title: Effects of Chronic Low-Dose Radiation on Human Neural Progenitor Cells.
abstract: The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells. Radiation at low doses of 31, 124 and 496 mGy per 72 h was administered to hNPCs. The effects were estimated by gene expression profiling with microarray analysis as well as morphological analysis. Gene expression was dose-dependently changed by radiation. By thirty-one mGy of radiation, inflammatory pathways involving interferon signaling and cell junctions were altered. DNA repair and cell adhesion molecules were affected by 124 mGy of radiation while DNA synthesis, apoptosis, metabolism, and neural differentiation were all affected by 496 mGy of radiation. These in vitro results suggest that 496 mGy radiation affects the development of neuronal progenitor cells while altered gene expression was observed at a radiation dose lower than 100 mGy. This study would contribute to the elucidation of the clinical and subclinical phenotypes of impaired neuronal development induced by chronic low-dose radiation.
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Katsura
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.|Center for Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.|Faculty of Pharmaceutical Sciences, Department of Pharmacy, Tokyo University of Science, Noda, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Cyou-Nakamine
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zen
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zen
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nansai
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Amagasa
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Kanki
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.|Division of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Kaneki
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.|Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Akashi
authors.initials: A
authors.lastname: Taguchi
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.|Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Pharmacy, Tokyo University of Science, Noda, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kaji
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.|Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kodama
authors.affiliation: Laboratory of Molecular Radiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Miyagawa
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.|Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Youichiro
authors.initials: Y
authors.lastname: Wada
authors.affiliation: Isotope Science Center, The University of Tokyo, Tokyo, Japan.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Akimitsu
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
authors.forename: Hideko
authors.initials: H
authors.lastname: Sone
mesh_terms: D002454:Cell Differentiation / Q000528:radiation effects; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000528:radiation effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D016501:Neurites / Q000528:radiation effects; D020411:Oligonucleotide Array Sequence Analysis; D011827:Radiation; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects