Effect of Hyaluronic Acid on HMGB-1 Expression in TMJ Chondrocytes

Objectives: High mobility group box chromosomal protein 1(HMGB-1) was found up-regulated in temporomandibular joint osteoarthritis (TMJOA) and translocated from nucleus to cytoplasm in TMJ chondrocytes stimulated by interleukin-1β(IL-1β). Hyaluronic acid(HA) injection was proved to be a valid method to treat TMJOA but the substantial mechanism is unknown. In this study the effect of HA on HMGB-1 expression of TMJ chondrocytes was clarified and the probably mechanism was discussed
Methods: HA (100μg/ml ) and glycyrrhizin (GL, 100μM) were respectively incubated in chondrocytes with 10ng/ml IL-1β stimulation. Total RNA and protein were collected 24h after stimulation. mRNA expression of HMGB-1 , Toll like receptor 2(TLR2 )and TLR4, and protein expression of HMGB-1 were detected.
Results: After IL-1β stimulation, the mRNA expressions of HMGB-1, TLR2 and TLR4 were increased. While the mRNA expressions of HMGB-1, TLR2 and TLR4 were significantly decreased with the addition of HA or GL comparing to IL-1β stimulation only (p<0.05). Also the protein expression of HMGB-1 was decreased after HA or GL stimulation (p<0.05)
Conclusions: HA could decrease the HMGB-1 expression of TMJ chondrocytes in IL-1β stimulation.