Duan Wenjuan, Zhou Juefei, Zhang Shen, Zhao Kai, Zhao Lijing, Ogata Kazumi, Sakaue Takahiro, Mori Akitane, Wei Taotao
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Biochim Biophys Acta. 2011 May;1813(5):772-83. doi: 10.1016/j.bbamcr.2011.01.019. Epub 2011 Jan 27.
The binding of lipopolysaccharides (LPS) to macrophages results in inflammatory responses. In extreme cases it can lead to endotoxic shock, often resulting in death. A broad range of antioxidants, including tocopherols, can reduce LPS activity in vitro and in vivo. To elucidate the underlying mechanisms of their action, we investigated the effect of the sodium salt of γ-L-glutamyl-S-[2-[[[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl]oxy]carbonyl]-3-[[2-(1H-indol-3-yl)ethyl]amino]-3-oxopropyl]-L-cysteinylglycine (ESeroS-GS), a novel α-tocopherol derivative, on LPS-induced inflammation in vitro and in vivo. ESeroS-GS reduced the transcription of TNF-α, IL-1β, IL-6 and iNOS genes in a dose-dependent manner in RAW264.7 macrophages, and inhibited the release of these inflammatory factors. In addition, ESeroS-GS inhibited LPS-induced mortality in a mouse sepsis model. Electrophoretic mobility shift assays (EMSA) and reporter gene assays revealed that ESeroS-GS down-regulated the transcriptional activity of NF-κB. By analyzing the partitioning of CD14 and Toll-like receptor 4 (TLR-4) in cell membrane microdomains, we found that ESeroS-GS attenuates the binding of LPS to RAW264.7 cells via interfering with the relocation of CD14 and TLR-4 to lipid rafts, blocking the activation of interleukin-1 receptor-associated kinase 1 (IRAK-1), and inhibiting the consequent phosphorylation of TAK1 and IKKα/β, which together account for the suppression of NF-κB activation. Taken together, our data suggest that ESeroS-GS can modulate LPS signaling in macrophages by impairing TLR-4 complex assembly via a lipid raft dependent mechanism. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
脂多糖（LPS）与巨噬细胞结合会引发炎症反应。在极端情况下，它会导致内毒素休克，常常导致死亡。包括生育酚在内的多种抗氧化剂在体外和体内均可降低LPS活性。为阐明其作用的潜在机制，我们研究了新型α-生育酚衍生物γ-L-谷氨酰-S-[2-[[[3,4-二氢-2,5,7,8-四甲基-2-(4,8,12-三甲基十三烷基)-2H-1-苯并吡喃-6-基]氧基]羰基]-3-[[2-(1H-吲哚-3-基)乙基]氨基]-3-氧代丙基]-L-半胱氨酰甘氨酸（ESeroS-GS）的钠盐对体外和体内LPS诱导的炎症的影响。ESeroS-GS在RAW264.7巨噬细胞中以剂量依赖的方式降低TNF-α、IL-1β、IL-6和iNOS基因的转录，并抑制这些炎症因子的释放。此外，ESeroS-GS在小鼠脓毒症模型中抑制LPS诱导的死亡率。电泳迁移率变动分析（EMSA）和报告基因分析表明，ESeroS-GS下调NF-κB的转录活性。通过分析细胞膜微区中CD14和Toll样受体4（TLR-4）的分布，我们发现ESeroS-GS通过干扰CD14和TLR-4向脂筏的重新定位，减弱LPS与RAW264.7细胞的结合，阻断白细胞介素-1受体相关激酶1（IRAK-1）的激活，并抑制随后TAK1和IKKα/β的磷酸化，这些共同导致NF-κB激活的抑制。综上所述，我们的数据表明ESeroS-GS可通过脂质筏依赖性机制损害TLR-4复合物组装来调节巨噬细胞中的LPS信号传导。本文是名为：第11届欧洲钙研讨会的特刊的一部分。
