1,528 research outputs found

    Predictable phenotypic, but not karyotypic, evolution of populations with contrasting initial history

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    This study was financed by Portuguese National Funds through FCT - ‘Fundação para a Ciência e Tecnologia’ within the projects PTDC/BIA-BEC/098213/2008, PTDC/BIA-BIC/2165/2012 and cE3c Unit FCT funding UID/BIA/00329/2013. I.F. had a PhD grant (SFRH/BD/60734/2009), P.S. has a Post Doc grant (SFRH/BPD/86186/2012) and S.G.S. has a Post Doc grant (SFRH/BPD/108413/2015) from FCT. M.S. is funded by grant CGL2013-42432-P from the Ministerio de Economía y Competitividad (Spain) and grant 2014 SGR 1346 from Generalitat de Catalunya. The datasets generated during and/or analysed during the current study are available in the figshare repository, at https://doi.org/10.6084/m9.figshare.4797550.The relative impact of selection, chance and history will determine the predictability of evolution. There is a lack of empirical research on this subject, particularly in sexual organisms. Here we use experimental evolution to test the predictability of evolution. We analyse the real-time evolution of Drosophila subobscura populations derived from contrasting European latitudes placed in a novel laboratory environment. Each natural population was sampled twice within a three-year interval. We study evolutionary responses at both phenotypic (life-history, morphological and physiological traits) and karyotypic levels for around 30 generations of laboratory culture. Our results show (1) repeatable historical effects between years in the initial state, at both phenotypic and karyotypic levels; (2) predictable phenotypic evolution with general convergence except for body size; and (3) unpredictable karyotypic evolution. We conclude that the predictability of evolution is contingent on the trait and level of organization, highlighting the importance of studying multiple biological levels with respect to evolutionary patterns.Publisher PDFPeer reviewe

    Cysteine Boosts Fitness Under Hypoxia-Mimicked Conditions in Ovarian Cancer by Metabolic Reprogramming

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    Funding Information: Funding. This research was supported by Funda??o para a Ci?ncia e Tecnologia (FCT) (Ph.D. ProRegeM program, Ref: PD/BD/105893/2014; FCT individual Ph.D. fellowship Ref: 2020.06956.BD) and iNOVA4 Health (Project 4 and Project 21). iNOVA4Health-UID/Multi/04462/2013 is a program financially supported by Funda??o para a Ci?ncia e Tecnologia/ Minist?rio da Educa??o e Ci?ncia, through national funds. The authors would like to acknowledge the Instituto Portugu?s de Oncologia de Lisboa Francisco Gentil (IPOLFG) for partially funding the project. Publisher Copyright: © Copyright © 2021 Nunes, Ramos, Santos, Mendes, Silva, Vicente, Pereira, Félix, Gonçalves and Serpa.Among gynecologic malignancies, ovarian cancer is the third most prevalent and the most common cause of death, especially due to diagnosis at an advanced stage together with resistance to therapy. As a solid tumor grows, cancer cells in the microenvironment are exposed to regions of hypoxia, a selective pressure prompting tumor progression and chemoresistance. We have previously shown that cysteine contributes to the adaptation to this hypoxic microenvironment, but the mechanisms by which cysteine protects ovarian cancer cells from hypoxia-induced death are still to be unveiled. Herein, we hypothesized that cysteine contribution relies on cellular metabolism reprogramming and energy production, being cysteine itself a metabolic source. Our results strongly supported a role of xCT symporter in energy production that requires cysteine metabolism instead of hydrogen sulfide (H2S) per se. Cysteine degradation depends on the action of the H2S-synthesizing enzymes cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and/or 3-mercaptopyruvate sulfurtransferase (MpST; together with cysteine aminotransferase, CAT). In normoxia, CBS and CSE inhibition had a mild impact on cysteine-sustained ATP production, pointing out the relevance of CAT + MpST pathway. However, in hypoxia, the concomitant inhibition of CBS and CSE had a stronger impact on ATP synthesis, thus also supporting a role of their hydrogen sulfide and/or cysteine persulfide-synthesizing activity in this stressful condition. However, the relative contributions of each of these enzymes (CBS/CSE/MpST) on cysteine-derived ATP synthesis under hypoxia remains unclear, due to the lack of specific inhibitors. Strikingly, NMR analysis strongly supported a role of cysteine in the whole cellular metabolism rewiring under hypoxia. Additionally, the use of cysteine to supply biosynthesis and bioenergetics was reinforced, bringing cysteine to the plateau of a main carbon sources in cancer. Collectively, this work supports that sulfur and carbon metabolism reprogramming underlies the adaptation to hypoxic microenvironment promoted by cysteine in ovarian cancer.publishersversionpublishe

    Enhanced lithium depletion in Sun-like stars with orbiting planets

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    The surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age, mass and metallicity is observed, but theoretically difficult to understand. An earlier suggestion that Li is more depleted in stars with planets was weakened by the lack of a proper comparison sample of stars without detected planets. Here we report Li abundances for an unbiased sample of solar-analogue stars with and without detected planets. We find that the planet-bearing stars have less than 1 per cent of the primordial Li abundance, while about 50 per cent of the solar analogues without detected planets have on average 10 times more Li. The presence of planets may increase the amount of mixing and deepen the convective zone to such an extent that the Li can be burned.Comment: 13 pages, 2 figure

    Different genomic changes underlie adaptive evolution in populations of contrasting history

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    Funding Information: This work was supported by Portuguese National Funds through “Fundac¸ão para a Ciência e a Tecnologia” (projects PTDC/ BIA-BEC/098213/2008, PTDC/BIA-BIC/2165/2012 and cE3c Unit FCT funding UID/BIA/00329/2013, grants SFRH/BD/ 60734/2009 to I.F. and SFRH/BPD/86186/2012 to P.S.). We thank Miguel Lopes-Cunha for help in the laboratory, Francisco Pina-Martins for help with computing, Josiane Santos and Ana Sofia Quina for discussions, and Mauro Santos and Anthony Long for advice on the study and comments on the manuscript. We also thank the three anonymous reviewers for their constructive suggestions.Experimental evolution is a powerful tool to understand the adaptive potential of populations under environmental change. Here, we study the importance of the historical genetic background in the outcome of evolution at the genomewide level. Using the natural clinal variation of Drosophila subobscura, we sampled populations from two contrasting latitudes (Adraga, Portugal and Groningen, Netherlands) and introduced them in a new common environment in the laboratory. We characterized the genome-wide temporal changes underlying the evolutionary dynamics of these populations, which had previously shown fast convergence at the phenotypic level, but not at chromosomal inversion frequencies. We found that initially differentiated populations did not converge either at genome-wide level or at candidate SNPs with signs of selection. In contrast, populations from Portugal showed convergence to the control population that derived from the same geographical origin and had been long-established in the laboratory. Candidate SNPs showed a variety of different allele frequency change patterns across generations, indicative of an underlying polygenic basis. We did not detect strong linkage around candidate SNPs, but rather a small but long-ranging effect. In conclusion, we found that history played a major role in genomic variation and evolution, with initially differentiated populations reaching the same adaptive outcome through different genetic routes.publishersversionpublishe

    Multiplex PCR identification of eight clinically relevant Candida species

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    Invasive fungal infections, specifically candidemia, constitute major public health problems with high mortality rates. Therefore, in the last few years, the development of novel diagnostic methods has been considered a critical issue. Herein we describe a multiplex PCR strategy allowing the identification of 8 clinically relevant yeasts of the Candida genus, namely C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, C. guilliermondii, C. lusitaniae and C. dubliniensis. This method is based on the amplification of two fragments from the ITS1 and ITS2 regions by the combination of 2 yeast-specific and 8 species-specific primers in a single PCR reaction. Results from the identification of 231 clinical isolates are presented pointing to the high specificity of this procedure. Furthermore, several Candida isolates were identified directly from clinical specimens which also attests to the method's direct laboratory application. The results from the multiplex reactions with other microorganisms that usually co-infect patients also confirmed its high specificity in the identification of Candida species. Moreover, this method is simple and presents a sensitivity of approximately 2 cells per ml within 5 hours. Furthermore, it allows discrimination of individual Candida species within polyfungal samples. This novel method may therefore provide a clinical diagnostic procedure with direct applicability.Agostinho Carvalho was financially supported by a fellowship from Fundação para a Ciência e Tecnologia, Portugal (contract SFRH/BD/11837/2003). This study was supported by Fundação para a Ciência e Tecnologia, Portugal (POCI/SAU-ESP/61080/2004)

    Activation pathway to amino acid adducts

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    Funding: This work was supported in part by Fundação para a Ciência e a Tecnologia (FCT), Portugal (PTDC/QUI-QUI/113910/2009, RECI/QEQ-MED/0330/2012, UID/QUI/00100/2013 and IF/ 01091/2013/CP1163/CT0001), and by Interagency Agreement Y1ES1027 between the National Center for Toxicological Research/Food and Drug Administration and the National Institute of Environmental Health Sciences/National Toxicology Program. The opinions expressed in this paper do not necessarily represent those of the U.S. Food and Drug Administration. RW, ALG, ILM and SGH thank FCT for postdoctoral and doctoral fellowships (SFRH/BPD/70953/2010, SFRH/BD/72301/2010, SFRH/BD/75426/2010 and SFRH/BD/ 80690/2011, respectively). AMM also acknowledges Programa Operacional Potencial Humano from FCT and the European Social Fund (IF/01091/2013), and the LRI Innovative Science Award. We thank the Portuguese NMR and MS networks (IST nodes) for providing access to the facilities.Nevirapine (NVP) is the non-nucleoside HIV-1 reverse transcriptase inhibitor most commonly used in developing countries, both as a component of combined antiretroviral therapy and to prevent mother-to-child transmission of the virus; however, severe hepatotoxicity and serious adverse cutaneous effects raise concerns about its safety. NVP metabolism yields several phenolic derivatives conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid derivatives prone to react with bionucleophiles and initiate toxic responses. We investigated the ability of two phenolic NVP metabolites, 2-hydroxy-NVP and 3-hydroxy-NVP, to undergo oxidation and subsequent reaction with bionucleophiles. Both metabolites yielded the same ring-contraction product upon oxidation with Frémy's salt in aqueous medium. This is consistent with the formation of a 2,3-NVP-quinone intermediate, which upon stabilization by reduction was fully characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. Additionally, we established that the oxidative activation of 2-hydroxy-NVP involved the transient formation of both the quinone and a quinone-imine, whereas 3-hydroxy-NVP was selectively converted into 2,3-NVP-quinone. The oxidations of 2-hydroxy-NVP and 3-hydroxy-NVP in the presence of the model amino acids ethyl valinate (to mimic the highly reactive N-terminal valine of hemoglobin) and N-acetylcysteine were also investigated. Ethyl valinate reacted with both 2,3-NVP-quinone and NVP-quinone-imine, yielding covalent adducts. By contrast, neither 2,3-NVP-quinone nor NVP-derived quinone-imine reacted with N-acetylcysteine. The product profile observed upon Frémy's salt oxidation of 2-hydroxy-NVP in the presence of ethyl valinate was replicated with myeloperoxidase-mediated oxidation. Additionally, tyrosinase-mediated oxidations selectively yielded 2,3-NVP-quinone-derived products, while quinone-imine-derived products were obtained upon lactoperoxidase catalysis. These observations suggest that the metabolic conversion of phenolic NVP metabolites into quinoid electrophiles is biologically plausible. Moreover, the lack of reaction with sulfhydryl groups might hamper the in vivo detoxification of NVP-derived quinone and quinone-imine metabolites via glutathione conjugation. As a result, these metabolites could be available for reaction with nitrogen-based bionucleophiles (e.g., lysine residues of proteins) ultimately eliciting toxic events.publishersversionpublishe

    Potential impact on stroke

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    Funding Information: The funding agency that supported the work \u201CFunda\u00E7\u00E3o para a Ci\u00EAncia e Tecnologia\u201D (FCT) with four projects: Applied Molecular Biosciences Unit-UCIBIO (UID/Multi/04378/2019), iNOVA4Health - Programme in Translational Medicine (UID/Multi/04462/2013), LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy and PTDC/MEC-NEU/28750/2017 and the PhD scholarship for NLS (PD/BD/127819/2016). Publisher Copyright: © 2024 The AuthorsRemote ischemic conditioning (RIC) is a procedure consisting of short cycles of ischemia applied in a limb that activates endogenous protection in distant organs, such as the brain. Despite the promising outcomes of RIC, the biochemical factors governing inter-organ communication remain largely unexplored, particularly in humans. A pilot study on 20 healthy humans was performed to identify potential circulating biochemical factors involved in RIC signalling. Blood was collected before and immediately, 4 and 22 h after the end of RIC. To characterize the responses triggered by RIC, a combination of biochemical and proteomic analysis, along with functional in vitro tests in human cells, were performed. RIC did not alter the levels of nitric oxide, bilirubin and cell-free mitochondrial DNA. In contrast, carboxyhaemoglobin levels increased following RIC at all time points and young subset, suggesting endogenous production of carbon monoxide that is a cytoprotective gasotransmitter. Additionally, the levels of glutathione and cysteinylglycine bound to proteins also increased after RIC, while glutathione catabolism decreased. Plasma proteomic analysis identified overall 828 proteins. Several steps of statistical analysis (Student's t-test, repeated measures ANOVA, with Holm corrected pairwise p-values <0.05 threshold and fold change higher or lower than 100 %) leaded to the identification of 9 proteins with altered circulating levels in response to RIC at 4h and 22h. All 9 proteins are from extracellular space or exosomes, being involved in inflammation, angiogenesis or metabolism control. In addition, RIC-conditioned plasma from young subjects protected microglial cell culture against inflammatory stimuli, indicating an anti-inflammatory effect of RIC. Nevertheless, other functional tests in neurons or endothelial cells had no effect. Overall, we present some evidence for RIC-induced anti-inflammatory and antioxidant responses in healthy human subjects, in particular in young subjects. This study is a first step towards the disclosure of signalling factors involved in RIC-mediated inter-organ communication.publishersversionpublishe

    Diversity and Relatedness Enhance Survival in Colour Polymorphic Grasshoppers

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    Evolutionary theory predicts that different resource utilization and behaviour by alternative phenotypes may reduce competition and enhance productivity and individual performance in polymorphic, as compared with monomorphic, groups of individuals. However, firm evidence that members of more heterogeneous groups benefit from enhanced survival has been scarce or lacking. Furthermore, benefits associated with phenotypic diversity may be counterbalanced by costs mediated by reduced relatedness, since closely related individuals typically are more similar. Pygmy grasshoppers (Tetrix subulata) are characterized by extensive polymorphism in colour pattern, morphology, behaviour and physiology. We studied experimental groups founded by different numbers of mothers and found that survival was higher in low than in high density, that survival peaked at intermediate colour morph diversity in high density, and that survival was independent of diversity in low density where competition was less intense. We further demonstrate that survival was enhanced by relatedness, as expected if antagonistic and competitive interactions are discriminately directed towards non-siblings. We therefore also performed behavioural observations and staged encounters which confirmed that individuals recognized and responded differently to siblings than to non-siblings. We conclude that negative effects associated with competition are less manifest in diverse groups, that there is conflicting selection for and against genetic diversity occurring simultaneously, and that diversity and relatedness may facilitate the productivity and ecological success of groups of interacting individuals
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