Navegando por Palavras-chave "Beta-oxidação"

Agora exibindo 1 - 1 de 1
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Efeitos dos ácidos graxos palmítico e palmitoleico sobre parâmetros metabólicos de adipócitos 3T3-L1
    (Universidade Federal de São Paulo, 2015-02-27) Cruz, Maysa Mariana [UNIFESP]; Vale, Maria Isabel Cardoso Alonso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    WAT is a body?s energy reservoir stocking lipids in the form of TAG and is considered an endocrine organ, it secretes hormones and cytokines (adipokines). There are recent reports describing the involvement of mitochondrial function in the regulation of various WAT?s processes: the proliferation of pre-adipocytes, adipogenesis and on lipids and carbohydrates metabolism. The palmitoleic acid (C16:1n7) is a monounsaturated fatty acid (FA) omega-7 present in macadamia oil. It have been demonstrated beneficial effects of this FA on pancreatic beta-cells, muscle and liver as well as on the plasma lipid profile in animal models and humans. Furthermore, recent studies have shown that the palmitoleic acid enhances the insulin action in muscle and suppresses hepatic steatosis. However, there are few data in the literature about the effects of C16:1n7 on the metabolism of white adipocytes. There are no reports about its effect on both metabolic and mitochondrial function of these cells. This project aims to investigate parameters of mitochondrial and metabolic function in adipocytes under the influence of both FA palmitic (saturated C16: 0) and palmitoleic. 3T3-L1 clonal cells were directed to differentiate into mature adipocytes and the following parameters were evaluated: cell viability, DNA fragmentation, lipolysis, lipogenesis, mitochondrial mass, gene expression, oxygen consumption, ATP contente, citrate synthase activity and proteic analysis of mitochondrial complexes and PGC1alpha. According to the interpretation of toxicity curves of both AG obtained by cell viability testing and DNA fragmentation, it was chosen to treat the 3T3-L1 cells with a concentration of 100 µM of the FA, from induction of differentiation to day 10 post-differentiation, condition which the majority of tests was carried out. The C16:1n7 treatment increased the basal and isoproterenol-stimulated lipolysis, the incorporation of FA into TAG and its oxidation into CO2, the basal incorporation of glucose into glycerol-3-P, the oxygen consumption and intracellular ATP concentration. In other hand, the C16:1n7 reduced the incorporation of acetate into TAG, the mitochondrial mass, the citrate synthase activity and proteic contente of mitochondrial complex I. These effects did not occur in adipocytes treated with C16:0. No changes in the expression of genes related to mitochondrial biogenesis (PGC-1?, TFAM and NRF1), mitochondrial function (CPT1 and UCP2) or antioxidant activity (SOD 1 and 2, catalase and glutathione peroxidase). Preliminary data also showed that the treatment with C16:1n7 increases the expression of the following genes: (1) the glucose transporter GLUT4, (2) the insulin sensitizing hormone, adiponectin, and (3) the lipolytic enzyme ATGL. There was no change in the expression of HSL, ACC, FAS, perilipin, glycerol kinase, lipin and PEPCK enzymes. In conclusion, the C16: 1n7 plays an important role on the metabolic and mitochondrial parameters, suggesting an increase in energy expenditure of adipocytes. One hypothesis to these effects is that the palmitoleic acid is accelerating cell energy metabolism by stimulating triglyceride/fatty acid cycle. We propose that the palmitoleic acid should be clinically tested in therapies against obesity and related diseases.