Project description:We sorted endothelial (EC), hematopoietic (HC) and hematopoietic stem/progenitor (HSPC) cell populations from AGM of E11.5 C57Bl6 embryos, established and compared their transcriptome to highlight specific regulators of hematopoietic emergence.
Project description:The aim of the experiment was to compare a newly defined population VE-Cadherin+GFP+ to control populations, VE-Cadherin- GFP+ and VE-Cadherin+GFP-.
Project description:By chemical modulation of the PKA/CREB and BMP pathways in isolated AGM VE-cadherin+ cells from mid-gestation embryos, we demonstrate that PKA/CREB regulates hematopoietic engraftment and clonogenicity of hematopoietic progenitors and is dependent on secreted BMP ligands through the type I BMP receptor. We used microarray to document upregulation of PKA/CREB-BMP pathway as well as global BMP target upregulation upon PKA/CREB activation. Isolated VE+ cells from E11.5 AGM were treated with BMP4 (4ng/ml), forskolin (25uM) or both for 8 hours before RNA isolation.
Project description:In order to identify genes regulated by VE-cadherin expression, we compared a mouse VE-cadherin null cell line (VEC null) with the same line reconstituted with VE-cadherin wild type cDNA (VEC positive). The morphological and functional properties of these cell lines were described previously [Lampugnani,M.G. et al. Contact inhibition of VEGF-induced proliferation requires vascular endothelial cadherin, beta-catenin, and the phosphatase DEP-1/CD148. J. Cell Biol. 161, 793-804 (2003)]. By Affymetrix gene expression analysis we found several genes up-regulated by VE-cadherin, among which claudin-5 reached remarkably high levels. The up-regulation of these genes required not only VE-cadherin expression but also cell confluence suggesting that VE-cadherin clustering at junctions was needed.
Project description:Vascular endothelial (VE-)cadherin is a homotypic adhesion protein that is expressed selectively by ECs in which it enables formation of tight vessels and regulation of vascular permeability. Since VE-cadherin is also strongly expressed in placental trophoblasts, it is a prime candidate for a molecular mechanism of vascular mimicry by those cells. Here, we show that the VE-cadherin is required for trophoblast migration and endovascular invasion into the maternal decidua. VE-cadherin deficiency results in loss of spiral artery remodeling due to a lack of invasive trophoblasts, leading to decreased flow of maternal blood into the placenta, fetal growth retardation and death. Loss of trophoblast invasion prevents decidualization, extracellular matrix remodeling, and immune cell clearance. These studies identify VE-cadherin as essential for trophoblast migration and coordination of decidual changes during endovascular invasion. They further suggest endothelial proteins such as VE-cadherin that are expressed by trophoblasts may play functionally distinct roles that do not simply mimic those in ECs.
Project description:The shear stress-regulated lncRNA LASSIE interacts with junctional proteins (e.g. PECAM-1, which interacts with VE-cadherin) and influences endothelial barrier function. Here we characterize the remodeling of the VE-Cadherin complex by the lncRNA LASSIE. LASSIE silenced HUVECs were subjected to co-immunoprecipitation using an anti-VE-cadherin antibody. Differentially associated proteins were identified by Mass spectrometry. This analysis revealed a significantly decreased association of cytoskeleton-linked proteins with VE-cadherin after silencing of LASSIE. Functional assays confirmed this result and characterized LASSIE as a stabilizer of junctional complexes in endothelial cells, important for normal shear stress sensing and barrier function.
Project description:Endothelial cells (ECs) express two members of the cadherin family, VE- and N-cadherin. While VE-cadherin induces EC homotypic adhesion, N-cadherin function in ECs remains largely unknown. EC-specific inactivation of either VE- or N-cadherin leads to early foetal lethality suggesting that these cadherins play a non-redundant role in vascular development. Goal of this study was to further investigate this hypothesis analyzing both additive and divergent functions of the two cadherins in ECs.
Project description:To clarify the relationship between eMPPs and other progenitors, including pre-HSCs, within the AGM landscape, we performed single cell RNA-sequencing of hematopoietic progenitors within the E11.5 AGM.