Mitochondrial behavior during nuclear and mitochondrial DNA repair in Trypanosoma cruzi epimastigotes

Different genotoxic agents can lead to DNA single- and double-strand breaks, base modification and oxidation. As most living organisms, Trypanosoma cruzi is subjected to oxidative stress during its life cycle; thus, DNA repair is essential for parasite survival and establishment of infection. The mitochondrion plays important roles beyond the production of ATP. For example, it is a source of signaling molecules, such as the superoxide anion and H2O2. Since T. cruzi has only one mitochondrion, the integrity of this organelle is pivotal for parasite viability. H2O2 and methyl methanesulfonate cause DNA lesions in T. cruzi that are repaired by different DNA repair pathways. Herein, we evaluate mitochondrial involvement during the repair of nuclear and mitochondrial DNA in T. cruzi epimastigotes incubated with these two genotoxic agents under conditions that induce repairable DNA damage. Overall, in both treatments, an increase in oxygen consumption rates and in mitochondrial H2O2 release was observed, as well as maintenance of ATP levels compared to control. Interestingly, these changes coincided with DNA repair kinetics, suggesting the importance of the mitochondrion for this energy-consuming process. (AU)