Behavioral heterogeneity of adult mouse lung epithelial progenitor cells.

The existence and identity of multipotent stem cells in the adult lung is currently highly debated. At present, it remains unclear whether candidate stem/progenitor cells are located in the airways, alveoli, or throughout the epithelial lining of the lung. Here, we introduce a method of airway microdissection, which enabled us to study the progenitor behavior of pulmonary epithelial cells in region-specific contexts. The progenitor characteristics of epithelial cells isolated from the trachea, proximal and distal airways, and lung parenchyme were evaluated in vitro and in vivo. We identified a population of airway-derived basal-like epithelial cells with the potential to self-renew and differentiate into airway and alveolar lineages in culture and in vivo after subcutaneous transplantation. The multipotent candidate progenitors originated from a minor fraction of the airway epithelial cell population characterized by high expression of α6 integrin. Results of the current study provide new insights into the regenerative potential of region-specific integrin α6-positive pulmonary epithelial cells.