[HTML][HTML] The role of Scgb1a1+ Clara cells in the long-term maintenance and repair of lung airway, but not alveolar, epithelium

EL Rawlins, T Okubo, Y Xue, DM Brass, RL Auten… - Cell stem cell, 2009 - cell.com
EL Rawlins, T Okubo, Y Xue, DM Brass, RL Auten, H Hasegawa, F Wang, BLM Hogan
Cell stem cell, 2009cell.com
To directly test the contribution of Scgb1a1+ Clara cells to postnatal growth, homeostasis,
and repair of lung epithelium, we generated a Scgb1a1-CreER TM" knockin" mouse for
lineage-tracing these cells. Under all conditions tested, the majority of Clara cells in the
bronchioles both self-renews and generates ciliated cells. In the trachea, Clara cells give
rise to ciliated cells but do not self-renew extensively. Nevertheless, they can contribute to
tracheal repair. In the postnatal mouse lung, it has been proposed that bronchioalveolar …
Summary
To directly test the contribution of Scgb1a1+ Clara cells to postnatal growth, homeostasis, and repair of lung epithelium, we generated a Scgb1a1-CreERTM "knockin" mouse for lineage-tracing these cells. Under all conditions tested, the majority of Clara cells in the bronchioles both self-renews and generates ciliated cells. In the trachea, Clara cells give rise to ciliated cells but do not self-renew extensively. Nevertheless, they can contribute to tracheal repair. In the postnatal mouse lung, it has been proposed that bronchioalveolar stem cells (BASCs) which coexpress Scgb1a1 (Secretoglobin1a1) and SftpC (Surfactant Protein C), contribute descendants to both bronchioles and alveoli. The putative BASCs were lineage labeled in our studies. However, we find no evidence for the function of a special BASC population during postnatal growth, adult homeostasis, or repair. Rather, our results support a model in which the trachea, bronchioles, and alveoli are maintained by distinct populations of epithelial progenitor cells.
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