Signaling by the cytokine LIF and its downstream transcription factor, STAT3, prevents differentiation of pluripotent embryonic stem cells (ESCs) by opposing MAP kinase signaling. This contrasts with most cell types where STAT3 signaling induces differentiation. We find that STAT3 binding across the pluripotent genome is dependent upon Brg, the ATPase subunit of a specialized chromatin remodeling complex (esBAF) found in ESCs. Brg is required to establish chromatin accessibility at STAT3 binding targets, in essence preparing these sites to respond to LIF signaling. Moreover, Brg deletion leads to rapid Polycomb (PcG) binding and H3K27me3-mediated silencing of many Brg-activated targets genome-wide, including the target genes of the LIF signaling pathway. Hence, one crucial role of Brg in ESCs involves its ability to potentiate LIF signaling by opposing PcG. Contrary to expectations, Brg also facilitates PcG function at classical PcG target including all four Hox loci, reinforcing their repression in ESCs. These findings reveal that esBAF does not simply antagonize PcG, but rather, the two chromatin regulators act both antagonistically and synergistically with the common goal of supporting pluripotency.
esBAF facilitates pluripotency by conditioning the genome for LIF/STAT3 signalling and by regulating polycomb function.
Cell line, Treatment
View SamplesDistinctive SWI/SNF-like ATP-dependent chromatin remodeling esBAF complexes are indispensable for the maintenance and pluripotency of mouse embryonic stem (ES) cells. To understand the mechanism underlying the roles of these complexes in ES cells, we performed high-resolution genome-wide mapping of the core ATPase subunit, Brg, using ChIP-Seq technology. We find that that esBAF, as represented by Brg, binds to genes encoding components of the core ES transcriptional circuitry, including Polycomb group proteins. esBAF colocalizes extensively with Oct4, Sox2 and Nanog genome-wide, and shows distinct functional interactions with Oct4 and Sox2 at its target genes. Surprisingly, no significant colocalization of esBAF with PRC2 complexes, represented by Suz12, is observed. Lastly, esBAF co-binds with Stat3 and Smad1 genome-wide, consistent with a direct and critical role in LIF and BMP signaling essential to maintain pluripotency. Taken together, our studies indicate that esBAF is both an essential component of the core pluripotency transcriptional network, and might also be a critical component of the LIF and BMP signaling pathways essential for maintenance of self-renewal and pluripotency.
An embryonic stem cell chromatin remodeling complex, esBAF, is an essential component of the core pluripotency transcriptional network.
No sample metadata fields
View SamplesThese experiments were designed to detect transcript (mRNA) changes in whole circulating blood in animals exposed to D-amphetamine under neurotoxic and non-neurotoxic conditions, or subjected to elevated environmental temperatures that produced a hyperthermia very similar to heat stroke. The study objectives were: 1) to detect transcript changes in blood due to life-threatening hyperthermia produced by elevated environmental temperatures (39°C, produces no or minimal neurotoxicity); 2) detect transcripts that could serve as biomarkers specific for neurotoxic amphetamine exposures and not seen with environmentally-induced hyperthermia; and 3) determine the transcript changes related to the immune system in circulating blood produced by either non-neurotoxic or neurotoxic amphetamine exposures. Amphetamine effects on gene expression are dependent on body temperature and indicate that many significant changes in genes related to the immune system occur, some likely in response to damage, even when animals remain normothermic during amphetamine exposure. Also, hyperthermia alone produces many changes in immune related genes in blood Overall design: Five groups of animals were necessary to meet the study objectives. All groups were given 4 injections of either normal saline or amphetamine, and the injections were sequentially given with 2 h between each injection. Dosing started at 7:30 to 8:30 a.m. The groups are: 1) normothermic controls given normal saline in a 22.5°C environment; 2) controls given normal saline in a 16°C environment (also remained normothermic); 3) environmentally-induced hyperthermia given saline in a 39°C environment; 4) non-neurotoxic amphetamine given in a 16°C environment and 5) neurotoxic amphetamine group given amphetamine in a 22.5°C environment. Note the the saline controls (normothermic data) is contained in a separate but linked GEO file GSE62368
Evaluating the Stability of RNA-Seq Transcriptome Profiles and Drug-Induced Immune-Related Expression Changes in Whole Blood.
No sample metadata fields
View SamplesSomatic progenitors suppress differentiation to maintain tissue self-renewal. While epigenetic regulators of DNA and histone modifications can support such repression, a role for nuclear actin-like proteins is unclear. In epidermis, ACTL6a/BAF53A was found enriched in progenitors and down-regulated during differentiation. Conditional ACTL6a deletion abolished epidermal self-renewal and induced terminal differentiation, whereas ectopically expressed ACTL6a suppressed differentiation. Among known activators of epidermal differentiation, KLF4 was found to control 227 genes also regulated by ACTL6a. ACTL6a loss upregulated KLF4 and its target genes, effects that were blocked by KLF4 depletion. Among multiple ACTL6a-interacting epigenetic regulators, the SWI/SNF complex was required for KLF4 activation and differentiation. In progenitors, ACTL6a loss led to enhanced SWI/SNF binding to the promoters of KLF4 and other differentiation genes. ACTL6a thus maintains the undifferentiated progenitor state, in part by suppressing SWI/SNF complex-enabled induction of KLF4.
ACTL6a enforces the epidermal progenitor state by suppressing SWI/SNF-dependent induction of KLF4.
Specimen part
View SamplesWe performed RNA-seq 72 h after acute deletion of Smarca4 in a line of conditional knockout mouse embryonic stem cells to examine altered gene expression. Overall design: Examination of mRNA in mouse embryonic stem cells expressing conditional knockout of the mSWI/SNF ATPase Smarca4. For these studies, mRNA was harvested from Smarca4-CreER (Smarca4flfl) conditional knockout cells 72 h after treatment with either ethanol (EtOH) or 0.8 uM 4-hydroxytamoxifen (Tam).
Smarca4 ATPase mutations disrupt direct eviction of PRC1 from chromatin.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Rapid chromatin repression by Aire provides precise control of immune tolerance.
Age, Specimen part
View SamplesGene Expression Profiles of mTECs from Aire-/- and Brg1-/- mice and their littermate controls.
Rapid chromatin repression by Aire provides precise control of immune tolerance.
Age, Specimen part
View SamplesBackground. Vaginal atrophy (VA) is the thinning of the vaginal epithelial lining, typically the result of lowered estrogen levels during menopause. Some of the consequences of VA include increased susceptibility to bacterial infection, pain during sexual intercourse, and vaginal burning or itching. Although estrogen treatment is highly effective, alternative therapies are also desired for women who are not candidates for hormone replacement therapy (HRT). The ovariectomized (OVX) rat is widely accepted as an appropriate animal model for many estrogen-dependent responses in humans; however, since reproductive biology can vary significantly between mammalian systems, this study examined how well the OVX rat recapitulates human biology at the transcriptional level. This report describes an analysis of expression profiling data, comparing the responses of rat and human vaginae to estrogen treatment. Results. The level of differential expression between pre- vs. post- estrogen treatment was calculated for each of the human and OVX rat datasets. Probe sets corresponding to orthologous rat and human genes were mapped to each other using NCBI Homologene. A positive correlation was observed between the rat and human responses to estrogen. Genes belonging to several biological pathways and GO categories were similarly differentially expressed in rat and human. A large number of the coordinately regulated biological processes are already known to be involved in human VA, such as inflammation, epithelial development, and EGF pathway activation. Conclusions. At the transcriptional level, there is evidence of significant overlap of the effects of estrogen treatment between the OVX rat and human VA samples.
Molecular analysis of the vaginal response to estrogens in the ovariectomized rat and postmenopausal woman.
Age
View SamplesUterine leiomyomata, or fibroids, are benign tumors of the uterine myometrium that significantly affect up to 30% of reproductive-age women. Despite being the primary cause of hysterectomy in the United States, accounting for up to 200,000 procedures annually, the etiology of leiomyoma remains largely unknown. Due to the lack of an effective medicinal therapy for these tumors, this disease continues to have a tremendous negative impact on womens health. As a basis for understanding leiomyoma pathogenesis and identifying targets for pharmacotherapy, we conducted transcriptional profiling of leiomyoma and unaffected myometrium from humans and Eker rats, the best characterized preclinical model of leiomyoma. A global comparison of mRNA from leiomyoma versus myometrium in human and rat identified a highly significant overlap of dysregulated gene expression in leiomyoma. An unbiased pathway analysis using a method of gene set enrichment based on the Sigpathway algorithm detected the mammalian target of rapamycin (mTOR) pathway as one of the most highly upregulated pathways in both human and rat tumors. Activation of this pathway was confirmed in both human and rat leiomyomata at the protein level via Western. Inhibition of mTOR in female Eker rats with the rapamycin analog WAY-129327 for 2 weeks decreased mTOR signaling and cell proliferation in tumors, and treatment for 4 months significantly decreased tumor incidence, multiplicity and size. These results identify dysregulated mTOR signaling as a component of leiomyoma etiology across species and directly demonstrate the dependence of these tumors on mTOR signaling for growth in the Eker rat. Modulation of this pathway warrants additional investigation as a potential therapy for uterine leiomyoma.
Comparison of human and rat uterine leiomyomata: identification of a dysregulated mammalian target of rapamycin pathway.
No sample metadata fields
View SamplesWe performed an RNA Sequencing experiment on dorsal hippocampal tissue from four groups of animals: Baf53b+/- homecage (Baf53b+/- HC); Baf53b+/- behavior (Baf53b+/- Beh); wildtype homecage (WT HC); and wildtype behavior (WT Beh). Homecage animals were sacrificed directly from the animal's cage. Behavior animals were sacrificed thirty minutes following Object Location Memory training. The objective of this study was to examine activity regulated gene expression following a learning event (HC vs Beh) in wildtype and Baf53b+/- mutant mice. Overall design: Examination of gene expression following a learning event in wildtype and Baf53b+/- mutant mice in dorsal hippocampus.
The neuron-specific chromatin regulatory subunit BAF53b is necessary for synaptic plasticity and memory.
Specimen part
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