Objective The study seeks to investigate the expression of S100A9 and its potential role in periodontal diseases induced by diabetes.Methods A diabetic SD rat model was established through intraperitoneal injection of streptozotocin (STZ). Hematoxylin-eosin (HE) staining was performed to study the structure of the periodontium of diabetic rats. Using immunohistochemical staining, the distribution of S100A9 expression was detected in the periodontium of diabetic rats. Expressions of Toll-like receptor 4 (TLR4) (ligands of S100A9) and p-P65/nuclear factor κB (NF-κB) were also measured.Results The trabecular structure of alveolar bone was sparser, and lamina dura was disappeared in diabetic rats. Obviously higher expressions of S100A9 were observed in the periodontal ligament, alveolar bone, and gingival epithelial of diabetic rats than in the control rats. TLR4 expressions in the periodontal ligament, alveolar bone and gingival epithelial of the diabetic rats were also higher as compared to the control rats. p-P65 expression was not detected in the control rats, but was detected in the periodontal ligament and alveolar bone of the diabetic rats.Conclusion Periodontium lesions in diabetes mellitus may be induced by the activation of TLR4 and NF-κB signaling pathway meditated by S100A9.
