The Roles of MicroRNA in Preeclampsia Induced Fetal Sex-specific Endothelial Dysfunction in Obese Pregnancies

Abstract

Preeclampsia (PE) is a hypertensive disorder that complicates 5-10% of human pregnancies and leads to high fetal morbidity and mortality. Maternal obesity increases the risks of PE by 3-fold in association with elevated circulating pro-inflammatory cytokines which are related to endothelial dysfunction observed in PE. MiR146a-5p is a cardiovascular disease-associated miRNA that regulates endothelial cell responses. We have previously reported fetal sex-specific fetal endothelial dysfunction in PE. Although miR146a-5p has been reported to be dysregulated in PE HUVECs, the role of miR146a-5p in PE-dysregulated fetal sex-specific endothelial dysfunction is unclear. We hypothesize that miR146a-5p differently mediate PE-induced sex-specific fetal endothelial dysfunction in lean and obese pregnancies. Human umbilical vein endothelial cells (unpassaged, P0-HUVECs; 5-12 days of culture, P1-HUVECs) were isolated immediately after delivery from normotensive (NT; 39±0.5 wks) and PE (38±0.5 wks) pregnancies (lean and OB) with female (F) and male (M) fetuses. Expression of miR146a-5p was examined in P1-HUVECs using RT-qPCR (n=8-10/group). Bioinformatics analysis was performed with our existing RNAseq data to identify PE-dysregulated miR146a-5p target genes in HUVECs. Endothelial proliferation, lipid uptake, monolayer integrity (MI), and migration responses to cytokines were examined in P1 HUVECs with and without miR146a-5p overexpression and knockdown (n=5-7/group/assay). PE upregulated miR146a-5p in lean F-HUVECs, while downregulated miR146a-5p in obese M-HUVECs. PE differentially dysregulated vascular/endothelial function-associated miR146a-5p target genes in F&M HUVECs. Lipid uptake was reduced in PE and OB.NT-F and M HUVECs from both LN/OB HUVECs. PE reduced the TNFα elevated cell proliferation in LN/OB-F/M HUVECs. Overexpression of miR146a-5p rescued PE impaired, TNFα treated cell proliferation in lean and obese PE-M. TNFα impaired MI recovered over time in NT-F but not PE. PE abolished TGFβ1 enhanced MI in LN.F but not M. Knockdown of miR146a-5p rescued the TNFα and TGFβ1 impaired MI in PE-F compared to NT. In conclusion, our data have shown that miR146a-5p plays important roles in mediating PE-induced fetal sex-specific fetal endothelial dysfunction in lean and obese pregnancies.