Interactions between Trypanosoma cruzi Secreted Proteins and Host Cell Signaling Pathways

Chagas disease is one of the prevalent neglected tropical diseases, affecting at least 6-7 million individuals in Latin America. It is caused by the protozoan parasite Trypanosoma cruzi, which is transmitted to vertebrate hosts by blood-sucking insects. After infection, the parasite invades and multiplies in the myocardium, leading to acute myocarditis that kills around 5% of untreated individuals. T. cruzi secretes proteins that manipulate multiple host cell signaling pathways to promote host cell invasion. The primary secreted lysosomal peptidase in T. cruzi is cruzipain, which has been shown to modulate the host immune response. Cruzipain hinders macrophage activation during the early stages of infection by interrupting the NF-kB P65 mediated signaling pathway. This allows the parasite to survive and replicate, and may contribute to the spread of infection in acute Chagas disease. Another secreted protein P21, which is expressed in all of the developmental stages of T. cruzi, has been shown to modulate host phagocytosis signaling pathways. The parasite also secretes soluble factors that exert effects on host extracellular matrix, such as proteolytic degradation of collagens. Finally, secreted phospholipase A from T. cruzi contributes to lipid modifications on host cells and concomitantly activates the PKC signaling pathway. Here, we present a brief review of the interaction between secreted proteins from T cruzi and the host cells, emphasizing the manipulation of host signaling pathways during invasion.Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNNUniv Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Biol Geral, Belo Horizonte, MG, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo, BrazilFAPESP: 07/50551-2FAPESP: 11/51475-3Web of Scienc

Protein tyrosine kinases in Schistosoma mansoni

The identification and description of signal transduction molecules and mechanisms are essential to elucidate Schistosoma mansoni host-parasite interactions and parasite biology. This mini review focuses on recent advancements in the study of signalling molecules and transduction mechanisms in S. mansoni, drawing special attention to the recently identified and characterised protein tyrosine kinases of S. mansoni.Fiocruz Centro de Pesquisas René RachouSanta Casa de Misericórdia de Belo Horizonte Programa de Pós-Graduação e PesquisaUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)UNIFESP, EPMSciEL

Trimethylguanosine nucleoside inhibits cross-linking between snurportin 1 and m3G-capped U1 snRNA

Macromolecular nuclear import is an energy-and signal-dependent process. The best characterized type of nuclear import consists of proteins carrying the classical NLS that is mediated by the heterodimeric receptor importin α/β. Spliceosomal snRNPs U1, U2, U4, and U5 nuclear import depend both on the 5' terminal m3G (trimethylguanosine) cap structure of the U snRNA and the Sm core domain. Snurportin 1 recognizes the m3G-cap structure of m3G-capped U snRNPs. In this report, we show how a synthesized trimethylguanosine nucleoside affects the binding of Snurportin 1 to m3G-capped U1 snRNA in a UV-cross-linking assay. The data indicated that TMG nucleoside is an essential component required in the recognition by Snurportin 1, thus suggesting that interaction of Snurportin 1 with U1 snRNA is not strictly dependent on the presence of the whole cap structure, but rather on the presence of the TMG nucleoside structure. These results indicate that the free nucleoside TMG could be a candidate to be an inhibitor of the interaction between Snurportin 1 and U snRNAs. We also show the behavior of free TMG nucleoside in in vitro U snRNPs nuclear import. Copyright © Taylor & Francis Group, LLC.This work was supported by Plan Nacional BFU2005-00701 and the Polish Committee for Scientific Research (KBN) # 6 P04A 055 17. D.B. was a recipient of a CNPq Brazilian fellowship and EMBO and FEBS short-term fellowshipsPeer Reviewe

Portuguese Adaptation of Students' Engagement in Schools International Scale (SESIS)

This work is financed by National Founds through FCT - Fundação para a Ciência e Tecnologia, in the context of the project PTDC/CPE-CED/114362/2009- Students Engagement in Schools: Differentiation and Promotion, coordinated by Prof. Feliciano H. Veiga.Context: The importance of student’s engagement has been recently pointed out in research. However, there has been a lack of engagement assessment instrument, pertaining psychometric qualities. Objective: This paper presents the Portuguese adaptation of the “Student’s Engagement in School International Scale” (SESIS), drawn up from a12 countries international study (Lam et al., 2012; Lam et al., in press). Method: Psychometric properties of this scale were examined with data from 685 students from different grades (6th, 7th, 9th and 10th), from both sexes, and different regions of the country. Results: Factorial analysis of the results, with varimax rotation, lead to three different factors which explain 50.88% of the variance. The scale integrates the original 33 items, and cognitive, affective and behavioural dimensions. For the external validity study, the relationship between student’s engagement in school results and other school variables — academic performance, self-concept —was considered, and significant relations were observed, as expected. Conclusion: The data presented highlights the qualities of SESIS, as well as its usefulness for research purposes. Suggestion: It is suggested the investigation of the extension of SESIS’s three-dimensionality, in future studiesKeywords: Innovation, technology, research projects, etc.This work is financed by National Founds through FCT - Fundação para a Ciência e Tecnologia, in the context of the project PTDC/CPE-CED/114362/2009- Students Engagement in Schools: Differentiation and Promotion, coordinated by Prof. Feliciano H. Veiga

Students’ Engagement in School: A literature review

This work is financed by National Founds through FCT-Fundação para a Ciência e Tecnologia, in the context of the project PTDC/CPE-CED/114362/2009- Students Engagement in Schools: Differentiation and Promotion, coordinated by Prof. Feliciano H. Veiga.Students’ Engagement in School has been the focus of debate concerning academic success and school dropout, and pointed out as a mean to address the problems affecting our schools and their students, not only for having value in itself, but also for being an important mediator between several academic variables. This paper reviews the research and literature on this concept and its relations with personal and contextual variables, as well as with academic performance, with the aim of summarizing the main relationships found. Literature presents a significant number of studies which sustain that personal variables, such as self-efficacy and self-concept, as well as contextual - peers, school, family- are related with school engagement. The adoption of mastery goals, for instance, has a positive impact on school, as they are related with the use of cognitive and self-regulatory strategies by students. Positive relationships with peers, teachers support and the quality of family relations are associated with higher levels of engagement and academic performance, while negative experiences, such as bullying, are related with educational difficulties. Following this, we reflect about the relevance of studying engagement in school, in the context of widespread financial crisis, and emphasize the need to rethink educational institutions considering the paradigmatic changes that currently occur.This work is financed by National Founds through FCT-Fundação para a Ciência e Tecnologia, in the context of the project PTDC/CPE-CED/114362/2009- Students Engagement in Schools: Differentiation and Promotion, coordinated by Prof. Feliciano H. Veiga

CA88, a nuclear repetitive DNA sequence identified in Schistosoma mansoni, aids in the genotyping of nine Schistosoma species of medical and veterinary importance

CA88 is the first long nuclear repetitive DNA sequence identified in the blood fluke, Schistosoma mansoni. The assembled S. mansoni sequence, which contains the CA88 repeat, has 8,887 nucleotides and at least three repeat units of approximately 360 bp. In addition, CA88 also possesses an internal CA microsatellite, identified as SmBr18. Both PCR and BLAST analysis have been used to analyse and confirm the CA88 sequence in other S. mansoni sequences in the public database. PCR-acquired nuclear repetitive DNA sequence profiles from nine Schistosoma species were used to classify this organism into four genotypes. Included among the nine species analysed were five sequences of both African and Asian lineages that are known to infect humans. Within these genotypes, three of them refer to recognised species groups. A panel of four microsatellite loci, including SmBr18 and three previously published loci, has been used to characterise the nine Schistosoma species. Each species has been identified and classified based on its CA88 DNA fingerprint profile. Furthermore, microsatellite sequences and intra-specific variation have also been observed within the nine Schistosoma species sequences. Taken together, these results support the use of these markers in studying the population dynamics of Schistosoma isolates from endemic areas and also provide new methods for investigating the relationships between different populations of parasites. In addition, these data also indicate that Schistosoma magrebowiei is not a sister taxon to Schistosoma mattheei, prompting a new designation to a basal clade.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Imunologia e ParasitologiaInstituto de Pesquisas René Rachou-FiocruzThe Natural History Museum Department of ZoologySanta Casa de Belo Horizonte Programa de Pós-Graduação e PesquisaUniversidade Federal de Ouro Preto Escola de Farmácia Laboratório de Pesquisas ClínicasUNIFESP, EPM, Imunologia e ParasitologiaSciEL

Biochemical characterization of a protein tyrosine phosphatase from Trypanosoma cruzi involved in metacyclogenesis and cell invasion

Protein tyrosine phosphatases (PTPs) form a large family of enzymes involved in the regulation of numerous cellular functions in eukaryotes. Several protein tyrosine phosphatases have been recently identified in trypanosomatides. Here we report the purification and biochemical characterization of TcPTP1, a protein tyrosine phosphatase from Trypanosoma cruzi, the causing agent of Chagas' disease. the enzyme was cloned and expressed recombinantly in Escherichia coli and purified by Ni-affinity chromatography. Biochemical characterization of recombinant TcPTP1 with the PTP pseudo-substrate pNPP allowed the estimation of a Michaelis-Menten constant K-m of 4.5 mM and a k(cat) of 2.8 s(-1). We were able to demonstrate inhibition of the enzyme by the PTP1b inhibitor BZ3, which on its turn was able to accelerate the differentiation of epimastigotes into metacyclic forms of T. cruzi induced by nutritional stress. Additionally, this compound was able to inhibit by 50% the infectivity of T. cruzi trypomastigotes in a separate cellular assay. in conclusion our results indicate that TcPTP1 is of importance for cellular differentiation and invasivity of this parasite and thus is a valid target for the rational drug design of potential antibiotics directed against T. cruzi. (C) 2011 Elsevier Inc. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol & Genet, BR-04023062 São Paulo, BrazilCtr Biol Mol Estrutural, Lab Nacl Luz Sincrotron, BR-13083100 Campinas, SP, BrazilUniversidade Federal de São Paulo, Dept Ciencia & Tecnol, BR-12231280 Sao Jose Dos Campos, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol & Genet, BR-04023062 São Paulo, BrazilWeb of Scienc

Inscrição votiva em língua lusitana (Arronches Portalegre)

Propõe-se leitura, interpretação e integração histórica da epígrafe redi- gida em língua lusitana, proveniente de uma herdade dos arredores de Arronches. Documenta o sacrifício de animais, designadamente de dez ovelhas, a divindades indígenas – Banda, Reva, Munis, Broeneia... – cujos nomes se fazem acompanhar de epítetos, um dos quais repetido com grafias diferentes (em dativo, Haracui, Aharacui, Harase), passí- vel de relacionar-se com o topónimo actual, Arronches. Na segunda parte, os três dedicantes, que poderão identificar-se como criadores de ovelhas, suplicam às divindades que lhes aceitem os sacrifícios. Considera-se muito viável a hipótese de relacionar esta e as outras epígrafes em língua lusitana – de Lamas de Moledo e Cabeço das Frá- guas – com as rotas da transumância logo nos primórdios da domina- ção romana

A successful strategy for the recovering of active P21, an insoluble recombinant protein of Trypanosoma cruzi

Structural studies of proteins normally require large quantities of pure material that can only be obtained through heterologous expression systems and recombinant technique. in these procedures, large amounts of expressed protein are often found in the insoluble fraction, making protein purification from the soluble fraction inefficient, laborious, and costly. Usually, protein refolding is avoided due to a lack of experimental assays that can validate correct folding and that can compare the conformational population to that of the soluble fraction. Herein, we propose a validation method using simple and rapid 1D H-1 nuclear magnetic resonance (NMR) spectra that can efficiently compare protein samples, including individual information of the environment of each proton in the structure.Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INBEQMeDIUniv Fed Uberlandia, Inst Ciencias Biomed, BR-38400 Uberlandia, MG, BrazilUniv São Paulo, Inst Fis Sao Carlos, Sao Carlos, SP, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Vila Mariana, SP, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Biol Geral, Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Vila Mariana, SP, BrazilFAPESP: 2010/51867-6FAPESP: 2012/21153-7FAPEMIG: APQ-00621-11FAPEMIG: APQ-00305-12CAPES: 23038.005295/2011-40Web of Scienc