DOCK2 protects against bacterial sepsis by constraining T helper 1 response
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PROVIDER: PRJNA1266715 | ENA |
REPOSITORIES: ENA
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Project description:Sepsis is a systemic host response to infection with life-threatening consequence, which ranks among the top 10 causes of death worldwide. Nevertheless, our understanding of the molecular and cellular impact of sepsis remains rudimentary. Here, we identified dedicator of cytokinesis 2 (DOCK2) is a critical downregulating factor for lipopolysaccharide (LPS) signal pathways. DOCK2-deficient mice were highly sensitive to LPS-induced sepsis and Escherichia coli sepsis with increased levels of inflammatory cytokines, especially interferon-g (IFN-g), which were mainly due to hyperresponsive T helper 1 (Th1) cells. Ulteriorly, we verified the vital role of DOCK2-mediated Th1 cells in sepsis by neutralizing both IFN-g and CD4 and found both of which blockade reduced the severity of sepsis in Dock2-/- mice. Mechanically, DOCK2-mediated cell cycle progression and cytokine signaling act in concert to govern peripheral Th1 cell fate. Taken together, our data indicate that DOCK2 acts as a protective role in regulating systemic inflammation and multi-organ injury in bacterial sepsis by constraining Th1 response.
2025-05-22 | GSE297913 | GEO
Project description:Xijiao Dihuang decoction protects against sepsis-induced cardiac dysfunction
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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:FXR protects against neonatal sepsis via enhancing the immunosuppressive function of MDSCs
| PRJNA1223799 | ENA
Project description:<h4><strong>INTRODUCTION:</strong> Sepsis is intricately linked to intestinal damage and barrier dysfunction. At present times, there is a growing interest in a metabolite-based therapy for multiple diseases.</h4><p><strong>METHODS:</strong> Serum samples from septic patients and healthy individuals were collected and their metabonomics profiling assessed using Ultra-Performance Liquid Chromatography-Time of Flight Mass Spectrometry (UPLC-TOFMS). The eXtreme Gradient Boosting algorithms (XGBOOST) method was used to screen essential metabolites associated with sepsis, and five machine learning models, including Logistic Regression, XGBoost, GaussianNB(GNB), upport vector machines(SVM) and RandomForest were constructed to distinguish sepsis including a training set (75%) and validation set(25%). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. Pearson analysis was used to analysis the relationship between the metabolites and the severity of sepsis. Both cellular and animal models were used to HYPERLINK 'javascript:;' assess the function of the metabolites.</p><p><strong>RESULTS:</strong> The occurrence of sepsis involve metabolite dysregulation. The metabolites mannose-6-phosphate and sphinganine as the optimal sepsis-related variables screened by XGBOOST algorithm. The XGBoost model (AUROC=0.956) has the most stable performance to establish diagnostic model among the five machine learning methods. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Pearson analysis reinforced the expression of Sphinganine, Mannose 6-phosphate were positively associated with the APACHE-II, PCT, WBC, CRP and IL-6. We also demonstrated that sphinganine strongly diminished the LDH content in LPS-treated Caco-2 cells. In addition, using both <em>in vitro</em> and <em>in vivo</em> examination, we revealed that sphinganine strongly protects against sepsis-induced intestinal barrier injury.</p><p><strong>DISCUSSION:</strong> These findings highlighted the potential diagnostic value of the ML, and also provided new insight into enhanced therapy and/or preventative measures against sepsis.</p>
2023-07-28 | MTBLS7878 | MetaboLights
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:Sepsis is a major cause of patient mortality and morbidity from bacterial infections. Although neutrophils are known to be important in the development of sepsis, how distinctive neutrophil subtypes regulate inflammatory processes involved in septicemia remains unclear. Preconditioning protects organisms against subsequent higher-dose exposures to the same, or even different, stimuli. Several studies have reported various effects of preconditioning on immune cells. However, the detailed mechanisms underlying neutrophil-mediated protection through preconditioning in sepsis remain unknown. Methods: Flow cytometry was conducted to sort the mice peritoneal lavage cells and the blood samples from patients with sepsis. Western blotting and ELISA were carried out to elucidate the expression of TLR9 signal transduction pathway proteins. Histological analysis was used to assess the effect of InP on intestine and liver structure in tlr9-/- and cav-1-/- mice. Fluorescence microscopy, Co-IP, and FRET were carried out to determine the association of TLR9 with Cav-1. Results: We show that membrane toll-like receptor-9 positive (mTLR9+) neutrophils exert a protective effect against fatal bacterial infections through the process of inflammatory preconditioning (InP). InP, which occurs in the setting of a low-dose bacterial challenge, active ingredient is Monophosphoryl lipid A (MPLA), triggers the membrane translocation of TLR9 from the neutrophil cytosol, where it binds to Cav-1. Our findings showed that InP enables TLR9 to facilitate MyD88-mediated TRAF3 and IRF3 signal transduction. Depletion of either TLR9 or Cav-1 largely eliminates the neutrophil-mediated InP effect in sepsis models in vitro and in vivo. Further, examination of clinical samples from patients with sepsis showed that clinical outcomes and likelihood of recovery are closely correlated with mTLR9 and Cav-1 expression in circulating neutrophils. Conclusion: These results demonstrate that the TLR9-Cav-1 axis is a critical signaling pathway involved in the regulation of neutrophil-dependent MPLA mediated InP, and the presence of mTLR9+ neutrophils could be an attractive indicator of clinical outcomes in bacterial sepsis that could be further explored as a potential therapeutic target.
| S-EPMC6735515 | biostudies-literature
Project description:We have developed a composite infection vaccine technology (ciVAX) assembled from approved products for rapid response to pandemics and biothreat agents. ciVAX consists of an injectable biomaterial scaffold containing factors that recruit, reprogram and release dendritic cells (DC) in vivo. For bacterial infections, ciVAX contains Fc-Mannose-Binding Lectin (FcMBL) microbeads with captured PAMPs fractions from inactivated bacterial cell-wall lysates. ciVAX vaccination generates potent humoral and T cell responses to bacterial antigens, and ciVAX protects mice and pigs against lethal E coli challenge in sepsis and septic shock models
2021-01-22 | MSV000086751 | MassIVE
Project description:Our experiments examined T-lymphocyte numbers and effector-functions in peritoneal contamination and infection (PCI) a mouse model of sepsis. One of our main questions was how T-lymphocytes reconstitute after sepsis-induced lymphopenia. We investigated the quantitative and qualitative recovery of T lymphocytes for 3.5 months after sepsis with or without IL-7 treatment. Sepsis is an immunological dysfunction against pathogens leading to inflammation with massive cytokine production. Simultaneously immunosuppression occurs e.g. lymphopenia, which is a hallmark of sepsis. The resulting immunosuppression is associated with secondary infections, which are often lethal. Moreover sepsis-survivors are burdened with increased morbidity and mortality for several years after the sepsis episode. The duration and clinical consequences of sepsis induced-immunosuppression are currently unknown. More than 50% of T-cells undergo apoptosis shortly after sepsis-induction. However, 8 days after sepsis onset, surviving mice present normal lymphocyte counts. Theoretically, T-cells could reconstitute in two different ways. Firstly, the diminished pool of T-cells is replenished by newly in thymus produced T-cells with new diverse T-cell-receptors (TCRs). Alternatively, remaining T-cells start to proliferate until reaching normal cell count. If this was the case all divided cells shared the same TCRs as primary cells. This could lead to a narrowed TCR diversity within a quantitative normalized T-cell pool and would be an explanation for the long-lasting immune incompetence. To address the question how T-cells recover from lymphopenia we applied next generation sequencing (NGS) to analyse TCR diversity in septic and healthy mice. One group of septic mice received Interleukin-7 (IL-7), an interleukin which regulates T-cell homeostasis and is a promising therapeutically approach for septic patients. 50000 sequences per mouse were analyzed and the three different groups (controls, sepsis, sepsis + IL-7 treatment) compared regarding their diversity. The sequenced raw data (fastq) are uploaded in this library.
2019-10-02 | E-MTAB-7483 | biostudies-arrayexpress
Project description:Neutropenic sepsis is a fatal consequence of chemotherapy, and septic complications are the principal cause of mortality. Chemotherapy-induced neutropenia leads to the formation of microscopic ulcers in the gastrointestinal epithelium that function as a portal of entry for intraluminal bacteria, which translocate across the intestinal mucosal barrier and gain access to systemic sites, causing septicemia. A cyclophosphamide-induced mouse model was developed to mimic the pathophysiologic sequence of events that occurs in patients with neutropenic sepsis. The TLR5 agonist bacterial flagellin derived from Vibrio vulnificus extended the survival of cyclophosphamide-treated mice by reducing the bacterial load in internal organs. The protective effect of flagellin was mediated by the antimicrobial protein lipocalin 2 (Lcn2), which is induced by TLR5-NF-κB activation in hepatocytes. Lcn2 sequestered iron from infecting bacteria, particularly siderophore enterobactin-dependent members of the Enterobacteriaceae family, thereby limiting their proliferation. Lcn2 should be considered for the treatment of neutropenic sepsis and gastrointestinal damage during chemotherapy to prevent or minimize the adverse effects of cancer chemotherapy.
| S-EPMC7284693 | biostudies-literature