Diacerein effect in the immunoexpression of TNF-±, IL-6, RANKL e OPG in the periodontium of rat molars with periodontal disease

• Grant number: 21/05016-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2021
• End date: October 31, 2022
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Paulo Sergio Cerri
• Grantee: Lucas de Andrade Rodrigues
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Periodontal disease (PD), triggered by subgingival bacterial accumulation, causes the periodontal tissues degradation (gingiva, cementum, periodontal ligament and bone alveolar). Bone loss is considered as hallmark of progression of PD. Therefore, the bone loss resulting of PD is closely associated with osteoclast formation and cytokines released by cells of inflamed periodontal. Cytokines such as interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-±), receptor activator of nuclear factor-kB ligand (RANKL), largely secreted by resident and inflammatory cells under stimuli of LPS, induce the osteoclastogenesis. Considering that diacerein inhibits the IL-1 and TNF-±, it is conceivable to suggest that this anti-inflammatory may interfere on osteoclastogenesis. Thus, the purpose of the present study is to evaluate whether diacerein administered in rats with induced periodontal disease interferes in the immunoexpression of TNF-±, IL-6, RANKL and OPG. Fifty-four Holtzman rats will be distributed into PDG (periodontitis diacerein-treated group), PDS (periodontitis sham group) and CG (Control group; healthy periodontium). Periodontitis (P) will be induced with the insertion of a cotton thread in the cervical colon of the upper left 1st molar. After 7 days, the ligature will be removed and the rats with induced periodontal disease will receive 100 mg/kg body weight of diacerein (PDG) by gavage or physiological solution (PSG) for 7, 15 and 30 days. In each period, 6 animals per group (PDG, PSG and CG) will be sacrificed. After euthanasia, maxilla fragments with the molars will be fixed in 4% formaldehyde buffered with 0.01 M sodium phosphate (pH 7.2) for 48 hours. The fragments of maxilla will be decalcified in 7% EDTA for 60 days and then processed for paraffin embedding. From each maxilla, non-serial sagittal sections will be stained with hematoxylin and eosin (HE) and Masson's trichrome for morphological analyses. Three sections of each specimen will be subjected to the tartrate-resistant acid phosphatase (TRAP), used as a marker of osteoclast, and the number of osteoclasts on the interdental alveolar process (between 1º and 2º molars) will be computed. Bone area occupied by interdental alveolar process will be also estimated. Non-serial sections will be adhered to the silane-treated slides and these sections will be submitted to immunohistochemistry reactions for detection of TNF-±, IL-6, RANKL and OPG. In the interdental gingival mucosa (between the 1st and 2nd molars), the numerical density of immunopositive cells for TNF-±, IL-6, RANKL and OPG will be obtained from all animals (6 rats per group/period). The quantitative data will be submitted to two-way ANOVA and Tukey post-test (p £ 0.05). (AU)