155 research outputs found

    Primary Effects on Skeletal Muscle

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    The present study was supported by the Portuguese Society of Diabetes. JS was supported by a PhD Grant from the Portuguese Foundation for Science and Technology, PD/BD/105890/2014.Epidemiological studies showed that chronic caffeine intake decreased the risk of type 2 diabetes. Previously, we described that chronic caffeine intake prevents and reverses insulin resistance induced by hypercaloric diets and aging, in rats. Caffeine has several cellular mechanisms of action, being the antagonism of adenosine receptors the only attained with human coffee consumption. Here, we investigated the subtypes of adenosine receptors involved on the effects of chronic caffeine intake on insulin sensitivity and the mechanisms and sex differences behind this effect. Experiments were performed in male and female Wistar rats fed either a chow or high-sucrose (HSu) diet (35% of sucrose in drinking water) during 28 days, to induce insulin resistance. In the last 15 days of diet the animals were submitted to DPCPX (A1 antagonist, 0.4 mg/kg), SCH58261 (A2A antagonist, 0.5 mg/kg), or MRS1754 (A2B antagonist, 9.5 μg/kg) administration. Insulin sensitivity, fasting glycaemia, blood pressure, catecholamines, and fat depots were assessed. Expression of A1, A2A, A2B adenosine receptors and protein involved in insulin signaling pathways were evaluated in the liver, skeletal muscle, and visceral adipose tissue. UCP1 expression was measured in adipose tissue. Paradoxically, SCH58261 and MRS1754 decreased insulin sensitivity in control animals, whereas they both improved insulin response in HSu diet animals. DPCPX did not alter significantly insulin sensitivity in control or HSu animals, but reversed the increase in total and visceral fat induced by the HSu diet. In skeletal muscle, A1, A2A, and A2B adenosine receptor expression were increased in HSu group, an effect that was restored by SCH58261 and MRS1754. In the liver, A1, A2A expression was increased in HSu group, while A2B expression was decreased, being this last effect reversed by administration of MRS1754. In adipose tissue, A1 and A2A block upregulated the expression of these receptors. A2 adenosine antagonists restored impaired insulin signaling in the skeletal muscle of HSu rats, but did not affect liver or adipose insulin signaling. Our results show that adenosine receptors exert opposite effects on insulin sensitivity, in control and insulin resistant states and strongly suggest that A2 adenosine receptors in the skeletal muscle are the majors responsible for whole-body insulin sensitivity.publishersversionpublishe

    Systematic comparison of the effects of Alpha-synuclein mutations on its oligomerization and aggregation

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    Copyright: © 2014 Lázaro et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Aggregation of alpha-synuclein (ASYN) in Lewy bodies and Lewy neurites is the typical pathological hallmark of Parkinson's disease (PD) and other synucleinopathies. Furthermore, mutations in the gene encoding for ASYN are associated with familial and sporadic forms of PD, suggesting this protein plays a central role in the disease. However, the precise contribution of ASYN to neuronal dysfunction and death is unclear. There is intense debate about the nature of the toxic species of ASYN and little is known about the molecular determinants of oligomerization and aggregation of ASYN in the cell. In order to clarify the effects of different mutations on the propensity of ASYN to oligomerize and aggregate, we assembled a panel of 19 ASYN variants and compared their behaviour. We found that familial mutants linked to PD (A30P, E46K, H50Q, G51D and A53T) exhibited identical propensities to oligomerize in living cells, but had distinct abilities to form inclusions. While the A30P mutant reduced the percentage of cells with inclusions, the E46K mutant had the opposite effect. Interestingly, artificial proline mutants designed to interfere with the helical structure of the N-terminal domain, showed increased propensity to form oligomeric species rather than inclusions. Moreover, lysine substitution mutants increased oligomerization and altered the pattern of aggregation. Altogether, our data shed light into the molecular effects of ASYN mutations in a cellular context, and established a common ground for the study of genetic and pharmacological modulators of the aggregation process, opening new perspectives for therapeutic intervention in PD and other synucleinopathies.This work was supported by the DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB).info:eu-repo/semantics/publishedVersio

    Ages and metallicities of stellar clusters using S-PLUS narrow-band integrated photometry: the Small Magellanic Cloud

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    The Magellanic Clouds are the most massive and closest satellite galaxies of the Milky Way, with stars covering ages from a few Myr up to 13 Gyr. This makes them important for validating integrated light methods to study stellar populations and star-formation processes, which can be applied to more distant galaxies. We characterized a set of stellar clusters in the Small Magellanic Cloud (SMC), using the Southern Photometric Local Universe Survey\textit{Southern Photometric Local Universe Survey}. This is the first age (metallicity) determination for 11 (65) clusters of this sample. Through its 7 narrow bands, centered on important spectral features, and 5 broad bands, we can retrieve detailed information about stellar populations. We obtained ages and metallicities for all stellar clusters using the Bayesian spectral energy distribution fitting code BAGPIPES\texttt{BAGPIPES}. With a sample of clusters in the color range 0.20<rz<+0.35-0.20 < r-z < +0.35, for which our determined parameters are most reliable, we modeled the age-metallicity relation of SMC. At any given age, the metallicities of SMC clusters are lower than those of both the Gaia Sausage-Enceladus disrupted dwarf galaxy and the Milky Way. In comparison with literature values, differences are Δ\Deltalog(age)0.31\approx0.31 and Δ\Delta[Fe/H]0.41\approx0.41, which is comparable to low-resolution spectroscopy of individual stars. Finally, we confirm a previously known gradient, with younger clusters in the center and older ones preferentially located in the outermost regions. On the other hand, we found no evidence of a significant metallicity gradient.Comment: 12 pages, 11 figure

    nutrition and performance in football

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    Nutrition is an undeniable part of promoting health and performance among football (soccer) players. Nevertheless, nutritional strategies adopted in elite football can vary significantly depending on culture, habit and practical constraints and might not always be supported by scientific evidence. Therefore, a group of 28 Portuguese experts on sports nutrition, sports science and sports medicine sought to discuss current practices in the elite football landscape and review the existing evidence on nutritional strategies to be applied when supporting football players. Starting from understanding football?s physical and physiological demands, five different moments were identified: preparing to play, match-day, recovery after matches, between matches and during injury or rehabilitation periods. When applicable, specificities of nutritional support to young athletes and female players were also addressed. The result is a set of practical recommendations that gathered consensus among involved experts, highlighting carbohydrates periodisation, hydration and conscious use of dietary supplements.D915-7373-ED16 | Cesar LeaoN/

    Activation of Type 1 Cannabinoid Receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures

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    The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive), neurons and astrocytes. Stimulation of the CB1R by (R)-(+)-Methanandamide (R-m-AEA) increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation), at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca2+](i)) in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.Fundacao para a Ciencia e a Tecnologia - Portugal [POCTI/SAU-NEU/68465/2006, PTDC/SAU-NEU/104415/2008, PTDC/SAU-NEU/101783/2008, POCTI/SAU-NEU/110838/2009]; Fundacao Calouste Gulbenkian [96542]; Fundacao para a Ciencia e Tecnologiainfo:eu-repo/semantics/publishedVersio

    Exosomes secreted by cardiomyocytes subjected to ischaemia promote cardiac angiogenesis

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    Funding Information: This work was supported by European Regional Development Fund (FEDER) through the Operational Program for Competitiveness Factors (COMPETE) [HealthyAging2020 CENTRO-01-0145-FEDER-000012-N2323, POCI-01-0145-FEDER-016385, POCI-01-0145-FEDER-007440 to CNC.IBILI, POCI-01-0145-FEDER-007274 to i3S/INEB and NORTE-01-0145-FEDER-000012 to T.L.L.]; national funds through the Portuguese Foundation for Science and Technology (FCT) [PTDC/SAU-ORG/119296/2010, PTDC/ NEU-OSD/0312/2012, PESTC/ SAU/UI3282/2013-2014, MITP-TB/ECE/0013/ 2013, FCT-UID/NEU/04539/2013], PD/BD/52294/2013 to T.M.R.R., SFRH/ BD/85556/2012 (co-financed by QREN) to V.C.S]; Lisboa Portugal Regional Operational Programme (LISBOA 2020) and Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement; and by INFARMED Autoridade Nacional do Medicamento e Produtos de Saúde, I.P. [FIS-FIS-2015-01_CCV_20150630-157]. Publisher Copyright: © 2017 The Author.Aims Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide and results from an obstruction in the blood supply to a region of the heart. In an attempt to replenish oxygen and nutrients to the deprived area, affected cells release signals to promote the development of new vessels and confer protection against MI. However, the mechanisms underlying the growth of new vessels in an ischaemic scenario remain poorly understood. Here, we show that cardiomyocytes subjected to ischaemia release exosomes that elicit an angiogenic response of endothelial cells (ECs). Methods and results Exosomes secreted by H9c2 myocardial cells and primary cardiomyocytes, cultured either in control or ischaemic conditions were isolated and added to ECs. We show that ischaemic exosomes, in comparison with control exosomes, confer protection against oxidative-induced lesion, promote proliferation, and sprouting of ECs, stimulate the formation of capillary-like structures and strengthen adhesion complexes and barrier properties. Moreover, ischaemic exosomes display higher levels of metalloproteases (MMP) and promote the secretion of MMP by ECs. We demonstrate that miR-222 and miR-143, the relatively most abundant miRs in ischaemic exosomes, partially recapitulate the angiogenic effect of exosomes. Additionally, we show that ischaemic exosomes stimulate the formation of new functional vessels in vivo using in ovo and Matrigel plug assays. Finally, we demonstrate that intramyocardial delivery of ischaemic exosomes improves neovascularization following MI. Conclusions This study establishes that exosomes secreted by cardiomyocytes under ischaemic conditions promote heart angiogenesis, which may pave the way towards the development of add-on therapies to enhance myocardial blood supply.publishersversionpublishe

    Enhancing Network Slicing Architectures with Machine Learning, Security, Sustainability and Experimental Networks Integration

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    Network Slicing (NS) is an essential technique extensively used in 5G networks computing strategies, mobile edge computing, mobile cloud computing, and verticals like the Internet of Vehicles and industrial IoT, among others. NS is foreseen as one of the leading enablers for 6G futuristic and highly demanding applications since it allows the optimization and customization of scarce and disputed resources among dynamic, demanding clients with highly distinct application requirements. Various standardization organizations, like 3GPP's proposal for new generation networks and state-of-the-art 5G/6G research projects, are proposing new NS architectures. However, new NS architectures have to deal with an extensive range of requirements that inherently result in having NS architecture proposals typically fulfilling the needs of specific sets of domains with commonalities. The Slicing Future Internet Infrastructures (SFI2) architecture proposal explores the gap resulting from the diversity of NS architectures target domains by proposing a new NS reference architecture with a defined focus on integrating experimental networks and enhancing the NS architecture with Machine Learning (ML) native optimizations, energy-efficient slicing, and slicing-tailored security functionalities. The SFI2 architectural main contribution includes the utilization of the slice-as-a-service paradigm for end-to-end orchestration of resources across multi-domains and multi-technology experimental networks. In addition, the SFI2 reference architecture instantiations will enhance the multi-domain and multi-technology integrated experimental network deployment with native ML optimization, energy-efficient aware slicing, and slicing-tailored security functionalities for the practical domain.Comment: 10 pages, 11 figure

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing

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    Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe
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