Figure 5.

Effects of siRNA directed to S1P receptors on HUVEC stimulated with COA-Cl or S1P. The results of immunoblot (IB) analyses using lysates derived from HUVEC treated with COA-Cl or S1P that had been transfected with siRNA directed to S1P receptor subtypes are shown. (A) HUVEC transfected with siRNA specific for S1P₁ or control oligonucleotides were treated with COA-Cl (100 μmol/L, upper half) for the times indicated, followed by IB analyses for phosphorylated and total forms of ERK1/2. (B) Transfection was performed using siRNA specific for S1P₃. (C and D) Cells were treated with S1P (100 nmol/L) instead of COA-Cl (n = 4) for each subset. *P < 0.05 versus vehicle alone. †P < 0.05 versus control siRNA.