Project description:Differential gene transcript amounts between Helicobacter pylori N6 (wild type strain) bacteria and isogenic tlpD mutant grown in liquid culture to similar O.D.600 (1.0; mid log)
Project description:We performed DNA-protein interaction (ChIP-seq) analyses for Helicobacter pylori N6 wild-type (WT) and HP1021 deletion mutant (ΔHP1021::aphA-3) under oxidative stress (21% O2) and optimal microaerobic growth (5% O2) conditions. We detected 100 binding sites of HP1021 on the H. pylori N6 chromosome, most of which are promoter-located, likely affecting gene transcription. 84 of 100 identified HP1021 binding sites were located near promoter regions. EMSA and ChIP-qPCR confirmed the binding of HP1021 to the promoter region of a few genes.
Project description:Helicobacter pylori (H.pylori) infection is an important factor in the occurrence of human gastric diseases, but its pathogenic mechanism is not clear. N6-methyladenosine (m6A) is the most prevalent reversible methylation modification in mammalian RNA and it plays a crucial role in controlling many biological processes. We used MeRIP-seq technology to sequence the GES-1 cells infected with Helicobacter pylori(H. pylori) for 48 h.
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
Project description:Helicobacter pylori enhances the risk for ulcer disease and gastric cancer, yet only a minority of H. pylori-colonized individuals develop disease. We examined the ability of two H. pylori isolates to induce differential host responses in vivo or in vitro, and then used an H. pylori whole genome microarray to identify bacterial determinants related to pathogenesis. Gastric ulcer strain B128 induced more severe gastritis, proliferation, and apoptosis in gerbil mucosa than did duodenal ulcer strain G1.1, and gastric ulceration and atrophy occurred only in B128+ gerbils. In vitro, gerbil-passaged B128 derivatives significantly increased IL-8 secretion and apoptosis compared with G1.1 strains. DNA hybridization to the microarray identified several strain-specific differences in gene composition including a large deletion of the cag pathogenicity island in strain G1.1. Partial and complete disruption of the cag island in strain B128 attenuated induction of IL-8 in vitro and significantly decreased gastric inflammation in vivo. These results indicate that the ability of H. pylori to regulate epithelial cell responses related to inflammation depends on the presence of an intact cag pathogenicity island. Use of an H pylori whole genome microarray is an effective method to identify differences in gene content between H. pylori strains that induce distinct pathological outcomes in a rodent model of H. pylori infection. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
Project description:The role of N6-methyladenosine (m6A) modification of host mRNA during bacterial infection is unclear. Here, we show that Helicobacter pylori infection upregulated major m6A “writers” and increased m6A level in gastric epithelial cells. Attenuating m6A increase by hemizygotic deletion of Mettl3 in mice or small interfering RNAs targeting m6A “writers” exacerbated H. pylori colonization. LOX-1 mRNA was identified as a key m6A-regulated target during H. pylori infection. m6A modification destabilized LOX-1 mRNA and reduced LOX-1 protein level. LOX-1 acted as a membrane receptor for H. pylori catalase to mediate the bacterial adhesion. BI-0115, a small-molecule inhibitor of LOX-1, suppressed H. pylori adhesion and colonization. Genetic ablation of Lox-1 also reduced H. pylori colonization in mice. In sum, this study reveals that m6A modification is an auto-protective mechanism against H. pylori infection by downregulating LOX-1 to prevent H. pylori adhesion. LOX-1 could be a druggable target for controlling H. pylori infection.
Project description:The role of N6-methyladenosine (m6A) modification of host mRNA during bacterial infection is unclear. Here, we show that Helicobacter pylori infection upregulated major m6A “writers” and increased m6A level in gastric epithelial cells. Attenuating m6A increase by hemizygotic deletion of Mettl3 in mice or small interfering RNAs targeting m6A “writers” exacerbated H. pylori colonization. LOX-1 mRNA was identified as a key m6A-regulated target during H. pylori infection. m6A modification destabilized LOX-1 mRNA and reduced LOX-1 protein level. LOX-1 acted as a membrane receptor for H. pylori catalase to mediate the bacterial adhesion. BI-0115, a small-molecule inhibitor of LOX-1, suppressed H. pylori adhesion and colonization. Genetic ablation of Lox-1 also reduced H. pylori colonization in mice. In sum, this study reveals that m6A modification is an auto-protective mechanism against H. pylori infection by downregulating LOX-1 to prevent H. pylori adhesion. LOX-1 could be a druggable target for controlling H. pylori infection.
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.