Semaglutide and pioglitazone restore airway mucosal homeostasis by resolving Pseudomonas aeruginosa pyocyanin-induced mucus hypersecretion, ciliostasis, and type 2 airway inflammation.

RATIONALE: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. As lung transplantation is the only curative option and current therapies are largely based on managing clinical symptoms, novel treatments are urgently needed. OBJECTIVE: Previously, we showed that the first-generation incretin Exedine-4 could attenuate airway mucus dysregulation induced by the Pseudomonas aeruginosa redox-active toxin pyocyanin by modulating GLP1R-PPARγ signaling. In this study, we compared the efficacy of currently approved next-generation GLP1R agonists and PPARγ agonists in improving airway mucus homeostasis, mucociliary escalator function, and P. aeruginosa clearance after chronic exposure to pyocyanin, as well as the underlying mechanisms. METHODS: Six GLP-1R agonists and two PPARγ agonists were compared based on their ability to attenuate pyocyanin-induced oxidative stress and mucin overexpression in 16HBE14o- cells by the cellular reactive oxygen species (ROS) assays, immunoblotting, and confocal immunofluorescence microscopy. The ability of these agonists to restore the mucociliary escalator function in air-liquid interface (ALI) cultures of primary human small airway epithelial cells (SAECs) was captured by confocal immunofluorescence microscopy. Then, we examined whether these agonists could restore mucus homeostasis, neutralize lung proinflammatory responses, and reduce bacterial burden in C57BL/6 mice. Finally, the expression of relevant pro- and anti-mucin biosynthesis signaling pathways was investigated. MEASUREMENTS AND MAIN RESULTS: Semaglutide and Pioglitazone are the most effective in decreasing the expression of mucus biomarker MUC5AC mucin and ROS production in response to pyocyanin, both in vitro and in vivo. Additionally, these agonists restore mucociliary beat frequency and mucociliary transport impaired by pyocyanin. The protective effects of these drugs were partially abolished by respective antagonists, Exendin(9-39) and GW9662, against GLP1R and PPARγ, confirming the GLP1R signaling pathway-dependent mechanisms. Moreover, Semaglutide and Pioglitazone also attenuated type 2 immune responses and neutrophil influx, both of which are known drivers of mucus hypersecretion, and reduced the P. aeruginosa burden in a chronic bronchitis model of infection in mouse lungs. CONCLUSIONS: Our findings identify a promising adjunctive therapeutic avenue for COPD by repurposing FDA-approved Semaglutide and Pioglitazone, which are readily available for clinical use.