FIG. 5.

Mechanism of DUOX1- and ROS-dependent mucin production involving PKCδ/θ in airway epithelial cells. Schematic model of Shao and Nadel (modified) (133). PKC isoforms are activated by stimulus (e.g., phorbol myristate acetate [PMA]). PKC then stimulates DUOX. In turn, ROS generated by DUOX activate TACE, which cleaves pro-TGF into TGF. TGF activates EGFR and initiates MAPK, leading to mucin gene expression. TACE, tumor necrosis factor-α-converting enzyme; TGF, transforming growth factor; EGFR, epidermal growth factor receptor; MAPK, mitogen-activated protein kinase; DUOX, dual oxidase.