title: Single Lgr5- or Lgr6-expressing taste stem/progenitor cells generate taste bud cells ex vivo.
abstract: Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) and its homologs (e.g., Lgr6) mark adult stem cells in multiple tissues. Recently, we and others have shown that Lgr5 marks adult taste stem/progenitor cells in posterior tongue. However, the regenerative potential of Lgr5-expressing (Lgr5(+)) cells and the identity of adult taste stem/progenitor cells that regenerate taste tissue in anterior tongue remain elusive. In the present work, we describe a culture system in which single isolated Lgr5(+) or Lgr6(+) cells from taste tissue can generate continuously expanding 3D structures ("organoids"). Many cells within these taste organoids were cycling and positive for proliferative cell markers, cytokeratin K5 and Sox2, and incorporated 5-bromo-2'-deoxyuridine. Importantly, mature taste receptor cells that express gustducin, carbonic anhydrase 4, taste receptor type 1 member 3, nucleoside triphosphate diphosphohydrolase-2, or cytokeratin K8 were present in the taste organoids. Using calcium imaging assays, we found that cells grown out from taste organoids derived from isolated Lgr5(+) cells were functional and responded to tastants in a dose-dependent manner. Genetic lineage tracing showed that Lgr6(+) cells gave rise to taste bud cells in taste papillae in both anterior and posterior tongue. RT-PCR data demonstrated that Lgr5 and Lgr6 may mark the same subset of taste stem/progenitor cells both anteriorly and posteriorly. Together, our data demonstrate that functional taste cells can be generated ex vivo from single Lgr5(+) or Lgr6(+) cells, validating the use of this model for the study of taste cell generation.
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104;
authors.forename: Wenwen
authors.initials: W
authors.lastname: Ren
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104;
authors.forename: Brian C
authors.initials: BC
authors.lastname: Lewandowski
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104;
authors.forename: Jaime
authors.initials: J
authors.lastname: Watson
authors.affiliation: Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH 45267; and.
authors.forename: Eitaro
authors.initials: E
authors.lastname: Aihara
authors.affiliation: Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Iwatsuki
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104;
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Bachmanov
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104;
authors.forename: Robert F
authors.initials: RF
authors.lastname: Margolskee
authors.affiliation: Monell Chemical Senses Center, Philadelphia, PA 19104; pjiang@monell.org.
authors.forename: Peihua
authors.initials: P
authors.lastname: Jiang
mesh_terms: D000818:Animals; D015415:Biomarkers; D002469:Cell Separation; D002478:Cells, Cultured; D019343:Citric Acid / Q000494:pharmacology; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D066298:In Vitro Techniques; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D009940:Organoids; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000096:biosynthesis; D012965:Sodium Chloride / Q000494:pharmacology; D012970:Sodium Glutamate / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology*; D013395:Sucrose / Q000031:analogs & derivatives / Q000494:pharmacology; D013629:Tamoxifen / Q000494:pharmacology; D013649:Taste / Q000502:physiology; D013650:Taste Buds / Q000166:cytology / Q000378:metabolism*; D013843:Thiazines / Q000494:pharmacology; D014059:Tongue / Q000166:cytology
chemical_list: D015415:Biomarkers; D019343:Citric Acid; D049452:Green Fluorescent Proteins; D000644:Quaternary Ammonium Compounds; D043562:Receptors, G-Protein-Coupled; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D012970:Sodium Glutamate; D013395:Sucrose; D013629:Tamoxifen; D013843:Thiazines; C493597:Lgr5 protein, mouse; C548022:Lgr6 protein, mouse; C485184:enhanced green fluorescent protein; C026285:trichlorosucrose; C006362:acetosulfame; C043414:denatonium
keywords: Lgr5; Lgr6; taste progenitor cells; taste stem cells