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Blancas-Luciano BE, Becker-Fauser I, Zamora-Chimal J, Jiménez-García L, Lara-Martínez R, Pérez-Torres A, González del Pliego M, Aguirre-Benítez EL, Fernández-Presas AM. Cystatin C: immunoregulation role in macrophages infected with Porphyromonas gingivalis. PeerJ 2024; 12:e17252. [PMID: 38708345 PMCID: PMC11067906 DOI: 10.7717/peerj.17252] [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: 08/09/2023] [Accepted: 03/26/2024] [Indexed: 05/07/2024] Open
Abstract
Background Periodontitis is a chronic infectious disease, characterized by an exacerbated inflammatory response and a progressive loss of the supporting tissues of the teeth. Porphyromonas gingivalis is a key etiologic agent in periodontitis. Cystatin C is an antimicrobial salivary peptide that inhibits the growth of P. gingivalis. This study aimed to evaluate the antimicrobial activity of this peptide and its effect on cytokine production, nitric oxide (NO) release, reactive oxygen species (ROS) production, and programmed cell death in human macrophages infected with P. gingivalis. Methods Monocyte-derived macrophages generated from peripheral blood were infected with P. gingivalis (MOI 1:10) and stimulated with cystatin C (2.75 µg/ml) for 24 h. The intracellular localization of P. gingivalis and cystatin C was determined by immunofluorescence and transmission electron microscopy (TEM). The intracellular antimicrobial activity of cystatin C in macrophages was assessed by counting Colony Forming Units (CFU). ELISA assay was performed to assess inflammatory (TNFα, IL-1β) and anti-inflammatory (IL-10) cytokines. The production of nitrites and ROS was analyzed by Griess reaction and incubation with 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA), respectively. Programmed cell death was assessed with the TUNEL assay, Annexin-V, and caspase activity was also determined. Results Our results showed that cystatin C inhibits the extracellular growth of P. gingivalis. In addition, this peptide is internalized in the infected macrophage, decreases the intracellular bacterial load, and reduces the production of inflammatory cytokines and NO. Interestingly, peptide treatment increased ROS production and substantially decreased bacterial-induced macrophage apoptosis. Conclusions Cystatin C has antimicrobial and immuno-regulatory activity in macrophages infected with P. gingivalis. These findings highlight the importance of understanding the properties of cystatin C for its possible therapeutic use against oral infections such as periodontitis.
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Affiliation(s)
- Blanca Esther Blancas-Luciano
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Circuito de Posgrados, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Departamento de Microbiología y Parasitologia, Facultad de Medicina, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Ingeborg Becker-Fauser
- Unidad de Investigación en Medicina Experimental, Hospital General de México, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jaime Zamora-Chimal
- Unidad de Investigación en Medicina Experimental, Hospital General de México, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Luis Jiménez-García
- Departamento de Biología Celular. Facultad de Ciencias, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Reyna Lara-Martínez
- Departamento de Biología Celular. Facultad de Ciencias, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Armando Pérez-Torres
- Departamento de Biología Celular y Tisular, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Margarita González del Pliego
- Departamento de Embriología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Elsa Liliana Aguirre-Benítez
- Departamento de Embriología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Ana María Fernández-Presas
- Departamento de Microbiología y Parasitologia, Facultad de Medicina, Ciudad Universitaria, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
- Centro de Investigación en Ciencias de la Salud, Huixquilucan, Universidad Anáhuac, Estado de México, México
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2
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Olczak T, Śmiga M, Antonyuk SV, Smalley JW. Hemophore-like proteins of the HmuY family in the oral and gut microbiome: unraveling the mystery of their evolution. Microbiol Mol Biol Rev 2024; 88:e0013123. [PMID: 38305743 PMCID: PMC10966948 DOI: 10.1128/mmbr.00131-23] [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] [Indexed: 02/03/2024] Open
Abstract
SUMMARY Heme (iron protoporphyrin IX, FePPIX) is the main source of iron and PPIX for host-associated pathogenic bacteria, including members of the Bacteroidota (formerly Bacteroidetes) phylum. Porphyromonas gingivalis, a keystone oral pathogen, uses a unique heme uptake (Hmu) system, comprising a hemophore-like protein, designated as the first member of the novel HmuY family. Compared to classical, secreted hemophores utilized by Gram-negative bacteria or near-iron transporter domain-based hemophores utilized by Gram-positive bacteria, the HmuY family comprises structurally similar proteins that have undergone diversification during evolution. The best characterized are P. gingivalis HmuY and its homologs from Tannerella forsythia (Tfo), Prevotella intermedia (PinO and PinA), Bacteroides vulgatus (Bvu), and Bacteroides fragilis (BfrA, BfrB, and BfrC). In contrast to the two histidine residues coordinating heme iron in P. gingivalis HmuY, Tfo, PinO, PinA, Bvu, and BfrA preferentially use two methionine residues. Interestingly, BfrB, despite conserved methionine residue, binds the PPIX ring without iron coordination. BfrC binds neither heme nor PPIX in keeping with the lack of conserved histidine or methionine residues used by other members of the HmuY family. HmuY competes for heme binding and heme sequestration from host hemoproteins with other members of the HmuY family to increase P. gingivalis competitiveness. The participation of HmuY in the host immune response confirms its relevance in relation to the survival of P. gingivalis and its ability to induce dysbiosis not only in the oral microbiome but also in the gut microbiome or other host niches, leading to local injuries and involvement in comorbidities.
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Affiliation(s)
- Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Svetlana V. Antonyuk
- Molecular Biophysics Group, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, the University of Liverpool, Liverpool, United Kingdom
| | - John W. Smalley
- Institute of Life Course and Medical Sciences, School of Dentistry, the University of Liverpool, Liverpool, United Kingdom
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3
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Abstract
Oral commensal streptococci are primary colonizers of the oral cavity. These streptococci produce many adhesins, metabolites, and antimicrobials that modulate microbial succession and diversity within the oral cavity. Often, oral commensal streptococci antagonize cariogenic and periodontal pathogens such as Streptococcus mutans and Porphyromonas gingivalis, respectively. Mechanisms of antagonism are varied and range from the generation of hydrogen peroxide, competitive metabolite scavenging, the generation of reactive nitrogen intermediates, and bacteriocin production. Furthermore, several oral commensal streptococci have been shown to alter the host immune response at steady state and in response to oral pathogens. Collectively, these features highlight the remarkable ability of oral commensal streptococci to regulate the structure and function of the oral microbiome. In this review, we discuss mechanisms used by oral commensal streptococci to interact with diverse oral pathogens, both physically and through the production of antimicrobials. Finally, we conclude by exploring the critical roles of oral commensal streptococci in modulating the host immune response and maintaining health and homeostasis.
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Affiliation(s)
- Joshua J. Baty
- Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Sara N. Stoner
- Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jessica A. Scoffield
- Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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4
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Zou R, Zhao L, Shen D, Wu Y. TrkA serves as a virulence modulator in Porphyromonas gingivalis by maintaining heme acquisition and pathogenesis. Front Cell Infect Microbiol 2022; 12:1012316. [PMID: 36405968 PMCID: PMC9666725 DOI: 10.3389/fcimb.2022.1012316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/12/2022] [Indexed: 01/25/2023] Open
Abstract
Periodontitis is an inflammatory disease of the supporting tissues of the teeth, with polymicrobial infection serving as the major pathogenic factor. As a periodontitis-related keystone pathogen, Porphyromonas gingivalis can orchestrate polymicrobial biofilm skewing into dysbiosis. Some metatranscriptomic studies have suggested that modulation of potassium ion uptake might serve as a signal enhancing microbiota nososymbiocity and periodontitis progression. Although the relationship between potassium transport and virulence has been elucidated in some bacteria, less is mentioned about the periodontitis-related pathogen. Herein, we centered on the virulence modulation potential of TrkA, the potassium uptake regulatory protein of P. gingivalis, and uncovered TrkA as the modulator in the heme acquisition process and in maintaining optimal pathogenicity in an experimental murine model of periodontitis. Hemagglutination and hemolytic activities were attenuated in the case of trkA gene loss, and the entire transcriptomic profiling revealed that the trkA gene can control the expression of genes in relation to electron transport chain activity and translation, as well as some transcriptional factors, including cdhR, the regulator of the heme uptake system hmuYR. Collectively, these results link the heme acquisition process to the potassium transporter, providing new insights into the role of potassium ion in P. gingivalis pathogenesis.
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Affiliation(s)
| | | | | | - Yafei Wu
- *Correspondence: Daonan Shen, ; Yafei Wu,
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5
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Insertional Inactivation and Gene Complementation of Prevotella intermedia Type IX Secretion System Reveals Its Indispensable Roles in Black Pigmentation, Hemagglutination, Protease Activity of Interpain A, and Biofilm Formation. J Bacteriol 2022; 204:e0020322. [PMID: 35862729 PMCID: PMC9380532 DOI: 10.1128/jb.00203-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Prevotella intermedia, a Gram-negative oral anaerobic bacterium, is frequently isolated from the periodontal pockets of patients with chronic periodontitis. In recent years, the involvement of the bacterium in respiratory tract infections as well as in oral infections has been revealed. P. intermedia possesses several potent virulence factors, such as cysteine proteinase interpain A encoded by the inpA gene. The genome of P. intermedia carries genes of the type IX secretion system (T9SS), which enables the translocation of virulence factors across the outer membrane in several pathogens belonging to the phylum Bacteroidetes; however, it is still unclear whether the T9SS is functional in this microorganism. Recently, we performed targeted mutagenesis in the strain OMA14 of P. intermedia. Here, we successfully obtained mutants deficient in inpA and the T9SS component genes porK and porT. None of the mutants exhibited protease activity of interpain A. The porK and porT mutants, but not the inpA mutant, showed defects in colony pigmentation, hemagglutination, and biofilm formation. We also obtained a complemented strain for the porK gene that recovered all the above abilities. These results indicate that T9SS functions in P. intermedia and that interpain A is one of the T9SS cargo proteins. IMPORTANCE The virulence factors of periodontal pathogens such as Prevotella intermedia have not been elucidated. Using our established procedure, we succeeded in generating type IX secretion system mutants and gene complementation strains that might transfer virulence factors to the bacterial surface. The generated strains clearly indicate that T9SS in P. intermedia is essential for colonial pigmentation, hemagglutination, and biofilm formation. These results indicated that interpain A is a T9SS cargo protein.
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Silver J, Al-Jaff G, Wilson MT, den Engelsen D, Fern GR, Ireland TG. Studies on the binding of nitrogenous bases to protoporphyrin IX iron(II) in aqueous solution at high pH values. J Biol Inorg Chem 2022; 27:297-313. [PMID: 35235042 PMCID: PMC8960585 DOI: 10.1007/s00775-022-01929-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/14/2022] [Indexed: 10/28/2022]
Abstract
Studies are reported on the formation of low-spin six-coordinate [Fe(PPIX)L2] complexes from iron(II) protoporphyrin where L is one of a series of nitrogenous ligands (aliphatic, aromatic or heterocyclic). The bonding constants have been determined by titration of the metal complex with these ligands and are compared in relation to previous studies. The adduct formation was monitored utilising optical spectroscopy. In addition, Mӧssbauer spectroscopic experiments were conducted to monitor the electronic environment around the central iron atom in these complexes. The two complementary spectroscopic methods indicated that all nitrogen ligands formed low-spin octahedral complexes. The magnitude of the overall binding constants (β2 values) are discussed and related to (a) the pKa values of the free ligands and (b) the Mössbauer parameter ΔEQ, which represents the quadrupole splitting of the haem iron. The β2 and ΔEQ values are also discussed in terms of the structure of the ligand. Cooperative binding was observed for nearly all the ligands with Hill coefficients close to 2 for iron(II) protoporphyrin; one of these ligands displayed a much greater affinity than any we previously studied, and this was a direct consequence of the structure of the ligand. Overall conclusions on these and previous studies are drawn in terms of aliphatic ligands versus aromatic ring structures and the absence or presence of sterically hindered nitrogen atoms. The implications of the work for the greater understanding of haem proteins in general and in particular how the nitrogenous ligand binding results are relevant to and aid the understanding of the binding of inhibitor molecules to the cytochrome P450 mono-oxygenases (for therapeutic purposes) are also discussed. Changes in the electronic absorption spectra of five-coordinate [Fe(II)(PPIX)(2-MeIm)] that occurred as the temperature was lowered from room temperature to 78° K.
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Affiliation(s)
- Jack Silver
- College of Engineering, Design and Physical Sciences, School of Engineering, Wolfson Centre for Materials Processing, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, Middlesex, UK
| | - Golzar Al-Jaff
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, Essex, UK.,Department of Chemistry, College of Education, Salahaddin University-Erbil, Erbil, Iraq
| | - Michael T Wilson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, Essex, UK
| | - Daniel den Engelsen
- College of Engineering, Design and Physical Sciences, School of Engineering, Wolfson Centre for Materials Processing, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, Middlesex, UK
| | - George R Fern
- College of Engineering, Design and Physical Sciences, School of Engineering, Wolfson Centre for Materials Processing, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, Middlesex, UK
| | - Terry G Ireland
- College of Engineering, Design and Physical Sciences, School of Engineering, Wolfson Centre for Materials Processing, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, Middlesex, UK.
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7
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Olsen I. Porphyromonas Gingivalis May Seek the Alzheimer's Disease Brain to Acquire Iron from Its Surplus. J Alzheimers Dis Rep 2021; 5:79-86. [PMID: 33681719 PMCID: PMC7903007 DOI: 10.3233/adr-200272] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Iron accumulates in the brain of subjects with Alzheimer’s disease (AD). Here it promotes the aggregation of amyloid-β plaques in which it is abundant. Iron induces amyloid-β neurotoxicity by damaging free radicals and causing oxidative stress in brain areas with neurodegeneration. It can also bind to tau in AD and enhance the toxicity of tau through co-localization with neurofibrillary tangles and induce accumulation of these tangles. Porphyromonas gingivalis is a key oral pathogen in the widespread biofilm-induced disease “chronic” periodontitis, and recently, has been suggested to have an important role in the pathogenesis of AD. P. gingivalis has an obligate requirement for iron. The current paper suggests that P. gingivalis seeks the AD brain, where it has been identified, to satisfy this need. If this is correct, iron chelators binding iron could have beneficial effects in the treatment of AD. Indeed, studies from both animal AD models and humans with AD have indicated that iron chelators, e.g., lactoferrin, can have such effects. Lactoferrin can also inhibit P. gingivalis growth and proteinases and its ability to form biofilm.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
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8
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Śmiga M, Olczak T. PgRsp Is a Novel Redox-Sensing Transcription Regulator Essential for Porphyromonas gingivalis Virulence. Microorganisms 2019; 7:microorganisms7120623. [PMID: 31795139 PMCID: PMC6955866 DOI: 10.3390/microorganisms7120623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022] Open
Abstract
Porphyromonas gingivalis is one of the etiological agents of chronic periodontitis. Both heme and oxidative stress impact expression of genes responsible for its survival and virulence. Previously we showed that P. gingivalis ferric uptake regulator homolog affects expression of a gene encoding a putative Crp/Fnr superfamily member, termed P. gingivalis redox-sensing protein (PgRsp). Although PgRsp binds heme and shows the highest similarity to proteins assigned to the CooA family, it could be a member of a novel, separate family of proteins with unknown function. Expression of the pgrsp gene is autoregulated and iron/heme dependent. Genes encoding proteins engaged in the oxidative stress response were upregulated in the pgrsp mutant (TO11) strain compared with the wild-type strain. The TO11 strain showed higher biomass production, biofilm formation, and coaggregation ability with Tannerella forsythia and Prevotella intermedia. We suggest that PgRsp may regulate production of virulence factors, proteases, Hmu heme acquisition system, and FimA protein. Moreover, we observed growth retardation of the TO11 strain under oxidative conditions and decreased survival ability of the mutant cells inside macrophages. We conclude that PgRsp protein may play a role in the oxidative stress response using heme as a ligand for sensing changes in redox status, thus regulating the alternative pathway of the oxidative stress response alongside OxyR.
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9
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Dou Y, Rutanhira H, Chen X, Mishra A, Wang C, Fletcher HM. Role of extracytoplasmic function sigma factor PG1660 (RpoE) in the oxidative stress resistance regulatory network of Porphyromonas gingivalis. Mol Oral Microbiol 2017; 33:89-104. [PMID: 29059500 DOI: 10.1111/omi.12204] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2017] [Indexed: 12/27/2022]
Abstract
In Porphyromonas gingivalis, the protein PG1660, composed of 174 amino acids, is annotated as an extracytoplasmic function (ECF) sigma factor (RpoE homologue-σ24). Because PG1660 can modulate several virulence factors and responds to environmental signals in P. gingivalis, its genetic properties were evaluated. PG1660 is co-transcribed with its downstream gene PG1659, and the transcription start site was identified as adenine residue 54-nucleotides upstream of the ATG translation start codon. In addition to binding its own promoter, using the purified rPG1660 and RNAP core enzyme from Escherichia coli with the PG1660 promoter DNA as template, the function of PG1660 as a sigma factor was demonstrated in an in vitro transcription assay. Transcriptome analyses of a P. gingivalis PG1660-defective isogenic mutant revealed that under oxidative stress conditions 176 genes including genes involved in secondary metabolism were downregulated more than two-fold compared with the parental strain. The rPG1660 protein also showed the ability to bind to the promoters of the highly downregulated genes in the PG1660-deficient mutant. As the ECF sigma factor PG0162 has a 29% identity with PG1660 and can modulate its expression, the cross-talk between their regulatory networks was explored. The expression profile of the PG0162PG1660-deficient mutant (P. gingivalis FLL356) revealed that the type IX secretion system genes and several virulence genes were downregulated under hydrogen peroxide stress conditions. Taken together, we have confirmed that PG1660 can function as a sigma factor, and plays an important regulatory role in the oxidative stress and virulence regulatory network of P. gingivalis.
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Affiliation(s)
- Y Dou
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - H Rutanhira
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - X Chen
- Department of Basic Sciences, School of Medicine, Center for Genomics, Loma Linda University, Loma Linda, CA, USA
| | - A Mishra
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - C Wang
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, USA.,Department of Basic Sciences, School of Medicine, Center for Genomics, Loma Linda University, Loma Linda, CA, USA
| | - H M Fletcher
- Division of Microbiology and Molecular Genetics, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, USA.,Institute of Oral Biology, Kyung Hee University, Seoul, Korea
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10
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Xu X, Tong T, Yang X, Pan Y, Lin L, Li C. Differences in survival, virulence and biofilm formation between sialidase-deficient and W83 wild-type Porphyromonas gingivalis strains under stressful environmental conditions. BMC Microbiol 2017; 17:178. [PMID: 28821225 PMCID: PMC5563019 DOI: 10.1186/s12866-017-1087-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 08/09/2017] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Porphyromonas gingivalis is a major causative pathogen of chronic periodontitis. Within the inflammatory microenvironment, there exists extreme pH values, elevated temperatures and oxidative stress. Pathogens adapt to these stressful environmental conditions by regulating the transcription of virulence genes, modifying themselves with macromolecules and by aggregating and entering into a biofilm growth phase. Our previous study showed that the P. gingivalis sialidase can help cells obtain sialic acid from the environment, which is used to modify macromolecules on the surface of P. gingivalis cells. In this study, we compared the survival, virulence factors and biofilm formation of a sialidase-deficient strain (ΔPG0352) and the wild-type P. gingivalis W83 strain under various pH values, temperatures and oxidative stress conditions to identify the roles of sialidase in the adaptation of P. gingivalis to stressful conditions. RESULTS Compared to the growth of the P. gingivalis W83 strain, the growth of the △PG0352 was more inhibited by oxidative stress (0.25 and 0.5 mM H2O2) and exhibited greater cell structure damage when treated with H2O2 as assessed by transmission electron microscopy. Both Lys-gingipain (Kgp) and Arg-gingipain (Rgp) activities were lower in the ΔPG0352 than those in the P. gingivalis W83 strain under all the assayed culture conditions. The lipopolysaccharide (LPS) activity of the W83 strain was higher than that of the ΔPG0352 under acidic conditions (pH 5.0), but no differences between the strains were observed under other conditions. Compared to the biofilms formed by P. gingivalis W83, those formed by the ΔPG0352 were decreased and discontinuous under acidic, alkaline and oxidative stress conditions. CONCLUSION Compared to the P. gingivalis W83 strain, the survival, virulence and biofilm formation of the ΔPG0352 were decreased under stressful environmental conditions.
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Affiliation(s)
- Xiaoyu Xu
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Tong Tong
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
- Department of Stomatology, Anshan Shuangshan Hospital, Anshan, Liaoning China
| | - Xue Yang
- Shenyang Medical College, Shenyang, Liaoning China
| | - Yaping Pan
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Li Lin
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
| | - Chen Li
- Department of Periodontics, School of Stomatology, China Medical University, No.117 Nanjing North Street, Heping District, Shenyang, Liaoning China
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11
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Dysbiosis by neutralizing commensal mediated inhibition of pathobionts. Sci Rep 2016; 6:38179. [PMID: 27897256 PMCID: PMC5126660 DOI: 10.1038/srep38179] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/04/2016] [Indexed: 12/16/2022] Open
Abstract
Dysbiosis in the periodontal microbiota is associated with the development of periodontal diseases. Little is known about the initiation of dysbiosis. It was hypothesized that some commensal bacteria suppress the outgrowth of pathobionts by H2O2 production. However, serum and blood components released due to inflammation can neutralize this suppressive effect, leading to the initiation of dysbiosis. Agar plate, dual-species and multi-species ecology experiments showed that H2O2 production by commensal bacteria decreases pathobiont growth and colonization. Peroxidase and blood components neutralize this inhibitory effect primarily by an exogenous peroxidase activity without stimulating growth and biofilm formation of pathobionts directly. In multi-species environments, neutralization of H2O2 resulted in 2 to 3 log increases in pathobionts, a hallmark for dysbiosis. Our data show that in oral biofilms, commensal species suppress the amounts of pathobionts by H2O2 production. Inflammation can neutralize this effect and thereby initiates dysbiosis by allowing the outgrowth of pathobionts.
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12
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Pessoa L, Galvão V, Damante C, Sant'Ana ACP. Removal of black stains from teeth by photodynamic therapy: clinical and microbiological analysis. BMJ Case Rep 2015; 2015:bcr2015212276. [PMID: 26701991 PMCID: PMC4691879 DOI: 10.1136/bcr-2015-212276] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2015] [Indexed: 11/03/2022] Open
Abstract
Black-pigmented bacteria (BPB) are Gram-negative anaerobic, non-motile, proteolytic rods strongly implicated in the pathogenesis of periodontal disease. Although pigments are produced in vitro, black pigmentation is rarely found clinically. However, it may compromise aesthetics and contribute to gingival inflammation. The aim of this report is to describe a clinical case of a 10-year-old boy showing black pigmentation covering all teeth and to propose an alternative therapy for removal of black pigmentation, based on photodynamic therapy (PDT). In order to perform microbiological analysis, plaque samples were collected before and after PDT, and analysed by real-time-PCR (RT-PCR). The results showed a significant reduction in BPB levels after therapy, along with clinical evidence of absence of black pigmentation and reduction in gingival bleeding, although the plaque index remained unaltered. This case showed that PDT is effective for eliminating black pigmentation caused by BPB, without recurrence during a follow-up period of 7 months.
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Affiliation(s)
- Larissa Pessoa
- Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | | | - Carla Damante
- Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
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13
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Leclerc J, Rosenfeld E, Trainini M, Martin B, Meuric V, Bonnaure-Mallet M, Baysse C. The Cytochrome bd Oxidase of Porphyromonas gingivalis Contributes to Oxidative Stress Resistance and Dioxygen Tolerance. PLoS One 2015; 10:e0143808. [PMID: 26629705 PMCID: PMC4668044 DOI: 10.1371/journal.pone.0143808] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 11/10/2015] [Indexed: 11/18/2022] Open
Abstract
Porphyromonas gingivalis is an etiologic agent of periodontal disease in humans. The disease is associated with the formation of a mixed oral biofilm which is exposed to oxygen and environmental stress, such as oxidative stress. To investigate possible roles for cytochrome bd oxidase in the growth and persistence of this anaerobic bacterium inside the oral biofilm, mutant strains deficient in cytochrome bd oxidase activity were characterized. This study demonstrated that the cytochrome bd oxidase of Porphyromonas gingivalis, encoded by cydAB, was able to catalyse O2 consumption and was involved in peroxide and superoxide resistance, and dioxygen tolerance.
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Affiliation(s)
- Julia Leclerc
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
| | - Eric Rosenfeld
- UMR CNRS 7266 LIENSs, University of La Rochelle, La Rochelle, France
| | - Mathieu Trainini
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
| | - Bénédicte Martin
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
| | - Vincent Meuric
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
- UMR CNRS 7266 LIENSs, University of La Rochelle, La Rochelle, France
- CHU Rennes, Rennes, France
| | - Martine Bonnaure-Mallet
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
- UMR CNRS 7266 LIENSs, University of La Rochelle, La Rochelle, France
- CHU Rennes, Rennes, France
| | - Christine Baysse
- EA1254 Microbiologie—Risques Infectieux, University of Rennes1, Rennes, France
- * E-mail:
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14
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McKenzie RME, Henry LG, Boutrin MC, Ximinies A, Fletcher HM. Role of the Porphyromonas gingivalis iron-binding protein PG1777 in oxidative stress resistance. MICROBIOLOGY-SGM 2015; 162:256-267. [PMID: 26581883 DOI: 10.1099/mic.0.000213] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Whole genome sequencing of the response of Porphyromonas gingivalis W83 to hydrogen peroxide revealed an upregulation of several uncharacterized, novel genes. Under conditions of prolonged oxidative stress in P. gingivalis, increased expression of a unique transcriptional unit carrying the grpE, dnaJ and three other hypothetical genes (PG1777, PG1778 and PG1779) was observed. The transcriptional start site of this operon appears to be located 91 bp upstream of the translational start, with a potential -10 region at -3 nt and a -35 region at -39 nt. Isogenic P. gingivalis mutants FLL273 (PG1777 : : ermF-ermAM) and FLL293 (PG1779 : : ermF-ermAM) showed increased sensitivity to and decreased survival after treatment with hydrogen peroxide. P. gingivalis FLL273 showed a fivefold increase in the formation of spontaneous mutants when compared with the parent strain after exposure to hydrogen peroxide. The recombinant PG1777 protein displayed iron-binding properties when incubated with FeSO4 and Fe(NH4)2(SO4).6H2O. The rPG1777 protein protected DNA from degradation when exposed to hydrogen peroxide in the presence of iron. Taken together, the data suggest that the grpE-dnaJ-PG1777-PG1778-PG1779 transcriptional unit may play an important role in oxidative stress resistance in P. gingivalis via its ability to protect against DNA damage.
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Affiliation(s)
- Rachelle M E McKenzie
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Leroy G Henry
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Marie-Claire Boutrin
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Alexia Ximinies
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea.,Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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15
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O'Flynn C, Deusch O, Darling AE, Eisen JA, Wallis C, Davis IJ, Harris SJ. Comparative Genomics of the Genus Porphyromonas Identifies Adaptations for Heme Synthesis within the Prevalent Canine Oral Species Porphyromonas cangingivalis. Genome Biol Evol 2015; 7:3397-413. [PMID: 26568374 PMCID: PMC4700951 DOI: 10.1093/gbe/evv220] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Porphyromonads play an important role in human periodontal disease and recently have been shown to be highly prevalent in canine mouths. Porphyromonas cangingivalis is the most prevalent canine oral bacterial species in both plaque from healthy gingiva and plaque from dogs with early periodontitis. The ability of P. cangingivalis to flourish in the different environmental conditions characterized by these two states suggests a degree of metabolic flexibility. To characterize the genes responsible for this, the genomes of 32 isolates (including 18 newly sequenced and assembled) from 18 Porphyromonad species from dogs, humans, and other mammals were compared. Phylogenetic trees inferred using core genes largely matched previous findings; however, comparative genomic analysis identified several genes and pathways relating to heme synthesis that were present in P. cangingivalis but not in other Porphyromonads. Porphyromonas cangingivalis has a complete protoporphyrin IX synthesis pathway potentially allowing it to synthesize its own heme unlike pathogenic Porphyromonads such as Porphyromonas gingivalis that acquire heme predominantly from blood. Other pathway differences such as the ability to synthesize siroheme and vitamin B12 point to enhanced metabolic flexibility for P. cangingivalis, which may underlie its prevalence in the canine oral cavity.
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Affiliation(s)
- Ciaran O'Flynn
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, United Kingdom
| | - Oliver Deusch
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, United Kingdom
| | - Aaron E Darling
- The ithree Institute, University of Technology Sydney, Ultimo, New South Wales, Australia
| | - Jonathan A Eisen
- Department of Evolution and Ecology, University of California, Davis Department of Medical Microbiology and Immunology, University of California, Davis UC Davis Genome Center, University of California, Davis
| | - Corrin Wallis
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, United Kingdom
| | - Ian J Davis
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, United Kingdom
| | - Stephen J Harris
- The WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, United Kingdom
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16
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Byrne DP, Manandhar SP, Potempa J, Smalley JW. Breakdown of albumin and haemalbumin by the cysteine protease interpain A, an albuminase of Prevotella intermedia. BMC Microbiol 2015; 15:185. [PMID: 26403890 PMCID: PMC4582931 DOI: 10.1186/s12866-015-0516-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 09/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Prevotella intermedia is a Gram-negative black-pigmenting oral anaerobe associated with periodontitis in humans, and has a haem requirement for growth, survival and virulence. It produces an iron porphyrin-containing pigment comprising monomeric iron (III) protoporphyrin IX (Fe(III)PPIX.OH; haematin). The bacterium expresses a 90-kDa cysteine protease termed interpain A (InpA) which both oxidizes and subsequently degrades haemoglobin, releasing haem. However, it is not known whether the enzyme may play a role in degrading other haem-carrying plasma proteins present in the gingival sulcus or periodontal pocket from which to derive haem. This study evaluated the ability of InpA to degrade apo- and haem-complexed albumin. RESULTS Albumin breakdown was examined over a range of pH and in the presence of reducing agent; conditions which prevail in sub- and supra-gingival plaque. InpA digested haemalbumin more efficiently than apoalbumin, especially under reducing conditions at pH 7.5. Under these conditions InpA was able to substantially degrade the albumin component of whole human plasma. CONCLUSIONS The data point to InpA as an efficient "albuminase" with the ability to degrade the minor fraction of haem-bound albumin in plasma. InpA may thus contribute significantly to haem acquisition by P. intermedia under conditions of low redox potential and higher pH in the inflamed gingival crevice and diseased periodontal pocket where haem availability is tightly controlled by the host.
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Affiliation(s)
- Dominic P Byrne
- Department of Biochemistry, Institute of Integrative Biology, The University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK.
| | - Surya P Manandhar
- Department of Biological Sciences, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, California, 90840, USA.
| | - Jan Potempa
- Malopolska Centre of Biotechnology and Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, Krakow, 30-387, Poland. .,Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, 501 S. Preston St., Louisville, KY, 40202, USA.
| | - John W Smalley
- The University of Liverpool, School of Dentistry, Daulby Street, Liverpool, L69 3GN, UK.
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17
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Benedyk M, Byrne DP, Glowczyk I, Potempa J, Olczak M, Olczak T, Smalley JW. Pyocyanina contributory factor in haem acquisition and virulence enhancement of Porphyromonas gingivalis in the lung [corrected]. PLoS One 2015; 10:e0118319. [PMID: 25706529 PMCID: PMC4338185 DOI: 10.1371/journal.pone.0118319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 01/13/2015] [Indexed: 01/08/2023] Open
Abstract
Several recent studies show that the lungs infected with Pseudomonas aeruginosa are often co-colonised by oral bacteria including black-pigmenting anaerobic (BPA) Porphyromonas species. The BPAs have an absolute haem requirement and their presence in the infected lung indicates that sufficient haem, a virulence up-regulator in BPAs, must be present to support growth. Haemoglobin from micro-bleeds occurring during infection is the most likely source of haem in the lung. Porphyromonas gingivalis displays a novel haem acquisition paradigm whereby haemoglobin must be firstly oxidised to methaemoglobin, facilitating haem release, either by gingipain proteolysis or capture via the haem-binding haemophore HmuY. P. aeruginosa produces the blue phenazine redox compound, pyocyanin. Since phenazines can oxidise haemoglobin, it follows that pyocyanin may also facilitate haem acquisition by promoting methaemoglobin production. Here we show that pyocyanin at concentrations found in the CF lung during P. aeruginosa infections rapidly oxidises oxyhaemoglobin in a dose-dependent manner. We demonstrate that methaemoglobin formed by pyocyanin is also susceptible to proteolysis by P. gingivalis Kgp gingipain and neutrophil elastase, thus releasing haem. Importantly, co-incubation of oxyhaemoglobin with pyocyanin facilitates haem pickup from the resulting methemoglobin by the P. gingivalis HmuY haemophore. Mice intra-tracheally challenged with viable P. gingivalis cells plus pyocyanin displayed increased mortality compared to those administered P. gingivalis alone. Pyocyanin significantly elevated both methaemoglobin and total haem levels in homogenates of mouse lungs and increased the level of arginine-specific gingipain activity from mice inoculated with viable P. gingivalis cells plus pyocyanin compared with mice inoculated with P. gingivalis only. These findings indicate that pyocyanin, by promoting haem availability through methaemoglobin formation and stimulating of gingipain production, may contribute to virulence of P. gingivalis and disease severity when co-infecting with P. aeruginosa in the lung.
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Affiliation(s)
- Malgorzata Benedyk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Dominic P Byrne
- Department of Biochemistry and Cell Biology, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Izabela Glowczyk
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland; Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, United States of America
| | - Mariusz Olczak
- Faculty of Biotechnology, Laboratory of Biochemistry, University of Wroclaw, Wroclaw, Poland
| | - Teresa Olczak
- Faculty of Biotechnology, Laboratory of Biochemistry, University of Wroclaw, Wroclaw, Poland
| | - John W Smalley
- School of Dentistry, University of Liverpool, Liverpool, United Kingdom
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18
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Moon JH, Lee JH, Lee JY. Microarray analysis of the transcriptional responses of Porphyromonas gingivalis to polyphosphate. BMC Microbiol 2014; 14:218. [PMID: 25148905 PMCID: PMC4236598 DOI: 10.1186/s12866-014-0218-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 08/12/2014] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Polyphosphate (polyP) has bactericidal activity against a gram-negative periodontopathogen Porphyromonas gingivalis, a black-pigmented gram-negative anaerobic rod. However, current knowledge about the mode of action of polyP against P. gingivalis is incomplete. To elucidate the mechanisms of antibacterial action of polyP against P. gingivalis, we performed the full-genome gene expression microarrays, and gene ontology (GO) and protein-protein interaction network analysis of differentially expressed genes (DEGs). RESULTS We successfully identified 349 up-regulated genes and 357 down-regulated genes (>1.5-fold, P < 0.05) in P. gingivalis W83 treated with polyP75 (sodium polyphosphate, Na(n+2)P(n)O3(n+1); n = 75). Real-time PCR confirmed the up- and down-regulation of some selected genes. GO analysis of the DEGs identified distinct biological themes. Using 202 DEGs belonging to the biological themes, we generated the protein-protein interaction network based on a database of known and predicted protein interactions. The network analysis identified biological meaningful clusters related to hemin acquisition, energy metabolism, cell envelope and cell division, ribosomal proteins, and transposon function. CONCLUSIONS polyP probably exerts its antibacterial effect through inhibition of hemin acquisition by the bacterium, resulting in severe perturbation of energy metabolism, cell envelope biosynthesis and cell division, and elevated transposition. Further studies will be needed to elucidate the exact mechanism by which polyP induces up-regulation of the genes related to ribosomal proteins. Our results will shed new light on the study of the antibacterial mechanism of polyP against other related bacteria belonging to the black-pigmented Bacteroides species.
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Affiliation(s)
- Ji-Hoi Moon
- Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
| | - Jae-Hyung Lee
- Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
- Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
| | - Jin-Yong Lee
- Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
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19
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Porphyromonas gingivalis-induced reactive oxygen species activate JAK2 and regulate production of inflammatory cytokines through c-Jun. Infect Immun 2014; 82:4118-26. [PMID: 25047843 DOI: 10.1128/iai.02000-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pathogen-induced reactive oxygen species (ROS) play a crucial role in host innate immune responses through regulating the quality and quantity of inflammatory mediators. However, the underlying molecular mechanisms of this effect have yet to be clarified. In this study, we examined the mechanism of action of ROS stimulated by Porphyromonas gingivalis in gingival epithelial cells. P. gingivalis induced the rapid production of ROS, which lead to the phosphorylation of JAK2 and increased levels of secreted proinflammatory cytokines interleukin-6 (IL-6) and IL-1β. Neutralization of ROS by N-acetyl-l-cysteine (NAC) abrogated the phosphorylation of JAK2 and suppressed the production of IL-6 and IL-1β. ROS-mediated phosphorylation of JAK2 induced the phosphoactivation of c-Jun amino-terminal protein kinase (JNK) and the downstream transcriptional regulator c-Jun. Inhibition of JAK2, either pharmacologically or by small interfering RNA (siRNA), reduced both the phosphorylation of these molecules and the production of proinflammatory cytokines in response to P. gingivalis. Furthermore, pharmacological inhibition or siRNA-mediated gene silencing of JNK or c-Jun mimicked the effect of JAK2 inhibition to suppress P. gingivalis-induced IL-6 and IL-1β levels. The results show that ROS-mediated activation of JAK2 is required for P. gingivalis-induced inflammatory cytokine production and that the JNK/c-Jun signaling axis is involved in the ROS-dependent regulation of IL-1β and IL-6 production.
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20
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Li N, Collyer CA. Gingipains from Porphyromonas gingivalis - Complex domain structures confer diverse functions. Eur J Microbiol Immunol (Bp) 2014; 1:41-58. [PMID: 24466435 DOI: 10.1556/eujmi.1.2011.1.7] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Gingipains, a group of arginine or lysine specific cysteine proteinases (also known as RgpA, RgpB and Kgp), have been recognized as major virulence factors in Porphyromonas gingivalis. This bacterium is one of a handful of pathogens that cause chronic periodontitis. Gingipains are involved in adherence to and colonization of epithelial cells, haemagglutination and haemolysis of erythrocytes, disruption and manipulation of the inflammatory response, and the degradation of host proteins and tissues. RgpA and Kgp are multi-domain proteins composed of catalytic domains and haemagglutinin/adhesin (HA) regions. The structure of the HA regions have previously been defined by a gingipain domain structure hypothesis which is a set of putative domain boundaries derived from the sequences of fragments of these proteins extracted from the cell surface. However, multiple sequence alignments and hidden Markov models predict an alternative domain architecture for the HA regions of gingipains. In this alternate model, two or three repeats of the so-called "cleaved adhesin" domains (and one other undefined domain in some strains) are the modules which constitute the substructure of the HA regions. Recombinant forms of these putative cleaved adhesin domains are indeed stable folded protein modules and recently determined crystal structures support the hypothesis of a modular organisation of the HA region. Based on the observed K2 and K3 structures as well as multiple sequence alignments, it is proposed that all the cleaved adhesin domains in gingipains will share the same β-sandwich jelly roll fold. The new domain model of the structure for gingipains and the haemagglutinin (HagA) proteins of P. gingivalis will guide future functional studies of these virulence factors.
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Affiliation(s)
- N Li
- School of Molecular Bioscience, University of Sydney NSW Australia
| | - C A Collyer
- School of Molecular Bioscience, University of Sydney NSW Australia
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21
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Henry LG, Aruni W, Sandberg L, Fletcher HM. Protective role of the PG1036-PG1037-PG1038 operon in oxidative stress in Porphyromonas gingivalis W83. PLoS One 2013; 8:e69645. [PMID: 23990885 PMCID: PMC3747172 DOI: 10.1371/journal.pone.0069645] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 06/13/2013] [Indexed: 12/15/2022] Open
Abstract
As an anaerobe, Porphyromonas gingivalis is significantly affected by the harsh inflammatory environment of the periodontal pocket during initial colonization and active periodontal disease. We reported previously that the repair of oxidative stress-induced DNA damage involving 8-oxo-7,8-dihydroguanine (8-oxoG) may occur by an undescribed mechanism in P. gingivalis. DNA affinity fractionation identified PG1037, a conserved hypothetical protein, among other proteins, that were bound to the 8-oxoG lesion. PG1037 is part of the uvrA-PG1037-pcrA operon in P. gingivalis which is known to be upregulated under H2O2 induced stress. A PCR-based linear transformation method was used to inactivate the uvrA and pcrA genes by allelic exchange mutagenesis. Several attempts to inactivate PG1037 were unsuccessful. Similar to the wild-type when plated on Brucella blood agar, the uvrA and pcrA-defective mutants were black-pigmented and beta-hemolytic. These isogenic mutants also had reduced gingipain activities and were more sensitive to H2O2 and UV irradiation compared to the parent strain. Additionally, glycosylase assays revealed that 8-oxoG repair activities were similar in both wild-type and mutant P. gingivalis strains. Several proteins, some of which are known to have oxidoreducatse activity, were shown to interact with PG1037. The purified recombinant PG1037 protein could protect DNA from H2O2-induced damage. Collectively, these findings suggest that the uvrA-PG1037-pcrA operon may play an important role in hydrogen peroxide stress-induced resistance in P. gingivalis.
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Affiliation(s)
- Leroy G. Henry
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Wilson Aruni
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Lawrence Sandberg
- Division of Biochemistry, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
| | - Hansel M. Fletcher
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California, United States of America
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22
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Byrne DP, Potempa J, Olczak T, Smalley JW. Evidence of mutualism between two periodontal pathogens: co-operative haem acquisition by the HmuY haemophore of Porphyromonas gingivalis and the cysteine protease interpain A (InpA) of Prevotella intermedia. Mol Oral Microbiol 2013; 28:219-29. [PMID: 23336115 DOI: 10.1111/omi.12018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2012] [Indexed: 11/27/2022]
Abstract
Haem (iron protoporphyrin IX) is both an essential growth factor and a virulence regulator of the periodontal pathogens Porphyromonas gingivalis and Prevotella intermedia, which acquire it through the proteolytic degradation of haemoglobin and other haem-carrying plasma proteins. The haem-binding lipoprotein HmuY haemophore and the gingipain proteases of P. gingivalis form a unique synthrophic system responsible for capture of haem from haemoglobin and methaemalbumin. In this system, methaemoglobin is formed from oxyhaemoglobin by the activities of gingipain proteases and serves as a facile substrate from which HmuY can capture haem. This study examined the possibility of cooperation between HmuY and the cysteine protease interpain A (InpA) of Pr. intermedia in the haem acquisition process. Using UV-visible spectroscopy and polyacrylamide gel electrophoresis, HmuY was demonstrated to be resistant to proteolysis and so able to cooperate with InpA to extract haem from haemoglobin, which was proteolytically converted to methaemoglobin by the protease. Spectroscopic pH titrations showed that both the iron(II) and iron(III) protoporphyrin IX-HmuY complexes were stable over the pH range 4-10, demonstrating that the haemophore could function over a range of pH that may be encountered in the dental plaque biofilm. This is the first demonstration of a bacterial haemophore working in conjunction with a protease from another bacterial species to acquire haem from haemoglobin and may represent mutualism between P. gingivalis and Pr. intermedia co-inhabiting the periodontal pocket.
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Affiliation(s)
- D P Byrne
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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23
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Liu M, Ferrandez Y, Bouhsira E, Monteil M, Franc M, Boulouis HJ, Biville F. Heme binding proteins of Bartonella henselae are required when undergoing oxidative stress during cell and flea invasion. PLoS One 2012; 7:e48408. [PMID: 23144761 PMCID: PMC3483173 DOI: 10.1371/journal.pone.0048408] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 10/01/2012] [Indexed: 11/24/2022] Open
Abstract
Bartonella are hemotropic bacteria responsible for emerging zoonoses. These heme auxotroph alphaproteobacteria must import heme for their growth, since they cannot synthesize it. To import exogenous heme, Bartonella genomes encode for a complete heme uptake system enabling transportation of this compound into the cytoplasm and degrading it to release iron. In addition, these bacteria encode for four or five outer membrane heme binding proteins (Hbps). The structural genes of these highly homologous proteins are expressed differently depending on oxygen, temperature and heme concentrations. These proteins were hypothesized as being involved in various cellular processes according to their ability to bind heme and their regulation profile. In this report, we investigated the roles of the four Hbps of Bartonella henselae, responsible for cat scratch disease. We show that Hbps can bind heme in vitro. They are able to enhance the efficiency of heme uptake when co-expressed with a heme transporter in Escherichia coli. Using B. henselae Hbp knockdown mutants, we show that these proteins are involved in defense against the oxidative stress, colonization of human endothelial cell and survival in the flea.
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Affiliation(s)
- MaFeng Liu
- UMR BIPAR Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, INRA-Anses-UPEC-ENVA, Maisons-Alfort, France.
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24
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Henry LG, McKenzie RME, Robles A, Fletcher HM. Oxidative stress resistance in Porphyromonas gingivalis. Future Microbiol 2012; 7:497-512. [PMID: 22439726 DOI: 10.2217/fmb.12.17] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Porphyromonas gingivalis, a black-pigmented, Gram-negative anaerobe, is an important etiologic agent of periodontal disease. The harsh inflammatory condition of the periodontal pocket implies that this organism has properties that will facilitate its ability to respond and adapt to oxidative stress. Because the stress response in the pathogen is a major determinant of its virulence, a comprehensive understanding of its oxidative stress resistance strategy is vital. We discuss multiple mechanisms and systems that clearly work in synergy to defend and protect P. gingivalis against oxidative damage caused by reactive oxygen species. The involvement of multiple hypothetical proteins and/or proteins of unknown function in this process may imply other unique mechanisms and potential therapeutic targets.
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Affiliation(s)
- Leroy G Henry
- Division of Microbiology & Molecular Genetics, School of Medicine, Loma Linda, CA 92350, USA
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25
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McKenzie RME, Johnson NA, Aruni W, Dou Y, Masinde G, Fletcher HM. Differential response of Porphyromonas gingivalis to varying levels and duration of hydrogen peroxide-induced oxidative stress. MICROBIOLOGY-SGM 2012; 158:2465-2479. [PMID: 22745271 DOI: 10.1099/mic.0.056416-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Porphyromonas gingivalis, an anaerobic oral pathogen implicated in adult periodontitis, can exist in an environment of oxidative stress. To evaluate its adaptation to this environment, we have assessed the response of P. gingivalis W83 to varying levels and durations of hydrogen peroxide (H(2)O(2))-induced stress. When P. gingivalis was initially exposed to a subinhibitory concentration of H(2)O(2) (0.1 mM), an adaptive response to higher concentrations could be induced. Transcriptome analysis demonstrated that oxidative stress can modulate several functional classes of genes depending on the severity and duration of the exposure. A 10 min exposure to H(2)O(2) revealed increased expression of genes involved in DNA damage and repair, while after 15 min, genes involved in protein fate, protein folding and stabilization were upregulated. Approximately 9 and 2.8% of the P. gingivalis genome displayed altered expression in response to H(2)O(2) exposure at 10 and 15 min, respectively. Substantially more genes were upregulated (109 at 10 min; 47 at 15 min) than downregulated (76 at 10 min; 11 at 15 min) by twofold or higher in response to H(2)O(2) exposure. The majority of these modulated genes were hypothetical or of unknown function. One of those genes (pg1372) with DNA-binding properties that was upregulated during prolonged oxidative stress was inactivated by allelic exchange mutagenesis. The isogenic mutant P. gingivalis FLL363 (pg1372 : : ermF) showed increased sensitivity to H(2)O(2) compared with the parent strain. Collectively, our data indicate the adaptive ability of P. gingivalis to oxidative stress and further underscore the complex nature of its resistance strategy under those conditions.
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Affiliation(s)
- Rachelle M E McKenzie
- Center for Dental Research, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA.,Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Neal A Johnson
- Department of Oral Diagnosis, Radiology, and Pathology, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA.,Center for Dental Research, School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA
| | - Wilson Aruni
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Yuetan Dou
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Godfred Masinde
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
| | - Hansel M Fletcher
- Division of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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Yanamandra SS, Sarrafee SS, Anaya-Bergman C, Jones K, Lewis JP. Role of the Porphyromonas gingivalis extracytoplasmic function sigma factor, SigH. Mol Oral Microbiol 2012; 27:202-19. [PMID: 22520389 DOI: 10.1111/j.2041-1014.2012.00643.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Little is known about the regulatory mechanisms that allow Porphyromonas gingivalis to survive in the oral cavity. Here we characterize the sigma (σ) factor SigH, one of six extracytoplasmic function (ECF) σ factors encoded in the P. gingivalis genome. Our results indicate that sigH expression is upregulated by exposure to molecular oxygen, suggesting that sigH plays a role in adaptation of P. gingivalis to oxygen. Furthermore, several genes involved in oxidative stress protection, such as sod, trx, tpx, ftn, feoB2 and the hemin uptake hmu locus, are downregulated in a mutant deficient in SigH designated as V2948. ECF σ consensus sequences were identified upstream of the transcriptional start sites of these genes, consistent with the SigH-dependent regulation of these genes. Growth of V2948 was inhibited in the presence of 6% oxygen when compared with the wild-type W83 strain, whereas in anaerobic conditions both strains were able to grow. In addition, reduced growth of V2948 was observed in the presence of peroxide and the thiol-oxidizing reagent diamide when compared with the W83 strain. The SigH-deficient strain V2948 also exhibited reduced hemin uptake, consistent with the observed reduced expression of genes involved in hemin uptake. Finally, survival of V2948 was reduced in the presence of host cells compared with the wild-type W83 strain. Collectively, our studies demonstrate that SigH is a positive regulator of gene expression required for survival of the bacterium in the presence of oxygen and oxidative stress, hemin uptake and virulence.
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Affiliation(s)
- S S Yanamandra
- The Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
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Abstract
Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease.
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Affiliation(s)
- Alexander Harms
- Focal Area Infection Biology, Biozentrum, University of Basel, Switzerland
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VimA-dependent modulation of acetyl coenzyme A levels and lipid A biosynthesis can alter virulence in Porphyromonas gingivalis. Infect Immun 2011; 80:550-64. [PMID: 22144476 DOI: 10.1128/iai.06062-11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Porphyromonas gingivalis VimA protein has multifunctional properties that can modulate several of its major virulence factors. To further characterize VimA, P. gingivalis FLL406 carrying an additional vimA gene and a vimA-defective mutant in a different P. gingivalis genetic background were evaluated. The vimA-defective mutant (FLL451) in the P. gingivalis ATCC 33277 genetic background showed a phenotype similar to that of the vimA-defective mutant (FLL92) in the P. gingivalis W83 genetic background. In contrast to the wild type, gingipain activity was increased in P. gingivalis FLL406, a vimA chimeric strain. P. gingivalis FLL451 had a five times higher biofilm-forming capacity than the parent strain. HeLa cells incubated with P. gingivalis FLL92 showed a decrease in invasion, in contrast to P. gingivalis FLL451 and FLL406, which showed increases of 30 and 40%, respectively. VimA mediated coenzyme A (CoA) transfer to isoleucine and reduced branched-chain amino acid metabolism. The lipid A content and associated proteins were altered in the vimA-defective mutants. The VimA chimera interacted with several proteins which were found to have an LXXTG motif, similar to the sorting motif of gram-positive organisms. All the proteins had an N-terminal signal sequence with a putative sorting signal of L(P/T/S)X(T/N/D)G and two unique signatures of EXGXTX and HISXXGXG, in addition to a polar tail. Taken together, these observations further confirm the multifunctional role of VimA in modulating virulence possibly through its involvement in acetyl-CoA transfer and lipid A synthesis and possibly by protein sorting.
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Moon JH, Park JH, Lee JY. Antibacterial action of polyphosphate on Porphyromonas gingivalis. Antimicrob Agents Chemother 2011; 55:806-12. [PMID: 21098243 PMCID: PMC3028800 DOI: 10.1128/aac.01014-10] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 09/15/2010] [Accepted: 11/15/2010] [Indexed: 11/20/2022] Open
Abstract
Polyphosphate [poly(P)] has antibacterial activity against various Gram-positive bacteria. In contrast, Gram-negative bacteria are generally resistant to poly(P). Here, we describe the antibacterial characterization of poly(P) against a Gram-negative periodontopathogen, Porphyromonas gingivalis. The MICs of pyrophosphate (Na(4)P(2)O(7)) and all poly(P) (Na(n + 2)P(n)O(3n + 1); n = 3 to 75) tested for the bacterium by the agar dilution method were 0.24% and 0.06%, respectively. Orthophosphate (Na(2)HPO(4)) failed to inhibit bacterial growth. Poly-P75 was chosen for further study. In liquid medium, 0.03% poly-P75 was bactericidal against P. gingivalis irrespective of the growth phase and inoculum size, ranging from 10(5) to 10(9) cells/ml. UV-visible spectra of the pigments from P. gingivalis grown on blood agar with or without poly-P75 showed that poly-P75 reduced the formation of μ-oxo bisheme by the bacterium. Poly-P75 increased hemin accumulation on the P. gingivalis surface and decreased energy-driven uptake of hemin by the bacterium. The expression of the genes encoding hemagglutinins, gingipains, hemin uptake loci, chromosome replication, and energy production was downregulated, while that of the genes related to iron storage and oxidative stress was upregulated by poly-P75. The transmission electron microscope showed morphologically atypical cells with electron-dense granules and condensed nucleoid in the cytoplasm. Collectively, poly(P) is bactericidal against P. gingivalis, in which hemin/heme utilization is disturbed and oxidative stress is increased by poly(P).
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Affiliation(s)
- Ji-Hoi Moon
- Departments of Maxillofacial Biomedical Engineering, Pediatric Dentistry, School of Dentistry, Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea
| | - Jae-Hong Park
- Departments of Maxillofacial Biomedical Engineering, Pediatric Dentistry, School of Dentistry, Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea
| | - Jin-Yong Lee
- Departments of Maxillofacial Biomedical Engineering, Pediatric Dentistry, School of Dentistry, Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea
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Guo Y, Nguyen KA, Potempa J. Dichotomy of gingipains action as virulence factors: from cleaving substrates with the precision of a surgeon's knife to a meat chopper-like brutal degradation of proteins. Periodontol 2000 2010; 54:15-44. [PMID: 20712631 DOI: 10.1111/j.1600-0757.2010.00377.x] [Citation(s) in RCA: 248] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Johnson NA, McKenzie RME, Fletcher HM. The bcp gene in the bcp-recA-vimA-vimE-vimF operon is important in oxidative stress resistance in Porphyromonas gingivalis W83. Mol Oral Microbiol 2010; 26:62-77. [PMID: 21214873 DOI: 10.1111/j.2041-1014.2010.00596.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ability of Porphyromonas gingivalis to overcome oxidative stress in the inflammatory environment of the periodontal pocket is critical for its survival. We have previously demonstrated that the recA locus, which carries the bacterioferritin co-migratory protein (bcp) gene and has a unique genetic architecture, plays a role in virulence regulation and oxidative stress resistance in P. gingivalis. To further characterize the bcp gene, which was confirmed to be part of the bcp-recA-vimA-vimE-vimF operon, we created a P. gingivalis bcp-defective isogenic mutant (FLL302) by allelic exchange. Compared with the wild-type, FLL302 had a similar growth rate, black pigmentation, β-hemolysis and UV sensitivity. Although there was no change in the distribution of gingipain activity, there was a 30% reduction in both Arg-X and Lys-X activities in the mutant strain compared with the wild-type. When exposed to 0.25 mm hydrogen peroxide, P. gingivalis FLL302 was more sensitive than the wild-type. In addition, the cloned P. gingivalis bcp gene increased resistance to 0.25 mm hydrogen peroxide in a bcp-defective Escherichia coli mutant. The mutant also demonstrated decreased aerotolerance when compared with the wild-type. Porphyromonas gingivalis FLL302 and the wild-type strain had similar virulence profiles in a mouse model of virulence. These observations suggest that the bcp gene may play a role in oxidative stress resistance but has a decreased functional significance in the pathogenic potential of P. gingivalis.
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Affiliation(s)
- N A Johnson
- Center for Dental Research, School of Dentistry, Loma Linda University, Loma Linda, CA, USA
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Lewis JP. Metal uptake in host-pathogen interactions: role of iron in Porphyromonas gingivalis interactions with host organisms. Periodontol 2000 2010; 52:94-116. [PMID: 20017798 DOI: 10.1111/j.1600-0757.2009.00329.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Role of the cysteine protease interpain A of Prevotella intermedia in breakdown and release of haem from haemoglobin. Biochem J 2009; 425:257-64. [PMID: 19814715 DOI: 10.1042/bj20090343] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The gram-negative oral anaerobe Prevotella intermedia forms an iron(III) protoporphyrin IX pigment from haemoglobin. The bacterium expresses a 90 kDa cysteine protease, InpA (interpain A), a homologue of Streptococcus pyogenes streptopain (SpeB). The role of InpA in haemoglobin breakdown and haem release was investigated. At pH 7.5, InpA mediated oxidation of oxyhaemoglobin to hydroxymethaemoglobin [in which the haem iron is oxidized to the Fe(III) state and which carries OH- as the sixth co-ordinate ligand] by limited proteolysis of globin chains as indicated by SDS/PAGE and MALDI (matrix-assisted laser-desorption ionization)-TOF (time-of-flight) analysis. Prolonged incubation at pH 7.5 did not result in further haemoglobin protein breakdown, but in the formation of a haemoglobin haemichrome (where the haem Fe atom is co-ordinated by another amino acid ligand in addition to the proximal histidine residue) resistant to degradation by InpA. InpA-mediated haem release from hydroxymethaemoglobin-agarose was minimal compared with trypsin at pH 7.5. At pH 6.0, InpA increased oxidation at a rate greater than auto-oxidation, producing aquomethaemoglobin (with water as sixth co-ordinate ligand), and resulted in its complete breakdown and haem loss. Aquomethaemoglobin proteolysis and haem release was prevented by blocking haem dissociation by ligation with azide, whereas InpA proteolysis of haem-free globin was rapid, even at pH 7.5. Both oxidation of oxyhaemoglobin and breakdown of methaemoglobin by InpA were inhibited by the cysteine protease inhibitor E-64 [trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane]. In summary, we conclude that InpA may play a central role in haem acquisition by mediating oxyhaemoglobin oxidation, and by degrading aquomethaemoglobin in which haem-globin affinity is weakened under acidic conditions.
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Wójtowicz H, Guevara T, Tallant C, Olczak M, Sroka A, Potempa J, Solà M, Olczak T, Gomis-Rüth FX. Unique structure and stability of HmuY, a novel heme-binding protein of Porphyromonas gingivalis. PLoS Pathog 2009; 5:e1000419. [PMID: 19424422 PMCID: PMC2671838 DOI: 10.1371/journal.ppat.1000419] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 04/07/2009] [Indexed: 11/18/2022] Open
Abstract
Infection, survival, and proliferation of pathogenic bacteria in humans depend on their capacity to impair host responses and acquire nutrients in a hostile environment. Among such nutrients is heme, a co-factor for oxygen storage, electron transport, photosynthesis, and redox biochemistry, which is indispensable for life. Porphyromonas gingivalis is the major human bacterial pathogen responsible for severe periodontitis. It recruits heme through HmuY, which sequesters heme from host carriers and delivers it to its cognate outer-membrane transporter, the TonB-dependent receptor HmuR. Here we report that heme binding does not significantly affect the secondary structure of HmuY. The crystal structure of heme-bound HmuY reveals a new all-β fold mimicking a right hand. The thumb and fingers pinch heme iron through two apical histidine residues, giving rise to highly symmetric octahedral iron co-ordination. The tetrameric quaternary arrangement of the protein found in the crystal structure is consistent with experiments in solution. It shows that thumbs and fingertips, and, by extension, the bound heme groups, are shielded from competing heme-binding proteins from the host. This may also facilitate heme transport to HmuR for internalization. HmuY, both in its apo- and in its heme-bound forms, is resistant to proteolytic digestion by trypsin and the major secreted proteases of P. gingivalis, gingipains K and R. It is also stable against thermal and chemical denaturation. In conclusion, these studies reveal novel molecular properties of HmuY that are consistent with its role as a putative virulence factor during bacterial infection. Pathogenic bacteria cause infection in humans as found in periodontitis, which is a chronic inflammation of the gums caused by Porphyromonas gingivalis. As part of the infective process, bacteria must acquire nutrients to survive and multiply at the infection site, and among such nutrients is heme. This is an iron-dependent co-factor of several indispensable enzymes and proteins. P. gingivalis liberates heme from host heme-binding proteins through the action of proteases and arranges its transport to the bacterial cell through two proteins, HmuY and HmuR. They grab free heme and transport it across the bacterial membrane into the cell, respectively. This function poses stringent conditions on these proteins regarding stability and resistance toward the host immune system. We report here that HmuY is very stable and that it displays a novel protein fold, which consists only of β-strands. It reminds us of a right hand, whose fingers trap heme. Once heme is bound, HmuY forms tetramers, which have the four heme-binding sites buried and thus protected from competing host heme-binding proteins. This feature also facilitates heme transport to HmuR and into the bacterial cell. All these data may help to develop new antibacterial agents at times in which resistance toward antibiotics, both at intensive healthcare stations and in the community, poses serious challenges to human health.
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Affiliation(s)
- Halina Wójtowicz
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Tibisay Guevara
- Proteolysis Lab, Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona, Spain
| | - Cynthia Tallant
- Proteolysis Lab, Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona, Spain
| | - Mariusz Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Aneta Sroka
- Laboratory of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Potempa
- Laboratory of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Department of Periodontics, University of Louisville School of Dentistry, Louisville, Kentucky, United States of America
| | - Maria Solà
- Structural MitoLab, Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona, Spain
| | - Teresa Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
- * E-mail: (TO); (FXG-R)
| | - F. Xavier Gomis-Rüth
- Proteolysis Lab, Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona, Spain
- * E-mail: (TO); (FXG-R)
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Abstract
The persistence of Porphyromonas gingivalis in the inflammatory environment of the periodontal pocket requires an ability to overcome oxidative stress. DNA damage is a major consequence of oxidative stress. Unlike the case for other organisms, our previous report suggests a role for a non-base excision repair mechanism for the removal of 8-oxo-7,8-dihydroguanine (8-oxo-G) in P. gingivalis. Because the uvrB gene is known to be important in nucleotide excision repair, the role of this gene in the repair of oxidative stress-induced DNA damage was investigated. A 3.1-kb fragment containing the uvrB gene was PCR amplified from the chromosomal DNA of P. gingivalis W83. This gene was insertionally inactivated using the ermF-ermAM antibiotic cassette and used to create a uvrB-deficient mutant by allelic exchange. When plated on brucella blood agar, the mutant strain, designated P. gingivalis FLL144, was similar in black pigmentation and beta-hemolysis to the parent strain. In addition, P. gingivalis FLL144 demonstrated no significant difference in growth rate, proteolytic activity, or sensitivity to hydrogen peroxide from that of the parent strain. However, in contrast to the wild type, P. gingivalis FLL144 was significantly sensitive to UV irradiation. The enzymatic removal of 8-oxo-G from duplex DNA was unaffected by the inactivation of the uvrB gene. DNA affinity fractionation identified unique proteins that preferentially bound to the oligonucleotide fragment carrying the 8-oxo-G lesion. Collectively, these results suggest that the repair of oxidative stress-induced DNA damage involving 8-oxo-G may occur by a still undescribed mechanism in P. gingivalis.
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Sheets SM, Robles-Price AG, McKenzie RME, Casiano CA, Fletcher HM. Gingipain-dependent interactions with the host are important for survival of Porphyromonas gingivalis. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2008; 13:3215-38. [PMID: 18508429 PMCID: PMC3403687 DOI: 10.2741/2922] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Porphyromonas gingivalis, a major periodontal pathogen, must acquire nutrients from host derived substrates, overcome oxidative stress and subvert the immune system. These activities can be coordinated via the gingipains which represent the most significant virulence factor produced by this organism. In the context of our contribution to this field, we will review the current understanding of gingipain biogenesis, glycosylation, and regulation, as well as discuss their role in oxidative stress resistance and apoptosis. We can postulate a model, in which gingipains may be part of the mechanism for P. gingivalis virulence.
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Affiliation(s)
- Shaun M. Sheets
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Antonette G. Robles-Price
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Rachelle M. E. McKenzie
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Carlos A. Casiano
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
- The Center for Health Disparities and Molecular Medicine, Loma Linda University, Loma Linda, California
| | - Hansel M. Fletcher
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, California
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Mydel P, Takahashi Y, Yumoto H, Sztukowska M, Kubica M, Gibson FC, Kurtz DM, Travis J, Collins LV, Nguyen KA, Genco CA, Potempa J. Roles of the host oxidative immune response and bacterial antioxidant rubrerythrin during Porphyromonas gingivalis infection. PLoS Pathog 2006; 2:e76. [PMID: 16895445 PMCID: PMC1522038 DOI: 10.1371/journal.ppat.0020076] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Accepted: 06/21/2006] [Indexed: 12/13/2022] Open
Abstract
The efficient clearance of microbes by neutrophils requires the concerted action of reactive oxygen species and microbicidal components within leukocyte secretory granules. Rubrerythrin (Rbr) is a nonheme iron protein that protects many air-sensitive bacteria against oxidative stress. Using oxidative burst-knockout (NADPH oxidase-null) mice and an rbr gene knockout bacterial strain, we investigated the interplay between the phagocytic oxidative burst of the host and the oxidative stress response of the anaerobic periodontal pathogen Porphyromonas gingivalis. Rbr ensured the proliferation of P. gingivalis in mice that possessed a fully functional oxidative burst response, but not in NADPH oxidase-null mice. Furthermore, the in vivo protection afforded by Rbr was not associated with the oxidative burst responses of isolated neutrophils in vitro. Although the phagocyte-derived oxidative burst response was largely ineffective against P. gingivalis infection, the corresponding oxidative response to the Rbr-positive microbe contributed to host-induced pathology via potent mobilization and systemic activation of neutrophils. It appeared that Rbr also provided protection against reactive nitrogen species, thereby ensuring the survival of P. gingivalis in the infected host. The presence of the rbr gene in P. gingivalis also led to greater oral bone loss upon infection. Collectively, these results indicate that the host oxidative burst paradoxically enhances the survival of P. gingivalis by exacerbating local and systemic inflammation, thereby contributing to the morbidity and mortality associated with infection.
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Affiliation(s)
- Piotr Mydel
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Yusuke Takahashi
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Oral Microbiology, Kanagawa Dental College, Yokosuka, Kanagawa, Japan
| | - Hiromichi Yumoto
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Conservative Dentistry, The University of Tokushima, School of Dentistry, Tokushima, Japan
| | - Maryta Sztukowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Malgorzata Kubica
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Frank C Gibson
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Donald M Kurtz
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia, United States of America
| | - Jim Travis
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States of America
| | - L. Vincent Collins
- Department of Rheumatology and Inflammation Research, University of Göteborg, Göteborg, Sweden
| | - Ky-Anh Nguyen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Caroline Attardo Genco
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail: (CAG); (JP)
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States of America
- * To whom correspondence should be addressed. E-mail: (CAG); (JP)
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Battisti JM, Sappington KN, Smitherman LS, Parrow NL, Minnick MF. Environmental signals generate a differential and coordinated expression of the heme receptor gene family of Bartonella quintana. Infect Immun 2006; 74:3251-61. [PMID: 16714552 PMCID: PMC1479232 DOI: 10.1128/iai.00245-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 03/10/2006] [Accepted: 03/17/2006] [Indexed: 01/18/2023] Open
Abstract
Of all bacteria, Bartonella quintana has the highest reported in vitro hemin requirement, yet an explanation for this remains elusive. To produce diseases such as trench fever, endocarditis, and bacillary angiomatosis, B. quintana must survive and replicate in the disparate environments of the Pediculus humanus corporis (body louse) gut and the human vasculature. We previously identified a five-member family of hemin binding proteins (Hbps) synthesized by B. quintana that bind hemin on the outer surface but share no similarity to known bacterial heme receptors. In the present study, we examine the transcription, regulation, and synthesis of this virulence factor family by cultivation of the bacterium in environments that simulate natural heme, oxygen, and temperature conditions encountered in the host and insect vector. First, quantitative real-time PCR data show that hbpC expression is regulated by temperature, where a >100-fold increase in transcript quantity was seen at 30 degrees C relative to 37 degrees C, suggesting that HbpC synthesis would be greatest in the cooler temperature of the louse. Second, cultivation at human bloodstream oxygen concentration (5% relative to 21% atmospheric) significantly decreases the transcript quantity of all hbp genes, indicating that expression is influenced by O2 and/or reactive oxygen species. Third, a differential expression pattern within the hbp family is revealed when B. quintana is grown in a range of hemin concentrations: subgroup I (hbpC and hbpB) predominates in a simulated louse environment (high heme), and subgroup II (hbpA, hbpD, and hbpE) is preferentially expressed in a simulated human background (low heme). By using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and matrix-assisted laser desorption ionization-time of flight mass spectrometry fingerprinting, we demonstrate that synthesis of HbpA correlates with hbpA transcript increases observed at low hemin concentrations. Finally, an hbpA promoter-lacZ reporter construct in B. quintana demonstrates that a transcriptional regulator(s) is controlling the expression of hbpA through a cis-acting regulatory element located in the hbpA promoter region.
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Affiliation(s)
- James M Battisti
- Division of Biological Sciences, The University of Montana, Missoula, MT 59812, USA
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Johnson NA, McKenzie R, McLean L, Sowers LC, Fletcher HM. 8-oxo-7,8-dihydroguanine is removed by a nucleotide excision repair-like mechanism in Porphyromonas gingivalis W83. J Bacteriol 2004; 186:7697-703. [PMID: 15516584 PMCID: PMC524907 DOI: 10.1128/jb.186.22.7697-7703.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A consequence of oxidative stress is DNA damage. The survival of Porphyromonas gingivalis in the inflammatory microenvironment of the periodontal pocket requires an ability to overcome oxidative stress caused by reactive oxygen species (ROS). 8-oxo-7,8-dihydroguanine (8-oxoG) is typical of oxidative damage induced by ROS. There is no information on the presence of 8-oxoG in P. gingivalis under oxidative stress conditions or on a putative mechanism for its repair. High-pressure liquid chromatography with electrochemical detection analysis of chromosomal DNA revealed higher levels of 8-oxoG in P. gingivalis FLL92, a nonpigmented isogenic mutant, than in the wild-type strain. 8-oxoG repair activity was also increased in cell extracts from P. gingivalis FLL92 compared to those from the parent strain. Enzymatic removal of 8-oxoG was catalyzed by a nucleotide excision repair (NER)-like mechanism rather than the base excision repair (BER) observed in Escherichia coli. In addition, in comparison with other anaerobic periodontal pathogens, the removal of 8-oxoG was unique to P. gingivalis. Taken together, the increased 8-oxoG levels in P. gingivalis FLL92 could further support a role for the hemin layer as a unique mechanism in oxidative stress resistance in this organism. In addition, this is the first observation of an NER-like mechanism as the major mechanism for removal of 8-oxoG in P. gingivalis.
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Affiliation(s)
- N A Johnson
- Department of Biochemistry and Microbiology, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
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Smalley JW, Thomas MF, Birss AJ, Withnall R, Silver J. A combination of both arginine- and lysine-specific gingipain activity of Porphyromonas gingivalis is necessary for the generation of the micro-oxo bishaem-containing pigment from haemoglobin. Biochem J 2004; 379:833-40. [PMID: 14741050 PMCID: PMC1224116 DOI: 10.1042/bj20031221] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2003] [Revised: 01/05/2004] [Accepted: 01/23/2004] [Indexed: 02/02/2023]
Abstract
The black pigment of Porphyromonas gingivalis is composed of the mu-oxo bishaem complex of Fe(III) protoporphyrin IX (mu-oxo oligomer, dimeric haem), namely [Fe(III)PPIX]2O. P. gingivalis W50 and Rgp (Arg-gingipain)- and Kgp (Lys-gingipain)-deficient mutants K1A, D7, E8 and W501 [Aduse-Opoku, Davies, Gallagher, Hashim, Evans, Rangarajan, Slaney and Curtis (2000) Microbiology 146, 1933-1940] were grown on horse blood/agar for 14 days and examined for the production of mu-oxo bishaem. Mu-oxo Bishaem was detected by UV-visible, Mössbauer and Raman spectroscopies in wild-type W50 and in the black-pigmented RgpA- and RgpB-deficient mutants (W501 and D7 respectively), whereas no haem species were detected in the straw-coloured colonies of Kgp-deficient strain K1A. The dark brown pigment of the double RgpA/RgpB knockout mutant (E8) was not composed of mu-oxo bishaem, but of a high-spin monomeric Fe(III) protoporphyrin IX species (possibly a haem-albumin complex). In vitro incubation of oxyhaemoglobin with cells of the W50 strain and the RgpA- and RgpB-deficient mutants (W501 and D7) resulted in the formation of mu-oxo bishaem via methaemoglobin as an intermediate. Although the Kgp-deficient strain K1A converted oxyhaemoglobin into methaemoglobin, this was not further degraded into mu-oxo bishaem. The double RgpA/RgpB knockout was also not capable of producing mu-oxo bishaem from oxyhaemoglobin, but instead generated a haemoglobin haemichrome. Inhibition of Arg-X protease activity of W50, W501, D7 and K1A with leupeptin, under conditions where Lys-X protease activity was unaffected, prevented the production of mu-oxo bishaem from oxyhaemoglobin, but resulted in the formation of a haemoglobin haemichrome. These results show that one or both of RgpA and RgpB gingipains, in addition to the lysine-specific gingipain, is necessary for the production of mu-oxo bishaem from haemoglobin by whole cells of P. gingivalis.
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Affiliation(s)
- John W Smalley
- Unit of Basic Dental Science, Department of Clinical Dental Sciences, University of Liverpool, The Edwards Building, Daulby Street, Liverpool L69 3GN, UK.
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Hunt TA, Kooi C, Sokol PA, Valvano MA. Identification of Burkholderia cenocepacia genes required for bacterial survival in vivo. Infect Immun 2004; 72:4010-22. [PMID: 15213146 PMCID: PMC427415 DOI: 10.1128/iai.72.7.4010-4022.2004] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia cenocepacia (formerly Burkholderia cepacia complex genomovar III) causes chronic lung infections in patients with cystic fibrosis. In this work, we used a modified signature-tagged mutagenesis (STM) strategy for the isolation of B. cenocepacia mutants that cannot survive in vivo. Thirty-seven specialized plasposons, each carrying a unique oligonucleotide tag signature, were constructed and used to examine the survival of 2,627 B. cenocepacia transposon mutants, arranged in pools of 37 unique mutants, after a 10-day lung infection in rats by using the agar bead model. The recovered mutants were screened by real-time PCR, resulting in the identification of 260 mutants which presumably did not survive within the lungs. These mutants were repooled into smaller pools, and the infections were repeated. After a second screen, we isolated 102 mutants unable to survive in the rat model. The location of the transposon in each of these mutants was mapped within the B. cenocepacia chromosomes. We identified mutations in genes involved in cellular metabolism, global regulation, DNA replication and repair, and those encoding bacterial surface structures, including transmembrane proteins and cell surface polysaccharides. Also, we found 18 genes of unknown function, which are conserved in other bacteria. A subset of 12 representative mutants that were individually examined using the rat model in competition with the wild-type strain displayed reduced survival, confirming the predictive value of our STM screen. This study provides a blueprint to investigate at the molecular level the basis for survival and persistence of B. cenocepacia within the airways.
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Affiliation(s)
- Tracey A Hunt
- Department of Microbiology and Immunology, Dental Sciences Building, Rm. 3014, University of Western Ontario, London, Ontario N6A 5C1, Canada
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Paramaesvaran M, Nguyen KA, Caldon E, McDonald JA, Najdi S, Gonzaga G, Langley DB, DeCarlo A, Crossley MJ, Hunter N, Collyer CA. Porphyrin-mediated cell surface heme capture from hemoglobin by Porphyromonas gingivalis. J Bacteriol 2003; 185:2528-37. [PMID: 12670977 PMCID: PMC152631 DOI: 10.1128/jb.185.8.2528-2537.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The porphyrin requirements for growth recovery of Porphyromonas gingivalis in heme-depleted cultures are investigated. In addition to physiologically relevant sources of heme, growth recovery is stimulated by a number of noniron porphyrins. These data demonstrate that, as for Haemophilus influenzae, reliance on captured iron and on exogenous porphyrin is manifest as an absolute growth requirement for heme. A number of outer membrane proteins including some gingipains contain the hemoglobin receptor (HA2) domain. In cell surface extracts, polypeptides derived from HA2-containing proteins predominated in hemoglobin binding. The in vitro porphyrin-binding properties of a recombinant HA2 domain were investigated and found to be iron independent. Porphyrins that differ from protoporphyrin IX in only the vinyl aspect of the tetrapyrrole ring show comparable effects in competing with hemoglobin for HA2 and facilitate growth recovery. For some porphyrins which differ from protoporphyrin IX at both propionic acid side chains, the modification is detrimental in both these assays. Correlations of porphyrin competition and growth recovery imply that the HA2 domain acts as a high-affinity hemophore at the cell surface to capture porphyrin from hemoglobin. While some proteins involved with heme capture bind directly to the iron center, the HA2 domain of P. gingivalis recognizes heme by a mechanism that is solely porphyrin mediated.
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Affiliation(s)
- Mayuri Paramaesvaran
- Institute of Dental Research, Centre for Oral Health, Westmead Hospital, Wentworthville, Sydney NSW 2145, Australia
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Smalley JW, Birss AJ, Withnall R, Silver J. Interactions of Porphyromonas gingivalis with oxyhaemoglobin and deoxyhaemoglobin. Biochem J 2002; 362:239-45. [PMID: 11829761 PMCID: PMC1222381 DOI: 10.1042/0264-6021:3620239] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
When grown on blood-containing solid media, the anaerobic periodontal pathogen Porphyromonas gingivalis produces a haem pigment, the major component of which is the mu-oxo bishaem of iron protoporphyrin IX [Smalley, Silver, Marsh and Birss (1998) Biochem. J. 331, 681-685]. In this study, mu-oxo bishaem generation by P. gingivalis from oxy- and deoxyhaemoglobin was examined. Bacterial cells were shown to convert oxyhaemoglobin into methaemoglobin, which was degraded progressively, generating a mixture of both monomeric and mu-oxo dimeric iron protoporphyrin IX. The rate of methaemoglobin formation was accelerated in the presence of bacterial cells, but was inhibited by N-ethylmaleimide and tosyl-lysylchloromethylketone. Interaction of cells with deoxyhaemoglobin resulted in formation of an iron(III) haem species (Soret gamma(max), 393 nm), identified as pure mu-oxo bishaem.
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Affiliation(s)
- John W Smalley
- Unit of Oral Biology, The Edwards Building, Department of Clinical Dental Sciences, University of Liverpool, Daulby Street, Liverpool L69 3GN, U.K.
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Smalley JW, Charalabous P, Birss AJ, Hart CA. Detection of heme-binding proteins in epidemic strains of Burkholderia cepacia. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2001; 8:509-14. [PMID: 11329449 PMCID: PMC96092 DOI: 10.1128/cdli.8.3.509-514.2001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A panel of 30 previously characterized strains representing five genomovars from the Burkholderia cepacia complex (E. Mahenthiralingam, T. Coenye, J. W. Chung, D. P. Speert, J. R. W. Govan, P. Taylor, and P. Vandamme, J. Clin. Microbiol. 38:910--913, 2000) were examined for their iron protoporphyrin IX-binding ability. These included B. cepacia genomovars I and III and B. stabilis (formerly B. cepacia genomovar IV), B. multivorans (formerly B. cepacia genomovar II), and B. vietnamiensis (formerly B. cepacia genomovar V). Cells were exposed to micro-oxo bisheme of iron protoporphyrin IX (micro-oxo dimers) and examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing, nondenaturing conditions for the presence of heme-binding proteins using tetramethylbenzidine-H(2)O(2) staining. Seven of the 30 strains, each belonging to B. cepacia genomovar III and designated epidemic (in possessing the B. cepacia epidemic strain marker), expressed a 96- to 100-kDa heme-binding protein which was located in the outer membrane. The heme-binding protein of B. cepacia genomovar III epidemic strain C5424 bound iron(III) protoporphyrin IX in both the monomeric and micro-oxo bisheme forms. Cells of all strains grown on Columbia agar bound iron protoporphyrin IX in the micro-oxo bisheme (dimeric) form. There were no statistical differences between the five genomovars, or those possessing the heme-binding protein, in their micro-oxo bisheme-binding ability. Possession of the outer membrane heme-binding protein may be a pathogenicity trait in enabling the bacterium to withstand oxidative stresses in inflammatory exudates in the lung and may aid identification of invasive epidemic strains of B. cepacia.
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Affiliation(s)
- J W Smalley
- Department of Clinical Dental Sciences, The University of Liverpool, Liverpool, United Kingdom.
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Abaibou H, Chen Z, Olango GJ, Liu Y, Edwards J, Fletcher HM. vimA gene downstream of recA is involved in virulence modulation in Porphyromonas gingivalis W83. Infect Immun 2001; 69:325-35. [PMID: 11119521 PMCID: PMC97887 DOI: 10.1128/iai.69.1.325-335.2001] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A 0.9-kb open reading frame encoding a unique 32-kDa protein was identified downstream of the recA gene of Porphyromonas gingivalis. Reverse transcription-PCR and Northern blot analysis showed that both the recA gene and this open reading frame are part of the same transcriptional unit. This cloned fragment was insertionally inactivated using the ermF-ermAM antibiotic resistance cassette to create a defective mutant by allelic exchange. When plated on Brucella blood agar, the mutant strain, designated P. gingivalis FLL92, was non-black pigmented and showed significant reduction in beta-hemolysis compared with the parent strain, P. gingivalis W83. Arginine- and lysine-specific cysteine protease activities, which were mostly soluble, were approximately 90% lower than that of the parent strain. Expression of the rgpA, rgpB, and kgp protease genes was the same in P. gingivalis FLL92 as in the wild-type strain. In contrast to the parent strain, P. gingivalis FLL92 showed increased autoaggregration in addition to a significant reduction in hemagglutinating and hemolysin activities. In in vivo experiments using a mouse model, P. gingivalis FLL92 was dramatically less virulent than the parent strain. A molecular survey of this mutant and the parent strain using all known P. gingivalis insertion sequence elements as probes suggested that no intragenomic changes due to the movement of these elements have occurred in P. gingivalis FLL92. Taken together, these results suggest that the recA downstream gene, designated vimA (virulence-modulating gene), plays an important role in virulence modulation in P. gingivalis W83, possibly representing a novel posttranscriptional or translational regulation of virulence factors in P. gingivalis.
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Affiliation(s)
- H Abaibou
- Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA
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