Airway basal stem cell-derived extracellular vesicles drive ECM remodeling and suppress fibroblasts activation via the miR-30a-5p/FAP axis in benign tracheal stenosis.

Abstract

INTRODUCTION: Benign tracheal stenosis (BTS) is characterized by granulation tissue hyperplasia, driven by abnormal fibroblast activation and excessive extracellular matrix deposition. Targeting these mechanisms with novel therapies may offer a promising approach to addressing or preventing re-stenosis. Our previous study demonstrated that airway basal stem cell (BSC) transplantation can inhibit granulation hyperplasia in BTS. OBJECTIVES: Given the therapeutic potential of extracellular vesicles (EVs) as mediators in cell-based therapies, we investigated the in vivo efficacy of airway BSC-derived EVs (BSC-EVs) and explored their underlying mechanisms. METHODS: BTS was induced in rabbits via tracheal mucosal injury. BSC-EVs were isolated, characterized, and intratracheally delivered. Then, therapeutic effects were evaluated using bronchoscopy,F-FAPI PET/CT, histology, and RNA-seq. The underlying mechanisms were investigated in vitro focusing on miRNA regulation of human airway fibroblasts (AFs). RESULTS: Our findings revealed that BSC-EVs significantly reduce granulation hyperplasia, promote ECM remodeling and improve collagen fiber alignment, leading to enhanced airway patency and prolonged survival. Mechanistically, we identified miR-30a-5p as a key functional cargo within BSC-EVs, which directly targets the fibroblast activation protein (FAP) gene. In vitro experiments demonstrated that miR-30a-5p mediates the anti-fibrotic effects of BSC-EVs by attenuating fibroblast activation, collagen contraction, and ECM deposition. CONCLUSIONS: These findings suggest that BSC-EVs represent a promising therapeutic strategy for BTS by inhibiting fibroblast activation and promoting ECM remodeling via the miR-30a-5p/FAP axis, offering a novel advancement beyond current treatment approaches.