Novel peptides that inhibit heparanase activation of the coagulation system

2014 ◽  
Vol 112 (09) ◽  
pp. 466-477 ◽  
Author(s):  
Elena Axelman ◽  
Israel Henig ◽  
Yonatan Crispel ◽  
Judith Attias ◽  
Jin-Ping Li ◽  
...  
Keyword(s):  
Vena Cava ◽  
Coagulation Factor ◽  
Procoagulant Activity ◽  
Coagulation System ◽  
Bleeding Tendency ◽  
Factor X ◽  
Tumour Metastasis ◽  
Accessible Surface ◽  
Solvent Accessible Surface

SummaryHeparanase is implicated in cell invasion, tumour metastasis and angiogenesis. It forms a complex and enhances the activity of the blood coagulation initiator – tissue factor (TF). We describe new peptides derived from the solvent accessible surface of TF pathway inhibitor 2 (TFPI-2) that inhibit the heparanase procoagulant activity. Peptides were evaluated in vitro by measuring activated coagulation factor X levels and co-immunoprecipitation. Heparanase protein and/or lipopolysaccharide (LPS) were injected intra-peritoneally and inhibitory peptides were injected subcutaneously in mouse models. Plasma was analysed by ELISA for thrombin-antithrombin complex (TAT), D-dimer as markers of coagulation activation, and interleukin 6 as marker of sepsis severity. Peptides 5, 6, 7, 21 and 22, at the length of 11–14 amino acids, inhibited heparanase procoagulant activity but did not affect TF activity. Injection of newly identified peptides 5, 6 and 7 significantly decreased or abolished TAT plasma levels when heparanase or LPS were pre-injected, and inhibited clot formation in an inferior vena cava thrombosis model. To conclude, the solvent accessible surface of TFPI-2 first Kunitz domain is involved in TF/heparanase complex inhibition. The newly identified peptides potentially attenuate activation of the coagulation system induced by heparanase or LPS without predisposing to significant bleeding tendency.

Characterization of Recombinant Human Coagulation Factor XFriuli

1996 ◽  
Vol 75 (02) ◽  
pp. 313-317 ◽  
Author(s):  
D J Kim ◽  
A Girolami ◽  
H L James
Keyword(s):  
Catalytic Domain ◽  
Coagulation Factor ◽  
Molecular Size ◽  
Binding Pocket ◽  
Site Directed Mutagenesis ◽  
Bleeding Tendency ◽  
Factor X ◽  
Amino Terminal ◽  
Normal Plasma ◽  
Plasma Factor

SummaryNaturally occurring plasma factor XFriuli (pFXFr) is marginally activated by both the extrinsic and intrinsic coagulation pathways and has impaired catalytic potential. These studies were initiated to obtain confirmation that this molecule is multi-functionally defective due to the substitution of Ser for Pro at position 343 in the catalytic domain. By the Nelson-Long site-directed mutagenesis procedure a construct of cDNA in pRc/CMV was derived for recombinant factor XFriuli (rFXFr) produced in human embryonic (293) kidney cells. The rFXFr was purified and shown to have a molecular size identical to that of normal plasma factor X (pFX) by gel electrophoretic, and amino-terminal sequencing revealed normal processing cleavages. Using recombinant normal plasma factor X (rFXN) as a reference, the post-translational y-carboxy-glutamic acid (Gla) and (β-hydroxy aspartic acid (β-OH-Asp) content of rFXFr was over 85% and close to 100%, respectively, of expected levels. The specific activities of rFXFr in activation and catalytic assays were the same as those of pFXFr. Molecular modeling suggested the involvement of a new H-bond between the side-chains of Ser-343 and Thr-318 as they occur in anti-parallel (3-pleated sheets near the substrate-binding pocket of pFXFr. These results support the conclusion that the observed mutation in pFXFr is responsible for its dysfunctional activation and catalytic potentials, and that it accounts for the moderate bleeding tendency in the homozygous individuals who possess this variant procoagulant.

scholarly journals Inhibition of human coagulation factor VIII by monoclonal antibodies. Mapping of functional epitopes with the use of recombinant factor VIII fragments

1989 ◽  
Vol 263 (1) ◽  
pp. 187-194 ◽  
Author(s):  
A Leyte ◽  
K Mertens ◽  
B Distel ◽  
R F Evers ◽  
M J M De Keyzer-Nellen ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Factor Viii ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Procoagulant Activity ◽  
Coagulation Factor Viii ◽  
Coagulation Cascade ◽  
Restriction Enzyme Digestion ◽  
Proteolytic Activation

The epitopes of four monoclonal antibodies against coagulation Factor VIII were mapped with the use of recombinant DNA techniques. Full-length Factor VIII cDNA and parts thereof were inserted into the vector pSP64, permitting transcription in vitro with the use of a promoter specific for SP6 RNA polymerase. Factor VIII DNA inserts were truncated from their 3′-ends by selective restriction-enzyme digestion and used as templates for ‘run-off’ mRNA synthesis. Translation in vitro with rabbit reticulocyte lysate provided defined radiolabelled Factor VIII fragments for immunoprecipitation studies. Two antibodies are shown to be directed against epitopes on the 90 kDa chain of Factor VIII, between residues 712 and 741. The 80 kDa chain appeared to contain the epitopes of the other two antibodies, within the sequences 1649-1778 and 1779-1840 respectively. The effect of antibody binding to these sequences was evaluated at two distinct levels within the coagulation cascade. Both Factor VIII procoagulant activity and Factor VIII cofactor function in Factor Xa generation were neutralized upon binding to the region 1779-1840. The antibodies recognizing the region 713-740 or 1649-1778, though interfering with Factor VIII procoagulant activity, did not inhibit in Factor Xa generation. These findings demonstrate that antibodies that virtually inhibit Factor VIII in coagulation in vitro are not necessarily directed against epitopes involved in Factor VIII cofactor function. Inhibition of procoagulant activity rather than of cofactor function itself may be explained by interference in proteolytic activation of Factor VIII. This hypothesis is in agreement with the localization of the epitopes in the proximity of thrombin-cleavage or Factor Xa-cleavage sites.

scholarly journals Manipulating Adenovirus Hexon Hypervariable Loops Dictates Immune Neutralisation and Coagulation Factor X-dependent Cell Interaction In Vitro and In Vivo

2015 ◽  
Vol 11 (2) ◽  
pp. e1004673 ◽  
Author(s):  
Jiangtao Ma ◽  
Margaret R. Duffy ◽  
Lin Deng ◽  
Rachel S. Dakin ◽  
Taco Uil ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Cell Interaction ◽  
Factor X ◽  
Dependent Cell

Platelet microparticle membranes have 50- to 100-fold higher specific procoagulant activity than activated platelets

2007 ◽  
Vol 97 (03) ◽  
pp. 425-434 ◽  
Author(s):  
Dmitry Kireev ◽  
Nadezhda Popenko ◽  
Aleksei Pichugin ◽  
Mikhail Panteleev ◽  
Olga Krymskaya ◽  
...  
Keyword(s):  
Blood Platelets ◽  
Calcium Ionophore ◽  
Coagulation Factors ◽  
In Vitro Models ◽  
Calcium Ionophore A23187 ◽  
Procoagulant Activity ◽  
Ionophore A23187 ◽  
Factor X ◽  
Activated Platelets

SummaryPlatelet microparticles (PMPs) are small vesicles released from blood platelets upon activation. The procoagulant activity of PMPs has been previously mainly characterized by theirability to bind coagulation factors VIII and Va in reconstructed systems. It can be supposed that PMPs can contribute to the development of thrombotic complications in the pathologic states associated with the increase of their blood concentration. In this study we compared procoagulant properties of calcium ionophore A23187-activated platelets and PMPs using several in-vitro models of hemostasis. Surface densities of phosphatidylserine, CD61, CD62P and factor X bound per surface area unit were determined by flow cytometry. They were 2.7-, 8.4-, 4.3-, and 13-fold higher for PMPs than for activated platelets, respectively. Spatial clot growth rate (Vclot) in the reaction-diffus ion experimental model and endogenous thrombin potential (ETP) were determined in plasma, which was depleted of phospholipid cell surfaces by ultra-centrifugation and supplemented with activated platelets or PMPs at different concentrations. Both Vcllot and ETP rapidly increased with the increase of PMP or platelet concentration until saturation was reached. The plateau values of Vclot and ETP for activated platelets and PMPs were similar. In both assays, the procoagulant activity of one PMP was almost equal to that of one activated platelet despite at least two-orders-of-magnitude difference in their surface areas. This suggests that the PMP surface is approximately 50- to 100-fold more procoagulant than the surface of activated platelets.

A hitherto undescribed plasma factor acting at the contact phase of blood coagulation (Flaujeac factor): case report and coagulation studies

Blood ◽  
1975 ◽  
Vol 46 (5) ◽  
pp. 761-768 ◽  
Author(s):  
MJ Lacombe ◽  
B Varet ◽  
JP Levy
Keyword(s):  
Blood Coagulation ◽  
Coagulation Factor ◽  
Old French ◽  
Bleeding Tendency ◽  
Contact Phase ◽  
Hageman Factor ◽  
Coagulation Defect ◽  
Plasma Factor ◽  
Fletcher Factor

Abstract This paper reports an asymptomatic coagulation defect responsible for an abnormality at the contact phase of blood coagulation in vitro, distinct from Hageman factor and Fletcher factor deficiencies. Coagulation studies in a 50-yr-old French woman without bleeding tendency revealed the following results: whole-blood clotting time in glass tubes and activated partial thromboplastin time with kaolin and ellagic acid were greatly prolonged; one-stage prothrombin was normal; no circulating anticoagulant was detected, and the infusion of normal plasma corrected the coagulation defect with an estimated half-life of 6.5 days; the levels of factor VIII, IX, XI, and XII were normal; mutual correction was obtained with a Fletcher factor-deficient plasma; the level of whole complement was normal. Studies of the contact phase of blood coagulation and contact-induced fibrinolysis showed the same abnormalities as in Hageman factor- and Fletcher-deficient plasmas. These results indicate that the patient's plasma is deficient in a previously undescribed coagulation factor, which participates in the initial stage of the blood coagulation process in vitro. Family studies revealed consanguinity in the propositus' parents. The assay of this newly described factor in the propositus' children revealed a partial defect, compatible with a heterozygous state, in three of the four tested children. This indicates a recessive inheritance of this new blood coagulation defect.

scholarly journals Evaluation Procoagulant Activity and Mechanism of Astragalin

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 177 ◽  
Author(s):  
Changqin Li ◽  
Miyun Hu ◽  
Shengjun Jiang ◽  
Zhenhua Liang ◽  
Jinmei Wang ◽  
...  
Keyword(s):  
Plasma Viscosity ◽  
Procoagulant Activity ◽  
Coagulation System ◽  
Control Group ◽  
Thrombin Time ◽  
Coagulation Time ◽  
Erythrocyte Sedimentation ◽  
Procoagulant Effect

Astragalin, isolated from flowers of Rosa chinensis Jacq., is a kind of flavonoid, with anti-inflammatory, antioxidant, antiviral, analgesic, antibacterial, antiallergic, and antihepatotoxic effects. However, no studieson the procoagulant effect of astragalin have been reported. This study aimed to investigate the procoagulant activity of astragalin and its mechanism. Its procoagulant effect was investigated by activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), and fibrinogen (FIB) in vitro, and a rat model established by heparin sodium was used to evaluate the mechanism for the procoagulant effect in vivo. The results showed that astragalin had good procoagulant effects compared with the control group in vitro. Compared with the model group in vivo, astragalin could shorten the coagulation time and significantly increase the number of platelets. Meanwhile, astragalin could significantly reduce the effectual time of PT and APTT and increase the content of FIB. The contents of 6-keto-PGF1α and eNOS significantly decreased. Astragalin could increase whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte sedimentation rate (ESR) and packedcell volume (PCV). All of the above revealed that astragalin had good procoagulant effects by promoting the intrinsic and extrinsic coagulation system.

DISTINCTIVE FEATURES OF PROCOAGULANT RESPONSE OF MONOCYTES FROM DIABETIC PATIENTS

1987 ◽  
Author(s):  
B JUDE ◽  
A WATEL ◽  
D FONTAINE ◽  
P FONTAINE ◽  
A COSSON
Keyword(s):  
Type I Diabetes ◽  
Vascular Complications ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Diabetic Patients ◽  
Type I ◽  
Factor X ◽  
Female Ratio ◽  
Male Female Ratio

Hypercoagulability is one of the possible factors reported in genesis or aggravation of vascular complications in diabetes mellitus. We therefore examined procoagulant activity (PCA) of disrupted monocytes frcm 26 patients with Type I diabetes and 6 with Type II, versus 32 control subjects (male/ female ratio = 1 in each group).Diabetes monocytes exhibited a slight but detectable PCA before any incubation or in vitro stimulation, whereas control monocytes did not. Data obtained with coagulation factor deficient plasmas or phospholipase C indicated that PCA was tissue factor (TF) alone in 22 cases and TF associated with a significant amount of factor VII/VIIa activity in 10 cases.Incubation in serum free medium led to significant raise of PCA in diabetes cells when stimulated with endotoxin or not, and in control cells only after stimulation. Furthermore, PCA appeared earlier in diabetes monocytes than in control ones, (4 hours, versus 20 hours). PCA frcm control cells was FT-like. PCA frcm diabetes cells was FT-like when no VII/VIIa activity was present on non-stimulated cells, and prothrombinase-like when VII/VIIa activity was early associated with the cells. In the latter case, trace amounts of factor X activity were also detectable. Whether factor VII and factor X activities were of plasmatic origin and associated to the cells, or synthesized in vitro by the cells remains unclear. The characteristics of PCA were net correlated with clinical features (age, diabetic complications) nor with the type of diabetes.Our data suggest that in diabetes patients, monocytes exhibit an increased PCA, possibly corresponding to a baseline stimulation, or at least a higher responsiveness to undergoing stimuli in vitro.

Natural IgM antibodies inhibit microvesicle-driven coagulation and thrombosis

Blood ◽  
2020 ◽  
Author(s):  
Georg Obermayer ◽  
Taras Afonyushkin ◽  
Laura Goederle ◽  
Florian Puhm ◽  
Waltraud C. Schrottmaier ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Coagulation Factor ◽  
Mechanistic Explanation ◽  
Factor X ◽  
Thrombotic Risk ◽  
Igm Antibodies ◽  
Plasmatic Coagulation ◽  
Natural Igm

Thrombosis and the complications associated with it are a major cause of morbidity and mortality worldwide. Microvesicles (MVs), a class of extracellular vesicles, are increasingly recognized as mediators of coagulation and biomarkers of thrombotic risk. Thus, identifying factors targeting MV-driven coagulation may help in the development of novel antithrombotic treatments. We have previously identified a subset of circulating MVs that is characterized by the presence of oxidation-specific epitopes and bound by natural IgM antibodies targeting these structures. Here, we investigated whether natural IgM antibodies, which are known to have important anti-inflammatory house-keeping functions, inhibit the procoagulatory properties of MVs. We found that the extent of plasma coagulation is inversely associated with the levels of both free and MV-bound endogenous IgM. Moreover, the oxidation epitope-specific natural IgM antibody LR04, which recognizes malondialdehyde adducts, reduced MV-dependent plasmatic coagulation and whole blood clotting without affecting thrombocyte aggregation. Intravenous injection of LR04 protected mice from MV-induced pulmonary thrombosis. Of note, LR04 competed the binding of coagulation factor X/Xa to MVs, providing a mechanistic explanation for its anticoagulatory effect. Thus, our data identify natural IgM antibodies as hitherto unknown modulators of MV-induced coagulation in vitro and in vivo and their prognostic and therapeutic potential in the management of thrombosis.

scholarly journals Biodistribution and retargeting of FX-binding ablated adenovirus serotype 5 vectors

Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. 2656-2664 ◽  
Author(s):  
Raul Alba ◽  
Angela C. Bradshaw ◽  
Lynda Coughlan ◽  
Laura Denby ◽  
Robert A. McDonald ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Adenovirus Type ◽  
Factor X ◽  
High Affinity ◽  
Serotype 5 ◽  
Adenoviral Transduction ◽  
High Doses ◽  
Immunohistochemical Studies

AbstractA major limitation for adenoviral transduction in vivo is the profound liver tropism of adenovirus type 5 (Ad5). Recently, we demonstrated that coagulation factor X (FX) binds to Ad5-hexon protein at high affinity to mediate hepatocyte transduction after intravascular delivery. We developed novel genetically FX-binding ablated Ad5 vectors with lower liver transduction. Here, we demonstrate that FX-binding ablated Ad5 predominantly localize to the liver and spleen 1 hour after injection; however, they had highly reduced liver transduction in both control and macrophage-depleted mice compared with Ad5. At high doses in macrophage-depleted mice, FX-binding ablated vectors transduced the spleen more efficiently than Ad5. Immunohistochemical studies demonstrated transgene colocalization with CD11c+, ER-TR7+, and MAdCAM-1+ cells in the splenic marginal zone. Systemic inflammatory profiles were broadly similar between FX-binding ablated Ad5 and Ad5 at low and intermediate doses, although higher levels of several inflammatory proteins were observed at the highest dose of FX-binding ablated Ad5. Subsequently, we generated a FX-binding ablated virus containing a high affinity Ad35 fiber that mediated a significant improvement in lung/liver ratio in macrophage-depleted CD46+ mice compared with controls. Therefore, this study documents the biodistribution and reports the retargeting capacity of FX binding-ablated Ad5 vectors in vitro and in vivo.

scholarly journals Overexpression of miR-24 Is Involved in the Formation of Hypocoagulation State after Severe Trauma by Inhibiting the Synthesis of Coagulation Factor X

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lu-Jia Chen ◽  
Lian Yang ◽  
Xing Cheng ◽  
Yin-Kai Xue ◽  
Li-Bo Chen
Keyword(s):  
Negative Correlation ◽  
Major Trauma ◽  
Injury Severity ◽  
Coagulation Factor ◽  
In Vitro Study ◽  
Severe Trauma ◽  
Trauma Patients ◽  
Factor Xii ◽  
Factor X

Background. Dysregulation of microRNAs may contribute to the progression of trauma-induced coagulopathy (TIC). We aimed to explore the biological function that miRNA-24-3p (miR-24) might have in coagulation factor deficiency after major trauma and TIC. Methods. 15 healthy volunteers and 36 severe trauma patients (Injury Severity Score ≥ 16 were enrolled. TIC was determined as the initial international normalized ratio >1.5. The miR-24 expression and concentrations of factor X (FX) and factor XII in plasma were measured. In vitro study was conducted on L02 cell line. Results. The plasma miR-24 expression was significantly elevated by 3.17-fold (P=0.043) in major trauma patients and reduced after 3 days (P<0.01). The expression level was significantly higher in TIC than in non-TIC patients (P=0.040). Multivariate analysis showed that the higher miR-24 expression was associated with TIC. The plasma concentration of FX in TIC patients was significantly lower than in the non-TIC ones (P=0.030) and controls (P<0.01). A negative correlation was observed between miR-24 and FX. miR-24 transduction significantly reduced the FX level in the supernatant of L02 cells (P=0.030). Conclusions. miR-24 was overexpressed in major trauma and TIC patients. The negative correlation of miR-24 with FX suggested the possibility that miR-24 might inhibit the synthesis of FX during TIC.

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