[Pro-inflammatory mechanism of lectin from Pinellia pedatisecta on macrophage]

To investigate the mechanism of lectin from Pinellia pedatisecta(PPL) on macrophage-induced inflammation and its association with inflammatory corpuscles NLRP3. Lectin from P. pedatisecta was isolated and purified by gel chromatography, and its purity was analyzed by using SDS-PAGE gel electrophoresis. ELISA was used to investigate the effect of PPL on inflammatory cytokines released by macrophages, with IL-1β as indicators;and fluorescence probe DCFH-DA fluorometer was used to determine changes in active oxygen ROS of macrophages after application of lectin from P. pedatisecta.RAW264.7 cells were pre-treated with ROS inhibitor N-acetylcysteine (NAC) to investigate the effect on ROS and the release of inflammatory factor IL-1β from macrophages to research the relationship between them. The protein levels of NLRP3, Caspase-1 p20, ASC and TXNIP were determined by Western blot.The results showed that isolated and purified PPL could reach electrophoretic purity; PPL stimulated macrophages and induced the excessive release of ROS, leading to strong oxidative stress reaction, and the levels of intracellular inflammatory factorsIL-1β were significantly increased. NAC could inhibit PPL-induced ROS excessive production and significantly reduce the release of IL-1β. In addition, PPL could induce the increase in protein expression levels of Caspase-1 p20, NLRP3 and ASC, and significantly reduce TXNIP expression. The results showed that PPL could cause a strong oxidative stress response by stimulating macrophages, activate inflammatory corpuscles NLRP3, and result in large amount of IL-1β release. That is, PPL could lead to inflammatory cascade reaction by promoting the maturation and secretion of IL-1β through ROS-TXNIP-NLRP3-IL-1β signaling pathway.