MiR-29a/c-3p knockdown sex-specifically impairs VEGFA-stimulated chemotaxis in male human endothelial cells

Preeclampsia (PE) is a severe hypertensive disorder of pregnancy, a leading cause of maternal and fetal morbidity and mortality. Its etiology remains complex, but widespread endothelial dysfunction in both mother and fetus is a hallmark. Current standard-of-care primarily manages symptoms, lacking targeted therapies for the underlying endothelial pathology. MicroRNAs (miRNAs) are emerging as key regulators of gene expression in endothelial cells, and their dysregulation is implicated in PE pathogenesis. Specifically, reduced levels of miR-29a-3p and miR-29c-3p (miR-29a/c-3p) have been linked to impaired human umbilical vein endothelial cell (HUVEC) function, highlighting a potential therapeutic avenue.

Researchers investigated the sex-specific impact of miR-29a/c-3p knockdown on human umbilical vein endothelial cells (HUVECs). Male and female HUVECs were treated with miR-29c-3p inhibitors to achieve knockdown of both miR-29a-3p and miR-29c-3p. The primary endpoints included assessing chemotactic and proliferative responses to vascular endothelial growth factor-A (VEGFA) and fibroblast growth factor 2 (FGF2). To understand the molecular mechanisms, RNA-seq was performed to identify miR-29a/c-3p-regulated genes and pathways in both sexes, comparing inhibitor-treated cells to untreated controls.

Knockdown analysis confirmed that miR-29c-3p inhibitors successfully decreased miR-29a/c-3p levels by over 95% in both male and female HUVECs. Functionally, the inhibitors significantly suppressed VEGFA-stimulated chemotaxis by 26% in male HUVECs, while FGF2-stimulated chemotaxis remained unaffected. Importantly, this effect was observed exclusively in male HUVECs, with no significant impact on female HUVECs' chemotactic responses. Proliferation was not significantly affected in either sex. RNA-seq revealed profound sex-specific transcriptional changes:

miR-29a/c-3p inhibitors dysregulated 47 genes in male HUVECs and 118 distinct genes in female HUVECs. Bioinformatics analyses further demonstrated that these miR-29a/c-3p-regulated genes were differentially associated with pathways relevant to hypertension, heart development, angiogenesis, and immunology in male versus female HUVECs. These findings strongly suggest a sex-specific role for miR-29a/c-3p in regulating endothelial cell function and gene expression.