基于肺与大肠相表里理论研究厚朴酚对重症急性胰腺炎肺损伤的作用机理和TLR4/AKT与SCF/c-kit信号通路串话的分子机制

Acute lung injury (ALI) is the earliest sequela in patients with severe acute pancreatitis (SAP), and has emerged as one of the leading cause of death in patients requiring critical care in intensive care unit. Limiting acute gut injury and promoting gastrointestinal motility were proven to be beneficial and have been instituted into clinical practice of severe acute pancreatitis. In previous studies, we found that magnolol can improve the intestinal oxidative stress, regulate the Interstitial cells of Cajal signaling pathway and autophagy to achieve the role of promoting gastrointestinal motility. Based on our supporting data, in this project will to explore the pathogenesis of early acute lung injury in patients with severe acute pancreatitis from the TLR4 and SCF / c-kit signaling pathways cross-talking, and the functional cycle of intestinal lymphatic circulation. We will apply a multidisciplinary approach to define the signaling mechanisms of magnolol-mediated protective effect in treating SAP and its complication ALI, with the intent of developing new regimen for clinical practice.

肺损伤是重症急性胰腺炎早期的严重并发症，属于中医基本理论“肺与大肠相表里”的“肠病及肺”范畴。我们在临床实践中长期应用厚朴三物汤治疗重症急性胰腺炎，对早期脏器功能维护效果显著，但作用机制不明。在拆方研究中，我们发现厚朴酚可以通过改善肠道氧化应激水平，调控肠道Cajal细胞信号通路和自噬等途径实现促进胃肠动力的作用，本研究拟从TLR4与SCF/c-kit信号通路串话、肠淋巴循环功能性阻断等多个环节上进一步探索重症急性胰腺炎早期肺损伤的发病机制和厚朴酚的作用机理。从炎症信号转导，解剖途径多方面入手，诠释肺与大肠相表里的现代医学内涵，为中西医结合治疗提供理论依据。

重症急性胰腺炎相关性肺损伤是SAP早期最常见、最严重的并发症。在SAP发病早期，肠道运动障碍，肠屏障功能受损，肠道细菌及内毒素经肠系膜淋巴途径转运至肺，导致肺损伤。厚朴酚具有抑制炎症反应，缓解炎性疼痛等作用。研究发现厚朴酚通过拮抗氧化应激和调控Cajal细胞改善脓毒症所致胃肠运动障碍。.本项目研究发现，通过引流肠系膜淋巴液，检测血清、淋巴液、肺及肠组织匀浆中D-乳酸，二胺氧化酶（D-AO），高迁移率族蛋白1（HMGB1），白介素1β（IL-1β），白介素8（IL-8），白介素10（IL-10），肿瘤因子α（TNF-α）。采用WB检测淋巴液中TLR4含量，研究厚朴酚对重症急性胰腺炎肺损伤的影响。结果厚朴酚治疗组淋巴液中TLR4表达降低，且血清、淋巴液、肺和肠组织中炎症指标均降低。这表明提示厚朴酚可以功能性阻断肠淋巴循环，降低炎症因子水平，调控炎症HMGB1-TLR4/NF-κB信号通路，降低炎症反应，以及改善肠道氧化应激水平，维护肠屏障功能，从而治疗SAP早期肺损伤。.我们以IL-6和IL-6/STAT3信号抑制剂AG490来验证miR-148a通过IL-6/STAT3信号对AP中胰腺腺泡内胰蛋白酶原激活的调节机制。构建miR-148a腺病毒载体，研究miR-148a通过自噬体溶酶体通路对AP中胰腺腺泡细胞自噬的调节作用。我们发现AP中miR-148a为低表达， 而miR-148a的过度表达降低了IL-6的mRNA和蛋白水平及胰腺组织损伤程度。 证实AP中miR-148a通过IL-6/STAT3信号通路对胰腺腺泡细胞自噬的调节作用。AP中miR-148a通过IL-6/STAT3信号通路和自噬体-溶酶体通路抑制了胰腺腺泡坏死。