Hydroxyl radical production via NADPH oxidase in rat striatum due to carbon monoxide poisoning
Hydroxyl radical production via NADPH oxidase in rat striatum due to carbon monoxide poisoning
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DOI：
10.1016/j.tox.2017.12.002
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发表时间：
2018-02-01
期刊：
影响因子：
4.5
通讯作者：
Mizukami, Hajime
中科院分区：
文献类型：
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作者：
Hara, Shuichi;Kobayashi, Masamune;Mizukami, Hajime
3000 ppm（而非 1000 ppm）的一氧化碳 (CO) 引起的严重中毒会增强大鼠纹状体中羟基自由基（中心点 OH）的产生，而纹状体对 NADPH 氧化酶 (NOX) 抑制剂（包括二亚苯基碘鎓 (DPI)）非常敏感，但对黄嘌呤氧化酶不敏感。定量实时 PCR 证实了之前的微阵列发现，3000 ppm（而非 1000 ppm）的 CO 增强了大鼠纹状体中双氧化酶 2 (DUOX2) 的 mRNA 表达，但不增强 DUOX1，这两种酶都是产生活性氧的 NOX 家族成员。然而，DUOX2 和 DUOX1 的蛋白质水平降低了 3000 ppm CO。 CO 诱导的中心点 OH 产生对白屈菜红碱和 SB230580（分别是蛋白激酶 C 和 p38MAPK 的抑制剂）具有抗性，据报道，它们分别介导 DUOX1 和 DUOX2 的激活。激活两种 DUOX 所需的 Ca2+ 的剥夺未能抑制 CO 诱导的中心点 OH 的产生。 CO 诱导的中心点 OH 的产生被 EHT1864 强烈抑制，EHT1864 是 Rac（Ras 相关的 C3 肉毒毒素底物）的抑制剂，它是 NOX1、NOX2 和 NOX3 激活的一个因素（Rac 对 Nox3 激活的作用是有争议的），与 DPI 所抑制的一样多。此外，EHT1864 与 DPI 结合进一步抑制了 CO 诱导的中心点 OH 的产生。 NOX1 至 NOX4 和 Rac1 的蛋白水平没有显着变化。 CO 诱导的中心点 OH 生成很可能是通过 Rac 依赖性 NOX 酶（例如 Nox1、Nox2 和 Nox3）的激活介导的。
Severe poisoning induced by carbon monoxide (CO) at 3000 ppm, but not 1000 ppm, enhances hydroxyl radical (center dot OH) production in rat striatum, which is greatly susceptible to inhibitors of NADPH oxidase (NOX), including diphenyleneiodonium (DPI), but not xanthine oxidase. The quantitative real-time PCR confirmed the previous microarray finding that CO at 3000 ppm, but not 1000 ppm, enhanced mRNA expression of dual oxidase 2 (DUOX2), but not DUOX1, in rat striatum, both of which are NOX family members producing reactive oxygen species. However, the protein levels of DUOX2 and DUOX1 were decreased by 3000 ppm CO. The CO-induced center dot OH production was resistant to chelerythrine and SB230580, inhibitors of protein kinase C and p38MAPK, respectively, which are reported to mediate activation of DUOX1 and DUOX2, respectively. Deprivation of Ca2+, which is required for activation of both DUOXs, failed to suppress the CO-induced center dot OH production. The CO induced center dot OH production was strongly suppressed by EHT1864, an inhibitor of Rac (Ras-related C3 botulinum toxin substrate), which is a factor for activation of NOX1, NOX2 and NOX3 (the role of Rac on Nox3 activation is controversial) as much as that was suppressed by DPI. In addition, EHT1864 in combination with DPI further suppressed the CO-induced center dot OH production. There were no significant changes in the protein levels of NOX1 through NOX4 and Rac1. It is likely that the CO-induced center dot OH production is mediated through the activation of Rac-dependent NOX enzymes, such as Nox1, Nox2, and Nox3.