Figure 3

DH-S1P enhances endothelial barrier in an S1P1 dependent manner. Confluent EC monolayers were grown under serum-free conditions until a minimal TEER plateau was reached. In A, EC monolayers were incubated with varying concentrations of DH-S1P [111-1000 nM]. In B, EC monolayers were incubated with varying concentrations of S1P [111-1000 nM]. In C, EC monolayers were incubated with DH-S1P [1000 nM] plus and minus the S1P1 antagonist W146 or the S1P1/S1P3 antagonist VPC23019 (each at 10 μM). In D, EC monolayers were incubated with S1P [1000 nM] plus and minus the S1P1 antagonist W146 or the S1P1/S1P3 antagonist VPC23019 (each at 10 μM). Each of the TEER tracings shown is an average from three independent experiments each with two replicates per condition. Impedance values were normalized by dividing each value by the level of impedance measured just prior to the addition of effectors. As a control for A and B, monolayers were treated with 40 μg/ml delipidated albumin (Control), a concentration corresponding to the amount of BSA carrier used for the highest concentration of DH-S1P and S1P tested. As controls for C and D, ECs were treated with delipidated albumin-containing serum free medium (SFM) plus vehicle buffer.