基于miRNA-146a调控TGFβ/Smads信号通路的疏肝活血化瘀方抗肝纤维化机制研究

Liver fibrosis represents chronic wound repair and is causally associated with persistent HSC activation. Thus better understanding of molecular mechanisms that underlie HSC activation is an important prerequisite for development of new therapeutic modalities for cirrhosis. Hepatic stellete cells (HSCs) play a pivotal role in liver fibrosis, the clearance of activated HSCs by apoptosis is associated with the resolution of liver fibrosis. So inhibiting the activation of HSCs and inducing activated HSCs to prevent progression of hepatic fibrosis is a beneficial method. Molecular mechanism investigation indicate that TGF-β, a potent regulator of cell growth and differentiation, play a key role in activating HSCs in liver. Active TGF-β binds to specific, high-affinity receptors present on most cells, initiating a signaling cascade that results in biological effects, including production of cytokines and inflammatory mediators, stimulation of extracellular matrix (ECM) synthesis, and inhibition of ECM degradation. The Shuganhuoxuehuayu(SGHXHY) recipe is effective in treating hepatic fibrosis, and is well used in clinical. But the mechanism of Ruanganling anti-hepatic fibrosis is unclear. In this project, we investigated the mechanism of SGHXHY in vivo and vitro assay through researching its inhibiting activation and inducing apoptosis on hepatic stellete cells. In China, chronic liver disease is very popular and harm people's health, hepatic fibrosis is "chronic hepatitis-liver fibrosis-liver cirrhosis-hepatocellular carcinoma" this chain of the development process of hub link. MiRNA-146a is a negative regulator of immune and inflammatory responses and is believed to be associated with the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. But the roles of miR-146a during TGF-β-induced HSC proliferation and function remain limited at the present. HSC proliferation, increased HSC apoptosis, and the expression of α-SMA in addition to its involvement in the well-known TGF-β/smad pathway. Here we want to investigate the targeting role of MiRNA-146a in TGF-β/smad pathway contributing to pathogenesis of liver fibrosis based on Shuganhuoxuehuayu recipe.

肝纤维化是各种慢性肝病向肝硬化发展的必经阶段，在此过程中TGFβ1/Smads发挥着关键的调控作用,有效干预其信号传导是治疗肝纤维化的重要策略。疏肝活血化瘀方是基于疏肝、活血化瘀理论的中药复方，已在临床应用多年，具有很好的抗纤维化作用，前期的研究提示调控Smad4蛋白表达是疏肝活血化瘀方调控肝纤维化发生的关键环节，而miRNA-146a与其表达密切相关。因此本项目提出疏肝活血化瘀方下调Smad4可能在于激活miRNA-146a表达这一假说。通过体内外实验相结合，采用基因转染miRNA和siRNA技术以及调控TGFβ1/Smads通路相关指标的观察，拟从miRNA水平揭示其抗肝纤维化的调控机制，围绕TGFβ1/Smads信号通路在肝纤维化发生中的作用，探讨miRNA-146a调控该通路的靶标作用。确证疏肝活血化瘀方抗肝纤维化的关键调控点，并解析其效应机制，为该复方治疗肝纤维化奠定科学基础。

肝纤维化是各种慢性肝病向肝硬化发展的必经阶段，在此过程中TGFβ1/Smads发挥着关键的调控作用。有效干预干预其信号传导是治疗肝纤维化的重要策略。疏肝活血化瘀方是基于疏肝、活血化瘀理论的中药复方，已在临床应用多年，具有明显的抗纤维化作用，前期的研究提示调控Smad4蛋白表达是疏肝活血化瘀方调控肝纤维化发生的关键环节，而miRNA-146a与其表达密切相关。本研究在前期研究基础上和科学假说基础上，考察了疏肝活血化瘀方调控miR-146a-TGFβ1/Smads通路发挥抗肝纤维化的作用机制。我们的研究结果显示，高表达的miR-146a可能通过下调smad4的表达，进而调控smad2、smad3的磷酸化水平以及smad7的表达，影响肝纤维化的发生发展。而疏肝活血化瘀方可能是靶向作用于smad4蛋白，进一步降低smad2和smad3的磷酸化水平，提高smad7的表达，抑制了肝细胞的增殖，从而发挥抗肝纤维化的作用。本研究为疏肝活血化瘀方在临床的应用提供的立功基础。