Identification of α- and β- adrenergic agonists inducing CFTR-independent fluid secretion in nasal airway organoids under IL-4 Inflammatory Conditions

Increasing airway epithelial fluid secretion is proposed as a therapeutic strategy to mitigate mucus obstruction in chronic airway diseases. While the role of the CFTR chloride channel in promoting fluid secretion is well-established, understanding the contribution of other ion channels and transporters is needed to identify target-specific therapies. In our study, we used nasal airway organoids from subjects with cystic fibrosis, lacking CFTR function, to identify drugs capable of inducing CFTR-independent fluid secretion under IL-4 inflammatory conditions. We conducted screening of an FDA-approved drug library containing ~1400 compounds in IL-4-treated nasal organoids cultured in a 384-well plate format. RNA-sequencing was employed to identify ion channels and transporters upregulated in IL-4-treated nasal organoids. Subsequently, CRISPR-Cas9-based gene knockouts were generated to investigate the involvement of identified ion channels and transporters in mediating organoid fluid secretion induced by FDA-approved drugs. We predominantly identified α- and β-agonists as hits among the FDA-approved drugs. RNA-sequencing analysis revealed elevated expression of TMEM16A, SLC26A9, and SLC26A4 in IL-4-treated organoids. However, gene knockout studies did not show significant alterations in fluid secretion induced by the identified drugs. In conclusion, we have identified α/β-agonists as inducers of CFTR-independent fluid secretion in IL-4 treated nasal organoids. However, the responsible ion channels and transporters mediating fluid secretion remain elusive. Further studies are therefore needed to elucidate alternative pathways.