981 resultados para Cavalo marinho
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The identification of genes involved in signaling and regulatory pathways, and matrix formation is paramount to the better understanding of the complex mechanisms of bone formation and mineralization, and critical to the successful development of therapies for human skeletal disorders. To achieve this objective, in vitro cell systems derived from skeletal tissues and able to mineralize their extracellular matrix have been used to identify genes differentially expressed during mineralization and possibly new markers of bone and cartilage homeostasis. Using cell systems of fish origin and techniques such as suppression subtractive hybridization and microarray hybridization, three genes never associated with mechanisms of calcification were identified: the calcium binding protein S100-like, the short-chain dehydrogenase/reductase sdr-like and the betaine homocysteine S-methyltransferase bhmt3. Analysis of the spatial-temporal expression of these 3 genes by qPCR and in situ hybridization revealed: (1) the up-regulation of sdr-like transcript during in vitro mineralization of gilthead seabream cell lines and its specificity for calcified tissues and differentiating osteoblasts; (2) the up-regulation of S100-like and the down-regulation of bhmt3 during in vitro mineralization and the central role of both genes in cartilaginous tissues undergoing endo/perichondral mineralization in juvenile fish. While expression of S100-like and bhmt3 was restricted to calcified tissues, sdr-like transcript was also detected in soft tissues, in particular in tissues of the gastrointestinal tract. Functional analysis of gene promoters revealed the transcriptional regulation of the 3 genes by known regulators of osteoblast and chondrocyte differentiation/mineralization: RUNX2 and RAR (sdr-like), ETS1 (s100-like; bhmt3), SP1 and MEF2c (bhmt3). The evolutionary relationship of the different orthologs and paralogs identified within the scope of this work was also inferred from taxonomic and phylogenetic analyses and revealed novel protein subfamilies (S100-like and Sdr-like) and the explosive diversity of Bhmt family in particular fish groups (Neoteleostei). Altogether our results contribute with new data on SDR, S100 and BHMT proteins, evidencing for the first time the role for these three proteins in mechanisms of mineralization in fish and emphasized their potential as markers of mineralizing cartilage and bone in developing fish.
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Tese de doutoramento, Ciências do Mar, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Ciências Farmacêuticas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Univerisdade do Algarve, 2015
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Tese de doutoramento, Ciências Geofísicas e da Geoinformação (Geofisíca), Universidade de Lisboa, Faculdade de Ciências, 2014
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Tese de doutoramento, Ciências e Tecnologias da Saúde (Desenvolvimento Humano e Social), Universidade de Lisboa, Faculdade de Medicina, 2015
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Tese de doutoramento, Geologia (Geodinâmica Interna), Universidade de Lisboa, Faculdade de Ciências, 2015
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Em Portugal a dimensão média das famílias reduziu-se significativamente em 50 anos, passando de 3,8 pessoas por família, em 1960, para 2,6 pessoas, em 2011. O casal (com e sem filhos) continua a ser a forma predominante de organização da vida familiar (62% das famílias em 1960 e 59% em 2011). Nos últimos 50 anos assistiu-se ao aumento do peso relativo dos casais sem filhos (de 15% em 1960, para 24% em 2011), dos núcleos familiares monoparentais (de 6% em 1960, para 9% em 2011) e das pessoas que vivem sós (de 12% em 1960, para 20% em 2011) e à diminuição do peso das famílias complexas (de 15% em 1960, para 9% em 2011).
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Conferência ministrada pelo Prof. Josaphat Marinho sobre a função de controle do Poder Legislativo.
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Dissertação de Mestrado, Estudos Integrados dos Oceanos, 25 de Julho 2013, Universidade dos Açores.
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Tese de Doutoramento, Ciências do Mar (Biologia Marinha)
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Cellular polarity concerns the spatial asymmetric organization of cellular components and structures. Such organization is important not only for biological behavior at the individual cell level, but also for the 3D organization of tissues and organs in living organisms. Processes like cell migration and motility, asymmetric inheritance, and spatial organization of daughter cells in tissues are all dependent of cell polarity. Many of these processes are compromised during aging and cellular senescence. For example, permeability epithelium barriers are leakier during aging; elderly people have impaired vascular function and increased frequency of cancer, and asymmetrical inheritance is compromised in senescent cells, including stem cells. Here, we review the cellular regulation of polarity, as well as the signaling mechanisms and respective redox regulation of the pathways involved in defining cellular polarity. Emphasis will be put on the role of cytoskeleton and the AMP-activated protein kinase pathway. We also discuss how nutrients can affect polarity-dependent processes, both by direct exposure of the gastrointestinal epithelium to nutrients and by indirect effects elicited by the metabolism of nutrients, such as activation of antioxidant response and phase-II detoxification enzymes through the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In summary, cellular polarity emerges as a key process whose redox deregulation is hypothesized to have a central role in aging and cellular senescence.