FIGURE 6.

Knockdown of integrin αVβ3 weakened the anti-inflammatory, anabolism enhancing, and catabolism inhibiting effect of PA on IL-1β-induced chondrocytes. (A,B) Relative mRNA levels of integrin αV (Itg αV) and integrin β3 (Itg β3) in chondrocytes stimulated with 5 ng/ml of IL-1β, alone or with PA (2.5, 5, and 10 μM) for 24 h (C,D) Itg αV and Itg β3 were knocked down by siRNA transfection, and the knockdown efficiency was verified by RT-PCR. (E,F) Inflammatory markers (COX2, iNOS) were detected by western blotting and the band density of protein levels were quantified after mice chondrocytes were added with or without 5 ng/ml of IL-1β, 10 μM of PA, and Itg αVβ3 siRNA. (G–I) Western blotting was applied to measure the anabolic (aggrecan, collagen II) and catabolic markers (MMP1, MMP3, MMP13, and ADAMTS5) in the Itg αVβ3-deficiency mice chondrocytes along with or without the administration of 5 ng/ml of IL-1β and 10 μM of PA, and the band density of these protein levels were quantified in the histogram. GAPDH was used as an internal reference. Data are presented as means ± SD (n = 3). The exact p value was marked in the corresponding figure and p < 0.05 was considered statistically significant.