Post-translational modifications (PTMs) of histones exert fundamental roles in regulating gene expression. During development, groups of PTMs are constrained by unknown mechanisms into combinatorial patterns, which facilitate transitions from uncommitted embryonic cells into differentiated somatic cell lineages. Repressive histone modifications such as H3K9me3 or H3K27me3 have been investigated in detail, but the role of H4K20me3 in development is currently unknown. Here we show that Xenopus laevis Suv4-20h1 and h2 histone methyltransferases (HMTases) are essential for induction and differentiation of the neuroectoderm. Morpholino-mediated knockdown of the two HMTases leads to a selective and specific downregulation of genes controlling neural induction, thereby effectively blocking differentiation of the neuroectoderm. Global transcriptome analysis supports the notion that these effects arise from the transcriptional deregulation of specific genes rather than widespread, pleiotropic effects. Interestingly, morphant embryos fail to repress the Oct4-related Xenopus gene Oct-25. We validate Oct-25 as direct target of xSu4-20h enzyme-mediated gene repression, showing by chromatin immunoprecipitaton that it is decorated with the H4K20me3 mark downstream of the promoter in normal, but not in double-morphant, embryos. Since knockdown of Oct-25 protein significantly rescues the neural differentiation defect in xSuv4-20h double-morphant embryos, we conclude that the epistatic relationship between Suv4- 20h enzymes and Oct-25 controls the transit from pluripotent to differentiation-competent neural cells. Consistent with these results in Xenopus, murine Suv4-20h1/h2 double-knockout embryonic stem (DKO ES) cells exhibit increased Oct4 protein levels before and during EB formation, and reveal a compromised and biased capacity for in vitro differentiation, when compared to normal ES cells. Together, these results suggest a regulatory mechanism, conserved between amphibian and mammals, in which H4K20me3-dependent restriction of specific POU-V genes directs cell fate decisions, when embryonic cells exit the pluripotent state.
Suv4-20h histone methyltransferases promote neuroectodermal differentiation by silencing the pluripotency-associated Oct-25 gene.
Specimen part, Treatment
View SamplesThe response of human neutrophils to the emerging pathogen Mycobacterium abscessus has not been described. However, M. abscessus infections are frequently associated with neutrophil-rich abscesses. To better understand the reponse of neutrophils to M. abscessus we performed gene expression analysis using Affymetrix HG-U133A Plus 2.0 microarrays. Human neutrophils from healthy donors were stimulated with isogenic rough and smooth morphotypes of M. abscessus. Staphylococcus aureus was used as a control. Gene expression was compared to neutrophils left unstimulated. Neutrophils from four individual donors were isolated on separate days and stimulated with freshly prepared bacteria. Neutrophils (stimulated and control) were left for 2 hours before total RNA was isolated, and biotinylated cRNA was prepared by standard methods. Analysis indicates that M. abscessus morphotypes induce a limited number of genes, when compared to S. aureus, which are enriched in genes for cytokines and chemokines, including neutrophil-specific chemokines. These data suggest that neutrophils have a limited response to M. abscessus, which may contribute to neutrophil-rich abscess formation.overall_design = Human neutrophils from healthy donors were exposed to rough Mab (ATCC 19977T), smooth Mab (ATCC 19977T) and S. aureus (CF clinical strain) for two hours; control cells were exposed to saline.
Mycobacterium abscessus induces a limited pattern of neutrophil activation that promotes pathogen survival.
Specimen part, Disease, Treatment
View SamplesBackground: Clinical trial and epidemiological data support that the cardiovascular effects of estrogen are complex, including a mixture of both potentially beneficial and harmful effects. In animal models, estrogen protects females from vascular injury and inhibits atherosclerosis. These effects are mediated by estrogen receptors (ERs), which when bound to estrogen can bind to DNA to directly regulate transcription. ERs can also activate several cellular kinases by inducing a rapid non-nuclear signaling cascade. However, the biologic significance of this rapid signaling pathway has been unclear.
Rapid estrogen receptor signaling is essential for the protective effects of estrogen against vascular injury.
No sample metadata fields
View SamplesWe generated genome-wide RNASeq data from freshly isolated airway epithelial cells of asthmatics and non-asthmatics. This data was paired with genome-wide genetic and methylation data from the same individuals allowing for an integrated analysis of genetic, transcriptional, and epigenetic signatures in asthma. Overall design: examination of genome-wide genome-wide gene expression levels and comparison to phenotypes
DNA methylation in lung cells is associated with asthma endotypes and genetic risk.
Specimen part, Disease, Subject
View SamplesMouse norovirus (MNV) causes acute or chronic infection in immunocompetent hosts, but the CD8 T cell determinants of viral persistence versus clearance are unknown.
Differentiation and Protective Capacity of Virus-Specific CD8<sup>+</sup> T Cells Suggest Murine Norovirus Persistence in an Immune-Privileged Enteric Niche.
Specimen part
View SamplesThe main goal of our study is to identify the molecular events that determine the gonadal identity in mammals. Although testis and ovary arise from a common embryonic primordium, they represent outcomes of opposing fate determination. This decision to differentiate into a testis or an ovary hinges upon the balance between two antagonizing factors, pro-testis SOX9 and pro-ovary -catenin.
Gonadal Identity in the Absence of Pro-Testis Factor SOX9 and Pro-Ovary Factor Beta-Catenin in Mice.
Specimen part
View SamplesAndrogen Receptor (AR) is essential for the growth and progression of prostate cancer in both hormone-sensitive and hormone-refractory disease. We have designed a sequence-specific DNA binding polyamide (1) that targets the consensus androgen response element (ARE). This polyamide binds the PSA promoter ARE, inhibits androgen-induced expression of PSA and several other AR-regulated genes in cultured prostate cancer cells, and reduces AR occupancy at the PSA promoter and enhancer. Down-regulation of PSA by this polyamide was comparable to that produced by the synthetic anti-androgen bicalutamide (Casodex) at the same concentration. Genome-wide expression analysis reveals that a similar number of transcripts are affected by treatment with the polyamide and with bicalutamide. Direct inhibition of AR-DNA binding by sequence-specific DNA binding small molecules could offer an alternative approach to antagonizing AR activity. A polyamide (2) that targets a different DNA sequence is included as a control.
Suppression of androgen receptor-mediated gene expression by a sequence-specific DNA-binding polyamide.
No sample metadata fields
View SamplesAnalysis of dexamethasone-stimulated A549 lung adenocarcinoma epithelial cells treated with a glucocorticoid response (GR) element (GRE) specific DNA binding polyamide. Polyamide designed to target the sequence 5'-WGWWCW-3' and disrupt GR-mediated gene expression. Effects of the GR antagonist mifepristone also examined.
Repression of DNA-binding dependent glucocorticoid receptor-mediated gene expression.
Cell line
View SamplesTranslation and mRNA decay are intimately connected processes, and translational inhibition often precedes and stimulates transcript degradation. Here, we have focused on methods that allow determination of mRNA stability on a transcriptome-wide scale. We describe experimental and computational methods for the two most commonly used approaches (transcriptional inhibition and metabolic labeling), and we discuss associated caveats. Overall design: Metabolic labeling time courses (1, 2, 4, 8, 12, 24 hr) using 4SU were performed in HEK293.
Determining mRNA half-lives on a transcriptome-wide scale.
Treatment, Subject
View SamplesCalcific aortic valvular disease (CAVD) is characterized by sclerosis of the aortic valve leaflets and recent clinical studies have linked several other risk factors to this disease, including male sex. In this study we examined potential sex-related differences in gene expression profiles between porcine male and female valvular interstitial cells (VICs) to explore possible differences in CAVD propensity on the cellular level.
Sex-related differences in gene expression by porcine aortic valvular interstitial cells.
Sex, Specimen part
View Samples