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: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:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
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: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:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
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.