芪冬活血饮调控急性肺损伤的机制及与miR-155的相关性研究

Pulmonary edema is the main feature of acute lung injury, which can improve the prognosis of acute lung injury. ALI is a serious respiratory disease caused by accumulation of pyretic toxicity and deficiency of both vital energy and yin based on theory of traditional Chinese medicine. However so far few active drug to cure the disease can be available. Recent studies found that SOCS1-ASK1 plays an important role in the regulation of alveolar sodium water transport in acute lung injury, and is closely related to microRNA-155. Our recent study revealed that QiDongHuoxue decoction, a traditional Chinese medicine, can reduce the secretion of inflammatory factors and improve the pulmonary edema in acute lung injury, but its mechanism remains unknown. So in the present project, we plan to investigate the mechanism of QiDongHuoxue decoction to cure ALI by inhibiting miR-155, promoting SOCS1 and inhibiting ASK1. Then alveolar epithelial cell inflammatory models as well as mouse ALI model will be established. All kinds of methods such as PCR, Western-Blot, immunofluorescence, silence expression, overexpression and specific inhibitor blockage technique were used to investigated the protective effect of QiDongHuoxue decoction, and to provide the theoretical and experimental evidences for QiDongHuoxue decoction to cure ALI patients in clinic.

肺水肿是急性肺损伤的主要特征，减轻甚至治愈肺水肿能改善急性肺损伤预后。中医对急性肺损伤病机归为热毒瘀结、气阴两虚危重呼吸道病症，但治疗ALI的有效药物甚少。新近发现SOCS1-ASK1在调控急性肺损伤肺泡钠水转运中发挥重要作用，且与microRNA-155密切相关。项目组前期研究发现芪冬活血饮能减轻炎症因子分泌，改善急性肺损伤肺水肿，但其机制不明。因此本项目拟从芪冬活血饮抑制microRNA-155、促进SOCS1的表达和抑制ASK1的思路出发，从小鼠ALI明确芪冬活血饮对肺泡钠水转运的作用，再以肺泡上皮细胞ALI为研究模型，采用PCR、Western-Blot和免疫荧光等研究手段、miR-155的过表达和抑制表达、腺病毒载体/siRNA对SOCS1进行过表达和沉默表达、以及ASK1特异性阻断技术，从各水平明确芪冬活血饮对ALI肺水肿的保护作用，为芪冬活血饮治疗ALI提供理论和实验依据。

肺水肿是急性肺损伤的早期并发症，如能减轻肺水肿有助于改善急性肺损伤的预后。肺泡上皮细胞和肺血管内皮细胞是发生肺水肿的主要细胞，而位于细胞膜上的ENaC-α和AQP-1是急性肺损伤肺水肿时肺泡钠水转运的关键位点。ALI时炎症因子的释放可以引起肺泡上皮细胞和血管内皮细胞损坏，肺泡正常钠水转运受阻。本研究从动物和细胞水平阐述了芪冬活血饮对ALI时肺水肿的保护作用。从动物水平得出芪冬活血饮能减轻ALI小鼠TNF-α、IL-1β、IL-6的释放，采用Western-Blot、ELISA、免疫组化法得出芪冬活血饮能恢复ENaC-α和AQP-1的功能，恢复肺泡的钠水转运功能。细胞水平以肺泡上皮细胞A549和巨噬细胞为研究对象，明确芪冬活血饮对抗炎症反应的效果，确定芪冬活血饮能促进改善ENaC-α和AQP-1的表达和释放，其分子机制是芪冬活血饮能抑制炎症引起的miR-155的表达，从而解除miR-155对SOCS1的靶向抑制，该通路是通过抑制ASK1-JNK/p38MAPK磷酸化而实现的。综上结果，我们得出芪冬活血饮抑制ALI时炎症因子的分泌，通过抑制ASK1-JNK/p38MAPK通路减少miR-155的释放，解除对SOCS1的抑制，恢复肺泡钠水转运从而减轻肺水肿的发生。该项目为中医“清热解毒、祛瘀通腑、益气养阴”提供理论和实验基础，为中医药治疗ALI提供了思路。本项目成果已在多家医院进行推广，临床治疗颇有疗效，在省内相关领域研究中起到学科交叉和带头作用。