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Lamont RJ, Miller DP, Bagaitkar J. Illuminating the oral microbiome: cellular microbiology. FEMS Microbiol Rev 2023; 47:fuad045. [PMID: 37533213 PMCID: PMC10657920 DOI: 10.1093/femsre/fuad045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 07/11/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023] Open
Abstract
Epithelial cells line mucosal surfaces such as in the gingival crevice and provide a barrier to the ingress of colonizing microorganisms. However, epithelial cells are more than a passive barrier to microbial intrusion, and rather constitute an interactive interface with colonizing organisms which senses the composition of the microbiome and communicates this information to the underlying cells of the innate immune system. Microorganisms, for their part, have devised means to manipulate host cell signal transduction pathways to favor their colonization and survival. Study of this field, which has become known as cellular microbiology, has revealed much about epithelial cell physiology, bacterial colonization and pathogenic strategies, and innate host responses.
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Affiliation(s)
- Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, KY, KY40202, United States
| | - Daniel P Miller
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, VA23298, United States
| | - Juhi Bagaitkar
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, OH43205, United States
- Department of Pediatrics, The Ohio State College of Medicine, Columbus, OH, OH43210, United States
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2
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Tremblay W, Mompart F, Lopez E, Quaranta M, Bergoglio V, Hashim S, Bonnet D, Alric L, Mas E, Trouche D, Vignard J, Ferrand A, Mirey G, Fernandez-Vidal A. Cytolethal Distending Toxin Promotes Replicative Stress Leading to Genetic Instability Transmitted to Daughter Cells. Front Cell Dev Biol 2021; 9:656795. [PMID: 34026755 PMCID: PMC8138442 DOI: 10.3389/fcell.2021.656795] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/23/2021] [Indexed: 12/30/2022] Open
Abstract
The cytolethal distending toxin (CDT) is produced by several Gram-negative pathogenic bacteria. In addition to inflammation, experimental evidences are in favor of a protumoral role of CDT-harboring bacteria such as Escherichia coli, Campylobacter jejuni, or Helicobacter hepaticus. CDT may contribute to cell transformation in vitro and carcinogenesis in mice models, through the genotoxic action of CdtB catalytic subunit. Here, we investigate the mechanism of action by which CDT leads to genetic instability in human cell lines and colorectal organoids from healthy patients’ biopsies. We demonstrate that CDT holotoxin induces a replicative stress dependent on CdtB. The slowing down of DNA replication occurs mainly in late S phase, resulting in the expression of fragile sites and important chromosomic aberrations. These DNA abnormalities induced after CDT treatment are responsible for anaphase bridge formation in mitosis and interphase DNA bridge between daughter cells in G1 phase. Moreover, CDT-genotoxic potential preferentially affects human cycling cells compared to quiescent cells. Finally, the toxin induces nuclear distension associated to DNA damage in proliferating cells of human colorectal organoids, resulting in decreased growth. Our findings thus identify CDT as a bacterial virulence factor targeting proliferating cells, such as human colorectal progenitors or stem cells, inducing replicative stress and genetic instability transmitted to daughter cells that may therefore contribute to carcinogenesis. As some CDT-carrying bacterial strains were detected in patients with colorectal cancer, targeting these bacteria could be a promising therapeutic strategy.
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Affiliation(s)
- William Tremblay
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Florence Mompart
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Elisa Lopez
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Muriel Quaranta
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Valérie Bergoglio
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Saleha Hashim
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Delphine Bonnet
- Department of Internale and Digestive Diseases, Pole Digestif, CHU Toulouse, Paul Sabatier University, Toulouse, France
| | - Laurent Alric
- Department of Internale and Digestive Diseases, Pole Digestif, CHU Toulouse, Paul Sabatier University, Toulouse, France
| | - Emmanuel Mas
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France.,Unité de Gastroentérologie, Hépatologie, Nutrition, Diabétologie et Maladies Héréditaires du Métabolisme, Hôpital des Enfants, CHU de Toulouse, Toulouse, France
| | - Didier Trouche
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julien Vignard
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Audrey Ferrand
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Gladys Mirey
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Anne Fernandez-Vidal
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France.,MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
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3
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The Cell-Cycle Regulatory Protein p21 CIP1/WAF1 Is Required for Cytolethal Distending Toxin (Cdt)-Induced Apoptosis. Pathogens 2020; 9:pathogens9010038. [PMID: 31906446 PMCID: PMC7168616 DOI: 10.3390/pathogens9010038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/22/2019] [Accepted: 12/28/2019] [Indexed: 12/27/2022] Open
Abstract
The Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) induces lymphocytes to undergo cell-cycle arrest and apoptosis; toxicity is dependent upon the active Cdt subunit, CdtB. We now demonstrate that p21CIP1/WAF1 is critical to Cdt-induced apoptosis. Cdt induces increases in the levels of p21CIP1/WAF1 in lymphoid cell lines, Jurkat and MyLa, and in primary human lymphocytes. These increases were dependent upon CdtB’s ability to function as a phosphatidylinositol (PI) 3,4,5-triphosphate (PIP3) phosphatase. It is noteworthy that Cdt-induced increases in the levels of p21CIP1/WAF1 were accompanied by a significant decline in the levels of phosphorylated p21CIP1/WAF1. The significance of Cdt-induced p21CIP1/WAF1 increase was assessed by preventing these changes with a two-pronged approach; pre-incubation with the novel p21CIP1/WAF1 inhibitor, UC2288, and development of a p21CIP1/WAF1-deficient cell line (Jurkatp21−) using clustered regularly interspaced short palindromic repeats (CRISPR)/cas9 gene editing. UC2288 blocked toxin-induced increases in p21CIP1/WAF1, and JurkatWT cells treated with this inhibitor exhibited reduced susceptibility to Cdt-induced apoptosis. Likewise, Jurkatp21− cells failed to undergo toxin-induced apoptosis. The linkage between Cdt, p21CIP1/WAF1, and apoptosis was further established by demonstrating that Cdt-induced increases in levels of the pro-apoptotic proteins Bid, Bax, and Bak were dependent upon p21CIP1/WAF1 as these changes were not observed in Jurkatp21− cells. Finally, we determined that the p21CIP1/WAF1 increases were dependent upon toxin-induced increases in the level and activity of the chaperone heat shock protein (HSP) 90. We propose that p21CIP1/WAF1 plays a key pro-apoptotic role in mediating Cdt-induced toxicity.
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4
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Belibasakis GN, Maula T, Bao K, Lindholm M, Bostanci N, Oscarsson J, Ihalin R, Johansson A. Virulence and Pathogenicity Properties of Aggregatibacter actinomycetemcomitans. Pathogens 2019; 8:E222. [PMID: 31698835 PMCID: PMC6963787 DOI: 10.3390/pathogens8040222] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023] Open
Abstract
Aggregatibacter actinomycetemcomitans is a periodontal pathogen colonizing the oral cavity of a large proportion of the human population. It is equipped with several potent virulence factors that can cause cell death and induce or evade inflammation. Because of the large genetic diversity within the species, both harmless and highly virulent genotypes of the bacterium have emerged. The oral condition and age, as well as the geographic origin of the individual, influence the risk to be colonized by a virulent genotype of the bacterium. In the present review, the virulence and pathogenicity properties of A. actinomycetemcomitans will be addressed.
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Affiliation(s)
- Georgios N. Belibasakis
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Terhi Maula
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland; (T.M.); (R.I.)
| | - Kai Bao
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Mark Lindholm
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
| | - Nagihan Bostanci
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, S-141 04 Huddinge, Sweden; (G.N.B.); (K.B.); (N.B.)
| | - Jan Oscarsson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
| | - Riikka Ihalin
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland; (T.M.); (R.I.)
| | - Anders Johansson
- Department of Odontology, Umeå University, S-901 87 Umeå, Sweden; (M.L.); (J.O.)
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5
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Aral K, Aral CA, Kapila Y. Six‐month clinical outcomes of non‐surgical periodontal treatment with antibiotics on apoptosis markers in aggressive periodontitis. Oral Dis 2019; 25:839-847. [DOI: 10.1111/odi.13032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 12/05/2018] [Accepted: 12/31/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Kübra Aral
- Division of Periodontics Malatya Oral and Dental Heath Hospital Malatya Turkey
| | - Cüneyt A. Aral
- Department of PeriodontologyFaculty of Dentistry, Inonu University Malatya Turkey
| | - Yvonne Kapila
- Department of Orofacial Sciences, School of DentistryUniversity of California California
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6
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The Typhoid Toxin Produced by the Nontyphoidal Salmonella enterica Serotype Javiana Is Required for Induction of a DNA Damage Response In Vitro and Systemic Spread In Vivo. mBio 2018; 9:mBio.00467-18. [PMID: 29588404 PMCID: PMC5874915 DOI: 10.1128/mbio.00467-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The Salmonella cytolethal distending toxin (S-CDT), first described as the “typhoid toxin” in Salmonella enterica subsp. enterica serotype Typhi, induces DNA damage in eukaryotic cells. Recent studies have shown that more than 40 nontyphoidal Salmonella (NTS) serotypes carry genes that encode S-CDT, yet very little is known about the activity, function, and role of S-CDT in NTS. Here we show that deletion of genes encoding the binding subunit (pltB) and a bacteriophage muramidase predicted to play a role in toxin export (ttsA) does not abolish toxin activity in the S-CDT-positive NTS Salmonella enterica subsp. enterica serotype Javiana. However, S. Javiana strains harboring deletions of both pltB and its homolog artB, had a complete loss of S-CDT activity, suggesting that S. Javiana carries genes encoding two variants of the binding subunit. S-CDT-mediated DNA damage, as determined by phosphorylation of histone 2AX (H2AX), producing phosphorylated H2AX (γH2AX), was restricted to epithelial cells in S and G2/M phases of the cell cycle and did not result in apoptosis or cell death. Compared to mice infected with a ΔcdtB strain, mice infected with wild-type S. Javiana had significantly higher levels of S. Javiana in the liver, but not in the spleen, ileum, or cecum. Overall, we show that production of active S-CDT by NTS serotype S. Javiana requires different genes (cdtB, pltA, and either pltB or artB) for expression of biologically active toxin than those reported for S-CDT production by S. Typhi (cdtB, pltA, pltB, and ttsA). However, as in S. Typhi, NTS S-CDT influences the outcome of infection both in vitro and in vivo. Nontyphoidal Salmonella (NTS) are a major cause of bacterial food-borne illness worldwide; however, our understanding of virulence mechanisms that determine the outcome and severity of nontyphoidal salmonellosis is incompletely understood. Here we show that S-CDT produced by NTS plays a significant role in the outcome of infection both in vitro and in vivo, highlighting S-CDT as an important virulence factor for nontyphoidal Salmonella serotypes. Our data also contribute novel information about the function of S-CDT, as S-CDT-mediated DNA damage occurs only during certain phases of the cell cycle, and the resulting damage does not induce cell death as assessed using a propidium iodide exclusion assay. Importantly, our data support that, despite having genetically similar S-CDT operons, NTS serotype S. Javiana has different genetic requirements than S. Typhi, for the production and export of active S-CDT.
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7
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Morales AJ, Carrero JA, Hung PJ, Tubbs AT, Andrews JM, Edelson BT, Calderon B, Innes CL, Paules RS, Payton JE, Sleckman BP. A type I IFN-dependent DNA damage response regulates the genetic program and inflammasome activation in macrophages. eLife 2017; 6. [PMID: 28362262 PMCID: PMC5409825 DOI: 10.7554/elife.24655] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/30/2017] [Indexed: 01/06/2023] Open
Abstract
Macrophages produce genotoxic agents, such as reactive oxygen and nitrogen species, that kill invading pathogens. Here we show that these agents activate the DNA damage response (DDR) kinases ATM and DNA-PKcs through the generation of double stranded breaks (DSBs) in murine macrophage genomic DNA. In contrast to other cell types, initiation of this DDR depends on signaling from the type I interferon receptor. Once activated, ATM and DNA-PKcs regulate a genetic program with diverse immune functions and promote inflammasome activation and the production of IL-1β and IL-18. Indeed, following infection with Listeria monocytogenes, DNA-PKcs-deficient murine macrophages produce reduced levels of IL-18 and are unable to optimally stimulate IFN-γ production by NK cells. Thus, genomic DNA DSBs act as signaling intermediates in murine macrophages, regulating innate immune responses through the initiation of a type I IFN-dependent DDR.
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Affiliation(s)
- Abigail J Morales
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York City, United States
| | - Javier A Carrero
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Putzer J Hung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Anthony T Tubbs
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Jared M Andrews
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Brian T Edelson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Boris Calderon
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Cynthia L Innes
- Environmental Stress and Cancer Group, National Institute of Environmental Health Sciences, Durham, United States.,NIEHS Microarray Group, National Institute of Environmental Health Sciences, Durham, United States
| | - Richard S Paules
- Environmental Stress and Cancer Group, National Institute of Environmental Health Sciences, Durham, United States.,NIEHS Microarray Group, National Institute of Environmental Health Sciences, Durham, United States
| | - Jacqueline E Payton
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, United States
| | - Barry P Sleckman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York City, United States
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8
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Cell resistance to the Cytolethal Distending Toxin involves an association of DNA repair mechanisms. Sci Rep 2016; 6:36022. [PMID: 27775089 PMCID: PMC5075911 DOI: 10.1038/srep36022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/10/2016] [Indexed: 02/06/2023] Open
Abstract
The Cytolethal Distending Toxin (CDT), produced by many bacteria, has been associated with various diseases including cancer. CDT induces DNA double-strand breaks (DSBs), leading to cell death or mutagenesis if misrepaired. At low doses of CDT, other DNA lesions precede replication-dependent DSB formation, implying that non-DSB repair mechanisms may contribute to CDT cell resistance. To address this question, we developed a proliferation assay using human cell lines specifically depleted in each of the main DNA repair pathways. Here, we validate the involvement of the two major DSB repair mechanisms, Homologous Recombination and Non Homologous End Joining, in the management of CDT-induced lesions. We show that impairment of single-strand break repair (SSBR), but not nucleotide excision repair, sensitizes cells to CDT, and we explore the interplay of SSBR with the DSB repair mechanisms. Finally, we document the role of the replicative stress response and demonstrate the involvement of the Fanconi Anemia repair pathway in response to CDT. In conclusion, our work indicates that cellular survival to CDT-induced DNA damage involves different repair pathways, in particular SSBR. This reinforces a model where CDT-related genotoxicity primarily involves SSBs rather than DSBs, underlining the importance of cell proliferation during CDT intoxication and pathogenicity.
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10
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Miller R, Wiedmann M. Dynamic Duo-The Salmonella Cytolethal Distending Toxin Combines ADP-Ribosyltransferase and Nuclease Activities in a Novel Form of the Cytolethal Distending Toxin. Toxins (Basel) 2016; 8:E121. [PMID: 27120620 PMCID: PMC4885037 DOI: 10.3390/toxins8050121] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 03/30/2016] [Accepted: 04/15/2016] [Indexed: 01/02/2023] Open
Abstract
The cytolethal distending toxin (CDT) is a well characterized bacterial genotoxin encoded by several Gram-negative bacteria, including Salmonella enterica (S. enterica). The CDT produced by Salmonella (S-CDT) differs from the CDT produced by other bacteria, as it utilizes subunits with homology to the pertussis and subtilase toxins, in place of the traditional CdtA and CdtC subunits. Previously, S-CDT was thought to be a unique virulence factor of S. enterica subspecies enterica serotype Typhi, lending to its classification as the "typhoid toxin." Recently, this important virulence factor has been identified and characterized in multiple nontyphoidal Salmonella (NTS) serotypes as well. The significance of S-CDT in salmonellosis with regards to the: (i) distribution of S-CDT encoding genes among NTS serotypes, (ii) contributions to pathogenicity, (iii) regulation of S-CDT expression, and (iv) the public health implication of S-CDT as it relates to disease severity, are reviewed here.
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Affiliation(s)
- Rachel Miller
- Department of Food Science, Cornell University, Ithaca, NY 14850 USA.
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY 14850 USA.
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11
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Kebschull M, Papapanou PN. Mini but mighty: microRNAs in the pathobiology of periodontal disease. Periodontol 2000 2015; 69:201-20. [PMID: 26252410 PMCID: PMC4530521 DOI: 10.1111/prd.12095] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2015] [Indexed: 12/19/2022]
Abstract
MicroRNAs (miRNAs) are a family of small, noncoding RNA molecules that negatively regulate protein expression either by inhibiting initiation of the translation of mRNA or by inducing the degradation of mRNA molecules. Accumulating evidence suggests that miRNA-mediated repression of protein expression is of paramount importance in a broad range of physiologic and pathologic conditions. In particular, miRNA-induced dysregulation of molecular processes involved in inflammatory pathways has been shown to contribute to the development of chronic inflammatory diseases. In this review, first of all we provide an overview of miRNA biogenesis, the main mechanisms of action and the miRNA profiling tools currently available. Then, we summarize the available evidence supporting a specific role for miRNAs in the pathobiology of periodontitis. Based on a review of available data on the differential expression of miRNAs in gingival tissues in states of periodontal health and disease, we address specific roles for miRNAs in molecular and cellular pathways causally linked to periodontitis. Our review points to several lines of evidence suggesting the involvement of miRNAs in periodontal tissue homeostasis and pathology. Although the intricate regulatory networks affected by miRNA function are still incompletely mapped, further utilization of systems biology tools is expected to enhance our understanding of the pathobiology of periodontitis.
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Affiliation(s)
- Moritz Kebschull
- Associate Professor of Dental Medicine, Consultant, Department of Periodontology, Operative and Preventive Dentistry, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany, Tel: +49-228-28722-007,
| | - Panos N. Papapanou
- Professor of Dental Medicine, Director, Division of Periodontics, Chair, Section of Oral and Diagnostic Sciences, Columbia University College of Dental Medicine, 630 West 168 Street, PH-7E-110, New York, NY 10032, USA, Tel: +1-212-342-3008, Fax: +1-212-305-9313,
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12
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Lai CH, Chang CS, Liu HH, Tsai YS, Hsu FM, Yu YL, Lai CK, Gandee L, Pong RC, Hsu HW, Yu L, Saha D, Hsieh JT. Sensitization of radio-resistant prostate cancer cells with a unique cytolethal distending toxin. Oncotarget 2015; 5:5523-34. [PMID: 25015118 PMCID: PMC4170639 DOI: 10.18632/oncotarget.2133] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cytolethal distending toxin (CDT) produced by Campylobacter jejuni is a genotoxin that induces cell-cycle arrest and apoptosis in mammalian cells. Recent studies have demonstrated that prostate cancer (PCa) cells can acquire radio-resistance when DOC-2/DAB2 interactive protein (DAB2IP) is downregulated. In this study, we showed that CDT could induce cell death in DAB2IP-deficient PCa cells. A combination of CDT and radiotherapy significantly elicited cell death in DAB2IP-deficient PCa cells by inhibiting the repair of ionizing radiation (IR)-induced DNA double-strand break (DSB) during G2/M arrest, which is triggered by ataxia telangiectasia mutated (ATM)-dependent DNA damage checkpoint responses. We also found that CDT administration significantly increased the efficacy of radiotherapy in a xenograft mouse model. These results indicate that CDT can be a potent therapeutic agent for radio-resistant PCa.
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Affiliation(s)
- Chih-Ho Lai
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. School of Medicine, China Medical University, Taichung, Taiwan
| | - Chia-Shuo Chang
- School of Medicine, China Medical University, Taichung, Taiwan
| | - Hsin-Ho Liu
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yuh-Shyan Tsai
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Department of Urology, Medical College and Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Feng-Ming Hsu
- Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan. Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yung-Luen Yu
- Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
| | - Cheng-Kuo Lai
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. School of Medicine, China Medical University, Taichung, Taiwan
| | - Leah Gandee
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Rey-Chen Pong
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Heng-Wei Hsu
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lan Yu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Debabrata Saha
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jer-Tsong Hsieh
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
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13
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Magni M, Ruscica V, Buscemi G, Kim JE, Nachimuthu BT, Fontanella E, Delia D, Zannini L. Chk2 and REGγ-dependent DBC1 regulation in DNA damage induced apoptosis. Nucleic Acids Res 2014; 42:13150-60. [PMID: 25361978 PMCID: PMC4245943 DOI: 10.1093/nar/gku1065] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/15/2014] [Indexed: 01/08/2023] Open
Abstract
Human DBC1 (Deleted in Breast Cancer 1; KIAA1967; CCAR2) is a protein implicated in the regulation of apoptosis, transcription and histone modifications. Upon DNA damage, DBC1 is phosphorylated by ATM/ATR on Thr454 and this modification increases its inhibitory interaction with SIRT1, leading to p53 acetylation and p53-dependent apoptosis. Here, we report that the inhibition of SIRT1 by DBC1 in the DNA damage response (DDR) also depends on Chk2, the transducer kinase that is activated by ATM upon DNA lesions and contributes to the spreading of DNA damage signal. Indeed we found that inactivation of Chk2 reduces DBC1-SIRT1 binding, thus preventing p53 acetylation and DBC1-induced apoptosis. These events are mediated by Chk2 phosphorylation of the 11S proteasome activator REGγ on Ser247, which increases REGγ-DBC1 interaction and SIRT1 inhibition. Overall our results clarify the mechanisms underlying the DBC1-dependent SIRT1 inhibition and link, for the first time, Chk2 and REGγ to the ATM-DBC1-SIRT1 axis.
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Affiliation(s)
- Martina Magni
- Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
| | - Vincenzo Ruscica
- Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
| | - Giacomo Buscemi
- Department of Biosciences, University of Milan, 20133 Milan, Italy
| | - Ja-Eun Kim
- Department of Pharmacology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
| | | | - Enrico Fontanella
- Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
| | - Domenico Delia
- Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
| | - Laura Zannini
- Department of Experimental Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133 Milan, Italy
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14
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Weitzman MD, Weitzman JB. What's the damage? The impact of pathogens on pathways that maintain host genome integrity. Cell Host Microbe 2014; 15:283-94. [PMID: 24629335 DOI: 10.1016/j.chom.2014.02.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Maintaining genome integrity and transmission of intact genomes is critical for cellular, organismal, and species survival. Cells can detect damaged DNA, activate checkpoints, and either enable DNA repair or trigger apoptosis to eliminate the damaged cell. Aberrations in these mechanisms lead to somatic mutations and genetic instability, which are hallmarks of cancer. Considering the long history of host-microbe coevolution, an impact of microbial infection on host genome integrity is not unexpected, and emerging links between microbial infections and oncogenesis further reinforce this idea. In this review, we compare strategies employed by viruses, bacteria, and parasites to alter, subvert, or otherwise manipulate host DNA damage and repair pathways. We highlight how microbes contribute to tumorigenesis by directly inducing DNA damage, inactivating checkpoint controls, or manipulating repair processes. We also discuss indirect effects resulting from inflammatory responses, changes in cellular metabolism, nuclear architecture, and epigenome integrity, and the associated evolutionary tradeoffs.
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Affiliation(s)
- Matthew D Weitzman
- Division of Cancer Pathobiology, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| | - Jonathan B Weitzman
- University Paris Diderot, Sorbonne Paris Cité, Epigenetics and Cell Fate, UMR 7216 CNRS, 75013 Paris, France.
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15
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Abstract
Some of the most potent toxins produced by plants and bacteria are members of a large family known as the AB toxins. AB toxins are generally characterized by a heterogenous complex consisting of two protein chains arranged in various monomeric or polymeric configurations. The newest class within this superfamily is the cytolethal distending toxin (Cdt). The Cdt is represented by a subfamily of toxins produced by a group of taxonomically distinct Gram negative bacteria. Members of this subfamily have a related AB-type chain or subunit configuration and properties distinctive to the AB paradigm. In this review, the unique structural and cytotoxic properties of the Cdt subfamily, target cell specificities, intoxication pathway, modes of action, and relationship to the AB toxin superfamily are compared and contrasted.
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16
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Yoshimoto T, Fujita T, Ouhara K, Kajiya M, Imai H, Shiba H, Kurihara H. Smad2 is involved in Aggregatibacter actinomycetemcomitans-induced apoptosis. J Dent Res 2014; 93:1148-54. [PMID: 25192897 DOI: 10.1177/0022034514550041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Apoptosis is thought to contribute to the progression of periodontitis. It has been suggested that the apoptosis of epithelial cells may contribute to the loss of epithelial barrier function. Smad2, a downstream signaling molecule of TGF-β receptors (TGF-βRs), is critically involved in apoptosis in several cell types. However, the relationship between smad2 and bacteria-induced apoptosis has not yet been elucidated. It is possible that the regulation of apoptosis induced by periodontopathic bacteria may lead to novel preventive therapies for periodontitis. Therefore, in the present study, we investigated the involvement of smad2 phosphorylation in apoptosis of human gingival epithelial cells induced by Aggregatibacter actinomycetemcomitans (Aa). Aa apparently induced the phosphorylation of smad2 in primary human gingival epithelial cells (HGECs) or the human gingival epithelial cell line, OBA9 cells. In addition, Aa induced phosphorylation of the serine residue of the TGF-β type I receptor (TGF-βRI) in OBA9 cells. SB431542 (a TGF-βRI inhibitor) and siRNA transfection for TGF-βRI, which reduced both TGF-βRI mRNA and protein levels, markedly attenuated the Aa-induced phosphorylation of smad2. Furthermore, the disruption of TGF-βRI signaling cascade by SB431542 and siRNA transfection for TGF-βRI abrogated the activation of cleaved caspase-3 expression and repressed apoptosis in OBA9 cells treated with Aa. Thus, Aa induced apoptosis in gingival epithelial cells by activating the TGF-βRI-smad2-caspase-3 signaling pathway. The results of the present study may suggest that the periodontopathic bacteria, Aa, activates the TGF-βR/smad2 signaling pathway in human gingival epithelial cells and induces apoptosis in epithelial cells, which may lead to new therapeutic strategies that modulate the initiation of periodontitis.
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Affiliation(s)
- T Yoshimoto
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - T Fujita
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - K Ouhara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - M Kajiya
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Imai
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Shiba
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Kurihara
- Department of Periodontal Medicine, Division of Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
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17
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Bezine E, Vignard J, Mirey G. The cytolethal distending toxin effects on Mammalian cells: a DNA damage perspective. Cells 2014; 3:592-615. [PMID: 24921185 PMCID: PMC4092857 DOI: 10.3390/cells3020592] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 05/28/2014] [Accepted: 05/28/2014] [Indexed: 12/27/2022] Open
Abstract
The cytolethal distending toxin (CDT) is produced by many pathogenic Gram-negative bacteria and is considered as a virulence factor. In human cells, CDT exposure leads to a unique cytotoxicity associated with a characteristic cell distension and induces a cell cycle arrest dependent on the DNA damage response (DDR) triggered by DNA double-strand breaks (DSBs). CDT has thus been classified as a cyclomodulin and a genotoxin. Whereas unrepaired damage can lead to cell death, effective, but improper repair may be detrimental. Indeed, improper repair of DNA damage may allow cells to resume the cell cycle and induce genetic instability, a hallmark in cancer. In vivo, CDT has been shown to induce the development of dysplastic nodules and to lead to genetic instability, defining CDT as a potential carcinogen. It is therefore important to characterize the outcome of the CDT-induced DNA damage and the consequences for intoxicated cells and organisms. Here, we review the latest results regarding the host cell response to CDT intoxication and focus on DNA damage characteristics, cell cycle modulation and cell outcomes.
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Affiliation(s)
- Elisabeth Bezine
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, F-31027 Toulouse, France.
| | - Julien Vignard
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, F-31027 Toulouse, France.
| | - Gladys Mirey
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, F-31027 Toulouse, France.
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18
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Breaking the Gingival Epithelial Barrier: Role of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin in Oral Infectious Disease. Cells 2014; 3:476-99. [PMID: 24861975 PMCID: PMC4092858 DOI: 10.3390/cells3020476] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/08/2014] [Accepted: 05/15/2014] [Indexed: 12/17/2022] Open
Abstract
The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is part of the HACEK group that causes infective endocarditis, a constituent of the oral flora that promotes some forms of periodontal disease and a member of the family of species that secrete a cytolethal distending toxin (Cdt). The family of bacteria that express the cdt genes participate in diseases that involve the disruption of a mucosal or epithelial layer. In vitro studies have shown that human gingival epithelial cells (HGEC) are native targets of the Cdt that typically induces DNA damage that signals growth arrest at the G2/M interphase of the cell cycle. The gingival epithelium is an early line of defense in the oral cavity against microbial assault. When damaged, bacteria collectively gain entry into the underlying connective tissue where microbial products can affect processes and pathways in infiltrating inflammatory cells culminating in the destruction of the attachment apparatus of the tooth. One approach has been the use of an ex vivo gingival explant model to assess the effects of the Cdt on the morphology and integrity of the tissue. The goal of this review is to provide an overview of these studies and to critically examine the potential contribution of the Cdt to the breakdown of the protective gingival barrier.
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19
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Cytolethal distending toxin (CDT) is a radiomimetic agent and induces persistent levels of DNA double-strand breaks in human fibroblasts. DNA Repair (Amst) 2014; 18:31-43. [PMID: 24680221 DOI: 10.1016/j.dnarep.2014.03.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 02/07/2014] [Accepted: 03/03/2014] [Indexed: 11/22/2022]
Abstract
Cytolethal distending toxin (CDT) is a unique genotoxin produced by several pathogenic bacteria. The tripartite protein toxin is internalized into mammalian cells via endocytosis followed by retrograde transport to the ER. Upon translocation into the nucleus, CDT catalyzes the formation of DNA double-strand breaks (DSBs) due to its intrinsic endonuclease activity. In the present study, we compared the DNA damage response (DDR) in human fibroblasts triggered by recombinant CDT to that of ionizing radiation (IR), a well-known DSB inducer. Furthermore, we dissected the pathways involved in the detection and repair of CDT-induced DNA lesions. qRT-PCR array-based mRNA and western blot analyses showed a partial overlap in the DDR pattern elicited by CDT and IR, with strong activation of both the ATM-Chk2 and the ATR-Chk1 axis. In line with its in vitro DNase I-like activity on plasmid DNA, neutral and alkaline Comet assay revealed predominant induction of DSBs in CDT-treated fibroblasts, whereas irradiation of cells generated higher amounts of SSBs and alkali-labile sites. Using confocal microscopy, the dynamics of the DSB surrogate marker γ-H2AX was monitored after pulse treatment with CDT or IR. In contrast to the fast induction and disappearance of γ-H2AX-foci observed in irradiated cells, the number of γ-H2AX-foci induced by CDT were formed with a delay and persisted. 53BP1 foci were also generated following CDT treatment and co-localized with γ-H2AX foci. We further demonstrated that ATM-deficient cells are very sensitive to CDT-induced DNA damage as reflected by increased cell death rates with concomitant cleavage of caspase-3 and PARP-1. Finally, we provided novel evidence that both homologous recombination (HR) and non-homologous end joining (NHEJ) protect against CDT-elicited DSBs. In conclusion, the findings suggest that CDT functions as a radiomimetic agent and, therefore, is an attractive tool for selectively inducing persistent levels of DSBs and unveiling the associated cellular responses.
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20
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Ando-Suguimoto ES, da Silva MP, Kawamoto D, Chen C, DiRienzo JM, Mayer MPA. The cytolethal distending toxin of Aggregatibacter actinomycetemcomitans inhibits macrophage phagocytosis and subverts cytokine production. Cytokine 2014; 66:46-53. [PMID: 24548424 DOI: 10.1016/j.cyto.2013.12.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 11/19/2013] [Accepted: 12/24/2013] [Indexed: 02/06/2023]
Abstract
Aggregatibacter actinomycetemcomitans is an important periodontal pathogen that can participate in periodontitis and other non-oral infections. The cytolethal distending toxin (Cdt) is among the virulence factors produced by this bacterium. The Cdt is also secreted by several mucosa-associated Gram-negative pathogens and may play a role in perpetuating the infection by modulating the immune response. Although the toxin targets a wide range of eukaryotic cell types little is known about its activity on macrophages which play a key part in alerting the rest of the immune system to the presence of pathogens and their virulence factors. In view of this, we tested the hypothesis that the A. actinomycetemcomitans Cdt (AaCdt) disrupts macrophage function by inhibiting phagocytic activity as well as affecting the production of cytokines. Murine macrophages were co-cultured with either wild-type A. actinomycetemcomitans or a Cdt(-) mutant. Viable counts and qPCR showed that phagocytosis of the wild-type strain was significantly reduced relative to that of the Cdt(-) mutant. Addition of recombinant Aa(r)Cdt to co-cultures along with the Cdt(-) mutant diminished the phagocytic activity similar to that observed with the wild type strain. High concentrations of Aa(r)Cdt resulted in decreased phagocytosis of fluorescent bioparticles. Nitric oxide production was modulated by the presence of Cdt and the levels of IL-1β, IL-12 and IL-10 were increased. Production of TNF-α did not differ in the co-culture assays but was increased by the presence of Aa(r)Cdt. These data suggest that the Cdt may modulate macrophage function in A. actinomycetemcomitans infected sites by impairing phagocytosis and modifying the pro-inflammatory/anti-inflammatory cytokine balance.
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Affiliation(s)
| | - Maike Paulino da Silva
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Dione Kawamoto
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Casey Chen
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, Ostrow School of Dentistry of University of Southern California, USA
| | - Joseph M DiRienzo
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, PA, USA
| | - Marcia Pinto Alves Mayer
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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21
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Li L, Ding C, Duan JL, Yang MF, Sun Y, Wang XQ, Xu Y. A new functional site W115 in CdtA is critical for Aggregatibacter actinomycetemcomitans cytolethal distending toxin. PLoS One 2013; 8:e65729. [PMID: 23755273 PMCID: PMC3670888 DOI: 10.1371/journal.pone.0065729] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Accepted: 05/03/2013] [Indexed: 11/18/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans, a specific pathogen of localized aggressive periodontitis, produces a cytolethal distending toxin (CDT) that arrests eukaryotic cells irreversibly in G0/G1 or G2/M phase of the cell cycle. Although structural studies show that the aromatic patch region of CdtA plays an important role in its biological activity, the functional sites of CdtA have not been firmly established. In this study, site-specific mutagenesis strategy was employed for cdtA point mutations construction so as to examine the contributions of individual amino acids to receptor binding and the biological activity of holotoxin. The binding ability was reduced in CdtAY181ABC holotoxin and the biological function of CDT was not weaken in CdtAY105ABC, CdtAY125ABC, CdtAF109ABC and CdtAS106NBC holotoxin suggesting that these sites were not critical to CDT. But the binding activity and cell cycle arrest ability of holotoxin complexes were inhibited in CdtAW115GBC. And this site did not affect the holotoxin assembly by size exclusion chromatography. Therefore, W115 might be a critical site of CdtA binding ability. These findings suggest that the functional sites of CdtA are not only in the aromatic patch region. W115, the new functional site is critical for receptor binding and cell cycle arrest, which provides potential targets for pharmacological disruption of CDT activity.
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Affiliation(s)
- Lu Li
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
| | - Cheng Ding
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
| | - Jun-lan Duan
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
| | - Mi-fang Yang
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
| | - Ying Sun
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
| | - Xiao-qian Wang
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yan Xu
- Laboratory of Oral Infection and Immunology, Institute of Stomatology, Nanjing Medical University, Nanjing, China
- Department of Periodontology, School of Stomatology, Nanjing Medical University, Nanjing, China
- * E-mail:
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22
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Fedor Y, Vignard J, Nicolau-Travers ML, Boutet-Robinet E, Watrin C, Salles B, Mirey G. From single-strand breaks to double-strand breaks during S-phase: a new mode of action of theEscherichia coli Cytolethal Distending Toxin. Cell Microbiol 2012; 15:1-15. [DOI: 10.1111/cmi.12028] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 12/12/2022]
Affiliation(s)
- Y. Fedor
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
| | - J. Vignard
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
| | - M.-L. Nicolau-Travers
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
| | - E. Boutet-Robinet
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
| | - C. Watrin
- INRA; USC 1360; F-31300 Toulouse France
- Université de Toulouse; UPS; Centre de Physiopathologie de Toulouse Purpan (CPTP); F-31400 Toulouse France
- Inserm; UMR1043; F-31300 Toulouse France
- CNRS; UMR5282; F-31400 Toulouse France
| | - B. Salles
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
| | - G. Mirey
- INRA; UMR1331; Toxalim; Research Centre in Food Toxicology; F-31027 Toulouse France
- Université de Toulouse; UPS, UMR1331, Toxalim; F-31062 Toulouse France
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23
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Paino A, Lohermaa E, Sormunen R, Tuominen H, Korhonen J, Pöllänen MT, Ihalin R. Interleukin-1β is internalised by viable Aggregatibacter actinomycetemcomitans biofilm and locates to the outer edges of nucleoids. Cytokine 2012; 60:565-74. [PMID: 22898394 DOI: 10.1016/j.cyto.2012.07.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/15/2012] [Accepted: 07/17/2012] [Indexed: 10/28/2022]
Abstract
The opportunistic pathogen Aggregatibacter actinomycetemcomitans causes periodontitis, which is a biofilm infection that destroys tooth-supportive tissues. Interleukin (IL)-1β, a central proinflammatory cytokine of periodontitis, is an essential first line cytokine for local inflammation that modulates the cell proliferation and anti-pathogen response of human gingival keratinocytes. Previously, we demonstrated that A. actinomycetemcomitans biofilms bind IL-1β; however, whether this binding is an active process is not known. In this study, we showed for the first time with immuno-electron microscopy that viable bacterial biofilm cells internalised IL-1β when co-cultured with an organotypic mucosa. Decreased biofilm viability hindered the ability of biofilm to sequester IL-1β and caused IL-1β leakage into the culture medium. In some A. actinomycetemcomitans cells, intracellular IL-1β localized to the outer edges of the nucleoids. We identified the DNA-binding protein HU as an IL-1β interacting protein with mass spectroscopy and showed the interaction of recombinant HU and IL-1βin vitro using enzyme-linked immunosorbent assay (ELISA). Close contact with a viable A. actinomycetemcomitans biofilm decreased the proliferation and apoptosis of human gingival keratinocytes as demonstrated using Ki-67 and the terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining, respectively. Our results suggest that viable A. actinomycetemcomitans biofilms may disturb the critical first steps of local inflammation in periodontitis by binding and internalising IL-1β. The interaction of IL-1β with conserved HU provides a potential mechanism for shaping bacterial gene expression.
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Affiliation(s)
- Annamari Paino
- Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland
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24
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Aggregatibacter actinomycetemcomitans infection enhances apoptosis in vivo through a caspase-3-dependent mechanism in experimental periodontitis. Infect Immun 2012; 80:2247-56. [PMID: 22451521 DOI: 10.1128/iai.06371-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The purpose of this study was to test the hypothesis that diabetes aggravates periodontal destruction induced by Aggregatibacter actinomycetemcomitans infection. Thirty-eight diabetic and 33 normal rats were inoculated with A. actinomycetemcomitans and euthanized at baseline and at 4, 5, and 6 weeks after inoculation. Bone loss and the infiltration of polymorphonuclear leukocytes (PMNs) in gingival epithelium were measured in hematoxylin-eosin-stained sections. The induction of tumor necrosis factor alpha (TNF-α) was evaluated by immunohistochemistry and of apoptotic cells by a TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay. After A. actinomycetemcomitans infection, the bone loss in diabetic rats was 1.7-fold and the PMN infiltration 1.6-fold higher than in normoglycemic rats (P < 0.05). The induction of TNF-α was 1.5-fold higher and of apoptotic cells was up to 3-fold higher in diabetic versus normoglycemic rats (P < 0.05). Treatment with a caspase-3 inhibitor significantly blocked noninflammatory cell apoptosis induced by A. actinomycetemcomitans infection in gingival epithelium and connective tissue (P < 0.05). These results provide new insight into how diabetes aggravates A. actinomycetemcomitans-induced periodontal destruction in rats by significantly increasing the inflammatory response, leading to increased bone loss and enhancing apoptosis of gingival epithelial and connective tissue cells through a caspase-3-dependent mechanism. Antibiotics had a more pronounced effect on many of these parameters in diabetic than in normoglycemic rats, suggesting a deficiency in the capacity of diabetic animals to resist infection.
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25
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Jinadasa RN, Bloom SE, Weiss RS, Duhamel GE. Cytolethal distending toxin: a conserved bacterial genotoxin that blocks cell cycle progression, leading to apoptosis of a broad range of mammalian cell lineages. MICROBIOLOGY-SGM 2011; 157:1851-1875. [PMID: 21565933 DOI: 10.1099/mic.0.049536-0] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important Gram-negative mucocutaneous bacterial pathogens. Irrespective of the bacterial species of origin, CDT causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. The active subunit CdtB has structural homology with the phosphodiesterase family of enzymes including mammalian DNase I, and alone is necessary and sufficient to account for cellular toxicity. Indeed, mammalian cells treated with CDT initiate a DNA damage response similar to that elicited by ionizing radiation-induced DNA double strand breaks resulting in cell cycle arrest and apoptosis. The mechanism of CDT-induced apoptosis remains incompletely understood, but appears to involve both p53-dependent and -independent pathways. While epithelial, endothelial and fibroblast cell lines respond to CDT by undergoing arrest of cell cycle progression resulting in nuclear and cytoplasmic distension that precedes apoptotic cell death, cells of haematopoietic origin display rapid apoptosis following a brief period of cell cycle arrest. In this review, the ecology of pathogens producing CDT, the molecular biology of bacterial CDT and the molecular mechanisms of CDT-induced cytotoxicity are critically appraised. Understanding the contribution of a broadly conserved bacterial genotoxin that blocks progression of the mammalian cell cycle, ultimately causing cell death, should assist with elucidating disease mechanisms for these important pathogens.
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Affiliation(s)
- Rasika N Jinadasa
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Stephen E Bloom
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Robert S Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Gerald E Duhamel
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
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