Inhibition of lipopolysaccharide-inducible nitric oxide synthase, TNF-α and COX-2 expression by sauchinone effects on I-κBα phosphorylation, C/EBP and AP-1 activation
Inhibition of lipopolysaccharide-inducible nitric oxide synthase, TNF-α and COX-2 expression by sauchinone effects on I-κBα phosphorylation, C/EBP and AP-1 activation
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DOI：
10.1038/sj.bjp.0705231
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发表时间：
2003-05-01
影响因子：
7.3
通讯作者：
Kim, SG
中科院分区：
文献类型：
--
作者：
Lee, AK;Sung, SH;Kim, SG
1Sauchinone 是从三白草（Saururaceae）中分离出来的一种木脂素，是一种非对映木脂素，在培养的肝细胞中具有细胞保护和抗氧化活性。 sauchinone 对诱导型一氧化氮合酶 (iNOS)、肿瘤坏死因子-α (TNF-α) 和环氧合酶 2 (COX-2) 基因表达以及对转录因子激活、核因子-KB (NF-KB)、CCAAT/增强子结合蛋白 (C/EBP)、激活蛋白-1 (AP-1) 和 cAMP 反应元件结合蛋白 (CREB) 的影响在Raw264.7 细胞作为其抗炎作用研究的一部分。2通过 Northern 和 Western 印迹分析评估 iNOS、TNF-a 和 COX-2 基因的表达。使用NO分析仪通过化学发光检测来监测NO的产生。为了确定受sauchinone影响的转录因子，测量了NF-KB、C/EBP、AP-1和CREB激活的程度。通过凝胶迁移率变动测定监测转录因子的激活，而通过免疫细胞化学和免疫印迹分析来分析 p65 和 I-KBα。3Sauchinone 通过抑制 mRNA 抑制脂多糖 (LPS) 对 iNOS、TNF-a 和 COX-2 的诱导（IC50 小于或等于 10 mum）。4Sauchinone (1 - 30 mum) 抑制 LPS 诱导的核NF-KB 激活和 p65 核转位，伴随着 I-KBα 磷酸化的抑制。5LPS 诱导的 C/EBP 与其共有序列结合强度的增加也被绍西酮抑制。 AP-1，但不是 CREB，DNA 结合活性被 sauchinone 弱抑制。 6这些结果表明，sauchinone 通过抑制 I-KBα 磷酸化和 p65 核转位以及 C/EBP 和/或 AP-1 激活，抑制巨噬细胞中 LPS 诱导的 iNOS、TNF-α 和 COX-2 表达，这可能构成木酚素的抗炎作用。
1Sauchinone, a lignan isolated from Saururus chinensis (Saururaceae), is a diastereomeric lignan with cytoprotective and antioxidant activities in cultured hepatocytes. The effects of sauchinone on the inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase 2 (COX-2) gene expression and on the activation of transcription factors, nuclear factor-KB (NF-KB), CCAAT/ enhancer-binding protein (C/EBP), activator protein-1 (AP-1) and cAMP-response element-binding protein (CREB) were determined in Raw264.7 cells as part of the studies on its anti-inflammatory effects.2Expression of the iNOS, TNF-a and COX-2 genes was assessed by Northern and Western blot analyses. NO production was monitored by chemiluminescence detection using a NO analyzer. To identify the transcriptional factors affected by sauchinone, the extents of NF-KB, C/EBP, AP-1 and CREB activation were measured. Activation of the transcription factors was monitored by gel mobility shift assay, whereas p65 and I-KBalpha were analyzed by immunocytochemical and immunoblot analyses.3Sauchinone inhibited the induction of iNOS, TNF-a and COX-2 by lipopolysaccharide (LPS) (IC50 less than or equal to 10 mum) with suppression of the mRNAs.4Sauchinone (1 - 30 mum) inhibited LPS-inducible nuclear NF-KB activation and nuclear translocation of p65, which was accompanied by inhibition of I-KBalpha phosphorylation.5LPS-inducible increase in the intensity of C/EBP binding to its consensus sequence was also inhibited by sauchinone. The AP-1, but not CREB, DNA binding activity was weakly inhibited by sauchinone.6These results demonstrate that sauchinone inhibits LPS-inducible iNOS, TNF-alpha and COX-2 expression in macrophages through suppression of I-KBalpha phosphorylation and p65 nuclear translocation and of C/EBP and/or AP-1 activation, which may constitute anti-inflammatory effects of the lignan.