Abstract Rationale Extracellular vesicles (EVs) released by lung tissue play key roles in cell-cell communication, extracellular matrix (ECM) maintenance, and tissue repair. In chronic obstructive pulmonary disease (COPD), and particularly in emphysema, progressive ECM degradation leads to irreversible structural damage and loss of lung elasticity. Whether lung tissue-derived EVs reflect or mediate these pathological changes remains largely unknown. We hypothesized that the protein cargo of lung-derived EVs mirrors disease-specific alterations in ECM homeostasis and influences fibroblast repair capacity in COPD. Methods Lung tissue was obtained from 22 patients undergoing resection for a solitary pulmonary nodule, stratified as smoker controls (SC; FEV1/FVC = 0.8; %LAA950 = 0.5), COPD without emphysema (FEV1/FVC = 0.6; %LAA950 = 2.6), and COPD with emphysema (EMPH; FEV1/FVC = 0.6; %LAA950 = 14.7). Emphysema was quantified as the percentage of lung voxels below -950 Hounsfield Units (%LAA950). Morphologically preserved tissue was enzymatically digested, and EVs were isolated from the non-cellular fraction by precipitation. Proteomic profiling was performed using single-run label-free LC-MS/MS and quantified via intensity-based absolute quantification (iBAQ). Differential expression and pathway analyses were performed in R. EV functional effects were evaluated by wound-healing assays in primary human lung fibroblasts treated with 1 × 109 EVs. Wound area was measured at 6, 12, and 24 h using ImageJ. Results Proteomic analysis revealed distinct EV signatures among all groups (SC vs COPD, SC vs EMPH, COPD vs EMPH), with no overlapping differentially expressed proteins. Principal component analysis demonstrated clear group separation (PC1 = 37.1%; PC2 = 11.9%). COPD and EMPH EVs exhibited progressive downregulation of proteins associated with ECM organization, collagen fibril assembly, and elastic fiber maintenance. KEGG and GO enrichment analyses confirmed disruptions in ECM-receptor interaction and focal adhesion pathways. Functionally, EVs from EMPH lungs significantly impaired fibroblast wound closure compared with SC and COPD EVs: at 6 h, healing area was 2.33% vs 20.11% and 14.43%, respectively (P 0.01), with differences persisting through 24 h (P 0.01). Conclusions Lung-derived EVs from COPD and emphysematous patients carry distinct proteomic alterations that mirror ECM dysregulation and compromise fibroblast regenerative function. These data implicate EV-mediated signaling as a key contributor to impaired tissue repair and elastic fiber loss in emphysema, suggesting that modulation of EV cargo may represent a novel therapeutic avenue to restore ECM homeostasis and lung resilience. This abstract is funded by: RO1 HL149744 and R01 HL171622. Instituto Salud Carlos III (CD22/00033 and MV23/00010)
Rubio et al. (Fri,) studied this question.