scholarly journals Modulation of endothelial cell hemostatic properties by tumor necrosis factor.

1986 ◽  
Vol 163 (3) ◽  
pp. 740-745 ◽  
Author(s):  
P P Nawroth ◽  
D M Stern
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Cell Surface ◽  
Protein C ◽  
Tumor Necrosis ◽  
Protein S ◽  
Active Role ◽  
Procoagulant Activity ◽  
Necrosis Factor

Tumor necrosis factor/cachectin (TNF) is a mediator of the septic state, which involves diffuse abnormalities of coagulation throughout the vasculature. Since previous studies have shown that endothelial cells can play an active role in coagulation, we wished to determine whether TNF could modulate endothelial cell hemostatic properties. Incubation of purified recombinant TNF with cultured endothelial cells resulted in a time- and dose-dependent acquisition of tissue factor procoagulant activity. Concomitant with enhanced procoagulant activity, TNF also suppressed endothelial cell cofactor activity for the anticoagulant protein C pathway; both thrombin-mediated protein C activation and formation of functional activated protein C-protein S complex on the cell surface were considerably attenuated. Comparable concentrations of TNF (half-maximal affect at approximately 50 pM) and incubation times (half-maximal affect by 4 h after addition to cultures) were required for each of these changes in endothelial cell coagulant properties. This unidirectional shift in cell surface hemostatic properties favoring promotion of clot formation indicates that, in addition to leukocyte procoagulants, endothelium can potentially be instrumental in the pathogenesis of the thrombotic state associated with inflammatory and malignant disorders.

Enhancement of tumor necrosis factor-induced endothelial cell injury by cycloheximide

1990 ◽  
Vol 259 (2) ◽  
pp. L123-L129
Author(s):  
K. B. Nolop ◽  
U. S. Ryan
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Morphological Evidence ◽  
Human Aorta ◽  
Dependent Manner ◽  
Inhibitor Of Protein Synthesis ◽  
Necrosis Factor

Tumor necrosis factor (TNF), a potent polypeptide mediator released by activated monocytes and macrophages, has a number of proinflammatory effects on endothelial cells. TNF is cytotoxic to tumor cells in vivo and in vitro, but TNF-induced toxicity to endothelial cells is less well established. We now report that cycloheximide (CHX), an inhibitor of protein synthesis, renders endothelial cells highly susceptible to TNF-induced lysis. TNF alone did not change the overall rate of protein synthesis by endothelial cells, whereas the addition of CHX completely abolished protein synthesis. Endothelial cells incubated in TNF alone in high concentrations (up to 1,000 U/ml) showed minimal rounding up and release of 51Cr. Likewise, CHX alone (5 micrograms/ml) had no significant effect on endothelial cell morphology and release of 51Cr. However, incubation of endothelial cells in both CHX and TNF caused injury in a dose-dependent manner. Morphological evidence of cell retraction, rounding, and detachment began within 2 h, but specific 51Cr release did not begin to rise until after 4 h. These changes were not observed when endothelial cells were incubated with TNF/CHX at 4 degrees C. The combination of TNF/CHX was lethal to all endothelial cells tested (bovine pulmonary artery, human umbilical vein, and human aorta), with human aortic cells showing the most pronounced changes. We conclude that healthy endothelial cells are resistant to TNF-induced lysis, but inhibition of their ability to make protein renders them highly susceptible.

scholarly journals Tumor necrosis factor and interleukin-1 induce expression of the verocytotoxin receptor globotriaosylceramide on human endothelial cells: implications for the pathogenesis of the hemolytic uremic syndrome

Blood ◽  
1992 ◽  
Vol 80 (11) ◽  
pp. 2755-2764 ◽  
Author(s):  
NC van de Kar ◽  
LA Monnens ◽  
MA Karmali ◽  
VW van Hinsbergh
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Tnf Alpha ◽  
Human Endothelial Cells ◽  
Uremic Syndrome ◽  
Necrosis Factor

Abstract The epidemic form of the hemolytic uremic syndrome (HUS), beginning with an acute gastroenteritis, has been associated with a verocytotoxin- producing Escherichia coli infection. The endothelial cell is believed to play an important role in the pathogenesis of HUS. Endothelial cell damage by verocytotoxin-1 (VT-1) in vitro is potentiated by the additional exposure of inflammatory mediators, such as tumor necrosis factor-alpha (TNF-alpha). Preincubation of human umbilical vein endothelial cells (HUVEC) with TNF-alpha resulted in a 10- to 100-fold increase of specific binding sites for 125I-VT-1. Furthermore, interleukin-1 (IL-1), lymphotoxin (TNF-beta), and lipopolysaccharide (LPS) also markedly increase VT-1 binding. Several hours' exposure to TNF-alpha was enough to enhance the number of VT-1 receptors on the endothelial cells for 2 days. The TNF-alpha-induced increase in VT-1 binding could be inhibited by simultaneous addition of the protein synthesis inhibitor cycloheximide. Glycolipid extracts of TNF-alpha- treated cells tested on thin-layer chromatography demonstrated an increase of globotriaosylceramide (GbOse3cer), a functional receptor for VT-1, which suggests that preincubation of human endothelial cells with TNF-alpha leads to an increase in GbOse3cer synthesis in these cells. We conclude from this study that TNF-alpha and IL-1 induce one (or more) enzyme(s) that is (are) rate-limiting in the synthesis of the glycolipid VT-1 receptor, GbOse3cer. These in vitro studies suggest that, in addition to VT-1, inflammatory mediators play an important role in the pathogenesis of HUS.

scholarly journals Tumor necrosis factor suppresses transcription of the thrombomodulin gene in endothelial cells.

1988 ◽  
Vol 8 (12) ◽  
pp. 5588-5592 ◽  
Author(s):  
E M Conway ◽  
R D Rosenberg
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Cell Surface ◽  
Tumor Necrosis ◽  
Endothelial Cell Surface ◽  
Histocompatibility Complex ◽  
Class 1 ◽  
The Stability ◽  
Endothelial Receptor ◽  
Necrosis Factor

Tumor necrosis factor (TNF) dramatically alters the levels of various surface components of the blood vessel wall, such as blood coagulation enzyme receptors, leukocyte-adhesive receptors, and class 1 major histocompatibility complex antigens, which may have relevance to its effects in septic shock, angiogenesis, and tumor growth. However, the precise mechanism by which the cytokine is able to accomplish this remodeling of the endothelial cell surface has not been defined. We have demonstrated that exposure of bovine and human endothelial cells to TNF leads to suppression of the functional cell surface thrombin receptor, thrombomodulin (TM), and TM mRNA of virtually identical magnitude. The cytokine has no significant effect on the stability of TM mRNA or endothelial receptor turnover. Nuclear run-on studies reveal that the treatment of endothelial cells with TNF for short periods reduces TM gene transcription to as little as 3% of control values and that this inhibition does not require new protein synthesis.

scholarly journals CytochromeP-450 epoxygenases protect endothelial cells from apoptosis induced by tumor necrosis factor-α via MAPK and PI3K/Akt signaling pathways

2007 ◽  
Vol 293 (1) ◽  
pp. H142-H151 ◽  
Author(s):  
Shilin Yang ◽  
Li Lin ◽  
Ji-Xiong Chen ◽  
Craig R. Lee ◽  
John M. Seubert ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Signaling Pathways ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Akt Signaling ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Endothelial cells play a vital role in the maintenance of cardiovascular homeostasis. Epoxyeicosatrienoic acids (EETs), cytochrome P-450 (CYP) epoxygenase metabolites of arachidonic acid in endothelial cells, possess potent and diverse biological effects within the vasculature. We evaluated the effects of overexpression of CYP epoxygenases on tumor necrosis factor-α (TNF-α)-induced apoptosis in bovine aortic endothelial cells. CYP epoxygenase overexpression significantly increased endothelial cell viability and inhibited TNF-α induction of endothelial cell apoptosis as evaluated by morphological analysis of nuclear condensation, DNA laddering, and fluorescent-activated cell sorting (FACS) analysis. CYP epoxygenase overexpression also significantly inhibited caspase-3 activity and downregulation of Bcl-2 expression induced by TNF-α. The antiapoptotic effects of CYP epoxygenase overexpression were significantly attenuated by inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt and MAPK signaling pathways; however, inhibition of endothelial nitric oxide synthase activity had no effect. Furthermore, CYP epoxygenase overexpression significantly attenuated the extent of TNF-α-induced ERK1/2 dephosphorylation in a time-dependent manner and significantly increased PI3K expression and Akt phosphorylation in both the presence and absence of TNF-α. Collectively, these results suggest that CYP epoxygenase overexpression, which is known to increase EET biosynthesis, significantly protects endothelial cells from apoptosis induced by TNF-α. This effect is mediated, at least in part, through inhibition of ERK dephosphorylation and activation of PI3K/Akt signaling.

scholarly journals Induction of permeability across endothelial cell monolayers by tumor necrosis factor (TNF) occurs via a tissue factor–dependent mechanism: relationship between the procoagulant and permeability effects of TNF

Blood ◽  
2002 ◽  
Vol 100 (4) ◽  
pp. 1334-1339 ◽  
Author(s):  
Josef Friedl ◽  
Markus Puhlmann ◽  
David L. Bartlett ◽  
Steven K. Libutti ◽  
Ewa N. Turner ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Tissue Factor ◽  
Tumor Necrosis ◽  
Surface Expression ◽  
Procoagulant Activity ◽  
Cell Surface Expression ◽  
Short Exposure ◽  
Clotting Factors ◽  
Necrosis Factor

Tumor necrosis factor (TNF) has marked effects on permeability and procoagulant activity on tumor-associated neovasculature when used in isolation perfusion, the latter effect primarily mediated via induction of cell surface expression of tissue factor (TF) on endothelial tissue. However, the cellular events that result in rapid alterations in endothelial cell (EC) permeability after intravascular TNF administration in isolation perfusion are not well characterized. We demonstrate that short exposure intervals to TNF induces TF expression on ECs but has no effect on permeability as assessed by flux of Evans blue–bound albumin across confluent EC monolayers using a 2-compartment model under basal culture conditions. However, a rapid and significant increase in EC permeability occurred with TNF in the presence of factor VIII–deficient plasma. Permeability was induced only with luminal versus abluminal TNF exposure and was blocked by antithrombin III, TF pathway inhibitor, or anti-TF antibody cotreatment. These data indicate that EC surface expression of TF and extrinsic clotting factors are critical in augmenting capillary leak following intravascular TNF administration. Alterations in permeability were associated with intercellular gap formation at sites of down-regulation of vascular endothelial (VE)–cadherin expression, the primary endothelial intercellular adhesion molecule, and intracellular contraction and alignment of F-actin cytoskeletal elements. Rapid induction of TF by TNF may be the primary EC response that results in alterations in permeability and procoagulant activity observed following intravascular TNF administration in isolation perfusion.

Tumor necrosis factor suppresses transcription of the thrombomodulin gene in endothelial cells

1988 ◽  
Vol 8 (12) ◽  
pp. 5588-5592
Author(s):  
E M Conway ◽  
R D Rosenberg
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Cell Surface ◽  
Tumor Necrosis ◽  
Endothelial Cell Surface ◽  
Histocompatibility Complex ◽  
Class 1 ◽  
The Stability ◽  
Endothelial Receptor ◽  
Necrosis Factor

Tumor necrosis factor (TNF) dramatically alters the levels of various surface components of the blood vessel wall, such as blood coagulation enzyme receptors, leukocyte-adhesive receptors, and class 1 major histocompatibility complex antigens, which may have relevance to its effects in septic shock, angiogenesis, and tumor growth. However, the precise mechanism by which the cytokine is able to accomplish this remodeling of the endothelial cell surface has not been defined. We have demonstrated that exposure of bovine and human endothelial cells to TNF leads to suppression of the functional cell surface thrombin receptor, thrombomodulin (TM), and TM mRNA of virtually identical magnitude. The cytokine has no significant effect on the stability of TM mRNA or endothelial receptor turnover. Nuclear run-on studies reveal that the treatment of endothelial cells with TNF for short periods reduces TM gene transcription to as little as 3% of control values and that this inhibition does not require new protein synthesis.

scholarly journals The Role of Osteoprotegerin and Tumor Necrosis Factor-related Apoptosis-inducing Ligand in Human Microvascular Endothelial Cell Survival

2004 ◽  
Vol 15 (6) ◽  
pp. 2834-2841 ◽  
Author(s):  
L. B. Pritzker ◽  
M. Scatena ◽  
C. M. Giachelli
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Necrosis Factor ◽  
Cell Survival ◽  
Tumor Necrosis ◽  
Microvascular Endothelial Cell ◽  
Endothelial Cell Survival ◽  
Trail Receptors ◽  
Microvascular Endothelial ◽  
Necrosis Factor

Endothelial cell survival and antiapoptotic pathways, including those stimulated by extracellular matrix, are critical regulators of vasculogenesis, angiogenesis, endothelial repair, and shear-stress-induced endothelial activation. One of these pathways is mediated by αvβ3 integrin ligation, downstream activation of nuclear factor-κB, and subsequent up-regulation of osteoprotegerin (OPG). In this study, the mechanism by which OPG protects endothelial cells from death was examined. Serum-starved human microvascular endothelial cells (HMECs) plated on the αvβ3 ligand osteopontin were protected from cell death. Immunoprecipitation experiments indicated that OPG formed a complex with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in HMECs under these conditions. Furthermore, inhibitors of TRAIL, including recombinant soluble TRAIL receptors and a neutralizing antibody against TRAIL, blocked apoptosis of serum-starved HMECs plated on the nonintegrin attachment factor poly-d-lysine. Whereas TRAIL was unable to induce apoptosis in HMECs plated on osteopontin, the addition of recombinant TRAIL did increase the percentage of apoptotic HMECs plated on poly-d-lysine. This evidence indicates that OPG blocks endothelial cell apoptosis through binding TRAIL and preventing its interaction with death-inducing TRAIL-receptors

Synergistic Effect of Low Doses of Tumor Necrosis Factor and Sera from Patients with Systemic Lupus Erythematosus on the Expression of Procoagulant Activity by Cultured Endothelial Cells

1989 ◽  
Vol 62 (02) ◽  
pp. 654-660 ◽  
Author(s):  
Paula Hasselaar ◽  
Ronald H W M Derksen ◽  
Janine D Oosting ◽  
Laya Blokzijl ◽  
Philip G de Groot
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Lupus Erythematosus ◽  
Tumor Necrosis ◽  
Connective Tissue Diseases ◽  
Procoagulant Activity ◽  
Antiphospholipid Antibody ◽  
Causative Role ◽  
History Of ◽  
Necrosis Factor

SummaryThe effect of 15 antiphospholipid antibody (APA) positive SLE sera, 13 APA negative SLE sera, 10 APA negative sera from patients with other connective tissue diseases (CTD) and 15 control sera on the expression of endothelial procoagulant activity (PCA) was studied. Endothelial cells (EC) were stimulated with tumor necrosis factor (TNF) and 20% serum for 4 hr and the surface PC A expression was measured. Without TNF, none of the sera stimulated PC A expression. With subop timal TNF stimulation, 14/15 APA positive SLE sera, 7/13 APA negative SLE sera, 2/10 CTD sera and 2/15 control sera enhanced PC A expression. This stimulating effect resided in the IgG fraction and was associated with the presence of APA, but not with a history of thrombosis. Purified APA had no PC A stimulating activity. PC A expression was inhibited by cycloheximide and heat treatment (30 min, 56° C) of serum.In conclusion, 21/28 (75%) SLE sera increase the TNF-induced endothelial PC A expression. Although this effect predominantly occurs with APA positive serum, a causative role of APA was not demonstrated.

SIMULTANEOUS PRODUCTION OF ENDOTHELIAL CELL-DERIVED PROTEIN S AND FACTOR V, AND INACTIVATION OF FACTOR Va AT THE ENDOTHELIAL CELL SURFACE

1987 ◽  
Author(s):  
P v d Waart ◽  
K T Preissner ◽  
U Delvos ◽  
G Müller-Berghaus
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Conditioned Medium ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Factor V ◽  
Endothelial Cell Surface ◽  
Factor Va

Several proteins synthesized and expressed by endothelial cells are involved in the regulation of coagulation. The synthesis and expression of factor V and protein S has been demonstrated in independent studies. The present work evaluates the simultaneous synthesis and expression of bovine factor V and protein S and the effect of endothelial protein S on the inactivation of endothelial factor Va by activated protein C. The accumulation of both proteins in conditioned medium was detected by SDS-PAGE followed by immunoblotting, and their activities were tested by functional assays. The synthesis of protein S and factor V per 105 cells over 24 h amounted up to 2 ng protein S and 440 ng factor V, respectively. The addition of thrombin did not increase the yield of synthesized cofactors. Thrombin did neither proteolyse protein S on endothelial cells nor in a purified system in the presence of thrombomodulin and calcium ions. Factor V was secreted partly in its activated form as evidenced by the appearance of active intermediates with M = 220,000-280,000 on immunoblots as well as by only a three-Fold further activation of factor V/Va following addition of thrombin. The rate constant for the inactivation of factor Va by activated protein C was only two-fold higher for factor Va derived from cells cultured in the presence of vitamin K as compared in the presence of warfarin. For the inactivation of comparable factor Va concentrations in conditioned medium a 10-fold higher and on endothelial cells a 40-fold higher concentration of activated protein C was required to obtain similar inactivation rates of factor Va as compared to a purified system. These results suggest that resting endothelial cells contain a factor V activator, and that a regulatory mechanism is operative on the endothelial cell surface that suppresses the inactivation potential of activated protein C/ protein S.

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