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

Abstract

c Acetylation of lysine is a major posttranslational modification of proteins and is catalyzed by lysine acetyltransferases, while lysine deacetylases remove acetyl groups. Among the deacetylases, the sirtuins are NAD ؉ -dependent enzymes, which modulate gene silencing, DNA damage repair, and several metabolic processes. As sirtuin-specific inhibitors have been proposed as drugs for inhibiting the proliferation of tumor cells, in this study, we investigated the role of these inhibitors in the growth and differentiation of Trypanosoma cruzi, the agent of Chagas disease. We found that the use of salermide during parasite infection prevented growth and initial multiplication after mammalian cell invasion by T. cruzi at concentrations that did not affect host cell viability. In addition, in vivo infection was partially controlled upon administration of salermide. There are two sirtuins in T. cruzi, TcSir2rp1 and TcSir2rp3. By using specific antibodies and cell lines overexpressing the tagged versions of these enzymes, we found that TcSir2rp1 is localized in the cytosol and TcSir2rp3 in the mitochondrion. TcSir2rp1 overexpression acts to impair parasite growth and differentiation, whereas the wild-type version of TcSir2rp3 and not an enzyme mutated in the active site improves both. The effects observed with TcSir2rp3 were fully reverted by adding salermide, which inhibited TcSir2rp3 expressed in Escherichia coli with a 50% inhibitory concentration (IC 50 ) ؎ standard error of 1 ؎ 0.5 M. We concluded that sirtuin inhibitors targeting TcSir2rp3 could be used in Chagas disease chemotherapy.

Chemogenetic Characterization of Inositol Phosphate Metabolic Pathway Reveals Druggable Enzymes for Targeting Kinetoplastid Parasites

“…In addition, IPMK inhibition was also lethal for intracellular T. cruzi amastigotes, demonstrating the potential value of this drug target in T. cruzi. This extends the short list of validated targets for drug development in T. cruzi , which includes cytochrome b, cruzain, sirtuins and sterol 14α-demethylase (Doyle, et al, 2010; Khare, et al, 2015; McGrath, et al, 1995; Moretti, et al, 2015). Some IPMK inhibitors are also effective against P. falciparum , suggesting that these inhibitors may be broadly used to develop new antiparasitic drugs.…”

Comparative effects of histone deacetylases inhibitors and resveratrol on Trypanosoma cruzi replication, differentiation, infectivity and gene expression

“…Resveratrol can stimulate yeast Sir2 and its mammalian ortholog Sirt1 (Howitz et al., 2003) but can also affect other targets that might be contributing to the effects observed (Valera Vera et al., 2016, Harikumar and Aggarwal, 2008). Moreover, the effect of resveratrol described in this study can be only partially compared with the effects observed in parasites over-expressing sirtuins (Ritagliati et al., 2015, Moretti et al., 2015), further supporting the notion that targets other than sirtuins might be also responsible for its trypanocidal action. Resveratrol is a natural occurring phytoalexin found in the skin of red grapes, originally reported as a potential anticancer agent (Jang et al., 1997, Boocock et al., 2007).…”

“…HDAC1 and 3 are essential for viability, while HDAC4 is required for normal cell cycle progression (Ingram and Horn, 2002). Coding sequences for HDACs have also been found in T. cruzi (El-Sayed et al., 2005), but only sirtuins deacetylases have been recently characterized (Ritagliati et al., 2015, Moretti et al., 2015). …”

Molecular characterization and protective efficacy of silent information regulator 2A from Eimeria tenella

“…Trypanosoma cruzi (Tc) has two sirtuins, TcSir2rp1 and TcSir2rp3. TcSir2rp1 was shown to be highly expressed in replicative parasite forms (epimastigotes and amastigotes) and less in metacyclic trypomastigotes and trypomastigotes derived from infected mammalian cells, while TcSir2rp3 was largely expressed in epimastigotes and cell-derived trypomastigotes, and much less in intracellular amastigotes and metacyclic trypomastigotes [37]. …”