Fig. 12
The role of MMP-3-cleaved OPN in Nano-CuO-induced activation of MRC-5 fibroblasts in the triple co-culture system. BEAS-2B and U937* cells were seeded at the ratio of 1:1 (a and b) or 9:1 (c and d) (BEAS-2B:U937*) in the inserts, and MRC-5 fibroblasts were seeded in the lower chambers of Transwell® units. MRC-5 fibroblasts were pretreated with 200 µg/mL of GRGDSP peptides, then BEAS-2B and U937* cells were exposed to 1 µg/mL of Nano-CuO for 12 h. After exposure, the inserts were taken out and the MRC-5 fibroblasts were incubated for another 36 h. The proteins from MRC-5 fibroblasts were isolated to determine the activation of MRC-5 fibroblasts by Western blot. a and c were the results of a single Western blot experiment. b and d were the average expression levels of α-SMA, Col1A1, and fibronectin normalized to β-actin from three independent experiments. Data represent mean ± SE (n = 3). * Significant difference as compared to the control group, p < 0.05; # Significant difference as compared to the Nano-CuO-treated alone group, p < 0.05