Extracellular vesicle microRNAs from small airways promote senescence and fibrosis in COPD

Chronic obstructive pulmonary disease (COPD) is a chronic lung condition characterized by accelerated lung ageing. Extracellular vesicles (EVs), which can be categorized into large EVs (LEVs) and small EVs (SEVs), contribute to the pathogenesis of COPD by transporting and transferring microRNAs (miRNAs). This study profiles cells and EV-associated miRNAs from both non-COPD and COPD small airway (SA)-epithelial cells and SA-fibroblasts and identifies the biological pathways associated with these miRNAs. EVs were isolated from conditioned media of non-COPD and COPD SA-epithelial cells and fibroblasts at baseline and after H₂O₂ exposure. miRNAs from cells and EVs were analysed by small RNA sequencing. SmRNA sequencing of COPD SA-epithelial cells showed four upregulated and fourteen downregulated miRNAs versus non-COPD controls. COPD-derived EVs showed distinct profiles: LEVs had nine upregulated and ten downregulated miRNAs, while SEVs had ten upregulated and eleven downregulated miRNAs. Only one miRNA was consistently upregulated across COPD SA-epithelial cells, LEVs, and SEVs, with most miRNAs associated with senescence pathways. In SA-fibroblasts, 39 miRNAs were upregulated in COPD cells. COPD fibroblast LEVs showed 14 upregulated and 11 downregulated miRNAs, whereas SEVs had 20 upregulated and 11 downregulated miRNAs, with limited overlap. Three miRNAs were consistently upregulated in cells and EVs and associated with fibrosis and senescence. Oxidative stress further altered miRNA profiles in cells and EVs differently between non-COPD and COPD donors. COPD alters miRNA signatures in cells and EVs, with limited overlap between compartments. These enriched miRNAs are associated with cellular senescence and fibrosis pathways, suggesting a role in disease progression.