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Kwack KH, Jang EY, Kim C, Choi YS, Lee JH, Moon JH. Porphyromonas gulae and canine periodontal disease: Current understanding and future directions. Virulence 2025; 16:2449019. [PMID: 39834343 PMCID: PMC11756583 DOI: 10.1080/21505594.2024.2449019] [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: 08/29/2024] [Revised: 10/01/2024] [Accepted: 12/28/2024] [Indexed: 01/22/2025] Open
Abstract
Porphyromonas gulae has emerged as a notable pathogen in canine periodontal disease, akin to Porphyromonas gingivalis in human periodontitis. This review examines the initial isolation, phylogenetic analysis, habitat, host range, relationships with host health status and age, and key pathogenic determinants, including fimbriae, proteases, citrullinating enzyme, and lipopolysaccharide. Control strategies discussed include polyphosphate to disrupt haeme/iron utilization, clindamycin with interferon alpha to reduce bacterial load and enhance the immune response, and a protease inhibitor. Further research is needed to understand strain-level diversity of virulence factors and interactions between P. gulae and other oral bacteria, particularly Fusobacterium nucleatum, a common pathogen in both dogs and humans. The potential for interspecies transmission between dogs and humans warrants further research into these interactions. Extensive in vivo studies across various breeds are crucial to validate the effectiveness of proposed treatment strategies. This review emphasizes P. gulae's role in periodontal health and disease, setting the stage for future research and improved management of canine periodontal disease.
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Affiliation(s)
- Kyu Hwan Kwack
- Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea
| | - Eun-Young Jang
- Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea
- Department of Dentistry, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Cheul Kim
- Research Institute of Oral Science, College of Dentistry, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Young-Suk Choi
- Department of Dental Hygiene, Kyung-In Women’s University, Incheon, Republic of Korea
| | - Jae-Hyung Lee
- Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea
| | - Ji-Hoi Moon
- Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea
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Alaei SR, King AJ, Banani K, Reddy A, Ortiz J, Knight AL, Haldeman J, Su TH, Park H, Coats SR, Jain S. Lipid a remodeling modulates outer membrane vesicle biogenesis by Porphyromonas gingivalis. J Bacteriol 2025; 207:e0033624. [PMID: 39660885 PMCID: PMC11784228 DOI: 10.1128/jb.00336-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Accepted: 11/08/2024] [Indexed: 12/12/2024] Open
Abstract
Outer membrane vesicles (OMVs) are small membrane enclosed sacs released from bacteria which serve as carriers of biomolecules that shape interactions with the surrounding environment. The periodontal pathogen, Porphyromonas gingivalis, is a prolific OMV producer. Here, we investigated how the structure of lipid A, a core outer membrane molecule, influences P. gingivalis OMV production, OMV-dependent TLR4 activation, and biofilm formation. We examined mutant strains of P. gingivalis 33277 deficient for enzymes that alter lipid A phosphorylation and acylation status. The lipid A C4'-phosphatase (lpxF)-deficient strain and strains bearing inactivating point mutations in the LpxF active site displayed markedly reduced OMV production relative to WT. In contrast, strains deficient for either the lipid A C1-phosphatase (lpxE) or the lipid A deacylase (PGN_1123; lpxZ) genes did not display alterations in OMV abundance compared to WT. These data indicate that lipid A C4'-phosphate removal is required for typical OMV formation. In addition, OMVs produced by ΔlpxF and ΔlpxZ strains, possessing only penta-acylated lipid A, stimulated robust TLR4 activation, whereas OMVs obtained from WT and ΔlpxE strains, containing predominantly tetra-acylated lipid A, did not. Hence, lipid A remodeling modulates the capacity of OMVs to engage host TLR4-dependent immunity. Finally, we demonstrate an inverse relationship between OMV abundance and biofilm density, with the ∆lpxF mutants forming denser biofilms than either WT, ΔlpxE, or ΔlpxZ strains. Therefore, OMVs may also contribute to pathogenesis by regulating biofilm formation and dispersal.IMPORTANCEPorphyromonas gingivalis is a bacterium strongly associated with periodontitis. P. gingivalis exports lipids, proteins, and other biomolecules that contribute to the bacterium's ability to persist in inflammatory conditions encountered during disease. These biomolecules are exported through several mechanisms, including via outer membrane vesicles (OMVs). Despite their ubiquity, the mechanisms that drive outer membrane vesicle production vary among bacteria and are not fully understood. In this study, we report that C4' dephosphorylation of lipid A, a major outer membrane molecule, is required for robust outer membrane vesicle production and biological function in P. gingivalis. This finding adds to the growing body of evidence that lipid A structure is an important factor in outer membrane vesicle biogenesis in diverse bacterial species.
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Affiliation(s)
- Sarah R. Alaei
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Alisa J. King
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Karim Banani
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
| | - Angel Reddy
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Joshua Ortiz
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Alexa L. Knight
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Jessica Haldeman
- Division of Science and Mathematics, School of Interdisciplinary Arts and Sciences, University of Washington, Tacoma, Washington, USA
| | - Thet Hnin Su
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
| | - Hana Park
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
| | - Stephen R. Coats
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
| | - Sumita Jain
- Department of Periodontics, School of Dentistry, University of Washington, Seattle, Washington, USA
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Śmiga M, Olczak T. Exploring heme and iron acquisition strategies of Porphyromonas gingivalis-current facts and hypotheses. FEMS Microbiol Rev 2025; 49:fuaf019. [PMID: 40343779 PMCID: PMC12094164 DOI: 10.1093/femsre/fuaf019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2025] [Revised: 05/02/2025] [Accepted: 05/08/2025] [Indexed: 05/11/2025] Open
Abstract
Iron and heme are crucial for pathogenic bacteria living in the human host but are not available in free form due to their binding by iron- and heme-sequestering proteins. Porphyromonas gingivalis causes dysbiosis in the oral microbiome and is considered a keystone pathogen in the onset and progression of periodontal diseases. Its ability to infect and multiply in host cells and its presence in distant tissues and fluids highlights its pathogenic versatility and explains the relationship between periodontal diseases and systemic or neurodegenerative diseases. Porphyromonas gingivalis has evolved specialized mechanisms that allow it to thrive in the host under adverse nutrient-limited conditions. This review presents the updated summary of the mechanisms of iron and heme acquisition by P. gingivalis, with a central role played by gingipains and the unique Hmu system. The potential role of other iron and heme acquisition systems, such as Hus and Iht, indicates the importance of the partially conserved heme biosynthesis pathway, involving homologs of the HemN, HemG, and HemH proteins. In light of increasing antibiotic resistance, difficulties with diagnosis, and drug administration, targeting the mechanisms of heme and iron acquisition of P. gingivalis represents a promising target for developing diagnostic tests, preventive or therapeutic strategies.
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Affiliation(s)
- Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, 14A F. Joliot-Curie, 50-383 Wrocław, Poland
| | - Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, 14A F. Joliot-Curie, 50-383 Wrocław, Poland
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Yu X, Mankia K, Do T, Meade J. Oral Microbiome Dysbiosis and Citrullination in Rheumatoid Arthritis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2025; 1472:185-199. [PMID: 40111693 DOI: 10.1007/978-3-031-79146-8_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2025]
Abstract
Rheumatoid arthritis and periodontal diseases, both characterized by chronic inflammation, share many common risk factors, sparking interest in understanding their established association. Emerging research has shed light on the link between these two diseases potentially occurring through the intricate interactions within the oral microbiome. The enrichment of pathogenic strains and species in this microbial community disrupts the delicate balance of both ecological and immunological homeostasis with the host. Particular attention has been paid to the role of key pathogens, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, known for their immunomodulatory abilities. The generation of an autoimmune response against proteins modified by citrullination is known to be a key step in the pathogenesis of RA. Importantly, the bidirectional citrullination mediated by both host innate immune cells and oral bacteria generates citrullinated peptide neoepitopes, which may serve as potential triggers for the loss of tolerance and subsequent autoimmunity in susceptible individuals. This review highlights the importance of understanding the mechanisms through which oral microbiome dysbiosis and citrullination contribute to the onset and progression of RA. Insights into these mechanisms not only advance pathobiological understanding but also offer potential therapeutic targets. Furthermore, we discuss the potential impact of nonsurgical periodontal treatment in modifying disease progression or mitigating RA, underscoring the critical role of periodontal health in managing systemic inflammatory conditions.
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Affiliation(s)
- Xia Yu
- Division of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK
| | - Kulveer Mankia
- Leeds Biomedical Centre-NIHR, Leeds, UK
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK
| | - Thuy Do
- Division of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK
| | - Josephine Meade
- Division of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK.
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Ghods S, Muszyński A, Yang H, Seelan RS, Mohammadi A, Hilson JS, Keiser G, Nichols FC, Azadi P, Ernst RK, Moradali F. The multifaceted role of c-di-AMP signaling in the regulation of Porphyromonas gingivalis lipopolysaccharide structure and function. Front Cell Infect Microbiol 2024; 14:1418651. [PMID: 38933693 PMCID: PMC11199400 DOI: 10.3389/fcimb.2024.1418651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024] Open
Abstract
Background This study unveils the intricate functional association between cyclic di-3',5'-adenylic acid (c-di-AMP) signaling, cellular bioenergetics, and the regulation of lipopolysaccharide (LPS) profile in Porphyromonas gingivalis, a Gram-negative obligate anaerobe considered as a keystone pathogen involved in the pathogenesis of chronic periodontitis. Previous research has identified variations in P. gingivalis LPS profile as a major virulence factor, yet the underlying mechanism of its modulation has remained elusive. Methods We employed a comprehensive methodological approach, combining two mutants exhibiting varying levels of c-di-AMP compared to the wild type, alongside an optimized analytical methodology that combines conventional mass spectrometry techniques with a novel approach known as FLATn. Results We demonstrate that c-di-AMP acts as a metabolic nexus, connecting bioenergetic status to nuanced shifts in fatty acid and glycosyl profiles within P. gingivalis LPS. Notably, the predicted regulator gene cdaR, serving as a potent regulator of c-di-AMP synthesis, was found essential for producing N-acetylgalactosamine and an unidentified glycolipid class associated with the LPS profile. Conclusion The multifaceted roles of c-di-AMP in bacterial physiology are underscored, emphasizing its significance in orchestrating adaptive responses to stimuli. Furthermore, our findings illuminate the significance of LPS variations and c-di-AMP signaling in determining the biological activities and immunostimulatory potential of P. gingivalis LPS, promoting a pathoadaptive strategy. The study expands the understanding of c-di-AMP pathways in Gram-negative species, laying a foundation for future investigations into the mechanisms governing variations in LPS structure at the molecular level and their implications for host-pathogen interactions.
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Affiliation(s)
- Shirin Ghods
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Hyojik Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Ratnam S. Seelan
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States
| | - Asal Mohammadi
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States
| | - Jacob S. Hilson
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Griffin Keiser
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Frank C. Nichols
- Division of Periodontology, University of Connecticut School of Dental Medicine, Farmington, CT, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD, United States
| | - Fata Moradali
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, United States
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Yáñez L, Soto C, Tapia H, Pacheco M, Tapia J, Osses G, Salinas D, Rojas-Celis V, Hoare A, Quest AFG, Díaz-Elizondo J, Pérez-Donoso JM, Bravo D. Co-Culture of P. gingivalis and F. nucleatum Synergistically Elevates IL-6 Expression via TLR4 Signaling in Oral Keratinocytes. Int J Mol Sci 2024; 25:3611. [PMID: 38612423 PMCID: PMC11011619 DOI: 10.3390/ijms25073611] [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: 02/23/2024] [Revised: 03/15/2024] [Accepted: 03/17/2024] [Indexed: 04/14/2024] Open
Abstract
Periodontitis, characterized by persistent inflammation in the periodontium, is intricately connected to systemic diseases, including oral cancer. Bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, play a pivotal role in periodontitis development because they contribute to dysbiosis and tissue destruction. Thus, comprehending the interplay between these bacteria and their impacts on inflammation holds significant relevance in clinical understanding and treatment advancement. In the present work, we explored, for the first time, their impacts on the expressions of pro-inflammatory mediators after infecting oral keratinocytes (OKs) with a co-culture of pre-incubated P. gingivalis and F. nucleatum. Our results show that the co-culture increases IL-1β, IL-8, and TNF-α expressions, synergistically augments IL-6, and translocates NF-kB to the cell nucleus. These changes in pro-inflammatory mediators-associated with chronic inflammation and cancer-correlate with an increase in cell migration following infection with the co-cultured bacteria or P. gingivalis alone. This effect depends on TLR4 because TLR4 knockdown notably impacts IL-6 expression and cell migration. Our study unveils, for the first time, crucial insights into the outcomes of their co-culture on virulence, unraveling the role of bacterial interactions in polymicrobial diseases and potential links to oral cancer.
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Affiliation(s)
- Lucas Yáñez
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Cristopher Soto
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Héctor Tapia
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Martín Pacheco
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Javiera Tapia
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Gabriela Osses
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - Daniela Salinas
- Oral Microbiology and Immunology Laboratory, Department of Pathology and Oral Medicine, Faculty of Dentistry, Universidad de Chile, Santiago 8380492, Chile; (D.S.); (A.H.)
| | - Victoria Rojas-Celis
- Virology Laboratory, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago 7800003, Chile;
| | - Anilei Hoare
- Oral Microbiology and Immunology Laboratory, Department of Pathology and Oral Medicine, Faculty of Dentistry, Universidad de Chile, Santiago 8380492, Chile; (D.S.); (A.H.)
| | - Andrew F. G. Quest
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
- Cellular Communication Laboratory, Center for Studies on Exercise, Metabolism and Cancer (CEMC), Program of Cell and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Jessica Díaz-Elizondo
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
| | - José Manuel Pérez-Donoso
- BioNanotechnology and Microbiology Laboratory, Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Denisse Bravo
- Microbial Interactions Laboratory, Faculty of Dentistry, Universidad Andrés Bello, Santiago 8370133, Chile; (L.Y.); (C.S.); (H.T.); (M.P.); (J.T.); (G.O.); (J.D.-E.)
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile;
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Śmiga M, Ślęzak P, Olczak T. Comparative analysis of Porphyromonas gingivalis A7436 and ATCC 33277 strains reveals differences in the expression of heme acquisition systems. Microbiol Spectr 2024; 12:e0286523. [PMID: 38289063 PMCID: PMC10913741 DOI: 10.1128/spectrum.02865-23] [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: 07/19/2023] [Accepted: 12/15/2023] [Indexed: 03/06/2024] Open
Abstract
Porphyromonas gingivalis strains exhibit different phenotypes in vitro, different virulence potential in animal models, and different associations with human diseases, with strains classified as virulent/more virulent (e.g., A7436 and W83) or as less virulent/avirulent (e.g., ATCC 33277). In this study, we comparatively analyzed the A7436 and ATCC 33277 strains to better understand their variability. Global gene expression analysis in response to heme and iron limitation revealed more pronounced differences in the A7436 than in the ATCC 33277 strain; however, in both strains, the largest changes were observed in genes encoding hypothetical proteins, genes whose products participate in energy metabolism, and in genes encoding proteins engaged in transport and binding proteins. Our results confirmed that variability between P. gingivalis strains is due to differences in the arrangement of their genomes. Analysis of gene expression of heme acquisition systems demonstrated that not only the availability of iron and heme in the external environment but also the ability to store iron intracellularly can influence the P. gingivalis phenotype. Therefore, we assume that differences in virulence potential may also be due to differences in the production of systems involved in iron and heme acquisition, mainly the Hmu system. In addition, our study showed that hemoglobin, in a concentration-dependent manner, differentially influences the virulence potential of P. gingivalis strains. We conclude that iron and heme homeostasis may add to the variability observed between P. gingivalis strains. IMPORTANCE Periodontitis belongs to a group of multifactorial diseases, characterized by inflammation and destruction of tooth-supporting tissues. P. gingivalis is one of the most important microbial factors involved in the initiation and progression of periodontitis. To survive in the host, the bacterium must acquire heme as a source of iron and protoporphyrin IX. P. gingivalis strains respond differently to changing iron and heme concentrations, which may be due to differences in the expression of systems involved in iron and heme acquisition. The ability to accumulate iron intracellularly, being different in more and less virulent P. gingivalis strains, may influence their phenotypes, production of virulence factors (including proteins engaged in heme acquisition), and virulence potential of this bacterium.
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Affiliation(s)
- Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Paulina Ślęzak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
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Xu J, Yu L, Ye S, Ye Z, Yang L, Xu X. Oral microbiota-host interaction: the chief culprit of alveolar bone resorption. Front Immunol 2024; 15:1254516. [PMID: 38455060 PMCID: PMC10918469 DOI: 10.3389/fimmu.2024.1254516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 02/02/2024] [Indexed: 03/09/2024] Open
Abstract
There exists a bidirectional relationship between oral health and general well-being, with an imbalance in oral symbiotic flora posing a threat to overall human health. Disruptions in the commensal flora can lead to oral diseases, while systemic illnesses can also impact the oral cavity, resulting in the development of oral diseases and disorders. Porphyromonas gingivalis and Fusobacterium nucleatum, known as pathogenic bacteria associated with periodontitis, play a crucial role in linking periodontitis to accompanying systemic diseases. In periodontal tissues, these bacteria, along with their virulence factors, can excessively activate the host immune system through local diffusion, lymphatic circulation, and blood transmission. This immune response disruption contributes to an imbalance in osteoimmune mechanisms, alveolar bone resorption, and potential systemic inflammation. To restore local homeostasis, a deeper understanding of microbiota-host interactions and the immune network phenotype in local tissues is imperative. Defining the immune network phenotype in periodontal tissues offers a promising avenue for investigating the complex characteristics of oral plaque biofilms and exploring the potential relationship between periodontitis and associated systemic diseases. This review aims to provide an overview of the mechanisms underlying Porphyromonas gingivalis- and Fusobacterium nucleatum-induced alveolar bone resorption, as well as the immunophenotypes observed in host periodontal tissues during pathological conditions.
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Affiliation(s)
- Jingyu Xu
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Changchun, China
| | - Ling Yu
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Changchun, China
| | - Surong Ye
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Changchun, China
| | - Zitong Ye
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Changchun, China
| | - Luyi Yang
- Department of Orthodontics, Hospital of Stomatology, Jilin University, Changchun, China
| | - Xiaoxi Xu
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China
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Baek DH, Lee SH. Anti-Inflammatory Efficacy of Human-Derived Streptococcus salivarius on Periodontopathogen-Induced Inflammation. J Microbiol Biotechnol 2023; 33:998-1005. [PMID: 37635315 PMCID: PMC10468666 DOI: 10.4014/jmb.2302.02002] [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: 02/02/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 08/29/2023]
Abstract
Streptococcus salivarius is a beneficial bacterium in oral cavity, and some strains of this bacterium are known to be probiotics. The purpose of this study was to investigate the anti-inflammatory effect and mechanism of S. salivarius G7 lipoteichoic acid (LTA) on lipopolysaccharide (LPS) and LTA of periodontopathogens. The surface molecules of S. salivarius G7 was extracted, and single- or co-treated on human monocytic cells with LPS and LTA of periodontopathogens. The induction of cytokine expression was evaluated by real-time PCR and ELISA. After labeling fluorescence on LPS and LTA of periodontopathogens, it was co-treated with S. salivarius LTA to the cell. The bound LPS and LTA were measured by a flow cytometer. Also, the biding assay of the LPS and LTA to CD14 and LPS binding protein (LBP) was performed. The surface molecules of S. salivarius G7 did not induce the expression of inflammatory cytokines, and S. salivarius G7 LTA inhibited the inflammatory cytokines induced by LPS and LTA of periodontopathogens. S. salivarius G7 LTA inhibited the binding of its LPS and LTA to cells. Also, S. salivarius G7 LTA blocked the binding of its LPS and LTA to CD14 and LBP. S. salivarius G7 has an inhibitory effect on inflammation induced by LPS or LTA of periodontopathogens, and may be a candidate probiotics for prevention of periodontitis.
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Affiliation(s)
- Dong-Heon Baek
- Department of Dental Hygiene, College of Health Science, Dankook University, Cheonan 31116, Republic of Korea
| | - Sung-Hoon Lee
- Department of Dental Hygiene, College of Health Science, Dankook University, Cheonan 31116, Republic of Korea
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Modulatory Mechanisms of Pathogenicity in Porphyromonas gingivalis and Other Periodontal Pathobionts. Microorganisms 2022; 11:microorganisms11010015. [PMID: 36677306 PMCID: PMC9862357 DOI: 10.3390/microorganisms11010015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
The pathogenesis of periodontitis depends on a sustained feedback loop where bacterial virulence factors and immune responses both contribute to inflammation and tissue degradation. Periodontitis is a multifactorial disease that is associated with a pathogenic shift in the oral microbiome. Within this shift, low-abundance Gram-negative anaerobic pathobionts transition from harmless colonisers of the subgingival environment to a virulent state that drives evasion and subversion of innate and adaptive immune responses. This, in turn, drives the progression of inflammatory disease and the destruction of tooth-supporting structures. From an evolutionary perspective, bacteria have developed this phenotypic plasticity in order to respond and adapt to environmental stimuli or external stressors. This review summarises the available knowledge of genetic, transcriptional, and post-translational mechanisms which mediate the commensal-pathogen transition of periodontal bacteria. The review will focus primarily on Porphyromonas gingivalis.
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11
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Aleksijević LH, Aleksijević M, Škrlec I, Šram M, Šram M, Talapko J. Porphyromonas gingivalis Virulence Factors and Clinical Significance in Periodontal Disease and Coronary Artery Diseases. Pathogens 2022; 11:1173. [PMID: 36297228 PMCID: PMC9609396 DOI: 10.3390/pathogens11101173] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/27/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
Porphyromonas gingivalis is a gram-negative, anaerobic bacterium that lives in the oral cavity. It is an integral part of the oral microbiome, which includes more than 500 types of bacteria. Under certain circumstances, as a consequence of virulence factors, it can become very destructive and proliferate to many cells in periodontal lesions. It is one of the causative agents present extremely often in dental plaque and is the main etiological factor in the development of periodontal disease. During various therapeutic procedures, P. gingivalis can enter the blood and disseminate through it to distant organs. This primarily refers to the influence of periodontal agents on the development of subacute endocarditis and can facilitate the development of coronary heart disease, atherosclerosis, and ischemic infarction. The action of P. gingivalis is facilitated by numerous factors of virulence and pathogenicity such as fimbriae, hemolysin, hemagglutinin, capsules, outer membrane vesicles, lipopolysaccharides, and gingipains. A special problem is the possibility of biofilm formation. P. gingivalis in a biofilm is 500 to 1000 times less sensitive to antimicrobial drugs than planktonic cells, which represents a significant problem in the treatment of infections caused by this pathogen.
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Affiliation(s)
- Lorena Horvat Aleksijević
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Marko Aleksijević
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Ivana Škrlec
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Marko Šram
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Miroslav Šram
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
- Department of Cardiology, Clinical Hospital Center Osijek, 31000 Osijek, Croatia
| | - Jasminka Talapko
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
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12
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Moradali MF, Ghods S, Bähre H, Lamont RJ, Scott DA, Seifert R. Atypical cyclic di-AMP signaling is essential for Porphyromonas gingivalis growth and regulation of cell envelope homeostasis and virulence. NPJ Biofilms Microbiomes 2022; 8:53. [PMID: 35794154 PMCID: PMC9259658 DOI: 10.1038/s41522-022-00316-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/13/2022] [Indexed: 02/04/2023] Open
Abstract
Microbial pathogens employ signaling systems through cyclic (di-) nucleotide monophosphates serving as second messengers to increase fitness during pathogenesis. However, signaling schemes via second messengers in Porphyromonas gingivalis, a key Gram-negative anaerobic oral pathogen, remain unknown. Here, we report that among various ubiquitous second messengers, P. gingivalis strains predominantly synthesize bis-(3',5')-cyclic di-adenosine monophosphate (c-di-AMP), which is essential for their growth and survival. Our findings demonstrate an unusual regulation of c-di-AMP synthesis in P. gingivalis. P. gingivalis c-di-AMP phosphodiesterase (PDE) gene (pdepg) positively regulates c-di-AMP synthesis and impedes a decrease in c-di-AMP concentration despite encoding conserved amino acid motifs for phosphodiesterase activity. Instead, the predicted regulator gene cdaR, unrelated to the c-di-AMP PDE genes, serves as a potent negative regulator of c-di-AMP synthesis in this anaerobe. Further, our findings reveal that pdepg and cdaR are required to regulate the incorporation of ATP into c-di-AMP upon pyruvate utilization, leading to enhanced biofilm formation. We show that shifts in c-di-AMP signaling change the integrity and homeostasis of cell envelope, importantly, the structure and immunoreactivity of the lipopolysaccharide layer. Additionally, microbe-microbe interactions and the virulence potential of P. gingivalis were modulated by c-di-AMP. These studies provide the first glimpse into the scheme of second messenger signaling in P. gingivalis and perhaps other Bacteroidetes. Further, our findings indicate that c-di-AMP signaling promotes the fitness of the residents of the oral cavity and the development of a pathogenic community.
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Affiliation(s)
- M Fata Moradali
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA.
| | - Shirin Ghods
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - Heike Bähre
- Research Core Unit Metabolomics, Hannover Medical School, Hanover, Germany
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - David A Scott
- Department of Oral Immunology and Infectious Diseases, University of Louisville, School of Dentistry, Louisville, KY, USA
| | - Roland Seifert
- Research Core Unit Metabolomics, Hannover Medical School, Hanover, Germany
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13
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Zenobia C, Darveau RP. Does Oral Endotoxin Contribute to Systemic Inflammation? FRONTIERS IN ORAL HEALTH 2022; 3:911420. [PMID: 35677024 PMCID: PMC9169450 DOI: 10.3389/froh.2022.911420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 04/29/2022] [Indexed: 12/27/2022] Open
Abstract
The oral microbiome, with a unique emphasis on Porphyromonas gingivalis has been associated with a constellation of inflammatory diseases such as cardiovascular disease, rheumatoid arthritis, Alzheimer's disease, type II diabetes, and non-alcoholic associated fatty liver disease. Periodontal disease has also been shown to induce "leaky gut" leading to metabolic endotoxemia. Several recent studies investigating the habitants of the blood microbiome have found the majority of species appear to be derived from oral and skin bacterial communities in otherwise healthy individuals. Many of the same pathologies associated with perturbations of oral health, such as cardiovascular disease, show alterations to the composition of the blood microbiome as well as circulating neutrophil phenotypes. Gingival inflammation is associated with activated blood neutrophil phenotypes that can exacerbate a distal inflammatory insult which may explain the connection between oral and systemic inflammatory conditions. While in the oral cavity, neutrophils encounter oral microbes that are adept in manipulating neutrophil activity which can re-enter the vasculature thereafter. Endotoxin from oral microbes can differ significantly depending on bacterial community and state of oral health to alter cellular LPS tolerance mechanisms which may contribute to the primed neutrophil phenotype seen in periodontitis and provide a mechanism by which the oral-microbes can affect systemic health outcomes. This review synthesizes the studies between inflammatory diseases and oral health with emphasis on microbiome and corresponding lipopolysaccharides in immune tolerance and activation.
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Affiliation(s)
| | - Richard P. Darveau
- Departments of Periodontology and Microbiology, University of Washington, Seattle, WA, United States
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14
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Lan C, Chen S, Jiang S, Lei H, Cai Z, Huang X. Different expression patterns of inflammatory cytokines induced by lipopolysaccharides from Escherichia coli or Porphyromonas gingivalis in human dental pulp stem cells. BMC Oral Health 2022; 22:121. [PMID: 35413908 PMCID: PMC9004173 DOI: 10.1186/s12903-022-02161-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 04/07/2022] [Indexed: 12/19/2022] Open
Abstract
Background Lipopolysaccharide (LPS) is one of the leading causes of pulpitis. The differences in establishing an in vitro pulpitis model by using different lipopolysaccharides (LPSs) are unknown. This study aimed to determine the discrepancy in the ability to induce the expression of inflammatory cytokines and the underlying mechanism between Escherichia coli (E. coli) and Porphyromonas gingivalis (P. gingivalis) LPSs in human dental pulp stem cells (hDPSCs).
Material and methods Quantitative real-time polymerase chain reaction (QRT-PCR) was used to evaluate the mRNA levels of inflammatory cytokines including IL-6, IL-8, COX-2, IL-1β, and TNF-α expressed by hDPSCs at each time point. ELISA was used to assess the interleukin-6 (IL-6) protein level. The role of toll-like receptors (TLR)2 and TLR4 in the inflammatory response in hDPSCs initiated by LPSs was assessed by QRT-PCR and flow cytometry. Results The E. coli LPS significantly enhanced the mRNA expression of inflammatory cytokines and the production of the IL-6 protein (p < 0.05) in hDPSCs. The peaks of all observed inflammation mediators’ expression in hDPSCs were reached 3–12 h after stimulation by 1 μg/mL E. coli LPS. E. coli LPS enhanced the TLR4 expression (p < 0.05) but not TLR2 in hDPSCs, whereas P. gingivalis LPS did not affect TLR2 or TLR4 expression in hDPSCs. The TLR4 inhibitor pretreatment significantly inhibited the gene expression of inflammatory cytokines upregulated by E. coli LPS (p < 0.05). Conclusion Under the condition of this study, E. coli LPS but not P. gingivalis LPS is effective in promoting the expression of inflammatory cytokines by hDPSCs. E. coli LPS increases the TLR4 expression in hDPSCs. P. gingivalis LPS has no effect on TLR2 or TLR4 expression in hDPSCs. Supplementary Information The online version contains supplementary material available at 10.1186/s12903-022-02161-x.
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Affiliation(s)
- Chunhua Lan
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road, Fuzhou, 350002, China.,Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Shuai Chen
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road, Fuzhou, 350002, China.,Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Shan Jiang
- Southern Medical University, Shenzhen Stomatology Hospital (Pingshan), Shenzhen, China
| | - Huaxiang Lei
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road, Fuzhou, 350002, China.,Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Zhiyu Cai
- Department of Stomatology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xiaojing Huang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road, Fuzhou, 350002, China. .,Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China.
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15
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Chinthamani S, Settem RP, Honma K, Stafford GP, Sharma A. Tannerella forsythia strains differentially induce interferon gamma-induced protein 10 (IP-10) expression in macrophages due to lipopolysaccharide heterogeneity. Pathog Dis 2022; 80:6566341. [PMID: 35404415 PMCID: PMC9053306 DOI: 10.1093/femspd/ftac008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/18/2022] [Accepted: 04/07/2022] [Indexed: 11/12/2022] Open
Abstract
Abstract
Tannerella forsythia is strongly implicated in the development of periodontitis, an inflammatory disease that destroys the bone and soft tissues supporting the tooth. To date, the knowledge of the virulence attributes of T. forsythia species has mainly come from studies with a laboratory adapted strain (ATCC 43 037). In this study, we focused on two T. forsythia clinical isolates, UB4 and UB20, in relation to their ability to activate macrophages. We found that these clinical isolates differentially induced proinflammatory cytokine expression in macrophages. Prominently, the expression of the chemokine protein IP-10 (CXCL10) was highly induced by UB20 as compared to UB4 and the laboratory strain ATCC 43 037. Our study focused on the lipopolysaccharide component (LPS) of these strains and found that UB20 expressed a smooth-type LPS, unlike UB4 and ATCC 43 037 each of which expressed a rough-type LPS. The LPS from UB20, via activation of TLR4, was found to be a highly potent inducer of IP-10 expression via signaling through STAT1 (signal transducer and activator of transcription-1). These data suggest that pathogenicity of T. forsythia species could be strain dependent and the LPS heterogeneity associated with the clinical strains might be responsible for their pathogenic potential and severity of periodontitis.
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Affiliation(s)
| | | | | | | | - Ashu Sharma
- Oral Biology, University at Buffalo, Buffalo, NY, USA
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16
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Marcano R, Rojo MÁ, Cordoba-Diaz D, Garrosa M. Pathological and Therapeutic Approach to Endotoxin-Secreting Bacteria Involved in Periodontal Disease. Toxins (Basel) 2021; 13:533. [PMID: 34437404 PMCID: PMC8402370 DOI: 10.3390/toxins13080533] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022] Open
Abstract
It is widely recognized that periodontal disease is an inflammatory entity of infectious origin, in which the immune activation of the host leads to the destruction of the supporting tissues of the tooth. Periodontal pathogenic bacteria like Porphyromonas gingivalis, that belongs to the complex net of oral microflora, exhibits a toxicogenic potential by releasing endotoxins, which are the lipopolysaccharide component (LPS) available in the outer cell wall of Gram-negative bacteria. Endotoxins are released into the tissues causing damage after the cell is lysed. There are three well-defined regions in the LPS: one of them, the lipid A, has a lipidic nature, and the other two, the Core and the O-antigen, have a glycosidic nature, all of them with independent and synergistic functions. Lipid A is the "bioactive center" of LPS, responsible for its toxicity, and shows great variability along bacteria. In general, endotoxins have specific receptors at the cells, causing a wide immunoinflammatory response by inducing the release of pro-inflammatory cytokines and the production of matrix metalloproteinases. This response is not coordinated, favoring the dissemination of LPS through blood vessels, as well as binding mainly to Toll-like receptor 4 (TLR4) expressed in the host cells, leading to the destruction of the tissues and the detrimental effect in some systemic pathologies. Lipid A can also act as a TLRs antagonist eliciting immune deregulation. Although bacterial endotoxins have been extensively studied clinically and in a laboratory, their effects on the oral cavity and particularly on periodontium deserve special attention since they affect the connective tissue that supports the tooth, and can be linked to advanced medical conditions. This review addresses the distribution of endotoxins associated with periodontal pathogenic bacteria and its relationship with systemic diseases, as well as the effect of some therapeutic alternatives.
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Affiliation(s)
- Rosalia Marcano
- Department of Cell Biology, Histology and Pharmacology, Faculty of Medicine and INCYL, University of Valladolid, 47005 Valladolid, Spain;
| | - M. Ángeles Rojo
- Area of Experimental Sciences, Miguel de Cervantes European University, 47012 Valladolid, Spain;
| | - Damián Cordoba-Diaz
- Area of Pharmaceutics and Food Technology, Faculty of Pharmacy, and IUFI, Complutense University of Madrid, 28040 Madrid, Spain;
| | - Manuel Garrosa
- Department of Cell Biology, Histology and Pharmacology, Faculty of Medicine and INCYL, University of Valladolid, 47005 Valladolid, Spain;
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17
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Zenobia C, Herpoldt KL, Freire M. Is the oral microbiome a source to enhance mucosal immunity against infectious diseases? NPJ Vaccines 2021; 6:80. [PMID: 34078913 PMCID: PMC8172910 DOI: 10.1038/s41541-021-00341-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/24/2021] [Indexed: 12/14/2022] Open
Abstract
Mucosal tissues act as a barrier throughout the oral, nasopharyngeal, lung, and intestinal systems, offering first-line protection against potential pathogens. Conventionally, vaccines are applied parenterally to induce serotype-dependent humoral response but fail to drive adequate mucosal immune protection for viral infections such as influenza, HIV, and coronaviruses. Oral mucosa, however, provides a vast immune repertoire against specific microbial pathogens and yet is shaped by an ever-present microbiome community that has co-evolved with the host over thousands of years. Adjuvants targeting mucosal T-cells abundant in oral tissues can promote soluble-IgA (sIgA)-specific protection to confer increased vaccine efficacy. Th17 cells, for example, are at the center of cell-mediated immunity and evidence demonstrates that protection against heterologous pathogen serotypes is achieved with components from the oral microbiome. At the point of entry where pathogens are first encountered, typically the oral or nasal cavity, the mucosal surfaces are layered with bacterial cohabitants that continually shape the host immune profile. Constituents of the oral microbiome including their lipids, outer membrane vesicles, and specific proteins, have been found to modulate the Th17 response in the oral mucosa, playing important roles in vaccine and adjuvant designs. Currently, there are no approved adjuvants for the induction of Th17 protection, and it is critical that this research is included in the preparedness for the current and future pandemics. Here, we discuss the potential of oral commensals, and molecules derived thereof, to induce Th17 activity and provide safer and more predictable options in adjuvant engineering to prevent emerging infectious diseases.
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Affiliation(s)
| | | | - Marcelo Freire
- Departments of Genomic Medicine and Infectious Diseases, J. Craig Venter Institute, La Jolla, CA, USA.
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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18
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Wadhawan A, Reynolds MA, Makkar H, Scott AJ, Potocki E, Hoisington AJ, Brenner LA, Dagdag A, Lowry CA, Dwivedi Y, Postolache TT. Periodontal Pathogens and Neuropsychiatric Health. Curr Top Med Chem 2021; 20:1353-1397. [PMID: 31924157 DOI: 10.2174/1568026620666200110161105] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/04/2019] [Accepted: 12/04/2019] [Indexed: 02/08/2023]
Abstract
Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.
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Affiliation(s)
- Abhishek Wadhawan
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States.,Department of Psychiatry, Saint Elizabeths Hospital, Washington, D.C. 20032, United States
| | - Mark A Reynolds
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore 21201, United States
| | - Hina Makkar
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States
| | - Alison J Scott
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, United States
| | - Eileen Potocki
- VA Maryland Healthcare System, Baltimore VA Medical Center, Baltimore, United States
| | - Andrew J Hoisington
- Air Force Institute of Technology, Wright-Patterson Air Force Base, United States
| | - Lisa A Brenner
- Departments of Psychiatry, Neurology, and Physical Medicine & Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States
| | - Aline Dagdag
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States
| | - Christopher A Lowry
- Departments of Psychiatry, Neurology, and Physical Medicine & Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States.,Department of Integrative Physiology, Center for Neuroscience and Center for Microbial Exploration, University of Colorado Boulder, Boulder, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, United States
| | - Yogesh Dwivedi
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Alabama, United States
| | - Teodor T Postolache
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, United States.,Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Aurora, United States.,Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, United States.,Mental Illness Research, Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 5, VA Capitol Health Care Network, Baltimore, United States
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19
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Swietnicki W, Caspi R. Prediction of Selected Biosynthetic Pathways for the Lipopolysaccharide Components in Porphyromonas gingivalis. Pathogens 2021; 10:pathogens10030374. [PMID: 33804654 PMCID: PMC8003790 DOI: 10.3390/pathogens10030374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022] Open
Abstract
Porphyromonas gingivalis is an oral human pathogen. The bacterium destroys dental tissue and is a serious health problem worldwide. Experimental data and bioinformatic analysis revealed that the pathogen produces three types of lipopolysaccharides (LPS): normal (O-type), anionic (A-type), and capsular (K-type). The enzymes involved in the production of all three types of lipopolysaccharide have been largely identified for the first two and partially for the third type. In the current work, we use bioinformatics tools to predict biosynthetic pathways for the production of the normal (O-type) lipopolysaccharide in the W50 strain Porphyromonas gingivalis and compare the pathway with other putative pathways in fully sequenced and completed genomes of other pathogenic strains. Selected enzymes from the pathway have been modeled and putative structures are presented. The pathway for the A-type antigen could not be predicted at this time due to two mutually exclusive structures proposed in the literature. The pathway for K-type antigen biosynthesis could not be predicted either due to the lack of structural data for the antigen. However, pathways for the synthesis of lipid A, its core components, and the O-type antigen ligase reaction have been proposed based on a combination of experimental data and bioinformatic analyses. The predicted pathways are compared with known pathways in other systems and discussed. It is the first report in the literature showing, in detail, predicted pathways for the synthesis of selected LPS components for the model W50 strain of P. gingivalis.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, L. Hirszfeld Institute of Immunology and Experimental Therapy of PAS, ul. R. Weigla 12, 53-114 Wroclaw, Poland
- Correspondence:
| | - Ron Caspi
- Artificial Intelligence Center, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493, USA;
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20
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Baek DH, Lee SH. Characteristics of Treponema denticola lipooligosaccharide in presence of hemin and quorum-sensing molecule. Arch Oral Biol 2021; 124:105062. [PMID: 33524879 DOI: 10.1016/j.archoralbio.2021.105062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/22/2020] [Accepted: 01/15/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVES The study aimed to examine the diverse bioactivity of lipooligosaccharide extracted from T. denticola cultured in the presence of hemin and quorum-sensing inhibitor. DESIGN T. denticola was cultured in the presence or absence hemin or 2(5 H)-furanone, and lipooligosaccharide from T. denticola cultured in various conditions was extracted using an extraction kit. To investigate bioactivity of the lipooligosaccharide, human gingival fibroblasts (HGFs) were treated with the extracted lipooligosaccharide in the presence or absence of Tannerella forsythia lipopolysaccharide. The induction of cytokine expressions was investigated by real-time RT-PCR and ELISA, and the signaling pathway was examined by immunoblotting. To investigate antagonistic mechanisms of the lipooligosaccharide, HGFs were cotreated with fluorescence-labeled T. forsythia lipopolysaccharide and the extracted lipooligosaccharide. Binding of T. forsythia lipopolysaccharide to the cell was analyzed by a flow cytometer. RESULTS Lipooligosaccharide induced a low level of cytokine expression at high concentration of hemin or 2(5 H)-furanone. Lipooligosaccharide extracted from T. denticola cultured in higher concentration of hemin and 2(5 H)-furanone had a greater inhibitory effect on induction of cytokine expression by T. forsythia lipopolysaccharide. Further, lipooligosaccharide inhibited the activation of NF-κB and mitogen-activated protein kinase signaling pathways by T. forsythia lipopolysaccharide. Lipooligosaccharide inhibited the binding of T. forsythia lipopolysaccharide to HGFs in the presence of CD14 and LBP. CONCLUSIONS The characteristics of T. denticola lipooligosaccharide may be altered by bacterial communication and host factors.
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Affiliation(s)
- Dong-Heon Baek
- Department of Oral Microbiology and Immunology, College of Dentistry, Dankook University, Cheonan, Republic of Korea
| | - Sung-Hoon Lee
- Department of Oral Microbiology and Immunology, College of Dentistry, Dankook University, Cheonan, Republic of Korea.
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21
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Microbial Lipid A Remodeling Controls Cross-Presentation Efficiency and CD8 T Cell Priming by Modulating Dendritic Cell Function. Infect Immun 2021; 89:IAI.00335-20. [PMID: 33257533 DOI: 10.1128/iai.00335-20] [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: 06/07/2020] [Accepted: 11/10/2020] [Indexed: 12/18/2022] Open
Abstract
The majority of Gram-negative bacteria elicit a potent immune response via recognition of lipid A expressed on the outer bacterial membrane by the host immune receptor Toll-like receptor 4 (TLR4). However, some Gram-negative bacteria evade detection by TLR4 or alter the outcome of TLR4 signaling by modification of lipid A species. Although the role of lipid A modifications on host innate immunity has been examined in some detail, it is currently unclear how lipid A remodeling influences host adaptive immunity. One prototypic Gram-negative bacterium that modifies its lipid A structure is Porphyromonas gingivalis, an anaerobic pathobiont that colonizes the human periodontium and induces chronic low-grade inflammation that is associated with periodontal disease as well as a number of systemic inflammatory disorders. P. gingivalis produces dephosphorylated and deacylated lipid A structures displaying altered activities at TLR4. Here, we explored the functional role of P. gingivalis lipid A modifications on TLR4-dependent innate and adaptive immune responses in mouse bone marrow-derived dendritic cells (BMDCs). We discovered that lipid A 4'-phosphate removal is required for P. gingivalis to evade BMDC-dependent proinflammatory cytokine responses and markedly limits the bacterium's capacity to induce beta interferon (IFN-β) production. In addition, lipid A 4'-phosphatase activity prevents canonical bacterium-induced delay in antigen degradation, which leads to inefficient antigen cross-presentation and a failure to cross-prime CD8 T cells specific for a P. gingivalis-associated antigen. We propose that lipid A modifications produced by this bacterium alter host TLR4-dependent adaptive immunity to establish chronic infections associated with a number of systemic inflammatory disorders.
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22
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Kim AR, Lim YK, Kook JK, Bak EJ, Yoo YJ. Lipopolysaccharides of Fusobacterium nucleatum and Porphyromonas gingivalis increase RANKL-expressing neutrophils in air pouches of mice. Lab Anim Res 2021; 37:5. [PMID: 33407938 PMCID: PMC7789191 DOI: 10.1186/s42826-020-00080-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/27/2020] [Indexed: 11/10/2022] Open
Abstract
Increases of neutrophils and osteoclasts are pathological changes of periodontitis. RANKL is an osteoclast differentiation factor. The effect of periodontopathogen LPS on RANKL-expressing neutrophils has not been clarified yet. We evaluated numerical changes of RANKL-expressing neutrophils in air pouches of mice injected with LPSs of Fusobacterium nucleatum and Porphyromonas gingivalis. Mice with air pouches were assigned into saline (C)-, E. coli LPS- (Ec LPS)-, F. nucleatum LPS (Fn LPS)-, P. gingivalis LPS (Pg LPS)-, and Fn LPS and Pg LPS (Fn + Pg LPS)-injected groups. CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils in blood and air pouch exudates were determined by flow cytometry. In blood, compared to the C group, the Fn LPS group showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils whereas the Pg LPS group showed no significant differences. These increases in the Fn LPS group were not different to those in the Ec LPS group. In exudates, Fn LPS and Pg LPS groups showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils compared to the C group. Increased levels in the Fn LPS group were not different to those in the Ec LPS group, but Pg LPS group was lower than those in the Ec LPS group. In blood and exudates, the Fn + Pg LPS group showed no difference in levels of these neutrophils compared to the Ec LPS group. LPSs of F. nucleatum and P. gingivalis increased RANKL-expressing neutrophils although the degrees of increases were different. These suggest that periodontopathogen LPS can act as a stimulant to increase RANKL-expressing neutrophils.
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Affiliation(s)
- Ae Ri Kim
- Department of Oral Biology, College of Dentistry, Yonsei University, Seoul, Republic of Korea
- Department of Applied Life Science, The Graduate School, Yonsei University, Seoul, Republic of Korea
- BK21 PLUS Project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Yun Kyong Lim
- Korean Collection for Oral Microbiology and Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju, Republic of Korea
| | - Joong-Ki Kook
- Korean Collection for Oral Microbiology and Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju, Republic of Korea
| | - Eun-Jung Bak
- Department of Oral Biology, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
| | - Yun-Jung Yoo
- Department of Oral Biology, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
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Kamarajan P, Ateia I, Shin JM, Fenno JC, Le C, Zhan L, Chang A, Darveau R, Kapila YL. Periodontal pathogens promote cancer aggressivity via TLR/MyD88 triggered activation of Integrin/FAK signaling that is therapeutically reversible by a probiotic bacteriocin. PLoS Pathog 2020; 16:e1008881. [PMID: 33002094 PMCID: PMC7529280 DOI: 10.1371/journal.ppat.1008881] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
Epidemiological studies reveal significant associations between periodontitis and oral cancer. However, knowledge about the contribution of periodontal pathogens to oral cancer and potential regulatory mechanisms involved is limited. Previously, we showed that nisin, a bacteriocin and commonly used food preservative, reduced oral cancer tumorigenesis and extended the life expectancy in tumor-bearing mice. In addition, nisin has antimicrobial effects on key periodontal pathogens. Thus, the purpose of this study was to test the hypothesis that key periodontal pathogens (Porphyromonas gingivalis, Treponema denticola, and Fusobacterium nucleatum) promote oral cancer via specific host-bacterial interactions, and that bacteriocin/nisin therapy may modulate these responses. All three periodontal pathogens enhanced oral squamous cell carcinoma (OSCC) cell migration, invasion, tumorsphere formation, and tumorigenesis in vivo, without significantly affecting cell proliferation or apoptosis. In contrast, oral commensal bacteria did not affect OSCC cell migration. Pathogen-enhanced OSCC cell migration was mediated via integrin alpha V and FAK activation, since stably blocking alpha V or FAK expression abrogated these effects. Nisin inhibited these pathogen-mediated processes. Further, Treponema denticola induced TLR2 and 4 and MyD88 expression. Stable suppression of MyD88 significantly inhibited Treponema denticola-induced FAK activation and abrogated pathogen-induced migration. Together, these data demonstrate that periodontal pathogens contribute to a highly aggressive cancer phenotype via crosstalk between TLR/MyD88 and integrin/FAK signaling. Nisin can modulate these pathogen-mediated effects, and thus has therapeutic potential as an antimicrobial and anti-tumorigenic agent.
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Affiliation(s)
- Pachiyappan Kamarajan
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA, United States of America
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, United States of America
| | - Islam Ateia
- Department of Oral Medicine and Periodontology, Mansoura University, Mansoura, Egypt
| | - Jae M. Shin
- Department of Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, United States of America
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, United States of America
| | - J. Christopher Fenno
- Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann arbor, MI, United States of America
| | - Charles Le
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA, United States of America
| | - Ling Zhan
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA, United States of America
| | - Ana Chang
- Department of Periodontics, Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, United States of America
| | - Richard Darveau
- Department of Periodontics, Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, United States of America
| | - Yvonne L. Kapila
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, CA, United States of America
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, United States of America
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Chopra A, Bhat SG, Sivaraman K. Porphyromonas gingivalis adopts intricate and unique molecular mechanisms to survive and persist within the host: a critical update. J Oral Microbiol 2020; 12:1801090. [PMID: 32944155 PMCID: PMC7482874 DOI: 10.1080/20002297.2020.1801090] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 12/17/2022] Open
Abstract
is an obligate, asaccharolytic, gram-negative bacteria commonly associated with increased periodontal and systemic inflammation. P. gingivalis is known to survive and persist within the host tissues as it modulates the entire ecosystem by either engineering its environment or modifying the host's immune response. It interacts with various host receptors and alters signaling pathways of inflammation, complement system, cell cycle, and apoptosis. P. gingivalis is even known to induce suicidal cell death of the host and other microbes in its vicinity with the emergence of pathobiont species. Recently, new molecular and immunological mechanisms and virulence factors of P. gingivalis that increase its chance of survival and immune evasion within the host have been discovered. Thus, the present paper aims to provide a consolidated update on the new intricate and unique molecular mechanisms and virulence factors of P. gingivalis associated with its survival, persistence, and immune evasion within the host.
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Affiliation(s)
- Aditi Chopra
- Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Subraya G. Bhat
- College of Dentistry, Imam Abdul Rahman Faisal University, Dammam, KSA
| | - Karthik Sivaraman
- Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
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Behm C, Blufstein A, Abhari SY, Koch C, Gahn J, Schäffer C, Moritz A, Rausch-Fan X, Andrukhov O. Response of Human Mesenchymal Stromal Cells from Periodontal Tissue to LPS Depends on the Purity but Not on the LPS Source. Mediators Inflamm 2020; 2020:8704896. [PMID: 32714091 PMCID: PMC7352132 DOI: 10.1155/2020/8704896] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 05/05/2020] [Accepted: 06/08/2020] [Indexed: 12/16/2022] Open
Abstract
Human periodontal ligament stromal cells (hPDLSCs) and gingival mesenchymal stromal cells (hGMSCs) are resident mesenchymal stromal cells (MSCs) of the periodontal tissue. The lipopolysaccharide (LPS) from Porphyromonas gingivalis is structurally distinct from that of other Gram-negative bacteria, and earlier studies linked this structural difference to a distinct virulence activity and the ability to activate toll-like receptor 2 (TLR-2), besides TLR-4 as commonly occurring upon LPS challenge. Later studies, in contrast, argue that TLR-2 activation by P. gingivalis LPS is due to lipoprotein contamination. In the present study, we aimed to define the influence of structure versus purity of P. gingivalis LPS on the immune response of hPDLSCs and hGMSCs. Cells were stimulated with commercially available "standard" P. gingivalis LPS, "ultrapure" P. gingivalis LPS, or "ultrapure" Escherichia coli LPS, and the expression of interleukin- (IL-) 8, IL-6, monocyte chemoattractant protein- (MCP-) 1, TLR-2, and TLR-4 was evaluated. The contribution of TLR-4 to the LPS-induced response was assessed using the specific TLR-4 inhibitor TAK-242. "Standard" P. gingivalis LPS induced significantly higher IL-8, IL-6, and MCP-1 production compared to the "ultrapure" LPS preparations, with no significant difference detectable for "ultrapure" LPS from P. gingivalis and E. coli. By using TAK-242, the response of hPDLSCs and hGMSCs to "ultrapure" LPS preparations was effectively inhibited to the levels comparable to those of nonstimulated controls. In contrast, high levels of response to "standard" LPS were observed, even in the presence of TAK-242. Our data show that the response of MSCs from periodontal tissue to LPS depends more on the purity of the LPS preparation than on the LPS source. Even a small amount of contaminating lipoproteins can drastically enhance the hPDLSCs' and hGMSCs; responsiveness to P. gingivalis LPS, which might also contribute to the progression of periodontal disease.
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Affiliation(s)
- Christian Behm
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Alice Blufstein
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Setareh Younes Abhari
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Christoph Koch
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Johannes Gahn
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Christina Schäffer
- Department of NanoBiotechnology/NanoGlycobiology Unit, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Andreas Moritz
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Xiaohui Rausch-Fan
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Oleh Andrukhov
- Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
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Application of the In Vitro HoxB8 Model System to Characterize the Contributions of Neutrophil-LPS Interaction to Periodontal Disease. Pathogens 2020; 9:pathogens9070530. [PMID: 32630208 PMCID: PMC7399906 DOI: 10.3390/pathogens9070530] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/21/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
(1) Background: Studying neutrophils in vitro is difficult since these cells are terminally differentiated and are easily activated during isolation. At the same time, most of the available model cell lines are associated with certain limitations, such as functional deficiency or a lack of expression of surface markers characteristic of neutrophils. P. gingivalis is a periodontopathogen that causes dysbiosis in subgingival bacterial biofilm. This triggers the accumulation of functional neutrophils in the periodontium. However, until now, the specific effects of P. gingivalis-derived lipopolysaccharide on neutrophil functions have not been analyzed. (2) Methods: The impact of two variants of commercially available P. gingivalis endotoxin on neutrophil functions was tested using the HoxB8 in vitro system that is well suited to analyze neutrophil response to different stimuli in a controlled manner. (3) Results: The Standard P. gingivalis lipopolysaccharide (LPS), known to activate cells through Toll-like receptor 2 (TLR2)- and Toll-like receptor 4 (TLR4)-dependent pathways, prolonged neutrophil survival and exhibited pro-inflammatory effects. In contrast, Ultrapure LPS, binding exclusively to TLR4, neither protected neutrophils from apoptosis, nor induced an inflammatory response. (4) Conclusion: Two variants of P. gingivalis-derived LPS elicited effects on neutrophils and, based on the obtained results, we concluded that the engagement of both TLR2 and TLR4 is required for the manipulation of survival and the stimulation of immune responses of HoxB8 neutrophils.
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Metronidazole-Treated Porphyromonas gingivalis Persisters Invade Human Gingival Epithelial Cells and Perturb Innate Responses. Antimicrob Agents Chemother 2020; 64:AAC.02529-19. [PMID: 32205352 DOI: 10.1128/aac.02529-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/01/2020] [Indexed: 11/20/2022] Open
Abstract
Periodontitis as a biofilm-associated inflammatory disease is highly prevalent worldwide. It severely affects oral health and yet closely links to systemic diseases like diabetes and cardiovascular disease. Porphyromonas gingivalis as a "keystone" periodontopathogen drives the shift of microbe-host symbiosis to dysbiosis and critically contributes to the pathogenesis of periodontitis. Persisters represent a tiny subset of biofilm-associated microbes highly tolerant to lethal treatment of antimicrobials, and, notably, metronidazole-tolerant P. gingivalis persisters have recently been identified by our group. This study further explored the interactive profiles of metronidazole-treated P. gingivalis persisters (M-PgPs) with human gingival epithelial cells (HGECs). P. gingivalis cells (ATCC 33277) at stationary phase were treated with a lethal dosage of metronidazole (100 μg/ml, 6 h) for generating M-PgPs. The interaction of M-PgPs with HGECs was assessed by microscopy, flow cytometry, cytokine profiling, and quantitative PCR (qPCR). We demonstrated that the overall morphology and ultracellular structure of M-PgPs remained unchanged. Importantly, M-PgPs maintained the capabilities to adhere to and invade HGECs. Moreover, M-PgPs significantly suppressed proinflammatory cytokine expression in HGECs at a level comparable to that seen with the untreated P. gingivalis cells, through the thermosensitive components. The present report reveals that P. gingivalis persisters induced by lethal treatment of antibiotics were able to maintain their capabilities to adhere to and invade human gingival epithelial cells and to perturb the innate host responses. Novel strategies and approaches need to be developed for tackling P. gingivalis and favorably modulating the dysregulated immunoinflammatory responses for oral/periodontal health and general well-being.
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28
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Vicencio E, Cordero EM, Cortés BI, Palominos S, Parra P, Mella T, Henrríquez C, Salazar N, Monasterio G, Cafferata EA, Murgas P, Vernal R, Cortez C. Aggregatibacter Actinomycetemcomitans Induces Autophagy in Human Junctional Epithelium Keratinocytes. Cells 2020; 9:E1221. [PMID: 32423042 PMCID: PMC7290389 DOI: 10.3390/cells9051221] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 12/23/2022] Open
Abstract
The adverse environmental conditions found in the periodontium during periodontitis pathogenesis stimulate local autophagy responses, mainly due to a continuous inflammatory response against the dysbiotic subgingival microbiome. The junctional epithelium represents the main site of the initial interaction between the host and the dysbiotic biofilm. Here, we investigated the role of autophagy in junctional epithelium keratinocytes (JEKs) in response to Aggregatibacter actinomycetemcomitans or its purified lipopolysaccharides (LPS). Immunofluorescence confocal analysis revealed an extensive nuclear translocation of transcription factor EB (TFEB) and consequently, an increase in autophagy markers and LC3-turnover assessed by immunoblotting and qRT-PCR. Correspondingly, challenged JEKs showed a punctuate cytosolic profile of LC3 protein contrasting with the diffuse distribution observed in untreated controls. Three-dimensional reconstructions of confocal images displayed a close association between intracellular bacteria and LC3-positive vesicles. Similarly, a close association between autophagic vesicles and the protein p62 was observed in challenged JEKs, indicating that p62 is the main adapter protein recruited during A. actinomycetemcomitans infection. Finally, the pharmacological inhibition of autophagy significantly increased the number of bacteria-infected cells as well as their death, similar to treatment with LPS. Our results indicate that A. actinomycetemcomitans infection induces autophagy in JEKs, and this homeostatic process has a cytoprotective effect on the host cells during the early stages of infection.
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Affiliation(s)
- Emiliano Vicencio
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- Center for Integrative Biology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (B.I.C.); (P.M.)
| | - Esteban M. Cordero
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- Parasitology Section, Instituto de Salud Pública de Chile, Avenida Marathon 1000, Ñuñoa 7780050, Chile
| | - Bastián I. Cortés
- Center for Integrative Biology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (B.I.C.); (P.M.)
| | - Sebastián Palominos
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Dentistry, Faculty of Science, Universidad Mayor, Avenida Libertador Bernardo O’higgins 2013, Huechuraba 8580745, Chile
| | - Pedro Parra
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Dentistry, Faculty of Science, Universidad Mayor, Avenida Libertador Bernardo O’higgins 2013, Huechuraba 8580745, Chile
| | - Tania Mella
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Medical Technology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile
| | - Constanza Henrríquez
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Medical Technology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile
| | - Nelda Salazar
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Medical Technology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile
| | - Gustavo Monasterio
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Sergio Livingstone Pohlhammer 943, Independencia 8380492, Chile; (G.M.); (E.A.C.)
| | - Emilio A. Cafferata
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Sergio Livingstone Pohlhammer 943, Independencia 8380492, Chile; (G.M.); (E.A.C.)
- Department of Periodontology, School of Dentistry, Universidad Científica del Sur, Av. Paseo de la República 5544, Lima 15074, Peru
| | - Paola Murgas
- Center for Integrative Biology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (B.I.C.); (P.M.)
| | - Rolando Vernal
- Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Sergio Livingstone Pohlhammer 943, Independencia 8380492, Chile; (G.M.); (E.A.C.)
| | - Cristian Cortez
- Center for Genomics and Bioinformatics, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile; (E.V.); (E.M.C.); (S.P.); (P.P.); (T.M.); (C.H.); (N.S.)
- School of Dentistry, Faculty of Science, Universidad Mayor, Avenida Libertador Bernardo O’higgins 2013, Huechuraba 8580745, Chile
- School of Medical Technology, Faculty of Science, Universidad Mayor, Camino la Pirámide 5750, Huechuraba 8580745, Chile
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Hajishengallis G, Diaz PI. Porphyromonas gingivalis: Immune subversion activities and role in periodontal dysbiosis. ACTA ACUST UNITED AC 2020; 7:12-21. [PMID: 33344104 DOI: 10.1007/s40496-020-00249-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Purpose of review This review summarizes mechanisms by which Porphyromonas gingivalis interacts with community members and the host so that it can persist in the periodontium under inflammatory conditions that drive periodontal disease. Recent findings Recent advances indicate that, in great part, the pathogenicity of P. gingivalis is dependent upon its ability to establish residence in the subgingival environment and to subvert innate immunity in a manner that uncouples the nutritionally favorable (for the bacteria) inflammatory response from antimicrobial pathways. While the initial establishment of P. gingivalis is dependent upon interactions with early colonizing bacteria, the immune subversion strategies of P. gingivalis in turn benefit co-habiting species. Summary Specific interspecies interactions and subversion of the host response contribute to the emergence and persistence of dysbiotic communities and are thus targets of therapeutic approaches for the treatment of periodontitis.
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Affiliation(s)
- George Hajishengallis
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, 240 S. 40 Street, Philadelphia, PA 19104, USA
| | - Patricia I Diaz
- Division of Periodontology, Department of Oral Health and Diagnostic Sciences, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
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30
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Martinho FC, de Rabello DGD, Ferreira LL, Nascimento GG. Participation of endotoxin in root canal infections: A systematic review and meta-analysis. Eur J Dent 2019; 11:398-406. [PMID: 28932155 PMCID: PMC5594974 DOI: 10.4103/ejd.ejd_84_17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This systematic review and meta-analysis aimed to evaluate the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features in patients with endodontic infection. Electronic searches were performed on Medline/PubMed, Embase, Cochrane Library, Scielo, Science Direct, Web of Knowledge and Scopus databases for identification of relevant studies published up to December 2016. Grey literature was searched in Google Scholar. The selected literature was reviewed independently by two authors. Clinical studies evaluating the levels of endotoxin and the presence of clinical and radiographic features were included in this review. In order to determine the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features meta-analyses were performed. Among the 385 articles identified in the initial search, 30 were included for full-text appraisal and only eight studies met the inclusion criteria for this systematic review. Meta-analysis revealed that individuals having teeth with tenderness to percussion (TTP) (P = 0.04; I2 57%) and previous episode of pain (PEP) (P = 0.001; I2 81%) had higher levels of endotoxin than their counterparts. Size of radiographic lesion >2 mm (P = 0.02; I2 68%) and presence of root canal exudation (EX) (P = 0.0007; I2 0%) were associated with higher levels of endotoxin. This systematic review and meta-analyses provided a strong evidence that endotoxin are related with the presence of clinical signs/symptoms and radiographic features in patients with endodontic infection.
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Affiliation(s)
- Frederico Canato Martinho
- Department of Restorative Dentistry, São José dos Campos Dental School, State University of São Paulo, São Paulo
| | | | - Luciana Louzada Ferreira
- Department of Restorative Dentistry, São José dos Campos Dental School, State University of São Paulo, São Paulo
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31
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Chopra A, Sivaraman K. An update on possible pathogenic mechanisms of periodontal pathogens on renal dysfunction. Crit Rev Microbiol 2019; 45:514-538. [PMID: 30729832 DOI: 10.1080/1040841x.2018.1553847] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 07/17/2018] [Accepted: 11/18/2018] [Indexed: 12/14/2022]
Abstract
Periodontitis is a potential source of permanent systemic inflammation that initiates renal dysfunction and contributes to the development of chronic kidney diseases (CKDs). Although numerous studies have confirmed the bidirectional role of periodontal infection and renal inflammation, no literature has yet highlighted the sophisticated pathogenic mechanisms by which periodontal pathogens, particularly Porphynomonas Gingivalis, induce renal dysfunction and contributed in the development of CKDs. The present review aims to critically analyze and highlight the novel pathogenesis of periodontitis induced CKDs.
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Affiliation(s)
- Aditi Chopra
- Department of Periodontology, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Karthik Sivaraman
- Department of Prosthodontics, Manipal College of Dental Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
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32
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Immunological Pathways Triggered by Porphyromonas gingivalis and Fusobacterium nucleatum: Therapeutic Possibilities? Mediators Inflamm 2019; 2019:7241312. [PMID: 31341421 PMCID: PMC6612971 DOI: 10.1155/2019/7241312] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/28/2019] [Accepted: 05/19/2019] [Indexed: 02/06/2023] Open
Abstract
Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) are Gram-negative anaerobic bacteria possessing several virulence factors that make them potential pathogens associated with periodontal disease. Periodontal diseases are chronic inflammatory diseases of the oral cavity, including gingivitis and periodontitis. Periodontitis can lead to tooth loss and is considered one of the most prevalent diseases worldwide. P. gingivalis and F. nucleatum possess virulence factors that allow them to survive in hostile environments by selectively modulating the host's immune-inflammatory response, thereby creating major challenges to host cell survival. Studies have demonstrated that bacterial infection and the host immune responses are involved in the induction of periodontitis. The NLRP3 inflammasome and its effector molecules (IL-1β and caspase-1) play roles in the development of periodontitis. We and others have reported that the purinergic P2X7 receptor plays a role in the modulation of periodontal disease and intracellular pathogen control. Caspase-4/5 (in humans) and caspase-11 (in mice) are important effectors for combating bacterial pathogens via mediation of cell death and IL-1β release. The exact molecular events of the host's response to these bacteria are not fully understood. Here, we review innate and adaptive immune responses induced by P. gingivalis and F. nucleatum infections and discuss the possibility of manipulations of the immune response as therapeutic strategies. Given the global burden of periodontitis, it is important to develop therapeutic targets for the prophylaxis of periodontopathogen infections.
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Identification of PGN_1123 as the Gene Encoding Lipid A Deacylase, an Enzyme Required for Toll-Like Receptor 4 Evasion, in Porphyromonas gingivalis. J Bacteriol 2019; 201:JB.00683-18. [PMID: 30782639 DOI: 10.1128/jb.00683-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/12/2019] [Indexed: 01/09/2023] Open
Abstract
Removal of one acyl chain from bacterial lipid A by deacylase activity is a mechanism used by many pathogenic bacteria to evade the host's Toll-like receptor 4 (TLR4)-mediated innate immune response. In Porphyromonas gingivalis, a periodontal pathogen, lipid A deacylase activity converts a majority of the initially synthesized penta-acylated lipid A, a TLR4 agonist, to tetra-acylated structures, which effectively evade TLR4 sensing by being either inert or antagonistic at TLR4. In this paper, we report successful identification of the gene that encodes the P. gingivalis lipid A deacylase enzyme. This gene, PGN_1123 in P. gingivalis 33277, is highly conserved within P. gingivalis, and putative orthologs are phylogenetically restricted to the Bacteroidetes phylum. Lipid A of ΔPGN_1123 mutants is penta-acylated and devoid of tetra-acylated structures, and the mutant strain provokes a strong TLR4-mediated proinflammatory response, in contrast to the negligible response elicited by wild-type P. gingivalis Heterologous expression of PGN_1123 in Bacteroides thetaiotaomicron promoted lipid A deacylation, confirming that PGN_1123 encodes the lipid A deacylase enzyme.IMPORTANCE Periodontitis, commonly referred to as gum disease, is a chronic inflammatory condition that affects a large proportion of the population. Porphyromonas gingivalis is a bacterium closely associated with periodontitis, although how and if it is a cause for the disease are not known. It has a formidable capacity to dampen the host's innate immune response, enabling its persistence in diseased sites and triggering microbial dysbiosis in animal models of infection. P. gingivalis is particularly adept at evading the host's TLR4-mediated innate immune response by modifying the structure of lipid A, the TLR4 ligand. In this paper, we report identification of the gene encoding lipid A deacylase, a key enzyme that modifies lipid A to TLR4-evasive structures.
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Díaz-Zúñiga J, Muñoz Y, Melgar-Rodríguez S, More J, Bruna B, Lobos P, Monasterio G, Vernal R, Paula-Lima A. Serotype b of Aggregatibacter actinomycetemcomitans triggers pro-inflammatory responses and amyloid beta secretion in hippocampal cells: a novel link between periodontitis and Alzheimer´s disease? J Oral Microbiol 2019; 11:1586423. [PMID: 31044031 PMCID: PMC6484476 DOI: 10.1080/20002297.2019.1586423] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/31/2019] [Accepted: 02/13/2019] [Indexed: 01/18/2023] Open
Abstract
Introduction: Previous reports have proposed that Periodontal disease (PDis) predisposes to Alzheimer's disease (AD), both highly prevalent pathologies among the elderly. The bacteria Aggregatibacter actinomycetemcomitans (Aa), associated with the most aggressive forms of PDis, are classified in different serotypes with distinct virulence according to the antigenicity of their lipopolysaccharide (LPS). Methods: Here, we determined the effects of purified LPS, from serotypes a, b or c of Aa, on primary cultures of microglia or mixed hippocampal cells. Results: We found that both culture types exhibited higher levels of inflammatory cytokines (IL-1β, IL-6 and TNFα) when treated with serotype b-LPS, compared with controls, as quantified by qPCR and/or ELISA. Also, cultures treated with serotype a-LPS displayed increased mRNA levels of the modulatory cytokines IL-4 and IL-10. Mixed hippocampal cultures treated with serotype b-LPS exhibited severe neuronal morphological changes and displayed increased levels of secreted Aβ1-42 peptide. These results indicate that LPS from different Aa serotypes triggers discriminatory immune responses, which differentially affect primary hippocampal cells. Conclusion: Altogether, our results show that treatment with serotype b-LPS triggers the secretion of proinflammatory cytokines by microglia, induces neurite shrinking, and increases the extracellular Aβ1-42 levels, all features strongly associated with the etiology of AD.
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Affiliation(s)
- J Díaz-Zúñiga
- Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Y Muñoz
- Aging Cellular Laboratory, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - S Melgar-Rodríguez
- Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - J More
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - B Bruna
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - P Lobos
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - G Monasterio
- Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
| | - R Vernal
- Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Dentistry Unit, Faculty of Health Sciences, Universidad Autónoma de Chile, Temuco, Chile
| | - A Paula-Lima
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
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Gomes BPFDA, Herrera DR. Etiologic role of root canal infection in apical periodontitis and its relationship with clinical symptomatology. Braz Oral Res 2018; 32:e69. [PMID: 30365610 DOI: 10.1590/1807-3107bor-2018.vol32.0069] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 06/12/2018] [Indexed: 12/16/2022] Open
Abstract
Evidence shows the polymicrobial etiology of endodontic infections, in which bacteria and their products are the main agents for the development, progression, and dissemination of apical periodontitis. Microbial factors in necrotic root canals (e.g., endotoxin) may spread into apical tissue, evoking and supporting a chronic inflammatory load. Thus, apical periodontitis is the result of the complex interplay between microbial factors and host defense against invasion of periradicular tissues. This review of the literature aims to discuss the complex network between endodontic infectious content and host immune response in apical periodontitis. A better understanding of the relationship of microbial factors with clinical symptomatology is important to establish appropriate therapeutic procedures for a more predictable outcome of endodontic treatment.
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Affiliation(s)
| | - Daniel Rodrigo Herrera
- Universidade Estadual de Campinas -Unicamp, Piracicaba Dental School, Department of Restorative Dentistry, Piracicaba, SP, Brazil
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Li P, Fung YME, Yin X, Seneviratne CJ, Che CM, Jin L. Controlled cellular redox, repressive hemin utilization and adaptive stress responses are crucial to metronidazole tolerance of Porphyromonas gingivalis
persisters. J Clin Periodontol 2018; 45:1211-1221. [DOI: 10.1111/jcpe.13002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/24/2018] [Accepted: 08/01/2018] [Indexed: 11/26/2022]
Affiliation(s)
- Peng Li
- Faculty of Dentistry; The University of Hong Kong; Hong Kong China
- Department of Periodontology; Peking University School and Hospital of Stomatology; Beijing China
| | - Yi-Man Eva Fung
- State Key Laboratory of Synthetic Chemistry and Chemical Biology Center; Department of Chemistry; The University of Hong Kong; Hong Kong China
| | - Xiaohui Yin
- Department of Periodontology; First Clinical Division; Peking University School and Hospital of Stomatology; Beijing China
| | | | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry and Chemical Biology Center; Department of Chemistry; The University of Hong Kong; Hong Kong China
| | - Lijian Jin
- Faculty of Dentistry; The University of Hong Kong; Hong Kong China
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Serotype a of Aggregatibacter actinomycetemcomitans down-regulates the increased serotype b-induced cytokine and chemokine production in dendritic cells. Arch Oral Biol 2018; 93:155-162. [DOI: 10.1016/j.archoralbio.2018.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 06/04/2018] [Accepted: 06/09/2018] [Indexed: 12/15/2022]
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Molteni M, Bosi A, Rossetti C. The Effect of Cyanobacterial LPS Antagonist (CyP) on Cytokines and Micro-RNA Expression Induced by Porphyromonas gingivalis LPS. Toxins (Basel) 2018; 10:toxins10070290. [PMID: 30012943 PMCID: PMC6071223 DOI: 10.3390/toxins10070290] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/06/2018] [Accepted: 07/11/2018] [Indexed: 12/31/2022] Open
Abstract
Lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg-LPS) is a key bacterial structure involved in the maintenance of a chronic pro-inflammatory environment during periodontitis. Similar to other gram-negative LPS, Pg-LPS induces the release of pro-inflammatory cytokines through interaction with Toll-Like Receptor 4 (TLR4) and is able to stimulate negative TLR4 regulatory pathways, such as those involving microRNA (miRNA). In this work, we employed CyP, an LPS with TLR4-MD2 antagonist activity obtained from the cyanobacterium Oscillatoria planktothrix FP1, to study the effects on pro-inflammatory cytokine production and miRNA expression in human monocytic THP-1 cells stimulated with Pg-LPS or E. coli LPS (Ec-LPS). Results showed that CyP inhibited TNF-α, IL-1β and IL-8 expression more efficiently when co-incubated with Pg-LPS rather than with Ec-LPS. The inhibition of pro-inflammatory cytokine production was maintained even when CyP was added 2 h after LPS. The analysis of the effects of CyP on miRNA expression showed that, although being an antagonist, CyP did not inhibit miR-146a induced by Pg-LPS or Ec-LPS, whereas it significantly inhibited miR-155 only in the cultures stimulated with Ec-LPS. These results suggest that CyP may modulate the pro-inflammatory response induced by Pg-LPS, not only by blocking TLR4-MD2 complex, but also by preserving miR-146a expression.
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Affiliation(s)
- Monica Molteni
- Laboratorio di Biologia Applicata, Dipartimento di Medicina e Chirurgia, Università degli Studi dell'Insubria, Via Dunant, 3-21100 Varese, Italy.
| | - Annalisa Bosi
- Laboratorio di Biologia Applicata, Dipartimento di Medicina e Chirurgia, Università degli Studi dell'Insubria, Via Dunant, 3-21100 Varese, Italy.
| | - Carlo Rossetti
- Laboratorio di Biologia Applicata, Dipartimento di Medicina e Chirurgia, Università degli Studi dell'Insubria, Via Dunant, 3-21100 Varese, Italy.
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Olsen I, Singhrao SK, Potempa J. Citrullination as a plausible link to periodontitis, rheumatoid arthritis, atherosclerosis and Alzheimer's disease. J Oral Microbiol 2018; 10:1487742. [PMID: 29963294 PMCID: PMC6022223 DOI: 10.1080/20002297.2018.1487742] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 05/29/2018] [Indexed: 12/12/2022] Open
Abstract
Periodontitis, rheumatoid arthritis (RA), atherosclerosis (AS), and Alzheimer’s disease (AD) are examples of complex human diseases with chronic inflammatory components in their etiologies. The initial trigger of inflammation that progresses to these diseases remains unresolved. Porphyromonas gingivalis is unique in its ability to secrete the P. gingivalis-derived peptidyl arginine deiminase (PPAD) and consequently offers a plausible and exclusive link to these diseases through enzymatic conversion of arginine to citrulline. Citrullination is a post-translational enzymatic modification of arginine residues in proteins formed as part of normal physiological processes. However, PPAD has the potential to modify self (bacterial) and host proteins by deimination of arginine amino acid residues, preferentially at the C-terminus. Migration of P. gingivalis and/or its secreted PPAD into the bloodstream opens up the possibility that this enzyme will citrullinate proteins at disparate body sites. Citrullination is associated with the pathogenesis of multifactorial diseases such as RA and AD, which have an elusive external perpetrator as they show epidemiological associations with periodontitis. Therefore, PPAD deserves some prominence as an external antigen, in at least, a subset of RA and AD cases, with as yet unidentified, immune/genetic vulnerabilities.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Sim K Singhrao
- Dementia and Neurodegeneration Research Group, Faculty of Clinical and Biomedical Sciences, University of Central Lancashire, Preston, UK
| | - Jan Potempa
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Microbiology, Jagiellonian University, Kraków, Poland.,Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA
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Marinho ACS, To TT, Darveau RP, Gomes BPFA. Detection and function of lipopolysaccharide and its purified lipid A after treatment with auxiliary chemical substances and calcium hydroxide dressings used in root canal treatment. Int Endod J 2018; 51:1118-1129. [PMID: 29505121 DOI: 10.1111/iej.12920] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 02/27/2018] [Indexed: 02/02/2023]
Abstract
AIM To investigate the influence of auxiliary chemical substances (ACSs) and calcium hydroxide [Ca(OH)2 ] dressings on lipopolysaccharides (LPS)/lipid A detection and its functional ability in activating Toll-like receptor 4 (TLR4). METHODOLOGY Fusobacterium nucleatum pellets were exposed to antimicrobial agents as following: (i) ACS: 5.25%, 2.5% and 1% sodium hypochlorite solutions (NaOCl), 2% chlorhexidine (CHX) (gel and solution) and 17% ethylenediaminetetraacetic acid (EDTA); (ii) intracanal medicament: Ca(OH)2 paste for various periods (1 h, 24 h, 7 days, 14 days and 30 days); (iii) combination of substances: (a) 2.5% NaOCl (1 h), followed by 17% EDTA (3 min) and Ca(OH)2 (7 days); (b) 2% CHX (1 h), afterwards, 17% EDTA (3 min) followed by Ca(OH)2 (7 days). Saline solution was the control. Samples were submitted to LPS isolation and lipid A purification. Lipid A peaks were assessed by matrix-assisted laser desorption ionization time-of-flight mass spectrom (MALDI-TOF MS) whilst LPS bands by SDS-PAGE separation and silver staining. TLR4 activation determined LPS function activities. Statistical comparisons were carried out using one-way anova with Tukey-Kramer post-hoc tests at the 5% significance level. RESULTS Matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of control lipid A demonstrated the ion cluster at mass/charge (m/z) 1882 and an intense band in SDS-PAGE followed by silver staining of control LPS. In parallel, LPS control induced a robust TLR4 activation when compared to ACS (P ≤ .001). 5.25% NaOCl treatment led to the absence of lipid A peaks and LPS bands, whilst no changes occurred to lipid A/LPS after treatment with others ACS. Concomitantly, 5.25% NaOCl-treated LPS did not activate TLR4 (P < .0001). As for Ca(OH)2 , lipid A was not detected by MALDI-TOF nor by gel electrophoresis within 24 h. LPS treated with Ca(OH)2 was a weak TLR4 activator (P < .0001). From 24 h onwards, no significant differences were found amongst the time periods tested (P > 0.05). The addition of Ca(OH)2 for 7 days to cells treated either with 2.5% NaOCl or 2% CHX led to the absence of lipid A peaks and LPS bands, leading to a lower activation of TLR4. CONCLUSION 5.25% NaOCl and Ca(OH)2 dressings from 24 h onwards were able to induce both, loss of lipid A peaks and no detection of LPS bands, rendering a diminished immunostimulatory activity through TLR4.
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Affiliation(s)
- A C S Marinho
- Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas (UNICAMP), Piracicaba, SP, Brazil
| | - T T To
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA, USA
| | - R P Darveau
- Department of Periodontics, University of Washington School of Dentistry, Seattle, WA, USA
| | - B P F A Gomes
- Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas (UNICAMP), Piracicaba, SP, Brazil
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Olsen I, Singhrao SK. Importance of heterogeneity in Porhyromonas gingivalis lipopolysaccharide lipid A in tissue specific inflammatory signalling. J Oral Microbiol 2018; 10:1440128. [PMID: 29503705 PMCID: PMC5827638 DOI: 10.1080/20002297.2018.1440128] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/09/2018] [Indexed: 02/08/2023] Open
Abstract
Lipopolysaccharide (LPS) of Porphyromonas gingivalis exists in at least two known forms, O-LPS and A-LPS. A-LPS shows heterogeneity in which two isoforms designated LPS1,435/1,449 and LPS1,690 appear responsible for tissue-specific immune signalling pathways activation and increased virulence. The modification of lipid A to tetra-acylated1,435/1,449 and/or penta-acylated1,690 fatty acids indicates poor growth conditions and bioavailability of hemin. Hemin protects P. gingivalis from serum resistance and the lipid A serves as a site for its binding. The LPS1,435/1,449 and LPS1,690 isoforms can produce opposite effects on the human Toll-like receptors (TLR) TLR2 and TLR4 activation. This enables P. gingivalis to select the conditions for its entry, survival, and that of its co-habiting species in the host, orchestrating its virulence to control innate immune pathway activation and biofilm dysbiosis. This review describes a number of effects that LPS1,435/1,449 and LPS1,690 can exert on the host tissues such as deregulation of the innate immune system, subversion of host cell autophagy, regulation of outer membrane vesicle production, and adverse effects on pregnancy outcome. The ability to change its LPS1,435/1,449 and/or LPS1,690 composition may enable P. gingivalis to paralyze local pro-inflammatory cytokine production, thereby gaining access to its primary location in periodontal tissue.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Sim K. Singhrao
- Dementia and Neurodegenerative Diseases Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, UK
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Harding A, Gonder U, Robinson SJ, Crean S, Singhrao SK. Exploring the Association between Alzheimer's Disease, Oral Health, Microbial Endocrinology and Nutrition. Front Aging Neurosci 2017; 9:398. [PMID: 29249963 PMCID: PMC5717030 DOI: 10.3389/fnagi.2017.00398] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 11/17/2017] [Indexed: 12/21/2022] Open
Abstract
Longitudinal monitoring of patients suggests a causal link between chronic periodontitis and the development of Alzheimer’s disease (AD). However, the explanation of how periodontitis can lead to dementia remains unclear. A working hypothesis links extrinsic inflammation as a secondary cause of AD. This hypothesis suggests a compromised oral hygiene leads to a dysbiotic oral microbiome whereby Porphyromonas gingivalis, a keystone periodontal pathogen, with its companion species, orchestrates immune subversion in the host. Brushing and chewing on teeth supported by already injured soft tissues leads to bacteremias. As a result, a persistent systemic inflammatory response develops to periodontal pathogens. The pathogens, and the host’s inflammatory response, subsequently lead to the initiation and progression of multiple metabolic and inflammatory co-morbidities, including AD. Insufficient levels of essential micronutrients can lead to microbial dysbiosis through the growth of periodontal pathogens such as demonstrated for P. gingivalis under low hemin bioavailability. An individual’s diet also defines the consortium of microbial communities that take up residency in the oral and gastrointestinal (GI) tract microbiomes. Their imbalance can lead to behavioral changes. For example, probiotics enriched in Lactobacillus genus of bacteria, when ingested, exert some anti-inflammatory influence through common host/bacterial neurochemicals, both locally, and through sensory signaling back to the brain. Early life dietary behaviors may cause an imbalance in the host/microbial endocrinology through a dietary intake incompatible with a healthy GI tract microbiome later in life. This imbalance in host/microbial endocrinology may have a lasting impact on mental health. This observation opens up an opportunity to explore the mechanisms, which may underlie the previously detected relationship between diet, oral/GI microbial communities, to anxiety, cognition and sleep patterns. This review suggests healthy diet based interventions that together with improved life style/behavioral changes may reduce and/or delay the incidence of AD.
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Affiliation(s)
- Alice Harding
- Dementia & Neurodegenerative Diseases Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, United Kingdom
| | - Ulrike Gonder
- Nutritionist, Freelance Science Writer, Hünstetten, Germany
| | - Sarita J Robinson
- Faculty of Science and Technology, School of Psychology, University of Central Lancashire, Preston, United Kingdom
| | - StJohn Crean
- Dementia & Neurodegenerative Diseases Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, United Kingdom
| | - Sim K Singhrao
- Dementia & Neurodegenerative Diseases Research Group, Faculty of Clinical and Biomedical Sciences, School of Dentistry, University of Central Lancashire, Preston, United Kingdom
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The making of a miscreant: tobacco smoke and the creation of pathogen-rich biofilms. NPJ Biofilms Microbiomes 2017; 3:26. [PMID: 29081982 PMCID: PMC5655325 DOI: 10.1038/s41522-017-0033-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/29/2017] [Accepted: 09/25/2017] [Indexed: 02/03/2023] Open
Abstract
We have previously reported that oral biofilms in clinically healthy smokers are pathogen-rich, and that this enrichment occurs within 24 h of biofilm formation. The present investigation aimed to identify a mechanism by which smoking creates this altered community structure. By combining in vitro microbial–mucosal interface models of commensal (consisting of Streptococcus oralis, Streptococcus sanguis, Streptococcus mitis, Actinomyces naeslundii, Neisseria mucosa and Veillonella parvula) and pathogen-rich (comprising S.oralis, S.sanguis, S.mitis, A.naeslundii, N.mucosa and V.parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, Filifactor alocis, Dialister pneumosintes, Selenonomas sputigena, Selenominas noxia, Catonella morbi, Parvimonas micra and Tannerella forsythia) communities with metatranscriptomics, targeted proteomics and fluorescent microscopy, we demonstrate that smoke exposure significantly downregulates essential metabolic functions within commensal biofilms, while significantly increasing expression of virulence genes, notably lipopolysaccharide (LPS), flagella and capsule synthesis. By contrast, in pathogen-rich biofilms several metabolic pathways were over-expressed in response to smoke exposure. Under smoke-rich conditions, epithelial cells mounted an early and amplified pro-inflammatory and oxidative stress response to these virulence-enhanced commensal biofilms, and a muted early response to pathogen-rich biofilms. Commensal biofilms also demonstrated early and widespread cell death. Similar results were observed when smoke-free epithelial cells were challenged with smoke-conditioned biofilms, but not vice versa. In conclusion, our data suggest that smoke-induced transcriptional shifts in commensal biofilms triggers a florid pro-inflammatory response, leading to early commensal death, which may preclude niche saturation by these beneficial organisms. The cytokine-rich, pro-oxidant, anaerobic environment sustains inflammophilic bacteria, and, in the absence of commensal antagonism, may promote the creation of pathogen-rich biofilms in smokers. Tobacco smoke inhibits the metabolism of beneficial bacteria in biofilms, while activating specific genes in pathogenic bacteria. This suggests a mechanism to explain how smoking quickly leads to the formation of damaging biofilms in the mouth and respiratory tract. Purnima Kumar and colleagues at Ohio State University, USA studied the effect of tobacco smoke on cultured biofilms used to model those that form on mucous membranes. They detected specific and varied changes in the activity of genes, proteins and metabolism that allowed pathogenic bacteria to displace beneficial “commensal” bacteria. The research suggests the transition toward pathogen-rich biofilms may contribute to the health effects of smoking by causing increased inflammation of mucous membranes and the production of damaging oxidant chemicals. Further research should investigate the chemical constituents of smoke responsible for these effects.
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Differential Regulation of Mas-Related G Protein-Coupled Receptor X2-Mediated Mast Cell Degranulation by Antimicrobial Host Defense Peptides and Porphyromonas gingivalis Lipopolysaccharide. Infect Immun 2017; 85:IAI.00246-17. [PMID: 28694291 DOI: 10.1128/iai.00246-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 07/03/2017] [Indexed: 12/14/2022] Open
Abstract
Porphyromonas gingivalis is a keystone pathogen that contributes to periodontal pathogenesis by disrupting host-microbe homeostasis and promoting dysbiosis. The virulence of P. gingivalis likely reflects an alteration in the lipid A composition of its lipopolysaccharide (LPS) from the penta-acylated (PgLPS1690) to the tetra-acylated (PgLPS1435/1449) form. Mast cells play an important role in periodontitis, but the mechanisms of their activation and regulation remain unknown. The expression of epithelium- and neutrophil-derived host defense peptides (HDPs) (LL-37 and human β-defensin-3), which activate mast cells via Mas-related G protein-coupled receptor X2 (MRGPRX2), is increased in periodontitis. We found that MRGPRX2-expressing mast cells are present in normal gingiva and that their numbers are elevated in patients with chronic periodontitis. Furthermore, HDPs stimulated degranulation in a human mast cell line (LAD2) and in RBL-2H3 cells stably expressing MRGPRX2 (RBL-MRGPRX2). PgLPS1690 caused substantial inhibition of HDP-induced mast cell degranulation, but PgLPS1435/1449 had no effect. A fluorescently labeled HDP (FAM-LL-37) bound to RBL-MRGPRX2 cells, and PgLPS1690 inhibited this binding, but PgLPS1435/1449 had no effect. These findings suggest that low-level inflammation induced by HDP/MRGPRX2-mediated mast cell degranulation contributes to gingival homeostasis but that sustained inflammation due to elevated levels of both HDPs and MRGPRX2-expressing mast cells promotes periodontal disease. Furthermore, differential regulation of HDP-induced mast cell degranulation by PgLPS1690 and PgLPS1435/1449 may contribute to the modulation of disease progression.
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Reyes L, Phillips P, Wolfe B, Golos TG, Walkenhorst M, Progulske-Fox A, Brown M. Porphyromonas gingivalis and adverse pregnancy outcome. J Oral Microbiol 2017; 10:1374153. [PMID: 29291034 PMCID: PMC5646603 DOI: 10.1080/20002297.2017.1374153] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/23/2017] [Indexed: 01/12/2023] Open
Abstract
Porphyromonas gingivalis is a Gram-negative, anaerobic bacterium considered to be an important pathogen of periodontal disease that is also implicated in adverse pregnancy outcome (APO). Until recently, our understanding of the role of P. gingivalis in APO has been limited and sometimes contradictory. The purpose of this review is to provide an overview of past and current research on P. gingivalis that addresses some of the controversies concerning the role of this organism in the pathogenesis of APO.
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Affiliation(s)
- Leticia Reyes
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, WI, USA
| | - Priscilla Phillips
- Microbiology & Immunology, A.T. Still University of Health Sciences, Kirksville College of Osteopathic Medicine, Kirksville, MO, USA
| | - Bryce Wolfe
- Wisconsin National Primate Research Center, University of Wisconsin - Madison, Madison, WI, USA.,Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, WI, USA
| | - Thaddeus G Golos
- Wisconsin National Primate Research Center, University of Wisconsin - Madison, Madison, WI, USA.,Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, WI, USA
| | - Molly Walkenhorst
- Microbiology & Immunology, A.T. Still University of Health Sciences, Kirksville College of Osteopathic Medicine, Kirksville, MO, USA
| | - Ann Progulske-Fox
- Department of Oral Microbiology, Center for Molecular Microbiology, University of Florida, Gainesville, FL, USA
| | - Mary Brown
- Infectious Disease and Immunology, College of Veterinary Medicine and D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville, FL, USA
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Miller DP, Hutcherson JA, Wang Y, Nowakowska ZM, Potempa J, Yoder-Himes DR, Scott DA, Whiteley M, Lamont RJ. Genes Contributing to Porphyromonas gingivalis Fitness in Abscess and Epithelial Cell Colonization Environments. Front Cell Infect Microbiol 2017; 7:378. [PMID: 28900609 PMCID: PMC5581868 DOI: 10.3389/fcimb.2017.00378] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022] Open
Abstract
Porphyromonas gingivalis is an important cause of serious periodontal diseases, and is emerging as a pathogen in several systemic conditions including some forms of cancer. Initial colonization by P. gingivalis involves interaction with gingival epithelial cells, and the organism can also access host tissues and spread haematogenously. To better understand the mechanisms underlying these properties, we utilized a highly saturated transposon insertion library of P. gingivalis, and assessed the fitness of mutants during epithelial cell colonization and survival in a murine abscess model by high-throughput sequencing (Tn-Seq). Transposon insertions in many genes previously suspected as contributing to virulence showed significant fitness defects in both screening assays. In addition, a number of genes not previously associated with P. gingivalis virulence were identified as important for fitness. We further examined fitness defects of four such genes by generating defined mutations. Genes encoding a carbamoyl phosphate synthetase, a replication-associated recombination protein, a nitrosative stress responsive HcpR transcription regulator, and RNase Z, a zinc phosphodiesterase, showed a fitness phenotype in epithelial cell colonization and in a competitive abscess infection. This study verifies the importance of several well-characterized putative virulence factors of P. gingivalis and identifies novel fitness determinants of the organism.
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Affiliation(s)
- Daniel P Miller
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Justin A Hutcherson
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Yan Wang
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Zuzanna M Nowakowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Jan Potempa
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland.,Malopolska Centre of Biotechnology, Jagiellonian UniversityKrakow, Poland
| | | | - David A Scott
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Marvin Whiteley
- Department of Molecular Biosciences, University of Texas at AustinAustin, TX, United States
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
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Porphyromonas gulae Activates Unprimed and Gamma Interferon-Primed Macrophages via the Pattern Recognition Receptors Toll-Like Receptor 2 (TLR2), TLR4, and NOD2. Infect Immun 2017. [PMID: 28630066 DOI: 10.1128/iai.00282-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Porphyromonas gulae is an anaerobic, Gram-negative coccobacillus that has been associated with periodontal disease in companion animals. The aims of this study were to analyze the ligation of pattern recognition receptors by P. gulae and the subsequent activation of macrophages. Exposure of HEK cells transfected with Toll-like receptors (TLRs) or NOD-like receptors to P. gulae resulted in the ligation of TLR2, TLR4, and NOD2. The effects of this engagement of receptors were investigated by measuring the synthesis of nitric oxide (NO), CD86 expression, and inflammatory cytokine production by wild-type, TLR2-/-, and TLR4-/- macrophages. The addition of P. gulae to unprimed and gamma interferon (IFN-γ)-primed (M1 phenotype) macrophages significantly increased the surface expression of CD86, but only M1 macrophages produced nitric oxide. P. gulae-induced expression of CD86 on unprimed macrophages was dependent on both TLR2 and TLR4, but CD86 expression and NO production in M1 macrophages were only TLR2 dependent. P. gulae induced an increase in secretion of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p70, IL-13, tumor necrosis factor alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1α (MIP-1α) by M1 macrophages compared to that by unprimed controls. Among these cytokines, secretion of IL-6 and TNF-α by M1 macrophages was dependent on either TLR2 or TLR4. Our data indicate that TLR2 and TLR4 are important for P. gulae activation of unprimed macrophages and that activation and effector functions induced in M1 macrophages by P. gulae are mainly dependent on TLR2. In conclusion, P. gulae induces a strong TLR2-dependent inflammatory M1 macrophage response which may be important in establishing the chronic inflammation associated with periodontal disease in companion animals.
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Li M, Zhang C, Jin L, Matsuo K, Yang Y. Porphyromonas gingivalis lipopolysaccharide regulates ephrin/Eph signalling in human periodontal ligament fibroblasts. J Periodontal Res 2017; 52:913-921. [PMID: 28590061 PMCID: PMC5600103 DOI: 10.1111/jre.12463] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2017] [Indexed: 12/29/2022]
Abstract
Objective EphrinA2‐EphA2 and ephrinB2‐EphB4 critically engage in bidirectional signalling to modulate alveolar bone remodelling. The present study aimed to investigate the effects of lipopolysaccharides (LPS) derived from Porphyromonas gingivalis on ephrin/Eph signalling in periodontal ligament fibroblasts (PDLFs). Material and Methods The primary cultured PDLFs were incubated in the absence (as a control) or presence of P. gingivalisLPS at 0.001‐10 μg/mL for 24 hours. The PDLFs were then stimulated with P. gingivalisLPS at the optimal concentration (0.1 μg/mL) for different periods (6‐48 hours). The expression of ephrinA2, ephrinB2, EphA2 and EphB4 was assessed by quantitative reverse‐transcription real‐time polymerase chain reaction and western blotting. The osteoblastic markers alkaline phosphatase, osteocalcin and Runt‐related transcription factor 2 (Runx2), and the osteoclastogenesis‐related factors receptor activator of nuclear factor kappa‐B ligand (RANKL) and osteoprotegerin were also evaluated. Results The ephrinA2 and EphA2 expression was upregulated and EphB4 expression was downregulated by stimulation of P. gingivalisLPS. EphrinA2 mRNA expression in the PDLFs was significantly upregulated from 12 to 48 hours (P<.05), whereas EphA2 exhibited no change for the first 24 hours, after which there was a significant increase at 48 hours (P<.05). EphB4 exhibited lower mRNA expression at 12 and 24 hours than did the control (P<.05), but the change was insignificant at 48 hours. In contrast, the expression of ephrinB2 remained unchanged. The expressions of ephrinA2, EphA2, ephrinB2 and EphB4 at the protein level showed a similar pattern to that at the mRNA level. The expression of Runx2 and osteocalcin significantly decreased, whereas that of RANKL/osteoprotegerin increased. Conclusion The present study suggest that P. gingivalisLPS would contribute to a dysregulation of bone remodelling, whereby ephrinA2/EphA2 expression is stimulated and EphB4 expression is inhibited.
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Affiliation(s)
- M Li
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
| | - C Zhang
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
| | - L Jin
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
| | - K Matsuo
- Keio University School of Medicine, Tokyo, Japan
| | - Y Yang
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
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Rangarajan M, Aduse-Opoku J, Hashim A, McPhail G, Luklinska Z, Haurat MF, Feldman MF, Curtis MA. LptO (PG0027) Is Required for Lipid A 1-Phosphatase Activity in Porphyromonas gingivalis W50. J Bacteriol 2017; 199:e00751-16. [PMID: 28320881 PMCID: PMC5424252 DOI: 10.1128/jb.00751-16] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/09/2017] [Indexed: 01/27/2023] Open
Abstract
Porphyromonas gingivalis produces outer membrane vesicles (OMVs) rich in virulence factors, including cysteine proteases and A-LPS, one of the two lipopolysaccharides (LPSs) produced by this organism. Previous studies had suggested that A-LPS and PG0027, an outer membrane (OM) protein, may be involved in OMV formation. Their roles in this process were examined by using W50 parent and the ΔPG0027 mutant strains. Inactivation of PG0027 caused a reduction in the yield of OMVs. Lipid A from cells and OMVs of P. gingivalis W50 and the ΔPG0027 mutant strains were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Lipid A from W50 cells contained bis-P-pentaacyl, mono-P-pentaacyl, mono-P-tetraacyl, non-P-pentaacyl, and non-P-tetraacyl species, whereas lipid A from ΔPG0027 mutant cells contained only phosphorylated species; nonphosphorylated species were absent. MALDI-TOF/TOF tandem MS of mono-P-pentaacyl (m/z 1,688) and mono-P-tetraacyl (m/z 1,448) lipid A from ΔPG0027 showed that both contained lipid A 1-phosphate, suggesting that the ΔPG0027 mutant strain lacked lipid A 1-phosphatase activity. The total phosphatase activities in the W50 and the ΔPG0027 mutant strains were similar, whereas the phosphatase activity in the periplasm of the ΔPG0027 mutant was lower than that in W50, supporting a role for PG0027 in lipid A dephosphorylation. W50 OMVs were enriched in A-LPS, and its lipid A did not contain nonphosphorylated species, whereas lipid A from the ΔPG0027 mutant (OMVs and cells) contained similar species. Thus, OMVs in P. gingivalis are apparently formed in regions of the OM enriched in A-LPS devoid of nonphosphorylated lipid A. Conversely, dephosphorylation of lipid A through a PG0027-dependent process is required for optimal formation of OMVs. Hence, the relative proportions of nonphosphorylated and phosphorylated lipid A appear to be crucial for OMV formation in this organism.IMPORTANCE Gram-negative bacteria produce outer membrane vesicles (OMVs) by "blebbing" of the outer membrane (OM). OMVs can be used offensively as delivery systems for virulence factors and defensively to aid in the colonization of a host and in the survival of the bacterium in hostile environments. Earlier studies using the oral anaerobe Porphyromonas gingivalis as a model organism to study the mechanism of OMV formation suggested that the OM protein PG0027 and one of the two lipopolysaccharides (LPSs) synthesized by this organism, namely, A-LPS, played important roles in OMV formation. We suggest a novel mechanism of OMV formation in P. gingivalis involving dephosphorylation of lipid A of A-LPS controlled/regulated by PG0027, which causes destabilization of the OM, resulting in blebbing and generation of OMVs.
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Affiliation(s)
- Minnie Rangarajan
- Institute of Dentistry, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, United Kingdom
| | - Joseph Aduse-Opoku
- Institute of Dentistry, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, United Kingdom
| | - Ahmed Hashim
- Institute of Dentistry, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, United Kingdom
| | - Graham McPhail
- Cellular Pathology, Barts Health NHS Trust, London, United Kingdom
| | - Zofia Luklinska
- Nanovision Centre, Advanced Electron Microscopy, School of Engineering & Materials Science, Queen Mary University of London, London, United Kingdom
| | - M Florencia Haurat
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Mario F Feldman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael A Curtis
- Institute of Dentistry, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, United Kingdom
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Sochalska M, Potempa J. Manipulation of Neutrophils by Porphyromonas gingivalis in the Development of Periodontitis. Front Cell Infect Microbiol 2017; 7:197. [PMID: 28589098 PMCID: PMC5440471 DOI: 10.3389/fcimb.2017.00197] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/04/2017] [Indexed: 12/31/2022] Open
Abstract
The pathogenesis of the chronic periodontal disease is associated with a skewed host inflammatory response to periodontal pathogens, such as Porphyromonas gingivalis, that accounts for the majority of periodontal tissue damage. Neutrophils are the most abundant leukocytes in periodontal pockets and depending on the stage of the disease, also plentiful PMNs are present in the inflamed gingival tissue and the gingival crevice. They are the most efficient phagocytes and eliminate pathogens by a variety of means, which are either oxygen-dependent or -independent. However, these secretory lethal weapons do not strictly discriminate between pathogens and host tissue. Current studies describe conflicting findings about neutrophil involvement in periodontal disease. On one hand literature indicate that hyper-reactive neutrophils are the main immune cell type responsible for this observed tissue damage and disease progression. Deregulation of neutrophil survival and functions, such as chemotaxis, migration, secretion of antimicrobial peptides or enzymes, and production of reactive oxygen species, contribute to observed tissue injury and the clinical signs of periodontal disease. On the other hand neutrophils deficiencies in patients and mice also result in periodontal phenotype. Therefore, P. gingivalis represents a periodontal pathogen that manipulates the immune responses of PMNs, employing several virulence factors, such as gingipains, serine proteases, lipid phosphatases, or fimbriae. This review will sum up studies devoted to understanding different strategies utilized by P. gingivalis to manipulate PMNs survival and functions in order to inhibit killing by a granular content, prolong inflammation, and gain access to nutrient resources.
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Affiliation(s)
- Maja Sochalska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland.,Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of LouisvilleLouisville, KY, United States
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