Nrf2通过调控CYP2E1蛋白稳定性在硫代乙酰胺致肝损伤中的作用与机制研究

硫代乙酰胺（TAA）是一种广泛用于工农业生产的化学物，具有肝脏毒性，但其毒作用分子机制尚不完全清楚。核因子E2相关因子2（Nrf2）作为调控抗氧化反应的重要转录因子，通常在防御化学物所致肝损伤中发挥保护作用。然而我们在前期研究中发现，TAA急性暴露后，Nrf2缺失小鼠肝损伤减轻，同时TAA代谢活化关键酶CYP2E1蛋白水平降低，提示Nrf2可能通过调控CYP2E1参与TAA代谢活化进而影响肝损伤。本项目拟将体内外实验相结合，以Nrf2调控CYP2E1蛋白稳定性为切入点，探讨Nrf2在TAA致肝损伤中的作用和机制：以Nrf2基因敲除小鼠为研究对象阐明Nrf2在TAA代谢活化及其所致肝损伤中的作用；通过原代肝细胞进一步解析Nrf2通过ROS-Heme途径对CYP2E1蛋白稳定性的调控机制，为TAA及其同类毒物肝毒性的干预策略和方法提供科学依据。

Thioacetamide (TAA), a chemical with hepatoxicity, is widely used in industrial and agricultural production, but the molecular mechanism of its toxicity is incompletely understood. As a crucial transcription factor in antioxidative defense, nuclear factor-E2-related factor 2 (Nrf2) is of great concern in defensing against chemical-induced hepatic injury. However, in our previous studies, we found that Nrf2 deficient mice were resistant to TAA-induced acute liver injury, and showed reduced protein level of CYP2E1, a key enzyme for TAA metabolic activation. These data indicate that Nrf2 may participates in TAA metabolic activation through regulating CYP2E1, and thereby is involved in TAA-induced liver injury. Thus, this project aims to explore the role and mechanism of Nrf2 in TAA-induced liver injury from the viewpoint of protein stability of CYP2E1 with in vivo and in vitro methods: Nrf2 knockout mice will be applied to clarify the role of Nrf2 in metabolic activation and liver injury of TAA; the primary mouse hepatocytes will be used to elucidate the mechanism of Nrf2 on regulating protein stability of CYP2E1 through the ROS-Heme pathway. The project will provide a scientific basis for intervention strategies and methods of hepatotoxicity induced by TAA and similar toxicants.