GY971 mitigates inflammation by reducing neutrophil recruitment in cystic fibrosis Ex Vivo and In Vivo models

Background: There is a prominent need for anti-inflammatory agents for people with CF (pwCF), even in the era of CFTR modulators. ETI (Elexacaftor/Tezacaftor/Ivacaftor) reduces but does not eliminate pulmonary inflammation, that chronically damages CF pulmonary tissues and favors recurrent pulmonary exacerbations. Furthermore, although known anti-inflammatory drugs are beneficial to pwCF, their side effects are limiting the clinical use. To address this issue, we developed a new synthetic furocoumarin molecule named GY971, able to reduce the excessive accumulation of neutrophils in the bronchial lumen, by targeting the nuclear transcription factor NF-kB. Methods: To assess its efficacy, GY971 was tested in human primary bronchial and nasal epithelial cells obtained ex vivo from different pwCF carrying the F508del mutation and infected with Pseudomonas aeruginosa. Moreover, GY971 was also administered in a zebrafish model infected with Pseudomonas aeruginosa in vivo. Results: GY971 reduced neutrophil chemotaxis mediators both in CF bronchial epithelial cell lines and in CF primary bronchial and nasal epithelial cells ex vivo. The expression of key inflammatory proteins involved in CF lung disease, including IL-8, IL-1beta, TNF-alpha and IL-6, was significantly reduced using nanomolar concentrations of GY971. Importantly, GY971 does not interfere with the ETI-mediated rescue of CFTR protein and showed no cytotoxic effects. Lastly, in vivo testing with a zebrafish model confirmed its effectiveness: GY971 decreased neutrophil recruitment in treated larvae across different concentrations, supporting earlier results from murine studies. Conclusions: GY971 appears to be a promising molecule for the future development of combinatorial anti-inflammatory treatments together with ETI.