肿瘤坏死因子预处理及其抗体对体外循环肺保护作用的新机制

Pulmonary injury is a common post-surgery complication associated with cardiopulmonary bypass (CPB). Understanding the mechanism of CPB-induced pulmonary injury is a challenge and the key to effectively manage the complication in clinical practice. Our previous studies have demonstrated that tumor necrosis factor-α (TNF- α) plays a critical role in mediating CPB-induced pulmonary injury. We also found that the expression of genes involved in the mitogen-activated protein kinase (MAPK) signaling pathway is significantly increased in CPB-induced pulmonary injury. In this study, we hypothesize that preventive intervention and neutralizing antibody-targeting TNF-α to interfere MAPK signaling pathway can attenuate CPB-induced pulmonary injury. In this project, we propose to establish a rabbit model of CPB and comprehensively investigate the molecular mechanism and therapeutic intervention of CPB-induced pulmonary injury at molecular, cellular, histological, and animal levels by using approaches in bioinformatics, histomorphology, and molecular biology . The aim of our study is to investigate the protective effects and molecular mechanism of preventive intervention and neutralizing antibody-targeting TNF-α on lung tissue after CPB, and to identify MAPK pathway-associated genes influenced by preventive intervention and neutralizing antibody-targeting TNF-α. Our study will shed new lights on therapeutic targets for pulmonary protection after CPB.

肺损伤是体外循环(CPB)术后的常见并发症，从机制进行防治是临床治疗的重点和难点。我们在前期研究中已经明确肿瘤坏死因子（TNF-α）在CPB相关肺损伤中起关键作用，并发现信号通路MAPK相关基因在肺损伤后表达显著升高。因此，我们提出"TNF-α保护性预处理及其抗体双重干预MAPK信号通路，减轻CPB相关肺损伤"的假说。本项目拟建立兔CPB模型，采用生物信息学、组织形态学、分子生物学、MAPK通道蛋白抑制剂、腺病毒载体转染和RNA干扰等手段，从分子、细胞、组织以及动物水平等层面阐明：1）TNF-α预处理及其抗体对CPB术后肺组织的保护作用；2）TNF-α预处理及其抗体对MAPK信号通路的作用机制；3）明确TNF-α预处理及其抗体作用下的MAPK信号通路的相关靶基因；4）揭示MAPK信号通路与CPB相关肺损伤的关系和TNF-α预处理及其抗体对CPB肺组织的保护机制，为CPB肺保护提供新的思路。

体外循环(cardiopulmonary bypass, CPB)术后肺损伤是临床上常见的并发症。目前认为，肺脏高温缺血是肺损伤发生的始动因素。随后，CPB 诱发的肺部炎症反应、细胞凋亡等多种机制参与了发病过程。肺源性肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)在其中发挥关键作用。据此，我们采用经气管内TNF-α预处理及肺动脉低温灌注抗肿瘤坏死因子-α抗体(anti-tumor necrosis factor-α antibody, TNF-αAb) 来实现对CPB 肺损伤的多层次保护。本研究建立了兔体外循环气管内TNF-α预处理及肺动脉低温灌注TNF-αAb 模型，通过对围CPB 期不同时点的肺功能、病理学、血液学、肺部炎症因子表达及细胞凋亡等指标动态观察，证实了经气管内TNF-α预处理联合肺动脉灌注TNF-αAb可明显改善肺功能，抑制CPB 期间肺内炎症细胞聚集，减少氧自由基的产生，减轻肺源性TNF-α等炎症因子的释放，尤其可从转录水平降低肺组织TNF-α表达，减少肺组织细胞凋亡的发生。因此，我们得出结论：经管内TNF-α预处理联合肺动脉低温灌注TNF-αAb 能明显减轻体外循环引起的炎性肺损伤，并从内源性和外源性两条途径减轻肺组织细胞凋亡，进而达到肺保护目的，并通过细胞实验进一步证实，为防治CPB 肺损伤提供新思路。