Epigenetic Dysregulation of H19/IGF2 in Hepatic Cells Exposed to Toxic Metal Mixtures In Vitro [RNA-seq]
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PROVIDER: PRJNA1175981 | ENA |
REPOSITORIES: ENA
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Project description:Exposure to mixtures of toxic metals is known to cause adverse health effects through epigenetic alterations. Here we aimed to examine the unexplored area of aberrant DNA methylation in the H19/IGF2 domain following combined toxic metal exposure. An in vitro epigenotoxicity assay using the human normal liver epithelial cell line THLE-3 was conducted. When THLE-3 cells were exposed to specific concentrations of either organic arsenic or MeHgCl, an increase in the H19 lncRNA levels and a marked reduction in the IGF2 mRNA levels were observed. In contrast, combined exposures coupled with CdCl2 resulted in the transcriptional repression of H19 and transcriptional activation of IGF2. It should be noted that the correlation between the dysregulated expression of H19/IGF2 and the hypermethylated CpG sites within the H19 differentially methylated region (DMR) was statistically significant. Furthermore, we performed transcriptomic analysis of the hepatocytes exposed to toxic metal combinations indicating enrichment of pro-inflammatory and anti-proliferative pathways compared to the unexposed cells. Our results suggest that hazardous metal mixtures may trigger epigenetic aberrations at the H19/IGF2 locus. We propose that altered CpG methylation in the H19 DMR could be a candidate biomarker for hepatic epigenotoxicity, in part, due to environmental exposure.
2024-10-27 | GSE280026 | GEO
Project description:Exposure to mixtures of toxic metals is known to cause adverse health effects through epigenetic alterations. Here we aimed to examine the unexplored area of aberrant DNA methylation in the H19/IGF2 domain following combined toxic metal exposure. An in vitro epigenotoxicity assay using the human normal liver epithelial cell line THLE-3 was conducted. When THLE-3 cells were exposed to specific concentrations of either organic arsenic or MeHgCl, an increase in the H19 lncRNA levels and a marked reduction in the IGF2 mRNA levels were observed. In contrast, combined exposures coupled with CdCl2 resulted in the transcriptional repression of H19 and transcriptional activation of IGF2. It should be noted that the correlation between the dysregulated expression of H19/IGF2 and the hypermethylated CpG sites within the H19 differentially methylated region (DMR) was statistically significant. Furthermore, we performed transcriptomic analysis of the hepatocytes exposed to toxic metal combinations indicating enrichment of pro-inflammatory and anti-proliferative pathways compared to the unexposed cells. Our results suggest that hazardous metal mixtures may trigger epigenetic aberrations at the H19/IGF2 locus. We propose that altered CpG methylation in the H19 DMR could be a candidate biomarker for hepatic epigenotoxicity, in part, due to environmental exposure.
2024-10-27 | GSE280025 | GEO
Project description:Epigenetic Dysregulation of H19/IGF2 in Hepatic Cells Exposed to Toxic Metal Mixtures In Vitro [Bisulfite-seq]
| PRJNA1175979 | ENA
Project description:Changes in microRNA expression in Igf2-p and H19-m mouse embryos (E9.5) were determined in order to assess whether perturbation of miR-483* and miR-675 in Igf2-p and H19-m mutants was likely to have contributed to a modification of tumour phenotype. The Igf2 gene contains miR-483* but the targeted deletion of Igf2-p in these mice spares the region encoding this microRNA. The H19 gene contains miR-675 and its expression was mono-allelelic in heterozygous H19-m mice as evidenced by a significant reduction in miR-675 in these mice relative to WT.
2011-12-01 | E-MTAB-873 | biostudies-arrayexpress
Project description:Imprinted genes occur in discrete clusters that are coordinately regulated by shared DNA elements. H19 and Igf2 are linked imprinted genes that play critical roles in development. Loss of imprinting at the IGF2/H19 locus is associated with Beckwith Wiedemann Syndrome (BWS). Here we use comprehensive genetic and genomic analyses to follow muscle development in a mouse model of BWS to dissect the separate and shared roles for Igf2 and H19 in the disease phenotype. We show that LOI results in defects in muscle differentiation and hypertrophy and we identify primary downstream targets of Igf2 (MAPK signaling) and of H19 (AKT/mTOR signaling). Moreover, we demonstrate instances where H19 and Igf2 misexpression work separately, cooperatively, and also antagonistically to establish the disease phenotype. This study underscores the fact that LOI phenotypes are multigenic and complex interactions contribute to disease outcomes.
2017-09-25 | GSE89136 | GEO
Project description:Abstract: Dysregulation of the imprinted H19/IGF2 locus can lead to Silver-Russell Syndrome (SRS) in humans. However, the mechanism of how abnormal H19/IGF2 expression contributes to various SRS phenotypes remains unclear, largely due to incomplete understanding of the developmental functions of these two genes. We previously generated a mouse model with humanized H19/IGF2 ICR (hIC1) on the paternal allele that exhibited H19/Igf2 dysregulation together with SRS-like growth restriction and perinatal lethality. Here we dissect the role of H19 and Igf2 in cardiac and placental development utilizing multiple mouse models with varying levels of H19 and Igf2. We report severe cardiac defects such as ventricular septal defects (VSDs) and thinned myocardium, placental anomalies including thrombosis and vascular malformations, together with growth restriction in mouse embryos that correlated with the extent of H19/Igf2 dysregulation. Transcriptomic analysis using cardiac endothelial cells of these mouse models shows that H19/Igf2 dysregulation disrupts pathways related to extracellular matrix (ECM) and proliferation of endothelial cells. Our work links the heart and placenta through regulation by H19 and Igf2, demonstrating that accurate dosage of both H19 and Igf2 is critical for normal embryonic development, especially related to the cardiac-placental axis. Methods: E12.5 hearts were lysed with Collagenase, Dispase II, and DNase I. Cardiac endothelial cells were collected using MACS CD31 microbeads and RNA was isolated using RNeasy Micro kit. After confirming RNA integrity using Bioanalyzer, mRNA library was generated from 25ng RNA using NEBNext Poly(A) mRNA Magnetic Isolation Module and Ultra II RNA Library Prep Kit. Library quality was assessed by Bioanalyzer and TapeStation. Sequencing was performed on NovaSeq 6000. Quality of raw fastq reads was assessed using FastQC version 0.11.5. Reads were aligned to the GRCm38/mm10 reference using STAR version 2.4.0i with default parameters and maximum fragment size of 2000 bp. Properly paired primary alignments were retained for downstream analysis using Samtools version 1.9. Count matrices were generated using FeatureCounts version 1.6.2 against RefSeq gene annotation and read into DESeq2 to perform normalization and statistical analysis.
2022-11-25 | GSE199377 | GEO
Project description:Igf2 and H19 are linked, reciprocally imprinted genes that play critical roles in mammalian development. Igf2 encodes a peptide hormone, Insulin-like Growth Factor 2, that binds to the InsR and Igf1R receptor kinases to regulate cell growth and metabolism through well-established pathways. H19 encodes a 2.3 kb lncRNA whose biochemical actions are only now being identified. Here we use a mouse model to investigate cardiomyopathies associated with maternal loss of imprinting at the locus. Increased circulating levels of IGF2 during fetal development result in activation of pAKT/mTOR signaling in cardiomyocytes to cause cellular hypertrophy and hyperplasia in neonatal hearts. This neonatal hypertrophy is unaffected by H19 RNA levels. However, loss of H19 does cause fibrosis and progressive cardiac pathology in adult mice. In hearts, H19 expression is concentrated in endothelial cells associated with blood vessels and capillaries and loss of H19 results in high incidence of trans differentiation of these cells to smooth muscle. H19 encoded miRNAs 675-3p and -5p are not sufficient to promote normal development. Thus these experiments define a novel role for the H19 lncRNA in regulating cell fate.
2020-03-01 | GSE111418 | GEO
Project description:The insulator model explains the workings of the H19 and Igf2 domain in the soma, where insulation of the Igf2 promoter from its enhancers occurs by CTCF in the maternally inherited unmethylated chromosome but not the paternally inherited methylated allele. The molecular mechanism that targets paternal methylation imprint establishment to the imprinting control region (ICR) in the male germline is unknown. We tested the function of a prospermatogonia-specific broad low-level transcription in this process using mouse genetics. Paternal imprint establishment was abnormal when transcription was stopped at the entry point to the ICR. The germline epimutation persisted into the paternal allele of the soma, resulting in reduced Igf2 in fetal organs, and reduced fetal growth, consistent with the insulator model and IGF2’s role as fetal growth factor. In summary, broad low-level transcription through the ICR initiates paternal imprint establishment at the H19/Igf2 ICR in the male germ line, with implications for Silver-Russell syndrome. The superseries contains RNAseq and ChIPseq data from 15.5 dpc fetal male germ cells that carry the RNA terminator cassette and also from control wild type mice.
2023-08-02 | GSE236416 | GEO
Project description:Silver-Russell syndrome(SRS, OMIM 180860) is an imprinting disordermanifesting in fetal and postnatal growth retardation. Loss of methylation (LOM) is detected in the imprinting control region 1 (ICR1) that controls the H19/IGF2 domain, in about 65% of SRS cases. The cause of this epigenetic deficiency is unknown. It may affect the process of imprint establishment --de novo methylation of ICR1 in the male germ line. In the paralogous mouse locus this process involves DNA methyltransferase DNMT3A and H3K36me2 histone methyltransferase NSD1, but the mechanism that targets these enzymes to this ICR is unknown. Based on our genome-wide deep-sequencing data of transcription and DNA methylation, we hypothesized that low-level transcription is required in prospermatogonia for targeting H3K36me2 and de novo methylation to ICR. We truncated this transcript at the entry point to ICR by gene-targeting. In response, the establishment of DNA methylation imprint was incomplete. The sporadic LOM persisted from the male germ line into the paternal allele of the soma, resulting in reduced Igf2, and increased, biallelic H19 RNA in the fetal organs, consistent with the insulator model. Fetus weight was also variably reduced upon paternal transmission of this mutation, consistent with the role of IGF2 as a fetal growth factor. We identify low-level transcription-through as the mechanism that initiates paternal imprint establishment at the H19/Igf2 ICR in the male germ line. The findings predict that RNA-dependent imprint establishment may be affected in human fetuses resulting in sporadic hypomethylation of the ICR1 in SRS.
2023-08-02 | GSE202875 | GEO
Project description:The recent development of a custom cDNA microarray platform for one of thé standard organisms in aquatic toxicology, Daphnia magna, opened up new ways to mechanistic insights of toxicological responses. In this study, gene expression and (sub)organismal responses (Cellular Energy Allocation, growth) were assayed after short-term waterborne metal exposure. Microarray analysis of Ni-exposed daphnids revealed several affected functional gene classes, of which the largest ones were involved in different metabolic processes (mainly protein and chitin related processes), cuticula turnover, transport and signal transduction. Furthermore, genes involved in oxygen transport and heme metabolism (hemoglobin, δ-aminolevilunate synthase) were down-regulated. Applying a Partial Least Squares regression on nickel fingerprints and biochemical (sub)organismal parameters revealed a set of co-varying genes (hemoglobin, RNA terminal phosphate cyclase, a ribosomal protein and an “unknown” gene fragment). An inverse relationship was seen between the mRNA expression levels of different cuticula proteins and available energy reserves. In addition to the nickel exposure, daphnids were exposed to binary mixtures of nickel and cadmium or nickel and lead. Using multivariate analysis techniques, the mixture gene expression fingerprints (Ni2++Cd2+, Ni2++Pb2+) were compared to those of the single metal treatments (Ni2+, Cd2+, Pb2+). It was hypothesized that the molecular fingerprints of the mixtures would be additive combinations of the gene expression profiles of the individual compounds present in the mixture. However, our results clearly showed additionally affected pathways after mixture treatment (e.g. additional affected genes involved in carbohydrate catabolic processes and proteolysis), indicating interactive molecular responses which are not merely the additive sum of the individual metals. These findings, although indicative of the complex nature of mixture toxicity evaluation, underline the potential of a toxicogenomics approach in gaining more mechanistic information on the effects of single compounds and mixtures.
2009-02-27 | GSE13866 | GEO