Aberrant epithelial–mesenchymal interactions have critical roles in regulating fibrosis development. The involvement of extracellular vesicles (EVs), including exosomes, remains to be elucidated in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Here, we found that lung fibroblasts (LFs) from patients with IPF induce cellular senescence via EV-mediated transfer of pathogenic cargo to lung epithelial cells. Mechanistically, IPF LF–derived EVs increased mitochondrial reactive oxygen species and associated mitochondrial damage in lung epithelial cells, leading to activation of the DNA damage response and subsequent epithelial-cell senescence. We showed that IPF LF-derived EVs contain elevated levels of microRNA-23b-3p (miR-23b-3p) and miR-494-3p, which suppress SIRT3, resulting in the epithelial EV-induced phenotypic changes. Furthermore, the levels of miR-23b-3p and miR-494-3p found in IPF LF–derived EVs correlated positively with IPF disease severity. These findings reveal that the accelerated epithelial-cell mitochondrial damage and senescence observed during IPF pathogenesis are caused by a novel paracrine effect of IPF fibroblasts via microRNA-containing EVs.

Thoracic diseases in patients with systemic lupus erythematosus (SLE), especially interstitial pneumonia (SLE-IP), are rare and have been poorly studied. The aims of this multicentre study were to evaluate SLE-IP and elucidate its clinical characteristics and prognosis. Fifty-five patients with SLE-IP who had attended the respiratory departments of participating hospitals were retrospectively evaluated in this multicentre study. Clinical information, high-resolution computed tomography (HRCT), and surgical lung biopsy/autopsy specimens were analysed by respiratory physicians, pulmonary radiologists, and pulmonary pathologists. IP patterns on HRCT and lung specimens were classified based on the international classification statement/guideline for idiopathic interstitial pneumonias. The most frequent form of SLE-IP at diagnosis was chronic IP (63.6%), followed by subacute (20.0%), and acute IP (12.7%). Radiologically, the most common HRCT pattern was “Unclassifiable” (54%). Histologically, “Unclassifiable” was the most frequently found (41.7%) among 12 patients with histologically proven IP. Interestingly, accompanying airway diseases were present in nine of these patients (75%). In multivariate analysis, current smoking (hazard ratio [HR] 6.105, p = 0.027), thrombocytopenia (HR 7.676, p = 0.010), anti-double-strand DNA titre (HR 0.956, p = 0.027), and nonspecific interstitial pneumonia (NSIP) + organizing pneumonia (OP) pattern on HRCT (vs. NSIP, HR 0.089, p = 0.023) were significant prognostic factors. In conclusion, chronic IP was the most frequent form of IP in patients with SLE-IP, and “Unclassifiable” was the commonest pattern radiologically and histologically.

Idiopathic pulmonary fibrosis (IPF) is a progressive aging-related lung disease associated with increased lung cancer risk. Although previous studies have shown that IPF worsens the survival of patients with lung cancer, whether IPF independently affects cancer malignancy and prognosis remains inconclusive. Extracellular vesicles (EVs) have recently emerged as active carriers of molecular biomarkers and mediators of intercellular communication in lung homeostasis and pathogenesis. EV cargo-mediated fibroblast–tumor cell communication might participate in the development and progression of lung cancer by modulating various signaling pathways. In this study, we examined the impact of lung fibroblast (LF)-derived EVs on non-small cell lung cancer (NSCLC) malignancy in the IPF microenvironment. Here, we showed that LFs derived from patients with IPF have phenotypes of myofibroblast differentiation and cellular senescence. Furthermore, we found that IPF LF-derived EVs have markedly altered microRNA compositions and exert proproliferative functions on NSCLC cells. Mechanistically, the phenotype was attributed mainly to the enrichment of miR-19a in IPF LF-derived EVs. As a downstream signaling pathway, mir-19a in IPF LF-derived EVs regulates ZMYND11-mediated c-Myc activation in NSCLC, potentially contributing to the poor prognosis of patients with NSCLC with IPF. Our discoveries provide novel mechanistic insights for understanding lung cancer progression in the IPF microenvironment. Accordingly, blocking the secretion of IPF LF-derived EV miR-19a and their signaling pathways is a potential therapeutic strategy for managing IPF and lung cancer progression.