Dataset Information

Response of gastric epithelial progenitors to Helicobacter pylori Isolates obtained from Swedish patients with chronic atrophic gastritis.

ABSTRACT: Helicobacter pylori infection is associated with gastric adenocarcinoma in some humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG). Gastric epithelial progenitors (GEPs) in transgenic gnotobiotic mice with a ChAG-like phenotype harbor intracellular collections of H. pylori. To characterize H. pylori adaptations to ChAG, we sequenced the genomes of 24 isolates obtained from 6 individuals, each sampled over a 4-year interval, as they did or did not progress from normal gastric histology to ChAG and/or adenocarcinoma. H. pylori populations within study participants were largely clonal and remarkably stable regardless of disease state. GeneChip studies of the responses of a cultured mouse gastric stem cell-like line (mGEPs) to infection with sequenced strains yielded a 695-member dataset of transcripts that are (i) differentially expressed after infection with ChAG-associated isolates, but not with a "normal" or a heat-killed ChAG isolate, and (ii) enriched in genes and gene functions associated with tumorigenesis in general and gastric carcinogenesis in specific cases. Transcriptional profiling of a ChAG strain during mGEP infection disclosed a set of responses, including up-regulation of hopZ, an adhesin belonging to a family of outer membrane proteins. Expression profiles of wild-type and DeltahopZ strains revealed a number of pH-regulated genes modulated by HopZ, including hopP, which binds sialylated glycans produced by GEPs in vivo. Genetic inactivation of hopZ produced a fitness defect in the stomachs of gnotobiotic transgenic mice but not in wild-type littermates. This study illustrates an approach for identifying GEP responses specific to ChAG-associated H. Pylori strains and bacterial genes important for survival in a model of the ChAG gastric ecosystem.

SUBMITTER: Giannakis M

PROVIDER: S-EPMC2781593 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

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Response of gastric epithelial progenitors to Helicobacter pylori Isolates obtained from Swedish patients with chronic atrophic gastritis.

Giannakis Marios M Bäckhed Helene Kling HK Chen Swaine L SL Faith Jeremiah J JJ Wu Meng M Guruge Janaki L JL Engstrand Lars L Gordon Jeffrey I JI

The Journal of biological chemistry 20090901 44

Helicobacter pylori infection is associated with gastric adenocarcinoma in some humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG). Gastric epithelial progenitors (GEPs) in transgenic gnotobiotic mice with a ChAG-like phenotype harbor intracellular collections of H. pylori. To characterize H. pylori adaptations to ChAG, we sequenced the genomes of 24 isolates obtained from 6 individuals, each sampled over a 4-year interval, as they did or did not pro ...[more]

PMID: 19723631

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Project description:Helicobacter pylori infection is associated with development of gastric adenocarcinoma in a subset of infected humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG) characterized by loss of acid-producing parietal cells. Studies in a gnotobiotic transgenic mouse model of ChAG, with an engineered ablation of parietal cells and an associated expansion of gastric epithelial progenitors (GEPs), have shown that a subset of GEPs is able to harbor intracellular collections of H. pylori. To better understand H. pylori’s adaptation to ChAG, we sequenced the genomes of 24 isolates, obtained from 6 individuals, each sampled over a 4-year interval, as they maintained normal gastric histology, or progressed from normal histology to ChAG, or experienced worsening ChAG, or proceeded from ChAG to cancer. Analyses of gene content and single nucleotide polymorphisms (SNPs) demonstrated that H. pylori populations within study participants were largely clonal, and remarkably stable over the 4-year interval, regardless of disease state. Because they exhibited such broad inter-host variation (38.6±4.7 SNPs/1000bp of genome), and did not cluster according to host pathology, we sought to identify common functional properties by performing GeneChip studies of the responses of a cultured mouse gastric stem cell-like line (mGEPs) to infection with sequenced strains. The results yielded a shared 695-member set of genes differentially expressed after infection with ChAG-associated, but not normal or heat killed strains: 434 of these genes were also represented in dataset of responses to the cancer-associated strain. Ingenuity Pathway Analysis revealed that ChAG- and ChAG/cancer- associated responses were significantly enriched in genes associated with tumorigenesis in general, and gastric carcinogenesis in specific cases. Whole genome transcriptional profiling of a sequenced ChAG strain during mGEP infection disclosed a set of responses that included upregulation of hopZ, an adhesin belonging to a family of outer membrane proteins. Expression profiles of wild-type and hopZ? strains revealed a number of pH-regulated genes affected by loss of HopZ, including HopP which binds sialylated glycans produced by GEPs in vivo. Genetic inactivation of hopZ produces a fitness defect in gnotobiotic transgenic mice but not their wild-type littermates. This study illustrates an approach for identifying GEP responses specific to ChAG, and bacterial genes important for survival in a gastric ecosystem that lacks parietal cells.

Project description:Helicobacter pylori infection is associated with development of gastric adenocarcinoma in a subset of infected humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG) characterized by loss of acid-producing parietal cells. Studies in a gnotobiotic transgenic mouse model of ChAG, with an engineered ablation of parietal cells and an associated expansion of gastric epithelial progenitors (GEPs), have shown that a subset of GEPs is able to harbor intracellular collections of H. pylori. To better understand H. pylori’s adaptation to ChAG, we sequenced the genomes of 24 isolates, obtained from 6 individuals, each sampled over a 4-year interval, as they maintained normal gastric histology, or progressed from normal histology to ChAG, or experienced worsening ChAG, or proceeded from ChAG to cancer. Analyses of gene content and single nucleotide polymorphisms (SNPs) demonstrated that H. pylori populations within study participants were largely clonal, and remarkably stable over the 4-year interval, regardless of disease state. Because they exhibited such broad inter-host variation (38.6±4.7 SNPs/1000bp of genome), and did not cluster according to host pathology, we sought to identify common functional properties by performing GeneChip studies of the responses of a cultured mouse gastric stem cell-like line (mGEPs) to infection with sequenced strains. The results yielded a shared 695-member set of genes differentially expressed after infection with ChAG-associated, but not normal or heat killed strains: 434 of these genes were also represented in dataset of responses to the cancer-associated strain. Ingenuity Pathway Analysis revealed that ChAG- and ChAG/cancer- associated responses were significantly enriched in genes associated with tumorigenesis in general, and gastric carcinogenesis in specific cases. Whole genome transcriptional profiling of a sequenced ChAG strain during mGEP infection disclosed a set of responses that included upregulation of hopZ, an adhesin belonging to a family of outer membrane proteins. Expression profiles of wild-type and hopZΔ strains revealed a number of pH-regulated genes affected by loss of HopZ, including HopP which binds sialylated glycans produced by GEPs in vivo. Genetic inactivation of hopZ produces a fitness defect in gnotobiotic transgenic mice but not their wild-type littermates. This study illustrates an approach for identifying GEP responses specific to ChAG, and bacterial genes important for survival in a gastric ecosystem that lacks parietal cells.

Project description:Helicobacter pylori infection is associated with development of gastric adenocarcinoma in a subset of infected humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG) characterized by loss of acid-producing parietal cells. Studies in a gnotobiotic transgenic mouse model of ChAG, with an engineered ablation of parietal cells and an associated expansion of gastric epithelial progenitors (GEPs), have shown that a subset of GEPs is able to harbor intracellular collections of H. pylori. To better understand H. pyloriâ??s adaptation to ChAG, we sequenced the genomes of 24 isolates, obtained from 6 individuals, each sampled over a 4-year interval, as they maintained normal gastric histology, or progressed from normal histology to ChAG, or experienced worsening ChAG, or proceeded from ChAG to cancer. Analyses of gene content and single nucleotide polymorphisms (SNPs) demonstrated that H. pylori populations within study participants were largely clonal, and remarkably stable over the 4-year interval, regardless of disease state. Because they exhibited such broad inter-host variation (38.6Â±4.7 SNPs/1000bp of genome), and did not cluster according to host pathology, we sought to identify common functional properties by performing GeneChip studies of the responses of a cultured mouse gastric stem cell-like line (mGEPs) to infection with sequenced strains. The results yielded a shared 695-member set of genes differentially expressed after infection with ChAG-associated, but not normal or heat killed strains: 434 of these genes were also represented in dataset of responses to the cancer-associated strain. Ingenuity Pathway Analysis revealed that ChAG- and ChAG/cancer- associated responses were significantly enriched in genes associated with tumorigenesis in general, and gastric carcinogenesis in specific cases. Whole genome transcriptional profiling of a sequenced ChAG strain during mGEP infection disclosed a set of responses that included upregulation of hopZ, an adhesin belonging to a family of outer membrane proteins. Expression profiles of wild-type and hopZ? strains revealed a number of pH-regulated genes affected by loss of HopZ, including HopP which binds sialylated glycans produced by GEPs in vivo. Genetic inactivation of hopZ produces a fitness defect in gnotobiotic transgenic mice but not their wild-type littermates. This study illustrates an approach for identifying GEP responses specific to ChAG, and bacterial genes important for survival in a gastric ecosystem that lacks parietal cells. H. pylori strains 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 grown in cell media for 24h in the absence of mGEP cells.

Project description:Helicobacter pylori infection is associated with development of gastric adenocarcinoma in a subset of infected humans, especially those that develop an antecedent condition, chronic atrophic gastritis (ChAG) characterized by loss of acid-producing parietal cells. Studies in a gnotobiotic transgenic mouse model of ChAG, with an engineered ablation of parietal cells and an associated expansion of gastric epithelial progenitors (GEPs), have shown that a subset of GEPs is able to harbor intracellular collections of H. pylori. To better understand H. pyloriâs adaptation to ChAG, we sequenced the genomes of 24 isolates, obtained from 6 individuals, each sampled over a 4-year interval, as they maintained normal gastric histology, or progressed from normal histology to ChAG, or experienced worsening ChAG, or proceeded from ChAG to cancer. Analyses of gene content and single nucleotide polymorphisms (SNPs) demonstrated that H. pylori populations within study participants were largely clonal, and remarkably stable over the 4-year interval, regardless of disease state. Because they exhibited such broad inter-host variation (38.6Â±4.7 SNPs/1000bp of genome), and did not cluster according to host pathology, we sought to identify common functional properties by performing GeneChip studies of the responses of a cultured mouse gastric stem cell-like line (mGEPs) to infection with sequenced strains. The results yielded a shared 695-member set of genes differentially expressed after infection with ChAG-associated, but not normal or heat killed strains: 434 of these genes were also represented in dataset of responses to the cancer-associated strain. Ingenuity Pathway Analysis revealed that ChAG- and ChAG/cancer- associated responses were significantly enriched in genes associated with tumorigenesis in general, and gastric carcinogenesis in specific cases. Whole genome transcriptional profiling of a sequenced ChAG strain during mGEP infection disclosed a set of responses that included upregulation of hopZ, an adhesin belonging to a family of outer membrane proteins. Expression profiles of wild-type and hopZÎ strains revealed a number of pH-regulated genes affected by loss of HopZ, including HopP which binds sialylated glycans produced by GEPs in vivo. Genetic inactivation of hopZ produces a fitness defect in gnotobiotic transgenic mice but not their wild-type littermates. This study illustrates an approach for identifying GEP responses specific to ChAG, and bacterial genes important for survival in a gastric ecosystem that lacks parietal cells. 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 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 or npGECs cells.

Dataset Information

Response of gastric epithelial progenitors to Helicobacter pylori Isolates obtained from Swedish patients with chronic atrophic gastritis.

Publications

Response of gastric epithelial progenitors to Helicobacter pylori Isolates obtained from Swedish patients with chronic atrophic gastritis.

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