SP activated the PI3K/AKT/NF-κB signaling pathway to induce pyroptotic cell death and cellular inflammation in the bronchial epithelial cells. (a): CCK8 analysis of cell viability treated with LY294002 or MG132. (b, c) Colony formation assays with control, SP, SP+MG132 and SP+LY294002 in 16-HBE and BEAS-2B cells. (d): Caspase-1 and ASC immunofluorescence of 16-HBE cells treated with LY294002 or MG132. (e): Caspase-1 and ASC immunofluorescence of BEAS-2B cells treated with LY294002 or MG132. (f, g): The release of LDH from LY294002 or MG132 treated 16-HBE and BEAS-2B cells was measured by LDH assay kit. (h, i): Protein levels of NLRP3, ASC and Caspase-1 were detected by Western blot. (j, k): The levels of IL-1β and IL-18 after LY294002 or MG132 treatment were determined by ELISA. Each experiment was conducted in triplicate. *P < 0.05, ** P < 0.01, ***P < 0.001, ****P < 0.0001.