Selective Involvement of Superoxide Anion, but Not Downstream Compounds Hydrogen Peroxide and Peroxynitrite, in Tumor Necrosis Factor-α-induced Apoptosis of Rat Mesangial Cells

• Published in: The Journal of biological chemistry Vol. 275; no. 17; pp. 12684 - 12691
• Main Authors: Moreno-Manzano, Victoria, Ishikawa, Yoshihisa, Lucio-Cazana, Javier, Kitamura, Masanori
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 28.04.2000
• Subjects: Animals; Apoptosis; Blotting, Northern; Cells, Cultured; Dose-Response Relationship, Drug; Glomerular Mesangium - pathology; Humans; hydrogen peroxide; Hydrogen Peroxide - metabolism; Male; Microscopy, Fluorescence; NF-kappa B - metabolism; Nitrates - metabolism; peroxynitrite; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species - metabolism; Signal Transduction; Superoxides - metabolism; Transfection; tumor necrosis factor-^a; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.275.17.12684

Tumor necrosis factor-α (TNF-α) induces reactive oxygen species (ROS) that serve as second messengers for intracellular signaling. Currently, precise roles of individual ROS in the actions of TNF-α remain to be elucidated. In this report, we investigated the roles of superoxide anion (O⨪2), hydrogen peroxide (H2O2), and peroxynitrite (ONOO−) in TNF-α-triggered apoptosis of mesangial cells. Mesangial cells stimulated by TNF-α produced O⨪2 and underwent apoptosis. The apoptosis was inhibited by transfection with manganese superoxide dismutase or treatment with a pharmacological scavenger of O⨪2, Tiron. In contrast, although exogenous H2O2 induced apoptosis, TNF-α-triggered apoptosis was not affected either by transfection with catalase cDNA or by treatment with catalase protein or glutathione ethyl ester. Similarly, although ONOO− precursor SIN-1 induced apoptosis, treatment with a scavenger of ONOO−, uric acid, or an inhibitor of nitric oxide synthesis,NG-nitro-l-argininemethyl ester hydrochloride, did not affect the TNF-α-triggered apoptosis. Like TNF-α-induced apoptosis, treatment with a O⨪2-releasing agent, pyrogallol, induced typical apoptosis even in the concurrent presence of scavengers for H2O2 and ONOO−. These results suggested that, in mesangial cells, TNF-α induces apoptosis through selective ROS. O⨪2, but not H2O2 or ONOO−, was identified as the crucial mediator for the TNF-α-initiated, apoptotic pathway.