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Vascular endothelial growth factor receptor-2 (VEGFR2) is the main pro-angiogenic receptor expressed by endothelial cells (ECs). Using surface plasmon resonance, immunoprecipitation, enzymatic digestion, immunofluorescence and cross-linking experiments with specific sugar-binding lectins, we demonstrated that VEGFR2 bears both α,1-fucose and α(2,6)-linked sialic acid (NeuAc). However, only the latter is required for VEGF binding to VEGFR2 and consequent VEGF-dependent VEGFR2 activation and motogenic response in ECs. Notably, downregulation of β-galactoside α(2,6)-sialyltransferase expression by short hairpin RNA transduction inhibits VEGFR2 α(2,6) sialylation that is paralleled by an increase of β-galactoside α(2,3)-sialyltransferase expression. This results in an ex-novo α(2,3)-NeuAc sialylation of the receptor that functionally replaces the lacking α(2,6)-NeuAc, thus allowing VEGF/VEGFR2 interaction. In keeping with the role of VEGFR2 sialylation in angiogenesis, the α(2,6)-NeuAc-binding lectin Sambucus nigra (SNA) prevents VEGF-dependent VEGFR2 autophosphorylation and EC motility, proliferation and motogenesis. In addition, SNA exerts a VEGF-antagonist activity in tridimensional angiogenesis models in vitro and in the chick-embryo chorioallantoic membrane neovascularization assay and mouse matrigel plug assay in vivo . In conclusion, VEGFR2-associated NeuAc plays an important role in modulating VEGF/VEGFR2 interaction, EC pro-angiogenic activation and neovessel formation. VEGFR2 sialylation may represent a target for the treatment of angiogenesis-dependent diseases.

Chronic hypoxia events are a common occurrence in Atlantic salmon ( Salmo salar ) sea-cages, especially during the summer, and their frequency and severity are predicted to increase with climate change. Although hypoxia is considered a very important fish health and welfare issue by the aquaculture industry, few studies have investigated the impact of chronic hypoxia on the fish immune system and its response to pathogen exposure. We exposed post-smolt Atlantic salmon to hypoxia (40% air sat.) for 6 weeks. Thereafter, we sampled fish prior to (i.e., at Time 0, to assess constitutive immune function), and after they were intraperitoneally injected with PBS (phosphate buffered saline) or formalin-killed Aeromonas salmonicida . We measured several innate immune parameters including: hematological immune responses [respiratory burst (RB), hemolytic activity of alternate complement system and plasma lysozyme concentration], and the relative percentage of circulating blood cells (erythrocytes/immature erythrocytes, monocytes, and granulocytes and lymphocytes) at Time 0 and at 24 hours post-injection (hpi); and the transcript expression levels of 8 anti-bacterial biomarkers in the head kidney [ interleukin-1 beta ( il1b ), interleukin-8a ( il8a ), cyclooxygenase-2 ( cox2 ), toll-like receptor 5, secreted ( strl5 ), CC chemokine-like 19b ( ccl19b ), serum amyloid A5 ( saa5 ), hepcidin anti-microbial peptide a ( hampa ) and cathelicidin anti-microbial peptide b ( campb )] at Time 0 and at 6 and 24 hpi. In addition, we measured serum immunoglobulin (IgM) levels at Time 0 and at 8 weeks post-injection (4 weeks after a ‘boost’ injection). Fish exposed to chronic hypoxia had greater numbers of monocytes, which was consistent with the increase in RB, plasma lysozyme concentration and upregulated head kidney anti-bacterial gene expression (i.e., campb , ccl19b , hampa , il8a , stlr5 ). In contrast, chronic hypoxia: reduced RB and leukocyte numbers at 24 hpi in Asal compared to PBS-injected fish, and the transcript levels of campb , il1b , saa5 , il8a and stlr5 at 6- and/or 24- hpi; but had no effect on constitutive or post-stimulation serum IgM titers. Overall, our results indicate that chronic hypoxia has differential effects on salmon constitutive innate immune function vs. following antigen exposure, and thus, it is still unclear how chronic hypoxia will impact the capacity of fish to defend against pathogens.

The present study evaluated the assay to quantify the respiratory burst activity of blood leukocytes of pacu as an indicator of the innate immune system, using the reduction of nitroblue tetrazolium (NBT) to formazan as a measure of the production of reactive oxygen species (ROS). In order to assess the accuracy of the assay, fish were challenged by Aeromonas hydrophila and sampled one week after challenge. The A. hydrophila infection increased the leukocyte respiratory burst activity. The protocol showed a reliable and easy assay, appropriate to determine the respiratory burst activity of blood leukocytes of pacu, a neotropical fish, in the present experimental conditions. O presente estudo avaliou o ensaio para quantificar a atividade respiratória dos leucócitos do sangue de pacu como um indicador do sistema imune inato, usando a redução do nitroazul tetrazólio (NBT) a formazan como medida da produção de espécies reativas de oxigênio (EROs). Para avaliar a precisão do ensaio, peixes foram desafiados por Aeromonas hydrophila e amostrados uma semana após o desafio. A infecção com A. hydrophila aumentou a atividade respiratória dos leucócitos. O protocolo se mostrou confiável e de fácil aplicação, apropriado para determinar a atividade respiratória de leucócitos do sangue do pacu, peixe neotropical, nas condições experimentais apresentadas.

This study concerns the application of different geomatic techniques in forestry sector. An accurate 3D model of a veteran chestnut tree (Castanea sativa Mill.) has been realised integrating point clouds by Mobile Laser Scanner (MLS) and photogrammetry techniques. The surveys were conducted in two seasons (summer time: July 22nd 2021; autumn time: December 10th 2021), since chestnut is a deciduous tree and thus taking the chance to detect it also without leaves. Therefore, it was obtained tree’s metric data such as the diameter at breast height (DBH), the total height (TH), the crown basal area, the wood and crown volume. Annual surveys will result in a dataset of virtual trees that will be used to monitor the evolution of these noteworthy plants through time, which are expected to be considered as cultural heritage, given their story and their importance at regional and landscape level. The 3D model was then released for virtualization, making it accessible and available as a data container for different users. Such data will also provide historical memory about the presence of these veteran trees that might be lost in the future if affected by species-specific phytopathologies such as Ink Disease (Phytophthora spp.).

Corn and soybeans are commodities and ingredients of global interest, whose prices fluctuate based on global demands. In this sense, this study aimed to assess ora-pro-nóbis (Pereskia aculeata) leaf meal (OLM) as an alternative to be included in the diets of Nile tilapia (Oreochromis niloticus). The optimal inclusion level of OLM in tilapia diets is investigated herein, aiming to improve their growth performance and health. Five diet variations containing OLM (0%, 5%, 10%, 15%, and 20%) were tested. Feed conversion and protein efficiency rates in the 5% and 10% OLM groups were statistically similar to the control group (p ≤ 0.05) and lower in the 15% and 20% OLM groups. Fish fed 5% and 10% OLM diets showed better feed efficiency, while higher OLM levels (15% and 20%) led to reduced carcass protein and ether extract levels. Increasing OLM levels enhanced intestinal villi height and area, associated with improved nutrient absorption and decreased liver fat degeneration, suggesting dietary adaptation and healthier liver conditions. Thus, OLM can be included up to 10% in tilapia diets, improving their growth performance, feed efficiency, and intestinal absorptive capacity without adversely affecting other parameters.

Syndecan-1 is a heparan sulfate proteoglycan (HSPG) commonly upregulated in AIDS-related B lymphoid malignancies. Tat is the main HIV-1 transactivating factor that has a major role in the pathogenesis of AIDS-related lymphomas (ARL) by engaging heparan sulfate proteoglycans (HSPGs), chemokine receptors and integrins at the lymphoid cell (LC) surface. Here B-lymphoid Namalwa cell clones that do not express or overexpress syndecan-1 (EV-Ncs and SYN-Ncs, respectively) were compared for their responsiveness with Tat: in the absence of syndecan-1, Tat induces a limited EV-Nc migration via C-X-C motif chemokine receptor 4 (CXCR4), G-proteins and Rac. Syndecan-1 overexpression increases SYN-Nc responsiveness to Tat and makes this response independent from CXCR4 and G-protein and dependent instead on pp60src phosphorylation. Tat-induced SYN-Nc migration and pp60src phosphorylation require the engagement of α v β 3 integrin and consequent pp125FAK phosphorylation. This complex set of Tat-driven activations is orchestrated by the direct interaction of syndecan-1 with pp60src and its simultaneous coupling with α v β 3 . The Tat/syndecan-1/α v β 3 interplay is retained in vivo and is shared also by other syndecan-1 + B-LCs, including BJAB cells, whose responsiveness to Tat is inhibited by syndecan-1 knockdown. In conclusion, overexpression of syndecan-1 confers to B-LCs an increased capacity to migrate in response to Tat, owing to a switch from a CXCR4/G-protein/Rac to a syndecan-1/α v β 3 /pp60src/pp125FAK signal transduction pathway that depends on the formation of a complex in which syndecan-1 interacts with Tat via its HS-chains, with α v β 3 via its core protein ectodomain and with pp60src via its intracellular tail. These findings have implications in ARL progression and may help in identifying new therapeutical targets for the treatment of AIDS-associated neoplasia.

Syndecan-1 is a heparan sulfate proteoglycan (HSPG) commonly upregulated in AIDS-related B lymphoid malignancies. Tat is the main HIV-1 transactivating factor that has a major role in the pathogenesis of AIDS-related lymphomas (ARL) by engaging heparan sulfate proteoglycans (HSPGs), chemokine receptors and integrins at the lymphoid cell (LC) surface. Here B-lymphoid Namalwa cell clones that do not express or overexpress syndecan-1 (EV-Ncs and SYN-Ncs, respectively) were compared for their responsiveness with Tat: in the absence of syndecan-1, Tat induces a limited EV-Nc migration via C-X-C motif chemokine receptor 4 (CXCR4), G-proteins and Rac. Syndecan-1 overexpression increases SYN-Nc responsiveness to Tat and makes this response independent from CXCR4 and G-protein and dependent instead on pp60src phosphorylation. Tat-induced SYN-Nc migration and pp60src phosphorylation require the engagement of [alpha].sub.v[beta].sub.3 integrin and consequent pp125FAK phosphorylation. This complex set of Tat-driven activations is orchestrated by the direct interaction of syndecan-1 with pp60src and its simultaneous coupling with [alpha].sub.v[beta].sub.3. The Tat/syndecan-1/[alpha].sub.v[beta].sub.3 interplay is retained in vivo and is shared also by other syndecan-1.sup.+ B-LCs, including BJAB cells, whose responsiveness to Tat is inhibited by syndecan-1 knockdown. In conclusion, overexpression of syndecan-1 confers to B-LCs an increased capacity to migrate in response to Tat, owing to a switch from a CXCR4/G-protein/Rac to a syndecan-1/[alpha].sub.v[beta].sub.3/pp60src/pp125FAK signal transduction pathway that depends on the formation of a complex in which syndecan-1 interacts with Tat via its HS-chains, with [alpha].sub.v[beta].sub.3via its core protein ectodomain and with pp60src via its intracellular tail. These findings have implications in ARL progression and may help in identifying new therapeutical targets for the treatment of AIDS-associated neoplasia.

Myotonic dystrophy (DM1) is an autosomal dominant neuromuscular disorder associated with a (CTG)(n) expansion in the 3'-untranslated region of the DM1 protein kinase (DMPK) gene. To explain disease pathogenesis, the RNA dominance model proposes that the DM1 mutation produces a gain-of-function at the RNA level in which CUG repeats form RNA hairpins that sequester nuclear factors required for proper muscle development and maintenance. Here, we identify the triplet repeat expansion (EXP) RNA-binding proteins as candidate sequestered factors. As predicted by the RNA dominance model, binding of the EXP proteins is specific for dsCUG RNAs and proportional to the size of the triplet repeat expansion. Remarkably, the EXP proteins are homologous to the Drosophila muscleblind proteins required for terminal differentiation of muscle and photoreceptor cells. EXP expression is also activated during mammalian myoblast differentiation, but the EXP proteins accumulate in nuclear foci in DM1 cells. We propose that DM1 disease is caused by aberrant recruitment of the EXP proteins to the DMPK transcript (CUG)(n) expansion.

Tested was the efficiency of dietary metyrapone (MTP) in the inhibition of cortisol biosynthesis, as a tool to elucidate the effects of this hormone in the tropical fish pacu (Piaractus mesopotamicus H.) during air‐exposure‐induced stress. Moreover, MTP efficiency was shown to be affected by both the dose and time of administration and that a daily dose of 30 mg kg⁻¹ body weight for 10 days reduced the levels of circulating cortisol in stressed fish. The tested method of MTP administration, including the concentration and the time of administration, efficiently regulated cortisol synthesis in a non‐invasive manner.

Effects of β-glucan on innate immune responses and survival were studied in pacu experimentally infected with Aeromonas hydrophila. Fish fed diets containing 0, 0.1% and 1% β-glucan were injected with A. hydrophila. β-glucan enhanced fish survival in both treated groups (26.7% and 21.2% of the control, respectively). Leukocyte respiratory burst and alternative complement pathway activities were elevated after bacterial challenge regardless the β-glucan concentration. Lysozyme activity was higher after infection and showed a gradual increase as β-glucan concentration increased. A significant elevation in WBC count was observed either after bacterial challenge or by influence of β-glucan separately. The same response was observed in the number of thrombocytes, lymphocytes, eosinophils, LG-PAS positive cell and monocytes. It can be concluded that feeding pacu with β-glucan can increase protection against A. hydrophila, due to changes in non-specific immune responses. Os efeitos da β-glucana sobre as respostas imunes inatas e a sobrevivência foram estudados em pacu experimentalmente infectado com Aeromonas hydrophila. Peixes alimentados com dietas contendo 0,1% e 1% de β-glucana foram injetados com 1 × 108 CFU de A. hydrophila após 7 dias de alimentação. A sobrevivência de peixes foi maior nos dois grupos tratados em comparação ao grupo controle (26,7% e 21,2%, respectivamente). A atividade respiratória de leucócitos e a atividade hemolítica do complemento – via alternativa estavam elevadas após desafio bacteriano independentemente da concentração de β-glucana. A atividade de lisozima foi maior após a infecção e mostrou um aumento gradual de acordo com a concentração do imunoestimulante. Observou-se um aumento significativo na contagem de leucócitos totais após o desafio bacteriano e influência de β-glucana. A mesma resposta foi observada para trombócitos, linfócitos, eosinófilos, leucócito PAS positivo e monócitos. Com exceção de neutrófilos, que diminuíram frente ao mais alto nível do imunoestimulante e não se alteraram após a infecção, as outras células aumentaram após a exposição à A. hydrophila. A β-glucana não afetou os níveis de proteína total do soro, que aumentaram após o desafio bacteriano. Conclui-se que a administração de β-glucana em pacu pode aumentar a proteção contra A. hydrophila, por alterações nas respostas imunes de não-específicas.