甘草酸对炎性刺激诱导气道黏蛋白5AC高表达的抑制作用

Glycyrrhizin inhibits human neutrophil elastase-inducedmucin 5AC overproduction in human bronchialepithelial cells

Objective: To investigate the effect of glycyrrhizin (Gly) on human neutrophil elastase (HNE)-
induced mucin (MUC) 5AC overproduction in human bronchial epithelial cells (16HBE), and the
potential signaling pathway involved in this process.
Methods: The cultured cells were divided into 3 groups: a control group, cultured in serum-free
DMEM medium; an HNE group, pretreated with HNE alone; and a Gly group, incubated with
HNE and Gly. After stimulation with a variety of Gly concentrations, the cytotoxicity was assessed by methyl thiazolyl tetrazolium method. The mRNA expressions of p38, nuclear factor κB (NF-κB)
p65, inhibitory κBα (IκBα) and MUC5AC were detected by real-time PCR. The phosphorylation
levels of p38 (p-p38), NF-κB p65 (p-NF-κB p65) and IκBα (p-IκBα) were measured by Western
blot while the levels of MUC5AC protein were analyzed by emzyme-linked immunosorbent assay
and immunofluorescence.
Results: Compared with the control group, the expression levels of MUC5AC mRNA and protein
in the HNE group were both significantly increased. There was a significant increase in p-p38
and p-NF-κB p65, while the production of IκBα was much lower than that in the control group. Gly
significantly inhibited the increase of MUC5AC, p38 and NF-κB p65, but increased the activity of IκBα.
Conclusion: Glycyrrhizin can inhibit MUC5AC overproduction via p38-NF-κB p65/IκBα signaling pathway.