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.
Overlapping and divergent signaling pathways of N-cadherin and VE-cadherin in endothelial cells.
Specimen part, Cell line
View SamplesIn 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.
Endothelial adherens junctions control tight junctions by VE-cadherin-mediated upregulation of claudin-5.
No sample metadata fields
View SamplesJunction Adhesion Molecule-A (JAM-A) is present on leukocytes and platelets where it promotes cell adhesion and motility. We are interested in an interaction between JAM-A and tumor progression/metastases. To address this point, we mated JAM-A-/- mice and mouse mammary tumor model MMTV-PyMT mice which, which express polyoma middle T antigen under the control of mouse mammary tumor virus. MMTV-PyMT mice show 100% penetration of mammary tumor and highly metastases to lung. MMTV-PyMT mice without JAM-A show less primary tumor progression, therefore JAM-A enhance primary tumor progression. Then we are addressing the molecular mechanism of this phenomenon by in vivo. Furthermore, we would like to examine JAM-A deficient MMTV tumor signature.
Abrogation of junctional adhesion molecule-A expression induces cell apoptosis and reduces breast cancer progression.
Specimen part
View SamplesMesoangioblasts are vessel-associated progenitor cells that show therapeutic promise for the treatment of muscular dystrophy. Mesoangioblasts have the ability to undergo skeletal muscle differentiation and cross the blood vessel wall regardless of the developmental stage at which they are isolated. Here we show that PW1/Peg3 is expressed at high levels in mesoangioblasts obtained from mouse, dog and human tissues and its level of expression correlates with their myogenic competence. Silencing PW1/Peg3 markedly inhibits myogenic potential of mesoangioblasts in vitro through MyoD degradation. Moreover, lack of PW1/Peg3 abrogates mesoangioblast ability to cross the vessel wall and to engraft into damaged myofibers through the modulation of the junctional adhesion molecule-A. We conclude that PW1/Peg3 function is essential for conferring proper mesoangioblast competence and that the determination of PW1/Peg3 levels in human mesoangioblasts may serve as a biomarker to identify the best donor populations for therapeutic application in muscular dystrophies.
PW1/Peg3 expression regulates key properties that determine mesoangioblast stem cell competence.
Sex, Specimen part
View SamplesIn an attempt to elucidate the molecular mechanisms underlying the multiple roles of L1 in endothelium, we checked whether manipulating its expression affected the transcriptome of lECs. To this purpose, we compared the gene expression profiles of L1-overexpressing and control lECs by Affymetrix, which revealed a remarkable effect of L1 overexpression on lECs transcriptome.
Endothelial deficiency of L1 reduces tumor angiogenesis and promotes vessel normalization.
Specimen part
View SamplesVascular permeability is frequently associated with inflammation and it is triggered by chemokines and by a cohort of secreted permeability factors, such as VEGF. In contrast, here we showed that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and it is independent of VEGF. Both global and endothelial-specific deletion of PR block physiological vascular permeability in the uterus while misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of genome-wide transcriptional profile of endothelium and ChIP-sequencing revealed that PR induces a NR4A1 (Nur77/TR3) specific transcriptional program that broadly regulates vascular permeability in response to progesterone. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely and venule-specific regulation of vascular barrier function. Silencing NR4A1 blocks PR-mediated permeability responses indicating a direct link between PR and NR4A1. These results reveal a previously unknown function for progesterone receptor on endothelial cell biology with consequences to physiological vascular permeability and implications to the clinical use of progestins and anti-progestins on blood vessel integrity. Overall design: Examination of PR target genes in human umbilical vein endothelial cells (HUVECs) using RNA-seq (PR infected only -PR only and PR infected followed by ligand treatment-PR+P)
Progesterone receptor in the vascular endothelium triggers physiological uterine permeability preimplantation.
Specimen part, Treatment, Subject
View SamplesAnalysis of gene expression profile in peritoneal macrophage extracted from LPS or PBS challenged DUSP3-/- and WT mice. DUSP3 deletion protects mice from sepsis and endotoxemia. We performed a microarray analysis to get insights into the differentially regulated pathways between WT and KO under inflammatory conditions.
DUSP3 Genetic Deletion Confers M2-like Macrophage-Dependent Tolerance to Septic Shock.
Sex, Age, Specimen part
View SamplesLymphotoxin-mediated activation of the lymphotoxin- receptor (LTR) has been implicated in several physiological and pathological processes, including lymphoid organ development, T-cell maturation, and solid and hematopoietic malignancies. Its role in T-cell acute lymphoblastic leukemia (T-ALL) or other T-cell malignancies has remained however to be investigated. Here we show that the genes encoding lymphotoxin (LT)- and LT were expressed in T-ALL patient samples, more abundantly in the TAL/LMO molecular subtype, and in the TEL-JAK2 mouse model of cortical/mature T-ALL. Surface LT12 protein was detected in primary mouse T-ALL cells, but only upon phorbol ester stimulation or absence of microenvironmental LTR interaction. Indeed, in contrast to leukemic cells collected from transplanted Ltbr/ mice or from co-cultures with Ltbr/ mouse embryonic fibroblasts (MEF), those collected from Ltbr+/+ mice or from Ltbr+/+ MEF co-cultures presented no surface LT expression. Supporting the notion that LT signaling plays a role in T-ALL, inactivation of the Ltbr gene in mice resulted in a statistically significant delay in TEL-JAK2-induced leukemia onset. Expression of the Lta and Ltb genes was found to be increased at the early asymtptomatic stages of TEL-JAK2 T-ALL, when only low proportions of malignant thymocytes are present in normal sized thymus. Interestingly, young asymptomatic TEL-JAK2;Ltbr/ mice presented significantly less leukemic thymocytes than TEL-JAK2;Ltbr+/+ mice. Together, these data indicate that early lymphotoxin expression by T-ALL cells activates LTR signaling in thymic stromal cells, thus promoting leukemogenesis.
Lymphotoxin-β receptor in microenvironmental cells promotes the development of T-cell acute lymphoblastic leukaemia with cortical/mature immunophenotype.
Sex, Age, Specimen part
View SamplesEnsuring cooperation among formerly autonomous cells has been a central challenge in the evolution of multicellular organisms. One solution is monoclonality, but this option does not eliminate genetic and epigenetic variability, leaving room for exploitative behavior. We therefore hypothesized that embryonic development must be protected by robust regulatory mechanisms that prevent aberrant clones from superseding wild-type cells. Using a genome-wide screen in murine induced pluripotent stem cells, we identified a network of genes (centered on p53, topoisomerase 1, and olfactory receptors) whose downregulation caused the cells to replace wild-type cells, both in vitro and in the mouse embryowithout perturbing normal development. These genes thus appear to fulfill an unexpected role in fostering cell cooperation.
Safeguards for cell cooperation in mouse embryogenesis shown by genome-wide cheater screen.
Specimen part, Treatment
View SamplesSenescence in WI-38 cell context was induce by RASv12 over expression Cellular senescence is a permanent cell cycle arrest that is triggered by cancer- initiating or promoting events in mammalian cells and is now considered a major tumour suppressor mechanism. Here, we did a transcriptomic analysis and compared WI-38 contol wich is a human fibroblaste cell line and WI-38 that overexpressed RASv12 a G protein that induce senescence. The goal of our project is to compare transciptomic profile of human growing fibroblast (WI-38 control) and senescent human fibroblast (WI-38 OERAS)
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
Specimen part
View Samples