Figure 1.

Role of matrix metalloproteinases (MMPs) in preeclampsia. (a) Impaired trophoblast invasion observed in early stage of preeclampsia is characterized by a decrease in MMP-2 and MMP-9, which affects spiral artery remodeling, causing a poorly perfused fetoplacental unit. (b) Vascular dysfunction developed during the late stage of preeclampsia is mediated by several MMPs including MMP-1, MMP-2 and MMP-9, which induce vasoconstriction, changes in vascular reactivity and endothelial damage. PAR-1, protease-activated receptor 1; VEGF, vascular endothelial growth factor; NK, natural killer cells; and TIMP-1, tissue inhibitor of matrix metalloproteinase-1.