title: Deficient DNA repair exacerbates ethanol-initiated DNA oxidation and embryopathies in ogg1 knockout mice: gender risk and protection by a free radical spin trapping agent.
abstract: Reactive oxygen species (ROS) have been implicated in the teratogenicity of alcohol (ethanol, EtOH). To determine the involvement of embryonic oxidative DNA damage, DNA repair-deficient oxoguanine glycosylase 1 (ogg1) knockout embryos were exposed in culture to EtOH (2 or 4 mg/ml), with or without pretreatment with the free radical spin trap phenylbutylnitrone (PBN) (0.125 mM). Visceral yolk sacs were used to genotype embryos for DNA repair status and gender. EtOH caused a concentration-dependent decrease in anterior neuropore closure (ANPC), somite development, turning, crown-rump length (CRL), yolk sac diameter (YSD) and head length (HL) (p < 0.001) in all 3 ogg1 genotypes. There was a further ogg1 gene dose-dependent decrease from +/+ to -/- embryos in ANPC, somite development, turning, CRL and HL (p < 0.05), and a gene-dependent correlation between HL and ANPC (p < 0.01). Female embryos exhibited lesser ANPC and turning than males (p < 0.05), suggesting underlying gender-dependent target-specific determinants. PBN pretreatment increased ANPC, somite development, turning, CRL, YSD and HL (p < 0.001), although this protection against EtOH was slightly less effective in -/- embryos. Oxidatively damaged DNA determined as 8-oxo-2'-deoxyguanosine (8-oxodGuo), which is repaired by OGG1, was measured in single embryos in vivo after maternal EtOH treatment (4 g/kg i.p). EtOH increased embryonic 8-oxodGuo in an ogg1 gene-dependent fashion, with the highest levels in -/- embryos. These results show that embryonic DNA repair status and gender are determinants of risk. ROS-initiated embryonic DNA oxidation is involved in EtOH embryopathies.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.|Southern Research Institute, 2000 9th Avenue South, Birmingham, AL, 35205, USA.
authors.forename: Lutfiya
authors.initials: L
authors.lastname: Miller-Pinsler
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada. pg.wells@utoronto.ca.|Division of Biomolecular Sciences, Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, ON, M5S 3M2, Canada. pg.wells@utoronto.ca.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Wells
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D004247:DNA / Q000378:metabolism; D045647:DNA Glycosylases / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D049914:DNA Repair-Deficiency Disorders / Q000139:chemically induced / Q000235:genetics*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000187:drug effects* / Q000473:pathology; D000431:Ethanol / Q000633:toxicity*; D005260:Female; D008297:Male; D018345:Mice, Knockout; D010084:Oxidation-Reduction; D010654:Phenylbutyrates / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000494:pharmacology; D012737:Sex Factors; D019097:Spin Trapping
chemical_list: D010654:Phenylbutyrates; D017382:Reactive Oxygen Species; D000431:Ethanol; D000080242:8-Hydroxy-2'-Deoxyguanosine; C010416:phenylbutyramide; D004247:DNA; D045647:DNA Glycosylases; C485990:Ogg1 protein, mouse; D003849:Deoxyguanosine
keywords: DNA oxidation; Embryo culture; Ethanol; Ogg1 mice; PBN; Reactive oxygen species