The Mechanosensitive Ion Channel Piezo1 Promotes Obliterative Bronchiolitis through YAP-Dependent Epithelial-to-Mesenchymal Transition.

Abstract

Introduction: Obliterative bronchiolitis (OB) is a severe and progressive complication characterized by the fibrotic obliteration of small airways, leading to significant morbidity and mortality, particularly in lung transplant recipients. The pathogenesis of OB involves complex cellular processes, among which epithelial-tomesenchymal transition (EMT) plays a crucial role. This study investigates the role of mechanosensitive ion channel Piezo1 in promoting OB through Yes-associated protein (YAP)-dependent EMT.

Method: Piezo1-induced signal pathway alterations, fibrosis, and EMT-related features were examined in the mouse OB model and BEAS-2B cells. The efficacy of Piezo1 in EMT and OB was explored and validated both in vitro and in vivo.

Results: Piezo1 was found to be upregulated in OB, and pharmacological inhibition of Piezo1 effectively alleviated EMT and fibrotic deposition. Piezo1 activation stimulated the Ca2+ influx and nuclear translocation of YAP that triggered the transition of epithelial cells into a mesenchymal phenotype, which contributed to airway fibrosis and obstruction. Furthermore, inhibition of YAP or calcium chelation significantly attenuated Piezo1 activation-induced EMT and OB, indicating that YAP and Ca2+ are critical mediators in this process.

Discussion: Piezo1 expression was found to be upregulated in OB, and its activation induced the epithelial-to-mesenchymal transition (EMT) process via a YAP-dependent pathway. Piezo1 could accelerate EMT and the occlusion rate of grafts via Ca2+ influx-dependent YAP activation in OB, suggesting a direct role in facilitating EMT and subsequent fibrotic remodeling in OB.

Conclusion: The present results highlight that Piezo1 promotes OB through a YAPdependent EMT pathway, suggesting Piezo1 as a novel therapeutic strategy for treating OB and potentially improving outcomes of lung transplant recipients.