Thrombin Promotes Matrix Metalloproteinase-13 Expression through the PKCδ/c-Src/EGFR/PI3K/Akt/AP-1 Signaling Pathway in Human Chondrocytes
Figure 5
Involvement of EGFR transactivation and subsequent PI3K/Akt activation in thrombin-induced MMP-13 expression. ((a) and (b)) qPCR and ELISA analyses of MMP-13 expression in chondrocytes, which were pretreated with Ly294002 or the Akt inhibitor for 30 min or transfected with siRNAs against p110 or Akt for 24 h and then stimulated with thrombin for 24 h. (c) Western blotting analyses of p110 and Akt phosphorylation in cells incubated with thrombin for the indicated time intervals. (d) Western blotting analyses of p110 and Akt phosphorylation in chondrocytes pretreated with rottlerin, PP2, or AG1478 for 30 min and then stimulated with thrombin for 60 min. * as compared with basal levels. # as compared with the levels in the thrombin-treated group.
