Figure 4. Effects of S1P receptor modulators on uptake of FITC-labeled dextran and PI3K activity.

XS52 cells were incubated with FITC-labeled dextran in the presence or absence of S1P (5 µM), FTY720-P (1 µM), VPC24191 (10 µM), and SEW2871 (1 µM) for 15 min. Fluorescence intensity of cells was analyzed by flow cytometry and relative endocytosis was calculated. Data are expressed as the mean ± SEM of results from at least three independent experiments. **P < 0.01 indicate a statistically significant difference vs. control experiments (A). Cells were treated with similar concentrations of S1P, FTY720-P, VPC24191, and SEW2871 for 15 min followed by the detection of Akt activity (B). Values of the densitometric analysis are expressed as x-fold decrease of p-Akt formation compared to untreated cells ± SEM from three experiments. **P<0.01 indicates a statistically significant difference versus control (B).