Studies of the RNA polymerase-binding molecule ppGpp in bacteria and plants have shown that changes to the kinetics of the RNA polymerase can have dramatic biological effects in the short-term as a stress response. Here we describe the reprogramming of the kinetic parameters of the RNAP through mutations arising during laboratory adaptive evolution of Escherichia coli in minimal media. The mutations cause a 10- to 30-fold decrease in open complex stability at a ribosomal promoter and approximately a 10-fold decrease in transcriptional pausing in the his operon. The kinetic changes coincide with large scale transcriptional changes, including strong downregulation of motility, acid-resistance, fimbria, and curlin genes which are observed in site-directed mutants containing the RNA polymerase mutations as well as the evolved strains harboring the mutations. Site-directed mutants also grow 60% faster than the parent strain and convert the carbon-source 15% to 35% more efficiently to biomass. The results show that long-term adjustment of the kinetic parameters of RNA polymerase through mutation can be important for adaptation to a condition.
RNA polymerase mutants found through adaptive evolution reprogram Escherichia coli for optimal growth in minimal media.
No sample metadata fields
View SamplesTransgenic StellaGFP ESCs were used to derive primordial germ cells during embryoid body (EB) differentiation, and microarry analysis used to compared FACS sorted Stella-positive cells of day 7 Ebs with the parental ESCs and Stella-negative cells of day 7 Ebs.
A role for Lin28 in primordial germ-cell development and germ-cell malignancy.
No sample metadata fields
View SamplesWe examined the microRNAs (miRNAs) expressed in chronic lymphocytic leukemia (CLL) and identified miR-150 as the most abundant, but with leukemia-cell-expression levels that varied among patients. CLL cells that expressed ZAP-70 or that used unmutated IGHV each had a median expression-level of miR-150 that was significantly lower than that of ZAP-70-negative CLL cells or those that used mutated IGHV. In samples stratified for expression of miR-150, CLL cells with low-level miR-150 expressed relatively higher levels of forkhead box P1 (FOXP1) and GRB2-associated binding protein 1 (GAB1), genes with 3 UTRs having evolutionary-conserved binding sites for miR-150. High-level expression of miR-150 could repress expression of these genes, which encode proteins that may enhance B-cell receptor (BCR) signaling, a putative CLL-growth/survival signal. Also, high-level expression of miR-150 levels was a significant independent predictor of longer treatment-free-survival (TFS) or overall survival (OS), whereas an inverse association was observed for high-level expression of GAB1 or FOXP1 for OS. This study demonstrates that expression of miR-150 can influence the relative expression of GAB1 and FOXP1 and the signaling potential of the B-cell receptor (BCR), thereby possibly accounting for the noted association of expression of miR-150 and disease outcome.
miR-150 influences B-cell receptor signaling in chronic lymphocytic leukemia by regulating expression of GAB1 and FOXP1.
Specimen part, Disease stage
View SamplesAnalysis of the transcriptome of mononuclear side population (SP) and main population (MP) cells of human fetal skeletal muscle from 12 human subjects of gestational age 14-18 weeks.
Regulation of myogenic progenitor proliferation in human fetal skeletal muscle by BMP4 and its antagonist Gremlin.
Specimen part
View SamplesFunctional analysis of ABCB5 in A375 and G3361 melanoma cells, by comparing stably-transfected controls to ABCB5-shRNA-targeted cells.
ABCB5 maintains melanoma-initiating cells through a proinflammatory cytokine signaling circuit.
Specimen part, Cell line
View SamplesTo find BMAL1-regulated genes in mice pituitary gland we performed a differential microarray from wild-type vs Bmal1-/- knock-out mice
Chromatin remodeling as a mechanism for circadian prolactin transcription: rhythmic NONO and SFPQ recruitment to HLTF.
Sex, Specimen part
View SamplesCortical GABAergic interneurons constitute a highly diverse population of inhibitory neurons that are key regulators of cortical microcircuit function. An important and heterogeneous group of cortical interneurons specifically expresses the serotonin receptor 3A (5-HT3AR) but how this diversity emerges during development is poorly understood. Here we use single-cell transcriptomics to identify gene expression patterns operating in Htr3a-GFP+ interneurons during early steps of cortical circuit assembly. We identify 3 main molecular types of Htr3a-GFP+ interneurons, each displaying distinct developmental dynamics of gene expression. The transcription factor Meis2 is specifically enriched in a type of Htr3a-GFP+ interneurons spatially confined to the cortical white matter. These MEIS2 expressing interneurons appear to originate from a restricted region located at the embryonic pallial-subpallial boundary. Overall, this study identifies MEIS2 as a subclass-specific marker for 5-HT3AR-containing interstitial interneurons and demonstrates that the transcriptional and anatomical parcellation of cortical interneurons is developmentally coupled. Overall design: Single cell transcriptomics of cortical interneurons FACS sorted according to GFP-Htr3a+. Acquired from mouse brains of 3 different developmental ages: E18, P2, P5
Transcriptomic and anatomic parcellation of 5-HT<sub>3A</sub>R expressing cortical interneuron subtypes revealed by single-cell RNA sequencing.
Subject
View SamplesGlucocorticoids remain the most widely used class of anti-inflammatory and immunosuppressive agents. They act primarily by binding to the glucocorticoid receptor, resulting in direct and indirect effects on gene expression. The current understanding of glucocorticoid effects on transcription in human cells is based mostly on studies of cancer cell lines, immortalized cell lines, or highly mixed populations of primary cells (such as peripheral blood mononuclear cells). To advance the understanding of the transcriptome-wide effects of glucocorticoids on highly pure populations of primary human cells, we performed RNA-seq on nine such cell populations at two time points after in vitro exposure to methylprednisolone or vehicle. Overall design: Nine cell types were studied: four hematopoietic (circulating B cells, CD4+ T cells, monocytes, and neutrophils) and five non-hematopoietic (endothelial cells, fibroblasts, myoblasts, osteoblasts, and preadipocytes). Each cell type was obtained from a separate cohort of 4 unrelated healthy human donors (4 biological replicates per cell type: BR1 - BR4). Cells form each donor were independently cultured and exposed in vitro to glucocorticoid or vehicle. Non-hematopoietic cells were incubated until the early plateau phase of growth, then exposed to methylprednisolone or vehicle. Hematopoietic cells were collected from peripheral blood, purified by magnetic selection (negative selection for B cells, CD4+ T cells and neutrophils; positive selection for monocytes). Purified B cells, CD4+ T cells, and monocytes were incubated overnight, then exposed to methylprednisolone or vehicle. Purified neutrophils were cultured for 4 hours, then exposed to methylprednisolone or vehicle. Ethanol was used as a vehicle for methylprednisolone. Estimated final concentrations were 8500 mcg/L (22.7 mcM) for methylprednisolone and 0.07% (15.57 mM) for ethanol (vehicle). For each cell type, samples were collected at two time points after treatment with methylprednisolone or vehicle: 2 hours and 6 hours. Samples were collected into TRIzol reagent and frozen at -80°C prior to RNA extraction. RNA-seq data for all samples is made available in this GEO Series.
Immune regulation by glucocorticoids can be linked to cell type-dependent transcriptional responses.
Specimen part, Subject, Time
View SamplesWe examined the effect pg IGF1 actibation on cellular contractility and migration in SSC osteoblast cells. Based on microarray levels of IGF1 expression, we selected fifteen cases and nine controls spanning from the highest IGF1 expression to the lowest in cases and controls. Subsequently, the pattern of IGF1 expressions in these cells was assessed using high throughput RNA sequencing. Overall design: RNA-seq based gene expression profiling of fifteen SSC osteoblasts and nine control osteoblasts.
Activation of the IGF1 pathway mediates changes in cellular contractility and motility in single-suture craniosynostosis.
No sample metadata fields
View SamplesMelanoma growth is driven by malignant melanoma initiating cells (MMIC) identified by expression of the ATP-binding cassette (ABC) member, ABCB5. ABCB5+ melanoma subpopulations have been shown to overexpress the vasculogenic differentiation markers CD144 (VE-cadherin) and TIE-1 and are associated with CD31-negative vasculogenic mimicry (VM), an established biomarker associated with increased patient mortality. Here we identify a critical role for VEGFR-1 signaling in ABCB5+ MMIC-dependent VM and tumor growth. Global gene expression analyses, validated by mRNA and protein determinations, revealed preferential expression of VEGFR-1 on ABCB5+ tumor cells purified from clinical melanomas and established melanoma lines. In vitro, VEGF induced in a VEGFR-1-dependent manner expression of CD144 in ABCB5+ subpopulations that constitutively expressed VEGFR-1, but not in ABCB5- bulk populations that were predominantly VEGFR-1-negative. In vivo, melanomaspecific shRNA-mediated knockdown of VEGFR-1 blocked the development of ABCB5+ VM morphology and inhibited ABCB5+ VM-associated production of the secreted melanoma mitogen, laminin. Moreover, melanoma-specific VEGFR-1 knockdown markedly inhibited tumor growth (by >90%). Our results demonstrate that VEGFR-1 function in MMIC regulates VM and associated laminin production, and show that this function represents one mechanism through which MMIC promote tumor growth.
VEGFR-1 expressed by malignant melanoma-initiating cells is required for tumor growth.
Specimen part
View Samples