Abstract
Trypanosoma cruzi is a protozoan responsible for Chagas disease and has a complex life cycle including vertebrate (mammals) and invertebrate (insects) hosts. The parasite presents proliferative and infective forms that are challenged throughout their cycle as different sources of nutrients, pH, immune system, and levels of reactive oxygen species (ROS). Although ROS cause damage to cells and tissues when their levels are controlled, they are involved in signal transduction pathways involved in cell growth and differentiation. Curiously, the proliferation of epimastigote inside the bug insect is favored by high levels of ROS from the digestion of blood meal, and it is regulated by a cellular signaling mechanism involving heme and CaMKII. On the other hand, the differentiation of epimastigote into metacyclic trypomastigote in the rectum occurs in the reduced state. Interestingly, when the parasite infects the vertebrate, the immune system recognizes this pathogen and macrophages become activated. Thus, NADPH oxidase produces ROS that helps the parasite enter the mammalian cells, improving the infection. The parasite thrives inside the mammalian cells also involving ROS. Thus, the life cycle of Trypanosoma cruzi obeys a fine tuning of the redox state, not affecting the host cells and being helpful to the parasite.
Keywords
- redox state
- reactive oxygen species
- redox signaling
- host-parasite interaction
- iron
1. Introduction
1.1 Chagas disease
Chagas disease was described in 1909 by a Brazilian researcher, Carlos Chagas, who discovered a new trypanosomiasis in Minas Gerais, Brazil, during his work on an anti-malaria campaign [1, 2]. The disease presents three phases: acute, indeterminate, and chronic. The acute phase is asymptomatic and presents nonspecific symptoms and signs, such as inflammatory lesions at the site of entry of the parasite (chagoma) and fever. At this stage, the parasitic load in the blood is high. The indeterminate phase is characterized by the presence of antibodies against
1.2 The biological cycle of Trypanosoma cruzi
The causative agent of the disease is a flagellate protozoan that belongs to the order Kinetoplastida and family Trypanosomatidae, the
It is known that during its life cycle
1.3 Redox signaling
Cells generate ROS endogenously and constitutively when oxygen is partially reduced in mitochondria-producing oxidants, the so-called reactive oxygen species (ROS), such as superoxide radicals (O2•−) and hydrogen peroxide (H2O2) [11]. To maintain their hemostasis, cells adopt strategies called antioxidant defense. ROS participate in signal transduction pathways involved in cell growth and differentiation [12]. However, when oxidant levels are high, the oxidative/antioxidant balance within the cells disrupts the redox signaling and the redox control, which can lead to cellular damage [13, 14, 15, 16]. This exacerbation of the endogenous production of ROS is known as oxidative stress. These oxidant species can lead to lipid peroxidation, affecting membrane integrity, DNA damage, and oxidation of sugars and protein thiols [14, 15]. On the other hand, controlled ROS increase leads to a temporary imbalance that represents the physiological basis for redox regulation [16, 17]. Indeed, redox processes have fundamental implications in biology.
In addition to ROS, other reactive species have notable impacts on redox biology, including the reactive nitrogen species (RNS), such as nitric oxide, nitrogen dioxide (both free radicals), peroxynitrite, and nitrite/nitrate. Besides these, forms of cysteine, methionine, and some low-molecular-mass compounds such as glutathione and trypanothione are called reactive sulfur species (RSS). Another group of reactive species is the reactive carbonyl species (RCS) including various forms of metabolically generated aldehydes and electronically excited (triplet) carbonyls. Finally, reactive selenium species (RSeS) include low molecular mass such as selenocysteine and selenomethionine residues in proteins [17].
2. ROS and Trypanosoma cruzi
2.1 The journey inside the bug insect
2.1.1 The epimastigotes and redox environment
Evidence in the literature indicates that the interaction between
Besides heme, ROS have been shown to trigger proliferation of the epimastigote forms of
Heme and two classical oxidants, H2O2 and the well-known superoxide generator, paraquat, are able to promote the growth of epimastigotes in vitro [24]. This effect was reversed in the presence of other reductive molecules (GSH, a thiol-based antioxidant found in the hemolymph of triatomines; urate, an important antioxidant rich in the urine of these insects [25], and n-acetylcysteine (NAC), a classic antioxidant) suggesting a competition between these molecules of antagonistic redox status. An important physiological molecule present in the midgut is hemozoin, a crystal composed of heme dimers [26, 27] that
Thus, the redox environment is considered to be very important for
2.1.2 Differentiation of epimastigotes into metacyclic trypomastigotes
Still on its journey inside the vector,
When the blood meal is supplemented with antioxidants, there is a shift in the redox status of the gut compartments (anterior midgut, posterior midgut, and rectum), increasing differentiation of the parasites in an unusual midgut region and greatly favoring metacyclogenesis in the bug rectum. Notably, contrary to proliferation, the differentiation process appears to be favored by reductive environments [24].
A
As demonstrated by science, the coevolution between parasites and their insect vectors has promoted an elegant strategy for the development and maintenance of the protozoa in the invertebrate vector.
2.2 The transmission of the disease: metacyclic trypomastigotes infect the vertebrate hosts—a new journey
2.2.1 The participation of NADPH oxidase in the infection
The immune system of the higher vertebrates is able to recognize pathogens and respond through their innate immune responses. ROS is an important component of this response produced by phagocytes and can be highly toxic. Macrophages are one of the first lines of defense in mammals, especially against pathogens [30], and become activated facing such challenges.
The O2•− production after NADPH oxidase activation in macrophages is converted inside the phagosome to H2O2 (spontaneously or via superoxide dismutase), and this ROS production, termed the “oxidative burst” of activated phagocytic cells, usually kills the pathogens. In order to infect the vertebrate host,
Peroxynitrite is also highly lethal and used by phagocytes against pathogens. It is formed when nitric oxide (NO) and O2•− react with each other. Thus, the production of peroxynitrite is decreased by the inhibition of ROS or NO production [35]. Paiva and collaborators, in 2012, showed that macrophages infected with T. cruzi and activated with the burst inducer phorbol 12-myristate 13-acetate (PMA) have stimulated the parasite load [36]. In conclusion, the generation and the regulation of the ROS level can help these parasites thrive in an oxidative environment [8, 35, 36, 37].
2.2.2 Murine models of Chagas disease and ROS
After the infective metacyclic forms invade host cells, macrophages, or cardiac cells, for example, they are transformed into the replicative intracellular amastigote form [6]. In response to infection, Chagas hearts present increased mitochondrial ROS [38, 39] because during
3. Conclusion
Several groups have carried out research on the influence of the oxidative environment on the growth and differentiation of
Thus, we have followed the journey of the parasite
Funding
This work was supported by grants from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and Instituto Nacional de Ciência e Tecnologia-Entomologia Molecular (INCT-EM).
References
- 1.
Chagas C. Nova tripanossomíase humana. Estudos sobre a morfologia e o ciclo evolutivo do Schizotrypanum cruzi n. gen., n. sp., agente etiológico de nova entidade mórbida do homem. Memórias do Instituto Oswaldo Cruz. 1909;1 :159-218 - 2.
Kropf SP. Doença de Chagas, doença do Brasil: Ciência, Saúde e Nação (1909-1962). Rio de Janeiro: Editora Fiocruz; 2009 - 3.
Machado FS, Jelicks LA, Kirchhoff LV, Shirani J, Nagajyothi F, Mukherjee S, et al. Chagas heart disease: Report on recent developments. Cardiology in Review. 2012; 20 (2):53-65 - 4.
Chatelain E. Chagas disease drug discovery: Toward a new era. Journal of Biomolecular Screening. 2015; 20 :22-35 - 5.
Martins-Melo FR, Ramos AN Jr, Alencar CH, Heukelbach J. Mortality due to Chagas disease in Brazil from 1979 to 2009: Trends and regional differences. Journal of Infection in Developing Countries. 2012; 6 (11):817-824 - 6.
Rassi A, Rassi A, Marin-Neto JA. Chagas disease. The Lancet. 2010; 375 :1388-1402 - 7.
Graça-Souza AV, Maya-Monteiro C, Paiva-Silva G, Braz GRC, Paes MC, Sorgine MHF, et al. Adaptations against heme toxicity in blood-feeding arthropods. Insect Biochemistry and Molecular Biology. 2006; 36 :322-335 - 8.
Goes GR, Rocha PS, Diniz ARS, Aguiar PHN, Machado CR, Vieira LQ. Trypanosoma cruzi needs a signal provided by reactive oxygen species to infect macrophages. PLoS Neglected Tropical Diseases. 2016;10 (4):e0004555 - 9.
Piacenza L, Zago MP, Peluffo G, Alvarez MN, Basombrio MA, Radi R. Enzymes of the antioxidant network as novel determiners of Trypanosoma cruzi virulence. International Journal of Parasitology. 2009;39 :1455-1464 - 10.
Nogueira NP, Souza CF, Saraiva FM, Sultano PE, Dalmau SR, Bruno RE, et al. Heme-induced ROS in Trypanosoma cruzi activates CaMKII-like that triggers epimastigote proliferation. One helpful effect of ROS. PLoS One. 2011;6 (10):e25935 - 11.
Boveris A, Chance B. The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen. The Biochemical Journal. 1973; 134 :707-716 - 12.
Droge W. Free radicals in the physiological control of cell function. Physiological Reviews. 2002; 82 :47-95 - 13.
Jones D. Redefining oxidative stress. Antioxidants & Redox Signaling. 2006; 8 :1865-1879 - 14.
Halliwell B, Gutteridge JMC. Free Radicals in Biology and Medicine. 4th ed. Oxford: Clarendon Press; 2007 - 15.
Sies H, Jones DP. Oxidative stress. In: Encyclopedia of Stress. 2nd ed. Vol. 3. Amsterdam: Elsevier; 2007. pp. 45-48 - 16.
Jones D. Radical-free biology of oxidative stress. American Journal of Physiology. Cell Physiology. 2008; 295 :C849-C868 - 17.
Sies H, Berndt C, Jones DP. Oxidative stress. Annual Review of Biochemistry. 2017; 86 :715-748 - 18.
Garcia ES, Ratcliffe NA, Whitten MM, Gonzalez MS, Azambuja P. Exploring the role of insect host factors in the dynamics of Trypanosoma cruzi-Rhodnius prolixus interactions. Journal of Insect Physiology. 2007;53 :11-21 - 19.
Schmitt TH, Frezzatti WA, Schreier S. Hemin-induced lipid membrane disorder and increased permeability: A molecular model for the mechanism of cell lysis. Archives of Biochemistry and Biophysics. 1993; 307 :96-103 - 20.
Ryter SW, Tyrrell RM. The heme synthesis and degradation pathways: Role in oxidant sensitivity. Heme oxygenase has both pro- and antioxidant properties. Free Radical Biology & Medicine. 2000; 28 :289-309 - 21.
Finzi JK, Chiavegatto CWM, Corat KF, et al. Trypanosoma cruzi response to the oxidative stress generated by hydrogen peroxide. Molecular and Biochemical Parasitology. 2004;133 :37-43 - 22.
Lara FA, Sant’Anna C, Lemos D, Laranja GAT, Coelho MGP, et al. Heme requirement and intracellular trafficking in Trypanosoma cruzi epimastigotes. Biochemical and Biophysical Research Communications. 2007;355 :16-22 - 23.
Souza CF, Carneiro AB, Silveira AB, Laranja GAT, Silva-Neto MAC, et al. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II. Biochemical and Biophysical Research Communications. 2009;390 :541-546. DOI: 10.1016/j.bbrc.2009.09.135 - 24.
Nogueira NP, Saraiva FM, Sultano PE, Cunha PR, Laranja GA, Justo GA, et al. Proliferation and differentiation of Trypanosoma cruzi inside its vector have a new trigger: Redox status. PLoS One. 2015;10 :e0116712 - 25.
Wigglesworth VB. The physiology of excretion in a blood-sucking insect. Rhodnius prolixus. III. The mechanism of uric acid excretion. The Journal of Experimental Biology. 1931;8 :443-451 - 26.
Stiebler R, Timm BL, Oliveira PL, Hearne GR, Egan TJ, et al. On the physico-chemical and physiological requirements of hemozoin formation promoted by perimicrovillar membranes in Rhodnius prolixus midgut. Insect Biochemistry and Molecular Biology. 2010;40 :284-292. DOI: 10.1016/j.ibmb.2009.12.013 - 27.
Ferreira CM, Stiebler R, Saraiva FM, Lechuga GC, Walter-Nuno AB, Bourguignon SC, et al. Heme crystallization in a Chagas disease vector acts as a redox-protective mechanism to allow insect reproduction and parasite infection. PLoS Neglected Tropical Diseases. 2018; 12 (7):e0006661. DOI: 10.1371/journal.pntd.0006661 - 28.
Nogueira NP, Saraiva FMS, Oliveira MP, et al. Heme modulates Trypanosoma cruzi bioenergetics inducing mitochondrial ROS production. Free Radical Biology & Medicine. 2017;108 :183-191 - 29.
Augusto LS, Moretti NS, Ramos TCP, de Jesus TCL, Zhang M, Castilho BA, et al. A membrane-bound eIF2 alpha kinase located in endosomes is regulated by heme and controls differentiation and ROS levels in Trypanosoma cruzi . PLoS Pathogens. 2015;11 :1-27 - 30.
Paiva CN, Bozza MT. Are reactive oxygen species always detrimental to pathogens? Antioxidants & Redox Signaling. 2014; 20 :1000-1037 - 31.
Kierszenbaum F, Knecht E, Budzko DB, Pizzimenti MC. Phagocytosis: A defense mechanism against infection with Trypanosoma cruzi . Journal of Immunology. 1974;112 :1839-1844 - 32.
Atwood JA, Weatherly DB, Minning TA, Bundy B, Cavola C, Opperdoes FR, et al. The Trypanosoma cruzi proteome. Science. 2005;309 :473-476 - 33.
Freire ACG, Alves CL, Goes GR, Resende BC, Moretti NS, Nunes VS, et al. Catalase expression impairs oxidative stress-mediated signaling in Trypanosoma cruzi . Parasitology. 2017;144 (11):1498-1510. DOI: 10.1017/S0031182017001044 - 34.
Melo RC, Fabrino DL, D’Avila H, Teixeira HC, Ferreira AP. Production of hydrogen peroxide by peripheral blood monocytes and specific macrophages during experimental infection with Trypanosoma cruzi in vivo . Cell Biology International. 2003;27 :853-861 - 35.
Alvarez MN, Peluffo G, Piacenza L, Radi R. Intraphagosomal peroxynitrite as a macrophage-derived cytotoxin against internalized Trypanosoma cruzi : Consequences for oxidative killing and role of microbial peroxiredoxins in infectivity. The Journal of Biological Chemistry. 2011;286 :6627-6640. DOI: 10.1074/jbc.M110.167247 - 36.
Paiva CN et al. Oxidative stress fuels Trypanosoma cruzi infection in mice. The Journal of Clinical Investigation. 2012;122 (7):2531-2542 - 37.
Andrews NW. Oxidative stress and intracellular infections: More iron to the fire. Journal of Clinical Investigation. 2012; 122 (7):2352-2354. DOI: 10.1172/JCI64239 - 38.
Wen JJ, Garg NJ. Manganese superoxide dismutase deficiency exacerbates the mitochondrial ROS production and oxidative damage in Chagas disease. PLoS Neglected Tropical Diseases. 2018; 12 (7):e0006687. DOI: 10.1371/journal.pntd.0006687 - 39.
Wen J-J, Garg NJ. Mitochondrial complex III defects contribute to inefficient respiration and ATP synthesis in the myocardium of Trypanosoma cruzi -infected mice. Antioxidants & Redox Signaling. 2010;12 :27, 10.1089/ARS.2008.2418-37 - 40.
Wen JJ, Garg NJ. Mitochondrial generation of reactive oxygen species is enhanced at the Q(o) site of the complex III in the myocardium of Trypanosoma cruzi -infected mice: Beneficial effects of an antioxidant. Journal of Bioenergetics and Biomembranes. 2008;40 :587-598. DOI: 10.1007/s10863-008-9184-4 - 41.
Machado-Silva A, Cerqueira PG, Grazielle-Silva V, Gadelha FR, Peloso EF, Teixeira SMR, et al. How Trypanosoma cruzi deals with oxidative stress: Antioxidant defence and DNA repair pathways. Mutation Research. 2016;767 :8-22 - 42.
Paiva CN, Medei E, Bozza MT. ROS and Trypanosoma cruzi : Fuel to infection, poison to the heart. PLoS Pathogens. 2018;14 (4):e1006928. DOI: 10.1371/journal.ppat.1006928 - 43.
Dias PP, Capila RF, do Couto NF, Estrada D, Gadelha FR, Radi R, et al. Cardiomyocyte oxidants production may signal to T. cruzi intracellular development. PLoS Neglected Tropical Diseases. 2017;11 (8):e0005852. DOI: 10.1371/journal.pntd.0005852 - 44.
Dhiman M, Garg NJ. P47phox−/− mice are compromised in expansion and activation of CD8+ T cells and susceptible to Trypanosoma cruzi infection. PLoS Pathogens. 2014;10 (12):e1004516. DOI: 10.1371/journal.ppat.1004516 - 45.
Gupta S, Bhatia V, Wen JJ, Wu W, Huang MH, Garg NJ. Trypanosoma cruzi infection disturbs mitochondrial membrane potential and ROS production rate in cardiomyocytes. Free Radical Biology & Medicine. 2009;47 (10):1414-1421. DOI: 10.1016/j.freeradbiomed.2009.08.008