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.

2024-04-18 | GSE264263 | GEO

Phasevarion mediated random switching of gene expression in Helicobacter Pylori

Project description:Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, Neissera Meningtidis and Neisseria Gonorrhoeae, the random switching of the modA gene, associated with a phase variable type III restriction modification (R-M) system, controls expression of a phase-variable regulon of genes (a “phasevarion”), via differential methylation of the genome in the modA ON and OFF states. Phase variable type III R-M systems are also found in Helicobacter pylori, suggesting that phasevarions may also exist in this intriguing pathogen. Phylogenetic studies on the phase-variable type III modC gene revealed that there are 12 distinct alleles in H. pylori, which differ only in their DNA recognition domain, with the majority containing the C5 allele. Microarray analysis comparing the H. pylori wild-type P12modC5 ON strain to the P12(delta)modC5 mutant revealed that six genes were either up-regulated or down-regulated, some of which were virulence-associated. For example flaA, which encodes a flagella protein important in motility and hopG, which encodes an important outer membrane protein. This study, in conjunction with our previous work, indicates that phasevarions may be a common strategy used by host-adapted bacterial pathogens to randomly switch between “differentiated” cell types.

2012-01-16 | GSE26759 | GEO

Phasevarion mediated random switching of gene expression in Helicobacter Pylori

Project description:Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, Neissera Meningtidis and Neisseria Gonorrhoeae, the random switching of the modA gene, associated with a phase variable type III restriction modification (R-M) system, controls expression of a phase-variable regulon of genes (a M-bM-^@M-^\phasevarionM-bM-^@M-^]), via differential methylation of the genome in the modA ON and OFF states. Phase variable type III R-M systems are also found in Helicobacter pylori, suggesting that phasevarions may also exist in this intriguing pathogen. Phylogenetic studies on the phase-variable type III modC gene revealed that there are 12 distinct alleles in H. pylori, which differ only in their DNA recognition domain, with the majority containing the C5 allele. Microarray analysis comparing the H. pylori wild-type P12modC5 ON strain to the P12(delta)modC5 mutant revealed that six genes were either up-regulated or down-regulated, some of which were virulence-associated. For example flaA, which encodes a flagella protein important in motility and hopG, which encodes an important outer membrane protein. This study, in conjunction with our previous work, indicates that phasevarions may be a common strategy used by host-adapted bacterial pathogens to randomly switch between M-bM-^@M-^\differentiatedM-bM-^@M-^] cell types. Direct comparison of biological triplicates of wild type and mutant strains

2012-01-16 | E-GEOD-26759 | biostudies-arrayexpress

Membrane substrates of HtrA from Helicobacter pylori

Project description:High temperature requirement A (HtrA) is a serine protease secreted by the group-I carcinogen Helicobacter pylori (H. pylori). The human cell adhesion protein and tumor suppressor E-cadherin (hCdh1) expressed on the surface of gastric epithelial cells was identified as the first HtrA substrate. HtrA-mediated hCdh1 cleavage and subsequent disruption of intercellular adhesion are considered as important steps in H. pylori pathogenesis. In this study, we performed a proteomic profiling of H. pylori HtrA (HpHtrA) to decipher the complex mechanism how H. pylori can interfere with epithelial barrier integrity.

2022-02-17 | PXD025360 | Pride

Transcription profiling of cell lines in response to Helicobacter pylori lipopolysaccharide shows Tribbles 3 - a novel regulator of TLR2-mediated signaling in response to Helicobacter pylori lipopolysaccharide

Project description:This SuperSeries is composed of the following subset Series: GSE25146: Changes in gene expression in AGS cells in response to Helicobacter pylori lipopolysaccharide GSE25147: Changes in gene expression in MKN45 cells in response to Helicobacter pylori lipopolysaccharide GSE25148: Changes in gene expression in HEK-TLR2 cells in response to Helicobacter pylori lipopolysaccharide Refer to individual Series

2011-01-12 | E-GEOD-25155 | biostudies-arrayexpress

Gene expression profiling of gastric cells infected by Helicobacter pylori

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.

2016-03-01 | GSE70394 | GEO

Helicobacter pylori pathogenic mechanism

Project description:Helicobacter pylori infection reprograms host gene expression and influences various cellular processes, which have been investigated by cDNA microarray in vitro culture cells and in vivo patients of the chronic abdominal complaint. In this study，the effects of H. pylori infection on host gene expression in the gastric antral mucosa of patients with chronic gastritis were examined. The gastric antral mucosa was obtained from a total of 6 untreated patients undergoing gastroscopic and pathologic confirmation of chronic superficial gastritis. Three patients infected by H. pylori and 3 patients uninfected were used to cDNA microarray experiment.

2012-04-29 | E-GEOD-30042 | biostudies-arrayexpress