Figure 4

Postn suppressed Col2a1 and Acan expression and promoted IL-6 and Mmp3 expression by activating the integrin-focal adhesion kinase (FAK)-Src-nuclear factor κB (NF-κB) signaling pathway in chondrocytes. (a) Relative mRNA expression of IL-6, Mmp3, Col2a1, Acan and Col1a1 in chondrocytes treated with recombinant Postn (rPostn) (0, 1, and 10 μg/ml) for 24 h (n = 6 per group). (b) Western blot analysis for evaluating p-FAK, FAK, p-Src, Src, p-p65, p65, and β-catenin expression in rat primary chondrocytes treated with rPostn (1 μg/ml) alone or together with integrin αVβ3 antibody or Cilengitide (2.5 μM) for 1 h. (c) Western blot analysis to detect the expression of p-FAK, FAK, p-Src, Src, p-p65, and p65 in rat primary chondrocytes treated with rPostn (1 μg/ml) alone or together with FAK inhibitor 14 (2.5 μM) or PP2 (2.5 μM) for 1 h. (d) Relative mRNA expression of IL-6 and Mmp3 in rat primary chondrocytes treated with rPostn (10 μg/ml) alone or together with Cilengitide, PP2, or BAY11-7082 (5 μM) for 24 h (n = 6 per group). The Kruskal–Wallis test was used for multiple comparisons. The Mann–Whitney U test was used for comparisons between two groups. Values indicate the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001.