title: Nitric oxide induces apoptosis via hydrogen peroxide, but necrosis via energy and thiol depletion.
abstract: We investigated the mechanisms by which two nitric oxide (NO) donors, diethylenetriamine/NO adduct (DETA/NO) and S-nitrosoglutathione (GSNO), induced cell death in a J774 macrophage cell line. Both NO donors induced caspase activation within 6 h, but only DETA/NO-induced caspase activation was sensitive to inhibition of p38 and was completely prevented by antioxidants catalase, ascorbate, dehydroascorbate, or N-acetylcysteine, suggesting that DETA/NO-induced apoptosis may be mediated by H(2)O(2). Consistent with this, DETA/NO acutely stimulated reactive oxygen species (ROS) production by mitochondria and cells, and inhibited catalase-mediated H(2)O(2) breakdown in cells. After prolonged, 24 h exposure of cells to DETA/NO, inactivation of caspases occurred, which was accompanied by an increase in necrosis. DETA/NO-induced necrosis was insensitive to caspase inhibitors, but was partially prevented by catalase or N-acetylcysteine, and was preceded by inhibition of glyceraldehyde-3-phosphate dehydrogenase and a decrease in cellular adenosine triphosphate (ATP). GSNO was even more potent in inhibiting glycolysis and switching apoptosis to necrosis. In cells depleted of glutathione, GSNO and DETA/NO induced rapid necrosis, which resulted from rapid depletion of ATP due to inhibition of glycolysis. Glycolytic intermediate 3-phosphoglycerate decreased DETA/NO-induced necrosis and increased apoptosis. We conclude that: (i). NO-induced apoptosis is mediated by H(2)O(2); (ii). NO-induced necrosis is mediated by energy failure speeded by thiol depletion.
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, UK.
authors.forename: Vilmante
authors.initials: V
authors.lastname: Borutaite
authors.forename: Guy C
authors.initials: GC
authors.lastname: Brown
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis; D020169:Caspases; D016923:Cell Death; D002460:Cell Line; D004789:Enzyme Activation; D005978:Glutathione / Q000378:metabolism; D006019:Glycolysis; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009336:Necrosis; D009569:Nitric Oxide / Q000378:metabolism; D011073:Polyamines / Q000494:pharmacology; D017382:Reactive Oxygen Species; D026422:S-Nitrosoglutathione / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000975:Antioxidants; D011073:Polyamines; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; C005391:diethylenetriamine; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020169:Caspases; D005978:Glutathione; D000111:Acetylcysteine