Exp Mol Med.  2004 Oct;36(5):420-427.

Sphingosine mediates FTY720-induced apoptosis in LLC-PK1 cells

• Lee WJ
• Yoo HS
• Suh PG
• Lim JS
• Oh S
• Lee YM

Abstract

FTY720, a synthetic sphingoid base analog, was examined as a new sphingosine kinase inhibitor, which converts endogenous sphingosine into its phosphate form. With 20 micrometer of FTY720, sphingosine accumulated in the LLC-PK1 cells in a time- and dose-dependent manner. The FTY720 treated cells showed a high concentration of fragmented DNA, a high caspase-3 like activity and TUNEL staining cells. It was also found that the sphingosine and sphinganine level increased in a time- and dose-dependent manner within 12 h after the FTY720 treatment. The sphingosine kinase activity was reduced by FTY720 as much as other sphingosine kinase inhibitors, N, N-dimethylsphingosine (DMS), dl-threo-dihydrosphingosine (DHS). The fragmented DNA content as a result of the 20 micrometer of FTY720 treatment and by 5 micrometer of the exogenously added BSA-sphingosine complex indicated typical apoptosis. Under similar conditions, the accumulated sphingosine concentration in all the cells was almost identical even though the sphingosine distribution inside the cells was somewhat different. These results indicate that the FTY720 induced apoptosis is associated with the inhibition of the sphingosine kinase activity and is strongly associated with the successive accumulation of sphingosine.

Keyword

apoptosis; FTY720; LLC-PK1 cells; sphingosine; sphingosine kinase

MeSH Terms

Animals
Apoptosis/*physiology
Caspases/biosynthesis
Cell Line
DNA Fragmentation
Endothelial Cells/drug effects
Enzyme Inhibitors/*pharmacology
Kidney/cytology
Phosphotransferases (Alcohol Group Acceptor)/*antagonists & inhibitors/physiology
Propylene Glycols/*pharmacology
Research Support, Non-U.S. Gov't
Sphingosine/pharmacology/*physiology
Swine
Up-Regulation