Nitric oxide stimulates heme oxygenase-1 gene transcription via the Nrf2/ARE complex to promote vascular smooth muscle cell survival
Nitric oxide stimulates heme oxygenase-1 gene transcription via the Nrf2/ARE complex to promote vascular smooth muscle cell survival
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DOI：
10.1016/j.cardiores.2007.03.004
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发表时间：
2007-07-15
影响因子：
10.8
通讯作者：
Durante, William
中科院分区：
文献类型：
--
作者：
Liu, Xiao-ming;Peyton, Kelly J.;Durante, William
目的：本实验室等前期研究发现，NO是血管平滑肌细胞（SNIC）血红素加氧酶-1（HO-1）基因转录的有效诱导剂，但诱导HO-1基因表达的机制尚未阐明。在本研究中，我们确定了负责诱导HO-I的信号通路及其生物学意义。方法：通过用各种NO供体或炎症细胞因子处理细胞，使培养的大鼠主动脉SMC暴露于亚硝化应激。结果：亚硝化应激刺激血管SMC中HO-1 mRNA表达和启动子活性增加。然而，HO-1 启动子中抗氧化反应元件 (ARE) 的突变或 NF-E2 相关因子 2 (Nrf2) 显性失活突变体的过度表达消除了 NO 的激活。使用 ARE 探针进行的电迁移率变化测定检测到一种复合物，该复合物的强度因 NO 而显着增加。此外，使用针对 Nrf2 的抗体可延缓该复合物的迁移。 NO 还增加了 Nrf2 mRNA 表达、总 Nrf2 水平和核 Nrf2 水平以及 Nrf2 与 HO-1 启动子的结合。最后，用 NO 处理 SMC 会刺激细胞凋亡，HO-I 抑制会增加细胞凋亡。结论：这些结果表明，亚硝化应激通过 Nrf2/ARE 复合物的激活诱导 HO-1 基因转录，从而抵消 NO 诱导的血管 SMC 细胞凋亡。亚硝化应激激活 Nrf2 并刺激 HO-1 基因转录的能力可能代表了维持血管炎症和动脉粥样硬化部位细胞活力的关键适应性反应。 (c) 2007 年欧洲心脏病学会。由 Elsevier B.V. 出版。保留所有权利。
Objective: Previous studies from our laboratory and others found that NO is a potent inducer of heme oxygenase-1 (HO-1) gene transcription in vascular smooth muscle cells (SNIC), however, the mechanism responsible for the induction of HO-1 gene expression has not been elucidated. In the present study, we detennined the signaling pathway responsible for the induction of HO-I and its biological significance.Methods: Cultured rat aortic SMC were exposed to nitrosative stress by treating cells with various NO donors or with inflammatory cytokines.Results: Nitrosative stress stimulated an increase in HO-1 mRNA expression and promoter activity in vascular SMC. However, mutation of the antioxidant response element (ARE) in the HO-1 promoter or overexpression of a dominant-negative mutant of NF-E2-related factor-2 (Nrf2) abrogated the activation by NO. Electromobility shift assays using an ARE probe detected a complex that was significantly increased in intensity by NO. In addition, the migration of this complex was retarded by using an antibody directed against Nrf2. NO also increased Nrf2 mRNA expression, total and nuclear Nrf2 levels, and the binding of Nrf2 to the HO-1 promoter. Finally, treatment of SMC with NO stimulated apoptosis that was increased by HO-I inhibition.Conclusions: These results demonstrate that nitrosative stress induces HO-1 gene transcription through the activation of the Nrf2/ARE complex to counteract NO-induced apoptosis of vascular SMC. The capacity of nitrosative stress to activate Nrf2 and stimulate HO-1 gene transcription may represent a critical adaptive response to maintain cell viability at sites of vascular inflammation and atherosclerosis. (c) 2007 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.