Cyclooxygenase-2 inhibitor rofecoxib prevents chondrocytes against hypertrophy via Wnt/ß-catenin pathway.

Previous reports indicated that specific cyclooxygenase-2 (COX-2) inhibitor suppresses osteoarthritis (OA). This study aimed to further explore the possible mechanism of Rofecoxib as a COX-2 inhibitor on the inhibition of chondrocyte (CH) hypertrophic development and tested the optimal treatment of Rofecoxib on CH. Basically, IL-1ß was used as a stimulus to establish a degenerated CH model. Immunofluorescence, Western blot, and RT-PCR were performed to determine the gene expression of Axin2, ß-catenin, GSK3ß, collagen X, collagen II, COX-2, PGE-2, SOX-9, Runx-2, and MMP- 13 expression. Cell Counting Kit (CCK-8) assay was used to analyze the viability of CHs. The data indicated that Rofecoxib significantly inhibited COX-2 expression and had less harmful effects on CH viability. Rofecoxib reversed the IL-1ß-induced upregulation of collagen X, COX-2, PGE-2, Runx-2, and MMP-13 expression, and promoted the viability of collagen II, SOX-9 expression of CHs. Furthermore, Rofecoxib suppressed Axin2, ß-catenin, and GSK3ß expression of the Wnt pathway, which was activated by IL-1ß or human recombinant Wnt-1 protein treatment. Therefore, Rofecoxib is an effective COX-2 inhibitor that protects CHs from hypertrophy by suppression of the Wnt/ß-catenin pathway.