Effect of inhibition of microglial activation on neuroimmunoendocrine parameters during sepsis

• Grant number: 16/07803-0
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): July 01, 2016
• Effective date (End): January 31, 2020
• Field of knowledge: Biological Sciences - Physiology
• Principal Investigator: Maria José Alves da Rocha
• Grantee: Luís Henrique Angenendt da Costa
• Home Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 17/25628-3 - Functional anatomy and modulation of sepsis-induced paraventricular nucleus activation, BE.EP.DR

Abstract

Sepsis, a systemic inflammatory condition triggered by an infectious agent, induces an inflammatory status in central nervous system (CSN) which leads to autonomic, cognitive and behavioral alterations. Microglia, a CNS resident cell type with important synaptic and immune regulation, is activated in several brain areas during sepsis, suggesting a role in neuroendocrine dysfunction observed in this disease. Our objective is to analyze the role of the microglial activation on neuroimmunendocrine parameters in septic animals. Male Wistar rats will have the lateral ventricle cannulated e after receiving an intracerebroventricular injection of minocycline (100µg/kg), an inhibitor of microglial activation or saline solution 0.9% (vehicle) as control, 15 minutes before the septic stimulus. Sepsis will be induced by cecal ligation and puncture (CLP) - 10 punctures, 16G needle. Control (sham) animals will have the cecum neither ligated nor perforated. Following 6 (acute phase) and 24 hours (late phase) after surgery, the animals will be separated in different groups in order to analyze the survival rate, nitric oxide (NO) concentration in plasma and cerebrospinal fluid, plasma cytokines (IL-1², IL-6, TNF-±- ELISA) and hormones (vasopressin, oxytocin, ACTH, corticosteron, prolactin), gene (qPCR) or protein (western blot) expression of hypothalamic factors involved in neuroinflammation (NFš-B, IL-1², MPO, iNOS), neurotransmission (synaptophysin), neurodegeneration (²-amyloid protein), apoptosis (cleaved-caspase 3, PARP) and glial activation (IBA-1, GFAP). Morphological analyses of microglia (IBA-1 and astrocytes (GFAP) will be analyzed by immunohistochemistry.