Similar Datasets
Project description:Itaconate is a unique regulatory metabolite that is induced upon Toll-like receptor (TLR) stimulation in myeloid cells. Here, we demonstrate major inflammatory tolerance and cell death phenotypes associated with itaconate production in activated macrophages. We show that endogenous itaconate is a key regulator of the signal 2 of NLR family pyrin domain containing 3 (NLRP3) inflammasome activation after long lipopolysaccharide (LPS) priming, which establishes tolerance to late NLRP3 inflammasome activation. We show that itaconate acts synergistically with inducible nitric oxide synthase (iNOS) and that the ability of various TLR ligands to establish NLRP3 inflammasome tolerance depends on the pattern of co-expression of IRG1 and iNOS. Mechanistically, itaconate accumulation upon prolonged inflammatory stimulation prevents full caspase-1 activation and processing of gasdermin D, which we demonstrate to be post-translationally modified by endogenous itaconate. Altogether, our data demonstrate that metabolic rewiring in inflammatory macrophages establishes tolerance to NLRP3 inflammasome activation that, if uncontrolled, can result in pyroptotic cell death and tissue damage.
| S-EPMC8039864 | biostudies-literature
Project description:Itaconate confers tolerance to late NLRP3 inflammasome activation
| PRJNA690253 | ENA
Project description:The objective was to investigate the disparity in gene expression between IRG1+/+ BMDMs and IRG1-/- BMDMs following VSV infection.
2024-06-01 | GSE249683 | GEO
Project description:To investigate the role of Irg1-itaconate or Hemin in macrophages, bone marrow-derived macrophages (BMDMs) from WT mice and Irg1 KO mice were extracted and cultured. After 7 days of cells culture, the BMDMs from WT mice were treated 120 μM 4-octyl itaconate (4-OI) for 15 h, 15 μM Hemin for 12 h, and the BMDMs from Irg1 KO mice and WT mice were treated Vehicle for 12 h. We then performed gene expression profiling analysis using data obtained from RNA-seq of 4-OI, Hemin or vehicle treated WT BMDMs and Irg1 KO BMDMs.
2024-06-28 | GSE221734 | GEO
Project description:Immune-response gene 1 (IRG1) transcription is rapidly induced by pathogen infections and inflammatory conditions primarily in cells of myeloid lineage. Deletion of Irg1 in mice causes severe defects in response to bacterial and viral infection and rapid death. IRG1 encodes a mitochondrial metabolic enzyme, aconitate decarboxylase 1 (ACOD1), that catalyzes the decarboxylation of cis-aconitate, a tricarboxylic acid cycle intermediate, to produce the anti-inflammatory metabolite itaconic acid (ITA). ITA can inhibit SDH5, resulting in elevated levels of succinate and metabolic reprogramming, or alkylate protein cysteine residues to induce electrophilic stress response mediated by NRF2 and IκBζ. Here we show that ITA is an antagonist of α-ketoglutarate (α-KG) and a potent inhibitor of α-KG/Fe2+-dependent TET family of DNA dioxygenases. In vitro, ITA binds to TET2 and inhibits the catalytic activity of TET2 and, reciprocally, α-KG blocks ITA binding to and inhibition of TET2. In vivo, lipopolysaccharides (LPS) treatment, which induces IRG1 expression and causes the intracellular accumulation of ITA, inhibits TET activity in Irg1-WT, but not Irg1-KO macrophages. Moreover, TET2 is a major target of ITA function in suppressing LPS-induced genes. LPS stimulates p65 NF-κB/RelA to bind with and recruit TET2 to hydroxymethylate and activate the Nfkbiz gene, which encodes IκBζ. Our results thus identify a physiological metabolite inhibitor of TET enzymes and reveal a novel mechanism for the anti-inflammatory function of ITA through dampening TET2-mediated NF-κB signaling.
2022-01-10 | GSE158580 | GEO
Project description:Itaconate is a metabolite naturally produced in large amounts in macrophages after exposure to immune stimulation. Following the discovery of itaconate’s immunoregulatory properties, several ester derivatives of this dicarboxylic acid were designed to further examine its role. We evaluated the metabolic, electrophilic, and immunologic profiles of macrophages treated with unmodified itaconate and a panel of itaconate derivatives. We found that only unmodified itaconate strongly enhances LPS-induced IFNb secretion after 12h pre-treatment. Thus, we compared the transcriptional profile of wild type and Irg1-/- cells, which are unable to produce itaconate, after 24h LPS stimulation. We find that cells lacking itaconate have impaired downstream type I interferon signaling, and that addition of itaconate Irg1-/- BMDMs restores this signaling back to levels comparable to wild type. This data highlights the role of itaconate as an immunoregulatory metabolite, and highlights the importance of using unmodified itaconate or genetic knockout models in future mechanistic studies.
2020-05-15 | GSE145950 | GEO
Project description:BMDMs of indicated phenotypes were stimulated with LPS for 24h and analyzed or restimulated with LPS for additional 3h and analyzed. In some experiments 1mM itaconate was added at 4h of LPS first stimulation.
2021-09-09 | PXD020089 | Pride
Project description:1) BMDMs treated with anti-VISTA under tolerizing and immunizing conditions. 2) Time course analysis of anti-VISTA-induced alterations in human monocytes after anti-VISTA treatment. 3) Time course analysis of anti-VISTA-induced alterations in BMDMs after anti-VISTA treatment. 4) Single cell ATAC-seq of BMDMs tolerized in the presence or IgG or anti-VISTA.
2020-09-05 | GSE157518 | GEO
Project description:The Krebs cycle-derived metabolite itaconate is highly upregulated in inflammatory macrophages and exerts immunomodulatory effects through cysteine modifications on target proteins. The NLRP3 inflammasome, which cleaves IL-1β, IL-18, and gasdermin D, must be tightly regulated to avoid excessive inflammation. Here we provide evidence that itaconate modifies NLRP3 and inhibits inflammasome activation. Itaconate and its derivative, 4-octyl itaconate (4-OI), inhibited NLRP3 inflammasome activation, but not AIM2 or NLRC4. Conversely, NLRP3 activation was increased in itaconate-depleted Irg1-/- macrophages. 4-OI inhibited the interaction between NLRP3 and NEK7, a key step in the activation process, and "dicarboxypropylated" C548 on NLRP3. Furthermore, 4-OI inhibited NLRP3-dependent IL-1β release from PBMCs isolated from cryopyrin-associated periodic syndrome (CAPS) patients, and reduced inflammation in an in vivo model of urate-induced peritonitis. Our results identify itaconate as an endogenous metabolic regulator of the NLRP3 inflammasome and describe a process that may be exploited therapeutically to alleviate inflammation in NLRP3-driven disorders.
| S-EPMC7422798 | biostudies-literature
Project description:Remodeling of the tricarboxylic acid (TCA) cycle is a metabolic adaptation mechanism accompanying inflammatory macrophage activation. During this process, endogenous metabolites can adopt regulatory roles that govern specific aspects of inflammatory response, as recently shown for succinate, which regulates the downstream pro-inflammatory IL-1β-HIF1a axis. Itaconate is one of the most highly induced metabolites in activated macrophages, yet its functional significance remains unknown. Here, we show that itaconate modulates macrophage metabolism and effector functions via its effect on succinate dehydrogenase, by inhibiting conversion of succinate to fumarate. Through this action, itaconate exerts anti-inflammatory effects when administered in vitro and in vivo during macrophage activation and ischemia-reperfusion injury. Using newly generated Irg1-/- mice, which lack the ability to produce itaconate, we show that endogenous itaconate regulates succinate levels and function, changes in mitochondrial respiration, and inflammatory cytokine production during macrophage activation. These studies highlight itaconate as a major physiological regulator of the global metabolic rewiring and effector functions of inflammatory macrophages. Experiment 1: mature WT BMDM were treated for 12h with 0.25 mM dimethyl itaconate (DI) or vehicle (Unst) and then stimulated with LPS (E. coli 0111:B4; 100 ng/ml, 4h) (DI+LPS; LPS); Experiment 2: mature Irg1-/- BMDM were stimulated with LPS (E. coli 0111:B4; 100 ng/ml) and murine recombinant IFNg (50 ng/ml) for 24h.
2016-07-01 | E-GEOD-82043 | biostudies-arrayexpress