基于FXR-NLRP3通路探讨栀子苷肝毒性作用机制研究

As a medicine and food dual-use Chinese medicine, Gardenia is of great significance in studying its hepatotoxic mechanism.Previous studies have shown that high doses of geniposide can cause significant liver damage in normal and jaundice model rats, and the dose of liver injury in rats with aggravated jaundice is significantly lower than that in normal rats. Liver injury is characterized by cholestasis and inflammatory injury. The specific mechanism is not clear.NLRP3 inflammatory body activation is an important new target for drug-induced liver injury,The FXR receptor is a key receptor regulating bile acid homeostasis and has a negative regulatory effect on NLRP3,Therefore, we speculate that the FXR-NLRP3 pathway may be the key link leading to cholestasis and inflammatory injury caused by geniposide, and may also be a key target for revealing the aggravated injury in the model of jaundice.This study is to investigate the FXR-NLRP3 pathway-associated protein and gene levels in normal rats , jaundice model rats and HL-7702 cell , and to verify the cholestasis and inflammatory damage caused by geniposide in combination with NLRP3 inhibitors and FXR agonists. To clarify the specific mechanism of geniposide and inflammatory injury caused by geniposide, and further clarify the mechanism of geniposide aggravating liver damage in jaundice model, and provide scientific basis for the clinical rational and safe use of Gardenia.

栀子作为药食两用中药，研究其肝毒性作用机制具有重要意义。前期研究表明栀子苷大剂量可对正常及黄疸大鼠造成明显肝损伤，且加重黄疸大鼠肝损伤剂量明显低于正常大鼠组，肝损伤表现为胆汁淤积与炎性损伤并存，具体机制尚不明确。NLRP3炎症小体激活是药物性肝损伤的重要新靶点，FXR受体是调节胆汁酸稳态的关键受体，同时对NLRP3具有负性调节作用，因此我们推测FXR-NLRP3通路可能是导致栀子苷胆汁淤积与炎性损伤的关键环节，也可能是揭示栀子苷加重黄疸模型损伤的关键靶点。本课题拟对栀子苷给药后正常及黄疸模型大鼠体内及人肝细胞HL-7702的FXR-NLRP3通路相关蛋白及基因水平进行研究，并结合NLRP3抑制剂和FXR激动剂进行反向验证，明确栀子苷导致胆汁淤积与炎性损伤具体机制，并进一步阐明栀子苷加重黄疸模型肝损伤的机制，为栀子临床合理安全用药提供科学依据。

栀子作为药食两用中药，研究其肝毒性作用机制具有重要意义。前期研究表明栀子苷大剂量可对正常及黄疸大鼠造成明显肝损伤，且加重黄疸大鼠肝损伤剂量明显低于正常大鼠组，肝损伤表现为胆汁淤积与炎性损伤并存，具体机制尚不明确。本课题通过对栀子苷给药后正常及黄疸模型大鼠体内及人肝细胞HL-7702的FXR-NLRP3通路相关蛋白及基因水平进行研究，并结合NLRP3抑制剂和FXR激动剂进行反向验证，明确栀子苷所致肝损伤具体机制。研究结果表明:1)NLRP3炎症小体通路的激活参与了栀子苷肝毒性的发生过程；2）栀子苷致肝毒性过程中NLRP3炎症小体的直接活化和FXR通路对NLRP3炎症小体的负向调节作用下降共同参与了栀子苷肝毒性的发生过程；3）栀子苷加重黄疸模型大鼠肝损伤与进一步加重了黄疸模型大鼠的FXR通路的抑制作用并加重NLRP3通路过表达作用有关；4）上调受抑制的FXR以及抑制NLRP3炎症小体的过表达都可以减轻栀子苷对正常大鼠和黄疸模型大鼠的肝毒性作用。