189 research outputs found

    R implementation of the Ecological Risk due to Flow Alteration (ERFA) method

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    The R implementation of the Ecological Risk due to Flow Alteration (ERFA) method is a product of “Translating Environmental Flow Research in Cambodia” (TEFRIC), a project funded by the UK Natural Environment Research Council (NERC) involving the UCL Department of Geography, the Centre for Ecology and Hydrology (both in the UK), the Institute of Technology of Cambodia and the Tonle Sap Authority (both in Cambodia). Whilst this software was developed as part of this project with a geographical focus on SE Asia (and the example data sets provided are for the Mekong River Basin), use of the code is not restricted to this region. Instead it can be applied for any situation where baseline and scenario river flow time series are available. The software is referred thereafter as TEFRIC ERFA and can be downloaded freely from NERC Environmental Information Data Centre (Laizé and Thompson, 2019)

    Vanadate effects on bone metabolism: fish cell lines as an alternative to mammalian in vitro systems

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    Vanadate, one of the most relevant forms of vanadium in solution, has been associated with the regulation of various enzyme activities (e.g. phosphatases, ribonucleases, ATPases, etc.) and shown to exhibit important biological effects. Several in vivo and in vitro studies have clearly demonstrated that any deficiency or excess of vanadium can seriously affect bone formation and its metabolism. Bone-related effects result largely from vanadium insulino-mimetic capabilities mediated by specific inhibition of protein tyrosine phosphatases (PTPases) and consequent activation of tyrosine kinase receptors (e.g. insulin receptor). Although mammals have been repetitively shown to be appropriate models to study vanadate mechanisms of action, fish have recently emerged as alternative models. Fish has been recognized as suitable model to study vertebrate bone formation and the natural presence of high quantities of vanadium in water makes it even more suitable to investigate vanadium effect on bone formation. Recent data obtained using fish bone-derived cells revealed that micromolar concentrations (5 mM) of monomeric and decameric vanadate slightly stimulate growth performances while strongly inhibiting extracellular matrix mineralization through mechanisms involving both alkaline phosphatase and MAPK pathways. Recent data obtained in fish cells will be discussed here and further compared to results obtained in mammalian systems

    Impairment of mineralization by metavanadate and decavanadate solutions in a fish bone-derived cell line

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    Vanadium, a trace metal known to accumulate in bone and to mimic insulin, has been shown to regulate mammalian bone formation using in vitro and in vivo systems. In the present work, short- and long-term effects of metavanadate (containing monomeric, dimeric, tetrameric and pentameric vanadate species) and decavanadate (containing decameric vanadate species) solutions on the mineralization of a fish bone-derived cell line (VSa13) were studied and compared to that of insulin. After 2 h of incubation with vanadate (10 μM in monomeric vanadate), metavanadate exhibited higher accumulation rates than decavanadate (6.85±0.40 versus 3.95±0.10 μg V/g of protein, respectively) in fish VSa13 cells and was also shown to be less toxic when applied for short periods. In longer treatments with both metavanadate and decavanadate solutions, similar effects were promoted: stimulation of cell proliferation and strong impairment (75%) of extracellular matrix (ECM) mineralization. The effect of both vanadate solutions (5 μM in monomeric vanadate), on ECM mineralization was increased in the presence of insulin (10 nM). It is concluded that chronic treatment with both vanadate solutions stimulated fish VSa13 cells proliferation and prevented ECM mineralization. Newly developed VSa13 fish cells appeared to be appropriate in the characterization of vanadate effects on vertebrate bone formation, representing a good alternative to mammalian systems

    Color Hit-or-Miss Transform (CMOMP)

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    Publication in the conference proceedings of EUSIPCO, Bucharest, Romania, 201

    Vanadate and bone metabolism: effect on proliferation and mineralization of fish bone-derived cells

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    Vanadate is known for mimicking insulin action through activation of insulin and/or insulin like growth factor 1 (IGF 1) receptors. Vanadate insulin- like effect on bone-related metabolism has been previously investigated using mammalian in vitro cell systems but other vertebrate systems have rarely been used. We have recently demonstrated the suitability of a fish bone derived cell line (VSa13) to study anti-mineralogenic effects of vanadate. Here, we propose that vanadate stimulation of cell proliferation involves MAPK signalling pathway and IGF 1 receptor activation, while impairment of extracellular matrix (ECM) mineralization is likely to involve both MAPK and PI 3K pathways and insulin receptor activation

    Transcriptional regulation of gilthead seabream bone morphogenetic protein (BMP) 2 gene by bone- and cartilage-related transcription factors

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    Bone morphogenetic protein (BMP) 2 belongs to the transforming growth factor (3 (TGF(3) superfamily of cytokines and growth factors. While it plays important roles in embryo morphogenesis and organogenesis, BMP2 is also critical to bone and cartilage formation. Protein structure and function have been remarkably conserved throughout evolution and BMP2 transcription has been proposed to be tightly regulated, although few data is available. In this work we report the cloning and functional analysis of gilthead seabream BMP2 promoter. As in other vertebrates, seabream BMP2 gene has a 5' non-coding exon, a feature already present in DPP gene, the fruit fly ortholog of vertebrate BMP2 gene, and maintained throughout evolution. In silico analysis of seabream BMP2 promoter revealed several binding sites for bone and cartilage related transcription factors (TFs) and their functionality was evaluated using promoter-luciferase constructions and TF-expressing vectors. Runt -related transcription factor 3 (RUNX3) was shown to negatively regulate BMP2 transcription and combination with the core binding factor beta (CBF(3) further reduced transcriptional activity of the promoter. Although to a lesser extent, myocyte enhancer factor 2C (MEF2C) had also a negative effect on the regulation of BMP2 gene transcription, when associated with SRY (sex determining region Y)-box 9 (SOX9b). Finally, v-ets avian erythroblastosis virus E26 oncogene homolog 1 (ETS1) was able to slightly enhance BMP2 transcription. Data reported here provides new insights toward the better understanding of the transcriptional regulation of BMP2 gene in a bone and cartilage context. (C) 2015 Elsevier B.V. All rights reserved

    Fish models of induced osteoporosis

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    Osteopenia and osteoporosis are bone disorders characterized by reduced bone mineral density (BMD), altered bone microarchitecture and increased bone fragility. Because of global aging, their incidence is rapidly increasing worldwide and novel treatments that would be more efficient at preventing disease progression and at reducing the risk of bone fractures are needed. Preclinical studies are today a major bottleneck to the collection of new data and the discovery of new drugs, since they are commonly based on rodent in vivo systems that are time consuming and expensive, or in vitro systems that do not exactly recapitulate the complexity of low BMD disorders. In this regard, teleost fish, in particular zebrafish and medaka, have recently emerged as suitable alternatives to study bone formation and mineralization and to model human bone disorders. In addition to the many technical advantages that allow faster and larger studies, the availability of several fish models that efficiently mimic human osteopenia and osteoporosis phenotypes has stimulated the interest of the academia and industry toward a better understanding of the mechanisms of pathogenesis but also toward the discovery of new bone anabolic or antiresorptive compounds. This mini review recapitulates the in vivo teleost fish systems available to study low BMD disorders and highlights their applications and the recent advances in the field.UIDB/04326/2020, EAPA_151/2016/BLUEHUMANinfo:eu-repo/semantics/publishedVersio

    New insights on vitamin K metabolism in senegalese sole (Solea senegalensis) based on ontogenetic and tissue-specific vitamin K epoxide reductase molecular data

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    Vitamin K (VK) is a key nutrient for several biological processes (e.g., blood clotting and bone metabolism). To fulfill VK nutritional requirements, VK action as an activator of pregnane X receptor (Pxr) signaling pathway, and as a co-factor of γ-glutamyl carboxylase enzyme, should be considered. In this regard, VK recycling through vitamin K epoxide reductases (Vkors) is essential and should be better understood. Here, the expression patterns of vitamin K epoxide reductase complex subunit 1 (vkorc1) and vkorc1 like 1 (vkorc1l1) were determined during the larval ontogeny of Senegalese sole (Solea senegalensis), and in early juveniles cultured under different physiological conditions. Full-length transcripts for ssvkorc1 and ssvkorc1l1 were determined and peptide sequences were found to be evolutionarily conserved. During larval development, expression of ssvkorc1 showed a slight increase during absence or low feed intake. Expression of ssvkorc1l1 continuously decreased until 24 h post-fertilization, and remained constant afterwards. Both ssvkors were ubiquitously expressed in adult tissues, and highest expression was found in liver for ssvkorc1, and ovary and brain for ssvkorc1l1. Expression of ssvkorc1 and ssvkorc1l1 was differentially regulated under physiological conditions related to fasting and re-feeding, but also under VK dietary supplementation and induced deficiency. The present work provides new and basic molecular clues evidencing how VK metabolism in marine fish is sensitive to nutritional and environmental conditions.FCT: UIDB/04326/2020. ALGASOLE-16-02-01-FMP-0058; RTI2018-099029-A-I00; RYC2018-025337-I.info:eu-repo/semantics/publishedVersio

    Validation et limitation de métriques couleur pour l'ordonnancement

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    International audienceLa morphologie mathématique repose sur la notion d'ordonnancement. Pour le traitement d'images couleur, l'écriture d'une relation d'ordre valide nécessite l'utilisation de distances couleur normalisées issues des espaces CIELAB ou CIELUV . Depuis les premières recommandations de la Commission Internationale de l'Éclairage (CIE), plusieurs distances couleur ont été proposées pour l'amélioration des traitements de petites différences couleurs. Le but de cet article est d'étudier l'impact de ces formules de distance couleur dans le contexte de la morphologie mathématique couleur. Les résultats sont développés pour une nouvelle construction des opérateurs morphologiques couleur basée sur la distance dans l'espace CIELAB

    Keutel Syndrome, a review of 50 years of literature

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    Keutel syndrome (KS) is a rare autosomal recessive genetic disorder that was first identified in the beginning of the 1970s and nearly 30 years later attributed to loss-of-function mutations in the gene coding for the matrix Gla protein (MGP). Patients with KS are usually diagnosed during childhood (early onset of the disease), and the major traits include abnormal calcification of cartilaginous tissues resulting in or associated with malformations of skeletal tissues (e.g., midface hypoplasia and brachytelephalangism) and cardiovascular defects (e.g., congenital heart defect, peripheral pulmonary artery stenosis, and, in some cases, arterial calcification), and also hearing loss and mild developmental delay. While studies on Mgp-/- mouse, a faithful model of KS, show that pathologic mineral deposition (ectopic calcification) in cartilaginous and vascular tissues is the primary cause underlying many of these abnormalities, the mechanisms explaining how MGP prevents abnormal calcification remain poorly understood. This has negative implication for the development of a cure for KS. Indeed, at present, only symptomatic treatments are available to treat hypertension and respiratory complications occurring in the KS patients. In this review, we summarize the results published in the last 50 years on Keutel syndrome and present the current status of the knowledge on this rare pathology.CA-16115 - EJPRD2019-290 - UIDB/04326/2020info:eu-repo/semantics/publishedVersio
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