Procoagulant Activity of Sulfated Polysaccharides

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4419-4419
Author(s):  
Michael Dockal ◽  
Sabine Knappe ◽  
Erwin Panholzer ◽  
Michael Palige ◽  
Hartmut J. Ehrlich ◽  
...  

Abstract Abstract 4419 BAX513, a Laminaria japonica-derived fucoidan and other non-anticoagulant sulfated polysaccharides (NASPs) have been shown to improve clotting in FVIII- and FIX-deficient plasma (Liu et al. Thromb Haemost 2006; 95:68). In this study we assessed the procoagulant activities of fucoidans derived from a variety of brown sea algae species, and correlated the activity with molecular weight (MW) and degree of sulfation. Highly purified fucoidan preparations were studied in FVIII-inhibited whole blood by tissue factor-triggered thromboelastography (TEG). The procoagulant activity was characterized by calibrated automated thrombography (CAT) in FVIII- and FIX-deficient plasma and in combination with established hemophilia therapeutics. A dilute prothrombin time assay based on tissue factor pathway inhibitor supplementation (TFPI-dPT) was used to demonstrate the dose-dependent TFPI-inhibiting effect of BAX513 (EC50 = 0.18 ± 0.03 μ g/mL) in FVIII-deficient plasma. TEG in normal and FVIII-inhibited blood showed a dose-dependent procoagulant effect of most compounds where the optimal concentrations (1-100 nM) were dependent on the MW of the fucoidan. In FVIII-inhibited blood BAX513 at concentrations of ~10 nM (1.2 μ g/mL) completely normalized the TEG parameters. In contrast to sulfated fucoidans, undersulfated fucoidan hardly affected thrombin generation (TG). By CAT, the procoagulant window of NASPs in hemophilic plasma spanned more than two orders of magnitude with maximum effects being equivalent to (mU/mL) 730–940 FVIII, 32–80 FIX and 590–1230 FEIBA. NASPs combined with FVIII, FEIBA or FVIIa had an additive procoagulant effect. The optimal selection of molecular characteristics of NASPs will support the development of alternative hemophilia therapies. Disclosures: Dockal: Baxter Innovations GmbH: Employment. Knappe:Baxter Innovations GmbH: Employment. Panholzer:Baxter Innovations GmbH: Employment. Palige:Baxter Innovations GmbH: Employment. Ehrlich:Baxter Innovations GmbH: Employment. Scheiflinger:Baxter Innovations GmbH: Employment.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4417-4417 ◽  
Author(s):  
Michael Palige ◽  
Christoph Redl ◽  
Sabine Knappe ◽  
Hartmut J. Ehrlich ◽  
Michael Dockal ◽  
...  

Abstract Abstract 4417 BAX513, a fucoidan derived from the brown seaweed Laminaria japonica, and other non-anticoagulant sulfated polysaccharides (NASPs) improve coagulation in hemophilic blood and plasma. Fucoidans are heterogeneous, polysulfated molecules with procoagulant activities in a wide concentration range. Tissue factor pathway inhibitor (TFPI) has been described as a potential target for the procoagulant activity of NASPs (Liu et al. Thromb Haemost 2006; 95:68). In the current study, we investigated the interaction of BAX513 with TFPI proteins to gain a detailed understanding of the mechanism of action of BAX513. We used calibrated automated thrombography to monitor the activity of BAX513 in normal, FX and TFPI-deficient plasma. TFPI plasma levels were varied by the addition of truncated TFPI (TFPI1-160) and TFPI-domain specific antibodies. Initiating thrombin generation by addition of FXa to plasma deficient in both, FX and FVIII-showed a BAX513-dose dependent increase of thrombin generation, which was completely abolished when TFPI-specific polyclonal antibodies were present. Furthermore, when full-length TFPI was inhibited in plasma and instead supplemented with increasing amounts of TFPI 1–160, BAX513 did not show any activity. The data are further supported by surface plasmon resonance experiments (BiaCore) exploring the BAX513-TFPI interaction. A high affinity interaction was only observed for BAX513 with full-length TFPI but not for BAX513 with TFPI1-160. Our findings support a mechanism of action in which BAX513 acts as a potent dose-dependent TFPI antagonist that requires the highly charged C-terminus of TFPI to unfold its full potential. Understanding the mechanism of action of BAX513 supports the development of BAX513 as a promising new therapeutic for hemophiliacs and FVIII-inhibitor patients. Disclosures: Palige: Baxter Innovations GmbH: Employment. Redl:Baxter Innovations GmbH: Employment. Knappe:Baxter Innovations GmbH: Employment. Ehrlich:Baxter Innovations GmbH: Employment. Dockal:Baxter Innovations GmbH: Employment. Scheiflinger:Baxter Innovations GmbH: Employment.


1999 ◽  
Vol 81 (04) ◽  
pp. 589-593 ◽  
Author(s):  
A. M. Gori ◽  
G. Pepe ◽  
M. Attanasio ◽  
M. Falciani ◽  
R. Abbate ◽  
...  

SummaryElevated plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) and large amounts of monocyte procoagulant activity (PCA) have been documented in unstable angina (UA) patients. In in vitro experiments heparin is able to blunt monocyte TF production by inhibiting TF and cytokine gene expression by stimulated cells and after in vivo administration it reduces adverse ischemic outcomes in UA patients. TF and TFPI plasma levels and monocyte PCA have been investigated in 28 refractory UA patients before and during anticoagulant subcutaneous heparin administration (thrice daily weight- and PTT-adjusted for 3 days) followed by 5000 IU × 3 for 5 days. After 2-day treatment, immediately prior to the heparin injection, TF and TFPI plasma levels [(median and range): 239 pg/ml, 130-385 pg/ ml and 120 ng/ml, 80-287 ng/ml] were lower in comparison to baseline samples (254.5 pg/ml, 134.6-380 pg/ml and 135.5 ng/ml, 74-306 ng/ml). Four h after the heparin injection TF furtherly decreased (176.5 pg/ml, 87.5-321 pg/ml; -32.5%, p<0.001) and TFPI increased (240.5 ng/ml, 140-450 ng/ml; +67%, p<0.0001).After 7-day treatment, before the injection of heparin, TF and TFPI plasma levels (200 pg/ml, 128-325 pg/ml and 115 ng/ml, 70-252 ng/ml) significantly decreased (p<0.05) in comparison to the pre-treatment values. On the morning of the 8th day, 4 h after the injection of heparin TF plasma levels and monocytes PCA significantly decreased (156.5 pg/ml, 74-259 pg/ml and from 180 U/105 monocytes, 109-582 U/105 monocytes to 86.1 U/105 monocytes, 28-320 U/105 monocytes; - 38% and -55% respectively) and TFPI increased (235.6 ng/ml, 152-423 ng/ ml; +70%, p<0.001). In conclusion, heparin treatment is associated with a decrease of high TF plasma levels and monocyte procoagulant activity in UA patients. These actions of heparin may play a role in determining the antithrombotic and antiinflammatory properties of this drug.


Blood ◽  
2001 ◽  
Vol 97 (12) ◽  
pp. 3721-3726 ◽  
Author(s):  
Ilka Ott ◽  
Martin Andrassy ◽  
Dominik Zieglgänsberger ◽  
Stefanie Geith ◽  
Albert Schömig ◽  
...  

In acute myocardial infarction (AMI), monocyte procoagulant activity is increased and may contribute to the risk for recurrence and other thrombotic events. This study sought to investigate the role tissue factor (TF) and tissue factor pathway inhibitor-1 (TFPI-1) in the regulation of monocyte procoagulant activity in AMI. Serial venous blood samples were obtained from 40 patients with AMI undergoing revascularization by stent placement. Twenty patients with elective stenting for stable angina served as control subjects. TF proteolytic activity was measured with spectrozyme factor Xa (FXa), TF and TFPI-1 surface expression on monocytes by flow cytometry, RNA expression in whole blood by reverse transcription–polymerase chain reaction, and concentrations of plasma prothrombin fragments F1 + 2 by immunoassay. Forty-eight hours after AMI, an increase was found in TF RNA, followed by an increase in TF surface expression by 24% ± 4% and in plasma concentration of F1 + 2 by 103% ± 17% (P &lt; .05). These changes could not be attributed to the intervention because they did not occur in the control group. TFPI-1 RNA and binding to the monocyte surface remained unchanged. FXa generation by monocytes of patients with AMI increased 53.6% ± 9% in the presence of polyclonal antibodies to TFPI-1, indicating that cell-associated TFPI-1 inhibits monocyte TF activity. The increased monocyte procoagulant activity in AMI was caused by an up-regulation of TF that was partially inhibited by surface-bound TFPI-1. Anticoagulant therapy by direct inhibition of TF activity may, thus, be particularly effective in AMI.


1992 ◽  
Vol 65 (4-5) ◽  
pp. 507-518 ◽  
Author(s):  
Philippe de Moerloose ◽  
Edoardo De Benedetti ◽  
Laurent Nicod ◽  
Catherine Vifian ◽  
Guido Reber

2008 ◽  
Vol 294 (5) ◽  
pp. L874-L881 ◽  
Author(s):  
Julie A. Bastarache ◽  
Ling Wang ◽  
Zhengming Wang ◽  
Kurt H. Albertine ◽  
Michael A. Matthay ◽  
...  

The alveolar compartment in acute lung injury contains high levels of tissue factor (TF) procoagulant activity favoring fibrin deposition. We previously reported that the alveolar epithelium can release TF procoagulant activity in response to a proinflammatory stimulus. To test the hypothesis that the alveolar epithelium further modulates intra-alveolar fibrin deposition through secretion of an endogenous inhibitor to TF, tissue factor pathway inhibitor (TFPI), we measured TFPI levels in edema fluid (EF) from patients with acute respiratory distress syndrome. To determine whether the alveolar epithelium can release TFPI, both full-length TFPI and truncated TFPI were measured (ELISA) in pulmonary edema fluid from patients with acute respiratory distress syndrome (ARDS) and a control group of patients with hydrostatic pulmonary edema (HYDRO). TFPI protein was also measured in conditioned media (CM) and cell lysates (CL) from human alveolar epithelial cells (A549) after exposure to cytomix (TNF-α, IL-1β, IFN-γ). TFPI protein levels were higher in pulmonary edema fluid from patients with ARDS vs. HYDRO. TFPI protein was increased in CM and did not change in CL after cytomix treatment; TFPI mRNA levels (RT-PCR) did not change. Despite the high levels of TFPI, both the EF and CM retained significant TF procoagulant activity as measured by plasma recalcification time. The majority of intra-alveolar TFPI was in a truncated, inactive form, whereas the majority of TFPI released from cells was full length, suggesting different mechanisms of inactivation. In summary, the alveolar epithelium releases TFPI in response to an inflammatory stimulus but does not increase TFPI gene transcription or protein production. Levels of intra-alveolar TFPI in ARDS are not sufficient to block intra-alveolar TF procoagulant activity due to truncation and inactivation of intra-alveolar TFPI.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2278-2278 ◽  
Author(s):  
Sarah C Bassi ◽  
Eduardo Magalhães Rego

Abstract The characteristic coagulopathy in Acute Promyelocytic Leukemia (APL) is unique among the leukemias and thrombotic and bleeding complications remain the major causes of early deaths. APL promyelocytes express tissue factor (TF) which, after activation by phospholipids, forms a complex with factor VII and converts factor X to activated factor X. TF plays a central role in the pathogenesis of APL coagulopathy, for the procoagulant activity of lysates from freshly isolated APL cells is mainly attributed to TF. During periods of increased apoptosis of promyelocytes, the procoagulant activity is correspondingly intensified. In addition, APL cells may also induce TF procoagulant activity of endothelial cells through their secretion of IL-1b. The activity of the complex FVIIa-TF can be inhibited by the tissue factor pathway inhibitor (TFPI), but its role in the APL-associated coagulopathy remains unknown. This study aimed to determine the time-course of TFPI levels in patients with APL at diagnosis and during the first two-weeks of treatment with ATRA and anthracyclines. Twenty patients with de novo APL (12 males, age ranging from 17 to 72 years) and 20 healthy blood donors (age and sex matched) were included in this study. Peripheral blood (PB) samples were collected at diagnosis, and at D3, D7 and D15 of the induction therapy with ATRA and daunorubicin. The following plasma concentrations were determined: Thrombin-Antithrombin complex (TAT) (Enzygnost¨ TAT micro, Dade Behring/Siemens, IL, EUA), total TFPI (Asserachrom¨ total TFPI, Diagnostica Stago, Frana) and free TFPI (Asserachrom¨ free TFPI, Diagnostica Stago, Frana). The plasma concentrations of TAT were significantly higher in APL patients at presentation, D3 and D7 compared to controls, suggesting that the pathologic activation of coagulation was reversed by D15 of treatment Figure 1). The concentrations of free-TFPI were significantly higher in APL samples compared to controls in all time-points (Figure 2). In contrast, the concentrations of the truncated form of TFPI (estimated by subtracting the free-TFPI values from total-TFPI concentration) did not vary significantly between the groups. Since, free-TFPI (intact form) has been proven to present higher capacity to inhibit the activated factor X and VIIa-TF proteases than truncated-TFPI (bound to lipoprotein), we hypothesized that our findings confirm the relevance of free-TFPI in APL coagulopathy. To test whether the administration of rh-TFPI may revert aberrant activation of coagulation in APL patients, we developed a murine model using the IV infusion of NB4 cells. Similarly to the reported in APL patients, we observed an increase on TAT levels in mice injected with 5x106 NB4 cells [(60.7 ng/ml (24 - 116 ng/ml) vs 11.5 ng/ml (2.2 - 27.8 ng/ml), p<0.05)]. In contrast, murine TFPI levels decreased 30 minutes after the infusion of NB4 cells [30 ng/ml (5.8 - 217 ng/ml) vs 202 ng/ml (46 - 354 ng/ml)], suggesting that it was rapidly consumed. Unfortunately, it was not possible to distinguish between truncated and intact TFPI forms in mice. Intravenous infusion of recombinant human (rh) TFPI at the dose of 10mg/Kg significantly decreased the TAT levels (Figure 3) and increased TFPI levels in the murine model. In conclusion, our data on clinical samples and pre-clinical data using a murine model suggest that treatment with rh-TFPI may be a strategy to counteract APL-associated coagulopathy. Disclosures No relevant conflicts of interest to declare.


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