Endothelial Cell vs Immune Cell Contribution to Atherosclerotic Plaque Inflammation Post Preeclampsia

Yale University, New Haven CT

Investigators

Abstract

PROJECT SUMMARY Preeclampsia (PE) affects 2-8% of pregnancies worldwide and is diagnosed as new-onset hypertension with signs of target organ damage. Women that survive PE are twice as likely to experience atherosclerosis-related conditions (coronary heart disease) leading to ischemic events (myocardial infarction and stroke) compared with women who have uncomplicated pregnancies. Epidemiological studies indicate residual risk for cardiovascular disease following PE that is not explained by pre-existing risk factors. Systemic vascular endothelial cell (EC) dysfunction and increased immune cell activation are correlated with PE and can persist sub-clinically in the years following pregnancy. Activated and dysfunctional ECs augment immune cell recruitment into the vascular wall contributing to atherosclerosis, but the effect of PE on mechanisms of atherosclerosis and the role of pre- existing risk factors remains a gap in knowledge. To understand the specific effect of PE, a well-established experimental mouse model known to elicit features seen in humans (soluble fms-like tyrosine kinase 1 (sFlt-1) adenoviral injection mid-gestation) will be studied, compared with a control pregnancy (empty vector adenovirus). Preliminary data demonstrate that mice exposed to experimental PE have 1) microvascular EC dysfunction in late gestation and 8 weeks postpartum and 2) increased number of leukocytes and T cells in atherosclerotic plaques 8 weeks postpartum, independent of plaque size, lipid content, necrotic core, or metabolic risk factors. Importantly, increased plaque inflammation contributes greatly to plaque instability and likelihood of rupture leading to ischemic events. Therefore, the hypothesis is that enhanced atherosclerotic plaque inflammation after PE is due to persistent, systemic vascular EC activation and dysfunction combined with increased proinflammatory immune cell activation and infiltration into atherosclerotic plaques. Aim 1 will test if experimental PE results in persistent EC activation, microvascular function, and large artery stiffness in atheroprone mice (LDLr-/- mice fed a high fat diet postpartum). EC activation will be assessed via immunofluorescence in mesenteric resistance arteries (microvasculature) and areas of atherosclerotic plaque development. EC dysfunction will be assessed ex vivo via wire myography, and large artery stiffness will be assessed in vivo via pulse wave velocity in late gestation, 4 weeks postpartum, and 8 weeks postpartum. Aim 2 will determine how experimental PE alters immune cell plaque inflammation using single cell RNA sequencing to determine alterations in subpopulations, cell states, gene expression, and cell-cell interactions in aortic plaques 8 weeks following PE in atheroprone mice. Completion of project aims will provide mechanisms of atherosclerosis EC dysfunction and leukocyte infiltration following PE, which can be used to investigate targeted prevention strategies and therapeutics in future work. This F32 fellowship also provides extensive training opportunities in basic science and professional development to support the applicant’s long-term goal of becoming an independent academic researcher studying female-specific cardiovascular health across the lifespan.