title: Origin of the adult intestinal stem cells induced by thyroid hormone in Xenopus laevis.
abstract: In the amphibian intestine during metamorphosis, de novo stem cells generate the adult epithelium analogous to the mammalian counterpart. Interestingly, to date the exact origin of these stem cells remains to be determined, making intestinal metamorphosis a unique model to study development of adult organ-specific stem cells. Here, to determine their origin, we made use of transgenic Xenopus tadpoles expressing green fluorescent protein (GFP) for recombinant organ cultures. The larval epithelium separated from the wild-type (Wt) or GFP transgenic (Tg) intestine before metamorphic climax was recombined with homologous and heterologous nonepithelial tissues and was cultivated in the presence of thyroid hormone, the causative agent of metamorphosis. In all kinds of recombinant intestine, adult progenitor cells expressing markers for intestinal stem cells such as sonic hedgehog became detectable and then differentiated into the adult epithelium expressing intestinal fatty acid binding-protein, a marker for absorptive cells. Notably, whenever the epithelium was derived from Tg intestine, both the adult progenitor/stem cells and their differentiated cells expressed GFP, whereas neither of them expressed GFP in the Wt-derived epithelium. Our results provide direct evidence that stem cells that generate the adult intestinal epithelium originate from the larval epithelium, through thyroid hormone-induced dedifferentiation.
authors.affiliation: Department of Biology, Nippon Medical School, 2-297-2 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-0063, Japan. a-oka@nms.ac.jp
authors.forename: Atsuko
authors.initials: A
authors.lastname: Ishizuya-Oka
authors.forename: Takashi
authors.initials: T
authors.lastname: Hasebe
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Buchholz
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Kajita
authors.forename: Liezhen
authors.initials: L
authors.lastname: Fu
authors.forename: Yun-Bo
authors.initials: YB
authors.lastname: Shi
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D002454:Cell Differentiation; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology* / Q000187:drug effects* / Q000254:growth & development; D007814:Larva / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008675:Metamorphosis, Biological; D008954:Models, Biological; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013963:Thyroid Hormones / Q000494:pharmacology*
chemical_list: D011994:Recombinant Proteins; D013963:Thyroid Hormones; D049452:Green Fluorescent Proteins