Papel de HMGB1 no processo de reparo ósseo alveolar em camundongos

• Ano de defesa: 2017
• Autor(a) principal: Moura, Tainah Oliveira
• Orientador(a): Repeke, Carlos Eduardo Palanch
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Ciências Aplicadas à Saúde
• Palavras-chave em Português: Proteínas; Agentes anti-inflamatórios; Imunologia; Ossos > Doenças; Osteogênese; HMGB1
• Palavras-chave em Inglês: Immunology; Inflammation; Osteogenesis
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/7206

Although the relationship between bone formation and the immune / inflammatory response is extremely important for the bone repair process, such interaction remains poorly understood. While an exaggerated immune / inflammatory response is associated with bone resorption, an ideal transient response of low magnitude is essential in the process. In this context, signaling mediated by Toll receptors (TLRs) and RAGE receptors plays a key role in initiating the immune / inflammatory response through the recognition of molecular patterns associated with damage (DAMPs). One of the major DAMPs recognized by TLR4 and RAGE is the HMGB1 protein. Once activated by HMGB1, these receptors are able to generate several important inflammatory mediators in the process of alveolar bone repair. Nevertheless, the mechanisms of "trigger" of the production of cytokines and inflammatory mediators with respect to the bone repair, nor the amount necessary, are not clear. In view of this, we aimed to investigate the influence of the HMGB1 ligand on the generation of immune / inflammatory response and on the bone repair subsequent to the extraction of the superior incisor of mice. For this, 40 mice were divided into two groups [Control Group - WT; Group GLY - treated with glycyrrhizin (HMGB1 inhibitor)] and analyzed for alveolar bone repair in the periods of 0, 7, 14, 21 days after exodontia. Samples were submitted to histological processing and analyzed under optical microscopy for histomorphometric characterization (qualitative and quantitative), and analyzed by MicroCt for description of bone structures. In the histomorphometric analysis, the results showed a higher clot density in the GLY group in the 14-day period (p <0.05); As well as more inflammatory cells in the period of 7 and 14 days compared to the control (p <0.05). As well, it presented higher density of fibroblasts in the periods of 7, 14 and 21 days and lower density of fibers in 7 days (p <0.05). The GLY group had lower vessel densities in the periods of 7, 14 and 21 days. (P <0.05). The GLY group presented lower osteoblasts and higher osteoclasts compared to the control group at 7 and 14 days (p <0.05). Regarding the MicroCt, the images of both groups were performed and did not present significant difference between the groups. Therefore, inhibiton of HMGB1 protein was not able to interfere in the kinetics of alveolar bone repair in mice, but showed differences in some components involved in alveolar bone repair kinetics.