Ang(1-7)抑制重症急性胰腺炎胰腺腺泡细胞自噬作用及其调控PI3K通路机制研究

Inflammation and the inappropriate activation of trypsinogen to trypsin within pancreatic acinar cells are key initiating event in pancreatitis. Autophagy has direct relationship with activation of trypsin, moreover, autophagy of pancreatic acinar cells can be activated by inflammatory cytokines. Our previous research indicated that Ang(1-7) suppressed the inflammation of pancreatic acinar cells and activated ClassI PI3K signal pathway of autophagy, however, the mechanisms responsible for Ang(1-7) in autophagy of pancreatic acinar cells have not been elucidated with certainty..In this study, we will first observe the dynamic expression of autophagy related proteins and the formation of autophagosome by electron microscope and acridine orange staining after using Ang(1-7) on SAP model in vivo and in vitro to confirm the role of Ang(1-7) in pancreatic acinar cell of SAP. Second, we will use Ang(1-7) on cerulein-treated over-expressed or down-expressed ClassI P13K or ClassIII PI3K AR42J or MPC-83 cells to clarify the molecular mechanism of Ang (1-7) in regulating autophagy of pancreatic acinar cell via PI3K pathways. Confirmating the role and mechanism of Ang (1-7) in autophagy can provide experimental and theoretical basis to find new targets for treatment of SAP.

胰酶异常激活和炎症反应是SAP发生发展的关键，自噬与胰酶激活呈正比关系，炎症因子能激活胰腺腺泡细胞自噬。本课题组前期发现，Ang(1-7)抑制胰腺腺泡细胞炎症反应，激活自噬信号ClassI PI3K通路，但Ang(1-7)在SAP胰腺细胞自噬中的作用及其机制尚不清楚。故本项目研究：Ang(1-7)在SAP胰腺腺泡细胞自噬中的作用：动态观察Ang(1-7)干预体内外SAP模型对自噬相关蛋白表达的影响，电镜和吖啶橙染色观察自噬体形成情况。明确Ang(1-7)在SAP细胞自噬中的作用，为寻找SAP治疗新靶点提供实验依据。

胰酶异常激活和炎症反应是SAP发生发展的关键，自噬与胰酶激活呈正比关系，炎症因子能激活胰腺腺泡细胞自噬。本课题组前期发现，Ang(1-7)抑制胰腺腺泡细胞炎症反应，激活自噬信号ClassI PI3K通路，但Ang(1-7)在SAP胰腺细胞自噬中的作用及其机制尚不清楚。.本项目通过：.（1）大鼠体内实验研究发现：在3.75%牛磺胆酸钠诱导的SAP大鼠中，胰腺腺泡细胞内自噬水平上调，但是同时自噬功能受损；而用50ug/Kg体重发的Ang(1-7)于大鼠造模后立即尾静脉注射，能下调SAP大鼠胰腺腺泡细胞的自噬水平。.（2）胰腺腺泡细胞AR42J体外实验研究发现：自噬起始蛋白Beclin1随着CAE（10-6mol/L）刺激诱导的胰腺腺泡细胞AR42J，自噬膜形成关键蛋白LC3显著下调，自噬降解载体蛋白p62随CAE的刺激不断显著聚集，提示自噬体降解受损。而低浓度Ang(1-7)（10-8mol/L）可显著降低胰腺炎腺泡细胞内自噬降解载体蛋白p62的聚集，提高自噬降解水平。提示，低浓度的Ang(1-7)能够稍微上调急性胰腺炎腺泡细胞内自噬水平，并提高自噬体的降解水平，减少自噬体的聚集。.综上，急性胰腺炎体内外研究证实，胰腺腺泡细胞内自噬在胰腺发生炎症是受到损伤，而Ang(1-7)可减轻受损的自噬体聚集，明确了Ang(1-7)对SAP胰腺腺泡细胞自噬的作用，或可减轻自噬功能异常所引起的胰酶异常激活及炎症反应，为研究胰腺炎的病理生理发病机制、寻找SAP治疗新靶点提供实验依据。