Project description:Helicobacter pylori (H. pylori) is a type of pathogen in humans that has infected nearly half of the population worldwide. Infections with H. pylori are typically associated with chronic gastritis and may even lead to gastric and duodenal ulcers and stomach cancer. While the mechanisms behind persistent colonization by H. pylori and the development of gastritis associated with it remain unclear, it is generally believed that the gastric epithelial cells (GECs) modulated by H. pylori in the gastric mucosa play a crucial role. We extensively studied the global gene expression patterns in H. pylori-infected AGS cells, a line of gastric epithelial cells, and identified genes that show increased expression upon infection with H. pylori.
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.
Project description:Helicobacter pylori are gram-negative bacteria that colonize the human stomach and are the major etiological factor in gastric carcinoma development. The aim of this work was to evaluate changes in gene expression in gastric cells induced by H. pylori. The human gastric carcinoma-derived cell line AGS was infected with H. pylori strain 60190 (ATCC 49503) for 24 hours. RNA was extracted from three independent experiments.
Project description:Helicobacter pylori (H. pylori) is a human pathogen that infects almost half of the world’s population. Infection with H. pylori is frequently associated with chronic gastritis and can even lead to gastric and duodenal ulcers and gastric cancer. Although the persistent colonization of H. pylori and the development of H. pylori-associated gastritis remain poorly understood, it is believed that, in gastric mucosa, the modulated gastric epithelial cells (GECs) by H. pylori are key contributors. We used microarrays to detail the global programme of gene expression in Helicobacter pylori infected-gastric epithelial cell line AGS cells and identified up-regulated genes induced by Helicobacter pylori infection.
Project description:H. pylori Outer membrane phospholipase A (OMPLA) has been suggested to play a role in the virulence of this bacterium. The aim of this study was to profile the most significant cellular pathways and biological processes affected in gastric epithelial cells during 24 hours of H. pylori exposure, and to study the inflammatory response to OMPLA+ and OMPLA- H. pylori variants
Project description:This study set out to identify global changes in gene expression in AGS gastric epithelial cells following 8 hours stimulation with 10 μg/ml lipopolysaccharide (LPS) from the gastric pathogen H. pylori. Microarray analysis was used to compare changes in gene expression between cells treated with 10 μg/ml H. pylori LPS and untreated cells at the same time point.
Project description:We performed genome-wide mRNA and miRNA expression analysis in gastric epithelial cell line AGS infected with Helicobacter pylori at 100 Multiplicity of Infection (MOI), comparing the expression profile of infected cells with uninfected cells. Differentially expressed mRNAs and miRNAs were identified, which showed a 1.5 fold change in expression in infected cells compared to uninfected cells. We performed in silico analysis of miRNA-mRNA target interactions among the inversely correlated differentially expressed miRNAs and mRNAs, and performed functional enrichment analysis of the target genes, to identify important cellular pathways that reflect the patho-biology of H. pylori infected cells. Among the important miRNA-mRNA target pairs, PHLPP1, reported to be associated with poor prognosis in cancer, was predicted to be a putative target of miR-29b-1-5p. Therefore, we focused on the miR-29b-1-5p/PHLPP1 miRNA/target pair for detailed investigation into their role in H. pylori-mediated signalling in gastric epithelial cells. This study demonstrates that an integrated analysis of global mRNA and miRNA expression patterns, combined with miRNA-mRNA target prediction and functional analysis of miRNA target genes can yield an understanding of the critical pathways regulating the behaviour of gastric epithelial cells challenged with H. pylori.
Project description:We performed genome-wide mRNA and miRNA expression analysis in gastric epithelial cell line AGS infected with Helicobacter pylori at 100 Multiplicity of Infection (MOI), comparing the expression profile of infected cells with uninfected cells. Differentially expressed mRNAs and miRNAs wered identified, which showed a 1.5 fold change in expression in infected cells compared to uninfected cells. We performed in silico analysis of miRNA-mRNA target interactions among the inversely correlated differentially expressed miRNAs and mRNAs, and performed functional enrichment analysis of the target genes, to identify important cellular pathways that reflect the patho-biology of H. pylori infected cells. Among the important miRNA-mRNA target pairs, PHLPP1, reported to be associated with poor prognosis in cancer, was predicted to be a putative target of miR-29b-1-5p. Therefore, we focused on the miR-29b-1-5p/PHLPP1 miRNA/target pair for detailed investigation into their role in H. pylori-mediated signalling in gastric epithelial cells. This study demonstrates that an integrated analysis of global mRNA and miRNA expression patterns, combined with miRNA-mRNA target prediction and functional analysis of miRNA target genes can yield an understanding of the critical pathways regulating the behaviour of gastric epithelial cells challenged with H. pylori.
Project description:This study set out to identify global changes in gene expression in AGS gastric epithelial cells following 8 hours stimulation with 10 μg/ml lipopolysaccharide (LPS) from the gastric pathogen H. pylori. Microarray analysis was used to compare changes in gene expression between cells treated with 10 μg/ml H. pylori LPS and untreated cells at the same time point. Total RNA was harvested from AGS cells following treatment with LPS for 8h or untreated cells at the same time-point. 2 independent experiments were carried out. RNA was labelled and hybridized to GeneChips to analyse changes in gene expression.