Project description:To gain additional insight into the role of IRAKM in dendritic cell activation in response to IL-33 challenge, we profiled transcriptomes of mouse DC2.4 dendritic cell lines with or without IRAKM following IL-33 treatment in vitro. IRAKM-sufficient and deficient DC2.4 cells were cultured overnight in the absence or presence of IL-33. Gene expression profiling was performed using Affymetrix platform.
Project description:To gain additional insight into the role of IRAKM in dendritic cell activation in response to IL-33 challenge, we profiled transcriptomes of mouse DC2.4 dendritic cell lines with or without IRAKM following IL-33 treatment in vitro.
Project description:Eosinophils are major effector cells in type 2 inflammatory responses and become activated in response to IL-4 and IL-33, yet the molecular mechanism remains unclear. We examined the direct effect of these cytokines on eosinophils and demonstrated that murine eosinophils respond to IL-4 and IL-33 by phosphorylation of STAT-6 and NFkB, respectively. RNA sequencing analysis of murine eosinophils indicated that IL-33 regulates 519 genes, whereas IL-4 regulates only 28 genes, including 19 IL-33-regulated genes. Interestingly, IL-33 induced eosinophil activation via two distinct mechanisms, IL-4 independent and IL-4 secretion/auto-stimulation dependent. Anti-IL-4 or anti-IL-4Ra antibody-treated eosinophils, as well as Il4- or Stat6-deficient eosinophils, had attenuated protein secretion of a subset of IL-33-induced genes, including Retnla and Ccl17. However, the induction of most IL-33-regulated transcripts (e.g. Il6 and Il13) was IL-4 independent and blocked by NFkB inhibition. Indeed, IL-33 induced the rapid release of pre-formed IL-4 protein from eosinophils by an NFkB-dependent mechanism. Thus, we have identified a novel activation pathway in murine eosinophils that is induced by IL-33 and differentially dependent upon IL-4. These data suggest that IL-4 plays a critical role in auto-amplification of IL-33-induced eosinophil activation and could be a potential target for therapeutic approaches in IL-33-related eosinophil-associated diseases. Low density bone marrow derived murine eosinophils were generated in culture over the period of 14 days. Eosinophils were activated by either IL-33 or IL-4 at 10 ng/ml for 1hr and 4hr. RNA was collected and subjected to next generation sequencing.
Project description:Acetaminophen is a widely used antipyretic and analgesic drug, and its overdose is the leading cause of drug-induced acute liver failure. This study aimed to investigate the effect and mechanism of Lacticaseibacillus casei Shirota (LcS), an extensively used and highly studied probiotic, on acetaminophen-induced acute liver injury. C57BL/6 mice were gavaged with LcS suspension or saline once daily for 7 days before the acute liver injury was induced via intraperitoneal injection of 300 mg/kg acetaminophen. The results showed that LcS significantly decreased acetaminophen-induced liver and ileum injury, as demonstrated by reductions in the increases in aspartate aminotransferase, total bile acids, total bilirubin, indirect bilirubin and hepatic cell necrosis. Moreover, LcS alleviated the acetaminophen-induced intestinal mucosal permeability, elevation in serum IL-1α and lipopolysaccharide, and decreased levels of serum eosinophil chemokine (eotaxin) and hepatic glutathione levels. Furthermore, analysis of the gut microbiota and metabolome showed that LcS reduced the acetaminophen-enriched levels of Cyanobacteria, Oxyphotobacteria, long-chain fatty acids, cholesterol and sugars in the gut. Additionally, the transcriptome and proteomics showed that LcS mitigated the downregulation of metabolism and immune pathways as well as glutathione formation during acetaminophen-induced acute liver injury. This is the first study showing that pretreatment with LcS alleviates acetaminophen-enriched acute liver injury, and it provides a reference for the application of LcS.
Project description:Eosinophils are major effector cells in type 2 inflammatory responses and become activated in response to IL-4 and IL-33, yet the molecular mechanism remains unclear. We examined the direct effect of these cytokines on eosinophils and demonstrated that murine eosinophils respond to IL-4 and IL-33 by phosphorylation of STAT-6 and NFkB, respectively. RNA sequencing analysis of murine eosinophils indicated that IL-33 regulates 519 genes, whereas IL-4 regulates only 28 genes, including 19 IL-33-regulated genes. Interestingly, IL-33 induced eosinophil activation via two distinct mechanisms, IL-4 independent and IL-4 secretion/auto-stimulation dependent. Anti-IL-4 or anti-IL-4Ra antibody-treated eosinophils, as well as Il4- or Stat6-deficient eosinophils, had attenuated protein secretion of a subset of IL-33-induced genes, including Retnla and Ccl17. However, the induction of most IL-33-regulated transcripts (e.g. Il6 and Il13) was IL-4 independent and blocked by NFkB inhibition. Indeed, IL-33 induced the rapid release of pre-formed IL-4 protein from eosinophils by an NFkB-dependent mechanism. Thus, we have identified a novel activation pathway in murine eosinophils that is induced by IL-33 and differentially dependent upon IL-4. These data suggest that IL-4 plays a critical role in auto-amplification of IL-33-induced eosinophil activation and could be a potential target for therapeutic approaches in IL-33-related eosinophil-associated diseases.
Project description:Interleukin-33 (IL-33) is elevated in afflicted tissues of patients with mast cell-dependent chronic allergic diseases. Based on its acute effects on mouse mast cells (MCs), IL-33 is thought to play a role in the pathogenesis of allergic disease through MC activation. However, the manifestations of chronic IL-33 exposure on human MC function, which best reflect the conditions associated with chronic allergic disease, are unknown. We now find that long-term exposure of human and mouse MCs to IL-33 results in a substantial reduction of MC activation in response to antigen. This reduction required >72 h exposure to IL-33 for onset and 1-2 wk for reversion following IL-33 removal. This hypo-responsive phenotype was determined to be a consequence of MyD88-dependent attenuation of signaling processes necessary for MC activation including antigen-mediated calcium mobilization and cytoskeletal reorganization; potentially as a consequence of down-regulation of the expression of PLCg1 and Hck. These findings suggest that IL-33 may play a protective, rather than a causative role in MC activation under chronic conditions and, furthermore, reveal regulated plasticity in the MC activation phenotype. The ability to down-regulate MC activation in this manner may provide alternative approaches for treatment of MC-driven disease. Mouse bone marrow-derived mast cells treated with IL3 or IL3+IL33. 6 replicates each.
Project description:Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by non-epithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin (IL)-33 as an epithelial cell-derived regulator of stromal cell activation and mediator of intestinal polyposis. IL-33 expression was elevated in the tumors and serum of colorectal cancer patients and induced in the adenomatous polyps of ApcMin/+ mutant mice. Genetic and antibody suppression of IL-33 signaling in ApcMin/+ mice inhibited proliferation, induced apoptosis, and suppressed angiogenesis in polyps, which reduced both tumor number and size. In ApcMin/+ polyps, IL-33 expression localized to tumor epithelial cells and expression of the IL-33 receptor, IL1RL1, associated with two stromal cell types, namely subepithelial myofibroblasts (SEMFs) and mast cells, whose activation was previously associated with polyposis. In vitro IL-33 stimulation of human SEMFs induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in ApcMin/+ polyps and expression of mast cell-derived proteases and cytokines known to promote polyposis. Together, our results suggest that IL-33 is a tumor epithelial cell-derived paracrine signal that promotes polyposis through the coordinated activation of stromal cells and the formation of a reactive stroma microenvironment. Six T-75 flasks of CCD-18Co cells were grown to 80% confluency; three were treated with rhIL-33, three were given vehicle control; cells were trypsinized and split in two--half of each flask used for sequencing and half for qPCR validation post-sequencing
Project description:Antigenic stimulation through cross-linking the IgE receptor and epithelial cell-derived cytokine IL-33 are potent stimuli of mast cell (MC) activation. Moreover, IL-33 primes a variety of cell types, including MCs to respond more vigorously to external stimuli. However, target genes induced by the combined IL-33 priming and antigenic stimulation have not been investigated in human skin mast cells (HSMCs) in a genome-wide manner. Furthermore, epigenetic changes induced by the combined IL-33 priming and antigenic stimulation have not been evaluated. In this study, we found that IL-33 priming of HSMCs enhanced their capacity to promote transcriptional synergy of the IL1B and CXCL8 genes by 16- and 3-fold, respectively, in response to combined IL-33 and antigen stimulation compared to without IL-33 priming. We identified the target genes in IL-33-primed HSMCs in response to the combined IL-33 and antigenic stimulation using RNA sequencing (RNA-seq). We found that the majority of genes synergistically upregulated in the IL-33-primed HSMCs in response to the combined IL-33 and antigenic stimulation were predominantly proinflammatory cytokine and chemokine genes. Moreover, the combined IL-33 priming and antigenic stimulation increase chromatin accessibility in the synergy target genes but not synergistically. Transcription factor binding motif analysis revealed more binding sites for NF-κB, AP-1, GABPA, and RAP1 in the induced or increased chromatin accessible regions of the synergy target genes. Our study demonstrates that IL-33 priming greatly potentiates MCs’ ability to transcribe proinflammatory cytokine and chemokine genes in response to antigenic stimulation, shining light on how epithelial cell-derived cytokine IL-33 can cause exacerbation of skin MC-mediated allergic inflammation.