Effect of osteopontin on the expression of hyaluronic acid in human knee osteoarthritic chondrocytes / 中国组织工程研究

ABSTRACT

BACKGROUND:Both osteopontin and hyaluronic acid involve in the pathological process of osteoarthritis, resulting in the abnormal expression levels of various cytokines and enzymes. However, the relationship between the high expression of osteopontin and hyaluronic acid in chondrocytes remains unclear. OBJECTIVE:To investigate the effect of osteopontin on the expression of hyaluronic acid in human knee osteoarthritic chondrocytes in vitro by modulating the level of osteopontin. METHODS:Chondrocytes from human knee osteoarthritic cartilage were cultured in vitro, and were then divided into three groupsblank control group without any treatment;osteopontin group and and pontin siRNA group were treated with 1 mg/L recombinant human osteopontin and osteopontin siRNA, respectively. Expression levels of osteopontin, hyaluronic acid synthase 1, 2 and 3 mRNA were detected by real-time PCR, and the levels of hyaluronic acid were measured using ELISA. RESULTS AND CONCLUSION:Compared with the blank control group, the mRNA expressions of hyaluronic acid synthase 1, 2 and 3 were remarkably increased in the osteopontin group, while siRNA made the significantly inhibitory effects on the hyaluronic acid synthase 1, 2 and 3 mRNA expressions (P<0.05). The level of hyaluronic acid in chondrocytes in the osteopontin group was significantly higher than that in the other two groups (P<0.05). Our results suggest that osteopontin induces the synthesis of hyaluronic acid in osteoarthritic chondrocytes through upregulating the hyaluronic acid synthases expression levels.