Modulation of macrophage infiltration in brown adipose tissue and white adipose tissue of obese rats : effects of treatment of GLP-1 analogue, DPP-4 inhibitor and physical exercise

Orientador: Mário José Abdalla SaadTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: A obesidade cresce de forma alarmante, sendo considerada uma epidemia mundial. É uma doença multifatorial, na qual fatores genéticos, metabólicos e ambientais (atividade física e dieta) estão envolvidos. Estudos recentes caracterizam a obesidade como uma inflamação sistêmica de baixo grau, que tem como consequência o desenvolvimento da resistência à insulina (RI). A RI está ligada a ativação de serinas quinases (JNK e IKK) e na síntese de citocinas pró-inflamatórias (TNF-? e IL-1?), que podem influenciar na infiltração de macrófagos no tecido adiposo. Em paralelo o tecido adiposo marrom também está envolvido no processo de termogênese e balanço energético corporal. Atualmente, drogas promissoras com efeito análogo aos hormônios incretina, como o análogo de GLP-1 e o inibidor de DPP-4, vem sendo amplamente utilizadas no tratamento da diabetes. Além disso, o exercício físico, que possui ações comprovadamente anti-inflamatórias, pode atuar como tratamento não medicamentoso da epidemia de obesidade. Diante do exposto, o objetivo do trabalho foi avaliar o efeito do exercício físico aeróbico crônico e dos incretinomiméticos, isolada ou associadamente, na resistência à insulina, na infiltração de macrófagos do tecido adiposo branco (TAB) e marrom (TAM) e no fenômeno inflamatório subclínico. Neste estudo, foram utilizados ratos da linhagem Wistar, com 6 semanas de idade, divididos, primeiramente, de acordo com alimentação (dieta hiperlipídica (DH) ou ração padrão): animais controle alimentados com dieta padrão para roedores e água ad libitum (CTL); - os demais animais foram introduzidos em DH e água ad libitum, após 12 semanas de dieta os animais alimentados com DH foram subdivididos em 6 subgrupos: (Veic-S) obesos, sedentários e que receberam solução veículo, (GLP-S) obesos sedentários e tratados com análogo de GLP-1, (DPP-S) obesos, sedentários e tratados com inibidor de DPP-4 (Veic-T) obesos, exercitados e que receberam solução veículo, (GLP-T) obesos, exercitados e tratado com análogo de GLP-1, (DPP-T) obesos, exercitados e tratado com inibidor de DPP-4. Os animais tratados com análogo de GLP-1 receberam injeção subcutânea de liraglutide 100 ?g/Kg, 2 vezes por dia, por 15 dias, os animais tratados com inibidor de DPP-4 receberam 10mg/Kg de vildagliptina via oral, 2 vezes ao dia, por 15 dias e os animais veículo receberam solução veículo (salina ou água potável). O exercício físico realizado foi de natação 1 hora por dia, 5 vezes na semana por 15 dias. Os medicamentos incretinomiméticos e o exercício físico foram eficientes em diminuir os depósitos do tecido adiposo branco na região visceral, o tamanho dos adipócitos tanto no TAB quanto no TAM, além de melhorar a sensibilidade à insulina, de aumentar a fosforilação da AKT, da taxa metabólica e da atividade do TAM. Foram capazes também de diminuir a inflamação além de reduziro número de macrófagos no TAB. O exercício físico por sua vez, diminuiu a quantidade de insulina sérica e promoveu o aumento do número de macrófagos M2 tanto no TAB quanto no TAM. Concluimos que não houve efeito aditivo, sugerindo que tanto o exercício físico quanto os medicamentos incretinomiméticos podem ter ações similares na diminuição da infiltração de macrófagos no TAB e no TAM e na melhora da sensibilidade à insulinaAbstract: Obesity has been growing in a threatening way, being considered a worldwide epidemic. It¿s a multifactorial disease, in which genetic, metabolic and environmental factors are involved (physical activity and diet). Studies characterize obesity as a low-grade systemic inflammation and consequent development of insulin resistance (IR). IR is linked to the activation of serine kinases (JNK and IKK) and pro inflammatory cytokines synthesis (TNF-? and IL-1?), which may influence the macrophages infiltration into adipose tissue. Parallel, the brown adipose tissue is also involved in the thermogenesis process. Currently, promising drugs with similar effect to the incretin hormones such as GLP-1 and DPP-4 inhibitor, has been widely used in the treatment of diabetes. Furthermore, physical exercise, which has proved anti-inflammatory actions, can act as a non-drug treatment for this obesity epidemic. Therefore, this research aimed to evaluate the effects of physical exercises and the incretin mimetics, alone or associated to the IR, in the macrophage infiltration into the white adipose tissue (WAT) and brown adipose tissue (BAT), and also to evaluate the subclinical inflammation phenomenon. Hereing were used Wistar rats, which at 6 weeks of age, were divided, primarily, according to the diet (high fat diet (HFD) or standard diet) CTL; control group was fed with standard diet to rodents and water ad libitum and HFD and the HFD group was fed water ad libitum. After 12 weeks of diet, the HFD group was divided into 6 smaller groups: (Veic-S) obese, sedentary that received vehicle solution; (GLP-S) obese, sedentary, treated with GLP-1 analogue; (DPP-S) obese, sedentary, treated with DPP-4 inhibitor; (Veic-T) obese, exercised that received vehicle solution; (GLP-T) obese, exercised, treated with GLP-1 analogue; (DPP-T) obese, exercised, treated with DPP-4 inhibitor. The animals treated with GLP-1 analogue received subcutaneous Liraglutide, 100 ug/Kg, twice a day, for 15 days; the animals treated with DPP-4 inhibitor received 10mg/Kg of Vildagliptina oral, twice a day; the vehicle group received vehicle solution (saline or potable water). The physical exercise applied was swimming 1 hour per day, 5 times per week for 15 days. As a result, the incretin mimetic drugs and the physical exercises were efficient to decrease the adipose tissue in the visceral region; the size of adipocytes in WAT and BAT improved the insulin sensitivity, increased AKT phosphorylation, metabolic rate, BAT activity and decreased the inflammation and reduced the number of macrophages in the WAT. Physical exercise by itself also decreased the quantity of serum insulin and increased the M2 macrophage number in WAT and BAT. There was no additive effect, suggesting that physical activity as much as incretin mimetic drugs can have similar actions in the decrease of macrophage infiltration in WAT and in the improvement of insulin sensitivityDoutoradoFisiopatologia MédicaDoutora em CiênciasCAPE

Aerobic capacity of wistar rats: the effects of training and physical detraining at middle-aged

It has been shown that engaging in regular physical exercise yields short- and long-term health benefits, primarily by mitigating the risk for cardiovascular disease, but little information is known about physical deconditioning at aging process. The aim of the present study was to analyze the aerobic capacity, through maximal lactate steady state (MLSS), in Wistar rats of different ages (2,4, 6 e 12 months ) and physical conditioning deconditioning responses in middle-aged rats. The results were significant for weight gain in the sedentary (588 ± 71 g) and detraining animals (576 ± 62 g) at 12 months, whereas the conditioned group maintained their original body weights – BW (515 ± 72 g), similar at four (455 ±17 g) and six months of age (471 ± 37 g). MLSS decreased with age (2 months sedentary (8.4 ± 1% Body Weight, 4 months sedentary (6.4 ± 0.6% BW), 6 months sedentary (5.8 ± 1% BW), 12 months sedentary (5.1 ± 0.7% BW), but physical exercise was effective in attenuating the age-related loss of aerobic capacity after 12 months (5.8 ± 1.3% BW). The physical detraining was (5.3 ± 0.4% BW) was similar at 12 months trained. The physical training in long term protected against the increased of the body weight and fat depots caused by aging, but, this effect was found by deconditioning physical. Additionally, the physical training attenuated the aerobic capacity loss due to aging process and this effect was maintained after detraining physical.Tem sido demonstrado que o engajamento em exercícios físicos regulares gera benefícios para a saúde a curto e a longo prazo, principalmente a redução do risco de doença cardiovascular, mas pouco se sabe sobre o destreinamento físico no processo de envelhecimento. O objetivo do presente estudo foi analisar a capacidade aeróbia, através da máxima fase estável de lactato (MFEL), em ratos Wistar de diferentes idades e em resposta ao treinamento e ao destreinamento físico em ratos de meia-idade. Os resultados foram significativos para o ganho de peso corporal no grupo sedentário (588 ± 71 g) e animais destreinados com 12 meses (576 ± 62 g), enquanto o grupo treinado manteve o peso corpo semelhante aosanimais – PC (515 ± 72 g), do grupo de quatro meses (455 ± 17 g) e seis meses de idade (471 ± 37 g). Como medida da capacidade aeróbia, a MFEL diminuiu com a idade (2 meses sedentários (8,4 ± 1% PC), 4 meses sedentários (6,4 ± 0,6% PC), 6 meses sedentários (5,8 ± 1% PC), 12 meses sedentários (5.1 ± 0,7% PC), mas o exercício físico foi eficaz em atenuar a perda da capacidade aeróbia relacionada com a idade, o grupo 12 meses treinados (5,8 ± 1,3% PC) e o grupo destreinado (5,3 ± 0,4% PC) tiveram resultados semelhante na capacidade aeróbia. O treinamento físico de longo prazo protege contra o aumento do peso corporal e o aumento de depósitos de gordura causada pelo envelhecimento. Porém, este efeito foi abolido pelo destreinametno físico. Além disso, o treinamento físico preveniu a diminuição da capacidade aeróbia, devido ao processo de envelhecimento e este efeito foi mantido após destreinamento físico

Exercise and spirulina control non-alcoholic hepatic steatosis and lipid profile in diabetic Wistar rats

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus is associated with metabolic dysfunctions, including alterations in circulating lipid levels and fat tissue accumulation, which causes, among other pathologies, non-alcoholic fatty liver disease (NAFLD).</p> <p>Aim of the study</p> <p>The objective of this study was to analyse the effects of physical exercise and <it>spirulina </it>intake on the control of NAFLD in diabetic Wistar rats.</p> <p>Methods</p> <p>Diabetes was induced in the animals through intravenous administration of alloxan. The rats were divided into four groups: Diabetic Control (DC) - diabetic rats fed with a control diet and no physical exercise; Diabetic <it>Spirulina </it>(DS) - diabetic rats fed with a diet that included <it>spirulina</it>; Diabetic <it>Spirulina </it>and Exercise (DSE) - diabetic rats fed with a diet that included <it>Spirulina </it>and that exercised; and Diabetic Exercise (DE) - diabetic rats fed with a control diet and that exercised.</p> <p>Results</p> <p>The groups DS, DSE, and DE presented lower plasma concentrations of LDL cholesterol than DC, as well as lower levels of total liver lipids in groups DS, DSE, and DE in comparison to DC.</p> <p>Conclusion</p> <p>Thus, <it>spirulina </it>appears to be effective in reducing total circulating levels of LDL-cholesterol and hepatic lipids, alone or in conjunction with physical exercise in diabetic rats.</p

Marcadores da síndrome metabólica e da capacidade aeróbia de ratos (Rattus Norvegicus Albinus, Wistar) em diferentes idades: efeito do exercício

A Síndrome Metabólica, nas últimas décadas, tornou-se um problema de saúde pública ao redor do mundo. Estudos longitudinais em humanos apresentam limitações quanto ao caráter invasivo de certas análises, ao tamanho e à aleatoriedade da amostra. Com isto, modelos animais, capazes de mimetizar as respostas fisiológicas humanas podem auxiliar na investigação desta doença. Nesse contexto, o presente estudo foi delineado para analisar marcadores da Síndrome Metabólica em ratos (Rattus norvergicus), da linhagem Wistar, variação albinus, em diferentes idades. Os animais foram divididos em seis grupos, sendo: Grupo I - foram avaliados aos dois meses (idade jovem), Grupo II – avaliado aos quatro meses (idade adulta jovem), Grupo III – avaliado aos seis meses (idade adulta), Grupo IV – avaliado aos doze meses de idade (maturidade), Grupo V – foram avaliados aos doze meses de idade, porém esses animais foram submetidos a treinamento de natação em tanques individuais na intensidade equivalente à 80% da Máxima fase estável de lactato, 1 hora por dia 5 vezes por semana, o treinamento foi iniciado aos 4 meses de idade e durou até os 12 meses, e o Grupo VI – avaliado aos doze meses de idade e foram submetidos ao mesmo tipo de treinamento do que o Grupo V, porém o treinamento durou dos 4 meses até os 8 meses para que fosse evidenciado os efeitos de destreinamento, após esse período foram mantidos sedentários até os 12 meses quando foram realizadas as análises. Todos os grupos foram analisados quanto à: tolerância à glicose (teste de tolerância à glicose); sensibilidade à insulina (teste de tolerância à insulina); máxima fase estável de lactato (MFEL); concentrações séricas de jejum de glicose, triglicerídeos, colesterol total, HDL-C e LDL-C, captação de glicose pelo músculo sóleo...In recent decades, metabolic syndrome has become a public health problem throughout the world. Longitudinal studies in humans have several limitations due to the invasive nature of certain analyses and the size and randomness of the study populations. Thus, animal models that are able to mimic human physiological responses could aid in investigating metabolic disease. Thus, the present study was designed to analyze metabolic disease markers in albino Wistar rats (Rattus norvegicus) of different ages. The following parameters were assessed at two (young), four (young adult), six (adult), and twelve (mature) months of age: glucose tolerance (glucose tolerance test); insulin sensitivity (insulin tolerance test); fasting serum glucose, triglycerides, total cholesterol, HDL cholesterol, and LDL cholesterol concentrations; glucose uptake in isolated soleus muscle; and total lipid concentration in subcutaneous, mesenteric, and retroperitoneal adipose tissue. We found that aging triggered signs of metabolic syndrome in Wistar rats. For example, mature rats showed a significant increase in body weight that was associated with an increase in the total lipid content in the adipose tissue of evaluated regions. In addition, mature rats showed an increase in the serum concentration of triglycerides, total cholesterol, and LDL cholesterol, which was characteristic of dyslipidemia. There was also an increase in serum glucose compared to the younger groups of animals. Therefore, aging Wistar rats appear to be an interesting model to study the changes related to metabolic syndrome. Thus, it can be concluded that with physical training at submaximal intensities (80% of MLSS) maintained for up to 12 months in mature rats led to important adaptations, such as a decrease in body weight and in total lipid concentration in the mesenteric region, an increase in workload... (Complete abstract click electronic access below

Impacto da nutrição materna sobre a homeostase glicêmica e a capacidade aeróbia da prole

A síndrome metabólica é um mal que, segundo projeções, poderá no ano de 2010, acometer de 50 a 75 milhões de pessoas somente nos Estados Unidos. Dessa forma, é de grande interesse a implementação de procedimentos mais eficazes para prevenção e tratamento desta doença. Uma vez que existem limitações nas pesquisas com seres humanos, torna-se necessário o desenvolvimento de modelos experimentais apropriados ao estudo desta questão. Na busca de um modelo experimental adequado ao estudo do papel do exercício na prevenção e no tratamento da síndrome metabólica, o presente estudo analisou o perfil metabólico e a capacidade aeróbia de ratos mantidos com dieta rica em frutose, substrato que tem sido associado à síndrome metabólica, na vida intra-uterina e pós-natal. Foram utilizadas ratas adultas (90 dias) da linhagem Wistar, alimentadas durante a prenhez e a lactação com dois tipos de dieta: balanceada (AIN-93G) e rica em frutose (60% de frutose). Durante a amamentação, os filhotes foram distribuídos em ninhadas pequenas (4/mãe) ou adequadas (8/mãe). Após o desmame, manteve-se as mesmas dietas até os 90 dias, quando foram analisados: tolerância à glicose (teste de tolerância à glicose), sensibilidade periférica à insulina (teste de tolerância à insulina); capacidade aeróbia (determinação da máxima fase estável de lactato em natação), conteúdo pancreático de insulina; peso e concentração de lipídios totais no tecido adiposo de diferentes regiões e concentrações séricas de glicose, insulina, triglicerídeos, colesterol total, colesterol LDL, colesterol HDL. Constatou-se que a dieta rica em frutose conduziu os animais a resistência à insulina. O grupo FP apresentou dislipidemia, com aumento nas concentrações séricas de colesterol total e triglicerídeos, mostrando que o modelo animal avaliado é potencialmente interessante para o estudo da síndrome metabólica

Higher blood glucose impairs cardiac autonomic modulation in fasting and after carbohydrate overload in adults

This study aimed to assess whether the blood glucose levels influence cardiac autonomic modulation under fasting and after carbohydrate overload conditions. Participants (n = 108) were separated into lower blood glucose and higher blood glucose groups, based on the median (90.5 mg·dL−1) of fasting glucose assessed. The SD2, SDNN, LF indices, and LF/HF increased, and HF decreased after dextrose overload compared with fasting (p < 0.05). Body mass (78.9 vs 69.7 kg), abdominal circumference (90.2 vs 82.2 cm), systolic (113 vs 108 mm Hg) and diastolic (72 vs 67 mm Hg) blood pressure were higher (p < 0.05) in the higher blood glucose group. Heart rate variability (HRV) indices (SD1: 21.0 vs 26.5; SD2: 76.8: vs 86.1; RMSSD: 28.7 vs 37.5; SDNN: 56.1 vs 62.5 ms; pNN50: 10.6 vs 18.9%, HF: 328.4 vs 506.0; LF: 982.8 vs 1259.0 ms2), and the area under the curve of these indices after dextrose overload were lower in the higher blood glucose group (p < 0.05). Additionally, glycemia after dextrose overload was correlated with HRV indices (ρ = –0.216 to −0.273, p < 0.05). Individuals with higher blood glucose, even in the normality range, showed impairment in the cardiac autonomic modulation both at fasting and after carbohydrate overload. Novelty: • Higher fasting blood glucose impairs cardiac autonomic modulation. • Carbohydrate overload impairs cardiac autonomic modulation.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Fructose-rich diet leads to reduced aerobic capacity and to liver injury in rats

The main purpose of this research was to investigate the alterations in the aerobic capacity and appearance of metabolic alterations in Wistar rats fed on fructose-rich diet. We separated twenty-eight rats into two groups according to diet: a control group (C) (balanced diet) and a fructose-rich diet group (F). The animals were fed these diets for 60 d (d 120 to 180). We performed insulin, glucose as well as a minimum lactate test, at d 120 and 180. At the end of the experiment, sixteen animals were euthanized, and the following main variables were analysed: aerobic capacity, the serum aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio, serum and liver triglyceride concentrations, serum and liver thiobarbituric acid reactive substance (TBARS) concentrations, serum and liver catalase and superoxide dismutase (SOD) activity and haematoxylin-eosin histology (HE) in hepatocytes. The remaining twelve animals were submitted to an analysis of their hepatic lipogenic rate. The animals fed a fructose-rich diet exhibited a reduction in aerobic capacity, glucose tolerance and insulin sensitivity and increased concentrations of triglycerides and TBARS in the liver. Catalase and SOD activities were reduced in the livers of the fructose-fed animals. In addition, the serum AST/ALT ratio was higher than that of the C group, which indicates hepatic damage, and the damage was confirmed by histology. In conclusion, the fructose-rich diet caused significant liver damage and a reduction in insulin sensitivity in the animals, which could lead to deleterious metabolic effects.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Muscle glycogen metabolism changes in rats fed early postnatal a fructose-rich diet after maternal protein malnutrition: effects of acute physical exercise at the maximal lactate steady-state intensity

Background: The objective was to evaluate the muscle glucose metabolism in rats fed a fructose-rich diet after fetal protein malnutrition, at rest and after acute physical exercise at maximal lactate steady-state intensity.Methods: The male offspring born of mothers fed on a balanced or low-protein diet were split in four groups until 60 days: Balanced (B): balanced diet during the whole period; Balanced/Fructose (BF): balanced diet in utero and fructose-rich diet after birth; Low protein/Balanced (LB): low-protein diet in utero and balanced diet after birth; Low protein/Fructose (LF): low protein diet in utero and fructose-rich diet after birth.Results: Acute physical exercise reduced the muscle glycogen concentrations in all groups, although the LF group showed higher concentrations at rest. There was no difference among the groups in the glucose uptake and oxidation rates in the isolated soleus muscle neither at rest nor after acute exercise. However, glycogen synthesis was higher in the LF muscle than in the others at rest. Acute physical exercise increased glycogen synthesis in all groups, and the LF group showed the highest values.Conclusion: The fructose-rich diet administered in rats after fetal protein malnutrition alters muscle glycogen concentrations and glycogen synthesis in the rest and after acute exercise at maximal lactate steady-state intensity

Glucose homeostasis in type 1 diabetic rats after acute physical activity

Physical activity is considered an extremely effective therapy in cases of type 1 diabetes (DM-1), as it promotes glucose uptake independent of insulin action. However, there are few studies on the effect of a single session of exercise on glucose uptake in DM-1 (i.e., in the absence of insulin). Therefore, the purpose of this study was to assess the effect of a single exercise session on glucose homeostasis in DM-1 rats. For this purpose, 30 male rats were divided into three groups: sedentary control (SC), sedentary diabetic (SD), and exercise diabetic (ED). DM was induced by administration of alloxan and identified by the value of fasting glucose. The physical activity consisted of a single swimming session at the anaerobic threshold intensity for diabetic rats (3.5% body weight overload) for 30 min. The oral glucose tolerance test (OGTT) was performed immediately after the physical activity. The animals were sacrificed 48 hr after the OGTT, and samples were taken from the blood, liver, gastrocnemius, and mesenteric and subcutaneous adipose tissue. We observed that DM caused significant reduction in body weight. A single session of physical activity did not modify the response to the OGTT or glucose. However, it resulted in increased HDL cholesterol and hepatic glycogen content. These results suggest that, despite not having an effect on glucose homeostasis, acute physical activity performed at anaerobic threshold intensity leads to beneficial changes in the context of type 1 diabetes