title: Plasticity within stem cell hierarchies in mammalian epithelia.
abstract: 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.
authors.affiliation: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Tetteh
authors.affiliation: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
authors.forename: Henner F
authors.initials: HF
authors.lastname: Farin
authors.affiliation: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands. Electronic address: h.clevers@hubrecht.eu.
authors.forename: Hans
authors.initials: H
authors.lastname: Clevers
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D054338:Cell Transdifferentiation; D044127:Epigenesis, Genetic; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D007422:Intestines / Q000166:cytology; D051379:Mice; D012038:Regeneration; D013234:Stem Cells / Q000166:cytology*
keywords: plasticity; quiescence; regeneration; stem cell; transdifferentiation