Reduction of insulin-stimulated glucose uptake by peroxynitrite is concurrent with tyrosine nitration of insulin receptor substrate-1
Reduction of insulin-stimulated glucose uptake by peroxynitrite is concurrent with tyrosine nitration of insulin receptor substrate-1
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DOI：
10.1016/j.bbrc.2004.06.019
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发表时间：
2004-07-30
影响因子：
3.1
通讯作者：
Watada, H
中科院分区：
文献类型：
--
作者：
Nomiyama, T;Igarashi, Y;Watada, H
诱导型一氧化氮合酶在高脂饮食诱导的胰岛素抵抗中起重要作用。一氧化氮与超氧化物反应生成过氧亚硝酸根(ONOO-)，可修饰多种蛋白质。在这项研究中，我们研究了过氧亚硝酸盐是否会损害胰岛素信号通路。我们的实验表明，过氧亚硝酸根的生成物3-(4-吗啉基)西多诺亚胺盐酸盐(SIN-1)可剂量依赖性地抑制胰岛素刺激的葡萄糖摄取。SIN-1不影响胰岛素受体蛋白水平和酪氨酸磷酸化水平，但降低胰岛素受体底物-1(IRS-1)蛋白水平和IRS-1相关磷脂酰肌醇-3激酶(PI-3激酶)活性。尽管SIN-1不能诱导IRS-1的Ser(307)磷酸化，但在表达人胰岛素受体的Rat1成纤维细胞中检测到IRS-1的酪氨酸硝化。质谱仪显示，过氧亚硝酸根在大鼠IRS-1中至少诱导了四个硝化酪氨酸残基，其中包括Tyr(939)，这是IRS-1与PI-3激酶的P85亚单位结合的关键。我们的结果表明，过氧亚硝酸盐降低了IRS-1的蛋白水平，降低了IRS-1的磷酸化，同时也减少了其酪氨酸残基的硝化。(C)2004 Elsevier Inc.保留所有权利。
Inducible nitric oxide synthetase plays an essential role in insulin resistance induced by a high-fat diet. The reaction of nitric oxide with superoxide leads to the formation of peroxynitrite (ONOO-), which can modify several proteins. In this study, we investigated whether peroxynitrite impairs insulin-signalling pathway. Our experiments showed that 3-(4-morpholinyl)sydnonimine hydrochloride (SIN-1), a constitutive producer of peroxynitrite, dose-dependently inhibited insulin-stimulated glucose uptake. While SIN-1 did not affect the insulin receptor protein level and tyrosine phosphorylation, it reduced the insulin receptor substrate-1 (IRS-1) protein level, and IRS-1 associated phosphatidylinositol-3 kinase (PI-3 kinase) activity. Although SIN-1 did not induce Ser(307) phosphorylation of IRS-1, tyrosine nitration of IRS-1 was detected in SIN-1-treated-Rat1 fibroblasts expressing human insulin receptors. Mass spectrometry showed that peroxynitrite induced at least four nitrated tyrosine residues in rat IRS-1, including Tyr(939), which is critical for association of IRS-1 with the p85 subunit of PI-3 kinase. Our results suggest that peroxynitrite reduces the IRS-1 protein level and decreases phosphorylation of IRS-1 concurrent with nitration of its tyrosine residues. (C) 2004 Elsevier Inc. All rights reserved.