Myeloid cell mPges-1 deletion attenuates mortality without affecting remodeling after acute myocardial infarction in mice

Selective deletion of microsomal prostaglandin E₂ synthase-1 (mPges-1) in myeloid cells retards atherogenesis and suppresses the vascular proliferative response to injury, while it does not predispose to thrombogenesis or hypertension. However, studies using bone marrow transplants from irradiated mice suggest that myeloid cellmPGES-1 facilitates cardiac remodeling and prolongs survival after experimental myocardial infarction (MI). Here, we addressed this question using mice lacking mPges-1 in myeloid cells, particularly macrophages [Mac-mPges-1-knockout (KO)], generated by crossing mPges-1 floxed mice with LysMCre mice and subjecting them to coronary artery ligation. Cardiac structure and function were assessed by morphometric analysis, echocardiography, and invasive hemodynamics 3, 7, and 28 days after MI. Despite a similar infarct size, in contrast to the prior report, the post-MI survival rate was markedly improved in the Mac-mPges-1-KO mice compared with wild-type controls. Left ventricular systolic (reflected by ejection fraction, fractional shortness end systolic volume, and +dP/dt) and diastolic function (reflected by end diastolic volume, -dP/dt, and Tau), cardiac hypertrophy (reflected by left ventricular dimensions), and staining for fibrosis did not differ between the groups. In conclusion, we found that Cre-loxP-mediated deletion of mPges-1 in myeloid cells has favorable effects on post-MI survival, with no detectable adverse influence on post-MI remodeling. These results add to evidence that targeting macrophage mPGES-1 may represent a safe and efficacious approach to the treatment and prevention of cardiovascular inflammatory disease.