This SuperSeries is composed of the SubSeries listed below.
No associated publication
Sex, Specimen part, Disease
View SamplesIgE antibodies are key mediators of food allergy, and the production of IgE is tightly regulated at the moleculaer and cellular level in the germinal center of lymph glands where specific sets of genes are up-regulated.
No associated publication
Sex, Specimen part, Disease
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 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 SamplesHepG2 and THP-1 cells, the latter differentiated by phorbol 12-myristate 13-acetate (PMA), were co-cultured and characterized for typical liver-specific functions, such as xenobiotic detoxification, lipid and cholesterol metabolism. Furthermore, liver injury-associated pathways, such as inflammation, were studied. In general, the co-cultivation of these cells produced a pro-inflammatory system, as indicated by increased levels of cytokines (IL-8, TGF-α, IL-6, GM-CSF, G-CSF, TGF-β, and hFGF) in the respective supernatant. Increased expression levels of target genes of the aryl hydrocarbon receptor (AHR), e.g., CYP1A1, CYP1A2 and CYP1B1, were detected, accompanied by the increased enzyme activity of CYP1A1. Moreover, transcriptome analyses indicated a significant upregulation of cholesterol biosynthesis, which could be reduced to baseline levels by lovastatin. In contrast, total de novo lipid synthesis was reduced in co-cultured HepG2 cells. Key events of the adverse outcome pathway (AOP) for fibrosis were activated by the co-cultivation, however, no increase in the concentration of extracellular collagen was detected. This indicates, that AOP should be used with care. In summary, the indirect co-culture of HepG2/THP 1 cells results in an increased release of pro-inflammatory cytokines, an activation of the AHR pathway and an increased enzymatic CYP1A activity.
Indirect co-cultivation of HepG2 with differentiated THP-1 cells induces AHR signalling and release of pro-inflammatory cytokines.
Treatment
View SamplesCompounds with direct immunotoxic properties, including metals, mycotoxins, agricultural pesticides and industrial chemicals, form potential human health risks due to exposure through food, drinking water, and the environment. Insights into the mechanisms of action are currently lacking for the majority of these direct immunotoxicants. Therefore, the present work aimed to gain insights into the molecular mechanisms underlying direct immunotoxicity. To this end, we assessed in vitro the effects of 31 test compounds on the transcriptome of the human Jurkat T cell line. These compounds included direct immunotoxicants, immunosuppressive drugs with different mode of actions, and non-immunotoxic control chemicals. Pathway analysis of the microarray data allowed us to identify canonical pathways and Gene Ontology processes that were transcriptionally regulated in common by immunotoxicants (i) with structural similarities, such as the tributyltins TBTC and TBTO that activated the retinoic acid / X receptor (RAR / RXR) signaling pathway, and (ii) without structural similarities, such as As2O3, DBTC, diazinon, MeHg, ochratoxin A, S9 treated ochratoxin A, S9 treated cyclophosphamide, and S9 treated benzo[a]pyrene, that activated unfolded protein response, and FTY720, lindane, and propanil, that activated the cholesterol biosynthesis pathway. In addition, processes uniquely affected by individual immunotoxicants were identified, such as the induction of Notch receptor signaling and the down regulation of acute phase response genes by ochratoxin A. These findings were validated by quantitative Real-Time PCR (Q-RT-PCR) analysis of genes involved in these processes. Our study indicated that diverse modes of action are involved in direct immunotoxicity and that a set of pathways or genes, rather than one single gene can be used to screen compounds for direct immunotoxicity.
Toxicogenomics-based identification of mechanisms for direct immunotoxicity.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Sex, Age, Specimen part, Disease, Cell line, Treatment
View SamplesThe capability to detect target organ toxicity as well as to determine the molecular mechanisms underlying such toxicity by employing surrogate biospecimens that can be obtained by a non-invasive or minimally invasive procedure has significant advantage in occupational toxicology. Pulmonary toxicity and global gene expression profile in the lungs, peripheral blood and bronchoalveolar lavage (BAL) cells were determined in rats at 44-weeks following pulmonary exposure to crystalline silica (15 mg/m3, 6-hours/day, 5 days). A significant elevation in lactate dehydrogenase activity and albumin content observed in the BAL fluid suggested the induction of pulmonary toxicity in the silica exposed rats. Similarly, the observation of histological alterations, mainly type II pneumocyte hyperplasia and fibrosis, in the lungs further confirmed silica-induced pulmonary toxicity in the rats. A significant increase in the number of neutrophils and elevated monocyte chemotactic protein 1 level in the BAL fluids suggested silica-induced pulmonary inflammation in the rats. Determination of global gene expression profile in the lungs, BAL cells, and peripheral blood of the silica exposed rats identified 144, 236, and 51 significantly differentially expressed genes (SDEGs), respectively, compared with the corresponding control samples. Bioinformatics analysis of the SDEGs demonstrated a remarkable similarity in the biological functions, molecular networks and canonical pathways that were significantly affected by silica exposure in the lungs, BAL cells and blood of the rats. Induction of inflammation was identified, based on the bioinformatics analysis of the significantly differentially expressed genes in the lungs, blood and BAL cells, as the major molecular mechanism underlying the silica-induced pulmonary toxicity. The findings of our study demonstrated the potential application of global gene expression profiling of peripheral blood and BAL cells as a valuable minimally invasive approach to study silica-induced pulmonary toxicity in rats.
Molecular mechanisms of pulmonary response progression in crystalline silica exposed rats.
Sex, Specimen part, Time
View SamplesA proper understanding of the mechanisms underlying crystalline silica-induced pulmonary toxicity has implications in the management and potential prevention of the adverse health effects associated with silica exposure including silicosis, cancer and several auto-immune diseases. Human lung type II epithelial cells and rat lungs exposed to crystalline silica were employed as experimental models to determine global gene expression changes in order to understand the molecular mechanisms underlying silica-induced pulmonary toxicity. The differential gene expression profile induced by silica correlated with its toxicity in the A549 cells. The biological processes perturbed by silica exposure in the A549 cells and rat lungs, as identified by the bioinformatic analysis of the differentially expressed genes, demonstrated significant similarity. Functional categorization of the differentially expressed genes identified cancer, cellular movement, cellular growth and proliferation, cell death, inflammatory response, cell cycle, cellular development, and genetic disorder as top-ranking biological functions perturbed by silica exposure in the A549 cells and rat lungs. The involvement of oxidative stress and apoptosis in the silica-induced pulmonary toxicity was confirmed by ELISA and confocal microscopy analysis, respectively, of the silica-exposed A549 cells. Results of our study, in addition to confirming several previously identified molecular targets and mechanisms involved in silica toxicity, identified novel molecular targets and mechanisms potentially involved in silica-induced pulmonary toxicity. Further investigations, including those focused on the novel molecular targets and mechanisms identified in the current study, may result in a better management and, possibly, reduction and/or prevention of the potential adverse health effects associated with crystalline silica exposure.
No associated publication
Sex, Age, Specimen part, Disease, Treatment
View Samples