Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) and non-progenitor gastric epithelial cells (npGECs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) and non-progenitor gastric epithelial cells (npGECs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Experiment Overall Design: mGEPs and npGECs were seeded and grown to 70% confluency in RPMI1640 medium supplemented with 10% FBS before being infected with H. pylori strains Kx1 or Kx2 that had been grown to log phase. After 24h, media and non-attached bacteria were washed off and the cells harvested by trypsinization. RNA was prepared from triplicate cultures of mGEP cells infected with Kx1 or Kx2, npGECs infected with Kx1 or Kx2 and uninfected mGEPs and npGECs that served as controls.
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 and Kx2 were also grown in cell media in the absence of cells. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array
Project description:Helicobacter pylori clinical isolates can establish themselves in gastric epithelial stem cells and this interaction may have implications for gastric tumorigenesis. Mouse gastric epithelial progenitor cells (mGEPs) were infected for 24hrs with Helicobacter pylori clinical isolates Kx1 and Kx2. Kx1 and Kx2 were also grown in cell media in the absence of cells. Kx1 was isolated from a patient with chronic atrophic gastritis (ChAG) and Kx2 from the same patient 4 years later, when he progressed to gastric adenocarcinoma. Keywords: RNA Expression Array H. pylori strains Kx1 or Kx2 that had been grown to log phase were used to infect mGEP cells.. After 24h, media and non-attached bacteria were washed off and the cells harvested by trypsinization. RNA was prepared from bacteria infecting mGEP cells or bacterial cultures of Kx1 and Kx2 grown in cell media for 24h in the absence of mGEP cells.
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: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:Chronic infection with the bacterial pathogen Helicobacter pylori is a risk factor for the development of gastric cancer, yet remains asymptomatic in a majority of individuals. We report here that the C57Bl6 mouse model of experimental infection with the closely related H. felis recapitulates this wide range in host susceptibility. A majority of infected mice develop premalignant lesions such as gastric atrophy, compensatory epithelial hyperplasia and intestinal metaplasia, whereas a minority is completely protected from preneoplasia. Protection is associated with the failure to mount an IFN-gamma response to the infection and an associated high Helicobacter burden. We demonstrate that IFN-gamma is essential for clearance of Helicobacter, but also mediates the formation of preneoplastic lesions. We further provide evidence that IFN-gamma triggers a specific transcriptional program in murine gastric epithelial cells in vitro and in vivo, and induces their preferential transformation to the hyperplastic phenotype. In summary, our data suggest a dual role for IFN-gamma in Helicobacter pathogenesis that could provide an explanation for the differential susceptibility to H. pylori-induced gastric pathology in the human population. Keywords: response to in vitro stimulus / comparison of histopathological states We chose mice for gene expression profiling that following Helicobacter infection had (a) symptoms of gastritis, but no epithelial changes, (b) atrophic gastritis accompanied by corpus gland hyperplasia or (c) atrophic gastritis accompanied by intestinal metaplasia. An uninfected control group was also included in the analysis, as were two groups of mice that lacked mature T- and B-cells due to a deletion mutation in the rag1 gene (Rag-1-/-) and that were either experimentally infected or served as Rag-1-/- uninfected controls. To see the effects of IFNg on murine gastric epithelial cells we analysed an immortalized murine primary gastric epithelial cell line treated with three different concentrations of IFNg in comparison to an untreated control.
Project description:The aim of this study is to identify alterations induced in gastric mucosa of mice exposed to Pteridium aquilinum and/or infected with Helicobacter pylori, in order to identify genes that are induced by bracken fern exerts exacerbating effects on gastric lesions associated to the infection. Six groups of C57Bl/6 mice were be used: 1) control, 2) infected Helicobacter pylori, 3) treated with Bracken fern extract orogastrically, 4) treated with Bracken fern extract in drinking water, 5) infected Helicobacter pylori + treated with Bracken fern extract orogastrically, 6) infected Helicobacter pylori + treated with Bracken fern extract in drinking water. The infection procedure was performed using an orogastric inoculation of H.pylori (strain SS1) twice in the first week. The RNA isolation was done in triplicate (3 mice per each condition). Further evaluation of morphological alterations on gastric mucosa, proliferative index and induction of DNA strand breaks will be performed in the mice stomach exposed to Pteridium aquilinum infected or not with Helicobacter pylori. Alterations of glycosylation in gastric tissues will also evaluated.
Project description:Chronic infection with the bacterial pathogen Helicobacter pylori is a risk factor for the development of gastric cancer, yet remains asymptomatic in a majority of individuals. We report here that the C57Bl6 mouse model of experimental infection with the closely related H. felis recapitulates this wide range in host susceptibility. A majority of infected mice develop premalignant lesions such as gastric atrophy, compensatory epithelial hyperplasia and intestinal metaplasia, whereas a minority is completely protected from preneoplasia. Protection is associated with the failure to mount an IFN-gamma response to the infection and an associated high Helicobacter burden. We demonstrate that IFN-gamma is essential for clearance of Helicobacter, but also mediates the formation of preneoplastic lesions. We further provide evidence that IFN-gamma triggers a specific transcriptional program in murine gastric epithelial cells in vitro and in vivo, and induces their preferential transformation to the hyperplastic phenotype. In summary, our data suggest a dual role for IFN-gamma in Helicobacter pathogenesis that could provide an explanation for the differential susceptibility to H. pylori-induced gastric pathology in the human population. Keywords: response to in vitro stimulus / comparison of histopathological states
Project description:We treated mouse gastric organoids with Helicobacter pylori, Fusobacterium nucleatum, and Neisseria subflava, and extracted RNA after 4 hours. RNAs were applied to RNA sequencing analysis to investigate bacteria-specific effects on gastric epithelial cells.