Nitric oxide-mediated protection of endothelial cells from hydrogen peroxide is mediated by intracellular zinc and glutathione
Nitric oxide-mediated protection of endothelial cells from hydrogen peroxide is mediated by intracellular zinc and glutathione
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DOI：
10.1152/ajpcell.00643.2008
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发表时间：
2009-04-01
影响因子：
5.5
通讯作者：
Kolb-Bachofen, Victoria
中科院分区：
文献类型：
--
作者：
Cortese-Krott, Miriam M.;Suschek, Christoph V.;Kolb-Bachofen, Victoria
Cortese-Krott MM、Suschek CV、Wetzel W、Kroncke KD、Kolb-Bachofen V。一氧化氮介导的内皮细胞免受过氧化氢影响的保护是由细胞内锌和谷胱甘肽介导的。 Am J Physiol Cell Physiol 296：C811-C820，2009。首次发表于 2009 年 2 月 4 日； doi:10.1152/ajpcell.00643.2008.-氧化应激可能导致内皮功能障碍和血管疾病。研究表明，NO 可以保护内皮细胞 (EC) 免受 H2O2 诱导的毒性。此外，众所周知，细胞内的一氧化氮会诱导含有锌硫复合物的蛋白质释放锌。本研究的目的是探讨 NO 在细胞内释放的锌是否在大鼠主动脉 EC 中 NO 介导的 H2O2 保护中发挥信号作用。我们的结果表明，NO 介导的对 H2O2 的保护取决于谷胱甘肽过氧化物酶和谷氨酸半胱氨酸连接酶 (GCL) 的活性，后者是谷胱甘肽 (GSH) 从头生物合成的限速酶。此外，NO 通过诱导 GCL (GCLC) 催化亚基的表达来增加抗氧化剂 GSH 的合成。螯合细胞内“游离”锌可以消除 NO 介导的 GCLC 和细胞 GSH 水平的增加。因此，NO 介导的针对 H2O2 引起的毒性的保护作用受到损害。我们还表明，在促炎条件下，细胞 NO 合成和细胞内“游离”锌都是维持细胞 GSH 水平所必需的。利用RNA干扰和激光扫描显微镜，我们发现NO诱导的GCLC表达依赖于转录因子Nrf2的激活，而不依赖于“锌感应”转录因子MTF-1的活性。这些发现表明，细胞内“游离”锌在 NO 的保护活性中发挥信号作用，并且可以解释为什么在内皮中维持足够的锌状态对于防止氧化应激和血管疾病的发展很重要。
Cortese-Krott MM, Suschek CV, Wetzel W, Kroncke KD, Kolb-Bachofen V. Nitric oxide-mediated protection of endothelial cells from hydrogen peroxide is mediated by intracellular zinc and glutathione. Am J Physiol Cell Physiol 296: C811-C820, 2009. First published February 4, 2009; doi:10.1152/ajpcell.00643.2008.-Oxidative stress may cause endothelial dysfunction and vascular disease. It has been shown that NO protects endothelial cells (EC) against H2O2-induced toxicity. In addition, it is known that NO within cells induces a zinc release from proteins containing zinc-sulfur complexes. The aim of this study was to investigate whether zinc released intracellularly by NO plays a signaling role in the NO-mediated protection against H2O2 in rat aortic EC. Our results show that the NO-mediated protection toward H2O2 depends on the activities of glutathione peroxidase and glutamate cysteine ligase (GCL), the rate-limiting enzyme of glutathione (GSH) de novo biosynthesis. Moreover, NO increases the synthesis of the antioxidant GSH by inducing the expression of the catalytic subunit of GCL (GCLC). Chelating intracellular "free" zinc abrogates the NO-mediated increase of GCLC and of cellular GSH levels. As a consequence, the NO-mediated protection against H2O2-induced toxicity is impaired. We also show that under proinflammatory conditions, both cellular NO synthesis and intracellular "free" zinc are required to maintain the cellular GSH levels. Using RNA interference and laser scanning microscopy, we found that the NO-induced expression of GCLC depends on the activation of the transcription factor Nrf2 but not on the activity of the "zinc- sensing" transcription factor MTF-1. These findings show that intracellular "free" zinc plays a signaling role in the protective activity of NO and could explain why maintenance of an adequate zinc status in the endothelium is important to protect from oxidative stress and the development of vascular disease.