Ozone基于Nrf2/HO-1/HIP-2α通路双靶点改善主动脉夹层CPB术后低氧肺损伤

Aortic dissection (AD) related postoperative hypoxemia (PHO) is an important complication after cardiopulmonary bypass (CPB), with high mortality and the problem hasn’t been resolved yet due to lack of effective measures which neither increase the oxygen supply nor promote the repair of lung injury. Ozone (O3) has been used in the treatment of some ischemic diseases because it can provide improve oxygenation. However, the mechanisms are seldom discussed. There are no reports on the application of Ozone to prevent PHO during the perioperative period of CPB. Previously, we confirmed that Ozone was proved to reduce lung ischemia-reperfusion injury in rats by inhibiting NLRP3 and enhancing the antioxidant capacity of Nrf2. In vitro experiments confirmed the safety and effectiveness of Ozone in human application. In the preliminary experiment, it was also found that HIF-2α and Nrf2 decreased after CPB operation and Ozone could up-regulate their expression. Therefore, it is speculated that Ozone, in addition to increasing oxygen supply, can also activate Nrf2/HO-1/HIF-2αsignaling pathway to maintain alveolar-capillary epithelial barrier and reduce lung injury. This study will verify or falsify this hypothesis by applying molecular biology, electron microscopy and other techniques and various interventions in three dimensions of cells-animal-human body, so as to clarify the molecular mechanism of Ozone to improve lung injury from a new perspective and provide new ideas and methods for clinical treatment of PHO.

主动脉夹层(AD)体外循环(CPB)术后低氧血症(PHO)是临床重要并发症，死亡率高且尚未得到有效解决，症结在于现有措施不能既增加机体氧供、又促进肺损伤修复。臭氧因有效改善氧合而应用于缺血性疾病的治疗，但机制不清；CPB围术期应用臭氧防治PHO更未见报道。前期，我们证实臭氧通过抑制NLRP3、增强Nrf2抗氧化，减轻鼠肺缺血-再灌注损伤；体外实验证实了Ozone人体应用的安全性和有效性；预实验观察到AD患者实施CPB后血清HIF-2α、Nrf2减少且臭氧上调其表达。鉴此，我们推测臭氧除增加氧供外，还可激活Nrf2/HO-1/HIF-2α信号通路维护肺泡-毛细血管上皮屏障而减轻肺损伤。为证实该假说，本研究将通过细胞-动物-人体三维度，应用分子生物学、电镜等技术和干预手段，阐明臭氧改善CPB术后肺损伤的分子机制，为PHO临床防治提供新思路和新方法。

本项目主要研究Ozone基于Nrf2/HO-1/HIF-2α通路双靶点改善主动脉夹层CPB术后低氧肺损伤.由于Ozone设备无法落实加上遇到疫情，因此方案执行遇到了困难，研究内容做了相应调整。基于主动脉夹层病例（急危重症，疫情影响小）进行一些基础（动物试验）和临床研究。研究内容集中在 1 证实了HIF及亚型与AD术后低氧肺损伤的关系。研究证实HIF-1α、HIF-2α、HIF-3α从术前到CPB结束均呈上升趋势，到术后第1天均呈下降趋势。此外，HIF-1α（但不是HIF-2α或HIF-3α）与CPB结束时和术后第1天的OI呈负相关。在CPB结束和术后第1天，HIF-1α更高，而死亡患者的HIF-3α与幸存者相比没有差异；进一步的受试者工作特征曲线分析显示，HIF-1α（但不是HIF-2α或HIF-3α）可以预测死亡风险。 因此，HIF-1α与OI相关，它可能是反映接受CPB合并手术的AD患者较高的死亡风险的一个可能的预后生物标志物。2.探索了主动脉综合征的主动脉夹层检测风险评分和d-二聚体最佳阈值和综合诊断价值，研究认为 ADD-RS>1和d-二聚体>2000 ng/mL是诊断AAS的最佳阈值。3.探索了Th及其亚型与临床预后的关系。研究证实Th1、Th2和Th17细胞调节异常，但只有Th17细胞与c反应蛋白、d-二聚体和死亡风险有关。4. 做了小鼠的AD模型和大鼠的CPB动物模型。本研究对AD的诊断，术后相关肺损伤 死亡预后的标志物做了探索，有利于临床更好的认识该疾病，改善临床预后。