Abstract 023: Prior Sflt1 Induced Preeclampsia Exacerbates Post-partum Hypertension-mediated Aortic Stiffness And Hypercholesterolemia-induced Atherosclerotic Inflammation

Abstract

Preeclampsia (PE) is new high blood pressure (BP) and organ damage occurring late in pregnancy in association with increased soluble VEGF receptor (sFlt1). PE survivors have increased risk of future hypertension and myocardial infarction/stroke. We hypothesized that exposure to high sFlt1 during pregnancy exacerbates hypertension and atherosclerosis post-partum. PE was induced by transient adenoviral expression of sFlt1 compared to control virus in pregnant mice. PE mice had elevated sFlt1, BP and kidney damage during pregnancy which resolve post partum. Two months post-partum, prior PE mice had significantly increased BP response to high salt diet. After high BP stimuli, we studied large and small artery function. Prior PE mice had diminished nitric oxide-mediated vasodilation and stiffer aortas with more fibrosis as measured by pulse wave velocity (Con:3.7 vs sFlt:5.9 mm/ms, p<0.0001) and trichrome staining (Con:13.7% vs sFlt:33.9%, p=0.0009). Atherosclerosis studies exposed LDLR knockout mice to PE followed by high fat diet feeding for 8 weeks. Body weight, fasting glucose and cholesterol were not altered by prior PE. Aortic roots were histologically analyzed for plaque size and composition. Aortic root plaque size (Con:73.3 vs sFlt:78.0 AU, p=0.60) and necrotic core were not different between groups. Aortic arch plaque inflammation was quantified via flow cytometry showing significantly increased plaque CD45+ leukocytes (sFlt:1.6 fold, p=0.036) and T cells (sFlt:1.8 fold, p=0.031) from mice with prior PE. Atheroprone mice with prior PE had significantly increased aortic expression of CCL22 (sFlt:1.5 fold, p=0.047), providing a potential mechanism for increased T cell infiltration into atherosclerotic plaques. Experimental PE produces a state of enhanced sensitivity to hypertensive stimuli and increased vascular inflammation in atherosclerotic plaques supporting the concept that PE directly exacerbates hypertension, vascular stiffness, and atherosclerotic inflammation independent of pre-existing risk factors.