Atualmente, a obesidade pode ser classificada como uma pandemia. Com a clonagem do gene ob e do seu receptor, foi descoberta a leptina. Secretada principalmente pelo tecido adiposo, está diretamente correlacionada à quantidade de gordura corporal. Entretanto, diversos fatores influenciam sua expressão e síntese, tais como jejum, atividade simpática, exercício físico e alterações no balanço energético. Os efeitos do treinamento aeróbio sobre este hormônio são ainda contraditórios. Desta forma, este estudo teve como objetivo a verificação dos efeitos do treinamento aeróbio nas concentrações plasmáticas de leptina. Ratos Wistar machos foram divididos em dois grupos: treinado (T) e controle (C). Não houve diferença na ingestão energética e no gasto energético de repouso. Ratos treinados apresentaram menor peso corporal final, conteúdo de gordura corporal, insulinemia e melhora na resposta glicêmica. Houve maior expressão do mRNA da leptina no tecido adiposo visceral do que no subcutâneo nos dois grupos. Não houve, entretanto, diferença na expressão da leptina entre os grupos em ambos os depósitos. A menor concentração de leptina plasmática nos animais treinados ocorreu, principalmente, devido ao menor conteúdo de gordura corporal deste grupo. No entanto, após a correção da concentração de xiii leptina pelo conteúdo de gordura corporal, ainda foi observada diferença significativa entre os grupos, sugerindo que exista(m) outro(s) fator(es) de modulação das concentrações de leptina após o treinamento aeróbio, sendo a principal candidata a tal regulação a insulina / Obesity currently qualifies as a worldwide health epidemic. With the cloning of mouse ob gene and its receptor leptin was discovered. Leptin is expressed and secreted primarily by adipose tissue and is highly correlated to body fat mass. Nevertheless many factors can regulate leptin synthesis and expression, such as fasting, sympathetic activity, insulin, exercise and changes in energy balance. Endurance training effects on leptin are still contradictory. Therefore the aim of the present study was to verify the effects of endurance training on leptin levels. Male Wistar rats were separated in two groups: trained (T) and sedentary control (C). Energy intake and basal energy expenditure were not different between groups. Trained rats had lower final body weight, body fat mass, insulin levels and improved glycemic response. Leptin mRNA expression was higher in visceral than in subcutaneous adipose tissue in both groups. However, no difference in leptin expression between groups in either fat depot was found. Lower leptin levels in trained rats were due primarily to their lower body fat mass. Nonetheless, after correction for body fat mass leptin levels were still lower in exercised rats, suggesting that there might be other regulators of leptin levels in response to endurance training, being insulin the main candidate for such role

A aplicação terapêutica de Células Tronco (CT) em equinos é um campo emergente. Nestes animais, as CT são promissoras para o tratamento de lesões nos tendões e rupturas de ligamentos. Apesar das características e do potencial na restauração de tecidos lesionados, bem como dos efeitos parácrinos destas células, não existem dados a respeito do seu uso no tratamento de desordens sistêmicas que podem acometer os equinos, tais como a endometrose. A endometrose é uma doença progressiva e irreversível que leva a degeneração do endométrio e a formação de um tecido fibroso periglandular, sendo de grande relevância na medicina veterinária, por ser uma das maiores causas de infertilidade. Apesar dos constantes avanços na busca de um tratamento, nenhum obteve sucesso. Levando-se em consideração a importância da doença, o objetivo deste projeto foi utilizar CT, previamente isoladas e caracterizadas pelo nosso grupo, no tratamento da endometrose, visando diminuir o processo inflamatório e a formação do tecido fibroso periglandular. Seis éguas com endometrose foram sincronizadas. Em quatro foram infundidas CT previamente marcadas com Vybrant, e nas outras duas (controle) apenas solução fisiológica. Antes da infusão, foram coletadas biópsias uterinas e amostras para citologia. Após 7, 21 e 61 dias da infusão, foram coletadas novas biópsias e amostras citológicas. Por meio da fluorescência direta observamos a presença das CT marcadas enxertadas tanto no corpo quanto nos cornos uterinos das éguas. Através de análises histológicas observamos uma significativa melhora no aspecto morfológico e na organização do tecido uterino, bem como, das glândulas endometriais, após a infusão das CT, tal resultado foi observado progressivamente ao longo dos dias. Notamos também uma diminuição no processo de fibrose do tecido periglandular. As análises de citologia demonstraram a ausência de inflamação uterina antes e após a infusão das CT. Nossos dados sugerem que existem benefícios na utilização de CT de tecido adiposo de equinos no tratamento do tecido uterino acometido pela endometrose, que clinicamente só poderão ser validados após a prenhez desses animais. / In horses, Stem Cell (SC) therapies are a promising tool to the treatment of many injuries, as tendon lesions and ligaments rupture. Besides the characteristics and the potential in tissue restoration, as well as, paracrine effects of SC, there is no information about the use of them for the treatment of systemic disorders which can commit horses, such as endometrosis. Endometrosis is a progressive and irreversible disease which is defined as active or inactive periglandular and stromal endometrial fibrosis, including glandular alterations within fibrotic foci. Modifications induced by this disease alter the surface of endometrium which, in consequence, led to infertility. Conventional treatments do not reduce the fibrotic process or even help to restore fertility. Considering the importance of this disease, the goal of this project is to use SC, previously isolated and characterized by our group, in the treatment of endometrosis, in order to reduce inflammatory process and periglandular fibrous tissue formation, typical of this disease. Six mares with confirmed endometrosis were synchronized for the use as animal model in this work. In four of animals we infused stem cells previously marked with Vybrant, and the other two (control group) were infused with saline solution. Before the infusion, uterine biopsies and also samples for cytology were collected. After 7, 21 and 61 days of cells infusion new biopsies and cytology samples for analysis were collected. We observed, by direct fluorescence, the presence of marked cells grafted in both body and uterine horns of treated animals. Through histological analysis we observed a significant improvement in morphology and organization of uterine tissue, as well as endometrial glands, after infusion of stem cells, this result was observed progressively throughout the days. Furthermore, we noted a decrease in the process of periglandular tissue fibrosis, after infusion of cells. Cytology analysis showed that the animals have no uterine inflammation before or after infusion of SC. Our data suggest that there are benefits of using stem cells from equine adipose tissue in the treatment of uterus tissue affected by endometriosis, which can only be clinically validated after pregnancy of these animals.

Atherosclerotic cardiovascular disease is a leading cause of death worldwide. Dysregulation of vascular redox state plays a crucial role in the atherosclerotic process. Increased production of vascular superoxide (O2·-) and other reactive oxygen species (ROS) leads to endothelial dysfunction, a key early step in atherogenesis. Adipose tissue is a source of vasoactive, hormone-like molecules which are termed adipokines. One of the most important adipokines is adiponectin. Adiponectin has been shown to have antioxidant, anti-atherosclerotic effects in cell culture studies and animal models. However, its role in human cardiovascular disease has not been extensively investigated. More specifically, its effects on the human vascular wall and the mechanisms regulating its synthesis in adipose tissue have not been studied before in humans. The aim of my thesis is to explore the role of adiponectin in human atherosclerosis. This was achieved through use of the Oxford CABG Bioresource: a well-phenotyped cohort and tissue bank of patients undergoing cardiac surgery. By employing a range of in vivo and ex vivo techniques, I demonstrate for the first time in humans that adiponectin has direct antioxidant effects in the vascular wall, by directly suppressing pro-oxidant vascular enzymes and restoring redox balance. These effects persist in type 2 diabetes, presence of which is linked to reduced circulating adiponectin levels. Indeed, a variety of stimuli affect adiponectin synthesis in human adipose tissue, with brain natriuretic peptide being a major driver of adiponectin synthesis. However, different adipose tissue depots demonstrate diverse responses to stimuli affecting adiponectin synthesis, owing to their functional and morphological differences. Of particular interest is the fact that synthesis of adiponectin in perivascular adipose tissue is driven by the oxidative stress status of the underlying vessel. This observation led me to document for the first time in humans the existence of a reciprocal, two-way interaction between perivascular adipose tissue and the vascular wall: high vascular oxidative stress leads to release of factors with the ability to up-regulate adiponectin expression in perivascular adipose tissue, acting as a local paracrine defence mechanism attempting to restore vascular redox state. My thesis provides proof-of-concept for this novel cross-talk between adipose tissue and the vascular wall. This can have significant impact in designing new therapeutic strategies against atherosclerosis.

Background: The incidence of coronary heart diseases, including atherosclerosis, increases with ageing. The factors which influence arterial function, and which may be changed with ageing, are multiple but effects of perivascular adipose tissue (PVAT) on large arteries have not previously been considered. A key role for nitric oxide (NO) in mediating the anti-contractile capacity of PVAT has been suggested. Caveolin-1 (Cav-1) modulates the production of NO in vivo by tonic inhibition of eNOS. The influence of aortic PVAT and the contribution of NO to vascular reactivity in ageing C57BL/6 mice, atherosclerotic ApoE knockout mice (ApoE-/-), Cav-1 knockout mice (Cav-1-/-) and atheroprotected ApoECav-1 double knockout mice (ApoE-/-Cav-1-/-) is unknown. Hypothesis: The influence of PVAT on vascular function is modulated by ageing and the development of atherosclerosis via NO bioavailability. Methods: Male mice were used in this study. C57BL/6 mice were obtained at 4 weeks of age and maintained on a normal rodent diet (ND) for 8, 16 or 26 weeks. ApoE-/- and Cav-1-/- mice were bred from in-house colonies and ApoE-/-Cav-1-/- mice were generated by interbreeding ApoE-/- and Cav-1-/- mice. Upon weaning, ApoE-/-, Cav-1-/- and ApoE-/-Cav-1-/- mice were maintained on either a ND or Western-type diet (WD) for 8, 16 or 26 weeks. Vascular reactivity studies on isolated aortic ring preparations were performed in the presence or absence of PVAT. The contribution of NO to the vascular reactivity of aortic PVAT was determined using pharmacological inhibition of NO synthase. Aortic PVAT was assessed for evidence of morphological and/or compositional changes associated with ageing or a WD. Results: NO mediated an anti-contractile effect of aortic PVAT in C57BL/6 mice fed a ND up to 16 weeks. The anti-contractile capacity of aortic PVAT was lost after 26 weeks on a ND and preceded endothelial dysfunction. Loss of the PVAT anti-contractile effect was accompanied by alterations in PVAT morphology and composition. Aortic PVAT from ND-fed ApoE-/- mice was dysfunctional and did not exert an anti-contractile effect. Furthermore, a WD did not alter the influence of PVAT on vascular reactivity in ApoE-/- mice and PVAT morphology and composition was unchanged. NOS inhibition did not alter the contractile responses. The aortic PVAT of ND-fed Cav-1-/- mice did not exert an anti-contractile effect and PVAT composition was unchanged with increasing age. However, after 26 weeks on a WD, aortic PVAT from Cav-1-/- mice potentiated contractions to phenylephrine and white adipocyte hypertrophy was observed. NOS inhibition revealed a pro-contractile effect of aortic PVAT from Cav-1-/- mice. Loss of Cav-1-/- conferred significant protection against the development of atherosclerosis in WD-fed ApoE-/-Cav-1-/- mice despite a proatherogenic lipid profile. Aortic PVAT from ND-fed ApoE-/-Cav-1-/- mice did not exhibit an anti-contractile capacity and PVAT morphology was unchanged with ageing. Additionally, a WD did not influence the effect of PVAT on vascular reactivity in ApoE-/-Cav-1-/- mice although white adipocyte hypertrophy was observed after 26 weeks of high fat feeding. NOS inhibition revealed a pro-contractile effect of aortic PVAT in 8-week ND-fed ApoE-/-Cav-1-/- mice. Conclusions: This work has produced novel insights into the influence of aortic PVAT and NO on vascular reactivity and the morphology of aortic PVAT in ageing C57BL/6 mice, atherosclerotic ApoE-/- mice, Cav-1-/- mice and athero-protected ApoE-/-Cav-1-/- double knockout mice. Ageing to pre-middle age in C57BL/6 mice results in a loss of the anti-contractile effect of PVAT prior to endothelial dysfunction. This is associated with altered NO bioavailability and changes to the morphology and composition of PVAT. This may reveal potential therapeutic targets to restore the anti-contractile capacity of PVAT if comparable age-related PVAT dysfunction is observed in humans. Aortic PVAT of ApoE-/- mice does not exert an anti-contractile effect which may be attributed to decreased basal eNOS activity. A WD does not alter the vascular reactivity of PVAT. In addition, aortic PVAT from Cav-1-/- mice does not exhibit an anti-contractile capacity yet it exerts a pro-contractile effect after 26 weeks on a WD. The aortic PVAT of ApoE-/-Cav-1-/- mice does not modulate vascular reactivity and this is unaltered with feeding of a WD although white adipocyte hypertrophy was observed within the PVAT. The critical role of Cav-1 in the initiation and progression of atherosclerosis is reinforced by the atheroprotected phenotype of the ApoE-/-Cav-1-/- mice even though a severely proatherogenic lipid profile is observed in both the ND and WD-fed mice. Therapeutically targeting LDL transcytosis into the arterial wall could potentially prevent or halt the development of atherosclerosis. Aortic PVAT of ND-fed Cav-1-/- and ApoE-/-Cav-1-/- mice may not be dysfunctional but unable to modulate vascular reactivity due to attenuated vasoconstrictor responses of PVAT-denuded aortic rings as a result of excess NO, although this requires further investigation.

O peso corporal dos animais tende a ser relativamente estável durante longos períodos de tempo. Situações de restrição calórica ou aumento na ingestão de calorias levam a alterações fisiológicas compensatórias que resistem aos efeitos destas perturbações. De fato, o gasto energético aumenta em animais submetidos à dieta hipercalórica, a chamada termogênese facultativa, de modo a manter os estoques energéticos constantes. É possível que defeitos na termogênese facultativa estejam envolvidos no desenvolvimento da obesidade. O BAT, o principal sítio de termogênese facultativa, é ativado pela liberação de NE pelo Sistema Nervoso Simpático, que se liga aos receptores adrenérgicos b1, b2 e b3 expressos nos adipócitos marrons. Diversos estudos demonstram que os receptores b são importantes na proteção contra a obesidade, mas ainda não é claro qual o papel de cada isoforma neste processo. Assim sendo, o objetivo do nosso trabalho foi avaliar o papel das isoformas b1 e b2 na mediação da termogênese facultativa induzida pela dieta. Para tanto, nós tratamos camundongos com nocaute para o receptor adrenérgico b1 (KOb1) e camundongos com nocaute para o receptor b2 (KOb2) com dieta hipercalórica por 22 semanas. O peso corporal foi medido diariamente e o consumo de oxigênio foi determinado usando-se um sistema de respirometria aberto ao final do experimento. A composição corporal foi determinada pela análise da carcaça. Animais foram expostos ao frio de 4ºC por 4h e sua temperatura corporal foi medida em vários tempos e a resposta térmica do iBAT foi determinada pela infusão de NE ou agonista b adrenérgico. Além disso, foram determinados os níveis de RNAm das isoformas de receptores adrenérgicos b nos animais nocaute. Os resultados obtidos em nosso estudo mostram que os animais KOb1 e KOb2 tratados com dieta hipercalórica não desenvolvem obesidade mais severa do que os animais selvagens mas não são capazes de aumentar o consumo de oxigênio induzido pela dieta, sugerindo que estes receptores não são relevantes na termogênese induzida pela dieta. Por outro lado, nossos dados indicam que a presença do receptor b1 é exigida para termogênese induzida pelo frio, uma vez que os camundongos KOb1 são sensíveis ao frio e a capacidade termogênica do BAT destes animais em reposta à NE é bastante reduzida quando comparados com animais selvagens. A ausência do receptor b2 não piora a resposta dos animais ao frio sugerindo que esta isoforma não esteja envolvida na termogênese induzida pela dieta ou pelo frio. Os nossos achados indicam que a isoforma do receptor adrenérgico b1 é fundamental na termogênese induzida pelo frio, mas não pela dieta. Além disso, é provável que a termogênese induzida pela dieta seja regulada por mecanismos distintos da termogênese induzida pelo frio. / The body weight of animals tends to be relatively stable over long periods of time. Situations of caloric restriction or increase in intake of calories lead to compensatory physiological changes that resist the effects of these disorders. In fact, the energy expenditure increases in animals treated with diet hypercaloric called facultative thermogenesis, in order to keep to energy stock constant. Defects in this facultative thermogenesis may be related to the development of obesity. Brown adipose tissue is the main site of facultative thermogenesis and is activated by signaling of b1, b2 e b3 adrenergic receptors by Norepinephrine released by Sympathetic Nervous System. Several studies showed that the isoforms b of adrenergic receptors are important in mechanisms involved in obesity and also in promoting cold tolerance. Nonetheless, it is unclear the role of each isoform in these process. Therefore, the purpose of our study was to evaluate the role of isoforms b1 and b2 in mediate the facultative thermogenesis. For that, we fed nocaute mice for the adrenergic receptor b1 (KOb1) and nocaute mice for the adrenergic receptor b2 (KOb2) with high fat diet for 22 weeks. During treatment body weight was determined daily. By the end of the experiment oxygen consumption was measured using a system of open respirometry and body composition was determined by analysis of the carcass. We also exposed KOb1 and KOb2 animals to cold (4C). The thermogenic response of iBAT was evaluated through i.v NE infusion. The results obtained in our study showed that the animals KOb1 and KOb2 treated with high fat diet did not gain more fat when compared to wild type animals, but are unable to increase the oxygen consumption, suggesting that these receptors are not relevant in development of obesity. Furthermore, our data indicate that the presence of the b1 receptor is required for cold-induced thermogenesis, since the KOb1 mice are sensitive to cold and BAT thermogenic response is significantly impaired when compared with animals wild type. The absence of b2 receptor does not worsen the response of animals to cold suggesting that this isoform is not involved in the diet- or cold- induced thermogenesis. In conclusion, our findings indicate that the b1 isoform of the adrenergic receptor is critical in the cold-induced thermogenesis, but not in diet induced thermogenesis. Moreover, it is likely that the diet-induced thermogenesis and cold-induced thermogenesis are regulated by different mechanisms.

Introdução: O número de indivíduos com sobrepeso e obesidade está aumentando, e a busca por entender mecanismo relacionados a esta doença se mostram cada vez mais importantes. O gene FTO foi o primeiro gene associado à obesidade, mas não se sabe muito a respeito de como é regulado e suas vias. MiRs são pequenos RNAs regulatórios que podem estar associados à obesidade, como também na regulação do gene FTO. Dessa forma, pretendemos identificar a relação do gene FTO e do hsamir-150 com sobrepeso/obesidade, perfil lipídico e glicemia de jejum. Métodos: Homens e mulheres (18 anos ou mais), com IMC > 25 kg/m2 participaram do presente estudo e foram analisadas a expressão do gene FTO, expressão do mir-150, parâmetros bioquímicos do sangue e antropometria. Resultados: Observamos a expressão do gene FTO estar relacionada à obesidade, LDL e glicemia de jejum. Conclusão: O gene FTO parece de fato estar relacionado à obesidade, LDL e glicemia de jejum, diferentemente do mir-150 / Introduction: The overweight population is growing in the entire world, and the search for obesity-associated mechanisms is important for a better understanding of this disease. The FTO gene was the first obesity associated gene. Otherwise, its pathways and how it can be regulated remain unknown. MiRs are small no coding RNAs that may be associated to obesity and FTO gene regulation. Thus, the aim of this study was to verify the relationship among the FTO gene and the mir-150 expression with overweight/obesity lipid profile and fast blood glucose. Methods: Men and woman (18 years older or above), with body mass index > 25 Kg/m2, were enrolled in the present work and the FTO gene and mir-150 expression, biochemical parameters of blood and anthropometric measure were analyzed. Results: The results highlight that the FTO gene expression is associated to obesity, LDL and fasting blood glucose. Conclusion: Indeed, the FTO gene seems to be related to obesity, LDL and blood fasting glucose, differently of the mir-150

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Ingestão precoce de dieta enriquecida com óleo de peixe reverte alterações bioquímicas, hepáticas e do tecido adiposo na prole de camundongos submetidos à restrição protéica. 2010. 61 f. Dissertação (Mestrado em Biologia Humana e Experimental) Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, 2010. Estudos relacionam obesidade na vida adulta com baixo peso ao nascer (programação metabólica). O fígado é um dos órgãos mais afetados pela programação. O óleo de peixe é rico em ácidos graxos poli-insaturados (AGP) da família n-3: ácido eicosapentaenóico (EPA) e docosahexaenóico (DHA). O EPA e DHA são relacionados com redução da pressão arterial sistólica e ação anti-inflamatória. Testar a hipótese que a ingestão precoce de óleo de peixe (FO) pode reverter os efeitos deletérios da programação na prole adulta de camundongos. Fêmeas grávidas foram alimentadas com ração padrão (SC) ou dieta restrita em proteínas (LP) durante a gestação e lactação. Ao desmame, os seguintes grupos foram formados (de acordo com a suplementação com FO): SC-SC e SC-FO, LP-SC e LP-FO. Foram aferidas massa corporal, ingestão e eficiência alimentar, pressão arterial sistólica (PAS), insulina plasmática, glicose, fator de necrose tumoral (TNF)-alfa, colesterol total (CT), triglicerídeos (TG) e alanina aminotransferase (ALT), morfometria dos adipócitos, estereologia do fígado e expressão proteínas SREBP-1c e PPAR-alfa. A prole LP apresentou maior massa corporal, hipercolesterolemia e hiperglicemia Na idade adulta, os animais restritos tornaram-se hipertensos, com esteatose hepática e elevado nível da SREBP-1c. Entretanto, a prole LP com dieta suplementada com FO ocasionou menor ganho e menor massa corporal final. A dieta FO melhorou o metabolismo lipídico, diminuiu a concentração plasmática de CT e TG, reduziu a massa adiposa e o tamanho dos adipócitos. Além disso, LP-FO mostrou níveis reduzidos da ALT, redução da esteatose hepática, baixa expressão da SREBP-1c e aumento da expressão do PPAR-alfa, além de redução da PAS e dos níveis de TNF-alfa. A dieta com FO teve efeitos benéficos revertendo as respostas da programação sobre o metabolismo da glicose e lipídios, estrutura hepática e tecido adiposo na prole adulta programada. / Studies related obesity in adult life with malnutrition in early life, called metabolic programming. The liver seems to be one of the most affected by fetal programming. Fish oil is rich in polyunsaturated fatty acids (PUFA) of n-3 family: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are related with several biological reactions, like systolic blood pressure reduction and anti-inflammatory properties. We hypothesized that early fish oil (FO) intake would revert the programming responses in adult offspring. Pregnant mice were fed either standard chow (SC) or low-protein diet (LP) throughout pregnancy/lactation. At weaning, the following groups were formed (FO means supplemented with fish oil): SC-SC and SC-FO, LP-SC and LP-FO. We measured body mass, food intake, feed efficiency, blood pressure (BP), levels of plasma insulin, glucose, tumor necrosis factor (TNF-alpha), total cholesterol (TC), triglycerides (TG) and alanine aminotransferase (ALT). We also measured adipocyte morphometry, liver stereology and expression of the SREBP-1 and PPAR-alpha proteins.The LP offspring are predisposed to becoming fat, hypercholesterolemic and hyperglycemic. In addition, during adulthood, they become hypertensive with hepatic steatosis and had high level of SREBP-1. However, LP offspring that were fed FO-enriched diet had decreased body mass gain and lower final body mass. In addition, with FO diet, these mice have improved lipid metabolism with decrease in plasma TC and TG levels, reduced fat pad masses and adipocyte size. Furthermore, LP-FO offspring show low ALT level, reduced liver steatosis with low SREBP-1 protein expression and high PPAR-alpha expression, and improvement of BP and TNF-alpha level. Early fish oil intake has beneficial effects reversing the programming responses that control body mass, glucose and lipid metabolism, and liver and adipose tissue structure in adult programmed offspring.

Une série d’études récentes chez l’homme et dans les modèles murins a conduit à la mise en évidence d’une réponse immune, qui met en jeu des cellules de l’immunité innée et de l’immunité adaptative dans le tissu adipeux (TA) obèse. Nous avons mis en évidence un dialogue pro-inflammatoire entre les macrophages et les LT CD4+ dans le TA humain obèse mettant en jeu l’IL-1β, l’IL-17 et l’IL-22. Le pourcentage de Th17 est positivement corrélé au % d’HbA1c. De plus, la sécrétion des cytokines impliquées dans cette boucle pro-inflammatoire diminuent après une perte de poids induite par la chirurgie bariatrique. Par la suite, nous avons montré que l’IL-1β et l’IL-17 induisent des programmes transcriptionnels pro-inflammatoires concordant dans trois types de cellules non-immunitaires du TA, les pré-adipocytes, les cellules endothéliales et les adipocytes, et diminuent les gènes du métabolisme dans les adipocytes. Les effets d’IL-1β sont nettement plus prononcés que ceux de l’IL-17. Le milieu conditionné de cellules immunitaires CD45+ reproduit les réponses pro-inflammatoire et catabolique induites par les cytokines recombinantes dans les adipocytes, et ces réponses sont inhibées après la neutralisation de l’IL-17 et l’IL-1β. Ces résultats démontrent une implication pathologique de l'IL-1β et de l'IL-17 dans les altérations du TA induites par l'obésité. / A series of recent studies in humans and mouse models has led to the detection of an immune response, which involves cells of the innate immunity and adaptive immunity in obese adipose tissue (AT).We highlighted a proinflammatory crosstalk between macrophages and CD4+ T cells in obese human AT involving IL-1β, IL-17 and IL-22. Percentage of Th17 is positively correlated with HbA1c %. Moreover, the secretion of the cytokines implicated in this proinflammatory loop decreased after weight loss induced by bariatric surgery.Subsequently, we have shown that IL-1β and IL-17 induce proinflammatory transcriptional programs in three types of non-immune cells of the TA, preadipocytes, endothelial cells and adipocytes , and decrease metabolism genes in adipocytes. IL-1β effects are much more pronounced than those of IL-17. The conditioned medium of CD45+ immune cells reproduces the pro-inflammatory and catabolic responses induced by the recombinant cytokines in adipocytes, and these responses are inhibited after the neutralization of IL-17 and IL-1β.These results demonstrate a pathological involvement of IL-1β and IL-17 in the AT dysfunction induced by obesity.

O objetivo deste trabalho foi o de averiguar se o exercício físico somado a suplementação com melatonina em animais pós-púberes, modifica a adiposidade e a regulação da atividade lipolítica, nos tecidos adiposos das regiões subcutânea inguinal e retroperitoneal, além de verificar possíveis efeitos antigonadotróficos decorrentes do tratamento com melatonina. A concomitância do treinamento físico e da suplementação com melatonina durante 8 semanas em ratos Wistar, foi mais eficiente em promover reduções no diâmetro dos adipócitos e, consequentemente, na adiposidade do que o uso isolado do treinamento físico ou da suplementação com melatonina. Entretanto, não foram observadas alterações na atividade lipolítica, e nem na lipogênese, medidas em adipócitos isolados das regiões estudadas. A suplementação promoveu hipogonadismo com consequente redução da testosteronemia, além de uma redução da massa do músculo extensor digital longo. evidenciando assim a necessidade de se aprofundar os estudos sobre os impactos do uso de melatonina sobre o eixo hipófise-hipotálamo-gônadas. / Hence, the purpose of this study was to investigate whether the physical exercise plus supplementation with melatonin in postpubertal animals modify adiposity and regulation of lipolysis in the inguinal subcutaneous and retroperitoneal adipose tissues, away from assessing the possible antigonadotropic effects resulting from melatonin treatment. The concomitance of physical training and melatonin supplementation for 8 weeks in rats were more efficient in promoting reductions in adipocyte size and hence in adiposity than physical training or melatonin supplementation alone. However, no changes were observed in lipolysis or in lipogenesis, measured in isolated adipocytes from investigated the fat depots. We also showed that, even at this low dose, melatonin promoted hypogonadism with consequent reduction of the testosteronemia and a reduction in extensor digitorum longus muscle mass, thus evidencing that further studies on the impacts of the use of melatonin the hypothalamic-pituitary-gonadal axis are actually needed.

A hiperglicemia crônica no diabetes está relacionada com distúrbios nas vias de sinalização da insulina e do mTOR, e com o desbalanço na secreção de adipocinas pelo tecido adiposo branco (TAB). Em longo prazo, esta disfunção metabólica pode causar uma perda severa de massa adiposa, o que agrava a resistência à insulina (RI). Estudos têm destacado o potencial efeito da suplementação com leucina no tratamento de doenças metabólicas como o diabetes tipo 2 e obesidade. No entanto, os efeitos da leucina sobre a homeostase glicêmica e a sensibilidade à insulina em doenças em que ocorre perda severa de gordura ainda necessitam melhores esclarecimentos. Portanto, foi investigado se a suplementação crônica com leucina pode afetar a adiposidade de ratos diabéticos com perda intensa de TAB, e melhorar a RI e outras desordens metabólicas relacionadas com TAB. Ratos recém-desmamados foram distribuídos em 3 grupos: i) Grupo controle (C) - não diabético e recebiam ração controle; ii) Grupo diabetes (D) - diabético e recebiam ração controle; iii) Grupo diabetes Leucina (DL) - diabético e recebiam ração suplementada com 5% de L-leucina. Após 8 semanas, foram analisados: glicemia e insulinemia de jejum, HOMAIR, citocinas pro- e anti-inflamatórias no soro e tecido adiposo branco, expressão de proteínas (mTOR, p-MTOR, p70S6K1, p-p70S6K1, PPAR&#947, C/EBPα, ACC1, FAS, AKT, p-AKT) nos tecidos adiposos subcutâneo (SC) e retroperitoneal (RP), bem como a expressão de RNAm da adiponectina e leptina no TAB. In vivo, foram realizados testes de tolerância oral à glicose (OGTT) e de sensibilidade à insulina (ITT), glicemia pós prandial e consumo de ração. O tratamento crônico com leucina reverteu a perda de massa adiposa dos coxins subcutâneo e viscerais neste modelo experimental, o que pode ser explicado pelo aumento da expressão da p-p70S6K1, PPARγ, ACC1 e FAS, proteínas que estimulam a adipogênese e lipogênese de novo nos adipócitos. Além disso, houve um aumento da expressão de AKT total no coxim SC no grupo DL, mas não foi alterada no coxim RP, indicando que a leucina também pode melhorar a resistência à insulina por ativar a AKT, que é considerada enzima limitante da cascata de fosforilação da insulina. Por outro lado, a leucina melhorou o perfil de adipocinas secretadas pelo coxim RP, pois aumentou a secreção de adiponectina e IL-10. Estas citocinas, direta ou indiretamente, reduzem a RI em tecidos como fígado, TAB e músculo esquelético. Isto sugere que a ação da leucina sobre a sensibilidade à insulina no coxim subcutâneo parece estar mais relacionada com a recuperação da via de sinalização da insulina, ao passo que, no coxim RP está indiretamente relacionada com a melhora do perfil de adipocinas secretadas por este tecido. Estes dados corroboram com os resultados de HOMAIR, glicemia de jejum e pós prandial, OGTT e ITT, nos quais foi observada uma significativa melhora do quadro de intolerância à glicose e resistência à insulina em ratos diabéticos tratados com leucina. Em conclusão, a suplementação crônica com leucina aumentou a adiposidade corporal em ratos diabéticos induzido por estreptozotocina no período neonatal, o que foi relacionado com a melhora da intolerância à glicose e da resistência à insulina. Isto demonstra que a recuperação trófica do tecido adiposo branco é fundamental para a melhora dos distúrbios metabólicos relacionados ao metabolismo da glicose neste modelo experimental. / The chronic hyperglycemia in diabetes is associated with disturbances in insulin and in mTOR pathways, and changes in adipokine secretion in white adipose tissue (WAT). Long-term, this metabolic dysfunction can cause a severe loss of fat mass, which increases insulin resistance (IR). Studies have highlighted the effect of leucine supplementation in treatment of metabolic diseases as type 2 diabetes and obesity. However, the effects of leucine on glucose homeostasis and insulin sensitivity in diseases with intense fat loss remain unknown. Therefore, was investigated whether chronic leucine supplementation can affect the adiposity of diabetic rats with severe adipose tissue loss, and to improve the IR and other metabolic disorders associated with WAT. After weaning, rats were distributed in 3 groups: i) control group (C) - no diabetic and received control chow ; ii) diabetes group (D) - diabetic and received control chow; iii) Leucine Diabetes Group (DL) - diabetic and received diet supplemented with 5% L-leucine. After 8 weeks, were analyzed: fasting glycaemia and insulin, HOMA>IR, antiinflammatory and proinflammatory cytokines in serum and in WAT, protein expression of mTOR, p-MTOR, p70S6K1, p-p70S6K1, PPARγ, C/EBPα, ACC1, FAS, AKT, p-AKT in subcutaneous (SC) and retroperitoneal adipose tissue, as well as the RNAm expression of adiponectin and leptin in WAT. In vivo, were realized oral glucose tolerance test (OGTT) and insulin sensitivity test (ITT), postprandial glycaemia and chow ingestion. O chronic treatment with leucine recovered the adipose mass in subcutaneous and visceral fat pad in this experimental model, this was explicated by increase of protein expression of p-p70S6K1, PPARγ, ACC1 and FAS that stimulate the adipogenesis and de novo lipogenesis in adipocytes. Moreover, had an increase of protein expression of total AkT in subcutaneous fat pad in group DL, but don\'t change in RP fat pad, indicating that the leucine can to activate the AKT, which is limiting enzyme of phosphorylation cascade of insulin, and improve the insulin resistance. On the other hand, leucine improved the profile of adipokines secreted in RP fat pad, because increased the secretion of adiponectin and IL-10. This cytokines reduced the insulin resistance in tissues as liver, WAT and skeletal muscle. This suggest that action of leucine on insulin sensitivity in subcutaneous fat pad is more related to recovery of insulin signaling, and in RP fat pad is indirectly related to improve of profile of adipokines secretion in this tissue. This data corroborates with results of HOMAIR, postprandial and fasting glycaemia, OGTT and ITT, which showed significant improve of glucose intolerance and insulin resistance in diabetic rats treated with leucine. In conclusion, the chronic leucine supplementation increased adiposity in streptozotocin-induced diabetic rats in neonatal period, which was related to improve of glucose intolerance and insulin resistance. This show that trophic recovery of white adipose tissue is important for improve of metabolic disturbances related to glucose metabolism in this experimental model.