As Várias Faces dos Jogos Digitais na Educação

Jogos digitais estão cada vez mais presentes no mundo, atingindo diferentes faixas etárias e camadas socioeconômicas, impactando a indústria de entretenimento e criando novas formas de diversão, aprendizado e até trabalho. Em face disto, muitos pesquisadores vêm refletindo sobre como empregá-los na educação. Contudo, para isto não basta que funcionem apenas como canais de transmissão de conteúdo, mas que as potencialidades únicas da mídia sejam aplicadas em favor do aprendizado. Neste trabalho, discutimos algumas perspectivas dos jogos no aprendizado, a saber os jogos educativos, jogos sérios, jogos epistêmicos e os jogos persuasivos e sua retórica procedimental. Apresentamos em seguida as características dos jogos que os tornam objetos de aprendizado relevantes, explorados em um contexto de educação. Concluímos que a capacitação para compreender e criar jogos pode ser uma habilidade empoderadora para crescimento do indivíduo e seu desenvolvimento como cidadão, abrindo novos espaços férteis para reflexão sobre a realidade

Schistosomal Lipids Activate Human Eosinophils via Toll-Like Receptor 2 and PGD2 Receptors: 15-LO Role in Cytokine Secretion

Parasite-derived lipids may play important roles in host-pathogen interactions and immune evasion mechanisms. Remarkable accumulation of eosinophils is a characteristic feature of inflammation associated with parasitic disease, especially caused by helminthes. Infiltrating eosinophils are implicated in the pathogenesis of helminth infection by virtue of their capacity to release an array of tissue-damaging and immunoregulatory mediators. However, the mechanisms involved in the activation of human eosinophils by parasite-derived molecules are not clear. Here we investigated the effects and mechanisms of schistosomal lipids-induced activation of human eosinophils. Our results showed that stimulation of human eosinophils in vitro with total lipid extracts from adult worms of S. mansoni induced direct activation of human eosinophils, eliciting lipid droplet biogenesis, synthesis of leukotriene (LT) C4 and eoxin (EX) C4 (14,15 LTC4) and secretion of eosinophil pre-formed TGFβ. We demonstrated that main eosinophil activating components within S. mansoni lipid extract are schistosomal-derived lysophosphatidylcholine (LPC) and prostaglandin (PG)D2. Moreover, TLR2 is up-regulated in human eosinophils upon stimulation with schistosomal lipids and pre-treatment with anti-TLR2 inhibited both schistosomal lipids- and LPC-, but not PGD2-, induced lipid droplet biogenesis and EXC4 synthesis within eosinophils, indicating that TLR2 mediates LPC-driven human eosinophil activation. By employing PGD2 receptor antagonists, we demonstrated that DP1 receptors are also involved in various parameters of human eosinophil activation induced by schistosomal lipids, but not by schistosomal LPC. In addition, schistosomal lipids and their active components PGD2 and LPC, triggered 15-LO dependent production of EXC4 and secretion of TGFβ. Taken together, our results showed that schistosomal lipids contain at least two components—LPC and PGD2—that are capable of direct activation of human eosinophils acting on distinct eosinophil-expressed receptors, noticeably TLR2 as well as DP1, trigger human eosinophil activation characterized by production/secretion of pro-inflammatory and immunoregulatory mediators

Here, There and Everywhere: The Ubiquitous Distribution of the Immunosignaling Molecule Lysophosphatidylcholine and its Role on Chagas Disease

Chagas disease is a severe illness, which can lead to death if the patients are not promptly treated. The disease is caused by the protozoan parasite Trypanosoma cruzi, which is mostly transmitted by a triatomine insect vector. There are 8-10 million people infected with T. cruzi in the world, but the vector-borne transmission occurs only in the Americas, especially Latin America. About 30 % of chronically infected people develop cardiac diseases and up to 10 % develop digestive, neurological or mixed disorders. Lysophosphatydilcholine (LPC) is the major phospholipid component of oxidized low-density lipoproteins associated with atherosclerosis-related tissue damage. Insect-derived LPC is a powerful chemoattractant for inflammatory cells at the site of the insect bite, enhances parasite invasion, and inhibits the production of nitric oxide (NO) by T. cruzi-stimulated macrophages. The recognition of the ubiquitous presence of LPC on the vector saliva, its production by the parasite itself and its presence both on patient plasma as well as its role on diverse host x parasite interaction systems lead us to compare its distribution in nature with the title of the famous Beatles song Here, There and Everywhere recorded exactly 50 years ago in 1966. Here, we review the major findings pointing out the role of such molecule as an immunosignaling modulator of Chagas disease transmission. Also, we believe that future investigation of the connection of this ubiquity and the immune role of such molecule may lead in the future to novel methods to control parasite transmission, infection and pathogenesis

Schistosomal Lipids Activate Human Eosinophils via Toll-Like Receptor 2 and PGD2 Receptors: 15-LO Role in Cytokine Secretion

Submitted by Sandra Infurna ([email protected]) on 2019-04-29T15:48:39Z No. of bitstreams: 1 KellyG_Magalhães_etal_IOC_2019.pdf: 1717602 bytes, checksum: b7904ecb828587beb8abcd5ff8b25d6a (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-04-29T16:02:59Z (GMT) No. of bitstreams: 1 KellyG_Magalhães_etal_IOC_2019.pdf: 1717602 bytes, checksum: b7904ecb828587beb8abcd5ff8b25d6a (MD5)Made available in DSpace on 2019-04-29T16:03:00Z (GMT). No. of bitstreams: 1 KellyG_Magalhães_etal_IOC_2019.pdf: 1717602 bytes, checksum: b7904ecb828587beb8abcd5ff8b25d6a (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ. Brasil / Universidade de Brasília. Laboratório de Imunologia e Inflamação. Brasília, DF, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil / Universidade do Estado do Rio de Janeiro. Instituto de Aplicação Fernando Rodrigues da Silveira. Departamento de Ciências da Natureza. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil / Centro Universitário da Zona Oeste. Unidade de Farmácia. Laboratório de Pesquisas em Análise Clínicas. Rio de Janeiro, RJ, Brasil.Universidade de Brasília. Laboratório de Imunologia e Inflamação. Brasília, DF, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Laboratório de Bioquímica de Lipídeos e Lipoproteínas. Rio de Janeiro, RJ, Brasil.Harvard Medical School. Allergy and Inflammation. Boston, MA, USA.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ. Brasil.Parasite-derived lipids may play important roles in host-pathogen interactions and immune evasion mechanisms. Remarkable accumulation of eosinophils is a characteristic feature of inflammation associated with parasitic disease, especially caused by helminthes. Infiltrating eosinophils are implicated in the pathogenesis of helminth infection by virtue of their capacity to release an array of tissue-damaging and immunoregulatory mediators. However, the mechanisms involved in the activation of human eosinophils by parasite-derived molecules are not clear. Here we investigated the effects and mechanisms of schistosomal lipids-induced activation of human eosinophils. Our results showed that stimulation of human eosinophils in vitro with total lipid extracts from adult worms of S. mansoni induced direct activation of human eosinophils, eliciting lipid droplet biogenesis, synthesis of leukotriene (LT) C4 and eoxin (EX) C4 (14,15 LTC4) and secretion of eosinophil pre-formed TGFβ. We demonstrated that main eosinophil activating components within S. mansoni lipid extract are schistosomal-derived lysophosphatidylcholine (LPC) and prostaglandin (PG)D2. Moreover, TLR2 is up-regulated in human eosinophils upon stimulation with schistosomal lipids and pre-treatment with anti-TLR2 inhibited both schistosomal lipids- and LPC-, but not PGD2-, induced lipid droplet biogenesis and EXC4 synthesis within eosinophils, indicating that TLR2 mediates LPC-driven human eosinophil activation. By employing PGD2 receptor antagonists, we demonstrated that DP1 receptors are also involved in various parameters of human eosinophil activation induced by schistosomal lipids, but not by schistosomal LPC. In addition, schistosomal lipids and their active components PGD2 and LPC, triggered 15-LO dependent production of EXC4 and secretion of TGFβ. Taken together, our results showed that schistosomal lipids contain at least two components-LPC and PGD2-that are capable of direct activation of human eosinophils acting on distinct eosinophil-expressed receptors, noticeably TLR2 as well as DP1, trigger human eosinophil activation characterized by production/secretion of pro-inflammatory and immunoregulatory mediators

Structural and functional study of YER067W, a new protein involved in yeast metabolism control and drug resistance.

The genome of Saccharomyces cerevisiae is arguably the best studied eukaryotic genome, and yet, it contains approximately 1000 genes that are still relatively uncharacterized. As the majority of these ORFs have no homologs with characterized sequence or protein structure, traditional sequence-based approaches cannot be applied to deduce their biological function. Here, we characterize YER067W, a conserved gene of unknown function that is strongly induced in response to many stress conditions and repressed in drug resistant yeast strains. Gene expression patterns of YER067W and its paralog YIL057C suggest an involvement in energy metabolism. We show that yeast lacking YER067W display altered levels of reserve carbohydrates and a growth deficiency in media that requires aerobic metabolism. Impaired mitochondrial function and overall reduction of ergosterol content in the YER067W deleted strain explained the observed 2- and 4-fold increase in resistance to the drugs fluconazole and amphotericin B, respectively. Cell fractionation and immunofluorescence microscopy revealed that Yer067w is associated with cellular membranes despite the absence of a transmembrane domain in the protein. Finally, the 1.7 A resolution crystal structure of Yer067w shows an alpha-beta fold with low similarity to known structures and a putative functional site.YER067W's involvement with aerobic energetic metabolism suggests the assignment of the gene name RGI1, standing for respiratory growth induced 1. Altogether, the results shed light on a previously uncharacterized protein family and provide basis for further studies of its apparent role in energy metabolism control and drug resistance

A novel antifouling defence strategy from red seaweed: fatty acid derivatives exocytosis and deposition at the cell wall surface

00000International audienceWe investigated the organelles involved in the biosynthesis of fatty acids (FA) derivatives in the cortical cells of Laurencia translucida (Rhodophyta) and the effect of these compounds as antifouling (AF) agents. A bluish autofluorescence (having emissions at 500 nm) within L. translucida cortical cells were observed above the thallus surface via laser scanning confocal microscopy (LSCM). A hexanic extract (HE) from L. translucida was split into two isolated fractions called hydrocarbons (HC) and Lipids (LI), which were injected in high performance liquid chromatograph (HPLC) coupled to a fluorescence detector and revealed the same autofluorescence pattern observed by LSCM analyses (emissions at 500 nm) in the LI fraction. These fractions were analyzed by gas chromatography mass spectrometry (GC-MS), which revealed that docosane is the primary constituent of HC, and hexadecanoic acid and cholesterol trimethylsilyl ether are the primary components of LI. Nile red (NR) labelling (lipid fluorochrome) presented a similar cellular localization to that of the auto-fluorescent molecules. Transmission and scanning electron microscopy (TEM and SEM) revealed vesicle transport processes involving small electron-lucent vesicles, from vacuoles to the inner cell wall. Both fractions (HC and LI) inhibited micro-fouling (HC: lower minimum inhibitory concentration - MIC values of 0.1 μg.mL-1; LI: lower MIC value of 10 μg.mL-1). The results suggested that L. translucida cortical cells can produce FA derivatives (e.g., HCs and FAs) and secrete them to the thallus surface, providing a unique and novel protective mechanism against microfouling colonization in red algae

Bacterial community composition in the salivary glands of triatomines (Hemiptera: Reduviidae).

BACKGROUND:Chagas disease is caused by the parasite Trypanosoma cruzi and is transmitted through triatomines (Hemiptera: Reduviidae). In the last year, many studies of triatomine gut microbiota have outlined its potential role in modulating vector competence. However, little is known about the microbiota present in the salivary glands of triatomines. Bacterial composition of salivary glands in selected triatomine species was investigated, as well as environmental influences on the acquisition of bacterial communities. METHODOLOGY/PRINCIPAL FINDINGS:The diversity of the bacterial communities of 30 pairs of salivary glands of triatomines was studied by sequencing of the V1- V3 variable region of the 16S rRNA using the MiSeq platform (Illumina), and bacteria isolated from skin of three vertebrate hosts were identified based on 16S rRNA gene sequence analysis (targeting the V3-V5 region). In a comparative analysis of microbiota in the salivary glands of triatomine species, operational taxonomic units belonging to Arsenophonous appeared as dominant in Triatoma spp (74% of the total 16S coverage), while these units belonging to unclassified Enterobacteriaceae were dominant in the Rhodnius spp (57% of the total 16S coverage). Some intraspecific changes in the composition of the triatomine microbiota were observed, suggesting that some bacteria may have been acquired from the environment. CONCLUSIONS AND SIGNIFICANCE:Our study revealed the presence of a low-diversity microbiota associated to the salivary glands of the evaluated triatomines. The predominant bacteria genera are associated with triatomine genera and the bacteria can be acquired in the environment in which the insects reside. Further studies are necessary to determine the influence of bacterial communities on vector competence