Phosphorylated FTY720 (FTY720-p)-mediated protection of cisplatin-induced injury in TKPTS cells. Incubation of TKPTS cells with cisplatin increased expression of BAX and translocation from the cytoplasm (monomeric form) to mitochondria (polymerized form); these changes were prevented by FTY720-p pretreatment. Immunofluorescent labeling of actin cytoskeleton (FITC-phalloidin; Actin, green), apoptotic marker (Bcl-2-associated X protein; BAX, white), and mitochondria (MitoTracker Red; Mito, red) in TKPTS cells treated with vehicle or cisplatin (20 μM for 24 hr) with or without prior incubation (1 hr) with FTY720-p (10 nM). Blue, nuclei stained with DAPI. Overlay of red Mitotracker and white BAX appears pink in merged images. Arrows, cells with increased BAX immunoreactivity. Scale bar=10 μm. Images are from a representative experiment that was performed at least three times with n=2-3 replicates of each treatment. Mark Okusa, University of Virginia Medicine, Charlottesville, Virginia