The role of gut microbiota in T lymphocytes profile of non-obese type 2 diabetic rats (Goto-Kakizaki rats)

• Grant number: 24/13202-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Renata Gorjao
• Grantee: Henrique de Souza Falcão
• Host Institution: Pró-Reitoria de Pós-Graduação e Pesquisa. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

The Goto-Kakizaki (GK) rats are widely recognized for developing insulin resistance (IR), resulting in basal hyperglycemia and, consequently, the pathogenesis of type 2 diabetes mellitus (T2DM). The development of this pathology may be related to the gut microbiome of these animals. Studies have shown differences in the composition of gut microbiota between GK and Wistar rats, which may be linked to changes in the cellular profile of T lymphocytes. Previously, our group observed that GK rats exhibit an increase in the percentage of Th1 cells in the mesenteric lymph nodes, characterized by a pro-inflammatory profile, and a reduction in regulatory T cells (Treg), which have immunosuppressive functions. Therefore, the aim of our study is to investigate the influence of the gut microbiota of non-obese diabetic rats (GK rats) on the polarization of T lymphocytes in secondary lymphoid organs. For this, GK (n=10) and Wistar (WT; n=10) animals will be divided into two groups: one group will receive a cocktail of antibiotics diluted in water (GKabx and WTabx), and the other group will receive only filtered water (GKct and WTct). During the protocol we will analyze food intake and gastrointestinal motility. In the end of protocol, we will conduct glucose and insulin tolerance tests (GTT and ITT, respectively). Subsequently, the animals will be euthanized to collect mesenteric lymph nodes, Peyer's patches (PP) and adipose tissues. Lipopolysaccharide (LPS) and insulin levels will also be assessed, along with HOMA-IR analysis. We will evaluate the T lymphocyte profile by flow cytometry, proliferative capacity by BRDU incorporation in the presence and absence of Concanavalin A (5 ¿g/mL) using flow cytometry, and expression of genes associated with Th1, Th2, Th17, Th22, and Treg profiles by real-time PCR. This project is fundamental for understanding how gut microbiota depletion and the subsequent alteration of lymphocyte profiles influence the pathogenesis of T2DM, enabling the development of new therapeutic strategies focused on modulating the gut microbiome and controlling the immune response for the prevention and treatment of the disease.