Production of reactive oxygen species in mitochondria of HeLa cells under oxidative stress

• Published in: Biochimica et biophysica acta Vol. 1757; no. 5; pp. 525 - 534
• Main Authors: Chernyak, Boris V., Izyumov, Denis S., Lyamzaev, Konstantin G., Pashkovskaya, Alina A., Pletjushkina, Olga Y., Antonenko, Yuri N., Sakharov, Dmitrii V., Wirtz, Karel W.A., Skulachev, Vladimir P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-05-2006
• Subjects: Antioxidants - pharmacology; Cell Death; Cell Respiration; Darkness; Gramicidin - metabolism; HeLa Cells; Humans; Hydrogen Peroxide - pharmacology; Light; Lipid Bilayers - chemistry; Methacrylates - pharmacology; Mitochondria; Mitochondria - drug effects; Mitochondria - physiology; Mitochondria - radiation effects; Onium Compounds - pharmacology; Organophosphorus Compounds - pharmacology; Oxidative Stress; Photo dynamic treatment; Photochemotherapy; Photosensitizing Agents - pharmacology; Reactive oxygen species; Reactive Oxygen Species - metabolism; Rotenone - pharmacology; Singlet Oxygen - metabolism; Superoxides - metabolism; Thiazoles - pharmacology; Ubiquinone - analogs & derivatives; Ubiquinone - pharmacology; Oxidative stress; PDT; Reactive oxygen species; BLM; MR; zVADfmk; FCCP; DPhPC; PTP; CM-DCF-DA; CsA; Mitochondria; TMRM; MitoQ; ROS; DPhPG; DPI; Photo dynamic treatment; AlPcS 4
• ISSN: 0005-2728; 0006-3002; 1879-2650
• DOI: 10.1016/j.bbabio.2006.02.019

Mitochondria can be a source of reactive oxygen species (ROS) and a target of oxidative damage during oxidative stress. In this connection, the effect of photodynamic treatment (PDT) with Mitotracker Red (MR) as a mitochondria-targeted photosensitizer has been studied in HeLa cells. It is shown that MR produces both singlet oxygen and superoxide anion upon photoactivation and causes photoinactivation of gramicidin channels in a model system (planar lipid bilayer). Mitochondria-targeted antioxidant (MitoQ) inhibits this effect. In living cells, MR-mediated PDT initiates a delayed (“dark”) accumulation of ROS, which is accelerated by inhibitors of the respiratory chain (piericidin, rotenone and myxothiazol) and inhibited by MitoQ and diphenyleneiodonium (an inhibitor of flavin enzymes), indicating that flavin of Complex I is involved in the ROS production. PDT causes necrosis that is prevented by MitoQ. Treatment of the cell with hydrogen peroxide causes accumulation of ROS, and the effects of inhibitors and MitoQ are similar to that described for the PDT model. Apoptosis caused by H
2O
2 is augmented by the inhibitors of respiration and suppressed by MitoQ. It is concluded that the initial segments of the respiratory chain can be an important source of ROS, which are targeted to mitochondria, determining the fate of the cell subjected to oxidative stress.