Cystic fibrosis (CF) is a genetic disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, leading to abnormal mucus production and progressive lung damage. While CFTR has mainly been associated with proximal airway cells, recent evidence suggests it is also expressed in distal lung regions—including alveolar type 2 (AT2) cells—though its role there remains unclear. Given the anatomical and cellular similarities between ferret and human lungs, the ferret was used as a model to study CFTR expression during postnatal lung development. This ongoing study aims to explore the significance of distal epithelial cells in both normal development and CF lung disease.

Lung tissue from healthy ferrets was collected at six time points ranging from 1 week to 2 years of age. Sections were stained for immunofluorescent antibodies anti-CFTR and DC-LAMP (an AT2 cell marker), imaged at 20× magnification, and analyzed for double-positive cells. We found that CFTR expression in AT2 cells decreases over time, with the highest expression in the first two weeks of life. This decline suggests that AT2 cells may play a more significant role in CFTR-mediated ion transport and mucus regulation during early lung maturation.

Ongoing studies are examining CFTR expression in respiratory airway secretory (RAS) cells marked by SCGB3A2. Overall, this research aims to clarify the role of CFTR in distal lung maturation and inform timing for early CF intervention strategies.