scholarly journals Endothelial cell infection in vivo by equine infectious anaemia virus

1999 ◽  
Vol 80 (9) ◽  
pp. 2393-2397 ◽  
Author(s):  
J. Lindsay Oaks ◽  
Catherine Ulibarri ◽  
Timothy B. Crawford
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Infection ◽  
Tissue Macrophage ◽  
Cell Type Specific ◽  
Weakly Virulent ◽  
Equine Infectious Anaemia Virus

Equine infectious anaemia virus (EIAV) infection of horses is characterized clinically by recurrent episodes of fever, thrombocytopenia and anaemia. In vivo, the only site of virus replication that has been previously demonstrated for EIAV is the tissue macrophage. In this study, in situ hybridization for EIAV was combined with immunohistochemistry for cell-type-specific markers to identify infected endothelial cells. EIAV-infected endothelial cells and macrophages were detected in horses infected with either virulent wild-type or with weakly virulent tissue culture-adapted strains of EIAV. The role of endothelial cell infection in the pathogenesis of EIAV remains undefined, but could contribute to the development of thrombocytopenia. However, endothelial cell infection does not appear to be a determinant of virulence for EIAV.

scholarly journals The tight junctions protein Claudin-5 limits endothelial cell motility

2020 ◽  
pp. jcs.248237
Author(s):  
Zhenguo Yang ◽  
Shuilong Wu ◽  
Federica Fontana ◽  
Yanyu Li ◽  
Wei Xiao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Motility ◽  
Dorsal Aorta ◽  
Aortic Endothelial Cells ◽  
Differential Adhesion ◽  
Adhesive Forces

Steinberg's differential adhesion hypothesis suggests that adhesive mechanisms are important for sorting of cells and tissues during morphogenesis (Steinberg, 2007). During zebrafish vasculogenesis, endothelial cells sort into arterial and venous vessel beds but it is unknown whether this involves adhesive mechanisms. Claudins are tight junction proteins regulating the permeability of epithelial and endothelial tissue barriers. Previously, the roles of Claudins during organ development have exclusively been related to their canonical functions in determining paracellular permeability. Here, we use atomic force microscopy to quantify Claudin-5-dependent adhesion and find that this strongly contributes to the adhesive forces between arterial endothelial cells. Based on genetic manipulations, we reveal a non-canonical role of Claudin-5a during zebrafish vasculogenesis, which involves the regulation of adhesive forces between adjacent dorsal aortic endothelial cells. In vitro and in vivo studies demonstrate that loss of Claudin-5 results in increased motility of dorsal aorta endothelial cells and in a failure of the dorsal aorta to lumenize. Our findings uncover a novel role of Claudin-5 in limiting arterial endothelial cell motility, which goes beyond its traditional sealing function during embryonic development.

Junctional Adhesion Molecule-1 Is Involved in bFGF-Induced Angiogenesis In Vivo.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 840-840
Author(s):  
Vesselina G. Cooke ◽  
Meghna U. Naik ◽  
William Skarnes ◽  
Ulhas P. Naik
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Vessels ◽  
Adhesion Molecule ◽  
The Body ◽  
Cell Junctions ◽  
Fluorescein Angiogram ◽  
And Migration

Abstract Neovascularization is a multistep process that occurs in the body in both physiological and pathological conditions. We have recently shown that Junctional Adhesion Molecule-1 (JAM-1), a member of the Ig superfamily of molecules, is involved in endothelial cell adhesion and migration, leading to angiogenesis. In quiescent endothelial cells, JAM-1 is located at the cell-cell junctions where it forms a complex with integrin αvβ3. Upon treatment of the cells with growth factors, such as bFGF, JAM-1 dissociates from its complex with αvβ3 and redistributes to the cell surface. Blockage of the extracellular domain of JAM-1 inhibits bFGF-induced endothelial cell morphology, proliferation and angiogenesis. Additionally, functional knock-down of JAM-1 using the RNAi technique in endothelial cells showed decreased adhesion and migration of these cells, indicating a possible role for JAM-1 in angiogenesis. In this report, we show that JAM-1 has an important role in bFGF-induced angiogenesis in vivo. Here we present for the first time the generation JAM-1 knock-out mice, using the gene trap strategy. We have successfully confirmed the JAM-1 −/− genotype via Southern, Northern, and Western blot analyses. JAM-1 −/− mice are viable and do not seem to have any external abnormalities, except that they appear to be smaller in size. Retinal fluorescein angiogram revealed no evidence for morphological defects in the vasculature of JAM-1 −/− mice. To evaluate the role of JAM-1 in angiogenesis, we performed an aortic ring assay with both wild type and JAM-1−/− mice. Mouse thoracic aortas were harvested, cross-sectioned into rings of 1-mm thickness, and cultured in a three-dimensional Matrigel supplied with 50 ng/ml bFGF. Vascular sproutings were counted every other day for a period of 7 days at which time they were stained with crystal violet and photographed. Aortic rings from WT mice treated with bFGF showed a 2.8-fold increase in microvessel growth, compared to WT controls with no supplementation of bFGF. In contrast, microvessel sproutings in bFGF treated aortic rings from JAM-1 −/− mice were no more than the vessels in the WT control mice. These results suggest that JAM-1 may be important for bFGF induced angiogenesis. To further confirm the role of JAM-1 in angiogenesis, WT and JAM-1 −/− mice were injected in their flank region with Matrigel containing 80 ng/ml bFGF and 60 U/ml heparin. Two weeks after injection, Matrigel plugs were excised, embedded in paraffin, and the presence of blood vessels was visualized by H&E staining. Matrigel plugs from control WT mice that were not treated with bFGF showed no vascularization, while bFGF supplied Matrigel plugs from WT mice showed a robust vessel growth. Interestingly, bFGF-treated Matrigel plugs form JAM-1−/− mice failed to produce any blood vessels. These ex vivo and in vivo studies using JAM-1−/− mice suggest that JAM-1 has a unique and essential role in bFGF-induced angiogenesis.

scholarly journals Gas6 promotes inflammation by enhancing interactions between endothelial cells, platelets, and leukocytes

Blood ◽  
2008 ◽  
Vol 111 (8) ◽  
pp. 4096-4105 ◽  
Author(s):  
Marc Tjwa ◽  
Lola Bellido-Martin ◽  
Yuan Lin ◽  
Esther Lutgens ◽  
Stéphane Plaisance ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Heart Transplantation ◽  
Mouse Models ◽  
Inflammatory Stimuli ◽  
Leukocyte Extravasation

AbstractThe role of Gas6 in endothelial cell (EC) function remains incompletely characterized. Here we report that Gas6 amplifies EC activation in response to inflammatory stimuli in vitro. In vivo, Gas6 promotes and accelerates the sequestration of circulating platelets and leukocytes on activated endothelium as well as the formation and endothelial sequestration of circulating platelet-leukocyte conjugates. In addition, Gas6 promotes leukocyte extravasation, inflammation, and thrombosis in mouse models of inflammation (endotoxinemia, vasculitis, heart transplantation). Thus, Gas6 amplifies EC activation, thereby playing a key role in enhancing the interactions between ECs, platelets, and leukocytes during inflammation.

scholarly journals Functional interactions of T cells with endothelial cells: the role of CD40L-CD40-mediated signals.

1995 ◽  
Vol 182 (6) ◽  
pp. 1857-1864 ◽  
Author(s):  
M J Yellin ◽  
J Brett ◽  
D Baum ◽  
A Matsushima ◽  
M Szabolcs ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Cell Activation ◽  
Endothelial Cell Activation ◽  
Cd40 Expression

CD40 is expressed on a variety of cells, including B cells, monocytes, dendritic cells, and fibroblasts. CD40 interacts with CD40L, a 30-33-kD activation-induced CD4+ T cell surface molecule. CD40L-CD40 interactions are known to play key roles in B cell activation and differentiation in vitro and in vivo. We now report that normal human endothelial cells also express CD40 in situ, and CD40L-CD40 interactions induce endothelial cell activation in vitro. Frozen sections from normal spleen, thyroid, skin, muscle, kidney, lung, or umbilical cord were studied for CD40 expression by immunohistochemistry. Endothelial cells from all tissues studied express CD40 in situ. Moreover, human umbilical vein endothelial cells (HUVEC) express CD40 in vitro, and recombinant interferon gamma induces HUVEC CD40 upregulation. CD40 expression on HUVEC is functionally significant because CD40L+ Jurkat T cells or CD40L+ 293 kidney cell transfectants, but not control cells, upregulate HUVEC CD54 (intercellular adhesion molecule-1), CD62E (E-selectin), and CD106 (vascular cell adhesion molecule-1) expression in vitro. Moreover, the kinetics of CD40L-, interleukin 1-, or tumor necrosis factor alpha-induced CD54, CD62E, and CD106 upregulation on HUVEC are similar. Finally, CD40L-CD40 interactions do not induce CD80, CD86, or major histocompatibility complex class II expression on HUVEC in vitro. These results demonstrate that CD40L-CD40 interactions induce endothelial cell activation in vitro. Moreover, they suggest a mechanism by which activated CD4+ T cells may augment inflammatory responses in vivo by upregulating the expression of endothelial cell surface adhesion molecules.

Effect of Ca2+ ionophores on membrane potential of pig coronary artery endothelial cells

1992 ◽  
Vol 262 (6) ◽  
pp. H1823-H1831 ◽  
Author(s):  
P. Y. von der Weid ◽  
J. L. Beny
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Coronary Artery ◽  
Maximal Response ◽  
Response Curves ◽  
Direct Role ◽  
Pig Coronary Artery ◽  
Endothelium Dependent Relaxation

Ca2+ ionophores (A23187 and ionomycin) were used to determine whether an increase in cytosolic Ca2+ plays a direct role in pig coronary endothelial cell hyperpolarization. Ionophores induced concentration-dependent hyperpolarizations that were not altered by the presence of N omega-nitro-L-argnine (L-NNA), and inhibitor of nitric oxide synthesis. d-Tubocurarine decreased by 65-89% the A23187- and substance P (SP)-generated hyperpolarization of endothelial cells. To study the role of endothelial cell hyperpolarization in the endothelium-dependent relaxation of precontracted coronary artery strips, A23187 and SP concentration-response curves were built up in the presence of d-tubocurarine and/or L-NNA. A decrease in the maximal response was observed only when both d-tubocurarine and L-NNA were present. Our direct in situ approach gives results in agreement with a gating of Ca(2+)-activated K+ channels during A23187- and SP-induced hyperpolarizations of endothelial cells. We suggest that these hyperpolarizations play a role in the endothelial cell-dependent relaxation induced by A23187 and SP in the pig coronary artery.

An Electron Microscopic Study of Platelet Thrombus Formation in the Rabbit with Particular Regard to 5-Hydroxytryptamine Release

1967 ◽  
Vol 18 (03/04) ◽  
pp. 592-604 ◽  
Author(s):  
H. R Baumgartner ◽  
J. P Tranzer ◽  
A Studer
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vessel Wall ◽  
Thrombus Formation ◽  
Endothelial Damage ◽  
Electron Microscopic ◽  
Rabbit Ear ◽  
Basement Lamina ◽  
Platelet Thrombus

SummaryElectron microscopic and histologic examination of rabbit ear vein segments 4 and 30 min after slight endothelial damage have yielded the following findings :1. Platelets do not adhere to damaged endothelial cells.2. If the vessel wall is denuded of the whole endothelial cell, platelets adhere to the intimai basement lamina as do endothelial cells.3. The distance between adherent platelets as well as endothelial cells and intimai basement lamina measures 10 to 20 mµ, whereas the distance between aggregated platelets is 30 to 60 mµ.4. 5-hydroxytryptamine (5-HT) is released from platelets during viscous metamorphosis at least in part as 5-HT organelles.It should be noted that the presence of collagen fibers is not necessary for platelet thrombus formation in vivo.

scholarly journals The role of anti-endothelial cell antibodies in Kawasaki disease -in vitro and in vivo studies

2002 ◽  
Vol 130 (2) ◽  
pp. 233-240 ◽  
Author(s):  
E. GRUNEBAUM ◽  
M. BLANK ◽  
S. COHEN ◽  
A. AFEK ◽  
J. KOPOLOVIC ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Kawasaki Disease ◽  
In Vivo Studies

scholarly journals Hyperglycaemia up-regulates placental growth factor (PlGF) expression and secretion in endothelial cells via suppression of PI3 kinase-Akt signalling and activation of FOXO1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samir Sissaoui ◽  
Stuart Egginton ◽  
Ling Ting ◽  
Asif Ahmed ◽  
Peter W. Hewett
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Endothelial Dysfunction ◽  
Akt Activation ◽  
Forkhead Box ◽  
Pi3k Activity ◽  
Binding Sequence

AbstractPlacenta growth factor (PlGF) is a pro-inflammatory angiogenic mediator that promotes many pathologies including diabetic complications and atherosclerosis. Widespread endothelial dysfunction precedes the onset of these conditions. As very little is known of the mechanism(s) controlling PlGF expression in pathology we investigated the role of hyperglycaemia in the regulation of PlGF production in endothelial cells. Hyperglycaemia stimulated PlGF secretion in cultured primary endothelial cells, which was suppressed by IGF-1-mediated PI3K/Akt activation. Inhibition of PI3K activity resulted in significant PlGF mRNA up-regulation and protein secretion. Similarly, loss or inhibition of Akt activity significantly increased basal PlGF expression and prevented any further PlGF secretion in hyperglycaemia. Conversely, constitutive Akt activation blocked PlGF secretion irrespective of upstream PI3K activity demonstrating that Akt is a central regulator of PlGF expression. Knock-down of the Forkhead box O-1 (FOXO1) transcription factor, which is negatively regulated by Akt, suppressed both basal and hyperglycaemia-induced PlGF secretion, whilst FOXO1 gain-of-function up-regulated PlGF in vitro and in vivo. FOXO1 association to a FOXO binding sequence identified in the PlGF promoter also increased in hyperglycaemia. This study identifies the PI3K/Akt/FOXO1 signalling axis as a key regulator of PlGF expression and unifying pathway by which PlGF may contribute to common disorders characterised by endothelial dysfunction, providing a target for therapy.

scholarly journals An autoantibody directed against human thrombin anion-binding exosite in a patient with arterial thrombosis: effects on platelets, endothelial cells, and protein C activation

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1843-1850 ◽  
Author(s):  
E Arnaud ◽  
M Lafay ◽  
P Gaussem ◽  
V Picard ◽  
M Jandrot-Perrus ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Arterial Thrombosis ◽  
Protein C ◽  
Receptor Activation ◽  
Anion Binding ◽  
Thrombin Receptor ◽  
Cell Functions ◽  
Human Thrombin

Abstract An autoantibody, developed by a patient with severe and recurrent arterial thrombosis, was characterized to be directed against the anion- binding exosite of thrombin, and inhibited all thrombin interactions requiring this secondary binding site without interfering with the catalytic site. The effect of the antibody was studied on thrombin interactions with platelets and endothelial cells from human umbilical veins (HUVEC). The autoantibody specifically and concentration- dependently inhibited alpha-thrombin-induced platelet activation and prostacyclin (PGI2) synthesis from HUVEC. It had no effect when gamma- thrombin or the thrombin receptor activation peptide SFLLR were the inducers. The effect of the antibody on protein C activation has been studied. The antibody blocked the thrombin-thrombomodulin activation of protein C. The inhibition of the activation was maximal with a low concentration of thrombomodulin. The fact that the autoantibody inhibited concentration-dependent alpha-thrombin-induced platelet and endothelial cell functions emphasizes the crucial role of the anion- binding exosite of thrombin to activate its receptor. In regard to the pathology, the antibody inhibited two vascular processes implicated in thrombin-antithrombotic functions, PGI2 secretion, and protein C activation, which could be implicated in this arterial thrombotic disease.

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