Figure 4.

Extracellular histones activate NLRP3 inflammasome during liver I/R. (A) Western blot images showing inflammasome protein level activated caspase-1, IL-1β and IL-18 in liver of WT (C57BL/6) mice at 6 hours after reperfusion. Sham or I/R-treated mice was given either a nonlethal dose of exogenous histone mixture (25 mg/kg body weight), vehicle PBS, anti-histone H3 antibody, anti-histone H4 antibody (20 mg/kg body weight) or control antibody intravenously 30 minutes prior to ischemia. Each lane represents a separate animal. (B) Activation of caspase-1 in WT mice treated with vehicle PBS, exogenous histone mixture, anti-histone H3 or anti-histone H4 antibody that were subjected to liver I/R compared to sham treated-mice, assessed by colorimetric assay. Data represent the mean ± SE (n = 6 mice per group). ANOVA Tukey test, *P < 0.05, PBS vs. Histones; **P < 0.05, anti-histone H3 or H4 vs. PBS. Extracellular histones activate NRLP3 inflammasome through TLR9 signaling pathway during liver I/R. (C) Protein levels of activated caspase-1, IL-1β and IL-18 in liver of TLR9 mutant or WT mice treated with PBS or exogenous histones (25 mg/kg body weight) and quantitative densitometry of the protein expressions of activated caspase-1. (D) Protein levels of activated caspase-1, IL-1β and IL-18 in liver of TLR9 inhibitor treated- or control CpG treated-mice administrated with PBS or exogenous histones and quantitative densitometry of the protein expressions of activated caspase-1. Each lane represents a separate animal and each animal was harvested after 6 hours of reperfusion. The blots shown are representatives of three experiments with similar results Student’s t-test, *P < 0.05, PBS vs. Histones.