Role of Trypanosoma cruzi peroxiredoxins in mitochondrial bioenergetics

Abstract

Trypanosoma cruzi cytosolic (TcCPx) and mitochondrial tryparedoxin peroxidase (TcMPx) play a fundamental role in H(2)O(2) detoxification. Herein, mitochondrial bioenergetics was evaluated in cells that overexpressed TcCPx (CPx) and TcMPx (MPx) and in pTEX. In MPx, a higher expression was observed for TcCPx, and the same correlation was true for CPx. Differences in H(2)O(2) release among the overexpressing cells were detected when the mitochondrial respiratory chain was inhibited using antimycin A or thenoyltrifluoroacetone. MPx had higher O(2) consumption rates than pTEX and CPx, especially in the presence of oligomycin. In all of the cells, the mitochondrial membrane potential and the ATP levels were similar. Because of the mild uncoupling that was observed in MPx, the presence or induction of a proton transporter in the mitochondrial membrane is suggested when TcMPx is expressed at higher levels. Our results show a possible interplay between the cytosolic and mitochondrial antioxidant systems in a trypanosomatid.

Golgi UDP-GlcNAc:Polypeptide O -α- N -Acetyl- d -Glucosaminyltransferase 2 (TcOGNT2) Regulates Trypomastigote Production and Function in Trypanosoma cruzi

“…1C). These values are comparable to those from other studies using pTEX or pTEX-derived vectors to overexpress proteins in the cytosol (78,79), mitochondria (80), glycosomes (81), endosomal/lysosomal system and reservosomes (75,82), ER (68), flagellar pocket (83), or plasma membrane (69,(84)(85)(86) of T. cruzi. The protein was stable, with no indication of a C-terminal proteolytic cleavage event observed when expressed in L. tarentolae (21), and it appeared to be inserted into the rER and N-glycosylated normally (Fig.…”

“…Although it is difficult to exclude the possibility that the 7-fold overexpression of a single protein, such as TcOGNT2, inhibits metacyclogenesis by a nonspecific stress effect, it is notable that proliferation and TCT production were not affected ( Fig. 8 and 9) and that overexpression of other proteins failed to inhibit this process (58,68,69,(78)(79)(80)(81)(82)(84)(85)(86). The protein burden of 7-fold accumulation of a single enzyme is not anticipated to be great, and indeed, overexpression of a truncated N-terminal fragment of the TcOGNT2 homolog TbOGNT2 in Trypanosoma brucei did not affect Golgi replication (93).…”

Oxidative Stress and DNA Lesions: The Role of 8-Oxoguanine Lesions in Trypanosoma cruzi Cell Viability

“…The protein extracts (30 µg) were separated and electroblotted onto a nitrocellulose membrane using the Trans-Blot SD Semi-Dry Electrophoretic Transfer Cell (Bio-Rad, CA, USA). The membranes were blocked by incubation with 5% instant nonfat dried milk in PBS 0.05% Tween 20 (PBS-T) for 1 h, washed and incubated in the presence of polyclonal antibodies raised against T. cruzi TcMPx (1∶2000) and TcCPx (1∶2500) for 2 h. After three 15 min washes with PBS-T, the membranes were incubated with HRP-linked anti-rabbit IgG (Cell Signaling Technology, MA, USA, 1∶5000 dilution) for 1 h at room temperature and washed three times with PBS [22], [37]. Bands were revealed using the Super Signal Detection Kit (Thermo Scientific, Pierce, IL, USA).…”

Redox Balance Keepers and Possible Cell Functions Managed by Redox Homeostasis in Trypanosoma cruzi

“…cytotoxic oxidants (Piacenza et al, 2008;Arias et al, 2013;Martínez et al, 2019). The expression levels of cTXNPx as well as of mTXNPx are increased in infective and intracellular stages of the parasite (Zago et al, 2016); these two enzymes work in concert to control the cytosolic and mitochondrial oxidative stress (De Figueiredo Peloso et al, 2011), and are extensively studied for the design of anti-parasite therapies. Lastly, annotation of the parasite genome has revealed that T. cruzi lacks catalase, glutathione reductase, thioredoxin reductase, and selenium-dependent glutathione peroxidases (El-Sayed et al, 2005).…”