Paradoxical Increase in Mortality and Rupture of Intracranial Aneurysms in Microsomal Prostaglandin E2 Synthase Type 1-Deficient Mice: Attenuation by Aspirin. Issue 4 (October 2015)

• Record Type: Journal Article
• Authors: Peña Silva, Ricardo A.; Mitchell, Ian J.; Kung, David K.; Pewe, Lecia L.; Granja, Manuel F.; Harty, John T.; Faraci, Frank M.; Heistad, Donald D.; Hasan, David M.
• Is Part Of: Neurosurgery. Volume 77:Issue 4(2015)
• Publication Date: 2015-10
• Subjects: Aspirin -- Intracranial aneurysm -- Microsomal prostaglandin E2 synthase type 1 -- Prostaglandin E2 -- Subarachnoid hemorrhage; Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1227/NEU.0000000000000883
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract : BACKGROUND: Inflammation plays an important role in formation and rupture of intracranial aneurysms. Expression of microsomal prostaglandin E2 (PGE2 ) synthase type 1 (mPGES-1) is increased in the wall of intracranial aneurysms in humans. PGE2, a by-product of mPGES-1, is associated with inflammation and cerebrovascular dysfunction. OBJECTIVE: To test the hypothesis that deletion of mPGES-1 decreases the formation and rupture of intracranial aneurysms in a murine model. METHODS: Intracranial aneurysms were induced in wild-type and mPGES-1 knockout (mPGES-1 KO) mice by using a combination of deoxycorticosterone acetate-salt-induced hypertension and intracranial injection of elastase in the basal cistern. Prevalence of aneurysms, subarachnoid hemorrhage, and mortality were assessed. We also tested the effects of administration of aspirin (6 mg/kg/d) by gavage and PGE2 (1 mg/kg/d) by subcutaneous infusion. RESULTS: Systolic blood pressure and prevalence of aneurysm were similar in wild-type and mPGES-1 KO mice. However, mortality and the prevalence of subarachnoid hemorrhage were markedly increased in mPGES-1 KO mice ( P < .05). Bone marrow reconstitution studies suggest that mPGES-1 derived from leukocytes does not appear to increase rupture of intracranial aneurysms. Aspirin, but not PGE2, attenuated the increased mortality in mPGES-1 KO mice ( P < .05). CONCLUSION: Vascular mPGES-1 plays a protective role in blood vessels and attenuates rupture of cerebral aneurysms. In contrast to effects on abdominal aneurysms, mPGES-1 deficiency is associated with an increase in rupture of cerebral aneurysms and mortality, which are attenuated by low-dose aspirin. ABBREVIATIONS: Cox, cyclooxygenase DOCA, deoxycorticosterone acetate mPGES-1 KO, microsomal prostaglandin E2 synthase type 1 knockout PGE 2, prostaglandin E2 SAH, subarachnoid hemorrhage WT, wild type Abstract : Supplemental Digital Content is Available in the Text.