Inhibition of NF-κB, iNOS mRNA, COX2 mRNA, and COX catalytic activity by phenyl-N-tert-butylnitrone (PBN)
Inhibition of NF-κB, iNOS mRNA, COX2 mRNA, and COX catalytic activity by phenyl-N-tert-butylnitrone (PBN)
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DOI：
10.1016/s0167-4889(98)00126-8
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发表时间：
1998-11-19
影响因子：
5.1
通讯作者：
Wallis, GL
中科院分区：
文献类型：
--
作者：
Kotake, Y;Sang, H;Wallis, GL
此前，自旋捕获剂苯基-N-叔丁基硝酮 (PBN) 已被证明可以降低体内一氧化氮合酶 mRNA 的水平。这种抑制作用被认为是 PBN 在动物模型中发挥多种药理作用的潜在机制。然而，PBN 的细胞药理活性的测定尚未进行，但对于了解体内作用是必要的。由于 PEN 已知的药理作用主要是抗炎性质，因此在本研究中，我们确定了 PEN 对两种炎症因子的抑制活性：诱导型一氧化氮合酶 (iNOS) 和诱导型环氧合酶 (COX2)。我们在此表明，在超药理学浓度下，PEN 会降低巨噬细胞培养物中的稳态 COX2 mRNA 水平和 COX2 催化活性。虽然 PEN 降低 iNOS mRNA，但它不会抑制 iNOS 催化活性，这与之前的体内研究一致。我们还研究了核因子 kappa B (NF-kappa B)，这是一种转录因子，可以快速激活参与炎症、免疫和急性期反应的基因表达。 NF-κB 与 iNOS 基因的结合已被证明对于 iNOS 基因表达至关重要，COX2 基因的启动子区域包含 NF-κB 共有序列。我们发现，PEN 可以抑制脂多糖介导的 NF-κ B DNA 结合活性的增加，其浓度低于非甾体抗炎药 (NSAID) 水杨酸盐。此外，我们发现 PEN 抑制 COX2 催化活性，表明 PEN 具有类似 NSAID 的功能。 (C) 1998 Elsevier Science B.V. 保留所有权利。
Previously, the spin trapping agent phenyl-N-tert-butylnitrone (PBN) has been shown to decrease the level of nitric oxide synthase mRNA in vivo. This inhibition is suggested to be an underlying mechanism for PBN's wide variety of pharmacological actions in animal models. However, the determination of PBN's cellular pharmacological activities has not been carried out, but is necessary for the understanding of the effects in vivo. Since the known pharmacological effects of PEN are primarily anti-inflammatory in nature, in this study we determined the inhibitory activities of PEN against two inflammatory factors: inducible nitric oxide synthase (iNOS) and inducible cyclooxygenase (COX2). We show here that PEN decreases steady state COX2 mRNA level and COX2 catalytic activity in macrophage cell culture at supra-pharmacological concentrations. While PEN decreases iNOS mRNA, it does not inhibit iNOS catalytic activity, which is consistent with previous in vivo studies. We also studied nuclear factor kappa B (NF-kappa B), a transcription factor that can rapidly activate the expression of genes involved in inflammatory, immune and acute phase responses. The binding of NF-kappa B to iNOS gene has been shown to be critical for iNOS gene expression, and the promoter region of COX2 gene contains NF-kappa B consensus sequence. We show that PEN inhibits lipopolysaccharide-mediated increase of NF-kappa B DNA binding activity with a lower concentration than that for the non-steroidal anti-inflammatory drug (NSAID), salicylate. Furthermore, we show that PEN inhibits COX2 catalytic activity, suggesting that PEN has an NSAID-like function. (C) 1998 Elsevier Science B.V. All rights reserved.