Ang-1 inhibition of EC permeability is independent of the S1P receptor. (A) HUVECs were transfected with control siRNA, siRNA against S1P1 or against S1P3. Seventy-two hours after transfection, cells were untreated (Nil), treated with Ang-1 for 30 minutes (Ang-1), or treated with S1P at 1 μM for 15 minutes (S-1-P) and permeability measured. Permeability is given as the FITC-dextran passage in 30 minutes. The pooled data from 3 experiments are shown (*P < .01 vs untreated cells). NS indicates no significant difference versus untreated cells. (B) HUVECs were untreated (Nil), treated with Ang-1 (Ang-1) 0.2 μg/mL for 30 minutes, S1P (S1P) 1 μM for 15 minutes, JET-013 (JET) 1μM, and VPC 23 019 (VPC) 10 μM for 30 minutes (JET + VPC), or pretreated with JET-013 and VPC 23 019 for 30 minutes then treated with Ang-1 (J + V + Ang) or S1P (J + V + S1P). Permeability is given as the FITC-dextran passage in 30 minutes. Pooled data from 3 experiments are shown (*P < .01 vs untreated cells). All data are mean plus or minus SEM. NS indicates no significant difference versus untreated cells.
