Misoprostol, an anti-ulcer agent and PGE2 receptor agonist, protects against cerebral ischemia.
Induction of COX-2 activity in cerebral ischemia results in increased neuronal injury and infarct size. Recent studies investigating neurotoxic mechanisms of COX-2 demonstrate both toxic and paradoxically protective effects of downstream prostaglandin receptor signaling pathways. We tested whether misoprostol, a PGE(2) receptor agonist that is utilized clinically as an anti-ulcer agent and signals through the protective PGE(2) EP2, EP3, and EP4 receptors, would reduce brain injury in the murine middle cerebral artery occlusion-reperfusion (MCAO-RP) model. Administration of misoprostol, at the time of MCAO or 2h after MCAO, resulted in significant rescue of infarct volume at 24 and 72h. Immunocytochemistry demonstrated dynamic regulation of the EP2 and EP4 receptors during reperfusion in neurons and endothelial cells of cerebral cortex and striatum, with limited expression of EP3 receptor. EP3-/- mice had no significant changes in infarct volume compared to control littermates. Moreover, administration of misoprostol to EP3+/+ and EP3-/- mice showed similar levels of infarct rescue, indicating that misoprostol protection was not mediated through the EP3 receptor. Taken together, these findings suggest a novel function for misoprostol as a protective agent in cerebral ischemia acting via the PGE(2) EP2 and/or EP4 receptors.
Li
Jun
J
Department of Neurology and Neuroscience, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT, United States.
Liang
Xibin
X
Wang
Qian
Q
Breyer
Richard M
RM
McCullough
Louise
L
Andreasson
Katrin
K
D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D002536:Cerebral Arteries / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002544:Cerebral Infarction / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D016595:Misoprostol / Q000494:pharmacology* / Q000627:therapeutic use; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018078:Receptors, Prostaglandin E / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D015427:Reperfusion Injury / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
D000897:Anti-Ulcer Agents; D018696:Neuroprotective Agents; C545645:Ptger2 protein, mouse; C545648:Ptger3 protein, mouse; C545651:Ptger4 protein, mouse; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D016595:Misoprostol; D051546:Cyclooxygenase 2; D015232:Dinoprostone