Stromal cell‐derived factor‐1 regulates the secretion of interleukin‐1β in the temporomandibular joint of rats with synovial inflammation

BACKGROUND: Synovitis is characterized by the infiltration of inflammatory cells and often accompanies the pathological progression of the clinical symptoms affecting the temporomandibular joint (TMJ), such as pain, snapping, and limited mouth opening. It has been suggested that the signal transduction pathway and resultant proinflammatory mediators play important roles in the pathogenesis of synovitis. Therefore, in this present research, we aimed to investigate the changes in the expressions of stromal cell‐derived factor 1 (SDF‐1) and interleukin (IL)‐1β in rats with occlusal interference. MATERIALS AND METHODS: We divided 36 male Wistar rats into the following groups: Group A (control group), Group B (occlusal interference group), and Group C (AMD3100 group). Synovial inflammation was induced in the rats in Groups B and C to establish the occlusal interference model. The inflammatory changes were detected, and the expressions of SDF‐1 and IL‐1β in the synovium were assayed via immunostaining and a real‐time quantitative polymerase chain reaction (PCR). RESULTS: In Group B, obvious inflammatory changes were observed in the synovial membranes; additionally, the SDF‐1 and IL‐1β expression levels were significantly higher at the protein and mRNA levels. However, in Group C, these experimental results were inhibited by an injection with AMD3100. CONCLUSION: These results may indicate that SDF‐1 regulates the expression level of inflammatory factors, such as IL‐1β, in the synovial membranes of rats with occlusal interference. Our findings suggest that the SDF‐1 axis may contribute to the onset of synovitis during the development of TMJ joint disease.