Novel NF-kB variant in preeclampsia

SUMMARY Preeclampsia (PE) remains a poorly understood, multiorgan vascular disease that is responsible for the death of up to 50,000 women and 1 million infants per year. Defective placentation and an abnormal immune microenvironment at the maternal-fetal interface are central to the etiology of PE. Specifically, insufficient

extravillous trophoblast (EVT) invasion and, in turn, incomplete remodeling of the uterine spiral arteries, limits placental perfusion and provokes the systemic maternal vascular endothelial dysfunction hallmark of PE. The nuclear factor kappa B (NF-κB) family of transcription factors is a master regulator of inflammatory responses

that promote EVT invasion. Yet, excessive NF-kB activation in the vascular endothelium can impair uterine vasodilation and reduce uteroplacental blood flow. We recently identified a novel NF-κB variant (rs230511) that is associated with PE. Here we will combine robust human physiological studies and CRISPR-Cas9 gene-editing

to establish the functional importance of this NF-κB variant for inflammatory responses in pregnancy, and the role of NF-κB more generally in PE. We hypothesize that rs230511 increases PE risk by enhancing inflammatory cytokine responses that, in turn, impair uteroplacental vascular function and perfusion. We will study a Bolivian

high-altitude (≥ 8,250 ft) population, where the incidence of PE is three-fold greater than at sea level. Aim 1 will establish whether rs230511 is associated with impaired spiral artery remodeling, elevated circulating inflammatory cytokine levels, lower uteroplacental perfusion, and reduced fetal growth. Using DNA isolated from

400 Andean maternal-infant pairs residing in La Paz, Bolivia, we will (1) determine maternal and infant rs230511 genotypes; (2) quantify the extent of spiral artery remodeling, (3) determine maternal and umbilical venous inflammatory cytokine levels, uteroplacental blood flow and fetal growth; and (4) contrast these primary variables

by rs230511 status in maternal-infant pairs. To account for the effects of admixture, we will estimate individual admixture using genotype data obtained by the Illumina Multi-Ethnic Genotyping Array. Aim 2 will determine whether rs230511 disrupts inflammatory responses in human vascular endothelial cells (HUVECs). We will use

the CRISPR-Cas9 system to create a targeted rs230511 conversion (C→T) in HUVECs and measure the effects on transcriptional responses of NF-κB target gene networks to TNFα exposure by RNASeq, and inflammatory cytokine secretion using a high-sensitivity multiplex assay. Our findings will be applicable for identifying novel

pathways to improve reproductive outcomes in other populations given that hypertensive disorders of pregnancy are HA are equivalent to those at LA in terms of risk factors, physiological manifestations and consequences for mother and child, and the genetic variant of interest is not confined to HA populations. By advancing the

understanding of maternal and fetal genetics for the regulation of inflammatory responses during pregnancy and PE, our project will help guide future mechanistic studies, aid the development of preventive strategies to improve reproductive outcomes and identify women at an increased risk of PE.