Trypanosoma cruzi Intracellular Amastigotes Isolated by Nitrogen Decompression Are Capable of Endocytosis and Cargo Storage in Reservosomes

Cebrián

International Journal for Parasitology: Drugs and Drug Resistan

et al. 2019

Chagas disease caused by the protozoan parasite Trypanosoma cruzi represents a significant public health problem in Latin America, affecting around 8 million cases worldwide. Nowadays is urgent the identification of new antichagasic agents as the only therapeutic options available, Nifurtimox and Benznidazole, are in use for >40 years, and present high toxicity, limited efficacy and frequent treatment failures in the chronic phase of the disease. Recently, it has been described the antiparasitic effect of AS-48, a bacteriocin produced by Enterococcus faecalis , against Trypanosoma brucei and Leishmania spp. In this work, we have demonstrated the in vitro potential of the AS-48 bacteriocin against T. cruzi . Interesting, AS-48 was more effective against the three morphological forms of different T. cruzi strains, and displayed lower cytotoxicity than the reference drug Benznidazole. In addition, AS-48 combines the criteria established as a potential antichagasic agent, resulting in a promising therapeutic alternative. According to the action mechanism, AS-48 trypanocidal activity could be explained in a mitochondrion-dependent manner through a reactive oxygen species production and mitochondrial depolarization, causing a fast and severe bioenergetic collapse.

Section: Resultsmentioning

confidence: 94%

Insights into Chagas treatment based on the potential of bacteriocin AS-48

Cebrián

International Journal for Parasitology: Drugs and Drug Resistan

et al. 2019

“…In addition, cells with a low expression of PS1 had diminished lysosomal acidification due to a dysfunction in glycosylation and the targeting of the v-ATPase VOa1 subunit [60]. reservosomes [67]. As amastigotes and epimastigotes are replicative forms, it would be expected that they would have a larger demand for molecules to sustain proliferation [68].…”

Section: Discussionmentioning

confidence: 99%

Trypanosoma Cruzi Presenilin-like Transmembrane Aspartyl Protease: Characterization and Cellular Localization

Lechuga

Napoleão-Pêgo

Bottino

et al. 2020

Preprint

The increasing detection of infections of Trypanosoma cruzi, the etiological agent of Chagas disease, in non-endemic regions beyond Latin America has risen to be a major public health issue. With an impact in the millions of people, current treatments rely on antiquated drugs that produce severe side effects and are considered nearly ineffective for the chronic phase. The minimal progress in the development of new drugs highlights the need for advances in basic research on crucial biochemical pathways in T. cruzi to identify new targets. Here, we report on the T. cruzi presenilin-like transmembrane aspartyl enzyme, a protease of the aspartic class in a unique phylogenetic subgroup with T. vivax separate from protozoans. Computational analyses suggests it contains 9 transmembrane domains and an active site with the characteristic PALP motif of the A22 family. Multiple linear B-cell epitopes were identified by SPOT synthesis analysis with Chagasic patient sera. Two were chosen to generate rabbit antisera, whose signal was primarily localized to the flagellar pocket, intracellular vesicles and endoplasmic reticulum in parasites by whole cell immunofluorescence. The results suggest that the parasitic presenilin-like enzyme could have a role in the secretory pathway and serve as a biomarker for infections.

“…After 24 and 48 h of treatment, the infected host cells were lysed by nitrogen decompression [35] and the number of released amastigotes was counted in a Neubauer chamber. Population density was then compared to the untreated control (medium with 0.125% DMSO).…”

Section: Methodsmentioning

confidence: 99%

“…To calculate the IC 50 value for intracellular amastigotes, 24-h-old infected Vero cell cultures (10 6 cells/mL) were incubated with 2-BP (0.4 to 125 μM) in biological triplicates in a humidified 5% CO 2 atmosphere. After 24 and 48 h of treatment, the infected host cells were lysed by nitrogen decompression [ 35 ] and the number of released amastigotes was counted in a Neubauer chamber. Population density was then compared to the untreated control (medium with 0.125% DMSO).…”

Section: Methodsmentioning

confidence: 99%

Treatment of Trypanosoma cruzi with 2-bromopalmitate alters morphology, endocytosis, differentiation and infectivity

et al. 2018

Self Cite

BackgroundThe palmitate analogue 2-bromopalmitate (2-BP) is a non-selective membrane tethered cysteine alkylator of many membrane-associated enzymes that in the last years emerged as a general inhibitor of protein S-palmitoylation. Palmitoylation is a post-translational protein modification that adds palmitic acid to a cysteine residue through a thioester linkage, promoting membrane localization, protein stability, regulation of enzymatic activity, and the epigenetic regulation of gene expression. Little is known on such important process in the pathogenic protozoan Trypanosoma cruzi, the etiological agent of Chagas disease.ResultsThe effect of 2-BP was analyzed on different developmental forms of Trypanosoma cruzi. The IC50/48 h value for culture epimastigotes was estimated as 130 μM. The IC50/24 h value for metacyclic trypomastigotes was 216 nM, while for intracellular amastigotes it was 242 μM and for cell derived trypomasigotes was 262 μM (IC50/24 h). Our data showed that 2-BP altered T. cruzi: 1) morphology, as assessed by bright field, scanning and transmission electron microscopy; 2) mitochondrial membrane potential, as shown by flow cytometry after incubation with rhodamine-123; 3) endocytosis, as seen after incubation with transferrin or albumin and analysis by flow cytometry/fluorescence microscopy; 4) in vitro metacyclogenesis; and 5) infectivity, as shown by host cell infection assays. On the other hand, lipid stress by incubation with palmitate did not alter epimastigote growth, metacyclic trypomastigotes viability or trypomastigote infectivity.ConclusionOur results indicate that 2-BP inhibits key cellular processes of T. cruzi that may be regulated by palmitoylation of vital proteins and suggest a metacyclic trypomastigote unique target dependency during the parasite development.Electronic supplementary materialThe online version of this article (10.1186/s12860-018-0170-3) contains supplementary material, which is available to authorized users.