Plasticity within stem cell hierarchies in mammalian epithelia

Trends Cell Biol. 2015 Feb;25(2):100-8. doi: 10.1016/j.tcb.2014.09.003. Epub 2014 Oct 9.


Tissue homeostasis and regeneration are fueled by resident stem cells that have the capacity to self-renew, and to generate all the differentiated cell types that characterize a particular tissue. Classical models of such cellular hierarchies propose that commitment and differentiation occur unidirectionally, with the arrows 'pointing away' from the stem cell. Recent studies, all based on genetic lineage tracing, describe various strategies employed by epithelial stem cell hierarchies to replace damaged or lost cells. While transdifferentiation from one tissue type into another ('metaplasia') appears to be generally forbidden in nonpathological contexts, plasticity within an individual tissue stem cell hierarchy may be much more common than previously appreciated. In this review, we discuss recent examples of such plasticity in selected mammalian epithelia, highlighting the different modes of regeneration and their implications for our understanding of cellular hierarchy and tissue self-renewal.

Keywords: plasticity; quiescence; regeneration; stem cell; transdifferentiation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Lineage
  • Cell Transdifferentiation*
  • Epigenesis, Genetic
  • Epithelial Cells / cytology*
  • Humans
  • Intestines / cytology
  • Mice
  • Regeneration
  • Stem Cells / cytology*