Participation of TCPTP in hypothalamic resistance to leptin induced by repeated exposure to endotoxin

• Grant number: 17/15156-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2017
• End date: April 30, 2019
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Lucila Leico Kagohara Elias
• Grantee: Hellen Veida Paraguassu da Silva
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 13/09799-1 - Energy balance and body fluid homeostasis control: from cells to the physiological systems, AP.TEM

Abstract

Lipopolyssaccharyde (LPS) is a cell-wall component of gram negative bacteria which acts as an activator of immune responses and is widely used in models that mimic inflammation. During acute endotoxemia it is possible to notice LPS induced hypophagia, however, in chronic endotoxemia this effect is ablated due to resistance to endotoxin effects. Additionally, animals receiving multiple LPS treatments become resistant to exogenous leptin treatment, an anorexigenic hormone that reduces food intake and increases energy expenditure. Furthermore, multiple doses can increase the expression of counter regulator proteins, such as SOCS3 and PTP1B, which may contribute to a leptin resistance phenotype. The aim of this study is to investigate the endotoxemia effects on food intake and energy expenditure through multiple or single intraperitoneal injections of LPS. C57bl-6 mice will be divided into the following groups: 7 saline injections; 6 saline injections + 1 LPS injection; 7 LPS injections. During the experimental period the animals will have daily food intake and body weight monitored. Additional groups are going to be used for brain collection, necessary for Western Blot and immunohistochemistry experiments. (AU)