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Hagen SJ, Ang LH, Zheng Y, Karahan SN, Wu J, Wang YE, Caron T, Gad A, Muthupalani S, Fox JG. Loss of Tight Junction Protein Claudin 18 Promotes Progressive Neoplasia Development in Mouse Stomach. Gastroenterology 2018; 155:1852-1867. [PMID: 30195448 PMCID: PMC6613545 DOI: 10.1053/j.gastro.2018.08.041] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 08/12/2018] [Accepted: 08/24/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Loss of claudin 18 (CLDN18), a membrane-spanning tight junction protein, occurs during early stages of development of gastric cancer and associates with shorter survival times of patients. We investigated whether loss of CLDN18 occurs in mice that develop intraepithelial neoplasia with invasive glands due to infection with Helicobacter pylori, and whether loss is sufficient to promote the development of similar lesions in mice with or without H pylori infection. METHODS We performed immunohistochemical analyses in levels of CLDN18 in archived tissues from B6:129 mice infected with H pylori for 6 to 15 months. We analyzed gastric tissues from B6:129S5-Cldn18tm1Lex/Mmucd mice, in which the CLDN18 gene was disrupted in gastric tissues (CLDN18-knockout mice), or from control mice with a full-length CLDN18 gene (CLDN18+/+; B6:129S5/SvEvBrd) or heterozygous disruption of CLDN18 (CLDN18+/-; B6:129S5/SvEvBrd) that were infected with H pylori SS1 or PMSS1 at 6 weeks of age and tissues collected for analysis at 20 and 30 weeks after infection. Tissues from CLDN18-knockout mice and control mice with full-length CLDN18 gene expression were also analyzed without infection at 7 weeks and 2 years after birth. Tissues from control and CLDN18-knockout mice were analyzed by electron microscopy, stained by conventional methods and analyzed for histopathology, prepared by laser capture microdissection and analyzed by RNAseq, and immunostained for lineage markers, proliferation markers, and stem cell markers and analyzed by super-resolution or conventional confocal microscopy. RESULTS CLDN18 had a basolateral rather than apical tight junction localization in gastric epithelial cells. B6:129 mice infected with H pylori, which developed intraepithelial neoplasia with invasive glands, had increasing levels of CLDN18 loss over time compared with uninfected mice. In B6:129 mice infected with H pylori compared with uninfected mice, CLDN18 was first lost from most gastric glands followed by disrupted and reduced expression in the gastric neck and in surface cells. Gastric tissues from CLDN18-knockout mice had low levels of inflammation but increased cell proliferation, expressed markers of intestinalized proliferative spasmolytic polypeptide-expressing metaplasia, and had defects in signal transduction pathways including p53 and STAT signaling by 7 weeks after birth compared with full-length CLDN18 gene control mice. By 20 to 30 weeks after birth, gastric tissues from uninfected CLDN18-knockout mice developed intraepithelial neoplasia that invaded the submucosa; by 2 years, gastric tissues contained large and focally dysplastic polypoid tumors with invasive glands that invaded the serosa. CONCLUSIONS H pylori infection of B6:129 mice reduced the expression of CLDN18 early in gastric cancer progression, similar to previous observations from human gastric tissues. CLDN18 regulates cell lineage differentiation and cellular signaling in mouse stomach; CLDN18-knockout mice develop intraepithelial neoplasia and then large and focally dysplastic polypoid tumors in the absence of H pylori infection.
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Affiliation(s)
- Susan J. Hagen
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Harvard Medical School, Boston, MA 02115, USA
| | - Lay-Hong Ang
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Harvard Medical School, Boston, MA 02115, USA
| | - Yi Zheng
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Harvard Medical School, Boston, MA 02115, USA,Present address: Perkin-Elmer Corporation, Hopkinton, MA 01748, USA
| | - Salih N. Karahan
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Dr. Karahan was a visiting medical student from the Koç University School of Medicine, Bakirkoy, Istanbul,TURKEY
| | - Jessica Wu
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Present address: Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yaoyu E. Wang
- Harvard Medical School, Boston, MA 02115, USA,Center for Cancer Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02130 USA
| | - Tyler Caron
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA,Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA,Present address: Broad Institute, Cambridge, MA 02142, USA
| | - Aniket Gad
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Sureshkumar Muthupalani
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - James G. Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Mannion A, Shen Z, Feng Y, Artim SC, Ravindra K, Ge Z, Fox JG. Gamma-glutamyltranspeptidase expression by Helicobacter saguini, an enterohepatic Helicobacter species isolated from cotton top tamarins with chronic colitis. Cell Microbiol 2018; 21:e12968. [PMID: 30365223 DOI: 10.1111/cmi.12968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/12/2018] [Accepted: 10/16/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Helicobacter saguini is a novel enterohepatic Helicobacter species isolated from captive cotton top tamarins with chronic colitis and colon cancer. Monoassociated H. saguini infection in gnotobiotic IL-10-/- mice causes typhlocolitis and dysplasia; however, the virulent mechanisms of this species are unknown. Gamma-glutamyltranspeptidase (GGT) is an enzymatic virulence factor expressed by pathogenic Helicobacter and Campylobacter species that inhibits host cellular proliferation and promotes inflammatory-mediated gastrointestinal pathology. The aim of this study was to determine if H. saguini expresses an enzymatically active GGT homologue with virulence properties. EXPERIMENTAL PROCEDURES Two putative GGT paralogs (HSGGT1 and HSGGT2) identified in the H. saguini genome were bioinformatically analysed to predict enzymatic functionality and virulence potential. An isogenic knockout mutant strain and purified recombinant protein of HSGGT1 were created to study enzymatic activity and virulence properties by in vitro biochemical and cell culture experiments. RESULTS Bioinformatic analysis predicted that HSGGT1 has enzymatic functionality and is most similar to the virulent homologue expressed by Helicobacter bilis, whereas HSGGT2 contains putatively inactivating mutations. An isogenic knockout mutant strain and recombinant HSGGT1 protein were successfully created and demonstrated that H. saguini has GGT enzymatic activity. Recombinant HSGGT1 protein and sonicate from wild-type but not mutant H. saguini inhibited gastrointestinal epithelial and lymphocyte cell proliferation without evidence of cell death. The antiproliferative effect by H. saguini sonicate or recombinant HSGGT1 protein could be significantly prevented with glutamine supplementation or the GGT-selective inhibitor acivicin. Recombinant HSGGT1 protein also induced proinflammatory gene expression in colon epithelial cells. CONCLUSIONS This study shows that H. saguini may express GGT as a potential virulence factor and supports further in vitro and in vitro studies into how GGT expression by enterohepatic Helicobacter species influences the pathogenesis of gastrointestinal inflammatory diseases.
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Affiliation(s)
- Anthony Mannion
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zeli Shen
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Yan Feng
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Stephen C Artim
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kodihalli Ravindra
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zhongming Ge
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Helicobacter pylori γ-glutamyl transferase contributes to colonization and differential recruitment of T cells during persistence. Sci Rep 2017; 7:13636. [PMID: 29057967 PMCID: PMC5651840 DOI: 10.1038/s41598-017-14028-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 10/05/2017] [Indexed: 12/22/2022] Open
Abstract
Helicobacter pylori γ-glutamyl transferase (gGT) is a key bacterial virulence factor that is not only important for bacterial gastric colonization but also related to the development of gastric pathology. Despite accumulating evidence for pathogenic and immunologic functions of H. pylori gGT, it is still unclear how it supports gastric colonization and how its specific effects on the host’s innate and adaptive immune responses contribute to colonization and pathology. We have compared mice showing similar bacterial load after infection with gGT-proficient or gGT-deficient H. pylori to analyse the specific role of the enzyme during infection. Our data indicate that H. pylori gGT supports initial colonization. Nevertheless, bacteria lacking gGT can still colonize and persist. We observed that the presence of gGT during infection favoured a proinflammatory innate and adaptive immune response. Notably, H. pylori gGT activity was linked to increased levels of IFNγ, which were attributed to a differential recruitment of CD8+ T cells to the stomach. Our data support an essential role for H. pylori gGT in gastric colonization and further suggest that gGT favours infiltration of CD8+ cells to the gastric mucosa, which might play an important and yet overlooked role in the pathogenesis of H. pylori.
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Alterations in metabolic pathways in stomach of mice infected with Helicobacter pylori. Microb Pathog 2017; 109:78-85. [DOI: 10.1016/j.micpath.2017.05.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/15/2017] [Accepted: 05/19/2017] [Indexed: 12/16/2022]
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Abstract
Helicobacter pylori is a ubiquitous gastropathogen infecting more than half of the world population. It is associated with dyspepsia, gastritis, gastroduodenal ulcers, mucus-associated lymphoid tissue lymphoma and gastric carcinoma. Current recommended therapy does not eradicate infection in all treated cases and at least 20% post-treatment patients continue to suffer. Salvage therapy helps some of these nonresponders, but resistance to available antibiotics is mounting. Hence, its treatment still remains a daunting task for the practicing physician. Novel medications with improved efficacy and tolerability and with less chances of resistance are required. The present review attempts to discuss the newer patents in this field, which demonstrate a promising future role in the management of H. pylori infection and its consequent problems.
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De Bruyne E, Ducatelle R, Foss D, Sanchez M, Joosten M, Zhang G, Smet A, Pasmans F, Haesebrouck F, Flahou B. Oral glutathione supplementation drastically reduces Helicobacter-induced gastric pathologies. Sci Rep 2016; 6:20169. [PMID: 26833404 PMCID: PMC4735851 DOI: 10.1038/srep20169] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 12/23/2015] [Indexed: 12/13/2022] Open
Abstract
Helicobacter (H.) suis causes gastric pathologies in both pigs and humans. Very little is known on the metabolism of this bacterium and its impact on the host. In this study, we have revealed the importance of the glutamate-generating metabolism, as shown by a complete depletion of glutamine (Gln) in the medium during H. suis culture. Besides Gln, H. suis can also convert glutathione (GSH) to glutamate, and both reactions are catalyzed by the H. suis γ-glutamyltranspeptidase (GGT). Both for H. pylori and H. suis, it has been hypothesized that the degradation of Gln and GSH may lead to a deficiency for the host, possibly initiating or promoting several pathologies. Therefore the in vivo effect of oral supplementation with Gln and GSH was assessed. Oral supplementation with Gln was shown to temper H. suis induced gastritis and epithelial (hyper)proliferation in Mongolian gerbils. Astonishingly, supplementation of the feed with GSH, another GGT substrate, resulted in inflammation and epithelial proliferation levels returning to baseline levels of uninfected controls. This indicates that Gln and GSH supplementation may help reducing tissue damage caused by Helicobacter infection in both humans and pigs, highlighting their potential as a supportive therapy during and after Helicobacter eradication therapy.
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Affiliation(s)
- Ellen De Bruyne
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Richard Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | | | | | - Myrthe Joosten
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Guangzhi Zhang
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Annemieke Smet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Bram Flahou
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Caron TJ, Scott KE, Fox JG, Hagen SJ. Tight junction disruption: Helicobacter pylori and dysregulation of the gastric mucosal barrier. World J Gastroenterol 2015; 21:11411-11427. [PMID: 26523106 PMCID: PMC4616217 DOI: 10.3748/wjg.v21.i40.11411] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 06/26/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
Long-term chronic infection with Helicobacter pylori (H. pylori) is a risk factor for gastric cancer development. In the multi-step process that leads to gastric cancer, tight junction dysfunction is thought to occur and serve as a risk factor by permitting the permeation of luminal contents across an otherwise tight mucosa. Mechanisms that regulate tight junction function and structure in the normal stomach, or dysfunction in the infected stomach, however, are largely unknown. Although conventional tight junction components are expressed in gastric epithelial cells, claudins regulate paracellular permeability and are likely the target of inflammation or H. pylori itself. There are 27 different claudin molecules, each with unique properties that render the mucosa an intact barrier that is permselective in a way that is consistent with cell physiology. Understanding the architecture of tight junctions in the normal stomach and then changes that occur during infection is important but challenging, because most of the reports that catalog claudin expression in gastric cancer pathogenesis are contradictory. Furthermore, the role of H. pylori virulence factors, such as cytotoxin-associated gene A and vacoulating cytotoxin, in regulating tight junction dysfunction during infection is inconsistent in different gastric cell lines and in vivo, likely because non-gastric epithelial cell cultures were initially used to unravel the details of their effects on the stomach. Hampering further study, as well, is the relative lack of cultured cell models that have tight junction claudins that are consistent with native tissues. This summary will review the current state of knowledge about gastric tight junctions, normally and in H. pylori infection, and make predictions about the consequences of claudin reorganization during H. pylori infection.
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Lee YM, Kim MJ, Kim Y, Kim H. Glutamine Deprivation Causes Hydrogen Peroxide-induced Interleukin-8 Expression via Jak1/Stat3 Activation in Gastric Epithelial AGS Cells. J Cancer Prev 2015; 20:179-84. [PMID: 26473156 PMCID: PMC4597806 DOI: 10.15430/jcp.2015.20.3.179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The Janus kinase (Jak)/Signal transducers of activated transcription (Stat) pathway is an upstream signaling pathway for NF-κB activation in Helicobacter pylori-induced interleukin (IL)-8 production in gastric epithelial AGS cells. H. pylori activates NADPH oxidase and produces hydrogen peroxide, which activates Jak1/Stat3 in AGS cells. Therefore, hydrogen peroxide may be critical for IL-8 production via Jak/Stat activation in gastric epithelial cells. Glutamine is depleted during severe injury and stress and contributes to the formation of glutathione (GSH), which is involved in conversion of hydrogen peroxide into water as a cofactor for GSH peroxidase. METHODS We investigated whether glutamine deprivation induces hydrogen peroxide-mediated IL-8 production and whether hydrogen peroxide activates Jak1/Stat3 to induce IL-8 in AGS cells. Cells were cultured in the presence or absence of glutamine or hydrogen peroxide, with or without GSH or a the Jak/Stat specific inhibitor AG490. RESULTS Glutamine deprivation decreased GSH levels, but increased levels of hydrogen peroxide and IL-8, an effect that was inhibited by treatment with GSH. Hydrogen peroxide induced the activation of Jak1/Stat3 time-dependently. AG490 suppressed hydrogen peroxide- induced activation of Jak1/Stat3 and IL-8 expression in AGS cells, but did not affect levels of reactive oxygen species in AGS cells. CONCLUSIONS In gastric epithelial AGS cells, glutamine deprivation increases hydrogen peroxide levels and IL-8 expression, which may be mediated by Jak1/Stat3 activation. Glutamine supplementation may be beneficial for preventing gastric inflammation by suppressing hydrogen peroxide-mediated Jak1/Stat3 activation and therefore, reducing IL-8 production. Scavenging hydrogen peroxide or targeting Jak1/Stat3 may also prevent oxidant-mediated gastric inflammation.
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Affiliation(s)
- Yun Mi Lee
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Korea
| | - Mi Jung Kim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Korea
| | - Youngha Kim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Korea
| | - Hyeyoung Kim
- Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Korea
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Wüstner S, Mejías-Luque R, Koch MF, Rath E, Vieth M, Sieber SA, Haller D, Gerhard M. Helicobacter pylori γ-glutamyltranspeptidase impairs T-lymphocyte function by compromising metabolic adaption through inhibition of cMyc and IRF4 expression. Cell Microbiol 2014; 17:51-61. [PMID: 25087912 DOI: 10.1111/cmi.12335] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/13/2014] [Accepted: 07/25/2014] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori (H. pylori) is a human-specific pathogen that has evolved to cope with the immune response elicited against the infection. We previously reported that H. pylori γ-glutamyltranspeptidase (gGT) impairs T-lymphocyte proliferation and thus might act as immune regulatory factor. In this study, we analysed the underlying mechanism and its implications for H. pylori persistence. We found that H. pylori gGT compromised T-cell proliferation, activation and effector cytokine expression by specifically depriving the extracellular space of glutamine. When assessing signalling cascades and transcription factors affected by H. pylori gGT, we found that expression of cMyc and IRF4, both required for metabolic adaptation of T-lymphocytes, was highly sensitive to extracellular glutamine levels and downregulated upon gGT treatment. Moreover, we could confirm decreased IRF4 expression in T-lymphocytes infiltrating the stomach of infected individuals. Thus, our results suggest that H. pylori gGT-mediated glutamine deprivation in the gastric mucosa may suppress T-cell function thereby contributing to bacterial persistence.
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Affiliation(s)
- Stefanie Wüstner
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, 81675, Munich, Germany
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Rimbara E, Mori S, Kim H, Shibayama K. Role of γ-glutamyltranspeptidase in the pathogenesis of Helicobacter pylori infection. Microbiol Immunol 2014; 57:665-73. [PMID: 23937242 DOI: 10.1111/1348-0421.12089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 02/06/2023]
Abstract
γ-Glutamyltranspeptidase and asparaginase have been shown to play important roles in Helicobacter pylori colonization and cell death induced by H. pylori infection. In this study, the association of γ-glutamyltranspeptidase and asparaginase was elucidated by comparing activities of both deamidases in H. pylori strains from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer. γ-Glutamyltranspeptidase activities in H. pylori strains from patients with gastric cancer were significantly higher than in those from patients with chronic gastritis or gastric ulcers. There was a wide range of asparaginase activities in H. pylori strains from patients with gastric cancer and these were not significantly than those from patients with other diseases. To identify the contributions of γ-glutamyltranspeptidase and asparaginase to gastric cell inflammation, human gastric epithelial cells (AGS line) were infected with H. pylori wild-type and knockout strains and inflammatory responses evaluated by induction of interleukin-8 (IL-8). IL-8 response was significantly decreased by knockout of the γ-glutamyltranspeptidase-encoding gene but not by knockout of the asparaginase-encoding gene. Additionally, IL-8 induction by infection with the H. pylori wild-type strain was significantly decreased by adding glutamine during infection. These findings indicate that IL-8 induction caused by γ-glutamyltranspeptidase activity in H. pylori is mainly attributable to depletion of glutamine. These data suggest that γ-glutamyltranspeptidase plays a significant role in the chronic inflammation caused by H. pylori infection.
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Affiliation(s)
- Emiko Rimbara
- Department of Bacteriology II, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama-Shi, Tokyo, 208-0011, Japan
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11
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Zhang G, Ducatelle R, Pasmans F, D’Herde K, Huang L, Smet A, Haesebrouck F, Flahou B. Effects of Helicobacter suis γ-glutamyl transpeptidase on lymphocytes: modulation by glutamine and glutathione supplementation and outer membrane vesicles as a putative delivery route of the enzyme. PLoS One 2013; 8:e77966. [PMID: 24147103 PMCID: PMC3797756 DOI: 10.1371/journal.pone.0077966] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 09/08/2013] [Indexed: 12/11/2022] Open
Abstract
Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4(+) T cells, CD8(+) T cells, and CD19(+) B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4(+) T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general.
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Affiliation(s)
- Guangzhi Zhang
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- * E-mail:
| | - Richard Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Katharina D’Herde
- Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Liping Huang
- Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Annemieke Smet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Bram Flahou
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Ren W, Liu S, Chen S, Zhang F, Li N, Yin J, Peng Y, Wu L, Liu G, Yin Y, Wu G. Dietary l-glutamine supplementation increases Pasteurella multocida burden and the expression of its major virulence factors in mice. Amino Acids 2013; 45:947-55. [DOI: 10.1007/s00726-013-1551-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 06/27/2013] [Indexed: 12/14/2022]
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13
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Seo JH, Fox JG, Peek RM, Hagen SJ. N-methyl D-aspartate channels link ammonia and epithelial cell death mechanisms in Helicobacter pylori Infection. Gastroenterology 2011; 141:2064-75. [PMID: 21925124 PMCID: PMC3658443 DOI: 10.1053/j.gastro.2011.08.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 08/12/2011] [Accepted: 08/29/2011] [Indexed: 01/29/2023]
Abstract
BACKGROUND & AIMS Helicobacter pylori infection is a risk factor for gastric cancer. Ammonia/ammonium (A/A) is a cytotoxin generated by H pylori that kills gastric epithelial cells. We investigated whether A/A cytotoxicity occurs by activating N-methyl d-aspartate (NMDA) channels, which results in Ca(2+) permeation and epithelial cell death. METHODS Gastric epithelial cells were cultured to confluence and then incubated with A/A and NMDA channel or cell signaling antagonists. Cells were incubated with wild-type H pylori or mutant strains that do not produce A/A. Changes in intracellular Ca(2+) were examined in living cells by confocal microscopy. Biochemical and histochemical techniques were used to examine the relationship between A/A-induced cell death and intracellular levels of Ca(2+). RESULTS A/A increased Ca(2+) permeation in gastric epithelial cells; the increase was blocked by NMDA receptor and cell signaling antagonists. Wild-type, but not mutant H pylori, also caused extensive Ca(2+) permeation of gastric epithelial cells, which was blocked when NMDA-receptor expression was repressed. Ca(2+) that entered cells was initially cytoplasmic and activated proteases. Later, the Ca(2+) was sequestered to cytoplasmic vacuoles that are dilatations of the endoplasmic reticulum. Inositol-3-phosphate-dependent release of Ca(2+) from the endoplasmic reticulum and protease activity damaged mitochondria, reduced levels of adenosine triphosphate, and transcriptionally up-regulated cell death effectors. Expression of the NMDA receptor was altered in stomachs of mice infected with H pylori. CONCLUSIONS A/A affects gastric epithelial cell viability by allowing excessive Ca(2+) permeation through NMDA channels. NMDA channels might thereby regulate cell survival and death pathways during development of gastric cancers associated with H pylori infection.
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Affiliation(s)
- Ji Hye Seo
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
| | - James G. Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, 02139.3
| | - Richard M. Peek
- Division of Gastroenterology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Susan J. Hagen
- Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215
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Coupled amino acid deamidase-transport systems essential for Helicobacter pylori colonization. Infect Immun 2010; 78:2782-92. [PMID: 20368342 DOI: 10.1128/iai.00149-10] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In addition to their classical roles as carbon or nitrogen sources, amino acids can be used for bacterial virulence, colonization, or stress resistance. We found that original deamidase-transport systems impact colonization by Helicobacter pylori, a human pathogen associated with gastric pathologies, including adenocarcinoma. We demonstrated that l-asparaginase (Hp-AnsB) and gamma-glutamyltranspeptidase (Hp-gammaGT) are highly active periplasmic deamidases in H. pylori, producing ammonia and aspartate or glutamate from asparagine and glutamine, respectively. Hp-GltS was identified as a sole and specialized transporter for glutamate, while aspartate was exclusively imported by Hp-DcuA. Uptake of Gln and Asn strictly relies on indirect pathways following prior periplasmic deamidation into Glu and Asp. Hence, in H. pylori, the coupled action of periplasmic deamidases with their respective transporters enables the acquisition of Glu and Asp from Gln and Asn, respectively. These systems were active at neutral rather than acidic pH, suggesting their function near the host epithelial cells. We showed that Hp-DcuA, the fourth component of these novel deamidase-transport systems, was as crucial as Hp-gammaGT, Hp-AnsB, and Hp-GltS for animal model colonization. In conclusion, the pH-regulated coupled amino acid deamidase-uptake system represents an original optimized system that is essential for in vivo colonization of the stomach environment by H. pylori. We propose a model in which these two nonredundant systems participate in H. pylori virulence by depleting gastric or immune cells from protective amino acids such as Gln and producing toxic ammonia close to the host cells.
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