FIGURE 4.

PA upregulated anabolic indicators including collagen II, aggrecan, and SOX9 expression in IL-1β-induced chondrocytes. (A) Western blotting results and (B–D) quantitative analysis of collagen II, aggrecan, and SOX9. (E) Safranin O staining reflected the content of proteoglycan among the control, IL-1β (5 ng/ml), and IL-1β (5 ng/ml) + PA (10 μM) groups (scale bar 200 μm). (F–H) Relative mRNA levels of collagen II, aggrecan, and SOX9 in chondrocytes stimulated with 5 ng/ml of IL-1β, alone or with PA (2.5, 5, and 10 μM) for 24 h. 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. (I,J) Collagen II and aggrecan expression observed by immunofluorescence staining when chondrocytes were treated with 5 ng/ml of IL-1β, alone or with 10 μM of PA (scale bar 200 μm).