RICARDO COSTA PETRONI
Projetos de Pesquisa
Unidades Organizacionais
LIM/51 - Laboratório de Emergências Clínicas, Hospital das Clínicas, Faculdade de Medicina
2 resultados
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- High-fat diet inhibits PGC-1 alpha suppressive effect on NF kappa B signaling in hepatocytes(2018) BARROSO, Wermerson Assuncao; VICTORINO, Vanessa Jacob; JEREMIAS, Isabela Casagrande; PETRONI, Ricardo Costa; ARIGA, Suely Kunimi Kubo; SALLES, Thiago A.; BARBEIRO, Denise Frediani; LIMA, Thais Martins de; SOUZA, Heraldo Possolo deThe peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha) regulates the expression of genes implicated in fatty acid oxidation and oxidative phosphorylation. Its role in liver steatosis is well established, since mice with liver-specific deletion of PGC-1 alpha exhibit lipid accumulation and high-fat diet reduces hepatic PGC-1 alpha expression in mice. In this study, we investigated the role of PGC-1 alpha in the inflammatory changes observed in steatohepatitis induced by high-fat diet. C57black/6 mice were fed a high-fat diet containing 30% fat for 10 weeks. After euthanasia, liver morphology was examined by HE staining and inflammation was determined by IL-6, TNF-alpha, and IL-1 beta quantification. Liver gene expression of PGC-1 isoforms was evaluated by real-time PCR and p65 NF kappa B nuclear translocation by Western blotting. HepG2 cells were treated with linoleic acid overload for 72 h to create an in vitro model of steatohepatitis. RNA interference (RNAi) was used to evaluate the involvement of PGC-1 alpha on inflammatory mediators' production by hepatocytes. The high-fat diet led to a state of nonalcoholic steatohepatitis, associated with increased deposits of intra-abdominal fat, hyperglycemia and hyperlipidemia. Mice liver also exhibited increased proinflammatory cytokines' levels, decreased PGC-1 alpha expression, and marked increase in p65 NF kappa B nuclear translocation. Linoleic acid treated cells also presented increased expression of proinflammatory cytokines and decreased PGC-1 alpha expression. The knockdown of PGC-1 alpha content caused an increase in IL-6 expression and release via enhanced I kappa B alpha phosphorylation and subsequent increase of p65 NF kappa B nuclear translocation. High-fat diet induces liver inflammation by inhibiting PGC-1 alpha expression and its suppressive effect in NF kappa B pathway.
- PGC-1 beta regulates HER2-overexpressing breast cancer cells proliferation by metabolic and redox pathways(2016) VICTORINO, Vanessa Jacob; BARROSO, W. A.; ASSUNCAO, A. K. M.; CURY, V.; JEREMIAS, I. C.; PETRONI, R.; CHAUSSE, B.; ARIGA, S. K.; HERRERA, A. C. S. A.; PANIS, C.; LIMA, T. M.; SOUZA, H. P.Breast cancer is a prevalent neoplastic disease among women worldwide which treatments still present several side effects and resistance. Considering that cancer cells present derangements in their energetic homeostasis, and that peroxisome proliferator-activated receptor- gamma coactivator 1 (PGC-1) is crucial for cellular metabolism and redox signaling, the main objective of this study was to investigate whether there is a relationship between PGC-1 expression, the proliferation of breast cancer cells and the mechanisms involved. We initially assessed PGC-1 beta expression in complementary DNA (cDNA) from breast tumor of patients bearing luminal A, luminal B, and HER2-overexpressed and triple negative tumors. Our data showed that PGC-1 beta expression is increased in patients bearing HER2-overexpressing tumors as compared to others subtypes. Using quantitative PCR and immunoblotting, we showed that breast cancer cells with HER2-amplification (SKBR-3) have greater expression of PGC-1 beta as compared to a non-tumorous breast cell (MCF-10A) and higher proliferation rate. PGC-1 beta expression was knocked down with short interfering RNA in HER2-overexpressing cells, and cells decreased proliferation. In these PGC-1 beta-inhibited cells, we found increased citrate synthase activity and no marked changes in mitochondrial respiration. Glycolytic pathway was decreased, characterized by lower intracellular lactate levels. In addition, after PGC-1 beta knockdown, SKBR-3 cells showed increased reactive oxygen species production, no changes in antioxidant activity, and decreased expression of ERR alpha, a modulator of metabolism. In conclusion, we show an association of HER2overexpression and PGC-1 beta. PGC-1 beta knockdown impairs HER2-overexpressing cells proliferation acting on ERR alpha signaling, metabolism, and redox balance.