Zhang Tianwei, Feng Shanshan, Li Jiahuan, Wu Zhitao, Deng Qiangqiang, Yang Wei, Li Jing, Pan Guoyu
Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Arch Toxicol. 2022 Jun;96(6):1829-1843. doi: 10.1007/s00204-022-03266-6. Epub 2022 Mar 10.
Farnesoid X receptor (FXR) plays an indispensable role in liver homeostasis and has been a promising drug target for hepatic diseases. However, the concerns of undesired biological actions limit the clinical applications of FXR agonists. To reveal the intrinsic mechanism of FXR agonist-induce hepatotoxicity, two typical FXR agonists with different structures (obeticholic acid (OCA) and Px-102) were investigated in the present study. By detecting MMP, ROS, and ATP and analyzing the fate of cells, we found that both OCA and Px-102 reduced the mitochondrial function of hepatocytes and promoted cell apoptosis. Gene ablation or inhibition of FXR or SHP ameliorated the cytotoxicities of OCA and Px-102, which indicated the adverse actions of FXR/SHP activation including down-regulation of phosphorylation of PI3K/AKT and functional hepatic genes. The dose-related injurious effects of OCA (10 mg/kg and 30 mg/kg) and Px-102 (5 mg/kg and 15 mg/kg) on the liver were confirmed on a high-fat diet mouse model. The decrease of hepatocyte-specific genes and augmenter of liver regeneration in the liver caused by OCA or Px-102 suggested an imbalance of liver regeneration and a disruption of hepatic functions. Exploration of intestinally biased FXR agonists or combination of FXR agonist with apoptosis inhibitor may be more beneficial strategies for liver diseases.
法尼酯X受体(FXR)在肝脏稳态中发挥着不可或缺的作用,并且一直是肝脏疾病颇具前景的药物靶点。然而,对不良生物学作用的担忧限制了FXR激动剂的临床应用。为揭示FXR激动剂诱导肝毒性的内在机制,本研究考察了两种具有不同结构的典型FXR激动剂(奥贝胆酸(OCA)和Px - 102)。通过检测线粒体膜电位(MMP)、活性氧(ROS)和三磷酸腺苷(ATP)并分析细胞命运,我们发现OCA和Px - 102均降低了肝细胞的线粒体功能并促进细胞凋亡。FXR或小异二聚体伴侣(SHP)的基因敲除或抑制减轻了OCA和Px - 102的细胞毒性,这表明FXR/SHP激活的不良作用包括下调磷脂酰肌醇-3激酶(PI3K)/蛋白激酶B(AKT)的磷酸化以及功能性肝脏基因。在高脂饮食小鼠模型上证实了OCA(10毫克/千克和30毫克/千克)和Px - 102(5毫克/千克和15毫克/千克)对肝脏的剂量相关损伤作用。OCA或Px - 102导致肝脏中肝细胞特异性基因和肝脏再生增强因子的减少,提示肝脏再生失衡和肝功能破坏。探索肠道偏向性FXR激动剂或FXR激动剂与凋亡抑制剂的联合使用可能是治疗肝脏疾病更有益的策略。