PT  - JOURNAL ARTICLE
AU  - Amit Roy
AU  - Agneyo Ganguly
AU  - Somdeb BoseDasgupta
AU  - Benu Brata Das
AU  - Churala Pal
AU  - Parasuraman Jaisankar
AU  - Hemanta K. Majumder
TI  - Mitochondria-Dependent Reactive Oxygen Species-Mediated Programmed Cell Death Induced by 3,3′-Diindolylmethane through Inhibition of F0F1-ATP Synthase in Unicellular Protozoan Parasite <em>Leishmania donovani</em>
AID  - 10.1124/mol.108.050161
DP  - 2008 Nov 01
TA  - Molecular Pharmacology
PG  - 1292--1307
VI  - 74
IP  - 5
4099  - http://molpharm.aspetjournals.org/content/74/5/1292.short
4100  - http://molpharm.aspetjournals.org/content/74/5/1292.full
SO  - Mol Pharmacol2008 Nov 01; 74
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