Evaluation of perineuronal nets associated with AgRP neurons in animals with diet-induced hypothalamic inflammation

• Grant number: 24/22256-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2025
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Licio Augusto Velloso
• Grantee: Julia Nicoly Bohn Couto
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 13/07607-8 - OCRC - Obesity and Comorbidities Research Center., AP.CEPID

Abstract

Obesity is a chronic inflammatory disease defined as the excessive accumulation of adipose tissue. It is suggested that microglia act as sensors and become activated following exposure to high-fat diets (HFD), triggering inflammatory responses that affect hypothalamic neuronal pathways. Additionally, microglial activation is associated with the release of MMPs, enzymes responsible for degrading extracellular matrix components, including the so-called perineuronal nets (PNNs), which surround neurons and reduce neuronal plasticity. Studies suggest that PNNs tend to particularly enwrap AgRP neurons, but the relationship between PNNs and AgRP neurons in animals consuming HFD remains unclear. Therefore, the aim of the present project is to evaluate the relationship between PNNs and AgRP neurons in microglia-depleted animal models exposed to HFD. For this purpose, 60 male C57BL/6 mice will be divided into three groups: CTL-SD and CTL-HFD will receive chow without the microglial inhibitor PLX5622 for 10 days, while PLX-HFD will receive chow formulated with PLX5622 for 10 days to induce microglial cell depletion. After this period, the CTL-HFD and PLX-HFD groups will be given HFD for 2 days, while the CTL-SD group will receive standard diet (SD) for 2 days. Following this phase, the animals will be euthanized and brains collected for immunofluorescence, RT-qPCR, and western blot analyses. Statistical analyses will be performed using Student's t-test or two-way ANOVA (p<0.05) with GraphPad Prism.