Dysplastic basal-like cells in alveolar repair and regeneration.

The lung is constantly exposed to environmental insults, leading to the evolution of diverse repair mechanisms that involve regional stem and progenitor cells. However, in response to severe alveolar injury, aberrant basal-like cells emerge in the alveolar regions, as observed in acute viral infections and chronic pulmonary diseases like lung fibrosis. While these cells can rapidly reseal the epithelial barrier, they fail to restore normal lung function and, if persistent, represent dysplastic repair. This review summarizes recent advances in understanding the cellular origin, regulation, and function of these basal-like cells. Elucidating how dysplastic repair arises and mechanistically links to alveolar regeneration and disease progression will provide insights into the mechanism of regeneration failure in chronic lung diseases and help inform the development of potential therapies.