R-spondin driven NF-κB signaling shapes the gastric gland base cell compartment and enables rapid inflammation upon infection of stem cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE165028 | GEO | 2022/05/13
REPOSITORIES: GEO
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Project description:Bacterial-modulated gastric epithelial cells (GECs) play key roles in H. pylori-associated pathology. Here we demonstrate a pro-colonization and pro-inflammation role of GEC-expressed glycerol-3-phosphate acyltransferase 3 (GPAT3), a lipid metabolism-associated protein, in H. pylori infection. GPAT3 expression was elevated in gastric mucosa of both patients and mice infected with H. pylori. GPAT3 in GECs was synergistically induced by H. pylori and IL-22 in a cagA-dependent manner. Human gastric GPAT3 correlated with H. pylori colonization and the severity of gastritis, and mouse GPAT3 from non-bone marrow-derived cells promoted bacteria colonization and inflammation. Importantly, H. pylori colonization and inflammation were attenuated in Il22-/-, Gpat3-/- and Il22-/-Gpat3-/- mice. Mechanistically, GPAT3 directly interacted with CCAR1 and activated IKKγ, subsequently promoted NF-κB phosphorylation whereby NF-kB directly bound to the promoters of MMP1, CXCL11 and IL-33 to activate their transcription, which not only led to decreased E-cadherin and zonula occludens-1 proteins by MMP1, thereby resulting in gastric mucosal damage and increased H. pylori colonization; but also resulted in increased gastric influx of CD8+ T cells via CXCL11-dependent migration and their subsequent IL-33-dependent IFN-γ production, thereby promoting H. pylori-associated gastritis. Overall, we propose a model in which GPAT3 collectively ensures H. pylori persistence and promotes gastritis.
2024-04-26 | GSE264450 | GEO
Project description:Helicobacter pylori (H. pylori) infection is characterized as progressive processes of bacterial persistence and chronic gastritis with features of infiltration of mononuclear cells more than granulocytes in gastric mucosa. Angiopoietin-like 4 (ANGPTL4) is considered a double-edged sword in inflammation-associated diseases, but its function and clinical relevance in H. pylori-associated pathology is unknown. Here we demonstrate both pro-colonization and pro-inflammation roles of ANGPTL4 in H. pylori infection. Increased ANGPTL4 in the infected gastric mucosa was produced from gastric epithelial cells (GECs) synergistically induced by H. pylori and IL-17A in a cagA-dependent manner. Human gastric ANGPTL4 correlated with H. pylori colonization and the severity of gastritis, and mouse ANGPTL4 from non-bone marrow-derived cells promoted bacteria colonization and inflammation. Importantly, H. pylori colonization and inflammation were attenuated in Il17a-/-, Angptl4-/-, Il17a-/-Angptl4-/- mice. Mechanistically, ANGPTL4 bound to integrin αV (ITGAV) on GECs to suppress CXCL1 production by inhibiting ERK, leading to decreased gastric influx of neutrophils, thereby promoting H. pylori colonization; ANGPTL4 also bound to ITGAV on monocytes to promote CCL5 production by activating PI3K-AKT-NF-κB, resulting in increased gastric influx of regulatory CD4+ T cells (Tregs) via CCL5-CCR4-dependent migration. In turn, ANGPTL4 induced Treg proliferation through binding to ITGAV to activate PI3K-AKT-NF-κB, promoting H. pylori-associated gastritis. Overall, we propose a model in which ANGPTL4 collectively ensures H. pylori persistence and promotes gastritis. Efforts to inhibit ANGPTL4-associated pathway may prove valuable strategies in treating H. pylori infection.
2024-05-15 | GSE266891 | GEO
Project description:R-spondin (Rspo) signaling is crucial for stem cell renewal and tissue homeostasis in the gastrointestinal tract. In the stomach, Rspo is secreted from myofibroblasts and controls epithelial gland regeneration by inducing proliferation of Wnt-responsive Axin2+ cells in the isthmus of the gland. Infection with H. pylori results in increased expression of stromal Rspo, leading to an expansion of Axin2+ isthmus stem cells and gland hyperplasia. Lgr5+ cells in the gland base are exposed to Rspo3 but the effects of this are not well understood. Here we demonstrate that apart from its activity as a mitogen, endogenous Rspo3 regulates gene expression of Lgr5+ cells in the gastric gland base. Surprisingly, Rspo3 induces differentiation within the Lgr5+ compartment towards secretory deep mucous cells. Moreover, the Rspo3-Lgr5 axis turns out to be a stimulus of epithelial antimicrobial defense. Infection with H. pylori induces a strong antimicrobial response, with Lgr5+ cells expressing antimicrobial compounds that are secreted into the lumen in an Rspo3-dependent manner. Depletion of Lgr5+ cells or knockout of Rspo3 in myofibroblasts leads to hyper-colonization of gastric glands, including the stem cell compartment, whereas systemic application of recombinant Rspo clears H. pylori from the glands. We provide an intriguing, unexpected feature of the Rspo3-Lgr5 axis in the stomach, exhibiting antimicrobial self-protection of the gland to protect the stem cell compartment from invading pathogens.
2019-03-25 | GSE124930 | GEO
Project description:Colonization by H. pylori is associated with a wide range of gastric diseases, ranging from superficial gastritis to more severe pathologies, including intestinal metaplasia and adenocarcinoma. The interplay of the host response and the pathogen affect the outcome of disease. One major component of the mucosal response to H. pylori is the activation of a strong, but inefficient immune response that fails to control the infection and frequently causes tissue damage. We have shown that polyamines can regulate H. pylori-induced inflammation. Chemical inhibition of ornithine decarboxylase (ODC), which generates putrescine from L-ornithine, reduces gastritis in mice and adenocarcinoma incidence in gerbils infected with H. pylori. However, we have also demonstrated that Odc deletion in myeloid cells enhances M1 macrophage activation and gastritis. Here we used a genetic approach to assess the specific role of gastric epithelial ODC during H. pylori infection. Deletion of Odc in gastric epithelial cells reduces gastritis, attenuates epithelial proliferaton, alters the metabolome, and dowregulates the expression of immune mediators induced by H. pylori. Inhibition of ODC activity in gastric epithelial cells reduces H. pylori-induced NF-B activation and CXCL8 mRNA expression. Chronic inflammation is a major risk factor for the progression to more severe pathologies associated with H. pylori infection and we now show that epithelial ODC plays an important role in mediating this inflammatory response.
2022-06-15 | MTBLS3235 | MetaboLights
Project description:In the present study, we observed spontaneous gastritis in 10-12 week old NF-κB1—/— mice with increased level of pro-inflammatory cytokines in gastric tissues. The NF-κB1—/— bone marrow derived macrophages showed increased level of cytokines which further exacerbated with H. pylori infection. To map the contribution of macrophages in the spontaneous gastritis, we performed comparative transcriptome analysis of NF-κB1—/— mice gastric macrophage and H. pylori treated macrophages. The transcriptome analysis showed an upregulation of innate immune response genes in NF-κB1—/— gastric macrophages, but not in H. pylori activated murine macrophages. Network analysis identified STAT1/TLR7/TLR13 as a key regulator and inhibition of STAT1 activation attenuated exacerbated innate immune response. NF-κB1—/— mice after infection with H. pylori showed increased histological gastritis and reduced level of H. pylori colonization. Our study indicates that H. pylori-mediated up-regulation of NF-κB1 mitigates host immune response and promotes chronic colonization of the pathogen.
2021-08-31 | GSE121583 | GEO
Project description:Gastric mucosa responds to the pathogen Helicobacter pylori (H. pylori) by producing and release of pro-inflammatory cytokines that activate the innate immune system mainly through activation of the transcription factor NF-κB. Although NF-κB signaling is well studied for many possible inducers, induction by H. pylori remains poorly understood. Here, we performed a high-throughput genome-wide RNAi screen for genes influencing H. pylori-induced NF-κB activation. In comparison to TNFα or IL‐1β NF‐κB signaling, we identified 21 proteins unique necessary for H. pylori NF-κB pathway and 24 factors that inhibited the activation. Furthermore, we present here the R/Bioconductor package Nested Effect Model for systematic use in high-throughput screens to classify newly identified factors. We identified alpha kinase 1 (ALPK1) as particular important for the H. pylori NF‐κB pathway without affecting TNFα or IL‐1β signaling. ALPK1 silencing inhibits activity of TAK1 and the IκB kinases (IKKs), degradation of the NF‐κB inhibitor IκBα, nuclear translocation of the NF‐κB subunit p65, and transcription of the NF‐κB target genes, e.g. IL‐8. Thus, we identify ALPK1 as a novel inflammatory regulator functioning particularly in the NF‐κB signaling network activated by H. pylori.
2019-09-02 | GSE89613 | GEO
Project description:Gastric epithelial stem cells are responsible for constant epithelial self-renewal, which is accelerated by infection with the gastric pathogen Helicobacter pylori. However, the mechanism that regulates stem cell turnover in the stomach remains unknown. Here we show that signaling by R-spondin 3 and Wnt hierarchically organizes the stem cell compartment in the antrum, producing two Wnt-responsive populations, which are either Lgr5+ve or Axin2 +ve. The positional identity of the Axin2+ve population relies on R-spondin 3 produced by stromal myofibroblasts. Increased availability of R-spondin induces hyperproliferation through specific expansion of Axin2+ve but not Lgr5+ve cells. Similarly, infection with H. pylori induces an increase in stromal R-spondin 3 expression, resulting in hyperplasia as well as shedding of bacteria that have entered the gland. This identifies a role for stromal cells in environmental sensing to orchestrate epithelial homeostasis via Wnt signaling.
2017-06-30 | GSE79494 | GEO
Project description:R-spondin (Rspo) signaling is crucial for stem cell renewal and tissue homeostasis in the gastrointestinal tract. In the stomach, Rspo is secreted from myofibroblasts and controls epithelial gland regeneration by inducing proliferation of Wnt-responsive Axin2+ cells. Infection with H. pylori results in increased expression of stromal Rspo, leading to an expansion of Axin2+ isthmus stem cells and gland hyperplasia. Lgr5+ stem cells are exposed to Rspo3 but the effects of this are not well understood. Here we demonstrate that in addition to its effect as a mitogen, endogenous Rspo3 regulates the gene expression of Lgr5+ cells in the gland base in both antrum and corpus. Rspo3 inhibits proliferation and induces differentiation within the Lgr5+ compartment towards a secretory phenotype. Strikingly, the Rspo3-Lgr5 axis turns out to be required for epithelial antimicrobial defense. Infection with H. pylori induces a strong antimicrobial response, with Lgr5+ cells expressing antimicrobial compounds that are secreted into the lumen in an Rspo3-dependent manner. Depletion of Lgr5+ cells or knockout of Rspo3 in myofibroblasts leads to dramatic hyper-colonization of gastric glands, including the stem cell compartment, whereas systemic application of recombinant Rspo is sufficient to clear H. pylori from the glands. We provide an intriguing, unexpected feature of Lgr5+ cells, exhibiting an indivisible connection between stem cell signaling and antimicrobial self-protection.
2019-01-01 | GSE108729 | GEO
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. Gastric mucosa from three groups of mice: uninfected, infected with H. pylori 26695 strain 98-325 (cagA+ wild-type) or infected with H. pylori mutant strain 99-305 (lacking cag pathogenicity island; cagA-)
2010-11-13 | E-GEOD-21833 | biostudies-arrayexpress
Project description:Helicobacter pylori (H. pylori) infection is the most common risk factor for gastric cancer (GC). The effect of the antioxidase manganese superoxide dismutase (SOD2) in gastric tumorigenesis remains unclear. We explored the molecular and mechanical links between H. pylori, inflammation, and SOD2 in GC. We found SOD2 was upregulated in GC. GC patients with high SOD2 expression showed worse overall survival. H. pylori infection promoted SOD2 expression by transcriptionally activating the NF-κB signaling pathway. Knockdown of SOD2 led to increased levels of reactive oxygen species and oxidative stress in response to H. pylori infection. Our research demonstrated that SOD2 can serve as an inhibitor of ferroptosis by activating AKT, stabilizing GPX4 protein, which subsequently induces 5-fluorouracil resistance. These findings reveal a mechanism whereby H. pylori can promote gastric carcinogenesis by activating the NF-κB/SOD2/AKT/GPX4 pathway, leading to the inhibition of ferroptosis. This may provide a promising therapeutic target for GC.
2024-10-14 | GSE278591 | GEO