This SuperSeries is composed of the SubSeries listed below.
Integrative "-Omics" Analysis in Primary Human Hepatocytes Unravels Persistent Mechanisms of Cyclosporine A-Induced Cholestasis.
Specimen part, Treatment, Time
View SamplesCyclosporine A (CsA), is an endecapeptide with strong immunosuppressant activities and has contributed significantly towards clinical progress in organ transplantation. Furthermore, it has various toxic effects in the kidney and especially in the liver where it may induce cholestasis. The CsA drug-induced cholestasis (DIC) pathway includes important genes involved in the uptake, synthesis, conjugation and secretion of bile acids, which can be verified also in hepatic models in vitro. However, whether changes in CsA-induced cholestasis pathway induced in vitro are persistent thus presenting important biomarkers for repeated dose toxicity, has not yet been investigated. We therefore performed multiple -omics analyses, including whole genome analysis of DNA methylation, gene expression and microRNA expression in primary human hepatocytes (PHH) cultured in sandwich configuration, during and after terminating CsA treatment. For this, cells were exposed to a non-cytotoxic dose of 30 M CsA daily for 3 and 5 days. To investigate the persistence of induced changes upon terminating the CsA exposure of 5 days, a subset of PHH was subjected to a washout period (WO-period) of three days. DNA methylation (using NimbleGen 2.1 deluxe promoter arrays), transcriptomic (using Affymetrix Human Genome U133 Plus 2.0 arrays) and microRNA (using Agilent Sureprint G3 Unrestricted Human miRNA V16 8 60 K microarrays) analyses were performed on days 3, 5 and 8. Identification of differentially methylated genes (DMGs), differentially expressed genes (DEGs), and differentially expressed microRNAs (DE-miRs) was performed using several R packages. DMGs, DEGs and DE-miRs were found after CsA treatment of PHH for 3 and 5 days as well after the WO-period. Interestingly, 828 persistent DEGs and 6 persistent DE-miRs, but no persistent DMGs, were found after the WO-period. These persistent DEGs and DE-miRs showed concordance for 22 genes (13 genes upregulated in gene expression and downregulated in microRNA expression; 9 genes downregulated in gene expression and upregulated in microRNA expression). Some of the persistent transcriptomic changes as well as DE-miRs could be successfully mapped onto the DIC pathway, while epigenetic changes not. Furthermore, 29 persistent DEGs in vitro showed changes in the same direction as observed in livers from cholestasis patients. None of those 29 DEGs were present in the DIC pathway or cholestasis adverse outcome pathway. We have for the first time demonstrated a persistent impact of gene expression and microRNA expression related to DIC after repeated dose administration of CsA in vitro.
Integrative "-Omics" Analysis in Primary Human Hepatocytes Unravels Persistent Mechanisms of Cyclosporine A-Induced Cholestasis.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aflatoxin B1 induces persistent epigenomic effects in primary human hepatocytes associated with hepatocellular carcinoma.
Specimen part, Disease, Compound
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aflatoxin B1 induces persistent epigenomic effects in primary human hepatocytes associated with hepatocellular carcinoma.
Specimen part
View SamplesThe study investigated differential gene expression, microRNA expression and DNA methylation changes in a pool of primary human hepatocyte RNA and DNA following 5 days of repetitive exposure to a low (LD) or moderate (MD) dose of aflatoxin B1 or DMSO. Three biological replicates per compound/solvent.
Aflatoxin B1 induces persistent epigenomic effects in primary human hepatocytes associated with hepatocellular carcinoma.
Specimen part, Compound
View SamplesChronic exposure to aflatoxin B1 (AFB1) has, in certain regions in the world, been strongly associated with the development of hepatocellular carcinoma (HCC). AFB1 is a very potent hepatotoxic and carcinogenic mycotoxin which is frequently reported as a food contaminant. Epigenetic modifications provoked by environmental exposures, such as AFB1, may create a so called persistent "epigenetic memory" or "footprint". Deregulation of epigenetic mechanisms has actually been reported in HCC patients following AFB1 exposure; however no attempts have yet been made to investigate early effects on the epigenome level which may be persistent on longer term thereby possibly initiating carcinogenic events. In this study, we aim to identify methyl DNA-mRNA-interactions representative for a persistent epigenetic "footprint" associated with the early onset of AFB1-induced HCC. For this, primary human hepatocytes were exposed to 0.3 M of AFB1 for 5 days. Persistent epigenetic effects were m easured 3 days after terminating the carcinogenic treatment. Whole genome DNA methylation changes and whole genome transcriptomic analysis were analyzed applying microarray technologies, and cross-omics interactions were evaluated. Upon combining transcriptomics data with results on DNA methylation, a range of persistent hyper- and hypomethylated genes was identified which appeared also affected on the transcriptome level. For six of the hypomethylated and upregulated genes, namely TXNRD1, PCNA, CCNK, DIAPH3, RAB27A and HIST1H2BF, a clear role in carcinogenic events could be identified. This study is the first to report on a carcinogen-induced persistent impact on the "epigenetic footprint" in relation with the transcriptome which could be indicative for the early onset of AFB1-related development of HCC.
Aflatoxin B1 induces persistent epigenomic effects in primary human hepatocytes associated with hepatocellular carcinoma.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic mechanisms underlying arsenic-associated lung carcinogenesis.
Specimen part, Disease, Treatment, Time
View SamplesArsenic is methylated during its metabolism, thereby depleting the intracellular methyl donor S-adenosyl-methionine, which may lead to disturbances in DNA methylation patterns which could lead to altered gene expression
Epigenetic mechanisms underlying arsenic-associated lung carcinogenesis.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative omics data analyses of repeated dose toxicity of valproic acid in vitro reveal new mechanisms of steatosis induction.
Specimen part, Treatment
View SamplesValproic acid (VPA) is a very potent anti-cancer and neuro-protective drug. However, exposure to VPA may cause accumulation of lipids in the liver which could result in the development of steatosis. As VPA is a fatty acid analogue, most of the performed studies focus on inhibition of the mitochondrial b-oxidation pathway as the possible mode of action. However, investigations exploring the contribution of other processes in particular by using whole genome studies in a relevant human liver model are limited. Furthermore, the contribution of gene expression regulation by DNA methylation changes and/or miRNA changes is hardly known. Therefore, in the present study, we investigated the effect of repetitive VPA exposure on primary human hepatocytes (PHH) on whole genome gene expression-, DNA methylation-, and miRNA changes, using microarrays and integrated data analyses. PHH were exposed to a non-cytotoxic dose of 15 mM VPA for 5 days daily thereby inducing accumulation of lipids. Part of the PHH was left untreated for an additional 3 days in order to study the persistence of changes. VPA modulated the expression of a number of nuclear receptors and their target genes, leading to disturbed fatty acid metabolism and - uptake, ultimately leading to accumulation of triglycerides in the liver which is the key event leading to steatosis. Part of the gene expression changes was epigenetically regulated. Furthermore, after terminating the treatment, the expression and DNA methylation changes of several genes remained persistent, indicating a permanent change in the PHH, causing steatosis development to continue and/or making the PHH more sensitive for steatosis development during a subsequent exposure.
Integrative omics data analyses of repeated dose toxicity of valproic acid in vitro reveal new mechanisms of steatosis induction.
Specimen part, Treatment
View Samples