Inhibition of NAD⁺-dependent histone deacetylases (sirtuins) causes growth arrest and activates both apoptosis and autophagy in the pathogenic protozoan Trypanosoma cruzi

Abstract

Chagas disease, which is caused by the parasite Trypanosoma cruzi, affects approximately 7-8 million people in Latin America. The drugs available to treat this disease are ineffective against chronic phase disease and are associated with toxic side effects. Therefore, the development of new compounds that can kill T. cruzi at low concentrations is critically important. Herein, we report the effects of a novel 3-arylideneindolin-2-one that inhibits sirtuins, which are highly conserved proteins that are involved in a variety of physiological processes. The compound KH-TFMDI was tested against the epimastigote, trypomastigote and amastigote forms of T. cruzi, and its effects were evaluated using flow cytometry, light and electron microscopy. KH-TFMDI inhibited the replication of T. cruzi intracellular amastigotes with an IC50 of 0.5 ± 0.2 μM, which is significantly lower than the IC50 of benznidazole. The compound also lysed the highly infectious bloodstream trypomastigotes (BST) with LC50 values of 0.8 ± 0.3 μM at 4 °C and 2.5 ± 1.1 μM at 37 °C. KH-TFMDI inhibited cytokinesis and induced several morphological changes in the parasite, leading to its death by apoptosis and autophagy. This study highlights sirtuins as a potential new target for Chagas disease therapy.

Characterization of Trypanosoma cruzi Sirtuins as Possible Drug Targets for Chagas Disease

“…This pronounced effect might be due to the low expression levels of endogenous protein in metacyclic trypomastigote and amastigote forms of the parasite in which the overexpression of a mutated version of the protein acted as a dominant negative in these forms, perhaps by competing with protein substrates and cofactors, such as NAD ϩ . The key role of sirtuins in the regulation of vital cellular processes in T. cruzi supports their use as targets for drug development, as proposed recently (23,(59)(60)(61). Here, we used salermide, a specific sirtuin inhibitor that had been tested for treatment of some kinds of cancers in vitro and in vivo, with high efficacy (39).…”

“…T. cruzi has only two genes coding for sirtuins, TcSir2rp1 and TcSir2rp3, and very little is known about their function in the parasite. As new drugs are required for the treatment of these parasitic diseases, and the effect of sirtuin inhibitors has not been extensively exploited for Chagas disease treatment (23), we decided to characterize T. cruzi sirtuins and test a new compound, called salermide, which was found to be very effective in the treatment of some cancers in vitro and in vivo. We initially found that sirtuin inhibitors affected T. cruzi growth and differentiation.…”

Effects of a novel β–lapachone derivative on Trypanosoma cruzi : Parasite death involving apoptosis, autophagy and necrosis

“…Nevertheless it may furnish significant insights for the infection chemotherapy, as β-lapachone was reported to produce similar alterations in T. cruzi epimastigotes, amastigotes and trypomastigotes (Docampo et al., 1978), the developmental forms that multiply within mammalian host cells and spread via blood, respectively. In addition, different antiparasitic compounds may display similar effects upon epimastigotes and trypomastigotes and/or amastigotes, the developmental forms (Urbina et al., 1988, Urbina et al., 1993; Moreira et al., 2013a; Costa et al., 2011, Azeredo et al., 2014, Díaz et al., 2014; Jimenez et al., 2014; Veiga-Santos et al., 2014, Britta et al., 2015, Meira et al., 2015, Volpato et al., 2015, Beer et al., 2016) and the epimastigotes may therefore comprise and/or take part in experimental models (Kessler et al., 2013, Benítez et al., 2014, Sangenito et al., 2014, Wong-Baeza et al., 2015, Khare et al., 2015, Pessoa et al., 2016, Valera Vera et al., 2016). Thus, numerous studies perform screening experiments with epimastigotes and/or trypomastigotes further approach the selected active compounds in intracellular amastigotes (e.g.…”

Inducible suicide vector systems for Trypanosoma cruzi

“…After 48 h induction with TMP-lactate the majority of amastigotes expressing these fusion proteins stained positive, indicating that apoptosis-like cell death in amastigotes occurred with the expression of all these proteins. It has been reported that T. cruzi could undergo apoptosis-like cell death [37,38]. However, the pathways leading to apoptosis-like cell death in this organism require further explorations.…”