Hypothermic oxygenated perfusion inhibits HECTD3-mediated TRAF3 polyubiquitination to alleviate DCD liver ischemia-reperfusion injury

Qifa Ye,Wei Zhou,Zhongshan Lu,Anxiong Liu,Danni Lin,Zhongzhong Liu,Qiuyan Zhang,Haoyang Xia,Shaojun Ye,Sheng Peng,Yanfeng Wang,Zibiao Zhong

doi:10.1038/s41419-021-03493-2

Abstract

Ischemia-reperfusion injury (IRI) is an inevitable and serious clinical problem in donations after heart death (DCD) liver transplantation. Excessive sterile inflammation plays a fateful role in liver IRI. Hypothermic oxygenated perfusion (HOPE), as an emerging organ preservation technology, has a better preservation effect than cold storage (CS) for reducing liver IRI, in which regulating inflammation is one of the main mechanisms. HECTD3, a new E3 ubiquitin ligase, and TRAF3 have an essential role in inflammation. However, little is known about HECTD3 and TRAF3 in HOPE-regulated liver IRI. Here, we aimed to investigate the effects of HOPE on liver IRI in a DCD rat model and explore the roles of HECTD3 and TRAF3 in its pathogenesis. We found that HOPE significantly improved liver damage, including hepatocyte and liver sinusoidal endothelial cell injury, and reduced DCD liver inflammation. Mechanistically, both the DOC and HECT domains of HECTD3 directly interacted with TRAF3, and the catalytic Cys (C832) in the HECT domain promoted the K63-linked polyubiquitination of TRAF3 at Lys138. Further, the ubiquitinated TRAF3 at Lys138 increased oxidative stress and activated the NF-κB inflammation pathway to induce liver IRI in BRL-3A cells under hypoxia/reoxygenation conditions. Finally, we confirmed that the expression of HECTD3 and TRAF3 was obviously increased in human DCD liver transplantation specimens. Overall, these findings demonstrated that HOPE can protect against DCD liver transplantation-induced-liver IRI by reducing inflammation via HECTD3-mediated TRAF3 K63-linked polyubiquitination. Therefore, HOPE regulating the HECTD3/TRAF3 pathway is a novel target for improving IRI in DCD liver transplantation.

Highlights

Owing to the shortage of donor organs, marginal donor allografts are increasing becoming the main source of grafts[1]
These findings demonstrated that hypothermic oxygenated perfusion (HOPE) can protect against donations after cardiac death (DCD) liver transplantation-induced-liver ischemia-reperfusion injury (IRI) by reducing inflammation via HECTD3-mediated Tumor necrosis factor receptor-associated factor 3 (TRAF3) K63-linked polyubiquitination
We and other researchers have previously demonstrated that HOPE has a significant improved liver IRI after transplantation by regulating inflammation[1,8,10]; the underlying protective mechanism is unclear

Summary

Introduction

Owing to the shortage of donor organs, marginal donor allografts are increasing becoming the main source of grafts[1]. Liver allografts from donations after cardiac death (DCD) may increase the pool of organs by as much as 20%2. Warm ischemia, cold ischemia, and subsequent reperfusion phases during DCD liver transplantation can lead to inevitable ischemia-reperfusion injury (IRI), which results in delayed graft dysfunction and decreases long-term graft survival[3,4,5]. In the subsequent reperfusion phase, the excessive activation of immune responses causes oxidative stress and, local. Zhou et al Cell Death and Disease (2021)12:211 and systemic inflammation, thereby aggravating liver damage[6,7]. Hypothermic oxygenated perfusion (HOPE) has been demonstrated to decrease oxidative stress and cellular inflammation in DCD liver transplantation[1,8,9,10]. Ubiquitin modification plays an indispensable role in regulating inflammation and immune responses[11]

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