Project description:Endothelial differentiation occurs during normal vascular development in the developing embryo. Mouse embryonic stem (ES) cells were used to further define the molecular mechanisms of endothelial differentiation. By flow cytometry a population of VEGF-R2 positive cells was identified as early as 2.5 days after differentiation of ES cells, and a subset of VEGF-R2 + cells, that were CD41+ positive at 3.5 days. A separate population of VEGF-R2+ stem cells expressing the endothelial-specific marker CD144 (VE-cadherin) was also identified at this same time point. Microarray analysis of >45,000 transcripts was performed on RNA obtained from cells expressing VEGF-R2, CD41, and CD144. Experiment Overall Design: We identified four populations of cells; cells expressing VEGF-R2 (day 2.5), CD41 expressing cells (day 3.5), cells expressing CD144 (VE-Cadherin, day 3.5), and cells expressing CD144 (day 6.5). In addition to this, we have also obtained the negative control cells at each time such as VEGF-R2 (day 2.5) negative, CD41 negative (day 3.5), CD144 negative (VE-Cadherin, day 3.5), and negative CD144 (day 6.5). RNA for the microarray experiments were obtained in duplicate from two separately conducted experiments using the murine embryonic stem cells..
Project description:Expression data from three endothelial cell lines derived from murine embryonic stem cells expressing VE-cadherin, N-cadherin or both
Project description:Endothelial differentiation occurs during normal vascular development in the developing embryo. Mouse embryonic stem (ES) cells were used to further define the molecular mechanisms of endothelial differentiation. By flow cytometry a population of VEGF-R2 positive cells was identified as early as 2.5 days after differentiation of ES cells, and a subset of VEGF-R2 + cells, that were CD41+ positive at 3.5 days. A separate population of VEGF-R2+ stem cells expressing the endothelial-specific marker CD144 (VE-cadherin) was also identified at this same time point. Microarray analysis of >45,000 transcripts was performed on RNA obtained from cells expressing VEGF-R2, CD41, and CD144. Keywords: expression analysis
Project description:RNA-seq of endothelial (Endo), Pre-hematopoietic progenitor cells (Pre-HPCs) and hematopoietic progenitors (HP) derived from the in-vitro hematopoietic differentiation of mouse Embryonic Stem Cells (mESCs) harboring a biallelic inactivating deletion of the endogenous Tal1 gene, and a construct for the dox-induced expression of the hematopoietic genes Tal1, Lyl1 and Lmo2 (i3TFs Tal1Δ/Δ mESCs). i: inducible. TFs: transcription factors. Cells were treated with dox at one (Dox Unt) or two (Dox Dox) time-points during hematopoietic differentiation to inducibly express the 3TFs. Sequenced cell populations were purified by FACS sorting based on the cell-surface expression of the endothelial marker VE-CADHERIN and the hematopoietic marker CD41. Endo: VE-CADHERIN+CD41- Pre-HPCs: VE-CADHERIN+CD41+ HP: VE-CADHERIN-CD41+
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: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:Rationale: The mechanistic foundation of vascular maturation is still largely unknown. Several human pathologies are characterized by deregulated angiogenesis and unstable blood vessels. Solid tumours, for instance, get their nourishment from newly formed structurally abnormal vessels which present wide and irregular inter-endothelial junctions. Expression and clustering of the main endothelial-specific adherens junction protein, vascular endothelial (VE)-cadherin (VEC), upregulate genes with key roles in endothelial differentiation and stability. Objective: We aim at understanding the molecular mechanisms through which VEC triggers the expression of a set of genes involved in endothelial differentiation and vascular stabilization. Methods and Results: We compared a VEC-null cell line with the same line reconstituted with VEC wild type cDNA. VEC expression and clustering upregulated endothelial-specific genes with key roles in vascular stabilization including claudin-5, Vascular Endothelial-Protein Tyrosine Phosphatase (VE-PTP) and von Willebrand factor (vWf). Mechanistically VEC exerts this effect by inhibiting Polycomb protein activity on the specific gene promoters. This is achieved by preventing nuclear translocation of FoxO1 and β-catenin, which contribute to Polycomb repressive complex-2 (PRC2) binding to promoter regions of claudin-5, VE-PTP and vWf. VE-cadherin/β-catenin complex also sequesters a core subunit of PRC2 (Ezh2) at the cell membrane, preventing its nuclear translocation. Inhibition of Ezh2/VE-cadherin association increases Ezh2 recruitment to claudin-5, VE-PTP and vWf promoters, causing gene downregulation. RNAseq comparison of VEC-null and VEC-positive cells suggested a more general role of VE-cadherin in activating endothelial genes and triggering a vascular stability-related gene expression program. In pathological angiogenesis of human ovarian carcinomas, reduced VEC expression paralleled decreased levels of Claudin-5 and VE-PTP. Conclusions: These data extend the knowledge of Polycomb-mediated regulation of gene expression to endothelial cell differentiation and vessel maturation. The identified mechanism opens novel therapeutic opportunities to modulate endothelial gene expression and induce vascular normalization through pharmacological inhibition of the Polycomb-mediated repression system. Keywords: Polycomb, endothelial cells, VE-cadherin, vessel maturation, vascular biology, vascular permeability, cell signalling, epigenetics, gene regulation. Downloaded from http://circres.ahajour Conclusions: These data extend the knowledge of Polycomb-mediated regulation of gene expression to endothelial cell differentiation and vessel maturation. The identified mechanism opens novel therapeutic opportunities to modulate endothelial gene expression and induce vascular normalization through pharmacological inhibition of the Polycomb-mediated repression system
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: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.