651 Apurinic/Apyrimidinic Endonuclease (APE-1) Regulates Oxidative Signaling Pathways Including RAC1 and NADPH Oxidase in H. pylori (HP) Infected Gastric Epithelial Cells (GEC)

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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Inflammatory signaling pathways induced by Helicobacter pylori in primary human gastric epithelial cells

Innate Immunity ◽

10.1177/1753425916681077 ◽

2016 ◽

Vol 23 (2) ◽

pp. 165-174 ◽

Cited By ~ 10

Author(s):

Cong Tri Tran ◽

Magali Garcia ◽

Martine Garnier ◽

Christophe Burucoa ◽

Charles Bodet

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Mrna Expression ◽

Signaling Pathways ◽

Post Infection ◽

Gastric Epithelial Cells ◽

Inflammatory Signaling ◽

Independent Manner ◽

Chemokine Production ◽

H Pylori

Inflammatory signaling pathways induced by Helicobacter pylori remain unclear, having been studied mostly on cell-line models derived from gastric adenocarcinoma with potentially altered signaling pathways and nonfunctional receptors. Here, H. pylori-induced signaling pathways were investigated in primary human gastric epithelial cells. Inflammatory response was analyzed on chemokine mRNA expression and production after infection of gastric epithelial cells by H. pylori strains, B128 and B128Δ cagM, a cag type IV secretion system defective strain. Signaling pathway involvement was investigated using inhibitors of epidermal growth factor receptor (EGFR), MAPK, JAK and blocking Abs against TLR2 and TLR4. Inhibitors of EGFR, MAPK and JAK significantly reduced the chemokine mRNA expression and production induced by both H. pylori strains at 3 h and 24 h post-infection. JNK inhibitor reduced chemokine production at 24 h post-infection. Blocking Abs against TLR2 but not TLR4 showed significant reduction of chemokine secretion. Using primary culture of human gastric epithelial cells, our data suggest that H. pylori can be recognized by TLR2, leading to chemokine induction, and that EGFR, MAPK and the JAK/STAT signaling pathways play a key role in the H. pylori-induced CXCL1, CXCL5 and CXCL8 response in a cag pathogenicity island-independent manner.

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Inhibitory Effect of Korean Red Ginseng Extract on Interleukin-8 Expression in Helicobacter pylori-Infected Gastric Epithelial Cells

Current Developments in Nutrition ◽

10.1093/cdn/nzab061_014 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 1130-1130

Author(s):

Haesou Kim ◽

Soon Ok Cho ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Epithelial Cells ◽

Nadph Oxidase ◽

Oxidase Activity ◽

Gastric Epithelial Cells ◽

Red Ginseng ◽

Korean Red Ginseng ◽

Ags Cells ◽

Ginseng Extract ◽

Nadph Oxidase Activity ◽

H Pylori

Abstract Objectives Infection of Helicobacter pylori (H. pylori), a gram-negative bacterium, leads to various gastric diseases, such as gastritis, peptic ulcer and gastric cancer. H. pylori increases cytokine release and activates inflammatory mediators in gastric mucosa. Particularly, H. pylori upregulates the inflammatory chemokine interleukin-8 (IL-8), which are activated by oxidative stress. IL-8 can cause severe inflammation of the stomach and gastric cancer. Korean red ginseng is the steamed root of 6-year-old Korean ginseng (Panax ginseng Meyer). Ginsenosides, triterpene glycosides, are the active components of Korean red ginseng. Ginsenosides have antioxidant, anti-inflammatory, and antitumor activities. The present study is aimed at determining whether Korean red ginseng extract inhibits H. pylori-induced IL-8 expression in gastric epithelial cells. Methods The human gastric epithelial cell line AGS was used. Gastric epithelial AGS cells were treated with Korean red ginseng extract, and infected with H. pylori (NCTC 11,637). Reactive oxygen species (ROS) levels were determined using dichlorofluorescein fluorescence. NADPH oxidase activity was measured using lucigenin chemiluminescence. IL-8 mRNA expression was measured by using real-time PCR. NADPH oxidase subunits were determined in cytosolic extract and membrane extract by using Western blotting. Results H. pylori increased NADPH oxidase activity, ROS levels, and upregulated IL-8 expression in gastric epithelial cells. Korean red ginseng extract inhibited IL-8 expression by suppressing NADPH oxidase activity and reducing ROS levels in gastric epithelial cells. H. pylori induced translocation of NADPH oxidase cytosolic subunits to membrane, which is a marker of NADPH oxidase activation, in AGS cells. Korean red ginseng extract inhibited translocation of cytosolic subunits of NADPH oxidase to membrane in AGS cells. Conclusions Korean red ginseng may be beneficial for preventing H. pylori-associated gastric inflammation by inhibiting oxidative stress and IL-8 expression. Funding Sources This study was supported by a Brain Korea 21 FOUR Project, Yonsei University, Seoul, Republic of Korea.

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Helicobacter pylori regulates ILK signaling pathways to influence autophagy in gastric epithelial cells

10.21203/rs.3.rs-63602/v1 ◽

2020 ◽

Author(s):

Zheng Xu ◽

Yunqiu Du ◽

Ruiqing Zhang ◽

Xiaohan Tong ◽

Boqing Li ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Signaling Pathways ◽

Negative Correlation ◽

Signal Molecules ◽

Gastric Epithelial Cells ◽

Marker Protein ◽

Autophagosome Formation ◽

H Pylori ◽

Rhoa Signaling

Abstract BackgroundThe ability of Helicobacter pylori to manipulate host autophagy is an important pathogenic mechanism.ResultsWe found a negative correlation between the expression of ILK and the autophagy marker protein LC3B in H. pylori-positive human samples and in H. pylori-infected GES-1 cell lines. There was a significant accumulation of autophagosomes in ILK-knockdown GES-1 cells, and the expression levels of both LC3B and p62 were also increased. Here, we showed the activities of Rac1 and RhoA were decreased in H. pylori-infected GES-1 cells and ILK-knockdown GES-1 cells. Inhibition of Rac1 and RhoA increased LC3B levels and autophagosome formation in GES-1 cells after H. pylori infection. Simultaneously, H. pylori infection activated downstream signal molecules of Rac1 (PAK1, LIMK1 and cofilin) and RhoA (ROCK1, ROCK2 and LIMK1 and cofilin).ConclusionsOur results demonstrated that H. pylori regulated autophagy through ILK/Rac1 and ILK/RhoA signaling pathways in gastric epithelial cells.

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α-Lipoic Acid InhibitsHelicobacter pylori-Induced Oncogene Expression and Hyperproliferation by Suppressing the Activation of NADPH Oxidase in Gastric Epithelial Cells

Mediators of Inflammation ◽

10.1155/2014/380830 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 10

Author(s):

Eunyoung Byun ◽

Joo Weon Lim ◽

Jung Mogg Kim ◽

Hyeyoung Kim

Keyword(s):

Epithelial Cells ◽

Nadph Oxidase ◽

Lipoic Acid ◽

Nuclear Translocation ◽

Viable Cell ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

Oncogene Expression ◽

H Pylori ◽

Nadph Oxidase Activation

Hyperproliferation and oncogene expression are observed in the mucosa ofHelicobacter pylori- (H. pylori-)infected patients with gastritis or adenocarcinoma. Expression of oncogenes such asβ-catenin and c-myc is related to oxidative stress.α-Lipoic acid (α-LA), a naturally occurring thiol compound, acts as an antioxidant and has an anticancer effect. The aim of this study is to investigate the effect ofα-LA onH. pylori-induced hyperproliferation and oncogene expression in gastric epithelial AGS cells by determining cell proliferation (viable cell numbers, thymidine incorporation), levels of reactive oxygen species (ROS), NADPH oxidase activation (enzyme activity, subcellular levels of NADPH oxidase subunits), activation of redox-sensitive transcription factors (NF-κB, AP-1), expression of oncogenes (β-catenin, c-myc), and nuclear localization ofβ-catenin. Furthermore, we examined whether NADPH oxidase mediates oncogene expression and hyperproliferation inH. pylori-infected AGS cells using treatment of diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase. As a result,α-LA inhibited the activation of NADPH oxidase and, thus, reduced ROS production, resulting in inhibition on activation of NF-κB and AP-1, induction of oncogenes, nuclear translocation ofβ-catenin, and hyperproliferation inH. pylori-infected AGS cells. DPI inhibitedH. pylori-induced activation of NF-κB and AP-1, oncogene expression and hyperproliferation by reducing ROS levels in AGS cells. In conclusion, we propose that inhibiting NADPH oxidase byα-LA could prevent oncogene expression and hyperproliferation occurring inH. pylori-infected gastric epithelial cells.

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Astaxanthin Inhibits Mitochondrial Dysfunction and Interleukin-8 Expression in Helicobacter pylori-Infected Gastric Epithelial Cells

Nutrients ◽

10.3390/nu10091320 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1320 ◽

Cited By ~ 17

Author(s):

Suhn Kim ◽

Joo Lim ◽

Hyeyoung Kim

Keyword(s):

Oxidative Stress ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Nadph Oxidase ◽

Mitochondrial Dysfunction ◽

Peroxisome Proliferator ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

Ppar Γ ◽

H Pylori

Helicobacter pylori (H. pylori) infection leads to gastric inflammation, peptic ulcer and gastric carcinoma. H. pylori activates NADPH oxidase and increases reactive oxygen species (ROS), which induce NF-κB activation and IL-8 expression in gastric epithelial cells. Dysfunctional mitochondria trigger inflammatory cytokine production. Peroxisome proliferator-activated receptors-γ (PPAR-γ) regulate inflammatory response. Astaxanthin is a powerful antioxidant that protects cells against oxidative stress. The present study was aimed at determining whether astaxanthin inhibits H. pylori-induced mitochondrial dysfunction, NF-κB activation, and IL-8 expression via PPAR-γ activation in gastric epithelial cells. Gastric epithelial AGS cells were treated with astaxanthin, NADPH oxidase inhibitor apocynin and PPAR-γ antagonist GW9662, and infected with H. pylori. As a result, H. pylori caused an increase in intracellular and mitochondrial ROS, NF-κB activation and IL-8 expression, but decreased mitochondrial membrane potential and ATP level. Astaxanthin inhibited H. pylori-induced alterations (increased ROS, mitochondrial dysfunction, NF-κB activation, and IL-8 expression). Astaxanthin activated PPAR-γ and its target gene catalase in H. pylori-infected cells. Apocynin reduced ROS and inhibited IL-8 expression while astaxanthin did not affect NADPH oxidase activity. Inhibitory effects of astaxanthin on ROS levels and IL-8 expression were suppressed by addition of GW9662. In conclusion, astaxanthin inhibits H. pylori-induced mitochondrial dysfunction and ROS-mediated IL-8 expression by activating PPAR-γ and catalase in gastric epithelial cells. Astaxanthin may be beneficial for preventing oxidative stress-mediated gastric inflammation-associated H. pylori infection.

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

Gastroenterology ◽

10.1016/s0016-5085(01)80398-x ◽

2001 ◽

Vol 120 (5) ◽

pp. A81-A81

Author(s):

J MARTIN ◽

A POTTHOFF ◽

M COMBERG ◽

I SOBEKKLOCKE ◽

S LEDIG ◽

...

Keyword(s):

Epithelial Cells ◽

Receptor Subtypes ◽

Trail Receptor ◽

Gastric Epithelial Cells ◽

H Pylori

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Rabeprazole inhibits inflammatory reaction by inhibition of cell pyroptosis in gastric epithelial cells

BMC Pharmacology and Toxicology ◽

10.1186/s40360-021-00509-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jing Xie ◽

Long Fan ◽

Liya Xiong ◽

Peiyu Chen ◽

Hongli Wang ◽

...

Keyword(s):

Epithelial Cells ◽

Clinical Sample ◽

Critical Role ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Peptic Ulcers ◽

Gastric Epithelial Cells ◽

Caspase 1 ◽

H Pylori

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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Helicobacter pylori regulates ILK to influence autophagy through Rac1 and RhoA signaling pathways in gastric epithelial cells

Microbial Pathogenesis ◽

10.1016/j.micpath.2021.105054 ◽

2021 ◽

pp. 105054

Author(s):

Zheng Xu ◽

Boqing Li ◽

Yunqiu Du ◽

Ruiqing Zhang ◽

Xiaohan Tong ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Signaling Pathways ◽

Gastric Epithelial Cells ◽

Rhoa Signaling

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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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