The Arabidopsis HSP101 protein belongs to the Hsp100/ClpB family of AAA+ proteins (ATPases Associated with various cellular Activities). This family of proteins, in collaboration with the Hsp70 chaperone system, has the remarkable ability to solubilize protein aggregates and refold proteins back to their native forms. Thus, their chaperone activity is necessary for acquired thermotolerance in organisms as diverse as bacteria and plants. My dissertation project focused on understanding the mechanism of HSP101 action using Arabidopsis thaliana as a model system. The first approach used genetics to screen for suppressors of a specific missense mutant allele of HSP101, hot1-4, in order to find interacting cofactor proteins or key substrates of HSP101, or other processes involved in thermotolerance. Four extragenic suppressors that can overcome the heat-hypersensitive phenotype caused by the hot1-4 mutation were isolated and one of them (shot1) was identified as a mutation in a mitochondrion-targeted protein. Although shot1 mutations do not directly interfere with HSP101 function, they reveal independent mechanisms required for thermotolerance, which involve reduced oxidative stress. The second approach used to investigate HSP101 function was to affinity-purify HSP101 and identify associated proteins. For this purpose, transgenic Arabidopsis plants were generated expressing affinity-tagged wild-type and mutant variants of HSP101. As predicted, cytosolic Hsp70s were identified as an interacting partner of HSP101. Surprisingly, 26S proteasome regulatory subunits were also identified, suggesting a possible link between the protein degradation and reactivation pathways. Further experiments were also undertaken to define the importance of different domains of HSP101, as well as the localization of HSP101. Transgenic Arabidopsis plants expressing N- or C-terminally truncated HSP101 indicate that the N-terminal domain of HSP101 is required for full activity in protecting plants from heat stress. However, in contrast to the yeast ortholog, Hsp104, the C-terminal extension of HSP101 was found to be completely dispensable for thermotolerance of Arabidopsis. Additional transgenic plants expressing an HSP101-GFP were also characterized. Initial microscopic analysis confirms nuclear/cytoplasmic localization as has been reported previously for yeast Hsp104. However, the dynamics of subcellular redistribution upon heat stress need to be further investigated to fully understand the potential significance of the observed localization.

Adaptability is one of the reasons for the success of bacteria, allowing them to survive in conditions where no other organisms would be able to thrive. Nitrogen deficiency, for example, can be a limiting factor for the growth of micro-organisms, as this element is an essential part of almost all types of biomolecules. As such, some bacteria have evolved specific mechanisms to overcome nitrogen limitation. Nitrogen fixing bacteria, or diazotrophs, use a specific enzyme complex, nitrogenase, in order to harness this element from the enormous reservoir that is the Earth’s atmosphere. However, nitrogen fixation is a demanding process for the cells, requiring vast amounts of energy and tight regulation. In this thesis we explore the mechanisms regulating nitrogen fixation in Rhodospirillum rubrum, a purple non-sulphur photosynthetic bacterium. Using proteomics tools, we show how the regulation of both the nitrogen and carbon fixation processes is interconnected, possibly in order to maintain the intracellular redox balance. Using a new detergent molecule, we also demonstrate how nitrogen availability affects the chromatophore membrane proteome. Our studies have revealed the crucial role of the cellular pool of 2-oxoglutarate (2OG) for adequate signaling through the PII proteins and the effects resulting from artificially manipulating this metabolite’s concentration. In R. rubrum nitrogenase is also subjected to post-translational control (the “switch-off” effect) and this work shows for the first time that the enzyme modifying nitrogenase (Dinitrogenase Reductase ADP-ribsosyl Transferase or DRAT) forms a complex with the PII protein GlnB. This complex allows DRAT activation and its formation – and, therefore, DRAT activity – is regulated by binding of ADP:ATP and 2OG to GlnB. Upon light withdrawal, nitrogenase activity anaerobically in the dark is also here demonstrated to be dependent on the activity of the pathway starting in pyruvate formate-lyase and we show how different nitrogen sources influence the switch-off response. This response can, in some conditions, be modified by addition of pyruvate and we have studied how this metabolite influences nitrogenase activity and switch-off regulation. This study allows a better understanding of the underlying processes controlling the metabolic routes in R. rubrum and also provides new insights into regulation of enzyme activity, paving the road for the complete establishment of the mechanisms regulating nitrogenase switch-off. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: Submitted. Paper 4: Manuscript. Paper 5: Submitted.</p>

Na Ficha Catalogr?fica consta o t?tulo: "Efeito da terapia por fotobiomodula??o (LED630nm) no equil?brio redox e nos aspectos hist?logicos da osteoartrite de joelho induzida por monoiodoacetato de s?dio em ratos". / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-08-30T15:08:00Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lorena_pacheco_oliveira_martins.pdf: 1327754 bytes, checksum: e69932636c7878e52b2b3d058f72ea94 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-01T17:08:53Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lorena_pacheco_oliveira_martins.pdf: 1327754 bytes, checksum: e69932636c7878e52b2b3d058f72ea94 (MD5) / Made available in DSpace on 2018-10-01T17:08:53Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lorena_pacheco_oliveira_martins.pdf: 1327754 bytes, checksum: e69932636c7878e52b2b3d058f72ea94 (MD5) Previous issue date: 2018 / A osteoartrite (OA) tem potencial cr?nico-degenerativo e car?ter inflamat?rio. Al?m do papel inflamat?rio, outros fatores, como o desequil?brio redox, parecem contribuir para altera??es na cartilagem articular, a principal estrutura articular afetada. A fotobiomodula??o (FBM) utilizando LED tem sido proposta para o tratamento da OA por atuar sobre os processos degenerativos da cartilagem, favorecer defesas antioxidantes e modular marcadores do estresse oxidativo. Diante disso, o objetivo foi avaliar o efeito da terapia por FBM utilizando LED (630 nm) sobre os aspectos histomorfom?tricos da cartilagem articular e no equil?brio redox na OA de joelho induzida por monoiodoacetato de s?dio em ratos. Foram utilizados 27 ratos Wistar, separados entre os grupos: Controle; osteoartrite (OA) e osteoartrite + LED (OALED). No grupo OALED foi aplicado o LED (630 nm; 300mW; 9 J/cm2; 0,3 W/cm2; 30 s; iniciando 24h ap?s indu??o; 3 vezes/semana; 8 semanas). A eutan?sia dos animais ocorreu 56 dias ap?s a indu??o da OA, o sangue foi coletado para an?lise do dano oxidativo (TBARS), da capacidade antioxidante enzim?tica (atividade da SOD e CAT) e o estado antioxidante total do plasma atrav?s (FRAP). O joelho direito foi utilizado para a morfometria da cartilagem atrav?s da medida da espessura e contagem de condr?citos. O grupo OALED apresentou maior espessura m?dia da cartilagem e m?dia dos condr?citos semelhante ao grupo Controle. Foi observado ainda maior atividade enzim?tica antioxidante (SOD e CAT) e menor concentra??o de TBARS (P<0,05) no grupo OALED comparado ao grupo OA. A terapia por FBM demonstrou ser efetiva sobre o equilibro redox e sobre a preserva??o da cartilagem articular em um modelo de OA induzida. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Reabilita??o e Desempenho Funcional, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / Osteoarthritis (OA) has chronic-degenerative potential and inflammatory character. In addition to the inflammatory role, other factors, such as redox imbalance, appear to contribute to changes in the articular cartilage, the main articular structure affected. Photobiomodulation (PBM) using LED has been proposed for the treatment of OA by acting on degenerative cartilage processes, favoring antioxidant defenses and modulating oxidative stress markers. The aim of this study was to evaluate the effect of PBM therapy using LED (630 nm) on the histomorphometric aspects of articular cartilage and redox balance in knee OA induced by sodium monoiodoacetate in rats. Wistar rats were used, separated between the groups: Control; osteoarthritis (OA) and osteoarthritis + LED (OALED). In the OALED group, the LED (630 nm, 300 mW, 9 J / cm2, 0.3 W / cm2, 30 s, starting 24 h after induction, 3 times / week, 8 weeks) was applied. The euthanasia of the animals occurred 56 days after induction of OA, blood was collected for analysis of oxidative damage (TBARS), enzymatic antioxidant capacity (SOD and CAT activity) and the total antioxidant status of plasma through (FRAP). The right knee was used for the morphometry of cartilage by measuring the thickness and counting of chondrocytes. The OALED group had a higher average cartilage thickness and mean chondrocytes similar to the control group. It was also observed higher antioxidant enzymatic activity (SOD and CAT) and lower level of TBARS (P <0.05) in the OALED group compared to the OA group. PBM therapy has been shown to be effective on redox balance and preservation of articular cartilage in an induced OA model.

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Thesis (PhD (Science) (Viticulture and Oenology. Wine Biotechnology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The production of glycerol by Saccharomyces cerevisiae under anaerobic conditions is essential for maintaining the intracellular redox balance thereby allowing continuous energy generation through conversion of sugars into ethanol. In addition, glycerol can act as an osmolyte and is synthesized to maintain turgor pressure under hyperosmotic conditions. The production of ethanol from sugars can be a redox-neutral process, where the NAD+ (nicotinamide adenine dinucleotide) that is consumed during the glycolytic conversion of glyceraldehyde-3-phosphate to pyruvate is later regenerated by the reduction of acetaldehyde to ethanol. However, in particular the redirection of metabolic flux of pyruvate to biomass formation leads to excess NADH formation. The intracellular redox balance in these conditions is then primarily maintained through formation of glycerol which is control by two main enzymes, namely Gpd1p and Gpd2p. Deletion of the genes coding for these two proteins leads to accumulation of NADH and renders the cells incapable of maintaining their fermentative ability and growth under anaerobic conditions. The goal of this study was to investigate the growth, fermentative ability and metabolite synthesis of various gpd1Δgpd2Δ double mutant (DM) strains in which the redox balancing potential was partially restored through expression of native or heterologous genes. Strains were constructed by introducing alternative NADH oxidizing pathways or manipulating existing pathways to favour the oxidation of excess NADH. More specifically, the modifications included (i) sorbitol formation; (ii) establishing a pathway for propane-1,2-diol formation; and (iii) increasing ethanol formation. Apart from genetically manipulating the gpd1Δgpd2Δ double mutant, the addition of pyruvate during growth was also investigated. The experiments were carried out under oxygen limited conditions in a high sugar medium and the fermented product was analyzed for total sugar consumed, biomass and primary and secondary metabolites formed by the different strains. The relationships between sugar consumption, growth and metabolite production by different strains were investigated by comparing the data generated from the different strains by using multivariate data analysis tools. Analysis of the pathways involved in the production of primary (acids, ethanol and other metabolites) and secondary metabolites (aroma compounds) were also carried out in order to establish flux modification in comparison to the wild type (WT) strain. The results revealed that these manipulations improved the fermentative capacity of the gpd1Δgpd2Δ double mutant, suggesting a partial recovery of NAD+ regeneration ability, albeit not to the extent of the WT strain. As expected a significant correlation was found between sugar consumption and ethanol and biomass formation. Ethanol yields but not final concentrations were increased by the genetic manipulations. Sorbitol by DM(srlD) and DM(SOR1) strains and propane-1,2-diol by DM(gldA, GRE3, mgsA) strain were formed in significant amounts although at lower molar yields than glycerol. Furthermore, by genetic manipulation the yield of secondary metabolites (isobutanol, isoamyl alcohol, 2-phenyl ethanol and isobutyric acid) was increased whereas the ethyl acetate concentration and yield decreased. The results indicate that aroma compound properties of wine yeasts could be favourably changed by manipulating the glycerol synthesizing pathway. The addition of pyruvate during the growth of gpd1Δgpd2Δ double mutant contributes to excess NADH re-oxidation through additional ethanol formation. / AFRIKAANSE OPSOMMING: Die produksie van gliserol deur Saccharomyces cerevisiae onder anaërobiese toestande is noodsaaklik vir die onderhouding van die intrasellulêre redoksbalans en maak dus ononderbroke energie-ontwikkeling tydens die omsetting van suikers in etanol moontlik. Daarbenewens kan gliserol as ‘n osmoliet optree en word dit gesintetiseer om turgordruk onder hiperosmotiese toestande te onderhou. Die produksie van etanol uit suikers kan ‘n redoksneutrale proses wees, waar die NAD+ (nikotinamiedadenien-dinukleotied) wat tydens die glikolitiese omskakeling van gliseraldehied-3-fosfaat na piruvaat verbruik word, later deur die reduksie van asetaldehied na etanol regenereer word. Die nasending van die metaboliese vloeiing van piruvaat na biomassavorming lei egter na ‘n oormaat NADH-vorming. Onder hierdie toestande word die intrasellulêre redoksbalans dan hoofsaaklik deur die vorming van gliserol onderhou. Laasgenoemde word veral deur twee ensieme beheer, naamlik Gpd1p en Gpd2p. Die delesie van die gene wat vir hierdie twee proteïene enkodeer, lei tot ‘n akkumulasie van NADH en veroorsaak dat die selle nie hulle gistingsvermoë en groei onder anaërobiese toestande kan onderhou nie. Die doelwit van hierdie studie was om die groei, gistingsvermoë en metabolietsintese van verskeie gpd1Δgpd2Δ dubbelmutant (DM) rasse te ondersoek waarin die redoksbalanseringspotensiaal gedeeltelik herstel is deur die uitdrukking van inheemse of heteroloë gene. Rasse is gekonstrueer deur alternatiewe NADH-oksiderende weë in te voer of deur bestaande weë te manipuleer om die oksidasie van oormaat NADH te bevoordeel. Meer spesifiek het die modifikasies die volgende ingesluit: (i) sorbitolvorming; (ii) die vestiging van ‘n weg vir propaan-1,2-diol-vorming; en (iii) die verhoging van etanolvorming. Buiten die genetiese manipulering van die gpd1Δgpd2Δ dubbelmutant, is die byvoeging van piruvaat tydens groei ook ondersoek. Die eksperimente is onder suurstofbeperkte toestande in ‘n hoë-suiker medium uitgevoer en die gegiste produk is ondersoek vir totale suikerverbruik, biomassa en primêre en sekondêre metaboliete wat deur die verskillende rasse gevorm is. Die verhoudings tussen suikerverbruik, groei en metabolietproduksie deur die verskillende rasse is ondersoek deur die data wat deur die verskillende rasse gegeneer is deur middel van meerveranderlike data-analise te vergelyk. Analise van die weë wat in die produksie van primêre (sure, etanol en ander metaboliete) en sekondêre metaboliete (aromaverbindings) betrokke is, is ook uitgevoer om die verandering in vloei te bepaal in vergelyking met die wildetipe (WT) ras. Die resultate het gewys dat hierdie manipulasies die gistingsvermoë van die gpd1Δgpd2Δ-dubbelmutant verbeter het, wat ‘n gedeeltelike herstel van NAD+- regenerasievermoë voorstel, hoewel nie tot dieselfde mate as in die WT-ras nie. Soos verwag, is ‘n beduidende korrelasie tussen suikerverbruik en etanol- en biomassavorming gevind. Etanolopbrengs is deur genetiese manipulasies verhoog, maar nie die finale konsentrasies van etanol nie. Sorbitol is in beduidende hoeveelhede deur die DM(srlD) en DM(SOR1)-rasse gevorm en propaan-1,2-diol deur die DM(gldA, GRE3, mgsA) -rasse, hoewel teen laer molare opbrengste as gliserol. Verder is die opbrengs van sekondêre metaboliete (isobutanol, iso-amielalkohol, 2-fenieletanol en isobottersuur) deur genetiese manipulasie verhoog, terwyl die etielasetaatkonsentrasie en -opbreng verlaag is. Die resultate dui aan dat die aromaverbindingseienskappe van wyngiste voordelig verander kan word deur die gliserolsintetiseringsweg te manipuleer. Die byvoeging van piruvaat tydens die groei van die gpd1Δgpd2Δ-dubbelmutant dra by tot uitermate NADH-reoksidasie tydens die bykomende vorming van etanol.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Chapter II: Football is a sport with intermittent characteristics, high intensity and emphasis on components of strength, speed and endurance. This sport competition offers a unique setting for assessing stress responses and changes in redox balance. The collection and analysis of less-invasive samples such as saliva, offer the opportunity to collect in the field of training or competition. So, the aim of this study was to evaluate the effect of competition on salivary biomarkers of stress and redox balance in soccer players. The sample consisted of 14 male subjects (24.05 ± 3.1 years, 173 ± 0.05 cm, 71.84 kg ± 8:50). The volunteers were monitored during the college national championship (four games) with an interval of 24 hours between games. Saliva samples were collected before and after the games and put up until the time of analysis. Our findings show that in 4 games SAA and the rate of secretion of total protein post-games showed significant increases over the pre-game moments. Game 1.2 and 3 cortisol levels showed significant increases in post-game moments in relation to pre-game moments. With regard to changes in redox balance, was not observed changes in rates of oxidative damage to lipids before and after 4 games, which were quantified by the concentration of the products of lipid peroxidation (TBARS). On the other hand, total antioxidant response in Game 3 was significantly increased in the post-game compared to the pre-game, shown by the total antioxidant capacity (FRAP). Catalase activity did not change significantly in any of the time points. These results suggest that 3 markers of stress (autonomous activity) showed changes due to athletic competition. The secretion rate of total protein can be an attractive marker of stress, ease and low cost of the method. The games even with little recovery range were not enough to promote oxidative damage to lipids, probably because of the induced training adaptations. / CAPITULO II: O futebol é um esporte com características intermitentes, de intensidade extenuante com ênfase nos componentes de força, velocidade e resistência. Nesse sentido, a competição esportiva oferece um cenário único para avaliar as respostas ao estresse e alterações no balanço redox. A análise e coleta de amostras menos-invasivas, como a coleta de saliva, têm se destacado por oferecer oportunidade de coletas no próprio campo de treinamento ou competição. O objetivo desse estudo foi avaliar o efeito da competição sobre biomarcadores salivares de estresse e balanço redox em atletas de futebol. A amostra foi composta por 14 indivíduos homens (24,05± 3.1 anos, 173 ± 0,05 cm, 71.84 ± 8.50 kg). Os voluntários foram monitorados durante o campeonato brasileiro universitário e realizaram quatro jogos de futebol com intervalo de 24h de descanso entre os jogos. Amostras de saliva foram coletadas antes e após o término dos jogos e acondicionadas até o momento da análise. Nossos achados mostram que nos 4 jogos a sAA e a taxa de secreção de Proteínas totais pós-jogos apresentaram aumentos significativos em relação aos momentos pré-jogos. No jogo 1, 2 e 3 a concentração de cortisol foi maior nos momentos pós-jogos em relação aos momentos pré-jogos. No que diz respeito às alterações do balanço redox, não foi verificado alterações nas taxas de danos oxidativos a lipídeos antes e após os 4 jogos, que foram quantificados através da concentração dos produtos de peroxidação lipídica (TBARS). Por outro lado, a resposta antioxidante total no jogo 3 apresentou aumento significativo no momento pós-jogo em relação ao pré-jogo, mostrado pela capacidade antioxidante total (FRAP). A atividade da catalase não sofreu alteração significativa em nenhum dos momentos avaliados. Esses resultados sugerem que os 3 marcadores de estresse (atividade autônoma) apresentaram alterações frente a competição esportiva. A taxa de secreção de Proteínas Totais pode ser um marcador atraente de estresse, pela facilidade e baixo custo do método. Os jogos mesmo com pouco intervalo de recuperação não foram suficiente para promover danos oxidativos a lipídeos, fato esse ocorreu provavelmente pelas adaptações induzidas pelo treinamento da equipe. / Mestre em Genética e Bioquímica

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O fenômeno da tolerância ao lipopolissacarídeo ocorre quando animais expostos a pequenas doses de LPS tornam-se hiporresponsivos a doses letais posteriores. Tendo em vista que a capacidade do hospedeiro de tolerar a presença de agentes patogênicos é uma estratégia do organismo humano e que reduz o impacto negativo durante a sepse, o objetivo do estudo foi investigar se a tolerância ao lipopolissacarídeo resulta em efeitos benéficos na atividade das enzimas antioxidantes e investigar possíveis diminuição da peroxidação lipídica, durante o estresse oxidativo. Após verificarmos a atividade das enzimas antioxidantes concluímos que tolerância ao lipopolissacarídeo tem um papel importante no equilíbrio redox, onde houve aumento da expressão de superóxido dismutase (SOD), nos animais tolerantes submetidos a ligadura e punção cecal, defendendo o hospedeiro de forma que o mesmo não respondesse de forma exacerbada nas exposições subsequentes a produtos de microrganismos patogênicos / Sepsis has recently been classified as a fatal organic dysfunction caused by dysregulation of the immune response to a particular infection. It is a serious condition that can cause failure of one or multiple organs. It represents the main cause of death in patients treated in an intensive care unit (ICU). Most registered cases of sepsis are due to gram-negative bacteria. Lipopolysaccharide (LPS), a component of the outer membrane of the bacterium, triggers a cascade of activities of the immune system. This response to LPS produces several inflammatory mediators and can generate oxidative stress also known as redox imbalance through the release of reactive oxygen species (EROS). Considering that the host\'s ability to tolerate the presence of pathogens is a strategy of the human organism and reduces the negative impact of the disease, we propose to investigate whether endotoxemia results in beneficial changes, maintaining the redox balance during the sepsis period. After verifying the relative mRNA expression and protein quantification, we conclude that endotoxemia caused by lipopolysaccharide plays an important role in the immunoregulation of the inflammatory response defending the host so that it does not respond exacerbatedly in subsequent exposures to products of pathogenic microorganisms

Changes in lifestyle of people has been dynamically observed in recent decades, emphasis is given to dietary issues. In this case, as directly responsible for chronic diseases, along with other aspects of lifestyle such as inactivity, smoking, quality of life. In the context of chronic diseases of high incidence and prevalence, the metabolic syndrome has gained prominence in clinical and experimental research in the search for early diagnostic methods for its various components such as the vascular, biochemical and liver, all also associated with diet. In this context, there was the inclusion of non-alcoholic fatty liver disease as liver component of the metabolic syndrome, which is the central object of this work. Objective: To evaluate the profile morphological, functional and redox balance in the liver of a novel induced-diet mice model for metabolic syndrome. Methods: Eleven isogenic male C57BL/6J mice were randomly divided into control (CT) and hypercaloric (HC) groups and fed with chow and hypercaloric diet, respectively, for 26 weeks. We did ratings serum markers of liver function (ALT, AST, ALP, &#947;-GT, LDH, albumin and total protein), analysis of local redox status (SOD, CAT and lipid peroxidation) and histological study of tissue. Results: There were significant elevations of the statistical point of view in the main markers of liver function in HC animals. This increase was approximately 1.5 times for ALT, 2.5 for AST and 7.4 for ALP. The activity of &#947;-GT followed the pattern of significant increase in the HC group, despite its low activity. There re no differences in the concentrations of albumin and total protein. On the local redox state, the activity of SOD was not different between groups, the catalase activity was significantly decreased in HC group and there re high levels of peroxidation in this same group. The histological findings corroborate these results, which corresponds to advanced liver disease in animals HC (default cirrhotic). Conclusion: The hepatic component in the novel induced-diet mice model for metabolic syndrome shows changes in your profile functional, redox balance and morphological. Keywords: Metabolic Syndrome, Liver Functions, Redox Balance, Novel Diet-induced Mice Model. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As alterações no estilo de vida das pessoas vem sendo dinamicamente observadas nas últimas décadas; destaque especial é dado aos aspectos dietéticos. Neste caso, como responsável direto por doenças crônicas, juntamente com outros aspectos do estilo de vida como sedentarismo, tabagismo, qualidade de vida. No contexto das doenças crônicas de elevada incidência e prevalência, a síndrome metabólica vem ganhando destaque nas pesquisas experimentais e clínicas na busca de métodos diagnósticos precoces para seus vários componentes a exemplo dos vasculares, bioquímicos e hepáticos, todos com associação também dietética. Neste contexto, destaca-se a inserção das doenças hepáticas gordurosas não alcoólicas como componente hepático da síndrome, sendo este o objeto central do presente trabalho. Objetivo: Avaliar o perfil morfológico, funcional e o balanço redox do fígado de um novo modelo murino dietético para síndrome metabólica. Métodos: Onze camundongos isogênicos machos C57BL/6J foram randomicamente divididos nos grupos Controle (CT) e Hipercalórico (HC) e alimentados com dieta chow e hipercalórica, respectivamente, durante 26 semanas. Foram procedidas avaliações plasmáticas de marcadores de função hepática (ALT, AST, ALP, &#947;-GT, LDH, albumina e proteínas totais), análise do estado redox local (SOD, CAT e peroxidação lipídica) e estudo histológico do tecido. Resultados: Foram encontradas elevações significativas do ponto de vista estatístico nos principais marcadores de função hepática nos animais HC. Esse aumento foi de aproximadamente 1,5 vezes para ALT, 2,5 para AST e de 7,4 para ALP. A atividade de &#947;-GT seguiu o padrão observado de elevação significativa no grupo HC, apesar de sua baixa atividade. Não foram observadas diferenças nas concentrações de albumina e proteínas totais. Relativo ao estado redox local, a atividade de SOD não foi diferente entre os grupos, a de catalase foi significativamente diminuída nos HC e os níveis de peroxidação elevados. Os achados histológicos corroboram esses resultados, sendo corresponde a doença hepática avançada nos animais HC (padrão cirrótico). Conclusão: O componente hepático no novo modelo murino dietético para síndrome metabólica estudado apresenta alterações em seu perfil morfológico, funcional e no balanço redox.