Abstract:
Objective Study the gene and protein expression of NACHT-PYD-containing protein 3 (NALP3) inflammasome and extracellular regulated protein kinase (ERK), the intervention effects of sodium ferulate (SF) in human lung epithelial cells A549 under oxidative stress, and to investigate the possible mechanism. Methods Human lung epithelial cells A549 cultured
in vitro were divided into 6 groups, including control group, H
2O
2 (200 μmol/L) group, SF group (400 μg/mL), caspase-1 blockers (Z-VAD) group (Z-VAD 20 μmol/L+H
2O
2 200 μmol/L), ERK blockers (PD98059) group (PD98059 50 μmol/L+H
2O
2 200 μmol/L), and SF+H
2O
2 group (SF 400 μg/mL+H
2O
2 200 μmol/L). Fluorescent quantitative real-time PCR (qRT-PCR) was performed to detect the mRNA levels of caspase-1 and
NALP3, the expression of caspase-1, NALP3, phosphorylated ERK p-ERK, ERK protein were evaluated by Western blot. The level of interleukin-1 beta (IL-1β) were detected by ELISA. Results Compared with the control group,H
2O
2 not only increased the mRNA and protein expression levels of caspase-1 and NALP3 and the protein expression levels of p-ERK/ERK, but also enhanced the secretion of IL-1β in human lung epithelial cells A549 (
P <0.05),while SF group showed no statistic significance of those indicators above (
P >0.05). The Z-VAD group, the PD98059 group and the SF+H
2O
2 group resisted the effects of H
2O
2 on A549 cells by decreasing the mRNA and protein expressions of caspase-1 and NALP3,and the protein expression of p-ERK/ERK, as well as reducing the secretion of IL-1β (
P < 0.05),when compared with the H
2O
2 group.Conclusion SF may reduce the expression of caspase-1, NALP3 and IL-1β by inhibiting ERK, so as to reduce the inflammation caused by oxidative stress.