scholarly journals The cofactor role of protein S in the acceleration of whole blood clot lysis by activated protein C in vitro

Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1189-1192 ◽  
Author(s):  
NJ de Fouw ◽  
F Haverkate ◽  
RM Bertina ◽  
J Koopman ◽  
A van Wijngaarden ◽  
...  
Keyword(s):  
Whole Blood ◽  
Protein C ◽  
Degradation Products ◽  
Blood Clot ◽  
Activated Protein C ◽  
Protein S ◽  
Tissue Type ◽  
Clot Lysis ◽  
Fibrin Degradation Products

Abstract The effect of purified human activated protein C (APC) and protein S on fibrinolysis was studied by using an in vitro blood clot lysis technique. Blood clots were formed from citrated blood (supplemented with 125I-fibrinogen) by adding thrombin and Ca2+-ions; lysis of the clots was achieved by adding tissue-type plasminogen activator. The release of labeled fibrin degradation products from the clots into the supernatant was followed in time. We clearly demonstrated that APC accelerates whole blood clot lysis in vitro. The effect of APC was completely quenched by antiprotein C IgG, pretreatment of APC with diisopropylfluorophosphate, and preincubation of the blood with antiprotein S IgG. This demonstrates that both the active site of APC and the presence of the cofactor, protein S, are essential for the expression of the profibrinolytic properties. At present, the substrate of APC involved in the regulation of fibrinolysis is not yet known. Analysis of the radiolabeled fibrin degradation products demonstrated that APC had no effect on the fibrin cross-linking capacity of factor XIII.

scholarly journals The cofactor role of protein S in the acceleration of whole blood clot lysis by activated protein C in vitro

Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1189-1192
Author(s):  
NJ de Fouw ◽  
F Haverkate ◽  
RM Bertina ◽  
J Koopman ◽  
A van Wijngaarden ◽  
...  
Keyword(s):  
Whole Blood ◽  
Protein C ◽  
Degradation Products ◽  
Blood Clot ◽  
Activated Protein C ◽  
Protein S ◽  
Tissue Type ◽  
Clot Lysis ◽  
Fibrin Degradation Products

The effect of purified human activated protein C (APC) and protein S on fibrinolysis was studied by using an in vitro blood clot lysis technique. Blood clots were formed from citrated blood (supplemented with 125I-fibrinogen) by adding thrombin and Ca2+-ions; lysis of the clots was achieved by adding tissue-type plasminogen activator. The release of labeled fibrin degradation products from the clots into the supernatant was followed in time. We clearly demonstrated that APC accelerates whole blood clot lysis in vitro. The effect of APC was completely quenched by antiprotein C IgG, pretreatment of APC with diisopropylfluorophosphate, and preincubation of the blood with antiprotein S IgG. This demonstrates that both the active site of APC and the presence of the cofactor, protein S, are essential for the expression of the profibrinolytic properties. At present, the substrate of APC involved in the regulation of fibrinolysis is not yet known. Analysis of the radiolabeled fibrin degradation products demonstrated that APC had no effect on the fibrin cross-linking capacity of factor XIII.

scholarly journals Alteration of fibrin network by activated protein C

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2541-2548 ◽  
Author(s):  
A Gruber ◽  
E Mori ◽  
GJ del Zoppo ◽  
L Waxman ◽  
JH Griffin
Keyword(s):  
Protein C ◽  
Degradation Products ◽  
Activated Protein C ◽  
Relative Number ◽  
Relative Mass ◽  
Clot Lysis ◽  
Fibrin Degradation Products ◽  
Rate Of Increase ◽  
Fibrin Network

Abstract The antithrombotic plasma enzyme, activated protein C (APC), may play a role in thrombolysis. In vitro, acceleration of clot lysis by APC depends on its ability to inhibit the activation of prothrombin. The effect of APC on the assembly and dispersion of fibrin network was studied using turbidimetry, plasmin digestion of fibrin, and electron microscopy of plasma clots. The addition of APC before clotting but not after clotting accelerated clot lysis. The rate of increase in the turbidity of clotting plasma was reduced by APC. The turbidity of plasma clots containing APC was directly related to the clot lysis time. Fibrin from plasma clots that were formed in the presence of APC yielded less fibrin degradation products than fibrin from clots without added APC. Furthermore, APC reduced the diameter and relative number of fibrin fibers in plasma clots during gel assembly. We propose that APC may enhance the efficacy of thrombolysis by reducing the relative mass of fibrin within maturing thrombi.

Whole blood clot lysis: In vitro modulation by activated protein C

1985 ◽  
Vol 37 (6) ◽  
pp. 639-649 ◽  
Author(s):  
Fletcher B. Taylor ◽  
Marion S. Lockhart
Keyword(s):  
Whole Blood ◽  
Protein C ◽  
Blood Clot ◽  
Activated Protein C ◽  
Clot Lysis

scholarly journals Alteration of fibrin network by activated protein C

Blood ◽  
1994 ◽  
Vol 83 (9) ◽  
pp. 2541-2548
Author(s):  
A Gruber ◽  
E Mori ◽  
GJ del Zoppo ◽  
L Waxman ◽  
JH Griffin
Keyword(s):  
Protein C ◽  
Degradation Products ◽  
Activated Protein C ◽  
Relative Number ◽  
Relative Mass ◽  
Clot Lysis ◽  
Fibrin Degradation Products ◽  
Rate Of Increase ◽  
Fibrin Network

The antithrombotic plasma enzyme, activated protein C (APC), may play a role in thrombolysis. In vitro, acceleration of clot lysis by APC depends on its ability to inhibit the activation of prothrombin. The effect of APC on the assembly and dispersion of fibrin network was studied using turbidimetry, plasmin digestion of fibrin, and electron microscopy of plasma clots. The addition of APC before clotting but not after clotting accelerated clot lysis. The rate of increase in the turbidity of clotting plasma was reduced by APC. The turbidity of plasma clots containing APC was directly related to the clot lysis time. Fibrin from plasma clots that were formed in the presence of APC yielded less fibrin degradation products than fibrin from clots without added APC. Furthermore, APC reduced the diameter and relative number of fibrin fibers in plasma clots during gel assembly. We propose that APC may enhance the efficacy of thrombolysis by reducing the relative mass of fibrin within maturing thrombi.

A Monoclonal Antibody-Based Enzyme Immunoassay for Fibrin Degradation Products in Plasma

1988 ◽  
Vol 59 (02) ◽  
pp. 310-315 ◽  
Author(s):  
P W Koppert ◽  
E Hoegee-de Nobel ◽  
W Nieuwenhuizen
Keyword(s):  
Enzyme Immunoassay ◽  
Degradation Products ◽  
Blood Clot ◽  
Tissue Type ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Strong Positive Reaction ◽  
Sandwich Type ◽  
Capture Antibody

SummaryWe have developed a sandwich-type enzyme immunoassay (EIA) for the quantitation of fibrin degradation products (FbDP) in plasma with a time-to-result of only 45 minutes.* The assay is based on the combination of the specificities of two monoclonal antibodies (FDP-14 and DD-13), developed in our institute. FDP-14, the capture antibody, binds both fibrinogen degradation products (FbgDP) and FbDP, but does not react with the parent fibrin(ogen) molecules. It has its epitope in the E-domain of the fibrinogen molecule on the Bβ-chain between amino acids 54-118. Antibody DD-13 was raised using D-dimer as antigen and is used as a tagging antibody, conjugated with horse-radish peroxidase. A strong positive reaction is obtained with a whole blood clot lysate (lysis induced by tissue-type plasminogen activator) which is used as a standard. The EIA does virtually not detect FbgDP i. e. purified fragments X, Y, or FbgDP generated in vitro in plasma by streptokinase treatment. This indicates that the assay is specific for fibrin degradation products.We have successfully applied this assay to the plasma of patients with a variety of diseased states. In combination with the assay previously developed by us for FbgDP and for the total amount of FbgDP + FbDP (TDP) in plasma, we are now able to study the composition of TDP in patients plasma in terms of FbgDP and FbDP.

Activated Protein C Increases Fibrin Clot Lysis by Neutralization of Plasminogen Activator Inhibitor No Evidence for a Cofactor Role of Protein S

1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina
Keyword(s):  
Plasminogen Activator ◽  
Protein C ◽  
Blood Platelets ◽  
Plasminogen Activator Inhibitor ◽  
Protein S ◽  
Tissue Type ◽  
Clot Lysis ◽  
Activator Inhibitor ◽  
Pai 1

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.

A NEW QUANTITATIVE ENZYME-IMMUNOASSAY FOR FIBRIN DEGRADATION PRODUCTS (FbDP) IN PLASMA, BASED ON MONOCLONAL ANTIBODIES

1987 ◽  
Author(s):  
P W Koppert ◽  
E Hoegee-de Nobel ◽  
W Nieuwenhuizen
Keyword(s):  
Monoclonal Antibodies ◽  
Enzyme Immunoassay ◽  
Degradation Products ◽  
Blood Clot ◽  
Tissue Type ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Strong Positive Reaction ◽  
Sandwich Type

We have developed a sandwich-type enzyme immunoassay (EIA) for the quantitation of fibrin degradation products (FbDP) in plasma with a time-to-result of only 45 minutes. The assay is based on the combination of the specificities of two monoclonal antibodies (FDP-14 and DD-13), developed in our institute. FDP-14, the catching antibody, binds both fibrinogen degradation products (FbgDP) and FbDP. It has its epitope in the E-domain of the fibrinogen molecule on the BB-chain between amino acids 54-118 (Blood 68, 437, 1986). Antibody DD-13 was raised using D-dimer as antigen and was used as a tagging antibody, conjugated with horse-radish peroxidase.A strong positive reaction is obtained with a whole blood clot lysate (lysis induced by tissue-type plasminogen activator) which is used as a standard.The EIA does not detect FbgDP i.e. purified fragments X, Y, D:E complexes or FbgDP in plasma treated in vitro with streptokinase. This indicates that the assay is specific for fibrin degradation products.We have successfully applied this assay to the plasma of patients with a variety of diseases. In combination with the assays previously developed by us for FbgDP (Thromb. Haemostas. 1987, in press) and for the total amount (TDP) of FbgDP + FbDP in plasma (J. Lab. Clin. Med. 1987, in press), we are now able to study the composition of TDP in terms of FbgDP and FbDP in patients.

The Measurement of Fibrinolysis in the Rat

1971 ◽  
Vol 26 (02) ◽  
pp. 295-310 ◽  
Author(s):  
M. J Gallimore ◽  
H. M Tyler ◽  
J. T. B Shaw
Keyword(s):  
Whole Blood ◽  
Fibrinolytic Activity ◽  
Factor Xiii ◽  
Degradation Products ◽  
Blood Clot ◽  
Clot Lysis ◽  
Plate Assay ◽  
Fibrin Degradation Products ◽  
Fibrin Plate ◽  
Dilute Blood

SummaryMethods are described for measuring fibrinolytic activity in the rat. These include dilute blood clot lysis, euglobulin clot lysis, a fibrin plate assay with euglobulin solutions, and an accelerated whole blood clot lysis technique in which limited fibrinolysis is induced with urokinase. In addition, methods have been worked out for the estimation of four plasma components closely involved in fibrinolysis: fibrinogen, factor XIII, plasma inhibitors and fibrin degradation products. The sensitivity and validity of the assays were tested by studying their capacity to detect changes resulting from the administration of eledoisin, Neohydrin and turpentine.

scholarly journals 3K3A-Activated Protein C Variant Does Not Interfere With the Plasma Clot Lysis Activity of Tenecteplase

Stroke ◽  
2020 ◽  
Vol 51 (7) ◽  
pp. 2236-2239
Author(s):  
Purba Mukherjee ◽  
Patrick Lyden ◽  
José A. Fernández ◽  
Thomas P. Davis ◽  
Kent E. Pryor ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Protein C ◽  
Activated Protein C ◽  
In Vitro Study ◽  
Tissue Type ◽  
Clot Lysis ◽  
Bolus Administration ◽  
Plasma Clot ◽  
Lysis Activity

Background and Purpose: A recombinant engineered variant of APC (activated protein C), 3K3A-APC, lacks anticoagulant properties (<10%) while preserving APCs anti-inflammatory, anti-apoptotic, and neuroprotective functions and is very promising in clinical trials for ischemic stroke. Therapeutic intervention with single bolus administration of the third-generation tPA (tissue-type plasminogen activator), tenecteplase, is anticipated to be widely adopted for treatment of acute ischemic stroke. 3K3A-APC is well-tolerated in stroke patients dosed with alteplase, and in vitro studies show 3K3A-APC does not interfere with alteplase-induced clot lysis. The purpose of this in vitro study was to assess the influence of 3K3A-APC on tenecteplase-induced clot lysis. Methods: Tenecteplase-mediated lysis of thrombin generated plasma clots of human normal pooled plasma was monitored in the presence of varying doses of 3K3A-APC. The effects on fibrinolysis by tenecteplase and alteplase were compared. Results: The presence of 3K3A-APC shortened the time for clot lysis induced by tenecteplase at very low levels but not at higher therapeutic concentrations of tenecteplase. Comparisons of alteplase-mediated clot lysis to tenecteplase clot lysis showed that both thrombolytic agents behaved similarly in the presence of 3K3A-APC. Conclusions: These results indicate that 3K3A-APC does not interfere with tenecteplase’s clot lysis function.

Influence of Factor Xllla Activity on Human Whole Blood Clot Lysis In Vitro

1987 ◽  
Vol 57 (02) ◽  
pp. 171-175 ◽  
Author(s):  
J W C M Jansen ◽  
F Haverkate ◽  
J Koopman ◽  
H K Nieuwenhuis ◽  
C Kluft ◽  
...  
Keyword(s):  
Whole Blood ◽  
Major Part ◽  
Blood Clot ◽  
Tissue Type ◽  
Clot Lysis ◽  
Type Plasminogen Activator ◽  
Blood Clots ◽  
Lysis Rate ◽  
Per Se

SummaryWe studied the influence of Factor XIII a (F XIII a) activity on the lysis rate of fresh whole human blood clots, without using anticoagulants. Clotting was induced by exogenous thrombin, lysis by tissue-type Plasminogen Activator (t-PA) added before clotting. After various periods of time, lysis rates were determined by measuring the radioactivity in the supernatant of the clot originating from 125I-Fibrinogen added before clotting.Lysis rates were determined in the presence of endogenous F XHIa and compared with those obtained after specific inhibition of F XIII a activity. We used an IgG fraction of an antiserum quenching the F XIII a activity. Addition of increasing amounts of the antibodies to normal blood resulted in a dramatic increase in clot lysis rate, concomitant with loss of F XIII activity. Lysis of blood clots from a patient with a congenital, homozygous, functional α2-Antiplasmin (α2-AP) deficiency (α2-AP-Enschede) was not or slightly increased by the anti F XIII antibodies indicating that fibrin-fibrin crosslinking per se does not contribute essentially to resistance of the blood clot against fibrinolysis. Both active α2-AP and F XIII a are required for the major part of the F XIII-dependent resistance of whole blood clots against lysis.

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