绿原酸通过双重调控转录因子Nrf2和Egr1信号通路抑制对乙酰氨基酚肝毒性的机理研究

Acetaminophen (AP) is a widely used over-the-counter (OTC) analgesic and antipyretic drug. Hepatotoxicity due to AP overdose is the most common cause of acute liver failure in both the United States and the United Kingdom. Numerous drugs and Chinese patent medicines in the market contain AP, and most of them are indexed in the OTC directory in China. In some cases, patients use a variety of such drugs, which will increase the possibility of AP overdose. However, at present AP-induced hepatotoxicity has not been fully recognized in our country. Our previous study has found that Flos Lonicerae, which is commonly combined with AP used for cold and fever, and its main ingredient chlorogenic acid, can prevent AP-induced liver injury. Further results show that cellular GSH and Trx antioxidant system, and MAPK signaling cascades participate in the prevention of chlorogenic acid against AP-induced liver injury. Based on the previous research, the present study aims to observe whether chlorogenic acid prevents AP-induced liver injury by dual regulating transcription factor Nrf2 and Egr1 signaling pathway, to further observe the therapeutic detoxification of chlorogenic acid against AP-induced liver injury, to observe the effect of chlorogenic acid on the analgesic and antipyretic activity induced by AP. This study will provide new strategy for the detoxification of AP-induced liver injury, and also provide the experimental basis for the combined application of AP and traditional Chinese medcicines, which contain chlorogenic acid.

对乙酰氨基酚(Acetaminophen)是广泛应用于临床的解热镇痛非处方药，其过量使用是导致美国和欧洲由药物引起急性肝功能衰竭的首要原因。我国含有AP的非处方药物多达数百种，易发生患者过量服用的情况，但我们对AP肝毒性还没有充分的认识。配伍是中医用药的特色之一，也是中医理论的精髓之一，通过配伍不仅可以协同促进药效，还能减少药物毒副作用。我们前期研究发现常与AP联合应用的中药金银花及其主要成分绿原酸可以抑制AP的肝毒性，进一步研究发现细胞内GSH和Trx抗氧化系统以及丝裂原活化蛋白激酶信号通路共同参与调控绿原酸抑制AP肝毒性的作用。本项目主要在前期工作基础上，通过双重调控转录因子Nrf2和Egr1信号通路揭示绿原酸抑制AP肝毒性的机理；研究其对AP肝毒性的治疗解毒作用；探索其对AP解热镇痛药效活性的影响，为AP肝毒性的防治提供新的解毒策略，也为含绿原酸中药和AP的联合应用提供实验证据。

对乙酰氨基酚 (Acetaminophen, APAP) 是广泛应用于临床的解热镇痛非处方药，其过量使用是导致美国和欧洲由药物引起急性肝功能衰竭的首要原因。通过本项目的研究发现绿原酸在体内动物上预防和治疗给药均可以缓解APAP诱导的急性肝毒性。深入机制研究发现，绿原酸可以通过降低蛋白磷酸酶PP2A-A和PP5的表达，导致ERK1/2的持续磷酸化，进一步诱导机体内重要的抗氧化分子Nrf2的磷酸化，导致Nrf2与其抑制蛋白Keap1解离，Nrf2 发生核转位激活，诱导下游抗氧化酶基因的表达，抵御APAP诱导的氧应激肝损伤；绿原酸还可以通过降低Nrf2调控的DAMPs (damage-associated molecular patterns) 如HMGB1和HSP60的释放，抑制炎性反应，缓解APAP诱导的炎性肝损伤。在APAP诱导的肝损伤中，Egr1与Nrf2存在相互的调控作用；在绿原酸抑制APAP肝毒性中，Egr1在调控绿原酸诱导的Nrf2激活中具有重要作用，而Nrf2的激活会反馈性地减少绿原酸诱导的Egr1入核激活，由此可见绿原酸通过双重调控Nrf2和Egr1发挥了抑制APAP诱导急性肝毒性的作用。进一步研究发现，APAP长期给药会诱导小鼠肝纤维化的形成，Nrf2和Egr1在APAP诱导肝纤维化中具有重要的调控作用。绿原酸是由咖啡酸和奎宁酸形成的酯，咖啡酸预防和治疗给药也可以缓解APAP诱导的急性肝毒性，进一步深入从双重调控Nrf2和Egr1信号通路的角度，揭示了咖啡酸抑制APAP诱导肝毒性的机制。绿原酸对APAP的镇痛活性有一定的协同增加作用，但是对APAP的解热活性没有明显影响。通过研究为APAP肝毒性的防治提供新的解毒策略，也为含绿原酸中药和APAP联合应用的合理性提供一定的实验证据。. 通过本项目的实施，发表受本课题资助的SCI收录科研论文8篇，包括氧应激、毒理学、药理学研究权威的SCI收录期刊如Free Radical Biology & Medicine, Toxicological Sciences, Biochemical Pharmacology等。培养博士研究生4人，硕士研究生4人。项目执行期间负责人季莉莉入选第三批国家“万人计划”科技领军人才 (2018)，科技部中青年科技创新领军人才计划 (2017)。