利用代谢组学揭示心肌缺血再灌注损伤过程中的类二十烷酸代谢特点及其作用机制

Myocardial ischemia-reperfusion (I/R) injury is a condition in which myocardial tissue suffer more severe injury and dysfunction than before reperfusion, involving various cell types and multiple biological processes. Eicosanoids are hundreds of small bioactive metabolites derived from polyunsaturated fatty acids. They affect multiple biological processes and play a role in a range of diseases. Some specific eicosanoids are proved to be involved in I/R process in some work, in which single eicosanoid and biological process was studied. Due to the complex functions of eicosanoids and the influence on their levels caused by each other, it is crucial to thoroughly study their metabolic characteristics in I/R. We will use metabolomics to study the metabolism of various eicosanoids during IRI, systematically exploring the function and mechanism induced by various eicosanoids in biological processes including the apoptosis and necrosis of cardiomyocyte, collagen secretion by cardiac fibroblasts, immune cell filtration and macrophage phenotype conversion in this project. This project also explores if the combined regulation of eicosanoid strategy can achieve an improved myocardial ischemia-reperfusion protective effect. The implementation of this project will comprehensively link eicosanoid metabolism to various important biological processes in I/R and provide potential targets for clinical treatment.

心肌缺血再灌注（I/R）损伤指心肌组织在较长时间缺血后恢复血液灌流，反而出现的更严重的功能障碍，是涉及多种细胞类型以及生物学途径的复杂过程。类二十烷酸是由多不饱和脂肪酸代谢而成的上百种具有丰富生物活性的小分子的总和，其功能影响多个生物学过程，在一系列疾病过程中发挥作用。目前已证明部分类二十烷酸分子在I/R损伤过程中起重要作用，然而以往研究都是针对单一细胞类型中的单一代谢产物而进行。由于类二十烷酸功能繁杂且代谢产物之间互相影响，全面研究其在I/R中的代谢特点至关重要。本项目运用代谢组学手段研究I/R过程中类二十烷酸代谢谱，系统性地阐述多种代谢产物对心肌细胞的凋亡、坏死、心肌成纤维细胞分泌胶原、免疫细胞浸润和巨噬细胞表型转换等生物学过程的作用和机制，探索组合式的类二十烷酸调控策略对I/R的保护效果。本项目的实施将全面将类二十烷酸代谢与I/R中的重要生物学过程联系起来，为临床治疗提供可能的靶点。

心肌缺血再灌注（I/R）损伤是心肌组织在较长时间缺血后恢复血液灌流，反而出现比再灌注前更严重的损伤和功能障碍，是涉及多种细胞类型以及多个生物学途径的复杂过程。类二十烷酸是由多不饱和脂肪酸代谢而成的上百种具有丰富生物活性的小分子代谢物的总和，其功能影响细胞凋亡、细胞纤维化、炎症信号传递等多个生物学过程，也在一系列疾病过程中发挥作用。本项目运用代谢组学手段呈现I/R过程中各种类二十烷酸的代谢水平，研究类二十烷酸分子对心肌细胞的调控作用和机制，为临床治疗提供可能的治疗靶点。我们利用左前降支结扎-再通手术构建小鼠心肌I/R模型，分别在小鼠再灌注4小时、12小时、24小时、7天后收集血浆和损伤部分的心脏组织进行了类二十烷酸靶向代谢组学实验，代谢组学结果揭示了多种代谢产物随着再灌注时间的变化而变化。脂质过氧化的加重提示再灌注过程中心肌细胞可能发生铁死亡，经过检测GPX4等铁死亡特异性蛋白的表达情况，确定心肌I/R过程中发生铁死亡。结合花生四烯酸代谢组学与RNA-Seq的结果我们发现在心肌I/R过程中花生四烯酸代谢产物15HpETE参与调控线粒体功能相关基因的表达从而造成心肌细胞铁死亡，加重心脏损伤。