Antagonists of the EP3 receptor for prostaglandin E2 are novel antiplatelet agents that do not prolong bleeding.
Myocardial infarction and stroke are caused by blood clots forming over a ruptured or denuded atherosclerotic plaque (atherothrombosis). Production of prostaglandin E(2) (PGE(2)) by an inflamed plaque exacerbates atherothrombosis and may limit the effectiveness of current therapeutics. Platelets express multiple G-protein coupled receptors, including receptors for ADP and PGE(2). ADP can mobilize Ca(2+) and through the P(2)Y(12) receptor can inhibit cAMP production, causing platelet activation and aggregation. Clopidogrel (Plavix), a selective P(2)Y(12) antagonist, prevents platelets from clotting but thereby increases the risk of severe or fatal bleeding. The platelet EP(3) receptor for PGE(2), like the P(2)Y(12) receptor, also inhibits cAMP synthesis. However, unlike ADP, facilitation of platelet aggregation via the PGE(2)/EP(3) pathway is dependent on co-agonists that can mobilize Ca(2+). We used a ligand-based design strategy to develop peri-substituted bicylic acylsulfonamides as potent and selective EP(3) antagonists. We show that DG-041, a selective EP(3) antagonist, inhibits PGE(2) facilitation of platelet aggregation in vitro and ex vivo. PGE(2) can resensitize platelets to agonist even when the P(2)Y(12) receptor has been blocked by clopidogrel, and this can be inhibited by DG-041. Unlike clopidogrel, DG-041 does not affect bleeding time in rats, nor is bleeding time further increased when DG-041 is co-administered with clopidogrel. This indicates that EP(3) antagonists potentially have a superior safety profile compared to P(2)Y(12) antagonists and represent a novel class of antiplatelet agents.
Singh
Jasbir
J
deCODE Chemistry, Woodridge, Illinois 60517, USA.
Zeller
Wayne
W
Zhou
Nian
N
Hategen
Georgeta
G
Mishra
Rama
R
Polozov
Alex
A
Yu
Peng
P
Onua
Emmanuel
E
Zhang
Jun
J
Zembower
David
D
Kiselyov
Alex
A
Ramírez
José L
JL
Sigthorsson
Gudmundur
G
Bjornsson
Jon Mar
JM
Thorsteinsdottir
Margret
M
Andrésson
Thorkell
T
Bjarnadottir
Maria
M
Magnusson
Olafur
O
Fabre
Jean-Etienne
JE
Stefansson
Kari
K
Gurney
Mark E
ME
D000178:Acrylamides / Q000494:pharmacology*; D000818:Animals; D000077144:Clopidogrel; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000378:metabolism; D005260:Female; D006470:Hemorrhage / Q000517:prevention & control; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D011448:Prostaglandin Antagonists / Q000494:pharmacology*; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D018078:Receptors, Prostaglandin E / Q000037:antagonists & inhibitors*; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058925:Receptors, Purinergic P2Y12; D013450:Sulfones / Q000494:pharmacology*; D013927:Thrombosis / Q000188:drug therapy / Q000378:metabolism; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000494:pharmacology
C531572:3-(1-((2,4-dichlorophenyl)methyl)-5-fluoro-3-methyl-1H-indol-7-yl)-N-((4,5-dichloro-2-thienyl)sulfonyl)-2-propenamide; D000178:Acrylamides; C548576:P2RY12 protein, human; C545647:PTGER3 protein, human; D010975:Platelet Aggregation Inhibitors; D011448:Prostaglandin Antagonists; D058919:Purinergic P2 Receptor Antagonists; D018078:Receptors, Prostaglandin E; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058925:Receptors, Purinergic P2Y12; D013450:Sulfones; D000077144:Clopidogrel; D015232:Dinoprostone; D013988:Ticlopidine