Most vertebrate organs are composed of epithelium surrounded by support and stromal tissues formed from mesenchyme cells, which are not generally thought to form organized progenitor pools. Here we use clonal cell labeling with multicolor reporters to characterize individual mesenchymal progenitors in the developing mouse lung. We observe a diversity of mesenchymal progenitor populations with different locations, movements, and lineage boundaries. Airway smooth muscle (ASM) progenitors map exclusively to mesenchyme ahead of budding airways. Progenitors recruited from these tip pools differentiate into ASM around airway stalks; flanking stalk mesenchyme can be induced to form an ASM niche by a lateral bud or by an airway tip plus focal Wnt signal. Thus, mesenchymal progenitors can be organized into localized and carefully controlled domains that rival epithelial progenitor niches in regulatory sophistication.
Mesenchymal cells. Defining a mesenchymal progenitor niche at single-cell resolution.
Specimen part, Treatment
View SamplesArabidopsis plants growing under diurnal conditions were transferred to cold of approximately one day duration, starting at different times of the day. All comparisons are of unreplicated pairs and are thus not designed to identify cold-responsive gens in isolation but are rather to supplement existing publicly available data. The overall aim was to use a diverse set of experiments to see which factors have the greatest influence on the identity of cold-responsive genes.
Disruption of the Arabidopsis circadian clock is responsible for extensive variation in the cold-responsive transcriptome.
Age, Specimen part, Time
View SamplesTo address the neglected possibility for global mRNA changes in microarray experiments we developed a simple method to generate external controls for Affymetrix microarrays to allow these platforms to measure absolute mRNA expression at the global level. We used publicly available data to select probesets that never detect endogenous transcripts, and used PCR and IVT to generate synthetic mRNAs corresponding to them. After quality control and testing, these control transcripts were spiked into total RNA samples from plants before and after 24 h of cold treatment. Due to changes in the proportion of mRNA, these data reveal intensity-dependent bias in expression estimates based on standard all-gene normalizations. When not accounted for, this leads to false classification of the differential expression for thousands of genes.
Disruption of the Arabidopsis circadian clock is responsible for extensive variation in the cold-responsive transcriptome.
Age, Specimen part
View SamplesThe Mediator complex allows communication between transcription factors and RNA polymerase II (RNAPII). CDK8, the kinase found in some variants of Mediator, has been characterized mostly as a transcriptional repressor. Recently, CDK8 was demonstrated to be a potent oncoprotein. Here we show that CDK8 is predominantly a positive regulator of gene expression within the serum response network, as it is required for expression of several members of the AP-1 and EGR family of oncogenic transcription factors (e.g. FOS, JUN, EGR1-3). Mechanistic studies demonstrate that CDK8 is not required for recruitment of RNAPII and promoter escape at these loci. Instead, CDK8 depletion leads to the appearance of slower elongation complexes carrying hypophosphorylated RNAPII. We show that CDK8-Mediator regulates precise steps in the assembly of a functional elongation complex, including the recruitment of P-TEFb and BRD4, but is dispensable for recruitment of SPT5 and FACT. Furthermore, CDK8-Mediator specifically interacts with P-TEFb. Thus, we uncovered a novel role for CDK8 in transcriptional regulation that may contribute to its oncogenic effects.
CDK8 is a positive regulator of transcriptional elongation within the serum response network.
Cell line
View SamplesAlternative 3-terminal exons, which use intronic polyadenylation sites, are generally unconserved and lowly expressed, while the main gene products end in the last exon of genes. In this study, we discover a class of human genes, where the last exon appeared recently during evolution, and the major gene product uses an alternative 3-terminal exon corresponding to the ancestral last exon of the gene. This novel class of alternative 3-terminal exons are down-regulated on a large scale by doxorubicin, a cytostatic drug targeting topoisomerase II, and play a role in cell cycle regulation, including centromere-kinetochore assembly. The RNA-binding protein, HuR/ELAVL1 is a major regulator of this specific set of alternative 3-terminal exons. HuR binding to the alternative 3-terminal exon in the pre-messenger RNA promotes its splicing, and is reduced by topoisomerase inhibitors. These findings provide new insights into the evolution, function and molecular regulation of alternative 3-terminal exons.
A recently evolved class of alternative 3'-terminal exons involved in cell cycle regulation by topoisomerase inhibitors.
Cell line
View SamplesTo identify mediators of obesity-linked reductions in PGC-1, we tested the effects of cellular nutrients in C2C12 myotubes. While overnight exposure to high insulin, glucose, glucosamine, or amino acids had no effect, saturated fatty acids (FA) potently reduced PGC-1a and b mRNA expression.
Peroxisome proliferator activator receptor gamma coactivator-1 expression is reduced in obesity: potential pathogenic role of saturated fatty acids and p38 mitogen-activated protein kinase activation.
No sample metadata fields
View SamplesNotch activation is instrumental in the development of most T-cell acute lymphoblastic leukemia (T-ALL) cases, yet Notch mutations alone are not sufficient to recapitulate the full human disease in animal models. We here found that Notch1 activation at the fetal liver (FL) stage expanded the hematopoietic progenitor population and conferred it transplantable leukemic-initiating capacity. However, leukemogenesis and leukemic-initiating cell capacity induced by Notch1 was critically dependent on the levels of ß-Catenin in both FL and adult bone marrow contexts. In addition, inhibition of ß-Catenin compromised survival and proliferation of human T-ALL cell lines carrying activated Notch1. By transcriptome analyses, we identified the MYC pathway as a crucial element downstream of ß-Catenin in these T-ALL cells and demonstrate that the MYC 3'' enhancer required ß-Catenin and Notch1 recruitment to induce transcription. Finally, PKF115-584 treatment prevented and partially reverted leukemogenesis induced by active Notch1. Overall design: Four T-ALL cell lines (RPMI8402, HPB-ALL, Jurkat, CCRF-CEM) were treated with DMSO (control) or PKF115-584 (310nM) for 3hrs. Gene expression changes were measured with Cufflinks comparing the 4 control with the 4 treated samples.
β-Catenin is required for T-cell leukemia initiation and MYC transcription downstream of Notch1.
No sample metadata fields
View SamplesWe have generated a mouse model for tumor initiation carrying a mutation in APC and lacking IKKa in intestinal epithelial cells. IKKa-deficient intestinal cells primarily failed to generate adenomas, and the few adenomas arising in this background displayed a significant reduction in cell proliferation. Using an in vitro model for intestinal tumoroids (derived from adenoma initiating cells), we have performed RNA sequencing of wild type and IKKa-deficient intestinal tumoroids. This has demonstrated that epithelial IKKa controls transcription of stem cell-related genes and genes associated with proliferation and apoptosis. Overall design: RNA sequencing of IKKa WT and KO tumoroids, done in triplicates
IKKα is required in the intestinal epithelial cells for tumour stemness.
Specimen part, Cell line, Subject
View SamplesHematopoietic Stem Cells (HSC) are originated during embryonic development from endothelial-like cells located in the ventral side of the dorsal aorta around day E10-12 of murine development. This region is called AGM for Aorta/Gonad/Mesonephros and refers to the tissues around the hemogenic aorta. Cells that emerge from the endothelium and show hematopoietic traits can be distinguished by the expression of the c-kit receptor and finally acquire the CD45 marker.
Hematopoietic stem cell development requires transient Wnt/β-catenin activity.
Specimen part
View SamplesSjgren's syndrome is an autoimmune disease manifesting primarily as dryness of eyes and mouth. In this study, we compared gene expression in PBMCs between age- and gender-matched patients with Sjgren's syndrome (diagnosed by ACR criteria) and healthy controls. Cells were collected in heparinized tubes and PBMCs were prepared using Ficoll.
Expression of the immune regulator tripartite-motif 21 is controlled by IFN regulatory factors.
Specimen part, Disease
View Samples