Cutaneous exposure to food antigen through impaired skin barrier has been shown to induce epicutaneous sensitization, and thereby cause IgE-mediated food allergy.
Skin inflammation exacerbates food allergy symptoms in epicutaneously sensitized mice.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Dual functions of Tet1 in transcriptional regulation in mouse embryonic stem cells.
Specimen part, Disease, Treatment
View SamplesEpigenetic modification of the mammalian genome by DNA methylation (5-methylcytosine) has a profound impact on chromatin structure, gene expression and maintenance of cellular identity. Recent demonstration that members of the Ten-eleven translocation (Tet) family proteins can convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) raised the possibility that Tet proteins are capable of establishing a distinct epigenetic state. We have recently demonstrated that Tet1 is specifically expressed in murine embryonic stem (ES) cells and is required for ES cell self-renewal and maintenance. Using chromatin immunoprecipitation coupled with high-throughput DNA sequencing (ChIP-seq), here we show that Tet1 is preferentially bound to CpG-rich sequences at promoters of both transcriptionally active and Polycomb-repressed genes. Despite a general increase in levels of DNA methylation at Tet1 binding-sites, Tet1 depletion does not lead to down-regulation of all the Tet1 targets. Interestingly, while Tet1-mediated promoter hypomethylation is required for maintaining the expression of a group of transcriptionally active genes, it is also required for repression of Polycomb-targeted developmental regulators. Tet1 contributes to silencing of this group of genes by facilitating recruitment of PRC2 to CpG-rich gene promoters. Thus, our study not only establishes a role for Tet1 in modulating DNA methylation levels at CpG-rich promoters, but also reveals a dual function of Tet1 in promoting transcription of pluripotency factors as well as participating in the repression of Polycomb-targeted developmental regulators.
Dual functions of Tet1 in transcriptional regulation in mouse embryonic stem cells.
Specimen part
View SamplesDietary collagen hydrolysate has been conjectured to improve skin barrier function. To investigate the effect of long-term collagen hydrolysate administration on the skin, we evaluated stratum corneum water content and skin elasticity in intrinsic aged mice. Female 9-week-old hairless mice were fed a control diet, or a collagen hydrolysate-containing diet, for 12 weeks. The stratum corneum water content and skin elasticity were sequentially decreased by chronological aging in control mice. Intake of collagen hydrolysate significantly suppressed such changes. Moreover, we comprehensively analyzed gene expression in the skin of mouse, which had been administered collagen hydrolysate, using DNA microarray. Twelve weeks after start of collagen intake, no significant differences appeared in gene expression profile compared to that of control group. However, 1 week after administration, 135 genes were up-regulated and 448 genes were down-regulated in collagen group compared to control group. It is indicate that gene changes preceded changes of barrier function and elasticity. We focused on several genes correlated with functional changes in the skin. Gene Ontology terms, especially related to epidermal cell development, were signicantly enriched in up-regulated genes. These skin function-related genes had properties that facilitate epidermal production and differentiation and suppress dermal degradation. Thus, dietary collagen hydrolysate induced positive gene changes. In conclusion, our results suggest that alteration of gene expression at early stages after collagen administration affect skin barrier function and mechanical properties. Long-term oral intake of collagen hydrolysate improves skin dysfunction by regulating genes related to production and maintenance of the skin tissue.
Effect of orally administered collagen hydrolysate on gene expression profiles in mouse skin: a DNA microarray analysis.
Sex, Age, Specimen part, Treatment
View SamplesMast cells, activated by antigen via the high affinity receptor for IgE (FcRI), release an array of pro-inflammatory mediators that contribute to allergic disorders such as asthma and anaphylaxis. The KIT ligand, stem cell factor (SCF), is critical for mast cell expansion, differentiation and survival, and, under acute conditions, enhances mast cell activation. However, extended SCF exposure in vivo conversely protects against fatal antigen-mediated anaphylaxis. In investigating this dichotomy, we identified a novel mode of regulation of the mast cell activation phenotype through SCF-mediated programming. We found that mouse bone marrow-derived mast cells chronically exposed to SCF displayed a marked attenuation of FcRI-mediated degranulation and cytokine production. The hypo-responsive phenotype was not a consequence of altered signals regulating calcium flux or protein kinase C, but of ineffective cytoskeletal reorganization, with evidence implicating a down-regulation of expression of the Src kinase Hck. Collectively, these findings demonstrate a major role for SCF in the homeostatic control of mast cell activation with potential relevance to mast cell-driven disease and the development of novel approaches for the treatment of allergic disorders.
Stem cell factor programs the mast cell activation phenotype.
Specimen part, Treatment
View SamplesTo elucidate the bioactive property of the dietary antioxidant curcumin, we examined tissue distribution and the gene expression- and lipidomic-profiles in epididymal white adipose tissue (eWAT) of the diet-induced obese mice. Dietary intake of curcumin (0.1% W/W) didnt affect the eWAT weight and the plasma lipid levels but reduced the levels of lipid peroxidation marker in eWAT. Curcumin was a slightly accumulated in eWAT and altered the gene expression associated with eukaryotic translation initiation factor 2 (EIF2) signaling. Curcumin suppressed the endoplasmic reticulum (ER) stress-related eIF2 phospholyration, the accumulation of macrophages and the expression of oxidative stress-sensitive transcription factor NF-B p65 and leptin, whereas anti-inflammatory effect wasnt enough to reduce the TNF- and IFN- levels. Lipidomic- and gene expression analysis suggests that curcumin reduced the contents of some diacylglyverols (DAGs) and DAG derived glycerophospholipids by suppressing the expressions of lipogenesis-related glycerol-3-phosphate acyltransferase 1 and lipolysis-related adipose triglyceride lipase.
Dietary Intake of Curcumin Improves eIF2 Signaling and Reduces Lipid Levels in the White Adipose Tissue of Obese Mice.
Sex, Specimen part
View SamplesTwo distinct Polycomb complexes, PRC1 and PRC2, collaborate to maintain epigenetic repression of key developmental loci in embryonic stem cells (ESCs). PRC1 and PRC2 have histone modifying activities, catalyzing mono-ubiquitination of histone H2A (H2AK119u1) and trimethylation of H3 lysine 27 (H3K27me3) respectively. Compared to H3K27me3, localization and role of H2AK119ub1 is not fully understood in ESCs. Here we present genome-wide H2AK119u1 maps in ESCs and identify a group of genes at which H2AK119u1 is deposited in a Ring1-dependent manner. These genes are a distinctive subset of genes with H3K27me3 enrichment and are the central targets of Polycomb silencing that are required to maintain ESC identity. We further show that the H2A ubiquitination activity of PRC1 is dispensable for its target binding and its activity to compact chromatin at Hox loci, but is indispensable for efficient repression of target genes and thereby ESC maintenance. These data demonstrate that multiple effector mechanisms including H2A ubiquitination and chromatin compaction combine to mediate PRC1-dependent repression of genes that are crucial for the maintenance of ESC identity. Utilization of these diverse effector mechanisms might provide a means to maintain a repressive state that is robust yet highly responsive to developmental cues during ES cell self-renewal and differentiation.
Histone H2A mono-ubiquitination is a crucial step to mediate PRC1-dependent repression of developmental genes to maintain ES cell identity.
Specimen part, Cell line, Treatment
View SamplesInterleukin-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.
IL-33 induces a hyporesponsive phenotype in human and mouse mast cells.
Specimen part, Treatment
View SamplesWe used microarrays to investigate the restoration of repression of PRC1 target gene expression in Ring1A/B-dKO ES cells stably expressing either of mock, WT or mutant Ring1B construct.
Histone H2A mono-ubiquitination is a crucial step to mediate PRC1-dependent repression of developmental genes to maintain ES cell identity.
Specimen part, Treatment
View SamplesAnalysis of mouse chondrocytes lacking the microRNA-140. MicroRNAs are genomically encoded small RNAs to regulate the gene expression. miR-140 shows high expression in cartilage. Results provide insight into the molecular mechanisms underlying miR-140 function in chondrocytes.
MicroRNA-140 plays dual roles in both cartilage development and homeostasis.
Specimen part
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