MiRNA-494 induces trophoblast senescence by targeting SIRT1

Although the mechanism underlying preeclampsia (PE) has been widely explored, the mechanisms related to senescence have not yet been fully revealed. Therefore, we investigated the role of the miR-494/longevity protein Sirtuin 1 (SIRT1) axis in PE.

Human placental tissue was obtained from severe preeclampsia (SPE) (n = 20) and gestational age-matched normotensive pregnancies (n = 20), and senescence-associated β-galactosidase (SAβG) and SIRT1 expression levels were measured. The TargetScan and miRDB databases predicted candidate miRNAs targeting SIRT1, and intersected with differentially expressed miRNAs in the GSE15789 dataset (p < 0.05, |log2FC|≥1.5). Subsequently, we showed that miRNA (miR)-494 expression was significantly elevated in SPE, revealing miR-494 as a candidate SIRT1-binding miRNA. A dual-luciferase assay confirmed the targeting relationship between miR-494 and SIRT1. The senescence phenotype, migration, cell viability, reactive oxygen species (ROS) production levels and inflammatory molecule expression levels were measured after miR-494 expression was altered. We conducted a rescue experiment using SIRT1 plasmids to further demonstrate the regulatory relationship.

SIRT1 expression was lower(p < 0.01) and miR-494 expression was higher (p < 0.001) in SPE, and SaβG staining showed premature placental aging in SPE (p < 0.001). Dual-luciferase reporter assays revealed that miR-494 targeted SIRT1. Compared to control cells, HTR-8/SVneo cells with upregulation of miR-494 had remarkably downregulated SIRT1 expression (p < 0.001), more SAβG-positive cells (p < 0.001), cell cycle arrested (p < 0.05), and upregulated P21 and P16 expression (p < 0.01). miR-494 overexpression also decreased HTR-8/SVneo cell migration (p < 0.05) and ATP synthesis (p < 0.001), increased ROS levels (p < 0.001), and upregulated NLRP3 and IL-1β expression (p < 0.01). SIRT1-overexpressing plasmids partially reversed the effects of miR-494 overexpression in HTR-8/SVneo cells.

The miR-494/SIRT1 interaction plays a role in the mechanism of premature placental aging in PE patients.