Dynamic interplay between the transcriptome and methylome in response to oxidative and alkylating stress
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Lize Deferme
PROVIDER: E-GEOD-63989 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Arsenic is methylated during its metabolism, thereby depleting the intracellular methyl donor S-adenosyl-methionine, which may lead to disturbances in DNA methylation patterns Cells were exposed to sodium arsenite (NaAsO2, Sigma) at concentrations of 0.08 M-BM-5M, 0.4 M-BM-5M and 2 M-BM-5M for 1, 2 and 8 weeks. A549 arsenic dose time response study.
2014-09-17 | E-GEOD-44173 | biostudies-arrayexpress
Project description:The human liver contains multiple cell types whose epigenetic patterns are undetermined. We examined the promoter methylome of purified and uncultured hepatic stellate cells (HSCs), hepatocytes (HEPs) and liver sinusoidal endothelial cells (LSECs), by methylated DNA immunoprecipitation (MeDIP) and array hybridization. Uncultured HSCs, LSECs and Heps show ~7000-8000 methylated promoters, with 60-70% similarity between all cell types. GO analysis for commonly methylated genes reveals involvement in germ cell development, segregating germ-line from somatic lineage methylation. HSCs, LSECs and HEPs also contain ~500-1000 uniquely methylated promoters; these are implicated in signaling and biosynthetic processes (HSCs), lipid transport and metabolism (LSECs), and chromatin assembly (HEPs). The promoter methylome of culture-activated HSCs deviates from that of their uncultured (quiescent) counterparts. HSC culture-induced activation also enhances methylation differences between individual donors; however this does not necessarily relate to changes in gene expression. HSc activation results in a net gain of promoter DNA methylation, despite the demethylation and de novo methylation of thousands of promoters. Our data provide to our knowledge the first genome-wide maps of promoter DNA methylation in human purified and uncultured liver cell types. Although methylation profiles are largely similar between HSCs, LSECs and hepatocytes, the detection of cell type-specific methylation patterns suggests a differential epigenetic programming of these cell types in the liver. Determine the promoter DNA methylation pattern of 3 uncultured, reshly isolated, human healthy liver cell types (hepatocytes (HEPs), liver sinusoidal endothelial cells (LSECs) and haptic stellate cells (HSCs), and of HSCs after a 24-h culture-induced activation.
2015-12-21 | E-GEOD-66796 | biostudies-arrayexpress
Project description:Hybrid quadrupole time-of-flight (QTOF) is one of the two major mass spectrometric technologies used in proteomics. Although based on simple fundamental principles, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated LC system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high MS/MS frequencies. The new reflectron and detector improve resolving power compared to the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4,800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2>0.99) and accurate fold change determination in spike-in experiments over three orders of magnitude in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originated from different tissues. Finally, after high pH reversed-phase fractionation we identified 9,515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in cerebellum – the highest proteome coverage measured with a QTOF instrument so far.
2015-05-26 | PXD001592 | Pride
Project description:Recent studies in non-human model systems have shown therapeutic potential of modified mRNA (modRNA) treatments for lysosomal storage diseases. Here, we assessed the efficacy of a modRNA treatment to restore the expression of the α-galactosidase (GLA) gene in a human cardiac model generated from induced-pluripotent stem cell-derived from two patients with Fabry disease. In line with the clinical phenotype, cardiomyocytes from Fabry patient’s induced pluripotent stem cells show accumulation of the glycosphinolipid Globotriaosylceramide (GB3), which is an α-galactosidase substrate. Further, the patient-specific cardiomyocytes have significant upregulation of lysosomal associated proteins. Upon modRNA treatment, a subset of lysosomal proteins were partially restored to wildtype levels, implying the rescue of the molecular phenotype associated with the Fabry genotype. Importantly, a significant reduction of GB3 levels was observed in GLA modRNA treated cardiomyocytes demonstrating that α-galactosidase enzymatic activity was restored. Together, our results validate the utility of patient IPSC-derived cardiomyocytes as a model to study disease processes in Fabry disease and the therapeutic potential of GLA modRNA treatment to reduce GB3 accumulation in the heart.
2023-07-20 | PXD038361 | Pride
Project description:Here, we successfully used NO as the direct electron acceptor for the enrichment of a microbial community in a continuous bioreactor. The enrichment culture, mainly comprised of two new organisms from the Sterolibacteriaceae family, grew on NO reduction to N2 and formate oxidation, with virtually no accumulation of N2O. The microbial growth kinetics of the enrichment culture as well as its affinity for different N-oxides were determined. In parallel, using metagenomics, metatranscriptomics, and metaproteomics, the biochemical reactions underlying the growth of these microorganisms on NO were investigated. This study demonstrates that microorganisms thrive and can be enriched on NO, and presents new opportunities to study microbial growth on this highly energetic and climate-active molecule that may have been pivotal in the evolution of aerobic respiration.
2023-06-09 | PXD037586 | Pride
Project description:We used a limited proteolysis-coupled mass spectrometry approach to pinpoint binding sites of cortisol on SARS-CoV-2 S1. Binding target identification is based on the principle that small-ligand binding alters (increases or decreases) the protease accessibility of the target protein37,38. The binding of the ligand (cortisol) to the target protein (SARS-CoV-2 S1) induces perturbations/conformational changes at the binding sites which can lead to either facilitating or preventing proteolysis by non-specific proteases (thermolysin and trypsin)37,38. We subjected SARS-CoV-2 S1 incubated with either cortisol or vehicle to proteolysis by thermolysin followed by trypsin digestion and mass spectrometry-based identification of the resultant peptides. We found that cortisol either facilitated or prevented S1 proteolytic cleavage at discrete sites. Six unique peptides were identified that were only present for SARS-CoV-2 S1 incubated with either cortisol or vehicle.
2022-06-10 | PXD032937 | Pride
Project description:Background Urothelial carcinoma of the bladder (UC) is a common malignancy. Although extensive transcriptome analysis has provided insights into the gene expression patterns of this tumor type, the mechanistic underpinnings of differential methylation remain poorly understood. Multi-level genomic data may be used to profile the regulatory potential and landscape of differential methylation in cancer and gain understanding of the processes underlying epigenetic and phenotypic characteristics of tumors. Methods We perform genome-wide DNA methylation profiling of 98 gene-expression subtyped tumors to identify between-tumor differentially methylated regions (DMRs). We integrate multi-level publically available genomic data generated by the ENCODE consortium to characterize the regulatory potential of UC DMRs. Results We identify 5,453 between-tumor DMRs and derive four DNA methylation subgroups of UC with distinct associations to clinicopathological features and gene expression subtypes. We characterize three distinct patterns of differential methylation and use ENCODE data to show that tumor subgroup-defining DMRs display differential chromatin state, and regulatory factor binding preferences. Finally, we characterize an epigenetic switch involving the HOXA-genes with associations to tumor differentiation states and patient prognosis. Conclusions Genome-wide DMR methylation patterns are reflected in the gene expression subtypes of UC. UC DMRs display three distinct methylation patterns, each associated with intrinsic features of the genome and differential regulatory factor binding preferences. Epigenetic inactivation of HOX-genes correlates with tumor differentiation states and may present an actionable epigenetic alteration in UC. MeDIP hybridizations on 98 human urothelial carcinoma samples and 4 normal urothelium samples on Nimblegen 3x720K RefSeq Promoter and CGI aCGH arrays.
2015-05-28 | E-GEOD-58256 | biostudies-arrayexpress
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. 5-mc is a well establisehd epigenetic mark typically related to gene silencing events. Phenobarbital (PB) is a well studied non-genotoxic carcinogen with roles in epigenetic perturbation. We profile 5mC in both control mouse livers as well as in the livers of 12 week PB treated mice. We also profile 5mC in liver tumours arising in the presence of long term PB exposure (35 week: resulting in Ctnnb1 mutated tumours) to a Ha-Ras liver tumour which arose without PB. Samples: 2 control and 2 PB exposed mouse livers, 3 liver tumours resulting from long term PB exposrue and 1 liver tumour arising without PB
2016-05-17 | E-GEOD-77727 | biostudies-arrayexpress
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. 5-hmC is a novel epigenetic mark derived from oxidation of methylcytosine. Phenobarbital (PB) is a well studied non-genotoxic carcinogen with roles in epigenetic perturbation. We profile 5hmC in both control mouse livers as well as in the livers of 12 week PB treated mice. We also profile 5hmC in liver tumours arising in the presence of long term PB exposure (35 week: resulting in Ctnnb1 mutated tumours) to a Ha-Ras liver tumour which arose without PB. Samples: 5hmC profiles in 2 control and 2 PB exposed mouse livers, 3 liver tumours resulting from long term PB exposrue and 1 liver tumour arising without PB
2016-05-17 | E-GEOD-77726 | biostudies-arrayexpress
Project description:we aimed to provide an objective roadmap for histone sample preparation wherein the most notable findings and most important metrics were highlighted. This roadmap included a Histone Coverage Tool that allows researchers to make a snapshot of public or in-house data in search of a protocol that suits their specific needs. However, despite the fact that the coverage provided by a sample preparation workflow is pivotal to answer specific research questions, it should be noted that other metrics such as enzyme specificity and workflow variability can be equally important. Moreover, when it comes to histone sample preparation there are multiple additional challenges and pitfalls compared to regular bottom-up proteomics workflows. First there is the abundance and unequal distribution of arginine and lysine cleavage sites, which makes it virtually impossible to cover the entire histone code with a single bottom-up workflow. The most widely spread workaround for the abundance of cleavage sites is derivatization of lysine residues used to block tryptic digest and create longer peptides. However, this also introduces chemical noise, which obscures biological PTMs, while lowering sensitivity due to diluted signal. The most obvious alternative is an arginine specific digest. However, on the one hand, derivatization of lysine residues not only increases peptide length but also increases retention on the LC-system, while decreasing charge state distribution of the precursor ions. The latter presumably reduces instrumental variation of the workflow, which is remarkable since this source of variation is generally assumed to be constant in the field of LC-MS/MS based proteomics. On the other hand, lysine derivatization also increases the singly charged precursor fraction, which is usually not fragmented in regular data dependent acquisitions, thus increasing the risk of losing annotations. It is clear that not one histone sample preparation workflow will fit all research questions. However, we hope that this manuscript will guide researchers in making informed decisions about the many pitfalls and trade-offs involved in optimizing or assessing histone sample preparation workflows.
2021-04-27 | PXD024423 | Pride