Effect of H. pylori on the expression of TRAIL receptor subtypes and apoptosis in human gastric epithelial cells

Abstract Background Helicobacter pylori (H. pylori) is a common pathogen in development of peptic ulcers with pyroptosis. Rabeprazole, a critical component of standard triple therapy, has been widely used as the first-line regimen for H. pylori infectious treatment. The aim of this study to explore the function of Rabeprazole on cell pyroptosis in vitro. Methods The clinical sample from patients diagnosed with or without H. pylori-infection were collected to analyze by Immunohistochemistry (IHC). Real-time quantitative PCR (qPCR), western blot (WB) and enzyme linked immunosorbent assay (Elisa) were performed to analyze the effect of Rabeprazole on cell pyroptosis, including LDH, IL-1β and IL-18. Results In this study, we showed that Rabeprazole regulated a phenomenon of cell pyroptosis as confirmed by lactate dehydrogenase (LDH) assay. Further results showed that Rabeprazole inhibited cell pyroptosis in gastric epithelial cells by alleviating GSDMD-executed pyroptosis, leading to decrease IL-1β and IL-18 mature and secretion, which is attributed to NLRP3 inflammasome activation inhibition. Further analysis showed that ASC, NLRP3 and Caspase-1, was significantly repressed in response to Rabeprazole stimulation, resulting in decreasing cleaved-caspase-1 expression. Most important, NLRP3 and GSDMD is significantly increased in gastric tissue of patients with H. pylori infection. Conclusion These findings revealed a critical role of Rabeprazole in cell pyroptosis in patients with H. pylori infection, suggesting that targeting cell pyroptosis is an alternative strategy in improving H. pylori treatment.

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Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells

Gastroenterology Research and Practice ◽

10.1155/2014/794342 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Liping Tao ◽

Hai Zou ◽

Zhimin Huang

Keyword(s):

Helicobacter Pylori ◽

Heat Shock ◽

Epithelial Cells ◽

Heat Shock Protein ◽

Mtt Assay ◽

Heat Shock Protein 70 ◽

Hsp70 Expression ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

H Pylori

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.

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Suppression of IL-8 production in gastric epithelial cells by MUC1 mucin and peroxisome proliferator-associated receptor-γ

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00023.2012 ◽

2012 ◽

Vol 303 (6) ◽

pp. G765-G774 ◽

Cited By ~ 9

Author(s):

Yong Sung Park ◽

Wei Guang ◽

Thomas G. Blanchard ◽

K. Chul Kim ◽

Erik P. Lillehoj

Keyword(s):

Epithelial Cells ◽

Negative Control ◽

Luciferase Reporter ◽

Peroxisome Proliferator ◽

Apical Surface ◽

Gastric Epithelial Cells ◽

Luciferase Reporter Gene ◽

Ags Cells ◽

Pparγ Agonist ◽

H Pylori

MUC1 is a membrane-tethered mucin expressed on the apical surface of epithelial cells. Our previous report (Guang W, Ding H, Czinn SJ, Kim KC, Blanchard TG, Lillehoj EP. J Biol Chem 285: 20547–20557, 2010) demonstrated that expression of MUC1 in AGS gastric epithelial cells limits Helicobacter pylori infection and reduces bacterial-driven IL-8 production. In this study, we identified the peroxisome proliferator-associated receptor-γ (PPARγ) upstream of MUC1 in the anti-inflammatory pathway suppressing H. pylori- and phorbol 12-myristate 13-acetate (PMA)-stimulated IL-8 production. Treatment of AGS cells with H. pylori or PMA increased IL-8 levels in cell culture supernatants compared with cells treated with the respective vehicle controls. Prior small interfering (si)RNA-induced MUC1 silencing further increased H. pylori - and PMA-stimulated IL-8 levels compared with a negative control siRNA. MUC1-expressing AGS cells pretreated with the PPARγ agonist troglitazone (TGN) had reduced H. pylori - and PMA-stimulated IL-8 levels compared with cells treated with H. pylori or PMA alone. However, following MUC1 siRNA knockdown, no differences in IL-8 levels were seen between TGN/ H. pylori and H. pylori -only cells or between TGN/PMA and PMA-only cells. Finally, TGN-treated AGS cells had increased Muc1 promoter activity, as measured using a Muc1-luciferase reporter gene, and greater MUC1 protein levels by Western blot analysis, compared with vehicle controls. These results support the hypothesis that PPARγ stimulates MUC1 expression by AGS cells, thereby attenuating H. pylori - and PMA-induced IL-8 production.

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TIFA Signaling in Gastric Epithelial Cells Initiates the cag Type 4 Secretion System-Dependent Innate Immune Response to Helicobacter pylori Infection

mBio ◽

10.1128/mbio.01168-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 54

Author(s):

Alevtina Gall ◽

Ryan G. Gaudet ◽

Scott D. Gray-Owen ◽

Nina R. Salama

Keyword(s):

Immune Response ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Inflammatory Response ◽

Secretion System ◽

Innate Immune ◽

Gastric Ulcers ◽

Bacterial Clearance ◽

Gastric Epithelial Cells ◽

H Pylori

ABSTRACT Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, causing inflammation which, in some cases, leads to gastric ulcers and cancer. The clinical outcome of infection depends on a complex interplay of bacterial, host genetic, and environmental factors. Although H. pylori is recognized by both the innate and adaptive immune systems, this rarely results in bacterial clearance. Gastric epithelial cells are the first line of defense against H. pylori and alert the immune system to bacterial presence. Cytosolic delivery of proinflammatory bacterial factors through the cag type 4 secretion system ( cag -T4SS) has long been appreciated as the major mechanism by which gastric epithelial cells detect H. pylori . Classically attributed to the peptidoglycan sensor NOD1, recent work has highlighted the role of NOD1-independent pathways in detecting H. pylori ; however, the bacterial and host factors involved have remained unknown. Here, we show that bacterially derived heptose-1,7-bisphosphate (HBP), a metabolic precursor in lipopolysaccharide (LPS) biosynthesis, is delivered to the host cytosol through the cag -T4SS, where it activates the host tumor necrosis factor receptor-associated factor (TRAF)-interacting protein with forkhead-associated domain (TIFA)-dependent cytosolic surveillance pathway. This response, which is independent of NOD1, drives robust NF-κB-dependent inflammation within hours of infection and precedes NOD1 activation. We also found that the CagA toxin contributes to the NF-κB-driven response subsequent to TIFA and NOD1 activation. Taken together, our results indicate that the sequential activation of TIFA, NOD1, and CagA delivery drives the initial inflammatory response in gastric epithelial cells, orchestrating the subsequent recruitment of immune cells and leading to chronic gastritis. IMPORTANCE H. pylori is a globally prevalent cause of gastric and duodenal ulcers and cancer. H. pylori antibiotic resistance is rapidly increasing, and a vaccine remains elusive. The earliest immune response to H. pylori is initiated by gastric epithelial cells and sets the stage for the subsequent immunopathogenesis. This study revealed that host TIFA and H. pylori -derived HBP are critical effectors of innate immune signaling that account for much of the inflammatory response to H. pylori in gastric epithelial cells. HBP is delivered to the host cell via the cag -T4SS at a time point that precedes activation of the previously described NOD1 and CagA inflammatory pathways. Manipulation of the TIFA-driven immune response in the host and/or targeting of ADP-heptose biosynthesis enzymes in H. pylori may therefore provide novel strategies that may be therapeutically harnessed to achieve bacterial clearance.

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Helicobacter pylori Induces Gastric Epithelial Cell Apoptosis in Association with Increased Fas Receptor Expression

Infection and Immunity ◽

10.1128/iai.67.8.4237-4242.1999 ◽

1999 ◽

Vol 67 (8) ◽

pp. 4237-4242 ◽

Cited By ~ 106

Author(s):

Nicola L. Jones ◽

Andrew S. Day ◽

Hilary A. Jennings ◽

Philip M. Sherman

Keyword(s):

Cell Death ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Receptor Expression ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

Fas Receptor ◽

Epithelial Cell Apoptosis ◽

H Pylori

ABSTRACT The mechanisms involved in mediating the enhanced gastric epithelial cell apoptosis observed during infection withHelicobacter pylori in vivo are unknown. To determine whether H. pylori directly induces apoptosis of gastric epithelial cells in vitro and to define the role of the Fas-Fas ligand signal transduction cascade, human gastric epithelial cells were infected with H. pylori for up to 72 h under microaerophilic conditions. As assessed by both transmission electron microscopy and fluorescence microscopy, incubation with acagA-positive, cagE-positive, VacA-positive clinical H. pylori isolate stimulated an increase in apoptosis compared to the apoptosis of untreated AGS cells (16.0% ± 2.8% versus 5.9% ± 1.4%, P < 0.05) after 72 h. In contrast, apoptosis was not detected following infection withcagA-negative, cagE-negative, VacA-negative clinical isolates or a Campylobacter jejuni strain. In addition to stimulating apoptosis, infection with H. pylorienhanced Fas receptor expression in AGS cells to a degree comparable to that of treatment with a positive control, gamma interferon (12.5 ng/ml) (148% ± 24% and 167% ± 24% of control, respectively). The enhanced Fas receptor expression was associated with increased sensitivity to Fas-mediated cell death. Ligation of the Fas receptor with an agonistic monoclonal antibody resulted in an increase in apoptosis compared to the apoptosis of cells infected with the bacterium alone (38.5% ± 7.1% versus 16.0% ± 2.8%,P < 0.05). Incubation with neutralizing anti-Fas antibody did not prevent apoptosis of H. pylori-infected cells. Taken together, these findings demonstrate that the gastric pathogen H. pylori stimulates apoptosis of gastric epithelial cells in vitro in association with the enhanced expression of the Fas receptor. These data indicate a role for Fas-mediated signaling in the programmed cell death that occurs in response toH. pylori infection.

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Lactobacillus fermentum UCO-979C beneficially modulates the innate immune response triggered by Helicobacter pylori infection in vitro

Beneficial Microbes ◽

10.3920/bm2018.0019 ◽

2018 ◽

Vol 9 (5) ◽

pp. 829-841 ◽

Cited By ~ 7

Author(s):

V. Garcia-Castillo ◽

H. Zelaya ◽

A. Ilabaca ◽

M. Espinoza-Monje ◽

R. Komatsu ◽

...

Keyword(s):

Immune Response ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Morphological Changes ◽

Helicobacter Pylori Infection ◽

Lactobacillus Fermentum ◽

Gastric Tissue ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

H Pylori

Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.

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Regulation of p14ARF by Siva1 in H. pylori-infected gastric epithelial cells.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.3_suppl.243 ◽

2021 ◽

Vol 39 (3_suppl) ◽

pp. 243-243

Author(s):

Manikandan Palrasu ◽

Elena Zaika ◽

El-Rifai Wael ◽

Richard Peek ◽

Alexander Zaika

Keyword(s):

Gastric Cancer ◽

Tumor Suppressor ◽

Epithelial Cells ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Bacterial Degradation ◽

Tumor Suppressor Protein ◽

Gastric Epithelial Cells ◽

H Pylori ◽

Oncogenic Stress

243 Background: Helicobacter pylori ( H. pylori) is the strongest known risk factor for gastric cancer. Bacterial degradation of tumor suppressor proteins affect the host microbe’s interactions and host cellular response, which contribute to tumorigenesis. p14ARF, a crucial tumor suppressor protein that activates p53 protein under oncogenic stress plays a major role in oncogenic stress response (OSR) regulation. However, little is known about the mechanism of ARF and OSR regulation in H. pylori-infected gastric epithelial cells. Methods: The expression of p14ARF and cytotoxin-associated gene A (CagA) were analyzed in gastric cells co-cultured with H. pylori strains isolated from high-gastric risk and low-gastric risk areas by immunoblotting. To investigate the potential role of CagA in regulation of p14ARF, we employed isogenic cagA− and cagE− H. pylori mutants in gastric epithelial cells, and C57BL/6 mice (n = 10). We also analyzed the expression of Siva1 in human individual infected with cagA-positive (n = 13) and cagA-negative (n = 13) bacteria as well as uninfected human subjects (n = 6). siRNA was used to inhibit activity of Siva1 protein. Results: In this study, H. pylori strains expressing high levels of CagA virulence factor and associated with a higher gastric cancer risk more strongly suppress p14ARF compared with low-risk strains in vivo and in vitro. We found that degradation of p14ARF induced by CagA is mediated by E3 ubiquitin ligase Siva1, which works in concert with another E3 ubiquitin ligase TRIP12. Decreased expression of Siva1 protein and consequent up-regulation of p14ARF was also found in gastric mucosa of H. pylori-infected mice and human individuals. Tumorigenic strain 7.13 was more potent in upregulation of Siva1 and downregulation of p14ARF than non-tumorigenic strain B128. Inhibition of p14ARF protein by H. pylori causes inhibition of autophagy in infected cells. Conclusions: Our results provide first evidence that carcinogenic H. pylori strains significantly alter the host tumor suppressor protein p14ARF, leading to suppression of host OSR and autophagy, which may affect host-bacteria interactions and tumorigenic alteration in the stomach.

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Helicobacter pylori induces intracellular galectin-8 aggregation around damaged lysosomes within gastric epithelial cells in a host O-glycan-dependent manner

Glycobiology ◽

10.1093/glycob/cwy095 ◽

2018 ◽

Vol 29 (2) ◽

pp. 151-162 ◽

Cited By ~ 6

Author(s):

Fang-Yen Li ◽

I-Chun Weng ◽

Chun-Hung Lin ◽

Mou-Chieh Kao ◽

Ming-Shiang Wu ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Rhesus Macaques ◽

Dependent Manner ◽

Gastric Epithelial Cells ◽

Vacuolating Cytotoxin ◽

Infected Cells ◽

H Pylori ◽

Autophagy Activity ◽

Binding Lectin

Abstract Galectin-8, a beta-galactoside-binding lectin, is upregulated in the gastric tissues of rhesus macaques infected with Helicobacter pylori. In this study, we found that H. pylori infection triggers intracellular galectin-8 aggregation in human-derived AGS gastric epithelial cells, and that these aggregates colocalize with lysosomes. Notably, this aggregation is markedly reduced following the attenuation of host O-glycan processing. This indicates that H. pylori infection induces lysosomal damage, which in turn results in the accumulation of cytosolic galectin-8 around damaged lysosomes through the recognition of exposed vacuolar host O-glycans. H. pylori-induced galectin-8 aggregates also colocalize with autophagosomes, and galectin-8 ablation reduces the activation of autophagy by H. pylori. This suggests that galectin-8 aggregates may enhance autophagy activity in infected cells. We also observed that both autophagy and NDP52, an autophagy adapter, contribute to the augmentation of galectin-8 aggregation by H. pylori. Additionally, vacuolating cytotoxin A, a secreted H. pylori cytotoxin, may contribute to the increased galectin-8 aggregation and elevated autophagy response in infected cells. Collectively, these results suggest that H. pylori promotes intracellular galectin-8 aggregation, and that galectin-8 aggregation and autophagy may reciprocally regulate each other during infection.

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Inhibitory Effect of β-Carotene on Helicobacter pylori-Induced TRAF Expression and Hyper-Proliferation in Gastric Epithelial Cells

Antioxidants ◽

10.3390/antiox8120637 ◽

2019 ◽

Vol 8 (12) ◽

pp. 637 ◽

Cited By ~ 2

Author(s):

Yongchae Park ◽

Hanbit Lee ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Gene Expression ◽

Gastric Cancer ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Nadph Oxidase ◽

Gastric Epithelial Cells ◽

Gastric Cancer Cells ◽

Ags Cells ◽

H Pylori ◽

Β Carotene

Helicobacter pylori infection causes the hyper-proliferation of gastric epithelial cells that leads to the development of gastric cancer. Overexpression of tumor necrosis factor receptor associated factor (TRAF) is shown in gastric cancer cells. The dietary antioxidant β-carotene has been shown to counter hyper-proliferation in H. pylori-infected gastric epithelial cells. The present study was carried out to examine the β-carotene mechanism of action. We first showed that H. pylori infection decreases cellular IκBα levels while increasing cell viability, NADPH oxidase activity, reactive oxygen species production, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation, and TRAF1 and TRAF2 gene expression, as well as protein–protein interaction in gastric epithelial AGS cells. We then demonstrated that pretreatment of cells with β-carotene significantly attenuates these effects. Our findings support the proposal that β-carotene has anti-cancer activity by reducing NADPH oxidase-mediated production of ROS, NF-κB activation and NF-κB-regulated TRAF1 and TRAF2 gene expression, and hyper-proliferation in AGS cells. We suggest that the consumption of β-carotene-enriched foods could decrease the incidence of H. pylori-associated gastric disorders.

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