HMGB1激活自噬信号在急性胰腺炎损伤中作用及机制研究

Acute pancreatitis (AP) is an acute abdominal disease commonly seen in general surgery and the mortality of severe AP can reach up to 30%. The treatment of AP has always been tricky. Previously, pro-inflammatory factors, such as IL-1 and TNF-α, are thought to play important roles in the development of AP. However, recent researches showed that HMGB1, a late inflammatory factor, is closely associated with the prognosis of AP, although the specific mechanisms remain unclear. We propose the hypothesis that HMGB1 is involved in the inflammation of AP, and also can activate the autophagy signaling pathway, thus resulting in more severe AP symptoms. We will investigate the apoptosis and autophage in the pancreatic inflammatory tissue and adjacent edema tissue in AP. HMGB1 expression will be related to the activation of autophagy molecules, such as LC3II, Beclin1, and VMP1. The expression of Beclin1 and HMGB1 will be downregulated by 3-MA (autophagy inhibitor), Rapamycin (activator), and shRNA. The protective effects of the treatment for AP will be studied. The understanding of the relationship between HMGB1 and autophage in AP will help to gain insight into the pathogenesis of AP and the development of treatment methods for this disorder.

急性胰腺炎为腹部外科常见急腹症，重型急性胰腺炎病死率仍为30%左右，一直是临床治疗难点。以往研究认为早期炎症因子（如IL-1，TNFα等）在急性胰腺炎的发生、发展中起重要作用，但近年来研究表明晚期炎症因子HMGB1对急性胰腺炎预后起更重要作用，但具体机制尚不明确。本课题提出如下假说认为：在急性胰腺炎中晚期炎症因子HMGB1不仅参与加重炎症，而且还能作为自噬激活分子增加胰腺组织细胞自噬，从而加重病情。本课题拟通过观察急性胰腺炎组织及周边充血水肿区细胞凋亡与自噬现象，研究HMGB1对自噬信号分子LC3II、Beclin1及VMP1表达的激活作用；采用自噬抑制剂3-MA、激活剂Rapamycin，以及采用shRNA手段抑制Beclin1、HMGB1表达，观察对急性胰腺炎损伤保护作用。课题从HMGB1与自噬角度研究，为临床治疗急性胰腺炎提供分子机制和潜在治疗方案。

急性胰腺炎为腹部外科常见急腹症，重型急性胰腺炎病死率仍为30%左右，一直是临床治疗难点。以往研究认为早期炎症因子（如IL-1，TNFα等）在急性胰腺炎的发生、发展中起重要作用，但近年来研究表明晚期炎症因子HMGB1对急性胰腺炎预后起更重要作用，但具体机制尚不明确。急性胰腺炎的与其它炎症不同，其胰蛋白酶原的激活是其始动因素之一，大量研究表明，自噬的过度激活或是自噬通路的受阻导致的自噬泡的堆积是导致胰蛋白酶提前激活引起胰腺炎发生发展的主要因素。本项目通过以5%牛黄胆酸钠逆行胰胆管注射的方法制作急性胰腺炎大鼠模型，观察不同时间点早期炎症因子（IL-1，TNFα等）、晚期炎症因子（HMGB1）、自噬信号分子的表达，研究HMGB1对自噬信号分子Beclin1的激活作用。课题从HMGB1与自噬角度研究，为临床治疗急性胰腺炎提供分子机制和潜在治疗方案。结果显示：HMGB1不同于早期炎症因子IL-1β、IL-6、TNF-α等，在急性胰腺炎胰腺组织炎症发生发展的晚期才明显表达增加，HMGB1从核内向胞浆转移，证明了HMGB1作为非核内组蛋白在致病因素的刺激下，通过定向转移而发挥其致病作用。进一步采用Western blot研究Beclin1蛋白在胰腺组织的表达，我们发现Beclin1随着急性胰腺炎炎症的加重而表达增加，这说明自噬的过度激活是导致胰腺炎发生发展的重要因素，HMGB1可能在其中发挥重要作用。