title: Immediate differentiation of neuronal cells from stem/progenitor-like cells in the avian iris tissues.
abstract: A simple culture method that was recently developed in our laboratory was applied to the chick iris tissues to characterize neural stem/progenitor-like cells. Iris tissue is a non-neuronal tissue and does not contain any neuronal cells. In the present study we isolated iris tissues from chick embryos just prior to hatching. The isolated iris pigmented epithelium (IPE) or the stroma was embedded in Matrigel and cultured in Dulbecco's MEM supplemented with either fetal bovine serum or the synthetic serum replacement solution B27. Within 24 h of culture, elongated cells with long processes extended out from the explants of both tissues and were positively stained for various neuronal markers such as transitin, Tuj-1 and acetylated tubulin. After a longer culture period, cells positive for photoreceptor markers like rhodopsin, iodopsin and visinin were found, suggesting that the iris tissues contain retinal stem/progenitor-like cells. Several growth factors were examined to determine their effects on neuronal differentiation. EGF was shown to dramatically enhance neuronal cell differentiation, particularly the elongation of neuronal fibers. The addition of exogenous FGF2, however, did not show any positive effects on neuronal differentiation, although FGF signaling inhibitor, SU5402, suppressed neuronal differentiation. The results show that neuronal stem/progenitor-like cells can differentiate into neuronal cells immediately after they are transferred into an appropriate environment. This process did not require any exogenous factors, suggesting that neural stem/progenitor-like cells are simply suppressed from neuronal differentiation within the tissue, and isolation from the tissue releases the cells from the suppression mechanism.
authors.affiliation: Developmental Neurobiology Laboratory, Nara Women's University, Nara 630-8506, Japan.
authors.forename: Tamami
authors.initials: T
authors.lastname: Matsushita
authors.affiliation: Developmental Neurobiology Laboratory, Nara Women's University, Nara 630-8506, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Fujihara
authors.affiliation: Developmental Neurobiology Laboratory, Nara Women's University, Nara 630-8506, Japan; Department of Genetics, University of Leicester, LE1 7RH, UK.
authors.forename: Lars
authors.initials: L
authors.lastname: Royall
authors.affiliation: Molecular and Cell Biology Laboratory, Nara Women's University, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kagiwada
authors.affiliation: Human Morphology, Faculty of Medicine, Okayama University, Japan.
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Kosaka
authors.affiliation: Developmental Neurobiology Laboratory, Nara Women's University, Nara 630-8506, Japan. Electronic address: masaaraki@cc.nara-wu.ac.jp.
authors.forename: Masasuke
authors.initials: M
authors.lastname: Araki
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D049109:Cell Proliferation; D002642:Chick Embryo; D019084:Fluorescent Antibody Technique, Indirect; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D007498:Iris / Q000196:embryology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D055351:Retinal Neurons / Q000166:cytology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins
keywords: extracellular matrix; iris; neural stem/progenitor; tissue culture