Chondrocytes were treated with IL-1脽 in the presence of different inhibitors. T脽RII and Cav-1 expression were assayed by Western blot and RT-PCR.
We showed that IL-1脽-induced degradation of T脽RII is dependent on proteasome and on its internalization in caveolae. In addition, IL-1脽 enhances Cav-1 expression, a major constituent of lipid raft.
In conclusion, we enlighten a new mechanism by which IL-1脽 antagonizes TGF脽 pathway and propose a model of T脽RII turnover regulation upon IL-1脽 treatment.