Oxidative DNA injury after experimental intracerebral hemorrhage
Oxidative DNA injury after experimental intracerebral hemorrhage
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DOI：
10.1016/j.brainres.2005.01.036
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发表时间：
2005-03-28
期刊：
影响因子：
2.9
通讯作者：
Xi, GH
中科院分区：
文献类型：
--
作者：
Nakamura, T;Keep, RF;Xi, GH
我们前期的研究表明，脑出血（ICH）后，脑内发生DNA损伤。DNA损伤可以由至少两种途径引起，核酸内切酶介导的DNA片段化或氧化损伤。本研究探讨了后者的发生后，脑出血和铁在这种损伤中的作用。雄性Sprague-Dawley大鼠接受自体全血或亚铁输注至右侧基底神经节。对照组大鼠仅进行针刺（假手术）。1、3或7天后处死大鼠。通过免疫组织化学分析8-羟基-2'-脱氧鸟苷（8-OHdG），同时还定量脱嘌呤/脱嘧啶脱碱基位点（AP位点）的数目。8-OHdG和AP位点是DNA氧化的两个标志。通过蛋白质印迹法测定二硝基苯基（DNP），以比较蛋白质氧化损伤与DNA氧化损伤的时间过程。DNA修复Ku蛋白通过Western印迹分析测定。用DNA聚合酶1介导的生物素-dATP缺口平移（PANT）标记法检测DNA损伤。8-OHdG、AP位点和DNP水平增加，Ku水平降低。脑出血后3天，血肿周围也有大量PANT阳性细胞。此外，脑内灌注铁增加脑DNP水平，导致DNA损伤。这些结果表明，氧化应激有助于脑出血后的DNA损伤和脑损伤。减少DNA氧化损伤（例如，通过铁螯合）可能是ICH的治疗靶点。(c)2005 Elsevier B.V.保留所有权利。
Our previous studies have demonstrated that DNA injury occurs in the brain after intracerebral hemorrhage (ICH). DNA damage can result from at least two pathways, either endonuclease-mediated DNA fragmentation or oxidative injury. The present study investigated the occurrence of the latter after ICH and the role of iron in such injury. Male Sprague-Dawley rats received an infusion of autologous whole blood or ferrous iron into the right basal ganglia. Control rats just had a needle insertion (sham). The rats were sacrificed 1, 3, or 7 days later. 8 -Hydroxyl-2'-deoxyguanosine (8-OHdG) was analyzed by immumohistochernistry while the number of apumic/apyrimidinic abasic sites (AP sites) was also quantified. 8-OHdG and AP sites are two hallmarks of DNA oxidation. Dinitrophenyl (DNP) was measured by Western blotting to compare the time course of protein oxidative damage to that of DNA. DNA repair Ku proteins were measured by Western blot analysis. DNA damage was also examined using DNA polymerase 1-mediated biotin-dATP nick translation (PANT) labeling. An increase of 8-OHdG, AP sites and DNP levels and a decrease of Ku levels were observed. Abundant PANT-positive cells were also observed in the perihematomal area 3 days after ICH. ln addition, intracerebral infusion of iron increased brain DNP levels and resulted in DNA injury. These results suggest that oxidative stress contributes to DNA damage and brain injury after ICH. Reducing DNA oxidative damage (for example, through iron chelation) may be a therapeutic target for ICH. (c) 2005 Elsevier B.V. All rights reserved.