RNA-seq analysis of gene expression in Helicobacter pylori expressing either WT Fur or a Fur variant (Fur-R88H).
Ontology highlight
ABSTRACT:
ORGANISM(S): Helicobacter pylori
PROVIDER: GSE214216 | GEO | 2023/01/06
REPOSITORIES: GEO
Similar Datasets
Project description:In this study, we tested the hypothesis that high salt concentrations might alter gene expression in H. pylori. Analysis here provides into the role that salt may play in H. pylori pathogenesis. . Keywords: comparison of salt reponsive gene expression, dose response
2008-03-01 | GSE7183 | GEO
Project description:Helicobacter pylori is a common bacterial infection. It can lead to severe stomach problems, including stomach cancer. Researchers want to look at samples of the bacteria. These H. pylori strains will be taken from chronically infected people. They want to identify the genetic and epigenetic differences in H. pylori strains. This could help predict which people who get infected with the bacteria will get stomach cancer. This could lead to the cancer being detected earlier. It could also mean less people get stomach cancer.
Objectives:
To study genetic variations of H. pylori strains based on samples from chronically infected people. To identify the features of strains that might lead to severe stomach problems or stomach cancer.
Eligibility:
People ages 30-70 years who need an upper endoscopy or who were recently diagnosed with stomach cancer
Design:
Participants will be screened by the doctor who does their procedure and a study nurse.
Participants who have endoscopy will have ~6 biopsies removed. These are tissue samples. They are about the size of a grain of rice. Participants will allow the study team to access reports from their stomach exam.
Participants with stomach cancer will donate some of the tissue that will be removed during their clinical care. They will allow the study team to access reports of their surgery. They will also allow them to access the microscope slides of their stomach.
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Project description:In this study, we tested the hypothesis that high salt concentrations might alter gene expression in H. pylori. Analysis here provides into the role that salt may play in H. pylori pathogenesis. . H. pylori strain 26695 (SC#7) was grown for 15 h in BB-FBS medium containing 0.5% sodium chloride (i.e. BB-FBS-0.5%) The bacterial cells were then grown for 10 h, in fresh brucella broth at either 0.25% or 1.5% salt, harvested by centrifugation, and frozen at -80oC. RNA isolated was reverse transcribed and used to probe H. pylori Panorama arrays
2010-06-25 | E-GEOD-7183 | biostudies-arrayexpress
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island. Keywords: other
2001-07-25 | GSE6 | GEO
Project description:Helicobacter pylori encounters a wide range of pH within the human stomach. In a comparison of H. pylori cultured in vitro under neutral or acidic conditions, about 15% of genes are26 differentially expressed, and corresponding changes are detectable for many of the encoded proteins. The ArsRS two-component system (TCS), comprised of the sensor kinase ArsS and its cognate response regulator ArsR, has an important role in mediating pH-responsive changes in H. pylori gene expression. In this study, we sought to delineate the pH-responsive ArsRS regulon and further define the role of ArsR in pH-responsive gene expression. We compared H. pylori strains containing an intact ArsRS system with an arsS null mutant or strains containing site32 specific mutations of a conserved aspartate residue (D52) in ArsR, which is phosphorylated in response to signals relayed by the cognate sensor kinase ArsS. We identified 178 genes that were pH-responsive in strains containing an intact ArsRS system but not in ∆arsS or arsR mutants. These constituents of the pH-responsive ArsRS regulon include genes involved in acid acclimatization (ureAB, amidases), oxidative stress responses (katA, sodB), transcriptional regulation related to iron or nickel homeostasis (fur, nikR), and genes encoding outer membrane proteins [including sabA, alpA, alpB, hopD (labA), and horA]. When comparing H. pylori strains containing an intact ArsRS TCS with arsRS mutants, each cultured at neutral pH, relatively few genes are differentially expressed. Collectively, these data suggest that ArsRS41 mediated gene regulation has an important role in H. pylori adaptation to changing pH conditions.
2022-02-16 | PXD023679 | Pride
Project description:Background: Helicobacter pylori has been shown to alter the secretion of gastric hormones that modulate body fat deposition. Since cag-positive H. pylori strains interact intimately with the host gastric epithelial cells and trigger higher inflammation than cag-negative strains, we hypothesized that gastric colonization with H. pylori strains without functional cagA ameliorates obesity and its complications by modulating gastric gene expression and inflammation. Methodology/Principal Findings: To test this hypothesis we examined the effects of gastric colonization on metabolic and inflammatory markers in mice infected with two isogenic strains of H. pylori: 26695 strain 98-325 (cagA+ wild-type) and its cag pathogenicity island (cagPAI) mutant strain 99-305, a knockout made by inserting a chloramphenicol resistance cassette. Only the cagPAI mutant decreased fasting blood glucose levels, improved glucose tolerance and suppressed weight gain in db/db mice and mice with diet-induced obesity. These effects were associated with increased gastric leptin levels, suppressed infiltration of macrophages, enhanced influx of regulatory T cells (Treg) in adipose tissue and suppressed gastric inflammation. Gene set enrichment analyses of gastric mucosal samples identified six differentially modulated pathways, including the Hedgehog signaling pathway that is associated with control of cellular proliferation and gastric carcinogenesis as well as the insulin signaling pathway. Conclusions/Significance: Gastric colonization with cagPAI-negative strains of H. pylori ameliorate obesity and inflammation by modulating gastric gene expression, suggesting that cag-negative H. pylori strains might be beneficial in ameliorating obesity and its co-morbidities.
2010-11-13 | GSE21833 | GEO
Project description:Helicobacter pylori (H. pylori) infection and excessive salt intake are known as important risk factors for stomach cancer in humans. However, interactions of these two factors with gene expression profiles during gastric carcinogenesis remain unclear. In this study, we established a mouse gastric tumor model combining a chemical carcinogen, H. pylori infection and a high-salt diet. The tumor incidence and multiplicity in N-methyl-N-nitrosourea-treated mice were significantly increased by combination of H. pylori with a high-salt diet. In addition, detailed examination indicated that excessive salt could regulate progression of gastric tumor. Global gene expression profiles in glandular stomach of the mouse model were investigated by cDNA microarray analysis, and 36 and 31 more than twofold up-regulated and down-regulated genes, respectively, were detected in the H. pylori-infection and high-salt diet combined group compared with the other groups. Quantitative RT-PCR confirmed significant over-expression of several candidate genes including Cd177, Reg3g, and Muc13. These results suggest that our mouse model combined with H. pylori infection and high-salt diet is useful for gene expression profiling in gastric carcinogenesis. Five- to six-week-old male C57BL/6J mice (CLEA Japan, Tokyo, Japan) were inoculated with Helicobacter pylori (Sydney strain 1) (Sample No. 2 and 4) or Brucella broth (Sample No. 1 and 3). The animals were administered 120 ppm N-methyl-N-nitrosourea (MNU) in their drinking water on alternate weeks (total exposure, 5 weeks). Mice were given basal diet (CE-2, CLEA Japan) (Sample No. 1 and 2) or high-salt diet containing 10% NaCl (Sample No. 3 and 4). At 40 weeks, the animals were subjected to deep anesthesia and laparotomy with excision of the stomach.
2011-05-25 | E-GEOD-29444 | biostudies-arrayexpress
Project description:Carcinogenic bacteria, Helicobacter pylori, induce DNA double-strand breaks in infected host cells, while ATM-dependent DNA damage responses in host cells suppress genome instabilities caused by DNA breakages, which resulting in the suppression of H. pylori-induced gastric cancers. Although Helicobacter pylori infection is etiologically related to the inflammation-related malignancy, gastric cancers, it role in the molecular pathogenesis of disease remains unclear. In vitro studies have suggested the infection may cause breaks in double-stranded DNA. We used microarray analysis of H. pylori-infected human gastric biopsies to investigate the effect of H. pylori on gene expression genes involved in DNA repair and DNA damage response. Micro-array analysis and immunohistochemistory showed that ATM (ataxia-telangiectasia mutated) was upregulated in H. pylori gastritis but down regulated in the premalignant lesion, intestinal metaplasia. Studies in gastric cancer cell lines showed that H. pylori-infection induced activation of ATM and formation of γ-H2AX. γ-H2AX formation was present following infection with bout cag pathogenicity island (PAI)- positive and negative strains but more robust with cag PAI positive strains consistent with the fact that both cag PAI positive negative strains are associated with gastric cancer but the risk is higher with cag PAI positive strains. Eradication of H. pylori infection is associated with a reduction in cancer risk even in the most high risk populations. These data provide a plausible molecular mechanism for a direct bacterial-host interaction increasing cancer risk.
2014-08-23 | GSE60662 | GEO
Project description:Helicobacter pylori (H. pylori) infection and excessive salt intake are known as important risk factors for stomach cancer in humans. However, interactions of these two factors with gene expression profiles during gastric carcinogenesis remain unclear. In this study, we established a mouse gastric tumor model combining a chemical carcinogen, H. pylori infection and a high-salt diet. The tumor incidence and multiplicity in N-methyl-N-nitrosourea-treated mice were significantly increased by combination of H. pylori with a high-salt diet. In addition, detailed examination indicated that excessive salt could regulate progression of gastric tumor. Global gene expression profiles in glandular stomach of the mouse model were investigated by cDNA microarray analysis, and 36 and 31 more than twofold up-regulated and down-regulated genes, respectively, were detected in the H. pylori-infection and high-salt diet combined group compared with the other groups. Quantitative RT-PCR confirmed significant over-expression of several candidate genes including Cd177, Reg3g, and Muc13. These results suggest that our mouse model combined with H. pylori infection and high-salt diet is useful for gene expression profiling in gastric carcinogenesis.
2011-05-25 | GSE29444 | GEO
Project description:Helicobacter pylori colonizes the stomach of half of the world's population, causing a wide spectrum of disease ranging from asymptomatic gastritis to ulcers to gastric cancer. Although the basis for these diverse clinical outcomes is not understood, more severe disease is associated with strains harboring a pathogenicity island. To characterize the genetic diversity of more and less virulent strains, we examined the genomic content of 15 H. pylori clinical isolates by using a whole genome H. pylori DNA microarray. We found that a full 22% of H. pylori genes are dispensable in one or more strains, thus defining a minimal functional core of 1281 H. pylori genes. While the core genes encode most metabolic and cellular processes, the strain-specific genes include genes unique to H. pylori, restriction modification genes, transposases, and genes encoding cell surface proteins, which may aid the bacteria under specific circumstances during their long-term infection of genetically diverse hosts. We observed distinct patterns of the strain-specific gene distribution along the chromosome, which may result from different mechanisms of gene acquisition and loss. Among the strain-specific genes, we have found a class of candidate virulence genes identified by their coinheritance with the pathogenicity island.
2001-07-25 | E-GEOD-6 | biostudies-arrayexpress