基于S1P相关炎症信号通路探讨芪冬活血饮治疗急性肺损伤的分子机制

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 no effective medicine is available.Our previous study confirmed that Qidong Huoxue Decoction(QD) has remarkbale effect of anti-inflammatory and regulation of cytokine balance in ALI.The mechanism is QD can inhibit NF-κB through TLR4/Cav-1. Recent studies found that S1P regulate inflammatory reaction in ALI by intracellular signaling pathway TLR4/TRAF6/NF-κB and extracellular signaling pathway S1P/S1PR/eNOS/NF-kB pathway. The role of S1P in TLR4 pathway has been determined. Cav-1 can regulate eNOS but the mechanism is unknown, and Ca-1 is binding site of S1PR,it is still a question whether Cav-1 and S1P interact with each other and regulate NF-κB through S1PR/PI3K/Akt/ eNOS pathway.This project intends to establish LPS-induced macrophage inflammatory model and LPS-induced rat ALI model, using methods such as siRNA target gene silence, phosphorylation detection and specific inhibitor blockage of critical signaling kinases,to clarify the interaction between Cav-1 and S1P and how Cav-1 regulate eNOS；and to ascertain the effects of QD on S1P related inflammatory signaling pathway,to determine the in-depth molecular mechanism of QD’s anti-inflammatory effect.

急性肺损伤（ALI）是呼吸系统急危重症，中医认为其病机是热毒瘀结、气阴两虚，目前尚缺乏有效治疗药物。我们前期研究证实芪冬活血饮对ALI疗效显著并有抗炎作用，其机制与抑制TLR4/Cav-1表达进而抑制NF-κB有关。新近发现S1P通过细胞内TLR4/S1P/TRAF6和细胞外S1P/S1PR/PI3K/Akt/eNOS途径活化NF-κB调控急性肺损伤炎症反应。S1P在TLR4通路中的作用已经明确；Cav-1可调控eNOS但机制不明，Caveolin-1是S1PR的结合部位，Cav-1是否与S1P相互作用经PI3K/Akt通路调控eNOS？本项目拟采用LPS诱导巨噬细胞炎症模型及大鼠ALI模型，应用siRNA基因沉默及信号激酶磷酸化检测及阻断等方法，明确Caveolin-1是否和S1P相互作用及其调控eNOS信号机制，明确芪冬活血饮对S1P相关炎症信号通路的影响，确定芪冬活血饮抗炎分子机制。