Coagulation Pathway Studies In Vitro

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• The normal function of the coagulation mechanism relies on the complex interaction of multiple proteins, collectively known as coagulation factors. Currently, there are 15 known coagulation factors, including 12 factors from the classical coagulation pathway (Factors I to XIII, excluding Factor VI), two factors from the kinin system, and vwf. The ultimate goal of the coagulation process is to convert fibrinogen into fibrin, and most coagulation factors are serine proteases.
  Specifically, the coagulation factors are as follows: Factor I: Fibrinogen; Factor II: Prothrombin; Factor III: Tissue Factor; Factor IV: Calcium Ion; Factor V: Labile Factor; Factor VII: Proconvertin; Factor VIII: Antihemophilic Factor A; Factor IX: Antihemophilic Factor B; Factor X: Stuart Factor; Factor XI: Plasma Thromboplastin Antecedent; Factor XII: Hageman Factor; Factor XIII: Fibrin-Stabilizing Factor.
  The traditional view of the coagulation cascade states that the blood clotting process consists of three parts: the intrinsic pathway, the extrinsic pathway, and the common pathway.

  The intrinsic pathway involves the activation of Factor XII, which forms the IXa-VIIIa-Ca2+-PL complex, subsequently activating Factor X.

  The extrinsic pathway involves the release of tissue factor (TF) and the formation of the TF-VIIa-Ca2+ complex, which activates Factor X. The common pathway is where activated Factor Xa and Factor Va bind and activate thrombin, resulting in the conversion of fibrinogen to fibrin.

  

  Figure.1. Coagulation pathway mechanism diagram
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  Figure.2. Common anticoagulant targets

  As our understanding has deepened, modifications and supplements have been made to the traditional coagulation cascade. It is now recognized that the coagulation process is primarily activated through the tissue factor pathway, rather than predominantly through the intrinsic pathway. Factor VIII and IX play essential roles in maintaining coagulation. Additionally, TFPI and other anticoagulant proteins regulate the coagulation process. The VIIa-TF complex can also activate Factor IX, and the activation of Factor XII and XI is not necessary. Furthermore, Zn2+ and Mg2+ also participate in the coagulation process. Therefore, the new model of coagulation activation suggests that initially, a small amount of thrombin is formed through TF release. Subsequently, thrombin further activates platelets, Factor VIII, and Factor V, amplifying and accelerating the coagulation process.
  The regulation of the coagulation mechanism is achieved through various enzymes and complexes, with thrombin playing a central role. After thrombin forms, its functions extend to at least five aspects: initiation, amplification, termination, clearance of the blood clot, and repair. Throughout the coagulation process, maintaining a delicate balance with the anticoagulant system is essential to maintain normal blood flow.

Medicilon case study

• Case One: Detect the Activation Effects of FXIa and FVIIa on BeneFⅨ^®
  BeneFIX is a recombinant human blood coagulation factor IX indicated for adults and children with hemophilia B (congenital factor IX deficiency or Christmas disease) for:
   On-demand treatment and control of bleeding episodes.   Perioperative management of bleeding.   Routine prophylaxis to reduce the frequency of bleeding episodes.
  BeneFIX is not indicated for induction of immune tolerance in patients with hemophilia B.
  

  
  
• Case Two: Detect FX Activation by Novoseven and the Affinity of Novoseven and ATIII
  NovoSeven is a medicine used to treat bleeding episodes and to prevent bleeding after surgical procedures. It is used in patients with the following conditions:
   congenital haemophilia (a bleeding disorder present from birth) who have developed or are expected to develop ‘inhibitors’ (antibodies) against factor VIII or IX; acquired haemophilia (a bleeding disease caused by the development of inhibitors to factor VIII); congenital factor VII deficiency; Glanzmann’s thrombasthenia (a rare bleeding disorder), whose patients cannot be treated with a transfusion of platelets (components that help the blood to clot).
  

  
• Case Three: Testing the Selective Inhibition on Factor XIa by BAY2433334
  Factor XI is a protein in the blood that converts into its activated form, Factor XIa, during coagulation reactions. Factor XI is a targeted focus in developing safer anticoagulant drugs because it plays a key role in both pathological and normal thrombosis processes, potentially decoupling coagulation from thrombosis. Patients with congenital Factor XI deficiency (Hemophilia C) have a lower risk of venous thromboembolism and ischemic stroke but rarely experience spontaneous bleeding.
  Asundexian (BAY2433334), developed by Bayer, is an oral Factor XIa inhibitor that binds directly, effectively, and reversibly to the active site of Factor XIa, thereby inhibiting its activity. It is used for secondary prevention in non-cardiac ischemic stroke patients, as well as for treating atrial fibrillation (arrhythmia) and recent myocardial infarction (heart attack). Asundexian's inhibitory effect on Factor XIa is expected to reduce thrombotic incidents without increasing bleeding risks.
  Our company has tested BAY2433334's inhibitory effects on FXIa, FVIIa, FXa, FXIIa, Thrombin, Trypsin, Plasmin, TPA, Urokinase, Plasma Kallikrein, Chymotrypsin, Activated Protein C, and TAFIa. The results, depicted in the figure below, indicate that BAY2433334 selectively inhibits Factor XIa.
  

  
  

  
  

  
  

  

  

  

  

  

  

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