STAT3 Regulation by S-Nitrosylation: Implication for Inflammatory Disease
STAT3 Regulation by S-Nitrosylation: Implication for Inflammatory Disease
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DOI：
10.1089/ars.2013.5223
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发表时间：
2014-06-01
影响因子：
6.6
通讯作者：
Singh, Inderjit
中科院分区：
文献类型：
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作者：
Kim, Jinsu;Won, Je-Seong;Singh, Inderjit
目的：S-亚硝基化和S-谷胱甘肽化，基于氧化还原的蛋白质巯基修饰，最近成为重要的信号传导机制。在这项研究中，我们评估了基于S-亚硝基化的Janus激活激酶2/信号转导和转录激活因子3（JAK 2/STAT 3）通路的调节，该通路在免疫/炎症反应和肿瘤发生中起着关键作用。结果如下：我们的研究表明，STAT 3在刺激的小胶质细胞经历了两个不同的氧化还原依赖性的修改，S-亚硝基化和S-谷胱甘肽化。STAT 3的S-亚硝基化与诱导型一氧化氮合酶（iNOS）产生的一氧化氮（NO）和S-亚硝基谷胱甘肽（GSNO）有关，而STAT 3的S-谷胱甘肽化与细胞氧化应激有关。由iNOS产生的NO或用外源性GSNO处理小胶质细胞通过抑制STAT 3磷酸化来抑制STAT 3活化（Tyr（705））。因此，白细胞介素-6（IL-6）诱导的小胶质细胞增殖和相关基因表达也减少。在使用纯化的JAK 2和STAT 3的无细胞激酶测定中，STAT 3磷酸化被其与GSNO的选择性预孵育抑制，但不被JAK 2与GSNO的预孵育抑制，表明GSNO介导的机制通过STAT 3而不是JAK 2的S-亚硝基化抑制STAT 3磷酸化。在这项研究中，我们确定Cys（259）是GSNO介导的STAT 3 S-亚硝基化的靶Cys残基。将Cys（259）残基替换为Ala后，GSNO对IL-6诱导的STAT 3磷酸化和转录激活的抑制作用消失，提示Cys（259）S-亚硝基化在STAT 3磷酸化中的作用。创新：NO通过STAT 3（Cys（259））的S-亚硝基化和STAT 3（Tyr（705））磷酸化的抑制来调节小胶质细胞增殖。结论：STAT 3的表达受NO的翻译后修饰（S-亚硝基化）的调控。这些发现对开发靶向STAT 3的新疗法具有重要意义，用于治疗与炎症/免疫反应和异常细胞增殖相关的疾病，包括癌症。抗氧化剂。氧化还原信号。20，2514-2527。
Aims: S-nitrosylation and S-glutathionylation, redox-based modifications of protein thiols, are recently emerging as important signaling mechanisms. In this study, we assessed S-nitrosylation-based regulation of Janus-activated kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway that plays critical roles in immune/inflammatory responses and tumorigenesis. Results: Our studies show that STAT3 in stimulated microglia underwent two distinct redox-dependent modifications, S-nitrosylation and S-glutathionylation. STAT3 S-nitrosylation was associated with inducible nitric oxide synthase (iNOS)-produced nitric oxide (NO) and S-nitrosoglutathione (GSNO), whereas S-glutathionylation of STAT3 was associated with cellular oxidative stress. NO produced by iNOS or treatment of microglia with exogenous GSNO inhibited STAT3 activation via inhibiting STAT3 phosphorylation (Tyr(705)). Consequently, the interleukin-6 (IL-6)-induced microglial proliferation and associated gene expressions were also reduced. In cell-free kinase assay using purified JAK2 and STAT3, STAT3 phosphorylation was inhibited by its selective preincubation with GSNO, but not by preincubation of JAK2 with GSNO, indicating that GSNO-mediated mechanisms inhibit STAT3 phosphorylation through S-nitrosylation of STAT3 rather than JAK2. In this study, we identified that Cys(259) was the target Cys residue of GSNO-mediated S-nitrosylation of STAT3. The replacement of Cys(259) residue with Ala abolished the inhibitory role of GSNO in IL-6-induced STAT3 phosphorylation and transactivation, suggesting the role of Cys(259) S-nitrosylation in STAT3 phosphorylation. Innovation: Microglial proliferation is regulated by NO via S-nitrosylation of STAT3 (Cys(259)) and inhibition of STAT3 (Tyr(705)) phosphorylation. Conclusion: Our results indicate the regulation of STAT3 by NO-based post-translational modification (S-nitrosylation). These findings have important implications for the development of new therapeutics targeting STAT3 for treating diseases associated with inflammatory/immune responses and abnormal cell proliferation, including cancer. Antioxid. Redox Signal. 20, 2514-2527.