Clade B serpins promote direct basal-to-goblet cell differentiation in airways of patients with chronic obstructive pulmonary disease.

Goblet cell hyperplasia (GCH) is a hallmark of chronic obstructive pulmonary disease (COPD) and contributes to morbidity and mortality. We investigated the cellular and molecular origins of GCH in COPD using single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and in vitro models. We identified "basal-to-goblet transitional cells" (BGTC) which are transcriptionally and physically located between basal and goblet cells and are characterized by expression of clade B serpins. In vitro studies indicate that inflammatory cytokines, including IL-1β, stimulate basal-to-goblet differentiation through a SERPINB3/4 + intermediate and SERPINB3 overexpression induces differentiation of airway basal cells into IL1B -producing inflammatory goblet cells. In addition, we identified a subset of SERPINB4 + "goblet-variant basal cells" from lungs of COPD patients that express goblet cell and inflammatory genes ex vivo. Together, these results indicate clade B serpins contribute to altered epithelial differentiation and inflammatory signaling in COPD and support therapeutic targeting of clade B serpins to reduce GCH.