ChIP-on-chip with anti-RBPj antibody from embryonic AGM E11.5
Ontology highlight
ABSTRACT: Hematopoietic 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 refering to the tissues around the hemogenic aorta. Hematopoiesis depends on the Notch pathway and the identification of Notch-targets is important for the understanding of blood origin. Hematopoietic Stem Cells (HSCs) specification occurs in the embryonic aorta and requires Notch activation, however which are the elements regulated by Notch that control this process are mainly unknown. Here, we took a genome-wide approach to identify putative direct Notch targets by precipitating the chromatin that binds to the Notch partner RBPj in the Aorta-Gonad-Mesonephros (AGM) tissue from E11.5 mouse embryos. This assay revealed 701 gene promoter regions as candidates to be regulated by Notch in the AGM. Chromatin was obtained from a pool of 40 dissected AGMs at E11.5. Chromatin immunoprecipitation (ChIP) was performed as previously described (Aguilera et al, PNAS 2004) with minor modifications. In brief, cross-linked chromatin was sonicated for 10 minutes, medium-power, 0.5-interval; with a Bioruptor (Diagenode) and precipitated with anti-RBPJ (Chu and Bresnick, 2004). After crosslinkage reversal, DNA was used as a template for PCR or for array hybridization. Mouse promoter chip on chip microarray SET (Agilent) was used to identify RBPj targets. It covers 70,000 best identified gene regions with a-5.5 kb to + 2.5 kb range, and has on average 25 probes per gene with an average probe to probe distance of 200 bp. The ChIP-on-chip was performed with dye swaps and one IgG control was brought along. Enrichment analysis was done by comparing the precipitation normalized dye swap signal with input control signal.
Project description:Hematopoietic 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 refering to the tissues around the hemogenic aorta. Hematopoiesis depends on the Notch pathway and the identification of Notch-targets is important for the understanding of blood origin.
Project description:Hematopoietic 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 refering 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. The effect of Notch activation by each one of the ligands has been tested on c-kit+ and ckit- cells from the endothelium of the E11.5 AGM . Incubations with stromal cell lines exposed the cells to high levels of ligand and induced changes in the transcriptome of these cells.
Project description:The aim of the experiment was to compare newly defined CD44Neg, CD44LoKitNeg, CD44LoKitPos and CD44High populations from mouse Aorta-Gonad-Mesonephros (AGM) region
Project description:The Notch pathway is a well conserved cell to cell communication mechanism that is normally involved in many developmental processes and when aberrantly activated it leads to diseases such as cancer. One such example is the neural stem cell tumours that arise from constitutive Notch activity in Drosophila neuroblasts from the larval Central Nervous System (CNS). To investigate how hyper-activation of Notch in larval neuroblasts leads to tumours, we mapped genome-widely the regions that are bound by Su(H) (the core Notch pathway transcription factor, known as CSL in mammals). We combined these results with the profiling of upregulated mRNAs in CNSs where Notch is hyper-activated for 24h vs control CNSs and identified 127 putative direct Notch targets in the hyperplastic CNSs. Included were genes associated with the neuroblast maintenance and self-renewal programme and genes coding for temporal transcription factors, which are involved in neuroblast progression and generation of progeny with specific identity over time. Thus, Notch induces neural stem cell tumors by promoting the expression of genes that contribute to stem cell identity and by reprogramming expression of temporal factors that regulate maturity. Su(H) binding profile in Drosophila larval CNSs where Notch is constitutively active for 24 hours. In total there are 3 samples of Su(H) ChIP in Notch hyper-activated larval CNSs.
Project description:Hematopoietic stem cells (HSCs) are at the basis of the hematopoietic hierarchy. Their ability to self-renew and differentiate is strictly controlled by molecular signals produced by their surrounding micorenvironments composed of stromal cells. HSCs first emerge in the AGM (Aorta Gonads Mesonephros) region, amplify in the fetal liver (FL) and are maintained in the adult bone marrow (BM). To further characterize the molecular program of the HSC niches, we have compared the global transcriptome of HSC-supportive and non-supportive stromal clones established from the AGM, FL and BM. Hematopoietic stem cells (HSCs) are at the basis of the hematopoietic hierarchy. Their ability to self-renew and differentiate is strictly controlled by molecular signals produced by their surrounding micorenvironments composed of stromal cells. HSCs first emerge in the AGM (Aorta Gonads Mesonephros) region, amplify in the fetal liver (FL) and are maintained in the adult bone marrow (BM). To further characterize the molecular program of the HSC niches, we have compared the global transcriptome of HSC-supportive line from Fetal Calvaria (OP9) and non-supportive stromal clones from fetal liver (BFC). Hematopoietic stem cells (HSCs) are at the basis of the hematopoietic hierarchy. Their ability to self-renew and differentiate is strictly controlled by molecular signals produced by their surrounding micorenvironments composed of stromal cells. HSCs first emerge in the AGM (Aorta Gonads Mesonephros) region, amplify in the fetal liver (FL) and are maintained in the adult bone marrow (BM). To further characterize the molecular program of the HSC niches, we have compared the global transcriptome of HSC-supportive and non-supportive stromal clones established from fetal liver. We took advantage of stromal clones established from the AGM, FL and BM and tested for their ability to support or not HSCs ex vivo. RNA were extracted from confluent stromal cultures or sorted cells and used for hybridization of Affymetrix (mouse gene 1.0 ST) microarrays.
Project description:Hematopoietic stem cells (HSC) develop from hemogenic endothelium (HE) within embryonic arterial vessels such as the aorta of the aorta-gonad-mesonephros region (AGM). To identify the signals responsible for HSC formation, we used single cell RNA-sequencing to simultaneously analyze the transcriptional profiles of AGM-derived cells transitioning from HE to HSC, and AGM-derived endothelial cells which provide signals sufficient to support HSC maturation and self-renewal. Pseudotemporal ordering revealed dynamics of gene expression during the HE to HSC transition, identifying surface receptors specifically expressed on developing HSC. Transcriptional profiles of niche endothelial cells enabled identification of corresponding ligands, including those signaling to Notch receptors, VLA-4 integrin, and CXCR4, which, when integrated in an engineered platform, were sufficient to support the generation of engrafting HSC. These studies provide a transcriptional map of the signaling interactions necessary for the development of HSC and advance the goal of engineering HSC for therapeutic applications
Project description:Hematopoietic 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. AGM regions were obtained from E11.5 embryos by dissection and digested with 0.1% collagenase. Cells were stained with anti-CD31, anti-ckit, anti-CD45 and anti-Ter119 antibodies. Sorting of the CD31+CD45-Ter119- population was performed, and cells were separated into c-kit+ and c-kit-. 3 replicates each of c-kit+ and c-kit- cells.
Project description:Hematopoietic stem cells (HSC) are generated from specialized endothelial cells of the embryonic aorta. Previously, inflammatory factors have been implicated in regulating mouse HSC development, but it is unclear what cells in the embryonic aorta-gonad- mesonephros (AGM) microenvironment produce these factors. In the adult, macrophages play both pro- and anti-inflammatory roles. We sought to examine whether macrophages or other hematopoietic cells found in the embryo prior to HSC generation are involved in the AGM HSC-generative microenvironment. Our CyTOF results indicate two abundant myeloid cell types - mannose-receptor positive AGM- associated macrophages (AGM-aM) and mannose-receptor negative macrophages/progenitors. We show that the appearance of macrophages in the AGM is dependent on CX3CR1. AGM-aM express a pro-inflammatory signature, localize to the embryonic aorta and dynamically interact with nascent and emerging intra-aortic hematopoietic cells (IAHC). Importantly, upon macrophage depletion, no adult- repopulating HSCs are detected, thus implicating unique pro-inflammatory AGM- associated macrophages in regulating the embryonic development of HSCs.
Project description:To investigate the influence of chromatin organization and dynamics on the response to Notch signaling, we partitioned Drosophila chromatin using histone modifications and established This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
Project description:The aim of this experiment was to compare by single-cell RNA sequencing the aorta-gonad-mesonephros (AGM) region and yolk sac (YS), the two major sites of embryonic hematopoietic, between 9.5 and 11.5 days of mouse embryonic development.