Nrf2与Smad3在肝纤维化-肝癌发展进程中的交互作用机制及黄芪甲苷的干预

氧化应激与炎症反应是促进肝纤维化-肝癌进程的重要因素。活化的核因子E2相关因子2（Nrf2）具有抗炎抗氧化作用而抗肝损伤，且其抗肝纤维化与TGF-β/Smad信号通路相关；近年发现Nrf2持续活化却促进肝癌的发生发展。鉴于Smad3的C末端向连接区磷酸化转换（pSmad3C→pSmad3L）亦促进肝纤维化-肝癌进程，黄芪甲苷（AS-IV）具有抗炎抗氧化作用。推测：肝纤维化-肝癌进程中可能存在Nrf2与Smad3交互作用，AS-IV可能通过干预该交互作用而延缓该进程。故拟采用Nrf2表达上调/下调、pSmad3C/pSmad3L质粒或点突变模式动物等体内外肝纤维化-肝癌模型，IHC/IF、IP/IB、qRT-PCR、荧光素酶报告基因等技术检测Nrf2、Smad3表达及活化情况，探讨Nrf2与Smad3的交互作用机制及AS-IV的干预，阐明肝癌发生发展机制并为AS-IV临床应用提供理论依据。

Oxidative stress and inflammatory response are important factors facilitating the progression of hepatic fibrosis-carcinoma. Activated nuclear factor erythroid 2-related factor 2 (Nrf2) exerts anti-inflammatory and antioxidant activities resulting in against liver injury, and activated Nrf2 has also anti-hepatofibrosis effect involved in modulating transforming growth factor beta (TGF-β)/Smad signal pathway; however recently, it is emerging that continuous activation of Nrf2 maybe facilitates hepatocarcinogenesis-progress. In view of these findings that the shift of Smad3 C-terminal and linker region phosphorylated respectively (pSmad3C/pSmad3L) facilitates the progression of hepatic fibrosis-carcinoma, astragaloside IV (AS-IV) has anti-inflammatory and antioxidant activities. We speculate that cross-talking between Nrf2 and Smad3 maybe occur in the progression of hepatic fibrosis-carcinoma, which is a possible molecular mechanism of AS-IV's anti-hepatic fibrosis-carcinoma. Therefore, in vitro and in vivo models of hepatic fibrosis-carcinoma with up-regulated or down-regulated expression of Nrf2 and/or variant phosphorylation of Smad3 at C-terminal and linker region (pSmad3C/pSmad3L plasmid transfection and/or mutant gene knock-in) will be used in the project; the expression and activation of Nrf2, Smad3 and will be detected by immunohistochemistry and/or immunofluorescence, immunoprecipitation and/or immunoblotting, quantitative real-time polymerase chain reaction, luciferase-reporter gene assays and so on. These studies purpose to uncover the cross-talking mechanisms between Nrf2 and Smad3 and the intervention of AS-IV, which is helpful to clarify the possible mechanisms of hepatocarcinogenesis-progress and provide a theoretical foundation for clinical application of AS-IV.