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Jarzab M, Skorko-Glonek J. There Are No Insurmountable Barriers: Passage of the Helicobacter pylori VacA Toxin from Bacterial Cytoplasm to Eukaryotic Cell Organelle. MEMBRANES 2023; 14:11. [PMID: 38248700 PMCID: PMC10821523 DOI: 10.3390/membranes14010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/20/2023] [Accepted: 12/23/2023] [Indexed: 01/23/2024]
Abstract
The Gram-negative bacterium Helicobacter pylori is a very successful pathogen, one of the most commonly identified causes of bacterial infections in humans worldwide. H. pylori produces several virulence factors that contribute to its persistence in the hostile host habitat and to its pathogenicity. The most extensively studied are cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA). VacA is present in almost all H. pylori strains. As a secreted multifunctional toxin, it assists bacterial colonization, survival, and proliferation during long-lasting infections. To exert its effect on gastric epithelium and other cell types, VacA undergoes several modifications and crosses multiple membrane barriers. Once inside the gastric epithelial cell, VacA disrupts many cellular-signaling pathways and processes, leading mainly to changes in the efflux of various ions, the depolarization of membrane potential, and perturbations in endocytic trafficking and mitochondrial function. The most notable effect of VacA is the formation of vacuole-like structures, which may lead to apoptosis. This review focuses on the processes involved in VacA secretion, processing, and entry into host cells, with a particular emphasis on the interaction of the mature toxin with host membranes and the formation of transmembrane pores.
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Affiliation(s)
| | - Joanna Skorko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
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Gao K, Yang M, Li B, Chen R, Dong J, Liu Q, Gao Z, Guo X, Deng X. Molecular response mechanisms of silkworm (Bombyx mori L.) to the toxicity of 1-octyl-3-methylimidazole chloride based on transcriptome analysis of midguts and silk glands. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 227:112915. [PMID: 34687943 DOI: 10.1016/j.ecoenv.2021.112915] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/30/2021] [Accepted: 10/16/2021] [Indexed: 06/13/2023]
Abstract
In a previous study, silkworm larvae were used as a novel model to assess the biotoxicity of ILs, which showed that ILs could cause significant physiological and biochemical changes in midguts and silk glands of the larvae, and result in the death of larvae. In order to investigate the toxicity of 1-octyl-3-methylimidazole chloride ([C8mim]Cl) to the larvae at molecular level, RNA-sequencing technology was used to construct transcriptomic profiles of midguts and silk glands in this work. Results showed that a lot of differentially expressed genes (DEGs) were effectively screened out through bioinformatics software based on the transcriptome data and reference genome. To give more detail, 5118 and 2211 DEGs (926 and 822 DEGs) were obtained in the midguts (silk glands) when the larvae were exposed to [C8mim]Cl for 6 and 12 h, respectively, relative to the controls. In addition, gene ontology (GO) analysis suggested that the DEGs could be divided into three categories (i.e., biological process, cellular component, and molecular function), and were involved in multiple organelle functions and complex biological processes. Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that the DEGs were enriched in a variety of pathways, such as signal transduction, apoptosis, glycolysis, peroxisome, autophagy, hippo signaling pathway, arginine and proline metabolism. Results of quantitative real-time PCR and histopathological observation indicated that molecular mechanism of the larvae against [C8mim]Cl toxicology may be attributed to cell apoptosis regulation via both the mitochondrial pathway and the death receptor-initiated pathway. Thus, these results provided useful data for exploring the toxicity of ILs to insects at molecular level.
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Affiliation(s)
- Kun Gao
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Mengting Yang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Bin Li
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Runzhen Chen
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Jingwei Dong
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Qiaoqiao Liu
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Zheng Gao
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Xijie Guo
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China
| | - Xiangyuan Deng
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, People's Republic of China.
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Activity and Functional Importance of Helicobacter pylori Virulence Factors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:35-56. [PMID: 31016624 DOI: 10.1007/5584_2019_358] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori is a very successful Gram-negative pathogen colonizing the stomach of humans worldwide. Infections with this bacterium can generate pathologies ranging from chronic gastritis and peptic ulceration to gastric cancer. The best characterized H. pylori virulence factors that cause direct cell damage include an effector protein encoded by the cytotoxin-associated gene A (CagA), a type IV secretion system (T4SS) encoded in the cag-pathogenicity island (cag PAI), vacuolating cytotoxin A (VacA), γ-glutamyl transpeptidase (GGT), high temperature requirement A (HtrA, a serine protease) and cholesterol glycosyl-transferase (CGT). Since these H. pylori factors are either surface-exposed, secreted or translocated, they can directly interact with host cell molecules and are able to hijack cellular functions. Studies on these bacterial factors have progressed substantially in recent years. Here, we review the current status in the characterization of signaling cascades by these factors in vivo and in vitro, which comprise the disruption of cell-to-cell junctions, induction of membrane rearrangements, cytoskeletal dynamics, proliferative, pro-inflammatory, as well as, pro-apoptotic and anti-apoptotic responses or immune evasion. The impact of these signal transduction modules in the pathogenesis of H. pylori infections is discussed.
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Blaser N, Backert S, Pachathundikandi SK. Immune Cell Signaling by Helicobacter pylori: Impact on Gastric Pathology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:77-106. [PMID: 31049845 DOI: 10.1007/5584_2019_360] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori represents a highly successful colonizer of the human stomach. Infections with this Gram-negative bacterium can persist lifelong, and although in the majority of cases colonization is asymptomatic, it can trigger pathologies ranging from chronic gastritis and peptic ulceration to gastric cancer. The interaction of the bacteria with the human host modulates immune responses in different ways to enable bacterial survival and persistence. H. pylori uses various pathogenicity-associated factors such as VacA, NapA, CGT, GGT, lipopolysaccharide, peptidoglycan, heptose 1,7-bisphosphate, ADP-heptose, cholesterol glucosides, urease and a type IV secretion system for controlling immune signaling and cellular functions. It appears that H. pylori manipulates multiple extracellular immune receptors such as integrin-β2 (CD18), EGFR, CD74, CD300E, DC-SIGN, MINCLE, TRPM2, T-cell and Toll-like receptors as well as a number of intracellular receptors including NLRP3, NOD1, NOD2, TIFA and ALPK1. Consequently, downstream signaling pathways are hijacked, inducing tolerogenic dendritic cells, inhibiting effector T cell responses and changing the gastrointestinal microbiota. Here, we discuss in detail the interplay of bacterial factors with multiple immuno-regulatory cells and summarize the main immune evasion and persistence strategies employed by H. pylori.
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Affiliation(s)
- Nicole Blaser
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Steffen Backert
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Suneesh Kumar Pachathundikandi
- Department of Biology, Institute for Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany.
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Shubin AV, Demidyuk IV, Komissarov AA, Rafieva LM, Kostrov SV. Cytoplasmic vacuolization in cell death and survival. Oncotarget 2018; 7:55863-55889. [PMID: 27331412 PMCID: PMC5342458 DOI: 10.18632/oncotarget.10150] [Citation(s) in RCA: 204] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 06/06/2016] [Indexed: 12/15/2022] Open
Abstract
Cytoplasmic vacuolization (also called cytoplasmic vacuolation) is a well-known morphological phenomenon observed in mammalian cells after exposure to bacterial or viral pathogens as well as to various natural and artificial low-molecular-weight compounds. Vacuolization often accompanies cell death; however, its role in cell death processes remains unclear. This can be attributed to studying vacuolization at the level of morphology for many years. At the same time, new data on the molecular mechanisms of the vacuole formation and structure have become available. In addition, numerous examples of the association between vacuolization and previously unknown cell death types have been reported. Here, we review these data to make a deeper insight into the role of cytoplasmic vacuolization in cell death and survival.
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Affiliation(s)
- Andrey V Shubin
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Moscow, Russia.,Laboratory of Chemical Carcinogenesis, N.N. Blokhin Russian Cancer Research Center, Moscow, Russia.,Laboratory of Biologically Active Nanostructures, N.F. Gamaleya Institute of Epidemiology and Microbiology, Moscow, Russia
| | - Ilya V Demidyuk
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Moscow, Russia
| | - Alexey A Komissarov
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Moscow, Russia
| | - Lola M Rafieva
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Moscow, Russia
| | - Sergey V Kostrov
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Moscow, Russia
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Foegeding NJ, Caston RR, McClain MS, Ohi MD, Cover TL. An Overview of Helicobacter pylori VacA Toxin Biology. Toxins (Basel) 2016; 8:toxins8060173. [PMID: 27271669 PMCID: PMC4926140 DOI: 10.3390/toxins8060173] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/18/2016] [Accepted: 05/27/2016] [Indexed: 12/11/2022] Open
Abstract
The VacA toxin secreted by Helicobacter pylori enhances the ability of the bacteria to colonize the stomach and contributes to the pathogenesis of gastric adenocarcinoma and peptic ulcer disease. The amino acid sequence and structure of VacA are unrelated to corresponding features of other known bacterial toxins. VacA is classified as a pore-forming toxin, and many of its effects on host cells are attributed to formation of channels in intracellular sites. The most extensively studied VacA activity is its capacity to stimulate vacuole formation, but the toxin has many additional effects on host cells. Multiple cell types are susceptible to VacA, including gastric epithelial cells, parietal cells, T cells, and other types of immune cells. This review focuses on the wide range of VacA actions that are detectable in vitro, as well as actions of VacA in vivo that are relevant for H. pylori colonization of the stomach and development of gastric disease.
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Affiliation(s)
- Nora J Foegeding
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Rhonda R Caston
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Mark S McClain
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | - Melanie D Ohi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Timothy L Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
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Jeon JI, Ko SH, Kim YJ, Choi SM, Kang KK, Kim H, Yoon HJ, Kim JM. The flavone eupatilin inhibits eotaxin expression in an NF-κB-dependent and STAT6-independent manner. Scand J Immunol 2015; 81:166-76. [PMID: 25565108 DOI: 10.1111/sji.12263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/19/2014] [Indexed: 12/31/2022]
Abstract
The CC chemokine eotaxin contributes to epithelium-induced inflammation in airway diseases such as asthma. Eupatilin (5,7-dihydroxy-3',4',6'-trimethoxyflavone), a bioactive component of Artemisia asiatica Nakai (Asteraceae), is reported to inhibit the adhesion of eosinophils to bronchial epithelial cells. However, little is known about the molecular mechanism of eupatilin-induced attenuation of bronchial epithelium-induced inflammation. In this study, we investigated the effect of eupatilin on expression of eotaxin-1 (CCL11), a potent chemoattractant for eosinophils. Eupatilin significantly inhibited eotaxin expression in bronchial epithelial cells stimulated with TNF-α, while NF-κB and IκBα kinase (IKK) activities declined concurrently. Eupatilin also inhibited mitogen-activated protein kinase (MAPK) activity; however, all of these anti-inflammatory activities were reversed by MAPK overexpression. In contrast, eupatilin did not affect the signal transducer and activator of transcription 6 (STAT6) signalling in bronchial epithelial cells stimulated with IL-4. Furthermore, eupatilin significantly attenuated TNF-α-induced eosinophil migration. These results suggest that the eupatilin inhibits the signalling of MAPK, IKK, NF-κB and eotaxin-1 in bronchial epithelial cells, leading to inhibition of eosinophil migration.
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Affiliation(s)
- J I Jeon
- Department of Microbiology and Department of Biomedical Science, Hanyang University College of Medicine and Hanyang University Graduate School of Biomedical Science and Engineering, Seoul, South Korea
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Helicobacter pylori outer membrane vesicle proteins induce human eosinophil degranulation via a β2 Integrin CD11/CD18- and ICAM-1-dependent mechanism. Mediators Inflamm 2015; 2015:301716. [PMID: 25821353 PMCID: PMC4364020 DOI: 10.1155/2015/301716] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/24/2014] [Accepted: 12/30/2014] [Indexed: 12/13/2022] Open
Abstract
Eosinophil cationic protein (ECP), a cytotoxic protein contained in eosinophils granules, can contribute to various inflammatory responses. Although Helicobacter pylori infection increases infiltration of eosinophils, the mechanisms of eosinophil degranulation by H. pylori infection are largely unknown. The goal of this study was to investigate the role of H. pylori outer membrane vesicles (OMVs) in modulating eosinophil degranulation. We found that eosinophils treated with H. pylori OMVs released significantly more ECP compared with untreated controls. In addition, eosinophils cocultured with OMV-preexposed primary gastric epithelial cells exhibited significantly increased ECP release. Similarly, eosinophils cocultured with culture supernatant (CM) from primary gastric epithelial cells exposed to OMVs (OMV-CM) released significantly higher amounts of ECP compared with eosinophils cocultured with CM from unexposed control cells. Furthermore, OMVs and OMV-CM both induced the upregulation of ICAM-1 on gastric epithelial cells and β2 integrin CD11b on eosinophils. In addition, both transduction of ICAM-1 shRNA into gastric epithelial cells and treatment with neutralizing mAbs to CD18 significantly decreased OMV-mediated or OMV-CM-mediated release of ECP. These results suggest that the eosinophil degranulation response to H. pylori OMVs occurs via a mechanism that is dependent on both β2 integrin CD11/CD18 and ICAM-1.
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Kim JM, Kim JS, Kim N, Ko SH, Jeon JI, Kim YJ. Helicobacter pylori vacuolating cytotoxin induces apoptosis via activation of endoplasmic reticulum stress in dendritic cells. J Gastroenterol Hepatol 2015; 30:99-108. [PMID: 25041690 DOI: 10.1111/jgh.12663] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/22/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIM Dendritic cells (DCs) are observed on the Helicobacter pylori-infected gastric mucosa. DCs generally play an important role in the regulation of inflammation. Although stimulation of gastric epithelial cells with H. pylori vacuolating cytotoxin (VacA) has been reported to induce apoptosis and endoplasmic reticulum (ER) stress, the effects of VacA on the DC apoptotic response have not been well elucidated. This study was conducted to investigate the role of H. pylori VacA on the apoptotic process and ER stress in DCs. METHODS Murine and human DCs were generated from specific pathogen-free C57BL/6 mice and human peripheral blood mononuclear cells, respectively. DCs were incubated with purified VacA, after which Bax activation, cytochrome c release, and DNA fragmentation for apoptosis were measured by fluorescent microscopy, immunoblot, and ELISA. ER stress-related molecules such as GRP78 and CHOP were analyzed by immunoblot. RESULTS Treatment of DCs with purified H. pylori VacA resulted in the induction of apoptosis. DC stimulation with VacA led to the translocation of cytoplasmic Bax to mitochondria and cytochrome c release from mitochondria. H. pylori VacA induced signals for ER stress early during the stimulation process in DCs. Furthermore, suppression of ER stress resulted in a significant inhibition of the VacA-induced apoptosis in DCs. CONCLUSION These results suggest that ER stress is critical for regulation of DC apoptotic process in response to VacA stimulation.
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Affiliation(s)
- Jung Mogg Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, Korea
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Ko SH, Jeon JI, Kim H, Kim YJ, Youn J, Kim JM. Mitogen-activated protein kinase/IκB kinase/NF-κB-dependent and AP-1-independent CX3CL1 expression in intestinal epithelial cells stimulated with Clostridium difficile toxin A. J Mol Med (Berl) 2013; 92:411-27. [PMID: 24362517 DOI: 10.1007/s00109-013-1117-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 12/01/2013] [Accepted: 12/03/2013] [Indexed: 12/18/2022]
Abstract
UNLABELLED Clostridium difficile toxin A causes acute colitis associated with inflammatory cell infiltration and increased production of proinflammatory mediators. Although CX3CL1 (fractalkine) plays a role in chemoattracting monocytes/macrophages, NK cells, and T cells, little information is available on the regulated expression of CX3CL1 in response to toxin A stimulation. In this study, we investigated the role of C. difficile toxin A on CX3CL1 induction in intestinal epithelial cells. Stimulation of murine intestinal epithelial cells with toxin A resulted in the upregulation of CX3CL1. Expression of CX3CL1 was dependent on nuclear factor-kappaB (NF-κB) and IκB kinase (IKK) activation, while the suppression of activator protein-1 (AP-1) did not affect toxin A-induced CX3CL1 expression. Suppression of p38 mitogen-activated protein kinase (MAPK) significantly inhibited IKK-NF-κB signaling leading to CX3CL1 induction in C. difficile toxin A-stimulated cells. CX3CL1 was mainly secreted from the basolateral surfaces in toxin A-treated cells. Furthermore, inhibition of p38 activity attenuated the toxin A-induced upregulation of CX3CL1 in the mouse ileum in vivo. These results suggest that a pathway, including p38 MAPK, IKK, and NF-κB activation, is required for CX3CL1 induction in intestinal epithelial cells exposed to C. difficile toxin A and may regulate the development of intestinal inflammation induced by infection with toxigenic C. difficile. KEY MESSAGE C. difficile toxin A causes colitis with inflammatory cell infiltration. CX3CL1 plays a role in chemoattracting immune cells. MAPK-NF-κB signaling is required for CX3CL1 induction in toxin A-exposed cells. CX3CL1 is mainly secreted from the basolateral surfaces. CX3CL1 may contribute to the regulation of toxigenic C. difficile infection.
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Affiliation(s)
- Su Hyuk Ko
- Department of Microbiology and Department of Biomedical Science, Hanyang University College of Medicine and Graduate School of Biomedical Science and Engineering, 17 Haengdang-dong, Sungdong-gu, Seoul, 133-791, South Korea
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11
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Jung J, Ko SH, Yoo DY, Lee JY, Kim YJ, Choi SM, Kang KK, Yoon HJ, Kim H, Youn J, Kim JM. 5,7-Dihydroxy-3,4,6-trimethoxyflavone inhibits intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 via the Akt and nuclear factor-κB-dependent pathway, leading to suppression of adhesion of monocytes and eosinophils to bronchial epithelial cells. Immunology 2012; 137:98-113. [PMID: 22862554 DOI: 10.1111/j.1365-2567.2012.03618.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
5,7-Dihydroxy-3',4',6'-trimethoxyflavone (eupatilin), the active pharmacological ingredient from Artemisia asiatica Nakai (Asteraceae), is reported to have a variety of anti-inflammatory properties in intestinal epithelial cells. However, little information is known about the molecular mechanism of eupatilin-induced attenuation of bronchial epithelial inflammation. This study investigates the role of eupatilin in the adhesion of inflammatory cells such as monocytes and eosinophils to bronchial epithelial cells. Stimulation of a human bronchial epithelial cell line (BEAS-2B) with tumour necrosis factor-α (TNF-α) increased the expression of surface adhesion molecules, including intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), in which eupatilin significantly inhibited the expression of those adhesion molecules in a dose-dependent manner. Eupatilin suppressed the TNF-α-induced activation of IκBα and nuclear factor-κB (NF-κB) signals in BEAS-2B cells. The IκB kinase (IKK) activation was also significantly reduced in eupatilin-pre-treated BEAS-2B and primary normal human bronchial epithelial (NHBE) cells. However, eupatilin did not influence AP-1 activity in TNF-α-stimulated cells. Suppression of NF-κB signalling induced by eupatilin resulted in the inhibition of the expression of adhesion molecules and the adhesion of monocytes and eosinophils to BEAS-2B cells. Furthermore, eupatilin suppressed the phosphorylation of Akt in TNF-α-stimulated BEAS-2B and NHBE cells, leading to down-regulation of NF-κB activation and adhesion molecule expression and finally to suppression of the inflammatory cell adhesion to epithelial cells. These results suggest that eupatilin can inhibit the adhesion of inflammatory cells to bronchial epithelial cells via a signalling pathway, including activation of Akt and NF-κB, as well as expression of adhesion molecules.
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Affiliation(s)
- Jireh Jung
- Departments of Microbiology and Biomedical Science, Hanyang University College of Medicine and Hanyang University Graduate School of Biomedical Science and Engineering, Seoul, South Korea
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12
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Prognostic value of Helicobacter pylori sinonasal colonization for efficacy of endoscopic sinus surgery. Eur Arch Otorhinolaryngol 2012; 269:2197-202. [DOI: 10.1007/s00405-012-1923-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 01/03/2012] [Indexed: 12/11/2022]
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Kim JM, Kim JS, Yoo DY, Ko SH, Kim N, Kim H, Kim YJ. Stimulation of dendritic cells with Helicobacter pylori vacuolating cytotoxin negatively regulates their maturation via the restoration of E2F1. Clin Exp Immunol 2011; 166:34-45. [PMID: 21910723 DOI: 10.1111/j.1365-2249.2011.04447.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori induces an infiltration of dendritic cells (DCs) into the infected gastric mucosa. Although DCs play an important role in the regulation of inflammation, the effects of H. pylori vacuolating cytotoxin (VacA) on DC maturation process have not yet been elucidated. The role of VacA in DC maturation following co-exposure to Escherichia coli lipopolysaccharide (LPS) was investigated. The treatment of immature DCs with LPS up-regulated the expression of surface molecules [e.g. CD40, CD80, CD86 and major histocompatibility complex (MHC) class II], as well as the production of cytokines [e.g. interleukin (IL)-1β, IL-12p70 and tumour necrosis gactor (TNF)-α] compared with those of unstimulated controls. Co-stimulation with H. pylori VacA significantly reduced the up-regulated DC maturation markers induced by LPS. In addition, VacA sustained the immature state of DCs with high endocytosis and low migratory capacity. The LPS-induced down-regulation of E2F1 expression in DCs was recovered by co-stimulation with VacA. Moreover, suppression of E2F1 by small interfering RNA resulted in a significant recovery of the inhibited DC maturation by VacA. In contrast, VacA did not affect nuclear factor (NF)-κB responses to LPS and the NF-κB signal was not associated with VacA-induced inhibition of DC maturation. These results suggest that the exposure of DCs to H. pylori VacA negatively regulates DC maturation via the restoration of E2F1. The immunomodulatory action of VacA on DCs may contribute to the ability of VacA-producing H. pylori to establish a persistent infection in the gastric mucosa.
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Affiliation(s)
- J M Kim
- Department of Microbiology, Hanyang University College of Medicine Department of Internal Medicine, Seoul National University College of Medicin Department of Food and Nutrition, Yonsei University, Seoul Department of Biotechnology, Joongbu University, Choongnam, Korea.
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Rassow J. Helicobacter pylori vacuolating toxin A and apoptosis. Cell Commun Signal 2011; 9:26. [PMID: 22044628 PMCID: PMC3266207 DOI: 10.1186/1478-811x-9-26] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 11/01/2011] [Indexed: 12/16/2022] Open
Abstract
VacA, the vacuolating cytotoxin A of Helicobacter pylori, induces apoptosis in epithelial cells of the gastic mucosa and in leukocytes. VacA is released by the bacteria as a protein of 88 kDa. At the outer surface of host cells, it binds to the sphingomyelin of lipid rafts. At least partially, binding to the cells is facilitated by different receptor proteins. VacA is internalized by a clathrin-independent mechanism and initially accumulates in GPI-anchored proteins-enriched early endosomal compartments. Together with early endosomes, VacA is distributed inside the cells. Most of the VacA is eventually contained in the membranes of vacuoles. VacA assembles in hexameric oligomers forming an anion channel of low conductivity with a preference for chloride ions. In parallel, a significant fraction of VacA can be transferred from endosomes to mitochondria in a process involving direct endosome-mitochondria juxtaposition. Inside the mitochondria, VacA accumulates in the mitochondrial inner membrane, probably forming similar chloride channels as observed in the vacuoles. Import into mitochondria is mediated by the hydrophobic N-terminus of VacA. Apoptosis is triggered by loss of the mitochondrial membrane potential, recruitment of Bax and Bak, and release of cytochrome c.
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Affiliation(s)
- Joachim Rassow
- Ruhr-Universität Bochum, Institut für Physiologische Chemie, Medizinische Fakultät, Gebäude MA3, D-44780 Bochum, Germany.
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Ko SH, Yoo DY, Kim YJ, Choi SM, Kang KK, Kim H, Kim N, Kim JS, Kim JM. A mechanism for the action of the compound DA-6034 on NF-κB pathway activation in Helicobacter pylori-infected gastric epithelial cells. Scand J Immunol 2011; 74:253-263. [PMID: 21623862 DOI: 10.1111/j.1365-3083.2011.02577.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
DA-6034 is a synthetic derivative of eupatilin, a flavonoid with anti-inflammatory effects. The aim of this study was to investigate the effects of DA-6034 on the interactions between IκB kinase (IKK) and heat shock protein 90 (Hsp90), and activation of the nuclear factor-kappaB (NF-κB) signalling pathway in human gastric epithelial cells infected with Helicobacter pylori. MKN-45 gastric epithelial cell line was treated with DA-6034 and H. pylori. DA-6034 significantly inhibited NF-κB activation and upregulated the expressions of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 in MKN-45 cells infected with H. pylori. However, DA-6034 did not influence activator protein-1 DNA binding activity in H. pylori-infected gastric epithelial cells. Pretreatment with DA-6034 attenuated the H. pylori-induced increase in IKK activity, and Hsp90 was associated with IKK-α and IKK-γ in MKN-45 cells. Treatment with DA-6034 dissociated the Hsp90 and IKK-γ complex in H. pylori-infected cells, leading to the inhibition of IL-8 expression. These results suggest that the eupatilin derivative 7-carboxymethyloxy-3',4',5-trimethoxy flavone has anti-inflammatory activity in gastric epithelial cells infected with H. pylori through the promotion of the dissociation of the IKK-γ-Hsp90 complex and suppression of NF-κB signalling.
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Affiliation(s)
- S H Ko
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - D Y Yoo
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Y-J Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - S M Choi
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - K K Kang
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - H Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - N Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - J S Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - J M Kim
- Department of Microbiology, Hanyang University College of Medicine, Seoul, KoreaDepartment of Biotechnology, Joongbu University, Choongnam, KoreaResearch Laboratory, Dong-A Pharmaceutical Company, Kyunggi-do, KoreaDepartment of Food and Nutrition, Yonsei University, Seoul, KoreaDepartment of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
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