Mitochondrial Transfer Triggered by TSLP Promotes Epithelial-Mesenchymal Transition in Human Lung Epithelial Cells Exposed to House Dust Mite

Background Airway remodeling is a key pathological feature of asthma, closely linked to lung function decline and disease severity. Persistent inflammation, EMT, and mitochondrial dysfunction all contribute to this process. Although HDM strongly induces epithelial alarmins such as TSLP, how cytokine priming cooperates with subsequent allergen exposure to alter mitochondrial function and promote EMT remains unclear. Methods This study investigated the effects of sequential TSLP and HDM exposure in A549 lung epithelial cells. Cell motility and EMT markers were assessed using wound-healing assays and Western Blot. Mitochondrial membrane potential and oxidative stress were examined by JC-1 staining and ROS quantification. To determine how TSLP priming shapes subsequent HDM responses, we analyzed intercellular mitochondrial transfer, and further assessed EMT phenotypes in recipient cells acquiring mitochondria from TSLP-treated donors. Results Sequential TSLP priming followed by HDM exposure markedly enhanced epithelial migration and accelerated EMT. This was accompanied by a collapse of mitochondrial membrane potential, impaired biogenesis, increased mtDNA release, and robust mitophagy activation. Notably, TSLP priming potentiated intercellular mitochondrial transfer, and recipient cells that acquired TSLP-conditioned mitochondria displayed amplified migratory and EMT behavior. These findings identify mitochondrial transfer as an additional layer by which epithelial cytokine priming amplifies allergen-driven remodeling. Conclusions Collectively, these results indicate that TSLP primes epithelial cells by reprogramming mitochondrial dynamics and promoting intercellular mitochondrial transfer, thereby heightening their sensitivity to environmental stimuli. Targeting TSLP signaling and mitochondrial regulation may provide novel therapeutic opportunities to mitigate airway remodeling in chronic respiratory diseases.