Gokce Goksel, Ozsarlak-Sozer Gonen, Oktay Gulgun, Kirkali Güldal, Jaruga Pawel, Dizdaroglu Miral, Kerry Zeliha
Department of Pharmacology, Faculty of Pharmacy, Ege University, Bornova, Izmir, Turkey.
Biochemistry. 2009 Jun 9;48(22):4980-7. doi: 10.1021/bi900030z.
Glutathione (GSH) exists in mammalian tissues in vivo at high concentrations and plays an important protective role against oxidatively induced damage to biological molecules, including DNA. We investigated oxidatively induced damage to DNA by GSH depletion in different organs of rabbits in vivo. Rabbits were treated subcutaneously with buthionine sulfoximine (BSO), an effective GSH-depleting compound. GSH levels were measured in heart, brain, liver, and kidney of animals. BSO treatment significantly reduced GSH levels in heart, brain, and liver, but not in kidney. DNA was isolated from these tissues to test whether GSH depletion causes oxidatively induced DNA damage in vivo. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry with isotope dilution methods were applied to measure typical products of oxidatively induced damage in isolated DNA samples. Several such products were identified and quantified in all organs. BSO treatment caused significant formation of 8-hydroxyguanine, 2,6-diamino-4-hydroxy-5-formamidopyrimidine, 8-hydroxyadenine, and (5'S)-8,5'-cyclo-2'-deoxyadenosine in DNA of organs of rabbits. Animals were fed with the semiessential amino acid 2-aminoethanesulfonic acid (taurine) during BSO treatment. Taurine significantly inhibited GSH depletion and also formation of DNA products. Depletion of GSH correlated well with formation of DNA products, indicating the role of GSH in preventing oxidatively induced DNA damage. Our findings might contribute to the understanding of pathologies associated with DNA damage, oxidative stress, and/or defective antioxidant responses and improve our understanding of the effect of BSO in increasing the efficacy of anticancer therapeutics.
谷胱甘肽（GSH）在哺乳动物体内组织中以高浓度存在，对包括DNA在内的生物分子免受氧化诱导的损伤起着重要的保护作用。我们研究了体内兔不同器官中谷胱甘肽耗竭对DNA的氧化诱导损伤。给兔子皮下注射丁硫氨酸亚砜胺（BSO），一种有效的谷胱甘肽耗竭化合物。测量动物心脏、大脑、肝脏和肾脏中的谷胱甘肽水平。BSO处理显著降低了心脏、大脑和肝脏中的谷胱甘肽水平，但肾脏中未降低。从这些组织中分离DNA，以测试谷胱甘肽耗竭是否会在体内引起氧化诱导的DNA损伤。应用气相色谱-质谱联用和液相色谱-质谱联用的同位素稀释法来测量分离的DNA样品中氧化诱导损伤的典型产物。在所有器官中鉴定并定量了几种此类产物。BSO处理导致兔器官DNA中8-羟基鸟嘌呤、2,6-二氨基-4-羟基-5-甲酰胺基嘧啶、8-羟基腺嘌呤和（5'S）-8,5'-环-2'-脱氧腺苷的显著形成。在BSO处理期间，给动物喂食半必需氨基酸2-氨基乙磺酸（牛磺酸）。牛磺酸显著抑制谷胱甘肽耗竭以及DNA产物的形成。谷胱甘肽的耗竭与DNA产物的形成密切相关，表明谷胱甘肽在预防氧化诱导的DNA损伤中的作用。我们的发现可能有助于理解与DNA损伤、氧化应激和/或抗氧化反应缺陷相关的病理学，并增进我们对BSO在提高抗癌治疗疗效方面作用的理解。
