Distinct Spatiotemporally Dynamic Wnt-Secreting Niches Regulate Proximal Airway Regeneration and Aging

Cell Stem Cell. 2020 Sep 3;27(3):413-429.e4. doi: 10.1016/j.stem.2020.06.019. Epub 2020 Jul 27.

Abstract

Our understanding of dynamic interactions between airway basal stem cells (ABSCs) and their signaling niches in homeostasis, injury, and aging remains elusive. Using transgenic mice and pharmacologic studies, we found that Wnt/β-catenin within ABSCs was essential for proliferation post-injury in vivo. ABSC-derived Wnt ligand production was dispensable for epithelial proliferation. Instead, the PDGFRα+ lineage in the intercartilaginous zone (ICZ) niche transiently secreted Wnt ligand necessary for ABSC proliferation. Strikingly, ABSC-derived Wnt ligand later drove early progenitor differentiation to ciliated cells. We discovered additional changes in aging, as glandular-like epithelial invaginations (GLEIs) derived from ABSCs emerged exclusively in the ICZ of aged mice and contributed to airway homeostasis and repair. Further, ABSC Wnt ligand secretion was necessary for GLEI formation, and constitutive activation of β-catenin in young mice induced their formation in vivo. Collectively, these data underscore multiple spatiotemporally dynamic Wnt-secreting niches that regulate functionally distinct phases of airway regeneration and aging.

Keywords: Wnt; aging; beta-catenin; homeostasis; intercartilaginous zone; lung repair; niche; signaling pathway.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging
  • Animals
  • Cell Differentiation
  • Cell Proliferation
  • Mice
  • Mice, Transgenic
  • Stem Cells* / metabolism
  • Wnt Signaling Pathway
  • beta Catenin* / metabolism

Substances

  • beta Catenin