Evidence That Glutathione Depletion Is a Mechanism Responsible for the Anti-Inflammatory Effects of Ethyl Pyruvate in Cultured Lipopolysaccharide-Stimulated RAW 264.7 Cells
Evidence That Glutathione Depletion Is a Mechanism Responsible for the Anti-Inflammatory Effects of Ethyl Pyruvate in Cultured Lipopolysaccharide-Stimulated RAW 264.7 Cells
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DOI：
10.1124/jpet.103.056622
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发表时间：
2004-01
影响因子：
3.5
通讯作者：
Mingchen Song;J. Kellum;H. Kaldas;M. Fink
中科院分区：
文献类型：
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作者：
Mingchen Song;J. Kellum;H. Kaldas;M. Fink
丙酮酸乙酯（EP）是一种有效的活性氧清除剂，也是多种体内和体外模型系统中的抗炎剂。为了更好地了解EP抗炎作用的分子基础，我们比较了EP和N-乙酰基-L-半胱氨酸（NAC）的药理学性质，NAC是一种研究充分的活性氧清除剂和内源性抗氧化剂谷胱甘肽（GSH）的前体。使用用脂多糖（LPS）刺激的RAW 264.7鼠巨噬细胞样细胞进行研究。虽然EP和NAC都能抑制LPS诱导的一氧化氮和白细胞介素（IL）-6的分泌，但前者比后者更有效。EP明显抑制诱导型一氧化氮合酶，IL-6和IL-10 mRNA的诱导，而NAC的影响很小。EP对LPS诱导的核因子-κB DNA结合的抑制程度远大于NAC。这两种化合物抑制LPS诱导的脂质过氧化反应，但这两种化合物对细胞水平的GSH有质的不同的影响。虽然NAC增加GSH水平，但EP具有相反的作用。当RAW 264.7细胞用细胞可渗透的GSH类似物谷胱甘肽乙酯处理时，EP的抗炎作用部分逆转。这些数据支持EP的抗炎作用至少部分是由EP消耗细胞GSH储存的能力介导的观点。此外，这里提出的研究结果表明，一个不寻常的组合的生化作用（抑制脂质过氧化和GSH消耗）可能占的抗炎作用的EP。
Ethyl pyruvate (EP), an effective scavenger of reactive oxygen species, is also an anti-inflammatory agent in a variety of in vivo and in vitro model systems. To gain a better understanding of the molecular basis for the anti-inflammatory effects of EP, we compared the pharmacological properties of EP andN-acetyl-l-cysteine (NAC), a well studied scavenger of reactive oxygen species and a precursor for the endogenous antioxidant glutathione (GSH). The studies were performed using RAW 264.7 murine macrophage-like cells that were stimulated with lipopolysaccharide (LPS). Although EP and NAC both inhibited LPS-induced nitric oxide and interleukin (IL)-6 secretion, the former compound was considerably more potent than the latter. EP markedly inhibited inducible nitric-oxide synthase, IL-6, and IL-10 mRNA induction, whereas the effects of NAC were minimal. EP inhibited LPS-induced nuclear factor-κB DNA binding to a much greater extent than did NAC. Both compounds inhibited LPS-induced lipid peroxidation, but the two compounds had qualitatively different effects on cellular levels of GSH. Although NAC increased GSH levels, EP had the opposite effect. The anti-inflammatory effects of EP were partially reversed when RAW 264.7 cells were treated with a cell-permeable GSH analog, glutathione ethyl ester. These data support the view that the anti-inflammatory effects of EP are mediated, at least in part, by the ability of EP to deplete cellular GSH stores. Moreover, the findings presented here suggest that an unusual combination of biochemical effects (inhibition of lipid peroxidation and GSH depletion) might account for the anti-inflammatory effects of EP.