Mouse microbiome and probiotics
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ABSTRACT:
PROVIDER: PRJNA943194 | ENA |
REPOSITORIES: ENA
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Project description:Preterm infants are highly susceptible to late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) but specific biomarkers for diagnosis and effective treatment are lacking. Neutrophil extracellular traps (NETs) are related to sepsis in adults but not investigated in infant conditions. This is the first proteome study to document that circulating NETs are involved in neonatal LOS and NEC. cfDNA and NET proteins may provide new potential diagnostic markers for these diseases.
2018-03-05 | PXD004082 | Pride
Project description:Group B Streptococcus (GBS) is a leading cause of infant sepsis worldwide. Colonization of the gastrointestinal tract is a critical precursor to late-onset disease in exposed newborns. Neonatal susceptibility to GBS intestinal translocation stems from intestinal immaturity; however, the mechanisms by which GBS exploits the immature host remain unclear. β-hemolysin/cytolysin (βH/C) is a highly conserved toxin produced by GBS capable of disrupting epithelial barriers. However, its role in the pathogenesis of late-onset GBS disease is unknown. Our aim was to determine the contribution of βH/C to intestinal colonization and translocation to extraintestinal tissues. Using our established mouse model of late-onset GBS disease, we exposed animals to GBS COH-1 (WT), a βH/C-deficient mutant (KO), or vehicle control (PBS) via gavage. Blood, spleen, brain, and intestines were harvested 4 days post-exposure for determination of bacterial burden and isolation of intestinal epithelial cells. We used RNA-sequencing to examine the transcriptomes and performed gene ontology enrichment and KEGG pathway analysis. A separate cohort of animals were followed longitudinally to compare colonization kinetics and mortality between WT and KO groups. We demonstrate that disseminated to extraintestinal tissues occurred only in the WT exposed animals. We observed major transcriptomic changes in the colon of colonized animals, but not in the small intestine. We noted differential expression of genes among WT and KO exposed mice indicating that βH/C contributes to alterations in epithelial barrier structure and immune response signaling. Overall, our results demonstrate an important role for βH/C in the pathogenesis of late-onset GBS disease.
2023-05-31 | GSE230856 | GEO
Project description:The presence of myeloid-derived suppressor cells (MDSCs) during the early postnatal period plays a protective role against neonatal inflammation. However, the mechanisms regulating neonatal MDSCs remain to be fully elucidated. In this study, we report that the bile acid receptor Farnesoid X receptor (FXR) acts as a pivotal positive regulator of neonatal MDSCs. Using FXR-deficient (FXR-/-) mice and FDA-approved FXR agonist obeticholic acid (OCA), we demonstrated that FXR deficiency impairs the immunosuppressive and antibacterial functions of neonatal MDSCs, thereby exacerbating the severity of neonatal sepsis. Adoptive transfer of MDSCs alleviates sepsis severity in FXR-/- neonatal pups. Mechanistic studies reveal that HIF1a, a well-established regulator of MDSCs, is a direct transcriptional target of FXR. Patients with neonatal sepsis displayed reduced MDSC frequencies and impaired expression of FXR and HIF-1α, which was negatively correlate with the clinical parameters. These observations highlight the important role of FXR in neonatal MDSCs and its therapeutic potential in neonatal sepsis.
2025-05-20 | GSE289598 | GEO
Project description:The aim of the project is to identify the late (24h) host response related to Gram positive (S. pyogenes) or Gram negative (E. coli) induced sepsis in a controlled sepsis model 24 hours a. Therefore a well defined baboon sepsis model, established at the Ludwig Boltzmann Institute for experimental and clinical traumatology of Vienna, is used. The overall goal of the project is to define differentially expressed or processed genes which give rise to diagnostic and therapeutic targets and consequently better monitoring and earlier onset of therapy.
2010-04-27 | E-MARS-15 | biostudies-arrayexpress
Project description:Cephazolin susceptibility of Staphylococcus capitis causing late onset neonatal bacteraemia
| PRJNA682233 | ENA
Project description:Vancomycin is a broad-spectrum antibiotic widely used in cases of suspected sepsis in premature neonates. While appropriate and potentially lifesaving in this setting, early life antibiotic exposure alters the developing microbiome and is associated with increased risk of deadly complications, including late-onset sepsis (LOS) and necrotizing enterocolitis (NEC). Recent studies show that neonatal vancomycin treatment disrupts postnatal enteric nervous system (ENS) development in mouse pups, which is in part dependent upon neuro-immune interactions. This suggests that early life antibiotic exposure could disrupt these interactions in the neonatal gut. Notably, a subset of tissue-resident intestinal macrophages, muscularis macrophages, have been identified as important contributors to the development of the postnatal ENS. We hypothesized that vancomycin-induced neonatal dysbiosis impacts postnatal ENS development through effects on macrophages. Using a mouse model, we found that exposure to vancomycin in the first ten days of life, but not in adult mice, resulted in an expansion of pro-inflammatory colonic macrophages by increasing the recruitment of bone-marrow derived macrophages. Single cell RNA sequencing of neonatal colonic macrophages revealed that early-life vancomycin exposure was associated with an increase in immature and inflammatory macrophages, consistent with an influx of circulating monocytes differentiating into macrophages. Lineage tracing confirmed that vancomycin significantly increased non-yolk sac derived macrophage population. Consistent with these results, early life vancomycin exposure did not expand the colonic macrophage population nor decrease enteric neuron density in CCR2 deficient mice. Collectively, these findings demonstrate that early life vancomycin exposure alters macrophage number and phenotypes in distinct ways compared to vancomycin exposure in adult mice and results in altered ENS development.
2023-11-13 | GSE245019 | GEO
Project description:Despite intensive research and constant medical progress, sepsis remains one of the most urgent unmet medical needs of today. Most studies have been focused on the inflammatory component of the disease, however, recent advances support the notion that sepsis is accompanied by extensive metabolic perturbations. During times of limited caloric intake and high energy needs, the liver acts as the central metabolic hub in which PPARa is crucial to coordinate the breakdown of fatty acids. The role of hepatic PPARa in liver dysfunction during sepsis has hardly been explored. We demonstrate that sepsis leads to a starvation response that is hindered by the rapid decline of hepatic PPARa levels, causing excess free fatty acids, leading to lipotoxicity, and glycerol. In addition, treatment of mice with the PPARa agonist pemafibrate protects against bacterial sepsis by improving hepatic PPARa function, reducing lipotoxicity and tissue damage. Since lipolysis is also increased in sepsis patients and pemafibrate protects after the onset of sepsis, these findings may point towards new therapeutic leads in sepsis.
2019-11-23 | GSE139484 | GEO
Project description:Neonates have increased vulnerability to life-threatening infections due to the distinct immune landscape. Interleukin (IL)-27 is a key component of this immune profile that we have previously shown to be elevated in both newborn humans and mice. IL-27 continues to increase in the serum and tissues consistent with poor outcomes during gram-negative neonatal bacterial sepsis. Presently, we dissected the IL-27 producer profile at a single-cell level using IL 27p28eGFP reporter mice in our previously established model of sepsis with luciferase-expressing Escherichia coli. Whole animal imaging regionally highlighted the spleen, liver, and lungs as key infection sites by bacterial luminescence. Flow cytometry showed that IL-27 producers increased in the liver with infection and were predominantly F4/80+ and CD11b+. This information paired with single-cell RNA sequencing further identified the most robust populations as monocytes and derived cells, neutrophils, and Kupffer cells. The transcriptome demonstrated that some populations increased in bactericidal, metabolic, and inflammatory activities while others became less active. Sepsis is a disease characterized by extreme immune dysregulation similar to that shown in our cells. The phenotype and transcriptome of IL-27 producers from the livers of infected animals suggests suppressive activity, which contributes to the dysregulated immune environment observed in sepsis. Together, this work provides previously undescribed insight into the details of IL-27 producers during systemic early life infection. This further provides essential information to support IL-27 as a therapeutic target for neonatal bacterial sepsis.
2025-05-20 | GSE283847 | GEO
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of early-onset neonatal bacterial infection. Evasion of innate immune defenses is critical to neonatal GBS disease pathogenesis. Effectors of the innate immune system such as antimicrobial peptides, as well as numerous antibiotics, target the peptidoglycan layer of the gram positive bacterial cell wall. The intramembrane-sensing histidine kinase class of two-component regulatory systems has recently been identified as important to the gram-positive response to cell wall stress. We identified and characterized the GBS homolog of LiaR, the response regulator component of the LiaFSR system and constructed site-directed, non-polar deletion mutations in the regulator gene liaR. GBS LiaR deletion mutant strains are more susceptible to cell wall active antibiotics (vancomycin and bacitracin) as well as antimicrobial peptides (colistin, nisin and the human cathelicidin LL-37) compared to isogenic wild-type GBS. LiaR mutant GBS are significantly attenuated in mouse models of both GBS sepsis and GBS pneumonia. To determine the genes regulated by LiaR that account for these defects, transcriptional profiling was performed using DNA microarray analysis, comparing wild-type GBS to LiaR mutant GBS under non-stressed conditions. Two separate RNA samples were extracted for each condition. One flip-dye replicate (2 hybridizations) was obtained for each pair of RNA samples for 4 hybridizations total.
2012-11-18 | E-GEOD-14571 | biostudies-arrayexpress