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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Efeito dos inibidores de serinoproteases rBmTI-A e rBmTI-6 em modelo de enfisema pulmonar em camundongos e em linhagem de células epiteliais pulmonares A549

Duran, Adriana Feliciano Alves January 2018 (has links)
Orientador: Prof. Dr. Sergio Daishi Sasaki / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, São Bernardo do Campo, 2018. / A doença pulmonar obstrutiva crônica é uma doença caracterizada por progressiva limitação do fluxo aéreo e suas principais manifestações são a bronquite crônica e o enfisema pulmonar. O quadro é geralmente irreversível e engloba uma série de processos que incluem a resposta inflamatória anormal dos pulmões com participação ativa de macrófagos, neutrófilos e linfócitos, a falha na reparação de células anormais, a apoptose precoce e a destruição da matriz extracelular ocasionada pelo desequilíbrio entre proteases e antiproteases, sendo esse desequilíbrio apontado como um dos principais mecanismos que levam à instalação da doença. O tabagismo é a principal causa atribuída ao seu aparecimento, seguida por fatores genéticos e ambientais. Algumas enzimas estão relacionadas ao processo de patogênese da DPOC como a elastase de neutrófilos humana e as metaloproteinases 9 e 12. Em trabalhos anteriores o uso do inibidor de serinoproteases rBmTI-A, inibidor do tipo Kunitz-BPTI, resultou na prevenção do enfisema pulmonar por meio do controle da resposta inflamatória comumente observada, além de redução da atividade proteolítica presente no lavado broncoalveolar. Nesse trabalho, o objetivo inicial foi dar prosseguimento à pesquisa com rBmTI-A, com a caracterização da expressão gênica diferencial no modelo de enfisema animal utilizando camundongos, indução realizada com a administração de elastase pancreática porcina (PPE); para isso foi utilizado o ensaio de micro arranjo de DNA (Microarray). Os ensaios de Microarray resultaram na identificação de genes que respondem ao tratamento nos animais induzidos ao enfisema e que receberam o tratamento com rBmTI-A, dentre estes genes estão: genes do sistema imune e inflamação, genes da contração muscular, genes da tradução em mitocôndria e genes de outras funções celulares. Na segunda parte do trabalho, o inibidor de serinoproteases rBmTI-6-D1, inibidor Kunitz-BPTI, foi aplicado no modelo de enfisema pulmonar em camundongos, resultados obtidos previamente já haviam mostrado que rBmTI-6 também apresenta a capacidade de prevenir o desenvolvimento do enfisema induzido por PPE, neste trabalho mostramos que o tratamento utilizando rBmTI-6-D1 evita a perda do recolhimento elástico dos pulmões dos animais induzidos ao enfisema, bem como também evita a degradação alveolar, e o aumento do número de macrófagos e linfócitos nos lavados broncoalveolares dos animais que receberam tratamento em comparação com os que não receberam. Também foi demonstrado que rBmTI-6 evita o aumento de atividade proteolítica (calicreínas e elastase de neutrófilos) no lavado broncoalveolar de animais tratados com o inibidor e induzidos ao enfisema em comparação aos controles. Na terceira parte do trabalho, foram realizados ensaios em cultura de células A549 para investigar o potencial anti-inflamatório dos inibidores rBmTI-A, rBmTI-6-D1 e rBmTI-6-D2/3, a aplicação dos inibidores nestas células mostrou um aparente papel antiinflamatório por meio da diminuição da secreção das citocinas IL-6 e IL-8, no tratamento utilizando rBmTI-6-D1 e rBmTI-6-D2/3. Concluímos que os inibidores rBmTI-A e rBmTI-6 apresentam atividade que previne o desenvolvimento do enfisema induzido por PPE, devido às atividades antiproteases destes inibidores e por interferirem na resposta inflamatória. / Chronic obstructive pulmonary disease is characterized by progressive airflow limitation and its main manifestations are chronic bronchitis and pulmonary emphysema. It is generally irreversible and encompasses a series of processes that include the abnormal inflammatory response of the lungs with active involvement of macrophages, neutrophils and lymphocytes, failure to repair abnormal cells, early apoptosis, and destruction of the extracellular matrix caused by the imbalance between proteases and antiproteases, and this imbalance is one of the main mechanisms that lead to the establishment of the disease. Smoking is the main cause attributed to its onset, followed by genetic and environmental factors. Some enzymes are related to the pathogenesis of COPD such as human neutrophil elastase and metalloproteinases 9 and 12. In previous studies, the use of the serine proteinase inhibitor, rBmTI-A, a Kunitz- BPTI inhibitor type, resulted in the prevention of pulmonary emphysema by controlling of the inflammatory response commonly observed, as well as reducing the proteolytic activity present in bronchoalveolar lavage. In this work, the initial objective was to continue the research with rBmTI-A, with the characterization of differential gene expression in the emphysema model using mice, induced to emphysema by porcine pancreatic elastase (PPE) instillation; to reach this aim a microarray assay was performed. The microarray results in the identification of some genes which are affected by the treatment using rBmTI-A in animals that received PPE instillation previously. Among these genes were identified immune and inflammatory related genes, muscular contraction related genes, translation in mitochondria related genes and genes of other cellular functions. In the second part of this work, the serine proteinase inhibitor rBmTI-6-D1, other Kunitz-BPTI inhibitor type, was applied in the emphysema model using mice; previous results had shown that rBmTI-6 also presented the ability to avoid the emphysema development in the PPE instillation model. The present work we showed that the rBmTI-6-D1 treatment was sufficient to avoid the loss of elastic recoil, an effective decrease in alveolar enlargement and in the number of macrophages and lymphocytes in bronchoalveolar lavage fluid. Proteolytic analysis showed a significant increase in elastase activity in induced emphysema group that is controlled by rBmTI-6-D1. Kallikrein activity was decreased in the induced emphysema and inhibitor treated group when compared to induced emphysema group without treatment. In the third part of this work, assays using A549 cells were performed to investigate the anti-inflammatory potential of rBmTI-A, rBmTI- 6-D1 and rBmTI-6-D2/3 inhibitors. These inhibitors presented an apparent antiinflammatory role, due the reduced levels of IL-6 and IL-8 that were secreted by A549 cell when treated with rBmTI-6-D1 and rBmTI-6-D2/3. We concluded that rBmTI-A and rBmTI-6 inhibitors prevent the emphysema development induced by PPE, due the anti-proteinases activities of these inhibitors and by its interference in inflammatory response.
12

Développement de modèles in vitro de la barrière alvéolo-capillaire pour l'étude de la toxicité et du passage des nanoparticules / Development of in vitro models of the alveolo-capillary barrier to study the toxicity and the passage of nanoparticles

Dekali, Samir 30 January 2013 (has links)
Après exposition par inhalation, les nanoparticules (NPs) peuvent atteindre les alvéoles pulmonaires, se retrouver au niveau de la barrière alvéolo-capillaire (BAC), et induire une toxicité locale et / ou franchir cette barrière pour se retrouver dans la circulation sanguine. Dans ce contexte, l’objectif de ce travail a été de développer des modèles de co-cultures in vitro simples à mettre en œuvre (utilisation de lignées cellulaires humaines), pour étudier les effets des NPs au niveau de la BAC. Dans un premier temps, des co-cultures de cellules épithéliales alvéolaires ou de phénotype proche (lignées A549 ou NCI-H441), et de macrophages (lignée THP-1), ont permis l’étude des effets pro-inflammatoires des NPs de SiO2 et de TiO2. Avec ces modèles nous avons montré l’importance de la coopération cellulaire mise en jeu lors des processus inflammatoires liés aux NPs, mais aussi le rôle du ratio cellulaire employé dans ces réponses. Dans un second temps, des co-cultures tridimensionnelles en chambres bicamérales associant des macrophages (lignée THP-1), des cellules épithéliales bronchiques (lignée Calu-3), et des cellules endothéliales pulmonaires microvasculaires (lignée HPMEC-ST1.6R), ont permis l’étude de l’impact de NPs fluorescentes de polystyrène sur l’intégrité de la BAC, et leur passage à travers cette barrière. Les cellules épithéliales Calu-3 permettent d’établir une barrière de qualité mais la membrane microporeuse servant de support aux cellules doit être optimisée pour ne pas être un frein au passage des NPs. Ce travail montre qu’un seul modèle ne permet pas d’étudier de façon optimale à la fois la toxicité et la translocation des NPs, et qu’une approche adaptée doit être envisagée en fonction du paramètre que l’on souhaite étudier. / After inhalation, nanoparticles (NPs) can reach the alveoli and the alveolo-capillary barrier (ACB), and consequently induce local toxicity and / or cross this barrier to reach the bloodstream. In this context, the aim of this work was to develop co-culture in vitro models simple to implement (using human cell lines), to study effects of NPs on the ACB. In a first time, pro-inflammatory effects of SiO2 and TiO2 NPs were studied on co-cultures of alveolar epithelial cells (A549 and NCI-H441 cell lines), and macrophages (THP-1 cell line). We demonstrated the importance of cell cooperation during inflammatory processes caused by these NPs, and the role of the cellular ratio in these inflammatory responses. In a second time, effects of fluorescent polystyrene NPs on the ACB integrity, and their translocation were studied on three-dimensional co-cultures in bicameral chambers involving macrophages (THP-1 cell line), bronchial epithelial cells (Calu-3 cell line), and micro-vascular pulmonary endothelial cells (HPMEC ST1.6R cell line). The use of Calu-3 has provided a good barrier, but further investigations on microporous membranes are still needed to not interfere with NPs translocation. Altogether, these results show that a tailored approach should be considered in order to study toxicity or translocation of NPs.

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