Trypanosoma cruzi Mitochondrial Peroxiredoxin Promotes Infectivity in Macrophages and Attenuates Nifurtimox Toxicity

Abstract

Trypanosoma cruzi is the causative agent of Chagas disease which is currently treated by nifurtimox (NFX) and benznidazole (BZ). Nevertheless, the mechanism of action of NFX is not completely established. Herein, we show the protective effects of T. cruzi mitochondrial peroxiredoxin (MPX) in macrophage infections and in response to NFX toxicity. After a 3-day treatment of epimastigotes with NFX, MPX content increased (2.5-fold) with respect to control, and interestingly, an MPX-overexpressing strain was more resistant to the drug. The generation of mitochondrial reactive species and the redox status of the low molecular weight thiols of the parasite were not affected by NFX treatment indicating the absence of oxidative stress in this condition. Since MPX was shown to be protective and overexpressed in drug-challenged parasites, non-classical peroxiredoxin activity was studied. We found that recombinant MPX exhibits holdase activity independently of its redox state and that its overexpression was also observed in temperature-challenged parasites. Moreover, increased holdase activity (2-fold) together with an augmented protease activity (proteasome-related) and an enhancement in ubiquitinylated proteins was found in NFX-treated parasites. These results suggest a protective role of MPX holdase activity toward NFX toxicity. Trypanosoma cruzi has a complex life cycle, part of which involves the invasion of mammalian cells, where parasite replication inside the host occurs. In the early stages of the infection, macrophages recognize and engulf T. cruzi with the generation of reactive oxygen and nitrogen species toward the internalized parasite. Parasites overexpressing MPX produced higher macrophage infection yield compared with wild-type parasites. The relevance of peroxidase vs. holdase activity of MPX during macrophage infections was assessed using conoidin A (CA), a covalent, cell-permeable inhibitor of peroxiredoxin peroxidase activity. Covalent adducts of MPX were detected in CA-treated parasites, which proves its action in vivo. The pretreatment of parasites with CA led to a reduced infection index in macrophages revealing that the peroxidase activity of peroxiredoxin is crucial during this infection process. Our results confirm the importance of peroxidase activity during macrophage infection and provide insights for the relevance of MPX holdase activity in NFX resistance.

Overoxidation and Oligomerization of Trypanosoma cruzi Cytosolic and Mitochondrial Peroxiredoxins

“…This suggests that the reduced form of Prxs with peroxidase activity is crucial for the infection process. This is consistent with previous results where the inhibition of the peroxidase activity of T. cruzi m-TXNPx, but not its chaperone activity, reduced infection in macrophages [10].…”

“…We and others have previously shown that cytosolic and mitochondrial T. cruzi Prxs have chaperone activities [9,10]. In this study, we show that T. cruzi m-TXNPx has chaperone holdase activity, preventing protein aggregation.…”

“…Recently, we showed that recombinant c-TXNPx exists in different oligomeric forms, from decameric to high molecular mass (HMM) aggregates, and functions as a dual-function protein, acting as both a peroxidase and a molecular chaperone [9]. Chaperone activity has also been demonstrated for mitochondrial Prxs from Leishmania infantum and T. cruzi [10,11]. In L. infantum, this activity may be relevant for infection and survival in vivo, as knock-out parasites for m-TXNPx were reported to be more sensitive to temperature changes and avirulent in a murine infection model [11].…”

Structural New Data for Mitochondrial Peroxiredoxin From Trypanosoma cruzi Show High Similarity With Human Peroxiredoxin 3: Repositioning Thiostrepton as Antichagasic Drug

“…The TcMPX have received particular attention due to their role as partner of several important proteins for cellular metabolism, as well as a virulence factor by protecting T. cruzi against NF effect, macrophage-derived peroxynitrite, and avoiding redox imbalance by ROS during mitochondrial energy generation ( Piacenza et al., 2008 ; Piacenza et al., 2009 ; Peloso Ede et al., 2011 ; Piacenza et al., 2013 ; Peloso et al., 2016 ; Specker et al., 2022 ). In this study, the TcMPX from Querétaro and Ninoa Mexican T. cruzi strains were sequenced and analyzed in silico .…”

“…In addition, during T. cruzi differentiation, there is an increase of TcMPX expression in trypomastigotes (infective stage) compared with epimastigotes (non-infective stage), analyzed in several T. cruzi strains ( Piacenza et al., 2009 ). Furthermore, there is a correlation between virulence and the expression levels of these proteins, which could facilitate the establishment of the parasite in the host and resistance to drugs such as Nifurtimox (NF) ( Piñeyro et al., 2008 ; Specker et al., 2022 ). Finally, TcMPX has a role as a partner of several proteins important for cellular metabolism ( Peloso et al., 2016 ).…”