A novel fluorescent probe with high sensitivity and selective detection of lipid hydroperoxides in cells

Spy-LHP was developed as a fluorescent probe for the detection and imaging of lipid hydroperoxides in living cells. Although Spy-LHP detection of lipid hydroperoxides is sensitive and selective, this probe is unsuitable for live-cell imaging because of its high hydrophobicity. To overcome this limitation, 2-(4-diphenylphosphanyl-phenyl)-9-(3,6,9,12-tetraoxatridecyl)-anthra2,1,9-def:6,5,10-d′e′f′diisoquinoline-1,3,8,10-tetraone, Liperfluo, was developed. Liperfluo is structurally similar to Spy-LHP, but is much more soluble in various organic solvents, such as ethanol and dimethylsulfoxide. The probe was successfully used to image lipid hydroperoxides in SH-SY5Y cells in which lipid peroxidation had been stimulated with 2,2′-azobis2-(2-imidazolin-2-yl)propane dihydrochloride or cumene hydroperoxide by using fluorescent microscopy and confocal laser scanning microscopy. Additionally, flow cytometric analysis showed that Liperfluo was four times more sensitive in detecting lipid hydroperoxides than Spy-LHP. These results suggest that Liperfluo is a useful fluorescent probe for investigating the roles of lipid peroxidation in a variety of cell pathophysiologies.