FIGURE 8.

NLRP-3 inflammasome activation by AgNP₁₅ is dependent on caspase-1 in human monocyte THP-1 cells. A–C, cells were transfected with siRNA targeting NLRP-3 or nonspecific sequence (Ctrl) for 24 or 48 h. A and B, protein expression of NLRP-3 was followed by Western blot, as described under “Experimental Procedures.” C, quantification of IL-1β secretion. si Ctrl, siRNA targeting nonspecific sequence; si NRLP-3, siRNA targeting NLRP-3. D, cells were primed with LPS (100 ng/ml) for 4 h, treated or not with 10 μm YVAD-CHO, and then stimulated for 1 h with 25 μg/ml AgNP₁₅, 2 mm ATP, or buffer (Ctrl). Supernatants were harvested to quantify IL-1β by ELISA. Data are from one representative experiment out of three (A) and are expressed as means ± S.E. of three independent experiments (B–D). Differences were considered statistically significant as follows: *, p ≤ 0.05, **, p ≤ 0.01, and ***, p ≤ 0.005 versus control or appropriate diluent.