Three Arachidonoylamide Derivatives Inhibit Pro-Inflammatory Genes Expression by Modulating NF-κB and AP1 Activities
作者:Alex Gregorelli、Anna Sgarbossa、Shahbaz Khan、Annunziata Soriente、Margherita De Rosa、Carmela Saturnino、Marta Menegazzi
DOI:10.2174/1573406412666160502154936
日期:2016.9.27
Background: Since the anti-inflammatory activity of arachidonic acid
derivatives was previously reported, we synthesized three new amide derivatives
of arachidonic acid (AA-Ds) and tested their anti-inflammatory effects on an in
vitro skin inflammation model. Aim of our study was to find derivatives of natural
compounds able to down regulate inflammatory signal transduction pathway.
Methods: Human keratinocytes cell line (HaCaT) was cultured and induced by
cytokines in the presence of AA-Ds. Cytokines administration elicited an inflammatory
response mediated by NF-κB and STAT-1 activation that induced proinflammatory
genes expression.
Results: By real time PCR we found that 24 hours after induction all AA-Ds significantly inhibit inducible
Nitric Oxide Synthase (iNOS), TNFα, Inhibitor α of NF-κB, chemokine (C-X-C motif)
ligand 9 and 10 genes expression. We analyzed their molecular effects in particular on the iNOS
gene expression. Since iNOS transcript half-life did not change with AA-Ds treatment, we excluded
a prominent role of post-transcriptional regulation for this gene and focused our attention on its
transcriptional regulation. Starting three-five hours after cytokines induction, HaCaT cells, pretreated
with each compound, showed inhibition of both NF-κB DNA-binding and NF-κB p65-Ser536
phosphorylation. STAT1 activation was inhibited only by AA-D4 derivative. To explain why the
inhibition of iNOS expression began late after induction we analyzed activities of others key
transcription factors. AA-Ds treatment elicited early increases of AP1 DNA binding as well
as c-Jun, c-Fos and Fra-1 mRNA levels. Our data agree with the repressing effects of AP1 on
human iNOS promoter previously described in others cell systems (Kleinert et al.).
Conclusion: AA-Ds shown to be good candidates as inhibitors of several pro-inflammatory
genes induction and our study provides indications for their possible use as new antiinflammatory
drugs.
背景:由于之前报道了花生四烯酸衍生物的抗炎活性,我们合成了三种新的花生四烯酸酰胺衍生物(AA-Ds),并测试了它们在体外皮肤炎症模型上的抗炎效果。本研究的目的是寻找能够下调炎症信号转导途径的天然化合物衍生物。
方法:培养人角质形成细胞系(HaCaT),并在AA-Ds的存在下用细胞因子诱导。细胞因子的给药引发了由NF-κB和STAT-1激活介导的炎症反应,进而诱导促炎基因的表达。
结果:通过实时PCR,我们发现诱导24小时后,所有AA-Ds显著抑制了诱导性一氧化氮合酶(iNOS)、TNFα、NF-κB抑制因子α、趋化因子(C-X-C基序)配体9和10基因的表达。我们分析了它们对iNOS基因表达的分子效应。由于iNOS转录本的半衰期在AA-Ds处理下没有变化,我们排除了该基因后转录调控的显著作用,转而关注其转录调控。从细胞因子诱导后3至5小时开始,预处理过每个化合物的HaCaT细胞显示出对NF-κB DNA结合和NF-κB p65-Ser536磷酸化的抑制。只有AA-D4衍生物抑制了STAT1的激活。为了解释为何iNOS表达的抑制在诱导后开始较晚,我们分析了其他关键转录因子的活性。AA-Ds处理引发了AP1 DNA结合以及c-Jun、c-Fos和Fra-1 mRNA水平的早期增加。我们的数据与其他细胞系统(Kleinert等)中描述的AP1对人类iNOS启动子的抑制效应一致。
结论:AA-Ds显示出作为多种促炎基因诱导抑制剂的良好候选者,我们的研究为它们作为新型抗炎药物的可能用途提供了依据。