L’exercice fractionné de haute intensité (HIIT) et continu d’intensité modéré (MOD) représentent les 2 grandes modalités d'endurance. Cependant, leur impact spécifique sur la performance physique et la plasticité cérébrale et musculaire reste controversé du fait de la diversité des protocoles d’exercice proposés chez les sédentaires. Notre 1er axe dégage chez des rats sains l’effet de ces 2 modalités sur la performance physique, la plasticité musculaire et cérébrale sur 8 semaines d’entrainement standardisée dont l'intensité est basées sur le seuil lactique. Nos résultats montrent des gains de performance d’endurance plus rapides et importants suite aux HIIT. La neuroplasticité serait stimulée par les HIIT uniquement et la plasticité musculaire semble spécifique à chacune. L’engouement pour les HIIT se répercute chez les patients subissant un accident vasculaire cérébral où l’efficacité des méthodes d’endurance n’est pas clairement justifiées. Une étude antérieure a montré l’intérêt majeur des HIIT dans la phase aiguë de la pathologie malgré une récupération sensorimotrice incomplète. D’où l’intérêt d’approfondir dans notre second axe l’effet des différentes formes de HIIT (longs et courts) dans la récupération. Nos résultats montrent principalement que ces deux formes de HIIT améliorent la capacité d’endurance et la force de la patte antérieure lésée avec une précocité pour les HIIT longs. Les deux formes de HIIT semblent induire une angiogenèse cérébrale. Néanmoins, ils n’améliorent pas les fonctions sensorimotrices et cognitives. Ainsi, il est nécessaire d’approfondir les répercussions de ces deux entrainements HIIT dans la plasticité musculaire et cérébrale. / Endurance exercise is essential for different reasons in athlete and also in aging and pathological people. Two training modalities were found: high intensity interval training (HIIT) and moderate intensity aerobic training (MOD). However, the specific outcomes of these modalities on physical performance and cerebral and muscular plasticity are controversial because many exercise protocols exist. The 1st study explore the impact of these 2 training on endurance and functional capacity and also on muscular and cerebral molecular modifications throughout 8 weeks in healthy rats. HIIT and MOD programs are work-matched and training intensity are determined thanks to the lactate threshold. Our results show a superior and fast effect on endurance capacity after HIIT compared to MOD. Hippocampal plasticity is stimulated only after HIIT and muscular modifications appear to be specific to each modality. A great interest of HIIT is found in stroke patients for whom evidence of endurance modalities efficiency is still missing. A previous study has shown a beneficial effect of HIIT in the acute phase of stroke despite incomplete sensorimotor recuperation. Hence, the interest to deepen in second part of this manuscript the impact of two HIIT modalities (short and long) in recovery optimisation. Our results show that 2 HIIT strongly improve endurance performance and strength of injured paw with a fast effect for long HIIT. The 2 modalities seem to induce cerebral angiogenesis. However, these 2 training do not increase sensorimotor and cognitive functions. In perspective, it appears necessary to develop muscular and cerebral outcomes induced by these 2 HIIT modalities.

L’hématopoïèse se déroule dans un microenvironnement spécialisé appelé niche où les cellules souches hématopoïétiques (CSH) sont en contact étroit avec les cellules stromales mésenchymateuses. Cette interaction cellulaire associée à d’autres facteurs environnementaux, comme la présence des espèces réactives à l’oxygène, est cruciale pour la régulation des CSH normales, mais aussi leucémiques. Pour étudier ce microenvironnement, il est donc important de développer un modèle in vitro de niche humaine qui mime la physiologie in vivo. Nous avons choisi comme modèle deux lignées mésenchymateuses stromales humaines HS-27a et HS-5, très peu décrites dans la littérature. Le premier objectif a été de déterminer la qualité de cette niche tant du point de vue cellulaire, moléculaire que fonctionnel. Nos résultats montrent clairement que les cellules HS-27a participent à la formation d’une niche « quiescente » alors que les cellules HS-5 représentent une niche « proliférative ». Le deuxième objectif a été de créer une niche contrôlée pour le métabolisme oxydatif en régulant l’expression d’une protéine antioxydante, la glutathion peroxydase 3 ou GPx3. L’originalité de ce travail repose sur l’utilisation d’une méthode non virale de transfert de gène par le transposon piggyBac. Le plasmide porteur du gène d'intérêt a été apporté sous forme d’ADN et une source de transposase, enzyme catalysant la réaction d'intégration sous forme d’ARNm. Notre travail montre que GPx3 est un régulateur clé de l’homéostasie hématopoïétique favorisant le maintien des progéniteurs immatures. Pour la première fois, nous créons par ingénierie in vitro une niche hématopoïétique « calibrée » capable de mimer le microenvironnement normal et leucémique. Ce modèle permet non seulement d’identifier les acteurs clés de la régulation des cellules médullaires, mais aussi de développer des stratégies thérapeutiques ciblées. / Hematopoiesis occurs in a hypoxic microenvironment or niche in which hematopoietic stem cells (HSCs) are in close contact with mesenchymal stromal cells. Cellular interactions as well as microenvironmental factors such as reactive oxygen species are crucial for the maintenance of normal and leukemic HSCs. Developing an in vitro human culture system that closely mimcs marrow physiology is therefore essential to study the niche. Here, we present a model using two human stromal cell lines, HS-27a and HS-5. Previously poorly described in the literature, we have further characterized both of these cell lines. The first objective was to assess the quality of HS-27a and HS-5 niches by investigating their cellular, molecular and functional characteristics. Our results clearly show that HS-27a cells display features of a “quiescent” niche whereas HS-5 cells rather represent a “proliferative” niche. The second objective was to engineer a hematopoietic niche where the oxidative metabolism is optimized for the expression of an antioxidant protein, glutathione peroxidase 3 (GPx3). The originality of this work is the use of a non-viral gene transfer system by using the transposon piggyBac. This strategy was achieved by delivering a DNA plasmid carrying the gene of interest, and an mRNA source of transposase, the enzyme which catalyzes the transgene integration. Functionally, GPx3 was shown to be a key regulator for sustaining hematopoietic homeostasis by maintaining immature progenitor cells. For the first time, an original non-viral gene transfer has been used to create an in vitro hematopoietic niche that recapitulates the complexity of normal and leukemic microenvironment. This niche not only provides a platform to identify regulatory factors controlling medullary cells, but may also help in the development of targeted therapeutic strategies.

Dans le monde, 350 000 leucémies sont diagnostiquées chaque année. La rechute reste un problème majeur des leucémies aiguës myéloïdes (LAM) et le métabolisme oxydatif pourrait jouer un rôle essentiel dans la réponse au traitement. Un faible niveau des espèces réactives de l’oxygène (ROS) est associé à des propriétés des cellules souches leucémiques et la quiescence alors qu’un niveau plus élevé caractérise les leucoblastes proliférants. L’homéostasie des ROS repose sur un équilibre entre les systèmes oxydants et antioxydants. Les antioxydants sont bien documentés dans les LAM alors que les connaissances sur l’activité oxydante sont encore limitées. Dans ce travail nous avons choisi d’étudier les sept complexes NADPH oxydases (NOX) dans 25 lignées issues de LAM humaines et des LAM primaires. L’analyse des ARNm et des protéines montre des profils d’expression variables entre les lignées avec une expression plus forte des sous-unités du complexe NOX2 dans les lignées correspondant à des stades de différenciation myéloïde plus avancés. L’activité enzymatique des NOX est cependant équivalente entre les lignées. Deux inhibiteurs, DPI et VAS3947, ont été utilisés pour connaître la contribution des NOX à la production des ROS cellulaires. Alors qu’ils ont inhibé l’activité, ils ont aussi généré un stress oxydatif majeur conduisant à une diminution de la prolifération cellulaire et une forte apoptose, le DPI en augmentant les ROS mitochondriaux et VAS3047 les ROS cytoplasmiques. Afin de connaitre les sous-unités impliquées et de mieux comprendre les mécanismes, les sous-unités NOX2 et p22phox ont été inhibée par ARN interférence. Celle-ci n’ont pas affecté la prolifération mais ont montré des effets compensatoires. Nos data montrent qu’inhiber les NOX pourrait s’avérer une stratégie thérapeutique en augmentant le stress oxydatif dans les cellules leucémiques. / 350,000 leukaemia are diagnosed each year worldwide. In acute myeloid leukaemia (AML), relapse remains a major problem and the oxidative metabolism might play a crucial role in the therapeutic response. Low level of reactive oxygen species (ROS) is associated with properties of leukemic stem cells and quiescence whereas higher level promotes leukoblasts proliferation. ROS homeostasis relies on a tightly regulated balance between the oxidant and antioxidant systems. Although the antioxidant system is extensively studied in AML, the oxidant system remains poorly documented. In this work we aimed to study the seven NADPH oxidases (NOX) complexes in 25 AML human cell lines and primary samples. NOX transcriptional and protein profiles are variable with a higher expression of NOX2 in cell lines belonging to mature differentiation stages. An equivalent level of enzymatic activity was observed across all the cell lines. To reveal the contribution of NOX to global ROS production in the cells, two NOX inhibitors, DPI and VAS3947, were then used. Although both inhibitors efficiently blocked NOX activity they unexpectedly triggered strong oxidative stress leading to reduced cell proliferation and strong apoptosis, DPI by increasing mitochondrial ROS while VAS3947 by increasing cytoplasmic ROS production. To highlight which of the subunits were involved and to understand the mechanisms, NOX2 and p22phox subunits were inhibited using shRNA strategy. These did not affect cell proliferation but revealed a compensation effect. Our data suggest that NOX inhibition might be potential therapeutic strategy by increasing oxidative stress in leukemic cells.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With advances in techniques of cell culture, stem cells (SCs) have to be used as an alternative therapy, firming the called regenerative medicine. An type of SC that has been studied is the Adipose-derived stem cell (ASCs) having identical characteristics of Mesenchymal Stem Cells (MSCs). To realize a transplanting of SCs, is necessary a large amount of cells, which makes such cultures are maintained in vitro for long periods of time, consequently these cells, with the repeated passages, enter cellular senescence, which prevents their use. Thus, some studies showed that the hydrogen peroxide (H2O2) can act to potentiate the proliferation of these cells. However, it is know that the oxidative metabolism can be associated with the senescence process. From this, the aim of this study was available the cito-genomic effect of the exposition of ASCs to H2O2 and to guaraná extract. Was realized isolation and cultivation of ASCs, that were, in forth passage, exposed to concentrations of 1-1000 μM of H2O2 and realized assays to available the cell viability, oxidative stress parameters, DNA damage and the apoptotic way of caspases. Moreover, senecents ASCs were treated with concentrations of 1-20 mg/mL of guaraná extract, being tested to the senescence reversion, cell viability, oxidative parameters, DNA damage and activity and expression of antioxidants enzymes. The results showed that the H2O2 cause cito-genomic damages to ASCs, with decrease in the cell viability mainly at the concentration of 200 μM, as well as increase the total reactive oxygen species (ROS) rate and lipidic peroxidation effect. The H2O2 also decreased the catalase activity in dose-dependent form e acted in the SOD activity. The treatments also conducted to a progressive increase of DNA damage. Moreover, in the eighth passage was observed the senescence of ASCs and the treatment with guaraná showed capacity to revert this phenotype in the concentration of 5 mg/mL, with reduction in the total ROS rate, lipoperoxidation, protein carbonyl and DNA damage, when compared with senescent ASCs untreated. The guaraná also was able to modulate the activity and expression of antioxidants enzymes, increasing the catalase, decreasing the total SOD and a light decrease in the glutathione peroxidase was observed. Therefore, it can be said that the acute exposition of no senescent ASCs to H2O2 was highly cytotoxic, demonstrating the high sensibility of these cells to this stressor agent. However, senescent ASCs treated with guaraná showed the potential effect of this extract in the reversion of the cellular senescence. / Com os avanços das técnicas de cultivo celular, as células tronco (CTs) passaram a ser utilizadas como forma de terapia alternativa, firmando a chamada medicina regenerativa. Um tipo de CT que vem sendo estudada são as Células Tronco derivada do tecido adiposo (ASCs) que possuem características idênticas as Células Tronco Mesenquimais (CTMs). Para realizar um transplante de CTs, se faz necessária uma grande quantidade de células, o que faz com que tais cultivos sejam mantidos in vitro por longos períodos de tempo, consequentemente tais células, com as repetidas passagens, entram em senescência celular, o que inviabiliza a sua utilização. Sendo assim, algumas pesquisas demonstraram que o peróxido de hidrogênio (H2O2) pode atuar potencializando a proliferação destas células. Contudo, sabe-se que o metabolismo oxidativo está intimamente associado ao processo de senescência celular. A partir disto, o objetivo deste trabalho foi avaliar o efeito cito-genômico da exposição de ASCs ao H2O2 e ao extrato de guaraná. Foi realizado isolamento e cultivo de ASCs, as quais em quarta passagem foram expostas as concentrações de 1-1000 μM de H2O2 e realizados ensaios para a avaliação da viabilidade celular, parâmetros de estresse oxidativo, danos ao DNA e rota apoptótica das caspases. Além disso, ASCs senescentes foram tratadas com concentrações de 1-20mg/mL de extrato de guaraná, sendo testadas para a reversão da senescência, viabilidade celular, parâmetros oxidativos, de danos ao DNA e atividade e expressão de enzimas antioxidantes. Os resultados mostraram que o H2O2 causa danos cito-genômicos as ASCs, havendo redução da viabilidade celular principalmente a partir da concentração de 200 μM, assim como aumento da taxa total de espécies reativas de oxigênio (EROs) e peroxidação lipídica. O H2O2 também diminuiu a atividade da catalase de forma dose-dependente e atuou sobre a atividade da SOD. Os tratamentos também conduziram a um aumento progressivo dos danos ao DNA. Além disso, na oitava passagem foi observada a senescência das ASCs e o tratamento com guaraná mostrou capacidade de reversão deste fenótipo na concentração de 5 mg/mL, de forma a reduzir a taxa total de EROS, a lipoperoxidação, a carbonilação de proteínas e os danos ao DNA, quando comparado às ASCs não tratadas. O guaraná também foi capaz de modular a atividade e expressão de enzimas antioxidantes, aumentando a catalase, reduzindo a SOD total e uma leve redução na expressão da glutationa peroxidase. Logo, pode-se dizer que a exposição aguda de ASCs não senescentes ao H2O2 foi altamente citotóxica, demonstrando a alta sensibilidade destas células a este agente estressor. Todavia, ASCs senescentes tratadas com guaraná demonstraram o potencial efeito deste extrato na reversão da senescência celular.

Breast cancer, due to their prevalence in our environment and global public health is a disease subject of numerous contemporary studies. Some of these studies suggest that certain genes related to cell cycle and apoptosis and acting on breast cancer can be modulated by bioactive compounds present in food, such as carotenoids. Fruits are foods rich in carotenoids, however, there is still a large number of species whose anticarcinogenic action was not investigated. This is the case of tucuma (Astrocaryum aculeatum) that is widely consumed, usually by Amazonian population and that recent studies shows antioxidant action. It is a fruit that presents high levels of carotenoids and other bioactive compounds that can act as anticarcinogenic pharmacogenomic modulators. Studies of this fruit are incipient, particularly those focused its potential role in the genesis and physiology of breast cancer. Thus, this research aimed to evaluate the effect of ethanol extracts of tucuma (peel and pulp) in the cyto-genotoxicity in human peripheral blood mononuclear cells (PBMCs). Additionally, the anticarcinogenic effect was evaluated in vitro in the commercial line MCF-7 breast cancer, determining the action on the viability, cell proliferation, modulation of apoptosis and oxidative metabolism. The study was conducted from ethanol extracts of peel and pulp, in which were determined the levels of total polyphenols, flavonoids, tannins, alkaloids by spectrophotometry and levels of beta-carotene, quercetin, rutin, gallic, chlorogenic and caffeic acids, by high performance liquid chromatography (HPLC). For investigation of cyto-genotoxic effects of pulp and peel tucuma extracts were used PBMCs obtained from healthy adults. These cells were grown in controlled conditions and exposed to different concentrations of the extracts for 24 and 72 hours. After these periods, viability analysis was conducted by the spectrophotometric assay of MTT (bromide of 3-(4,5)-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium). The levels of caspase-1 protein that is associated with events of programmed cell death (apoptosis/pyroptosis) were determined by enzyme immunoassay ELISA. The genotoxic effects were measured by analysis of DNA fragmentation by fluorometric assay using the DNA Picogreen ® dye that is specific for double-stranded DNA molecules (dsDNA). In this case, treatment with higher genomic damage have lower fluorescence levels when compared to control. To evaluate the genotoxicity was also carried out the DNA Alkaline Comet assay and the evaluation of chromosomal instability (G-band cytogenetic). The concentration of reactive oxygen species (ROS) was assessed by fluorimetric assay of DCFH-DA. Considering the results obtained in the first study, only the anticarcinogenic effect of the pulp extract was evaluated in the second study. Initially, MCF-7 cells grown under controlled conditions were exposed to concentrations from 1 to 1000 μg/mL of the extract, in order to determine the concentration range with greater anticarcinogenic potential. Following MCF-7 cells were exposed to three concentrations of the tucuma pulp extract using as positive control chemotherapy all-trans retinoic acid ATRA (1μM). The choice of ATRA concentration was based on previous studies reported in the literature. The action on cell viability and proliferation was determined by MTT assay after 24, 48 and 72h of exposure to treatments. The effect of the treatments in induced apoptosis was evaluated by analyzing the levels of caspases (1, 3 and 8), by ELISA immunoassay and expression of Bcl-2 and BAX genes via RT-PCR technic. Once the tucuma extract is rich in antioxidants, the effect on oxidative metabolism was also evaluated through the analysis of the modulation of gene expression of antioxidant enzymes superoxide dismutase (SOD) 1 and 2, catalase (CAT) and glutathione peroxidase (GPX) and the activity of these enzymes, using the levels of thiols (protein and non-protein) as an indirect measure of GPX. Statistical comparison between different treatments was performed via ANOVA One-Way and post hoc Tukey test. The results showed that the extracts had high levels of polyphenols and beta-carotene. In the first study, high cyto-genotoxic effect was observed at concentrations > 500 μg/mL. The pulp showed lower cyto-genotoxicity and, therefore, was used to evaluate the anticarcinogenic effect. In the second study, concentrations between 300 to 1,000 μg/mL decreased the viability of MCF-7 cells. Thus, concentrations of 300, 500 and 900 μg/mL were used in further testing. Similarly to ATRA, the extract reduced the viability and proliferation of breast cancer cells (p ≤ 0.01). The action in the viability probably involved apoptotic pathway since there was an increase in the levels of caspases 1, 3, 8, and inhibiting the expression of anti-apoptotic Bcl-2 gene. In general, these results were similar to ATRA. The tucuma, as well as ATRA, caused an imbalance in the oxidative metabolism. However, while the ATRA altered the oxidative balance in both cytosolic level as for mitochondrial level, tucuma acted only in cytosolic level, mainly, via decreasing levels of gene expression and activity of SOD1, CAT and increased levels of lipid peroxidation and proteins carbonylation. The overall results, despite the methodological limitations associated with in vitro studies indicates that the tucuma ethanolic extract has anticarcinogenic effect in breast cancer cells MCF-7 involving potential pharmacogenomics modulation of genes and molecules of the apoptotic pathway and oxidative metabolism. This is the first study reporting anticarcinogenic activity of this fruit, and these results open the prospect of further scientific, epidemiological and clinical interest studies. / O câncer de mama, devido a sua importância epidemiológica em nosso meio e na saúde pública mundial, é uma doença objeto de inúmeros estudos contemporâneos. Alguns destes trabalhos sugerem que determinados genes relacionados ao ciclo celular e à apoptose e que atuam sobre o câncer de mama, podem ser modulados por compostos bioativos presentes na alimentação, como os carotenóides. Frutas são alimentos ricos em carotenóides, entretanto, existe ainda um número extenso de espécies cuja ação anticarcinogênica não foi investigada. Este é o caso do tucumã (Astrocaryum aculeatum) que é muito consumido, habitualmente, pela população amazônica e que estudos recentes indicam ação antioxidante. Trata-se de um fruto rico em carotenóides e outros compostos bioativos que podem atuar como moduladores farmacogenomicos anticarcinogênicos. Estudos sobre este fruto são incipientes, principalmente aqueles voltados a sua potencial ação na gênese e na fisiologia do câncer de mama. Deste modo, esta investigação teve como objetivo avaliar o efeito de extratos etanólicos do tucumã (casca e polpa) na cito-genotoxicidade em células mononucleares do sangue periférico (CMSPs). Adicionalmente, foi avaliado o efeito anticarcinogênico in vitro na linhagem comercial MCF-7 de câncer de mama, determinando a ação sobre a viabilidade, proliferação celular, modulação do metabolismo apoptótico e oxidativo. O trabalho foi conduzido a partir de extratos etanólicos de polpa e casca, nos quais foram determinados os níveis de polifenóis totais, flavonóides, taninos, alcalóides por espectrofotometria e os níveis de beta-caroteno, quercetina, rutina, ácidos gálico, clorogênico e cafeíco, por cromatografia líquida de alta eficiência (CLAE). Para a investigação dos efeitos cito-genotóxicos dos extratos da polpa e da casca do tucumã foram utilizadas CMSPs obtidas de adultos saudáveis. Estas células foram cultivadas em condições controladas e expostas a diferentes concentrações dos extratos durante 24h e 72h. Após estes períodos foi efetuada a análise da viabilidade pelo ensaio espectrofotométrico do MTT (brometo de 3-(4,5)-dimetil-2-tiazolil-2,5-difenil-2H-tetrazólio). Os níveis da proteína caspase-1 que está associada a eventos de morte celular programada (apoptose/piroptose) foram determinados por ensaio imunoenzimático de ELISA. Os efeitos genotóxicos foram medidos através da análise de fragmentação do DNA através de ensaio fluorimétrico utilizando o corante DNA Picogreen® que é específico para moléculas de DNA dupla-fita (DNAdf). No caso, tratamentos que apresentam maior dano genômico possuem níveis menores de fluorescência quando comparados ao controle. Para avaliar a genotoxicidade também foi realizado o ensaio do DNA Cometa Alcalino e a avaliação da instabilidade cromossômica (citogenética por Banda G). A concentração de espécies reativas de oxigênio (EROs) foi avaliada via ensaio fluorimétrico da DCFH-DA. Considerando os resultados obtidos no primeiro estudo, somente o efeito anticarcinogênico do extrato da polpa foi avaliado no segundo estudo. Inicialmente, células MCF-7 cultivadas em condições controladas foram expostas a concentrações de 1 a 1000 μg/mL do extrato, a fim de se determinar a faixa de concentração com maior potencial anticarcinogênico. A seguir as células MCF-7 foram expostas a três concentrações do extrato de polpa do tucumã utilizando como controle positivo o quimioterápico ácido all-trans retinóico ATRA (1μM). A escolha da concentração do ATRA foi feita com base em estudos prévios publicados na literatura. A ação na viabilidade e proliferação celular foi determinada a partir do ensaio do MTT após 24, 48 e 72h de exposição aos tratamentos. O efeito dos tratamentos na indução da apoptose foi avaliado através da análise dos níveis das caspases (1, 3 e 8) por imunoensaio ELISA e da expressão dos genes Bcl-2 e BAX via técnica de RT-PCR. Uma vez que o extrato do tucumã é rico em antioxidantes, o efeito no metabolismo oxidativo foi, também, avaliado através da análise da modulação da expressão dos genes das enzimas antioxidantes superóxido dismutase (SOD) 1 e 2, catalase (CAT) e glutationa peroxidase (GPX) e da atividade destas enzimas, utilizando os níveis de tióis (proteicos e não proteicos) como medida indireta da GPX. A comparação estatística entre os diferentes tratamentos foi efetuada via análise de variância One-Way e teste post hoc de Tukey. Os resultados mostraram que os extratos possuíam níveis elevados de polifenóis e de beta-caroteno. No primeiro estudo, foi observado efeito cito-genotóxico alto nas concentrações > 500 μg/mL. A polpa apresentou menor cito-genotoxicidade e, por este motivo, foi utilizada para avaliar o efeito anticarcinogênico. No segundo estudo, as concentrações entre 300 a 1000 μg/mL diminuíram a viabilidade das células MCF-7. Assim, as concentrações de 300, 500 e 900 μg/mL foram utilizadas nos testes adicionais. Similarmente ao ATRA, o extrato diminuiu a viabilidade e a proliferação das células de câncer de mama (p< 0.01). A ação na viabilidade, provavelmente, envolveu a via apoptótica já que ocorreu um aumento nos níveis das caspases 1, 3 e 8 e inibição na expressão do gene antiapoptótico Bcl-2. Em geral estes resultados foram similares ao ATRA. O tucumã, assim como o ATRA, causou desbalanço no metabolismo oxidativo. Entretanto, enquanto o ATRA alterou o balanço oxidativo tanto em nível citosólico quanto em nível mitocondrial, o tucumã agiu somente em nível citosólico, principalmente, via diminuição nos níveis da expressão gênica e atividade da SOD1, CAT e aumento nos níveis de lipoperoxidação e carbonilação de proteínas. O conjunto dos resultados, a despeito das limitações metodológicas associadas aos estudos in vitro, indica que o extrato etanólico do tucumã possui efeito anticarcinogênico em células de câncer de mama MCF-7 envolvendo potencial modulação farmacogenomica de genes e moléculas da via apoptótica e do metabolismo oxidativo. Este é o primeiro estudo que relata atividade anticarcinogênica deste fruto, e, tais resultados abrem a perspectiva de estudos adicionais de interesse científico, epidemiológico e clínico.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Epidemiological studies suggest that the imbalance in antioxidant enzymes activity genetically caused, increases the risk of metabolic disorders and chronic noncommunicable diseases. This is the case of polymorphism that occurs in an substitution of Alanine (A) by a Valine (V) at codon 16 of the gene for superoxide dismutase manganese-dependent (Ala16Val-SOD2). The A allele has a higher efficiency of catalysis than allele V. However, this efficiency increases the levels of H2O2 leading to a consequent oxidative imbalance that, in turn, increases the risk of cancer. Furthermore, the V allele that presents a smaller efficiecy SOD2 is associated with endothelial dysfunction and cardiometabolic. Therefore, Ala16VALSOD2 polymorphism serves as a model for in vitro analysis of differential responses to pro and antioxidants factors. The objective of this study was to investigate the in vitro response of lymphocytes culture with different genotypes (AA, VV and AV) from healthy subjects exposed to ultraviolet (UV) is a pro-oxidant factor. In lymphocyte not exposed and UV exposed it was analyzed the cytotoxic variables (cell viability, mitotic index), biomarkers of oxidative metabolism (lipid peroxidation, enzymatic activity of SOD, catalase, thiol groups, protein carbonylation, total polyphenols and ascorbic acid) and genotoxic effects (by Comet Assay and chromosomal instability). The results showed that cells carrying the AA genotype had higher cell viability and mitotic index. However, after UV exposure such viability was similar between genotypes. At baseline levels higher SOD and total polyphenol levels were observed in AA genotype when compared to the VV genotype. However, lymphocytes AA had higher rates of DNA damage in the presence of UV radiation. These results suggest that the polymorphism Ala16Val-SOD2 may differentially affect the toxicity factors such as UV radiation. / Estudos epidemiológicos sugerem que o desbalanço na atividade de enzimas antioxidantes, geneticamente causado, aumenta o risco de disfunções metabólicas e doenças crônicas não-transmissíveis. Este é o caso do polimorfismo em que ocorre uma troca da Alanina (A) por uma Valina (V) no códon 16 do gene da enzima superóxido dismutase dependente de manganês (Ala16Val-SOD2). O alelo A possui uma eficiência de catálise maior do que o alelo V. Entretanto, esta maior eficiência aumenta os níveis de H2O2 levando a um conseqüente desbalanço oxidativo que, por sua vez, aumenta o risco de neoplasias. Por outro lado, o alelo V que apresenta uma SOD2 menos eficiente está associado a disfunções endoteliais e cardiometabólicas. Portanto, este polimorfismo serve como modelo in vitro para análises de respostas diferenciais a agentes pró e antioxidantes. Sendo assim, o objetivo desse estudo foi investigar a resposta in vitro de cultura de linfócitos com diferentes genótipos (AA, VV e AV), provenientes de indivíduos saudáveis, expostas a radiação ultravioleta (UV) que é um fator pró-oxidante. Antes e após exposição, foram analisados os efeitos citotóxicos (viabilidade celular e índice mitótico), indicadores do metabolismo oxidativo (peroxidação lipídica, atividade enzimática da SOD, catalase, grupos tióis, polifenóis totais e de ácido ascórbico) e efeitos genotóxicos (dano de DNA pelo Ensaio Cometa e instabilidade cromossômica,). Os resultados mostraram que as células portadoras do genótipo AA apresentaram maior viabilidade celular e índice mitótico. Entretanto, após a exposição UV tal viabilidade foi similar entre os genótipos. Em condições basais níveis elevados de SOD e polifenóis totais plasmáticos foram observados no genótipo AA em relação ao genótipo VV. Porém, linfócitos AA apresentaram maior índice de danos no DNA na presença da radiação UV. Estes resultados sugerem que o polimorfismo Ala16Val- SOD2 pode afetar diferencialmente a toxicidade a fatores como a radiação UV.

Made available in DSpace on 2014-06-11T19:23:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-03-03Bitstream added on 2014-06-13T20:30:49Z : No. of bitstreams: 1 machado_lp_me_botfmvz.pdf: 341603 bytes, checksum: b779869a2fd113691f68f4c66bf1832f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The objective of this study was to evaluate the oxidative erythrocyte metabolism in equines submitted to exercise on high-speed treadmill and the effect of vitamin E supplementation. Eight adults Arabian horses, males and females, were divided: control group (CG) and group supplemented with vitamin E (EG), (1000 UI/animal/day). All the equines were submitted to exercise with two incremental tests (T1 and T2). Exercise protocol for two tests started with 1.8m/s for 5 min, 4m/s for 3 min, 6m/s for 2 min and right after, periods of 1 min, challenging the equines with increasing speeds until the animals had no condition to keep the exercise on a treadmill inclined at 7%. Between the tests, a training protocol was performed for 20 days. Blood samples were taken before, during, and until 120 hours after exercise to determine erytrogram, erythrocyte reduced glutathione (GSH), superoxide dismutase (SOD), methemoglobin, erythrocyte osmotic fragility (EOF), total plasmatic protein (TPP), seric malondialdehyde (MDA) and vitamin E, seric enzymatic activity of aspartate aminotransferase (AST) and creatine kinase (CK), blood lactate and bloodgas. The results were compared by non-parametric Mann-Whitney and Friedman tests. Although differences were detected in only a few variables, it was possible to see increase in erytrogram and TPP by spleenic contraction and/or decrease of the plasma volume, and increase the erythrocyte volume by swelling. Sport anemia was observed between 24h and 120h after the exercise. The methemoglobin was compatible with the physiological levels and the EOF increased during the exercise in both groups. The MDA elevation confirm the liperoxidation by exercise effect, less intense EG by the supplementation with vitamin E. The exercise also induced increase of AST and CK enzymes, increase of blood lactate and metabolic acidosis.

Made available in DSpace on 2016-12-06T17:07:30Z (GMT). No. of bitstreams: 1 Cleber.pdf: 974012 bytes, checksum: dbb791b7e561536b085ed8b846d258c7 (MD5) Previous issue date: 2011-03-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cardiovascular diseases are a major cause of death in Brazil and physical exercise is considered an important agent in the prevention and treatment of these conditions. Studies related to the type, intensity and volume of physical training required to trigger biochemical protective material are still controversial. This study investigated the effects of two exercise protocols on parameters of ventricular oxidative metabolism in rats after myocardial infarction. Thirty-six male Wistar rats of two months were divided randomly into two groups (n = 18): Sham and Acute Myocardial Infarction (AMI). The rats were anesthetized and the AMI was induced by coronary artery occlusion. Thirty days after AMI induction, the rats were subdivided into six groups (n = 6): Sham, Sham + continuous training (SCT, 60 minutes), Sham + fractionated training (10x5 min with 1 minute interval), AMI, AMI + continuous training and AMI + fractionated training. The exercise sessions were conducted in water (30-32 º C), 5 times/wk for six-wk. Forty-eight hours after the last exercise session, the rats were killed and the left ventricle was surgically removed and stored at -80 º C for analysis of oxidative stress (activity and expression of antioxidant enzymes and oxidative damage to lipids and proteins) and oxidative metabolism (respiratory chain proteins). After AMI, superoxide production decreased significantly in both training models. The activity and expression of superoxide dismustase didn t change by training, but there was an increase on catalase levels in the continuous training group. Glutation peroxidase decreased in both groups. The damage in lipids decreased only in the continuous training group while the protein damage was reduced in the fractionated training group. Cytochrome C increased in both groups, and peroxisome proliferator-activated receptor-&#947; coactivator increased in the group under continuous training. Thehypoxia-inducible factor was significantly reduced with both training protocols. These results suggest a significant improvement in the redox state of the myocardium of AMI-induced rats exposed to different training models, but the continuous training seems to be more efficient for the evaluated parameters. / As doenças cardiovasculares se destacam como a principal causa de morte no Brasil e o exercício físico tem sido considerado como sendo um importante agente tanto na prevenção quanto no tratamento dessas doenças. Entretanto, os estudos ainda são controversos quanto ao tipo e à intensidade de esforço necessária para provocar alterações bioquímicas protetoras significativas. Verificar os efeitos de dois protocolos de exercício sobre parâmetros do metabolismo oxidativo ventricular em ratos pós-infarto. Foram utilizados 36 ratos Wistar machos, dois meses de idade, pesando entre 200-250g e divididos randomicamente em 2 grupos (n=18): Sham e Infarto Agudo do Miocárdio (IAM). Os animais foram anestesiados e induzidos ao IM por oclusão da coronária . Trinta dias após a indução do IAM os animais foram divididos em 6 subgrupos (n=6): Sham, Sham + treinamento contínuo (60 minutos), Sham + treinamento fracionado (10 x 5 minutos com 1 minuto de intervalo), IAM, IAM + treinamento contínuo e IAM + treinamento fracionado. As sessões de exercício foram realizadas na água (30-32ºC), 5 vezes por semana, durante 6 semanas. Quarenta e oito horas após a última sessão de exercício os animais foram mortos por decapitação, o ventrículo esquerdo foi cirurgicamente removido e armazenado em freezer -80ºC para análises de estresse oxidativo (atividade e expressão de enzimas antioxidantes e danos oxidativos em lipídeos e proteínas) e metabolismo oxidativo (complexos da cadeia respiratória). Após o infarto do miocárdio, a produção de superóxido reduziu significativamente em ambos os modelos de treinamento. A atividade e a expressão da SOD não foram alteradas pelos treinamentos, mas a CAT aumentou sua expressão com o treinamento contínuo e a expressão da GPX reduziu em ambos os grupos treinados coincidindo com o aumento de sua atividade. Os danos em lipídeos reduziram apenas no grupo submetido ao treinado contínuo enquanto que os danos em proteínas somente no grupo com treinado fracionado. Citocromo C aumentou em ambos os grupos enquanto PGC1-alfa teve sua expressão aumentada no grupo submetido ao treinamento contínuo. HIF-1 reduziu significativamente com ambos os protocolos de treinamento. Esses resultados sugerem uma melhora significativa no estado redox do miocárdio de ratos induzidos ao IAM e expostos a diferentes modelos de treinamento, porém o treinamento contínuo parece ser mais eficiente sobre os parâmetros analisados.

Orientador : Aguemi Kohayagawa / Banca: Alexandre Secorun Borges / Banca: Maria Adriana Machado Loba e Silva / Abstract: The objective of this study was to evaluate the oxidative erythrocyte metabolism in equines submitted to exercise on high-speed treadmill and the effect of vitamin E supplementation. Eight adults Arabian horses, males and females, were divided: control group (CG) and group supplemented with vitamin E (EG), (1000 UI/animal/day). All the equines were submitted to exercise with two incremental tests (T1 and T2). Exercise protocol for two tests started with 1.8m/s for 5 min, 4m/s for 3 min, 6m/s for 2 min and right after, periods of 1 min, challenging the equines with increasing speeds until the animals had no condition to keep the exercise on a treadmill inclined at 7%. Between the tests, a training protocol was performed for 20 days. Blood samples were taken before, during, and until 120 hours after exercise to determine erytrogram, erythrocyte reduced glutathione (GSH), superoxide dismutase (SOD), methemoglobin, erythrocyte osmotic fragility (EOF), total plasmatic protein (TPP), seric malondialdehyde (MDA) and vitamin E, seric enzymatic activity of aspartate aminotransferase (AST) and creatine kinase (CK), blood lactate and bloodgas. The results were compared by non-parametric Mann-Whitney and Friedman tests. Although differences were detected in only a few variables, it was possible to see increase in erytrogram and TPP by spleenic contraction and/or decrease of the plasma volume, and increase the erythrocyte volume by swelling. Sport anemia was observed between 24h and 120h after the exercise. The methemoglobin was compatible with the physiological levels and the EOF increased during the exercise in both groups. The MDA elevation confirm the liperoxidation by exercise effect, less intense EG by the supplementation with vitamin E. The exercise also induced increase of AST and CK enzymes, increase of blood lactate and metabolic acidosis. / Mestre

Orientador: Paulo César Ciarlini / Banca: Mary Marcondes / Banca: Raimundo Souza Lopes / Resumo: O metabolismo oxidativo e apoptose dos neutrófilos de pacientes humanos nefropatas e sua relação com as toxinas urêmicas tem sido, nos últimos anos, amplamente investigados devido sua importância como elemento imunossupressor. Recentemente surgiram evidências de que a uremia causa disfunção neutrofílica em cães nefropatas, porém não se sabe se o acúmulo de compostos nitrogenados, que também ocorrem nas azotemias não renais, igualmente afeta a função dos neutrófilos. O objetivo do presente estudo foi testar ex vivo a hipótese de que plasmas urêmicos e azotêmicos igualmente afetam o metabolismo oxidativo e a apoptose dos neutrófilos de cães. Para tal, neutrófilos de cães sadios foram isolados e incubados com plasma autólogo, plasma de cão azotêmico e urêmico. A produção de superóxido, com e sem o estimulo com PMA, foi estimada pelo método de redução do nitroazul tetrazólio (NBT) e por citometria de fluxo capilar utilizando-se a sonda hidroetidina (HE). A taxa de neutrófilos viáveis, em apoptose inicial e final, foi quantificada por citometria utilizando-se Anexina V-PE e o índice apoptótico mensurado pelo método morfométrico. A produção de superóxido gerada pelos neutrófilos isolados, em ambos os tratamentos (plasma urêmico e azotêmico) apresentou significante redução (p<0,05). Já a apoptose dos neutrófilos de cães sadios foi acelerada, quando incubados com plasmas urêmico e azotêmico. Pode-se concluir que os componentes presentes nos plasmas urêmicos e azotêmicos alteram ex vivo o metabolismo oxidativo e a apoptose dos neutrófilos, fortalecendo a hipótese de que in vivo ambas condições podem comprometer a imunidade inata de cães / Abstract: The oxidative metabolism and apoptosis of neutrophils from human patients with nephropathy and its relation with uremic toxins has been widely investigated in the last years because of its importance as an immunosuppressive element. Recently evidences suggests that uremia causes neutrophil dysfunction in dogs with renal disease, but it is unclear whether the accumulation of nitrogen compounds, which also occur in non-renal azotemia, can as well affect the role of neutrophils. The objective of this study was to test ex vivo the hypothesis that uremic and azotemic plasma also affects the oxidative metabolism and apoptosis of neutrophils in dogs. To this end, neutrophils from healthy dogs were isolated and incubated with autologous plasma, plasma of azotemic and uremic dog. The production of superoxide, with and without PMA stimulation was estimated by the method of nitroblue tetrazolium reduction (NBT) and by capillary flow cytometry using the hydroethidine probe (HE). The rate of viable, in early and late apoptosis neutrophils was quantified by flow cytometry using Annexin V-PE and theapoptotic index was measured by morphometric method. The production of superoxide generated by isolated neutrophils in both treatments (azotemic and uremic plasma) showed a significant reduction (p <0.05). Neutrophil apoptosis of healthy dogs was accelerated when incubated with uremic and azotemic plasma. In conclusion, the components present in uremic and azotemic plasma change ex vivo the oxidative metabolism and apoptosis of neutrophils, emphasizing the hypothesis that in vivo both conditions can compromise the innate immunity of dogs / Mestre