title: Frizzled7 functions as a Wnt receptor in intestinal epithelial Lgr5(+) stem cells.
abstract: The mammalian adult small intestinal epithelium is a rapidly self-renewing tissue that is maintained by a pool of cycling stem cells intermingled with Paneth cells at the base of crypts. These crypt base stem cells exclusively express Lgr5 and require Wnt3 or, in its absence, Wnt2b. However, the Frizzled (Fzd) receptor that transmits these Wnt signals is unknown. We determined the expression profile of Fzd receptors in Lgr5(+) stem cells, their immediate daughter cells, and Paneth cells. Here we show Fzd7 is enriched in Lgr5(+) stem cells and binds Wnt3 and Wnt2b. Conditional deletion of the Fzd7 gene in adult intestinal epithelium leads to stem cell loss in vivo and organoid death in vitro. Crypts of conventional Fzd7 knockout mice show decreased basal Wnt signaling and impaired capacity to regenerate the epithelium following deleterious insult. These observations indicate that Fzd7 is required for robust Wnt-dependent processes in Lgr5(+) intestinal stem cells.
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Flanagan
authors.affiliation: Walter and Eliza Hall Institute and Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: Toby J
authors.initials: TJ
authors.lastname: Phesse
authors.affiliation: Institute of Medical Biology, Singapore 138648, Singapore; MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Barker
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Renate H M
authors.initials: RH
authors.lastname: Schwab
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Nancy
authors.initials: N
authors.lastname: Amin
authors.affiliation: Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: Jordane
authors.initials: J
authors.lastname: Malaterre
authors.affiliation: Hubrecht Institute for Developmental Biology and Stem Cell Research, 3584CT Utrecht, the Netherlands.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Stange
authors.affiliation: Walter and Eliza Hall Institute and Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Nowell
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Currie
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Jarel T S
authors.initials: JT
authors.lastname: Saw
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia.
authors.forename: Eva
authors.initials: E
authors.lastname: Beuchert
authors.affiliation: Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Ramsay
authors.affiliation: Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK.
authors.forename: Owen J
authors.initials: OJ
authors.lastname: Sansom
authors.affiliation: Walter and Eliza Hall Institute and Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ernst
authors.affiliation: Hubrecht Institute for Developmental Biology and Stem Cell Research, 3584CT Utrecht, the Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Clevers
authors.affiliation: Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC 3010, Australia; Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC 3000, Australia; Curtin University, Perth, WA 6845, Australia. Electronic address: evincan@unimelb.edu.au.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Vincan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D051157:Frizzled Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019879:Paneth Cells / Q000166:cytology; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D060449:Wnt Signaling Pathway; D060508:Wnt3 Protein / Q000378:metabolism
chemical_list: D051157:Frizzled Receptors; C489739:Fzd1 protein, mouse; C489743:Fzd2 protein, mouse; C492041:Fzd7 protein, mouse; C493597:Lgr5 protein, mouse; D043562:Receptors, G-Protein-Coupled; D060508:Wnt3 Protein; C555508:Wnt3 protein, mouse