983 resultados para ACTING MUTAGENS


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Diante da crescente competitividade, característica do mercado global, e da necessidade de melhorar a eficiência e a produtividade nas organizações, torne-se imperativo o aperfeiçoamento, incessante, na forma de actuação dos gestores. Consciente que, até então, as empresas suportam, essencialmente, no sistema contabilístico, este que, muitas vezes, fornece informações insuficientes e restringidos à tomada de decisões de curto prazo, mostra-se necessário investir em sistemas de medição, ligado à estratégia organizacional, que permitam melhor planeamento e controlo e, ainda, gerar e medir indicadores de longo prazo. No intuito de contribuir para a melhoria do paradigma da gestão, mais concretamente da gestão das empresas Cabo-Verdianas, e, em particular a da empresa em estudo, propomos, como objectivo desta dissertação, o estudo da utilização das ferramentas de gestão tradicional, face às novas ferramentas emergentes. Nisto, apresentamos, como estudo de caso, a avaliação do sistema de controlo de gestão da Empresa Bento - Comércio, Construtores, Imobiliária e Investimentos, Sociedade Anónima, (Bento S.A.), analisando, à luz da literatura consultada, o sistema de gestão estratégica, seguido pela empresa de modo a poder propor eventuais melhorias. Durante a revisão bibliográfica, foram estudadas várias ferramentas da gestão estratégica, das quais escolhemos o Balanced Scorecard (BSC) como um instrumento capaz de responder às lacunas detectadas na estratégia de gestão da Empresa, em que após uma breve descrição dos aspectos teóricos do conceito, suportado nos estudos empíricos publicados, apresentámos uma proposta para sua adopção, concepção e implementação. É de realçar que, durante o estudo constatou-se, por parte da administração da empresa, uma maior consciência da importância da comunicação e divulgação da sua estratégia entre os diferentes níveis hierárquicos, o que evidencia que ela está, mesmo, disposta a apostar na sua inovação estratégica. With the raising competitiveness, characteristic of the global market, and of the need of improving the efficiency and productivity in organizations, the constant improvement in the way of acting of managers it becomes peremptory. Aware that, so far, enterprises support, essentially, on the accounting system, which, many times, gives restrict and insufficient information for the taking of decisions in a short term, it is shown to be necessary to invest in measuring systems, connected to the organizational strategy, which contains signs that allow a better planning and control and, furthermore, give birth to and measure signs on a long term. With the aim of contributing for the improvement of the managing pattern, specifically, the management of Cape Verdean enterprises, and, in particular, the one of the enterprise in study, we propose, as an aim of this dissertation, the study of the use of the traditional managing tools, in view of the emerging new tools. Thus, we present, as study case, the evaluation of the system of management control of the Enterprise Bento - Comércio, Construtores, Imobiliária e Investimentos, Sociedade Anónima, (Bento, S.A.), analyzing the system of strategic management, used by the enterprise to be able to propose eventual improvements. During the bibliographic revision, we studied many strategic management tools, among which we chose the Balanced Scorecard (BSC) as an instrument capable to respond to the gaps detected in the management strategy of the enterprise, in which, after a brief description of the theoretical aspects of the concept, supported on the empiric studies published, we present a proposal for its adoption, conception and implementation. We would like to accentuate that, during the study we noticed that there exists, on the behalf of the management of the enterprise, a major awareness of the importance of communication and diffusion of its strategy among the different hierarchical levels, what makes clear that the enterprise is really open to bet on its strategic innovation.

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Objective Analyzing the conceptions of supervision of nurses in the Family Health Strategy (ESF - Estratégia Saúde da Família) in relation to community health workers (ACS – Agente Comunitário de Saúde), taking for reference the work process and the power relations. Method A qualitative study, in which 18 interviews were carried out with nurses from the ESF in the countryside of the state of Goiás. Following transcription, the data were subjected to thematic content analysis and the following categories were identified: Supervision with that sees it all and Supervision is participating and working together. Results Among the findings, it is clear the character of control and monitoring that is carried out primarily through printed instruments and home visits, which constitute vertical and impositive relations, and suffer influence of the local health management. Another finding is the supervision as acting together and with the educational perspective. Conclusion The supervision carried out does not provide the changes intended by the ESF.

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The position of a gene in the genome may have important consequences for its function. Therefore, when a new duplicate gene arises, its location may be critical in determining its fate. Our recent work in humans, mouse, and Drosophila provided a test by studying the patterns of duplication in sex chromosome evolution. We revealed a bias in the generation and recruitment of new gene copies involving the X chromosome that has been shaped largely by selection for male germline functions. The gene movement patterns we observed reflect an ongoing process as some of the new genes are very young while others were present before the divergence of humans and mouse. This suggests a continuing redistribution of male-related genes to achieve a more efficient allocation of male functions. This notion should be further tested in organisms employing other sex determination systems or in organisms differing in germline sex chromosome inactivation. It is likely that the selective forces that were detected in these studies are also acting on other types of duplicate genes. As a result, future work elucidating sex chromosome differentiation by other mutational mechanisms will shed light on this important process.

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Summary [résumé français voir ci-dessous] From the beginning of the 20th century the world population has been confronted with the human immune deficiency virus 1 (HIV-1). This virus has the particularity to mutate fast, and could thus evade and adapt to the human host. Our closest evolutionary related organisms, the non-human primates, are less susceptible to HIV-1. In a broader sense, primates are differentially susceptible to various retrovirus. Species specificity may be due to genetic differences among primates. In the present study we applied evolutionary and comparative genetic techniques to characterize the evolutionary pattern of host cellular determinants of HIV-1 pathogenesis. The study of the evolution of genes coding for proteins participating to the restriction or pathogenesis of HIV-1 may help understanding the genetic basis of modern human susceptibility to infection. To perform comparative genetics analysis, we constituted a collection of primate DNA and RNA to allow generation of de novo sequence of gene orthologs. More recently, release to the public domain of two new primate complete genomes (bornean orang-utan and common marmoset) in addition of the three previously available genomes (human, chimpanzee and Rhesus monkey) help scaling up the evolutionary and comparative genome analysis. Sequence analysis used phylogenetic and statistical methods for detecting molecular adaptation. We identified different selective pressures acting on host proteins involved in HIV-1 pathogenesis. Proteins with HIV-1 restriction properties in non-human primates were under strong positive selection, in particular in regions of interaction with viral proteins. These regions carried key residues for the antiviral activity. Proteins of the innate immunity presented an evolutionary pattern of conservation (purifying selection) but with signals of relaxed constrain if we compared them to the average profile of purifying selection of the primate genomes. Large scale analysis resulted in patterns of evolutionary pressures according to molecular function, biological process and cellular distribution. The data generated by various analyses served to guide the ancestral reconstruction of TRIM5a a potent antiviral host factor. The resurrected TRIM5a from the common ancestor of Old world monkeys was effective against HIV-1 and the recent resurrected hominoid variants were more effective against other retrovirus. Thus, as the result of trade-offs in the ability to restrict different retrovirus, human might have been exposed to HIV-1 at a time when TRIM5a lacked the appropriate specific restriction activity. The application of evolutionary and comparative genetic tools should be considered for the systematical assessment of host proteins relevant in viral pathogenesis, and to guide biological and functional studies. Résumé La population mondiale est confrontée depuis le début du vingtième siècle au virus de l'immunodéficience humaine 1 (VIH-1). Ce virus a un taux de mutation particulièrement élevé, il peut donc s'évader et s'adapter très efficacement à son hôte. Les organismes évolutivement le plus proches de l'homme les primates nonhumains sont moins susceptibles au VIH-1. De façon générale, les primates répondent différemment aux rétrovirus. Cette spécificité entre espèces doit résider dans les différences génétiques entre primates. Dans cette étude nous avons appliqué des techniques d'évolution et de génétique comparative pour caractériser le modèle évolutif des déterminants cellulaires impliqués dans la pathogenèse du VIH- 1. L'étude de l'évolution des gènes, codant pour des protéines impliquées dans la restriction ou la pathogenèse du VIH-1, aidera à la compréhension des bases génétiques ayant récemment rendu l'homme susceptible. Pour les analyses de génétique comparative, nous avons constitué une collection d'ADN et d'ARN de primates dans le but d'obtenir des nouvelles séquences de gènes orthologues. Récemment deux nouveaux génomes complets ont été publiés (l'orang-outan du Bornéo et Marmoset commun) en plus des trois génomes déjà disponibles (humain, chimpanzé, macaque rhésus). Ceci a permis d'améliorer considérablement l'étendue de l'analyse. Pour détecter l'adaptation moléculaire nous avons analysé les séquences à l'aide de méthodes phylogénétiques et statistiques. Nous avons identifié différentes pressions de sélection agissant sur les protéines impliquées dans la pathogenèse du VIH-1. Des protéines avec des propriétés de restriction du VIH-1 dans les primates non-humains présentent un taux particulièrement haut de remplacement d'acides aminés (sélection positive). En particulier dans les régions d'interaction avec les protéines virales. Ces régions incluent des acides aminés clé pour l'activité de restriction. Les protéines appartenant à l'immunité inné présentent un modèle d'évolution de conservation (sélection purifiante) mais avec des traces de "relaxation" comparé au profil général de sélection purifiante du génome des primates. Une analyse à grande échelle a permis de classifier les modèles de pression évolutive selon leur fonction moléculaire, processus biologique et distribution cellulaire. Les données générées par les différentes analyses ont permis la reconstruction ancestrale de TRIM5a, un puissant facteur antiretroviral. Le TRIM5a ressuscité, correspondant à l'ancêtre commun entre les grands singes et les groupe des catarrhiniens, est efficace contre le VIH-1 moderne. Les TRIM5a ressuscités plus récents, correspondant aux ancêtres des grands singes, sont plus efficaces contre d'autres rétrovirus. Ainsi, trouver un compromis dans la capacité de restreindre différents rétrovirus, l'homme aurait été exposé au VIH-1 à une période où TRIM5a manquait d'activité de restriction spécifique contre celui-ci. L'application de techniques d'évolution et de génétique comparative devraient être considérées pour l'évaluation systématique de protéines impliquées dans la pathogenèse virale, ainsi que pour guider des études biologiques et fonctionnelles

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BACKGROUND/AIMS: Gluco-incretin hormones increase the glucose competence of pancreatic beta-cells by incompletely characterized mechanisms. METHODS: We searched for genes that were differentially expressed in islets from control and Glp1r-/-; Gipr-/- (dKO) mice, which show reduced glucose competence. Overexpression and knockdown studies; insulin secretion analysis; analysis of gene expression in islets from control and diabetic mice and humans as well as gene methylation and transcriptional analysis were performed. RESULTS: Fxyd3 was the most up-regulated gene in glucose incompetent islets from dKO mice. When overexpressed in beta-cells Fxyd3 reduced glucose-induced insulin secretion by acting downstream of plasma membrane depolarization and Ca++ influx. Fxyd3 expression was not acutely regulated by cAMP raising agents in either control or dKO adult islets. Instead, expression of Fxyd3 was controlled by methylation of CpGs present in its proximal promoter region. Increased promoter methylation reduced Fxyd3 transcription as assessed by lower abundance of H3K4me3 at the transcriptional start site and in transcription reporter assays. This epigenetic imprinting was initiated perinatally and fully established in adult islets. Glucose incompetent islets from diabetic mice and humans showed increased expression of Fxyd3 and reduced promoter methylation. CONCLUSIONS/INTERPRETATION: Because gluco-incretin secretion depends on feeding the epigenetic regulation of Fxyd3 expression may link nutrition in early life to establishment of adult beta-cell glucose competence; this epigenetic control is, however, lost in diabetes possibly as a result of gluco-incretin resistance and/or de-differentiation of beta-cells that are associated with the development of type 2 diabetes.

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É indubitável que o sistema financeiro é parte integrante de qualquer sociedade. Através da sua função de intermediação, as instituições financeiras recebem recursos dos agentes superavitários e emprestam aos agentes deficitários mediante promessa de pagamento futuro. Num banco, que tem intermediação financeira como sua principal actividade, o crédito consiste em disponibilizar ao cliente recursos em valores sob a forma de financiamento e ou empréstimo mediante uma promessa de pagamento numa data acordada entre as partes. A discussão e implementação dos acordos de BASILEIA, nomeadamente o Basileia II, veio dar uma nova forma a esse relacionamento sector bancário/clientes determinando as regras no que respeita a concessão de crédito e gestão de risco, estabelecendo os limites de crédito associado ao grau de risco das operações. Surge então, por parte das instituições uma maior preocupação em gerir o crédito e os riscos inerentes a cada operação, apostando em ferramentas e metodologias adequadas ao processo creditício. As instituições bancárias passam a criar departamentos de risco, colocando a gestão de crédito e de risco nas mãos de profissionais especializados, agindo sob regras e padrões internacionais uniformizados. There is no doubt that the financial system is an integral part of any society. Through their intermediary role, financial institutions receive funds from surplus agents and lend to deficit agents, with promises of future payment. Banks, with their primary activity being the financial intermediation, the credit is provided to customers in the form of funding or loans and a promise of payment on a date agreed between the parties. The discussion and implementation of the Basel Accord, Basel II in particular, has given a new form to that relationship banking/customer, setting out the rules regarding the granting of credit and risk management, establishing credit limits associated with the degree of risk of operations. Banking institutions got more and more concerned with credit and risk management, in all of their operations, using tools and methodologies that are designed to meet the needs of crediting processes. Banking institutions are creating departments of risk, putting the management of credit risk in the hands of trained professionals, acting under internationally uniform rules and standards

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O reconhecimento e mensuração do rédito tornaram-se cada vez mais complexos devido a factores como a concorrência internacional e a rápida evolução dos modelos empresariais. O rédito é a componente do rendimento proveniente da actividade operacional da empresa, daí ser de suprema importância determinar-se o momento em que o mesmo deve ser reconhecido bem como os critérios adequados para mensurá-lo. Neste trabalho debruçamo-nos sobre os processos de reconhecimento e mensuração do rédito. Este trabalho foi elaborado em duas partes, na primeira, efectuou-se uma revisão às normas de referência ao tratamento do rédito, com o objectivo de esclarecer algumas questões que suscitam grandes dúvidas, quer no meio académico, quer no meio profissional como é o exemplo do tratamento a dar ao rédito proveniente dos contratos de construção de imóveis numa empresa do ramo imobiliário. Na segunda parte do trabalho, elaborou-se um estudo de caso sobre a empresa TECNICIL Imobiliária, precisamente para verificar na prática o tratamento dado ao rédito proveniente dos acordos de construção levados a cabo por esta entidade. E desse estudo podemos concluir que a entidade não observa o tratamento prescrito pelas normas de referência, particularmente a IFRIC 15 – Acordos para Construção de Imóveis e IAS 18 – Rédito. There is no doubt that the financial system is an integral part of any society. Through their intermediary role, financial institutions receive funds from surplus agents and lend to deficit agents, with promises of future payment. Banks, with their primary activity being the financial intermediation, the credit is provided to customers in the form of funding or loans and a promise of payment on a date agreed between the parties. The discussion and implementation of the Basel Accord, Basel II in particular, has given a new form to that relationship banking/customer, setting out the rules regarding the granting of credit and risk management, establishing credit limits associated with the degree of risk of operations. Banking institutions got more and more concerned with credit and risk management, in all of their operations, using tools and methodologies that are designed to meet the needs of crediting processes. Banking institutions are creating departments of risk, putting the management of credit risk in the hands of trained professionals, acting under internationally uniform rules and standards.

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O foco central deste relatório consiste em mostrar a total importância da Análise Económica e Financeira como instrumento de apoio ao processo decisório. No contexto actual onde a concorrência é cada vez mais forte e a busca pela competitividade é uma necessidade constante, as empresas necessitam de informações precisas e oportunas para apoiar o processo decisório. A escassez de recursos financeiros e o elevado custo, aliado com a falta de planeamento e controle, têm contribuído para que muitas empresas encerrem suas actividades. A tomada de boas decisões torna-se, então, um factor crucial para assegurar a sobrevivência, crescimento e permanência da empresa no mercado. Neste sentido, buscamos trazer para todos os interessados alguns conceitos e técnicas fundamentais de análise e medição da performance económica e financeira das empresas que será igualmente útil, quer a nível académica, como também a nível profissional. Procuramos evidenciar a importância de se conhecer os indicadores que podem ser vistos como alertas de possíveis falências de empresas e com base nisso, tomar decisões que determinam que estratégias utilizar para enfrentar a concorrência. A finalizar este relatório procedemos a uma pesquisa Estudo de Caso que engloba uma análise económica e financeira, baseada na análise das Demonstrações Financeiras e demais informações complementares da TRANSCOR-SV, S.A. Foram explorados alguns conceitos relacionados com o tema, mostrando de forma simples e objectiva a situação de como a empresa vem actuando no mercado. Constámos algumas deficiências, pois, foram verificados alguns pontos fracos. Diante dos problemas, sugerimos formas de mudanças e de viabilidade dos mesmos. Esperamos, então, que este relatório contribua para a empresa analisar melhor a forma de administrar a parte económica e financeira e demais sectores.The central focus of this report consists of showing to total importance of the Analysis Economic and Financial as support instrument to the ruling process. In the context actual where the competition is more and more strong and the search for the competitiveness is a constant need, the companies need necessary and opportune information to support the ruling process. The shortage of financial resources and the high cost, ally with the planning lack and control, they have been contributing so that a lot of companies contain their activities. The socket of good decisions becomes, then, a crucial factor to assure the survival, growth and permanence of the company in the market. In this sense, we looked for to bring for all the interested parties, some concepts and fundamental techniques of analysis and measurement of the performance economic and financial of the companies, which will be equally useful, he/she wants to academic level, as well as at professional level. We tried to evidence, the importance of knowing the indicators that you/they can be seen as alerts of possible bankruptcies of companies and with base in that, to make decisions that determine which strategies to use to face the competition. To conclude this report we proceeded to a research Study of Case that includes an analysis economic and financial, based on the analysis of the Financial Demonstrations and other complementary information of TRANSCOR-S.V., S.A. Some concepts related with the theme were explored, showing the situation of simple form and objective of as the company is acting in the market. It was verified some deficiencies, because, some weak points were verified. Before the problems, we suggested forms of changes and of viability of the same ones.We waited, then, which this report contributes to company to analyze the form better of administering the part economic and financial and other sectors.

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OBJECTIVETo analyze the weaknesses and strengths of nursing care in the Family Health Strategy and its interfaces with the Unified Health System network.METHODA qualitative study performed by means of semi-structured interviews and systematic observations, with the participation of a nursing team of 15 people from October of 2012 to January of 2013.RESULTSStrengths that were emphasized: the nurse's versatility in conducting users within the unit and the health system, therefore directly acting upon access to these services. The nurse is the main subject that participates in the care processes for the person, family and social groups. Weaknesses that were highlighted: fragile embracement and low resolution of users' and families' problems.CONCLUSIONThe nursing care process in health units still lacks collective articulation, involvement of the team, and decentralization of the decisions.

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In a classical dogma, pathogens are sensed (via recognition of Pathogen Associated Molecular Patterns (PAMPs)) by innate immune cells that in turn activate adaptive immune cells. However, recent data showed that TLRs (Toll Like Receptors), the most characterized class of Pattern Recognition Receptors, are also expressed by adaptive immune B cells. B cells play an important role in protective immunity essentially by differentiating into antibody-secreting cells (ASC). This differentiation requires at least two signals: the recognition of an antigen by the B cell specific receptor (BCR) and a T cell co-stimulatory signal provided mainly by CD154/CD40L acting on CD40. In order to better understand interactions of innate and adaptive B cell stimulatory signals, we evaluated the outcome of combinations of TLRs, BCR and/or CD40 stimulation. For this purpose, mouse spleen B cells were activated with synthetic TLR agonists, recombinant mouse CD40L and agonist anti-BCR antibodies. As expected, TLR agonists induced mouse B cell proliferation and activation or differentiation into ASC. Interestingly, addition of CD40 signal to TLR agonists stimulated either B cell proliferation and activation (TLR3, TLR4, and TLR9) or differentiation into ASC (TLR1/2, TLR2/6, TLR4 and TLR7). Addition of a BCR signal to CD40L and either TLR3 or TLR9 agonists did not induce differentiation into ASC, which could be interpreted as an entrance into the memory pathway. In conclusion, our results suggest that PAMPs synergize with signals from adaptive immunity to regulate B lymphocyte fate during humoral immune response.

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OBJECTIVETo know the production of theoretical approaches on issues related to offshore work and the work of offshore nurses.METHODIntegrative literature review conducted in the databases of LILACS, BDENF, MEDLINE, SciELO and Index PSI.RESULTSWe selected 33 studies published in national and international journals between 1997 and 2014. The thematic analysis corpus resulted in four central themes: offshore work environment; amid work adversities, an escape; structuring of offshore health and safety services; in search of safe practices.CONCLUSIONThis study contributes to the offshore work of nurses in relation to the nature of work, acting amid adversities and the restless search for safe practices in the open sea.

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Studying the geographic variation of phenotypic traits can provide key information about the potential adaptive function of alternative phenotypes. Gloger's rule posits that animals should be dark-vs. light-colored in warm and humid vs. cold and dry habitats, respectively. The rule is based on the assumption that melanin pigments and/or dark coloration confer selective advantages in warm and humid regions. This rule may not apply, however, if genes for color are acting on other traits conferring fitness benefits in specific climes. Covariation between coloration and climate will therefore depend on the relative importance of coloration or melanin pigments and the genetically correlated physiological and behavioral processes that enable an animal to deal with climatic factors. The Barn Owl (Tyto alba) displays three melanin-based plumage traits, and we tested whether geographic variation in these traits at the scale of the North American continent supported Gloger's rule. An analysis of variation of pheomelanin-based reddish coloration and of the number and size of black feather spots in 1,369 museum skin specimens showed that geographic variation was correlated with ambient temperature and precipitation. Owls were darker red in color and displayed larger but fewer black feather spots in colder regions. Owls also exhibited more and larger black spots in regions where the climate was dry in winter. We propose that the associations between pigmentation and ambient temperature are of opposite sign for reddish coloration and spot size vs. the number of spots because selection exerted by climate (or a correlated variable) is plumage trait-specific or because plumage traits are genetically correlated with different adaptations.

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Summary Skin is the essential interface between our body and its environment; not only does it prevent water loss and protect us from external insults it also plays an essential role in the central nervous system acting as a major sense organ primarily for touch and pain. The main cell type present in skin, keratinocyte, undergoes a differentiation process leading to the formation of this protecting barrier. This work is intended to contribute to the understanding of how keratinocyte differentiates and skin functions. To do this, we studied two genetic skin diseases: Erythrokeratodermia variabilis and Mal de Meleda. Our approach was to examine the expression and localization of proteins implicated in these two pathologies in normal and diseased tissues and to determine the influence of mutant proteins at the molecular and cellular levels. Connexins are major components of gap junctions, channels allowing direct communication between cells. Our laboratory has identified mutations in both connexin 30.3 (Cx30.3) and 31 (Cx31) to be causally involved in erythrokeratodermia variabilis (EKV), an autosomal dominant disorder of keratinization. In the first chapter, we show a new mutation of Cx31, L209P-Cx31, in 3 EKV patients, extending the field of EKV-causing mutations although the mechanism by which connexin mutations lead to the disease is unclear. In the second chapter, we studied the effect of F137L-Cx30.3 on expression, trafficking and localization of cotransfected Cx31 and Cx30.3 in connexin-deficient HeLa cells. The F137 amino acid, highly conserved in connexin family, is oriented towards the channel pore and F137L mutation in either Cx30.3 or Cx31 lead to EKV. As two genes can lead to EKV when mutated, our hypothesis was that Cx31 and Cx30.3 might cooperate at a molecular level. We were able to demonstrate a physical interaction between Cx31 and Cx30.3. The presence of F137L-Cx30.3 disturbed the trafficking of both connexins, less connexins were integrated into gap junctions and thus, the coupling between cell was diminished. Connexins formed in the presence of F137L-Cx30.3 are degraded at their exit from the endoplasmic reticulum. In conclusion, our results indicate that the genetic heterogeneity of EKV is due to mutations in two interacting proteins. F137L-Cx30.3 has a dominant negative effect and affects Cx31, disturbing cellular communication in epidermal cells. Mal de Meleda is an autosomal recessive inflammatory and a keratotic palmoplantar skin disorder due to mutations in SLURP1 (secreted LY6/PLAUR-related protein 1). SLURP1 belongs to the LY6/PLAUR family of proteins and has the particularity of being secreted instead of being GPI-anchored. The high degree of structural similarity between SLURP1 and the three fingers motif of snake neurotoxins and LYNX 1-C suggests that this protein could interact with the neuronal acetylcholine receptors. In the third chapter, we show that SLURP1 potentiates responses of the a7 nicotinic acetylcholine receptor (nAchR) to acetylcholine. These results identify SLURP1 as a secreted epidermal neuromodulator that is likely to be essential for palmoplantar skin. In the fourth chapter, we show that SLURP1 is expressed in the granular layer of the epidermis but is absent from skin biopsies of Mal de Meleda patients. SLURP1 is also present in secretions such as sweat, tears or saliva. An in vitro analysis on two mutant of SLURP-I demonstrates that W15R-SLURP1 is absent in cells while G86R-SLURP1 is expressed and secreted, suggesting that SLURP1 can lead to the disease by either an absent or an abnormal protein. Finally, in the fifth chapter, we analyse the expression and biological properties of other LY6/PLAUR members, clustered around SLURP] on chromosome 8. Their GPI-anchored or secreted status were analysed in vitro. SLURP1, LYNX1-A and -B are secreted while LYPDC2 and LYNX 1-C are GPI anchored. Three of these proteins are expressed in the epidermis and in cultured keratinocytes. These results suggest that these LY6/PLAUR members may have an important role in skin homeostasis. Résumé Résumé La peau est la barrière essentielle entre notre corps et l'environnement, nous protégeant des agressions extérieures, de la déshydratation et assurant aussi un rôle dans le système nerveux central en tant qu'organe du toucher et de la douleur. Le principal type de cellules présent dans la peau est le kératinocyte qui suit un processus de différenciation aboutissant à la formation de cette barrière protectrice. Ce travail est destiné à comprendre la différenciation des kératinocytes et le fonctionnement de la peau. Pour cela, nous avons étudié deux maladies génodermatoses : l'Erthrokeratodermia Variabilis (EKV) et le Mal de Meleda. Nous avons examiné l'expression et la localisation des protéines impliquées dans ces deux pathologies dans des tissus normaux et malades puis déterminé l'influence des protéines mutantes aux niveaux moléculaires et cellulaires. Les connexines (Cx) sont les composants majeurs des jonctions communicantes, canaux permettant la communication directe entre les cellules. Notre laboratoire a identifié des mutations dans les Cx30.3 et Cx31 comme responsables de l'EKV, génodermatose de transmission autosomique dominante. Dans le ler chapitre, nous décrivons une nouvelle mutation de Cx31, L209-Cx31, et contribuons à l'établissement du catalogue des mutations de Cx31 entraînant cette maladie. Cependant, le mécanisme par lequel les mutations de Cx31 et C3x0.3 provoquent l'EKV est inconnu. Dans le 2ème chapitre, nous étudions les effets de la mutation F137L-Cx30.3 sur l'expression, le trafic et la localisation des Cx31 et Cx30.3 transfectées dans des cellules HeLa, déficientes en connexines. Comme deux gènes peuvent causer une EKV quand ils sont mutés, notre hypothèse était que Cx31 et Cx30.3 pourraient coopérer au niveau moléculaire. Nous avons montré l'existence d'une interaction physique entre ces deux connexines. La présence de la mutation F137L-Cx30.3 perturbe le trafic des deux connexines, moins de connexines sont intégrées dans les jonctions communicantes et donc le couplage entre les cellules est diminué. Les connexons formés en présence de cette mutation sont dégradés à leur sortie du réticulum endoplasmique. En conclusion, nos résultats indiquent que l'hétérogénéité génétique de EKV est due à des mutations dans deux protéines qui interagissent. F137L-Cx30.3 a un effet dominant négatif et affecte Cx31, perturbant la communication entre les cellules épidermiques. Le Mal de Meleda est une maladie récessive de la peau palmoplantaire due à des mutations dans SLURP1. SLURP1 appartient à la famille des protéines contenant un domaine LY6/PLAUR et a la particularité d'être sécrétée. La grande homologie de structure existant entre SLURP1, les neurotoxines de serpent et LYNX1-C suggère que la protéine pourrait interagir avec des récepteurs à acétylcholine (Ach). Dans le 3ème chapitre, nous montrons que SLURP1 module la réponse à l'Ach du récepteur nicotinique α7. Ces résultats identifient SLURP1 comme un neuromodulateur épidermique sécrété, probablement essentiel pour la peau palmoplantaire. Dans le 4ème chapitre, nous montrons que SLURP1 est exprimé dans la couche granuleuse de l'épiderme et qu'il est absent des biopsies des patients. SLURP1 a aussi été détecté dans des sécrétions telles que la sueur, les lamies et la salive. Une analyse in vitro de deux mutants de SLURP1 a montré que W15R-SLURP1 est absent des cellules tandis que G86R-SLURP1 est exprimé et sécrété, suggérant qu'une absence ou une anomalie de SLURP1 peuvent causer la maladie. Finalement, dans le 5ème chapitre, nous analysons l'expression et les propriétés biologiques d'autres membres de la famille LY6/PLAUR localisés autour de SLURP1 sur le chromosome 8. Leur statut de protéines sécrétées ou liées à la membrane par une ancre GPI est analysé in vitro. SLURP1, LYNXI-A et -B sont sécrétées alors que LYPDC2 et LYNX1-C sont liés à la membrane. Trois de ces protéines sont exprimées dans l'épiderme et dans des kératinocytes cultivés. Ces résultats suggèrent que la famille LY6/PLAUR pourrait avoir un rôle important dans l'homéostasie de la peau.

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Vibrio vulnificus and Vibrio cholerae are Gram-negative pathogens that cause serious infectious disease in humans. The beta form of pro-IL-1 is thought to be involved in inflammatory responses and disease development during infection with these pathogens, but the mechanism of beta form of pro-IL-1 production remains poorly defined. In this study, we demonstrate that infection of mouse macrophages with two pathogenic Vibrio triggers the activation of caspase-1 via the NLRP3 inflammasome. Activation of the NLRP3 inflammasome was mediated by hemolysins and multifunctional repeat-in-toxins produced by the pathogenic bacteria. NLRP3 activation in response to V. vulnificus infection required NF-kappaB activation, which was mediated via TLR signaling. V. cholerae-induced NLRP3 activation also required NF-kappaB activation but was independent of TLR stimulation. Studies with purified V. cholerae hemolysin revealed that toxin-stimulated NLRP3 activation was induced by TLR and nucleotide-binding oligomerization domain 1/2 ligand-mediated NF-kappaB activation. Our results identify the NLRP3 inflammasome as a sensor of Vibrio infections through the action of bacterial cytotoxins and differential activation of innate signaling pathways acting upstream of NF-kappaB.

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Aim Specialized mutualistic clades may revert and thus increase their autonomy and generalist characteristics. However, our understanding of the drivers that trigger reductions in mutualistic traits and of the consequences for the tolerance of these species to various environmental conditions remains limited. This study investigates the relationship between the environmental niche and the degree of myrmecophily (i.e. the ability to interact with ants) among members of the Lycaenidae. Location The western Swiss Alps. Methods We measured the tolerance of Lycaenidae species to low temperatures by comparing observations from a random stratified field sampling with climatic maps. We then compared the species-specific degree of myrmecophily with the species range limits at colder temperatures while controlling for phylogenetic dependence. We further evaluated whether the community-averaged degree of myrmecophily increases with temperature, as would be expected in the case of environmental filters acting on myrmecophilous species. Results Twenty-nine Lycaenidae species were found during sampling. Ancestral state reconstruction indicated that the 24 species of Polyommatinae displayed both strong myrmecophily and secondary loss of mutualism; these species were used in the subsequent statistical analyses. Species with a higher degree of ant interaction were, on average, more likely to inhabit warmer sites. Species inhabiting the coldest environments displayed little or no interaction with ants. Main conclusions Colder climates at high elevations filter out species with a high degree of myrmecophily and may have been the direct evolutionary force that promoted the loss of mutualism. A larger taxon sampling across the Holarctic may help to distinguish between the ecological and evolutionary effects of climate.