Involvement of reactive oxygen species-mediated NF-κB activation in TNF-α-induced cardiomyocyte hypertrophy
Involvement of reactive oxygen species-mediated NF-κB activation in TNF-α-induced cardiomyocyte hypertrophy
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DOI：
10.1006/jmcc.2001.1505
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发表时间：
2002-02-01
影响因子：
5
通讯作者：
Hori, M
中科院分区：
文献类型：
--
作者：
Higuchi, Y;Otsu, K;Hori, M
我们研究了肿瘤坏死因子-α（TNF-α）诱导的心肌肥大的细胞内信号转导机制，TNF-α以剂量依赖的方式增强了瞬时转染心肌细胞的κ B依赖性报告基因构建体的表达。电泳迁移率变动分析表明，TNF-α诱导核因子-κ B（NF-κ B）特异性DNA结合。用表达IkappaB α的抗降解突变体（AdIkappaBalpha 32/36 A）的重组腺病毒载体感染培养的心肌细胞。IkappaB α突变体抑制TNF-α诱导的NF-κ B活化。在感染AdIkappaBalpha 32/36 A的心肌细胞中，与感染表达细菌β-半乳糖苷酶的腺病毒的细胞相比，TNF-α诱导的肥大反应，包括细胞大小、蛋白质合成和心房利钠因子产生的增加以及肌节组织的增强显著减弱。使用活性氧（ROS）敏感的荧光染料，2 '，7'-二氯荧光素，我们观察到心肌细胞中的荧光信号随时间增加，在加入TNF-α后，在TNF-α处理前，抗氧化剂n-乙酰半胱氨酸（NAC）的预孵育，消除了TNF-α诱导的ROS产生。NAC消除TNF-α诱导的NF-κ B活化和肥大反应。这些发现表明TNF-α诱导的心肌细胞肥大是通过ROS的产生通过NF-κ B活化介导的。(C)2002年爱思唯尔科学有限公司
We examined the intracellular signaling mechanism for tumor necrosis factor-alpha (TNF-alpha)-induced cardiac hypertrophy in isolated rat neonatal cardiomyocytes, TNF-alpha enhanced the expression of a kappaB-dependent reporter gene construct in a dose-dependent manner, which was transiently transfected in cardiomyocytes. Electrophoretic mobility shift assay demonstrated that TNF-alpha induced nuclear factor-kappaB (NF-kappaB)-specific DNA binding. Cultured cardiomyocytes were infected with a recombinant adenoviral vector expressing a degradation-resistant mutant of IkappaBalpha (AdIkappaBalpha32/36A). The IkappaBalpha mutant suppressed NF-kappaB activation induced by TNF-alpha. In cardiomyocytes infected with AdIkappaBalpha32/36A, TNF-alpha-induced hypertrophic responses, including increases in cell size, protein synthesis and atrial natriuretic factor production and enhancement of sarcomeric organization, were remarkably attenuated compared to the cells infected with an adenovirus expressing bacterial beta-galactosidase. Using a reactive oxygen species (ROS)-sensitive fluorescent dye, 2', 7'-dichlorofluorescin, we observed an increase in fluorescent signal in cardiomyocytes over time, upon addition of TNF-alpha Preincubation of n-acetyl cysteine (NAC), an antioxidant, prior to TNF-alpha treatment, abolished TNF-alpha -induced ROS generation. NAC abolished TNF-alpha-induced NF-kappaB activation and hypertrophic responses. These findings indicated that TNF-alpha-induced cardiomyocyte hypertrophy is mediated through NF-kappaB activation via the generation of ROS. (C) 2002 Elsevier Science Ltd.