Determining mechanism-based biomarkers that distinguish adaptive and adverse cellular processes is critical to understanding the health effects of environmental exposures. Shifting from in vivo, low-throughput toxicity studies to high-throughput screening (HTS) paradigms and risk assessment based on in vitro and in silico testing requires utilizing toxicity pathway information to distinguish adverse outcomes from recoverable adaptive events. Little work has focused on oxidative stresses in human airway for the purposes of predicting adverse responses. We hypothesize that early gene expression-mediated molecular changes could be used to delineate adaptive and adverse responses to environmentally-based perturbations. Here, we examined cellular responses of the tracheobronchial airway to zinc (Zn) exposure, a model oxidant. Airway derived BEAS-2B cells exposed to 210 M Zn2+ elicited concentration- and time-dependent cytotoxicity. Normal, adaptive, and cytotoxic Zn2+ exposure conditions were determined with traditional apical endpoints, and differences in global gene expression around the tipping point of the responses were used to delineate underlying molecular mechanisms. Bioinformatic analyses of differentially expressed genes indicate early enrichment of stress signaling pathways, including those mediated by the transcription factors p53 and NRF2. After 4 h, 154 genes were differentially expressed (p <0.01) between the adaptive and cytotoxic Zn2+ concentrations. Nearly 40% of the biomarker genes were related to the p53 signaling pathway with 30 genes identified as likely direct targets using a database of p53 ChIP-seq studies. Despite similar p53 activation profiles, these data revealed widespread dampening of p53 and NRF2-related genes as early as 4 h after exposure at higher, unrecoverable Zn2+ exposures. Thus, in our model early increased activation of stress response pathways indicated a recoverable adaptive event. Overall, this study highlights the importance of characterizing molecular mechanisms around the tipping point of adverse responses to better inform HTS paradigms.
Developing a Gene Biomarker at the Tipping Point of Adaptive and Adverse Responses in Human Bronchial Epithelial Cells.
Cell line, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative epigenome-wide analysis demonstrates that DNA methylation may mediate genetic risk in inflammatory bowel disease.
Sex, Age, Specimen part, Subject
View SamplesEpigenetic alterations may provide important insights into gene-environment interaction in inflammatory bowel disease (IBD). Here we observe epigenome-wide DNA methylation differences in 240 newly-diagnosed IBD cases and 190 controls. These include 439 differentially methylated positions (DMPs) and 5 differentially methylated regions (DMRs), which we study in detail using whole genome bisulphite sequencing. We replicate the top DMP (RPS6KA2) and DMRs (VMP1, ITGB2, TXK) in an independent cohort.
Integrative epigenome-wide analysis demonstrates that DNA methylation may mediate genetic risk in inflammatory bowel disease.
Sex, Age, Specimen part
View SamplesWe present primary results from the Sequencing Quality Control (SEQC) project, coordinated by the United States Food and Drug Administration. Examining Illumina HiSeq, Life Technologies SOLiD and Roche 454 platforms at multiple laboratory sites using reference RNA samples with built-in controls, we assess RNA sequencing (RNA-seq) performance for sequence discovery and differential expression profiling and compare it to microarray and quantitative PCR (qPCR) data using complementary metrics. At all sequencing depths, we discover unannotated exon-exon junctions, with >80% validated by qPCR. We find that measurements of relative expression are accurate and reproducible across sites and platforms if specific filters are used. In contrast, RNA-seq and microarrays do not provide accurate absolute measurements, and gene-specific biases are observed, for these and qPCR. Measurement performance depends on the platform and data analysis pipeline, and variation is large for transcriptlevel profiling. The complete SEQC data sets, comprising >100 billion reads (10Tb), provide unique resources for evaluating RNA-seq analyses for clinical and regulatory settings.
A comprehensive assessment of RNA-seq accuracy, reproducibility and information content by the Sequencing Quality Control Consortium.
No sample metadata fields
View SamplesHuntington's disease (HD) is an inherited neurodegenerative disorder caused by an expanded stretch of CAG trinucleotide repeats that results in neuronal dysfunction and death. We made induced pluripotent stem cell (iPSC) lines from HD patients and controls. Though no obvious effects of the CAG expansion on reprogramming or subsequent neural stem cell (NSC) production were seen, HD-NSCs showed CAG expansion-associated gene expression patterns and, upon differentiation, changes in electrophysiology, metabolism, cell adhesion, and ultimately an increased risk of cell death for both medium and longer CAG repeat expansions, with some deficits greater in cells from longer repeat HD NSCs. The HD180 lines were more vulnerable than control lines to cellular stressors and BDNF withdrawal using a range of assays across consortium laboratories. This HD iPSC collection represents a unique and well-characterized resource to elucidate disease mechanisms in HD and provides a novel human stem cell platform for screening new candidate therapeutics.
Induced pluripotent stem cells from patients with Huntington's disease show CAG-repeat-expansion-associated phenotypes.
Specimen part, Disease, Disease stage
View SamplesIn order to study parent-of-origin effects on gene expression, we performed RNAseq analysis (100bp single end reads) of 165 children who formed part of mother/father/child trios where genotype data was available from the HapMap and/or 1000 Genomes Projects. Based on phased genotypes at heterozygous SNP positions, we generated allelic counts for expression of the maternal and paternal alleles in each individual. This analysis reveals significant bias in the expression of the parental alleles for dozens of genes, including both previously known and novel imprinted transcripts. Overall design: This submission contains RNAseq data from 165 children from mother/father/child trios studied as part of the 1000 genomes and/or HapMap projects. We provide raw fastq format reads, and processed read counts per gene. Allelic count information can be provided by directly contacting the authors.
RNA-Seq in 296 phased trios provides a high-resolution map of genomic imprinting.
Specimen part, Cell line, Subject
View SamplesWe performed whole-genome gene expression profiling in Pik3cg-/- mice and subsequent gene ontology clustering of differentially expressed genes compared to wild type mice, in order to investigate the role of Pik3cg in platelet membrane biogenesis and blood coagulation.
Maps of open chromatin guide the functional follow-up of genome-wide association signals: application to hematological traits.
Sex, Specimen part
View SamplesThese samples are part of the ENCODE consortiums proposed time-limited Pilot Study for confirmation of the utility of RNA abundance measurements as a standard reference phenotyping tool.
A user's guide to the encyclopedia of DNA elements (ENCODE).
Cell line
View SamplesMicroarray analysis was performed to determine the transcriptional profiles of NKT, CD1d-aGC+ Va24-, and CD4 T cells.
A naive-like population of human CD1d-restricted T cells expressing intermediate levels of promyelocytic leukemia zinc finger.
Specimen part
View Samples4 chorionic villus sampling specimens in pregnancies destined for preeclampsia and 8 matched controls were analyzed
Altered global gene expression in first trimester placentas of women destined to develop preeclampsia.
No sample metadata fields
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