H.T.); (D.S.)
| | - Dennis Schöttelndreier
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany; (D.H.); (H.T.); (D.S.)
| | - Liang Tao
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (L.T.); (M.D.)
- Departments of Surgery and Microbiology, Harvard Medical School, Boston, MA 02115, USA
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Westlake University Hangzhou, Hangzhou 310000, China
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA; (L.T.); (M.D.)
- Departments of Surgery and Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany; (D.H.); (H.T.); (D.S.)
- Correspondence:
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26
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Xu Q, Li Y, Zheng Y, Chen Y, Xu X, Wang M. Clostridium difficile toxin B-induced colonic inflammation is mediated by the FOXO3/PPM1B pathway in fetal human colon epithelial cells. Am J Transl Res 2020; 12:6204-6219. [PMID: 33194024 PMCID: PMC7653611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 08/01/2020] [Indexed: 06/11/2023]
Abstract
Clostridium difficile (C. difficile) toxin B (TcdB) is as an inflammatory enterotoxin that accounts for manifestations of widespread healthcare-associated C. difficile infection, including colonic inflammation. The present work explored the molecular mechanism by which TcdB activates innate immunity and stimulates pro-inflammatory cytokine release. Fetal human colon epithelial cells (FHCs) were treated with recombinant TcdB protein. Cell growth inhibition and apoptosis were measured with Cell Counting Kit-8 and Annexin V-fluorescein isothiocyanate Apoptosis Detection Kit, respectively. Flow cytometry analysis was also performed. Inflammatory cytokine induction was determined with enzykeme-linked immunosorbent assay analyses. Protein expression was assessed by western blot analysis. Gene overexpression and knockdown were performed with lentiviral transduction. Real-time quantitative polymerase chain reaction was used to examine gene expression. Dual-luciferase reporter assays and chromatin immunoprecipitation were implemented to explore transcriptional regulation. Mouse colon tissues were analyzed with hematoxylin and eosin staining. The results show that TcdB-induced cell growth and apoptosis and enhanced expression of interleukin-6 and tumor necrosis factor alpha in FHCs. We identified protein phosphatase magnesium-dependent 1B (PPM1B) as the key mediator promoting the phosphorylation of nuclear factor-κB p65, which accounted for the increase in pro-inflammatory cytokines. The findings demonstrate that PPM1B expression is directly regulated by the AKT/FOXO3 signaling pathway in FHCs. We confirmed the molecular mechanism with in vivo studies using a mouse model infected with C. difficile and treated with a phosphoinositide 3-kinase/AKT signaling inhibitor. In conclusion, TcdB induces inflammation in human colon epithelial cells by regulating the AKT/FOXO3/PPM1B pathway.
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Affiliation(s)
- Qingqing Xu
- Institute of Antibiotics, Huashan Hospital, Fudan UniversityShanghai 200040, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning CommisionShanghai 200040, China
| | - Ying Li
- Institute of Antibiotics, Huashan Hospital, Fudan UniversityShanghai 200040, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning CommisionShanghai 200040, China
| | - Yuejuan Zheng
- Department of Immunology and Microbiology, Shanghai University of Traditional Chinese MedicineShanghai 201203, China
| | - Yijian Chen
- Institute of Antibiotics, Huashan Hospital, Fudan UniversityShanghai 200040, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning CommisionShanghai 200040, China
| | - Xiaogang Xu
- Institute of Antibiotics, Huashan Hospital, Fudan UniversityShanghai 200040, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning CommisionShanghai 200040, China
| | - Minggui Wang
- Institute of Antibiotics, Huashan Hospital, Fudan UniversityShanghai 200040, China
- Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning CommisionShanghai 200040, China
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27
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Bilverstone TW, Garland M, Cave RJ, Kelly ML, Tholen M, Bouley DM, Kaye P, Minton NP, Bogyo M, Kuehne SA, Melnyk RA. The glucosyltransferase activity of C. difficile Toxin B is required for disease pathogenesis. PLoS Pathog 2020; 16:e1008852. [PMID: 32960931 PMCID: PMC7531778 DOI: 10.1371/journal.ppat.1008852] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/02/2020] [Accepted: 08/03/2020] [Indexed: 01/01/2023] Open
Abstract
Enzymatic inactivation of Rho-family GTPases by the glucosyltransferase domain of Clostridioides difficile Toxin B (TcdB) gives rise to various pathogenic effects in cells that are classically thought to be responsible for the disease symptoms associated with C. difficile infection (CDI). Recent in vitro studies have shown that TcdB can, under certain circumstances, induce cellular toxicities that are independent of glucosyltransferase (GT) activity, calling into question the precise role of GT activity. Here, to establish the importance of GT activity in CDI disease pathogenesis, we generated the first described mutant strain of C. difficile producing glucosyltransferase-defective (GT-defective) toxin. Using allelic exchange (AE) technology, we first deleted tcdA in C. difficile 630Δerm and subsequently introduced a deactivating D270N substitution in the GT domain of TcdB. To examine the role of GT activity in vivo, we tested each strain in two different animal models of CDI pathogenesis. In the non-lethal murine model of infection, the GT-defective mutant induced minimal pathology in host tissues as compared to the profound caecal inflammation seen in the wild-type and 630ΔermΔtcdA (ΔtcdA) strains. In the more sensitive hamster model of CDI, whereas hamsters in the wild-type or ΔtcdA groups succumbed to fulminant infection within 4 days, all hamsters infected with the GT-defective mutant survived the 10-day infection period without primary symptoms of CDI or evidence of caecal inflammation. These data demonstrate that GT activity is indispensable for disease pathogenesis and reaffirm its central role in disease and its importance as a therapeutic target for small-molecule inhibition.
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Affiliation(s)
- Terry W. Bilverstone
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, United kingdom
| | - Megan Garland
- Cancer Biology Program, Stanford School of Medicine, Stanford, CA, United States of America
- Department of Pathology, Stanford School of Medicine, Stanford, CA, United States of America
| | - Rory J. Cave
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, United kingdom
| | - Michelle L. Kelly
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, United kingdom
| | - Martina Tholen
- Department of Pathology, Stanford School of Medicine, Stanford, CA, United States of America
| | - Donna M. Bouley
- Department of Comparative Medicine, Stanford School of Medicine, Stanford, CA, United States of America
| | - Philip Kaye
- Department of Histopathology, Nottingham University Hospitals and University of Nottingham NDDC NIHR BRC, Nottingham, United Kingdom
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, Centre for Biomolecular Sciences, The University of Nottingham, Nottingham, United kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, United Kingdom
| | - Matthew Bogyo
- Department of Pathology, Stanford School of Medicine, Stanford, CA, United States of America
- Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, CA, United States of America
| | - Sarah A. Kuehne
- Oral Microbiology Group, School of Dentistry and Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - Roman A. Melnyk
- Department of Biochemistry, University of Toronto, and Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
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28
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Farrow MA, Chumber NM, Bloch SC, King M, Moton-Melancon K, Shupe J, Washington MK, Spiller BW, Lacy DB. Small Molecule Inhibitor Screen Reveals Calcium Channel Signaling as a Mechanistic Mediator of Clostridium difficile TcdB-Induced Necrosis. ACS Chem Biol 2020; 15:1212-1221. [PMID: 31909964 DOI: 10.1021/acschembio.9b00906] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Clostridioides difficile is the leading cause of nosocomial diarrhea in the United States. The primary virulence factors are two homologous glucosyltransferase toxins, TcdA and TcdB, that inactivate host Rho-family GTPases. The glucosyltransferase activity has been linked to a "cytopathic" disruption of the actin cytoskeleton and contributes to the disruption of tight junctions and the production of pro-inflammatory cytokines. TcdB is also a potent cytotoxin that causes epithelium necrotic damage through an NADPH oxidase (NOX)-dependent mechanism. We conducted a small molecule screen to identify compounds that confer protection against TcdB-induced necrosis. We identified an enrichment of "hit compounds" with a dihydropyridine (DHP) core which led to the discovery of a key early stage calcium signal that serves as a mechanistic link between TcdB-induced NOX activation and reactive oxygen species (ROS) production. Disruption of TcdB-induced calcium signaling (with both DHP and non-DHP molecules) is sufficient to ablate ROS production and prevent subsequent necrosis in cells and in a mouse model of intoxication.
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Affiliation(s)
- Melissa A. Farrow
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - Nicole M. Chumber
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - Sarah C. Bloch
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - McKenzie King
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - Kaycei Moton-Melancon
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - John Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - Mary K. Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
| | - Benjamin W. Spiller
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, A4116A Medical Center North, 1161 21st Avenue South, Nashville, Tennessee 37232-2363, United States
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee 37212, United States
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29
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Identification of the role of toxin B in the virulence of Clostridioides difficile based on integrated bioinformatics analyses. Int Microbiol 2020; 23:575-587. [PMID: 32388701 DOI: 10.1007/s10123-020-00128-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/03/2020] [Accepted: 04/13/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Clostridioides difficile toxin B (TcdB) plays a critical role in C. difficile infection (CDI), a common and costly healthcare-associated disease. The aim of the current study was to explore the intracellular and potent systemic effects of TcdB on human colon epithelial cells utilizing Gene Expression Omnibus and bioinformatic methods. METHODS Two datasets (GSE63880 and GSE29008) were collected to extract data components of mRNA of TcdB-treated human colon epithelial cells; "limma" package of "R" software was used to screen the differential genes, and "pheatmap" package was applied to construct heat maps for the differential genes; Metascape website was utilized for protein-protein interaction network and Molecular Complex Detection analysis, and Genome Ontology (GO) was used to analyze the selected differential genes. Quantitative real-time PCR (qRT-PCR) and Western blot were performed to validate the expression of hub genes. RESULTS GO terms involved in DNA replication and cell cycle were identified significantly enriched in TcdB-treated human colon epithelial cells. Moreover, the decreased expression of DNA replication-related genes, MCM complex, and CDC45 in C. difficile (TcdA-/TcdB+)-infected Caco-2 cells were validated via qRT-PCR and Western blot assays. CONCLUSIONS In conclusion, the integrated analysis of different gene expression datasets allowed us to identify a set of genes and GO terms underlying the mechanisms of CDI induced by TcdB. It would aid in understanding of the molecular mechanisms underlying TcdB-exposed colon epithelial cells and provide the basis for developing diagnosis biomarkers, treatment, and prevention strategies.
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Asadzadeh Z, Safarzadeh E, Safaei S, Baradaran A, Mohammadi A, Hajiasgharzadeh K, Derakhshani A, Argentiero A, Silvestris N, Baradaran B. Current Approaches for Combination Therapy of Cancer: The Role of Immunogenic Cell Death. Cancers (Basel) 2020; 12:E1047. [PMID: 32340275 PMCID: PMC7226590 DOI: 10.3390/cancers12041047] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/08/2020] [Accepted: 04/17/2020] [Indexed: 12/31/2022] Open
Abstract
Cell death resistance is a key feature of tumor cells. One of the main anticancer therapies is increasing the susceptibility of cells to death. Cancer cells have developed a capability of tumor immune escape. Hence, restoring the immunogenicity of cancer cells can be suggested as an effective approach against cancer. Accumulating evidence proposes that several anticancer agents provoke the release of danger-associated molecular patterns (DAMPs) that are determinants of immunogenicity and stimulate immunogenic cell death (ICD). It has been suggested that ICD inducers are two different types according to their various activities. Here, we review the well-characterized DAMPs and focus on the different types of ICD inducers and recent combination therapies that can augment the immunogenicity of cancer cells.
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Affiliation(s)
- Zahra Asadzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5165665811, Iran; (Z.A.); (S.S.); (K.H.); (A.D.)
| | - Elham Safarzadeh
- Department of Immunology and Microbiology, Faculty of Medicine, Ardabil University of Medical Sciences, Ardabil 5618985991, Iran;
| | - Sahar Safaei
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5165665811, Iran; (Z.A.); (S.S.); (K.H.); (A.D.)
| | - Ali Baradaran
- Research & Development Lab, BSD Robotics, 4500 Brisbane, Australia;
| | - Ali Mohammadi
- Department of Cancer and Inflammation Research, Institute for Molecular Medicine, University of Southern Denmark, 5230 Odense, Denmark;
| | - Khalil Hajiasgharzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5165665811, Iran; (Z.A.); (S.S.); (K.H.); (A.D.)
| | - Afshin Derakhshani
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5165665811, Iran; (Z.A.); (S.S.); (K.H.); (A.D.)
| | | | - Nicola Silvestris
- IRCCS Istituto Tumori “Giovanni Paolo II” of Bari, 70124 Bari, Italy;
- Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz 5165665811, Iran; (Z.A.); (S.S.); (K.H.); (A.D.)
- Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz 5166614766, Iran
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31
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Probiotic Supplementation in a Clostridium difficile-Infected Gastrointestinal Model Is Associated with Restoring Metabolic Function of Microbiota. Microorganisms 2019; 8:microorganisms8010060. [PMID: 31905795 PMCID: PMC7023328 DOI: 10.3390/microorganisms8010060] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 01/19/2023] Open
Abstract
Clostridium (C.) difficile-infection (CDI), a nosocomial gastrointestinal disorder, is of growing concern due to its rapid rise in recent years. Antibiotic therapy of CDI is associated with disrupted metabolic function and altered gut microbiota. The use of probiotics as an adjunct is being studied extensively due to their potential to modulate metabolic functions and the gut microbiota. In the present study, we assessed the ability of several single strain probiotics and a probiotic mixture to change the metabolic functions of normal and C. difficile-infected fecal samples. The production of short-chain fatty acids (SCFAs), hydrogen sulfide (H2S), and ammonia was measured, and changes in microbial composition were assessed by 16S rRNA gene amplicon sequencing. The C. difficile-infection in fecal samples resulted in a significant decrease (p < 0.05) in SCFA and H2S production, with a lower microbial alpha diversity. All probiotic treatments were associated with significantly increased (p < 0.05) levels of SCFAs and restored H2S levels. Probiotics showed no effect on microbial composition of either normal or C. difficile-infected fecal samples. These findings indicate that probiotics may be useful to improve the metabolic dysregulation associated with C. difficile infection.
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Chen KY, Rathod J, Chiu YC, Chen JW, Tsai PJ, Huang IH. The Transcriptional Regulator Lrp Contributes to Toxin Expression, Sporulation, and Swimming Motility in Clostridium difficile. Front Cell Infect Microbiol 2019; 9:356. [PMID: 31681632 PMCID: PMC6811523 DOI: 10.3389/fcimb.2019.00356] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/02/2019] [Indexed: 12/17/2022] Open
Abstract
Clostridium difficile is a Gram-positive, spore-forming bacterium, and major cause of nosocomial diarrhea. Related studies have identified numerous factors that influence virulence traits such as the production of the two primary toxins, toxin A (TcdA) and toxin B (TcdB), as well as sporulation, motility, and biofilm formation. However, multiple putative transcriptional regulators are reportedly encoded in the genome, and additional factors are likely involved in virulence regulation. Although the leucine-responsive regulatory protein (Lrp) has been studied extensively in Gram-negative bacteria, little is known about its function in Gram-positive bacteria, although homologs have been identified in the genome. This study revealed that disruption of the lone lrp homolog in C. difficile decelerated growth under nutrient-limiting conditions, increased TcdA and TcdB production. Lrp was also found to negatively regulate sporulation while positively regulate swimming motility in strain R20291, but not in strain 630. The C. difficile Lrp appeared to function through transcriptional repression or activation. In addition, the lrp mutant was relatively virulent in a mouse model of infection. The results of this study collectively demonstrated that Lrp has broad regulatory function in C. difficile toxin expression, sporulation, motility, and pathogenesis.
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Affiliation(s)
- Kuan-Yu Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jagat Rathod
- Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ching Chiu
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jenn-Wei Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Pei-Jane Tsai
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan.,Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - I-Hsiu Huang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
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Probiotic Supplementation is Associated with Increased Antioxidant Capacity and Copper Chelation in C. difficile-Infected Fecal Water. Nutrients 2019; 11:nu11092007. [PMID: 31454897 PMCID: PMC6769851 DOI: 10.3390/nu11092007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/19/2019] [Accepted: 08/23/2019] [Indexed: 12/23/2022] Open
Abstract
Probiotic supplementation plays a key role in maintaining intestinal homeostasis due to its ability to modulate gut microbiota. Although their potential as potent antioxidants have previously been explored, their ability to affect the redox status in the gut lumen of healthy subjects or those with gastrointestinal (GI) disorders remains unclear. In our study, we assessed the ability of single strain and multispecies probiotic supplementation to cause a change in the redox status of normal fecal water and in Clostridium (C.) difficile-infected fecal water using a simulated gastrointestinal model. Changes in redox status were assessed by ferric-reducing antioxidant power (FRAP), 2’,2’-diphenyl-1-picrylhydrazyl (DPPH), and iron and copper chelation assays. The findings from our study showed that in normal fecal water, probiotic supplements, apart from Lactobacillus (L.) rhamnosus R0011, showed a significant increase in iron chelation (p < 0.05), which was associated with lower FRAP and copper chelation. In C. difficile-infected fecal water, all probiotic supplements showed a significant increase in FRAP (p < 0.05) and were associated with increased copper chelation. The DPPH assay showed no treatment effect in either fecal water. These findings suggest that C. difficile mediates dysregulation of redox status, which is counteracted by probiotics through ferric-reducing ability and copper chelation.
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34
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Jiang Y, Xu L, Yu L, Xu X, Feng C, Li J. NOX4 inhibition protects enteric glial cells against Clostridium difficile toxin B toxicity via attenuating oxidative and Endoplasmic reticulum stresses. Free Radic Res 2019; 53:932-940. [PMID: 31370714 DOI: 10.1080/10715762.2019.1649670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Enteric glial cells (EGCs), one main cell population of the enteric nervous system (ENS), play a major role in regulating intestinal barrier function. Clostridium difficile toxin B (TcdB) is the major virulence factor produced by C. difficile and estimated to be toxic to EGCs by inducing cell death, cell cycle arrest, and inflammatory cytokine production; however, the detailed mechanism for such effect is still unclear. In this study, we further evaluated the toxic effect of TcdB on EGCs and the involvement of NADPH oxidases in such process using the rat-transformed EGCs (CRL-2690). The results showed that NOX4 was activated by TcdB in EGCs and functioned as the major factor causing cytotoxicity and cell apoptosis. Mechanically, NOX4-generated H2O2 was the inducer of oxidative stress, Ca2+ homeostasis disorder, and ER stress in EGCs upon TcdB treatment, and NOX4 inhibition protected EGCs against TcdB toxicity via attenuating these dysfunctions. These findings contribute to our understanding of the mechanism by which TcdB affects EGCs and suggest the potential value of NOX4 inhibition for treatment against C. difficile infection.
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Affiliation(s)
- Yanmin Jiang
- Department of Endocrinology, Wuxi People's Hospital Affiliated to Nanjing Medical University , Wuxi , China
| | - Lan Xu
- Department of Endocrinology, Wuxi People's Hospital Affiliated to Nanjing Medical University , Wuxi , China
| | - Lin Yu
- Department of Endocrinology, Wuxi People's Hospital Affiliated to Nanjing Medical University , Wuxi , China
| | - Xiang Xu
- Department of Endocrinology, Wuxi People's Hospital Affiliated to Nanjing Medical University , Wuxi , China
| | - Chen Feng
- Department of Endocrinology, Wuxi People's Hospital Affiliated to Nanjing Medical University , Wuxi , China
| | - Jianbo Li
- Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University , Nanjing , China
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35
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Mileto S, Das A, Lyras D. Enterotoxic Clostridia: Clostridioides difficile Infections. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0015-2018. [PMID: 31124432 PMCID: PMC11026080 DOI: 10.1128/microbiolspec.gpp3-0015-2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile is a Gram-positive, anaerobic, spore forming pathogen of both humans and animals and is the most common identifiable infectious agent of nosocomial antibiotic-associated diarrhea. Infection can occur following the ingestion and germination of spores, often concurrently with a disruption to the gastrointestinal microbiota, with the resulting disease presenting as a spectrum, ranging from mild and self-limiting diarrhea to severe diarrhea that may progress to life-threating syndromes that include toxic megacolon and pseudomembranous colitis. Disease is induced through the activity of the C. difficile toxins TcdA and TcdB, both of which disrupt the Rho family of GTPases in host cells, causing cell rounding and death and leading to fluid loss and diarrhea. These toxins, despite their functional and structural similarity, do not contribute to disease equally. C. difficile infection (CDI) is made more complex by a high level of strain diversity and the emergence of epidemic strains, including ribotype 027-strains which induce more severe disease in patients. With the changing epidemiology of CDI, our understanding of C. difficile disease, diagnosis, and pathogenesis continues to evolve. This article provides an overview of the current diagnostic tests available for CDI, strain typing, the major toxins C. difficile produces and their mode of action, the host immune response to each toxin and during infection, animal models of disease, and the current treatment and prevention strategies for CDI.
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Affiliation(s)
- S Mileto
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
| | - A Das
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
| | - D Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia, 3800
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36
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Ivarsson ME, Durantie E, Huberli C, Huwiler S, Hegde C, Friedman J, Altamura F, Lu J, Verdu EF, Bercik P, Logan SM, Chen W, Leroux JC, Castagner B. Small-Molecule Allosteric Triggers of Clostridium difficile Toxin B Auto-proteolysis as a Therapeutic Strategy. Cell Chem Biol 2019; 26:17-26.e13. [DOI: 10.1016/j.chembiol.2018.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 06/27/2018] [Accepted: 09/28/2018] [Indexed: 01/19/2023]
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37
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Genth H, Junemann J, Lämmerhirt CM, Lücke AC, Schelle I, Just I, Gerhard R, Pich A. Difference in Mono-O-Glucosylation of Ras Subtype GTPases Between Toxin A and Toxin B From Clostridioides difficile Strain 10463 and Lethal Toxin From Clostridium sordellii Strain 6018. Front Microbiol 2018; 9:3078. [PMID: 30622517 PMCID: PMC6308379 DOI: 10.3389/fmicb.2018.03078] [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: 06/21/2018] [Accepted: 11/29/2018] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile toxin A (TcdA) and Toxin B (TcdB) trigger inflammasome activation with caspase-1 activation in cultured cells, which in turn induce the release of IL-6, IFN-γ, and IL-8. Release of these proinflammatory responses is positively regulated by Ras-GTPases, which leads to the hypothesis that Ras glucosylation by glucosylating toxins results in (at least) reduced proinflammatory responses. Against this background, data on toxin-catalyzed Ras glucosylation are required to estimate of pro-inflammatory effect of the glucosylating toxins. In this study, a quantitative evaluation of the GTPase substrate profiles glucosylated in human colonic (Caco-2) cells treated with either TcdA, TcdB, or the related Clostridium sordellii lethal toxin (TcsL) was performed using multiple reaction monitoring (MRM) mass spectrometry. (H/K/N)Ras are presented to be glucosylated by TcsL and TcdA but by neither TcdB isoform tested. Furthermore, the glucosylation of (H/K/N)Ras was detected in TcdA-(not TcdB)-treated cells, as analyzed exploiting immunoblot analysis using the Ras glucosylation-sensitive 27H5 antibody. Furthermore, [14C]glucosylation of substrate GTPase was found to be increased in a cell-free system complemented with Caco-2 lysates. Under these conditions, (H/K/N)Ras glucosylation by TcdA was detected. In contrast, TcdB-catalyzed (H/K/N)Ras glucosylation was detected by neither MRM analysis, immunoblot analysis nor [14C]glucosylation in a cell-free system. The observation that TcdA (not TcdB) glucosylates Ras subtype GTPases correlates with the fact that TcdB (not TcdA) is primarily responsible for inflammatory responses in CDI. Finally, TcsL more efficaciously glucosylated Ras subtype GTPase as compared with TcdA, reinforcing the paradigm that TcsL is the prototype of a Ras glucosylating toxin.
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Affiliation(s)
- Harald Genth
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | | | | | | | - Ilona Schelle
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
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38
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Junemann J, Just I, Gerhard R, Pich A. Quantitative Phosphoproteome Analysis of Clostridioides difficile Toxin B Treated Human Epithelial Cells. Front Microbiol 2018; 9:3083. [PMID: 30619164 PMCID: PMC6304397 DOI: 10.3389/fmicb.2018.03083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/29/2018] [Indexed: 01/02/2023] Open
Abstract
The large clostridial glucosylating toxin B (TcdB) is a major virulence factor of the nosocomial pathogen Clostridioides difficile. TcdB inhibits small GTPases by glucosylation leading to impaired downstream signaling. TcdB also possesses a glucosyltransferase independent effect described as pyknosis. To elucidate the impact of TcdB and its glucosylation-inactive mutant TcdBNXN on the kinome of human cells, SILAC labeled HEp-2 cells were treated with 2 nM TcdB for 8 h. Phosphopeptides were enriched using SCX chromatography, IMAC and TiO2 followed shotgun mass spectrometry analysis. Overall 4,197 phosphopeptides were identified; more than 1,200 phosphosites responded to treatment with TcdB or TcdBNXN. The data suggested that predominantly stress-activated MAPK-dependent signaling pathways were triggered by toxin B treatment.
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Affiliation(s)
| | - Ingo Just
- Hannover Medical School, Institute for Toxicology, Hanover, Germany
| | - Ralf Gerhard
- Hannover Medical School, Institute for Toxicology, Hanover, Germany
| | - Andreas Pich
- Hannover Medical School, Institute for Toxicology, Hanover, Germany
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39
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Tam J, Hamza T, Ma B, Chen K, Beilhartz GL, Ravel J, Feng H, Melnyk RA. Host-targeted niclosamide inhibits C. difficile virulence and prevents disease in mice without disrupting the gut microbiota. Nat Commun 2018; 9:5233. [PMID: 30531960 PMCID: PMC6286312 DOI: 10.1038/s41467-018-07705-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 11/19/2018] [Indexed: 12/13/2022] Open
Abstract
Clostridium difficile is the leading cause of nosocomial diarrhea and colitis in the industrialized world. Disruption of the protective gut microbiota by antibiotics enables colonization by multidrug-resistant C. difficile, which secrete up to three different protein toxins that are responsible for the gastrointestinal sequelae. Oral agents that inhibit the damage induced by toxins, without altering the gut microbiota, are urgently needed to prevent primary disease and break the cycle of antibiotic-induced disease recurrence. Here, we show that the anthelmintic drug, niclosamide, inhibits the pathogenesis of all three toxins by targeting a host process required for entry into colonocytes by each toxin. In mice infected with an epidemic strain of C. difficile, expressing all three toxins, niclosamide reduced both primary disease and recurrence, without disrupting the diversity or composition of the gut microbiota. Given its excellent safety profile, niclosamide may address an important unmet need in preventing C. difficile primary and recurrent diseases. Clostridium difficile causes diarrhea and colitis by producing up to three different protein toxins. Here, Tam et al. show that an anthelmintic drug, niclosamide, inhibits the pathogenesis of all three toxins by targeting a host process required for toxin entry into host cells, without disrupting the gut microbiota.
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Affiliation(s)
- John Tam
- Molecular Medicine, Hospital for Sick Children, 686 Bay St., Toronto, ON, M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Therwa Hamza
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD, 21201, USA
| | - Bing Ma
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kevin Chen
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD, 21201, USA
| | - Greg L Beilhartz
- Molecular Medicine, Hospital for Sick Children, 686 Bay St., Toronto, ON, M5G 0A4, Canada
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Hanping Feng
- Department of Microbial Pathogenesis, University of Maryland Dental School, Baltimore, MD, 21201, USA
| | - Roman A Melnyk
- Molecular Medicine, Hospital for Sick Children, 686 Bay St., Toronto, ON, M5G 0A4, Canada. .,Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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40
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Critical role of MAVS in the protection against Clostridium difficile-induced colitis. Microb Pathog 2018; 125:306-312. [DOI: 10.1016/j.micpath.2018.09.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 09/20/2018] [Accepted: 09/20/2018] [Indexed: 12/15/2022]
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41
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Nordzieke DE, Medraño-Fernandez I. The Plasma Membrane: A Platform for Intra- and Intercellular Redox Signaling. Antioxidants (Basel) 2018; 7:antiox7110168. [PMID: 30463362 PMCID: PMC6262572 DOI: 10.3390/antiox7110168] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/15/2018] [Accepted: 11/17/2018] [Indexed: 02/06/2023] Open
Abstract
Membranes are of outmost importance to allow for specific signal transduction due to their ability to localize, amplify, and direct signals. However, due to the double-edged nature of reactive oxygen species (ROS)—toxic at high concentrations but essential signal molecules—subcellular localization of ROS-producing systems to the plasma membrane has been traditionally regarded as a protective strategy to defend cells from unwanted side-effects. Nevertheless, specialized regions, such as lipid rafts and caveolae, house and regulate the activated/inhibited states of important ROS-producing systems and concentrate redox targets, demonstrating that plasma membrane functions may go beyond acting as a securing lipid barrier. This is nicely evinced by nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases (NOX), enzymes whose primary function is to generate ROS and which have been shown to reside in specific lipid compartments. In addition, membrane-inserted bidirectional H2O2-transporters modulate their conductance precisely during the passage of the molecules through the lipid bilayer, ensuring time-scaled delivery of the signal. This review aims to summarize current evidence supporting the role of the plasma membrane as an organizing center that serves as a platform for redox signal transmission, particularly NOX-driven, providing specificity at the same time that limits undesirable oxidative damage in case of malfunction. As an example of malfunction, we explore several pathological situations in which an inflammatory component is present, such as inflammatory bowel disease and neurodegenerative disorders, to illustrate how dysregulation of plasma-membrane-localized redox signaling impacts normal cell physiology.
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Affiliation(s)
- Daniela E Nordzieke
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg August University Göttingen, Grisebachstr. 8, D-37077 Göttingen, Germany.
| | - Iria Medraño-Fernandez
- Protein Transport and Secretion Unit, Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale San Raffaele, Università Vita-Salute San Raffaele, 20132 Milan, Italy.
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42
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Beer LA, Tatge H, Reich N, Tenspolde M, Olling A, Goy S, Rottner K, Alekov AK, Gerhard R. Early cell death induced by Clostridium difficile TcdB: Uptake and Rac1-glucosylation kinetics are decisive for cell fate. Cell Microbiol 2018; 20:e12865. [PMID: 29904993 DOI: 10.1111/cmi.12865] [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: 02/07/2018] [Revised: 05/23/2018] [Accepted: 05/26/2018] [Indexed: 12/29/2022]
Abstract
Toxin A and Toxin B (TcdA/TcdB) are large glucosyltransferases produced by Clostridium difficile. TcdB but not TcdA induces reactive oxygen species-mediated early cell death (ECD) when applied at high concentrations. We found that nonglucosylated Rac1 is essential for induction of ECD since inhibition of Rac1 impedes this effect. ECD only occurs when TcdB is rapidly endocytosed. This was shown by generation of chimeras using the trunk of TcdB from a hypervirulent strain. TcdB from hypervirulent strain has been described to translocate from endosomes at higher pH values and thus, meaning faster than reference type TcdB. Accordingly, intracellular delivery of the glucosyltransferase domain of reference TcdB by the trunk of TcdB from hypervirulent strain increased ECD. Furthermore, proton transporters such as sodium/proton exchanger (NHE) or the ClC-5 anion/proton exchanger, both of which contribute to endosomal acidification, also affected cytotoxic potency of TcdB: Specific inhibition of NHE reduced cytotoxicity, whereas transfection of cells with the endosomal anion/proton exchanger ClC-5 increased cytotoxicity of TcdB. Our data suggest that both the uptake rate of TcdB into the cytosol and the status of nonglucosylated Rac1 are key determinants that are decisive for whether ECD or delayed apoptosis is triggered.
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Affiliation(s)
| | - Helma Tatge
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Nicole Reich
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Michel Tenspolde
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Alexandra Olling
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Sebastian Goy
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, Braunschweig, Germany.,Molecular Cell Biology Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
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43
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Abstract
Each year in the United States, billions of dollars are spent combating almost half a million Clostridium difficile infections (CDIs) and trying to reduce the ∼29,000 patient deaths in which C. difficile has an attributed role. In Europe, disease prevalence varies by country and level of surveillance, though yearly costs are estimated at €3 billion. One factor contributing to the significant health care burden of C. difficile is the relatively high frequency of recurrent CDIs. Recurrent CDI, i.e., a second episode of symptomatic CDI occurring within 8 weeks of successful initial CDI treatment, occurs in ∼25% of patients, with 35 to 65% of these patients experiencing multiple episodes of recurrent disease. Using microbial communities to treat recurrent CDI, either as whole fecal transplants or as defined consortia of bacterial isolates, has shown great success (in the case of fecal transplants) or potential promise (in the case of defined consortia of isolates). This review will briefly summarize the epidemiology and physiology of C. difficile infection, describe our current understanding of how fecal microbiota transplants treat recurrent CDI, and outline potential ways that knowledge can be used to rationally design and test alternative microbe-based therapeutics.
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44
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Thent ZC, Froemming GRA, Muid S. Bisphenol A exposure disturbs the bone metabolism: An evolving interest towards an old culprit. Life Sci 2018; 198:1-7. [DOI: 10.1016/j.lfs.2018.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/08/2018] [Accepted: 02/08/2018] [Indexed: 10/18/2022]
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45
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Zhang Y, Li Y, Li H, Chen W, Liu W. Clostridium difficile toxin B recombinant protein inhibits tumor growth and induces apoptosis through inhibiting Bcl-2 expression, triggering inflammatory responses and activating C-erbB-2 and Cox-2 expression in breast cancer mouse model. Biomed Pharmacother 2018; 101:391-398. [PMID: 29501042 DOI: 10.1016/j.biopha.2018.02.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/10/2018] [Accepted: 02/13/2018] [Indexed: 01/16/2023] Open
Abstract
Clostridium difficile toxin B (cdtB) is a critical virulence factor characterized with potential cytotoxicity and pro-inflammatory activity. This study aims to investigate anti-tumor effects of cdtB on breast cancer development. Clostridium difficile strain was cultured and cdtB recombinant protein (rcdtB) was synthesized. Breast cancer cell line, MDA-MB-231, was divided into Normal control, rcdtB 50, 100, 200 and 400 ng/ml group in vitro. Mice were divided into Normal control and rcdtB treatment group (400 ng/ml) in vivo. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to evaluate inhibitive effects of rcdtB on cell growth. Flow cytometry and transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) were employed to examine apoptosis in vitro and in vivo, respectively. Cell cycle distribution was analyzed by utilizing commercial kit. B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) were examined using western blot. Inflammatory response was detected using haematoxylin and eosin (HE). Erythroblastic leukemia viral oncogene homolog 2 (C-erbB-2) and cyclooxygenase-2 (Cox-2) were examined using immunohistochemical and immunofluorescence assay, respectively. The results indicated that rcdtB significantly induced MDA-MB-231 death, inhibited growth and decreased S-phase cells compared to Normal control group (P < 0.05). rcdtB significantly induced early and late apoptosis, and decreased Bcl-2 levels compared to Normal control group (P < 0.05). rcdtB significantly inhibited cell migration compared to Normal control group (P < 0.05). rcdtB significantly inhibited tumor growth and activated inflammation of breast cancer model compared to Normal control group (P < 0.01). rcdtB significantly reduced C-erbB-2 and Cox-2 in tumor tissues compared to Normal control group (P < 0.01). In conclusion, rcdtB treatment inhibited tumor growth and induced apoptosis through inhibiting Bcl-2 expression, inflammatory responses, and activating C-erbB-2 and Cox-2 expression in breast cancer mouse model.
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Affiliation(s)
- Yunli Zhang
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China
| | - Yanming Li
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China
| | - Hongling Li
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China
| | - Wei Chen
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China
| | - Wenen Liu
- Department of Clinical Laboratory, Xiangya Hospital of Central South University, Changsha 410008, China.
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Chan H, Zhao S, Zhang L, Ho J, Leung CCH, Wong WT, Tian Y, Liu X, Kwong TNY, Chan RCY, Yu SSB, Wang MHT, Tse G, Wong SH, Chan MTV, Wu WKK. Clostridium difficile toxin B induces autophagic cell death in colonocytes. J Cell Mol Med 2018; 22:2469-2477. [PMID: 29383879 PMCID: PMC5867081 DOI: 10.1111/jcmm.13555] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 01/01/2018] [Indexed: 01/07/2023] Open
Abstract
Toxin B (TcdB) is a major pathogenic factor of Clostridum difficile. However, the mechanism by which TcdB exerts its cytotoxic action in host cells is still not completely known. Herein, we report for the first time that TcdB induced autophagic cell death in cultured human colonocytes. The induction of autophagy was demonstrated by the increased levels of LC3‐II, formation of LC3+ autophagosomes, accumulation of acidic vesicular organelles and reduced levels of the autophagic substrate p62/SQSTM1. TcdB‐induced autophagy was also accompanied by the repression of phosphoinositide 3‐kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) complex 1 activity. Functionally, pharmacological inhibition of autophagy by wortmannin or chloroquine or knockdown of autophagy‐related genes Beclin 1, Atg5 and Atg7 attenuated TcdB‐induced cell death in colonocytes. Genetic ablation of Atg5, a gene required for autophagosome formation, also mitigated the cytotoxic effect of TcdB. In conclusion, our study demonstrated that autophagy serves as a pro‐death mechanism mediating the cytotoxic action of TcdB in colonocytes. This discovery suggested that blockade of autophagy might be a novel therapeutic strategy for C. difficile infection.
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Affiliation(s)
- Hung Chan
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Shan Zhao
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Lin Zhang
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Jeffery Ho
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Czarina C H Leung
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Wai T Wong
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Yuanyuan Tian
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Xiaodong Liu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Thomas N Y Kwong
- Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong.,State Key Laboratory of Digestive Disease, LKS Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Raphael C Y Chan
- Department of Microbiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Sidney S B Yu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Maggie H T Wang
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Gary Tse
- Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Sunny H Wong
- Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong.,State Key Laboratory of Digestive Disease, LKS Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Matthew T V Chan
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - William K K Wu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong.,State Key Laboratory of Digestive Disease, LKS Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong
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47
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Cellular Uptake and Mode-of-Action of Clostridium difficile Toxins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1050:77-96. [DOI: 10.1007/978-3-319-72799-8_6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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48
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Chandrasekaran R, Lacy DB. The role of toxins in Clostridium difficile infection. FEMS Microbiol Rev 2017; 41:723-750. [PMID: 29048477 PMCID: PMC5812492 DOI: 10.1093/femsre/fux048] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/10/2017] [Indexed: 02/06/2023] Open
Abstract
Clostridium difficile is a bacterial pathogen that is the leading cause of nosocomial antibiotic-associated diarrhea and pseudomembranous colitis worldwide. The incidence, severity, mortality and healthcare costs associated with C. difficile infection (CDI) are rising, making C. difficile a major threat to public health. Traditional treatments for CDI involve use of antibiotics such as metronidazole and vancomycin, but disease recurrence occurs in about 30% of patients, highlighting the need for new therapies. The pathogenesis of C. difficile is primarily mediated by the actions of two large clostridial glucosylating toxins, toxin A (TcdA) and toxin B (TcdB). Some strains produce a third toxin, the binary toxin C. difficile transferase, which can also contribute to C. difficile virulence and disease. These toxins act on the colonic epithelium and immune cells and induce a complex cascade of cellular events that result in fluid secretion, inflammation and tissue damage, which are the hallmark features of the disease. In this review, we summarize our current understanding of the structure and mechanism of action of the C. difficile toxins and their role in disease.
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Affiliation(s)
- Ramyavardhanee Chandrasekaran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37232, USA
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49
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Abstract
Clostridium difficile is a leading cause of nosocomial infections, causing disease that ranges from mild diarrhea to potentially fatal colitis. A variety of surface proteins, including flagella, enable C. difficile colonization of the intestine. Once in the intestine, toxigenic C. difficile secretes two glucosylating toxins, TcdA and TcdB, which elicit inflammation and diarrheal disease symptoms. Regulation of colonization factors and TcdA and TcdB is an intense area of research in C. difficile biology. A recent publication from our group describes a novel regulatory mechanism that mediates the ON/OFF expression of co-regulated virulence factors of C. difficile, flagella and toxins. Herein, we review key findings from our work, present new data, and speculate the functional consequence of the ON/OFF expression of these virulence factors during host infection.
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Affiliation(s)
- Brandon R. Anjuwon-Foster
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,CONTACT Rita Tamayo 125 Mason Farm Rd., CB #7290, Chapel Hill, NC, 27599
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50
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Gupta P, Zhang Z, Sugiman-Marangos SN, Tam J, Raman S, Julien JP, Kroh HK, Lacy DB, Murgolo N, Bekkari K, Therien AG, Hernandez LD, Melnyk RA. Functional defects in Clostridium difficile TcdB toxin uptake identify CSPG4 receptor-binding determinants. J Biol Chem 2017; 292:17290-17301. [PMID: 28842504 DOI: 10.1074/jbc.m117.806687] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/11/2017] [Indexed: 12/11/2022] Open
Abstract
Clostridium difficile is a major nosocomial pathogen that produces two exotoxins, TcdA and TcdB, with TcdB thought to be the primary determinant in human disease. TcdA and TcdB are large, multidomain proteins, each harboring a cytotoxic glucosyltransferase domain that is delivered into the cytosol from endosomes via a translocation domain after receptor-mediated endocytosis of toxins from the cell surface. Although there are currently no known host cell receptors for TcdA, three cell-surface receptors for TcdB have been identified: CSPG4, NECTIN3, and FZD1/2/7. The sites on TcdB that mediate binding to each receptor are not defined. Furthermore, it is not known whether the combined repetitive oligopeptide (CROP) domain is involved in or required for receptor binding. Here, in a screen designed to identify sites in TcdB that are essential for target cell intoxication, we identified a region at the junction of the translocation and the CROP domains that is implicated in CSPG4 binding. Using a series of C-terminal truncations, we show that the CSPG4-binding site on TcdB extends into the CROP domain, requiring three short repeats for binding and for full toxicity on CSPG4-expressing cells. Consistent with the location of the CSPG4-binding site on TcdB, we show that the anti-TcdB antibody bezlotoxumab, which binds partially within the first three short repeats, prevents CSPG4 binding to TcdB. In addition to establishing the binding region for CSPG4, this work ascribes for the first time a role in TcdB CROPs in receptor binding and further clarifies the relative roles of host receptors in TcdB pathogenesis.
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Affiliation(s)
- Pulkit Gupta
- From Merck & Co., Inc., Kenilworth, New Jersey 07033
| | - Zhifen Zhang
- Molecular Medicine, The Hospital for Sick Children, Ontario M5G 0A4, Canada.,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
| | | | - John Tam
- Molecular Medicine, The Hospital for Sick Children, Ontario M5G 0A4, Canada
| | - Swetha Raman
- Molecular Medicine, The Hospital for Sick Children, Ontario M5G 0A4, Canada
| | - Jean-Phillipe Julien
- Molecular Medicine, The Hospital for Sick Children, Ontario M5G 0A4, Canada.,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
| | - Heather K Kroh
- the Departments of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37212
| | - D Borden Lacy
- the Departments of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37212
| | | | | | | | | | - Roman A Melnyk
- Molecular Medicine, The Hospital for Sick Children, Ontario M5G 0A4, Canada, .,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
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