49 research outputs found

    Cutaneous Leishmaniosis in Portugal Due to Leishmania Infantum Mon-1

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    Leishmania infantum zimodeme MON-1 foi isolado a partir de uma lesão cutânea da face de uma criança, residente em Lisboa e que nunca saíu do país. Após biópsia excisional não houve recorrência da lesão. Este é o primeiro caso em que este agente é identificado como responsável pela leishmaniose cutãnea em Portugal

    Towards Responsible Research Career Assessment

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    Contact: [email protected] Policy brief Growing evidence suggests that the evaluation of researchers’ careers on the basis of narrow definitions of excellence is restricting diversity in academia, both in the development of its labour force and its approaches to address societal challenges. The current research evaluation system is hampering diverse career pathways spanning research, teaching and (community) service. It inhibits the inclusion and retention of minorities, women, people from lower socio-economic backgrounds and meaningful public engagement with research. Improving the evaluation system in a concerted effort with research institutes and other funders will help fully realize a European Research Area (ERA) that is open to all talents. This diversity is essential to sustain academic careers, to strengthen the relevance and impact of science for society, and to enhance the resilience of our society and environment. Advice to MSCA policymakers Increasing attention to responsibility in, of and for research practices (as evidenced in Responsible Research and Innovation and Open Science in the ERA), has galvanized researchers and organisations to call for a change in the research evaluation system. While the academic evaluation landscape is shifting (as documented in the following pages), much remains to be done. The Marie Skłodowska-Curie Actions (MSCA) can spearhead these developments by implementing the following recommendations: Broaden current evaluation criteria of MSCA calls in dialogue with all relevant stakeholders, making responsible use of the options outlined below, to enlarge and modernize the notion of excellence (as done with the Gender dimension). Reward applicants and organisations that engage in open and responsible research through public engagement, science education, open science and ethical research; Provide (online) training for evaluators on implicit bias to reduce the risks of perpetuating narrow interpretations of research excellence in their evaluations; Offer training within the MSCA programme, such as via Innovative Training Networks, to prepare researchers and organizations for open and responsible, academic as well as non-academic careers. This includes a focus on transferable skills such as leadership and community engagement and attention to societal challenges; Reward and showcase MSCA grantees who excel in multiple dimensions of research, teaching, and service by showcasing and rewarding their work prominently on the MSCA website and social media; Support knowledge exchange and communities of practice around diverse and inclusive forms of excellence by involving a wide range of stakeholders (including civil society) in the ongoing discussion around modernizing and diversifying the concepts of excellence, and what counts as good and impactful academic practice. [ this is an excerpt, see pdf below for full policy brief ] For more from the Marie Curie Alumni Association, please see: https://zenodo.org/communities/mca

    Ataxin-3 Plays a Role in Mouse Myogenic Differentiation through Regulation of Integrin Subunit Levels

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    BACKGROUND: During myogenesis several transcription factors and regulators of protein synthesis and assembly are rapidly degraded by the ubiquitin-proteasome system (UPS). Given the potential role of the deubiquitinating enzyme (DUB) ataxin-3 in the UPS, and the high expression of the murine ataxin-3 homolog in muscle during embryogenesis, we sought to define its role in muscle differentiation. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence analysis, we found murine ataxin-3 (mATX3) to be highly expressed in the differentiated myotome of E9.5 mouse embryos. C2C12 myoblasts depleted of mATX3 by RNA interference exhibited a round morphology, cell misalignment, and a delay in differentiation following myogenesis induction. Interestingly, these cells showed a down-regulation of alpha5 and alpha7 integrin subunit levels both by immunoblotting and immunofluorescence. Mouse ATX3 was found to interact with alpha5 integrin subunit and to stabilize this protein by repressing its degradation through the UPS. Proteomic analysis of mATX3-depleted C2C12 cells revealed alteration of the levels of several proteins related to integrin signaling. CONCLUSIONS: Ataxin-3 is important for myogenesis through regulation of integrin subunit levels.This work was financed by the Fundacao para a Ciencia e a Tecnologia (FCT) (POCI/SAU-MMO/60412/2002) and by National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS) grant RO1 NS038712 to HLP. MCC, FB, AJR, and RJT were supported by the FCT fellowships (SFRH/BD/9759/2003 and SFRH/BPD/28560/2006), (SFRH/BPD/17368/2004), (SFRH/BD/17066/2004), (SFRH/BD/29947/2006), respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Time-Lapse Analysis and Mathematical Characterization Elucidate Novel Mechanisms Underlying Muscle Morphogenesis

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    Skeletal muscle morphogenesis transforms short muscle precursor cells into long, multinucleate myotubes that anchor to tendons via the myotendinous junction (MTJ). In vertebrates, a great deal is known about muscle specification as well as how somitic cells, as a cohort, generate the early myotome. However, the cellular mechanisms that generate long muscle fibers from short cells and the molecular factors that limit elongation are unknown. We show that zebrafish fast muscle fiber morphogenesis consists of three discrete phases: short precursor cells, intercalation/elongation, and boundary capture/myotube formation. In the first phase, cells exhibit randomly directed protrusive activity. The second phase, intercalation/elongation, proceeds via a two-step process: protrusion extension and filling. This repetition of protrusion extension and filling continues until both the anterior and posterior ends of the muscle fiber reach the MTJ. Finally, both ends of the muscle fiber anchor to the MTJ (boundary capture) and undergo further morphogenetic changes as they adopt the stereotypical, cylindrical shape of myotubes. We find that the basement membrane protein laminin is required for efficient elongation, proper fiber orientation, and boundary capture. These early muscle defects in the absence of either lamininβ1 or lamininγ1 contrast with later dystrophic phenotypes in lamininα2 mutant embryos, indicating discrete roles for different laminin chains during early muscle development. Surprisingly, genetic mosaic analysis suggests that boundary capture is a cell-autonomous phenomenon. Taken together, our results define three phases of muscle fiber morphogenesis and show that the critical second phase of elongation proceeds by a repetitive process of protrusion extension and protrusion filling. Furthermore, we show that laminin is a novel and critical molecular cue mediating fiber orientation and limiting muscle cell length

    Transcriptome analyses based on genetic screens for Pax3 myogenic targets in the mouse embryo

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    <p>Abstract</p> <p>Background</p> <p>Pax3 is a key upstream regulator of the onset of myogenesis, controlling progenitor cell survival and behaviour as well as entry into the myogenic programme. It functions in the dermomyotome of the somite from which skeletal muscle derives and in progenitor cell populations that migrate from the somite such as those of the limbs. Few Pax3 target genes have been identified. Identifying genes that lie genetically downstream of <it>Pax3 </it>is therefore an important endeavour in elucidating the myogenic gene regulatory network.</p> <p>Results</p> <p>We have undertaken a screen in the mouse embryo which employs a <it>Pax3<sup>GFP </sup></it>allele that permits isolation of Pax3 expressing cells by flow cytometry and a <it>Pax3<sup>PAX3-FKHR </sup></it>allele that encodes PAX3-FKHR in which the DNA binding domain of Pax3 is fused to the strong transcriptional activation domain of FKHR. This constitutes a gain of function allele that rescues the <it>Pax3 </it>mutant phenotype. Microarray comparisons were carried out between <it>Pax3<sup>GFP/+ </sup></it>and <it>Pax3<sup>GFP/PAX3-FKHR </sup></it>preparations from the hypaxial dermomyotome of somites at E9.5 and forelimb buds at E10.5. A further transcriptome comparison between Pax3-GFP positive and negative cells identified sequences specific to myogenic progenitors in the forelimb buds. Potential Pax3 targets, based on changes in transcript levels on the gain of function genetic background, were validated by analysis on loss or partial loss of function <it>Pax3 </it>mutant backgrounds. Sequences that are up- or down-regulated in the presence of PAX3-FKHR are classified as somite only, somite and limb or limb only. The latter should not contain sequences from Pax3 positive neural crest cells which do not invade the limbs. Verification by whole mount <it>in situ </it>hybridisation distinguishes myogenic markers. Presentation of potential Pax3 target genes focuses on signalling pathways and on transcriptional regulation.</p> <p>Conclusions</p> <p>Pax3 orchestrates many of the signalling pathways implicated in the activation or repression of myogenesis by regulating effectors and also, notably, inhibitors of these pathways. Important transcriptional regulators of myogenesis are candidate Pax3 targets. Myogenic determination genes, such as <it>Myf5 </it>are controlled positively, whereas the effect of <it>Pax3 </it>on genes encoding inhibitors of myogenesis provides a potential brake on differentiation. In the progenitor cell population, <it>Pax7 </it>and also <it>Hdac5 </it>which is a potential repressor of <it>Foxc2</it>, are subject to positive control by <it>Pax3</it>.</p

    Sex Determination in the Squalius alburnoides Complex: An Initial Characterization of Sex Cascade Elements in the Context of a Hybrid Polyploid Genome

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    BACKGROUND:Sex determination processes vary widely among different vertebrate taxa, but no group offers as much diversity for the study of the evolution of sex determination as teleost fish. However, the knowledge about sex determination gene cascades is scarce in this species-rich group and further difficulties arise when considering hybrid fish taxa, in which mechanisms exhibited by parental species are often disrupted. Even though hybridisation is frequent among teleosts, gene based approaches on sex determination have seldom been conducted in hybrid fish. The hybrid polyploid complex of Squalius alburnoides was used as a model to address this question. METHODOLOGY/PRINCIPAL FINDINGS:We have initiated the isolation and characterization of regulatory elements (dmrt1, wt1, dax1 and figla) potentially involved in sex determination in S. alburnoides and in the parental species S. pyrenaicus and analysed their expression patterns by in situ hybridisation. In adults, an overall conservation in the cellular localization of the gene transcripts was observed between the hybrids and parental species. Some novel features emerged, such as dmrt1 expression in adult ovaries, and the non-dimorphic expression of figla, an ovarian marker in other species, in gonads of both sexes in S. alburnoides and S. pyrenaicus. The potential contribution of each gene to the sex determination process was assessed based on the timing and location of expression. Dmrt1 and wt1 transcripts were found at early stages of male development in S. alburnoides and are most likely implicated in the process of gonad development. CONCLUSIONS/SIGNIFICANCE:For the first time in the study of this hybrid complex, it was possible to directly compare the gene expression patterns between the bisexual parental species and the various hybrid forms, for an extended set of genes. The contribution of these genes to gonad integrity maintenance and functionality is apparently unaltered in the hybrids, suggesting that no abrupt shifts in gene expression occurred as a result of hybridisation

    Epidemiology of Superficial Fungal Infections in Portugal: 3-Year Review (2014-2016)

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    Introdução: As infeções fúngicas superficiais são as dermatoses infeciosas mais frequentes e a sua incidência continua a aumentar. Os dermatófitos são os principais agentes causais apresentando, contudo, uma distribuição geográfica variável. Material e Métodos: O presente estudo teve como objetivo a caracterização epidemiológica das infeções fúngicas superficiais diagnosticadas nos Serviços/Unidades de Dermatologia pertencentes ao Serviço Nacional de Saúde Português entre janeiro de 2014 e dezembro 2016 através da análise retrospetiva dos resultados das culturas realizadas durante esse período. Resultados: Foram estudados 2375 isolamentos, pertencentes a 2319 doentes. O dermatófito mais frequentemente isolado foi o Trichophyton rubrum (53,6%), tendo sido o principal agente causal da tinha da pele glabra (52,4%) e das onicomicoses (51,1%). Relativamente às tinhas do couro cabeludo, globalmente o Microsporum audouinii foi o agente mais prevalente (42,6%), seguido do Trichophyton soudanense (22,1%). Enquanto na área metropolitana de Lisboa estes dermatófitos foram os principais agentes de tinha do couro cabeludo, nas regiões Norte e Centro o agente mais frequente foi o Microsporum canis (58,5%). Os fungos leveduriformes foram os principais responsáveis pelas onicomicoses das mãos (76,7%). Conclusão: Os resultados deste estudo estão globalmente concordantes com a literatura científica. O Trichophyton rubrum apresenta-se como o dermatófito mais frequentemente isolado em cultura. Na tinha do couro cabeludo, na área metropolitana de Lisboa, as espécies antropofílicas de importação assumem particular destaque.info:eu-repo/semantics/publishedVersio

    Basement membrane components are key players in specialized extracellular matrices

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    More than three decades ago, basement membranes (BMs) were described as membrane-like structures capable of isolating a cell from and connecting a cell to its environment. Since this time, it has been revealed that BMs are specialized extracellular matrices (sECMs) with unique components that support important functions including differentiation, proliferation, migration, and chemotaxis of cells during development. The composition of these sECM is as unique as the tissues to which they are localized, opening the possibility that such matrices can fulfill distinct functions. Changes in BM composition play significant roles in facilitating the development of various diseases. Furthermore, tissues have to provide sECM for their stem cells during development and for their adult life. Here, we briefly review the latest research on these unique sECM and their components with a special emphasis on embryonic and adult stem cells and their niches

    ENDOGLIN is dispensable for vasculogenesis, but required for vascular endothelial growth factor-induced angiogenesis

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    ENDOGLIN (ENG) is a co-receptor for transforming growth factor-β (TGF-β) family members that is highly expressed in endothelial cells and has a critical function in the development of the vascular system. Mutations in Eng are associated with the vascular disease known as hereditary hemorrhagic telangiectasia type l. Using mouse embryonic stem cells we observed that angiogenic factors, including vascular endothelial growth factor (VEGF), induce vasculogenesis in embryoid bodies even when Eng deficient cells or cells depleted of Eng using shRNA are used. However, ENG is required for the stem cell-derived endothelial cells to organize effectively into tubular structures. Consistent with this finding, fetal metatarsals isolated from E17.5 Eng heterozygous mouse embryos showed reduced VEGF-induced vascular network formation. Moreover, shRNA-mediated depletion and pharmacological inhibition of ENG in human umbilical vein cells mitigated VEGF-induced angiogenesis. In summary, we demonstrate that ENG is required for efficient VEGF-induced angiogenesis

    Z-disc protein CHAPb induces cardiomyopathy and contractile dysfunction in the postnatal heart

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    The Z-disc is a crucial structure of the sarcomere and is implicated in mechanosensation/transduction. Dysregulation of Z-disc proteins often result in cardiomyopathy. We have previously shown that the Z-disc protein Cytoskeletal Heart-enriched Actin-associated Protein (CHAP) is essential for cardiac and skeletal muscle development. Furthermore, the CHAP gene has been associated with atrial fibrillation in humans. Here, we studied the misregulated expression of CHAP isoforms in heart disease. Mice that underwent transverse aortic constriction and calcineurin transgenic (Tg) mice, both models of experimental heart failure, displayed a significant increase in cardiac expression of fetal isoform CHAPb. To investigate whether increased expression of CHAPb postnatally is sufficient to induce cardiomyopathy, we generated CHAPb Tg mice under the control of the cardiac-specific αMHC promoter. CHAPb Tg mice displayed cardiac hypertrophy, interstitial fibrosis and enlargement of the left atrium at three months, which was more pronounced at the age of six months. Hypertrophy and fibrosis were confirmed by evidence of activation of the hypertrophic gene program (Nppa, Nppb, Myh7) and increased collagen expression, respectively. Connexin40 and 43 were downregulated in the left atrium, which was associated with delayed atrioventricular conduction. Tg hearts displayed both systolic and diastolic dysfunction partly caused by impaired sarcomere function evident from a reduced force generating capacity of single cardiomyocytes. This co-incided with activation of the actin signalling pathway leading to the formation of stress fibers. This study demonstrated that the fetal isoform CHAPb initiates progression towards cardiac hypertrophy, which is accompanied by delayed atrioventricular conduction and diastolic dysfunction. Moreover, CHAP may be a novel therapeutic target or candidate gene for screening in cardiomyopathies and atrial fibrillatio
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