Leptin sensibility influences on mouse sexual maturation.

Author(s)

Tabata Mariz Bohlen

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2019-05-10

Examining board members

Renata Frazão; Claudimara Ferini Pacicco Lotfi; Raphael Escorsim Szawka; Ana Claudia Latrônico Xavier

• Advisor: Renata Frazão; José Donato Júnior

Abstract

As the incidence of obesity in children has increased and leptin is a permissive factor for the onset of puberty, elevated circulating leptin levels have become a common factor that may cause puberty to progress. However, the increase in fat accumulation in organisms is associated with resistance to the hormone leptin. There is currently little information on how sensitivity to this hormone affects sexual development. Therefore, this project aimed to investigate how different models of leptin sensitivity or resistance act in the puberty of female mice. Techniques such as in vivo monitoring of the different stages of sexual maturation and body composition, leptin sensitivity tests, glucose and insulin tolerance tests, and real-time PCR were used. Animals with higher body weight since childhood presented an advance of sexual maturation, greater accumulation of body fat and alterations in the expression of metabolic genes. On the other hand, animals that underwent inactivation of the Socs3 gene in the central nervous system or cells expressing the leptin receptor showed a delay in sexual maturation and alterations in the expression of genes related to food consumption, but in cases of inactivation in Kiss1 cells, animals did not present any type of change. Thus, we conclude that body weight is more important for the onset of sexual maturation than the body\'s sensitivity to the hormone leptin, suggesting that leptin acts indirectly on sexual maturation on the hypothalamus - pituitary - gonadal axis. In addition, in the analysis of gene expression along the development we have traced a profile of genes associated with reproduction and metabolism, which will serve as a basis for comparison to other studies. (AU)

• FAPESP's process: 15/14588-5 - Influence of leptin sensitivity in mice sexual maturation
• Grantee: Tabata Mariz Bohlen
• Support Opportunities: Scholarships in Brazil - Doctorate