The lack of mouse models permitting the specific ablation of tissue-resident macrophages and monocyte-derived cells complicates understanding of their contribution to tissue integrity and to immune responses. Here we use a new model permitting diphtheria-toxin (DT)-mediated depletion of those cells and in which dendritic cells are spared. We showed that the myeloid cells of the mouse ear skin dermis are dominated by a population of melanin-laden macrophages, called melanophages, that has been missed in most previous studies. By using gene expression profiling, DT-mediated ablation and parabiosis, we determined their identity including their similarity to other skin macrophages, their origin and their dynamics. Limited information exist on the identity of the skin cells responsible for long-term tattoo persistence. Benefiting of our knowledge on melanophages, we showed that they are responsible for retaining tattoo pigment particles through a dynamic process which characterization has direct implications for improving strategies aiming at removing tattoos.
Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal.
Specimen part, Treatment
View SamplesThe aim of the dataset was to study on a genome-wide level the impact of Lat deficiency on gene expression in resting and activated CD4+ T cells
Quantitative proteomics analysis of signalosome dynamics in primary T cells identifies the surface receptor CD6 as a Lat adaptor-independent TCR signaling hub.
Specimen part
View SamplesOverall goal: To elucidate the endothelial-specific role of Gata4 signaling in endothelial maturation and vascular maintenance. Purpose of analysis: To generate a transcriptional profile of Gata4-deficient endothelial cells in the adult myocardium under homeostatic conditions. Overall design: Experimental structure: Transcriptional profile generated using RNAseq and differential gene expression analyses of endothelial cells lacking Gata4 isolated from healthy hearts.
Gata4-Dependent Differentiation of c-Kit<sup>+</sup>-Derived Endothelial Cells Underlies Artefactual Cardiomyocyte Regeneration in the Heart.
Specimen part, Subject
View SamplesThe chromatin modifying enzymes that drive the erythroid-specific transcription program are incompletely understood. Setd8 is the sole histone methyltransferase in mammals capable of generating mono-methylated histone H4 lysine 20 (H4K20me1) and is expressed at significantly higher levels in erythroid cells than any other cell- or tissue- type, suggesting that Setd8 has an erythroid-specific function. To test this hypothesis, stable knockdown of Setd8 was established in extensively self-renewing erythroblasts (ESREs), a well-characterized, non-transformed, model of erythroid maturation. Setd8 knockdown impaired erythroid maturation, characterized by a delay in hemoglobin accumulation, larger cell area, persistent kit expression, incomplete nuclear condensation, and lower rates of enucleation than control cells. Setd8 knockdown did not alter ESRE proliferation or viability, or result in accumulation of DNA damage. Global gene expression analyses following Setd8 knockdown suggests that in erythroid cells, Setd8 functions primarily as a repressor and demonstrated high levels of Gata2 expression. Setd8 occupies critical regulatory elements in the Gata2 locus, and knockdown of Setd8 resulted in loss of H4K20me1 and gain of H4 acetylation at the Gata2 1S promoter. Taken together, these results imply that Setd8 is an important regulator of erythroid maturation that works in part through repression of Gata2. Overall design: RNA-seq was performed of Setd8 knockdown and control cells, both while the cells were proliferating, and after 6 hours of maturation.
Histone methyltransferase Setd8 represses Gata2 expression and regulates erythroid maturation.
No sample metadata fields
View SamplesPsoriasis is a chronic inflammatory skin disease of unknown etiology. Although macrophages and dendritic cells (DCs) have been proposed to drive the psoriatic cascade, their largely overlapping phenotype hampered studying their respective role. Topical application of Imiquimod, a Toll-like receptor 7 agonist, induces psoriasis in patients and psoriasiform inflammation in mice. We showed that daily application of Imiquimod for 14 days recapitulated both the initiation and the maintenance phase of psoriasis. Based on our ability to discriminate Langerhans cells (LCs), conventional DCs, monocytes, monocyte-derived DCs and macrophages in the skin, we characterized their dynamics during both phases of psoriasis. During the initiation phase, neutrophils infiltrated the epidermis whereas monocytes and monocyte-derived DCs were predominant in the dermis. During the maintenance phase, LCs and macrophage numbers increased in the epidermis and dermis, respectively. LC expansion resulted from local proliferation, a conclusion supported by transcriptional analysis. Continuous depletion of LCs during the course of Imiquimod treatment aggravated chronic psoriatic symptoms as documented by an increased influx of neutrophils and a stronger inflammation. Therefore, by developing a mouse model that mimics the human disease more accurately, we established that LCs play a negative regulatory role during the maintenance phase of psoriasis.
Dynamics and Transcriptomics of Skin Dendritic Cells and Macrophages in an Imiquimod-Induced, Biphasic Mouse Model of Psoriasis.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reconstruction of gene regulatory networks reveals chromatin remodelers and key transcription factors in tumorigenesis.
Specimen part, Cell line
View SamplesThe mechanistic links between transcription factors and the epigenetic landscape, which coordinate the deregulation of gene networks during cell transformation are largely unknown. We used an isogenic model of stepwise tumorigenic transformation of human primary cells to monitor the progressive deregulation of gene networks upon immortalization and oncogene-induced transformation. By combining transcriptome and epigenome data for each step during transformation and by integrating transcription factor (TF) - target gene associations, we identified 142 Tfs and 24 chromatin remodelers/modifiers (CRMs), which are preferentially associated with specific co-expression paths that originate from deregulated gene programming during tumorigenesis. These Tfs are involved in the regulation of divers processes, including cell differentiation, immune response and establishment/modification of the epigenome. Unexpectedly, the analysis of chromatin state dynamics revealed patterns that distinguish groups of genes, which are not only co-regulated but also functionally related. Further decortication of TF targets enabled us to define potential key regulators of cell transformation, which are engaged in RNA metabolism and chromatin remodelling. Our study suggests a direct implication of CRMs in oncogene-induced tumorigenesis and identifies new CRMs involved in this process. This is the first comprehensive view of gene regulatory networks that are altered during the process of stepwise human cellular tumorigenesis in a virtually isogenic system.
Reconstruction of gene regulatory networks reveals chromatin remodelers and key transcription factors in tumorigenesis.
Specimen part, Cell line
View SamplesCardiac fibroblasts convert to myofibroblasts with injury to mediate healing after acute myocardial infarction and to mediate long-standing fibrosis with chronic disease. Myofibroblasts remain a poorly defined cell-type in terms of their origins and functional effects in vivo. Methods: Here we generate Postn (periostin) gene-targeted mice containing a tamoxifen inducible Cre for cellular lineage tracing analysis. This Postn allele identifies essentially all myofibroblasts within the heart and multiple other tissues. Results: Lineage tracing with 4 additional Cre-expressing mouse lines shows that periostin-expressing myofibroblasts in the heart derive from tissue-resident fibroblasts of the Tcf21 lineage, but not endothelial, immune/myeloid or smooth muscle cells. Deletion of periostin+ myofibroblasts reduces collagen production and scar formation after myocardial infarction. Periostin-traced myofibroblasts also revert back to a less activated state upon injury resolution. Conclusions: Our results define the myofibroblast as a periostin-expressing cell-type necessary for adaptive healing and fibrosis in the heart, which arises from Tcf21+ tissue-resident fibroblasts. Overall design: Fluidigm C1 whole genome transcriptome analysis of lineage mapped cardiac myofibroblasts
Genetic lineage tracing defines myofibroblast origin and function in the injured heart.
Specimen part, Cell line, Subject
View SamplesDouble-stranded RNA (dsRNA) can enter different pathways in mammalian cells, including sequence-specific RNA interference, sequence-independent interferon response and editing by adenosine deaminases. To assess the potential of expressed dsRNA to induce interferon stimulated genes in somatic cells, we performed microarray analysis of HEK293 and HeLa cells transfected with a MosIR plasmid expressing an mRNA with a long inverted repeat structure in its 3UTR (MosIR) or with a parental MosIR plasmid (without inverted repeat) as a control.
dsRNA expression in the mouse elicits RNAi in oocytes and low adenosine deamination in somatic cells.
Specimen part
View SamplesRNA-seq was performed on eosinophils isolated from colons of naive C57/BL6 mice. Overall design: 2 samples of naive colonic eosinophils
Reuse of public, genome-wide, murine eosinophil expression data for hypotheses development.
Specimen part, Cell line, Subject
View Samples