RESUMO
Noncoding microRNAs are involved in lipid and carbohydrate metabolism pathways and are powerful regulators of gene expression. The goals of this study were to evaluate the temporal expression profiles of miRNAs in rat adipose tissue and predict mRNA−microRNA interactions. Newly weaned Wistar rats were divided into groups fed a standard diet and high-sucrose diet (HSD). The HSD contains 66.86% carbohydrates (40.45% standard diet, 40.45% condensed milk, and 8.58% crystal sugar), and the HSD was provided for 4, 8 and 15-week periods to investigate the expression levels of miRNAs in visceral adipose tissue using RT−qPCR. Target selection, enriched pathways and networks were analyzed in silico. The factor consumption time significantly was associated to decreases (p < 0.05) in the expression levels of the following miRNAs: 124-5p, 125-5p, 126-5p, 200c-3p, and 212-3p in all experimental groups. The factor diet significantly influenced rno-miR-124-5p, 200c-3p, and 212-3p expression (p < 0.05). A significant reduction (p < 0.05) in rno-miR-27a-3p expression was observed. The biological processes involved key pathways regulating fat deposition. Our findings provide important insights into downregulated miRNA expression patterns in visceral adipose tissue, adiposity level, hyperinsulinemia and increased VLDL-c and triglyceride levels.
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Sacarose Alimentar , Gordura Intra-Abdominal , MicroRNAs , Animais , Sacarose Alimentar/efeitos adversos , Gordura Intra-Abdominal/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Ratos , Ratos WistarRESUMO
Metabolic dysfunctions, such as hyperglycemia and insulin resistance, have been associated to cognitive impairment and dementia regardless of advanced age, although the underlying mechanisms are still elusive. Thus, this study investigates the deleterious effects of metabolic syndrome (MetS) induced by long-term exposure to a high-sucrose diet on motor and cognitive functions of male adult rats and its relationship with hippocampal endoplasmic reticulum (ER) stress. Weaned Wistar male rats were fed a high-sucrose diet until adulthood (HSD; 6 months old) and compared to both age-matched (CTR; 6 months old) and middle-aged chow-fed rats (OLD; 20 months old). MetS development, serum redox profile, behavioral, motor, and cognitive functions, and hippocampal gene/protein expressions for ER stress pro-adaptive and pro-apoptotic pathways, as well as senescence markers were assessed. Prolonged exposure to HSD induced MetS hallmarked by body weight gain associated to central obesity, hypertriglyceridemia, insulin resistance, and oxidative stress. Furthermore, HSD rats showed motor and cognitive decline similar to that in OLD animals. Noteworthy, HSD rats presented marked hippocampal ER stress characterized by failure of pro-adaptive signaling and increased expression of Chop, p21, and Parp-1 cleavage, markers of cell death and aging. This panorama resembles that found in OLD rats. In toto, our data showed that early and sustained exposure to a high-sucrose diet induced MetS, which subsequently led to hippocampus homeostasis disruption and premature impairment of motor and cognitive functions in adult rats.
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The prevalence of the metabolic syndrome (MetS) and its cardiac comorbidities as cardiac hypertrophy (CH) have increased considerably due to the high consumption of carbohydrates, such as sucrose and/or fructose. We compared the effects of sucrose (S), fructose (F) and their combination (S + F) on the development of MetS in weaned male Wistar rats and established the relationship between the consumption of these sugars and the degree of cardiac CH development, oxidative stress (OS) and Calcium/calmodulin-dependent protein kinase type II subunit delta oxidation (ox-CaMKIIδ). 12 weeks after the beginning of treatments with S, F or S + F, arterial pressure was measured and 8 weeks later (to complete 20 weeks) the animals were sacrificed and blood samples, visceral adipose tissue and hearts were obtained. Biochemical parameters were determined in serum and cardiac tissue to evaluate the development of MetS and OS. To evaluate CH, atrial natriuretic peptide (ANP), CaMKIIδ and ox-CaMKIIδ were determined by western blot and histological studies were performed in cardiac tissue. Our data showed that chronic consumption of S + F exacerbates MetS-induced CH which is related with a higher OS and ox-CaMKIIδ.
Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Cardiomegalia/enzimologia , Carboidratos da Dieta/efeitos adversos , Frutose/efeitos adversos , Síndrome Metabólica/enzimologia , Miocárdio/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Sacarose/efeitos adversos , Animais , Carboidratos da Dieta/farmacologia , Frutose/farmacologia , Masculino , Oxirredução/efeitos dos fármacos , Ratos , Ratos Wistar , Sacarose/farmacologiaRESUMO
Increasing evidence suggests that long-term consumption of high-caloric diets increases the risk of developing cognitive dysfunctions. In the present study, we assessed the catecholaminergic activity in the hippocampus as a modulatory mechanism that is altered in rats exposed to six months of a high-sucrose diet (HSD). Male Wistar rats fed with this diet developed a metabolic disorder and showed impaired spatial memory in both water maze and object location memory (OLM) tasks. Intrahippocampal free-movement microdialysis showed a diminished dopaminergic and noradrenergic response to object exploration during OLM acquisition compared to rats fed with normal diet. In addition, electrophysiological results revealed an impaired long-term potentiation (LTP) of the perforant to dentate gyrus pathway in rats exposed to a HSD. Local administration of nomifensine, a catecholaminergic reuptake inhibitor, prior to OLM acquisition or LTP induction, improved long-term memory and electrophysiological responses, respectively. These results suggest that chronic exposure to HSD induces a hippocampal deterioration which impacts on cognitive and neural plasticity events negatively; these impairments can be ameliorated by increasing or restituting the affected catecholaminergic activity.
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Catecolaminas , Sacarose Alimentar , Hipocampo , Animais , Catecolaminas/fisiologia , Sacarose Alimentar/efeitos adversos , Hipocampo/fisiopatologia , Potenciação de Longa Duração/fisiologia , Masculino , Transtornos da Memória/fisiopatologia , Ratos , Ratos Wistar , Memória Espacial/fisiologiaRESUMO
AIMS: Liver cirrhosis is the main chronic liver disease and is considered a catabolic disease. Cirrhotic patients have a low energy intake and high energy expenditure at rest, leading to metabolic disorders. Malnutrition is associated with complications of cirrhosis and has been shown that a nutritional intervention with increase of energy intake improves the survival of cirrhotic patients. Therefore, our aim was to evaluate the effect of a high sucrose diet in the liver of animals with cirrhosis induced by thioacetamide and investigate the mechanism involved. MAIN METHODS: Male Wistar rats were divided into three groups: Control; Thioacetamide; and Thioacetamide + high sucrose diet. The thioacetamide was administrated (100 mg kg-1) intraperitoneally and the sucrose was offered in drinking water (300 g L-1). KEY FINDINGS: The administration of thioacetamide was associated with fibrosis and inflammatory infiltrate in the liver and increased levels of transaminases enzymes. The high sucrose diet promoted a reduction of theses parameters in cirrhotic rats. The malnutrition observed in cirrhotic rats was attenuated by the high sucrose diet shown by the improvements in weight loss, subcutaneous fat, and caloric intake. The high sucrose diet also attenuated the oxidative stress present in the liver of animals with thioacetamide-induced cirrhosis. SIGNIFICANCE: The high sucrose diet had anti-inflammatory and anti-oxidant effects in the liver of animals with thioacetamide-induced cirrhosis. In addition, the high sucrose diet also improved malnutrition and catabolism present in cirrhosis. Thus, a high sucrose diet may be a therapeutic option for cirrhotic patients in a catabolic state.
Assuntos
Sacarose Alimentar/farmacologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Animais , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dieta , Sacarose Alimentar/metabolismo , Inflamação , Fígado/metabolismo , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Sacarose/metabolismo , Sacarose/farmacologia , Tioacetamida/efeitos adversos , Tioacetamida/farmacologiaRESUMO
Childhood consumption of added sugars, such as sucrose, has been associated to increased risk of metabolic syndrome (MetS) and nonalcoholic fatty liver disease (NAFLD). Although the mechanisms underlying NAFLD onset are incompletely defined, recent evidence has proposed a role for the endoplasmic reticulum (ER) stress. Thus, the present study sought to investigate the metabolic outcomes of high-sucrose intake on weaned Swiss mice fed a 25% sucrose diet for 30, 60 and 90 days in comparison to regular chow-fed controls. High-sucrose feeding promoted progressive metabolic and oxidative disturbances, starting from fasting and fed hyperglycemia, hyperinsulinemia, glucose intolerance and increased adiposity at 30-days; passing by insulin resistance, hypertriglyceridemia and NAFLD onset at 60 days; until late hepatic oxidative damage at 90 days. In parallel, assessment of transcriptional and/or translational levels of de novo lipogenesis (DNL) and ER stress markers showed up-regulation of both fatty acid synthesis (ChREBP and SCD1) and oxidation (PPARα and CPT-1α), as well as overexpression of unfolded protein response sensors (IRE1α, PERK and ATF6), chaperones (GRP78 and PDIA1) and antioxidant defense (NRF2) genes at 30 days. At 60 days, fatty acid oxidation genes were down-regulated, and ER stress switched over toward a proapoptotic pattern via up-regulation of BAK protein and CHOP gene levels. Finally, down-regulation of both NRF2 and CPT-1α protein levels led to late up-regulation of SREBP-1c and exponential raise of fatty acids synthesis. In conclusion, our study originally demonstrates a temporal relationship between DNL and ER stress pathways toward MetS and NAFLD development on weaned rats fed a high-sucrose diet.
Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Lipogênese/efeitos dos fármacos , Síndrome Metabólica/etiologia , Sacarose/efeitos adversos , Animais , Biomarcadores/metabolismo , Dieta/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/fisiologia , Lipogênese/fisiologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fatores de Tempo , DesmameRESUMO
OBJECTIVE: Consumption of a cafeteria-like diet and chronic stress have a negative impact on kidney function and morphology in adult rats. However, the interaction between chronic restraint stress and high-sucrose diet on renal morphology in young rats is unknown. A high-sucrose diet does not modify serum glucose levels but reduces serum corticosterone levels in stressed young rats, in this way it is confusing a possible potentiate or protector effect of this diet on kidney damage induced by stress. METHODS: Wistar male rats at 4 weeks of age were randomly assigned into 4 groups: control (C), stressed (St), high-sucrose diet (S30), and chronic restraint stress plus a 30% sucrose diet (Stâ¯+â¯S30). Rats were fed with a standard chow and tap water (C group) or 30% sucrose diluted in water (S30 group). Chronic restraint stress consisted of 1-h daily placement into a plastic cylinder, 5 days per week, and for 4 weeks. RESULTS: Stressed rats exhibited a low number of corpuscles, glomeruli, high number of mesangial cells, major deposition of mesangial matrix and aquaporin-2 protein (AQP-2) expression, and low creatinine levels. Meanwhile, high-sucrose diet ameliorated AQP-2 expression and avoided the reduction of creatinine levels induced by chronic stress. The combination of stress and high-sucrose diet maintained similar effects on the kidney as stress alone, although it induced a greater reduction in the area of proximal tubules. CONCLUSIONS: Our results show that both chronic stress and a high-sucrose diet induce histological changes, but chronic stress may generate an accelerated glomerular hypertrophy associated with functional changes before puberty.
Assuntos
Aquaporina 2/biossíntese , Sacarose Alimentar/efeitos adversos , Rim/metabolismo , Rim/patologia , Estresse Psicológico/metabolismo , Animais , Aquaporina 2/genética , Doença Crônica , Sacarose Alimentar/administração & dosagem , Expressão Gênica , Masculino , Tamanho do Órgão , Ratos , Ratos Wistar , Estresse Psicológico/complicações , Estresse Psicológico/psicologiaRESUMO
INTRODUCTION/AIMS: In recent years, it has been shown that free fatty acids receptors (FFAR) of whose function in the cell surface plays a significant role in the regulation of cell function and nutrition as well are activated by various endogenous ligands, but mainly by fatty acids. Within FFAR of our interest are GPR 41, 43 and 120. The functions of these receptors are varied and dependent on the tissue where they are. The activation and signaling of these receptors, FFAR, are involved in many physiological processes, and currently the target of many drugs in metabolic disorders like obesity, diabetes and atherosclerosis. MATERIAL AND METHODS: Obesity was induced with hypercaloric diet (HD) in male Wistar rats for 20 weeks (n = 10). At the end, adipose tissue (abdominal and subcutaneous) was taken to perform assays for relative quantification mRNA expression by end-point RT-PCR and protein level expression by Western blot. RESULTS: These present data have shown for the first time that total mRNA isolation and protein expression from both adipose tissues (abdominal and subcutaneous) of rat in obesity condition yield significative statistical difference among the control versus obese groups, showing that the diet high in carbohydrates modifies the total presence of mRNA and protein level expression of the receptors GPR41, 43 and 120. CONCLUSIONS: Further comparative methods are in process to clarify whether or not the obesity changes the functional receptors in these two tissues for new pharmacological approaches.
Assuntos
Obesidade/tratamento farmacológico , Obesidade/genética , Receptores Acoplados a Proteínas G/genética , Tecido Adiposo/metabolismo , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/patologia , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/patologia , Dieta Hiperlipídica , Modelos Animais de Doenças , Ácidos Graxos não Esterificados/genética , Ácidos Graxos não Esterificados/metabolismo , Regulação da Expressão Gênica/genética , Humanos , Insulina/genética , Insulina/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Ratos , Receptores Acoplados a Proteínas G/metabolismoRESUMO
PURPOSE: Rats fed a long-term sucrose-rich diet (SRD) developed adipose tissue dysfunction. In the adipose tissue of these SRD-fed rats, the present study analyzed the possible beneficial effects of dietary Salba (chia) seeds in improving or reversing the depletion of antioxidant defenses, changes in pro-inflammatory cytokines and ROS production. METHODS: Wistar rats were fed a SRD for 3 months. After that, half of the animals continued with the SRD until month 6, while in the other half, corn oil was replaced by chia seeds for 3 months (SRD + chia). A reference group consumed a control diet all the time. RESULTS: Compared with the SRD-fed rats, the animals fed a SRD + chia showed a reduction in epididymal fat pad weight; the activities of antioxidant enzymes CAT, SOD and GPx returned to control values, while GR significantly improved; mRNA GPx increased, and both mRNA SOD and the redox state of glutathione returned to control values; a significant increase in the expression of Nrf2 was recorded. These results were accompanied by a decrease in XO activity and ROS contents as well as plasma IL-6 and TNF-α levels. Chia seeds reversed the decrease in PPARγ protein mass level and increased the n-3/n-6 fatty acids ratio of membrane phospholipids. Besides, dyslipidemia and insulin sensitivity were normalized. CONCLUSION: This study provides new information concerning some mechanisms related to the beneficial effects of dietary chia seeds in reversing adipose tissue oxidative stress and improving the adipose tissue dysfunction induced by a SRD.
Assuntos
Tecido Adiposo/fisiopatologia , Citocinas/fisiologia , Dislipidemias/dietoterapia , Estresse Oxidativo/fisiologia , PPAR gama/fisiologia , Salvia , Tecido Adiposo/química , Tecido Adiposo/patologia , Animais , Antioxidantes/metabolismo , Dieta , Sacarose Alimentar/efeitos adversos , Dislipidemias/patologia , Dislipidemias/fisiopatologia , Ingestão de Energia , Ácidos Graxos/administração & dosagem , Ácidos Graxos/análise , Inflamação , Resistência à Insulina/fisiologia , Masculino , Tamanho do Órgão , Ratos , Ratos Wistar , SementesRESUMO
The present study investigates the benefits of the dietary intake of soy protein on adipose tissue dysfunction in a rat model that mimics several aspects of the human metabolic syndrome. Wistar rats were fed a sucrose-rich diet (SRD) for 4 months. After that, half of the animals continued with SRD until month 8 while in the other half, casein protein was replaced by isolated soy protein for 4 months (SRD-S). A reference group consumed a control diet all the time. In adipose tissue we determined: i) the activities of antioxidant enzymes, gene expression of Mn-superoxide dismutase (SOD) and glutathione peroxidase (GPx), and glutathione redox state ii) the activity of xanthine oxidase (XO), ROS levels and the gene expression of NAD(P)H oxidase iii) the expression of the nuclear factor erythroid-2 related factor-2 (Nrf2). Besides, adiposity visceral index, insulin sensitivity, and tumor necrosis factor-α (TNF-α) in plasma were determined. Compared with the SRD-fed rats, the animals fed a SRD-S showed: activity normalization of SOD and glutathione reductase, improvement of mRNA SOD and normalization of mRNA GPx without changes in the expression of the Nrf2, and improvement of glutathione redox state. These results were accompanied by a normalization of XO activity and improvement of both the ROS production as well as TNF-α levels in plasma. Besides, adipocyte size distribution, adiposity visceral index and insulin sensitivity improved. The results suggest that soy protein can be a complementary nutrient for treating some signs of the metabolic syndrome.
Assuntos
Tecido Adiposo/patologia , Tecido Adiposo/fisiopatologia , Proteínas Alimentares/uso terapêutico , Dislipidemias/tratamento farmacológico , Dislipidemias/fisiopatologia , Insulina/metabolismo , Estresse Oxidativo , Proteínas de Soja/uso terapêutico , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adipócitos/patologia , Tecido Adiposo/efeitos dos fármacos , Adiposidade/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Peso Corporal/efeitos dos fármacos , Proteínas Alimentares/farmacologia , Sacarose Alimentar , Dislipidemias/sangue , Metabolismo Energético/efeitos dos fármacos , Epididimo/efeitos dos fármacos , Epididimo/metabolismo , Glucose/administração & dosagem , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Proteínas de Soja/farmacologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
Early-life environmental insults have been shown to promote long-term development of chronic non-communicable diseases, including metabolic disturbances and mental illnesses. As such, premature consumption of high-sugar foods has been associated to early onset of detrimental outcomes, whereas underlying mechanisms are still poorly understood. In the present study, we sought to investigate whether early and sustained exposure to high-sucrose diet promotes metabolic disturbances that ultimately might anticipate neurological injuries. At postnatal day 21, weaned male rats started to be fed a standard chow (10 % sucrose, CTR) or a high-sucrose diet (25 % sucrose, HSD) for 9 weeks prior to euthanasia at postnatal day 90. HSD did not alter weight gain and feed efficiency between groups, but increased visceral, non-visceral and brown adipose tissue accumulation. HSD rats demonstrated elevated blood glucose levels in both fasting and fed states, which were associated to impaired glucose tolerance. Peripheral insulin sensitivity did not change, whereas hepatic insulin resistance was supported by increased serum triglyceride levels, as well as higher TyG index values. Assessment of hippocampal gene expression showed endoplasmic reticulum (ER) stress pathways were activated in HSD rats, as compared to CTR. HSD rats had overexpression of unfolded protein response sensors, PERK and ATF6; ER chaperone, PDIA2 and apoptosis-related genes, CHOP and Caspase 3; but decreased expression of chaperone GRP78. Finally, HSD rats demonstrated impaired neuromuscular function and anxious behavior, but preserved cognitive parameters. In conclusion, our data indicate that early exposure to HSD promote metabolic disturbances, which disrupt hippocampus homeostasis and might precociously affect its neurobehavioral functions.
Assuntos
Comportamento Animal/efeitos dos fármacos , Sacarose Alimentar/administração & dosagem , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Síndrome Metabólica/metabolismo , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Ansiedade/metabolismo , Glucose/metabolismo , Hipocampo/metabolismo , Resistência à Insulina/fisiologia , Masculino , Ratos , Ratos Wistar , Triglicerídeos/metabolismoRESUMO
This study explores the mechanisms underlying the altered lipid metabolism in the heart of dyslipemic insulin-resistant (IR) rats fed a sucrose-rich diet (SRD) and investigates if chia seeds (rich in α-linolenic acid 18:3, n-3 ALA) improve/reverse cardiac lipotoxicity. Wistar rats received an SRD-diet for three months. Half of the animals continued with the SRD up to month 6. The other half was fed an SRD in which the fat source, corn oil (CO), was replaced by chia seeds from month 3 to 6 (SRD+chia). A reference group consumed a control diet (CD) all the time. Triglyceride, long-chain acyl CoA (LC ACoA) and diacylglycerol (DAG) contents, pyruvate dehydrogenase complex (PDHc) and muscle-type carnitine palmitoyltransferase 1 (M-CPT1) activities and protein mass levels of M-CPT1, membrane fatty acid transporter (FAT/CD36), peroxisome proliferator activated receptor α (PPARα) and uncoupling protein 2 (UCP2) were analyzed. Results show that: (a) the hearts of SRD-fed rats display lipotoxicity suggesting impaired myocardial lipid utilization; (b) Compared with the SRD group, dietary chia normalizes blood pressure; reverses/improves heart lipotoxicity, glucose oxidation, the increased protein mass level of FAT/CD36, and the impaired insulin stimulated FAT/CD36 translocation to the plasma membrane. The enhanced M-CPT1 activity is markedly reduced without similar changes in protein mass. PPARα slightly decreases, while the UCP2 protein level remains unchanged in all groups. Normalization of dyslipidemia and IR by chia reduces plasma fatty acids (FAs) availability, suggesting that a different milieu prevents the robust translocation of FAT/CD36. This could reduce the influx of FAs, decreasing the elevated M-CPT1 activity and lipid storage and improving glucose oxidation in cardiac muscles of SRD-fed rats.
RESUMO
UNLABELLED: It is still unclear if an isoenergetic, sucrose-rich diet leads to health consequences. AIMS: To investigate the effects of excessive sucrose within an isoenergetic diet on metabolic parameters in male C57BL/6 mice. METHODS: Animals were fed a control diet (10% fat, 8% sucrose - SC group), a high-sucrose diet (10% fat, 32% sucrose - HSu group), a high-fat diet (42% fat, 8% sucrose - HF group) or a high-fat/high-sucrose diet (42% fat, 32% sucrose - HF/HSu group) for 8 weeks. RESULTS: Mice fed HF and HF/HSu diets gained more body mass (BM) and more body adiposity than SC- or Hsu-fed mice. Despite the unchanged BM and adiposity indices, HSu mice presented adipocyte hypertrophy, which was also observed in the HF and HF/HSu groups (P<.0001). The HF, HSu and HF/HSu mice were glucose intolerant and had elevated serum insulin levels (P<.05). The levels of leptin, resistin and monocyte chemotactic protein-1 increased, while the serum adiponectin decreased in the HF, HSu and HF/HSu groups (P<.05). In the adipose tissue, the HF, HSu and HF/HSu groups showed higher levels of leptin expression and lower levels of adiponectin expression in comparison with the SC group (P<.05). Liver steatosis was higher in the HF, HSu and HF/HSu groups than in the SC group (P<.0001). Hepatic cholesterol was higher in the HF and HF/HSu groups, while hepatic TG was higher in the HSu and HF/HSu groups (P<.05). In hepatic tissue, the sterol receptor element-binding protein-1c expression was increased in the HF, HSu and HF/HSu groups, unlike the peroxisome proliferator-activated receptor-alpha expression that decreased in the HF, HSu and HF/HSu groups in comparison with the SC group (P<.05). CONCLUSION: A sucrose-rich diet does not lead to a state of obesity but has the potential to cause changes in the adipocytes (hypertrophy) as well as glucose intolerance, hyperinsulinemia, hyperlipidemia, hepatic steatosis and increases in the number of inflammatory cytokines. The deleterious effects of a sucrose-rich diet in an animal model, even when the sucrose replaces starch isocalorically in the feed, can have far-reaching consequences for health.
Assuntos
Carboidratos da Dieta/administração & dosagem , Inflamação/metabolismo , Fígado/patologia , Sacarose/administração & dosagem , Adiposidade , Animais , Western Blotting , Insulina/sangue , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Long-chain polyunsaturated n-3 fatty acids (n-3 LCPUFAs) have hypolipidemic effects and modulate intermediary metabolism to prevent or reverse insulin resistance in a way that is not completely elucidated. Here, effects of these fatty acids on the lipid profile, phosphoenolpyruvate carboxykinase (PEPCK) activity, lipid synthesis from glucose in epididymal adipose tissue (Ep-AT) and liver were investigated. Male rats were fed a high-sucrose diet (SU diet), containing either sunflower oil or a mixture of sunflower and fish oil (SU-FO diet), and the control group was fed a standard diet. After 13 weeks, liver, adipose tissue and blood were harvested and analysed. The dietary n-3 LCPUFAs prevented sucrose-induced increase in adiposity and serum free fat acids, serum and hepatic triacylglycerol and insulin levels. Furthermore, these n-3 LCPUFAs decreased lipid synthesis from glucose and increased PEPCK activity in the Ep-AT of rats fed the SU-FO diet compared to those fed the SU diet, besides reducing lipid synthesis from glucose in hepatic tissue. Thus, the inclusion of n-3 LCPUFAs in the diet may be beneficial for the prevention or attenuation of dyslipidemia and insulin resistance, and for reducing the risk of related chronic diseases.
Assuntos
Tecido Adiposo/metabolismo , Sacarose Alimentar/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/farmacologia , Glucose/metabolismo , Lipídeos/biossíntese , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Tecido Adiposo/efeitos dos fármacos , Animais , Sacarose Alimentar/farmacologia , Suplementos Nutricionais , Ativação Enzimática/efeitos dos fármacos , Glucose/química , Masculino , Ratos , Ratos WistarRESUMO
Este trabalho teve o objetivo de estudar o efeito de medicamentos com diferentes ações agonista PPAR (rosiglitazona, fenofibrato e bezafibrato) sobre o perfil lipídico, glicídico e alterações na massa corporal e morfologia do tecido adiposo e pancreático em modelo de diabetes e sobrepeso induzido por dieta. Camundongos C57BL/6 (2 meses de idade) foram alimentados com dieta padrão (SC, n=10) ou dieta hiperlipídica rica em sacarose (HFHS, n=40) por 6 semanas. Logo após, os animais HFHS foram subdividos em: HFHS não tratado e HFHS tratado com rosiglitazona (HFHS-Ro), fenofibrato (HFHS-Fe) ou bezafibrato (HFHS-BZ) (5 semanas). Os camundongos alimentados com dieta HFHS apresentaram maior glicemia e insulina de jejum (+33% e +138%, respectivamente), intolerância à glicose, resistência à insulina, aumento da massa corporal (MC) (+20%) e adiposidade, hipertrofia de adipócitos e redução da imunocoloração para adiponectina no tecido adiposo. No pâncreas houve aumento da massa (+28%), acúmulo de gordura (+700%), hipertrofia da ilhota (+38%) e redução da imunocoloração para GLUT-2 (-60%). A rosiglitazona diminuiu a glicemia e insulina de jejum, porém induziu o ganho de MC e hipertrofia cardíaca. O fenofibrato estabilizou a MC, enquanto o bezafibrato levou a perda de MC. Apenas o bezafibrato impediu a hipertrofia da ilhota. A imunocoloração para GLUT-2 foi aumentada por todos os medicamentos, e não houve alterações na imunocoloração para o PPARalfa. Sinais morfológicos de pancreatite foram vistos no grupo HFHS-Fe, apesar dos níveis normais de amilase e lipase séricos. A rosiglitazona exacerbou a infiltração intrapancreática de gordura (+75% vs. HFHS), e o bezafibrato aumentou a imunocoloração para o PPARbeta/delta nas ilhotas pancreáticas. Em conclusão, o bezafibrato apresentou um efeito mais amplo sobre as alterações metabólicas, morfológicas e biométricas decorrentes da dieta HFHS, sugerindo que a inibição das três isoformas do PPAR seria melhor do que a inibição...
This work aimed to evaluate the effect of peroxisome proliferator-activated receptor (PPAR) agonists (rosiglitazone, fenofibrate and bezafibrate) on lipid and glucose metabolism, body mass, and adipose and pancreatic tissue morphology in a model of diet-induced type 2 diabetes and overweight in mice. Two-month-old male C57BL/6 mice were fed a standard chow (SC, n=10) or a high-fat high-sucrose chow (HFHS, n=40) for 6 weeks, and then HFHS-fed mice were subdivided by treatment: untreated HFHS and HFHS treated with rosiglitazone (HFHS-Ro), fenofibrate (HFHS-Fe), or bezafibrate (HFHS-Bz) (5 weeks on medication). HFHS-fed mice have altered fasting glucose (+33%) and insulin (+138%), GI, IR, increased body mass (+20%) and fat pad weight, adipocyte hypertrophy, and decreased adiponectin immunostain. They also presented increased pancreatic (+28%) mass, intrapancreatic fat (+700%), islet hypertrophy (+38%), and decreased GLUT-2 immunostain (-60%). Rosiglitazone reduced fasting glucose and insulin but induced weight gain and heart hypertrophy. Fenofibrate impaired body mass gain, while bezafibrate induced weight loss. Only bezafibrate impaired islet hypertrophy. GLUT-2 immunostain was improved by all treatments, and there were no alterations in PPAR-alfa stain. There were morphological signs of pancreatitis in fenofibrate-treated mice, although there was no alteration in serum amylase and lipase. Rosiglitazone exacerbated pancreatic fat infiltration (+75% vs. HFHS group), and bezafibrate increased PPAR-beta expression in pancreatic islets. In conclusion, bezafibrate showed a wider range of action on metabolic, morphologic, and biometric alterations due to HFHS intake, suggesting that inhibiting the three PPAR isoforms is better than inhititing each isoform alone. Rosiglitazone exacerbated body mass gain, pancreatic fat infiltration and induced heart hyperthophy as well, thus, precaution has to be taken in prescribing rosiglitazone to obese patients.