Infection and apoptosis associated with inflammation in periodontitis: An immunohistologic study

Objective Evidence of increased apoptosis is observed in periodontitis, and may be associated with destruction of the periodontal tissue caused by the increased cell death, with the release of danger signals and subsequent stimulation of the proinflammatory processes. However, the exact mechanisms associated with these processes remain unclear. This study aimed to investigate the presence of the periodontal pathogen Treponema denticola, apoptosis, High Mobility Group Box1 as a damage-associated molecular pattern and several inflammatory markers in periodontitis and gingivitis subjects. Materials and methods Soft tissue specimens from gingival tissues of periodontitis and gingivitis patients were used for immunohistochemical and immunofluorescence staining of Treponema denticola chymotrypsin-like proteinase (CTLP), apoptosis markers, High Mobility Group Box1, Toll-like receptor 4, inflammatory cell markers and proinflammatory cytokines. Results Treponema denticola was detected in all periodontitis-affected tissues. This was associated with a significant increase in the number of apoptotic cells, including macrophages, alterations in the expression of High Mobility Group Box1 and its receptor, and increased levels of proinflammatory cytokines compared with gingivitis. Conclusions In summary, the presence of Treponema denticola (especially its CTLP), apoptosis, High Mobility Group Box1, and inflammatory markers suggest their potential involvement in the pathogenesis of periodontitis. This article is protected by copyright. All rights reserved.