scholarly journals Antithrombotic Effects of Montelukast by Targeting Coagulation Factor XIa

2021 ◽  
Author(s):  
Dong Wang ◽  
Yang Zhou ◽  
Yingying Qi ◽  
Meiru Song ◽  
Huiqiao Yao ◽  
...  
Keyword(s):  
Oral Anticoagulants ◽  
Coagulation Factor ◽  
Healthy Individuals ◽  
Prevention Of Thrombosis ◽  
Factor Xia ◽  
Severe Hemorrhage ◽  
Antithrombotic Effects ◽  
Antiasthmatic Drug ◽  
Increase Blood Loss

Abstract Current oral anticoagulants prescribed for the prevention of thrombosis suffer from severe hemorrhagic problems. Coagulation factor XIa (FXIa) has been confirmed as a safer antithrombotic target as intervention with FXIa causes lower hemorrhagic risks. In this study, by a high-throughput virtual screening, we identified Montelukast (MK), an oral antiasthmatic drug, as a potent and specific FXIa inhibitor (IC50 = 0.17 µM). Compared with the two mostly prescribed anticoagulants (Warfarin and Apixaban), MK demonstrated comparable or even higher antithrombotic effects in three independent animal models. More importantly, in contrast to the severe hemorrhage caused by Warfarin or Apixaban, MK did not measurably increase blood loss in vivo. In addition, MK did not affect the hemostatic function in plasma from healthy individuals. In contrast, MK suppressed clot formation in clinical hypercoagulable plasma samples. This study provides a lead compound of anticoagulants targeting FXIa, and suggests the exploratory clinical researches on antithrombotic therapies using MK.

Binding of amyloid β precursor protein to coagulation factor XIa in vivo may favour haemorrhagic stroke

1998 ◽  
Vol 245 (2) ◽  
pp. 111-115 ◽  
Author(s):  
M. Bornebroek ◽  
Peter A. Kr. von dem Borne ◽  
Joost Haan ◽  
Joost C. M. Meijers ◽  
William E. Van Nostrand ◽  
...  
Keyword(s):  
Amyloid Β ◽  
Coagulation Factor ◽  
Haemorrhagic Stroke ◽  
Precursor Protein ◽  
Factor Xia

scholarly journals Identification of an alpha-1 antitrypsin variant with enhanced specificity for factor XIa by phage display, bacterial expression, and combinatorial mutagenesis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Varsha Bhakta ◽  
Mostafa Hamada ◽  
Amy Nouanesengsy ◽  
Jessica Lapierre ◽  
Darian L. Perruzza ◽  
...  
Keyword(s):  
Phage Display ◽  
Activated Protein C ◽  
Coagulation Factor ◽  
Bacterial Expression ◽  
Antithrombotic Agent ◽  
Expression Library ◽  
Factor Xia ◽  
Combinatorial Mutagenesis ◽  
Alpha 1 Antitrypsin

AbstractCoagulation Factor XIa (FXIa) is an emerging target for antithrombotic agent development. The M358R variant of the serpin alpha-1 antitrypsin (AAT) inhibits both FXIa and other proteases. Our aim was to enhance the specificity of AAT M358R for FXIa. We randomized two AAT M358R phage display libraries at reactive centre loop positions P13-P8 and P7-P3 and biopanned them with FXIa. A bacterial expression library randomized at P2′-P3′ was also probed. Resulting novel variants were expressed as recombinant proteins in E. coli and their kinetics of FXIa inhibition determined. The most potent FXIa-inhibitory motifs were: P13-P8, HASTGQ; P7-P3, CLEVE; and P2-P3′, PRSTE (respectively, novel residues bolded). Selectivity for FXIa over thrombin was increased up to 34-fold versus AAT M358R for these single motif variants. Combining CLEVE and PRSTE motifs in AAT-RC increased FXIa selectivity for thrombin, factors XIIa, Xa, activated protein C, and kallikrein by 279-, 143-, 63-, 58-, and 36-fold, respectively, versus AAT M358R. AAT-RC lengthened human plasma clotting times less than AAT M358R. AAT-RC rapidly and selectively inhibits FXIa and is worthy of testing in vivo. AAT specificity can be focused on one target protease by selection in phage and bacterial systems coupled with combinatorial mutagenesis.

Factor XIa Induced Activation of the Intrinsic Cascade In Vivo

1996 ◽  
Vol 75 (03) ◽  
pp. 445-449 ◽  
Author(s):  
Hugo ten Cate ◽  
Bart J Biemond ◽  
Marcel Levi ◽  
Walter A Wuillemin ◽  
Kenneth Bauer ◽  
...  
Keyword(s):  
Human Factor ◽  
Coagulation Factor ◽  
Thrombin Inhibitor ◽  
Bleeding Tendency ◽  
Loading Dose ◽  
Factor Xi ◽  
Factor Xia ◽  
Initial Activation ◽  
Baseline Values

SummaryCoagulation factor XI is a glycoprotein of the contact factor system. Its deficiency is associated with a highly variable bleeding tendency, thus a role in relation to hemostasis appears to exist. However, the importance of factor XI for stimulating intrinsic coagulation in vivo has not yet been determined. To study the procoagulant effects of human factor Xla in vivo, we infused the purified enzyme into normal chimpanzees (100 Μg) in the absence or presence of the thrombin inhibitor rec-hirudin (1.0 mg/kg loading dose plus 0.3 mg/kg body wt continuous infusion). Factor Xla elicited an immediate activation of factors IX, X, and prothrombin, as measured by their respective activation fragments. However, whereas the activation of factors IX and X was immediate and shortlasting, (peak increments of 6- and 1.4-fold of baseline at 5 minutes after injection), the conversion of prothrombin gradually increased, reaching a summit of 6-fold baseline values after 60 min, and remaining elevated during the course of the experiments. Thrombin-antithrombin complexes also remained elevated during the study period. In the presence of hirudin, the initial activation of factors IX, X, and prothrombin was unchanged, however the further increment in prothrombin fragment FI+2 was markedly inhibited. These results demonstrate that factor Xla is a potential agonist of the intrinsic cascade in vivo, which activity is enhanced in the presence of thrombin.

Immunoradiometric Assays for Human Coagulation Factor VII Using Polyclonal Antibodies Against the Ca(II)-Dependent and Ca(II)-Independent Conformation

1986 ◽  
Vol 56 (03) ◽  
pp. 343-348 ◽  
Author(s):  
V J J Bom ◽  
N H van Tilburg ◽  
C Krommenhoek-van Es ◽  
R M Bertina
Keyword(s):  
Comparative Study ◽  
Vitamin K ◽  
Polyclonal Antibodies ◽  
Oral Anticoagulants ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Antigen Level ◽  
Healthy Individuals ◽  
Coagulation Factor Vii ◽  
Human Coagulation Factor Vii

SummaryHuman coagulation factor VII is a trace plasma protein belonging to the vitamin K-dependent factors. Two specific and sensitive immunoradiometric assays for factor VII were developed using immunopurified rabbit antibodies against the Ca(II)-independent and Ca(II)-dependent conformation of factor VII. Both assays were insensitive to the activation state of factor VII. The distribution of factor VII antigen was studied in 40 healthy individuals and the antigen level in normal plasma was calculated to be 0.52-0.62 μg/ml. The two assays were used in a comparative study of factor VII procoagulant activity and factor VII antigen in patients treated with oral anticoagulants.

Phenylimidazoles as Potent and Selective Inhibitors of Coagulation Factor XIa with in Vivo Antithrombotic Activity

2014 ◽  
Vol 57 (23) ◽  
pp. 9915-9932 ◽  
Author(s):  
Jon J. Hangeland ◽  
Todd J. Friends ◽  
Karen A. Rossi ◽  
Joanne M. Smallheer ◽  
Cailan Wang ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Selective Inhibitors ◽  
Antithrombotic Activity ◽  
Factor Xia

scholarly journals The Safety and Efficacy of Novel Agents Targeting Factors XI and XII in Early Phase Human Trials

2019 ◽  
Vol 45 (05) ◽  
pp. 502-508 ◽  
Author(s):  
Emma P. DeLoughery ◽  
Sven R. Olson ◽  
Cristina Puy ◽  
Owen J. T. McCarty ◽  
Joseph J. Shatzel
Keyword(s):  
Monoclonal Antibody ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Anticoagulation Therapy ◽  
Coagulation Factor ◽  
Selective Inhibition ◽  
Factor Xii ◽  
Preclinical Data ◽  
Contact Pathway

AbstractAlthough anticoagulation without hemorrhage is a primary aim, this vision has remained as yet out of reach. Even despite the superior safety profile of the direct oral anticoagulants, hemorrhage remains a major risk of anticoagulation. Selective inhibition of the contact pathway of coagulation, specifically coagulation factor XI (FXI) and/or factor XII (FXII), has now substantial epidemiologic and preclinical data supporting the notion that these factors contribute to pathologic thrombosis and are yet primarily dispensable for in vivo hemostasis. In this way, targeting FXI and FXII may revolutionize the future anticoagulation landscape. Several drugs are under development for this purpose, including: ISIS 416858, a FXI antisense oligonucleotide which impairs hepatic synthesis of FXI; MAA868, a monoclonal antibody that binds the procoagulant enzymatic site of both zymogen and activated FXI (FXIa); BAY 1213790, a monoclonal antibody that binds the procoagulant enzymatic site of FXIa only; and AB023, a monoclonal antibody that inhibits activated FXII-mediated activation of FXI, along with two small molecules in clinical trials. Each of these drugs have demonstrated favorable safety profiles in their phases 1 and 2 studies to date, with preclinical data also supporting efficacy of abrogating thrombosis in various animal models. Other benefits of some of these drugs include once-monthly dosing and safety in patients with renal or hepatic impairment, while others offer quickly metabolized parenteral options, thus providing more convenient and widely available anticoagulation options. Though still far from the marketplace, drugs targeting FXI and FXII have the potential to usher in a new era of anticoagulation therapy.

Ancylostoma caninum Anticoagulant Peptide Blocks Metastasis In Vivo and Inhibits Factor Xa Binding to Melanoma Cells In Vitro

1998 ◽  
Vol 79 (05) ◽  
pp. 1041-1047 ◽  
Author(s):  
Kathleen M. Donnelly ◽  
Michael E. Bromberg ◽  
Aaron Milstone ◽  
Jennifer Madison McNiff ◽  
Gordon Terwilliger ◽  
...  
Keyword(s):  
Active Site ◽  
Thrombin Generation ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Melanoma Cells ◽  
Factor V ◽  
Ancylostoma Caninum ◽  
Metastatic Activity

SummaryWe evaluated the in vivo anti-metastatic activity of recombinant Ancylostoma caninum Anticoagulant Peptide (rAcAP), a potent (Ki = 265 pM) and specific active site inhibitor of human coagulation factor Xa originally isolated from bloodfeeding hookworms. Subcutaneous injection of SCID mice with rAcAP (0.01-0.2 mg/mouse) prior to tail vein injection of LOX human melanoma cells resulted in a dose dependent reduction in pulmonary metastases. In order to elucidate potential mechanisms of rAcAP’s anti-metastatic activity, experiments were carried out to identify specific interactions between factor Xa and LOX. Binding of biotinylated factor Xa to LOX monolayers was both specific and saturable (Kd = 15 nM). Competition experiments using antibodies to previously identified factor Xa binding proteins, including factor V/Va, effector cell protease receptor-1, and tissue factor pathway inhibitor failed to implicate any of these molecules as significant binding sites for Factor Xa. Functional prothrombinase activity was also supported by LOX, with a half maximal rate of thrombin generation detected at a factor Xa concentration of 2.4 nM. Additional competition experiments using an excess of either rAcAP or active site blocked factor Xa (EGR-Xa) revealed that most of the total factor Xa binding to LOX is mediated via interaction with the enzyme’s active site, predicting that the vast majority of cell-associated factor Xa does not participate directly in thrombin generation. In addition to establishing two distinct mechanisms of factor Xa binding to melanoma, these data raise the possibility that rAcAP’s antimetastatic effect in vivo might involve novel non-coagulant pathways, perhaps via inhibition of active-site mediated interactions between factor Xa and tumor cells.

Antithrombotic Effects and Bleeding Time Prolongation with Synthetic Platelet GPIIb/llla Inhibitors in Animal Models of Platelet-Mediated Thrombosis

1994 ◽  
Vol 71 (01) ◽  
pp. 095-102 ◽  
Author(s):  
Désiré Collen ◽  
Hua Rong Lu ◽  
Jean-Marie Stassen ◽  
Ingrid Vreys ◽  
Tsunehiro Yasuda ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Bolus Injection ◽  
Cell Injury ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Femoral Vein ◽  
Thrombotic Occlusion ◽  
Antithrombotic Effects

SummaryCyclic Arg-Gly-Asp (RGD) containing synthetic peptides such as L-cysteine, N-(mercaptoacetyl)-D-tyrosyl-L-arginylglycyl-L-a-aspartyl-cyclic (1→5)-sulfide, 5-oxide (G4120) and acetyl-L-cysteinyl-L-asparaginyl-L-prolyl-L-arginyl-glycyl-L-α-aspartyl-[0-methyltyrosyl]-L-arginyl-L-cysteinamide, cyclic 1→9-sulfide (TP9201) bind with high affinity to the platelet GPIIb/IIIa receptor.The relationship between antithrombotic effect, ex vivo platelet aggregation and bleeding time prolongation with both agents was studied in hamsters with a standardized femoral vein endothelial cell injury predisposing to platelet-rich mural thrombosis, and in dogs with a carotid arterial eversion graft inserted in the femoral artery. Intravenous administration of G4120 in hamsters inhibited in vivo thrombus formation with a 50% inhibitory bolus dose (ID50) of approximately 20 μg/kg, ex vivo ADP-induccd platelet aggregation with ID50 of 10 μg/kg, and bolus injection of 1 mg/kg prolonged the bleeding time from 38 ± 9 to 1,100 ± 330 s. Administration of TP9201 in hamsters inhibited in vivo thrombus formation with ID50 of 30 μg/kg, ex vivo platelet aggregation with an ID50 of 50 μg/kg and bolus injection of 1 mg/kg did not prolong the template bleeding time. In the dog eversion graft model, infusion of 100 μg/kg of G4120 over 60 min did not fully inhibit platelet-mediated thrombotic occlusion but was associated with inhibition of ADP-induccd ex vivo platelet aggregation and with prolongation of the template bleeding time from 1.3 ± 0.4 to 12 ± 2 min. Infusion of 300 μg/kg of TP9201 over 60 min completely prevented thrombotic occlusion, inhibited ex vivo platelet aggregation, but was not associated with prolongation of the template bleeding time.TP9201, unlike G4120, inhibits in vivo platelet-mediated thrombus formation without associated prolongation of the template bleeding time.

Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors

1990 ◽  
Vol 63 (02) ◽  
pp. 220-223 ◽  
Author(s):  
J Hauptmann ◽  
B Kaiser ◽  
G Nowak ◽  
J Stürzebecher ◽  
F Markwardt
Keyword(s):  
Factor Xa ◽  
Thrombin Inhibitors ◽  
Factor Xa Inhibitors ◽  
Venous Stasis ◽  
Clotting Time ◽  
Thrombosis Model ◽  
Activity Factor ◽  
Antithrombotic Effects

SummaryThe anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas the opposite was true of thrombin inhibitors.In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosageThe results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.

Inactivation of Factor XIa in Vivo: Studies in Chimpanzees and in Humans

1996 ◽  
Vol 76 (04) ◽  
pp. 549-555 ◽  
Author(s):  
Walter A Wuillemin ◽  
C Erik Hack ◽  
Wim K Bleeker ◽  
Bart J Biemond ◽  
Marcel Levi ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Life Time ◽  
In Vivo Studies ◽  
Clinical Samples ◽  
Plasma Samples ◽  
C1 Inhibitor ◽  
Elimination Kinetics ◽  
Factor Xia ◽  
Best Parameter

SummaryC1-inhibitor (C1Inh), antithrombin III (ATIII), α1-antitrypsin (a1AT), and α2-antiplasmin (a2AP) are known inhibitors of factor XIa (FXIa). However, their precise contribution to FXIa inactivation in vivo is not known. We investigated FXIa inactivation in chimpanzees and assessed the contribution of these inhibitors to FXIa inactivation in patients with presumed FXI activation.Chimpanzees were infused with FXIa and the various FXIa-FXIa inhibitor complexes formed were measured. Most of FXIa was complexed to C1Inh (68%), followed by a2AP (13%), a1AT (10%), and ATIII (9%). Analysis of the plasma elimination kinetics revealed a half-life time of clearance (t1/2) for the FXIa-FXIa inhibitor complexes of 95 to 104 min, except for FXIa-a1AT, which had a t1/2 of 349 min. Due to this long t1/2, FXIa-a1AT complexes were predicted to show the highest levels in plasma samples from patients with activation of FXI. This was indeed shown in patients with disseminated intravascular coagulation, recent myocardial infarction or unstable angina pectoris. We conclude from this study that in vivo C1Inh is the predominant inhibitor of FXIa, but that FXIa-a1 AT complexes due to their relatively long t1/2 may be the best parameter to assess FXI activation in clinical samples.

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