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Efeitos dos aminoácidos de cadeia ramificada na resposta inflamatória induzida por lipopolissacarídeo em macrófagos de linhagem celular RAW 264.7 / Effects of branched-chain amino acids in the inflammatory response induced by lipopolysaccharide in a macrophage cell line RAW 264.7Bonvini, Andrea 08 August 2019 (has links)
Os aminoácidos de cadeia ramificada (ACR) são considerados indispensáveis, pois não podem ser sintetizados endogenamente, sendo facilmente obtidos pela dieta. Entretanto, em determinadas condições clínicas, tanto a ingestão quando a absorção desses aminoácidos pode estar comprometida, levando ao estado hipercatabólico e prejudicando a função imune. O papel imunomodulador dos ACR tem sido relacionado com a melhora no balanço nitrogenado e o aumento da síntese e proliferação de células imunes, bem como, da síntese de mediadores inflamatórios. Entretanto, o mecanismo pelo qual os ACR exercem essas funções supracitadas ainda não é claro na literatura científica. Desta forma, esse trabalho teve como objetivo avaliar os efeitos da suplementação com ACR sobre os parâmetros inflamatórios e moleculares em macrófagos RAW 264.7 estimulados com lipopolissacarídeo (LPS). As culturas celulares foram distribuídas em cinco grupos: CTL - sem suplementação com ACR; LEU - suplementado com leucina (2 mmol/L); ISO - suplementado com isoleucina (2mmol/L); VAL - suplementado com valina (2 mmol/L) e LIV - suplementado com leucina (2 mmol/L), isoleucina (2 mmol/L) e valina (2 mmol/L). O estado inflamatório foi induzido pela adição de LPS (1 µg/mL) ao meio de cultura, seguindo quatro protocolos de tratamento: PT - pré-tratamento; TA - tratamento agudo; TC - tratamento crônico e TT - tratamento tardio. O ensaio de viabilidade celular foi realizado pelo teste MTT e a dosagem de óxido nítrico (NO) pela reação de Griess. As citocinas pró e anti-inflamatórias, e a prostaglandina E2 (PGE2) foram analisadas pelo método de ELISA. Para a avaliação dos parâmetros moleculares foi utilizado o método de western blotting. Houve aumento da viabilidade celular em todos os grupos suplementados em relação ao grupo controle no TA, no TC e no TT. Acerca da síntese de NO, a suplementação com ACR foi capaz de aumentar esse parâmetro em três dos quatro tratamentos propostos (PT, TA e TC). Em relação à síntese de citocinas pró e anti-inflamatórias, o PT e o TC foram mais eficazes em aumentar esse parâmetro em comparação aos outros tratamentos. Não houve diferença entre os grupos em relação à capacidade de síntese de PGE2 e à fosforilação de proteínas intracelulares. A partir dos resultados obtidos é possível concluir que os ACR contribuem significativamente para a viabilidade celular, bem como para a síntese de mediadores pró e anti-inflamatórios, sendo que o protocolo de suplementação se apresenta como fator determinante para obtenção desses resultados. Apesar da literatura científica atribuir grande parte dos efeitos imunomodulatórios à leucina, os resultados obtidos nesse estudo atribuem relevante potencial imunomodulador à isoleucina, abrindo espaço para um importante tema de estudo. / Branched chain amino acids (BCAA) are considered indispensable, since they cannot be endogenously synthesized, being easily obtained by diet. However, in certain clinical conditions, both the intake and absorption of these amino acids may be compromised, leading to the hypercatabolic state and impairing the immune function. The immunomodulatory role of BCAA has been associated with the nitrogen balance improvement and the increase of production and proliferation of immune cells, as well as the synthesis of inflammatory mediators. However, the mechanisms by which BCAA modulate the immune system have not yet been completely elucidated. In this sense, this study aimed to evaluate the effects of BCAA supplementation on intracellular mechanisms and inflammatory parameters in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Cell cultures were distributed into five groups: CTL - without ACR supplementation; LEU - supplemented with leucine (2 mmol/L); ISO - supplemented with isoleucine (2mmol / L); VAL - supplemented with valine (2 mmol/L) and LIV - supplemented with leucine (2 mmol/L), isoleucine (2 mmol/L) and valine (2 mmol/L). The inflammatory state was induced by the addition of LPS (1 µg/ml) to the culture medium, following four treatment protocols: PT - pre-treatment; TA - acute treatment; TC - chronic treatment and TT - late treatment. The cell viability assay was performed by the MTT test and the nitric oxide (NO) dosage by the Griess reaction. Pro- and anti-inflammatory cytokines, and prostaglandin E2 (PGE2) were analyzed by ELISA. For the evaluation of the molecular parameters, the western blotting method was used. There was an increase in cell viability in all supplemented groups in relation to the control group in the TA, TC and TT treatments. Regarding NO synthesis, BCAA supplementation was able to increase NO production in three of the four proposed treatments (PT, TA and TC). In relation to the production of pro- and anti-inflammatory cytokines, PT and CT were more effective in increasing this parameter, compared to the other treatments. There was no difference between groups in relation to PGE2 production and intracellular protein phosphorylation. From the obtained results it is possible to conclude that the BCAA significantly contributed to the cell viability, as well as, for the production of pro and anti-inflammatory mediators, and the supplementation protocol presents as determinant factor to obtain these results. Although the scientific literature attributed a large part of the immunomodulatory effects to leucine, the results obtained in this study attribute relevant immunomodulatory potential to isoleucine, opening space for an important study topic.
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Implementação e otimização do teste Lal para análise de LPS de cianobacérias em cultura e da região estuarina da Lagoa dos Patos e praia adjacenteGutierrez, Fabiane Bretanha January 2007 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Oceanografia Física, Química e Geológica, Instituto de Oceanografia, 2007. / Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2013-02-18T15:57:58Z
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Previous issue date: 2007 / Florações de cianobactérias têm sido freqüentemente encontradas nas águas do estuário da Lagoa dos Patos (RS). Um das principais cianobactérias de ocorrência local é o gênero Microcystis. As células de Microcystis têm tolerância a baixas salinidades, porém com o aumento abrupto da salinidade, as células podem sofrer lise. Muitas vezes, em função da hidrodinâmica local, essas florações de cianobactérias podem atingir a região da Praia do Cassino, possibilitando o contato com banhistas. Devido à natureza Gram-negativa da composição da parede celular das cianobactérias, esse contato com as células pode resultar em na ocorrência de casos de irritação epicutânea e reações alérgicas. O agente causador é o lipídeo A (endotoxina), encontrado no
lipopolissacarídeo (LPS) da membrana externa das cianobactérias. Com o objetivo de
detectar concentrações ambientais de LPS das florações de cianobactérias foi utilizado o
método cromogênico cinético de ponto final do teste do Lisado do Amebócito de Limulus polyphemus (teste LAL). O teste LAL foi realizado em amostras de água de superfície coletadas nas regiões de São Lourenço do Sul, Praia do Laranjal (Pelotas), Museu Oceanográfico da FURG, Yacht Club do Rio Grande e Praia do Cassino (Rio Grande), entre os meses de dezembro de 2005 e março de 2006. Nestas amostras também foram estimados a abundância celular dos principais grupos do fitoplâncton, a concentração de clorofila-a, e medida a salinidade local no momento da coleta. Para avaliar a possível interferência dos sais nos resultados do teste LAL, também foram realizados cultivos da cianobactéria Microcystis crescendo em diferentes salinidades, onde também foram estimados a abundância celular, e as concentrações de clorofila-a, LPS e microcistinas. Os ajustes metodológicos realizados no teste LAL durante o trabalho resultaram em uma sensibilidade para sua aplicação nas amostras ambientais.
As maiores concentrações de endotoxinas detectadas nas amostras ambientais (109,5
EU.mL-1, 71,8 EU.mL-1 e 93,7 EU.mL-1) se correlacionaram positivamente com as
maiores abundâncias celulares (aproximadamente 600.000 células.mL-1, 400.000 células.mL-1 e 300.000 células.mL-1, respectivamente), todas com a presença da
cianobactéria Microcystis. / Cyanobacterial blooms have been frequently observed in the waters of the Patos Lagoon
estuary (RS). One of the main cyanobacterium of local occurrence is the genus Microcystis. The Microcystis cells present some tolerance to low salinity, but with the rapid salt increase the cells may suffer breakdown. Usually due to the local hydrodynamics these blooms may reach the recreational waters of the Cassino Beach, exposing swimming bathers to its contact. Due to the Gram-negative nature of the cyanobacterial cell membrane, this contact with the cells may result in case occurrences of epicutaneous irritation and allergic reactions. The causing agent is the lipid A (endotoxin), found on the lipopolysaccharide (LPS) of the external membrane of cyanobacteria. With the objective to detect environmental concentrations of LPS from cyanobacterial blooms, it was used the kinetic chromogenic endpoint method of the
Limulus polyphemus Amebocyte Lisate test (LAL test). The LAL test was performed in surface water samples collected from the regions of São Lourenço do Sul, Laranjal Beach (Pelotas), FURG’s Oceanographic Museum, Yacht Club Rio Grande, and Cassino Beach (Rio Grande) betwen December 2005 and March 2006. In these samples it was also estimated the cellular abundance of the main phytoplanktonic groups, the chlorophyll-a concentration, and measured the local salinity. To evaluate the possible
interference of salinity in the LAL test results, it was also cultivated the cyanobacterium Microcystis growing in different salinities. From these cultures it was estimate the cellular abundance, and chlorophyll-a, LPS and microcystin concentrations.. The methodological adjustments performed in the LAL test during this work resulted in a sensitivity for its application in environmental samples. The highest endotoxin concentrations detected in the environmental samples (109.5 EU.mL-1, 71.8 EU.mL-1 and 93.7 EU.mL-1) have positively correlated with the highest cell abundances (approximately 600,000 cells.mL-1, 400,000 cells.mL-1 and 300,000 cells.mL-1,
respectively), all of them with the presence of the cyanobacteria Microcystis.
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Efeitos da exposição in vivo à hidroquinona sobre funções do tecido traqueal e de macrófagos alveolares de camundongos / Effects of in vivo hydroquinone exposure on functions of alveolar macrophages and tracheal tissue in miceAna Lucia Borges Shimada 08 April 2011 (has links)
A hidroquinona (HQ) é um composto fenólico de origem natural ou antropogênica, encontrada em grandes concentrações no cigarro, além de ser produto da biotransformação do benzeno. Nosso grupo de pesquisa tem demonstrado que a exposição à HQ compromete a resposta inflamatória in vivo. Dando continuidade a estas investigações, este trabalho visou investigar os efeitos da exposição in vivo à HQ sobre funções do tecido traqueal e atividades de macrófagos alveolares. Para tanto, camundongos Swiss machos foram expostos à HQ 25ppm (1,5mg/60mL/1h; 5 dias) ou veículo (solução salina etanol 1:20) por via sistêmica (nebulização). Concentrações de mediadores inflamatórios (interleucina (IL) 1β, IL-6, IL-10, IL-4, IL-12 fator de necrose tumoral-α (TNF-α) ou proteína quimiotáxica de monócitos (MCP-1); ensaio imunoenzimático (ELISA) e óxido nítrico (NO; reação de Griess) foram quantificados no lavado bronco-alveolar (LBA) em condições basais ou 3 horas após estímulo inflamatório (LPS in vivo; 100µL/mL; 10min) e no sobrenadante de macrófagos (MΦs) alveolares ou de cultura da traquéia obtidos dos animais e posteriormente estimulados in vitro (MΦs: 5µg/mL de LPS + 10ng/mL de IFN-γ; traquéia: 1µg/mL de LPS; 24h). Atividades fagocítica e fungicida (microscopia óptica) e a expressão de receptores envolvidos na fagocitose toll-like receptor (TLR, TLR-2, TLR4 e dectina-1; citometria de fluxo) foram determinadas após incubação in vitro de MΦs alveolares com o fungo Candida albicans e a expressão protéica de MyD88 foi realizada em MΦs alveolares (western blot). Quantificação do RNAm para MCP-1 (reação da transcriptase reversa em cadeia de polimerase, RT-PCR) foi realizada em tecido traqueal e células de linhagem monocítica humana THP-1 foram empregadas em ensaios de quimiotaxia in vitro (Câmara de Boyden) frente a diferentes concentrações de MCP-1. Reatividade do tecido traqueal foi quantificada frente à metacolina. Os resultados obtidos mostraram que a exposição in vivo à HQ reduziu a concentração de MCP-1 (54,98% vs. controle LPS) e IL-12 (51,45% vs. controle LPS) no LBA após inflamação; reduziu a secreção de MCP-1 por MΦs (basal: 87,96%; LPS+INF-γ: 61,20%) e tecido traqueal em cultura (79,77% vs. controle LPS). Neste último tecido, a diminuição foi dependente da menor expressão gênica. Concentrações de MCP-1 semelhantes à detectada no sobrenadante de cultura de traquéia de animais expostos à HQ induziram migração de células THP-1 menor (38,2%) que à provocada pela concentração de MCP-1 no sobrenadante da cultura traquéia de animais controles. Traquéias de animais expostos à HQ apresentaram hiperreatividade (193,48%), a qual foi revertida pela remoção do epitélio traqueal. Adicionalmente, cultura de MΦs obtidos de animais expostos à HQ apresentaram maior atividade fagocítica (porcentagem de fagocitose: 36,30%; índice de fagocitose: 83,97%) e fungicida (68,47%), que não foram dependentes de alterações nos receptores TLR2, TLR4 e dectina-1, mas podem ser decorrentes da menor expressão protéica de MyD88. Em conjunto, os dados obtidos apontam para alterações importantes resultantes da exposição in vivo à HQ sobre funções de MΦs alveolares e do tecido traqueal que, em conjunto, podem ser determinantes para a toxicidade observada nestes animais que culmina com prejuízo na defesa do organismo. / Hydroquinone (HQ) is a phenolic compound of natural or anthropogenic source, also found in high concentrations in cigarette, as well as benzene´s metabolite. Our research group has demonstrated that exposure to HQ impairs in vivo inflammatory response. Following these investigations, this work aimed to study the effects of in vivo exposure to HQ on tracheal tissue and alveolar macrophages (MΦs) activities. For this purpose, male Swiss mice were systemically (aerolised) exposed to 25ppm HQ (1.5 mg/60mL/1h; 5 days) or vehicle (saline ethanol solution, 1:20). Concentrations of inflammatory mediators (interleukin (IL) IL-1β, IL- 6, IL-10, IL-4, IL-12 tumor necrosis factor-α (TNF-α ) or monocyte chemoattractant protein (MCP-1); (enzyme immune assay, ELISA)) and nitric oxide (NO; Griess reaction) were quantified in bronchoalveolar lavage (BAL) at baseline or 3 hours after inflammatory stimulus (in vivo LPS, 100µL/mL; 10min); in the supernatant of cultured alveolar macrophages (MΦs) or trachea obtained from animals and subsequently in vitro stimulated (MΦs: 5µg/mL of LPS plus 10ng/mL IFN-γ; trachea: 1µg/mL LPS; 24 hours). Phagocytic and fungicidal activities (light microscopy) and expression of receptors involved in phagocytosis (toll-like receptor (TLR, TLR2, TLR4 and dectin-1, flow cytometry) were determined after in vitro incubation of alveolar MΦs with Candida albicans fungus and expression of MyD88 pathway was held in alveolar MΦs (western blot). Quantification of mRNA for MCP-1 (reaction of reverse transcriptase polymerase chain reaction, RT-PCR) was performed in tracheal tissue and cells human monocytic THP-1 were used in in vitro chemotaxis assays (Boyden chamber) using different concentrations of MCP-1. Tracheal reactivity was measured in response to methacholine. The results showed that in vivo HQ exposure reduced the concentration of MCP-1 (54.98% vs. control) and IL-12 (51.45% vs. control) in the BAL after inflammation; decreased secretion of MCP-1 by MΦs (basal: 87.96%, LPS+INF-γ: 61.20%) and in tracheal culture after LPS stimulation (79.77% vs. control). In the latter tissue, the MCP-1 protein content was dependent on impaired gene expression. Concentrations of MCP-1 similar to those detected in the supernatant of tracheal from HQ exposed rats induced smaller migration of THP-1 cells (38.2%) than that evoked by the MCP-1 concentration obtained in trachea supernatants collected from control animals. Tracheas from HQ exposed rats showed hyper reactivity (193.48%), which was reversed by removal of the tracheal epithelium. Additionally, culture of MΦs obtained from HQ exposed rats showed increased phagocytic (percentage of phagocytosis: 36.30%; phagocytosis index: 83.97%) and fungicide activity (68.47%), which were not dependent on changes in the receptors TLR2, TLR4 and dectin-1, but could be due to reduced MyD88 expression. Together, these data point out important alterations on MΦs and trachea after in vivo HQ exposure, which may be crucial for the toxicity observed in these animals that culminates with impaired host defense.
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Efeitos transgeracionais da administração pré-natal do lipopolissacarídeo sobre o comportamento e sistema imune de camundongos avaliados por modelos de depressão / Transgenerational Effects of Prenatal Lipopolissacaride Exposure on The Behavior and Immune System of Mice Rated by Animal Models of DepressionThiago M. Reis-Silva 10 May 2013 (has links)
A depressão é hoje a doença mental mais comum do mundo, afetando mais de 121 milhões de pessoas. Além disso, estima-se que em aproximadamente uma década ela se torne a 2º doença responsável pela perda prematura de vida entre todas as idades e sexos. Diferentes propostas foram feitas no intuito de se compreender os mecanismos pelos quais essa doença incide, contudo a etiologia dos transtornos depressivos ainda não é totalmente entendida. Existem consideráveis evidências de que a administração perinatal de lipopolissacarídeo (LPS), uma endotoxina bacteriana, promove efeitos persistentes no desenvolvimento e comportamento da prole de camundongos, os quais podem-se manter até a idade adulta. Ainda, esses eventos podem ter implicações evolucionárias ligadas a alterações transgeracionais. Tendo em vista que a ativação do sistema imune pode estar relacionada com os transtornos depressivos, o presente trabalho expos pré-natalmente ao LPS uma geração de camundongos avaliando os efeitos comportamentais dessa exposição em três gerações subsequentes levando-se em consideração os comportamentos depressivos e não depressivos de cada geração avaliada. Para isso camundongos fêmeas, após terem o comportamento selecionado pelo teste de suspensão da cauda (TSC), foram cruzadas com machos de mesmo comportamento recebendo 100g/kg de LPS ou solução salina no 15º dia de prenhez. Após os nascimentos, as gerações subsequentes tiveram o comportamento em questão avaliado pelo TSC, bem como a atividade geral em campo aberto. Além disso, a interação materno-filhote foi avaliada, uma vez que alterações na mesma poderiam contribuir para os efeitos do tratamento com a endotoxina. Ainda, foi-se realizado um desafio com LPS na geração filial 3, na qual o nível de citocinas e a expressão do comportamento doentio foram avaliadas. Os resultados mostraram que (i) a administração do LPS na geração parental não afetou o comportamento depressivo e não depressivo nas três gerações avaliadas, dado que animais com comportamento depressivo tiveram mais filhotes com o mesmo comportamento em todas as gerações. (ii) Foram observadas alterações no comportamento materno da geração parental, possivelmente ligadas a motivação materna desses animais. (iii) Foram encontradas alterações transgeracionais na atividade geral de camundongos machos e fêmeas das gerações filiais 1 e 2. Tais alterações foram mais x expressivas nos machos e, havendo diferenças entre o comportamento. Esses dados apontam que a exposição a endotoxina possui diferentes consequências de acordo com o comportamento e, (iv) os animais da geração filial 3 quando desafiados com a endotoxina apresentaram maior comportamento doentio e maiores níveis de citocinas. Esses dados apontam para um forte componente genético na transmissão do comportamento, além de, uma influencia epigenética na modulação do mesmo. Ainda, foi possível concluir que a inflamação gerada pela administração pré-natal do LPS atua de forma distinta entre os sexos, bem como o histórico comportamental, no caso, o comportamento depressivo e não depressivo estudados nesse trabalho / Depression disorders are to be considered the most common mental illness affecting more than 121 million people worldwide. It is estimated that approximately one decade it becomes the 2nd disease most responsible for premature loss of life of all ages and sexes. Different proposals to understand this disorders have been made in the past years, however its etiology it is still yet fully understood. There is considerable evidence that the administration of lipopolysaccharide (LPS), a bacterial endotoxin, promotes persistent effects on development and behavior of the offspring of mice, which are maintained into adulthood. Still, these events may have evolutionary implications related to transgenerational changes. Given that activation of the immune system may be related to depressive disorders, this study aimed to expose a generation of mice to LPS evaluating the behavioral effects on three subsequent generations taking into account the depressive-like and non depressive-like behaviors assessed on each generation by the tail suspension test (TST). For this, female mice after behavior selected by the tail suspension test (TST) were crossed with males of the same behavior and exposed to 100g/kg of LPS or saline solution on day 15th of pregnancy. After births, the subsequent generations were also evaluated on the TST and in the open field for general activity. In addition, the maternal interaction was also evaluated, since changes on this parameter could contribute to the treatment effects of the endotoxin. Yet, has been performed a challenge with LPS in the generation branch 3, wherein the level of expression of cytokines and sickness behavior were evaluated. The results showed that (i) the administration of LPS in the parental generation did not affect the depressive-like behaviors on the three generations evaluated, since animals with depressive-like and non depressive-like behavior had more offspring with the same behavior in all generations. (ii) Changes were observed in maternal behavior of the parental generation which is possibly related to a change in motivational state of those animals. (iii) Transgenerational alterations were found in the general activity of male and female mice of the filial generation 1 and 2. These changes were more significant in males and differences between depressive-like e non depressive-like behaviors were also observed. Together, these data indicate that the exposure to endotoxin has different consequences according to the animal historical behavior and, xii finally, (iv) the animals of filial generation 3 when challenged with endotoxin had higher sickness behavior and higher levels of cytokines when evaluated in the open field test. These data point to a strong genetic component in the transmission of behavior and, besides, a possible influence of epigenetic mechanism of the same. Furthermore it was possible to concluded that inflammation state created by the prenatal LPS exposure acts differently according to the animal historical behavior, in this case, the depressive-like and non depressive-like behavior studied, and also acting differently according to the sexes
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Etude synergique du couplage du Système Lactoperoxydase avec d’autres molécules naturelles actives ayant des propriétés antifongiques pour l’amélioration de la conservation en frais des bananes / Synergetic study of coupling Lactoperoxydase System with other natural active molecules having antifungal properties to improve the preservation in fresh of bananasSagoua, Woeheoudama 10 December 2009 (has links)
L'anthracnose constitue pour plusieurs productions végétales une maladie importante qui engendre des pertes post récoltes considérables. Colletotrichum musae est le responsable de cette maladie chez la banane dessert. L'utilisation d'antimicrobiens naturels comme le système lactoperoxydase (LPS) représente une voie naturelle de lutte intéressante contre l'anthracnose. Dans cette étude, nous avons amélioré le LPS en ajoutant de l'iode dans le système existant ou en substituant le thiocyanate par de l'iode. La substitution du thiocyanate à l'iode a permis d'avoir un effet fongicide du LPS. De plus, d'autres substances comme la lactoferrine, le Bioxeda® et l'huile de Neem ont été étudiées pour leur effet antifongique. Les deux dernières substances ont donné une inhibition supérieure respectivement à 90% et à 40%., tandis qu'il n'y a eu aucun effet de la lactoferrine / Postharvest diseases are a major concern for several plant products, leading to considerable postharvest losses. Colletotrichum musae is responsible for anthracnose and is also involved in crown rot, the two main postharvest diseases of bananas. The use of natural anti-microbial agents such as the lactoperoxidase system (LPS) represents an interesting alternative to the use of fungicides for the control of postharvest diseases of bananas. This study consisted on optimization of the LPS by adding iodide or substituting the thiocyanate by iodide. Moreover, other substances like lactoferrin, Bioxeda® and Neem oil were analyzed for their antifungal effect. The last two compounds gave an inhibition higher than 90% and 40% respectively. No effect of lactoferrin was observed
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Rôle de l’environnement microbien dans la régulation de l’immunoglobuline A mucosale et dans le développement de la maladie de Berger / Role of microbial environment on the mucosal immunoglobulin A regulation and in the development of IgA nephropathyArchelus, Anderson 04 May 2018 (has links)
La maladie de Berger est la glomérulonéphrite la plus fréquente avec une estimation selon laquelle 1% de la population mondiale serait touchée. L’agent causal est une immunoglobuline (Ig)A anormale (polymérique et hypogalactosylée) qui se dépose dans le mésangium et provoque un dysfonctionnement rénal (protéinurie, hématurie) et des lésions glomérulaires. Dans 25% des cas, la maladie évolue sur 20 ans vers l’insuffisance rénale terminale. Des évidences, de plus en plus nombreuses, montrent que l’environnement microbien, en particulier bactérien, commensal ou pathogène, a un impact important sur le développement de la maladie. Au cours de ma thèse, j’ai d’abord étudié l’effet d’une molécule de la paroi bactérienne, le lipopolysaccharide (LPS), sur la production des IgA dans les muqueuses chez la souris normale. Les résultats que j’ai obtenus et ceux publiés permettent de proposer que la stimulation chronique des muqueuses par l’environnement microbien conduit à une augmentation de la production d’IgA néphrotoxiques, qui, du fait d’un déficit de leur récepteur pIgR mucosal, sont anormalement dirigées vers la circulation plûtôt que dans la lumière es muqueuses. Dans une seconde partie de mon travail, j’ai étudié l’effet du LPS sur le développement de la maladie de Berger dans un modèle de souris 1KI. Ces souris génétiquement modifiées produisent de l’IgA humaine et développent spontanément des dépôts mésangiaux d’IgA mais n’ont pas de protéinurie, d’hématurie ou de lésions glomérulaires. Nos résultats montrent que le LPS provoque une forte hématurie dans les souris 1KI lorsque celles-ci expriment le récepteur des IgA humaines, CD89, à la surface des polymorphonucléaires neutrophiles. En conclusion, mon travail de thèse a permis de mettre en lumière un impact de l’environnement microbien sur pIgR et sur les polymorphonucléaires neutrophiles dont la déficience ou l’activation pourrait contribuer au développement de la maladie de Berger. / IgA nephropathy is the most frequent glomerulonephritis worldwide. It features mesangial immunoglobulin (Ig)A deposits and proteinuria, hematuria and glomerular histological lesions. In 25% patients, it evolves, within 20 years, towards the end stage renal disease. Microbial environment, through the interaction with mucosa, is believed to play a crucial role in the development of the disease. The objectives of my work were to evaluate the effect of the microbial compound lipopolysaccharide (LPS) on the production of the nephritogenic IgA in the mucosa of mice and on the development of IgA nephropathy in the murine model 1KI that spontaneously develops mesangial IgA deposits without the other signs of the disease. Our results and those previously published suggest that the chronic stimulation of mucosa by microbiota leads to the increased production of nephritogenic IgA in the mucosa. These IgA, thanks to a deficient mucosal receptor pIgR in patients with IgA nephropathy, may be abnormally routed in the blood. We also showed that LPS provokes hematuria in the 1KI mice, when they express a specific IgA receptor, CD89, on the surface of polymorphonuclear neutrophils. Altogether our findings highlight the impact of microbial environment on pIgR and on polymorphonuclear neutrophils and thus, potentially, on IgA nephropathy.
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Avaliação de MPLA como adjuvante em formulações vacinais contra leptospirose. / Avaliation of MPLA as adjuvant in vaccine formulation against leptospirosis.Marina Yukari Kubota 01 July 2015 (has links)
Lipopolissacarídeos (LPS) de L. interrogans, S. enterica e B. pertussis foram extraídos e as subfrações monofosforil lipídeo A (MPLA) preparadas por hidrólise. O LPS é responsável por forte resposta imunológica e endotóxica em mamíferos, enquanto o MPLA apresenta baixa endotoxicidade e boa capacidade imunomoduladora. Estudamos a atividade adjuvante de LPS e de MPLA em formulações com antígenos LigA ou OmpA contra leptospirose. Testes de imunização e desafio em hamsters confirmaram alta atividade imunoprotetora de LigA e capacidade adjuvante do MPLA de salmonela e de LPS de leptospiras, mas as formulações não foram capazes de bloquear a colonização renal na leptospirose. Os resultados sugerem diferenças na imunidade protetora sistêmica da imunidade protetora renal. / Lipopolysaccharides (LPS) of L. interrogans, S. enterica and B. pertussis were extracted and the subfraction monophosphoril lipid A (MPLA) prepared by hydrolysis. The LPS is responsible for immunological response and endotoxicity in mammallians, while MPLA has reduced endotoxic activity, but maintain the immunomodulatory capacity. We studied the adjuvant capacity of LPS and MPLA in formulations with LigA or OmpA antigens against leptospirosis. Tests of immunization and challenge in hamsters confirmed the high immune protection activity of LigA and adjuvant capacity of MPLA of salmonela and LPS of lepstopiras, however formulations did not block the renal colonization. The results suggest that there are differences in the systemic immune protection from the kidney immune protection.
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LTA kontra självfall : Ett långsiktigt perspektiv / Pressure sewage systems : A long term perspectiveHolmberg, Mattias, Hen, Stefan January 2013 (has links)
Detta arbete syftar till att göra en utvärdering av hur de två skilda spillvattensystemen LTA (Lätt TryckAvlopp) och konventionellt självfallsavlopp står sig mot varandra ur ett långtidsperspektiv. Aspekter så som investering, drift, underhåll, miljöpåverkan, teknik och anläggning har analyserats och sammanställs av denna rapport, samt ett program som beräknar den ekonomiska aspekten mellan respektive system. Programmet, där användaren ges möjligheten att specificera sitt eget område, ger en fingervisning om den lösning som ur ekonomisk aspekt är mest fördelaktig. Detta kombinerat med den kunskap som samlats i rapporten ska leda till ett mer medvetet val hos kommuner och andra VA-huvudmän i Sverige. / The purpose of this report is to make a comparison between the two currently used sewage solutions, PSS (Pressure Sewage System) and the more conventional gravity based sewage-system during a vast period of time. Aspects such as investment, maintenance, upkeep, environmental, technology and terrain have been analyzed. The research has resulted in this report and an Excel-program which calculates an estimated economical difference between the two solutions, in a specific case chosen by the user, to determine which is more economically beneficial. This program, used hand in hand with the report, is suppose to increase the knowledgebase regarding the subject of sewage solutions among officials working with these kinds of matters in Sweden.
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Regulation of Proliferation of Alveolar Macrophages in Acute Respiratory Distress SyndromeGholamhosseinian Najjar, Sara 03 June 2024 (has links)
Alveolar macrophages comprising up to 95% of the pulmonary alveoli, are the gate-keepers of homeostasis by ensuring efficient tissue function through metabolizing excessive surfactant and phagocyting inhaled day-to-day and innocuous pathogens and particles, without triggering an immune response. Despite that, they are capable of orchestrating a very well-balanced immune response upon invasion of pathogens. These embryonic-derived cells are capable of self-renewal and therefore maintain themselves in the lungs throughout adult life, with minimal contribution from the circulating monocytes. This self-renewal capacity is attained intrinsically by maintaining low levels of transcription factors MafB and cMaf, and extrinsically through two main cytokines, namely GM-CSF secreted by alveolar epithelial type II cells, and TGFb secreted by AMs themselves in an autocrine manner. However, in inflammatory conditions such as acute respiratory distress syndrome (ARDS), depletion of AM pool and upregulation of MAFB among lung macrophages have been reported. Keeping in mind the role of transcription factors MafB and cMaf in inhibiting proliferative capacity of macrophages; we hypothesized that this depletion is due to upregulation of MafB and hence the suppression of enhancer regions of self-renewal genes in AMs. To investigate the role of MafB and its compensatory partner cMaf in ARDS, we have established a mouse model of ARDS using oropharyngeal instillation of LPS in WT and MafB/cMaf double-knockout (Maf-DKO) mice. Alongside, the molecular mechanisms of the effect of LPS on AMs was investigated ex-vivo. The obtained results have clearly shown that ex-vivo, LPS inhibits proliferation of AMs in a dose dependent manner, and induces apoptosis significantly. Regain of proliferative potential of LPS-stimulated AMs was evident upon TLR4 inhibition, and MyD-88 was shown to be the dominant adaptor downstream of TLR4 (as opposed to TRIF). Both WT and DKO AMs responded to LPS stimulation within 2 hours, by switching from OXPHOS to glycolysis, which accounts for their efficient pro-inflammatory phenotype once activated. Upon activation, MafB and cMaf were upregulated after 48 hours and the inhibition of AM proliferation was shown to be Maf-independent. Similarly, depletion of AM pool was shown to be Maf independent invivo, evident by similar kinetics of AM numbers in WT and DKO at different timepoints upon LPS stimulation. However, several findings indicated potential advantage of Maf-deficiency in tissue regeneration; this includes: 1) higher number of Ly6C+ monocytes and their earlier differentiation into resident AMs, 2) lower degree of tissue damage revealed by H&E staining, 3) higher number of alveolar epithelial type II cells, 4) significantly higher levels of cytotoxicity pointing towards cellular turnover, and 5) significantly higher levels of SP-D and thus its antiinflammatory effects. In a quest for investigating factors which could enhance proliferative potential of AMs and ultimately neutralize the inhibitory effect of LPS, the impact of TGFb and ActivinA was studied. I have shown that TGFb and to a higher extend ActivinA boost the proliferation rate of AMs, ex-vivo. The autocrine effect of these cytokines was validated by blocking signal transduction through inhibition of SMAD2/3, which resulted in a significant increase in doubling time of AMs. Interestingly, Inhba was shown to be significantly upregulated in AMs, as opposed to TGFb. The importance of ActivinA was further demonstrated by its direct inhibition and the resulting reduction in growth rate of AMs. On the contrary to the significant role of these cytokines in enhancing the growth rate of AMs ex-vivo, they could rescue AM proliferation under the effect of LPS. In conclusion, I have demonstrated that LPS inhibits AM proliferation in a dose dependent and Maf-independent manner. Furthermore, neither TGFb nor ActivinA could rescue proliferation of LPS-stimulated AMs. Although Maf-deficiency was not shown to be beneficial during the inflammatory phase of ARDS, due to the fact that both WT and DKO AMs were equally depleted at the peak of inflammation, multiple data indicated potential advantage of Maf deficiency during resolution phase.
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Der Effekt von Antithrombin III auf die pulmonalvaskuläre Freisetzung von Big Endothelin-1, Endothelin-1 und Prostanoiden unter septischen und nichtseptischen Bedingungen sowie seine MechanismenPfannenschmidt, Gerd 27 July 2000 (has links)
Die Arbeit sollte klären, ob die pulmonalprotektiven Effekte von AT III bei LPS-induziertem ARDS auch auf einer Stimulation der pulmonalvaskulären PGI2-Freisetzung beruhen. Die Freisetzung von Big ET-1 und ET-1 unter septischen Bedingungen sollte quantifiziert sowie mögliche Effekte von AT III auf diese Freisetzung untersucht werden. Dabei wurde das Modell der isolierten Rattenlunge verwendet. Die Perfusion der Lunge mit LPS führte zu einer Steigerung der Kon-zentration von 6-Keto-PGF1(, dem stabilen Metaboliten von PGI2, auf das 1,6fache und der Konzentration von TxB2, dem stabilen Metaboliten von TxA2, auf das 2,9fache gegenüber der Kontrollgruppe. Die Konzentration von ET-1 erhöhte sich unter LPS auf das 1,6fache, während der Big ET-1 Spiegel konstant blieb. Die Gabe von AT III hatte keinen Effekt auf die Freisetzung von PGI2 und TxA2. Die kombinierte Gabe von LPS und AT III wirkte ebenso wie die Gabe von LPS allein. Die Konzentrationen von Big ET-1 und ET-1 erhöhten sich unter 2 U/ml AT III auf das 1,7- bzw. 1,2fache und unter 5 U/ml AT III auf das 1,6- bzw. 1,3fache gegen-über den Kontrollen. Die kombinierte Gabe von LPS und AT III führte zu einem signifikant höheren Big ET-1-Spiegel vom 2,6fachen des Basalwertes, während sich die Konzentration von ET-1 nicht von der unter LPS bzw. AT III allein unterschied. Die Gabe von Cicaprost, einem stabilen synthetischen PGI2-Analogon, beeinflußte weder die basale noch die durch 2 U/ml AT III und 50 µg/ml LPS stimulierte Big-ET-1- und ET-1-Freisetzung. Nicardipin, ein Blocker der L-Typ-Kalzium-Kanäle, Heparin und N-Acetyl-Heparin, ein nicht an AT III bindendes Heparin, antagonisierten jeweils den stimulierenden Effekt von AT III auf die Big-ET-1- und ET-1-Freisetzung komplett. Staurosporin, ein Proteinkinase C-Inhibitor und Genistein, ein Tyrosinkinase-Inhibitor hatten keinen Effekt auf die durch AT III stimulierte Big-ET-1- und ET-1-Freisetzung. SCHLUßFOLGERUNGEN: Das für den protektiven Effekt des AT III bei ARDS verantwortlich gemachte PGI2 scheint nichtpulmonalen Ursprungs zu sein. Eine PGI2-mediierte Hemmung der pulmonalen ET-1-Sekretion war nicht zu beobachten und scheint somit nicht am protektiven Effekt des AT III beim septischen ARDS beteiligt zu sein. Der beobachtete stimulierende Effekt des AT III auf die Freisetzung der pulmonalen Endotheline ist von möglicher pathophysiologischer Relevanz, da er die erwähnte protektive Wirkung des AT III mit hoher Wahrscheinlichkeit abschwächt. Dieser stimulierende Effekt des AT III scheint dabei an der intakten Rattenlunge weder von der Proteinkinase C noch von Tyrosinkinasen vermittelt zu sein. Weiterhin ist festzustellen, daß die stimulierende Wirkung des AT III auf die pulmonalvaskuläre Freisetzung von Big ET-1 und ET-1 von einem Kalziumeinstrom durch L-Typ-Kalzium-Kanäle und damit von der intrazellulären Kalziumkonzentration abhängig ist. Wie die gleiche Wirksamkeit von Heparin und N-Azetyl-Heparin zeigt, erfordert die Blockade des AT-III-Effektes durch die Heparine keine direkte Bindung an AT III, was auf die zusätzliche Rolle der intrazellulären Kalziumfreisetzung über IP3 hinweist. / The aim of the present study was to clarify if the pulmonary protective effects of AT III in LPS-induced ARDS can be attributed to a stimulation of the pulmonary vascular release of PGI2. The pulmonary vascular release of big ET-1 and ET-1 under septic conditions and the possible influence of AT III was to be investigated. To this end, we used the model of the isolated perfused rat lung. Exposure of the lung to LPS increased the release of 6-Keto-PGF1(, the stable metabolite of PGI2, 1.6fold and the production of TxB2, the stable metabolite of TxA2, 2.9fold compared with control lungs. The release of ET-1 increased 1.6fold under LPS, whereas the concentration of big ET-1 was unchanged. The application of AT III had no effect on the release of PGI2 and TxA2. The effects following combined application of LPS and AT III were similar to the effects of LPS alone. Compared with controls, AT III, at 2 U/ml, increased the perfusate levels of big ET-1 and ET-1 1.7fold and 1.2fold, respectively; the administration of 5 U/ml AT III raised big ET-1 and ET-1 1.6fold and 1.3fold, respectively. Combined application of LPS and AT III resulted in a 2.6fold rise of big ET-1 levels compared with controls, whereas concentrations of ET-1 did not differ from those in the presence of LPS or AT III alone. Cicaprost, a stable PGI2 analogue, affected neither the basal nor the AT III plus LPS-stimulated release of big ET-1 and ET-1. Nicardipin, an L-type calcium channel blocker, heparin and N-acetyl heparin, a heparin derivative devoid of AT III affinity, each antagonized completely the AT III-stimulated increase in big ET-1 and ET-1 levels. Staurosporin, an inhibitor of protein kinase C, and genistein, an inhibitor of tyrosine kinases, did not influence the AT III effects on endothelins. CONCLUSIONS: In ARDS, the well-known rise in plasma PGI2 in response to AT III obviously originates from non-pulmonary sources. PGI2 does not suppress the pulmonary ET-1 secretion; therefore, this mechanism seems not involved in the AT III-induced lung protection during septic ARDS. The AT III-mediated stimulation of the release of pulmonary endothelins is of potential pathophysiological relevance, because it may blunt the protective effects of AT III in ARDS. In the intact rat lung, this stimulatory effect of AT III is mediated neither by protein kinase C nor by tyrosine kinases. Moreover, the observed effect of AT III on pulmonary endothelins is based on calcium influx through L-type calcium channels and depends on the intracellular calcium activity. The equipotency of heparin and N-acetyl heparin in inhibiting the AT III action demonstrates that direct binding of AT III is not essential for the blocking effect of heparins. This fact points to additional involvement of an IP3-dependent intracellular calcium release.
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