Dysregulated mRNA and miRNA expression networks in Helicobacter pylori infected gastric epithelial cell line, AGS
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE108307 | GEO | 2017/12/20
SECONDARY ACCESSION(S): PRJNA423064
REPOSITORIES: GEO
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Project description:We performed genome-wide mRNA and miRNA expression analysis in gastric epithelial cell line AGS infected with Helicobacter pylori at 100 Multiplicity of Infection (MOI), comparing the expression profile of infected cells with uninfected cells. Differentially expressed mRNAs and miRNAs were identified, which showed a 1.5 fold change in expression in infected cells compared to uninfected cells. We performed in silico analysis of miRNA-mRNA target interactions among the inversely correlated differentially expressed miRNAs and mRNAs, and performed functional enrichment analysis of the target genes, to identify important cellular pathways that reflect the patho-biology of H. pylori infected cells. Among the important miRNA-mRNA target pairs, PHLPP1, reported to be associated with poor prognosis in cancer, was predicted to be a putative target of miR-29b-1-5p. Therefore, we focused on the miR-29b-1-5p/PHLPP1 miRNA/target pair for detailed investigation into their role in H. pylori-mediated signalling in gastric epithelial cells. This study demonstrates that an integrated analysis of global mRNA and miRNA expression patterns, combined with miRNA-mRNA target prediction and functional analysis of miRNA target genes can yield an understanding of the critical pathways regulating the behaviour of gastric epithelial cells challenged with H. pylori.
2017-12-20 | GSE108306 | GEO
Project description:We performed genome-wide mRNA and miRNA expression analysis in gastric epithelial cell line AGS infected with Helicobacter pylori at 100 Multiplicity of Infection (MOI), comparing the expression profile of infected cells with uninfected cells. Differentially expressed mRNAs and miRNAs wered identified, which showed a 1.5 fold change in expression in infected cells compared to uninfected cells. We performed in silico analysis of miRNA-mRNA target interactions among the inversely correlated differentially expressed miRNAs and mRNAs, and performed functional enrichment analysis of the target genes, to identify important cellular pathways that reflect the patho-biology of H. pylori infected cells. Among the important miRNA-mRNA target pairs, PHLPP1, reported to be associated with poor prognosis in cancer, was predicted to be a putative target of miR-29b-1-5p. Therefore, we focused on the miR-29b-1-5p/PHLPP1 miRNA/target pair for detailed investigation into their role in H. pylori-mediated signalling in gastric epithelial cells. This study demonstrates that an integrated analysis of global mRNA and miRNA expression patterns, combined with miRNA-mRNA target prediction and functional analysis of miRNA target genes can yield an understanding of the critical pathways regulating the behaviour of gastric epithelial cells challenged with H. pylori.
2017-12-20 | GSE108305 | GEO
Project description:Dysregulated mRNA and miRNA expression networks in Helicobacter pylori infected gastric epithelial cell line, AGS (miRNA)
| PRJNA423069 | ENA
Project description:Helicobacter pylori induces cell death by apoptosis. However, the apoptosis-inducing factor is still unknown. The virulence factor vacuolating cytotoxin A (VacA) is a potential candidate, and thus its role in apoptosis induction was investigated in the human gastric epithelial cell line AGS. The supernatant from the vacA wild-type strain P12 was able to induce apoptotic cell death, whereas the supernatant from its isogenic mutant strain P14 could not. That VacA was indeed the apoptosis-inducing factor was demonstrated further by substantial reduction of apoptosis upon treatment of AGS cells with a supernatant specifically depleted of native VacA. Furthermore, a recombinant VacA produced in Escherichia coli was also able to induce apoptosis in AGS cells but failed to induce cellular vacuolation. These findings demonstrate that the vacuolating cytototoxin of H. pylori is a bacterial factor capable of inducing apoptosis in gastric epithelial cells.
| S-EPMC98603 | biostudies-literature
Project description:Dysregulated mRNA and miRNA expression networks in Helicobacter pylori infected gastric epithelial cell line, AGS
| PRJNA423064 | ENA
Project description:Helicobacter pylori strains possessing the cag pathogenicity island (PaI) are associated with the development of gastroduodenal diseases, including gastric cancer. cag PaI products induce the secretion of interleukin-8 (IL-8) from epithelial cells and facilitate the translocation of CagA into the cell cytosol. In East Asia, where the incidence of gastric cancer is high, most strains possess the cag PaI. To date, however, no cag PaI phenotypic data have been provided for strains isolated in mainland China. Here we used 31 Chinese strains to determine the genotypic and phenotypic status of the cag PaI. All strains possessed cagA and cagE, and we observed a variation in the length of cagA variable regions. Nucleotide sequencing of the cagA variable region revealed that CagA was of two types, a short "Western" form with two tyrosine phosphorylation sites and a longer "East Asian" form with three tyrosine phosphorylation sites. Coculture of strains with AGS epithelial cells showed that strains could induce IL-8 secretion from the cells and that CagA with three phosphorylation sites became more phosphorylated than that with two and could induce significantly (P < 0.001) more cells to elongate. We hypothesize that the preponderance of the more active East Asian form of cagA may underlie the high rate of gastric cancer in China.
| S-EPMC548088 | biostudies-literature
Project description:Dysregulated mRNA and miRNA expression networks in Helicobater pylori infected gastric epithelial cell line, AGS (mRNA)
| PRJNA423068 | ENA
Project description:Helicobacter pylori induces the antiapoptotic protein myeloid cell leukemia 1 (Mcl1) in human gastric epithelial cells (GECs). Apoptosis of oncogenic protein Mcl1-expressing cells is mainly regulated by Noxa-mediated degradation of Mcl1. We wanted to elucidate the status of Noxa in H. pylori-infected GECs. For this, various GECs such as AGS, MKN45, and KATO III were either infected with H. pylori or left uninfected. The effect of infection was examined by immunoblotting, immunoprecipitation, chromatin immunoprecipitation assay, in vitro binding assay, flow cytometry, and confocal microscopy. Infected GECs, surgical samples collected from patients with gastric adenocarcinoma as well as biopsy samples from patients infected with H. pylori showed significant up-regulation of both Mcl1 and Noxa compared with noninfected samples. Coexistence of Mcl1 and Noxa was indicative of an impaired Mcl-Noxa interaction. We proved that Noxa was phosphorylated at Ser(13) residue by JNK in infected GECs, which caused cytoplasmic retention of Noxa. JNK inhibition enhanced Mcl1-Noxa interaction in the mitochondrial fraction of infected cells, whereas overexpression of nonphosphorylatable Noxa resulted in enhanced mitochondria-mediated apoptosis in the infected epithelium. Because phosphorylation-dephosphorylation can regulate the apoptotic function of Noxa, this could be a potential target molecule for future treatment approaches for H. pylori-induced gastric cancer.
| S-EPMC4422360 | biostudies-literature
Project description:Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H. pylori co-cultures with gastric cancer cell lines. In vitro infections of different gastric cancer cell lines with H. pylori strains were performed, and the expression of ANGPT1, ANGPT2, and TEK genes, and miR-135a, miR-200a, and miR-203a, was quantified after 24 h of infection (h.p.i.). We performed a time course experiment of H. pylori 26695 infections in AGS cells at 6 different time points (3, 6, 12, 28, 24, and 36 h.p.i.). The angiogenic response induced by supernatants of non-infected and infected cells at 24 h.p.i. was evaluated in vivo, using the chicken chorioallantoic membrane (CAM) assay. In response to infection, ANGPT2 mRNA was upregulated at 24 h.p.i, and miR-203a was downregulated in AGS cells co-cultured with different H. pylori strains. The time course of H. pylori 26695 infection in AGS cells showed a gradual decrease of miR-203a expression concomitant with an increase of ANGPT2 mRNA and protein expression. Expression of ANGPT1 and TEK mRNA or protein could not be detected in any of the infected or non-infected cells. CAM assays showed that the supernatants of AGS-infected cells with 26695 strain induced a significantly higher angiogenic and inflammatory response. Our results suggest that H. pylori could contribute to the process of carcinogenesis by downregulating miR-203a, which further promotes angiogenesis in gastric mucosa by increasing ANGPT2 expression. Further investigation is needed to elucidate the underlying molecular mechanisms.
| S-EPMC10235401 | biostudies-literature
Project description:RANTES, a CC chemokine, plays an important role in the inflammatory response associated with Helicobacter pylori infection. However, the mechanism by which H. pylori induces RANTES expression in the gastric mucosa is unknown. We cocultured gastric epithelial cells with wild-type H. pylori, isogenic oipA mutants, cag pathogenicity island (PAI) mutants, or double knockout mutants. Reverse transcriptase PCR showed that RANTES mRNA was induced by H. pylori and that the expression was both OipA and cag PAI dependent. Luciferase reporter gene assays and electrophoretic mobility shift assays showed that maximal H. pylori-induced RANTES gene transcription required the presence of the interferon-stimulated responsive element (ISRE), the cyclic AMP-responsive element (CRE), nuclear factor-interleukin 6 (NF-IL-6), and two NF-kappaB sites. OipA- and cag PAI-dependent pathways included NF-kappaB-->NF-kappaB/NF-IL-6/ISRE pathways, and cag PAI-dependent pathways additionally included Jun N-terminal kinase-->CRE/NF-kappaB pathways. The OipA-dependent pathways additionally included p38-->CRE/ISRE pathways. We confirmed the in vitro effects in vivo by examining RANTES mRNA levels in biopsy specimens from human gastric antral mucosa. RANTES mRNA levels in the antral mucosa were significantly higher for patients infected with cag PAI/OipA-positive H. pylori than for those infected with cag PAI/OipA-negative H. pylori or uninfected patients. The mucosal inflammatory response to H. pylori infection involves different signaling pathways for activation of the RANTES promoter, with both OipA and the cag PAI being required for full activation of the RANTES promoter.
| S-EPMC1273890 | biostudies-literature