title: Cellular defense against singlet oxygen-induced oxidative damage by cytosolic NADP+-dependent isocitrate dehydrogenase.
abstract: Singlet oxygen (1O2) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. Recently, we have shown that NADP+-dependent isocitrate dehydrogenase is involved in the supply of NADPH needed for GSH production against cellular oxidative damage. In this study, we investigated the role of cytosolic form of NADP+-dependent isocitrate dehydrogenase (IDPc) against singlet oxygen-induced cytotoxicity by comparing the relative degree of cellular responses in three different NIH3T3 cells with stable transfection with the cDNA for mouse IDPc in sense and antisense orientations, where IDPc activities were 2.3-fold higher and 39% lower, respectively, than that in the parental cells carrying the vector alone. Upon exposure to singlet oxygen generated from photoactivated dye, the cells with low levels of IDPc became more sensitive to cell killing. Lipid peroxidation, protein oxidation, oxidative DNA damage and intracellular peroxide generation were higher in the cell-line expressing the lower level of IDPc. However, the cells with the highly over-expressed IDPc exhibited enhanced resistance against singlet oxygen, compared to the control cells. The data indicate that IDPc plays an important role in cellular defense against singlet oxygen-induced oxidative injury.
authors.affiliation: Department of Biochemistry, College of Natural Sciences, Kyungpook National University, Taegu, South Korea.
authors.forename: Sun Yee
authors.initials: SY
authors.lastname: Kim
authors.forename: Jeen-Woo
authors.initials: JW
authors.lastname: Park
mesh_terms: D016475:3T3 Cells; D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D002244:Carbon / Q000737:chemistry; D002460:Cell Line; D002461:Cell Line, Transformed; D002474:Cell-Free System; D003600:Cytosol / Q000378:metabolism*; D004249:DNA Damage; D018076:DNA, Complementary / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000494:pharmacology; D005822:Genetic Vectors; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007521:Isocitrate Dehydrogenase / Q000737:chemistry* / Q000378:metabolism; D015227:Lipid Peroxidation; D008751:Methylene Blue / Q000494:pharmacology; D051379:Mice; D008856:Microscopy, Fluorescence; D009249:NADP / Q000378:metabolism*; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism*; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D011506:Proteins / Q000737:chemistry; D011725:Pyridines / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012395:Rose Bengal / Q000494:pharmacology; D026082:Singlet Oxygen; D014162:Transfection; D020298:U937 Cells
chemical_list: D018076:DNA, Complementary; D005456:Fluorescent Dyes; D011506:Proteins; D011725:Pyridines; D017382:Reactive Oxygen Species; C062804:4,4-dicarboxy-5-(pyridoxyl-5'-phosphate)proline; D026082:Singlet Oxygen; D012395:Rose Bengal; D009249:NADP; D002244:Carbon; D000080242:8-Hydroxy-2'-Deoxyguanosine; D011392:Proline; D007521:Isocitrate Dehydrogenase; D003849:Deoxyguanosine; D005978:Glutathione; D010100:Oxygen; D008751:Methylene Blue