This SuperSeries is composed of the SubSeries listed below.
Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.
Specimen part, Cell line
View SamplesThe goal of the study was to understand whether mitochondrial-driven epigenetic changes regulate gene expression. Mitochondrial metabolism has been implicated in epigenetics but the extent to which this impacts gene expression is unclear. Here we show that loss of mitochondrial DNA (mtDNA) results in locus-specific alterations in histone acetylation, DNA methylation and expression of a subset of genes. Most of these changes are rescued by restoring mitochondrial electron transport in a way that maintains the oxidative tricarboxylic acid cycle, but not reactive oxygen species or ATP production, or by modulating the mitochondrial pool of acetyl-CoA. Changes in acetyl-CoA and histone acetylation precede overt mitochondrial dysfunction and significant changes in gene expression and DNA methylation. This suggests that acetyl-CoA levels signal mitochondrial status to the nucleus. Differentially expressed genes with altered histone marks or DNA methylation regulate amino acid degradation, which likely compensates for the changes in acetyl-CoA and one carbon metabolism. These have the potential to further affect methylation reactions, redox control and nucleotide levels. These results illustrate the extent to which mitochondria impact cell physiology through epigenetic remodeling.
Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.
Cell line
View SamplesHere we describe three new small-molecule activators of BMP signaling found by high throughput screening of a library of ~600,000 small molecules. Using a cell-based luciferase assay in the BMP4-responsive human cervical carcinoma clonal cell line, C33A-2D2, we identified three compounds with similar chemotypes, each ventralized zebrafish embryos and stimulated increased expression of the Bmp target genes, bmp2b and szl. Because these compounds ventralize zebrafish embryos, we have termed them ventromorphins. As expected for a BMP pathway activator, they induce the differentiation of C2C12 myoblasts to osteoblasts. Affymetrix RNA analysis confirmed the differentiation results and showed that ventromorphin treatments elicits a genetic response similar to BMP-4 treatment. Unlike isoliquiritigenin (SJ000286273), a flavone that maximally activates the pathway after 24 hours of treatment, all three ventromorphins induced SMAD1/5/8 phosphorylation within 30 minutes of treatment and achieved peak activity at 30 minutes or 1 hour, indicating that their direct responses are consistent with activated BMP signaling.
Ventromorphins: A New Class of Small Molecule Activators of the Canonical BMP Signaling Pathway.
Specimen part, Cell line, Treatment
View SamplesSoybean (Glycine max) seeds are an important source of seed storage compounds, including protein, oil, and sugar used for food, feed, chemical, and biofuel production. We assessed detailed temporal transcriptional and metabolic changes in developing soybean embryos to gain a systems biology view of developmental and metabolic changes and to identify potential targets for metabolic engineering. Two major developmental and metabolic transitions were captured enabling identification of potential metabolic engineering targets specific to seed filling and to desiccation. The first transition involved a switch between different types of metabolism in dividing and elongating cells. The second transition involved the onset of maturation and desiccation tolerance during seed filling and a switch from photoheterotrophic to heterotrophic metabolism. Clustering analyses of metabolite and transcript data revealed clusters of functionally related metabolites and transcripts active in these different developmental and metabolic programs. The gene clusters provide a resource to generate predictions about the associations and interactions of unknown regulators with their targets based on guilt-by-association relationships. The inferred regulators also represent potential targets for future metabolic engineering of relevant pathways and steps in central carbon and nitrogen metabolism in soybean embryos and drought and desiccation tolerance in plants. Overall design: Total mRNA profiles of 10 time course samples of Soybean developing embryos with three replicates per sample were generated by deep sequencing, using Illumina HiSeq 2000
Transcriptome-wide functional characterization reveals novel relationships among differentially expressed transcripts in developing soybean embryos.
Age, Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Age, Specimen part, Treatment, Subject, Time
View SamplesThe carcinogenic potential of chemicals is currently evaluated with rodent life-time bioassays, which are time consuming, and expensive with respect to cost, number of animals and amount of compound required. For insight into early mechanisms of non-genotoxoc carcinogenesis and for identification of potential early biomarkers of non-genotoxic carcinogenesis, groups of rats were treated with a range of known non-genotoxic carcinogens for a period of 14, 28, or 90 days, and liver tissue was harvested for expression profiling. Control groups were treated with appropriate vehicles.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment, Subject
View SamplesConventional notion regards the action of non-genotoxic carcinogens (NGC) an autonomous process largely confined to parenchymal cells. Here we aim to elucidate the role of the hepatic mesenchyme for the action of two prototypical NGC, phenobarbital (PB), an anti-epileptic drug, and cyproterone acetate (CPA) a gestagen used in contraceptive pills.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment
View SamplesHere we investigate the difference in global gene expression in different tumor types found in the liver of rats after NNM-initiation/PB-promotion of tumor growth. We aim to identify tumor characteristic expression in nodules, focii, adenomas and carcinomas.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment
View SamplesEvidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment, Subject
View Samples