EVALUATION OF PULPITIS AS A CAUSE OF CENTRAL INFLAMMATION AND ALTERATION OF SENSORY AND BEHAVIORAL PARAMETERS IN A PRECLINICAL MODEL

• Grant number: 23/10160-7
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: August 31, 2027
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Jardel Francisco Mazzi Chaves
• Grantee: Jardel Francisco Mazzi Chaves
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Christie Ramos Andrade Leite Panissi ; Fabiane Carneiro Lopes Olhê ; Francisco Wanderley Garcia de Paula e Silva ; IGOR BASSI FERREIRA PETEAN ; Manoel Damiao de Sousa Neto

Abstract

The relationship between acute pulp inflammatory conditions, nociceptive pathways, and alterations related to behavior and peripheral sensory sensitivity still needs to be elucidated. Thus, the objective of this study is to evaluate inflammatory aspects in experimentally induced pulpitis in mice and correlate them with behavioral changes, peripheral sensitivity, and food consumption. For this purpose, methodologies will be used to assess mechanical sensitivity in the mice's paw (von Frey test), anxious-type behavior (open field test), food consumption, peripheral nociceptive sensitivity in the paw (formalin test), gene expression of precursor genes involved in the inflammatory process through real-time polymerase chain reaction (RT-PCR), and histological evaluation of pulp tissue inflammation, as well as the relative expression of molecular and cellular inflammatory markers at the central level through immunohistochemistry and Western blotting. This project will begin after approval from the Animal Ethics Committee (CEUA). A total of 192 WT, C57BL/6J mice will be used, comprising 96 females and 96 males. Of the total number of animals, 144 (72 males and 72 females) will be subjected to experimentally induced pulpitis, and 48 (24 males and 24 females) will be used as the control group. Experimental pulpitis will be performed after anesthesia, by accessing the coronal pulp tissue of the right lower first molar and inoculating 10 µL of LPS suspension (1 µg/µL). During the development of pulpitis, the mice (G1 and G2) will be evaluated for mechanical sensitivity, nociceptive sensitivity, and behavioral analysis at different time points. Euthanasia is scheduled for three different time points (days 02, 05, and 10). After euthanasia, biological materials of interest will be collected, including blocks containing the right mandible and teeth for histological analysis using eosin-hematoxylin, analysis of tartrate-resistant acid phosphatase (TRAP) activity, and gene expression analysis by qRT-PCR. The brain will also be preserved for analysis through immunohistochemistry and for the relative expression of inflammatory markers by Western blotting. The results of the inflammatory conditions will be correlated with each other (local and central) and with behavioral parameters, peripheral sensitivity, and food consumption. Data will be statistically described by mean and standard deviation and checked for normality using the Shapiro-Wilk test and homoscedasticity using the Levene test (p > 0.05). Depending on the data distribution, they will be analyzed using parametric tests or corresponding non-parametric tests, considering the correlation between gene expression and behavioral data, comparison of gene expression data, and evaluation of repeated measures of behavioral data (p < 0.05). (AU)