Fig. 7
Silica-induced phosphorylation of S198 NLRP3 leads to mitochondrial depolarization. a Western blot analysis of S198 phosphorylated NLRP3 (pNLRP3 in 16HBE cells treated with silica (5 μg/cm2) for times indicated. b Immunoprecipitation analysis of pNLRP3 (S198) in 16HBE cells transfected with WT NLRP3-Flag or mutant S198A NLRP3-Flag for 24 h and thereafter exposed to silica for times indicated. c Western blot analysis of pNLRP3 (S198) in 16HBE cells pretreated (1 h) with JNK inhibitor (10 μM) and thereafter treated with silica (5 μg/cm2) for times indicated. d Mitochondrial membrane potential (JC-1 staining) in 16HBE cells pretreated with JNK inhibitor (20 μM) and thereafter treated with silica (5 μg/cm2) for times indicated. e, f Mitochondrial membrane potential (JC-1 staining) in A549 NLRP3 KO cells transfected with WT NLRP3-Flag or mutant S198A NLRP3-Flag plasmids for 24 h (e) and thereafter treated with silica (f) for times indicated. g Representative confocal images showing co-localization of Flag (green) and Tom20 (red) in 16HBE cells treated as in b. Bars show means ± SD. All experiments were performed at least in triplicate. *p < 0.05, **p < 0.01 compared to untreated cells, or #p < 0.05 compared to cells not exposed to inhibitor, as determined by ANOVA