HNF4α抑制非酒精性脂肪性肝炎进展的机制研究

Non-alcoholic steatohepatitis(NASH) is regarded as a burgeoning public health problem and there are not many effective therapeutic methods to date. Our previous study demonstrated that hepatocyte nuclear factor-4α(HNF4α) could induce the expression of many important genes which involved in metabolism of glucose and lipid in liver cells and might play crucial roles in the treatment of NASH by improving insulin resistance and alleviating the steatohepatitis and apoptosis of hepatocytes. In this study, hepatocytes will be isolated from hepatocyte-specific HNF4α knock-out mice and infected with AdHNF4α. The effect of HNF4α on insulin resistance and steatohepatitis of hepatocytes will be evaluated in vitro, and the degree of lipid peroxidation and activity of NF-κB/IKK signaling pathway will be measured at the same time. In addition, the molecular mechanism will be explored. Furthermore, the role of HNF4α knock-out on NASH will be studied in the HNF4α conditional knock-out mice in vivo, and the therapeutic effect of HNF4α on NASH will be investigated in hepatocyte-specific HNF-/- mice and experimental NASH rats. This study will furtherly clarify the role of HNF4α on the development of NASH and provide a new strategy for the treatment of NASH.

非酒精性脂肪性肝炎（NASH）严重危害人类健康，目前缺乏有效治疗手段。前期工作证实，肝细胞核因子4α（HNF4α）可诱导肝细胞糖脂代谢相关重要基因表达，可能同时在胰岛素抵抗及炎症导致细胞变性凋亡两个环节发挥抗NASH作用。本研究分离肝细胞特异HNF4α敲除小鼠肝细胞，利用腺病毒（AdHNF4α）上调HNF4α，观察HNF4α基因表达缺失及上调对肝细胞胰岛素抵抗和脂肪变性的影响，检测该过程中脂质过氧化及NF-κB/IKK通路活性变化，并进一步探讨相关分子机制。利用肝细胞特异HNF4α敲除小鼠及NASH大鼠模型，体内观察HNF4α缺失对NASH的影响及AdHNF4α对NASH的治疗作用。本研究将进一步明确HNF4α在NASH发生发展中的作用，为NASH治疗提供新策略。

非酒精性脂肪性肝炎（NASH）严重危害人类健康，目前缺乏有效治疗手段。前期工作证实，肝细胞核因子4α（HNF4α）可诱导肝细胞糖脂代谢相关重要基因表达，可能同时在胰岛素抵抗及炎症导致细胞变性凋亡两个环节发挥抗NASH作用。本研究按计划进行。利用肝肿瘤细胞株HepG2及肝细胞株BRL-3A、特异性肝敲除HNF4α模型HNF4α-/-小鼠肝细胞，在体外油酸成功诱导脂肪变性，发现利用高效表达HNF4α的腺病毒在上述细胞中外源表达HNF4α，可调控肝细胞糖脂代谢相关基因表达，且改善炎症反应、抑制凋亡；NF-κB/IKK通路抑制剂PDTC及激活剂LPS可调控该过程。体内研究中，成功构建蛋氨酸缺乏饮食（MCD）诱导小鼠NASH模型，证实MCD可诱导小鼠特异性肝敲除HNF4α模型HNF4α-/-小鼠及对照小鼠（HNF4α+/+）NASH发生，且HNF4α-/-小鼠肝脏脂质合成相关基因表达升高，肝脏炎症相关基因表达及通路活性显著升高，NASH更为严重；利用腺病毒上调HNF4α表达，可减轻NASH，其机制与调控肝脏脂质合成相关基因及炎症信号通路有关。上述研究结果证实，HNF4α可通过调控糖脂代谢及肝脏炎症在体内外发挥抗 NASH 作用，HNF4α可能成为NASH治疗的有效方案。通过该研究，发表SCI收录论著1篇，核心期刊论文1篇，培养硕士研究生1名，协助培养硕士研究生1名。