Senescence is a mechanism associated with aging that alters tissue regeneration by depleting the stem cell pool. Chronic obstructive pulmonary disease (COPD) displays hallmarks of senescence, including a diminished stem cell population. DNA damage from cigarette smoke (CS) induces senescence via the p16 pathway. This study evaluated the contribution of p16 to CS-associated lung pathologies. p16 expression was prominent in human COPD lungs compared with normal subjects. CS induces impaired pulmonary function, emphysema, and increased alveolar epithelial cell (AECII) senescence in wild-type mice, whereas CS-exposed p16−/− mice exhibit normal pulmonary function, reduced emphysema, diminished AECII senescence, and increased pro-growth IGF1 signaling, suggesting that improved lung function in p16−/− mice was due to increased alveolar progenitor cell proliferation. In conclusion, our study suggests that targeting senescence may facilitate alveolar regeneration in COPD emphysema by promoting IGF1 proliferative signaling.
Cottage et al. show that p16 deficiency promotes the proliferation of alveolar progenitor cells, improving the lung function in mice. This study suggests that targeting senescence pathways may facilitate alveolar regeneration in chronic obstructive pulmonary diseases by activating cell-proliferation signals through insulin-like growth factor 1.