title: Deletion of Polycomb Repressive Complex 2 From Mouse Intestine Causes Loss of Stem Cells.
abstract: The polycomb repressive complex 2 (PRC2) regulates differentiation by contributing to repression of gene expression and thereby stabilizing the fate of stem cells and their progeny. PRC2 helps to maintain adult stem cell populations, but little is known about its functions in intestinal stem cells. We studied phenotypes of mice with intestine-specific deletion of the PRC2 proteins embryonic ectoderm development (EED) (a subunit required for PRC2 function) and enhancer of zeste homolog 2 (EZH2) (a histone methyltransferase).
  
  
  
  We performed studies of AhCre;EedLoxP/LoxP (EED knockout) mice and AhCre;Ezh2LoxP/LoxP (EZH2 knockout) mice, which have intestine-specific disruption in EED and EZH2, respectively. Small intestinal crypts were isolated and subsequently cultured to grow organoids. Intestines and organoids were analyzed by immunohistochemical, in situ hybridization, RNA sequence, and chromatin immunoprecipitation methods.
  
  
  
  Intestines of EED knockout mice had massive crypt degeneration and lower numbers of proliferating cells compared with wild-type control mice. Cdkn2a became derepressed and we detected increased levels of P21. We did not observe any differences between EZH2 knockout and control mice. Intestinal crypts from EED knockout mice had signs of aberrant differentiation of uncommitted crypt cells-these differentiated toward the secretory cell lineage. Furthermore, crypts from EED-knockout mice had impaired Wnt signaling and concomitant loss of intestinal stem cells, this phenotype was not reversed upon ectopic stimulation of Wnt and Notch signaling in organoids. Analysis of gene expression patterns from intestinal tissues of EED knockout mice showed dysregulation of several genes involved in Wnt signaling. Wnt signaling was regulated directly by PRC2.
  
  
  
  In intestinal tissues of mice, PRC2 maintains small intestinal stem cells by promoting proliferation and preventing differentiation in the intestinal stem cell compartment. PRC2 controls gene expression in multiple signaling pathways that regulate intestinal homeostasis. Sequencing data are available in the genomics data repository GEO under reference series GSE81578; RNA sequencing data are available under subseries GSE81576; and ChIP sequencing data are available under subseries GSE81577.
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Martijn A J
authors.initials: MA
authors.lastname: Koppens
authors.affiliation: Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Gergana
authors.initials: G
authors.lastname: Bounova
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Gargiulo
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Ellen
authors.initials: E
authors.lastname: Tanger
authors.affiliation: Division of Cell Biology II, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Janssen
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Paulien
authors.initials: P
authors.lastname: Cornelissen-Steijger
authors.affiliation: Transgenic Core Facility, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: Blom
authors.affiliation: Department of Experimental Animal Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Ji-Ying
authors.initials: JY
authors.lastname: Song
authors.affiliation: Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Department of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Delft, The Netherlands; Cancer Genomics Centre Netherlands, Utrecht, The Netherlands.
authors.forename: Lodewyk F A
authors.initials: LF
authors.lastname: Wessels
authors.affiliation: Division of Molecular Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Cancer Genomics Centre Netherlands, Utrecht, The Netherlands. Electronic address: M.V.Lohuizen@NKI.NL.
authors.forename: Maarten
authors.initials: M
authors.lastname: van Lohuizen
mesh_terms: D053687:Adult Stem Cells / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000172:deficiency; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology*; D051379:Mice; D018345:Mice, Knockout; D063151:Polycomb Repressive Complex 2 / Q000172:deficiency* / Q000235:genetics; D060449:Wnt Signaling Pathway
chemical_list: C107275:Eed protein, mouse; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2
keywords: Development; ISC; PRC1; Small Intestine