Role and Mechanisms of Lipid and Lipoprotein Dysregulation in Sepsis
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PROVIDER: PRJNA1076655 | ENA |
REPOSITORIES: ENA
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Project description:Role and Mechanisms of Lipid and Lipoprotein Dysregulation in Sepsis
| PRJNA1076654 | ENA
Project description:Innate immune memory is the process by which pathogen exposure elicits cell-intrinsic states to alter the strength of future immune challenges. Such altered memory states drive monocyte dysregulation during sepsis, promoting pathogenic behavior characterized by pro-inflammatory, immunosuppressive gene expression and emergency hematopoiesis. Epigenetic changes, notably via histone modifications, have been shown to underlie innate immune memory, but the contribution of DNA methylation remains poorly understood. Using an ex vivo sepsis model, we discovered broad changes in DNA methylation throughout the genome of exhausted monocytes, including at several genes implicated in immune dysregulation during sepsis and Covid-19 infection (e.g. Plac8). Methylome reprogramming is driven in part by Wnt signaling inhibition in exhausted monocytes, and can be reversed with DNA methyltransferase inhibitors, Wnt agonists, or immune training molecules. These changes are recapitulated in septic mice following cecal slurry injection, supporting the involvement of DNA methylation in acute and long-term monocyte dysregulation during sepsis.
2024-03-05 | GSE242816 | GEO
Project description:Innate immune memory is the process by which pathogen exposure elicits cell-intrinsic states to alter the strength of future immune challenges. Such altered memory states drive monocyte dysregulation during sepsis, promoting pathogenic behavior characterized by pro-inflammatory, immunosuppressive gene expression and emergency hematopoiesis. Epigenetic changes, notably via histone modifications, have been shown to underlie innate immune memory, but the contribution of DNA methylation remains poorly understood. Using an ex vivo sepsis model, we discovered broad changes in DNA methylation throughout the genome of exhausted monocytes, including at several genes implicated in immune dysregulation during sepsis and Covid-19 infection (e.g. Plac8). Methylome reprogramming is driven in part by Wnt signaling inhibition in exhausted monocytes, and can be reversed with DNA methyltransferase inhibitors, Wnt agonists, or immune training molecules. These changes are recapitulated in septic mice following cecal slurry injection, supporting the involvement of DNA methylation in acute and long-term monocyte dysregulation during sepsis.
2024-03-05 | GSE253201 | GEO
Project description:The project examines the mechanisms of neutrophil dysfunction during sepsis. Our work uncovered the central role of cell free circulating histones in eliminating mature neutrophil in favour of immature cells and characterized the mechanisms that regulate their release following systemic infection. Mature and immature neutrophil Ly6Ghigh and Ly6Glow populations isolated from the spleens of WT and TCRα-deficient mice either naïve or infected with C. albicans were characterized. In addition, these populations were compared to neutrophils isolated from WT mice receiving Clodronate-liposomes and recombinant G-CSF. These studies demonstrated that T-cell derived histones drive the release of G-CSF in the spleen and progressively eliminate mature neutrophils by shortening their lifespan. Finally, we conducted proteomic analysis of plasmas isolated from patients with microbial sepsis to correlate markers of neutrophil death to plasma cytokine and histone levels, confirming the pathogenic role these molecules play during sepsis in humans.
2022-12-13 | PXD032961 | Pride
Project description:Lipids are essential components of cancer cells due to their structural and signaling roles. To meet metabolic demands, many cancers take up extracellular lipids; however, how these lipids contribute to cancer growth and progression remains poorly understood. Here, using functional genetic screens, we identify lipoprotein uptake—the primary mechanism for lipid transport in circulation—as a key determinant of ferroptosis sensitivity in cancer. Lipoprotein supplementation robustly inhibits ferroptosis across diverse cancer types, primarily through the delivery of α-tocopherol (α-toc), the most abundant form of vitamin E in human lipoproteins. Mechanistically, cancer cells take up lipoproteins through a pathway dependent on sulfated glycosaminoglycans (GAGs) linked to cell-surface proteoglycans. Disrupting GAG biosynthesis or acutely degrading surface GAGs reduces lipoprotein uptake, sensitizes cancer cells to ferroptosis, and impairs tumour growth in mice. Notably, human clear cell renal cell carcinomas, a lipid-rich malignancy, exhibit elevated levels of chondroitin sulfate and increased lipoprotein-derived α-toc compared to normal kidney tissue. Altogether, our work establishes lipoprotein uptake as a critical anti-ferroptotic mechanism in cancer and implicates GAG biosynthesis as a therapeutic target.
2025-05-06 | GSE296260 | GEO
Project description:Sepsis is an uncontrolled, systemic response to infection with life-threatening consequences. Our understanding of the pathogenesis of sepsis across organs of the body is rudimentary. Here, using mouse models of sepsis, we generate a dynamic, organism-wide map of the pathogenesis of the disease, revealing the spatiotemporal patterns of well-known and previously unrecognized effects of sepsis on the body. By combining functional perturbations with organism-wide profiling, we discover two interorgan mechanisms that are key to the pathophysiology of sepsis. First, we find that a hierarchical cytokine circuit arising from the pairwise effects of TNF plus IL-18, IFN-γ, or IL-1β suffices to explain a large fraction of the molecular effects of sepsis on the body. Moreover, the effects of these three cytokine pairs on the abundance of nearly two hundred cell types across nine organ types recapitulate half of all the cellular effects of sepsis. Second, we uncover an interorgan pathway whereby a gut-derived, secreted phospholipase, Pla2g5, mediates hemolysis in the blood circulation and contributes to multi-organ failure during sepsis. Thus, a simplifying principle in the systemic behavior of the cytokine network and a lipase misdirected from gut to blood provide fundamental insights to help build a unifying mechanistic framework for the pathophysiological effects of sepsis on the organ systems of the body.
2024-01-11 | GSE253061 | GEO
Project description:ABCA7 deficiency causes neuronal dysregulation by altering mitochondrial lipid metabolism
| PRJNA1037158 | ENA
Project description:The effect of perfluoroalkyl sulfonates on lipoprotein metabolism was investigated in APOE*3-Leiden.CETP mice with a humanized lipoprotein profile. Perfluorohexane sulfonate and perfluorooctane sulfonate markedly reduced both plasma TG and TC by decreasing nonHDL-C and HDL-C accompanied by a reduction in apoAI. Mechanistic studies showed that these effects were mainly caused by impaired lipoprotein production. Male E3L.CETP mice on a C57Bl/6 background were fed a Western-type diet, containing 0.25% (w/w) cholesterol, 1% (w/w) corn oil and 14% (w/w) bovine fat (Western-type diet) (Hope Farms, Woerden, The Netherlands) for 4 to 6 weeks in three independent experiments. Upon randomization according to total plasma cholesterol (TC) and TG levels, mice received the Western-type diet without or with PFBS (30 mg/kg/day), PFHxS (6 mg/kg/day) or PFOS (3 mg/kg/day) during 4-6 weeks. The effects of these PFAS on plasma lipids and lipoproteins were determined. In addition, PFAS levels were determined in plasma and livers were isolated for hepatic lipid analysis and hepatic gene expression analysis using an Affymetrix technology platform and Affymetrix GeneChip® mouse genome 430 2.0 arrays.
2011-01-01 | E-GEOD-22940 | biostudies-arrayexpress
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:Altered DNA methylation underlies monocyte dysregulation and immune exhaustion memory in sepsis
| PRJNA1064413 | ENA