Cag pathogenicity island-specific responses of gastric epithelial cells to Helicobacter pylori infection.
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE3556 | GEO | 2005/11/04
SECONDARY ACCESSION(S): PRJNA93633
REPOSITORIES: GEO
Similar Datasets
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12.
2005-09-30 | E-SMDB-1661 | biostudies-arrayexpress
Project description:TC1: gastric epithelial (AGS) cells infected with wild type H. pylori (G27) and isogenic mutants in cagA and vacA for 0, 0.5, 3, 6, and 12 hours. Total RNA was used to make single stranded Cy5 labelled probe and compared to Cy3 labelled probe from uninfected AGS cells. Hybridizations of G27 (trial 4) and cagA- (trial 3) timecourses were done in parallel. A technical replicate of the G27 time course (trial 5) and hybridization of vacA- (trial 3) time course were done in parallel. The cagA 6 and 12 hour time points were technically replicated (trial 4) (the cagA 6 hour sample of trial 3 was lost). TC2: Biological replication and expansion of TC1, using more isogenic mutants and timepoints. AGS cells were mock infected, infected with G27, and isogenic mutants in cagN, cagA, cagE, and a deletion of the cag PAI for 0. 1, 3, 6, 12, and 24 hours. Probe synthesis and hybridization was done as in TC1. Note: there may have been a sample mix-up with PAI 12, swapping it with G27 or cagN 12. Groups of assays that are related as part of a time series. Computed
2005-11-03 | E-GEOD-3556 | biostudies-arrayexpress
Project description:H. pylori infection of human gastric epithelial cells (GEC) represses H,K-ATPase alpha subunit (HK-alpha) gene transcription through NF-Kappa B p50 homodimer binding to HK-alpha promoter. The bacterial cagA and slt gene products have been implicated in HK-alpha repression, which facilitates gastric H. pylori colonization and may underlie transient clinical hypochlorhydria. We hypothesized that H. pylori also regulates H,K-ATPase expression post-transcriptionally by micro-RNA interaction with HK-alpha mRNA. Our microarray experiment examined the effect of infection by wildtype H. pylori infection or a delta-cagA H. pylori mutant on miRNA expression of human gastric cells (AGS). Our results indicate that H. pylori infection up-regulates GEC miRNAs that target the HK-alpha 3' UTR and block translation, and that CagA activity is implicated in the miRNA up-regulation. Three types of samples were generated for microarray analysis: 1) AGS cells infected with wildtype H. pylori; 2) AGS cells infected with cagA-deficient H. pylori; 3) a mock-infected sample, prepared as a control by combining total RNA from uninfected AGS cells with total RNA from wildtype H. pylori, with relative eukaryotic and prokaryotic RNA amounts matching those observed in infected samples, based on proportional ribosomal peak heights quantified by Bioanalyzer. Three experimental replicates were generated for each type of treatment.
2016-01-18 | E-GEOD-51306 | biostudies-arrayexpress
Project description:H. pylori virulence factors have been suggested to be important in determining the outcome of infection. The H. pylori adhesion protein BabA2 is thought to play an crucial role in bacterial colonization and in induction of a severe gastric inflammation, particularly in combination with expression of CagA and VacA. However, the influence of these virulence factors on the pathogenesis of H. pylori infection, is still poorly understood. To address this question, the inflammatory gene expression profiles from two groups of patients infected with triple-negative strains (lacking expression of CagA, BabA2 and VacAs1, but expressing VacAs2) and triple-positive strains (expressing CagA, VacAs1 and BabA2, but lacking expression of VacAs2) were investigated. The gene expression pattern in the antrum gastric mucosa from patients infected with different H. pylori strains was very similar, and no differentially expressed genes could be identified by pair-wise comparisons. Our data thus suggest a lack of correlation between the host inflammatory responses in the gastric mucosa and expression of the BabA2, CagA and VacAs1 genes. Two groups of patients who infected with double-positive strains (type I strains, expressing CagA and VacAs1 genes) and triple-negative strains (lacking the CagA, BabA2 and VacAs1, but expressing VacAs2) were investigated in this study.
2008-05-01 | E-GEOD-6143 | biostudies-arrayexpress
Project description:H. pylori virulence factors have been suggested to be important in determining the outcome of infection. The H. pylori adhesion protein BabA2 is thought to play an crucial role in bacterial colonization and in induction of a severe gastric inflammation, particularly in combination with expression of CagA and VacA. However, the influence of these virulence factors on the pathogenesis of H. pylori infection, is still poorly understood. To address this question, the inflammatory gene expression profiles from two groups of patients infected with triple-negative strains (lacking expression of CagA, BabA2 and VacAs1, but expressing VacAs2) and triple-positive strains (expressing CagA, VacAs1 and BabA2, but lacking expression of VacAs2) were investigated. The gene expression pattern in the antrum gastric mucosa from patients infected with different H. pylori strains was very similar, and no differentially expressed genes could be identified by pair-wise comparisons. Our data thus suggest a lack of correlation between the host inflammatory responses in the gastric mucosa and expression of the BabA2, CagA and VacAs1 genes. Keywords: diseases analysis
2008-05-01 | GSE6143 | GEO
Project description:Helicobacter pylori infection promotes chronic inflammation and plethora of DNA damages including strand breaks, base alterations, point mutations, microsatellite instability and epigenetic alterations. The gastric epitheliaI cells, in order to prevent genomic instability, require an integrous DNA damage repair (DDR) machinery which, however, has been reported to be modulated by the infection. CagA is a major Hp virulence factor that deregulates host cell functions such as proliferation, apoptosis and chromosomal integrity. Its pathogenic activity is partly regulated by tyrosine phosphorylation on repeated EPIYA-motifs. Our aim was to identify putative effects of H. pylori infection and CagA protein on DDR machinery, investigating the transcriptome of AGS cells, infected with P12 H. pylori wild-type strain, as well as, its corresponding CagA knock-out and the CagA phosphorylation-defective mutant following tyrosine (EPIYA) substitution by phenylalanine (EPIFA) in the EPIYA-C motifs. Upon RNA-Sequencing on polyA-selected transcripts we performed Differential Expression Analysis, Pathway Enrichment Analysis and visualization on KEGG Pathway Maps per DDR mechanism. Key DDR components that were observed to be downregulated in a CagA-related manner were validated via Western Blot utilizing AGS and the non-cancerous GES1 cell lines. Transcriptome analysis revealed that a notable number of DDR genes were downregulated during H. pylori infection resulting to potential modulation of Base Excision Repair, Mismatch Repair and a more intricate deregulation of Nucleotide Excision Repair, Homologous Recombination and Non-Homologous End-Joining. CagA contributes to MUTYH, FEN1, APE1, POLD1 and LIG1 downregulation and those observations were verified on the protein expression level, with the exception of APE1 that was on contrary observed to be upregulated. Our study accentuates the role of CagA, as a significant contributor of the H. pylori infection-mediated DDR modulation, disrupting the balance between DNA damage introduction and repair thus favoring genomic instability and potentially contributing to gastric carcinogenesis.
2020-12-17 | GSE162056 | GEO
Project description:Helicobacter pylori is a human gastric pathogen associated with gastric and duodenal ulcers as well as specific gastric cancers. It is well-evidenced that motility is essential for this pathogen to colonize human gastric tissues. We found that the H. pylori G27 HP0518 mutant showed greater motility than the parental strain, leading to increased cell adhesion and subsequent CagA translocation and NF-κB activation in AGS cells. This mutant expressed a higher molecular mass flagellin A (FlaA) than the parental wild-type strain and the complemented HP0518 mutant, which correlated with differences in motility. Deglycosylation assays indicated that the increased molecular mass of the FlaA protein expressed by the mutant was due to O-linked glycoside modifications. Electron micrographs demonstrated that expression of bundle-formed flagellin filaments in the HP0518 mutant was enhanced in comparison to the wild-type strain. Different degrees of FlaA glycosylation between H. pylori strains suggested that glycosylation could affect both virulence and persistence in vivo. In conclusion, HP0518 inactivation resulted in FlaA hyper-glycosylation leading to increased virulence and motility.
2010-12-22 | GSE14752 | GEO
Project description:Helicobacter pylori is a human gastric pathogen associated with gastric and duodenal ulcers as well as specific gastric cancers. It is well-evidenced that motility is essential for this pathogen to colonize human gastric tissues. We found that the H. pylori G27 HP0518 mutant showed greater motility than the parental strain, leading to increased cell adhesion and subsequent CagA translocation and NF-κB activation in AGS cells. This mutant expressed a higher molecular mass flagellin A (FlaA) than the parental wild-type strain and the complemented HP0518 mutant, which correlated with differences in motility. Deglycosylation assays indicated that the increased molecular mass of the FlaA protein expressed by the mutant was due to O-linked glycoside modifications. Electron micrographs demonstrated that expression of bundle-formed flagellin filaments in the HP0518 mutant was enhanced in comparison to the wild-type strain. Different degrees of FlaA glycosylation between H. pylori strains suggested that glycosylation could affect both virulence and persistence in vivo. In conclusion, HP0518 inactivation resulted in FlaA hyper-glycosylation leading to increased virulence and motility. Microarray experiments were carried out as two-color hybridizations with a color-swap dye-reversal setting to compensate Cy-dye specific effects and to ensure statistically relevant data.
2010-12-22 | E-GEOD-14752 | biostudies-arrayexpress
Project description:Background: Helicobacter pylori is an important human pathogen that infects the human gastric mucosa leading to chronic inflammation which is responsible for severe gastroduodenal diseases. The Outer Inflammatory Protein A (OipA) of H. pylori is an important virulence factor. However, the role of OipA in gastric cancer and ulcer development is still not well-established. Phase variation within a CT dinucleotide repeat motif of oipA switches its expression “on” and “off”. This study aims to elucidate the role of OipA in H. pylori infection using oipA “on” and “off” clinical strains and oipA deletion mutant. Methods: Proteomics analysis was performed on AGS human gastric epithelial cell line post-infection with oipA “on” and “off” H. pylori using liquid chromatography / mass spectrometry (LC/MS). In addition, AGS apoptosis and cell cycle assays were performed. To confirm the findings, oipA deletion mutant (ΔoipA) was generated and expression of VacA was detected using Western blotting. Result: Expression of AGS proteins involve in human disease was suppressed / down-regulated post-infection with oipA “off” strains, as well as oipA mutant, compared to oipA “on” strains. Furthermore, oipA “off” strains and oipA mutant resulted in a higher level of apoptosis and G0/G1 cell-cycle arrest in AGS cells than oipA “on” strains. Interestingly, deletion of oipA was found to increase VacA production by the bacterium. Discussion: The capability of oipA “off” strains to induce apoptosis and suppress proteins having roles in human disease may suggest that these H. pylori may be less virulent or may even be protective against carcinogenesis compared to its oipA “on” counterparts. This may potentially explain the higher incidence of gastric cancer among East Asian which oipA “on” strains predominates. Conclusions: Data from this study strengthened our understanding of the role of H. pylori OipA as a virulence factor in chronic inflammation, metastasis and carcinogenesis.
2022-03-14 | PXD005020 | Pride
Project description:H. pylori infection of human gastric epithelial cells (GEC) represses H,K-ATPase alpha subunit (HK-alpha) gene transcription through NF-Kappa B p50 homodimer binding to HK-alpha promoter. The bacterial cagA and slt gene products have been implicated in HK-alpha repression, which facilitates gastric H. pylori colonization and may underlie transient clinical hypochlorhydria. We hypothesized that H. pylori also regulates H,K-ATPase expression post-transcriptionally by micro-RNA interaction with HK-alpha mRNA. Our microarray experiment examined the effect of infection by wildtype H. pylori infection or a delta-cagA H. pylori mutant on miRNA expression of human gastric cells (AGS). Our results indicate that H. pylori infection up-regulates GEC miRNAs that target the HK-alpha 3' UTR and block translation, and that CagA activity is implicated in the miRNA up-regulation.
2016-01-18 | GSE51306 | GEO