Fig. 4

Spermidine inhibits macrophage NLRP3 inflammasome activation and IL-1β production. PMA-differentiated THP-1 macrophages were pretreated with spermidine for 1 h and then stimulated by LPS (200 ng/ml) for 24 h. A NLRP3 and B pro-IL-1β mRNA expression were detected by qPCR. C Secretion of IL-1β was determined by ELISA. D THP-1 macrophages were pretreated with spermidine (50 μM) for 1 h and then stimulated by LPS (200 ng/ml) for 24 h. Western blot analysis of NLRP3, pro-IL-1β, p-NF-κB, NF-κB and β-actin. Cellular mRNA levels of E CXCL-1, F MCP-1, G IL-6, H TNF-α, I CXCL-2 were examined by qPCR. Levels of J MCP-1 and K IL-6 in the culture supernatants were determined by ELISA. Experiments were performed in triplicate. Data are expressed as mean ± SEM. One-way ANOVA followed by post hoc Sidak test. *P < 0.05, **P < 0.01, ***P < 0.001