Transcriptome of S. cerevisiae in shifts between glucose and maltose media with different re-growth conditions Overall design: Cells are pregrown in maltose, then grown for different durations in glucose and then washed back to maltose
A new protocol for single-cell RNA-seq reveals stochastic gene expression during lag phase in budding yeast.
Subject
View SamplesThe heart adapts to increased workload through hypertrophic growth of cardiomyocytes. Although beneficial when induced physiologically by exercise, pathological cues including hypertension cause reexpression of fetal genes and dysfunctional hypertrophy, with lasting consequences for cardiac health. We hypothesised that these differences are driven by changes in chromatin-encoded cellular memory. We generated genome-wide maps of transcription and of two stable epigenetic marks, H3K9me2 and H3K27me3, specifically in hypertrophied cardiomyocytes, by selectively flow-sorting their nuclei. This demonstrated a pervasive loss of euchromatic H3K9me2 specifically upon pathological but not physiological hypertrophy, derepressing genes associated with pathological hypertrophy. Levels of the H3K9 methyltransferases, G9a and GLP, were correspondingly reduced. Importantly, pharmacological or genetic inactivation of these enzymes was sufficient to induce pathological hypertrophy and the dedifferentiation associated with it. These findings suggest novel therapeutic opportunities by defining an epigenetic state of cardiomyocytes, acquired during maturation, which is required for maintaining cardiac health. Overall design: Examination of 2 different histone modifications and RNA expression in cardiomyocyte nuclei flow-sorted from hypertrophic rat hearts
The H3K9 dimethyltransferases EHMT1/2 protect against pathological cardiac hypertrophy.
No sample metadata fields
View SamplesHeterogeneity of meningeal cortical cells was deciphered on the molecular level using single cell RNA seq Overall design: RNA sequencing of 179 meningeal cortical cells isolated from naive wild-type mice
Neurogenic Radial Glia-like Cells in Meninges Migrate and Differentiate into Functionally Integrated Neurons in the Neonatal Cortex.
Sex, Specimen part, Subject
View SamplesHypermethylation of tumor suppressor gene (TSG) promoters confers growth advantages to cancer cells, but how these changes arise is poorly understood. Here, we report that tumor hypoxia reduces the activity of oxygen-dependent TET enzymes, which catalyze DNA de-methylation through 5-methylcytosine oxidation. This occurs independently of hypoxia-associated alterations in TET gene expression, basal metabolism, HIF activity or nuclear reactive oxygen species, but directly depends on oxygen shortage. Hypoxia-induced loss of TET activity increases hypermethylation at gene promoters in vitro, while also in patients, gene promoters are markedly more methylated in hypoxic than normoxic tumors. Affected genes are frequently involved in DNA repair, cell cycle regulation, angiogenesis and metastasis, indicating cellular selection of hypermethylation events. Overall, up to 50% of the tumor-associated hypermethylation is ascribable to hypoxia across various cancer types. Accordingly, spontaneous murine breast tumors become hypermethylated when rendered hypoxic through vessel pruning, whereas vessel normalisation rescues this effect. Tumor hypoxia thus acts as a novel regulator underlying DNA methylation. Overall design: RNAseq of MCF7 cells grown under hypoxic and normoxic conditions. Submission includes data on 5 independent RNAseq experiments, each containing biological replicates grown under hypoxic conditions (0.5% oxygen), and under normoxic conditions.
Tumour hypoxia causes DNA hypermethylation by reducing TET activity.
Subject
View SamplesThe organization of mammalian DNA replication is poorly understood. We have produced genome-wide high-resolution dynamic maps of the timing of replication in human erythroid, mesenchymal and embryonic stem cells using TimEX, a method that relies on gaussian convolution of massive, highly redundant determinations of DNA copy number variations during S phase obtained using either high-density oligonucleotide tiling arrays or massively-parallel sequencing to produce replication timing profiles. We show that in untransformed human cells, timing of replication is highly regulated and highly synchronous, and that many genomic segments are replicated in temporal transition regions devoid of initiation where replication forks progress unidirectionally from origins that can be hundreds of kilobases away. Absence of initiation in one transition region is shown at the molecular level by SMARD analysis. Comparison of ES and erythroid cells replication patterns revealed that these cells replicate about 20% of their genome in different quarter of S phase and that ES cells replicate a larger proportion of their genome in early S phase than erythroid cells. Importantly, we detected a strong inverse relationship between timing of replication and distance to the closest expressed gene. This relationship can be used to predict tissue specific timing of replication profiles from expression data and genomic annotations. We also provide evidence that early origins of replication are preferentially located near highly expressed genes, that mid firing origins are located near moderately expressed genes and that late firing origins are located far from genes.
Predictable dynamic program of timing of DNA replication in human cells.
Specimen part
View SamplesThe comparative advantages of RNA-Seq and microarrays in transcriptome profiling were evaluated in the context of a comprehensive study design. Gene expression data from Illumina RNA-Seq and Affymetrix microarrays were obtained from livers of rats exposed to 27 agents that comprised of seven modes of action (MOAs); they were split into training and test sets and verified with real time PCR. Overall design: 105 samples were selected from the DrugMatirx tissue/RNA bank that is now owned by the National Toxicology Program (NTP). The samples were split into 2 sets, training and test, to allow for the evaluation of classifiers derived from the data. There were 63 samples in the training set and 42 in the test set. Of the 63 samples in the training set 45 were derived from rats treated with test agent and 18 were control samples (3 sets of 6). 39 of the test set samples were derived from test agent treated animals and 6 were from vehicle and route matched controls. Five MOAs were represented in the training set and 4 MOAs were in the test set. Two of the MOAs were duplicated from the test set and two were without representation in the training set. For each test agent there were three rats treated, in accordance with the common practice in the field of toxicology. For each MOA there were three representative test agents to ensure adequate power for detecting the MOA signatures. 6 samples from the training set had duplicate libraries sequenced and duplicate sequencing runs for the first library. DrugMatrix, National Toxicology program (NTP) Sequencing was carried out in Dr. Charles Wang's Functional Genomics Core at City of Hope Comprehensive Cancer Center, Duarte, CA
Transcriptomic profiling of rat liver samples in a comprehensive study design by RNA-Seq.
No sample metadata fields
View SamplesHMG-CoA reductase inhibitors, statins, have beneficial vascular effects beyond their cholesterol-lowering action. These pleiotropic effects include an anti-inflammatory effect on macrophages. Since macrophages play a central role in atherogenesis, we further characterized the effects on peripheral blood monocyte-macrophages (HPBM). Using Affymetrix gene chip analysis of simvastatin-treated HPBM, we found that simvastatin treatment lead to the downregulation of the expression of many proinflammatory genes including several chemokines (e.g. MCP-1, MIP-1 alpha and , RANTES, several other CC and CXC chemokines, IL-2 receptor-, and leukemia inhibitory factor), members of the tumor necrosis factor family (e.g. lymphotoxin beta and TRAIL), VCAM-1, ICAM-3, and tissue factor (TF). Simvastatin also modulated the expression of several transcription factors essential for the inflammatory response: simvastatin downregulated the expression of NF-kappaB relA/p65 subunit and ets-1 transcription factor, and upregulated the expression of a novel atheroprotective transcription factor, Kruppel-like factor 2 (KLF-2). The effects of simvastatin on KLF-2 and its target genes were dependent on protein prenylation, since inhibitors of protein prenylation had a similar inhibitory effect in THP-1 derived macrophages. Additionally, by lentiviral overexpression KLF-2 we showed that the effect of simvastatin on MCP-1 and TF were dependent on KLF-2. We concluded that simvastatin had a strong anti-inflammatory effect on macrophages, which includes upregulation of the atheroprotective transcription factor KLF-2. These findings further explain the beneficial pleiotropic effects of statins on cardiovascular diseases.
Simvastatin has an anti-inflammatory effect on macrophages via upregulation of an atheroprotective transcription factor, Kruppel-like factor 2.
No sample metadata fields
View SamplesSignal transduction processes mediated by phosphatidyl inositol phosphates affect a broad range of cellular processes such as cell cycle progression, migration and cell survival. The protein kinase AKT is one of the major effectors in this signaling network. Chronic AKT activation contributes to oncogenic transformation and tumor development. Therefore, new small drugs were designed to block AKT activity for cancer treatment.
Characterization of AKT independent effects of the synthetic AKT inhibitors SH-5 and SH-6 using an integrated approach combining transcriptomic profiling and signaling pathway perturbations.
Specimen part, Cell line
View SamplesThe objective of the present study was to identify genes that are involved in increasing the ovulation number in mouse line FL1 that had been selected for high fertility performance.
Expression profiling of a high-fertility mouse line by microarray analysis and qPCR.
No sample metadata fields
View SamplesmRNA expression levels in synovial fibroblasts in 6 rheumatoid arthritis patients versus 6 osteoarthritis patients.
Constitutive upregulation of the transforming growth factor-beta pathway in rheumatoid arthritis synovial fibroblasts.
No sample metadata fields
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