TNF-related apoptosis-inducing ligand (TRAIL) promotes trophoblast cell invasion via miR-146a-EGFR/CXCR4 axis: A novel mechanism for preeclampsia?

Abstract Introduction Preeclampsia (PE) is associated with failure of uterovascular transformation due to impaired trophoblast invasion. Previously, TNF-related apoptosis-inducing ligand (TRAIL) has been controversially reported to correlate with PE, but whether it regulates trophoblast invasion yet to be defined. Methods We treated HTR8/SVneo cells with sTRAIL at concentrations of 0.1 ng/mL, 1 ng/mL and 10 ng/mL for a 72-h time course and compared cell proliferation, apoptosis and invasion ability by CCK8 assay, flow cytometry analysis and Matrigel cell invasion assay, respectively. The expressions levels of miR-146a, CXCR4, EGFR and MMP2 were quantified by qRT-PCR and Western blot. Moreover, HTR8/SVneo cells were transfected with miR-146a mimics and miR-146a inhibitor, followed by analyzing invasion ability and gene expressions of CXCR4, EGFR and MMP2. Finally, both serum and placental samples from preeclamptic and gestational week-matched normotensive women were collected and assessed for the expression levels of TRAIL by ELISA assay and immunochemistry staining. Results sTRAIL treatment of HTR8/SVneo cells resulted in no change in proliferation or apoptosis, but dose- and time-dependently enhanced invasion. TRAIL downregulated the expressions of miR-146a and upregulated CXCR4, EGFR and MMP2. Transfection of miR-146a resulted in the inhibition of invasion and downregulation of CXCR4, EGFR and MMP2. Lastly, the expression levels of TRAIL decreased in both serum and placenta of preeclamptic pregnancies and correlated with the disease severity. Discussion TRAIL regulated miR-146a-CXCR/EGFR axis to promote the invasion of trophoblast like cells. Its deceased levels in preeclamptic sera and placenta, suggest that low levels of TRAIL might contribute to the pathogenesis of preeclampsia.