无缺血移植技术通过维持供肝戊糖磷酸代谢预防缺血再灌注损伤的机制研究

缺血再灌注损伤（IRI）是导致移植失败的主要原因之一。在获取、保存与植入过程中器官缺血引起的低温和无氧代谢是其始动因素。为此，本团队通过外科创新和机械灌注建立了无缺血移植技术，使供肝在移植全过程保持常温、有氧代谢，显著改善了临床疗效，供肝IRI明显减轻，但机制未明。代谢组学显示新技术与常规技术供肝的戊糖磷酸通路差异最显著，转录组学分析显示新技术供肝复流后上调表达的基因数量减少了98.6%，众多炎症反应相关通路未激活。本项目拟利用临床标本，结合人肝机械灌注模型和动物实验，综合应用代谢组学、单细胞测序等手段，进一步探讨在IRI中戊糖磷酸途径如何影响供肝各细胞亚群的基因转录，及其调控炎症小体/焦亡介导的炎症反应的作用机制，并揭示其对供肝区域免疫的调控作用。本项目的顺利开展，将明确无缺血移植技术对供肝的保护作用，并从代谢角度揭示其预防IRI的作用机制，为临床应用该技术改善移植预后提供理论依据。

Graft ischemia-reperfusion injury (IRI) is one of the leading causes of graft failure. The hypothermic and anaerobic metabolism is the initial factor. Thus, our team established a novel procedure called ischemia-free liver transplantation (IFLT) to maintain normothermic and aerobic metabolism during the whole transplant procedure, by using innovative surgical and machine perfusion techniques. The preliminary data showed that the outcomes of IFLT recipients were substantially improved and IRI was largely avoided when compared to those undergoing the conventional procedure (CLT). The metabolonomics analysis showed that the change of the PPP was the most pronounced pathway in the IFLT versus CLT grafts. The transcriptome analysis showed that the number of differentially expressed genes after graft revascularization in the IFLT group was reduced by 98.6% when compared to the CLT group. Multiple inflammation pathways were not activated in the IFLT group. In the proposed study, we will take full advantage of the clinical samples, combined with human liver ex situ perfusion model and animal studies, by using the techniques of metabolonomics, single cell sequencing and other methods, to explore how the pentose-phosphate pathway (PPP) regulates the gene transcription of different cell groups in the liver, to dissect how the PPP prevents the sterile inflammation via inhibiting the inflammasome/pyroptosis, and subsequently re-shapes the local immunity in the graft during IRI. The conduction of this project will confirm the protective effects of IFLT on the liver grafts, and identify the mechanisms by which IFLT prevents IRI in the view of cell metabolism, which provides evidences of supporting the use of IFLT to improve transplant outcomes in the clinical practice.