PROJECT SUMMARY / ABSTRACT Preeclampsia (PE) is a hypertensive disorder and one of the leading causes of fetal/maternalmorbidity and mortality during pregnancy. PE is characterized by impaired fetal and maternal endothelialfunction and excessive inflammation. Children born to PE will face increased risks of cardiovasculardisorders later in life suggesting that PE programs fetal vascular cells in utero. To date the mechanismsunderlying PE-associated fetal endothelial dysfunction remain elusive. Maternal obesity is one of theprevalent risk factors that associated with PE in developed countries. Maternal obesity increases theoverall risk of PE by 3 fold. Children born to obese mother also exhibit higher blood pressure andincreased risks of adverse cardiovascular outcomes in adulthood. Elevated TNF and TGF1 levels areassociated with endothelial dysfunction in PE. Compared with lean subjects obese women haveincreased pro-inflammatory cytokines (e.g. TNF) levels in placenta and increased TGF1 levels inmaternal circulation. Human umbilical vein is the blood vessel transporting all nutrition O2 and otherhumoral factors (e.g. cytokines) from the placenta and maternal system into the fetus. Hence humanumbilical vein endothelial cells (HUVECs) is widely used as a human fetal endothelial cell model. MiR192-5p is a cardiovascular diseases-associated microRNA which regulates endothelial cell growth in culturedHUVECs. Our preliminary data have shown that increased miR192-5p expression inhibits the TNF- andTGF1-induced cell migration in HUVECs. We and others have reported that PE decreases miR192expression in freshly isolated and unpassaged (P0)-HUVECs and in placentas. Our data furtherdemonstrated that i) PE downregulated miR192-5p in male but not in female P0-HUVECs from leanpregnancies; ii) PE upregulated miR192-5p in both female and male P0-HUVECs from obesepregnancies; and iii) Male P1-HUVECs from lean PE exhibit weaker responses (monolayer integrity) toTNF and TGF-1 than female cells did. As TNF and TGF1 are both upstream regulators of miR192-5p these data suggest that miR192-5p plays an important and differential role in TNF and/or TGF1-regulated fetal endothelial function in lean and obese PE. Overall hypothesis: PE programs fetalendothelial cells by dysregulating endothelial function-associated microRNAs and their target genesleading to fetal endothelial dysfunction and ultimately laying the groundwork for adult onsetcardiovascular disorders in children born to PE. Specifically in this application I will test the hypothesisthat miR192-5p differentially regulates the PE-induced fetal endothelial dysfunction in lean and obesepregnancies via the TNF and/or TGF1 signaling pathways using HUVECs as a model. Results fromour proposed studies will advance our understanding of the roles of miRNAs in PE-induced fetal sex-specific endothelial dysfunction in lean and obese pregnancies. In the long term these studies may revealnovel biomarkers or therapeutic targets for fetal sex-specific cardiovascular risk prediction treatmentand even prevention in children born to lean and obese PE.