Tumor Necrosis Factor Alpha and Lipopolysaccharide Induce Shiga Toxin Sensitivity in Endothelial Cells Through p38 Mitrogen Activated Protein Kinase

2008 ◽  
Author(s):  
Matthew Kevin Stone
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Shiga Toxin ◽  
Tumor Necrosis ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Toxin Sensitivity ◽  
Necrosis Factor

scholarly journals Tumor Necrosis Factor Alpha Increases Human Cerebral Endothelial Cell Gb3 and Sensitivity to Shiga Toxin

2001 ◽  
Vol 69 (3) ◽  
pp. 1889-1894 ◽  
Author(s):  
Patricia B. Eisenhauer ◽  
Prasoon Chaturvedi ◽  
Richard E. Fine ◽  
Andrew J. Ritchie ◽  
Jordan S. Pober ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Shiga Toxin ◽  
Tumor Necrosis ◽  
Umbilical Vein ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Hemolytic uremic syndrome (HUS) is associated with intestinal infection by enterohemorrhagic Escherichia coli strains that produce Shiga toxins. Globotriaosylceramide (Gb3) is the functional receptor for Shiga toxin, and tumor necrosis factor alpha (TNF-α) upregulates Gb3 in both human macrovascular umbilical vein endothelial cells and human microvascular brain endothelial cells. TNF-α treatment enhanced Shiga toxin binding and sensitivity to toxin. This upregulation was specific for Gb3 species containing normal fatty acids (NFA). Central nervous system (CNS) pathology in HUS could involve cytokine-stimulated elevation of endothelial NFA-Gb3 levels. Differential expression of Gb3 species may be a critical determinant of Shiga toxin toxicity and of CNS involvement in HUS.

Tumor necrosis factor-alpha activates pulmonary artery endothelial protein kinase C

1993 ◽  
Vol 264 (1) ◽  
pp. L7-L14 ◽  
Author(s):  
T. J. Ferro ◽  
D. M. Parker ◽  
L. M. Commins ◽  
P. G. Phillips ◽  
A. Johnson
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Pulmonary Artery ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Necrosis Factor Alpha ◽  
Kinase C ◽  
Factor Alpha ◽  
Necrosis Factor

We investigated the hypothesis that tumor necrosis factor-alpha (TNF) activates pulmonary endothelial protein kinase C (PKC). Confluent bovine pulmonary artery endothelial monolayers were exposed to recombinant human TNF, and the translocation of PKC, an indicator of enzyme activation, was studied using both slot immunoblotting and immunofluorescence. For slot immunoblot analysis, membrane and cytosol lysate fractions were prepared, and PKC antigen was assessed using MC5 monoclonal anti-PKC antibody. TNF (1,000 U/ml for 15 min) induced translocation of PKC into the membrane. Immunofluorescence analysis with the MC5 antibody was also used. Monolayers treated with culture medium showed diffuse cytoplasmic fluorescence. In contrast, treatment with either TNF (1,000 U/ml for 15 min) or 1,2-dioctanoylglycerol (4 x 10(-5) M for 5 min), a diacylglycerol that activates PKC, resulted in translocation of fluorescence to the cell periphery; fine, punctate PKC-associated fluorescence was localized to the margins of cells. The TNF-induced translocation of PKC was inhibited using either IP-300 polyclonal anti-TNF antibody (indicating that the TNF effect was not due to the vehicle or contaminating endotoxin) or calphostin C (10(-6) M for 15 min), which inhibits PKC activation by interacting with the regulatory diacylglycerol-binding domain. TNF treatment had no effect on either the content of PKC, or of total protein, in the membrane + cytosol, and cycloheximide (40 microM for 5 min) did not alter the translocation of PKC induced by TNF; these results indicate that the effect of TNF on PKC translocation was related to neither de novo membrane synthesis of PKC (as opposed to translocation per se) nor nonspecific augmentation of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Regulation of thrombomodulin by tumor necrosis factor-alpha: comparison of transcriptional and posttranscriptional mechanisms

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 542-550 ◽  
Author(s):  
SR Lentz ◽  
M Tsiang ◽  
JE Sadler
Keyword(s):  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Posttranscriptional Regulation ◽  
Tumor Necrosis ◽  
Vascular Endothelial Cells ◽  
Necrosis Factor Alpha ◽  
Subsequent Decrease ◽  
Factor Alpha ◽  
Necrosis Factor

Abstract The procoagulant properties of cultured vascular endothelial cells are enhanced in response to inflammatory cytokines such as tumor necrosis factor-alpha (TNF). A major component of this response is a reduction in expression of thrombomodulin, a cell surface cofactor for the activation of protein C. Regulation of thrombomodulin expression by TNF has been reported to occur through multiple mechanisms. To determine the relative roles of transcriptional and posttranscriptional regulation, the effect of TNF on the turnover of thrombomodulin protein and mRNA was examined in human and bovine endothelial cells. Quantitative nuclease S1 protection assays showed a 70% to 90% reduction in thrombomodulin mRNA within 4 hours of the addition of 1.0 nmol/L TNF to the culture medium. The decrease in thrombomodulin mRNA resulted from inhibition of transcription, followed by rapid degradation of thrombomodulin transcripts (t1/2 less than or equal to 3 hours). In pulse-chase incubations, thrombomodulin synthesis decreased parallel with mRNA, but the rate of degradation of radiolabeled thrombomodulin was not significantly altered by TNF. Human thrombomodulin was degraded with a t1/2 of 8.2 +/- 2.4 hours (SD) or 7.5 +/- 1.3 hours (SD) in the absence or presence of TNF, respectively. We conclude that TNF acts primarily to inhibit thrombomodulin transcription. The subsequent decrease in activity results from the inherent instability of thrombomodulin mRNA and protein in these cells, and not from the regulation of thrombomodulin degradation.

scholarly journals Shiga Toxin 1-Induced Inflammatory Response in Lipopolysaccharide-Sensitized Astrocytes Is Mediated by Endogenous Tumor Necrosis Factor Alpha

2009 ◽  
Vol 78 (3) ◽  
pp. 1193-1201 ◽  
Author(s):  
Verónica I. Landoni ◽  
Marcelo de Campos-Nebel ◽  
Pablo Schierloh ◽  
Cecilia Calatayud ◽  
Gabriela C. Fernandez ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Inflammatory Response ◽  
Tumor Necrosis Factor Alpha ◽  
Shiga Toxin ◽  
Tumor Necrosis ◽  
Brain Inflammation ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Hemolytic-uremic syndrome (HUS) is generally caused by Shiga toxin (Stx)-producing Escherichia coli. Endothelial dysfunction mediated by Stx is a central aspect in HUS development. However, inflammatory mediators such as bacterial lipopolysaccharide (LPS) and polymorphonuclear neutrophils (PMN) contribute to HUS pathophysiology by potentiating Stx effects. Acute renal failure is the main feature of HUS, but in severe cases, patients can develop neurological complications, which are usually associated with death. Although the mechanisms of neurological damage remain uncertain, alterations of the blood-brain barrier associated with brain endothelial injury is clear. Astrocytes (ASTs) are the most abundant inflammatory cells of the brain that modulate the normal function of brain endothelium and neurons. The aim of this study was to evaluate the effects of Stx type 1 (Stx1) alone or in combination with LPS in ASTs. Although Stx1 induced a weak inflammatory response, pretreatment with LPS sensitized ASTs to Stx1-mediated effects. Moreover, LPS increased the level of expression of the Stx receptor and its internalization. An early inflammatory response, characterized by the release of tumor necrosis factor alpha (TNF-α) and nitric oxide and PMN-chemoattractant activity, was induced by Stx1 in LPS-sensitized ASTs, whereas activation, evidenced by higher levels of glial fibrillary acid protein and cell death, was induced later. Furthermore, increased adhesion and PMN-mediated cytotoxicity were observed after Stx1 treatment in LPS-sensitized ASTs. These effects were dependent on NF-κB activation or AST-derived TNF-α. Our results suggest that TNF-α is a pivotal effector molecule that amplifies Stx1 effects on LPS-sensitized ASTs, contributing to brain inflammation and leading to endothelial and neuronal injury.

scholarly journals The Extracellular Adherence Protein from Staphylococcus aureus Inhibits Neutrophil Binding to Endothelial Cells

2004 ◽  
Vol 72 (10) ◽  
pp. 6164-6167 ◽  
Author(s):  
Axana Haggar ◽  
Cecilia Ehrnfelt ◽  
Jan Holgersson ◽  
Jan-Ingmar Flock
Keyword(s):  
Staphylococcus Aureus ◽  
Endothelial Cells ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis Factor Alpha ◽  
Tumor Necrosis ◽  
Neutrophil Adhesion ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Necrosis Factor ◽  
Adhesion Assays

ABSTRACT Extracellular adherence protein (Eap) from Staphylococcus aureus inhibits the adherence of neutrophils to nonstimulated and tumor necrosis factor alpha-stimulated endothelial cells in both static adhesion assays and flow adhesion assays. Consequently, Eap also impaired their transendothelial migration. During an S. aureus infection, Eap may thus serve to reduce inflammation by inhibiting neutrophil adhesion and extravasation.

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