scholarly journals Defective fibrin deposition and thrombus stability in Bambi −/− mice are mediated by elevated anticoagulant function

2019 ◽  
Vol 17 (11) ◽  
pp. 1935-1949
Author(s):  
James T. B. Crawley ◽  
Argita Zalli ◽  
James H. Monkman ◽  
Anastasis Petri ◽  
David A. Lane ◽  
...  
Keyword(s):  
Fibrin Deposition ◽  
Anticoagulant Function

Focal Procoagulant Activity in Space Between TNF-α Treated Endothelial Cells Mediates Focal Fibrin Accumulation and Anti-Streptococcal Function

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3307-3307
Author(s):  
Junhong Lu ◽  
Gary E. Gilbert
Keyword(s):  
Innate Immunity ◽  
Endothelial Cells ◽  
Confocal Microscopy ◽  
Bacterial Activity ◽  
Procoagulant Activity ◽  
Fibrin Deposition ◽  
Cellular Space ◽  
Anticoagulant Function ◽  
Coagulation Pathway ◽  
Bulk Plasma

Abstract Abstract 3307 Background: Stimulated endothelial cells withdraw from the junctions with neighboring cells and develop a mounded morphology. These cells have mixed procoagulant and anticoagulant function, in contrast to the dominant anticoagulant function of quiescent cells. Recent findings from our laboratory indicate that tumor necrosis factor-a (TNFα) treated endothelial cells support localized assembly of the prothrombinase complex on the margins of cells and on filopodia that span the inter-cellular space. The prothrombinase binding sites are characterized by exposed phosphatidylserine and high convex curvature. We asked whether this inter-cellular space is a focal procoagulant environment while the body of the endothelial cell maintains an overall anticoagulant function. We also asked whether focal procoagulant activity has a function in innate immunity. Methods: Human umbilical vein endothelial cells (HUVECs) were grown to a confluent monolayer on coverslips coated with 1% gelatin or Sigmacote. Cells were treated with 5 nM TNFα or an equal volume of saline for 12 hr. Rinsed cells were then overlaid with re-calcified plasma, diluted 1:4 with buffered saline and placed on a shaker plate at 37 °C at 1000 rpm. Plasma was removed from cells at various times and the cells and fibrin were assessed by confocal microscopy. Fluorescein-labeled fibrinogen was added to plasma to enable imaging fibrin deposition. Alternatively, fibrin derived from native fibrinogen was imaged with fluorescein-labeled mAb 59D8, specific for the beta-chain of fibrin. Streptococci pyogenes strain 700294 was obtained from ATCC and grown and plated using standard techniques. Results: Quiescent endothelial cells responded to TNFα by retracting from the cell-cell junctions, as previously described. As we previously reported, the filopodia and localized regions on the cell margins stained with lactadherin, indicating phosphatidylserine exposure and convex curvature, while the cell bodies did not. The plasma-saline mixtures incubated over endothelial cells did not clot over a 2 hr time span, but plasma incubated over control gelatin-coated coverslips clotted within 10 min. Confocal microscopy indicated that fibrin strands were deposited between TNFa-treated endothelial cells but were largely absent from cover slips with untreated cells. Soluble, fluorescent fibrin bound to the margins of TNFα-treated endothelial cells but not to quiescent endothelial cells or to the Sigmacote-treated cover slips. Fibrin deposition was greatly diminished by reducing Ca++ to < 1 mM, by an anti-tissue factor mAb, and by hirudin. The quantity of fibrin was increased by an anti-tissue factor pathway inhibitor antibody but not by corn trypsin inhibitor, anti-activated protein C mAb, anti-thrombomodulin mAb, or anti-factor VIII mAb. Thus, focal procoagulant activity is mediated by the extrinsic coagulation pathway. To determine whether the fibrin deposition has a function in innate immunity, Streptococcus pyogenes, was added to plasma at a concentration of 106cfu/ml. The streptococci concentration was decreased to <40% in three hours in the presence of TNFa treated endothelial cells, but increased more than 3-fold in the presence of control cells. Addition of hirudin to the TNFα-treated cells enabled Streptococci to grow at the same rate as in citrated plasma alone or re-calcified plasma incubated over quiescent endothelial cells. Confocal microscopy indicated that streptococci decorated the fibrin strands in the inter-endothelial space but not the intercellular matrix or the endothelial cell bodies. Conclusion: TNFα treated HUVECs support focal procoagulant activity via the extrinsic coagulation pathway while maintaining anticoagulant function toward bulk plasma. Focal endothelial procoagulant activity leads to cell-bound fibrin and anti-streptococcal activity, independent of leukocytes and platelets. Discussion: Focal support of procoagulant activity by endothelial cells may have a role in innate immunity without clotting of bulk plasma and independent of leukocytes or platelets. The conditions under which vascular beds react in this manner, the breadth of anti-bacterial activity, and the mechanisms of coagulation-dependent anti-bacterial activity are promising areas for further investigation. Disclosures: No relevant conflicts of interest to declare.

High Levels of Circulating Thrombomodulin in Human Foetuses and Children

1999 ◽  
Vol 81 (06) ◽  
pp. 906-909 ◽  
Author(s):  
Marie-Hélène Aurousseau ◽  
Danielle Gozin ◽  
Fernand Daffos ◽  
Armando D’Angelo ◽  
François Forestier ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Protein C ◽  
Endothelial Cell Surface ◽  
A Value ◽  
Median Level ◽  
Group A ◽  
Anticoagulant Function ◽  
Cell Surface Proteoglycan ◽  
Human Foetuses

SummaryThrombomodulin (TM) is an endothelial cell surface proteoglycan with anticoagulant functions, also implicated in cell proliferation, cell-cell adhesion and differentiation. In this study we determined circulating plasma TM (pTM) levels in human foetuses at different stages of pregnancy, at birth and in childhood. TM levels increased with gestational age, the median level reaching a peak of approximately 165 ng/ml between the 23rd and 26th week, thereafter decreasing gradually, reaching a value of 108 ng/ml at birth. pTM continues to decrease progressively during childhood, reaching in the 5-15 years group a median of 56 ng/ml which approaches the adult value. The pTM peak was statistically significant and represents a specific foetal phenomenon as it was independent of the corresponding maternal values. As a whole, the pTM pattern during foetal maturation appears totally different from that of protein C, prothrombin and other coagulation activators and inhibitors and thus, TM may play in the foetus another role in addition to its well-known anticoagulant function.

Binding of 131I-Labeled Tissue-Type Plasminogen Activator on De-Endothelialized Lesions in Rabbits

1987 ◽  
Vol 26 (05) ◽  
pp. 224-228 ◽  
Author(s):  
Y. Isaka ◽  
H. Etani ◽  
K. Kimura ◽  
S. Yoneda ◽  
T. Kamada ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Abdominal Aorta ◽  
Half Life ◽  
Balloon Catheter ◽  
Biochemical Properties ◽  
Tissue Type ◽  
Fibrin Deposition ◽  
Tissue Type Plasminogen Activator ◽  
High Affinity ◽  
Type Plasminogen Activator

Tissue-type plasminogen activator (t-PA) which has a high affinity for fibrin in the clot, was labeled with 131I by the iodogen method, and its binding to de-endothelialized lesions in the rabbit was measured to assess the detectability of thrombi. The de-endothelialized lesion was induced in the abdominal aorta with a Fogarty 4F balloon catheter. Two hours after the de-endothelialization, 131I-labeled t-PA (125 ± 46 μCi) was injected intravenously. The initial half-life of the agent in blood (n = 12) was 2.9 ± 0.4 min. The degree of binding of 131I-labeled t-PA to the de-endothelialized lesion was evaluated at 15 min (n = 6) or at 30 min (n = 6) after injection of the agent. In spite of the retention of the biochemical properties of 131I-labeled t-PA and the presence of fibrin deposition at the de-endothelialized lesion, the binding of t-PA to the lesion was not sufficiently strong. Lesion-to-control ratios (cpm/g/cpm/g) were 1.65 ± 0.40 (at 15 min) and 1.39 ± 1.31 (at 30 min), and lesion-to-blood ratios were 1.39 ± 0.32 (at 15 min) and 1.36 ± 0.23 (at 30 min). These results suggest that radiolabeled t-PA may be inappropriate as a radiopharmaceutical for the scintigraphic detection of a pre-existing thrombotic lesion.

Fibrin Derivatives, Plasma Hemoglobin and Glomerular Fibrin Deposition in Experimental Intravascular Coagulation

1973 ◽  
Vol 29 (02) ◽  
pp. 363-374 ◽  
Author(s):  
F. K Beller ◽  
W Theiss
Keyword(s):  
Quantitative Measurement ◽  
Plasma Fibrinogen ◽  
Moderate Increase ◽  
Consumption Coagulopathy ◽  
Fibrin Deposition ◽  
Intravascular Coagulation ◽  
Plasma Hemoglobin ◽  
Three Stages ◽  
Two Parameters ◽  
Gelation Test

SummaryPlasma fibrinogen, circulating fibrinmonomers (as indicated by a positive ethanol gelation test), fibrinolysis breakdown products and plasma hemoglobin were assayed in 122 rats subjected to endotoxin injection or infusion. The results were correlated with the quantitative measurement of glomerular fibrin deposition. Based on these data four groups were determined : consumption coagulopathy and three stages of increasing severity of disseminated intravascular coagulation (DIG).Consumption coagulopathy was defined by a decrease in plasma fibrinogen and a positive ethanol gelation test in the absence of glomerular fibrin deposition. Plasma hemoglobin and fibrinolysis breakdown products were normal or only slightly increased.DIG as characterized by glomerular fibrin deposition was defined as moderate (1 to 20% glomeruli showing fibrin strands), intermediate (21 to 80%), and severe (81 to 100%). Decrease in plasma fibrinogen and frequence of a positive ethanol gelation test in all stages of DIG were only slightly different from the findings in consumption coagulopathy. However, a sharp increase in plasma hemoglobin levels was noted when glomerular fibrin deposition did occur even in small amounts. At this time only a moderate increase was noted in fibrin(ogen) breakdown products. These two parameters increased only slightly in the group of intermediate DIG. Severe DIG was characterized by a massive increase in fibrin (ogen) breakdown products and high levels of plasma hemoglobin.

Fibrinolysis in Decidual Spiral Arteries in Late Pregnancy

1978 ◽  
Vol 39 (03) ◽  
pp. 751-758 ◽  
Author(s):  
B L Sheppard ◽  
J Bonnar
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Fibrinolytic Activity ◽  
Physiological Mechanism ◽  
Late Pregnancy ◽  
Full Term ◽  
Fibrin Deposition ◽  
Placental Villi ◽  
The Media ◽  
Slide Technique

SummaryThe fibrinolytic activity of the intimal cells of decidual spiral arteries and the syncytium of placental villi was studied by electron microscopy in ten normal full-term human pregnancies using a modification of the fibrin slide technique. Endothelial cells lining the intima of the decidual spiral arteries showed a considerably greater fibrinolytic activity than intimal cytotrophoblast and the syncytiotrophoblast showed no activity.The replacement of endothelial cells by an intimal lining of cytotrophoblast, and the presence of cytotrophoblast in the media, appears to play an important role in the reduction of the fibrinolytic activity of the vessel. This inhibition of fibrinolytic activity in the utero-placental arteries may be the physiological mechanism which controls fibrin deposition in these vessels and on the placental villi.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

Hypercoagulability and High Lipoprotein(a) Levels in Patients with Central Retinal Vein Occlusion

1994 ◽  
Vol 72 (01) ◽  
pp. 039-043 ◽  
Author(s):  
Francesco Bandello ◽  
Silvana Vigano’ D’Angelo ◽  
Mariella Parlavecchia ◽  
Alessandra Tavola ◽  
Patrizia Della Valle ◽  
...  
Keyword(s):  
Retinal Vein Occlusion ◽  
Central Retinal Vein Occlusion ◽  
Specific Treatment ◽  
Fibrin Deposition ◽  
Heparin Cofactor Ii ◽  
Lipoprotein A ◽  
Vein Occlusion ◽  
Acute Event ◽  
D Dimer ◽  
Central Retinal Vein

SummaryA series of coagulation parameters and lipoprotein(a) (Lp(a)) were explored in plasma from 40 patients with central retinal vein occlusion (CRVO, non-ischemic type n = 12; ischemic type n = 28) free of local and systemic predisposing factors, 1 to 12 months after the acute event. Forty age- and sex-matched patients with cataract served as controls. Prothrombin fragment 1.2 (FI.2), D-dimer, FVII:C - but not FVII: Ag - were higher and fibrinogen was lower in CRVO patients than in controls. Patients with non-ischemic CRVO had higher FI .2 and FVII:C and lower heparin cofactor II than patients with ischemic CRVO. Lp(a) levels greater than 300 mg/1 were observed in 12 patients with CRVO and in 4 controls (30% vs 10%, p <0.025). Patients with high Lp(a) - consistently associated with the S2 phenotype - had higher FVII:C, FVII:C/Ag ratio, and fibrinogen than the remaining CRVO patients. Plasma FI.2 and D-dimer correlated fairly in controls (r = 0.41) and patients with normal Lp(a) levels (r = 0.55), but they did not in the group of patients with high Lp(a) (r = 0.19), where the latter parameter was negatively related to D-dimer (r = −0.55). There was no dependence of the abnormalities observed on the time elapsed from vein occlusion. The findings of activated FVII and high FI.2, D-dimer, and Lp(a) are not uncommon in patients with CRVO. Increased thrombin formation with fibrin deposition and impaired fibrinolysis may play a role in the pathophysiology of CRVO and require specific treatment

The Intravascular Generation of Fibrinogen Derivatives and the Blood Vessel Wall in Venous Thrombosis and Disseminated Intravascular Coagulation

1977 ◽  
Vol 38 (04) ◽  
pp. 0831-0849 ◽  
Author(s):  
Gwendolyn J. Stewart
Keyword(s):  
Blood Vessel ◽  
Venous Thrombosis ◽  
Vessel Wall ◽  
Fluid Phase ◽  
Primary Site ◽  
Blood Vessel Wall ◽  
Fibrin Deposition ◽  
Tissue Destruction ◽  
Fibrin Formation ◽  
Rich Material

SummaryBoth deep venous thrombosis and DIC are intermediate mechanisms of disease – both are a consequence of the deposition of fibrin-rich material in blood vessels some distance from the primary site of tissue destruction. The great difference in the sites of fibrin deposition may depend on the extent and site of activation of the clotting mechanism. DIC likely occurs in the fluid phase of the blood as a consequence of massive fibrin formation while thrombosis results from limited fibrin formation at the interface between blood and vessel wall. Leukocytes may be essential for attaching thrombi to the vessel wall in many places.

Abnormal Haemostasis and Blood Viscosity in Malignant Hypertension

1984 ◽  
Vol 52 (03) ◽  
pp. 253-255 ◽  
Author(s):  
C Isles ◽  
G D O Lowe ◽  
B M Rankin ◽  
C D Forbes ◽  
N Lucie ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Viscosity ◽  
Renal Damage ◽  
Antithrombin Iii ◽  
Plasma Viscosity ◽  
Malignant Hypertension ◽  
Fibrin Deposition ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.

scholarly journals S62798, a TAFIa inhibitor, accelerates endogenous thrombolysis in a murine model of pulmonary thromboembolism

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
P Sansilvestri-Morel ◽  
F Bertin ◽  
I Lapret ◽  
B Neau ◽  
V Blanc-Guillemaud ◽  
...  
Keyword(s):  
Pulmonary Thromboembolism ◽  
Prediction Interval ◽  
Therapeutic Option ◽  
Geometric Mean ◽  
Active Form ◽  
Cardiovascular Death ◽  
Vehicle Group ◽  
Fibrin Deposition ◽  
Minimal Effective Dose ◽  
Endogenous Fibrinolysis

Abstract   Pulmonary embolism (PE) is the third leading cause of cardiovascular death in western countries. The enhancement of fibrinolysis constitutes a promising approach to treat thrombotic diseases. In patients, venous thrombosis and thromboembolism risks are associated with increased plasma levels of TAFI (Thrombin Activatable Fibrinolysis Inhibitor) antigen as well as the active form TAFIa. S62798 is a competitive, selective and potent human TAFIa inhibitor (IC50±SD=11.2±0.4nM). It is however less potent on mouse TAFIa (IC50±SD=270±39nM). Here, we tested the ability of S62798 to enhance endogenous fibrinolysis in a mouse model of pulmonary thromboembolism. Human Tissue Factor (TF) was injected in C57Bl6 male mice. Ten minutes later, mice (n=4 to 14 per group) were treated (IV) with S62798 (from 0.01 to 100mg/kg) or vehicle (0.9% NaCl). Ten or twenty minutes (min) later, mice were anesthetized and lungs were collected, homogenized and pulmonary fibrin was quantified by ELISA. Results are expressed as ratio of geometric mean of pulmonary fibrin (μg/mL): tested treatment/ vehicle [95% confidence interval (CI)]. Ten minutes after S62798 treatment, pulmonary fibrin deposition was dose-dependently decreased with a Minimal Effective Dose of 0.04mg/kg [90% prediction interval 0.037 - 0.051] and an ED50 of 0.03mg/kg [95% CI: 0.01; 0.06]. Mice were then treated with 0.1mg/kg S62798 or vehicle (10 min after TF induction) and fibrin deposition in lungs was quantified 10 and 20 minutes post S62798 treatment. The level of pulmonary fibrin deposition was significantly decreased (p&lt;0.0001) compared to vehicle group (ratio 0.31 [0.21; 0.45] at 10 min; 0.35 [0.24; 0.51] at 20 min). Finally, the effect of S62798 (1mg/kg) in combination with heparin was evaluated (n=10/group). When administered 10 min before TF injection, heparin (2000IU/kg) significantly (p&lt;0.0001) decreased pulmonary fibrin level (20 min post TF: ratio 0.03 [0.01; 0.05]). When treatment was done in a curative setting (10 min post TF), heparin alone had no effect (p=0.85) on fibrin deposition (ratio 0.96 [0.65; 1.43]) whereas a similar significant (p&lt;0.0001) decreased pulmonary fibrin deposition was observed in response to S62798 alone or associated with heparin (ratio 0.27 [0.18; 0.40] (S62798 alone) and 0.29 [0.20; 0.43] (S62798+heparin)). In this model, curative S62798 treatment, alone or associated to heparin, accelerated clot degradation by potentiating endogenous fibrinolysis and thus decreased pulmonary fibrin deposition. Due to its capacity to enhance endogenous fibrinolysis, S62798, which has completed phase I studies, is expected to be a therapeutic option for intermediate high risk PE patients on top of anticoagulants. With early recanalization, S62798 should rapidly reduce pulmonary artery pressure and resistance, with concomitant improvement in right ventricular function, preserving cardiac function, and reducing acute PE-related morbidity and mortality in these patients. Funding Acknowledgement Type of funding source: None

Sign in / Sign up

Export Citation Format

Share Document