Fenofibrato (agonista PPAR-alfa) induz a formação de células beges no tecido adiposo branco subcutâneo em camundongos obesos induzidos por dieta

• Autor(a) principal: Rachid, Tamiris Lima
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7861
• topic: Fenofibrate; White adipose tissue; Browning; Fenofibrato; Tecido adiposo branco; Browning; Fenofibrato; Tecido adiposo branco; Camundongo como animal de laboratório; Obesidade; Dietas; PPAR alfa; CNPQ::CIENCIAS BIOLOGICAS::MORFOLOGIA

The current situation of obesity in the world encourages the study for its treatment. Fenofibrate, a PPAR-α agonist, is currently used to treat dyslipidemia. However, its pleiotropic effects upon body mass loss and fat pads reduction remain to be unraveled. This study aimed to examine the effects of PPAR-α agonist fenofibrate on energy expenditure, body mass, carbohydrate metabolism, secretory profile of adipokines, plasticity and thermogenesis in adipose tissue in diet-induced obese mice. Male C57BL/6 mice were fed a standard chow (SC; 10% lipids) diet or a high-fat (HF; 50% lipids) diet for 10 weeks. Afterwards, groups were subdivided into: SC, SC-F, HF and HF-F (n=10, each). Treatment with fenofibrate (100 mg/kg BM, mixed into the diet) was maintained for five weeks, totalizing fifteen weeks of experiment. All procedures were approved by the Animal Ethics Committee of UERJ (CEUA/032/2013). The differences among the groups were tested by one-way analysis of variance (ANOVA), followed by the Holm-Sidak post-hoc test. Two-way ANOVA was applied to test interactions between diet and treatment upon the evaluated outcomes. In all cases, P<0.05 was considered statistically significant. HF presented overweight, insulin resistance, besides adverse subcutaneous white adipose tissue (sWAT) remodeling. Fenofibrate attenuated significantly these parameters (P<0.05). Treated groups showed beige cells in sWAT, confirmed through higher gene expression of PPAR-α, PPAR-β, PGC1-α, BMP8, UCP-1, PRDM16 and FNDC5/Irisin in treated groups than in their counterparts (P<0.05). The treatment with fenofibrate was also able to increase plasma levels of FNDC5/Irisin in both treated groups (P<0.005). SC-F and HF-F groups presented increase in energy expenditure, CO2 production and O2 consumption after treatment with fenofibrate (P<0.05). Activation of PPAR-α seems to be pivotal to trigger browning through irisin induction and UCP-1 transcription. Fenofibrate restored body mass, insulin sensitivity and sWAT morphometry. Importantly, fenofibrate increased the expression of genes typical from brown adipose tissue (BAT) in sWAT, characterizing the plasticity of sWAT in beiges cells with thermogenic capacity, a phenomenon so-called browning.