Regular physical exercise is recommended as a strategy and prevention of metabolic diseases, such as obesity, type 2 diabetes mellitus, cardiovascular diseases, and non-alcoholic fatty liver disease. When it comes to liver disease, it is known that physical exercise can promote the regression of liver injuries. These results are associated with weight reduction, changes in body composition, and glycemic homeostasis. It is necessary to understand the molecular components modulated by exercise acts directly in hepatic metabolism, mainly through Notch1 signaling. This pathway acts as a regulatory agent for hepatic metabolism. In mice exposed to a non-alcoholic diet to induce steatohepatitis, the high liver protein content of Notch1 was identified. However, the molecular mechanisms that cause the increase in protein content and increase in Notch1 activity have not been clarified and there are gaps in the mechanisms of activity activation and control of gluconeogenesis and lipogenesis. Thus, the aim is to elucidate the effects of resistance exercise on hepatic metabolism under the Nocth1 pathway in obese and hyperglycemic mice. The first stage of the project is to identify the effects of Notch1 on hepatocytes, as well as the activators and inhibitors of this protein. Cultures of human liver and mouse cells will be used. It will be induced to the overexpression of Notch1 and the intracellular domain of Notch1 (NICD). Then, treatments with palmitate and lipopolysaccharide will be performed, which trigger inflammation, deletion, and inhibition of Notch1. To optimize the experiments, current molecular biology techniques will be used, such as the use of antivirus and CRISPR / Cas9. With the Notch1 receptors pointed out in step 1, we will start step 2. In step 2, we intend to evaluate, using mice induced by obesity by a diet rich in fat (Swiss) or genetically (ob/ob), if there is an increase in Notch1 and its target genes. Besides to trying to assess whether the inflammatory process increases Notch1 cleavage by the gamma-secretase complex and activates the transcription of Notch1 ligands, such as the Jagged and Delta proteins in the context of obesity. It is proposed that the pharmacological inhibitor of gamma-secretase mitigates the effects associated with Notch1 and that animals TLR4 KO do not suffer damage caused by obesity-associated with Notch1. Also, the aim is to verify the metabolic changes resulting from the overexpression of the NICD domain in mice. In the third stage, a resistance exercise protocol will be applied to the Swiss, ob/ob, and TLR4KO animals. Physiological tests, analysis of hepatic glucose production in applied hepatocytes from trained animals, overexpression, and pharmacological inhibition experiments will be performed in experimental models. Besides, the anti-inflammatory effects of resistance exercise will be possible. It is hoped that this project will help to understand the components involved in the Notch1 signaling pathway, its activators, and the accumulation of fat in the liver, as well as clarifying the effects of physical exercise in this pathway.
News published in Agência FAPESP Newsletter about the scholarship: