Culture of impact in agricultural research organizations: what for and how? - insights from a cross-analysis of Cirad, Embrapa, and Agrosavia institutes.

A degradação dos recursos hídricos é alvo de grandes preocupações, principalmente emrazão da intensa atividade antropogênica sobre o meio ambiente, pois sabe-se que o número decompostos de origem natural ou sintéticos são difundidos nos ecossistemas, acarretando inúmerasalterações. Dentre estes compostos, destaca-se o Triclosan (TCS) que é um agente bactericida usado em produtos de higiene pessoal, cosméticos e perfumes, possuindo a capacidade de causardistúrbios aos peixes. Podem ocorrer alterações a nível celular, genéticas, do crescimento e damorfologia dos embriões. O presente estudo teve como objetivo avaliar a toxicidade do TCS emlarvas de lambari-do-rabo-amarelo (Astyanax altiparanae), avaliando os padrões de crescimentoalométrico durante a ontogenia inicial no período larval. O experimento foi conduzido noLaboratório de Aquicultura e Ecotoxicologia (LAE), da Embrapa Meio Ambiente, Jaguariúna-SP,com um período experimental de 96 horas. Foram utilizados 252 embriões, distribuídos em placasde Petri e avaliados com lupa estereoscópica (70x) para determinar sua viabilidade. As larvasforam expostas às seguintes concentrações de TCS: 0,000574; 0,01794; 0,0018081; 0,0005695 e0,0574 mg.L-1. Paralelamente utilizou-se dois controles, sendo um com meio embrião e outro comadição de etanol ao meio embrião (0,01 mg.L-1) que atuou como adjuvante de solubilização. Após48 horas pós-eclosão, foi adicionado o composto no meio embrião. As larvas ficaram mantidas emincubadora a 26 ± 1 ºC e com ciclo claro/escuro de 15/9 h. A cada 24 h foi realizada a renovaçãodas soluções-teste e procedida a medição. Não se constataram diferenças significativas entre oscontroles (com e sem etanol) quanto aos parâmetros avaliados. Entretanto, as concentraçõessuperiores a 0,01794 mg.L-1 demostraram ter diferenças significativas (p<0,001) em relação aoscontroles, sendo que, quanto maior a concentração, menor o comprimento das larvas. Quanto aotempo de exposição, houve uma interação significativa (p<0,001) na concentração de 0,0574mg.L-1, apresentando a maior diminuição de comprimento em 48h, consequentemente, nos tempode 72h e 96h também. Quanto à interação da concentração ao tempo de exposição foi realizadauma regressão, o resultado da curva demonstrou um efeito inverso para as concentrações e umdireto para o tempo de exposição. Portanto, concluiu-se que o Triclosan tem efeito adverso sobre ocrescimento de larvas de lambari-do-rabo-amarelo

Effects of Helicobacter suis γ-glutamyl transpeptidase on lymphocytes: modulation by glutamine and glutathione supplementation and outer membrane vesicles as a putative delivery route of the enzyme

Helicobacter (H.) suis colonizes the stomach of the majority of pigs as well as a minority of humans worldwide. Infection causes chronic inflammation in the stomach of the host, however without an effective clearance of the bacteria. Currently, no information is available about possible mechanisms H. suis utilizes to interfere with the host immune response. This study describes the effect on various lymphocytes of the γ-glutamyl transpeptidase (GGT) from H. suis. Compared to whole cell lysate from wild-type H. suis, lysate from a H. suis ggt mutant strain showed a decrease of the capacity to inhibit Jurkat T cell proliferation. Incubation of Jurkat T cells with recombinantly expressed H. suis GGT resulted in an impaired proliferation, and cell death was shown to be involved. A similar but more pronounced inhibitory effect was also seen on primary murine CD4+ T cells, CD8+ T cells, and CD19+ B cells. Supplementation with known GGT substrates was able to modulate the observed effects. Glutamine restored normal proliferation of the cells, whereas supplementation with reduced glutathione strengthened the H. suis GGT-mediated inhibition of proliferation. H. suis GGT treatment abolished secretion of IL-4 and IL-17 by CD4+ T cells, without affecting secretion of IFN-γ. Finally, H. suis outer membrane vesicles (OMV) were identified as a possible delivery route of H. suis GGT to lymphocytes residing in the deeper mucosal layers. Thus far, this study is the first to report that the effects on lymphocytes of this enzyme, not only important for H. suis metabolism but also for that of other Helicobacter species, depend on the degradation of two specific substrates: glutamine and reduced glutatione. This will provide new insights into the pathogenic mechanisms of H. suis infection in particular and infection with gastric helicobacters in general

NM23 proteins: innocent bystanders or local energy boosters for CFTR?

NM23 proteins NDPK-A and -B bind to the cystic fibrosis (CF) protein CFTR in different ways from kinases such as PKA, CK2 and AMPK or linkers to cell calcium such as calmodulin and annexins. NDPK-A (not -B) interacts with CFTR through reciprocal AMPK binding/control, whereas NDPK-B (not -A) binds directly to CFTR. NDPK-B can activate G proteins without ligand-receptor coupling, so perhaps NDPK-B's binding influences energy supply local to a nucleotide-binding site (NBD1) needed for CFTR to function. Curiously, CFTR (ABC-C7) is a member of the ATP-binding cassette (ABC) protein family that does not obey 'clan rules'; CFTR channels anions and is not a pump, regulates disparate processes, is itself regulated by multiple means and is so pleiotropic that it acts as a hub that orchestrates calcium signaling through its consorts such as calmodulin/annexins. Furthermore, its multiple partners make CFTR dance to different tunes in different cellular and subcellular locations as it recycles from the plasma membrane to endosomes. CFTR function in airway apical membranes is inhibited by smoking which has been dubbed 'acquired CF'. CFTR alone among family members possesses a trap for other proteins that it unfurls as a 'fish-net' and which bears consensus phosphorylation sites for many protein kinases, with PKA being the most canonical. Recently, the site of CFTR's commonest mutation has been proposed as a knock-in mutant that alters allosteric control of kinase CK2 by log orders of activity towards calmodulin and other substrates after CFTR fragmentation. This link from CK2 to calmodulin that binds the R region invokes molecular paths that control lumen formation, which is incomplete in the tracheas of some CF-affected babies. Thus, we are poised to understand the many roles of NDPK-A and -B in CFTR function and, especially lumen formation, which is defective in the gut and lungs of many CF babies