Current smoking and COPD are associated with differentiation-dependent secretory and inflammatory programs in airway basal cells.

Abstract

Background: Persistent airway epithelial abnormalities contribute to chronic obstructive pulmonary disease (COPD), but it remains unclear whether smoking- and COPD-associated epithelial remodeling is retained in airway basal cells and transmitted during differentiation. We determined whether current smoking and COPD are associated with methylation-linked regulatory programs in airway basal cells that shape epithelial differentiation in patient-derived bronchial organoids.

Methods: We integrated DNA methylation profiling and bulk transcriptomics in patient-derived airway basal cells and matched three-dimensional bronchial organoids. Methylation-defined gene sets were mapped to organoid epithelial cell states using single-cell RNA-seq and contextualized with publicly available airway epithelial datasets.

Results: In this exploratory cohort, current smoking was associated with a predominant shift toward promoter hypomethylation in airway basal cells and matched organoids. Hypomethylated promoters were enriched for genes preferentially expressed in secretory epithelial cells, including BPIFB1, BPIFA2, MSMB and GALNT6. These genes showed little smoking-associated expression difference in basal-cell culture but were upregulated after organoid differentiation, indicating a differentiation-dependent epithelial memory of smoking. In COPD-derived basal cells, promoter methylation changes involved reduced xenobiotic metabolism and enhanced immune- and infection-related programs. Consistently, COPD-derived organoids showed reduced expression of detoxification-associated pathways and increased lysosomal, endocytic and host-defense programs.

Conclusions: Current smoking and COPD are associated with persistent methylation-linked regulatory alterations in airway basal cells that become functionally apparent during epithelial differentiation. These findings support a model in which airway basal-cell memory contributes to secretory, inflammatory and host-defense remodeling in chronic airway disease.