Benznidazole-resistance in Trypanosoma cruzi: Evidence that distinct mechanisms can act in concert

Campos, Mónica; Leon, Leonor L.; Taylor, Martin C.; Kelly, John M.

doi:10.1016/j.molbiopara.2014.01.002

Cited by 88 publications

(60 citation statements)

References 16 publications

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“…T. cruzi strains show great discrepancy in susceptibility to chemotherapy, being resistance detected on wild-type strains or after prolonged treatment (11)(12)(13). Resistance to benznidazole in T. cruzi is multifactorial and results from mechanisms involving prodrug activation, defenses against free radicals and drug efflux (14).…”

Section: Introductionmentioning

confidence: 99%

Thiol efflux mediated by an ABCC-like transporter participates forTrypanosoma cruziadaptation to environmental and chemotherapeutic stresses

Costa

et al. 2020

Preprint

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The protozoan Trypanosoma cruzi is the etiologic agent for Chagas disease, which affects 6-7 million people worldwide. The parasite presents high biological diversity, reflecting on the inefficiency of benznidazole in chronic or older patients. ABC superfamily proteins contain active transporters involved in the xenobiotic and endobiotic efflux and overexpressed in MDR cells. An ABCC-like transport was identified in the T. cruzi Y strain, being able to extrude thiol-conjugated compounds. As non-protein thiols represent prime line of defense towards reactive species, ABCC-like activity could participate in the regulation of mediators implicated in responses to cellular stress arising from a variety of stimuli, as environmental or chemotherapeutic. This study shows that T. cruzi ABCC-like protein transports GSH, GSSG and ceramides, all implicated in cellular stress. Hemin, representative from the hematophagous feeding of the vector, was transported as well, suggesting a role for ABCC as a metal-thiol transporter. In addition, all strains evaluated showed ABCC-like activity, while no ABCB1-like activity was detected. Also, results suggest that ABCC-like does not associate to natural resistance to benznidazole, considering that the sensitive strains CL Brener and Berenice showed higher ABCC-like activity than the resistant strains Y and Colombiana. Instead, ABCC-like efflux increased after continuous exposure of Y strain to benznidazole. Moreover, ABCC does not perform direct efflux of drug and its participation in the machinery of protection against stress depends on the efflux of metabolites in conjugation to or in cotransport with thiol.

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Section: Introductionmentioning

confidence: 99%

Thiol efflux mediated by an ABCC-like transporter participates forTrypanosoma cruziadaptation to environmental and chemotherapeutic stresses

Costa

et al. 2020

Preprint

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“…12 In addition, both drugs require long treatment schedules (60 d for benznidazole and 90 d for nifurtimox), making treatment logistically difficult, and increasing the risk for drug resistance. 5,11,[13][14][15][16] These drugs also have the potential to cause anemia in pregnant mothers and insufficient weight gain in their children. 16 A recent multicenter randomized study of benznidazole on patients with chronic Chagas cardiomyopathy showed a significant reduction in the number of circulating parasites, but there was no reduction in the progression of cardiac symptoms over a 5 y period, indicating that drug alone is ineffective against disease progression during the chronic stage of disease.…”

Section: Introductionmentioning

confidence: 99%

Cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease

Seid

Jones

Pollet

et al. 2016

Human Vaccines & Immunotherapeutics

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A therapeutic vaccine for human Chagas disease is under development by the Sabin Vaccine Institute Product Development Partnership. The aim of the vaccine is to significantly reduce the parasite burden of Trypanosoma cruzi in humans, either as a standalone product or in combination with conventional chemotherapy. Vaccination of mice with Tc24 formulated with monophosphoryl-lipid A (MPLA) adjuvant results in a Th1 skewed immune response with elevated IgG2a and IFNg levels and a statistically significant decrease in parasitemia following T. cruzi challenge. Tc24 was therefore selected for scale-up and further evaluation. During scale up and downstream process development, significant protein aggregation was observed due to intermolecular disulfide bond formation. To prevent protein aggregation, cysteine codons were replaced with serine codons which resulted in the production of a non-aggregated and soluble recombinant protein, Tc24-C4. No changes to the secondary structure of the modified molecule were detected by circular dichroism. Immunization of mice with wild-type Tc24 or Tc24-C4, formulated with E6020 (TLR4 agonist analog to MPLA) emulsified in a squalene-oil-in-water emulsion, resulted in IgG2a and antigen specific IFNg production levels from splenocytes that were not significantly different, indicating that eliminating putative intermolecular disulfide bonds had no significant impact on the immunogenicity of the molecule. In addition, vaccination with either formulated wild type Tc24 or Tc24-C4 antigen also significantly increased survival and reduced cardiac parasite burden in mice. Investigations are now underway to examine the efficacy of Tc24-C4 formulated with other adjuvants to reduce parasite burden and increase survival in pre-clinical studies.

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“…Although the mechanism of action of these nitroheterocyclic compounds is not clearly understood, it is known that, to exert their trypanocidal effects, they need to be activated through the reduction of their nitro group (5). Several studies have proposed that an NADH-dependent trypanosomal type I nitroreductase (NTR I) is a key enzyme which catalyzes Bz and Nx activation in vivo (6,7,8,9). However, evidence indicates that although Bz is reduced to its anion radical, redox cycling may not be relevant for its mode of action, as is the case with Nx (8,10,11,12,13).…”

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confidence: 99%

Putative Role of the Aldo-Keto Reductase from Trypanosoma cruzi in Benznidazole Metabolism

Garavaglia

Laverrière

Cannata

et al. 2016

Antimicrob Agents Chemother

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b Benznidazole (Bz), the drug used for treatment of Chagas' disease (caused by the protozoan Trypanosoma cruzi), is activated by a parasitic NADH-dependent type I nitroreductase (NTR I). However, several studies have shown that other enzymes are involved. The aim of this study was to evaluate whether the aldo-keto reductase from T. cruzi (TcAKR), a NADPH-dependent oxido-reductase previously described by our group, uses Bz as the substrate. We demonstrated that both recombinant and native TcAKR enzymes reduce Bz by using NADPH, but not NADH, as a cofactor. TcAKR-overexpressing epimastigotes showed higher NADPH-dependent Bz reductase activity and a 50% inhibitory concentration (IC 50 ) value for Bz 1.8-fold higher than that of the controls, suggesting that TcAKR is involved in Bz detoxification instead of activation. To understand the role of TcAKR in Bz metabolism, we studied TcAKR expression and NADPH/NADH-dependent Bz reductase activities in two T. cruzi strains with differential susceptibility to Bz: CL Brener and Nicaragua. Taking into account the results obtained with TcAKR-overexpressing epimastigotes, we expected the more resistant strain, Nicaragua, to have higher TcAKR levels than CL Brener. However, the results were the opposite. CL Brener showed 2-fold higher TcAKR expression and 5.7-fold higher NADPH-Bz reduction than the Nicaragua strain. In addition, NADH-dependent Bz reductase activity, characteristic of NTR I, was also higher in CL Brener than in Nicaragua. We conclude that although TcAKR uses Bz as the substrate, TcAKR activity is not a determinant of Bz resistance in wild-type strains and may be overcome by other enzymes involved in Bz activation, such as NADPH-and NADH-dependent reductases.C hagas' disease, caused by the protozoan Trypanosoma cruzi, affects 11 million people in Latin America (1). The parasite is usually transmitted to humans and other mammals by triatomine bugs. However, transmission can also be oral (through contaminated food), congenital, or transfusional or by organ transplantation, even in countries where the disease is not endemic (2). The course of infection includes an acute phase followed by an indeterminate phase without symptoms, which lasts throughout life in most infected people. Approximately 30% of patients can develop a chronic phase characterized by cardiac and/or digestive pathologies that can lead to death (3).Benznidazole (Bz) and, to a lesser extent, nifurtimox (Nx) are the drugs currently used for treatment of T. cruzi infection (4). Although the mechanism of action of these nitroheterocyclic compounds is not clearly understood, it is known that, to exert their trypanocidal effects, they need to be activated through the reduction of their nitro group (5). Several studies have proposed that an NADH-dependent trypanosomal type I nitroreductase (NTR I) is a key enzyme which catalyzes Bz and Nx activation in vivo (6,7,8,9). However, evidence indicates that although Bz is reduced to its anion radical, redox cycling may not be relevant for its mode of action, as ...

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Benznidazole-resistance in Trypanosoma cruzi: Evidence that distinct mechanisms can act in concert

Abstract: Graphical abstractClones isolated from a single benznidazole-resistant Trypanosoma cruzi population contain a stop-codon-generating mutation in the nitroreductase gene TcNTR. Clonal variation in resistance suggests that additional mechanisms must also operate.

Cited by 88 publications

References 16 publications

Thiol efflux mediated by an ABCC-like transporter participates forTrypanosoma cruziadaptation to environmental and chemotherapeutic stresses

Thiol efflux mediated by an ABCC-like transporter participates forTrypanosoma cruziadaptation to environmental and chemotherapeutic stresses

Cysteine mutagenesis improves the production without abrogating antigenicity of a recombinant protein vaccine candidate for human chagas disease

Putative Role of the Aldo-Keto Reductase from Trypanosoma cruzi in Benznidazole Metabolism

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