Philosophiae Doctor - PhD / Obesity is a medical condition in which an energy imbalance leads to excessive accumulation of body fat. Obesity leads to a reduction in life expectancy through its association with chronic diseases of lifestyle. The prevalence of obesity is rapidly increasing throughout the world. It is now accepted that most cases of obesity result from an interaction between genetic and environmental factors. This rapid increase in obesity generally leads to an increase in morbidity and mortality from chronic diseases such as cardiovascular disease, type 2 diabetes, osteoarthritis and cancer of which obesity is a risk factor. There is a lack of information in molecular research to explain how obesity predisposes individuals to these diseases. Proteomics is a molecular tool and a set of techniques used to identify changes at protein level from a diseased state. This study aims to identify differentially expressed proteins in serum of obese rats fed different isocaloric diets using proteomics.

Uma nutrição maternal rica em lipídios pode causar prejuízos no desenvolvimento e na vida adulta dos descendentes, como elevado risco de desenvolver alterações metabólicas e obesidade, e também parece alterar a sinalização central por opióides. Porém, estudos realizados a fim de investigar a influência da dieta hiperlipídica (HF) materna sobre o comportamento materno e o desenvolvimento da prole não são conclusivos. Este trabalho investigou a influência da dieta HF sobre a interação mãe-filhote, em duas gerações, e os efeitos imediatos e tardios sobre a prole, relacionando-os ao sistema opióide. As mães HF apresentaram prejuízos na ejeção do leite e maior expressão dos receptores opióides no hipotálamo. No geral, os descendentes HF apresentaram elevados níveis de colesterol, baixa leptina plasmática, maior expressão de peptídeos relacionados à ingestão alimentar, e menor peso. Portanto, o consumo materno de dieta HF causou alterações metabólicas, comportamentais e na expressão gênica na mãe e nos descendentes, mesmo que esses animais não tenham se tornado obesos. / A maternal nutrition high in fat may impair offspring development and adulthood, increasing the risk to develop metabolic alterations and obesity, and may modify the opioids central signaling. However, studies investigating maternal high fat (HF) diet influences on maternal behavior and offspring development are inconclusive. This study aimed to evaluate the influences of a diet high in fat on mother-pup interaction, in two generations, and its early and late effects in the offspring, connecting them to the opioid system. HF dams show decreased milk ejections and higher expression of opioid receptors in the hypothalamus. Overall, HF offspring had higher cholesterol levels, less serum leptin, higher expression of peptides related to food intake, and were lighter. Therefore, maternal intake of HF diet promoted metabolic, behavioral and gene expression alterations in the mother and her offspring, even though these animals did not become obese.

Introdução: as gorduras interesterificadas, ricas em ácidos graxos saturados, vêm sendo utilizadas pela indústria alimentícia em substituição aos ácidos graxos trans. Os principais ácidos graxos saturados empregados no processo de interesterificação são o palmítico e o esteárico, os quais podem, respectivamente, apresentar efeitos deletérios ou serem neutros, do ponto de vista cardiovascular e metabólico. A quantidade de ácido esteárico na dieta é menor em comparação ao palmítico, e não está elucidada a implicação de seu alto consumo. O propósito deste estudo foi avaliar o efeito das gorduras interesterificadas contendo ácido palmítico ou ácido esteárico sobre as principais vias de sinalização envolvidas no metabolismo do tecido hepático e adiposo. Métodos: camundongos machos LDLr-KO foram alimentados durante 16 semanas com dieta hiperlipídica (40% de energia em forma de gordura) contendo maior concentração de poli-insaturados (POLI), palmítico (PALM), palmítico interesterificado (PALM INTER), esteárico (ESTEAR) ou esteárico interesterificado (ESTEAR INTER). Determinaram-se a composição corporal, conteúdo de gordura no fígado, concentração plasmática de colesterol, triglicérides, glicose e insulina. A expressão de genes envolvidos no metabolismo lipídico e vias inflamatórias no tecido adiposo visceral e hepático foi determinada por RT-qPCR. Além disso, a síntese de proteínas e proteínas fosforiladas foi medida por Imunnoblotting. O infiltrado de células inflamatórias no tecido hepático e histologia do tecido adiposo, bem como o conteúdo de colágeno do fígado, foram determinados por coloração com eosina e hematoxilina e Sirius Red, respectivamente. Resultados: o processo de interesterificação não alterou parâmetros bioquímicos plasmáticos e as quantidades de CT e TG no tecido hepático. No entanto, ambas as gorduras interesterificadas induziram maior conteúdo de colágeno no fígado e fosforilação de JNK. Adicionalmente, o grupo ESTEAR INTER desenvolveu NASH, associada a maior infiltrado de neutrófilos. Por outro lado, PALM INTER induziu maior expansão do tecido adiposo, juntamente com hipertrofia de adipócitos, condições associadas à ativação da via de sinalização \"upstream\" do NFkB, observada para a fosforilação de IKK, o que contribuiu para maior teor de TNFalfa. Conclusão: as gorduras interesterificadas enriquecidas com ácido palmítico induziram fibrose hepática, bem como a expansão do tecido adiposo, com hipertrofia dos adipócitos; e as gorduras contendo ácido esteárico induziram NASH em camundongos LDLr-KO / Background: interesterified fats, rich in saturated fatty acids, have been used by the food industry as a substitute for trans fatty acids. The main saturated fatty acids used in the interesterification process are palmitic and stearic, which may, respectively, have deleterious effects or be cardiovascular and metabolic neutral. Objetive: to evaluate the effect of interesterified fats containing palmitic or stearic acids on signaling pathways involved in the hepatic and adipose tissue lipid metabolism. Methods: Weaning male LDLr-KO mice were fed a high-fat diet (40% energy as fat) containing polyunsaturated (PUFA), palmitic (PALM), palmitic interesterified (PALM INTER), stearic (STEAR) or stearic interesterified (STEAR INTER) fats for 16 weeks. Body composition, liver fat content, total plasma cholesterol, triglycerides, glucose and insulin concentrations were determined. Gene expression involved in lipid metabolism and inflammation process in liver and white adipose tissue was determined by quantitative RT-PCR. Furthermore, amount of proteins and activated proteins were measured by Western blot. Hepatic and adipose tissue inflammatory cells infiltration as well as liver collagen content were determined by eosin and hematoxylin and Sirius Red staining, respectively. Results: Interesterified process did not alter plasma biochemical parameters and amounts of TC and TG in hepatic tissue. However, both interesterified fats brought on a higher liver collagen content and JNK phosphorylation. Additionally, STEAR INTER group developed NASH associated with a higher neutrophil infiltration. On the other hand, PALM INTER induced a higher adipose tissue expansion together with the enlargement of adipocytes, conditions associated with the activation of upstream NFkB signaling pathway as observed for IKK phosphorylation, contributing to higher TNFalpha protein content. Conclusions: Interesterified fats containing stearic acid induced NASH and enriched with palmitic acid trigger on steatosis with fibrosis as well as hypertrophy and inflammatory signaling activation in the adipose tissue in LDLr-KO mice

Introdução - A dieta hiperlipídica é uma das principais causas da obesidade, provocando importantes alterações metabólicas, como aumento de gordura corporal, dislipidemia e resistência à ação da insulina. Além disso, a obesidade gera um quadro inflamatório crônico e de baixa intensidade no tecido adiposo branco, que é caracterizado pela ativação de vias inflamatórias, como a via do fator de transcrição nuclear kappa B (NF-kB), que é responsável pela transcrição de genes com ação pró-inflamatória, como o fator de necrose tumoral (TNF)-alfa e a proteína quimiotática para monócitos (MCP)-1. A erva-mate (Ilex paraguariensis) contém compostos bioativos, como o ácido clorogênico, a quercetina e o kaempferol, os quais apresentam a capacidade de modular a expressão de genes envolvidos na resposta inflamatória. Objetivo - Investigar o efeito da ingestão do extrato aquoso de erva-mate sobre os parâmetros metabólicos e sobre a resposta inflamatória no tecido adiposo branco de ratos alimentados com ração hiperlipídica. Material e métodos - Ratos machos Wistar foram submetidos à ração controle ou hiperlipídica por 12 semanas. Após esse período, 12 animais de cada grupo foram eutanasiados, constituindo os grupos baseline. O restante dos animais foi distribuído em quatro grupos que receberam, por gavagem, o extrato aquoso de erva-mate (1 g/kg massa corporal/dia) ou água, durante quatro semanas. Após esse período, todos os animais foram eutanasiados. Durante a 12a e a 16a semana do protocolo experimental, os animais foram submetidos ao teste oral de tolerância à glicose e ao teste intraperitoneal de tolerância à insulina. A partir do sangue, foram determinadas as concentrações de glicose, de insulina e de biomarcadores inflamatórios, bem como o perfil lipídico. A composição corporal foi determinada por meio da análise química da carcaça. A partir do tecido adiposo periepididimal, foi avaliada a expressão das proteínas chaves envolvidas na inflamação crônica e na resistência à ação da insulina, por Western blot, bem como a expressão gênica de adipocinas por PCR em tempo real. Resultados - A ração hiperlipídica provocou aumento da adiposidade, alteração do perfil lipídico, intolerância à glicose e inflamação sistêmica. No tecido adiposo periepididimal, a ração hiperlipídica provocou redução da fosforilação da AKT nos animais estimulados agudamente com insulina. A ingestão do extrato aquoso de erva-mate, por quatro semanas, reduziu o ganho de peso corporal e melhorou o perfil lipídico nos animais alimentados com a ração hiperlipídica em relação ao correspondente grupo tratado com água. Contudo, o extrato aquoso de erva-mate não foi capaz de reverter as demais alterações metabólicas provocadas pela ingestão da ração hiperlipídica. Conclusão - A ingestão da ração hiperlipídica promoveu alterações metabólicas, todavia, não induziu inflamação crônica no tecido adiposo periepididimal. Por outro lado, a ingestão do extrato aquoso de ervamate foi capaz de reduzir o ganho de peso corporal e melhorar o perfil lipídico dos animais que consumiram a ração hiperlipídica / Introduction - High-fat diet is one of the main causes of obesity, inducing significant metabolic changes, such as increased fat mass, dyslipidemia and insulin resistance. Furthermore, obesity is associated with a chronic state of low-grade inflammation in white adipose tissue, which is characterized by activation of inflammatory pathways, like nuclear factor kappa B (NF-kB) pathway, implicated in the transcription of many genes with pro-inflammatory action, such as tumor necrosis factor (TNF)-alpha and monocyte chemotatic protein (MCP)-1. Yerba mate (Ilex paraguariensis) contains bioactive compounds, such as chlorogenic acid, quercetin and kaempferol that have the ability to modulate genes envolved in inflammatory response. Objective - To investigate the effect of yerba mate aqueous extract consumption on metabolic parameters and on inflammatory response in white adipose tissue of high-fat diet-fed rats. Material and methods - Male Wistar rats were submitted a control or a high-fat diet for 12 weeks. After this period, 12 rats of each group were euthanized, constituting the baseline groups. The remainder animals were distributed into four groups, which received by intragastric gavage the yerba mate aqueous extract or vehicle (1 g/kg body weight/day) for four weeks and then, all animals were euthanized. Oral glucose and intraperitoneal insulin tolerance tests were performed at 12 and 16 weeks of experimental protocol. Blood glucose, insulin, lipid profile and inflammatory markers were measured. Water, lipid, protein and ash content were analyzed by carcass chemical composition. Periepididymal adipose tissue were employed to evaluate key proteins involved in inflammatory and insulin signaling pathway by Western blot, and adipokines gene expression by real time PCR. Results - High-fat diet induced body adiposity, dyslipidemia, glucose intolerance and systemic inflammation. In periepididymal fat, high-fat diet decreased AKT phosphorylation in rats acutelly stimulated with insulin. The consumption of yerba mate aqueous extract for four weeks reduced body weight gain and improved lipid profile in high-fat diet group compared to non-treated group. However, yerba mate did not repair others dysfunctions induced by high-fat feeding. Conclusion - High-fat feeding produced some metabolic dysfunctions, but did not induce chronic inflammation in periepididymal adipose tissue. On the other hand, the yerba mate aqueous extract consumption reduced body weight gain and improved lipid profile of rats fed a high-fat diet

Les patients atteints de lupus érythémateux systémique ont une augmentation de la prévalence du syndrome métabolique (MetS) mais les mécanismes sous-jacents ne sont pas connus. Le récepteur de type Toll 7 (TLR7), qui reconnait de l’ARN simple brin, joue un rôle important dans la défense anti-microbienne de l’hôte, mais contribue également au développement et à la progression du lupus. Cependant, l’implication de TLR7 dans le MetS est inconnue. L’objectif de mon projet de thèse était d’explorer l’idée nouvelle que la signalisation de TLR7 peut conduire non seulement au lupus mais aussi à des anomalies métaboliques.Nous avons trouvé que l’obésité induite par un régime riche en gras (régime HFD) a conduit à une exacerbation du lupus et de paramètres métaboliques dans des souris TLR8ko, qui développent spontanément une auto-immunité de type lupique à cause d’une augmentation de la signalisation de TLR7 dans les cellules dendritiques (DCs). Au contraire, sous un régime HFD, les souris TLR7/8ko n’ont pas développé de lupus, et les souris TLR7ko et TLR7/8ko ont été protégées contre les anomalies métaboliques incluant l'augmentation de poids et l’intolérance au glucose. De manière intéressante, dans des souris sauvages (WT) le régime HFD a conduit à une augmentation de l’expression de TLR7 et de la production de TNF par les DCs spléniques et hépatiques, et ce phénotype était plus profond dans les souris TLR8ko. Mon étude montre l’implication de la signalisation de TLR7 dans l’interconnexion entre le lupus et les anomalies métaboliques, donc cibler TLR7 pourrait constituer une nouvelle approche comme thérapie contre le lupus et les maladies métaboliques. / Systemic lupus erythematosus (SLE) patients have increased prevalence of metabolic syndrome but the underlying mechanisms are unknown. Toll-like receptor 7 (TLR7) that detects single stranded-RNA plays a key role in antimicrobial host defence, but also contributes in the initiation and progression of SLE. However, the implication of TLR7 in MetS is unknown. The objective of my PhD project was to explore the novel idea that TLR7 signalling can lead not only to SLE but also to metabolic abnormalities. We found that high fat diet (HFD)-induced obesity led to exacerbation of lupus and metabolic parameters in TLR8ko mice, which develop spontaneous lupus-like disease due to increased TLR7 signalling by dendritic cells (DCs). In contrast, upon HFD TLR7/8ko mice did not develop SLE, and both TLR7ko and TLR7/8ko mice were protected from metabolic abnormalities including body weight gain and glucose intolerance. Interestingly, in wild-type mice HFD led to an increase of TLR7 expression and TNF production by hepatic and splenic DCs, and this phenotype was more profound in TLR8ko mice. My study uncovers the implication of TLR7 signalling in the interconnection of SLE and metabolic abnormalities, thus targeting TLR7 might be a novel approach as a tailored therapy in SLE and metabolic diseases.

La ménopause est un facteur de risques associé au développement des maladies métaboliques. Du fait de ce déficit hormonal, les femmes ménopausées pourraient présenter des risques particuliers une fois exposées à des agents chimiques capables de perturber le système endocrinien. Pour en savoir plus, nous avons mis au point un modèle de souris ovariectomisées supplémentées ou non en œstradiol (E2), et exposées de manière chronique à un mélange de polluants (TCDD, PCB153, DEHP et BPA) ajoutés à une alimentation obésogène. Chaque polluant est utilisé à une dose équivalente à la Dose Journalière Tolérable, et l’exposition recouvre différents stades de développement, incluant ou non la période maternelle (gestation + lactation). Nos résultats indiquent qu’en condition d’obésité induite par le régime, l’ovariectomie accentue la prise de poids, l’intolérance au glucose et l’insulino-résistance chez les souris femelles adultes. Ce phénotype est associé à une diminution de la signalisation œstrogénique dans le foie et une dérégulation de l’adipogenèse et de l’inflammation dans le tissu adipeux. De manière intéressante, le mélange de polluants réduit l’impact délétère de l’ovariectomie sur le phénotype métabolique, possiblement par une amélioration de la signalisation œstrogénique dans le foie et le tissu adipeux. Nos résultats suggèrent fortement que ces effets dépendent d’une exposition maternelle. En conclusion, nous montrons que notre mélange de polluants possède une activité œstrogéno-mimétique. Ceci pourrait avoir une implication dans la compréhension du rôle des polluants environnementaux dans le développement des maladies métaboliques chez la femme en transition ménopausique / Menopause is a risk factor associated with the development of metabolic diseases. Because of estrogen deficiency, postmenopausal women may be at particular risk when exposed to chemical agents that can disrupt the endocrine system. To get more insight, we have developed a model of ovariectomized mice supplemented or not with estradiol (E2), and chronically exposed to a mixture of pollutants (TCDD, PCB153, DEHP and BPA) added to an obesogenic diet. Each pollutant was used at a dose close to the Tolerable Daily Intake dose, and the exposure had covered different stages of development, including or not the maternal period (gestation + lactation). Our results indicate that in diet-induced obesity, ovariectomy triggered weight gain, increase glucose intolerance and insulin resistance. This phenotype was associated with decreased estrogenic signaling in liver and deregulation of adipogenesis and inflammation in adipose tissues. Interestingly, the mixture of pollutants reduced the deleterious impact of ovariectomy on the metabolic phenotype, possibly through an alleviation of estrogenic signaling in both liver and adipose tissues. These data were not reproduced in mice not exposed to pollutants during the maternal life. In conclusion, the mixture of pollutants displayed some estrogeno-mimetic activity. This could have implications in understanding the role of environmental pollutants in the development of metabolic diseases in women in menopausal transition.

Les problèmes de santé liés à l’alimentation hyperlipidique chez l’humain sont en constante progression. Or, une perturbation de l’environnement fœtal induit chez la descendance une susceptibilité plus grande à développer des maladies à l’âge adulte (DOHad : Developmental Origins of Health and Disease). L’objectif de ce travail de Thèse est d’évaluer, chez le lapin, les conséquences d’une alimentation hypercholestérolémique et hyperlipidique sur le développement embryonnaire, fœtal, et la survenue de troubles métaboliques à long terme.Nous avons nourri des lapines ad libitum avec un régime hypercholéstérolémique (0,2%) et hyperlipidique (8%) (HH) ou un régime témoin (C) à partir de l'âge de 10 (expérience 1) ou de 18 semaines (age de la mise à la reproduction, expérience 2). A la naissance, les portées ont été équilibrées et des croisements effectués pour différencier l'effet de l'alimentation de la mère pendant la gestation et pendant la lactation. Ainsi des lapereaux nés de mères HH ont été allaités par des mères C (groupe HH-C) ou HH (groupe HH-HH) et des lapereaux nés de mère C ont été allaités par des mères C (groupe C-C) ou HH (groupe C-HH). Au cours de l’expérience 1, un retard de croissance intra utérin (RCIU) significatif a été mis en évidence dès 9 jours de gestation par échographie dans le groupe HH (P<0,05). A la naissance, les laperaux étaient significativement plus légers (P<0,05). En raison d’un rattrapage pondéral rapide, il n’existait plus de différence significative au sevrage. Tous les lapins ont alors reçu un aliment témoin distribué ad libitum. A J176, il n’y avait pas de différence de poids entre les groupes HH-HH et HH-C, mais les animaux de ces deux groupes étaient significativement plus lourds que les groupes C-C and C-HH (P<0.05). De plus, la tension artérielle était plus élevée dans le groupe HH-HH par rapport à tous les autres groupes (P<0.05). Au cours de l’expérience 2, de tels effets physiologiques n’ont pas été observés. Les effets physiologiques n'ayant été observés que lorsque le régime avait été commencé avant la gestation, nous avons émis l'hypothèse que l'environnement maternel précoce avait été modifié, entrainant une perturbation du développement embryonnaire à l'origine des conséquences à long terme. l’expression des gènes au moment de la mise en route du génome embryonnaire a été étudié à l’aide d’une puce dédiée. L’analyse transcriptomique a permis de suggérer que certains transcrits étaient présents en quantités différentes. Nous avons montré par qRT-PCR que le régime HH induit une augmentation transitoire de la quantité de transcrit de l’adipophiline (présente à J2 mais pas à J5,5). L’analyse immunohistochimique montre une quantité plus importante de gouttelettes lipidiques localisées près du noyau dans les embryons issus de mères nourries par le régime HH à J5,5 comparé aux témoins. Ces résultats illustrent l’importance de la nutrition avant et pendant la gestation pour la determination de la croissance in utero et postnatale, ainsi que pour le développement de maladies métaboliques à long terme. La nutrition maternelle avant la gestation peut engendrer des modifications d’expression de gènes au moment de la transmission materno embryonnaire. / The prevalence of human health problems associated with high-fat diets continues to rise, as does the number of such problems known to be associated with this diet. Disruption of the fetal environment induces in progeny a greater susceptibility to developing diseases in adulthood (DOHad: Developmental Origins of Health and Disease). The objective of the work for this thesis was to assess in rabbits the consequences of a high-cholesterol and high-fat diet on embryonic and fetal development and on the onset of metabolic disorders in the long term.We fed rabbits ad libitum with a high-cholesterol (0.2%) and high-fat (8%) (HH) diet or a control (C) diet, starting at the age of 10 (experiment 1) or 18 weeks (age at which reproduction began, experiment 2).The litters were balanced at birth, and crossings were performed to differentiate the effect of the mother's food during gestation and during lactation. Accordingly, rabbits born to HH mothers were nursed by C (HH-C group) or HH (HH-HH) mothers and those born to C mothers were nursed either by C (C-C) or HH (C-HH) mothers. During experiment 1, ultrasound clearly showed significant intrauterine growth restriction (IUGR) beginning at 9 days of gestation in the HH group (P<0.05). At birth, these rabbits weighed significantly less than their C counterparts (P<0.05). Because of their rapid weight catch-up, the significant difference had disappeared at weaning. All the rabbits thereafter received control food distributed ad libitum. At D176, there was no difference in weight between the HH-HH and HH-C groups but the animals in both these groups were significantly heavier than those in the C-C and C-HH groups (P<0.05). Moreover, blood pressure was higher in the HH-HH group than in any of the other groups (P<0.05). These physiological effects were not observed during experiment 2. Because the physiological effects were observed only when the diet began before gestation, we hypothesized that the early maternal environment been modified, a change that resulted in disruption of embryo development with long-term consequences. We then used a specially designed chip to study gene expression at the maternal to embryonic transition. Transcriptomic analysis suggested that some transcripts were present in different quantities. We showed with qRT-PCR that the HH diet induced a transient augmentation in the quantity of adipophilin transcripts (present at D2 but not at D5.5). The immunohistochemical analysis on D5.5 showed a higher quantity of lipid droplets localized near the nucleus of embryos from mothers fed with the HH diet than in embryos of control mothers. These results illustrate the importance of nutrition before and during pregnancy in the determination of in utero and postnatal growth as well as in the development of metabolic diseases over the long term. Maternal nutrition before conception can engender modifications in gene expression at the moment of the maternal to embryonic transition.

<p>Conclusion of this study: These data suggest that 6 weeks of high-fat feeding induces hypertension but does not produce obesity, dyslipidemia and insulin resistance. However, this model may be useful in studying vascular reactivity in hypertension in the absence of insulin resistance.</p>

To gain insight in the relationship between innate immune system and metabolic disease, we aimed to investigate the effects of lactoferrin in obesity-related metabolic disturbances. Circulating lactoferrin concentration was significantly decreased in subjects with altered glucose tolerance (AGT) and associated negatively with obesity-related metabolic disturbances. The SNPs-induced aminoacidic changes in lactoferrin N-terminus region were associated with a low atherogenic lipid profile. Lactoferrin production in neutrophils decreased significatively in aging, chronic low-grade inflammation and type 2 diabetes. In vitro, lactoferrin increased insulin signaling pathway, even under insulin resistance conditions and displayed dual effects on adipogenesis (antiadipogenic in 3T3-L1 and adipogenic in human adipocytes). In conclusion, lactoferrin might play a potential protective role against insulin resistance and obesity related metabolic disturbances. / Per aprofundir en la relació entre el sistema immunològic innat i els trastorns metabólics, s’investiga l’efecte de la lactoferrina en els desordres metabòlics associats a l’obesitat. Els nivells circulants de lactoferrina es trobaven significativament disminuits en subjetes amb la tolerància a la glucosa alterada (AGT), i aquests es correlacionaven negativament amb trastorns metabòlics associats a obesitat i resistència a la insulina. Els canvis aminoacídics en la seva regió N-Terminal s’associaven a un perfil lipídic menys aterogènic. La producció de lactoferrina es troba reduïda en condicions d’envelliment, inflamació crònica i diabetes tipus 2. In vitro, la lactoferrina incrementava la via de senyalització de la insulina, inclús en condicions de resistència a la insulina i presentava efectes dual en la adipogenesis (antiadipogenic en 3T3-L1 i adipogenic en adipòcits humans). En conclusió, la lactoferrina podria tenir un potencial efecte protector enfront les enfermetats metabòliques associades a obesitat i resistència a la insulina.

O ψευδάργυρος -Zn ελέγχει τον μεταβολισμό των λιπιδίων και γλυκόζης μέσω Ζn-μεταγραφικών παραγόντων. Δίαιτες υψηλών λιπαρών οδηγούν στην ενδοκυτταρική συσσώρευση ελευθέρων ριζών, μειώνουν την μεταγραφική έκφραση των εκκαθαριστών τους και την ενεργότητα αντιοξειδωτικών ενζύμων και οδηγούν σε μεταβολικό σύνδρομο. Οι πρωτεϊνες του θερμικού shock (Heat shock proteins-HSP) παίζουν σημαντικό ρόλο στην αντίσταση στο κυτταρικό stress ως προσαρμογή ,μετά από έκθεση, σε διάφορα ερεθίσματα. ΣΚΟΠΟΣ : Μελέτη της επίδρασης του διατροφικού Ζn και των Hsp70,στην μεταβονομική των λιπιδίων αίματος και ήπατος ποντικών ΥΛΙΚΟ-ΜΕΘΟΔΟΙ :Ενήλικα αρσενικά ποντίκια: 1. Wild type (Wt) Hybrid (F1/F1) C57Bl/6 x CBA και 2. Transgenic (Tg) human HSP70 overexpressing mice, από ηλικίας ενός μηνός εντάχθηκαν στις παρακάτω διατροφές ,επί 10 εβδομάδες. Διατροφή Αριθμός Wt Αριθμός Tg Chow Diet (30 Zn) 6 10 High Fat Diet (3 Zn) 13 12 High Fat Diet (30 Zn) 9 8 High Fat Diet (300 Zn) 12 12 Σύνθεση των τριών διαιτών υψηλών λιπαρών -HFD: 3mg, 30mg, 300mg Zn /kg τροφής (mucedoola s.r.l Ιtaly-55% Cal από λιπαρά στοιχεία), Chow : δίαιτα ελέγχου Βιοχημικές αναλύσεις: Cholesterol ,Triglycerides ,HDL-cholesterol, Glucose ,Insulin Μετρήσεις μετάλλων και αντιοξειδωτικών παραγόντων: SOD (ερυθρά αιμοσφαίρια ) TAC (ορός αίματος) Zn , Cu (ερυθρά αιμοσφαίρια και ιστός ήπατος) Μεταβονομική ανάλυση και αξιολόγηση λιπιδίων :Εκχύλιση ορού αίματος και ηπατικού ιστού για λήψη Φάσματος 1H-NMR ΣΥΜΠΕΡΑΣΜΑΤΑ 1. Η HF δίαιτα αύξησε σημαντικά ,το τελικό βάρος και τον ρυθμό αύξησης βάρους ,τη χοληστερόλη -CL και την λιποπρωτεϊνη υψηλής πυκνότητας-ΗDL ,την ινσουλίνη –Ins, στα WT & Tg και μείωσε την ολική αντιοξειδωτική ικανότητα-TAC στο πλάσμα και την δραστηριότητα της σουπεροξείδιο-δισμουτάσης-SOD στα ερυθροκύταρα των WΤ και Tg 2. Ο επαρκής διατροφικός Zn (30mg/kgτροφής) φαίνεται να αποτελεί κρίσιμο παράγοντα διαμόρφωσης προστατευτικού ηπατολιπιδαιμικού προφίλ, ποντικών σε υπερλιπιδική δίαιτα. Η αύξηση ή μείωση του Zn σε HFDς φαίνεται να μειώνει την TAC του πλάσματος σε WΤ και Tg ενώ η δραστικότητα της SOD φαίνεται ανάλογη των επιπέδων του Zn Η ανεπάρκεια ή περίσσεια Zn αυξάνει τα αθηρογόνα SFA και μειώνει τα αντι-αθηρογόνα λιπίδια, PC, DU, LA DIAL ,UFA στις HDL, nonHDL και το ήπαρ, στα WΤHFD και στα ΤgHFD 3. Οι HSP70 : Τα διαγονιδιακά ζώα που φέρουν το γονίδιο hHsp70, φαίνεται ότι είτε σε έλλειψη είτε σε περίσσεια Ζn, που συνήθως συνοδεύoνται από μεταβολικό σύνδρομο, κατορθώνουν να διατηρούν καλλίτερους δείκτες λιπιδικού προφίλ σε σχέση με τα WT ζώα. Τα Τg εμφάνισαν σημαντικά χαμηλότερη CL ,TG , HDL σε σύγκριση με τα WT ενώ η HSP70 αύξησε σημαντικά την ενεργότητα της ολικής SOD στα ερυθρά αιμοσφαίρια. Η HSP70 μείωσε τα αθηρογόνα SFA και αύξησε τα αντιαθηρογόνα λιπίδια DIAL, DU, LA, UFA, SM στις HDL, nonHDL , και στο ήπαρ ποντικών που εκτέθηκαν σε HFD και σε όλες τις συγκεντρώσεις Zn. / Zinc –Zn controls lipid and glucose metabolism via Zn-transcription factors. High fat diets –HFDs lead to intracellular free radicals accumulation, decrease the transcriptional expression of their scavengers and anti-oxidative enzymes’ activity leading finally to metabolic syndrome. Heat shock proteins-HSPs play a significant role in cellular resistance response , as an adaptation mechanism, after exposure to various stimuli. SCOPE: To study the effects of nutritional Zn and HSP70s on the metabonomics of serum and liver lipids in mice MATERIALS-METHODS: Male mice: 1. Wild type (Wt) Hybrid (F1/F1) C57Bl/6 x CBA και 2. Transgenic (Tg) human HSP70 overexpressing mice, one month old, were subjected for 10 weeks to the following diets : Diet Number of Wt Number of Tg Chow Diet (30 Zn) 6 10 High Fat Diet (3 Zn) 13 12 High Fat Diet (30 Zn) 9 8 High Fat Diet (300 Zn) 12 12 Composition of the three HF Diets: 3mg, 30mg, 300mg Zn /kg τροφής (mucedoola s.r.l Ιtaly-55% Cal from greasy ingredients),Chow :control diet Biochemical analyses: Cholesterol ,Triglycerides ,HDL-cholesterol, Glucose ,Insulin Metals and antioxidative factors levels: SOD (red blood cells )TAC (blood serum) Zn , Cu (red blood cells and liver tissue) Lipids metabonomics : Blood serum and liver tissue extracts for 1H-NMR spectrum analysis and evaluation CONCLUSIONS 1. HFDiet significantly increased the rate of mice body weight gaining, as well as, cholesterol-CL, high density lipoproteins-HDL, insulin, in WT and Tg mice and decreased plasma total antioxidant capacity-TAC and red blood cell super oxide dismutase –SOD activity , in WT and Tg mice 2.Suficient nutritional Zn (30 mg/kg food) prevails as a crucial modulator of a protective hepato-lipidaemic profil of mice in high fat diet. Zinc deficiency or excessiveness , in HFDiets , decreases plasma TAC in WT and Tg mice, while SOD activity shows proportional to Zn levels. Zinc deficiency or excessiveness increases the atherogenic SFA and decreases the anti –atherogenic lipids : PC, DU, LA DIAL ,UFA, in HDL, nonHDL and liver, in WΤ-HFD and Τg-HFD mice 3. HSP70s : Transgenic mice over-expressing hHsp70 gene and exposed either to Zn deficiency or Zn excessiveness , both driving usually to metabolic syndrome , reveal significantly better lipid profile indicators, comparing to WT mice. Tg mice revealed significantly lower CL , TG , HDL levels compared to WT, while HSP70 in Τg mice significantly increased total SOD activity in red blood cells. HSP70 also decreased the atherogenic SFAs and increased the anti-atherogenic lipids DIAL, DU, LA, UFA, SM in HDL, nonHDL and in the liver of mice exposed to HFDiets and all Zn concentrations