Homeostatic hematopoietice stem cells (HSCs) with greater divisional history lose repopulating potential after very few cell divisions. Divisional history overrides both phenotype and immediate quiescence in determining functional activity. In GFP label retaining system GFP is progressively diluted when cells proceed through a cascade of divisions.
Divisional history and hematopoietic stem cell function during homeostasis.
Specimen part
View SamplesDefinitive hematopoiesis emerges via an endothelial-to-hematopoietic transition in the aorta-gonad-mesonephros (AGM) region and placenta. We have recently demonstrated the induction of hematopoietic stem/progenitors (HSPCs) from mouse fibroblasts with a combination of transcription factors progressing through endothelial-like precursors. Here, guided by our in vitro programming experiments we analyzed mouse placentas for the presence of the precursor phenotype. We identified a small population of CD34+ Sca1+Prom1+ (34PS) cells in mid-gestation placentas that do not express the pan-hematopoietic marker CD45. After isolation and culture 34PS cells acquire CD45 and generate large hematopoietic as well as cobblestone colonies. Prom1+ cells localize to the placental vascular labyrinth where HSPCs emerge. 34PS cells express markers associated with the hemogenic endothelium (CD31, Tie2, VE-Cadherin, Sox17, Runx1, Scl) and also markers identified by direct induction (Itga6/CD49f). This population is heterogeneous for the early hematopoietic marker CD41 and expresses the programming transcription factors. Remarkably, global gene expression profiles of placental 34PS cells correlate with AGM-derived hemogenic endothelium and fibroblast-derived precursors. Finally, when co-cultured with stroma placental 34PS cells give rise to B/T lymphoid cells as well as mixed colonies containing erythroid, myeloid and megakaryocytic cell lineages. In summary, we show that direct in vitro conversion provided a cell surface phenotype for the isolation of hemogenic precursors in vivo. Our findings provide insights into the specification of definitive hemogenesis in the placenta, in depth characterization of hemogenic precursor populations and the first evidence that direct in vitro conversion approaches can be used as a valuable tool to address basic developmental questions in vivo. Overall design: mRNAseq profiling on populations isolated by selected marker fluorescence activated cell sorting The 'E10_E12_HSPC_SingleCell_FPKM.txt.gz' contains the processed data for GSM1890353-GSM1890496.
Hematopoietic Reprogramming In Vitro Informs In Vivo Identification of Hemogenic Precursors to Definitive Hematopoietic Stem Cells.
No sample metadata fields
View SamplesDefinitive hematopoiesis emerges during embryogenesis via an endothelial-to-hematopoietic transition. We attempted to induce this process in mouse fibroblasts by screening a panel of factors for hemogenic activity. We identified a combination of four transcription factors, Gata2, Gfi1b, cFos, and Etv6 that efficiently induces endothelial-like precursor cells with the subsequent appearance of hematopoietic cells. The precursor cells express a human CD34 reporter, Sca1 and Prominin1 within a global endothelial transcription program. Emergent hematopoietic cells possess nascent/specifying hematopoietic stem cell gene expression profiles and cell surface phenotypes. After transgene silencing and reaggregation culture, the specified cells generate hematopoietic colonies in vitro. Thus, we have shown that a simple combination of transcription factors is sufficient to induce a complex, dynamic and multi-step developmental program in vitro. These findings provide insights into the specification of definitive hemogenesis and a platform for future development of patient-specific stem/progenitor cells as well as more differentiated blood products. Overall design: mRNA-seq profiling on populations generated after transduction with Gata2, Gfi1b, cFos and Etv6 at day 20 and day 35.
Induction of a hemogenic program in mouse fibroblasts.
Specimen part, Subject, Time
View SamplesExpression data from LEOPARD Syndrome-iPS clones, BJ-iPS cells and parental Fibroblasts
Patient-specific induced pluripotent stem-cell-derived models of LEOPARD syndrome.
Sex, Specimen part, Subject
View SamplesMicroRNA-520f regulates EMT, as it activates CDH1 (mRNA) and E-cadherin (protein) expression, and it suppresses tumor cell invasion. We have characterized miR-520f target genes through whole genome transcriptional profiling of miRNA transfected pancreas cancer cells (PANC-1).
miRNA-520f Reverses Epithelial-to-Mesenchymal Transition by Targeting <i>ADAM9</i> and <i>TGFBR2</i>.
Cell line, Treatment
View SamplesStudies investigating the causes of autism spectrum disorder (ASD) point to genetic as well as epigenetic mechanisms of the disease. Identification of epigenetic processes that contribute to ASD development and progression is of major importance and may lead to the development of novel therapeutic strategies. Here we identify the bromodomain and extra-terminal domain containing transcriptional regulators (BETs) as epigenetic drivers of an ASD-like disorder in mice. We found that the pharmacological suppression of the BET proteins by a novel, highly selective and brain-permeable inhibitor, I-BET858, leads to selective suppression of neuronal gene expression followed by the development of an autism-like syndrome in mice. Many of the I-BET858 affected genes have been linked to ASD in humans thus suggesting the key role of the BET-controlled gene network in ASD. Our studies also suggest that environmental factors controlling BET proteins or their target genes may contribute to the epigenetic mechanism of ASD.
Autism-like syndrome is induced by pharmacological suppression of BET proteins in young mice.
Specimen part
View SamplesE47 represses Foxp3 transcription, albeit indirectly through the activation of unknown negative regulatory of Foxp3 transcription.
Id3 Maintains Foxp3 Expression in Regulatory T Cells by Controlling a Transcriptional Network of E47, Spi-B, and SOCS3.
Age, Specimen part
View SamplesIn chicks, the avian homologue of the early growth response protein-1 (ZENK) has been shown to be increased in a special cell type of the retina, the glucagonergic amacrine cells, under conditions that lead to a reduction in eye growth (myopic defocus, recovery of myopia) and decreased under conditions that enhance ocular growth (hyperopic defocus, form-deprivation). The investigation of Egr-1 knock-out mice showed that homozygous knock-out mice with no functional Egr-1 protein developed relative axial myopia at the age of 42 and 56 days, compared to heterozygous- and wildtype Egr-1 knock-out mice.
Microarray analysis of retinal gene expression in Egr-1 knockout mice.
Sex, Age, Specimen part
View SamplesThe retina plays an important regulatory role in ocular growth. To screen for new retinal candidate genes that could be involved in the inhibition of ocular growth, we used chick microarrays to analyze the changes in retinal mRNA expression after myopic defocus was imposed by positive lens-wear.
Microarray analysis of retinal gene expression in chicks during imposed myopic defocus.
Sex, Age
View SamplesTransplanting renal allografts represents the major curative treatment of chronic renal failure. Despite recent advances in immunosuppressive therapy, long-term survival of allografts remains a major clinical problem. Kidney function depends in part on transport proteins such as MRP2 (ABCC2) which facilitates renal secretion of amphiphilic exogenous and endogenous compounds. Inherited variants of genes not related to the immune system have been shown to modify the outcome after renal transplantation. We investigated whether ABCC2 gene variants in the donor kidney affect renal graft function.
Multidrug resistance-related protein 2 genotype of the donor affects kidney graft function.
Sex
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