Prolactina induz aumento na expressão das proteinas SNARE e da sinaptotagmina 4 em ilhotas de ratos

Orientador: Antonio Carlos BoscheroDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Muitas proteínas estão envolvidas no processo de extrusão de grânulos e fusão de membranas nas células ß pancreáticas, e entre estas se destacam as proteínas da família SNARE, composta pela sintaxina, VAMP, SNAP-25 e as sinaptotagminas. Durante a prenhez e o período pós-natal, a prolactina (PRL) e os lactogênios placentários induzem a maturação do processo secretório nas ilhotas pancreáticas por um mecanismo que não está totalmente conhecido. Assim, o objetivo deste trabalho foi analisar se o aumento na resposta secretória frente à glicose observado durante a prenhez envolve alterações na expressão das proteínas SNARE e das sinaptotagminas 1 e 4. Observamos aumento na expressão gênica e protéica da sintaxina 1A, SNAP-25, VAMP-2 e da sinaptotagmina 4 nas ilhotas de neonatos (1 ¿ 2 dias de vida) tratadas com PRL. Demonstramos também que ilhotas de ratas prenhes (17 ¿ 18 dias após cópula) apresentam maior expressão da sintaxina 1A, SNAP-25 e sinaptotagmina 4 que ilhotas controle. Além disso, a inibição das vias da PI3-cinase pela wortmanina ou da MAP-cinase pelo PD098059, não alterou a transcrição destes genes. Desta forma, podemos concluir que prolactina modula a expressão gênica e protéica de parte dos componentes ligados aos passos finais da extrusão dos grânulos de insulina e que este efeito não é mediado pelas vias da PI3- ou da MAPcinaseAbstract: The soluble N-ethylmaleimide-sensitive factor attached protein receptor (SNARE) molecules SNAP-25, syntaxin and VAMP-2 as well as synaptotagmins participate in the extrusion of insulin containing granules in pancreatic ß-cells. During pregnancy and the perinatal periods of life, prolactin (PRL) and other lactogenic substances induce maturation of the stimulus-secretion coupling in the pancreatic islets by a mechanism that is still unclear. In the present study, we investigated whether the improvement in the secretory response to glucose during those periods involves alteration in the expression of syntaxin 1A, SNAP-25, VAMP-2 and synaptotagmins 1 and 4. In islets from pregnant rats (17th ¿ 18th days of pregnancy) and islets from neonatal rats (1-2 days old) treated with PRL for five days, the expression of syntaxin, SNAP-25 and synaptotagmin 4 genes and their encoded proteins was increased compared with controls. VAMP-2 gene and protein was increased in PRL treated-islets from neonatal rats but not in islets from pregnants rats. Wortmannin, a PI3-kinase inhibitor, and PD098059 (PD), a MAP-kinase inhibitor, failed to abrogate the effect of treatment with PRL on the expression of the above proteins. In conclusion, these data indicate that PRL modulates the final steps of insulin secretion by increasing the expression of proteins involved in membrane fusion. These experiments also indicate that effects of PRL occur mainly through a signaling cascade distinct from the PI3-kinase or MAP-kinase pathwaysMestradoFisiologiaMestre em Biologia Funcional e Molecula

Negative interference on growth and morpho-anatomical modifications in young Parkia gigantocarpa plants under waterlogging

Abstract The aim of this study was to investigate the responses linked to growth and morphological and anatomical changes in young plants of Parkia gigantocarpa subjected to waterlogging conditions. The experimental design was completely randomized with two water conditions (control and waterlogging) combined with five evaluation times (0, 4, 8, 12 and 16-days waterlogging conditions). The parameters evaluated were leaf specific hydraulic conductance, plant height, stem diameter, numbers of leaf and leaflets, as well as shoot dry matter, root dry matter, and total dry matter. The data were subjected to an analysis of variance, and significant differences between the means were determined using the F-test at a probability level of 5 %. Additionally, transversal sections linked to primary and secondary roots were described. The segments from the primary root (removed from region located 4 cm below of the soil surface) and the secondary root (removed from region located 4 cm from the root apex) were fixed, stained and mounted, and subsequently photo-documented. The waterlogging provoked reduction in leaf specific hydraulic conductance, as well as negative interferences on growth. Anatomically, this stress induced the appearance of hypertrophic lenticels in base of the stem, adventitious root and formation of schizogenous aerenchyma located in cortical parenchyma of the secondary root. Therefore, these results reveal the susceptibility of young Parkia gigantocarpa plants subjected to waterlogging conditions

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

Desafios e avanços na antibioticoterapia para exacerbações pulmonares na fibrose cística

A fibrose cística é uma doença genética complexa que afeta a produção de muco e a função pulmonar. Exacerbações pulmonares, muitas vezes provocadas por Pseudomonas aeruginosa, são comuns. O diagnóstico requer testes de suor e genéticos para guiar a terapia antibiótica. Avanços com moduladores CFTR melhoram a função pulmonar, mas desafios como resistência bacteriana persistem. Este estudo busca analisar a antibioticoterapia para exacerbações pulmonares na fibrose cística, com foco em abordagens inovadoras e personalizadas. O estudo, baseado em uma revisão sistemática da literatura científica, abrange o período de 2016 a 2024, utilizando as bases de dados PubMed (Medline), Cochrane Library e Scientific Electronic Library Online (SciELO). No primeiro estudo, sobre adjuvantes antibióticos no tratamento de infecções pulmonares em pacientes com fibrose cística, não houve impacto significativo nas exacerbações pulmonares ou na função respiratória. O KB001-A não alterou o tempo para a próxima administração de antibióticos em comparação ao placebo. Evidências apontam uma possível redução na densidade de Pseudomonas aeruginosa com o KB001-A e reduções em Staphylococcus aureus e quase-Pseudomonas aeruginosa com o óxido nítrico, sem diferenças na qualidade de vida. O segundo estudo, em um modelo suíno de pneumonia por Pseudomonas aeruginosa multirresistente, a terapia inalatória de amicacina combinada com meropenem mostrou maior eficácia bactericida nas secreções traqueais em comparação à monoterapia intravenosa. A administração inalatória não preveniu a disseminação da infecção, mas a amicacina evitou o aumento da concentração inibitória mínima de meropenem, com alta concentração nas amostras sem diferenças entre pulmões infectados e não infectados. No terceiro estudo, O estudo das nanopartículas poliméricas na eliminação de biofilmes bacterianos em cepas resistentes e suscetíveis associadas à fibrose cística mostrou potencial promissor contra bactérias multirresistentes. Os nanoportadores de lipídios demonstraram eficácia terapêutica significativa, ressaltando a necessidade de mais pesquisas para confirmar seu benefício clínico. Em resumo, os adjuvantes antibióticos não impactaram significantemente o tratamento de infecções pulmonares na fibrose cística. A combinação de amicacina e meropenem foi eficaz contra pneumonia por Pseudomonas aeruginosa multirresistente. As nanopartículas poliméricas e nanoportadores de lipídios mostraram potenciais terapêuticos promissores, demandando mais pesquisas para validar seus benefícios clínicos

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