Investigação de componentes específicos e essenciais para exportação de mRNA de tripanossomatídeos

Orientadora : Dra. Andréa Rodrigues ÁvilaCoorientador : Prof. Dr. Alexandre Haruo InoueDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 23/02/2017Inclui referências : f. 151-158Resumo: Trypanosoma cruzi é o protozoário causador da doença de Chagas, uma endemia da América Latina que afeta milhões de pessoas. Este parasita tem um ciclo de vida alternado entre hospedeiros vertebrados e invertebrados, e necessita se adaptar a mudanças em diferentes ambientes que encontra ao longo do ciclo de transmissão. O T. cruzi controla a expressão de genes a partir de eventos majoritariamente pós-transcricionais. Vias que controlam a estabilidade do mRNA ou a tradução de proteínas são bem conhecidas, enquanto que mecanismos moleculares de exportação de mRNA do núcleo para o citoplasma ainda não são bem compreendidos nem em tripanossomatídeos, nem em outros patógenos. Sabe-se, até o momento, que a maioria das proteínas envolvidas com o transporte de mRNA em outros eucariotos não está conservada em diversas espécies de parasitas. Exceto pela proteína Sub2 de T. cruzi (TcSub2), homóloga das proteínas de mamífero e levedura (UAP56/Sub2) e essencial para exportação de mRNA em tripanossomatídeos. Logo, para investigar os componentes desta via, nosso grupo tem investido em identificar proteínas exclusivas e essenciais para a exportação de mRNA em T. cruzi. Abordagens de proteômica, usando como alvo TcSub2, vem permitindo a identificação de fatores com função ainda desconhecida e/ou que são conservados apenas entre espécies de tripanossomatídeos, tornando-os alvos de interesse. Assim, o objetivo deste trabalho foi avaliar a interação de proteínas alvo com TcSub2 e seu papel na exportação de mRNA em T.cruzi. Duas proteínas não caracterizadas apresentaram motivos conservados e foram denominadas como TcFOP-like e TcAPI5-like. Interessantemente, estes motivos estão presentes em proteínas de outros organismos que estão envolvidas com a via de exportação de mRNA. Aqui, nós confirmamos que TcFOP-like e TcAPI5-like são proteínas nucleares e parecem interagir com TcSub2. Além disso, silenciamento e supereexpressão de TcFOP-like afeta o crescimento do parasita, e nós confirmamos sua interação com outros componentes da via de exportação de mRNA, tais como TcMex67 e TcHel45. Estas evidências suportam presença de components diveregentes na via de exportação de mRNA em Tripanossomatídeos. Palavras chaves: Trypanosoma cruzi. Exportação de mRNA. TcSub2.TcHel45Abstract: Trypanosoma cruzi is the protozoan causative of Chagas disease, an endemic disease in Latin America that affects millions of people. This parasite alternates between vertebrate and invertebrate hosts during his life cycle, and needs to adapt to the changes in different environments along the transmission cycle. T. cruzi controls the gene expression mostly by post-transcriptional events. Pathways that control mRNA stability or protein translation are well known, while the molecular mechanisms for mRNA export from nucleus to cytoplasm are still not well understood nether in trypanosomatids or other pathogens. So far, it's known that the most of the proteins that are involved in mRNA transport of other eukaryotes are not conserved in many species of parasites. One exception is T. cruzi Sub2 (TcSub2), a homologue of the proteins in mammalian and yeast (UAP56 / Sub2) and essential for mRNA export in tripanossomatids. Therefore, to investigate the components of this pathway, our group has invested in identifying unique and essential proteins for the export of mRNA in T. cruzi. Proteomic approaches, using TcSub2 as target, have allowed identification of factors with the unknown function and/or that are conserved only in species of trypanosomatids, turning into interesting targets. Then, the aim of this work was to evaluate the interaction of target proteins with TcSub2 and their role in the mRNA export pathway in T. cruzi. Two uncharacterized proteins presented conserved motifs and were named here as TcFOP-Like and TcAPI5-like. Interestingly, those motifs are present in proteins of other organisms which are involved in mRNA export pathway. Here, we confirmed that TcFOP-like and TcAPI5-like are nuclear proteins and seems to interact with TcSub2. Furthemore, knockdown and overexpression of TcFOP-like affect the growth of parasites and we confirmed its interaction with other components of the mRNA export pathway, such as TcMex67 and TcHel45. Those evidences supporte the presence of divergent components in the mRNA export pathway of Tripanossomatids. Keywords: Trypanosoma cruzi. Export of mRNA. TcSub2. TcHel45

High-power LED units currently available for dental resin-based materials—A review

The pursuit of less time-consuming procedures led to the development of high-power light-curing-units (LCU) to light-cure dental-resin-based-materials. This review aims to describe high-power light-emitting-diode (LED)-LCUs, by a bibliometric systematization of in vitro and in vivo studies. The research-question, by PICO model, aimed to assess the current knowledge on dentistry-based high-power LED-LCUs by analyzing to what extent their use can promote adverse events on materials and patients’ oral condition when compared to low-power LED-LCUs, on daily dental practice. PubMed and B-on database search focused on high-power (≥2000 mW/cm2 ) LED-LCUs outputs. Studies assessing performance of high-power LED-LCUs for light-curing dental-resin-based-materials were included. From 1822 screened articles, 21 fulfilled the inclusion criteria. Thirty-two marketed units with high levels of radiant emittance (≥2000 mW/cm2 up to 6000 mW/cm2 ) were identified. Most output values vary on 2000–3000 mW/cm2 . The highest output found was 6000 mW/cm2 , in FlashMax™P3. Reports suggest that light-curing protocols with lower emittance irradiance and longer exposure outperforms all other combination, however in some clinical procedures high-power LED-LCUs are advocated when compared to low-power LED-LCUs. Moreover, long time exposures and over-curing can be dangerous to the biological vital pulp, and other oral tissues. Evidence showing that high-power LCUs are the best clinical option is still very scarce

EFEITO DA FORMA FÍSICA DA RAÇÃO SOBRE O DESEMPENHO DE FRANGOS DE CORTE

Um experimento foi conduzido com o objetivo de avaliar o efeito de diferentes formas físicasde rações sobre o desempenho de frangos de corte, lote misto, nas fases pré-inicial (1 a 7 dias deidade), inicial (8 a 21 dias de idade), de crescimento (22 a 42 dias de idade), final (43 a 49 diasde idade) e período total (1 a 49 dias de idade). Foram distribuidos 2.880 frangos de corte emum delineamento inteiramente casualizado, com oito tratamentos e seis repetições, totalizando48 parcelas. Os tratamentos utilizados foram: ração farelada; ração expandida - triturada; raçãoexpandida - peletizada - triturada; ração expandida e 50% peletizada; ração expandida e 60%peletizada; ração expandida e 70% peletizada; ração expandida e 80% peletizada; e, ração expandidae 90% peletizada. Os dados obtidos foram submetidos à análise de variância pelo programaSAS ® e as médias comparadas pelo teste Student-Newman-Keuls em um nível de 5% de probabilidade.De acordo com os resultados, recomenda-se para as fases pré-inicial, inicial e final autilização de ração farelada e, para a fase de crescimento, recomenda-se o uso de ração expandidae peletizada (a partir de 60%) para lotes de frangos de corte mistos.Palavras-chave: Ração expandida. Ração farelada. Ração peletizada. Ração triturada

Proteomics uncovers novel components of an interactive protein network supporting RNA export in trypanosomes

In trypanosomatids, transcription is polycistronic and all mRNAs are processed by trans-splicing, with export mediated by noncanonical mechanisms. Although mRNA export is central to gene regulation and expression, few orthologs of proteins involved in mRNA export in higher eukaryotes are detectable in trypanosome genomes, necessitating direct identification of protein components. We previously described conserved mRNA export pathway components in Trypanosoma cruzi, including orthologs of Sub2, a component of the TREX complex, and eIF4AIII (previously Hel45), a core component of the exon junction complex (EJC). Here, we searched for protein interactors of both proteins using cryomilling and mass spectrometry. Significant overlap between TcSub2 and TceIF4AIII-interacting protein cohorts suggests that both proteins associate with similar machinery. We identified several interactions with conserved core components of the EJC and multiple additional complexes, together with proteins specific to trypanosomatids. Additional immunoisolations of kinetoplastid-specific proteins both validated and extended the superinteractome, which is capable of supporting RNA processing from splicing through to nuclear export and cytoplasmic events. We also suggest that only proteomics is powerful enough to uncover the high connectivity between multiple aspects of mRNA metabolism and to uncover kinetoplastid-specific components that create a unique amalgam to support trypanosome mRNA maturation

COEDUCAÇÃO INTERGERACIONAL E EDUCAÇÃO POPULAR: revisão crítica sobre uma relação dialético-dialógica

Este artigo realiza a proposta dialética e dialógica na perspectiva da coeducação entre as gerações e da educação popular. Trata-se de um estudo qualitativo, exploratório-descritivo, do tipo revisão crítica de literatura, que visa analisar as relações existentes entre esses dois processos na contemporaneidade. Busca-se refletir sobre a potência social transformadora das interações geracionais e evoca-se a necessidade de investimentos para alcançar a convivência intergeracional em prol da coeducação efetiva, sinalizando a importância da mediação como um meio de solução consensual de conflitos apto para (re)estabelecer a comunicação nas relações intra e intergeracionais e multiculturais, em consonância com a proposta pedagógica freiriana. Inferiu-se que a educação popular é uma abordagem com potencial para impulsionar a coeducação intergeracional e romper com a segregação societária de grupos geracionais, ao passo que a mediação de conflitos é uma ferramenta social privilegiada para qualificação do diálogo, favorecendo a integração dos sujeitos de múltiplas gerações e culturas em prol da aprendizagem ao longo da vida

Plant traits controlling growth change in response to a drier climate

This is the final version. Available on open access from Wiley via the DOI in this recordPlant traits are increasingly being used to improve prediction of plant function, including plant demography. However, the capability of plant traits to predict demographic rates remains uncertain, particularly in the context of trees experiencing a changing climate. Here we present data combining 17 plant traits associated with plant structure, metabolism and hydraulic status, with measurements of long-term mean, maximum and relative growth rates for 176 trees from the world’s longest running tropical forest drought experiment. We demonstrate that plant traits can predict mean annual tree growth rates with moderate explanatory power. However, only combinations of traits associated more directly with plant functional processes, rather than more commonly employed traits like wood density or leaf mass per area, yield the power to predict growth. Critically, we observe a shift from growth being controlled by traits related to carbon cycling (assimilation and respiration) in well-watered trees, to traits relating to plant hydraulic stress in drought-stressed trees. We also demonstrate that even with a very comprehensive set of plant traits and growth data on large numbers of tropical trees, considerable uncertainty remains in directly interpreting the mechanisms through which traits influence performance in tropical forests.Conselho Nacional de Desenvolvimento Científico e TecnológicoNatural Environment Research Council (NERC)Australian Research Council (ARC)European Union FP7Fundação de Amparo à Pesquisa do Estado de São Paul

The response of carbon assimilation and storage to long‐term drought in tropical trees is dependent on light availability

Whether tropical trees acclimate to long‐term drought stress remains unclear. This uncertainty is amplified if drought stress is accompanied by changes in other drivers such as the increases in canopy light exposure that might be induced by tree mortality or other disturbances. Photosynthetic capacity, leaf respiration, non‐structural carbohydrate (NSC) storage and stomatal conductance were measured on 162 trees at the world's longest running (15 years) tropical forest drought experiment. We test whether surviving trees have altered strategies for carbon storage and carbon use in the drier and elevated light conditions present following drought‐related tree mortality. Relative to control trees, the surviving trees experiencing the drought treatment showed functional responses including: (a) moderately reduced photosynthetic capacity; (b) increased total leaf NSC; and (c) a switch from starch to soluble sugars as the main store of branch NSC. This contrasts with earlier findings at this experiment of no change in photosynthetic capacity or NSC storage. The changes detected here only occurred in the subset of drought‐stressed trees with canopies exposed to high radiation and were absent in trees with less‐exposed canopies and also in the community average. In contrast to previous results acquired through less intensive species sampling from this experiment, we also observe no species‐average drought‐induced change in leaf respiration. Our results suggest that long‐term responses to drought stress are strongly influenced by a tree's full‐canopy light environment and therefore that disturbance‐induced changes in stand density and dynamics are likely to substantially impact tropical forest responses to climate change. We also demonstrate that, while challenging, intensive sampling is essential in tropical forests to avoid sampling biases caused by limited taxonomic coverage.Publicado online em 29 set. 2020

Engolo and Capoeira. From Ethnic to Diasporic Combat Games in the Southern Atlantic

This article provides a re-examination of the main Afrocentric narrative of capoeira origins, the engolo or ‘Zebra Dance’, in light of historical primary sources and new ethnographic evidence gathered during fieldwork in south-west Angola. By examining engolo’s bodily techniques, its socio-historical context and cultural meanings, the piece emphasises its insertion into a pastoral lifestyle and highlights the relatively narrow ethnic character of the practice in Angola. This analysis and the comparison with capoeira helps us to develop certain hypotheses about the formation, migration, and re-invention of diasporic combat games between southern Angola and coastal Brazil, and more broadly, to increase our understanding of how African cultures spread across the southern Atlantic

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio