TLR7-expressing cells comprise an interfollicular epidermal stem cell population in murine epidermis

Sci Rep. 2014 Jul 25:4:5831. doi: 10.1038/srep05831.

Abstract

Normal interfollicular epidermis (IFE) homeostasis is maintained throughout the entire life by its own stem cells that self-renew and generate progeny that undergo terminal differentiation. However, the fine markers of the stem cells in interfollicular epidermis are not well defined yet. Here we found that TLR7 identified the existence of progenitors and interfollicular epidermal stem cells in murine skin. In vitro, TLR7-expressing cells comprised of two subpopulations that were competent to proliferate and exhibited distinct differentiation potentials. Three-dimensional (3D) organotypic culture and skin reconstitution assays showed that TLR7-expressing cells were able to reconstruct the interfollicular epidermis. Finally, TLR7-expressing cells maintained the intact interfollicular epidermal structures revealed in serial transplantation assays in vivo in mice. Taken together, our results suggest that TLR7-expressing cells comprise an interfollicular epidermal stem cell population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoquinolines / pharmacology
  • Animals
  • Cell Culture Techniques
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Epidermal Cells*
  • Epidermis / metabolism
  • Epidermis / pathology
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Hair Follicle / metabolism
  • Imiquimod
  • Keratinocytes / cytology
  • Keratinocytes / drug effects
  • Keratinocytes / transplantation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Regeneration
  • Skin / metabolism
  • Skin / pathology
  • Stem Cell Transplantation
  • Stem Cells / cytology*
  • Stem Cells / metabolism
  • Tissue Engineering
  • Toll-Like Receptor 7 / agonists
  • Toll-Like Receptor 7 / genetics
  • Toll-Like Receptor 7 / metabolism*

Substances

  • Aminoquinolines
  • Toll-Like Receptor 7
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Imiquimod