无缺血肝移植技术通过维持供肝FXR表达抑制焦亡预防缺血再灌注损伤的机制研究

缺血再灌注损伤（IRI）是影响移植预后和边缘性器官使用率的主要因素之一。本团队发明了无缺血肝移植技术（IFLT），在不中断血流下完成移植全过程，显著改善了临床疗效，供肝IRI明显减轻，但机制尚不清楚。预实验中发现，在常规肝移植复流后FXR表达下降、NF-κB等炎症因子和焦亡相关蛋白表达明显增加，而IFLT中均保持不变；FXR敲除小鼠肝脏IRI明显加重，FXR可通过抑制NF-κB信号通路预防IRI。研究表明，NF-κB可激活细胞焦亡。据此，我们提出假设，IFLT通过维持FXR水平介导NF-κB降低肝内焦亡预防肝脏IRI。本项目拟采用小鼠IRI和细胞缺氧/复氧模型，FXR、NF-κB和GSDMD抑制剂和激活剂，小型猪体外常温机械灌注模型模拟IFLT和常规肝移植等，阐明IFLT是否通过FXR抑制焦亡预防IRI，为IFLT临床应用提供科学依据。

Ischemia-reperfusion injury (IRI) is one of the main factors affecting the prognosis of transplantation and the utilization of marginal organs. Our team invented the world's first ischemic-free liver transplantation (IFLT). The donor liver does not interrupt blood flow throughout the transplantation process. IFLT could significantly reduce liver IRI and improve clinical outcome. However, the mechanism of IFLT is remain unclear. In the preliminary experiment, it was found that the liver IRI was significantly increased in FXR knockout mice. FXR can prevent the expression of inflammatory factors via competitively binding the transcription regulator p300 with NF-κB. Clinical specimen testing found that FXR levels decreased and inflammatory factors, NF-κB, and pyroptosis-related proteins increased after recanalization in conventional liver transplantation, but these were unchanged in IFLT. Studies have shown that NF-κB can activate cell pyroptosis. Based on this, we propose a hypothesis that IFLT prevents IRI via maintaining FXR levels to inhibit NF-κB leading to reduce intrahepatic pyroptosis. This project intends to use mouse IRI and cell hypoxia / reoxygenation models, inhibitors and activators of FXR、NF-κB and GSDMD, IFLT and conventional liver transplantation model using normothermic machine perfusion to preserve mini-pig liver, etc., to clarify the molecular mechanism of IFLT on protection of donor liver. These would provide a scientific basis for the global promotion of IFLT.