Poly(ADP-ribose) synthetase activation mediates mitochondrial injury during oxidant-induced cell death

László Virág, Andrew L. Salzman, Csaba Szabó

    Research output: Contribution to journalArticlepeer-review

    234 Scopus citations


    Reactive oxidant species are important mediators of tissue injury in shock, inflammation, and reperfusion injury. The actions of a number of these oxidants (e.g., hydroxyl radical and peroxynitrite, a reactive oxidant produced by the reaction of nitric oxide and superoxide) are mediated in part by the activation of the nuclear nick sensor enzyme, poly(ADP)-ribose synthetase (PARS), with consequent cellular energy depletion. Here we investigated whether PARS activation contributes to the mitochondrial alterations in cells exposed to oxidants. Authentic peroxynitrite (20 μM), the peroxynitrite-generating compound 3-morpholinosid-nonimine, the combination of pyrogallol and S-nitroso-N-acetyl-D,L-penicillamine, as well as hydrogen peroxide induced a time-and dose-dependent decrease in mitochondrial transmembrane potential (ΔΩ(m)) in thymocytes, as determined by flow cytometry using the mitochondrial potential sensitive dyes DiOC6(3) and JC-1. A time- and dose-dependent increase in secondary reactive oxygen intermediate production and loss of cardiolipin, an indicator of mitochondrial membrane damage, were also observed, as measured by flow cytometry using the fluorescent dyes dihydroethidine and nonyl-acridine orange, respectively. Inhibition of PARS by 3-aminobenzamide or 5-iodo-6- amino-1,2-benzopyrone attenuated peroxynitrite-induced ΔΩ(m) reduction, secondary reactive oxygen intermediate generation, cardiolipin degradation, and intracellular calcium mobilization. Furthermore, thymocytes from PARS- deficient animals were protected against the peroxynitrite- and hydrogen peroxide-induced functional and ultrastructural mitochondrial alterations. In conclusion, mitochondrial perturbations during oxidant-mediated cytotoxicity are, to a significant degree, related to PARS activation rather than to direct effects of the oxidants on the mitochondria.

    Original languageEnglish (US)
    Pages (from-to)3753-3759
    Number of pages7
    JournalJournal of Immunology
    Issue number7
    StatePublished - Oct 1 1998

    ASJC Scopus subject areas

    • Immunology and Allergy
    • Immunology


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