Figure 1.

The interaction of decidual cell– and trophoblast-derived exosomes creates a favorable microenvironment for extravillous trophoblasts (EVTs) in the uterine endometrium, which promotes the invasion of EVTs and the remodeling of spiral arteries for adequate placentation in normal pregnancy. Disturbance of the remodeling in the first stage leads to poor placentation, resulting in preeclampsia pathophysiology in the second stage by placenta-derived humoral factors. dNK: decidual natural killer cell, sFlt-1: soluble fms-like tyrosine kinase 1, sEng: soluble endoglin, STBs: syncytiotrophoblasts, TNF-α: tumor necrosis factor-α, IFN-γ: interferon-γ.