NADH oxidase activation is involved in arsenite-induced oxidative DNA damage in human vascular smooth muscle cells
NADH oxidase activation is involved in arsenite-induced oxidative DNA damage in human vascular smooth muscle cells
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DOI：
10.1161/01.res.86.5.514
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发表时间：
2000-03-17
影响因子：
20.1
通讯作者：
Jan, KY
中科院分区：
文献类型：
--
作者：
Lynn, S;Gurr, JR;Jan, KY
砷具有致动脉粥样硬化、致癌性和遗传毒性。由于动脉粥样硬化斑块被认为是一种良性平滑肌细胞肿瘤，我们研究了亚砷酸盐对人类血管平滑肌细胞DNA完整性的影响。通过单细胞碱性电泳，用浓度高于1μmol/L的亚砷酸盐处理4小时，检测到明显的DNA链断裂。亚砷酸盐处理的细胞的 DNA 链断裂被大肠杆菌甲酰胺嘧啶-DNA 糖基化酶增加，并被二亚苯基碘、超氧化物歧化酶、过氧化氢酶、丙酮酸、DMSO 或 D-甘露醇减少。当反应混合物中包含 NADH 时，经亚砷酸盐处理的细胞提取物显示出产生超氧化物的能力增加；然而，向未经处理的细胞提取物中添加亚砷酸盐并不会增加超氧化物的产生。亚砷酸盐处理的细胞产生超氧化物的能力也受到二亚苯基碘、4,5-二羟基-1,2-苯二磺酸二钠盐（Tiron）或超氧化物歧化酶的抑制。亚砷酸盐处理的细胞中超氧化物的产生和 DNA 链断裂也可以通过转染 p22phox（NADH 氧化酶的重要组成部分）的反义寡核苷酸来抑制。亚砷酸盐处理也增加了 p22phox 的 mRNA 水平。这些结果表明亚砷酸盐激活 NADH 氧化酶产生超氧化物，然后引起氧化性 DNA 损伤。低浓度的亚砷酸盐会增加氧化剂水平，并引起血管平滑肌细胞的氧化DNA损伤，这可能在砷引起的动脉粥样硬化中起重要作用。
Arsenic is atherogenic, carcinogenic, and genotoxic. Because atherosclerotic plaque has been considered a benign smooth muscle cell tumor, we have studied the effects of arsenite on DNA integrity of human vascular smooth muscle cells. By using single-cell alkaline electrophoresis, apparent DNA strand breaks were detected in a 4-hour treatment with arsenite at a concentration above 1 mu mol/L. DNA strand breaks of arsenite-treated cells were increased by Escherichia coli formamidopyrimidine-DNA glycosylase and decreased by diphenylene iodinium, superoxide dismutase, catalase, pyruvate, DMSO, or D-mannitol. Extract from arsenite-treated cells showed increased capacity for producing superoxide when NADH was included in the reaction mixture; however, addition of arsenite to extract from untreated cells did not increase superoxide production. The superoxide-producing ability of arsenite-treated cells was also suppressed by diphenylene iodinium, 4,5-dihydroxy-1,2-benzenedisulfonic acid disodium salt (Tiron), or superoxide dismutase. Superoxide production and DNA strand breaks in arsenite-treated cells were also suppressed by transfecting antisense oligonucleotides of p22phox, an essential component of NADH oxidase. Treatment with arsenite also increased the mRNA level of p22phox. These results suggest that arsenite activates NADH oxidase to produce superoxide, which then causes oxidative DNA damage. The result that arsenite at low concentrations increases oxidant levels,and causes oxidative DNA damage in vascular smooth muscle cells may be important in arsenic-induced atherosclerosis.