Elevated miR-200a and miR-141 inhibit endocrine gland-derived vascular endothelial growth factor expression and ciliogenesis in preeclampsia

Key points: Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is a critical factor that facilitates trophoblast invasion in placenta. Plasma miR-141 and miR-200a levels were elevated, while EG-VEGF was decreased in peripheral blood and placenta of preeclamptic patients. Furthermore, numbers of cilia in the placenta from preeclamptic women were significantly decreased. Elevated miR-141 and miR-200a inhibited the expression of EG-VEGF, downstream extracellular signal-regulated kinase (ERK)/matrix metalloproteinase 9 signalling and cilia formation, thus leading to defective trophoblast invasion. The growth of the primary cilium, which transduced ERK signalling upon EG-VEGF induction for proper trophoblast invasion, was also inhibited by miR-141 and miR-200a upregulation. Abstract: Preeclampsia is a severe gestational complication, and inadequate trophoblast invasion during placental development is an important pathoaetiology. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is a critical factor that facilitates trophoblast invasion in placenta. By binding to the primary cilium, EG-VEGF initiates the signalling cascade for proper embryo implantation and placental development. The miR-200 family was predicted to target the EG-VEGF 5′-untranslated region, and its specific binding site was confirmed using a dual luciferase and a co-transfection assay. In the peripheral blood and placenta of preeclamptic patients, EG-VEGF showed significantly lower expression, whereas plasma miR-141 and miR-200a had higher expression compared with the controls. The biological significance of miR-141 and miR-200a was verified using an overexpression method in a trophoblast cell line (HTR-8/SVneo). Elevated miR-141 and miR-200a inhibited the expression of EG-VEGF, matrix metalloproteinase 9 (MMP9) and downstream extracellular signal-regulated kinase (ERK) signalling, thus leading to defective trophoblast invasion. Additionally, the growth of the primary cilium, which transduces ERK/MMP9 signalling upon EG-VEGF induction, was inhibited by miR-141 and miR-200a upregulation. Furthermore, the number of cilia in the human placenta of preeclamptic women was significantly decreased compared to normal placenta. In conclusion, the study uncovers the clinical correlations among the miR-200 family, EG-VEGF and the primary cilium in preeclampsia and the underlying molecular mechanisms. The results indicate that miR-141 and miR-200a directly targeted EG-VEGF, suppressed primary cilia formation and inhibited trophoblast invasion. Thus, miR-141 and miR-200a could be explored as promising miRNA biomarkers and therapeutic targets in preeclampsia.