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

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.

HIF-1α Induces HECTD2 Up-Regulation and Aggravates the Malignant Progression of Renal Cell Cancer via Repressing miR-320a

“…Hypothermic oxygenated perfusion (HOP) prevents ischemia-reperfusion-mediated liver damage. The underlying mechanism revealed that both the DOC and HECT domains of HECTD3 induce polyubiquitination of TRAF3 at Lys138, and ubiquitinated TRAF3 promotes oxidative stress and inflammation (Zhou et al, 2021). Here, we showed that HECTD2 upregulation enhances RCC progression both in vitro and in vivo, and HIF-1α had a positives relationship with HECTD2 and increased its expression.…”

Progress and Prospects of Non-Canonical NF-κB Signaling Pathway in the Regulation of Liver Diseases

“…Recombinant RANKL ameliorates HIRI [55]. TRAF3 plays an essential role in HIRI [56,57]. Hepatocytespecific knockout of TRAF3 ameliorates cell death and immune responses both in vitro and in vivo hepatic I/R models, whereas myeloid cell-specific deletion of TRAF3 does not affect HIRI [58].…”

“…Hepatic ischemia/reperfusion disturbs liver function, leading to irreversible damage and even multiple organ failure [86]. In HIRI, CD40 [48][49][50][51][52][53], OX40 [54], RANKL [55], TRAF2 [87,88], TRAF3 [56][57][58], cIAP1 [89], RELB [59] are upregulated in the liver. CD40, as an M1 macrophage marker gene, is increased in purified Kupffer cells in mice under IR conditions [53].…”

Novel Targets and Therapeutic Strategies to Protect Against Hepatic Ischemia Reperfusion Injury

“…The defatted liver transplantation can be safely used in liver transplantation in rats, which may lay a solid foundation for its subsequent clinical application. Another experimental animal study by Zhou et al ( 83 ) indicated that HOPE alleviated DCD rat liver I/R by suppressing HECTD3-mediated TRAF3 polyubiquitination, which might be a useful target for improving IRI in DCD liver transplantation. To further investigate the clinical utility of HOPR for DCD liver, Switzerland scholars Dutkowski et al ( 84 ) firstly performed a clinical trial involving eight patients with end stage liver diseases receiving DCD liver transplantation, and found that the application of HOPE for DCD livers appeared to be well-tolerated and easy-to-use, providing better clinical outcomes than the matched liver grafts from cardiac death donors.…”