title: 8-Hydroxyguanine levels and repair capacity during mouse embryonic stem cell differentiation.
abstract: To evaluate the defence capacities of embryonic stem (ES) cells against gene impairment, this study measured the levels of 8-hydroxyguanine (8-OH-Gua), a well-known marker of oxidative stress in DNA, and its repair capacity during differentiation. Undifferentiated ES cells (EB3) were cultured without leukaemia inhibitory factor (LIF) for 0, 4 and 7 days and are referred to as ES-D0, ES-D4 and ES-D7, respectively. These three cell lines were treated with 300 μM hydrogen peroxide (H(2)O(2)) for 48 and 72 h. After treatment, the amounts of 8-OH-Gua in the cells were determined by the high-performance liquid chromatography (HPLC)-electrochemical detector (ECD) method. The levels of 8-OH-Gua in ES-D7 treated with H(2)O(2) were higher than those in ES-D0 and ES-D4, suggesting that the DNA in the undifferentiated cells was protected against gene impairment, as compared to that in the differentiated cells. To examine the repair capacity for 8-OH-Gua, this study analysed the expression of 8-OH-Gua repair-associated genes, 8-oxoguanine DNA glycosylase 1 (OGG1), MutY homolog (MUTYH) and Mut T homolog 1 (MTH1), in ES-D0, ES-D4 and ES-D7. The mRNA levels of MUTYH and MTH1 showed no significant change, whereas OGG1 mRNA was significantly decreased in ES-D7 treated with H(2)O(2). Moreover, it was observed that ES-D7 treated with H(2)O(2) readily underwent apoptosis, in comparison to its undifferentiated counterparts, ES-D0 and ES-D4. Taken together, ES cells are more resistant to DNA oxidative stresses than differentiated cells.
authors.affiliation: Department of Chemical Processes and Environments, Faculty of Environmental Engineering, The University of Kitakyushu, Kitakyushu, Fukuoka, 808-0135, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kuboyama
authors.forename: Shoichi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kawai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kasai
authors.forename: Haruki
authors.initials: H
authors.lastname: Morii
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Tamae
authors.forename: Tamiji
authors.initials: T
authors.lastname: Nakashima
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirano
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D045647:DNA Glycosylases / Q000378:metabolism; D004260:DNA Repair; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D006147:Guanine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D051379:Mice; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D018384:Oxidative Stress; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D050814:Octamer Transcription Factor-3; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C024829:8-hydroxyguanine; D006147:Guanine; D004247:DNA; D006861:Hydrogen Peroxide; D010744:Phosphoric Monoester Hydrolases; D045647:DNA Glycosylases; C485990:Ogg1 protein, mouse; C061738:mutY adenine glycosylase; C509779:Nudt1 protein, mouse