Hydrogen Peroxide Produced Inside Mitochondria Takes Part in Cell-to-Cell Transmission of Apoptotic Signal

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O. Yu. Pletjushkina¹, E. K. Fetisova¹, K. G. Lyamzaev¹, O. Yu. Ivanova¹, L. V. Domnina¹, M. Yu. Vyssokikh¹, A. V. Pustovidko¹, A. V. Alexeevski¹, D. A. Alexeevski¹, J. M. Vasiliev¹, M. P. Murphy², B. V. Chernyak^1*, and V. P. Skulachev¹

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (7-495) 939-0338; E-mail: bchernyak@yahoo.com; skulach@belozersky.msu.ru

²MRC-Dunn Human Nutrition Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK

^* To whom correspondence should be addressed.

Received July 26, 2005; Revision received October 10, 2005

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In monolayer of HeLa cells treated with tumor necrosis factor (TNF), apoptotic cells formed clusters indicating possible transmission of apoptotic signal via the culture media. To investigate this phenomenon, a simple method of enabling two cell cultures to interact has been employed. Two coverslips were placed side by side in a Petri dish, one coverslip covered with apoptogen-treated cells (the inducer) and another with non-treated cells (the recipient). TNF, staurosporine, or H₂O₂ treatment of the inducer cells is shown to initiate apoptosis on the recipient coverslip. This effect is increased by a catalase inhibitor aminotriazole and is arrested by addition of catalase or by pre-treatment of either the inducer or the recipient cells with nanomolar concentrations of mitochondria-targeted cationic antioxidant MitoQ (10-(6´-ubiquinolyl)decyltriphenylphosphonium), which specifically arrests H₂O₂-induced apoptosis. The action of MitoQ is abolished by an uncoupler preventing accumulation of MitoQ in mitochondria. It is concluded that reactive oxygen species (ROS) produced by mitochondria in the apoptotic cells initiate the release of H₂O₂ from these cells. The H₂O₂ released is employed as a long-distance cell suicide messenger. In processing of such a signal by the recipient cells, mitochondrial ROS production is also involved. It is suggested that the described phenomenon may be involved in expansion of the apoptotic region around a damaged part of the tissue during heart attack or stroke as well as in “organoptosis”, i.e. disappearance of organs during ontogenesis.

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KEY WORDS: mitochondria, H₂O₂, transmission of apoptotic signal, MitoQ, TNF, staurosporine

DOI: 10.1134/S0006297906010093

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