Lifespan Analysis of the Lung Epithelium Reveals Inflammatory Reprogramming and Regenerative Decline

Aging is a major risk factor for chronic lung diseases, associated with chronic low-grade inflammation (inflammaging(definition)) and impaired epithelial regeneration. How epithelial-intrinsic aging intersects with inflammaging across the lifespan remains poorly understood. Here, we systematically analyzed lung epithelial cells from neonatal, young adult, and aged mice to define age-dependent changes in regenerative capacity. RNA sequencing revealed lifespan-associated shifts characterized by early repression of developmental and WNT/β-catenin programs and progressive activation of DNA damage, inflammation, and senescence(definition) signatures. Functionally, neonatal epithelial cells exhibited markedly enhanced organoid-forming capacity compared with young and aged cells. Aged organoids maintained a pro-inflammatory secretory profile indicative of cell-intrinsic inflammaging, and transfer of the aged secretome or TNF-α to young cultures significantly impaired regeneration. Comparison of freshly isolated cells and long-term organoid cultures revealed sustained repression of regenerative pathways with age, consistent with stable epigenetic imprinting. Pharmacological inhibition of DNA methylation and WNT signalling partially restored regenerative capacity in adult organoids. Together, these findings identify epigenetic reprogramming and epithelial-intrinsic inflammaging as key determinants of age-dependent regenerative decline.