Glutathione Peroxidase-1 Deficiency Augments Proinflammatory Cytokine-induced Redox Signaling and Human Endothelial Cell Activation

Glutathione peroxidase-1 (GPx-1) is a crucial antioxidant enzyme, the deficiency of which promotes atherogenesis. Accordingly, we examined the mechanisms by which GPx-1 deficiency enhances endothelial cell activation and inflammation. In human microvascular endothelial cells, we found that GPx-1 deficiency augments intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression by redox-dependent mechanisms that involve NFκB. Suppression of GPx-1 enhanced TNF-α-induced ROS production and ICAM-1 expression, whereas overexpression of GPx-1 attenuated these TNF-α-mediated responses. GPx-1 deficiency prolonged TNF-α-induced IκBα degradation and activation of ERK1/2 and JNK. JNK or NFκB inhibition attenuated TNF-α induction of ICAM-1 and VCAM-1 expression in GPx-1-deficient and control cells, whereas ERK1/2 inhibition attenuated only VCAM-1 expression. To analyze further signaling pathways involved in GPx-1-mediated protection from TNF-α-induced ROS, we performed microarray analysis of human microvascular endothelial cells treated with TNF-α in the presence and absence of GPx-1. Among the genes whose expression changed significantly, dual specificity phosphatase 4 (DUSP4), encoding an antagonist of MAPK signaling, was down-regulated by GPx-1 suppression. Targeted DUSP4 knockdown enhanced TNF-α-mediated ERK1/2 pathway activation and resulted in increased adhesion molecule expression, indicating that GPx-1 deficiency may augment TNF-α-mediated events, in part, by regulating DUSP4.

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Direct Activation of Human Endothelial Cells by Plasmodium falciparum-Infected Erythrocytes

Infection and Immunity ◽

10.1128/iai.73.6.3271-3277.2005 ◽

2005 ◽

Vol 73 (6) ◽

pp. 3271-3277 ◽

Cited By ~ 37

Author(s):

Nicola K. Viebig ◽

Ulrich Wulbrand ◽

Reinhold Förster ◽

Katherine T. Andrews ◽

Michael Lanzer ◽

...

Keyword(s):

Endothelial Cells ◽

Plasmodium Falciparum ◽

Endothelial Cell ◽

Adhesion Molecule ◽

Cell Activation ◽

Physical Contact ◽

Intercellular Adhesion Molecule ◽

Immune Reactivity ◽

Human Endothelial Cells ◽

Tnf Α

ABSTRACT Cytoadherence of Plasmodium falciparum-infected erythrocytes (PRBC) to endothelial cells causes severe clinical disease, presumably as a of result perfusion failure and tissue hypoxia. Cytoadherence to endothelial cells is increased by endothelial cell activation, which is believed to occur in a paracrine fashion by mediators such as tumor necrosis factor alpha (TNF-α) released from macrophages that initially recognize PRBC. Here we provide evidence that PRBC directly stimulate human endothelial cells in the absence of macrophages, leading to increased expression of adhesion-promoting molecules, such as intercellular adhesion molecule 1. Endothelial cell stimulation by PRBC required direct physical contact for a short time (30 to 60 min) and was correlated with parasitemia. Gene expression profiling of endothelial cells stimulated by PRBC revealed increased expression levels of chemokine and adhesion molecule genes. PRBC-stimulated endothelial cells especially showed increased expression of molecules involved in parasite adhesion but failed to express molecules promoting leukocyte adhesion, such as E-selectin and vascular cell adhesion molecule 1, even after challenge with TNF-α. Collectively, our data suggest that stimulation of endothelial cells by PRBC may have two effects: prevention of parasite clearance through increased cytoadherence and attenuation of leukocyte binding to endothelial cells, thereby preventing deleterious immune reactivity.

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Proinflammatory factors present in sera from patients with acute dengue infection induce activation and apoptosis of human microvascular endothelial cells: Possible role of TNF-α in endothelial cell damage in dengue

Cytokine ◽

10.1016/j.cyto.2005.01.021 ◽

2005 ◽

Vol 30 (6) ◽

pp. 359-365 ◽

Cited By ~ 80

Author(s):

José E. Cardier ◽

Eliana Mariño ◽

Egidio Romano ◽

Peter Taylor ◽

Ferdinando Liprandi ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Cell Damage ◽

Dengue Infection ◽

Microvascular Endothelial Cells ◽

Endothelial Cell Damage ◽

Tnf Α ◽

Microvascular Endothelial ◽

Proinflammatory Factors

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Brucella abortus-Stimulated Platelets Activate Brain Microvascular Endothelial Cells Increasing Cell Transmigration through the Erk1/2 Pathway

Pathogens ◽

10.3390/pathogens9090708 ◽

2020 ◽

Vol 9 (9) ◽

pp. 708

Author(s):

Ana María Rodríguez ◽

Aldana Trotta ◽

Agustina P. Melnyczajko ◽

M. Cruz Miraglia ◽

Kwang Sik Kim ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Brucella Abortus ◽

Cell Activation ◽

Transendothelial Migration ◽

Endothelial Activation ◽

Microvascular Endothelial Cell ◽

Inflammatory Disorder ◽

Endothelial Cell Activation ◽

Microvascular Endothelial

Central nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. A common feature associated with this pathology is blood–brain barrier (BBB) activation. However, the underlying mechanisms involved with such BBB activation remain unknown. The aim of this work was to investigate the role of Brucella abortus-stimulated platelets on human brain microvascular endothelial cell (HBMEC) activation. Platelets enhanced HBMEC activation in response to B. abortus infection. Furthermore, supernatants from B. abortus-stimulated platelets also activated brain endothelial cells, inducing increased secretion of IL-6, IL-8, CCL-2 as well as ICAM-1 and CD40 upregulation on HBMEC compared with supernatants from unstimulated platelets. Outer membrane protein 19, a B. abortus lipoprotein, recapitulated B. abortus-mediated activation of HBMECs by platelets. In addition, supernatants from B. abortus-activated platelets promoted transendothelial migration of neutrophils and monocytes. Finally, using a pharmacological inhibitor, we demonstrated that the Erk1/2 pathway is involved in the endothelial activation induced by B. abortus-stimulated platelets and also in transendothelial migration of neutrophils. These results describe a mechanism whereby B. abortus-stimulated platelets induce endothelial cell activation, promoting neutrophils and monocytes to traverse the BBB probably contributing to the inflammatory pathology of neurobrucellosis.

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Effects of Ebola Virus Glycoproteins on Endothelial Cell Activation and Barrier Function

Journal of Virology ◽

10.1128/jvi.79.16.10442-10450.2005 ◽

2005 ◽

Vol 79 (16) ◽

pp. 10442-10450 ◽

Cited By ~ 129

Author(s):

Victoria M. Wahl-Jensen ◽

Tatiana A. Afanasieva ◽

Jochen Seebach ◽

Ute Ströher ◽

Heinz Feldmann ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Barrier Function ◽

Cell Activation ◽

Matrix Protein ◽

Ebola Virus ◽

Endothelial Barrier ◽

Endothelial Barrier Function ◽

Endothelial Cell Activation ◽

Tnf Α

ABSTRACT Ebola virus causes severe hemorrhagic fever with high mortality rates in humans and nonhuman primates. Vascular instability and dysregulation are disease-decisive symptoms during severe infection. While the transmembrane glycoprotein GP1,2 has been shown to cause endothelial cell destruction, the role of the soluble glycoproteins in pathogenesis is largely unknown; however, they are hypothesized to be of biological relevance in terms of target cell activation and/or increase of endothelial permeability. Here we show that virus-like particles (VLPs) consisting of the Ebola virus matrix protein VP40 and GP1,2 were able to activate endothelial cells and induce a decrease in barrier function as determined by impedance spectroscopy and hydraulic conductivity measurements. In contrast, the soluble glycoproteins sGP and Δ-peptide did not activate endothelial cells or change the endothelial barrier function. The VLP-induced decrease in barrier function was further enhanced by the cytokine tumor necrosis factor alpha (TNF-α), which is known to induce a long-lasting decrease in endothelial cell barrier function and is hypothesized to play a key role in Ebola virus pathogenesis. Surprisingly, sGP, but not Δ-peptide, induced a recovery of endothelial barrier function following treatment with TNF-α. Our results demonstrate that Ebola virus GP1,2 in its particle-associated form mediates endothelial cell activation and a decrease in endothelial cell barrier function. Furthermore, sGP, the major soluble glycoprotein of Ebola virus, seems to possess an anti-inflammatory role by protecting the endothelial cell barrier function.

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Role of endothelial nitric oxide synthase in endothelial activation: insights from eNOS knockout endothelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.00546.2002 ◽

2004 ◽

Vol 286 (5) ◽

pp. C1195-C1202 ◽

Cited By ~ 82

Author(s):

Peter J. Kuhlencordt ◽

Eva Rosel ◽

Robert E. Gerszten ◽

Manuel Morales-Ruiz ◽

David Dombkowski ◽

...

Keyword(s):

Endothelial Cells ◽

Cell Adhesion ◽

Endothelial Cell ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Cell Activation ◽

Cell Interactions ◽

Wild Type ◽

Endothelial Cell Activation ◽

Endothelial Nitric Oxide

The objective of this study was to determine whether absence of endothelial nitric oxide synthase (eNOS) affects the expression of cell surface adhesion molecules in endothelial cells. Murine lung endothelial cells (MLECs) were prepared by immunomagnetic bead selection from wild-type and eNOS knockout mice. Wild-type cells expressed eNOS, but eNOS knockout cells did not. Expression of neuronal NOS and inducible NOS was not detectable in cells of either genotype. Upon stimulation, confluent wild-type MLECs produced significant amounts of NO compared with Nω-monomethyl-l-arginine-treated wild-type cells. eNOS knockout and wild-type cells showed no difference in the expression of E-selectin, P-selectin, intracellular adhesion molecule-1, and vascular cell adhesion molecule-1 as measured by flow cytometry on the surface of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31)-positive cells. Both eNOS knockout and wild-type cells displayed the characteristics of resting endothelium. Adhesion studies in a parallel plate laminar flow chamber showed no difference in leukocyte-endothelial cell interactions between the two genotypes. Cytokine treatment induced endothelial cell adhesion molecule expression and increased leukocyte-endothelial cell interactions in both genotypes. We conclude that in resting murine endothelial cells, absence of endothelial production of NO by itself does not initiate endothelial cell activation or promote leukocyte-endothelial cell interactions. We propose that eNOS derived NO does not chronically suppress endothelial cell activation in an autocrine fashion but serves to counterbalance signals that mediate activation.

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Characterization of adhesion receptors on cultured microvascular endothelial cells derived from the retroorbital connective tissue of patients with Graves' ophthalmopathy

Acta Endocrinologica ◽

10.1530/eje.0.1340051 ◽

1996 ◽

Vol 134 (1) ◽

pp. 51-60 ◽

Cited By ~ 18

Author(s):

Armin E Heufelder ◽

Peter C Scriba

Keyword(s):

T Cells ◽

Endothelial Cells ◽

Endothelial Cell ◽

Connective Tissue ◽

Adhesion Molecule ◽

Microvascular Endothelial Cells ◽

Cell Populations ◽

Graves Ophthalmopathy ◽

Microvascular Endothelial

Heufelder AE, Scriba PC. Characterization of adhesion receptors on cultured microvascular endothelial cells derived from the retroorbital connective tissue of patients with Graves' ophthalmopathy. Eur J Endocrinol 1996:134:51–60 T lymphocytes have been demonstrated recently to play an important role in the pathogenesis and propagation of Graves' ophthalmopathy (GO). Recruitment of T cells to the retroorbital tissue in GO involves the activation of certain adhesion molecules both in the vascular endothelium and in the extravascular connective tissue within the retroorbital space. To characterize the interactions between orbital endothelial cells (OECs) and circulating T cells in vitro, we designed a two-step immunopurification procedure with bead-immobilized Ulex europaeus I lectin and anti-human endothelial cell antigen (CD3I) monoclonal antibody for rapid and reproducible isolation of highly pure microvascular endothelial cell populations from small quantities of retroorbital connective tissue. Endothelial origin of the resulting cell populations was confirmed by positive immunoreactivity for von Willebrand factor. CD 3 I and thrombomodulin. Under baseline conditions, GO-OECs, but not normal OECs, expressed intercellular adhesion molecule 1 (ICAM-1) and CD44 immunoreactivity but no immunoreactivity for endothelial leukocyte adhesion molecule I (ELAM-1) and vascular cell adhesion molecule I (VCAM-1) was detected. Exposure of GO-OEC and normal OEC monolayers to interferon γ, interleukin 1 α and tumor necrosis factor α resulted in marked up-regulation of immunoreactivity for ICAM-1 and in induction of ELAM-1 and VCAM-1. Blocking experiments using monoclonal antibodies directed against various adhesion molecules demonstrated that interactions between matched activated T lymphocytes and OECs were mediated by integrin-dependent ICAM-1/leukocyte function-associated antigen 1 (LFA-1): VCAM-1/very late antigen 4 (VLA-4)) and integrin-independent (CD44) pathways, and revealed marked differences when comparing GO-OECs and normal OECs. In conclusion, the availability of OECs from affected retroorbital tissue of patients with GO provides a valuable tool for studying further the mechanisms responsible for orbit-specific lymphocyte recruitment in GO. Armin E Heufelder, Molecular Thyroid Research Unit, Medizinische Klinik, Klinikum Innenstadt, Ziemssenstrasse 1, 80336 München, Germany

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In vitro endothelial cell activation and inflammatory responses in end-stage heart failure

Journal of Applied Physiology ◽

10.1152/japplphysiol.01497.2005 ◽

2006 ◽

Vol 101 (5) ◽

pp. 1466-1473 ◽

Cited By ~ 5

Author(s):

Ginette S. Hoare ◽

Emma J. Birks ◽

Christopher Bowles ◽

Nandor Marczin ◽

Magdi H. Yacoub

Keyword(s):

Heart Failure ◽

Endothelial Cells ◽

Endothelial Cell ◽

Cell Activation ◽

Endothelial Cell Activation ◽

Tnf Α ◽

Patients With Heart Failure ◽

End Stage Heart Failure ◽

End Stage ◽

Iκbα Degradation

Background: vascular endothelial cell activation and dysfunction are observed in patients with severe heart failure and may contribute to systemic manifestations of this syndrome. It remains unknown whether inflammatory activation of these cells occurs in these patients because of increased circulating proinflammatory mediators. Aim: to determine whether the serum from patients with heart failure possesses a net proinflammatory bioactivity to active proinflammatory pathways in cultured endothelial cells. Methods: serum was obtained from stable patients with end-stage heart failure undergoing elective cardiac transplantation (Tx) and severely decompensated patients with heart failure requiring emergency left ventricular assist device (LVAD) implantation. Net proinflammatory bioactivity of serum was investigated by monitoring IκBα degradation and E-selectin expression in cultured human pulmonary artery endothelial cells (HPAEC) following incubation with serum samples. Serum cytokine concentrations were measured by ELISA and neutralizing antibodies were used to determine the role of specific factors in the observed bioactivity. Result: serum from both patient groups induced HPAEC IκBα degradation. Low basal HPAEC E-selectin expression significantly increased following treatment with Tx but not LVAD serum. Serum tumor necrosis factor-α (TNF-α) and IL-10 concentrations were higher in patients with LVAD than those with Tx, and soluble TNF-α receptor expression was high in both groups. Neither TNF-α nor IL-10 blocking experiments altered either bioassay result. Conclusion: activation of a specific profile of pro- and anti-inflammatory mediators is associated with heart failure resulting in HPAEC nuclear factor (NF)-κB activation. However, E-selectin expression is further regulated by unidentified factors. TNF-α is upregulated but appears to play no part in NFκB activation in these patients. These findings could have important therapeutic implications.

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Verocytotoxin-Induced Apoptosis of Human Microvascular Endothelial Cells

Journal of the American Society of Nephrology ◽

10.1681/asn.v124767 ◽

2001 ◽

Vol 12 (4) ◽

pp. 767-778

Author(s):

ANTONETTA H. J. M. PIJPERS ◽

PETRA A. VAN SETTEN ◽

LAMBERTUS P. W. J. VAN DEN HEUVEL ◽

KAREL J. M. ASSMANN ◽

HENDRIKUS B. P. M. DIJKMAN ◽

...

Keyword(s):

Endothelial Cells ◽

Cell Death ◽

Protein Synthesis ◽

Endothelial Cell ◽

Umbilical Vein ◽

Microvascular Endothelial Cells ◽

Tnf Α ◽

Microvascular Endothelial ◽

Induced Apoptosis ◽

Umbilical Vein Endothelial Cells

Abstract. The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-α (TNF-α). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-α interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-α-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

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