Tag Archives: hemostasis

Novel monoclonal antibody to fibrin(ogen) αC-region for detection of the earliest forms of soluble fibrin

N. E. Lugovska1, I. M. Kolesnikova1, Ye. M. Stohnii1, V. O. Chernyshenko1*,
A. V. Rebriev1, O. P. Kostiuchenko1, G .K. Gogolinska1, N. A. Dziubliuk2,
L. D. Varbanets2, T. M. Platonova1, S. V. Komisarenko1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Zabolotny Institute of Microbiology and Virology,National Academy of Sciences of Ukraine, Kyiv;
*e-mail: bio.cherv@gmail.com

Received: 08 May 2020; Accepted: 30 June 2020

Obtaining new monoclonal antibodies (mAbs) towards fibrin(ogen) and its fragments is an important task for studying mechanisms of blood clot formation, searching for novel antithrombotic agents and developing immunodiagnostics. The aim of the present work was to create and characterize a new mAb towards the fibrin(ogen) αС-region. We surmise that having a specific mAb towards this flexible part of the molecule will allow us to study the role of the αС-region in fibrin polymerization and also to develop an approach for detecting the earliest forms of soluble fibrin by sandwich ELISA. Using hybridoma technology we оbtained mAb 1-5A to the αC-region of fibrinogen.. It was characterized using several variations of ELISA and Western blot. Application of specific proteases together with MALDI-TOF analysis allowed us to localize its epitope that is located in fragment 537-595 of the Aα-chain of fibrin(ogen). МAb 1-5A can be used as a detecting tag-antibody in sandwich ELISA for the quantification of the earliest forms of soluble fibrin which are uncleaved by plasmin and preserved C-terminal portions of αC-regions. These earliest forms of soluble fibrin are direct evidence of blood coagulation system activation, thrombin generation and the danger of intravascular thrombus formation. Their determination will provide additional, more accurate information about the state of the blood coagulation system and the risk of blood clotting, which is very important for the timely and correct selection of adequate antithrombotic therapy. MAb 1-5A effectively binds the αC-containing molecules of fibrinogen and fibrin in blood plasma. It also can be used for studying protein-protein and protein-cellular interactions of the αC-regions of fibrin(ogen).

Protective action of N-stearoylethanolamine on blood coagulation and arterial changes in spontaneously hypertensive rats fed cholesterol-rich diet

O. S. Tkachenko1, Ie. A. Hudz1*, H. V. Kosiakova1,
P. P. Klymenko2, Y. M. Stohnii1, V. A. Didkivskyi1,
T. M. Chernyshenko1, V. O. Chernyshenko1, T. M. Platonova1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2SI “D. F. Chebotarev Institute of Gerontology of the National Academy of Medical Sciences of Ukraine”, Kyiv;
*e-mail: goudziegor@gmail.com

Received: 24 December 2019; Accepted: 27 March 2020

In this work we aimed to test the atherosclerotic changes in the aortic wall and pro-coagulant response of the blood coagulation system of spontaneously hypertensive rats (SHR) fed cholesterol-rich diet (CRD) and to study the effect of the anti-inflammatory agent N-stearoylethanolamine (NSE) on the development of atherosclerosis in this model. Female rats (n = 30) with genetically determined hypertension proven by direct measurement of blood pressure were fed CRD (5% cholesterol) for 2 months. Control group of SHR (n = 10) received standard pellet diet, 10 were fed CRD and 10 received CRD with daily per os application of NSE at a dose of 50 mg/kg of body weight. Histological analysis detected swelling and detachment of endothelial cells, huge edema of the subendothelial layer and a disruption of the middle shell integrity. CRD rats had higher fibrinogen concentration, increased rate of platelet aggregation and decreased level of anticoagulant PC. Platelet aggregation speed increased in CRD-fed rats (52.5±4.1%/min) was slightly normalized under the action of NSE (40±8.3 vs 35±9%/min in controls). Fibrinogen concentration was slightly increased in CRD-fed rats (2.75±0.7 vs 1.9±0.5 mg/ml in controls). However, the level of anticoagulant PC that was decreased in CRD-fed rats (65±16 vs 100±11% in controls) was normalized under the action of NSE (92±17%). NSE also influenced the aorta architecture, however normalizing the thickness of the aorticwall did not change the cholesterol-induced inclusions within aorta media. NSE anti-inflammatory action changes the atherogenic processes in CRD-fed rats mainly protecting PC from consumption during the inflammatory process and reducing edema of the aorta. However hematological parameters (including clotting time in the APTT test and fibrinogen concentration) changed independently on NSE application. Anti-aggregatory action of NSE on platelets can be a result of direct action on platelets or the consequence of its anti-inflammatory action. During atherogenesis induced by CRD in the model, NSE demonstrated valuable anti-inflammatory action protecting the organism during atherogenesis, however it cannot be assumed as an antithrombotic or antiatherogenic agent because it is unable to influence hemostasis directly.

A mathematical model of the metabolic process of atherosclerosis

V. I. Grytsay

Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, Kyiv;
e-mail: vgrytsay@bitp.kiev.ua

A mathematical model of the metabolic process of atherosclerosis is constructed. The functioning of the polyenzymatic prostacyclin-thromboxane system of blood and the influence of a level of “bad cholesterol”, namely low density lipoproteins (LDL), on it are studied. With the help of the numerical experiment, we analyze the influence of the concentration of molecules of fat on hemostasis of blood in blood vessels. The kinetic curves for components of the system, phase-periodic bifurcation diagrams, attractors for various modes, and Poincaré cross-section and image of a strange attractor are constructed. The complete spectra of Lyapunov’s exponents, divergencies, KS-entropies, predictability horizons, and Lyapunov dimensions of the fractality of strange attractors are calculated. Conclusions about the structural-functional connections, which determine the dependence of hemostasis of a circulatory system on the level of cholesterol in blood are drawn.