Figure 9.

A peroxynitrite decomposition catalyst (Fe-TPPS) decreases ATP-induced activation of the NLRP3 inflammasome. Fibroblasts were challenged with LPS (1 μg/mL) for 6 h. Subsequently, the fibroblasts were treated with Fe-TPPS (25 μM) or vehicle for 15 min, followed by ATP (3 mM) for an additional 30 min. (A–C) NLRP3 and pro-IL-1β protein levels were indices of inflammasome priming. Representative Western blots are shown in (A) and densitometric analyses in (B,C). Of note, NLRP3 and pro-IL-1β were increased after the initial LPS challenge, but the subsequent challenge with ATP was without effect on these two indices of inflammasome priming. (D–F) Caspase1 activation (p20) and IL-1β protein levels in the supernatant were indices of inflammasome activation. Representative Western blot for caspase1 p20 is shown in (D) and densitometric analysis in (E). Protein levels of IL-1β were assessed in supernatants by ELISA. n = 3, *p < 0.05 as compared with control; ^#p < 0.05 as compared with LPS+ATP.