Synergistic Inhibition of Both P2Y ₁ and P2Y ₁₂ Adenosine Diphosphate Receptors As Novel Approach to Rapidly Attenuate Platelet-Mediated Thrombosis

Abstract

Objective Unlike currently approved adenosine diphosphate (ADP) receptor antagonists, the new diadenosine tetraphosphate derivative GLS-409 targets not only P2Y12 but also the second human platelet ADP receptor P2Y1, and may therefore be a promising antiplatelet drug candidate. The current study is the first to investigate the in vivo antithrombotic effects of GLS-409. Approach and Results We studied (1) the in vivo effects of GLS-409 on agonist-stimulated platelet aggregation in anesthetized rats, (2) the antithrombotic activity of GLS-409 and the associated effect on the bleeding time in a canine model of platelet-mediated coronary artery thrombosis, and (3) the inhibition of agonist-stimulated platelet aggregation by GLS-409 versus selective P2Y1 and P2Y12 inhibition in vitro in samples from healthy human subjects before and 2 hours after aspirin intake. In vivo treatment with GLS-409 significantly inhibited ADP- and collagen-stimulated platelet aggregation in rats. Further, GLS-409 attenuated cyclic flow variation, i.e., platelet-mediated thrombosis, in vivo in our canine model of unstable angina. The improvement in coronary patency was accompanied by a non-significant 30% increase in bleeding time. Of note, GLS-409 exerted its effects without affecting rat and canine hemodynamics. Finally, in vitro treatment with GLS-409 showed effects similar to that of cangrelor and the combination of cangrelor with the selective P2Y1 inhibitor MRS 2179 on agonist-stimulated platelet aggregation in human platelet-rich plasma and whole blood before and 2 hours after aspirin intake. Conclusions Synergistic inhibition of both P2Y1 and P2Y12 ADP receptors by GLS-409 immediately attenuates platelet-mediated thrombosis and effectively blocks agonist-stimulated platelet aggregation irrespective of concomitant aspirin therapy.

Novel aspects of antiplatelet therapy in cardiovascular disease

“…Currently available ADP receptor antagonists target only P2Y 12 , but not the second ADP receptor on human platelets, P2Y 1 (Figure ) . Activation of P2Y 1 initiates ADP‐induced platelet aggregation, and is responsible for platelet shape change, while P2Y 12 activation leads to amplification and stabilization of the aggregation response . A complex interplay between P2Y 1 and P2Y 12 has been described previously, and coactivation of both seems essential for full platelet aggregation .…”

“…Activation of P2Y 1 initiates ADP‐induced platelet aggregation, and is responsible for platelet shape change, while P2Y 12 activation leads to amplification and stabilization of the aggregation response . A complex interplay between P2Y 1 and P2Y 12 has been described previously, and coactivation of both seems essential for full platelet aggregation . However, ADP may activate platelets of patients receiving P2Y 12 inhibitors via P2Y 1 to some extent, resulting in HRPR and an increased risk of ischemic outcomes despite antiplatelet therapy .…”

Adenosine Receptor Agonists Exhibit Anti-Platelet Effects and the Potential to Overcome Resistance to P2Y12 Receptor Antagonists

“…Taken together, our findings provide further support for the potential therapeutic use of AR agonists in dual anti-platelet therapy in combination with P2Y 12 receptor inhibitors. Adenosine receptor agonists seem to be an attractive alternative to GPIIbIIIa or P2Y 1 receptor antagonists, which were demonstrated to have favorable effects on platelet function in combined therapy with thienopyridines [46,47].…”

Purinergic Signaling in the Cardiovascular System

“…189 An account of ischemia in the by guest on May 9, 2018 http://circres.ahajournals.org/ Downloaded from heart was included earlier, and detailed coverage of the involvement of purinergic signaling in ischemia in blood vessels in a wide range of organs can be found in a review by Burnstock and Ralevic 24 and in some more recent articles since then. 197 Adenosine, acting via A 2A and A 3 receptors, has antithrombotic effects, perhaps by blocking induction of circulating tissue factor. CD39 mediates resistance to occlusive arterial thrombus formation after vascular injury in mice.…”