Effect of HNE-induced PKCδ/θ -Duox1-ROS on airway mucus hypersecretion: A vitro experimental study.

Objective: To investigate regulatory effect and mechanism of protein kinase C (PKC)δ/θ-dual functional oxidase 1 (Duox1)-reactive oxygen species (ROS) signaling pathway on human airway mucin (MUC) 5AC, to provide a new target for treatment of high secretion of airway mucus. Methods: Human airway epithelial cells 16HBE were pretreated with PKC and its subunit PKCδ/θ inhibitor, Duox1 inhibitor or free radical scavenger DMTU, respectively, and then human neutrophil elastase (HNE) stimulation to establish an in vitro airway inflammatory cell model. Generation level of ROS in each group of cells was determined by kit, mRNA levels of Duox1 and MUC5AC were detected by real-time fluorescent quantitative PCR, influence of interfering factors of each group of cells on Duox1 protein level was determined by Western blot, and protein expression of MUC5AC in each group of cells was detected by ELISA and immunofluorescence. Results: Compared with control group, ROS production in HNE group was increased significantly, expressions of Duox1 and MUC5AC mRNA and protein were also increased (P<0.05). After administration of Duox1 inhibitors, free radical scavengers or PKC inhibitors and PKCδ/θ inhibitors, ROS production was significantly inhibited, Duox1 and MUC5AC mRNA and protein expressions were decreased (P<0.05), while after giving PKCα/β, ROS generation, Duox1 and MUC5AC mRNA and protein expressions were not significantly changed compared with HNE group (P>0.05). Conclusion: HNE can mediate high expression of MUC5AC through PKCδ/θ-Duox1-ROS, which plays an important role in development of high secretion of airway mucus in vitro cell model experiment. [ABSTRACT FROM AUTHOR]