Exposure to higher concentrations of exogenous ELABELA causes HTR-8/SVneo trophoblast cell dysfunction: A possible pathogenesis of pre-eclampsia.

Pre-eclampsia (PE) is a multi-system disorder of pregnancy which constitute one of the leading causes of maternal and perinatal mortality worldwide. Dysfunction of trophoblast cells have been play an a significant role in the development and progression of PE. ELABELA (ELA), an endogenous apelin receptor (APJ) ligand, is a hormone secreted by the placenta into circulation, we previously identified ELA and its cognate apelin receptor (APJ) as proteins that are differentially expressed in the placentas of humans with PE. However, a fact known to few about the potential regulatory effects of ELA on the functions of trophoblast cells. In this study, our experiments showed that exogenous ELA did not effectively affect the proliferation and apoptosis of HTR-8/SVneo cells in higher concentrations but inhibited the invasion and migration capabilities. Studies have shown that the epithelial-mesenchymal transition (EMT) event of trophoblast cells is abnormal through regulate the P13K/AKT pathway in PE. First we confirmed APJ expression in HTR-8/SVneo cells and ELA suppressed P13K/AKT signalling pathway-related factors (AKT, phospho (p)-AKT) phosphorylation in HTR-8/SVneo cells in a concentration-dependent manner. Next, we found that treatment with higher concentrations of ELA or the P13K inhibitor LY294002 significantly increased the expression of β-catenin which is the classical epithelial marker relative to the control group. Moreover, treatment with both LY294002 and ELA more strongly affected the β-catenin expression and the HTR8/SVneo cells invasion and migration. These results demonstrate that ELA inhibits trophoblast cell functions by altering the β-catenin expression get though the PI3K/AKT signalling pathway in PE. Thus, this result might provide a new therapeutic target for the treatment of PE.