title: Multipotent cells from mammalian iris pigment epithelium.
abstract: The regeneration of lens tissue from the iris of newts has become a classical model of developmental plasticity, although little is known about the corresponding plasticity of the mammalian iris. We here demonstrate and characterize multipotent cells within the iris pigment epithelium (IPE) of postnatal and adult rodents. Acutely-isolated IPE cells were morphologically homogeneous and highly pigmented, but some produced neurospheres which expressed markers characteristic of neural stem/progenitor cells. Stem/progenitor cell markers were also expressed in the IPE in vivo both neonatally and into adulthood. Inner and outer IPE layers differentially expressed Nestin (Nes) in a manner suggesting that they respectively shared origins with neural retina (NR) and pigmented epithelial (RPE) layers. Transgenic marking enabled the enrichment of Nes-expressing IPE cells ex vivo, revealing a pronounced capacity to form neurospheres and differentiate into photoreceptor cells. IPE cells that did not express Nes were less able to form neurospheres, but a subset initiated the expression of pan-neural markers in primary adherent culture. These data collectively suggest that discrete populations of highly-pigmented cells with heterogeneous developmental potencies exist postnatally within the IPE, and that some of them are able to differentiate into multiple neuronal cell types.
authors.affiliation: Research Unit for Cell Plasticity, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Asami
authors.forename: Guangwei
authors.initials: G
authors.lastname: Sun
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Kosaka
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D002454:Cell Differentiation / Q000502:physiology*; D017931:DNA Primers; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D007498:Iris / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D039902:Multipotent Stem Cells / Q000166:cytology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D001973:Bromodeoxyuridine