scholarly journals Monocytes Maintain Tissue Factor Activity after Cytolysis of Bacteria‐Infected Endothelial Cells in an In Vitro Model of Bacterial Endocarditis

2002 ◽  
Vol 186 (8) ◽  
pp. 1145-1154 ◽  
Author(s):  
Marcel H. A. M. Veltrop ◽  
Henry Beekhuizen
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
In Vitro Model ◽  
Bacterial Endocarditis ◽  
Factor Activity ◽  
Tissue Factor Activity ◽  
Vitro Model

Stimulation of Proteinase Activated Receptor-2 Causes Endothelial Cells to Promote Blood Coagulation In Vitro

1999 ◽  
Vol 81 (06) ◽  
pp. 984-988 ◽  
Author(s):  
Eva Norström ◽  
Johan Sundelin ◽  
Sverker Nystedt ◽  
Anna-Karin Alm
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Serine Proteases ◽  
Umbilical Vein ◽  
Mrna Level ◽  
Maximum Level ◽  
Factor Activity ◽  
Endothelial Cell Surface ◽  
Tissue Factor Activity

SummaryProteolytically activated receptors define a new subclass among the G-protein coupled receptors. Proteinase activated receptor-2 (PAR-2), the second member to be identified of this growing receptor subclass, can be activated by trypsin and trypsin-like serine proteases such as mast cell tryptase. PAR-2 is expressed in endothelial cells. Here we have studied if activation of PAR-2 changes the coagulation properties of cultured human umbilical vein endothelial cells. We show that activation of PAR-2 induces rapid and transient formation of tissue factor mRNA with a maximum level 1 hour after receptor stimulation. The increased mRNA level was accompanied by an increased tissue factor activity at the endothelial cell surface, shortening coagulation time in a standard clotting assay. The level of tissue factor activity after PAR-2 activation was comparable with the effects of thrombin receptor (PAR-1) activation although neither of the two protease receptors were as strong inducers of tissue factor as tumor necrosis factor-α.

scholarly journals Use of annexin-V to demonstrate the role of phosphatidylserine exposure in the maintenance of haemostatic balance by endothelial cells

1992 ◽  
Vol 282 (1) ◽  
pp. 7-13 ◽  
Author(s):  
C Ravanat ◽  
G Archipoff ◽  
A Beretz ◽  
G Freund ◽  
J P Cazenave ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Protein C ◽  
Activated Protein C ◽  
Factor Xa ◽  
Annexin V ◽  
Factor Activity ◽  
Cells In Culture ◽  
Tissue Factor Activity

Annexin-V (PAP-I, lipocortin-V) acts as a potent anticoagulant in vitro by binding to negatively charged phospholipids with higher affinity than vitamin K-dependent proteins, with a Kd in the 10(-10) M range. The purpose of the present study was to use annexin-V as a probe to assess the catalytic potential of phospholipids in pro- and anti-coagulant reactions in purified systems and at the surface of endothelial cells in culture after stimulation. Procoagulant tissue factor and anticoagulant thrombomodulin activities were compared by using specific two-stage amidolytic assays performed with purified proteins. Procoagulant activity was estimated by the generation of Factor Xa by the Factor VII(a)-tissue factor complex. Anticoagulant activity was estimated by the generation of activated protein C by either the thrombin-thrombomodulin complex or Factor Xa. Annexin-V induced a decrease of 70% of thrombomodulin activity when thrombomodulin (5.4-214 nM) was reconstituted into phosphatidylcholine/phosphatidylserine (1:1, mol/mol) vesicles at 37.5 or 75 microM-phospholipid concentration, the apparent Ki being 0.5 microM at 75 microM-lipid. The saturating concentration of annexin-V was dependent on phospholipid concentration, but was independent of the phospholipid/thrombomodulin ratio. By contrast, when thrombomodulin was not reconstituted in vesicles, annexin-V had no effect. At 2 microM, annexin-V totally inhibited the generation of activated protein C by Factor Xa in the presence of 75 microM-lipid, the saturating inhibitory concentration being dependent on phospholipid concentration. At 0.1 microM, annexin-V totally inhibited tissue-factor activity present in crude brain thromboplastin. In the absence of stimulation, human endothelial cells in culture expressed significant thrombomodulin activity and no detectable tissue-factor activity. Basal thrombomodulin activity was only slightly inhibited (less than 15%) by 0.5 microM-annexin-V. Phorbol myristate acetate (PMA) induced the expression of tissue-factor activity and decreased thrombomodulin activity at the endothelial-cell surface. Annexin-V, at a concentration of 16 microM, caused an 80% decrease of tissue-factor activity induced by PMA at 10 ng/ml, whereas it inhibited thrombomodulin activity by only 15% on the same stimulated cells. Our results confirm that annexin-V inhibits, in vitro, procoagulant tissue-factor activity and anticoagulant activities (activation of protein C by the thrombin-thrombomodulin complex and by Factor Xa), through phospholipid-dependent mechanisms.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Interleukin-10 Regulates the Tissue Factor Activity of Monocytes in an In Vitro Model of Bacterial Endocarditis

2001 ◽  
Vol 69 (5) ◽  
pp. 3197-3202 ◽  
Author(s):  
Marcel H. A. M. Veltrop ◽  
Jan A. M. Langermans ◽  
Jan Thompson ◽  
Maurice J. L. M. F. Bancsi
Keyword(s):  
Tissue Factor ◽  
Bacterial Endocarditis ◽  
Coagulation System ◽  
Minor Role ◽  
Factor Activity ◽  
Necrosis Factor Alpha ◽  
Tissue Factor Activity ◽  
Fibrin Matrix ◽  
Tnf Α

ABSTRACT Monocytes are important effector cells in the pathogenesis of bacterial endocarditis since they provide the tissue factor that activates the coagulation system and maintains established vegetations. Monocytes secrete cytokines that can modulate monocyte tissue factor activity (TFA), thereby affecting the formation and maintenance of vegetations. In this study, we show that monocytes cultured for 4 h on a Streptococcus sanguis-infected fibrin matrix mimicking the in vivo vegetational surface express high levels of TFA. This was accompanied by secretion of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-1α (IL-1α), and IL-1β. After a 24-h incubation period the anti-inflammatory cytokine IL-10 could also be detected. Our data show that, whereas TNF-α and IL-1 have a minor role in the induction of TFA by monocytes cultured on a fibrin matrix, TNF-α but not IL-1 plays an important role in the induction of IL-10 by these cells. In turn, our data show that IL-10 is an important factor in the downregulation of monocyte TFA. In summary, we conclude that IL-10 is an important factor in the control of monocyte TFA in endocardial vegetations.

scholarly journals Plasmin enhances cell surface tissue factor activity in mesothelial and endothelial cells

2009 ◽  
Vol 7 (1) ◽  
pp. 121-131 ◽  
Author(s):  
H. KOTHARI ◽  
G. KAUR ◽  
S. SAHOO ◽  
S. IDELL ◽  
L. V. M. RAO ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Surface ◽  
Tissue Factor ◽  
Factor Activity ◽  
Tissue Factor Activity

scholarly journals Generation of a Novel In Vitro Model to Study Endothelial Dysfunction from Atherothrombotic Specimens

2021 ◽  
Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
In Vitro Model ◽  
Umbilical Vein ◽  
Coronary Syndrome ◽  
Coronary Endothelial Cells ◽  
Vitro Model ◽  
Umbilical Vein Endothelial Cells

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.

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