Transcription is a multi-stage process that coordinates several steps within the transcription cycle including chromatin reorganization, RNA polymerase II recruitment, initiation, promoter clearance and elongation. Recent advances have identified the super elongation complex (SEC), containing the eleven nineteen lysine rich leukemia protein (ELL), as a key regulator of transcriptional elongation. We show here that ELL plays a diverse and kinetically distinct role prior to its assembly into the SEC by stabilizing Pol II recruitment/initiation and entry into the pause site. Loss of ELL destabilizes the PIC complexes and results in disruption of early elongation and promoter proximal chromatin structure prior to recruitment of AFF4 and other SEC components. These changes result in significantly reduced transcriptional activation of rapidly induced genes. Thus, ELL plays an early and essential role during rapid high amplitude gene expression that is required for both Pol II pause site entry and release.
ELL facilitates RNA polymerase II pause site entry and release.
Specimen part, Cell line
View SamplesGene expression analysis identified 27 of these 744 p300 and pol II associated genes as significantly increased (p 0.05) within the first hour following mitogen stimulation
Dynamic bookmarking of primary response genes by p300 and RNA polymerase II complexes.
No sample metadata fields
View SamplesSeveral different mechanical signals have been proposed to control the extent and pattern of myocardial growth and remodeling, though this has largely been studied using in vitro model systems that are not representative of intact myocardium or in vivo models in which isolating the effects of individual candidate stimuli is exceedigly difficult. We used a unique tissue culture system that allows the simultaneous control of multiple mechanical inputs and other potentially confounding stimuli (e.g., hormonal).
Effects of stretch and shortening on gene expression in intact myocardium.
Sex, Age
View SamplesIn this study, we aim to identify candidate biomarkers which may be useful as surrogate indicators of toxicity for pre-clinical development of panPPAR-agonist drug candidates. Gene expression microarray, histopathology and clinical chemistry data were generated from liver, heart, kidney and skeletal muscles of three groups of mice administered with three different dosages of an experimental pan-peroxisome proliferator-activated receptor (pan-PPAR) agonist, PPM-201, for 14 days. The histopathology and clinical chemistry data were compared with the gene expression analysis and candidate biomarker genes were identified.
Simultaneous non-negative matrix factorization for multiple large scale gene expression datasets in toxicology.
Specimen part, Treatment
View SamplesHere we uncover antagonistic regulation of transcript levels in the germline of Caenorhabditis elegans hermaphrodites. The histone methyltransferase MES-4 marks genes expressed in the germline with methylated Lys36 on histone H3 (H3K36me) and promotes their transcription; MES-4 also represses genes normally expressed in somatic cells and genes on the X chromosomes. The DRM complex, which includes E2F/DP and Retinoblastoma homologs, affects germline gene expression and prevents excessive repression of X-chromosome genes. Using genome-scale analyses of germline tissue, we show that common germline-expressed genes are activated by MES-4 and repressed by DRM, and that MES-4 and DRM co-bind many germline-expressed genes. Reciprocally, MES-4 represses and DRM activates a set of autosomal soma-expressed genes and overall X-chromosome gene expression. Mutations in mes-4 or the DRM subunit lin-54 oppositely skew target transcript levels and cause sterility; a double mutant restores near wild-type transcript levels and germ cell development. Together, yin-yang regulation by MES-4 and DRM ensures transcript levels appropriate for germ cell function, elicits robust but not excessive dampening of X-chromosome-wide transcription, and may poise genes for future expression changes. Our study reveals that conserved transcriptional regulators implicated in development and cancer counteract each other to fine-tune transcript dosage.
Opposing activities of DRM and MES-4 tune gene expression and X-chromosome repression in Caenorhabditis elegans germ cells.
Sex
View SamplesWe compared human female hiPSC lines (all derived from IMR-90 fibroblasts) that were XIST RNA-positive and XIST RNA-negative. We also examined the gene expression patterns for 2 female hIPSCs (derived from different disease model fibroblasts) that were also negative for XIST RNA. hiPS 12D-1 is derived from Huntington's Disease patient and 6C-1 is derived from a Type I Diabetes Mellitus patient (Park et al Nature 2008).
Molecular signatures of human induced pluripotent stem cells highlight sex differences and cancer genes.
Specimen part
View SamplesContractile and highly synthetic myofibroblasts are the key effector cells involved in excessive extracellular matrix (ECM) deposition in multiple fibrotic conditions, including idiopathic pulmonary fibrosis (IPF). In order to define the key drivers of the fibrotic response, we used laser capture microdissection to isolate RNA from myofibroblasts within fibroblastic foci and performed microarray analysis in combination with a novel eigengene approach to identify functional clusters of genes which associate with collagen gene expression.
Transcriptome analysis of IPF fibroblastic foci identifies key pathways involved in fibrogenesis.
Specimen part, Disease, Subject
View SamplesRemembrances of traumata range among the most enduring forms of memories. Despite the elevated lifetime prevalence of anxiety disorders, effective strategies to attenuate long-term traumatic memories are scarce. The most efficacious treatments to diminish recent (i.e., day-old) traumata capitalize on memory updating mechanisms during reconsolidation that are initiated upon memory recall. Here, we show that in mice successful reconsolidation-updating paradigms for recent memories fail to attenuate remote (i.e., month-old) ones. We find that whereas recent memory recall induces a limited period of hippocampal neuroplasticity mediated, in part, by S-nitrosylation of HDAC2 and histone acetylation, such plasticity is absent for remote memories. However, by using an HDAC2-targeting inhibitor (HDACi) during reconsolidation, even remote memories can be persistently attenuated. This intervention epigenetically primes the expression of neuroplasticity-related genes as revealed by whole genome RNA sequencing, which is accompanied by higher metabolic, synaptic and structural plasticity. Thus, applying HDACis during memory reconsolidation might constitute a treatment option for remote traumata. Overall design: 3 biological replicates per group were analyzed. The material analyzed was whole hippocampi from one brain hemisphere, from which total RNA was extracted.
Epigenetic priming of memory updating during reconsolidation to attenuate remote fear memories.
No sample metadata fields
View SamplesTruncating mutations of CHD8, encoding a chromodomain helicase, and of many other genes with diverse functions, are strong-effect risk factors for autism spectrum disorder (ASD), suggesting multiple mechanisms of pathogenesis. We explored the transcriptional networks that CHD8 regulates in neural progenitor cells (NPCs) by reducing its expression and then integrating transcriptome sequencing (RNA-seq) with genome-wide CHD8 binding (ChIP-seq). Suppressing CHD8 to levels comparable with loss of a single allele caused altered expression of 1,756 genes, 64.9% of which were up-regulated. CHD8 showed widespread binding to chromatin, with 7,324 replicated sites that marked 5,658 genes. Integration of these data suggests that a limited array of direct regulatory effects of CHD8 produced a much larger network of secondary expression changes. Genes indirectly down-regulated (i.e., without CHD8 binding sites) reflect pathways involved in brain development, including synapse formation, neuron differentiation, cell adhesion, and axon guidance, whereas CHD8-bound genes are strongly associated with chromatin modification and transcriptional regulation. Genes associated with ASD were strongly enriched among indirectly down-regulated loci (p = 1.01x10-9) and CHD8-bound genes (p = 4.34x10-3), which align with previously identified co-expression modules during fetal development. We also find an intriguing enrichment of cancer related gene-sets among CHD8-bound genes (p < 1.9x10-11). In vivo suppression of chd8 in zebrafish produced macrocephaly comparable to that of humans with inactivating mutations. These data indicate that heterozygous disruption of CHD8 precipitates a network of gene expression changes involved in neurodevelopmental pathways in which many ASD-associated genes may converge on shared mechanisms of pathogenesis. Overall design: RNA-seq in NPCs treated with shRNAs targeting CHD8. For controls, NPCs were treated with shRNAs targeting GFP and LacZ. Infection and sequencing was carried out in two separate batches, with one GFP and one LacZ sample in each batch. All samples were sequenced in two technical replicates.
CHD8 regulates neurodevelopmental pathways associated with autism spectrum disorder in neural progenitors.
No sample metadata fields
View SamplesHere, we examined mouse brain trancriptional changes 1 hour after the 10th daily i.p. treament with one of the four following treaments: i) vehicle control (45% saline, 45% PEG-400 and 10% DMSO administered at 7.5mL/kg), ii) Cpd-60, 45mg/kg , administered at 7.5mL/kg or iii) SAHA, 25mg/kg, administered at 5mL/kg) or iv) CI-994, 10mg/kg, administered at 5mL/kg. Cpd-60 is a benzamide HDAC inhibitor with selectivity for class I HDAC subtypes HDAC1 and HDAC2; CI-994 is a benzamide inhibitor with selectivity for HDACs1,2 and 3; SAHA is a hydroxamic acid HDAC inhibitor with selectivity for class I HDAC subtypes 1,2, and 3 and the class II HDAC subtype HDAC 6. We examined transcript differences using the Illumnia WG-6 2.0 whole genome expression array and profiled 3 specific brain regions (prefrontal cortex, nucleus accumbens, hippocampus) from each of 36 mice (n=6 mice / treatment group) . For application to array chips, we pooled two biological replicates from like treatment and brain region-groups such that 36 samples were applied in total: 4 treatment groups x 3 brain regions per treament group x 3 pools of two samples each for each treatment/brain region.
A selective HDAC 1/2 inhibitor modulates chromatin and gene expression in brain and alters mouse behavior in two mood-related tests.
Sex, Treatment
View Samples