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Chu L, Wu Y, Xu X, Phillips L, Kolodrubetz D. Glutathione catabolism by Treponema denticola impacts its pathogenic potential. Anaerobe 2020; 62:102170. [PMID: 32044394 PMCID: PMC7153967 DOI: 10.1016/j.anaerobe.2020.102170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 01/14/2020] [Accepted: 02/04/2020] [Indexed: 12/28/2022]
Abstract
Treponema denticola is a spirochete that is etiologic for periodontal diseases. This bacterium is one of two periodontal pathogens that have been shown to have a complete three step enzymatic pathway (GTSP) that catabolizes glutathione to H2S. This pathway may contribute to the tissue pathology seen in periodontitis since diseased periodontal pockets have lower glutathione levels than healthy sites with a concomitant increase in H2S concentration. In order to be able to demonstrate that glutathione catabolism by the GTSP is critical for the pathogenic potential of T. denticola, allelic replacement mutagenesis was used to make a deletion mutant (Δggt) in the gene encoding the first enzyme in the GTSP. The mutant cannot produce H2S from glutathione since it lacks gamma-glutamyltransferase (GGT) activity. The hemolytic and hemoxidation activities of wild type T. denticola plus glutathione are reduced to background levels with the Δggt mutant and the mutant has lost the ability to grow aerobically when incubated with glutathione. The Δggt bacteria with glutathione cause less cell death in human gingival fibroblasts (hGFs) in vitro than do wild type T. denticola and the levels of hGF death correlate with the amounts of H2S produced. Importantly, the mutant spirochetes plus glutathione make significantly smaller lesions than wild type bacteria plus glutathione in a mouse back lesion model that assesses soft tissue destruction, a major symptom of periodontal diseases. Our results are the first to prove that T. denticola thiol-compound catabolism by its gamma-glutamyltransferase can play a significant role in the in the types of host tissue damage seen in periodontitis.
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Affiliation(s)
- Lianrui Chu
- Department of Developmental Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Yimin Wu
- Department of Developmental Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Xiaoping Xu
- Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Linda Phillips
- Department of Microbiology, Immunology and Molecular Genetics, UT Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - David Kolodrubetz
- Department of Microbiology, Immunology and Molecular Genetics, UT Health San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
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Koregol AC, Kalburgi NB, Wagh AUK, Warad S. Gamma Glutamyl Transpeptidase, Smokeless Tobacco, Chronic Periodontitis: Exploring the Link. J Clin Diagn Res 2017; 11:ZC17-ZC20. [PMID: 28511501 DOI: 10.7860/jcdr/2017/23598.9476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/04/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Oxidative Stress (OS) is implicated in the pathogenesis of many systemic and oral diseases such as periodontal disease. Smokeless tobacco extract produces apoptosis and causes an imbalance between reactive oxygen species and antioxidants, such as Gamma Glutamyl Transpeptidase (GGT). Epidemiological research implied serum GGT within its normal range to be an early sensitive enzyme related to OS. AIM To assess how GGT fares as a biomarker in periodontitis subjects with or without the usage of smokeless tobacco and correlate it with clinical parameters. MATERIALS AND METHODS Ninety subjects were divided into three groups of healthy, chronic periodontitis, and smokeless tobacco users with chronic periodontitis from the dental outpatient department of P.M. Nadagouda Memorial Dental College and Hospital. Serum samples of patients were collected after obtaining consent and analyzed for GGT. Statistical Analysis was performed using ANOVA, and Pearson's correlation coefficient. RESULTS GGT levels were found to be significantly higher in chronic periodontitis patients compared to smokeless tobacco users with chronic periodontitis and healthy subjects. Conclusion: GGT may be used as a quick, easy and precise marker for measuring OS in patients with chronic periodontitis and smokeless tobacco users.
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Affiliation(s)
- Arati C Koregol
- Professor, Department of Periodontics, P.M. Nadagouda Memorial Dental College, Bagalkot, Karnataka, India
| | - Nagaraj B Kalburgi
- Professor, Department of Periodontics, P.M. Nadagouda Memorial Dental College, Bagalkot, Karnataka, India
| | - Apoorva U Kamat Wagh
- Postgraduate Student, Department of Periodontics, P.M. Nadagouda Memorial Dental College, Bagalkot, Karnataka, India
| | - Shivraj Warad
- Professor, Department of Periodontics, P.M. Nadagouda Memorial Dental College, Bagalkot, Karnataka, India
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Sreeram M, Suryakar AN, Dani NH. Is gamma-glutamyl transpeptidase a biomarker for oxidative stress in periodontitis? J Indian Soc Periodontol 2015; 19:150-4. [PMID: 26015663 PMCID: PMC4439622 DOI: 10.4103/0972-124x.149032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 10/08/2014] [Indexed: 12/30/2022] Open
Abstract
CONTEXT Periodontal disease and oxidative stress (OS) are part of a vicious cycle with each causing a deleterious effect on the other causing changes in the levels of antioxidants, and enzymes of antioxidant defense. Biomarkers and methods used for measuring OS are very expensive. AIMS To see how gamma-glutamyltransferase (GGT) fares, as a biomarker for OS in periodontits along with other routinely used biomarkers. DESIGN A cross-sectional study involving 300 people of which 150 were cases and 150 were controls. SETTING Candidates enrolled were patients visiting the OPD of MGV's Dental College and Hospital, Nasik, India between January 2011 and December 2012. MATERIALS AND METHODS Serum samples of patients with periodontitis, and controls were analyzed for malondialdehyde, superoxide dismutase (SOD), glutathione peroxidase (GPx), uric acid, and GGT. STATISTICAL ANALYSIS USED Analysis was performed using Student's t test. P <0.05 were considered to be significant. RESULTS Malondialdehyde values were found to be significantly higher cases, while SOD, GPx and uric acid levels were found to be lower than controls. GGT levels were significantly higher in cases as compared to controls. CONCLUSIONS GGT may be used as a cheap, quick, easy and precise marker for measuring OS.
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Affiliation(s)
- Meenakshi Sreeram
- Department of Physiology and Biochemistry, MGV's KBH Dental College and Hospital, Nasik, Maharashtra, India
| | | | - Nitin Hemchandra Dani
- Department of Periodontology, MGV's KBH Dental College and Hospital, Nasik, Maharashtra, India
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Dashper SG, Seers CA, Tan KH, Reynolds EC. Virulence factors of the oral spirochete Treponema denticola. J Dent Res 2010; 90:691-703. [PMID: 20940357 DOI: 10.1177/0022034510385242] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
There is compelling evidence that treponemes are involved in the etiology of several chronic diseases, including chronic periodontitis as well as other forms of periodontal disease. There are interesting parallels with other chronic diseases caused by treponemes that may indicate similar virulence characteristics. Chronic periodontitis is a polymicrobial disease, and recent animal studies indicate that co-infection of Treponema denticola with other periodontal pathogens can enhance alveolar bone resorption. The bacterium has a suite of molecular determinants that could enable it to cause tissue damage and subvert the host immune response. In addition to this, it has several non-classic virulence determinants that enable it to interact with other pathogenic bacteria and the host in ways that are likely to promote disease progression. Recent advances, especially in molecular-based methodologies, have greatly improved our knowledge of this bacterium and its role in disease.
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Affiliation(s)
- S G Dashper
- Cooperative Research Centre for Oral Health, Melbourne Dental School and Bio21 Institute, The University of Melbourne, 720 Swanston Street, Victoria 3010, Australia
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Grant MM, Brock GR, Matthews JB, Chapple ILC. Crevicular fluid glutathione levels in periodontitis and the effect of non-surgical therapy. J Clin Periodontol 2010; 37:17-23. [DOI: 10.1111/j.1600-051x.2009.01504.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Chu L, Xu X, Su J, Song L, Lai Y, Dong Z, Cappelli D. Role of Aggregatibacter actinomycetemcomitans in glutathione catabolism. ACTA ACUST UNITED AC 2009; 24:236-42. [PMID: 19416454 DOI: 10.1111/j.1399-302x.2008.00501.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Our previous studies demonstrated that three enzymes, gamma-glutamyltransferase (GGT), cysteinylglycinase (CGase) and cystalysin, are required for the catabolism of glutathione to produce hydrogen sulfide (H(2)S) in Treponema denticola. In this study, we examined glutathione catabolism in Aggregatibacter actinomycetemcomitans. METHODS The GGT and CGase of A. actinomycetemcomitans were determined by biological methods and GGT was characterized using a molecular biological approach. RESULTS A. actinomycetemcomitans showed GGT and CGase activity, but could not produce H(2)S from glutathione. The addition of recombinant T. denticola cystalysin, an l-cysteine desulfhydrase, to whole cells of A. actinomycetemcomitans resulted in the production of H(2)S from glutathione. Subsequently, we cloned A. actinomycetemcomitans GGT gene (ggt) and overexpressed the 63 kDa GGT protein. The recombinant A. actinomycetemcomitans GGT was purified and identified. The K(cat)/K(m) of the recombinant GGT from N-gamma-l-glutamyl-4-nitroaniline as substrate was 31/microm/min. The activity of GGT was optimum at pH 6.9-7.1 and enhanced by thiol-containing compounds. CONCLUSION The results demonstrated that A. actinomycetemcomitans had GGT and CGase activities and that the GGT was characterized. The possible role of A. actinomycetemcomitans in glutathione metabolism and H(2)S production from oral bacteria was discussed.
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Affiliation(s)
- L Chu
- Department of Orthodontics, University of Texas Health Sciences Center, San Antonio, TX 78229, USA.
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Chu L, Lai Y, Xu X, Eddy S, Yang S, Song L, Kolodrubetz D. A 52-kDa leucyl aminopeptidase from treponema denticola is a cysteinylglycinase that mediates the second step of glutathione metabolism. J Biol Chem 2008; 283:19351-8. [PMID: 18482986 PMCID: PMC2443665 DOI: 10.1074/jbc.m801034200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 04/28/2008] [Indexed: 11/06/2022] Open
Abstract
The metabolism of glutathione by the periodontal pathogen Treponema denticola produces hydrogen sulfide, which may play a role in the host tissue destruction seen in periodontitis. H2S production in this organism has been proposed to occur via a three enzyme pathway, gamma-glutamyltransferase, cysteinylglycinase (CGase), and cystalysin. In this study, we describe the purification and characterization of T. denticola CGase. Standard approaches were used to purify a 52-kDa CGase activity from T. denticola, and high pressure liquid chromatography electrospray ionization tandem mass spectrometry analysis of this molecule showed that it matches the amino acid sequence of a predicted 52-kDa protein in the T. denticola genome data base. A recombinant version of this protein was overexpressed in and purified from Escherichia coli and shown to catalyze the hydrolysis of cysteinylglycine (Cys-Gly) with the same kinetics as the native protein. Surprisingly, because sequence homology indicates that this protein is a member of a family of metalloproteases called M17 leucine aminopeptidases, the preferred substrate for the T. denticola protein is Cys-Gly (k cat/Km of 8.2 microm(-1) min(-1)) not l-Leu-p-NA (k cat/Km of 1.1 microm(-1) min(-1)). The activity of CGase for Cys-Gly is optimum at pH 7.3 and is enhanced by Mn2+, Co2+, or Mg2+ but not by Zn2+ or Ca2+. Importantly, in combination with the two other previously purified T. denticola enzymes, gamma-glutamyltransferase and cystalysin, CGase mediates the in vitro degradation of glutathione into the expected end products, including H2S. These results prove that T. denticola contains the entire three-step pathway to produce H2S from glutathione, which may be important for pathogenesis.
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Affiliation(s)
- Lianrui Chu
- Department of Orthodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA.
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Lai Y, Chu L. Novel mechanism for conditional aerobic growth of the anaerobic bacterium Treponema denticola. Appl Environ Microbiol 2008; 74:73-9. [PMID: 17981934 PMCID: PMC2223203 DOI: 10.1128/aem.01972-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Accepted: 10/25/2007] [Indexed: 01/08/2023] Open
Abstract
Treponema denticola, a periodontal pathogen, has recently been shown to exhibit properties of a facultative anaerobic spirochete, in contrast to its previous recognition as an obligate anaerobic bacterium. In this study, the capacity and possible mechanism of T. denticola survival and growth under aerobic conditions were investigated. Factors detrimental to the growth of T. denticola ATCC 33405, such as oxygen concentration and hydrogen sulfide (H(2)S) levels as well as the enzyme activities of gamma-glutamyltransferase, cysteinylglycinase, and cystalysin associated with the cells were monitored. The results demonstrated that T. denticola grew only at deeper levels of broth (>or=3 ml in a 10-ml tube), high inoculation ratios (>or=20% of culture in medium), and short cultivation times (
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Affiliation(s)
- Yanlai Lai
- Department of Orthodontics, University of Texas Health Science Center, San Antonio, TX 78229, USA
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Chapple ILC, Matthews JB. The role of reactive oxygen and antioxidant species in periodontal tissue destruction. Periodontol 2000 2007; 43:160-232. [PMID: 17214840 DOI: 10.1111/j.1600-0757.2006.00178.x] [Citation(s) in RCA: 524] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Iain L C Chapple
- Unit of Periodontology, The University of Birmingham School of Dentistry, Birmingham, UK
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Chu L, Xu X, Dong Z, Cappelli D, Ebersole JL. Role for recombinant gamma-glutamyltransferase from Treponema denticola in glutathione metabolism. Infect Immun 2003; 71:335-42. [PMID: 12496183 PMCID: PMC143415 DOI: 10.1128/iai.71.1.335-342.2003] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Volatile sulfur compounds, including hydrogen sulfide (H(2)S), have been implicated in the development of periodontal disease. Glutathione is an important thiol source for H(2)S production in periodontal pockets. Our recent studies have delineated a pathway of glutathione metabolism in Treponema denticola that releases H(2)S. In this pathway, gamma-glutamyltransferase (GGT) has been proposed to catalyze the first step of glutathione degradation. We have cloned the gene of GGT from T. denticola, which contains an open reading frame of 726 bp encoding a protein of 241 amino acids. Transformation of this gene into Escherichia coli led to the expression of a recombinant protein. After purification by chromatography, the recombinant protein showed enzymatic activity typical of GGT, catalyzing the degradation of Na-gamma-glutamyl-4-nitroaniline (GNA) and the hydrolysis of glutathione, releasing glutamic acid or glutamine and cysteinylglycine. L-Cysteine is not a substrate of GGT. Importantly, GNA, when added to T. denticola, was able to compete with glutathione and inhibit the production of H(2)S, ammonia, and pyruvate. This was accompanied by the suppression of hemoxidative and hemolytic activities of the bacteria. Purified GGT was inactivated by TLCK (Nalpha-p-tosyl-L-lysine chloromethyl ketone) and proteinase K treatment. However, higher enzymatic activity was demonstrated in the presence of 2-mercaptoethanol and dithiothreitol. Our further experiments showed that the addition of recombinant GGT to Porphyromonas gingivalis, a bacterium without significant glutathione-metabolizing capacity, drastically increased the utilization of glutathione by the bacterium, producing H(2)S, ammonia, and pyruvate. This was again accompanied by enhanced bacterial hemoxidative and hemolytic activities. Together, the results suggest an important role for GGT in glutathione metabolism in oral bacteria.
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Affiliation(s)
- Lianrui Chu
- Department of Orthodontics, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
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Sela MN. Role of Treponema denticola in periodontal diseases. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2002; 12:399-413. [PMID: 12002822 DOI: 10.1177/10454411010120050301] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Among periodontal anaerobic pathogens, the oral spirochetes, and especially Treponema denticola, have been associated with periodontal diseases such as early-onset periodontitis, necrotizing ulcerative gingivitis, and acute pericoronitis. Basic research as well as clinical evidence suggest that the prevalence of T denticola, together with other proteolytic gram-negative bacteria in high numbers in periodontal pockets, may play an important role in the progression of periodontal disease. The accumulation of these bacteria and their products in the pocket may render the surface lining periodontal cells highly susceptible to lysis and damage. T. denticola has been shown to adhere to fibroblasts and epithelial cells, as well as to extracellular matrix components present in periodontal tissues, and to produce several deleterious factors that may contribute to the virulence of the bacteria. These bacterial components include outer-sheath-associated peptidases, chymotrypsin-like and trypsin-like proteinases, hemolytic and hemagglutinating activities, adhesins that bind to matrix proteins and cells, and an outer-sheath protein with pore-forming properties. The effects of T. denticola whole cells and their products on a variety of host mucosal and immunological cells has been studied extensively (Fig. 1). The clinical data regarding the presence of T. denticola in periodontal health and disease, together with the basic research results involving the role of T. denticola factors and products in relation to periodontal diseases, are reviewed and discussed in this article.
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Affiliation(s)
- M N Sela
- Deportment of Oral Biology, Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel.
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Chu L, Dong Z, Xu X, Cochran DL, Ebersole JL. Role of glutathione metabolism of Treponema denticola in bacterial growth and virulence expression. Infect Immun 2002; 70:1113-20. [PMID: 11854190 PMCID: PMC127775 DOI: 10.1128/iai.70.3.1113-1120.2002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hydrogen sulfide (H(2)S) is a major metabolic end product detected in deep periodontal pockets that is produced by resident periodontopathic microbiota associated with the progression of periodontitis. Treponema denticola, a member of the subgingival biofilm at disease sites, produces cystalysin, an enzyme that catabolizes cysteine, releasing H(2)S. The metabolic pathway leading to H(2)S formation in periodontal pockets has not been determined. We used a variety of thiol compounds as substrates for T. denticola to produce H(2)S. Our results indicate that glutathione, a readily available thiol source in periodontal pockets, is a suitable substrate for H(2)S production by this microorganism. In addition to H(2)S, glutamate, glycine, ammonia, and pyruvate were metabolic end products of metabolism of glutathione. Cysteinyl glycine (Cys-Gly) was also catabolized by the bacteria, yielding glycine, H(2)S, ammonia, and pyruvate. However, purified cystalysin could not catalyze glutathione and Cys-Gly degradation in vitro. Moreover, the enzymatic activity(ies) in T. denticola responsible for glutathione breakdown was inactivated by trypsin or proteinase K, by heating (56 degrees C) and freezing (-20 degrees C), by sonication, and by exposure to N alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK). These treatments had no effect on degradation of cysteine by the purified enzyme. In this study we delineated an enzymatic pathway for glutathione metabolism in the oral spirochete T. denticola; our results suggest that glutathione metabolism plays a role in bacterial nutrition and potential virulence expression.
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Affiliation(s)
- Lianrui Chu
- Department of Periodontics, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
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Chu L, Ebersole JL, Holt SC. Hemoxidation and binding of the 46-kDa cystalysin of Treponema denticola leads to a cysteine-dependent hemolysis of human erythrocytes. ORAL MICROBIOLOGY AND IMMUNOLOGY 1999; 14:293-303. [PMID: 10551156 DOI: 10.1034/j.1399-302x.1999.140505.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cystalysin, a 46-kDa protein isolated from the cytosol of Treponema denticola, was capable of both cysteine dependent hemoxidation and hemolysis of human and sheep red blood cells. The activities were characteristic of a cysteine desulfhydrase. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western immunoblotting analysis of the interaction of cystalysin with the red blood cells revealed an interaction of the protein with the red blood cell membrane. Substrates for the enzyme (including L-cysteine and beta-chloroalanine) enhanced the interaction, which occurred with both whole red blood cells as well as with isolated and purified red blood cell ghosts. SDS-PAGE and western immunoblotting employing anti-hemoglobin serum revealed that, during the hemoxidative events, the hemoglobin molecule associated with the red blood cell membrane, forming putative Heinz bodies. Spectrophotometric analysis of the hemoxidative events (cystalysin + cysteine + red blood cells) revealed a chemical modification of the native hemoglobin to sulfhemoglobin and methemoglobin. Hemoxidation also resulted in the degradation of both the red blood cell alpha- and beta-spectrin. The results presented suggest that the interaction of cystalysin with the red blood cell membrane results in the chemical oxidation of the hemoglobin molecule as well as an alteration in the red blood cell membrane itself.
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Affiliation(s)
- L Chu
- Department of Microbiology, University of Texas Health Science Center at San Antonio 78284, USA
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