晚期氧化蛋白产物诱导Kupffer细胞异常活化及相关炎症反应在肝再生障碍中的作用及机制研究

Impairment of liver regeneration is a critical factor affecting prognosis of the patients after partial hepatectomy. The pathological mechanism underlying impairment of liver regeneration remains elusive. Our study recently verified that advanced oxidation protein products (AOPP) as a kind of endogenous pathological mediator, it induces impairment of liver regeneration by stimulating S-phase arrest in hepatocytes directly. Our preliminary data further revealed that AOPP increases the release of inflammatory factors and intensifies the inflammatory responses in remnant liver of rats after partial hepatectomy. In addition, we also found that AOPP are predominantly deposited in the KCs. Therefore, we speculate that AOPP can induce impairment of liver regeneration through overactivating the KCs function and aggravating the KCs mediated inflammatory responses. By in vivo and in vitro studies, the project is planned to investigate: ①the pathological role of AOPP on KCs overactivation and its mediated inflammatory responses; ②the molecular mechanism underlying the KCs overactivation and its mediated inflammatory responses triggered by AOPP; ③the critical role of the crosstalk among KCs, hepatocytes and hepatic stellate cells mediated by inflammatory factors in the pathological process of AOPP-induced impairment of liver regeneration. Our study will clarify the role and mechanism of AOPP-induced KCs overactivation and its mediated inflammatory responses, thus revealing the new pathogenetic mechanism underlying impairment of liver regeneration and providing a new view for the development of prevention and treatment strategies in impairment of liver regeneration.

肝再生障碍是影响肝部分切除术患者预后的重要因素，其发生机制尚未完全阐明。本课题组前期研究证实晚期氧化蛋白产物（AOPP）作为一类重要的内源性致病介质，通过直接诱导肝细胞S期阻滞参与肝部分切除术后肝再生障碍的发生。预实验结果显示AOPP可导致肝部分切除术后大鼠残肝炎症因子释放增多及炎症损伤加剧，同时AOPP在残肝Kupffer细胞（KCs）中显著沉积。因此，我们推测KCs异常活化及相关炎症反应是AOPP诱导肝再生障碍的关键环节。本课题将延续前期研究，通过体内、外实验进一步探讨①AOPP诱导KCs异常活化及相关炎症反应的病理作用；②AOPP诱导KCs异常活化的分子途径；③KCs在炎症因子介导下与肝细胞、肝星状细胞发生病理性串扰在AOPP诱导肝部分切除术后肝再生障碍发生中的调控机制。这一假说如能证实，不仅可以更深入的阐明肝再生障碍的发病机制，并将为肝部分切除术后肝再生障碍的精准防治提供新的思路。

肝切除术后肝功能障碍是一种威胁生命的疾病，缺乏有效的治疗。参与巨噬细胞极化的生物活性脂类对组织损伤和再生起着至关重要的调节作用。在此，我们研究了介导极化巨噬细胞对肝切除术后肝功能障碍的细胞治疗潜力的关键生物活性脂质。非靶向脂质组学发现，神经酰胺(CER)代谢产物的升高是与小鼠骨髓源性巨噬细胞(BMDMs)中M1/M2极化相关的标志性脂质物种。M1 BMDMs表达CER-generation- metabolism模式，导致CER升高;M2 bmdm表达了cern分解代谢模式，导致鞘氨醇-1-磷酸(S1P)上调。在肝切除术后的小鼠肝脏中注入M1-或m2极化的bmdm后，我们发现M1- bmdm的注入增加了M1极化和CER积累，导致肝细胞凋亡和肝功能障碍的放大。相反，M2- bmdm灌注增强了M2的极化和S1P的生成，导致肝功能障碍的缓解，改善了肝细胞增殖。外源性CER和S1P处理或靶向相关酶的siRNA抑制CER和S1P的合成进一步表明，CER诱导肝切除术后原代肝细胞凋亡，而S1P促进细胞增殖。总之，CER和S1P被发现分别是M1和m2极化的BMDMs促进肝切除术后肝脏损伤和再生的关键脂质介质。M2-BMDM输注诱导的肝S1P上调可能对肝切除术后肝功能障碍有治疗潜力。