title: Visualization of a short-range Wnt gradient in the intestinal stem-cell niche.
abstract: Mammalian Wnt proteins are believed to act as short-range signals, yet have not been previously visualized in vivo. Self-renewal, proliferation and differentiation are coordinated along a putative Wnt gradient in the intestinal crypt. Wnt3 is produced specifically by Paneth cells. Here we have generated an epitope-tagged, functional Wnt3 knock-in allele. Wnt3 covers basolateral membranes of neighbouring stem cells. In intestinal organoids, Wnt3-transfer involves direct contact between Paneth cells and stem cells. Plasma membrane localization requires surface expression of Frizzled receptors, which in turn is regulated by the transmembrane E3 ligases Rnf43/Znrf3 and their antagonists Lgr4-5/R-spondin. By manipulating Wnt3 secretion and by arresting stem-cell proliferation, we demonstrate that Wnt3 mainly travels away from its source in a cell-bound manner through cell division, and not through diffusion. We conclude that stem-cell membranes constitute a reservoir for Wnt proteins, while Frizzled receptor turnover and 'plasma membrane dilution' through cell division shape the epithelial Wnt3 gradient.
authors: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands.|German Cancer Consortium (DKTK), 69120 Heidelberg, Germany.|Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt am Main, Germany.|German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
authors: Henner F
authors: HF
authors: Farin
authors: Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, the Netherlands.
authors: Ingrid
authors: I
authors: Jordens
authors: German Cancer Consortium (DKTK), 69120 Heidelberg, Germany.|Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt am Main, Germany.|German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
authors: Mohammed H
authors: MH
authors: Mosa
authors: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands.
authors: Onur
authors: O
authors: Basak
authors: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands.
authors: Jeroen
authors: J
authors: Korving
authors: Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, the Netherlands.
authors: Daniele V F
authors: DV
authors: Tauriello
authors: The Maastricht Multimodal Molecular Imaging institute, Maastricht University, 6229ER Maastricht, the Netherlands.
authors: Karin
authors: K
authors: de Punder
authors: Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
authors: Stephane
authors: S
authors: Angers
authors: The Maastricht Multimodal Molecular Imaging institute, Maastricht University, 6229ER Maastricht, the Netherlands.
authors: Peter J
authors: PJ
authors: Peters
authors: Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, the Netherlands.
authors: Madelon M
authors: MM
authors: Maurice
authors: Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584CT Utrecht, the Netherlands.
authors: Hans
authors: H
authors: Clevers
mesh_terms: D000483:Alleles; D000818:Animals; D002448:Cell Adhesion; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism*; D004058:Diffusion; D005260:Female; D051157:Frizzled Receptors / Q000378:metabolism; D055879:Gene Knock-In Techniques; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology*; D008297:Male; D051379:Mice; D009940:Organoids / Q000166:cytology / Q000378:metabolism; D019879:Paneth Cells / Q000166:cytology / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D055153:Stem Cell Niche; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D060449:Wnt Signaling Pathway; D060508:Wnt3 Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D051157:Frizzled Receptors; D036341:Intercellular Signaling Peptides and Proteins; C496200:LGR4 protein, mouse; D043562:Receptors, G-Protein-Coupled; D060508:Wnt3 Protein; C555508:Wnt3 protein, mouse; C575493:RNF43 protein, mouse; D044767:Ubiquitin-Protein Ligases; C572951:Znrf3 protein, mouse