Involvement of lysosomal destabilization and cathepsin B activity with IL-1β production in the presence of silver materials.

<p>(A) PMA-primed THP-1 cells were treated with each of the silver materials (100 µg/mL) for 24 h. At the end of exposure, the cells were loaded with acridine orange (20 µg/mL) for 15 min at 37°C and photographed using a fluorescence microscope (400×). (B) Lysosomal destabilization as measured by loss of fluorescence with increasing concentration of silver materials. The cells were preloaded with acridine orange (0.5 µg/mL) for 30 min, treated with silver materials, and analyzed using FACS to determine the loss of acridine orange from lysosome. Data are represented as the mean ±SD (n = 3). (C) Involvement of cathepsin B in silver materials-induced IL-1β production. The cells were treated with different forms of silver materials for 24 h in both the absence and presence of cathepsin B inhibitor (CA-074-Me; 10 µM). IL-1β levels were measured using ELISA. Data are represented as the mean ±SD (n = 3).