The Clotting Trigger Is an Important Determinant for the Coagulation Pathway In Vivo or In Vitro—Inference from Data Review

2020 ◽  
Author(s):  
Shu He ◽  
Honglie Cao ◽  
Charlotte Thålin ◽  
Jan Svensson ◽  
Margareta Blombäck ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Coagulation Cascade ◽  
Factor Vii ◽  
Enzymatic Reactions ◽  
Rotational Thromboelastometry ◽  
Coagulation Factor Vii ◽  
Charged Surfaces ◽  
Coagulation Pathway

AbstractBlood coagulation comprises a series of enzymatic reactions leading to thrombin generation and fibrin formation. This process is commonly illustrated in a waterfall-like manner, referred to as the coagulation cascade. In vivo, this “cascade” is initiated through the tissue factor (TF) pathway, once subendothelial TF is exposed and bound to coagulation factor VII (FVII) in blood. In vitro, a diminutive concentration of recombinant TF (rTF) is used as a clotting trigger in various global hemostasis assays such as the calibrated automated thrombogram, methods that assess fibrin turbidity and fibrin viscoelasticity tests such as rotational thromboelastometry. These assays aim to mimic in vivo global coagulation, and are useful in assessing hyper-/hypocoagulable disorders or monitoring therapies with hemostatic agents. An excess of rTF, a sufficient amount of negatively charged surfaces, various concentrations of exogenous thrombin, recombinant activated FVII, or recombinant activated FIXa are also used to initiate activation of specific sub-processes of the coagulation cascade in vitro. These approaches offer important information on certain specific coagulation pathways, while alterations in pro-/anticoagulants not participating in these pathways remain undetectable by these methods. Reviewing available data, we sought to enhance our knowledge of how choice of clotting trigger affects the outcome of hemostasis assays, and address the call for further investigations on this topic.

scholarly journals 111Indium Labelling of Recombinant Activated Coagulation Factor VII: In Vitro and Preliminary In Vivo Studies in Healthy Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Amarnadh Nalla ◽  
Inge Buch ◽  
Maibritt Sigvardt ◽  
Rasmus Poul Bodholdt ◽  
Andreas Kjaer ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
In Vivo Studies ◽  
Factor Vii ◽  
Acute Bleeding ◽  
Coagulation Factor Vii ◽  
Cardiac Region ◽  
Vitro Binding ◽  
Liver Region

The aim of this study is to investigate whether 111Indium-labelled recombinant FVIIa (rFVIIa) could be a potential radiopharmaceutical for localization of bleeding sources. DTPA-conjugated rFVIIa was radiolabelled with 111In chloride. In vitro binding efficiency of 111In-DTPA-rFVIIa to F1A2-Mab-sepharose was 99% in buffer, while it was 88–82% in serum. The binding efficiency of 111In-DTPA-rFVIIa to TF (1–209)-sepharose was 48% in buffer whereas 39%–36% in serum, respectively. In vivo experiment was conducted in healthy rats, and gamma camera images were taken immediately after iv. administration of 1.6–1.8 MBq 111In-DTPA-rFVIIa up to 120–130 min. Five min after administration of 111In-DTPA-rFVIIa, percentage of 111In activity was 6.0% in the cardiac region and 24.5% in the liver region. After 2 hours activity was decreased to 3.3% in heart while it had increased to 42.0% in the liver. The 111In-DTPA-rFVIIa might be a potential radiopharmaceutical for visualisation of tissues with significant TF expression such as acute bleeding lesions in the gastrointestinal tract.

scholarly journals In vivo roles of factor XII

Blood ◽  
2012 ◽  
Vol 120 (22) ◽  
pp. 4296-4303 ◽  
Author(s):  
Thomas Renné ◽  
Alvin H. Schmaier ◽  
Katrin F. Nickel ◽  
Margareta Blombäck ◽  
Coen Maas
Keyword(s):  
Thrombus Formation ◽  
Coagulation Factor ◽  
Special Focus ◽  
Factor Xii ◽  
Excessive Bleeding ◽  
Charged Surfaces ◽  
Factor Xiia ◽  
Knockout Model

Abstract Coagulation factor XII (FXII, Hageman factor, EC = 3.4.21.38) is the zymogen of the serine protease, factor XIIa (FXIIa). FXII is converted to FXIIa through autoactivation induced by “contact” to charged surfaces. FXIIa is of crucial importance for fibrin formation in vitro, but deficiency in the protease is not associated with excessive bleeding. For decades, FXII was considered to have no function for coagulation in vivo. Our laboratory developed the first murine knockout model of FXII. Consistent with their human counterparts, FXII−/− mice have a normal hemostatic capacity. However, thrombus formation in FXII−/− mice is largely defective, and the animals are protected from experimental cerebral ischemia and pulmonary embolism. This murine model has created new interest in FXII because it raises the possibility for safe anticoagulation, which targets thrombosis without influence on hemostasis. We recently have identified platelet polyphosphate (an inorganic polymer) and mast cell heparin as in vivo FXII activators with implications on the initiation of thrombosis and edema during hypersensitivity reactions. Independent of its protease activity, FXII exerts mitogenic activity with implications for angiogenesis. The goal of this review is to summarize the in vivo functions of FXII, with special focus to its functions in thrombosis and vascular biology.

scholarly journals Demonstration of the extrinsic coagulation pathway in teleostei: Identification of zebrafish coagulation factor VII

2001 ◽  
Vol 98 (15) ◽  
pp. 8768-8773 ◽  
Author(s):  
J. Sheehan ◽  
M. Templer ◽  
M. Gregory ◽  
R. Hanumanthaiah ◽  
D. Troyer ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Factor Vii ◽  
Coagulation Factor Vii ◽  
Coagulation Pathway

scholarly journals Gene-based FVIIa prophylaxis modulates the spontaneous bleeding phenotype of hemophilia A rats

2019 ◽  
Vol 3 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Shannon M. Zintner ◽  
Juliana C. Small ◽  
Giulia Pavani ◽  
Lynn Dankner ◽  
Oscar A. Marcos-Contreras ◽  
...  
Keyword(s):  
Statistical Power ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Spontaneous Bleeding ◽  
Coagulation Factor Vii ◽  
On Demand ◽  
Activated Factor Vii

Abstract A sizable proportion of hemophilia inhibitor patients fails immune tolerance induction and requires bypass agents for long-term bleed management. Recombinant human-activated coagulation Factor VII (rhFVIIa) is an on-demand bypass hemostatic agent for bleeds in hemophilia inhibitor patients. Prophylactic use of rhFVIIa may enable sustained hemostatic management of inhibitor patients, but the critical relationship of rhFVIIa circulating levels and clinical outcome in that setting remains unclear. To address this in vivo, we used the rat hemophilia A (HA) model that exhibits spontaneous bleeds and allows longitudinal studies with sufficient statistical power. We simulated activated Factor VII (FVIIa) prophylaxis by adeno-associated virus (AAV) gene transfer of a rat FVIIa transgene. Compared with naive HA animals, rat FVIIa continuous expression affected the overall observed bleeds, which were resolved with on-demand administration of recombinant rat FVIIa. Specifically, although 91% of naive animals exhibited bleeds, this was reduced to 83% and 33% in animals expressing less than 708 ng/mL (<14 nM) and at least 708 ng/mL (≥14 nM) rat FVIIa, respectively. No bleeds occurred in animals expressing higher than 1250 ng/mL (>25 nM). Rat FVIIa expression of at least 708 ng/mL was also sufficient to normalize the blood loss after a tail vein injury. Continuous, AAV-mediated rat FVIIa transgene expression had no apparent adverse effects in the hemostatic system of HA rats. This work establishes for the first time a dose dependency and threshold of circulating FVIIa antigen levels for reduction or complete elimination of bleeds in a setting of FVIIa-based HA prophylaxis.

scholarly journals Tissue Factor–Factor VII Complex as a Key Regulator of Ovarian Cancer Phenotypes

2015 ◽  
Vol 7s2 ◽  
pp. BIC.S29318 ◽  
Author(s):  
Shiro Koizume ◽  
Yohei Miyagi
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Tissue Factor ◽  
Intracellular Signaling ◽  
Coagulation Factor ◽  
Coagulation Cascade ◽  
Factor Vii ◽  
Ovarian Cancer Cells ◽  
Coagulation Factor Vii ◽  
Cancer Tissues

Tissue factor (TF) is an integral membrane protein widely expressed in normal human cells. Blood coagulation factor VII (fVII) is a key enzyme in the extrinsic coagulation cascade that is predominantly secreted by hepatocytes and released into the bloodstream. The TF–fVII complex is aberrantly expressed on the surface of cancer cells, including ovarian cancer cells. This procoagulant complex can initiate intracellular signaling mechanisms, resulting in malignant phenotypes. Cancer tissues are chronically exposed to hypoxia. TF and fVII can be induced in response to hypoxia in ovarian cancer cells at the gene expression level, leading to the autonomous production of the TF–fVII complex. Here, we discuss the roles of the TF–fVII complex in the induction of malignant phenotypes in ovarian cancer cells. The hypoxic nature of ovarian cancer tissues and the roles of TF expression in endometriosis are discussed. Arguments will be extended to potential strategies to treat ovarian cancers based on our current knowledge of TF–fVII function.

scholarly journals Molecular characterization of iranian patients with inherited coagulation factor VII deficiency

2017 ◽  
Vol 20 (2) ◽  
pp. 19-25
Author(s):  
S Shahbazi ◽  
R Mahdian ◽  
K Karimi ◽  
A Mashayekhi
Keyword(s):  
Coagulation Factor ◽  
Compound Heterozygote ◽  
Phenotypic Heterogeneity ◽  
Coagulation Cascade ◽  
Factor Vii ◽  
Missense Mutations ◽  
Protein Activity ◽  
Coagulation Factor Vii ◽  
Fvii Deficiency ◽  
Iranian Patients

AbstractCoagulation factor VII (FVII) is a key enzyme of the extrinsic coagulation cascade that is predominantly produced by hepatocytes. TheF7gene mutations cause FVII deficiency with considerable molecular and phenotypic heterogeneity. We characterized the molecular alterations of theF7gene and their corresponding mRNA transcripts in Iranian patients from eight unrelated families. The mutations were detected by polymerase chain reaction (PCR)-sequencing of allF7gene exons, their flanking intronic sequences, as well as their corresponding cDNA fragments. Homozygous P303T, C91S and R304Q mutations were detected in patient 2, patient 5, and patient 6, respectively. Patient 7 was a compound heterozygote for S282R and H348R and patient 8 was a compound heterozygote for R304Q and IVS7+7A>G mutations. Furthermore, our investigation revealed three heterozygous individuals, patient 1 and patient 3 with the A244V mutation who were symptomatic and patient 4 with V(–39)I mutation who was also asymptomatic. TheF7mRNA expression analysis revealed that, except the transcript of V(–39)I, other mutation-harboring transcripts were expressed at detectable levels. In conclusion, this report reinforces the genetic and phenotypic heterogeneity of FVII deficiency. The findings of the mRNA study implied that decreased FVII protein activity subsequent to missense mutations does not completely reflect the degradation of mutation-harboring mRNA.

The In Vitro Analysis of the Coagulation Mechanism of Activated Factor VII Using Thrombelastogram

2002 ◽  
Vol 88 (11) ◽  
pp. 768-772 ◽  
Author(s):  
Chiharu Kawaguchi ◽  
Yae Hanesaka ◽  
Akira Yoshioka ◽  
Yukihiro Takahashi
Keyword(s):  
Platelet Rich Plasma ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Factor V ◽  
Coagulation Factor Vii ◽  
Activated Factor Vii ◽  
Coagulation Mechanism ◽  
Vitro Analysis ◽  
Hemostatic Effects

SummaryWe investigated the effects of addition of recombinant activated coagulation factor VII (rFVIIa) to coagulation factor-deficient plasma and whole blood, using thrombelastograms (TEGs). The addition of rFVIIa to factor II-or X-deficient plasma did not correct hemostatic parameters, whereas it produced partial responses in factor V-, VIII-or IX-deficient plasma and good responses in factor VII-, XI-or XII-deficient plasma. Furthermore, the addition of rFVIIa and platelets (30-100 X 103/µl) to platelet-poor plasma produced marked corrections, producing TEGs similar to those of platelet-rich plasma. These results indicate that factors II and X are essential for the hemostatic effects of rFVIIa, and that factors V and VIII promote these effects. We believe that TEGs are, at present, one of the most useful tools for evaluating in vitro hemostatic effects of rFVIIa.

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