title: The role of Scgb1a1+ Clara cells in the long-term maintenance and repair of lung airway, but not alveolar, epithelium.
abstract: To directly test the contribution of Scgb1a1(+) Clara cells to postnatal growth, homeostasis, and repair of lung epithelium, we generated a Scgb1a1-CreER "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.
authors.affiliation: Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Rawlins
authors.forename: Tadashi
authors.initials: T
authors.lastname: Okubo
authors.forename: Yan
authors.initials: Y
authors.lastname: Xue
authors.forename: David M
authors.initials: DM
authors.lastname: Brass
authors.forename: Richard L
authors.initials: RL
authors.lastname: Auten
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Fan
authors.initials: F
authors.lastname: Wang
authors.forename: Brigid L M
authors.initials: BL
authors.lastname: Hogan
mesh_terms: D000818:Animals; D055745:Bronchioles / Q000166:cytology; D004848:Epithelium; D006706:Homeostasis; D008168:Lung / Q000166:cytology* / Q000254:growth & development; D051379:Mice; D008822:Mice, Transgenic; D011650:Pulmonary Alveoli / Q000166:cytology; D012038:Regeneration; D012137:Respiratory System / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology*; D014132:Trachea / Q000166:cytology; D014598:Uteroglobin; D014945:Wound Healing
chemical_list: C556390:Scgb1a1 protein, mouse; D014598:Uteroglobin