Fang Peng, Liang Jiajun, Jiang Xuejiao, Fang Xian, Wu Mengli, Wei Xiaoyi, Yang Wenlong, Hou Weixin, Zhang Qiuyun
Beijing Key Laboratory of TCM Collateral Disease Theory Research, School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.
Front Pharmacol. 2020 May 5;11:608. doi: 10.3389/fphar.2020.00608. eCollection 2020.
High mobility group box-1 (HMGB1) plays an important role in various liver injuries. In the case of acute liver injury, it leads to aseptic inflammation and other reactions, and also regulates specific cell death responses in chronic liver injury. HMGB1 has been demonstrated to be a good therapeutic target for treating liver failure. Quercetin (Que), as an antioxidant, is a potential phytochemical with hepatocyte protection and is also considered to be an inhibitor of HMGB1. However, the mechanism of its hepatoprotective effects remains to be characterized. The present study explored whether the hepatoprotective effect of Que antagonizes HMGB1, and subsequent molecular signaling events. Our results indicated that Que protects L02 cells from d-galactosamine (d-GaLN)-induced cellular damage by reducing intracellular reactive oxygen species (ROS) production and apoptotic responses in the mitochondrial pathway. Immunofluorescence and Western blot assays showed that HMGB1 was involved in d-GaLN-induced L02 cell damage. Further research showed that after transfection with HMGB1 short hairpin RNA (shRNA), cell viability was improved, and intracellular ROS production and apoptosis were suppressed. When co-treated with Que, the expression of HMGB1 was decreased significantly, the expression of proteins in the corresponding signal pathway were further reduced, and the production of ROS and apoptosis were further suppressed. Molecular docking also indicated the binding of Que and HMGB1. Taken together, these results indicate that Que significantly improves d-GaLN-induced cellular damage by inhibiting oxidative stress and mitochondrial apoptosis inhibiting HMGB1.
高迁移率族蛋白B1（HMGB1）在各种肝损伤中起重要作用。在急性肝损伤情况下，它会引发无菌性炎症等反应，在慢性肝损伤中还能调节特定的细胞死亡反应。HMGB1已被证明是治疗肝衰竭的良好治疗靶点。槲皮素（Que）作为一种抗氧化剂，是一种具有肝细胞保护作用的潜在植物化学物质，也被认为是HMGB1的抑制剂。然而，其肝保护作用的机制仍有待阐明。本研究探讨了Que的肝保护作用是否通过拮抗HMGB1以及随后的分子信号事件来实现。我们的结果表明，Que通过减少细胞内活性氧（ROS）的产生以及线粒体途径中的凋亡反应，保护L02细胞免受d-半乳糖胺（d-GaLN）诱导的细胞损伤。免疫荧光和蛋白质印迹分析表明，HMGB1参与了d-GaLN诱导的L02细胞损伤。进一步研究表明，用HMGB1短发夹RNA（shRNA）转染后，细胞活力得到改善，细胞内ROS产生和凋亡受到抑制。当与Que共同处理时，HMGB1的表达显著降低，相应信号通路中的蛋白质表达进一步减少，ROS产生和凋亡进一步受到抑制。分子对接也表明了Que与HMGB1的结合。综上所述，这些结果表明，Que通过抑制氧化应激和线粒体凋亡，抑制HMGB1，显著改善d-GaLN诱导的细胞损伤。
