Trophoblast Cell Line Maintenance and Manipulation

Human trophoblast cell line HTR8/SVneo was maintained as described^{25 (link)}. Additional human trophoblast cell line Sw.71 was kindly provided by Dr. Gil Mor (Yale University), and maintained as described previously^{29 (link)}. In siRNA experiments, cells were transfected with the siRNAs (ThermoFisher) shown in Online Supplemental Materials and Methods using siPORT Amine transfection reagent as previously described^{24 (link)}. Control siRNA was purchased from GE Dharmacon (ON-TARGETplus Non-targeting Control siRNA). For reconstitution experiments, cells were first transfected with siRNA targeting endogenous ApoER2, and subsequently the cells were transfected with adenoviral particles (10¹⁰ particles/ml) encoding ApoER2 constructs^{24 (link)}. Twenty-four hours after adenoviral transfection, experiments were performed. Pharmacological inhibition studies were performed using HIF1α inhibitor (1μM, GN44028, TOCRIS), MMP14 inhibitor (10nM, NSC405020, Sigma-Aldrich), or p38 inhibitor SB 202190 (10 μM, Selleckchem) in the presence of NHIgG or aPL (100 μg/ml).