Unraveling the mechanisms underlying early neural differentiation of ESCs is crucial to the cell-based therapies of neurodegenerate diseases. Neural fate acquisition is proposed to be controlled by a default mechanism, for which the molecular regulation is not well understood. In this study, we investigated the functional roles of Mediator Med23 in pluripotency and lineage commitment of embryonic stem cells (ESCs). Unexpectedly we found that, despite the largely unchanged pluripotency and self-renewal of ESCs, Med23-depletion rendered the cells prone to neural differentiation in different differentiation assays. Knockdown of other Mediator subunit, Med1 or Med15, did not alter the neural differentiation of ESCs; and Med15 knockdown selectively inhibited endoderm differentiation, suggesting the specificity of cell fate control by distinctive Mediator subunits. Gene profiling revealed that Med23-depletion attenuated the BMP signaling in ESCs. Mechanistically, MED23 modulated Bmp4 expression by controlling the activity of ETS1 that is involved in the Bmp4 promoter-enhancer communication. Interestingly, Med23 knockdown in zebrafish embryos also enhanced the neural development at early embryogenesis, which could be reversible by coinjection of bmp4 mRNA. Taken together, our study reveals an intrinsic, restrictive role of MED23 in early neural development, thus providing new molecular insights for neural fate determination.
Mediator Med23 deficiency enhances neural differentiation of murine embryonic stem cells through modulating BMP signaling.
No sample metadata fields
View SamplesDNA methylation on N6-adenine (6mA) has recently been found as a potentially new epigenetic mark in several unicellular and multicellular eukaryotes. However, its distribution patterns and potential functions in land plants, which are primary producers for most ecosystems, remain completely unknown. Here we report global profiling of 6mA sites at single-nucleotide resolution in the genome of Arabidopsis thaliana using single-molecule real-time sequencing. 6mA sites are widely distributed across the Arabidopsis genome and enriched over the pericentromeric heterochromatin regions. Nearly 30% of 6mA sites are present in gene bodies. Further analysis of 6mA methylome and RNA-sequencing data demonstrates that 6mA frequency positively correlates with the gene expression level in Arabidopsis. Consistently, histone variants associated with actively expressed genes interact with 6mA DNA. Our results uncover 6mA as a DNA mark associated with actively expressed genes in Arabidopsis, suggesting that 6mA serves as a novel epigenetic mark in land plants. Overall design: RNA-seq in 3-week-old Arabidopsis thaliana (Col-0) wild-type with three replicates.
DNA N<sup>6</sup>-Adenine Methylation in Arabidopsis thaliana.
Subject
View SamplesIntroduction: Though heavy alcohol drinking has been well characterized as causing a variety of injuries, recent epidemiological evidence in humans suggests moderate consumption may provide beneficial effects. For example, there exists a J- or U-shaped relationship between the level of alcohol intake and cardiovascular disease risk. We investigated the underlying mechanisms of these positive consequences by identifying which genes are responsive to moderate alcohol intake in the liver, the primary site for alcohol metabolism. Methods: Twelve female, inbred, alcohol-preferring (iP10a) rats were split equally between chronic water exposure and voluntary chronic ethanol exposure. Hepatic cholesterol and triglyceride levels were analyzed both histologically and biochemically. Hepatic transcriptomes were paired-end sequenced on the Illumina HiScanSQ system. Reads were analyzed and mapped using CLCbio Genomics Workbench 4.9. We confirmed altered expression of a subset of genes using TaqMan-based qRT-PCR. To quantify DNA methylation, we first digested DNA with methylation sensitive restriction enzymes and then performed qPCR using TaqMan assays surrounding the digest sites. Calculating ?Ct between a mock digest and digest determines the percent methylation in that locus. Results: Voluntary alcohol consumption in iP10a rats modeled moderate consumption in humans. These levels did not result in intrahepatic fat accumulation. Sequencing produced ~1.2 Gb of sequence per sample, and 65% of reads mapped uniquely. Using a FDR corrected p value of 0.05 we found 250 altered transcripts. Ontology analysis of genes with a fold change =1.3 identified many cholesterol synthesis genes and cytoskeleton subunit genes, all of which were down-regulated. Of the 28 genes reanalyzed by qRT-PCR, altered expression was confirmed in 24 genes including the majority of the cholesterol synthesis and cytoskeleton subunit genes. Lastly, we profiled methylation throughout the promoter and gene body of four genes elicited in the RNA-Seq experiment. We found that alcohol caused demethylation at all loci; however this loss happened in a site-specific, tightly regulated manner. Conclusion: Voluntary consumption in the iP10a animals models moderate consumption in humans, does not produce intrahepatic fat accumulation, and causes down-regulation of a majority of cholesterol synthesis genes. Moderate alcohol also results in a tightly-regulated demethylation effect. Our results explain, at least in part, the J- or U-shaped relationship between level of alcohol intake and cardiovascular disease risk. Overall design: We sequenced 12 female iP10a rat hepatic transcriptomes providing 6 biological replicates for water control and 6 for ethanol treatment.
A snapshot of the hepatic transcriptome: ad libitum alcohol intake suppresses expression of cholesterol synthesis genes in alcohol-preferring (P) rats.
No sample metadata fields
View SamplesFbw7 plays a negative role in pancreatic cancer tumorigenesis and progression. To further clarify the function and mechanism that Fbw7 plays in pancreatic cancer,mRNA microarray assays were performed to identify the genes and signaling pathways that were changed upon Fbw7 overexpression.
FBW7 (F-box and WD Repeat Domain-Containing 7) Negatively Regulates Glucose Metabolism by Targeting the c-Myc/TXNIP (Thioredoxin-Binding Protein) Axis in Pancreatic Cancer.
Cell line, Treatment
View SamplesExosomes, endosome-derived membrane microvesicles, contain a specific set of RNA transcripts that are involved in cell-cell communication and hold a great potential as disease biomarkers. To systemically characterize exosomal RNA profiles, we performed RNA sequencing analysis using three human plasma samples and evaluated efficacies of small RNA library preparation protocols from 3 manufacturers. Overall design: We tested the six samples (A1 and A2, B1 and B2, C1 and C2) using two small RNA library preparation kits: NEBNext Multiplex Small RNA library Prep Set from New England Biolab (NEB) and NEXTflex Small RNA Sequencing Kit from Bioo Scientific (BS). We also tested Illumina’s TrueSeq Small RNA Sample Preparation Kit (ILMN) in sample A1 and A2. Together, we tested these plasma samples by sequencing 14 indexed libraries. This study allowed direct comparison of current small RNA library preparation protocols and identified the most suitable strategy for future exosomal RNA sequencing analysis.
Characterization of human plasma-derived exosomal RNAs by deep sequencing.
Specimen part
View SamplesDeciphering gene regulatory mechanisms through the analysis of high-throughput expression data is a challenging computational problem. Previous computational studies have used large expression datasets in order to resolve fine patterns of coexpression, producing clusters or modules of potentially coregulated genes. These methods typically examine promoter sequence information, such as DNA motifs or transcription factor occupancy data, in a separate step after clustering. We needed an alternative and more integrative approach to study the oxygen regulatory network in Saccharomyces cerevisiae using a small dataset of perturbation experiments. Mechanisms of oxygen sensing and regulation underlie many physiological and pathological processes, and only a handful of oxygen regulators have been identified in previous studies. We used a new machine learning algorithm called MEDUSA to uncover detailed information about the oxygen regulatory network using genome-wide expression changes in response to perturbations in the levels of oxygen, heme, Hap1, and Co2+. MEDUSA integrates mRNA expression, promoter sequence, and ChIP-chip occupancy data to learn a model that accurately predicts the differential expression of target genes in held-out data. We used a novel margin-based score to extract significant condition-specific regulators and assemble a global map of the oxygen sensing and regulatory network. This network includes both known oxygen and heme regulators, such as Hap1, Mga2, Hap4, and Upc2, as well as many new candidate regulators. MEDUSA also identified many DNA motifs that are consistent with previous experimentally identified transcription factor binding sites. Because MEDUSA's regulatory program associates regulators to target genes through their promoter sequences, we directly tested the predicted regulators for OLE1, a gene specifically induced under hypoxia, by experimental analysis of the activity of its promoter. In each case, deletion of the candidate regulator resulted in the predicted effect on promoter activity, confirming that several novel regulators identified by MEDUSA are indeed involved in oxygen regulation. MEDUSA can reveal important information from a small dataset and generate testable hypotheses for further experimental analysis.
A predictive model of the oxygen and heme regulatory network in yeast.
No sample metadata fields
View SamplesTranscriptomic comparison of FVB mouse strain lung Cells one week upon injecting mice intraperitoneally with either saline or Urethane. Mouse lung cell were also compared at the transcriptomic level with the mouse lung adenocarcinoma cell line FULA 1, which was established in our lab
IκB Kinase α Is Required for Development and Progression of <i>KRAS</i>-Mutant Lung Adenocarcinoma.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNA-188 regulates age-related switch between osteoblast and adipocyte differentiation.
Specimen part
View SamplesWe identified microRNA-188 differentially expressed in the BMSCs of aged and young mice and influenced on BMSCs differentiation with ageing.
MicroRNA-188 regulates age-related switch between osteoblast and adipocyte differentiation.
Specimen part
View SamplesWe identified microRNA-188 differentially expressed in the BMSCs of aged and young mice and influented on BMSCs differentiation with ageing.
MicroRNA-188 regulates age-related switch between osteoblast and adipocyte differentiation.
Specimen part
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