RT Journal Article SR Electronic T1 Mitochondria-Dependent Reactive Oxygen Species-Mediated Programmed Cell Death Induced by 3,3′-Diindolylmethane through Inhibition of F0F1-ATP Synthase in Unicellular Protozoan Parasite Leishmania donovani JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 1292 OP 1307 DO 10.1124/mol.108.050161 VO 74 IS 5 A1 Amit Roy A1 Agneyo Ganguly A1 Somdeb BoseDasgupta A1 Benu Brata Das A1 Churala Pal A1 Parasuraman Jaisankar A1 Hemanta K. Majumder YR 2008 UL http://molpharm.aspetjournals.org/content/74/5/1292.abstract AB Mitochondria are the principal site for the generation of cellular ATP by oxidative phosphorylation. F0F1-ATP synthase, a complex V of the electron transport chain, is an important constituent of mitochondria-dependent signaling pathways involved in apoptosis. In the present study, we have shown for the first time that 3,3′-diindolylmethane (DIM), a DNA topoisomerase I poison, inhibits mitochondrial F0F1-ATP synthase of Leishmania donovani and induces programmed cell death (PCD), which is a novel insight into the mechanism in protozoan parasites. DIM-induced inhibition of F0F1-ATP synthase activity causes depletion of mitochondrial ATP levels and significant stimulation of mitochondrial reactive oxygen species (ROS) production, followed by depolarization of mitochondrial membrane potential (ΔΨm). Because ΔΨm is the driving force for mitochondrial ATP synthesis, loss of ΔΨm results in depletion of cellular ATP level. The loss of ΔΨm causes the cellular ROS generation and in turn leads to the oxidative DNA lesions followed by DNA fragmentation. In contrast, loss of ΔΨm leads to release of cytochrome c into the cytosol and subsequently activates the caspase-like proteases, which lead to oligonucleosomal DNA cleavage. We have also shown that mitochondrial DNA-depleted cells are insensitive to DIM to induce PCD. Therefore, mitochondria are necessary for cytotoxicity of DIM in kinetoplastid parasites. Taken together, our study indicates for the first time that DIM-induced mitochondrial dysfunction by inhibition of F0F1-ATP synthase activity leads to PCD in Leishmania spp. parasites, which could be exploited to develop newer potential therapeutic targets. The American Society for Pharmacology and Experimental Therapeutics