Effect of FTY720 on apoptosis of smooth muscle cells

BACKGROUND: Hyperproliferation of smooth muscle cells (SMCs) plays a key role in allograft arteriosclerosis. This prompted us to investigate the effect of the novel immune modulator and synthetic sphingolipid FTY720 on apoptosis of SMCs. METHODS: Rabbit SMC cultures were treated with FTY720 and apoptosis and necrosis were detected by fluorescence microscopy. RESULTS: We investigated dose- and time-dependent effects of FTY720 and found that clinically relevant low doses of FTY720 (<1 micromol/L) did not induce apoptosis, whereas 10 micromol/L FTY720 induced apoptosis after 48 hours incubation. CONCLUSION: At doses of FTY720 used in clinics for treatment of renal allografts and multiple sclerosis. FTY720 did not induce SMC apoptosis.