title: Reactive oxygen species participate in peroxynitrite-induced apoptosis in HL-60 cells.
abstract: Peroxynitrite (ONOO-) is a physiological product generated by the interaction of superoxide (O2.-) and nitric oxide (.NO). We have previously shown that peroxynitrite induces apoptosis in HL-60 cells. In the present study, we demonstrated that peroxynitrite generates reactive oxygen species (ROS) in HL-60 cells. Brief exposure of HL-60 cells to ONOO- induced elevation of lucigenin chemiluminescence, indicating generation of superoxide anion. Exogenous superoxide dismutase (SOD), a scavenger of O2.-, fully abolished the chemiluminescence response, further supporting this notion. Following O2.- generation, the accumulation of hydrogen peroxide (H2O2) was observed. The addition of SOD exacerbated but that of catalase attenuated peroxynitrite-induced DNA fragmentation, suggesting that this H2O2 production contributes to the apoptotic process. In addition, pre-treatment of HL-60 cells with N-acetyl-L-cysteine (15 mM), a ROS scavenger, fully scavenged peroxynitrite-elicited ROS generation and effectively inhibited (ONOO-)-induced apoptosis, further enforcing this hypothesis. In summary, our results suggest that (ONOO-)-stimulated ROS formation may serve as a mechanism for the propagation of peroxynitrite-mediated apoptotic cell death in an intact cell system.
authors.affiliation: Department of Cell Biology, School of Osteopathic Medicine, Stratford, New Jersey 08084, USA.
authors.forename: K T
authors.initials: KT
authors.lastname: Lin
authors.forename: J Y
authors.initials: JY
authors.lastname: Xue
authors.forename: F F
authors.initials: FF
authors.lastname: Sun
authors.forename: P Y
authors.initials: PY
authors.lastname: Wong
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002374:Catalase / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase; D008163:Luminescent Measurements; D009566:Nitrates / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism
chemical_list: D004273:DNA, Neoplasm; D016166:Free Radical Scavengers; D009566:Nitrates; D017382:Reactive Oxygen Species; D013481:Superoxides; C039642:peroxynitric acid; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D002374:Catalase; D013482:Superoxide Dismutase