Release of the cytosolic tryparedoxin peroxidase into the incubation medium and a different profile of cytosolic and mitochondrial peroxiredoxin expression in H2O2-treated Trypanosoma cruzi tissue culture-derived trypomastigotes

Trypanosoma cruzi antioxidant enzymes are among the factors that guarantee parasite survival and maintain infection, enabling T. cruzi to cope with oxidative stress. Herein, the expression of cytosolic (TcCPx) and mitochondrial (TcMPx) typaredoxin peroxidases was evaluated in tissue culture-derived trypomastigotes upon incubation with different concentrations of H2O2. TcCPx expression slightly increased (5.4%) in cells submitted to 10 mu M H2O2 treatment when compared to the control, but decreased when higher H2O2 concentrations (20-50 mu M) were employed. Under these conditions, TcMPx expression increased (similar to 53%) with 10 mu M-treatment compared to the control, followed by a reduction that reached similar to 46% of the control when using the highest concentration tested. Interestingly, in the supernatant of the incubations, TcCPx, but not TcMPx, was detected, and its levels increased concomitantly with its decreased expression in the intracellular compartment. Our data show that peroxiredoxins in the tissue culture-derived trypomastigote can be modulated under oxidative stress and are present in higher amounts when compared to the epimastigote stage of T. cruzi. Additionally, due to the different expression patterns observed upon H2O2-treatment, each peroxiredoxin may play a distinct role in protecting the parasite under oxidative stress conditions. (c) 2012 Elsevier Inc. All rights reserved.