Figure 6.

Modulation of TGF-β1-induced Erk signaling in chondrocytes. Chondrocytes were stimulated with indicated concentrations of TGF-β1 alone or in combination with COMP (10 µg/mL) or TSP-4 (10 µg/mL) before Erk1/2 proteins were detected by immunoblot. (a) Representative immunoblots show the concentration-dependent TGF-β1 induced phosphorylation of Erk1/2 (pErk1/2) and total Erk1/2. Representative immunoblots show the influence of COMP (b) and TSP-4 (c) on the concentration-dependent TGF-β1 induction of Erk1/2 phosphorylation. GAPDH was used as a loading control; (n = 4).