The expression of high-mobility group box protein-1 in temporomandibular joint osteoarthritis with disc perforation.

Background High-mobility group box protein-1 (HMGB-1), a potent promoter of inflammation, was believed to be a potential trigger of osteoarthritis (OA). Only a few studies have investigated the role of HMGB-1 in temporomandibular joint (TMJ) OA, especially in disc perforation cases. But in this study, not only the expression of HMGB-1 in TMJ OA with disc perforation was investigated but also the possible role of HMGB-1 in TMJ OA was discussed. Methods Synovial membrane and disc specimens were collected from patients with TMJ OA, and the expression of HMGB-1 was detected using immunohistochemistry, real-time quantitative PCR and Western blotting. Results High-mobility group box protein-1 expressed strongly in cytoplasm and nucleus of lining layer cells and endothelial cells in osteoarthritic synovium. Staining of HMGB-1 was found intensive in the frontier tissue of the perforation in the perforated discs. HMGB-1 expression was also upregulated in osteoarthritic synovial cells and disc cells according to real-time quantitative PCR and Western blotting analysis. Conclusions High-mobility group box protein-1 expression was upregulated in TMJ OA and might promote the progression of TMJ OA.