关键词: 木犀草素, 脂多糖, 肠上皮细胞, 核苷酸结合寡聚化结构域样受体家族吡啉结构域蛋白 3, 半 胱氨酸蛋白酶 1, 炎性损伤

Abstract: Objective To investigate the effect of luteolin on lipopolysaccharide ( LPS) -induced intestinal epithelial cell pyroptosis via NOD-like receptor family pyrin domain containing 3 (NLRP3) / caspase-1 pathway. Methods Human intestinal epithelial cells HIEC-6 were cultured in vitro, and induced by LPS (1. 0 μg / mL), then the cells were divided into control group, LPS group, LPS + (25, 50, 100 μmol / L) luteolin groups, luteolin + NLRP3 activator nigericin sodium (NSS) group. LPS (1. 0 μg / mL) was added in each group except for the control group. Cell viability was assayed by the MTT method. Monolayer epithelial transmembrane resistance (TEER) was determined by the resistance meter. The levels of lactate dehydrogenase (LDH), tumor necro- sis factor-α ( TNF-α) and interleukin-6 ( IL-6) in each group were measured by the enzyme-linked immunosorbent (ELISA) method. The expression levels of pyroptosis-related proteins (GS-DMD, GSDMD-N) and NLRP3, caspase-1, IL-1β in each group were detected by Western blotting (WB). Results Compared with the control group, the cell viability and TEER value in the LPS group were significantly reduced, and the levels of cell supernatant LDH, TNF-α, IL-6, and the expression levels of GSDMD, GSDMD-N, NLRP3, caspase-1 and IL-1β were significantly increased (P< 0. 05). Compared with the LPS group, the cell viability and TEER value in the LPS + (25, 50, 100 μmol / L) luteolin groups were significantly higher, and the levels of cell supernatant LDH, TNF-α, IL-6, and the expression levels of GSDMD, GSDMD-N, NLRP3, caspase-1, IL-1β were significantly reduced (P< 0. 05). Compared with the LPS + 100μmol / L luteolin group, the cell viability and TEER value in the luteolin + NSS group were significantly reduced, and the levels of cell supernatant LDH, TNF-α, IL-6, the expression levels of GSDMD, GSDMD-N, NLRP3, caspase-1, IL-1β were significantly increased (P< 0. 05). Conclusion Luteolin can alleviate the pyroptosis and inflammatory injury of human intestinal epithelial cells HIEC-6 induced by LPS, this may be related to the inhibition of NLRP3 / caspase-1 signaling pathway.

Key words: luteolin, lipopolysaccharide, intestinal epithelial cells, NOD-like receptor family pyrin domain containing 3, caspase-1, inflammatory injury