MicroRNAs (miRNAs) have emerged as a class of small, endogenous, regulatory RNAs that exhibit the ability to epigenetically modulate the translation of mRNAs into proteins. This feature enables them to control cell phenotypes and, consequently, modify cell function in a disease context. The role of inflammatory miRNAs in Alzheimer's disease (AD) and their ability to modulate glia responses are now beginning to be explored. In this study, we propose to disclose the functional role of miR-155, one of the most well studied immune-related miRNAs in AD-associated neuroinflammatory events, employing the 3xTg AD animal model. A strong upregulation of miR-155 levels was observed in the brain of 12-month-old 3xTg AD animals. This event occurred simultaneously with an increase of microglia and astrocyte activation, and before the appearance of extracellular Aβ aggregates, suggesting that less complex Aβ species, such as Aβ oligomers may contribute to early neuroinflammation. In addition, we investigated the contribution of miR-155 and the c-Jun transcription factor to the molecular mechanisms that underlie Aβ-mediated activation of glial cells. Our results suggest early miR-155 and c-Jun upregulation in the 3xTg AD mice, as well as in Aβ-activated microglia and astrocytes, thus contributing to the production of inflammatory mediators such as IL-6 and IFN-β. This effect is associated with a miR-155-dependent decrease of suppressor of cytokine signaling 1. Furthermore, since c-Jun silencing decreases the levels of miR-155 in Aβ-activated microglia and astrocytes, we propose that miR-155 targeting can constitute an interesting and promising approach to control neuroinflammation in AD.

Five polyphosphazenes with different hydrophilicites were synthesized and screened in vitro. The purpose was to identify unique types of polymeric substrates that distinctly favored or markedly prevented cellular adhesion. The SK-N-BE(2c) human neuroblastoma cell line, utilized for its electrogenic responses, was used to test this differential adhesion. In particular, the objective was to specifically culture this cell line in a highly selective pattern. Each candidate polymer was cast into films and plated with neuroblastoma cells for 3 days. The polyphosphazene materials which showed negative cellular adhesive properties (-CAPs) were poly[bis(trifluoroethoxy)phosphazene] (TFE) and poly[bis(methoxyethoxyethoxy)phosphazene] (MEEP). The polyphosphazenes which showed positive cellular adhesive properties (+CAPs) were poly[(methoxyethoxyethoxy)(1.0)(carboxylatophenoxy)(1.0)phosphazene] (PMCPP), poly[(methoxyethoxyethoxy)(1.0)(cinnamyloxy)(1.0)phosphazene] (PMCP), and poly[(methoxyethoxyethoxy)(1.0)(p-methylphenoxy)(1.0)phosphazene] (PMMP). To test cellular selectivity, films of -CAP and +CAP were copatterned onto glass substrates. The micropatterned films were plated with SK-N-BE(2c) neuroblastoma cells for one week. The results showed that neuroblastoma cells adhere selectively (over 60%) to the +CAP microfeatures. We also showed that multiple properties can be achieved with a single material and that we can use TFE as both a -CAP and an insulation layer and PMCP as a conductive +CAP layer.

Os besouros rola-bostas são insetos copro-necrófagos e utilizam primariamente fezes e carcaça de mamíferos como fonte de alimento e nidificação. Estes insetos são sensíveis à modificação do habitat principalmente relacionados à cobertura da vegetação. A substituição da floresta Amazônica por pastagem altera drasticamente o habitat das espécies nativas e acarreta redução da riqueza de espécies e modificação na composição das assembleias locais. O objetivo deste trabalho foi compreender os efeitos da substituição da floresta nativa por pastagem introduzida na riqueza, abundância, composição de espécies e estrutura das guildas alimentares dos besouros rola-bostas no sudoeste da Amazônia brasileira. Foram coletados 10.073 indivíduos de besouros rola-bostas pertencentes a 84 espécies e 22 gêneros. As florestas (seis fragmentos de floresta secundária) apresentaram 71 espécies em sua maioria com abundância intermediária. As pastagens (áreas vizinhas onde a floresta original foi substituída por pastagens introduzidas) apresentaram redução significativa no número de espécies, e composição de espécies diferente. Nas florestas a maioria das espécies foi considerada generalista, enquanto as pastagens apresentaram maior abundância de espécies coprófagas o que demonstra uma modificação na guilda alimentar causado pela substituição da floresta por pastagem. Entre as 30 espécies coletadas nas pastagens, doze estão presentes em vegetação aberta nativa (cerrado e chaco). Isto retrata, provavelmente, um processo de colonização regional recente. Onde espécies de besouros rola-bostas, oriundas de áreas abertas, estão invadindo as pastagens amazônicas.

No abstract