Adenosine Receptor Agonist HE-NECA Enhances Antithrombotic Activities of Cangrelor and Prasugrel in vivo by Decreasing of Fibrinogen Density in Thrombus.

Dawid Polak,Kamil Karolczak,Dagmara W Wojkowska,Tomasz A Bonda,Nina Wolska,Marcin Talar,Tomasz Przygodzki,Karol Kramkowski,Cezary Watala

doi:10.3390/ijms22063074

Abstract

Blood platelets’ adenosine receptors (AR) are considered to be a new target for the anti-platelet therapy. This idea is based on in vitro studies which show that signaling mediated by these receptors leads to a decreased platelet response to activating stimuli. In vivo evidence for the antithrombotic activity of AR agonists published to date were limited, however, to the usage of relatively high doses given in bolus. The present study was aimed at verifying if these substances used in lower doses in combination with inhibitors of P2Y12 could serve as components of dual anti-platelet therapy. We have found that a selective A2A agonist 2-hexynyl-5’-N-ethylcarboxamidoadenosine (HE-NECA) improved the anti-thrombotic properties of either cangrelor or prasugrel in the model of ferric chloride-induced experimental thrombosis in mice. Importantly, HE-NECA was effective not only when applied in bolus as other AR agonists in the up-to-date published studies, but also when given chronically. In vitro thrombus formation under flow conditions revealed that HE-NECA enhanced the ability of P2Y12 inhibitors to decrease fibrinogen content in thrombi, possibly resulting in their lower stability. Adenosine receptor agonists possess a certain hypotensive effect and an ability to increase the blood–brain barrier permeability. Therefore, the effects of anti-thrombotic doses of HE-NECA on blood pressure and the blood–brain barrier permeability in mice were tested. HE-NECA applied in bolus caused a significant hypotension in mice, but the effect was much lower when the substance was given in doses corresponding to that obtained by chronic administration. At the same time, no significant effect of HE-NECA was observed on the blood–brain barrier. We conclude that chronic administration of the A2A agonist can be considered a potential component of a dual antithrombotic therapy. However, due to the hypotensive effect of the substances, dosage and administration must be elaborated to minimize the side-effects. The total number of animals used in the experiments was 146.

Highlights

Antiplatelet therapies decrease the ability of blood platelets to form occlusive thrombus and limit the occurrence of such pathological conditions as stroke or heart attacks
The anti-aggregatory effect of adenosine receptor agonist HE-NECA was tested using human whole blood stimulated with 10 μM adenosine diphosphate (ADP)
HE-NECA was used in a combination with two P2Y12 receptor antagonists: either cangrelor or prasugrel metabolite R-138727 (PM)

Summary

Introduction

Antiplatelet therapies decrease the ability of blood platelets to form occlusive thrombus and limit the occurrence of such pathological conditions as stroke or heart attacks. Dual therapy is applied where cyclooxygenase-1 inhibition is accompanied by a P2Y12 inhibitor The effectiveness of such dual strategy stems from the fact that two distinct molecular pathways which lead to platelet activation are compromised. A target, which has recently been considered in the context of dual therapy, is adenosine receptors (AR) They are expressed on blood platelets as two sub-types: A2A and A2B [1]. Their naturally occurring ligand is adenosine, a purine metabolite that is present in plasma mainly due to the activity of ecto-5 -nucleotidaze (CD73), which hydrolyses adenosine monophosphate. The present study is aimed at providing evidence for the in vivo effectiveness of such a dual approach

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Results

Conclusion