<p dir="ltr">In the three conducted studies, we investigated the role of serum albumin in metabolic processes, particularly in lipid metabolism and glucoregulation. The first study explored how disrupting the binding of free fatty acids (FFA) to circulating albumin affects lipid metabolism and glucose control. Male and female albumin knockout mice exhibited significantly reduced plasma FFA levels, hepatic lipid content, and blood glucose during tolerance tests compared to wild-type mice. Additionally, albumin deficiency led to changes in adipose tissue gene expression, indicating the importance of albumin and plasma FFA concentration in metabolic regulation. In the second study, the focus was on determining if impeding serum albumin's function in transporting FFAs could prevent hepatic steatosis and metabolic dysfunction in obesity. Albumin knockout mice, despite being obese due to a high-fat diet, showed lower plasma FFA levels, improved glucose tolerance, and reduced hepatic lipid accumulation compared to wild-type mice. Elevated gene expression in liver and adipose tissues suggested albumin's involvement in hepatic lipid accumulation and glucose metabolism in obesity. Lastly, in the third study, we examined the phenotype of heterozygous albumin knockout mice and compared it to wild-type and homozygous knockout mice. While homozygous knockout mice exhibited improved glucoregulation and reduced plasma FFA concentration, heterozygous knockout mice did not show significant improvements compared to wild-type mice. The findings imply that a minor suppression of albumin expression may not be adequate to enhance glucoregulation. In summary, the studies emphasize the crucial role of serum albumin in metabolic processes, illustrating how disrupting FFA binding to albumin leads to improved glucose control and reduced hepatic lipid accumulation. However, minor suppression of albumin expression may not effectively enhance metabolic health. These findings provide valuable insights into potential therapeutic interventions targeting the albumin-FFA pathway to improve metabolic outcomes.</p><p dir="ltr"><br></p>

Three dimensional multicell tumor spheroids (MCTS) provide an experimental model where the influence of microenvironmental conditions on protein expression can be determined. Sequential trypsin digestion of HT29 colon carcinoma MCTS enabled segregation into four populations comprising proliferating cells from the surface (SL), an intermediate region (IR), nonproliferating hypoxic cells from the perinecrotic region (PN), and a necrotic core (NC). Total protein was extracted from each population and subjected to iTRAQ-based quantitative proteomics analysis. From a total of 887 proteins identified, 209 were observed to be up-regulated and 114 were down-regulated in the PN and NC regions relative to the SL. Among the up-regulated proteins, components of glycolysis, TCA cycle, lipid metabolism, and steroid biosynthesis increased progressively toward the PN and NC regions. Western blotting, immunohistochemistry, and enzyme assays confirmed that significant changes in the expression of proteins involved in cellular metabolism occur in the nonproliferating fraction of cells within the viable rim. The presence of full length, functional proteins within the NC was unexpected, and further analysis demonstrated that this region contains cells that are undergoing autophagy. This study has identified possible targets that may be suitable for therapeutic intervention, and further studies to validate these are required.

Les nucléotides et nucléosides sont des molécules essentielles à la vie. Outre leurs fonctions intracellulaires, ils jouent un rôle dans la communication intercellulaire. Les nucléotides et nucléosides sont libérés dans l’espace extracellulaire par différents mécanismes et ensuite rapidement métabolisés par des ecto-nucléotidases. Ils exercent leurs effets paracrines et/ou autocrines en activant des récepteurs présents à la surface membranaire des cellules. Les récepteurs P1, au nombre de quatre (A1, A2A, A2B et A3), sont activés par l’adénosine. Les récepteurs P2X1-7 ont une activité intrinsèque de canal ionique et sont essentiellement activés par l’ATP. Les récepteurs P2Y possèdent sept domaines transmembranaires et sont couplés à des protéines G. A ce jour huit sous-types ont été identifiés : P2Y1,2,4,6,11,12,13,14. Ces récepteurs sont activés par des nucléotides adényliques (ATP et ADP) et/ou uridyliques (UTP, UDP et UDP-glucose). Les récepteurs P1 et P2 modulent l’activité de multiples processus biologiques : système immunitaire (A2A, P2X7, P2Y11,…), agrégation plaquettaire (P2Y1, P2Y12, P2X1), tonus vasculaire, angiogenèse,… Notre laboratoire a identifié et caractérisé plusieurs récepteurs P2Y : P2Y4, P2Y6, P2Y11 et P2Y13. Ce dernier est activé par l’ADP et est couplé à une protéine Gi. L’abondance du transcrit P2Y13 murin est caractérisée par l’ordre suivant : rate >> pancréas > foie = cerveau. Afin de déterminer son rôle physiologique, nous avons généré une lignée de souris invalidées pour le récepteur P2Y13. Après avoir validé l’inactivation du gène P2Y13 dans ces souris, nous avons analysé leur phénotype. Les souris P2Y13-/- ne présentent pas d’anomalie évidente : elles sont viables, fertiles et se développent normalement. Etant donné le profil d’expression de ce récepteur, nous avons analysé leur système immunitaire, en particulier les cellules dendritiques (DC). In vivo, l’invalidation du récepteur P2Y13 ne semble pas avoir d’impact sur les réponses inflammatoires (choc septique, infiltration de neutrophiles, test à la formaline) et auto-immunes (uvéorétinite expérimentale). In vitro, nous avons montré que l’ADPβS induit une mobilisation de calcium cytoplasmique dans les DC spléniques et qu’il stimule l’endocytose d’antigènes par celles-ci. L’utilisation de DC transgéniques a permis d’exclure l’implication du récepteur P2Y13 et a montré que ces effets sont médiés par le récepteur P2Y12 qui est également activé par l’ADPβS. Ces observations suggèrent qu’il serait intéressant d’analyser le système immunitaire des souris P2Y12-/-, en particulier les réponses immunes dépendantes des DC. D’autre part, ce travail a débouché sur la mise en évidence d’un effet anti-inflammatoire médié par le récepteur de l’adénosine A2B dans les DC dérivées de la moelle osseuse. Enfin, nous avons récemment mis en évidence un rôle potentiel du récepteur P2Y13 dans le métabolisme des glucides et des lipides. Nous avons observé que les souris P2Y13-/- produisent plus d’insuline en réponse à une injection de glucose que les souris contrôles tandis que leur glycémie ne semble pas altérée. De plus, les souris P2Y13-/- sous régime riche en graisses reproduisent 3 caractéristiques du syndrome métabolique chez l'homme : surpoids, dyslipidémie (augmentation des triglycérides et du non HDL-cholestérol) et hyperinsulinémie. Notre travail de thèse débouche donc sur deux conclusions et une perspective : • l’adénosine exerce une action anti-inflammatoire sur les cellules dendritiques dérivées de moelle osseuse via l’activation du récepteur A2B ; • le récepteur P2Y12 est exprimé fonctionnellement dans les cellules dendritiques murines et stimule l’endocytose ; • le récepteur P2Y13 pourrait jouer un rôle important dans le contrôle du métabolisme des lipides et des glucides ainsi que du poids corporel, suggérant que des agonistes spécifiques de ce récepteur pourraient permettre de contrecarrer l’obésité et ses conséquences métaboliques néfastes.

La dégénérescence maculaire liée à l’âge (DMLA) représente actuellement la principale cause de cécité dans les pays industrialisés. Les traitements disponibles ne concernent qu’une partie des cas (DMLA néovasculaire) et n’évitent pas toujours le développement de déficiences visuelles sévères. L’identification de facteurs modifiables, tels que la nutrition, pourrait représenter des moyens de prévention permettant de diminuer la fréquence de cette maladie handicapante dans nos populations. L’objectif de la thèse était d’étudier d’un point de vue épidémiologique, la relation entre nutrition et DMLA chez les 963 sujets de l’étude Aliénor (Antioxydants Lipides Essentiels Nutrition et maladies OculaiRes), âgés de 73 ans et plus, avec un intérêt particulier pour les lipides. La relation entre les lipides et la DMLA repose principalement sur la potentielle implication du métabolisme lipidique dans la physiopathologie de la DMLA, ainsi que sur le triple rôle structurel, fonctionnel et protecteur des acides gras polyinsaturés (AGPI) n-3 au sein de la rétine. Dans un premier temps, nous avons mis en évidence une diminution du risque de DMLA chez les sujets ayant des apports alimentaires élevés en AGPI n-3. L’estimation des apports alimentaires étant sujette à de nombreuses imperfections (déclaration des sujets, biais de mémorisation, imprécisions des tables de composition alimentaire…), nous avons ensuite utilisé un biomarqueur du statut en AGPI n-3 afin de s’affranchir de ces limites. Ce travail nous a permis de mettre en évidence une diminution du risque de DMLA prévalente et incidente chez les sujets ayant des niveaux plasmatiques élevés d’AGPI n-3. Enfin, nous avons étudié les relations de certains gènes impliqués dans le métabolisme lipidique avec DMLA, les niveaux de lipides sanguins et de xanthophylles. Il ressort que les sujets TT pour le polymorphisme du gène LIPC (rs493258) présentaient un risque diminué de DMLA ainsi que des niveaux plasmatiques de zéaxanthine plus élevés. Ces travaux viennent compléter et enrichir la littérature à ce sujet et apportent des arguments nouveaux quant au rôle des AGPI n-3 dans la rétine ; ils pourront également servir de support en matière de recommandations nutritionnelles et de prévention de la DMLA. Nos travaux sur l’implication des gènes du métabolisme des lipides soulèvent de nouvelles questions quant aux mécanismes impliqués dans cette pathologie et pourraient suggérer de nouvelles pistes de recherche thérapeutiques et préventives. / Age-related macular degeneration (AMD) is the leading cause of blindness in industrialized countries. Current treatments are limited to the neovascular form of the disease only and do not always prevent the development of severe visual impairment. The identification of modifiable risk factors, such as nutrition, may lead to preventive strategies, which may have the potential to reduce the impact and burden of AMD on the global aging population. The objective of the thesis was to study the association between nutrition and AMD in the 963 subjects, aged 73 years or older, from the Alienor Study, with a particular emphasis on lipids. The relationship between lipids and AMD is primarily based on the potential involvement of lipid metabolism in the pathogenesis of AMD and on the structural, functional and protective roles of omega-3 polyunsaturated fatty acids (PUFAs) in the retina. First, we showed that high intakes of omega 3 PUFAs were associated with a decreased risk for AMD. Estimation of dietary intakes being affected by many imperfections (bias in reporting, memory bias, inaccuracies from food composition tables...); we used an omega 3 PUFAs biomarker in order to overcome these limitations. This second work showed that high plasma levels of omega 3 PUFAs were associated with a decreased risk for prevalent and incident AMD. Finally, we studied the associations of genes involved in lipid metabolism with AMD, plasma lipids and xanthophylls. It appears that subjects bearing TT genotype for LIPC gene had a decreased risk of AMD and higher plasma levels of zeaxanthin. These results provide new arguments about the role of omega-3 PUFAs in the retina. They can also provide support and recommendations for prevention of AMD. This work on genes involved in lipid metabolism suggest new questions about mechanisms involved in AMD and may suggest new way of research in treatment and prevention.

Une étude comparative de la régulation nutritionnelle du métabolisme des lipides chez la vache et la chèvre laitières a été réalisée afin d’identifier les mécanismes et préciser les spécificités de ces 2 espèces en vue d’une meilleure maîtrise de la quantité et de la qualité de la matière grasse laitière (MGL). Les effets respectifs de régimes riches en concentrés non supplémenté (CTL) ou supplémentés en huile de maïs et en amidon (COS), ou en poudre d’algues (MAP) ou en huile de palme hydrogénée (HPO) sur la plasticité et la composition de la MGL, et sur des indicateurs des métabolismes ruminal, intermédiaire et mammaire ont été étudiés chez la vache et la chèvre (n=12 par espèce) conduites simultanément selon un carré latin 4X4. Les régimes n’ont pas eu d’effet sur la production laitière quelle que soit l’espèce. Cependant, une différence de réponse inter-espèces au régime COS a été observée avec une forte chute de la teneur en MGL (-45%) chez la vache mais pas chez la chèvre. Le régime MAP a conduit à une diminution de la teneur en MGL chez la vache (-22%) et, dans une moindre mesure, chez la chèvre (-15%), tandis que HPO l'a augmentée seulement chez la vache (+13%). Les différences majeures observées avec COS entre les 2 espèces sont attribuées 1/ à des différences de biohydrogénations ruminales (BHR) des AG polyinsaturés avec une plus grande stabilité des voies classiques de BHR chez la chèvre ; 2/ au métabolisme intermédiaire, avec une augmentation des lipides circulants chez la chèvre suggérant une plus grande disponibilité en AG longs pour la glande mammaire (GM). Les réponses à MAP ont été attribuées à des mécanismes similaires chez les 2 espèces mais différents en termes d’indicateurs des métabolismes ruminal et intermédiaire de ceux identifiés pour COS. Chez la vache HPO se distingue par une augmentation du C16:0 et C16:1 cis-9 du lait suggérant un transport et/ou un captage privilégié du C16:0 chez cette espèce. Quel que soit le régime, le métabolisme mammaire des lipides, étudié via l’abondance des ARNm de gènes de la lipogenèse, n’a pas été relié aux données de sécrétions des AG du lait. Nos résultats montrent que la plasticité de la MGL chez deux espèces de ruminants, à priori proches, est contrôlée par des mécanismes différents selon l’espèce et le régime. Nous avons construit une base de données phénotypiques sur 24 animaux de 2 espèces recevant 4 régimes dont l’analyse nous a permis de préciser les mécanismes de synthèse de la MGL. Ce projet de recherche pourrait permettre, in fine, de proposer des outils de monitoring via le phénotypage de la composition fine du lait et de proposer des stratégies d’élevage pour moduler les performances de l’animal. / A comparative study of the nutritional regulation of lipid metabolism in dairy cows and goats was performed to identify the mechanisms and clarify the specificities of these 2 ruminant species in order to better control milk fat yield and quality. The effects of diets containing no additional lipid (CTL) or supplemented with corn oil (5% dry matter intake (DMI)) and wheat starch (COS), marine algae powder (MAP) (1.5% DMI), or hydrogenated palm oil (HPO) (3% DMI), on milk fat plasticity and composition, and on indicators of ruminal, intermediary and mammary metabolisms were studied in cows and goats (n=12 per species) conducted simultaneously according to a 4x4 Latin square design. Dietary treatments had no significant effects on milk yield in both species. Conversely, species-specific response of milk fat content to dietary treatment were observed: in cows, milk fat content was lowered by COS (-45%) and MAP (-22%) and increased by HPO (+13%) compared with CTL, and in goats, only MAP had an effect compared with CTL by decreasing milk fat content by 15%. The major differences observed for COS among species were attributed 1/ at differences in the polyunsaturated fatty acids (FA) ruminal biohydrogenation (RBH) processes with a greater stability of the classical RBH pathways in goats; 2/ at the intermediary metabolism, with an increase in circulating lipids in goats suggesting a higher availability of long chain FA for mammary gland (MG). Responses on MAP treatment were attributed to similar mechanisms among species but different to those outlined for COS in terms of indicators of ruminal and intermediary metabolisms. In cows, HPO was characterized by an increased in milk 16:0 et cis-9 16:1 suggesting a favoured transport and/or uptake of 16:0 in this species. Whatever the dietary treatment the mammary lipid metabolism studied by the mRNA abundance of few lipogenic genes was not related with milk FA yields. Our results demonstrated that the milk fat plasticity in two closely related ruminant species is controlled by different mechanisms depending on species and dietary treatments. We produced a database on 24 animals of 2 species receiving 4 dietary treatments. The dataset analysis allowed us to enhance our knowledge on regulation mechanisms of milk fat synthesis. This research project will contribute for the development of monitoring tools based on milk composition phenotyping, and to propose husbandry strategies that modulate animal performance.

Farnesoid X receptor is mostly expressed in liver cells and its activation may be used for the treatment of cirrhosis causing diseases, especially biliary cirrhosis and nonalcoholic steatosis. These two latter diseases are most common in developed countries and, as of date, no effective treatments are available. Therefore, the aim of this project is the design and synthesis of novel bile acid analogues with subsequent biological evaluation towards farnesoid X receptor. Thus, a series of new compounds were designed using computational modeling studies and chemical synthesis was done to develop structure-activity relationships. Chemical structure analysis and purity was confirmed by conventional analytical methods. Finally, synthetic compounds were profiled against farnesoid X receptor in collaboration with the Pharmaceutical faculty of Charles University in Hradec Králové. Keywords: farnesoid X receptor, FXR, bile acids

L’annotation des génomes est un défi majeur pour lier les génotypes aux phénotypes. Identifier les ARN longs non-codants (ARNlnc) dans les génomes fait partie de ce défi ; d’expression relativement faible, ils n’ont été mis en évidence que récemment (2012) par l’avènement des technologies de séquençage haut débit. Ces travaux de recherche ont permis à partir de données RNA-seq, de mettre en lumière un grand nombre d’ARNlnc chez les espèces d’élevage et en particulier chez la poule chez qui aucun ARNlnc n’était décrit au début de cette thèse (2015). Un premier travail a consisté à identifier ces ARNlnc en utilisant des échantillons de foie et tissu adipeux puis nous avons amélioré ce catalogue par intégration d’autres bases de données publiques d’ARNlnc disparates. De plus, d’après la littérature, les ARNlnc ont été décrits comme intervenant dans la régulation de tous les processus biologiques :de la structure cellulaire à l’expression des gènes. La problématique de l’équipe étant associée à la compréhension de la régulation du métabolisme des lipides chez la poule, mon second travail a consisté à établir la liste des ARNlnc connus dans le règne animal comme étant impliqués dans ce métabolisme ou dans le processus de stockage et de formation du tissu adipeux, l’adipogenèse. Les analyses de conservation par synténie ont permis de retrouver une vingtaine de ces ARNlnc chez la poule. Enfin, à partir de lignées divergentes pour le poids de gras abdominal, j’ai également mis en évidence de nouveaux ARNlnc potentiellement régulateurs de ce métabolisme lipidique. / Genome annotation is a major challenge in connecting genotypes with phenotypes. Identifying long noncoding RNAs (lncRNA) in genomes is part of this challenge; they are relatively low-expressed and have only been highlighted in 2012 thanks to the development of high throughput sequencing technologies. This research work has led to the identification of a large number of lncRNAs in livestock species, particularly in the chicken, in which no lncRNA had yet been described at the beginning of this thesis (2015). First, my aim was to identify these lncRNAs using liver and adipose tissue and to improve this catalogue by integrating other existing lncRNA public databases.Moreover, according to the literature, lncRNAs are involved in the regulation of any biological process, from gene expression to cell structure. One of the goals of our team is to understand the regulation of lipid metabolism in the chicken, I thus established the list of all lncRNAs known within the animal kingdom and involved in this metabolism or in adipogenesis, the process of storage and formation of adipose tissue. The conservation by synteny analyses revealed around twenty conserved lncRNAs in the chicken. From divergent abdominal fat weight chicken lines, I lastly identified new lncRNAs that potentially regulate this lipid metabolism.

A associação de uma série de influências ambientais como dietas com excesso de gordura ou falta de atividade física regular (sedentarismo) são importantes fatores que podem levar ao desenvolvimento da obesidade e dislipidemias. Portanto, a prática de atividade física regular, caracterizada pelo treinamento, mostra-se atualmente como parte de estratégias para combater problemas como dislipidemias. Sabe-se que o aumento do gasto calórico e a melhora no desempenho podem ser atingidos com treinamentos de endurance ou intermitentes, uma vez que ambos levam à alterações fisiológicas e metabólicas semelhantes. O treinamento intermitente é caracterizado pela execução de repetidas sessões de curtos ou longos períodos, preferencialmente de alta intensidade (aproximadamente 100% do VO2máx.), intercaladas por pausas ou períodos de menor intensidade, visando a recuperação do indivíduo. Dada a importância do fígado no metabolismo lipídico em repouso e no exercício foi nosso interesse avaliarmos o comportamento do fígado frente a oito semanas de treinamento intermitente de alta intensidade e comparar tais alterações às promovidas pelo treinamento de endurance em ratos, com especial atenção a síntese e secreção de VLDL. Os animais foram divididos em três grupos: sedentário (SD), treinamento contínuo (TC) e treinamento intermitente de alta intensidade (TI). Os dois protocolos de treinamento resultaram em menor ganho de peso em comparação com o grupo SD. Ainda o grupo TI apresentou maior secreção de VLDL em comparação aos grupos TC e SD. Além disso, a expressão gênica da MTP, proteína chave na montagem da VLDL e da LPL muscular responsável por catalisar a liberação de TAG da VLDL para captação pelo músculo esquelético demonstrou aumento no grupo TI em comparação ao SD. Tais resultados inferem que o treinamento intermitente modulou o transporte de TAG para a periferia e contribui para um efeito hipotrigliceridêmico após o exercício de alta intensidade / The combination of environmental influence, including high fat diets and lack of regular physical activity (sedentary lifestyle) are important factors leading to the development of obesity and dyslipidemias. Regular practice of physical activity, characterized by training, appears as important strategy to reduce such problems. Increased caloric expenditure and improvement of physical performance can be reached with endurance or intermittent training since both lead to similar physiological and metabolic adaptations. Intermittent training is characterized by the execution of repeated bouts of physical effort (high intensity, approximately 100% of VO2max.) Due to the importance of the liver in lipid metabolism during rest and exercise, we examined the adaptations of organ to 8 weeks of high intensity intermittent training, compared with the effect of endurance exercise with special attention to VLDL synthesis and secretion. The animals were randomized into three groups: sedentary (SD), continuous training (TC) and intermittent training (TI). Both training protocols resulted in reduced weight body gain compared with SD, although IT presents higher VLDL secretion, compared with TC and SD. In addition, gene expression of MTP, a key protein in the assembly of VLDL and LPL muscle responsible for catalyzing the release of TAG for VLDL uptake by skeletal muscle, showed an increase in TI compared to SD. These results suggest that intermittent training modulated the transport of TAG to the periphery and contributed to an hypotriglyceridemic effect caused by high intensity exercise

As leishmanioses são um conjunto de doenças causadas por parasitos de diferentes espécies do gênero Leishmania, sendo a leishmaniose visceral a causa de grande morbidade e mortalidade, principalmente, em países em desenvolvimento como o Brasil. Apesar dos inúmeros estudos focados na participação dos sistemas imunes inato e adaptativo na proteção ou desenvolvimento da doença, pouco se conhece das alterações que ocorrem na célula hospedeira no início da infecção. Ao mesmo tempo em que as células suscitam respostas que levam à eliminação do parasito, esse pode induzir alterações nos processos celulares para sua evasão, sobrevivência e proliferação. Para o entendimento desses processos propomos identificar as vias biológicas moduladas na infecção de células THP-1 por Leishmania infantum. Para isso, células monocíticas humanas THP-1 foram infectadas ou não por Leishmania infantum por 6, 10, 24, 48 e 72 h. A partir do RNA total dessas células, bibliotecas de cDNA foram obtidas e submetidas ao sequenciamento pela técnica de RNA-seq. Posteriormente, o número total de sequências por gene foi obtido por meio do alinhamento das sequências de DNA ao genoma humano de referência GRCh37 (hg19) empregando o programa CLC Genomics Workbench 7.1. Esses dados foram então utilizados na composição da matriz de dados de expressão gênica global das amostras, que serviu como base para obtenção de duas redes de co-expressão gênica utilizando o programa Weighted Gene Co-expression Network Analysis (WGCNA). As redes foram compostas pelos dados de expressão gênica global das amostras controle e infectadas dos períodos 6 h e 10 h (Rede 1) e 24 h, 48 h e 72 h (Rede 2). A partir da análise dessas redes foi possível selecionar módulos altamente correlacionados às amostras controle e infectadas nos diferentes períodos, realizar o enriquecimento funcional dos genes contidos nos módulos, como também identificar genes HGS-hub (genes hub diferencialmente expressos). O enriquecimento funcional dos genes contidos nos módulos altamente correlacionados com as amostras mostrou que as maiores mudanças no perfil de expressão gênica das células infectadas, em relação às células não infectadas, ocorreram nas primeiras 10 h de infecção e que muitos dos genes relacionados com a resposta imune são expressos nas primeiras 6 h de infecção. Já a partir de 24 h de infecção, pequenas alterações no perfil de expressão entre as células não infectadas e infectadas foram observadas. A determinação dos genes HGS-hub mostrou que dentre os processos biológicos alterados por Leishmania infantum nas células THP-1, o metabolismo de lipídios foi o que mais apresentou genes diferencialmente expressos, além da resposta imune. Esses resultados sugerem que além do sistema imune, a Leishmania infantum também é capaz de modular o metabolismo de lipídios das células THP-1 infectadas. / Leishmaniasis is a group of diseases caused by parasites of different species of the genus Leishmania, with visceral leishmaniasis being the cause of great morbidity and mortality, especially in developing countries such as Brazil. Despite the numerous studies focused on the participation of innate and adaptive immune systems in the protection or development of the disease, little is known about the changes that occur in the host cell at the beginning of the infection. At the same time as the cells elicit responses that lead to the elimination of the parasite, it can induce changes in the cellular processes for their evasion, survival and proliferation. To understanding these processes, we aim to identify the biological pathways modulated in THP-1 cell infected by Leishmania infantum. For this, THP-1 human monocytic cells were infected or not by Leishmania infantum for 6, 10, 24, 48 and 72 h. Using total RNA extracted from these cells, cDNA libraries were obtained and submitted to RNA sequencing. Subsequently, the total number of sequences per gene was obtained by aligning the DNA sequences to the reference human genome GRCh37 (hg19) using CLC Genomics Workbench 7.1 software. These data were then used to compose the samples\' global gene expression data matrix, which was employed to obtain two gene co-expression networks using the Weighted Gene Co-expression Network Analysis (WGCNA) program. The networks were composed by the global gene expression data from the control and infected samples at 6 h and 10 h (Network 1) and at 24 h, 48 h and 72 h (Network 2). Analysis of these networks allowed the selection of modules highly correlated to the control and infected samples in different periods, as well as the identification of HGS-hub genes (differentially expressed hub genes). The functional enrichment of the genes showed that the major changes in the infected cells gene expression profile compared to uninfected cells occurred within 10 h of infection and the genes of the biological pathway related to the immune response are expressed in the first 6 h of infection. Starting at 24 h of infection, small changes in the gene expression profile between uninfected and infected cells were observed. The HGS-hub genes analysis showed that among the biological processes altered by Leishmania infantum in THP-1 cells, lipid metabolism was the one that presented a great number of differentially expressed genes, besides the immune response. These results suggest that in addition to the immune system, Leishmania infantum is also able to modulate THP-1 macrophages\' lipid metabolism.

Introdução: Atualmente as Doenças Crônicas não Transmissíveis (DCNTs) são um dos maiores problemas de saúde pública da sociedade. É bastante claro o papel da dieta no controle do colesterol e na incidência de doenças cardiovasculares. Neste sentido, o amaranto desperta grande interesse devido a sua propriedade hipocolesterolemizante. Estudos sugerem que seu efeito hipocolesterolemizante está associado à inibição da enzima HMG-CoA redutase, chave na síntese do colesterol endógeno. Objetivo: Avaliar a atividade enzimática hepática da HMG-CoA redutase de hamsters alimentados com proteína de amaranto. Metodologia: Trinta hamsters foram divididos em 5 grupos e receberam dieta diferenciadas pela fonte protéica. Os grupos I e Icol receberam dieta com 20% de proteína de amaranto e os grupos caseína C e Ccol receberam dieta com 20% de caseína. Os grupos \"col\" apresentavam dieta com 0,1% de colesterol e 13,5% de gordura de coco. O metabolismo lipídico foi acompanhado através do monitoramento das concentrações plasmáticas de colesterol total, triacilgliceróis, HDL, e fração não-HDL nos animais. A excreção de colesterol e ácidos biliares foram quantificados nas fezes dos animais e o grau de esteatose hepática foi determinada através de análises histológicas do lobo direito do fígado. A atividade da enzima HMGR nos fígados foi medida por meio do Kit CS 1090 da Sigma-Aldrich com adaptações segundo Cong et al, 2012. A análise é baseada em espectrometria com absorbância de 340nm a 37ºC, que representa a oxidação de NADPH pela HMG-CoA redutase, na presença do substrato HMG-CoA. Conclusões: A proteína de amaranto pode ser considerado um aliado na redução dos agravos gerados pela dislipidemia, uma vez que reduziu significativamente os níveis de colesterol plasmático e gordura hepática, além de ser demonstrado seu efeito na redução da atividade da enzima HMG-CoA redutase dos animais hipercolesterolemizados que se alimentaram com proteína de amaranto. Uma vez verificado o efeito hipocolesterolemizante e seu possível mecanismo de ação por meio da enzima HMG-CoA redutase, espera-se com isso, estimular o consumo pela população brasileira produção de amaranto no Brasil, como alternativa para diversificar a dieta e a agricultura. / Introduction: Nowadays, Non-Communicable Chronic Diseases (NCCD) are a major challenge in health public. It is evident the role of diet in the control of cholesterol and incidence of cardiovascular disease. In this sense, amaranth arouses great interest due to its hypocholesterolemic property. Studies suggest that amaranth\'s hypocholesterolemic effect is associated with the inhibition of the enzyme HMG-CoA reductase, known as the key process to the endogenous cholesterol synthesis. Objective: Evaluate the hepatic enzymatic activity of HMG-CoA reductase in hamsters fed with amaranth protein. Methodology: Amaranth protein was isolated according to the conventional isoelectric precipitation methodology. Thirty hamsters were divided in 5 groups and were fed diets with different protein source. Experimental groups (I and lcol) had a diet containing 20% of protein amaranth and control groups(C and Cool) received a diet with 20% of casein. Moreover, groups \"col\" had also a diet with 0.1% cholesterol and 13.5% coconut oil in their composition. The lipid metabolism was accompanied through monitoring of plasma concentrations of total cholesterol, triglycerides, HDL and non-HDL fraction in animals. Excretion of cholesterol and bile acids were quantified in the feces of animals and the degree of hepatic steatosis was determined by histological analysis of the liver\'s right lobe. The HMGR enzyme activity in the liver was measured by the CS 1090 Kit from Sigma-Aldrich adjusted in accordance with Cong et al, 2012. The analysis is based on spectrometry with absorbance of 340nm at 37 ° C, which represents the oxidation of NADPH by HMG-CoA reductase in the presence of HMG-CoA substrate. Conclusions: Amaranth protein can be considered as an ally in reducing of injuries generated by dyslipidemia, since it significantly reduced levels of plasma cholesterol and hepatic fat. Furthermore, it was demonstrated its effect on reducing activity of HMG-CoA reductase enzyme in hypercholesterolemic animals, which were fed with amaranth protein. Therefore, once verified the hypocholesterolemic effect of amaranth and its possible action mechanism through HMG-CoA reductase enzyme, stimuli on the production of amaranth are expected as an alternative to diversify the diet and agriculture.