Nrf2 knockdown attenuates the ameliorative effects of ligustrazine on hepatic fibrosis by targeting hepatic stellate cell transdifferentiation
Nrf2 knockdown attenuates the ameliorative effects of ligustrazine on hepatic fibrosis by targeting hepatic stellate cell transdifferentiation
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Nrf2 敲低通过靶向肝星状细胞转分化减弱川芎嗪对肝纤维化的改善作用
DOI：
10.1016/j.tox.2016.07.018
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发表时间：
2016-07-15
期刊：
影响因子：
4.5
通讯作者：
Zheng, Shizhong
中科院分区：
文献类型：
--
作者：
Lu, Chunfeng;Xu, Wenxuan;Zheng, Shizhong
肝纤维化是慢性肝损伤和炎症反应的一种常见的修复过程，其主要原因是肝星状细胞（HSC）的活化。核因子（红细胞衍生2）样2（Nrf 2）最近被强调为HSC行为的负调控。我们以前的研究显示了川芎嗪的有效抗纤维化作用，但没有阐明潜在的分子机制。在这项工作中，我们在体外的结果表明，川芎嗪显着提高Nrf 2的表达和核转位在HSC。利用RNAi技术的机制研究表明，Nrf 2敲低取消了川芎嗪对血清酶活性、肝组织结构、血清和肝脏中促炎细胞因子水平、肝内炎性细胞浸润的改善作用。Nrf 2 shRNA也消除了川芎嗪的抗纤维化作用，其证据是血清纤维化生物标志物、肝羟脯氨酸、血清和肝脏中的促纤维化因子以及肝内胶原沉积增加。川芎嗪可抑制CCl 4对HSC β-catenin的诱导作用，而Nrf 2 shRNA慢病毒则可消除CCl 4对HSC β-catenin的诱导作用。体外实验也表明，Nrf 2 siRNA解除了川芎嗪对β-catenin表达的抑制。应用Nrf 2 siRNA和β-catenin特异性拮抗剂IWR-1-endo研究Nrf 2和β-catenin在川芎嗪介导的作用中的相关性。结果表明，川芎嗪不仅抑制人HSC的活力，收缩和迁移，但也减轻脂滴丢失和细胞外基质的产生。而IWR-1-endo则进一步削弱了川芎嗪对Nrf 2 siRNA的抑制作用，恢复了川芎嗪的抑制能力。总之，川芎嗪的抗肝纤维化作用可能与其阻断Nrf 2/beta-catenin通路对HSC行为的负性调节有关。这些发现拓宽了川芎嗪作用的分子机制的广度和深度，促进了川芎嗪在抗纤维化治疗中的发展。(C)2016爱思唯尔爱尔兰有限公司版权所有。
Hepatic fibrosis is a frequent reparative process in response to chronic liver injury and inflammation, which is mainly attributed to hepatic stellate cell (HSC) activation. Nuclear factor (erythroid-derived 2) like 2 (Nrf2) was recently highlighted for its negative regulation of HSC behaviors. Our previous studies have revealed the potent antifibrotic effects of ligutrazine without elaborating potential molecular mechanisms. In this work, our in vitro results showed that ligustrazine significantly enhanced Nrf2 expression and nuclear translocation in HSC. Mechanistic investigations using RNAi technology demonstrated that Nrf2 knockdown abolished the ameliorative effects of ligustrazine on serum enzyme activities, hepatic histological architecture, levels of proinflammatory cytokines in serum and liver, intrahepatic inflammatory cell infiltration. Nrf2 shRNA also abrogated the antifibrotic effects of ligustrazine evidenced by increased serum fibrotic biomarkers, hepatic hydroxyproline, profibrogenetic factors in serum and liver, and intrahepatic collagen deposition. Ligustrazine inhibited the induction of CCl4 on beta-catenin in HSC, which was cancelled by Nrf2 shRNA lentivirus. In vitro experiments also showed that Nrf2 siRNA abrogated the inhibition of ligustrazine on p-catenin expression. Nrf2 siRNA and IWR-1-endo (a specific antagonist of beta-catenin) were applied to investigate the correlation between Nrf2 and beta-catenin in mediating the effects of ligustrazine. Results suggested that ligustrazine not only suppressed the viability, contraction, and migration of human HSC but also alleviated lipid droplet loss and extracellular matrix production. Nrf2 siRNA yet weakened the inhibitory action of ligustrazine on HSC behaviors while IWR-1-endo further impaired the suppression of Nrf2 siRNA and restored the capacity of ligustrazine. Collectively, we drew a conclusion that the favorable antifibrotic effects of ligustrazine were attributed to its negative modulation on HSC behaviors by interrupting Nrf2/beta-catenin pathway. The findings broaden the width and depth of molecular mechanisms involved in the ligustrazine action, facilitating the development of ligustrazine in antifibrotic therapies. (C) 2016 Elsevier Ireland Ltd. All rights reserved.