Role of physical exercise in rock protein regulation in the hypothalamus from obese rats: effects on insulin and leptin signaling

Author(s)

Luciana Santos Souza Pauli

• Document type: Doctoral Thesis
• Press: Limeira, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Aplicadas
• Defense date: 2017-07-14

Examining board members

Eduardo Rochete Ropelle; Leandro Pereira de Moura; Adelino Sanchéz Ramos da Silva; Ellen Cristini de Freitas; Angélica Rossi Sartori Cintra

• Advisor: Eduardo Rochete Ropelle

Abstract

The objective of this study was to evaluate the effects of acute physical exercise on the protein expression of Rock1 in hypothalamus and to relate this phenomenon with insulin and leptin sensitivity and food intake of obese mice. To achieve the objectives Swiss mice were used in the control groups (CTL), animals that received a standard diet; Obese-induced high-fat diet (Hyper-SD), animals that received a high- fat diet; And obese exercised acutely (Hyper-EA), animals that received a high-fat diet and were submitted an acute exercise protocol. Blood samples were collected for analysis of insulinemia and glycemia fasting. Subsequently, hypothalamus extraction and Western blot analysis of the proteins of interest were performed. The data were analyzed by Student's test, when two groups were compared. And analysis of variance (Anova), followed by Bonferroni's multiple means test, when appropriate for the controlled and experimental groups. The statistical significance was set at p <0.05. The results show that obese mice present a change in the signaling pathway of leptin and insulin in the hypothalamus and this resulted were accompanied by not increased in content of Rock protein and increased food intake. Contrary to the animals submitted to the acute exercise protocol showed increased sensitivity to leptin and insulin and higher protein content of Rock1 in the hypothalamus compared to their non-exercised obese mice. In addition, there was an increases in phosphorylation of JAK2 and Akt proteins, the association of JAK2 with Rock1 and IRS-1 with Rock1, and increased phosphorylation of IRS-1 in serine 632/635 in the hypothalamus. Considering these data, it is possible to consider, at least in part, that protein levels of the Rock protein can be associated with a condition of reduced sensitivity to leptin and insulin in hypothalamus and increased food intake in obesity. On the other hand, physical exercise was able to act positively on a rock pathway and increase a sensitivity of both leptin and insulin in hypothalamic neurons and attenuate hyperphagia in obese mice. This discovery broadens the knowledge about the effects of physical exercise on the process of food intake control and opens the door to new therapeutic actions against obesity and associated diseases (AU)

• FAPESP's process: 13/21061-8 - Role of physical exercise in rock protein regulation in the hypothalamus from obese rats: effects on insulin and leptin signaling
• Grantee: Luciana Santos Souza Pauli
• Support Opportunities: Scholarships in Brazil - Doctorate