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Trypanosoma cruzi

Carlos L Hoyos, Silvana P Cajal, Marisa Juarez, Jorge D Marco, Anahí M Alberti D'Amato, Melina Cayo, Irma Torrejón, Rubén O Cimino, Patricio Diosque, Alejandro J Krolewiecki, Julio R Nasser, José F Gil
Background. Endemic areas of tegumentary leishmaniasis (TL) in Salta, Argentina, present some overlap zones with the geographical distribution of Chagas disease, with mixed infection cases being often detected. Objectives. The purpose of this study was to determine the magnitude of Leishmania sp. infection and potential associated risk factors, the serologic prevalence of T. cruzi, and the presence of T. cruzi-Leishmania sp. mixed infection in a region of the northwest of Argentina. Methods. Cross-sectional studies were conducted to detect TL prevalence and T...
2016: BioMed Research International
Victor Monteon, Enrique Quen-Rámirez, Veronica Macedo-Reyes, Ruth Lopez, Karla Acosta-Viana, Pamela Pennigton, Angel Ramos-Ligonio
Under natural conditions, Trypanosoma cruzi infection is transmitted to mammals when faeces contaminated with metacyclic trypomastigotes gain access through skin lesions, mucosa or bite wounds. Natural infection of bugs with T. cruzi can vary greatly from less than 1% up to 70%, depending on triatomine species: in the case of Triatoma dimidiata, the percentage of infection is around 30%. In this work uses biological fluids (saliva and faeces) from Triatoma dimidiata to inoculate experimental animals once or multiple times, before inoculation with faeces contaminated with metacyclic trypomastigotes discrete type unit Ia (TcI)...
October 1, 2016: Annals of Parasitology
Danielle Oliveira Dos Anjos, Eliomara Sousa Sobral Alves, Vinicius Tomaz Gonçalves, Sheila Suarez Fontes, Mateus Lima Nogueira, Ana Márcia Suarez-Fontes, João Batista Neves da Costa, Fabricio Rios-Santos, Marcos André Vannier-Santos
Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T...
October 12, 2016: International Journal for Parasitology, Drugs and Drug Resistance
Hugo de Almeida, Vincent Leroux, Flávia Nader Motta, Philippe Grellier, Bernard Maigret, Jaime M Santana, Izabela Marques Dourado Bastos
We have previously demonstrated that the secreted prolyl oligopeptidase of Trypanosoma cruzi (POPTc80) is involved in the infection process by facilitating parasite migration through the extracellular matrix. We have built a 3D structural model where POPTc80 is formed by a catalytic α/β-hydrolase domain and a β-propeller domain, and in which the substrate docks at the inter-domain interface, suggesting a "jaw opening" gating access mechanism. This preliminary model was refined by molecular dynamics simulations and next used for a virtual screening campaign, whose predictions were tested by standard binding assays...
October 21, 2016: Journal of Computer-aided Molecular Design
Matías Hernández, Susana Wicz, Ricardo S Corral
BACKGROUND: Diverse cardiovascular signaling routes have been considered critical for Chagas cardiomyopathy caused by the protozoan parasite Trypanosoma cruzi. Along this line, T. cruzi infection and endothelin-1 (ET-1) have been shown to cooperatively activate the Ca(2+)/NFAT cascade in cardiomyocytes, leading to cyclooxygenase type 2 (COX-2) induction and increased release of prostanoids and prohypertrophic peptides. PURPOSE: To determine whether the well-known cardioprotective and anti-inflammatory effects of curcumin (Cur) could be helpful to interfere with this key machinery for pathogenesis of Chagas myocarditis...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Xianxiu Wan, Jian-Jun Wen, Sue-Jie Koo, Lisa Yi Liang, Nisha Jain Garg
Chronic chagasic cardiomyopathy (CCM) is presented by increased oxidative/inflammatory stress and decreased mitochondrial bioenergetics. SIRT1 senses the redox changes and integrates mitochondrial metabolism and inflammation; and SIRT1 deficiency may be a major determinant in CCM. To test this, C57BL/6 mice were infected with Trypanosoma cruzi (Tc), treated with SIRT1 agonists (resveratrol or SRT1720), and monitored during chronic phase (~150 days post-infection). Resveratrol treatment was partially beneficial in controlling the pathologic processes in Chagas disease...
October 2016: PLoS Pathogens
Camila Oliveira, Paulo Costa Carvalho, Lysangela Ronalte Alves, Samuel Goldenberg
The regulation of gene expression in trypanosomatids occurs mainly at the post-transcriptional level. Despite the importance of this type of control in Trypanosoma cruzi, few RNA binding proteins have been characterized. The RRM domain (RNA Recognition Motif) is one of the most abundant domains found in RNA-binding proteins in higher eukaryotes. Proteins containing the RRM domain are involved in the majority of post-transcriptional processes regulating gene expression. In this work, we aimed to characterize the protein TcNRBD1 from T...
2016: PloS One
Alice Ricardo-Silva, Teresa Cristina Monte Gonçalves, José Francisco Luitgards-Moura, Catarina Macedo Lopes, Silvano Pedrosa da Silva, Amanda Queiroz Bastos, Nathalia Coelho Vargas, Maria-Rosa Goreti Freitas
During a medical entomology course in Boa Vista, Roraima, colonies of Triatoma maculata closely associated with pigeon nests were observed in concrete air-conditioner box located on the external plastered and cemented walls of a modern brick-built apartment block. In only one eight-hole ceramic brick, located inside one air-conditioner box, 127 specimens of T. maculata were collected. T. maculata is a recognised vector of Trypanosoma cruzi in the surrounding area and its domiciliation increases the risk of Chagas disease transmission...
October 13, 2016: Memórias do Instituto Oswaldo Cruz
Juan Felipe Osorio-Méndez, Andrea Vizcaíno-Castillo, Rebeca Manning-Cela, Roberto Hernandez, Ana María Cevallos
The role and regulation of actin in Trypanosoma cruzi and other related parasites is largely unknown. Based on early genome analysis, it was proposed that there was a reduced dependency on the acto-myosin system in the trypanosomatid parasites. However, more recent studies have extended the set of potential actin regulatory proteins, particularly for T. cruzi. One of the identified actin-binding proteins in trypanosomatids is profilin. In other systems, it is capable of simultaneously binding both monomeric actin and several actin-regulatory factors...
October 15, 2016: Biochemical and Biophysical Research Communications
J A DE Fuentes-Vicente, M Cabrera-Bravo, J N Enríquez-Vara, M I Bucio-Torres, A E Gutiérrez-Cabrera, D G Vidal-López, J A Martínez-Ibarra, P M Salazar-Schettino, A Córdoba-Aguilar
Little is known about how the virulence of a human pathogen varies in the environment it shares with its vector. This study focused on whether the virulence of Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae), the causal agent of Chagas' disease, is related to altitude. Accordingly, Triatoma dimidiata (Hemiptera: Reduviidae) specimens were collected at three different altitudes (300, 700 and 1400 m a.s.l.) in Chiapas, Mexico. The parasite was then isolated to infect uninfected T. dimidiata from the same altitudes, as well as female CD-1 mice...
October 18, 2016: Medical and Veterinary Entomology
Zheng Liu, Cristina Gutierrez-Vargas, Jia Wei, Robert A Grassucci, Noel Espina, Susan Madison-Antenucci, Liang Tong, Joachim Frank
With the advance of new instruments and algorithms, and the accumulation of experience over decades, single-particle cryo-EM has become a pivotal part of structural biology. Recently, we determined the structure of a eukaryotic ribosome at 2.5 Å for the large subunit. The ribosome was derived from Trypanosoma cruzi, the protozoan pathogen of Chagas disease. The high-resolution density map allowed us to discern a large number of unprecedented details including rRNA modifications, water molecules, and ions such as Mg(2+) and Zn(2+) ...
October 17, 2016: Protein Science: a Publication of the Protein Society
Amanda Fortes Francisco, Shiromani Jayawardhana, Michael D Lewis, Karen L White, David M Shackleford, Gong Chen, Jessica Saunders, Maria Osuna-Cabello, Kevin D Read, Susan A Charman, Eric Chatelain, John M Kelly
The insect-transmitted protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, and infects 5-8 million people in Latin America. Chagas disease is characterised by an acute phase, which is partially resolved by the immune system, but then develops as a chronic life-long infection. There is a consensus that the front-line drugs benznidazole and nifurtimox are more effective against the acute stage in both clinical and experimental settings. However, confirmative studies have been restricted by difficulties in demonstrating sterile parasitological cure...
October 17, 2016: Scientific Reports
Jian-Jun Wen, Xianxiu Wan, John Thacker, Nisha Jain Garg
BACKGROUND: Chagasic cardiomyopathy (CCM) caused by Trypanosoma cruzi (Tc) infection is prevalent in Latin America and recognized as an emerging infectious heart disease in the US. The NO-cGMP-PKG1α pathway maintains cardiac homeostasis and inotropy and may be disturbed due to phosphodiesterase (PDE5) mediated cGMP catabolism in CCM. METHODS AND RESULTS: C57BL/6 mice were infected with Tc, and at the end of acute parasitemia (i.e. 45 days post-infection), treated with sildenafil (SIL, 1 mg/kg) twice per week for 3 weeks...
June 2016: JACC. Basic to Translational Science
Christopher A Seid, Kathryn M Jones, Jeroen Pollet, Brian Keegan, Elissa Hudspeth, Molly Hammond, Junfei Wei, C Patrick McAtee, Leroy Versteeg, Amanda Gutierrez, Zhuyun Liu, Bin Zhan, Jonathan L Respress, Ulrich Strych, Maria Elena Bottazzi, Peter J Hotez
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 IFNγ levels and a statistically significant decrease in parasitemia following T...
October 13, 2016: Human Vaccines & Immunotherapeutics
Paula Regina Elias, Gleicekelly Silva Coelho, Viviane Flores Xavier, Policarpo Ademar Sales Junior, Alvaro José Romanha, Silvane Maria Fonseca Murta, Claudia Martins Carneiro, Nilton Soares Camilo, Flaviane Francisco Hilário, Jason Guy Taylor
A series of novel xylitan derivatives derived from xylitol were synthesized using operationally simple procedures. A xylitan acetonide was the key intermediate used to prepare benzoate, arylsulfonate esters and 1,2,3-triazole derivatives of xylitan. These compounds were evaluated for their in vitro anti-Trypanosoma cruzi activity against trypomastigote and amastigote forms of the parasite in T. cruzi-infected cell lineages. Benznidazole was used as positive control against T. cruzi and cytotoxicity was determined in mammalian L929 cells...
October 10, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Monica Rodríguez-Bolaños, Nallely Cabrera, Ruy Perez-Montfort
The reactivation of triosephosphate isomerase (TIM) from unfolded monomers induced by guanidine hydrochloride involves different amino acids of its sequence in different stages of protein refolding. We describe a systematic mutagenesis method to find critical residues for certain physico-chemical properties of a protein. The two similar TIMs of Trypanosoma brucei and Trypanosoma cruzi have different reactivation velocities and efficiencies. We used a small number of chimeric enzymes, additive mutants and planned site-directed mutants to produce an enzyme from T...
October 2016: Open Biology
M B Huante, S Gupta, V C Calderon, S J Koo, M Sinha, B A Luxon, N J Garg, J J Endsley
Pathogens frequently exploit or evade inflammasome activation in order to survive and proliferate. Alternatively, inadequate inflammasome activation by attenuated microorganisms or adjuvanted subunit vaccines may contribute to poor longevity of protection. To further understand these pathways, we determined the differential inflammasome transcriptome of human THP monocyte-derived macrophages in response to Mycobacterium bovis BCG, as compared to LPS or Trypanosoma cruzi. The results identify the highly specific innate recognition programs associated with inflammasome activation by human macrophages exposed to these microbial stimuli...
September 28, 2016: Tuberculosis
Lygia M Malvestio, Mara Rúbia N Celes, Linda A Jelicks, Herbert B Tanowitz, Cibele M Prado
Dystrophin, an important protein of the dystrophin-glycoprotein complex, has been implicated in the pathogenesis of experimental Chagas disease. It is important for the maintenance of cell shape and contraction force transmission. Dystrophin loss has been related to end-stage cardiac myopathies and proposed as a common route for myocardial dysfunction and progression to advanced heart failure. Evidence suggests that calpains, calcium-dependent proteases, digest dystrophin when the calcium concentration is compatible with their activation...
October 11, 2016: Parasitology Research
Gyongseon Yang, Nakyung Lee, Jean-Robert Ioset, Joo Hwan No
In order to understand the key parameters influencing drug susceptibility, different Trypanosoma cruzi assay protocols were evaluated using a comparative assay design. The assays compared in this study were an image-based intracellular T. cruzi assay quantified through an image-mining algorithm and an intracellular assay utilizing a β-galactosidase-expressing T. cruzi strain. Thirty-one reference compounds known to exhibit activities against intracellular T. cruzi were used as benchmarks. Initial comparison using EC50 values from two assays showed a very poor correlation, with an R(2) value of 0...
October 11, 2016: Journal of Biomolecular Screening
Verónica Seguel, Lorena Castro, Chantal Reigada, Leonel Cortes, María V Díaz, Mariana R Miranda, Claudio A Pereira, Michel Lapier, Carolina Campos-Estrada, Antonio Morello, Ulrike Kemmerling, Juan D Maya, Rodrigo López-Muñoz
Benznidazole is the first-line drug used in treating Chagas disease, which is caused by the parasite Trypanosoma cruzi (T. cruzi). However, benznidazole has limited efficacy and several adverse reactions. Pentamidine is an antiprotozoal drug used in the treatment of leishmaniasis and African trypanosomiasis. In T. cruzi, pentamidine blocks the transport of putrescine, a precursor of trypanothione, which constitutes an essential molecule in the resistance of T. cruzi to benznidazole. In the present study, we describe the effect of the combination of benznidazole and pentamidine on isolated parasites, mammalian cells and in mice infected with T...
October 8, 2016: Experimental Parasitology
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