Acylated 1H-1,2,4-Triazol-5-amines Targeting Human Coagulation Factor XIIa and Thrombin: Conventional and Microscale Synthesis, Anticoagulant Properties, and Mechanism of Action

2020 ◽  
Vol 63 (21) ◽  
pp. 13159-13186
Author(s):  
Marvin Korff ◽  
Lukas Imberg ◽  
Jonas M. Will ◽  
Nico Bückreiß ◽  
Svetlana A. Kalinina ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Coagulation Factor ◽  
Factor Xiia

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.

Coagulation Factor XIIa Activates Platelets and Is the Physiological Agonist of Protease-Activated Receptor 3.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 770-770 ◽  
Author(s):  
Yingying Mao ◽  
Todd M Getz ◽  
Jianguo Jin ◽  
Satya P. Kunapuli
Keyword(s):  
Intracellular Calcium ◽  
Platelet Activation ◽  
Conflicts Of Interest ◽  
Thrombus Formation ◽  
Shape Change ◽  
Coagulation Factor ◽  
Calcium Mobilization ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Factor Xiia

Abstract Abstract 770 Protease-activated receptors (PARs) are G-protein coupled receptors that are activated by proteases. Thrombin is the major agonist for PAR1 and PAR4, whereas tryptase and coagulation factor Xa are the agonists for PAR2. In addition to these major agonists, PARs can be activated by other coagulation proteases. The physiological agonist of PAR3 has not been identified to date; as a result, the molecular pharmacology and physiology of PAR3 remain poorly understood. The purpose of this study is to identify a physiological agonist to PAR3. We used PAR4 null murine platelets, which are known to express only PAR3. In this study, we tested the effect of several coagulation proteases and found that only coagulation factor XIIa (FXIIa) activated PAR4-/- murine platelets, in a concentration-dependent manner. FXIIa caused murine platelet shape change, aggregation, secretion and thromboxane A2 generation and this activation was abolished by C1 esterase inhibitor, a FXIIa inhibitor. FXIIa-induced murine platelet activation was completely abolished by BMS200261, a PAR1 antagonist, without affecting the catalytic activity of FXIIa. As murine platelets do not express PAR1, these data indicate that BMS200261 acts as an antagonist of PAR3 and hence inhibits FXIIa-induced platelet activation. FXIIa also caused mobilization of intracellular calcium from murine platelets and this calcium increase is abolished by BMS200261 in the presence or absence of the PAR4. PAR1 and PAR4 couple to Gq to cause intracellular calcium increases. YM-254890, a Gq inhibitor, abrogates PAR1- or PAR4-mediated calcium mobilization. However, YM-254890 did not affect FXIIa –induced platelet calcium mobilization in murine platelets. FXIIa caused activation of Gq-/- mice platelets similar to wild -type platelets, suggesting that FXIIa -induced calcium mobilization in platelets is independent of Gq pathways. Furthermore, FXIIa-induced platelet activation was completely abolished by BAPTA-AM, which indicates that calcium is required for FXIIa-induced platelet activation. Furthermore, FXIIa caused phosphorylation of Erk and Akt in PAR4 null murine platelets and this phosphorylation was abolished by BMS200261, but not by YM-254890. These observations may explain previous reports that demonstrated lack of stable thrombus formation in FXII null mice. We conclude that FXIIa activates platelets through PAR3 independently of Gq pathways leading to calcium mobilization and activation of Erk and Akt. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Mitogenic effects of coagulation factor XII and factor XIIa on HepG2 cells.

1991 ◽  
Vol 88 (10) ◽  
pp. 4382-4385 ◽  
Author(s):  
K. T. Schmeidler-Sapiro ◽  
O. D. Ratnoff ◽  
E. M. Gordon
Keyword(s):  
Hepg2 Cells ◽  
Coagulation Factor ◽  
Factor Xii ◽  
Factor Xiia

scholarly journals Crystal structures of the recombinant β-factor XIIa protease with bound Thr-Arg and Pro-Arg substrate mimetics

2019 ◽  
Vol 75 (6) ◽  
pp. 578-591 ◽  
Author(s):  
Monika Pathak ◽  
Rosa Manna ◽  
Chan Li ◽  
Bubacarr G. Kaira ◽  
Badraldin Kareem Hamad ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Conformational Changes ◽  
Cleavage Site ◽  
Coagulation Factor ◽  
Factor Xii ◽  
Chloromethyl Ketone ◽  
Factor Xiia ◽  
Contact Pathway ◽  
Inhibitor Recognition ◽  
Insight Into

Coagulation factor XII (FXII) is a key initiator of the contact pathway, which contributes to inflammatory pathways. FXII circulates as a zymogen, which when auto-activated forms factor XIIa (FXIIa). Here, the production of the recombinant FXIIa protease domain (βFXIIaHis) with yields of ∼1–2 mg per litre of insect-cell culture is reported. A second construct utilized an N-terminal maltose-binding protein (MBP) fusion (MBP-βFXIIaHis). Crystal structures were determined of MBP-βFXIIaHisin complex with the inhibitor D-Phe-Pro-Arg chloromethyl ketone (PPACK) and of βFXIIaHisin isolation. The βFXIIaHisstructure revealed that the S2 and S1 pockets were occupied by Thr and Arg residues, respectively, from an adjacent molecule in the crystal. The Thr-Arg sequence mimics the P2–P1 FXIIa cleavage-site residues present in the natural substrates prekallikrein and FXII, and Pro-Arg (from PPACK) mimics the factor XI cleavage site. A comparison of the βFXIIaHisstructure with the available crystal structure of the zymogen-like FXII protease revealed large conformational changes centred around the S1 pocket and an alternate conformation for the 99-loop, Tyr99 and the S2 pocket. Further comparison with activated protease structures of factors IXa and Xa, which also have the Tyr99 residue, reveals that a more open form of the S2 pocket only occurs in the presence of a substrate mimetic. The FXIIa inhibitors EcTI and infestin-4 have Pro-Arg and Phe-Arg P2–P1 sequences, respectively, and the interactions that these inhibitors make with βFXIIa are also described. These structural studies of βFXIIa provide insight into substrate and inhibitor recognition and establish a scaffold for the structure-guided drug design of novel antithrombotic and anti-inflammatory agents.

scholarly journals Serum stimulation of CCR7 chemotaxis due to coagulation factor XIIa-dependent production of high-molecular-weight kininogen domain 5

2016 ◽  
Vol 113 (45) ◽  
pp. E7059-E7068 ◽  
Author(s):  
Manish P. Ponda ◽  
Jan L. Breslow
Keyword(s):  
Molecular Weight ◽  
Lymph Nodes ◽  
High Molecular Weight ◽  
Matrix Protein ◽  
Critical Role ◽  
Coagulation Factor ◽  
Extracellular Matrix Protein ◽  
High Molecular Weight Kininogen ◽  
Factor Xiia ◽  
Cofactor Activity

Chemokines and their receptors play a critical role in immune function by directing cell-specific movement. C-C chemokine receptor 7 (CCR7) facilitates entry of T cells into lymph nodes. CCR7-dependent chemotaxis requires either of the cognate ligands C-C chemokine ligand 19 (CCL19) or CCL21. Although CCR7-dependent chemotaxis can be augmented through receptor up-regulation or by increased chemokine concentrations, we found that chemotaxis is also markedly enhanced by serum in vitro. Upon purification, the serum cofactor activity was ascribed to domain 5 of high-molecular-weight kininogen. This peptide was necessary and sufficient for accelerated chemotaxis. The cofactor activity in serum was dependent on coagulation factor XIIa, a serine protease known to induce cleavage of high-molecular-weight kininogen (HK) at sites of inflammation. Within domain 5, we synthesized a 24-amino acid peptide that could recapitulate the activity of intact serum through a mechanism distinct from up-regulating CCR7 expression or promoting chemokine binding to CCR7. This peptide interacts with the extracellular matrix protein thrombospondin 4 (TSP4), and antibodies to TSP4 neutralize its activity. In vivo, an HK domain 5 peptide stimulated homing of both T and B cells to lymph nodes. A circulating cofactor that is activated at inflammatory foci to enhance lymphocyte chemotaxis represents a powerful mechanism coupling inflammation to adaptive immunity.

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