Pre-eclampsia: Challenges for Nanomedicine Development in Pregnancy

Upregulation of SEMP1 Contributes to Improving the Biological Functions of Trophoblast via the PI3K/AKT Pathway in Preeclampsia

Disturbance of extravillous trophoblast infiltration is associated with preeclampsia (PE), a severe condition of pregnancy characterized by hypertension and proteinuria. Senescence-associated epithelial membrane protein 1 (SEMP1), an integral membrane protein, is a vital component of tight junction strands in epithelial or endothelial cells, with no clear function reported in PE. Gene Expression Omnibus (GEO) datasets showed that SEMP1 expression was downregulated in the placental tissues of PE patients, which was confirmed by assessing SEMP1 levels in placental samples collected in our hospital. Furthermore, less SEMP1 was detected in cytokeratin 7 positive trophoblast cells in the spiral arteries of rat placentas post L-arginine methyl ester hydrochloride (L-NAME) treatment. Trophoblast cells acquired robust ability of proliferation, migration, and invasion when SEMP1 was overexpressed. Such capability was weakened in SEMP1-silenced cells. Trophoblast cells overexpressing SEMP1 secreted more vascular endothelial growth factor A (VEGFA), which facilitated the tube formation of human umbilical vein endothelial cells. Blockade of PI3K/AKT signaling transduction with LY294002 dampened the effects of SEMP1 on trophoblast cells. Collectively, we firstly indicated that SEMP1 inhibition is a potential driver for PE, which may be associated with the deactivation of the PI3K/AKT pathway.

The Complement System, T Cell Response, and Cytokine Shift in Normotensive versus Pre-Eclamptic and Lupus Pregnancy

Successful pregnancy requires an immunological shift with T helper CD4⁺ bias based on disbalance Th1/Th17 versus Th2/T regulatory (Tregs) required to induce tolerance against the semi-allogeneic fetus and placenta and to support fetal growth. Considered a pregnancy-specific hypertensive disorder, pre-eclampsia is characterized by multifaceted organ involvement related to impaired maternal immune tolerance to paternal antigens triggered by hypoxic placental injury as well as excessive local and systemic anti-angiogenic and inflammatory factor synthesis. Both systemic and local Th1/Th2 shift further expands to Th17 cells and their cytokines (IL-17) complemented by suppressive Treg and Th2 cytokines (IL-10, IL-4); alterations in Th17 and Tregs cause hypertension during pregnancy throughout vasoactive factors and endothelial dysfunction, providing an explanatory link between immunological and vascular events in the pathobiology of pre-eclamptic pregnancy. Apart from immunological changes representative of normotensive pregnancy, lupus pregnancy is generally defined by higher serum pro-inflammatory cytokines, lower Th2 polarization, defective and lower number of Tregs, potential blockade of complement inhibitors by anti-phospholipid antibodies, and similar immune alterations to those seen in pre-eclampsia. The current review underpins the immune mechanisms of pre-eclampsia focusing on local (placental) and systemic (maternal) aberrant adaptive and innate immune response versus normotensive pregnancy and pregnancy in systemic autoimmune conditions, particularly lupus.