Ethyl pyruvate inhibits nuclear factor-κB-dependent signaling by directly targeting p65
Ethyl pyruvate inhibits nuclear factor-κB-dependent signaling by directly targeting p65
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DOI：
10.1124/jpet.104.079707
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发表时间：
2005-03-01
影响因子：
3.5
通讯作者：
Fink, MP
中科院分区：
文献类型：
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作者：
Han, YS;Englert, JA;Fink, MP
丙酮酸乙酯在许多细胞培养和动物研究中显示出具有抗炎特性。在这一系列实验中，我们测试了丙酮酸乙酯抑制促炎转录因子NF-κ B信号传导的假设。丙酮酸乙酯可抑制转染NF-κ B依赖性荧光素酶报告载体的脂多糖刺激的鼠巨噬细胞样RAW 264.7细胞中荧光素酶的表达。丙酮酸乙酯还降低了脂多糖刺激的RAW 264.7细胞中NF-κ B DNA结合活性，并降低了脂多糖诱导的NF-κ B依赖性基因诱导型一氧化氮合酶的表达。丙酮酸乙酯对脂多糖刺激的RAW 264.7细胞中的IkappaB α或IkappaB α的降解没有影响，表明丙酮酸乙酯在NF-κ B活化中的这一步骤的远端起作用。在无细胞系统中，p50同二聚体与NF-κ B共有寡核苷酸序列的结合在很宽的浓度范围内不受丙酮酸乙酯的影响，表明丙酮酸乙酯可能不修饰NF-κ B的p50亚基或与NF-κ B的p50亚基相互作用。相反，丙酮酸乙酯抑制DNA结合异位过表达的野生型p65同源二聚体。然而，丙酮酸乙酯未能抑制同型二聚体的DNA结合活性的过度表达的突变形式的p65与取代丝氨酸的半胱氨酸38。总之，这些结果表明丙酮酸乙酯通过共价修饰p65的Cys来抑制DNA结合（38）。我们得出结论，丙酮酸乙酯的一些有益的抗炎作用可能是由于p65的修饰，从而抑制通过NF-κ B通路的信号传导。
Ethyl pyruvate has been shown to have anti-inflammatory properties in numerous cell culture and animal studies. In this series of experiments, we tested the hypothesis that ethyl pyruvate inhibits signaling by the pro-inflammatory transcription factor, NF-kappaB. Ethyl pyruvate inhibited luciferase expression in lipopolysaccharide-stimulated murine macrophage-like RAW 264.7 cells transfected with an NF-kappaB-dependent luciferase reporter vector. Ethyl pyruvate also decreased NF-kappaB DNA-binding activity in lipopolysaccharide-stimulated RAW 264.7 cells and decreased lipopolysaccharide-induced expression of an NF-kappaB-dependent gene, inducible nitric oxide synthase. Ethyl pyruvate had no effect on the degradation of IkappaBalpha or IkappaBalpha in lipopolysaccharide-stimulated RAW 264.7 cells, suggesting that ethyl pyruvate acts distally to this step in the activation of NF-kappaB. In a cell-free system, binding of p50 homodimers to an NF-kappaB consensus oligonucleotide sequence was unaffected by ethyl pyruvate over a wide range of concentrations, indicating that ethyl pyruvate probably does not modify or interact with the p50 subunit of NF-kappaB. In contrast, ethyl pyruvate inhibited DNA binding by ectopically overexpressed wild-type p65 homodimers. However, ethyl pyruvate failed to inhibit the DNA-binding activity of homodimers of an overexpressed mutant form of a p65 with substitution of serine for cysteine 38. Taken together, these results suggest that ethyl pyruvate inhibits DNA-binding by covalently modifying p65 at Cys(38). We conclude that some of the beneficial anti-inflammatory effects of ethyl pyruvate may be due to modification of p65, thereby inhibiting signaling via the NF-kappaB pathway.