Sexually Dimorphic Regulation of MiR-29a/c-3p in Human Endothelial Cells: Cell Functions and Transcriptome

Preeclampsia (PE) is a major cause of maternal and fetal morbidity and mortality during pregnancy. PE is characterized by widespread endothelial dysfunction in mothers and fetuses. The etiology of PE remains elusive, but the dysregulation of microRNAs (miRNAs) in endothelial cells may contribute to the pathogenesis of PE. We have reported that PE downregulates expression of two miRNAs, miR-29a-3p and miR-29c-3p (miR-29a/c-3p), and knockdown of miR-29a/c-3p impairs functions of human umbilical vein endothelial cells (HUVECs). Herein, we tested the hypothesis that knockdown of miR-29a/c-3p sex-specifically impairs cellular responses to vascular endothelial growth factor-A (VEGFA) and fibroblast growth factor 2 (FGF2) via disrupting the transcriptome in HUVECs. MiR-29a/c-3p were knocked down using miR-29c-3p inhibitors in male and female HUVECs. Chemotactic and proliferative responses to VEGFA and FGF2 were assessed. RNA-seq was performed to identify miR-29a/c-3p regulated genes and pathways. Knockdown analysis demonstrated that miR-29c-3p inhibitors decreased miR-29a/c-3p levels by over 95% in male and female HUVECs. Functionally, miR-29c-3p inhibitors suppressed VEGFA-, but not FGF2-stimulated chemotaxis by 26% in male, but not female HUVECs. RNA-seq revealed that miR-29a/c-3p inhibitors dysregulated 47 and 118 genes in male and female HUVECs, respectively. Bioinformatics analyses showed that miR-29a/c-3p-regulated genes were differently associated with hypertension, heart, angiogenesis, and immunology in male and female HUVECs. These data demonstrate that knockdown of miR-29a/c-3p sex-specifically affects cellular responses to VEGFA and FGF2 in HUVECs, possibly via disrupting the transcriptome and relevant pathways. These miR-29a/c-3p-regulated genes might represent promising sex-specific therapeutic targets for PE-associated endothelial dysfunction pending further in vivo and clinical verification.