The objectives of this study were to measure effects of an aspirin intervention on gene expression in normal colonic epithelial and stromal tissue in healthy humans and to determine whether response differed by UGT1A6*2 genotype. We also sought to characterize gene expression differences within colonic tissue microenvironments by identifying genes that were differentially expressed between epithelial and stromal tissue.
Tissue-specific patterns of gene expression in the epithelium and stroma of normal colon in healthy individuals in an aspirin intervention trial.
Sex, Specimen part
View Samples1,2-unsaturated pyrrolizidine alkaloids (PA) are plant metabolites predominantly occurring in the plant families Asteraceae and Boraginaceae. Acute and chronic PA poisoning causes severe hepatotoxicity. So far, the molecular mechanisms of PA toxicity are not well understood. To analyze its mode of action, primary human hepatocytes were exposed to a non-cytotoxic dose of 100 M of four structurally different PA: echimidine, heliotrine, senecionine, senkirkine. Changes in mRNA expression were analyzed by a whole genome microarray. Employing cut-off values with a |fold change| of 2 and a q-value of 0.01, data analysis revealed numerous changes in gene expression. In total, 4556, 1806, 3406 and 8623 genes were regulated by echimidine, heliotrine, senecione and senkirkine, respectively. 1304 genes were identified as commonly regulated. PA affected pathways related to cell cycle regulation, cell death and cancer development. The transcription factors TP53, MYC, NFB and NUPR1 were predicted to be activated upon PA treatment. Furthermore, gene expression data showed a considerable interference with lipid metabolism and bile acid flow. The associated transcription factors FXR, LXR, SREBF1/2, and PPAR// were predicted to be inhibited. In conclusion, though structurally different, all four PA significantly regulated a great number of genes in common. This proposes similar molecular mechanisms, although the extent seems to differ between the analyzed PA as reflected by the potential hepatotoxicity and individual PA structure.
Disturbance of gene expression in primary human hepatocytes by hepatotoxic pyrrolizidine alkaloids: A whole genome transcriptome analysis.
No sample metadata fields
View SamplesSilver nanoparticles are used in consumer products like food contact materials, drinking water technologies and supplements, due to their antimicrobial properties. This leads to an oral uptake and exposure of intestinal cells. In contrast to other studies we found no apoptosis induction by surfactant coated silver nanoparticles in the intestinal cell model Caco-2 in a previous study, although the particles induced oxidative stress, morphological changes and cell death. Therefore, this study aimed to analyze the molecular mechanism of silver nanoparticles in Caco-2 cells. We used global gene expression profiling in differentiated Caco-2 cells, supported by verification of the microarray data by quantitative real time RT-PCR and microscopic analysis, impedance measurements and assays for apoptosis and oxidative stress. Our results revealed that the majority of surfactant coated silver nanoparticles are not taken up into differentiated Caco-2 cells. and probably affect the cells by outside-in signaling. They induce oxidative stress and have an influence on canonical pathways related to FAK, ILK, ERK, MAPK, integrins and adherence and tight junctions, thereby inducing transcription factors like AP1, NFB and NRF2, which mediate cellular reactions in response to oxidative stress and metal ions and induce changes in the cytoskeleton and cell-cell and cell-matrix contacts. The present data confirm the absence of apoptotic cell death. Non-apoptotic, necrotic cell death, especially in the intestine, can cause inflammation and influence the mucosal immune response.
Molecular mechanism of silver nanoparticles in human intestinal cells.
Cell line
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 SamplesBromodomain-containing proteins bind acetylated lysine residues on histone tails and are involved in the recruitment of additional factors that mediate histone modifications and enable transcription. A compound, I-BET-762, that inhibits binding of an acetylated histone peptide to BRD4 and other proteins of the BET (bromodomain and extra-terminal domain) family, was previously shown to suppress the production of pro-inflammatory proteins by macrophages and block acute inflammation in mice. Here we investigate the effect of I-BET-762 on T cell function. We show that treatment of nave CD4+ T cells with I-BET-762 during early differentiation modulates subsequent cytokine production, and inhibits the ability of Th1-skewed cells to induce autoimmune pathogenesis in a model of experimental autoimmune encephalomyelitis (EAE) in vivo. The suppressive effects of I-BET-762 on T-cell mediated inflammation were not due to inhibition of expression of the pro-inflammatory cytokines, IFN-. or IL-17, but correlated with the ability to suppress GM-CSF production from CNS-infiltrating T cells, resulting in decreased recruitment of macrophages and granulocytes. The effects of I-BET-762 were distinct from those of the fumarate ester, dimethyl fumarate (DMF), a candidate drug for treatment of multiple sclerosis (MS). Our data suggest that I-BET and DMF could have complementary roles in the treatment of MS, and provide a strong rationale for inhibitors of BET-family proteins in the treatment of autoimmune diseases, based on their dual ability to suppress granulocyte and macrophage recruitment by T cells as well as production of pro-inflammatory proteins by macrophages.
Selective inhibition of CD4+ T-cell cytokine production and autoimmunity by BET protein and c-Myc inhibitors.
Specimen part
View SamplesThe Ca2+/calmodulin-dependent kinase II is expressed in smooth muscle and believed to mediate intracellular calcium handling and calcium-dependent gene transcription. CaMKII is activated by Angiotensin-II.
Calcium/calmodulin-dependent kinase II inhibition in smooth muscle reduces angiotensin II-induced hypertension by controlling aortic remodeling and baroreceptor function.
Specimen part, Treatment
View SamplesMutations of -catenin gene (CTNNB1) are frequent in adrenocortical adenomas (AA) and carcinomas (ACC). However, the target genes of CTNNB1 have not yet been identified in adrenocortical tumors.
Characterization of differential gene expression in adrenocortical tumors harboring beta-catenin (CTNNB1) mutations.
Specimen part
View SamplesDirect conversion of somatic cells into neural stem cells (NSCs) by defined factors holds great promise for mechanistic studies, drug screening, and potential cell therapies for different neurodegenerative diseases. Here, we report that a single zinc-finger transcription factor, Zfp521, is sufficient for direct conversion of human fibroblasts into long-term self-renewable and multipotent NSCs. In vitro, Zfp521-induced NSCs maintained their characteristics in the absence of exogenous factor expression and exhibited morphological, molecular, developmental, and functional properties that were similar to control NSCs. Additionally, the single seeded induced NSCs were able to form NSC colonies with efficiency comparable to control NSCs and expressed NSC markers. The converted cells were capable of surviving, migrating and attaining neural phenotypes after transplantation into neonatal mouse- and adult rat brains, without forming tumors. Moreover, the Zfp521-induced NSCs predominantly expressed rostral genes. Our results suggest a facilitated approach for establishing human NSCs through Zfp521-driven conversion of fibroblasts. Overall design: RNA-Seq of 3 replicates each of iNSC, WT-NSC, and HNF
Conversion of Human Fibroblasts to Stably Self-Renewing Neural Stem Cells with a Single Zinc-Finger Transcription Factor.
No sample metadata fields
View SamplesGene expression profiles were assessed for vincristine-sensitive parental ovarian tumor cell line (SKOV3) and its highly vincristine-resistant derivative (SKVCR 2.0)
Genetic changes in the evolution of multidrug resistance for cultured human ovarian cancer cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription Factor EB Controls Metabolic Flexibility during Exercise.
Age, Specimen part
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