FIGURE 8.

Summary of mechanisms by which CS negatively regulates IL-1β secretion in murine macrophages. A treatment with LPS activates NF-κB signaling via TLR4 (Signal 1), and induces the expression of NLRP3 and pro-IL-1β. NLRP3 inflammasome components, which consist of NLRP3, ASC, and caspase-1, are assembled after exposure to extracellular ATP via P2X7 receptors (Signal 2), and induces the activation of caspase-1, which leads to the secretion of IL-1β and pyroptosis. CS does not interfere with NF-κB signaling (Signal 1), but inhibits the activation of caspase-1 (Signal 2) by attenuating the adenosine monophosphate (AMP) kinase pathway, which is followed by the negative regulation of IL-1β secretion and pyroptosis.