Xiao Qingrong, Zhou Xiangdong
Department of Respiration, Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2014 Mar;39(3):252-7. doi: 10.11817/j.issn.1672-7347.2014.03.005.
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.
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.
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.
Glycyrrhizin can inhibit MUC5AC overproduction via p38-NF-κB p65/IκBα signaling pathway.
研究甘草酸（Gly）对人中性粒细胞弹性蛋白酶（HNE）诱导的人支气管上皮细胞（16HBE）中黏蛋白（MUC）5AC过度产生的影响，以及该过程中潜在的信号通路。
将培养的细胞分为3组：对照组，在无血清DMEM培养基中培养；HNE组，仅用HNE预处理；Gly组，用HNE和Gly孵育。用不同浓度的Gly刺激后，采用甲基噻唑基四氮唑法评估细胞毒性。通过实时PCR检测p38、核因子κB（NF-κB）p65、抑制性κBα（IκBα）和MUC5AC的mRNA表达。用蛋白质免疫印迹法检测p38（p-p38）、NF-κB p65（p-NF-κB p65）和IκBα（p-IκBα）的磷酸化水平，同时用酶联免疫吸附测定法和免疫荧光法分析MUC5AC蛋白水平。
与对照组相比，HNE组中MUC5AC mRNA和蛋白的表达水平均显著升高。p-p38和p-NF-κB p65显著增加，而IκBα的产生远低于对照组。Gly显著抑制MUC5AC、p38和NF-κB p65的增加，但增加了IκBα的活性。
甘草酸可通过p38-NF-κB p65/IκBα信号通路抑制MUC5AC的过度产生。
