Yang Hsin-Ling, Lin Ming-Wei, Korivi Mallikarjuna, Wu Jia-Jiuan, Liao Chun-Huei, Chang Chia-Ting, Liao Jiunn-Wang, Hseu You-Cheng
Institute of Nutrition, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung 40402, Taiwan.
Graduate Institute of Veterinary Pathology, National Chung Hsing University, Taichung 402, Taiwan.
Biochim Biophys Acta. 2016 Feb;1859(2):246-61. doi: 10.1016/j.bbagrm.2015.11.001. Epub 2015 Nov 5.
Coenzyme Q (CoQ) analogs with variable number of isoprenoid units have been demonstrated as anti-inflammatory and antioxidant/pro-oxidant molecules. In this study we used CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero isoprenoid side-chains), a novel quinone derivative, and investigated its molecular actions against LPS-induced inflammation and redox imbalance in murine RAW264.7 macrophages and mice. In LPS-stimulated macrophages, non-cytotoxic concentrations of CoQ0 (2.5-10 μM) inhibited iNOS/COX-2 protein expressions with subsequent reductions of NO, PGE2, TNF-α and IL-1β secretions. This inhibition was reasoned by suppression of NFκB (p65) activation, and inhibition of AP-1 (c-Jun., c-Fos, ATF2) translocation. Our findings indicated that IKKα-mediated I-κB degradation and MAPK-signaling are involved in regulation of NFκB/AP-1 activation. Furthermore, CoQ0 triggered HO-1 and NQO-1 genes through increased Nrf2 nuclear translocation and Nrf2/ARE-signaling. This phenomenon was confirmed by diminished CoQ0 protective effects in Nrf2 knockdown cells, where LPS-induced NO, PGE2, TNF-α and IL-1β productions remained high. Molecular evidence revealed that CoQ0 enhanced Nrf2 steady-state level at both transcriptional and translational levels. CoQ0-induced Nrf2 activation appears to be regulated by ROS-JNK-signaling cascades, as evidenced by suppressed Nrf2 activation upon treatment with pharmacological inhibitors of ROS (N-acetylcysteine) and JNK (SP600125). Besides, oral administration of CoQ0 (5 mg/kg) suppressed LPS-induced (1 mg/kg) induction of iNOS/COX-2 and TNF-α/IL-1β through tight regulation of NFκB/Nrf2 signaling in mice liver and spleen. Our findings conclude that pharmacological actions of CoQ0 are mediated via inhibition of NFκB/AP-1 activation and induction of Nrf2/ARE-signaling. Owing to its potent anti-inflammatory and antioxidant properties, CoQ0 could be a promising candidate to treat inflammatory disorders.
具有不同数量异戊二烯单元的辅酶Q（CoQ）类似物已被证明是抗炎和抗氧化/促氧化分子。在本研究中，我们使用了CoQ0（2,3-二甲氧基-5-甲基-1,4-苯醌，零个异戊二烯侧链），一种新型醌衍生物，并研究了其对小鼠RAW264.7巨噬细胞和小鼠中脂多糖（LPS）诱导的炎症和氧化还原失衡的分子作用。在LPS刺激的巨噬细胞中，非细胞毒性浓度的CoQ0（2.5 - 10μM）抑制诱导型一氧化氮合酶（iNOS）/环氧化酶-2（COX-2）蛋白表达，随后减少一氧化氮（NO）、前列腺素E2（PGE2）、肿瘤坏死因子-α（TNF-α）和白细胞介素-1β（IL-1β）的分泌。这种抑制作用是由于抑制核因子κB（NFκB，p65）的激活以及抑制活化蛋白-1（AP-1，c-Jun、c-Fos、活化转录因子2（ATF2））的易位。我们的研究结果表明，IKKα介导的I-κB降解和丝裂原活化蛋白激酶（MAPK）信号通路参与了NFκB/AP-1激活的调节。此外，CoQ0通过增加核因子E2相关因子2（Nrf2）的核转位和Nrf2/抗氧化反应元件（ARE）信号通路触发血红素加氧酶-1（HO-1）和醌氧化还原酶-1（NQO-1）基因。在Nrf2基因敲低的细胞中，LPS诱导的NO、PGE2、TNF-α和IL-1β的产生仍然很高，CoQ0的保护作用减弱，这证实了这一现象。分子证据表明，CoQ0在转录和翻译水平上均提高了Nrf2的稳态水平。CoQ0诱导的Nrf2激活似乎受活性氧（ROS）-应激活化蛋白激酶（JNK）信号级联调节，用ROS（N-乙酰半胱氨酸）和JNK（SP600125）的药理抑制剂处理后Nrf2激活受到抑制证明了这一点。此外，口服CoQ0（5mg/kg）通过严格调节小鼠肝脏和脾脏中的NFκB/Nrf2信号通路，抑制LPS诱导（1mg/kg）的iNOS/COX-2和TNF-α/IL-1β的表达。我们的研究结果得出结论，CoQ0的药理作用是通过抑制NFκB/AP-1激活和诱导Nrf2/ARE信号通路介导的。由于其强大的抗炎和抗氧化特性，CoQ0可能是治疗炎症性疾病的有前途的候选药物。
