A unique feature of the tumour cells (Hodgkin/Reed-Sternberg (HRS)) of classical Hodgkin lymphoma (cHL) is the loss of their B-cell phenotype despite their B-cell origin. Several lines of evidence suggest that epigenomic events, especially promoter DNA-methylation, are involved in this silencing of many B-cell associated genes. Here we show that DNA-demethylation alone or in conjunction with histone-acetylation is not able to reconstitute the B-cell gene expression program in cultured HRS cells. Instead, combined DNA-demethylation and histone-acetylation of B cells induce a nearly complete extinction of their B-cell expression program and a tremendous up-regulation of numerous cHL characteristic genes including key players such as Id2 known to be involved in the suppression of the B-cell phenotype. Since the up-regulation of cHL characteristic genes and the extinction of the B-cell expression program occurred simultaneously, epigenetic changes may also be responsible for the malignant transformation of cHL. The epigenetic up-regulation of cHL characteristic genes thus play - in addition to promoter DNA-hypermethylation of B-cell associated genes a pivotal role for the reprogramming of HRS cells and explain why DNA-demethylation alone is unable to reconstitute the B-cell expression program in HRS cells.
Histone acetylation and DNA demethylation of B cells result in a Hodgkin-like phenotype.
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View SamplesMycobacterium avium infection in mice induces granuloma necrosis in the lung which is dependent on IFNg. IRF1 is a transcription factor activated by IFNg signaling. The effect of IFNg and IRF1 on immunopathology and transcriptional changes in the lung were analysed using gene-deficient mice.
Mycobacteria-induced granuloma necrosis depends on IRF-1.
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View SamplesThe cytokine IL-10 deactivates macrophages and has been shown to impair resistance to mycobacterial infection. We have infected transgenic mice overexpressing IL-10 under control of the macrophage-specific CD68 promoter (macIL-10tg mice) with Mycobacterium tuberculosis by aerosol and found increased bacterial loads in the lungs of macIL-10tg mice.
Autocrine IL-10 induces hallmarks of alternative activation in macrophages and suppresses antituberculosis effector mechanisms without compromising T cell immunity.
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Inhibition of Endothelial NOTCH1 Signaling Attenuates Inflammation by Reducing Cytokine-Mediated Histone Acetylation at Inflammatory Enhancers.
Specimen part
View SamplesNotch1 is a key regulator of endothelial cell behaviour. This experiment was designed to identify genes regulated by Notch1 signaling in inflammatory activated mouse endothelial cells.
Inhibition of Endothelial NOTCH1 Signaling Attenuates Inflammation by Reducing Cytokine-Mediated Histone Acetylation at Inflammatory Enhancers.
Specimen part
View SamplesProinflammatory activation of endothelial cells leads to recruitment of leukocytes by upregulation of adhesion molecules and presentation of chemoattractants. In response to such activation there is also a strong shift in the endothelial expression of Notch ligands, with downregulation of Dll4 and a upregulation of JAG1. To assess whether Jagged1 would affect the endothelial activation profile, we suppressed JAG1 expression during IL-1-induced activation by means of siRNA and performed a genome-wide transcriptome analysis. Our results show for the first time that Jagged1 modulates the transcription profile of activated endothelial cells and describe data that imply a role for Jagged1 in sharpening the inflammatory profile of the vasculature, giving it an edge towards leukocyte recruitment. These findings imply that Jagged1 might be a potential therapeutic target to attenuate inflammation and reduce tissue damage in inflammatory diseases.
Inhibition of Endothelial NOTCH1 Signaling Attenuates Inflammation by Reducing Cytokine-Mediated Histone Acetylation at Inflammatory Enhancers.
Specimen part
View SamplesInflammatory activation of endothelial cells enables leukocyte recruitment to tissues. We here investigate how Notch1 signaling affects the transcriptional profile of inflammatory activated human umbilical vein cells.
Inhibition of Endothelial NOTCH1 Signaling Attenuates Inflammation by Reducing Cytokine-Mediated Histone Acetylation at Inflammatory Enhancers.
Specimen part
View SamplesBreakdown products of some glucosinolates defense chemicals of Brassicales induce detoxifying enzymes and demonstrate preventive activities against chemically induced tumorigenesis in animal models. However, other breakdown products are genotoxic. 1-Methoxy-3-indolylmethyl alcohol (1-MIM-OH) is mutagenic in bacterial and mammalian cells upon activation by sulphotransferases and forms DNA adducts in mouse tissues. This effect was enhanced in mice transgenic for human sulphotransferases 1A1/2 (FVB/N-hSULT1A1/2). In this study we explored gene expression changes induced by 1-MIM-OH in mouse liver. FVB/N-hSULT1A1/2 mice were orally treated with 1-MIM-OH for 21 or 90 days, leading to high levels of hepatic 1-MIM-DNA adducts. Genome-wide expression analyzes in this tissue demonstrated no influence on detoxifying enzymes, but up-regulation of many mediators of the tumour suppressor p53 and down-regulation of Fhit and other long genes. In conclusion, 1-MIM-OH did not induce protective enzymes, but formed high levels of DNA adducts, which were recognized by affected cells as reflected by p53 activation. While this p53 response might aim to protection, it was unable to prevent the accumulation of DNA adducts. However, various epdemiological studies reported inverse associations between the intake of cruciferous vegetables and cancer. This association might be due to the presence of other glucosinolates with tumour-preventing influences possibly outweighing adverse effects of some metabolites. Nevertheless, 1-MIM-OH is a genotoxic substance inducing a gene expression profile similar to the expression signature caused by known genotoxic hepatocarcinogens.
The glucosinolate metabolite 1-methoxy-3-indolylmethyl alcohol induces a gene expression profile in mouse liver similar to the expression signature caused by known genotoxic hepatocarcinogens.
Sex, Specimen part, Treatment
View SamplesNaturally occurring FoxP3+CD4+CD25+high regulatory T cells (Tregs) play an important role in dominant tolerance, suppressing auto-reactive CD4+CD25- T cell activity. Although Tregs from T1D subjects are functionally deficient, there is little knowledge of the molecular mechanisms that orchestrate this loss of Treg function. We observed increased apoptosis (by a novel YOPRO-1/7AAD dual staining protocol) and decreased suppression in polyclonal Tregs in the periphery from high at-risk and T1D subjects. We hypothesize that prior to and during the onset of disease, Tregs lack pro-survival signals and are caught up in a relatively deficient cytokine milieu whose effects may be detectable in the periphery.
Apoptosis of CD4+ CD25(high) T cells in type 1 diabetes may be partially mediated by IL-2 deprivation.
Sex, Age, Race
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Classical Hodgkin's lymphoma shows epigenetic features of abortive plasma cell differentiation.
Specimen part, Cell line, Treatment
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