FTY720에 의한 LLC-PK1 세포내 sphingoid bases의 축적

Endogenous Sphingoid Bases Accumulation by FTY720 in LLC-PK1 Cells

FIY720, a novel immunosuppressant, elevated the level of endogenous sphingoid bases in a dose-dependent manner within 3 hr in LLC-PK1 cells. The relative molar ratio of sphingolipid bases expressed as sphingosine/sphinganine (SPN/SPA), a biomarker of altered sphingolipid biosynthesis, in 10mcM of FTY720 showed tow-fold increase as compared with the one in control culture. FTY720 under the serum-free medium condition increased only cytosolic free sphingosine concentration, not sphinganine concentration m a time-dependent manner over the 8hr incubation under the same condition as in serum free cultures, the SPN/SPA ratio began to fluctuate and the number of floating cells as an indicator of cytotoxicity was increased 8hr after the addition of FTY720 to cultured cells. These results suggest that the process of FTY720-induced cell death in LLC-PK1 cells.