Background: Impaired airway epithelial barrier function and repair are thought to be key drivers in chronic obstructive pulmonary disease (COPD) pathology, however, the mechanisms involved remain not fully understood.

Objective: Assess bronchial epithelial cell differentiation in an organoid model by COPD severity using single-cell RNA sequencing (ScRNAseq).

Methods: Bronchial epithelial cells were obtained from bronchial brushings of ex-smokers with normal lung function, mild-moderate (MM)-COPD, and severe COPD (n=6 per group) and cultured in an organoid model using matrigel to allow self-organization and differentiation. Organoids were harvested at days 3, 10 and 17 and processed for scRNAseq. The number and size of organoids were quantified on day 12.

Results: There was no difference in the number of organoids formed from each group. However, organoids from severe COPD patients were significantly larger than those from MM-COPD and ex-smoker donors (p=0.032). The scRNAseq identified 5 different cell types: basal, dividing basal, suprabasal, secretory and ionocytes. We observed a significantly larger suprabasal cell population in the severe COPD group compared to the MM-COPD and ex-smokers on day 17 (p=0.041).

Conclusions: In summary, bronchial epithelial cells from patients with severe COPD form larger organoids which contain more suprabasal cells indicating defective differentiation which could impair epithelial repair and homeostasis in severe COPD.