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:Transcriptional changes in liver sinusoidal endothelial cells (LSECs) from mutant mouse embryos lacking endothelial chromatin-remodeling enzymes need investigation. In this study, we compared the transcriptomes of CD146+ LSECs and the non-EC liver cells from control, Chd4fl/fl;Brg1fl/+;VE-cadherin-Cre+, Chd4fl/+;Brg1fl/fl;VE-cadherin-Cre+, and Chd4fl/fl;Brg1fl/fl;VE-cadherin-Cre+ mice at embryonic day 12.5. Our results show that inflammation-related gene expression is upregulated in endothelial mutants lacking Chd4 and returns to normal when both Chd4 and Brg1 are deleted.
Project description:The endothelial cells lining the vascular wall maintain a selective barrier between blood and tissue. Structural connections between these endothelial cells are formed through vascular endothelial (VE)-cadherin-based adherens junctions. The extracellular domain of VE-cadherin forms homotypic bonds between neighboring cells, while its intracellular domain connects to the actin cytoskeleton via a conserved protein complex including α-, ß- and p120-catenins. Whether additional proteins bind to VE-cadherin and contribute to endothelial junction integrity remains unclear. By using mass spectrometry after VE-cadherin immunoprecipitations from human endothelial cells, we have determined the molecular interactions with VE-cadherin. The proteomics identified a core VE-cadherin interactome, consisting of nine proteins, which bind to VE-cadherin even in the absence of tyrosine phosphorylation of its intracellular domain. The core VE-cadherin interactome includes the known catenin proteins as well as four new interactors: ARVCF, ARHGAP23, KEAP1 and NGLY1. Co-immunoprecipitation and co-localization experiments verified that the VE-cadherin-binding protein ARVCF is an important component of endothelial adherens junctions. ARVCF binds to a selective pool of VE-cadherin proteins during junction maturation that is unbound from p120-catenin, through a mechanism involving the C-terminal intrinsically disordered regions of ARVCF. Depletion of ARVCF results in loss of endothelial barrier function and impairs collective cell migration. Accordingly, ARVCF is needed for VE-cadherin-based junction stabilization. Together, our results demonstrate that ARVCF is a key regulator of VE-cadherin to safeguard junctional stability and endothelial integrity.
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: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: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: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. The three endothelial cell lines were cultured. Total RNA was extracted using commercial homogenization (QIAshredder) and purification (RNeasy Mini Kit) reagents (Qiagen). Quality control (QC) of the RNA samples was performed using an Agilent Bioanalyzer 2100 (Agilent Technologies). Two different RNA extractions were processed for each of the cell lines under analysis, and each sample was labelled and hybridized to a Mouse Gene 1.0 ST Genechip array according to the manufacturer’s specifications (Affymetrix Inc). Data were analysed using Partek Genomics Suite v6.3 software (RMA algorithm). Differentially expressed genes were identified through ANOVA, using a fold change cutoff >2 and a p-value of 0.05.
Project description:We performed lineage tracing experiments using VE-Cadherin-Cre;LoxP-tdTomato mice. In these mice, endothelial cells (ECs) and their progeny are permanently marked by tdTomato fluorescence. We found that a substantial subset of stromal cells is derived from ECs, as indicated by their tdTomato expression. These findings support the notion that endothelial to mesenchymal transition (EndoMT) contributes to hematopoietic bone marrow niche formation in mice. Here we sought to determine the transcriptomic differences between endothelial-derived (tdTomato-positive) and non-endothelial-derived (tdTomato-negative) bone marrow stromal cells (BMSCs) and osteo/chondrolineage progenitor cells (OLCs). Murine niche populations were obtained from collagenased bone fraction of VE-Cadherin-Cre;LoxP-tdTomato mice at 3 weeks (n=2) or 11 weeks (n=2) of age. BMSCs (CD45-TER119-CD31-CD144-SCA-1+ CD51+ cells) and OLCs (CD45-TER119-CD31-CD144-Sca1-CD51+ cells) were FACS-purified and sequenced.