scholarly journals Genes of Helicobacter pylori Regulated by Attachment to AGS Cells

2004 ◽  
Vol 72 (4) ◽  
pp. 2358-2368 ◽  
Author(s):  
Nayoung Kim ◽  
Elizabeth A. Marcus ◽  
Yi Wen ◽  
David L. Weeks ◽  
David R. Scott ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Quantitative Pcr ◽  
Stress Responses ◽  
Gastric Epithelium ◽  
Rt Pcr ◽  
Down Regulation ◽  
Ags Cells ◽  
H Pylori

ABSTRACT Reciprocal interactions between Helicobacter pylori and cells of the gastric epithelium to which it adheres may affect colonization. Changes in gene expression of H. pylori induced by adhesion to AGS gastric cancer cells by coculture were compared to changes in gene expression of H. pylori cultured without AGS cells by using cDNA filter macroarrays. Adhesion was quantitatively verified by confocal microscopy of green fluorescent protein-expressing bacteria. Four experiments showed that 22 and 21 H. pylori genes were consistently up- and down-regulated, respectively. The up-regulated genes included pathogenicity island, motility, outer membrane protein, and translational genes. The σ28 factor antagonist flgM, flgG, the stress response gene, flaA, omp11, and the superoxide dismutase gene (sodB) were down-regulated. The up-regulation of cag3, flgB, tonB, rho, and deaD was confirmed by quantitative PCR, and the up-regulation of lpxD, omp6, secG, fabH, HP1285, HP0222, and HP0836 was confirmed by reverse transcription (RT)-PCR. The down-regulation of flaA, sodB, and HP0874 was confirmed by quantitative PCR, and the down-regulation of omp11 was confirmed by RT-PCR. The alteration of gene expression in H. pylori after adhesion to gastric cells in vitro suggests that changes in motility, outer membrane composition, and stress responses, among other changes, may be involved in gastric colonization.

scholarly journals Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development

2021 ◽  
Vol 22 (9) ◽  
pp. 4823
Author(s):  
María Fernanda González ◽  
Paula Díaz ◽  
Alejandra Sandoval-Bórquez ◽  
Daniela Herrera ◽  
Andrew F. G. Quest
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Extracellular Vesicles ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Gastric Epithelium ◽  
Infected Cells ◽  
H Pylori

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.

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

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 637 ◽  
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.

scholarly journals Comparison of CXC Chemokines ENA-78 and Interleukin-8 Expression in Helicobacter pylori-Associated Gastritis

2001 ◽  
Vol 69 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Gabriele Rieder ◽  
Wolfgang Einsiedl ◽  
Rudolf A. Hatz ◽  
Manfred Stolte ◽  
Georg A. Enders ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Protein Expression ◽  
Outer Membrane Proteins ◽  
Water Soluble ◽  
Interleukin 8 ◽  
Gastric Epithelium ◽  
Mrna Levels ◽  
Rt Pcr ◽  
H Pylori

ABSTRACT Colonization of the gastric mucosa with Helicobacter pylori is associated with a dense infiltration of granulocytes into the lamina propria in the active phase of gastritis. In this study, we investigated the involvement of epithelial cell-derived neutrophil-activating protein 78 (ENA-78) in development of H. pylori-associated gastritis. Antral biopsies from 27 patients with H. pylori-associated gastritis and 25 from H. pylori-negative individuals were first analyzed for ENA-78 and interleukin-8 (IL-8) mRNA by semiquantitative reverse transcription (RT)-PCR. In H. pylori-positive patients, significantly elevated levels were found for both chemokines (P < 0.05). Only IL-8 mRNA levels differed significantly (P< 0.05) in H. pylori-infected individuals who had serum antibodies for cytotoxin-associated protein CagA versus H. pylori-infected CagA-negative persons. Quantification of ENA-78 transcript levels by competitive RT-PCR yielded a significant 45-fold upregulation for ENA-78 transcripts in biopsies of H. pylori-positive versus H. pylori-negative patients (P < 0.05). In contrast to earlier findings with IL-8, the degree of ENA-78 mRNA upregulation was independent of the grade of activity of gastritis. Immunofluorescence studies on tissues of antral biopsies localized ENA-78 protein expression mainly to the gastric epithelium of H. pylori-positive patients, while control tissues were negative. Upregulation of ENA-78 and IL-8 mRNA and protein expression was also observed in an in vitro system using a gastric adenocarcinoma cell line. Only viable H. pyloriyielded a strong ENA-78 and IL-8 induction, while H. pyloriouter membrane proteins or water-soluble proteins had no significant effect. These data provide evidence for the importance of both IL-8 and ENA-78 in the development and perpetuation of H. pylori-associated gastritis.

scholarly journals Effect of Inhibition of Extracellular Signal-Regulated Kinase 1 and 2 Pathway on Apoptosis and bcl-2 Expression in Helicobacter pylori-Infected AGS Cells

2003 ◽  
Vol 71 (2) ◽  
pp. 830-837 ◽  
Author(s):  
Il Ju Choi ◽  
Joo Sung Kim ◽  
Jung Mogg Kim ◽  
Hyun Chae Jung ◽  
In Sung Song
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Epithelial Cell ◽  
Cell Apoptosis ◽  
Ags Cells ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Epithelial Cell Apoptosis ◽  
H Pylori ◽  
Induced Apoptosis

ABSTRACT Helicobacter pylori induces activation of mitogen-activated protein kinases (MAPKs). However, its effect on H. pylori-induced apoptosis has not been evaluated. Thus, we examined whether H. pylori-induced extracellular signal-regulated kinase 1 and 2 (ERK1/2) and p38 MAPK activation affects gastric epithelial cell apoptosis and bcl-2 family gene expression, especially in relation to the cagA status of an H. pylori strain. In flow cytometric and oligonucleosome-bound DNA enzyme-linked immunosorbent assay analyses, infection with cagA + H. pylori strains induced gastric cancer cell apoptosis in AGS cells more prominently than infection with cagA mutants. Activation of ERK1/2 and p38 MAPKs was also more prominent in cagA + strains. Pretreatment with a MEK inhibitor (PD98059) inhibited ERK1/2 activation and increased H. pylori-induced apoptosis significantly. This increased apoptosis was accompanied by decreased antiapoptotic bcl-2 mRNA expression among bcl-2-related genes (bcl-2, bax, bak, mcl-1, and bcl-XL/S ), and the effect was also more prominent in the cagA + strains. However, the alteration of bcl-2 gene expression was not accompanied by protein level changes. Inhibition of p38 using specific inhibitor SB203580 decreased H. pylori-induced apoptosis but resulted in little alteration of bcl-2-related gene expression. In conclusion, H. pylori-induced ERK1/2 activation, especially by the cagA + H. pylori strain, may play a protective role against gastric epithelial cell apoptosis partially through maintenance of bcl-2 gene expression.

scholarly journals Assessment of Helicobacter pylori Gene Expression within Mouse and Human Gastric Mucosae by Real-Time Reverse Transcriptase PCR

2001 ◽  
Vol 69 (8) ◽  
pp. 4759-4766 ◽  
Author(s):  
Bachra Rokbi ◽  
Delphine Seguin ◽  
Bruno Guy ◽  
Véronique Mazarin ◽  
Emmanuel Vidor ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
16S Rrna ◽  
Mouse Model ◽  
Reverse Transcriptase ◽  
Real Time ◽  
Rt Pcr ◽  
Reverse Transcriptase Pcr ◽  
H Pylori

ABSTRACT Despite increasing knowledge on the biology of Helicobacter pylori, little is known about the expression pattern of its genome during infection. While mouse models of infection have been widely used for the screening of protective antigens, the reliability of the mouse model for gene expression analysis has not been assessed. In an attempt to address this question, we have developed a quantitative reverse transcriptase PCR (RT-PCR) that allowed the detection of minute amounts of mRNA within the gastric mucosa. The expression of four genes, 16S rRNA, ureA (encoding urease A subunit), katA (catalase), and alpA (an adhesin), was monitored during the course of a 6-month infection of mice and in biopsy samples from of 15 infected humans. We found that the selected genes were all expressed within both mouse and human infected mucosae. Moreover, the relative abundance of transcripts was the same (16S rRNA > ureA >katA > alpA), in the two models. Finally, results obtained with the mouse model suggest a negative effect of bacterial burden on the number of transcripts of each gene expressed per CFU (P < 0.05 for 16S rRNA, alpA, andkatA). Overall, this study demonstrates that real-time RT-PCR is a powerful tool for the detection and quantification ofH. pylori gene expression within the gastric mucosa and strongly indicates that mice experimentally infected with H. pylori provide a valuable model for the analysis of bacterial gene expression during infection.

scholarly journals Outer Membrane Vesicle Production by Helicobacter pylori Represents an Approach for the Delivery of Virulence Factors CagA, VacA and UreA into Human Gastric Adenocarcinoma (AGS) Cells

2021 ◽  
Vol 22 (8) ◽  
pp. 3942
Author(s):  
Yongyu Chew ◽  
Hsin-Yu Chung ◽  
Po-Yi Lin ◽  
Deng-Chyang Wu ◽  
Shau-Ku Huang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Gastric Adenocarcinoma ◽  
Virulence Factors ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Ags Cells ◽  
Α Subunit ◽  
Human Gastric Adenocarcinoma ◽  
H Pylori

Helicobacter pylori infection is the etiology of several gastric-related diseases including gastric cancer. Cytotoxin associated gene A (CagA), vacuolating cytotoxin A (VacA) and α-subunit of urease (UreA) are three major virulence factors of H. pylori, and each of them has a distinct entry pathway and pathogenic mechanism during bacterial infection. H. pylori can shed outer membrane vesicles (OMVs). Therefore, it would be interesting to explore the production kinetics of H. pylori OMVs and its connection with the entry of key virulence factors into host cells. Here, we isolated OMVs from H. pylori 26,695 strain and characterized their properties and interaction kinetics with human gastric adenocarcinoma (AGS) cells. We found that the generation of OMVs and the presence of CagA, VacA and UreA in OMVs were a lasting event throughout different phases of bacterial growth. H. pylori OMVs entered AGS cells mainly through macropinocytosis/phagocytosis. Furthermore, CagA, VacA and UreA could enter AGS cells via OMVs and the treatment with H. pylori OMVs would cause cell death. Comparison of H. pylori 26,695 and clinical strains suggested that the production and characteristics of OMVs are not only limited to laboratory strains commonly in use, but a general phenomenon to most H. pylori strains.

scholarly journals Zak Gene֝s Expression in Patients With Helicobacter Pylori Infection

2021 ◽  
Author(s):  
Delniya Khani ◽  
Manouchehr Ahmadi Hedayati ◽  
Farshad Sheikhesmaeili ◽  
Roghaie Ghadiany ◽  
Sherko Nasseri
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Cell Cycle ◽  
Helicobacter Pylori ◽  
Gastric Adenocarcinoma ◽  
Case Control Study ◽  
Case Control ◽  
Rt Pcr ◽  
H Pylori ◽  
Control Study

Abstract Background: ZAK protein is a member of the MLK family proteins defined as mediators in the cell cycle. A survey of zak gene expression in gastric antral epithelial cells (GAECs) of gastritis and gastric adenocarcinoma patients with Helicobacter pylori genotypes infection can elucidate carcinogenesis of H. pylori genotypes.Methods: In a case-control study, zak gene expression was evaluated in GAECs biopsy samples of gastritis patients with (n 23) and without H. pylori infection (n 27) and gastric adenocarcinoma patients with (n 21) and without (n 32) H. pylori infection. The zak gene expression was measured using the relative Real-Time RT PCR.Results: zak gene expression was higher in GAECs of gastritis cancer than in gastric adenocarcinoma, indicating the protective effect of ZAK against gastric cancer (p< 0.005). Conclusion: Reducing zak gene expression has the negative corelations with H. pylori infection and gastric adenocarcinoma.

scholarly journals Helicobacter pylori-associated oxidant monochloramine induces reactivation of Epstein–Barr virus (EBV) in gastric epithelial cells latently infected with EBV

2006 ◽  
Vol 55 (7) ◽  
pp. 905-911 ◽  
Author(s):  
Junko Minoura-Etoh ◽  
Kazuyo Gotoh ◽  
Ryugo Sato ◽  
Masao Ogata ◽  
Naomi Kaku ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Epstein Barr Virus ◽  
Lytic Infection ◽  
Gastric Epithelium ◽  
Human Pathogens ◽  
Ags Cells ◽  
Barr Virus ◽  
Latently Infected ◽  
Epstein Barr ◽  
H Pylori

To investigate the possibility of an interaction between two ubiquitous human pathogens, Helicobacter pylori and Epstein–Barr virus (EBV), the effect of monochloramine (NH2Cl), locally produced by H. pylori infection, on gastric epithelium latently infected with EBV was examined, by assessing the induction of EBV lytic infection. AGS cells harbouring latently infected EBV were used as the indicator of lytic change caused by NH2Cl treatment. Lytic infection, determined by morphological change and EA-D antigen expression, occurred immediately after treatment with in vitro-synthesized NH2Cl. Analysis of EBV infection in human gastric tissue revealed that out of 48 H. pylori-positive patients, 24 were positive for EBER-1, and 18 and 13 were positive for EBNA1 and LMP-1 antigen, respectively. The results suggest that H. pylori-associated NH2Cl induces EBV lytic conversion in gastric epithelium latently infected with EBV.

scholarly journals Status of kinases in Epstein-Barr virus and Helicobacter pylori Coinfection in gastric Cancer cells

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Charu Sonkar ◽  
Tarun Verma ◽  
Debi Chatterji ◽  
Ajay Kumar Jain ◽  
Hem Chandra Jha
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Epstein Barr Virus ◽  
Morphological Changes ◽  
Ags Cells ◽  
Barr Virus ◽  
Apoptotic Genes ◽  
Epstein Barr ◽  
H Pylori

Abstract Background Helicobacter pylori (H. pylori) and Epstein - Barr virus (EBV) plays a significant role in aggressive gastric cancer (GC). The investigation of genes associated with these pathogens and host kinases may be essential to understand the early and dynamic progression of GC. Aim The study aimed to demonstrate the coinfection of EBV and H. pylori in the AGS cells through morphological changes, expression of the kinase and the probable apoptotic pathways. Methods Genomic DNA isolation of H. pylori and its characterization from clinical samples were performed. RT-qPCR of kinases was applied to scrutinize the gene expression of kinases in co-infected GC in a direct and indirect (separated through insert size 0.45 μm) H. pylori infection set up. Morphological changes in co-infected GC were quantified by measuring the tapering ends of gastric epithelial cells. Gene expression profiling of apoptotic genes was assessed through RT-qPCR. Results An interleukin-2-inducible T-cell kinase (ITK) showed significant upregulation with indirect H. pylori infection. Moreover, Ephrin type-B receptor six precursors (EPHB6) and Tyrosine-protein kinase Fyn (FYN) showed significant upregulation with direct coinfection. The tapering ends in AGS cells were found to be extended after 12 h. A total of 24 kinase genes were selected, out of which EPHB6, ITK, FYN, and TYK2 showed high expression as early as 12 h. These kinases may lead to rapid morphological changes in co-infected gastric cells. Likewise, apoptotic gene expression such as APAF-1 and Bcl2 family genes such as BAD, BID, BIK, BIM, BAX, AND BAK were significantly down-regulated in co-infected AGS cells. Conclusion All the experiments were performed with novel isolates of H. pylori isolated from central India, for the functional assessment of GC. The effect of coinfection with EBV was more profoundly observed on morphological changes in AGS cells at 12 h as quantified by measuring the tapering of ends. This study also identifies the kinase and apoptotic genes modulated in co-infected cells, through direct and indirect approaches. We report that ITK, EPHB6, TYK2, FYN kinase are enhanced, whereas apoptotic genes such as APAF-1, BIK, FASL, BAX are significantly down-regulated in AGS cells coinfected with EBV and H. pylori.

scholarly journals Helicobacter pylori VacA Toxin Promotes Bacterial Intracellular Survival in Gastric Epithelial Cells

2006 ◽  
Vol 74 (12) ◽  
pp. 6599-6614 ◽  
Author(s):  
M. R. Terebiznik ◽  
C. L. Vazquez ◽  
K. Torbicki ◽  
D. Banks ◽  
T. Wang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Small Gtpase ◽  
Host Cells ◽  
Gastric Epithelium ◽  
Current Evidence ◽  
Causative Role ◽  
Peptic Ulcers ◽  
Ags Cells ◽  
H Pylori

ABSTRACT Helicobacter pylori colonizes the gastric epithelium of at least 50% of the world's human population, playing a causative role in the development of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. Current evidence indicates that H. pylori can invade epithelial cells in the gastric mucosa. However, relatively little is known about the biology of H. pylori invasion and survival in host cells. Here, we analyze both the nature of and the mechanisms responsible for the formation of H. pylori's intracellular niche. We show that in AGS cells infected with H. pylori, bacterium-containing vacuoles originate through the fusion of late endocytic organelles. This process is mediated by the VacA-dependent retention of the small GTPase Rab7. In addition, functional interactions between Rab7 and its downstream effector, Rab-interacting lysosomal protein (RILP), are necessary for the formation of the bacterial compartment since expression of mutant forms of RILP or Rab7 that fail to bind each other impaired the formation of this unique bacterial niche. Moreover, the VacA-mediated sequestration of active Rab7 disrupts the full maturation of vacuoles as assessed by the lack of both colocalization with cathepsin D and degradation of internalized cargo in the H. pylori-containing vacuole. Based on these findings, we propose that the VacA-dependent isolation of the H. pylori-containing vacuole from bactericidal components of the lysosomal pathway promotes bacterial survival and contributes to the persistence of infection.

Sign in / Sign up

Export Citation Format

Share Document