Ontology highlight
ABSTRACT:
PROVIDER: PRJNA593936 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Various bacteria are suggested to contribute to colorectal cancer (CRC) development, including pks+ E. coli, which produces the genotoxin colibactin that induces characteristic mutational signatures in host epithelial cells. However, it remains unclear how the highly unstable colibactin molecule is able to access host epithelial cells to cause harm. Using the microbiota-dependent ZEB2-transgenic mouse model of invasive CRC, we demonstrate that the oncogenic potential of pks+ E. coli critically depends on bacterial adhesion to host epithelial cells, mediated by the type-1 pilus adhesin FimH and the F9-pilus adhesin FmlH. Blocking bacterial adhesion using a pharmacological FimH inhibitor attenuates colibactin-mediated genotoxicity and CRC exacerbation. We also show that allelic switching of FimH strongly influences genotoxic potential of pks+ E. coli and can induce a genotoxic gain-of-function in the probiotic strain Nissle 1917. Adhesin-mediated epithelial binding subsequently allows the production of the genotoxin colibactin in close proximity to host epithelial cells, which promotes DNA damage and drives CRC development. These findings present promising therapeutic avenues for the development of anti-adhesive therapies aimed at mitigating colibactin-induced DNA damage and inhibiting the initiation and progression of CRC, particularly in individuals at risk for developing CRC.
2024-08-19 | GSE241851 | GEO
Project description:Colibactin, a potent genotoxin of Escherichia coli, causes DNA double strand breaks (DSBs). We investigated if colibactin creates a particular DNA damage signature in infected human cells. Genomic contexts of colibactin-induced DSBs were enriched for a distinct AT-rich hexameric sequence motif. A survey of somatic mutations at the colibactin target sites of several thousand cancer genomes revealed significant enrichment of the motif in colorectal cancers. Moreover, the exact break point location corresponded with mutational hot spots in these cancers corresponding to a distinct trinucleotide signature. This work provides evidence for a role of colibactin in the etiology of human cancer.
2020-04-22 | GSE145594 | GEO
Project description:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clb’s) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clb’s by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of γH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
2021-07-15 | PXD025088 | Pride
Project description:Colibactin, a bacterial genotoxin produced by E. coli harboring the pks genomic island, induces cytopathic effects such as DNA breaks, cell cycle arrest and apoptosis. Patients with a colonic dysfunction due to inflammatory bowel disease such as ulcerative colitis have an elevated likelihood of carrying pks+ E. coli in their colon microbiota but it is not clear whether and how they contribute to the pathogenesis of colitis. Using a gnotobiotic mouse model, we show that pks+ E. coli do not affect colonic integrity under homeostatic conditions, with the microbiota remaining separated from the epithelium by a mucus barrier. However, upon chemical disruption of this barrier by DSS, the microbes gain direct access to the epithelium, causing severe epithelial injury, and development of colitis, while mice colonized with an isogenic ΔclbR mutant incapable of producing colibactin suffer significantly less pronounced effects. While ΔclbR-colonized animals show efficient recovery of the mucus barrier and crypt homeostasis, recovery in WT-colonized mice is impaired. Instead, the mucosa remains in a chronic regenerative state characterized by high proliferation and impaired differentiation of enterocytes and goblet cells, preventing the re-establishment of a functional barrier. In turn, pks+ E. coli remain in direct contact with the epithelium, perpetuating the process and triggering chronic mucosal inflammation that morphologically and transcriptionally resembles human ulcerative colitis. It is characterized by high levels of stromal R-spondin 3. Genetic overexpression of R-spondin 3 in colon myofibroblasts is sufficient to mimic this chronic regenerative state, resulting in barrier disruption and expansion of E. coli. Together, our data reveal that pks+ E. coli are pathobionts that upon contact with the epithelium promote severe injury and interfere with recovery, initiating chronic tissue dysfunction and inflammation.
2023-07-10 | GSE205403 | GEO
Project description:The complex reservoir of metabolite-producing bacteria in the gastrointestinal tract contributes tremendously to human health and disease. Bacterial composition, and by extension gut metabolomic composition, is undoubtably influenced by the use of modern antibiotics. Herein, we demonstrate that polymyxin B, a last resort antibiotic used for chronic multidrug resistant infections infections, influences the production of the genotoxic metabolite colibactin from adherent-invasive Escherichia coli (AIEC) NC101. Colibactin can augment colorectal cancer (CRC) through DNA double stranded breaks and interstrand crosslinks. While the structure and biosynthesis of colibactin has been elucidated, chemical-induced regulation of its biosynthetic gene cluster and subsequent production of the genotoxin by pathogenic E. coli are largely unexplored. This research highlights the regulation of the colibactin-producing biosynthetic gene cluster under polymyxin stress. Using a multi-omic approach, we have identified that polymyxin stress enhances the abundance of colibactin biosynthesis proteins (Clbs) in multiple pks+ E. coli strains, including pro-carcinogenic AIEC: NC101, the probiotic strain: E. coli Nissle 1917, and the antibiotic testing strain: E. coli ATCC 25922. Expression analysis via qPCR revealed that increased transcription of clb genes likely contributes to elevated Clb protein levels in NC101. Enhanced production of Clbs by NC101 under polymyxin stress matched an increased production of the colibactin prodrug motif, a proxy for the mature genotoxic metabolite. Furthermore, E. coli with heightened tolerance for polymyxin antibiotics induced greater DNA damage, assessed by quantification of yH2AX staining in cultured intestinal epithelial cells. This study establishes a key link between the polymyxin B stress response and colibactin production in pks+ E. coli. Ultimately, our findings will inform future studies investigating colibactin regulation, the microbial response to antibiotics in the gut, and the ability of seemingly innocuous commensal microbes to induce host disease.
2021-03-25 | MSV000087101 | MassIVE
Project description:We have previously demonstrated that the gut microbiota can play a role in the pathogenesis of conditions associated with exposure to environmental pollutants. It is well accepted that diets high in fermentable fibers such as inulin can beneficially modulate the gut microbiota and lessen the severity of pro-inflammatory diseases. Therefore, we aimed to test the hypothesis that hyperlipidemic mice fed a diet enriched with inulin would be protected from the pro-inflammatory toxic effects of PCB 126.
2020-02-27 | E-MTAB-8798 | biostudies-arrayexpress
Project description:Colorectal cancer is driven by a sequential cascade of mutations known as the adenoma-carcinoma sequence. Recent studies have revealed that specific bacterial species present in the colonic microbiota can induce mutations and contribute to this malignancy. Specifically, genotoxic colibactin-producing pks+ Escherichia coli strains can induce DNA double strand breaks (DSBs) and promote tumor development in mouse models of colorectal cancer. Here, we investigated the transformation potential of colibactin by using organoids and polarized monolayers derived from primary murine colon epithelial cells and reveal striking phenotypic changes upon short-term infection. This study demonstrates the direct pro-oncogenic potential of pks+ E. coli, as such transformations in vivo could facilitate colitis-associated colorectal carcinogenesis.
2020-12-03 | GSE140929 | GEO
Project description:Analysis of breast cancer survivors' gut microbiota after lifestyle intervention, during the COVID-19 lockdown, by 16S sequencing of fecal samples.
2023-01-13 | E-MTAB-12486 | biostudies-arrayexpress
Project description:Intracerebral hemorrhage (ICH) induces alterations in the gut microbiota composition, significantly impacting neuroinflammation post-ICH. However, the impact of gut microbiota absence on neuroinflammation following ICH-induced brain injury remain unexplored. Here, we observed that the gut microbiota absence was associated with reduced neuroinflammation, alleviated neurological dysfunction, and mitigated gut barrier dysfunction post-ICH. In contrast, recolonization of microbiota from ICH-induced SPF mice by transplantation of fecal microbiota (FMT) exacerbated brain injury and gut impairment post-ICH. Additionally, microglia with transcriptional changes mediated the protective effects of gut microbiota absence on brain injury, with Apoe emerging as a hub gene. Subsequently, Apoe deficiency in peri-hematomal microglia was associated with improved brain injury. Finally, we revealed that gut microbiota influence brain injury and gut impairment via gut-derived short-chain fatty acids (SCFA).
2024-05-13 | GSE266602 | GEO
Project description:The aim of this project was to explore the role of gut microbiota in the development of small intestine. The gut microbiota from different groups was used to treat the mice for 1 or 2 weeks. Then the small intestine samples were collected. The RNA was used for the RNA-seq analysis to search the role of gut microbiota in the development of small intestine. Groups: IMA100 mean gut microbiota from Alginate oligosaccharide 100mg/kg treated mice; IMA10 mean gut microbiota from Alginate oligosaccharide 10mg/kg treated mice; IMC mean gut microbiota from control group mice (dosed with water); Sa mean dosed with saline (no gut microbiota). "1" mean dosed for 1 week, "2" means dosed for 2 weeks.
2020-07-29 | GSE137999 | GEO