FIGURE 2.

DH-S1P, phyto-S1P, and C₁₇-S1P are released from hSPNS2-expressing cells. CHO/SPHK1 (mock) or CHO/SPHK1/hSPNS2 (SPNS2) cells were grown for 2 days and incubated with the releasing medium containing DH-Sph, phyto-Sph, or C₁₇-Sph at 5 μm for 2 h. The cells (A) and releasing medium (B) were collected, and sphingolipid contents were measured by HPLC. C₁₇-S1P was used as the internal standard for measuring DH-S1P and phyto-S1P, whereas phyto-S1P was used as the internal standard for measuring C₁₇-S1P. Experiments were performed more than three times, and error bars indicate the S.D.