XRCC1 protects against the lethality of induced oxidative DNA damage in nondividing neural cells
XRCC1 protects against the lethality of induced oxidative DNA damage in nondividing neural cells
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DOI：
10.1093/nar/gkn480
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发表时间：
2008-09-01
影响因子：
14.9
通讯作者：
Wilson, David M., III
中科院分区：
文献类型：
--
作者：
Kulkarni, Avanti;McNeill, Daniel R.;Wilson, David M., III
XRCC 1是一种重要的支架蛋白，可协调有效的单链断裂修复（SSBR）。最近的数据发现XRCC 1与人脊髓小脑共济失调蛋白和酪氨酰-DNA磷酸二酯酶1有因果关系的蛋白质的关联，暗示SSBR在保护神经元细胞损失和神经退行性疾病中具有保护作用。我们在此证明，在人SH-SY 5 Y神经母细胞瘤细胞中，shRNA慢病毒介导的XRCC 1敲低导致非分裂（即终末分化）细胞群体对氧化还原循环剂甲萘醌和百草枯的敏感性在很大程度上选择性增加;这种存活率降低伴随着DNA链断裂的积累。使用次黄嘌呤氧化酶作为氧化方法，XRCC 1缺乏会影响分裂和非分裂的SH-SY 5 Y细胞，在前一种情况下对生存的影响更大，这表明所产生的氧化DNA损伤谱决定了XRCC 1的具体贡献对细胞的抵抗力。原代XRCC 1杂合子小鼠小脑颗粒细胞表现出增加链断裂积累和减少的生存，由于甲萘醌治疗后增加的凋亡。此外，在原代人胎脑神经元中敲低XRCC 1导致对甲萘醌的敏感性增强，如相对于对照细胞增加的DNA链断裂水平所示。累积结果表明，XRCC 1，更广泛地说，SSBR，在保护非分裂神经元细胞免受氧化应激的遗传毒性后果。
XRCC1 is a critical scaffold protein that orchestrates efficient single-strand break repair (SSBR). Recent data has found an association of XRCC1 with proteins causally linked to human spinocerebellar ataxiasaprataxin and tyrosyl-DNA phosphodiesterase 1implicating SSBR in protection against neuronal cell loss and neurodegenerative disease. We demonstrate herein that shRNA lentiviral-mediated XRCC1 knockdown in human SH-SY5Y neuroblastoma cells results in a largely selective increase in sensitivity of the nondividing (i.e. terminally differentiated) cell population to the redox-cycling agents, menadione and paraquat; this reduced survival was accompanied by an accumulation of DNA strand breaks. Using hypoxanthinexanthine oxidase as the oxidizing method, XRCC1 deficiency affected both dividing and nondividing SH-SY5Y cells, with a greater effect on survival seen in the former case, suggesting that the spectrum of oxidative DNA damage created dictates the specific contribution of XRCC1 to cellular resistance. Primary XRCC1 heterozygous mouse cerebellar granule cells exhibit increased strand break accumulation and reduced survival due to increased apoptosis following menadione treatment. Moreover, knockdown of XRCC1 in primary human fetal brain neurons leads to enhanced sensitivity to menadione, as indicated by increased levels of DNA strand breaks relative to control cells. The cumulative results implicate XRCC1, and more broadly SSBR, in the protection of nondividing neuronal cells from the genotoxic consequences of oxidative stress.