Influence of obesity on the progression of induced experimental periodontal disease in rats: histological, microtomographic and proteomic analysis

Author(s)

Maria Eduarda Scordamaia Lopes

• Document type: Master's Dissertation
• Press: Araraquara. 2021-08-03.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2021-06-23
• Advisor: Joni Augusto Cirelli

Abstract

Many studies have been conducted to understand better the molecular mechanism of periodontal disease progression in different periodontal tissues. However, the literature is limited on the influence of obesity on these mechanisms. This study aimed to evaluate in vivo the effect of obesity on periodontal disease progression. Sixteen Holtzman rats were distributed into 2 groups: ligature-induced periodontal disease (P), and obesity induction followed by ligature-induced periodontal disease (OP). Obesity was induced by a high-fat diet for 90 days. The body mass of the animals was recorded weekly. After 21 days of the induction of periodontal disease, the animals were sacrificed and the adipose tissues were removed and weighed on precision scales. Serological analysis was performed to observe the lipid profile and blood glucose levels. Microtomographic analysis was performed on the hemimaxillae to measure the percentage of alveolar bone volume (BVF), alveolar bone density (BMD), and linear analysis of bone loss. Alveolar bone loss was measured histologically by histometry. The proportion of tissue components was determined histologically by stereometry. The protein composition of the periodontal ligament was evaluated by proteomic analysis. From this analysis, three proteins with significant differences between groups and that have a relevant function in the inflammatory process were selected to validate their presence in the periodontal ligament by immunohistochemistry. The statistical t-student test was used and a 5% significance level was adopted. There was a significant increase in body mass and adipose tissue weight in the animals of the OP group. The groups showed no statistical difference in the analyses of bone loss. In the proteomic analysis, a total of 819 proteins were identified. In the clinical condition of periodontal disease associated with obesity, the proteins Spondin 1, Vinculin and TRAP were more abundant and were selected for their clinical relevance. We conclude that although obesity has not favoured the progression of periodontal disease in the alveolar bone loss parameter, the protein characterization of the periodontal ligament in periodontal disease conditions, associated or not with obesity, may be an auxiliary method of study for the identification of new disease-associated biomarkers, demonstrating molecular changes and favouring studies for therapeutic targets for periodontal disease. (AU)

• FAPESP's process: 18/23599-9 - Proteomic analysis of periodontal ligament of rats submitted to experimental periodontal disease induction and obesity
• Grantee: Maria Eduarda Scordamaia Lopes
• Support Opportunities: Scholarships in Brazil - Master