Among the multiple mechanisms that control the intensity and duration of macrophage activation, the development of a state of refractoriness to a second stimulation in cells treated with LPS has long been recognized. Release of inhibitory cytokines and alterations in intracellular signaling pathways may be involved in the development of LPS tolerance. Although a number of molecules have been implicated, a detailed picture of the molecular changes in LPS tolerance is still missing. We have used a genome-wide gene expression analysis approach to (i) define which fraction of LPS target genes are subject to tolerance induction and (ii) identify genes that are expressed at high levels in tolerant macrophages. Our data show that in LPS tolerant macrophages the vast majority of LPS-induced gene expression is abrogated. The extent of tolerance induction varies for individual genes, and a small subset appears to be excepted. Compared to other negative control mechanisms of macrophages, e.g. IL-10-induced deactivation, LPS-tolerance inhibits a much wider range of transcriptional targets. Some previously described negative regulators of TLR-signaling (e.g. IRAK-M) were confirmed as expressed at higher levels in LPS-tolerant macrophages. In addition, we discuss other potential players in LPS tolerance identified in this group of genes.
A genome-wide analysis of LPS tolerance in macrophages.
No sample metadata fields
View SamplesAlthough mast cells elicit proinflammatory and type I IFN responses upon VSV infection, in response to L.monocytogenes (L.m) or S. Typhimurium (S.t), such cells elicit a transcriptional program devoid of type I IFN response.
Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria.
Specimen part
View SamplesCocaine-mediated repression of the histone methyltransferase (HMT) G9a has recently been implicated in transcriptional, morphological, and behavioral responses to chronic cocaine administration. Here, using a ribosomal affinity purification approach, we find that G9a repression by cocaine occurs in both Drd1 (striatonigral)- and Drd2 (striatopallidal)-expressing medium spiny neurons (MSNs). Conditional knockout and overexpression of G9a within these distinct cell types, however, reveals divergent behavioral phenotypes in response to repeated cocaine treatment. Our studies further indicate that such developmental deletion of G9a selectively in Drd2 neurons results in the unsilencing of transcriptional programs normally specific to striatonigral neurons, and the acquisition of Drd1-associated projection and electrophysiological properties. This partial striatopallidal to striatonigral switching phenotype in mice indicates a novel role for G9a in contributing to neuronal subtype identity, and suggests a critical function for cell-type specific histone methylation patterns in the regulation of behavioral responses to environmental stimuli.
G9a influences neuronal subtype specification in striatum.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
GATA4-dependent organ-specific endothelial differentiation controls liver development and embryonic hematopoiesis.
Specimen part, Cell line
View SamplesImmune deficiency is common in cancer, but the biological basis for this and ways to reverse it remains elusive. Here we present a mouse model of B cell chronic lymphocytic leukemia (CLL) that recapitulates changes in the non-malignant circulating T cells seen in patients with this illness.1 To validate this model, we examined changes in T cell gene expression, protein expression and function in Em-TCL1 transgenic mice as they developed CLL 2,3 and demonstrate that development of CLL in these transgenic mice is associated with changes in impaired T cell function and in gene expression in CD4 and CD8 T cells similar to those observed in patients with this disease. Infusion of CLL cells into non-leukemia bearing Em-TCL1 mice rapidly induces these changes, demonstrating a causal relationship between leukemia and the induction of T cell changes. This model allows dissection of the molecular changes induced in CD4 and CD8 T cells by interaction with leukemia cells and further supports the concept that cancer results in complex abnormalities in the immune microenvironment.
E(mu)-TCL1 mice represent a model for immunotherapeutic reversal of chronic lymphocytic leukemia-induced T-cell dysfunction.
No sample metadata fields
View SamplesBackground: It is recognized that atherosclerosis can regresses at least in animal models. However, little is known about the mechanisms. We induced regression of advanced atherosclerosis in apolipoprotein E deficient (APOE/) mice and studied underlying mechanisms. Unexpectedly, our study led to the role of interleukin-7 (IL-7) in atherogenesis.
Interleukin-7 induces recruitment of monocytes/macrophages to endothelium.
Sex, Age
View SamplesComparison of mRNA expression from FACS isolated Gli1 expressing stromal cells from mice given SAG21k versus vehicle
Control of inflammation by stromal Hedgehog pathway activation restrains colitis.
Sex, Specimen part, Treatment
View SamplesDREAM (downstream regulatory element antagonist modulator) is a Ca2+-binding protein that binds DNA and represses transcription in a Ca2+-dependent manner. Previous studies have shown a role for DREAM in cerebellar function regulating the expression of the sodium/calcium exchanger3 (NCX3) in cerebellar granules to control Ca2+ homeostasis and survival of these neurons. To achieve a more global view of the genes regulated by DREAM in the cerebellum, we performed a genome-wide analysis in transgenic cerebellum expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Our results indicate that DREAM is a major transcription factor in the cerebellum that regulates genes important for cerebellar development.
Reduced Mid1 Expression and Delayed Neuromotor Development in daDREAM Transgenic Mice.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
NRASG12V oncogene facilitates self-renewal in a murine model of acute myelogenous leukemia.
Specimen part
View SamplesUnlike human hearts, zebrafish hearts efficiently regenerate after injury. Regeneration is driven by the strong proliferation response of its cardiomyocytes to injury. In this study, we show that active telomerase is required for cardiomyocyte proliferation and full organ recovery, supporting the potential of telomerase therapy as a means of stimulating cell proliferation upon myocardial infarction. Overall design: Heart transcriptomes of WT and telomerase defective adult zebrafish animals were profiled by RNASeq, in control conditions and 3 days after heart cryoinjury.
Telomerase Is Essential for Zebrafish Heart Regeneration.
No sample metadata fields
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