Repairing the Lungs One Breath at a Time: How Dedicated or Facultative Are You?

The document reviews the mechanisms of lung tissue regeneration, focusing on the distinction between dedicated stem cells, such as basal cells in the trachea and large airways, and facultative stem/progenitor cells, like alveolar epithelial progenitors (AEPs) in the alveoli. Basal cells, which express Trp63 and Keratin 5, are capable of proliferating and differentiating into various airway epithelial cells, while AEPs can self-renew and differentiate into alveolar type 1 (AT1) cells for alveolar repair. The review emphasizes the importance of understanding these processes for developing regenerative therapies. It also discusses the role of signaling pathways, cellular niches, and the potential need for a scaffold in tissue regeneration, drawing parallels with other tissues such as skeletal muscle and skin. Advances in single-cell transcriptomics are highlighted as a tool for furthering knowledge in this area.