Fig. 5

NLRP3 inflammasome involvement in AuNP pro-inflammatory responses. THP-1 cells were treated with AuNPs at 3.2 (Au_SC) or 2.5 (Au_CHIT) µg/ml. mRNA of (a) IL-1β and (b) NLRP3 was determined by qRT-PCR after 1 and 24 h exposure; results are expressed in relation to the RPLP0 housekeeping gene, and each data point represents the mean ± SEM of at least three independent biological replicates; statistical significance (determined by ANOVA with Tukey posthoc) of particle treatments compared to controls is shown by *p < 0.05 for medium only, and ^p < 0.05 for 1 ng/ml LPS. The effect of Ac-YVAD-CMK (caspase-1 inhibitor) on AuNP-induced IL-1β and TNF-α secretion was determined by ELISA after 4 and 24 h; AuNP exposures were performed in c absence or d presence of LPS co-stimulation; results are expressed as cytokine release (pg/ml), and each data point represents the mean ± SEM of at least three independent biological replicates. Statistical significance (determined by ANOVA with Tukey posthoc) is shown by *p < 0.05 compared to relevant negative controls, and (determined by T-Test) with ^p < 0.05 when comparing corresponding inhibited and uninhibited exposures