Glycosomal bromodomain factor 1 from Trypanosoma cruzi enhances trypomastigote cell infection and intracellular amastigote growth

2015 ◽  
Vol 473 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Carla Ritagliati ◽  
Gabriela Vanina Villanova ◽  
Victoria Lucia Alonso ◽  
Aline Araujo Zuma ◽  
Pamela Cribb ◽  
...  

We characterized bromodomain factor 1 from Trypanosoma cruzi (TcBDF1), a developmentally regulated protein that localizes in the glycosomes of epimastigotes. The overexpression of wild-type TcBDF1 is detrimental for epimastigotes, but favours trypomastigote infection, whereas mutant TcBDF1 diminishes the infectivity rate.

2004 ◽  
Vol 72 (7) ◽  
pp. 4081-4089 ◽  
Author(s):  
Kara L. Cummings ◽  
Rick L. Tarleton

ABSTRACT Immune control of many intracellular pathogens, including Trypanosoma cruzi, is reported to be dependent on the production of nitric oxide. In this study, we show that mice deficient in inducible nitric oxide synthase (iNOS or NOS2) exhibit resistance to T. cruzi infection that is comparable to that of wild-type mice. This is the case for two iNOS-deficient mouse strains, Nos2tm1Lau and Nos2 N5, infected with the Brazil or Tulahuen strain of T. cruzi. In all cases, blood parasitemia, tissue parasite load, and survival rates are similar between wild-type and iNOS-deficient mice. In contrast, both wild-type and Nos2tm1Lau mice died within 32 days postinfection when treated with the nitric oxide synthase inhibitor aminoguanidine. Increased transcription of NOS1 or NOS3 is not found in iNOS-knockout (KO) mice, indicating that the absence of nitric oxide production through iNOS is not compensated for by increased production of other NOS isoforms. However, Nos2tm1Lau mice exhibit enhanced expression of tumor necrosis factor alpha, interleukin-1, and macrophage inflammatory protein 1α compared to that of wild-type mice, and these alterations may in part compensate for the lack of iNOS. These results clearly show that iNOS is not required for control of T. cruzi infection in mice.


2019 ◽  
Author(s):  
Lucia Fargnoli ◽  
Esteban A. Panozzo-Zénere ◽  
Lucas Pagura ◽  
María Julia Barisón ◽  
Julia A. Cricco ◽  
...  

L-Proline is an important amino acid for the pathogenic protists belonging to <i>Trypanosoma</i> and <i>Leishmania </i>genera. In <i>Trypanosoma cruzi</i>, the etiological agent of Chagas disease, this amino acid is involved in fundamental biological processes such as ATP production, differentiation of the insect and intracellular stages, the host cell infection and the resistance to a variety of stresses, including nutritional and osmotic as well as oxidative imbalance. In this study, we explore the L-Proline uptake as a chemotherapeutic target for <i>T. cruzi</i>. For this, we propose a novel rational to design inhibitors containing this amino acid as a recognizable motif. This rational consists of conjugating the amino acid (proline in this case) to a linker and a variable region able to block the transporter. We obtained a series of sixteen 1,2,3-triazolyl-proline derivatives through alkylation and copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry) for <i>in vitro</i> screening against <i>T. cruzi </i>epimastigotes, trypanocidal activity and proline uptake. We successfully obtained inhibitors that are able to interfere with the amino acid uptake, which validated the first example of a rationally designed chemotherapeutic agent targeting a metabolite's transport. Additionally, we designed and prepared fluorescent analogues of the inhibitors that were successfully taken up by <i>T. cruzi</i>, allowing following up their intracellular fate. In conclusion, we successfully designed and produced a series of metabolite uptake inhibitors. This is one of few examples of rationally designed amino acid transporter inhibitor, being the first case where the strategy is applied on the development of chemotherapy against Chagas disease. This unprecedented development is remarkable having in mind that only a small percent of the metabolite transporters has been studied at the structural and/or molecular level.


2021 ◽  
Author(s):  
Jean A. Bernatchez ◽  
Yun-Seo Kil ◽  
Elany Barbosa da Silva ◽  
Diane Thomas ◽  
Laura-Isobel McCall ◽  
...  

Safe and effective treatments for Chagas disease, a potentially fatal parasitic infection associated with cardiac and gastrointestinal pathology and caused by the kinetoplastid parasite Trypanosoma cruzi, have yet to be developed. Benznidazole and nifurtimox, which are currently the only available drugs against T. cruzi, are associated with severe adverse effects and questionable efficacy in the late stage of the disease. Natural products have proven to be a rich source of new chemotypes for other infectious agents. We utilized a microscopy-based high-throughput phenotypic screen to identify inhibitors of T. cruzi from a library of natural product samples obtained from fungi procured through a Citizen Science Soil Collection Program (https://whatsinyourbackyard.org/), and the Great Lakes (USA) benthic environment. We identified five leucinostatins (A, B, F, NPDG C and NPDG D) as potent inhibitors of the intracellular amastigote form of T. cruzi. Leucinostatin B also showed in vivo efficacy in a mouse model of Chagas disease. Given prior reports that leucinostatins A and B have antiparasitic activity against the related kinetoplastid T. brucei, our findings suggest a potential cross-trypanocidal compound class and provide a platform for further chemical derivatization of a potent chemical scaffold against T. cruzi.


2020 ◽  
Vol 114 (7) ◽  
pp. 492-498 ◽  
Author(s):  
Gabriele Sass ◽  
Laura C Miller Conrad ◽  
Terrence-Thang H Nguyen ◽  
David A Stevens

Abstract Background Bacteria are sources of numerous molecules used in treatment of infectious diseases. We investigated effects of molecules produced by 26 Pseudomonas aeruginosa strains against infection of mammalian cell cultures with Trypanosoma cruzi, the aetiological agent of Chagas disease. Methods Vero cells were infected with T. cruzi in the presence of wild-type P. aeruginosa supernatants or supernatants of mutants with defects in the production of various virulence, quorum sensing and iron acquisition factors. Quantification of T. cruzi infection (percentage of infected cells) and multiplication (number of amastigotes per infected cell) was performed and cell viability was determined. Results Wild-type P. aeruginosa products negatively affected T. cruzi infection and multiplication in a dose-dependent manner, without evident toxicity for mammalian cells. PvdD/pchE mutation (loss of the P. aeruginosa siderophores pyoverdine and pyochelin) had the greatest impact on anti–T. cruzi activity. Negative effects on T. cruzi infection by pure pyochelin, but not pyoverdine, or other P. aeruginosa exoproducts studied, were quantitatively similar to the effects of benznidazole, the current standard therapy against T. cruzi. Conclusions The P. aeruginosa product pyochelin showed promising activity against T. cruzi and might become a new lead molecule for therapy development.


2015 ◽  
Vol 59 (8) ◽  
pp. 4669-4679 ◽  
Author(s):  
Nilmar Silvio Moretti ◽  
Leonardo da Silva Augusto ◽  
Tatiana Mordente Clemente ◽  
Raysa Paes Pinto Antunes ◽  
Nobuko Yoshida ◽  
...  

ABSTRACTAcetylation 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 ofTrypanosoma 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 byT. cruziat concentrations that did not affect host cell viability. In addition,in vivoinfection was partially controlled upon administration of salermide. There are two sirtuins inT. 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 inEscherichia coliwith a 50% inhibitory concentration (IC50) ± standard error of 1 ± 0.5 μM. We concluded that sirtuin inhibitors targeting TcSir2rp3 could be used in Chagas disease chemotherapy.


2006 ◽  
Vol 26 (18) ◽  
pp. 6762-6771 ◽  
Author(s):  
Martha L. Peterson ◽  
Gina L. Bingham ◽  
Clarissa Cowan

ABSTRACT The secretory-specific poly(A) signal (μs) of the immunoglobulin μ gene plays a central role in regulating alternative RNA processing to produce RNAs that encode membrane-associated and secreted immunoglobulins. This poly(A) signal is in direct competition with a splice reaction, and regulation requires that these two reaction efficiencies be balanced. The μs poly(A) signal has several unique sequence features that may contribute to its strength and regulation. Site-directed mutations and small internal deletions made in the intact μ gene show that an extensive AU/A-rich sequence surrounding AAUAAA enhances signal use and that, of the two potential downstream GU-rich elements, both of which appear suboptimally located, only the proximal GU-rich sequence contributes substantially to use of this signal. A GU-rich sequence placed at a more standard location did not improve μs poly(A) signal use. All μ genes tested that contained modified μs poly(A) signals were developmentally regulated, indicating that the GU-rich sequences, the sequences between them previously identified as suboptimal U1A binding sites, and an upstream suboptimal U1A site do not contribute to μ mRNA processing regulation. Expression of wild-type and modified μ genes in HeLa cells overexpressing U1A also failed to demonstrate that U1A contributes to μs poly(A) signal regulation.


2000 ◽  
Vol 20 (22) ◽  
pp. 8390-8396 ◽  
Author(s):  
Michael Ku ◽  
Kimberly Mayer ◽  
James D. Forney

ABSTRACT The micronuclear DNA of Paramecium tetraurelia is estimated to contain over 50,000 short DNA elements that are precisely removed during the formation of the transcriptionally active macronucleus. Each internal eliminated sequence (IES) is bounded by 5′-TA-3′ dinucleotide repeats, a feature common to some classes of DNA transposons. We have developed an in vivo assay to analyze these highly efficient and precise DNA excision events. The microinjection of a cloned IES into mating cells results in accurately spliced products, and the transformed cells maintain the injected DNA as extrachromosomal molecules. A series of deletions flanking one side of a 28-bp IES were constructed and analyzed with the in vivo assay. Whereas 72 bp of DNA flanking the eliminated region is sufficient for excision, lengths of 31 and 18 bp result in reduced excision and removal of all wild-type sequences adjacent to the TA results in complete failure of excision. In contrast, nucleotide mutations within the middle of the 28-bp IES do not prevent excision. The results are consistent with a functional role for perfect inverted repeats flanking the IES.


2020 ◽  
Vol 11 ◽  
Author(s):  
Jorge A. Arias-del-Angel ◽  
Rebeca G. Manning-Cela ◽  
Moisés Santillán

1987 ◽  
Vol 7 (6) ◽  
pp. 2231-2242 ◽  
Author(s):  
J E Rudolph ◽  
M Kimble ◽  
H D Hoyle ◽  
M A Subler ◽  
E C Raff

The genomic DNA sequence and deduced amino acid sequence are presented for three Drosophila melanogaster beta-tubulins: a developmentally regulated isoform beta 3-tubulin, the wild-type testis-specific isoform beta 2-tubulin, and an ethyl methanesulfonate-induced assembly-defective mutation of the testis isoform, B2t8. The testis-specific beta 2-tubulin is highly homologous to the major vertebrate beta-tubulins, but beta 3-tubulin is considerably diverged. Comparison of the amino acid sequences of the two Drosophila isoforms to those of other beta-tubulins indicates that these two proteins are representative of an ancient sequence divergence event which at least preceded the split between lines leading to vertebrates and invertebrates. The intron/exon structures of the genes for beta 2- and beta 3-tubulin are not the same. The structure of the gene for the variant beta 3-tubulin isoform, but not that of the testis-specific beta 2-tubulin gene, is similar to that of vertebrate beta-tubulins. The mutation B2t8 in the gene for the testis-specific beta 2-tubulin defines a single amino acid residue required for normal assembly function of beta-tubulin. The sequence of the B2t8 gene is identical to that of the wild-type gene except for a single nucleotide change resulting in the substitution of lysine for glutamic acid at residue 288. This position falls at the junction between two major structural domains of the beta-tubulin molecule. Although this hinge region is relatively variable in sequence among different beta-tubulins, the residue corresponding to glu 288 of Drosophila beta 2-tubulin is highly conserved as an acidic amino acid not only in all other beta-tubulins but in alpha-tubulins as well.


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