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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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Physiology of Escherichia coli in batch and fed-batch cultures with special emphasis on amino acid and glucose metabolismHan, Ling January 2002 (has links)
The objective of this work is to better understand themetabolism and physiology ofEscherichiacoli(W3110) in defined medium cultures with thelong-term goal of improving cell yield and recombinant proteinproductivity. The order of amino acid utilization inE. colibatch cultures was investigated in a medium with16 amino acids and glucose. Ser, Pro, Asp, Gly, Thr, Glu andAla were rapidly consumed and depleted at the end of theexponential phase, while His, Arg, Val, Met, Ile, Leu, Phe, Lysand Tyr were consumed slowly during the following linear growthphase. The uptake order correlated to the maximum specificconsumption rate. Of the rapidly consumed amino acids onlyglyine and threonine improved growth when added individually.Serine was the first amino acid to be consumed, but inhibitedglucose uptake initially, which presumably is related to thefunction of PTS. Valine inhibited cell growth could be releasedby isoleucine. The critical medium concentration of valinetoxicity was 1.5 - 3 µmol L-1. Valine uptake was associated with exchange ofisoleucine out of the cells. Glycine significantly increased the cell yield,Yx/s,and growth rate ofE. coliin batch cultures in a glucose-mineral medium.Maximum effect occurred at pH 6.8, at 6 - 12 mmol L-1glycine, and below 1.15 g dw L-1.13C NMR technique was employed to identify [1-13C], [2-13C]and [1,2-13C]acetate in the cultures supplied with [2-13C]glycine. The NMR data revealed that littledegradation of added glycine occurred, and that serine/glycinebiosynthesis was repressed below 1.15 g dw L-1, implicating that glycine was a source ofglycine, serine, one-carbon units, and threonine. Above 1.15 gdw L-1, 53% of the consumed glycine carbon was excretedas acetate. Degradation of glycine was associated with anincreased uptake rate, cleavage by GCV, and degradation of bothglycine- and glucose-derived serine to pyruvate. This switch inmetabolism appears to be regulated by quorum sensing. A cell density-dependent metabolic switch occurred also inthe central metabolism. A 2 - 3 fold decrease in mostglycolytic and TCA cycle metabolites, but an increase inacetyl-CoA, occurred after the switch. The acetate productionrate decreased throughout the culture with a temporary increaseat the switch point, but the intracellular acetate poolremained relatively constant. Two mixtures of amino acids were fed together with glucosein fed-batch cultures ofE. coliW3110 pRIT44T2, expressing the recombinantprotein ZZT2. One mixture contained 20 amino acids and theother 5 so-called 'protein amino acids': Ala, Arg, Met, His andPhe. Although the amino aids increased the cell yield anddecreased the proteolysis rate in both cases, ZZT2 productionwas decreased. A decrease of ZZT2 synthesis rate is consideredto be the reason. Further studies of the 5 amino acidsindicated that a few amino acids disturb metabolism. Carbon mass balances were calculated in glucose limitedfed-batch cultures ofE. coli. In the end, the carbon recovery was ~90% basedon biomass, CO2and acetate, but ~100% if the all carbon in themedium was included. Outer membrane (OM) constituents,lipopolysaccharide, phospholipids, and carbohydratescontributed to 63% of the extracellular carbon. Little celllysis occurred and the unidentified (~30%) carbon was assumedto constitute complex carbohydrates. A novel cultivationtechnique Temperature-Limited Fed-Batch (TLFB) is developed toprevent OM shedding in high-cell density cultures. <b>Keywords</b>: Escherichia coli, amino acids, glycine, quorumsensing, metabolic switch, metabolite pools, carbon balance,outer membrane, lipopolysaccharide, batch culture, fed-batchculture
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Mechanisms of Lung Inflammation Following Exposure to Swine Barn AirCharavaryamath, Chandrashekhar 04 September 2008
Occupational exposure to endotoxin-rich swine barn air induces respiratory diseases and loss of lung function. Barn exposure induces recruitment of pulmonary intravascular monocytes/macrophages (PIMMs) and subsequent increased host sensitivity to <i>Escherichia coli</i> LPS challenge. Therefore, to further clarify the biology of PIMMs we examined the role of recruited PIMMs in a rat <i>Escherichia coli</i>-induced lung inflammation model. Following sepsis, lung inflammation was induced with recruitment of PIMMs and subsequently, <i>Escherichia coli</i> LPS challenge exacerbated the lung inflammation with localization of multiple inflammatory cytokines in PIMMs to suggest their possible involvement in modulating lung inflammation in this model.<p>
In order to delineate mechanisms of barn air induced lung dysfunction, a rat model of occupational exposure was characterized to show that one and five exposures to the barn environment induced acute lung inflammation and increased airway hyperresponsiveness (AHR). Following 20 exposures, AHR was dampened to indicate adaptive responses. Barn air contains high levels of endotoxin which led us to investigate its role in lung inflammation and AHR. Exposure of mice with either a functional TLR4 (WT) or non-functional TLR4 (mutants) to barn air revealed dependence of lung inflammation but not AHR on a functional TLR4.<p>
I investigated whether exposure to barn air alters host responses to a subsequent microbial challenge. Following one day barn exposure and <i>Escherichia coli</i> LPS challenge, lung inflammation was exacerbated with increased granulocytes and IL-1β levels compared to one day barn exposed rats without <i>Escherichia coli</i> LPS challenge. However, increased granulocytes and IL-1β levels in barn exposed and <i>Escherichia coli</i> LPS challenged rats were not different from control rats treated with <i>Escherichia coli</i> LPS indicating a lack of priming effect of barn exposure. However, above results are suggestive of an underlying risk of increased lung inflammation following secondary microbial infection in naïve barn workers.<p>
Lastly, I investigated the expression and activity of novel signalling molecules called <i>N</i>-myristoyltransferase and calcineurin in barn air and <i>E. coli</i> LPS induced lung inflammation models. Following one day barn exposure, increased protein expression but not activity of <i>N</i>-myristoyltransferase and calcineurin was shown. However, there is a need to identify the specific role of these two molecules in barn air induced lung inflammation. To conclude, animal models of barn exposure are useful tools to understand mechanisms of lung inflammation and AHR. However, there is still a need to examine endotoxin-independent nature of AHR and roles of other molecules of the innate immune system in regulating barn air induced effects.
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Mechanisms of Lung Inflammation Following Exposure to Swine Barn AirCharavaryamath, Chandrashekhar 04 September 2008 (has links)
Occupational exposure to endotoxin-rich swine barn air induces respiratory diseases and loss of lung function. Barn exposure induces recruitment of pulmonary intravascular monocytes/macrophages (PIMMs) and subsequent increased host sensitivity to <i>Escherichia coli</i> LPS challenge. Therefore, to further clarify the biology of PIMMs we examined the role of recruited PIMMs in a rat <i>Escherichia coli</i>-induced lung inflammation model. Following sepsis, lung inflammation was induced with recruitment of PIMMs and subsequently, <i>Escherichia coli</i> LPS challenge exacerbated the lung inflammation with localization of multiple inflammatory cytokines in PIMMs to suggest their possible involvement in modulating lung inflammation in this model.<p>
In order to delineate mechanisms of barn air induced lung dysfunction, a rat model of occupational exposure was characterized to show that one and five exposures to the barn environment induced acute lung inflammation and increased airway hyperresponsiveness (AHR). Following 20 exposures, AHR was dampened to indicate adaptive responses. Barn air contains high levels of endotoxin which led us to investigate its role in lung inflammation and AHR. Exposure of mice with either a functional TLR4 (WT) or non-functional TLR4 (mutants) to barn air revealed dependence of lung inflammation but not AHR on a functional TLR4.<p>
I investigated whether exposure to barn air alters host responses to a subsequent microbial challenge. Following one day barn exposure and <i>Escherichia coli</i> LPS challenge, lung inflammation was exacerbated with increased granulocytes and IL-1β levels compared to one day barn exposed rats without <i>Escherichia coli</i> LPS challenge. However, increased granulocytes and IL-1β levels in barn exposed and <i>Escherichia coli</i> LPS challenged rats were not different from control rats treated with <i>Escherichia coli</i> LPS indicating a lack of priming effect of barn exposure. However, above results are suggestive of an underlying risk of increased lung inflammation following secondary microbial infection in naïve barn workers.<p>
Lastly, I investigated the expression and activity of novel signalling molecules called <i>N</i>-myristoyltransferase and calcineurin in barn air and <i>E. coli</i> LPS induced lung inflammation models. Following one day barn exposure, increased protein expression but not activity of <i>N</i>-myristoyltransferase and calcineurin was shown. However, there is a need to identify the specific role of these two molecules in barn air induced lung inflammation. To conclude, animal models of barn exposure are useful tools to understand mechanisms of lung inflammation and AHR. However, there is still a need to examine endotoxin-independent nature of AHR and roles of other molecules of the innate immune system in regulating barn air induced effects.
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Physiology of Escherichia coli in batch and fed-batch cultures with special emphasis on amino acid and glucose metabolismHan, Ling January 2002 (has links)
<p>The objective of this work is to better understand themetabolism and physiology of<i>Escherichiacoli</i>(W3110) in defined medium cultures with thelong-term goal of improving cell yield and recombinant proteinproductivity.</p><p>The order of amino acid utilization in<i>E. coli</i>batch cultures was investigated in a medium with16 amino acids and glucose. Ser, Pro, Asp, Gly, Thr, Glu andAla were rapidly consumed and depleted at the end of theexponential phase, while His, Arg, Val, Met, Ile, Leu, Phe, Lysand Tyr were consumed slowly during the following linear growthphase. The uptake order correlated to the maximum specificconsumption rate. Of the rapidly consumed amino acids onlyglyine and threonine improved growth when added individually.Serine was the first amino acid to be consumed, but inhibitedglucose uptake initially, which presumably is related to thefunction of PTS. Valine inhibited cell growth could be releasedby isoleucine. The critical medium concentration of valinetoxicity was 1.5 - 3 µmol L<sup>-1</sup>. Valine uptake was associated with exchange ofisoleucine out of the cells.</p><p>Glycine significantly increased the cell yield,<i>Y</i><sub>x/s,</sub>and growth rate of<i>E. coli</i>in batch cultures in a glucose-mineral medium.Maximum effect occurred at pH 6.8, at 6 - 12 mmol L<sup>-1</sup>glycine, and below 1.15 g dw L<sup>-1</sup>.<sup>13</sup>C NMR technique was employed to identify [1-<sup>13</sup>C], [2-<sup>13</sup>C]and [1,2-<sup>13</sup>C]acetate in the cultures supplied with [2-<sup>13</sup>C]glycine. The NMR data revealed that littledegradation of added glycine occurred, and that serine/glycinebiosynthesis was repressed below 1.15 g dw L<sup>-1</sup>, implicating that glycine was a source ofglycine, serine, one-carbon units, and threonine. Above 1.15 gdw L<sup>-1</sup>, 53% of the consumed glycine carbon was excretedas acetate. Degradation of glycine was associated with anincreased uptake rate, cleavage by GCV, and degradation of bothglycine- and glucose-derived serine to pyruvate. This switch inmetabolism appears to be regulated by quorum sensing.</p><p>A cell density-dependent metabolic switch occurred also inthe central metabolism. A 2 - 3 fold decrease in mostglycolytic and TCA cycle metabolites, but an increase inacetyl-CoA, occurred after the switch. The acetate productionrate decreased throughout the culture with a temporary increaseat the switch point, but the intracellular acetate poolremained relatively constant.</p><p>Two mixtures of amino acids were fed together with glucosein fed-batch cultures of<i>E. coli</i>W3110 pRIT44T2, expressing the recombinantprotein ZZT2. One mixture contained 20 amino acids and theother 5 so-called 'protein amino acids': Ala, Arg, Met, His andPhe. Although the amino aids increased the cell yield anddecreased the proteolysis rate in both cases, ZZT2 productionwas decreased. A decrease of ZZT2 synthesis rate is consideredto be the reason. Further studies of the 5 amino acidsindicated that a few amino acids disturb metabolism.</p><p>Carbon mass balances were calculated in glucose limitedfed-batch cultures of<i>E. coli</i>. In the end, the carbon recovery was ~90% basedon biomass, CO<sub>2</sub>and acetate, but ~100% if the all carbon in themedium was included. Outer membrane (OM) constituents,lipopolysaccharide, phospholipids, and carbohydratescontributed to 63% of the extracellular carbon. Little celllysis occurred and the unidentified (~30%) carbon was assumedto constitute complex carbohydrates. A novel cultivationtechnique Temperature-Limited Fed-Batch (TLFB) is developed toprevent OM shedding in high-cell density cultures.</p><p><b>Keywords</b>: Escherichia coli, amino acids, glycine, quorumsensing, metabolic switch, metabolite pools, carbon balance,outer membrane, lipopolysaccharide, batch culture, fed-batchculture</p>
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Using Live Cell Imaging to Probe Biogenesis of the Gram-Negative Cell EnvelopeYao, Zhizhong January 2012 (has links)
In Gram-negative bacteria, the three-layered cell envelope, including the cell wall, outer and inner membranes, is essential for cell survival in the changing, and often hostile environments. Conserved in all prokaryotes, the cell wall is incredibly thin, yet it functions to prevent osmotic lysis in diluted conditions. Based on observations obtained by genetic and chemical perturbations, time-lapse live cell imaging, quantitative imaging and statistical analysis, Part I of this dissertation explores the molecular and physical events leading to cell lysis induced by division-specific beta-lactams. We found that such lysis requires the complete assembly of all essential components of the cell division apparatus and the subsequent recruitment of hydrolytic amidases. We propose that division-specific beta-lactams lyze cells by inhibiting FtsI (PBP3) without perturbing the normal assembly of the cell division machinery and the consequent activation of cell wall hydrolases. On the other hand, we demonstrated that cell lysis by beta-lactams proceeds through four physical phases: elongation, bulge formation, bulge stagnation and lysis. Bulge formation dynamics is determined by the specific perturbation of the cell wall and outer membrane plays an independent role in stabilizing the bulge once it is formed. The stabilized bulge delays lysis, and allows escape and recovery upon drug removal. Asymmetrical in structure and unique to Gram-negative bacteria, outer membrane prevents the passage of many hydrophobic, toxic compounds. Together with inner membrane and the cell wall, three layers of the Gram-negative cell envelope must be well coordinated throughout the cell cycle to allow elongation and division. Part II of this dissertation explores the essentiality of the LPS layer, the outer leaflet of the outer membrane. Using a conditional mutant severely defective in LPS transport, we found that mutations in the initiation phase of fatty acid synthesis suppress cells defective in LPS transport. The suppressor cells are remarkably small with a 70% reduction in cell volume and a 50 % reduction in growth rate. They are also blind to nutrient excess with respect to cell size control. We propose a model where fatty acid synthesis regulates cell size in response to nutrient availability, thereby influencing growth rate. / Chemistry and Chemical Biology
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Effects of Tetrastarch Administration on Hemostatic, Laboratory, and Hemodynamic Variables in Healthy Dogs and Dogs with Systemic InflammationGauthier, Vincent 05 September 2013 (has links)
Hydroxyethyl starches (HES) are the most routinely used synthetic colloids during fluid resuscitation and have reported effects on coagulation. The overall goal of the investigation in this thesis was to evaluate the effects of tetrastarch administration on hemodynamic, laboratory, and hemostatic variables in healthy dogs and dogs with systemic inflammation. The objectives were to compare hemodynamic and laboratory variables in dogs receiving an isotonic crystalloid (0.9% NaCl) or tetrastarch during health and after induction of systemic inflammation; to compare the hemostatic effects of an isotonic crystalloid (0.9% NaCl) and synthetic colloid (tetrastarch) in healthy dogs and dogs with induced systemic inflammation; to compare two different protocols for TEG® activation and to determine the correlation between TEG® variables and traditional coagulation test results.
Sixteen adult purpose-bred Beagles were randomized into one of two groups receiving fluid resuscitation with either 40 mL/kg IV isotonic crystalloid (0.9% NaCl) or synthetic colloid (tetrastarch) after administration of lipopolysaccharide (LPS; 5 μg/kg, IV) or an equal volume of placebo (0.9% NaCl, IV). Blood samples, for analysis, were collected at 0, 1, 2, 4, and 24 hours from the time of fluid resuscitation. After a 14-day washout period, the study was repeated such that dogs received the opposite treatment (LPS or placebo) and the same resuscitation fluid. Resuscitation with equal volumes of 0.9% NaCl and tetrastarch caused similar changes in hemodynamic and laboratory variables in dogs with LPS-induced systemic inflammation; however, larger increases in HR and blood pressure were seen within the first 2 hours following tetrastarch administration compared to 0.9% NaCl. Tetrastarch administration increased COP in all dogs, despite a decrease in TS. Tetrastarch bolus administration to dogs with LPS-induced systemic inflammation also resulted in a transient hypocoagulability characterized by a prolonged PTT, decreased clot formation speed and clot strength, and acquired type 1 von Willebrand disease.
Considering the limited additional benefit of tetrastarch administration on hemodynamic variables demonstrated, as well as the transient adverse hemostatic effects of tetrastarch administration, the increased cost associated with the use of tetrastarch likely negates its use as a first line treatment during fluid resuscitation in dogs. / Pet Trust Fund
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Interação entre Lipopolissacarídeo de Salmonella Typhimurium e Fumonisina B1 em frangos de corteRauber, Ricardo Hummes January 2012 (has links)
Lipopolissacarídeo (LPS) é o principal componente da parede celular de bactérias Gram-negativas, sendo liberado durante a divisão celular ou morte da bactéria após lise. O LPS é um dos mais potentes ativadores do sistema imune, desencadeando uma resposta inflamatória inespecífica. A exposição ao LPS tem sido associada a uma gama de efeitos tóxicos em frangos e outras aves, como hipertermia, inflamação, caquexia e, eventualmente, morte. A fumonisina B1 (FB), um metabólito secundário produzido pelo Fusarium verticilloides, tem sido descrita como causa de doenças previamente conhecidas (leucoencefalomalácea equina e edema pulmonar suíno), bem como causando alguns efeitos em aves. Os principais sinais clínicos da intoxicação por FB em frangos são desempenho reduzido, ascite, edema e congestão dos rins, diarreia, peso relativo do fígado aumentado e mortalidade. O objetivo deste trabalho foi avaliar os efeitos individuais e combinados do LPS de Salmonella Typhimuruim (sLPS) e FB sobre o desempenho produtivo (peso corporal [PC], consumo de ração [CR] e conversão alimentar [C]), peso relativo de fígado (PRF), parâmetros biológicos (proteínas plasmáticas totais [PPT], albumina [Alb], cálcio [Ca], triglicerídeos [Tri], colesterol total [Col], fósforo [P], ácido úrico [AU], proteína C-reativa [CRP], alanina aminotransferase [ALT], aspartato aminotransferase [AST], fosfatase alcalina [FA], gama glutamiltransferase [GGT] e relação esfinganina/esfingosina [SA:SO]), avaliação morfológica do intestino delgado (altura de vilosidades [AV], profundidade de criptas [PC] e relação vilosidade/cripta [V:C]) e avaliações histológicas de vários tecidos de 432 frangos de corte, machos, com um dia de idade, divididos em nove tratamentos, conforme a dose de FB (0, 100 ou 200 mg/kg, do primeiro ao 28º dia de experimento) e sLPS (0, 250 ou 500 μg/ave por aplicação, a cada 48 horas, do 15º ao 27º dia. Ao final do experimento (28 dias): efeitos significativos do sLPS foram observados sobre PC, Ca, Col, P, AU, CRP, AST, FA e AV; efeitos significativos da FB foram observados sobre PC, CR, C, PRF, PPT, Alb, Ca, Tri, Col, AU, CRP, ALT, GGT, SA:SO, AV e V:C; efeitos significativos da interação sLPS*FB foram observados sobre PRF, Alb, Col, P, AU e CRP. Alterações histológicas foram observadas para sLPS, FB e sLPS*FB no fígado e rins. De acordo com estes resultados, sLPS e FB (isolados ou associados) determinam efeitos sobre o desempenho e parâmetros biológicos de frangos de corte. / Lipopolysaccharide (LPS) is the main component of Gram-negative bacterial cell wall, and is released during cellular division or bacterial death after lysis. This is one of the most powerful activators of the immune system, leading to a non-specific inflammatory response. LPS exposure has been related to a role of effects in broilers and other avian species, such as hyperthermia, inflammation, cachexia, and eventually, death. Fumonisin B1 (FB), a secondary metabolite produced by Fusarium verticilloides, has been shown to be associated to some previously known diseases or syndromes (equine leucoencephalomalacea and porcine pulmonary edema) and has also been described as causing some effects in poultry. The main clinical signs of FB intoxication in broilers are reduced productive performance, ascites, kidney edema and congestion, diarrhea, increased relative weight of the liver, and mortality. The aim of this research was to evaluate the individual and combined effects of Salmonella Typhimurium Lipopolysaccharide (sLPS) and FB on performance (body weight, feed intake, and feed conversion rate), relative weight of the liver, biological parameters (total plasma proteins [TPP], albumin [Alb], calcium [Ca], triglycerides [Tri], total cholesterol [Col], phosphorus [Ph], uric acid [UA], C-reactive protein [CRP], alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [AP], gamma glutamiltransferase [GGT] and sphinganine-to-sphingosine [SA:SO] ratio), morphological evaluation of jejunum/ileum (villous height [VH], crypt depth [CD], and villous-to-crypt [V:C] ratio), and histological evaluation of several tissues from 432 day-old male broiler chickens divided into nine treatments according to the dose of FB (0, 100, or 200 mg/kg, from day 1 to day 28) and sLPS (0, 250, or 500 μg/application/bird, every other day, from day 15 do day 27). At the end of the experiment (28 d), significant effects of: sLPS were observed on BW, Ca, Col, Ph, UA, CRP, AST, AP, and VH; FB were observed on BW, FI, FCR, RWL, TPP, Alb, Ca, Tri, Col, UA, CRP, ALT, GGT, SA:SO, VH, and V:C; Interaction sLPS*FB were observed on RWL, Alb, Col, Ph, UA, and CRP. Histopathological evaluations showed significant lesions in liver and kidney caused by sLPS, FB and their association. According to these results, both sLPS and FB (isolated or associated) determine significant effects on performance and biological parameters of broilers at 28 days of age.
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Estudo dos mecanismos de ação do peptídeo Ac2-26 e da Piplartina nas células endoteliais de veias umbilicais humanas (HUVEC) ativadas pelo lipopolissacarídeo / Study of the mechanisms of action of the peptide Ac2-26 and Piplartina in human umbilical vein endothelial cells (HUVEC) activated by lipopolysaccharideCarvalho, Caroline de Freitas Zanon de 21 June 2018 (has links)
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Agradecemos a compreensão.
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Previous issue date: 2018-06-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os avanços recentes nos mecanismos de inflamação e a descoberta de vários mediadores endógenos anti-inflamatórios levaram a novas investigações sobre as possibilidades terapêuticas. A demonstração, em estudos científicos, da ação anti-inflamatória da proteína anexina A1 (ANXA1) e do seu peptídeo mimético Ac2-26, têm sido fonte de sucesso para o desenvolvimento de novos fármacos. A descoberta da interação biofísica da piplartina (PL) com a região N-terminal da ANXA1 abriu um novo e instigante campo de investigação para o nosso grupo de pesquisa. Diante destas considerações, o objetivo do presente trabalho foi investigar a atuação da PL nas células endoteliais da veia umbilical humana (HUVEC), ativadas pelo lipopolissacarídeo (LPS). Ainda, se a interação Ac2-26/PL influência nas ações anti-inflamatórias da PL, favorecendo ou atenuando os seus efeitos nos processos inflamatórios. Inicialmente foi utilizada a Espectroscopia de Absorbância UV-Vis e de Fluorescência para investigar as interações entre o ligante PL e Ac2-26. In vitro, as células HUVEC foram ativadas pelo LPS (10 μg/mL), nos tempos de 8, 24, 48 e 72 horas, seguido pelos tratamentos com Ac2-26 (1µM) e/ou PL (10µM), demonstrando resultados expressivos em 24 e 72 horas. Os efeitos foram avaliados nos seguintes aspectos: proliferação celular, viabilidade celular, dosagens da quimiocina MCP-1 e das citocinas IL-8 e IL-1β e expressão da proteína α-tubulina. A presença de um anel trimetoxiaromático na estrutura da PL, o que pode favorecer uma interação com a tubulina, motivou as análises de Western blotting, as quais demonstraram que a PL inibiu a síntese da proteína endógena α-tubulina, em todas as condições experimentais. Nossos resultados mostraram efeitos pró-proliferativos do peptídeo Ac2-26 e, por outro lado, antiproliferativos e pró-apoptóticos da PL. Os níveis das citocinas pró-inflamatórias confirmaram o papel anti-inflamatório do Ac2-26 nas células ativadas pelo LPS, com redução dos níveis de MCP-1 e IL-8, em 24 horas. O tratamento PL reduziu os níveis de MCP-1 nas células ativadas pelo LPS, e aumentou IL-8, inclusive no tratamento associado Ac2-26/PL. Em conjunto, os resultados com as células HUVEC indicam que a PL inibe a proliferação por meio da ativação da apoptose celular, regulada pela inibição da polimerização da α-tubulina e dos níveis elevados da citocina IL-8. A PL e o Ac2-26 mostraram ações anti-inflamatórias, e a interação Ac2-26/PL parece ser neutra em relação às propriedades anti-inflamatórias da PL. / Recent advances in inflammation mechanisms and the discovery of several endogenous anti-inflammatory mediators have led to further investigations into the therapeutic possibilities. The demonstration, in scientific studies, of the annexin A1 protein (ANXA1) anti-inflammatory action and its peptide mimetic Ac2-26, have been a source of success for the development of new drugs. The discovery of the biophysical interaction of piplartin (PL) with the N-terminal region of ANXA1 opened a new and exciting field of investigation for our research group. In view of these considerations, the objective of the present study was to investigate the role of PL in lipopolysaccharide (LPS) activated human umbilical vein endothelial cells (HUVEC). Also, if the interaction Ac2-26/PL influences the anti-inflammatory actions of PL, favoring or attenuating its effects on inflammatory processes. Initially, UV-Vis Absorbance Spectroscopy and Fluorescence were used to investigate the interactions between the PL ligand and Ac2-26. In vitro, HUVEC cells were activated by LPS (10 μg/mL) at 8, 24, 48 and 72 hours, followed by treatments with Ac2-26 (1μM) and/or PL (10μM), demonstrating expressive results in 24 and 72 hours. The effects were evaluated in the following aspects: cell proliferation, cell viability, MCP-1 chemokine and IL-8 and IL-1β cytokines and α-tubulin protein expression. The presence of a trimethoxyaromatic ring in the PL structure, which may favor an interaction with tubulin, motivated Western blotting analyzes, which demonstrated that PL inhibited endogenous α-tubulin protein synthesis in all experimental conditions. Our results showed pro-proliferative effects of the peptide Ac2-26 and, on the other hand, antiproliferative and pro-apoptotic of PL. Proinflammatory cytokine levels confirmed the anti-inflammatory role of Ac2-26 in LPS-activated cells, reducing MCP-1 and IL-8 levels within 24 hours. PL treatment reduced MCP-1 levels in LPSactivated cells, and increased IL-8, including in the treatment associated with Ac226/PL.Taken together, the results with HUVEC cells indicate that PL inhibits proliferation through the activation of cellular apoptosis, regulated by the inhibition of α-tubulin polymerization and elevated IL-8 cytokine levels. PL and Ac2-26 showed anti-inflammatory actions, and the Ac2-26/PL interaction appears to be neutral in relation to the anti-inflammatory properties of PL. / CNPq: 142274/2014 / CNPq UNIVERSAL: 474596/2013-3
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Análise in vitro da N-Acetilcisteína em fibroblastos do ligamento periodontal estimulados por LPS bacteriano / In vitro analysis of N-Acetylcysteine in periodontal ligament fibroblasts stimulated by bacterial LPSBittencourt, Tatiane Sampaio 16 February 2018 (has links)
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Previous issue date: 2018-02-16 / O objetivo deste estudo foi avaliar in vitro o comportamento biológico celular da N-Acetilcisteína (NAC), diante da estimulação ou não pelo LPS bacteriano. Foram utilizados fibroblastos do ligamento periodontal, que ficaram em contato por 48 horas com as substâncias testadas: NAC, Hidróxido de cálcio p.a. (HC), Lipopolissacarídeo de Escheria Coli (LPS), NAC + LPS e HC + LPS. Para os grupos NAC + LPS, HC + LPS e LPS, as células foram estimuladas com 2µg/mL de LPS por 24 horas, previamente aos tratamentos descritos. Foram realizados os testes biológicos de viabilidade celular (XTT), Espécies Reativas de Oxigênio (ROS), Elisa (para as citocinas IL-6, IL-8, IL-10, IL-1β e TNF-α) e Micronúcleo (MNT). Os dados foram analisados estatisticamente pela análise descritiva e pelos testes ANOVA e Kruskall Wallis, seguido do teste Dunn (p˂0.05) para os testes de XTT, ROS e MNT, e para o teste Elisa foi realizado cálculo das médias e desvio padrão. Os resultados obtidos mostraram que NAC teve um bom comportamento, frente à agressão provocada pelo LPS, quanto à produção de ROS. HC apresentou maior viabilidade celular que NAC, embora NAC não tenha apresentado citotoxicidade. Em relação à expressão das citocinas, NAC foi capaz de reduzir o potencial inflamatório do LPS quando da análise do TNF- α e IL-1β. NAC foi capaz de reduzir a genotoxicidade do LPS, como mostrado pelo teste MNT. Concluiu-se que NAC apresentou um comportamento biológico satisfatório, pela viabilidade celular dos fibroblastos, pela redução da geração de ROS e do potencial inflamatório provocado pelo LPS, e por reduzir a sua genotoxicidade. / The purpose of this study was to evaluate in vitro the action of N-Acetylcysteine (NAC) and calcium hydroxide (CH) on biological activity, either without or with LPS stimulation in periodontal ligament fibroblasts (PDLF) cells. PDLF were placed in contact with NAC, CH, NAC + LPS, LPS and CH + LPS for 48 hours. PDLF were stimulated by bacterial LPS for 24 hours in NAC + LPS, LPS and CH + LPS groups, before the substances described above are applied. The LPS and NAC effect on cell viability was measured using a XTT test. Reactive oxygen species (ROS) production was evaluated using ROS/superoxide detection kit. Inflammatory cytokines (IL-6, IL-8, IL-10, IL-1β and TNF-α) were evaluated by enzyme-linked immunosorbent (ELISA) assay. Genotoxicity was measured using micronucleus test (MNT). The means and standard deviation for all tests were calculated. Data were analyzed statistically by descriptive analysis, ANOVA and Kruskall Wallis tests, followed by Dunn test (p˂.05). CH was superior to NAC on cellular viability, although NAC was not cytotoxic. The results showed that NAC was able to reduce ROS production of LPS. NAC was able to reduce the inflammatory potential of LPS by decreasing the TNF-α and IL-1β release. NAC was able to reduce the genotoxicity of LPS. It was concluded that NAC showed a satisfactory biological activity, presenting a minimal effect on cell viability of PDLF cells and reducing ROS production and inflammatory potential provoked by LPS, and to decrease its genotoxicity.
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