Hematopoietic stem cells (HSCs) balance self-renewal and differentiation to maintain homeostasis. With aging, the frequency of polar HSCs decreases. Cell polarity in HSCs is controlled by the activity of the small RhoGTPase Cdc42. Here we demonstrate, using a comprehensive set of paired daughter cell analyses that include single cell 3D-confocal imaging, single cell transplants, single cell RNA-seq as well as single cell ATAC-seq, that the outcome of HSC divisions is strongly linked to the polarity status before mitosis, which is in turn determined by the level of the activity Cdc42 in stem cells. Aged apolar HSCs undergo preferentially self-renewing symmetric divisions, resulting in daughter stem cells with reduced regenerative capacity and lymphoid potential, while young polar HSCs undergo preferentially asymmetric divisions. Mathematical modeling in combination with experimental data implies a mechanistic role of the asymmetric sorting of Cdc42 in determining the potential of daughter cells via epigenetic mechanisms. Therefore, molecules that control HSC polarity might serve as modulators of the mode of stem cell division regulating the potential of daughter cells. Overall design: Sorted single cells were cultured with and without treatment in the presence of cytokines until first cell division (40-44hrs). The daughter cells were manually separated, washed with PBS and collected for RNA sequencing.
Aging alters the epigenetic asymmetry of HSC division.
Specimen part, Cell line, Treatment, Subject
View SamplesClassically activated (M1) macrophages protect from infection but can cause inflammatory disease and tissue damage while alternatively activated (M2) macrophages reduce inflammation and promote tissue repair. Modulation of macrophage phenotype may be therapeutically beneficial and requires further understanding of the molecular programs that control macrophage differentiation. A potential mechanism by which macrophages differentiate may be through microRNA (miRNA), which bind to messenger RNA and post-transcriptionally modify gene expression, cell phenotype and function. The inflammation-associated miRNA, miR-155, was rapidly up-regulated over 100-fold in M1, but not M2, macrophages. Inflammatory M1 genes and proteins iNOS, IL-1b and TNF-a were reduced up to 72% in miR-155 knockout mouse macrophages, but miR-155 deficiency did not affect expression of genes associated with M2 macrophages (e.g., Arginase-1). Additionally, a miR-155 oligonucleotide inhibitor efficiently suppressed iNOS and TNF-a gene expression in wild-type M1 macrophages. Comparative transcriptional profiling of unactivated (M0) and M1 macrophages derived from wild-type and miR-155 knockout (KO) mice revealed an M1 signature of approximately 1300 genes, half of which were dependent on miR-155. Real-Time PCR of independent datasets validated miR-155's contribution to induction of iNOS, IL-1b, TNF-a, IL-6 and IL-12, as well as suppression of miR-155 targets Inpp5d, Tspan14, Ptprj and Mafb. Overall, these data indicate that miR-155 plays an essential role in driving the differentiation and effector potential of inflammatory M1 macrophages.
Control of the Inflammatory Macrophage Transcriptional Signature by miR-155.
Specimen part, Treatment
View SamplesUbiquitin Ligase (UBE4B) and Lysine-Specific Demethylase (LSD1) are post-translational modifying enzymes affecting lysine ubiquitination and methylation of several important regulatory proteins, and are synergisticaly important for protein quality control. To inwestigate their role in cell signaling, we analyzed global mRNA levels in HEK293T cells that were knocked down with shRNAs against UBE4B, LSD1, both UBE4B and LSD1, and non-targeting control (CTRL).
Regulation of protein quality control by UBE4B and LSD1 through p53-mediated transcription.
Cell line, Time
View SamplesClassically (M1) and alternatively activated (M2) macrophages play distinct roles in various physiological and disease processes. Understanding the gene transcription programs that contribute to macrophage polarization along the M1/M2 spectrum may lead to new tools to detect and therapeutically manipulate macrophage phenotype. Here, we define the M1 and M2 macrophage signature through mRNA microarray. The M1 macrophage signature was defined by 629 up-regulated and 732 down-regulated genes while the M2 macrophage signature was formed by 388 up-regulated and 425 down-regulated genes. While a subset of probes was common to both M1 and M2 cells, others were exclusive to each macrophage subset. The common M1/M2 pathways were characterized by changes in various transcriptional regulators and signaling partners, including increases in Kruppel-like Factor (Klf) 4, but decreases in Klf2. To identify M1 and M2 biomarkers that help discriminate these populations, we selected genes that were increased during M1 or M2 differentiation but decreased in the opposite population. Among top novel M1-distinct genes, we identified CD38, G-protein coupled receptor 18 (Gpr18) and Formyl peptide receptor 2 (Fpr2). Among top M2 genes, we found early growth response protein 2 (Egr2) and Myc. We validated these genes by Real-Time PCR and developed a CD38/Egr2-based flow cytometry assay that discriminates between M1 and M2 macrophages. Overall, this work defines the M1 and M2 signature and identifies several novel M1 and M2 genes that may be used to distinguish and manipulate M1 and M2 macrophages.
Novel Markers to Delineate Murine M1 and M2 Macrophages.
Specimen part, Treatment
View SamplesExpression data from this experiment is part of a larger project aimed at defining the individual effects and synergistic effects of ROCK inhibitor Y-27632 and conditioned media from irradiated J2 cells when applied to epithelial cells. This data set consists of four individual samples, each of which are total RNA collected from human foreskin keratinocyte cells, either grown in F medium (control), treated with Y-27632, grown in conditioned medium (as described in associated publication), or both treatments.
Multifactorial analysis of conditional reprogramming of human keratinocytes.
Specimen part, Treatment
View SamplesThe Arabidopsis thaliana transcription factor LATERAL ORGAN BOUNDARIES (LOB) is expressed in the boundary between the shoot apical meristem and initiating lateral organs. To identify genes regulated by LOB activity, we used an inducible 35S:LOB-GR line. This analysis identified genes that are differentially expressed in response to ectopic LOB activity.
Arabidopsis lateral organ boundaries negatively regulates brassinosteroid accumulation to limit growth in organ boundaries.
Age, Specimen part, Treatment
View Samplesp53 inactivation occurs only rarely in neuroblastoma, although miR-34, a transcriptional target of p53, is often deleted in neuroblastoma, suggesting another way in which p53 signaling might be impaired. In this study we show that miR-34 directly targets and downregulates the Polycomb Repressive Complex 2 (PRC2) and its associated histone demethylase, JARID1A, in a p53-dependent manner,
KDM5A Regulates a Translational Program that Controls p53 Protein Expression.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Functional and evolutionary significance of human microRNA seed region mutations.
Cell line
View SamplesMicroRNAs (miRNAs) are small non-coding RNAs that play a central role in the regulation of gene expression at the post transcriptional and/or translational level thus impacting various biological processes. Dysregulation of miRNAs could affect processes associated with progression of a variety of diseases including cancer. Majority of miRNA targeting in animals involves a 7-nt seed region mapping to positions 2-8 at the molecules 5' end. The importance of this 7 nt sequence to miRNA function is evidenced by the fact that the seed region sequence of many miRNAs is highly conserved within and between species. In this study, we computationally and experimentally explore the functional significance of sequence variation within the seed region of human miRNAs. Our results indicate that change of a single nt within the 7-nt seed region changes the spectrum of targeted mRNAs significantly meanwhile further nt changes have little to no additional effect. This high functional cost of even a single nucleotide change within the seed region of miRNAs explains why the seed sequence is highly conserved among many miRNA families both within and between species and could help clarify the likely mechanisms underlying the evolution of miRNA regulatory control.
Functional and evolutionary significance of human microRNA seed region mutations.
Cell line
View SamplesMicroRNAs (miRNAs) are small non-coding RNAs that play a central role in the regulation of gene expression at the post transcriptional and/or translational level thus impacting various biological processes. Dysregulation of miRNAs could affect processes associated with progression of a variety of diseases including cancer. Majority of miRNA targeting in animals involves a 7-nt seed region mapping to positions 2-8 at the molecules 5' end. The importance of this 7 nt sequence to miRNA function is evidenced by the fact that the seed region sequence of many miRNAs is highly conserved within and between species. In this study, we computationally and experimentally explore the functional significance of sequence variation within the seed region of human miRNAs. Our results indicate that change of a single nt within the 7-nt seed region changes the spectrum of targeted mRNAs significantly meanwhile further nt changes have little to no additional effect. This high functional cost of even a single nucleotide change within the seed region of miRNAs explains why the seed sequence is highly conserved among many miRNA families both within and between species and could help clarify the likely mechanisms underlying the evolution of miRNA regulatory control.
Functional and evolutionary significance of human microRNA seed region mutations.
Cell line
View Samples