Chronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. Additionally, these differential methylation changes correlated positively with changes in gene expression and alternative splicing. Interestingly, most of these differentially methylated genes function in cell adhesion and communication pathways. To gain insight into how genomic DNA methylation patterns are regulated iAs-mediated carcinogenesis, we show that iAs probably targets CTCF binding at the promoter of DNA methyltransferases, regulating their expression. These findings reveal how transcription factor binding regulates DNA methyltransferase to reprogram the methylome in response to an environmental toxin.
Genome-wide DNA methylation reprogramming in response to inorganic arsenic links inhibition of CTCF binding, DNMT expression and cellular transformation.
Specimen part, Cell line, Treatment
View SamplesArsenic (As) exposure is a significant worldwide environmental health concern. Low dose, chronic arsenic exposure has been associated with higher risk of skin, lung, and bladder cancer, as well as cardiovascular disease and diabetes. While arsenic-induced biological changes play a role in disease pathology, little is known about the dynamic cellular changes due to arsenic exposure and withdrawal. In these studies, we seek to understand the molecular mechanisms behind the biological changes induced by chronic low doses of arsenic exposure. We used a comprehensive approach involving chromatin structural studies and mRNA microarray analyses to determine how chromatin structure and gene expression patterns change in response to chronic low dose arsenic exposure and its subsequent withdrawal. Our results show that cells exposed to low doses of sodium arsenite have distinct temporal and coordinated chromatin, gene expression and miRNA changes that are consistent with differentiation and activation of multiple biochemical pathways. Most of these temporal patterns in gene expression are reversed when arsenic was withdrawn. However, some of the gene expression patterns remained altered, plausibly as a result of an adaptive response by these cells. Additionally, these gene expression patterns correlated with changes in chromatin structure, further solidifying the role of chromatin structure in gene regulatory changes due to arsenite exposure. Lastly, we show that arsenite exposure influences gene regulation both at the transcription initiation as well as at the splicing level. Thus our results suggest that general patterns of alternative splicing, as well as expression of particular gene regulators, can be indicative of arsenite-induced cell transformation.
Inorganic Arsenic-induced cellular transformation is coupled with genome wide changes in chromatin structure, transcriptome and splicing patterns.
Cell line
View SamplesTo identify MED1 target genes involved in prostate tumorigenesis.
ERK and AKT signaling drive MED1 overexpression in prostate cancer in association with elevated proliferation and tumorigenicity.
Specimen part, Cell line
View SamplesThe approval of genetically modified (GM) crops is preceded by years of intensive research to demonstrate safety to humans and environment. We recently showed that in vitro culture stress is the major factor influencing proteomic differences of GM vs. non-GM plants. This made us question the number of generations needed to erase such memory. We also wondered about the relevance of alterations promoted by transgenesis as compared to environment-induced ones.
Environmental stress is the major cause of transcriptomic and proteomic changes in GM and non-GM plants.
Specimen part
View SamplesMolecular pathways activated in MALT lymphoma are not well defined.
Gene expression profiling of pulmonary mucosa-associated lymphoid tissue lymphoma identifies new biologic insights with potential diagnostic and therapeutic applications.
Sex
View SamplesIdentification of TBF1-dependent and SA, elf18-responsive genes in Arabidopsis
The HSF-like transcription factor TBF1 is a major molecular switch for plant growth-to-defense transition.
Specimen part, Treatment
View SamplesC. elegans exhibit an age-dependent mechanical stress response to blunt force injury.
Trauma-induced regulation of VHP-1 modulates the cellular response to mechanical stress.
Specimen part, Treatment
View SamplesWe report here that REV-ERBa influences nuclear localization of the glucocorticoid receptor and vice versa. As a consequence these two nuclear receptors influence each others transcriptome. REV-ERBa (Nr1d1) is a nuclear receptor that is part of the circadian clock mechanism and regulates metabolism and inflammatory processes. The glucocorticoid receptor (GR, Nr3c1) influences similar processes, but is not part of the circadian clock mechanism although glucocorticoid signaling affects resetting of the circadian clock in peripheral tissues. Because of their similar impact on physiological processes we studied the interplay between these two nuclear receptors. We found that REV-ERBa competes with GR for binding to HSP90, a chaperone responsible for the activation of substrate proteins to ensure survival of a cell. This competition affected stability and nuclear localization of GR, thereby affecting GR target gene expression such as I?B and alcohol dehydrogenase 1 (Adh1). Our findings highlight an important interplay between two nuclear receptors that influence each others transcritpional potential indicating that the transcriptional landscape is strongly dependent on dynamic processes at the protein level. Overall design: In this dataset, we isolated livers at Zeitgebertime (ZT) 8 and ZT20 of wild type and Rev-erb alpha knock-out animals. Liver samples were immediately flash frozen in liquid N2 and stored at -80?°C. RNA was extracted using NucleoSpin RNA (Machery-Nagel, Düren, Germany) according to the instructions of the manufacturer. Quality of the RNA samples was analysed with a spectrophotometer, agarose gel electrophoresis and reverse transcription-PCR. Library construction starting from the poly(A)-tail and multiplexing was performed according to the instructions of the manufacturer (Illumina). The samples were organized as follows: Three replicas (1-WT, 2-WT, 3-WT) correspond to genotype WT at ZT8. Three replicas (4-Rev, 5-Rev, 6-Rev) correspond to genotype Rev-/- at ZT8. Three replicas (7-WT, 8-WT, 9-WT) correspond to genotype WT at ZT20. Three replicas (10-Rev, 11-Rev, 12-Rev) correspond to genotypeRev-/- at ZT20. For the experiment, complementary DNA (cDNA) libraries were barcoded using Illumina primers and loaded onto one lane of an IlluminaHS2000 machine. cDNA libraries were diluted and loaded onto each lane. The samples were sequenced for a maximum sequencing length of 75?bp. Sequences were aligned to the mouse genome (UCSC version mm10 database). Numbers of the sequences obtained for each library can be found in Supplementary Table 3. Sequences (fastq format) were mapped with Tophat (Trapnell, C. 2009), uniquely mapped sequences from the output files (bam format) were then used for further analysis, percentage of the mapping obtained for each sample can be found in Supplementary Table 3. For all files the reads were counted with HTSeq-count using the following criteria: samtools view sample.bam | htseq-count -m union -a 10 -s no -i gene_name Mus_Musculus.gtf > sample_counts.txt Tests for differential expression between the samples were performed in R software (R Core Team, 2014 http://www.R-project.org/) using the DESeq2 package (Version 1.6.3) (Love, M. 2014). A threshold on the corrected P value was used to call for differentially expressed genes (P.adjust<0.05).
REV-ERBα influences the stability and nuclear localization of the glucocorticoid receptor.
Age, Specimen part, Subject, Time
View SamplesBACKGROUND: Combination antiretroviral therapy (cART) is able to control HIV-1 viral replication, however long-lived latent infection in resting memory CD4+ T-cells persist. The mechanisms for establishment and maintenance of latent infection in resting memory CD4+ T-cells remain unclear. Previously we have shown that HIV-1 infection of resting CD4+ T-cells co-cultured with CD11c+ myeloid dendritic cells (mDC) produced a population of non-proliferating T-cells with latent infection. Here we asked whether different antigen presenting cells (APC), including subpopulations of DC and monocytes, were able to induce post-integration latent infection in resting CD4+ T-cells, and examined potential cell interactions that may be involved using RNA-seq. RESULTS: mDC (CD1c+), SLAN+ DC and CD14+ monocytes were most efficient in stimulating proliferation of CD4+ T-cells during syngeneic culture and in generating post-integration latent infection in non-proliferating CD4+ T-cells following HIV-1 infection of APC-T-cell co-cultures. In comparison, plasmacytoid DC (pDC) and B-cells did not induce latent infection in APC-T-cell co-cultures. We compared the RNA expression profiles of APC subpopulations that could and could not induce latency in non-proliferating CD4+ T-cells. Gene expression analysis, comparing the mDC, SLAN+ DC and CD14+ monocyte subpopulations to pDC identified 53 upregulated genes that encode proteins expressed on the plasma membrane that could signal to CD4+ T-cells via cell-cell interactions (32 genes), immune checkpoints (IC) (5 genes), T-cell activation (9 genes), regulation of apoptosis (5 genes), antigen presentation (1 gene) and through unknown ligands (1 gene). CONCLUSIONS: APC subpopulations from the myeloid lineage, specifically mDC subpopulations and CD14+ monocytes, were able to efficiently induce post-integration HIV-1 latency in non-proliferating CD4+ T-cells in vitro. Inhibition of key pathways involved in mDC-T-cell interactions and HIV-1 latency may provide novel targets to eliminate HIV latency. Overall design: mRNA profiles of sorted, pure antigen presenting cells including, CD1c+ myleoid dendirtic cells (mDC), SLAN+ mDC, CD14+ monocytes and plasmacytoid DC (pDC), were generated using next generation sequencing in triplicate, using Illumina Illumina Hiseq 2000.
The role of antigen presenting cells in the induction of HIV-1 latency in resting CD4(+) T-cells.
No sample metadata fields
View SamplesRelatively little is known about how the identity of early neuronal stem cells changes before and after neural tube closure (neurulation). We performed RNA sequencing on microdissected forebrain precursors and revealed sharp reductions in expresion of protein biosynthetic machinery after neurulation. These reductions were paralleled by down-regulation of Myc, which regulated forebrain precursor ribosome ribosome biogenesis. To study consequences of Myc dysregulation, we overexpressed Myc in Nestin+ neural progenitors, sorted these progenitors for RNA sequencing, and identified 135 genes that are differentially expressed between Myc-overexpressed embryos and their wildtype littermates. Overall design: The first RNA sequencing dataset contains micordissected neuroepithelium from E8.5 and E10.5 mouse embryos, two biological replicates for each age. The second RNA sequencing dataset contain FACS isolated Pax6+ neural progenitors form the cortex of E13.5 MYC-overexpressed embryos and their wildtype littermates, three biological replicates for each genotype.
Downregulation of ribosome biogenesis during early forebrain development.
Specimen part, Cell line, Subject
View Samples