title: Ascorbic acid promotes osteoclastogenesis from embryonic stem cells.
abstract: Ascorbic acid (AA) is known to regulate cell differentiation; however, the effects of AA on osteoclastogenesis, especially on its early stages, remain unclear. To examine the effects of AA throughout the process of osteoclast development, we established a culture system in which tartrate-resistant acid phosphate (TRAP)-positive osteoclasts were induced from embryonic stem cells without stromal cell lines. In this culture system, the number of TRAP-positive cells was strongly increased by the addition of AA during the development of osteoclast precursors, and reducing agents, 2-mercaptoethanol, monothioglycerol, and dithiothreitol, failed to substitute for AA. The effect of AA was stronger when it was added during the initial 4 days during the development of mesodermal cells than when it was added during the last 4 days. On day 4 of the culture period, AA increased the total cell recovery and frequency of osteoclast precursors. Magnetic cell sorting using anti-Flk-1 antibody enriched osteoclast precursors on day 4, and the proportion of Flk-1-positive cells but not that of platelet-derived growth factor receptor alpha-positive cells was increased by the addition of AA. These results suggest that AA might promote osteoclastogenesis of ES cells through increasing Flk-1-positive cells, which then give rise to osteoclast precursors.
authors.affiliation: Division of Immunology, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan. tsune13@grape.med.tottori-u.ac.jp
authors.forename: Motokazu
authors.initials: M
authors.lastname: Tsuneto
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Miya
authors.initials: M
authors.lastname: Yoshino
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yamada
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Hayashi
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*
chemical_list: D001205:Ascorbic Acid