scholarly journals Restoring Mitochondrial Function While Avoiding Redox Stress: The Key to Preventing Ischemia/Reperfusion Injury in Machine Perfused Liver Grafts?

2020 ◽  
Vol 21 (9) ◽  
pp. 3132 ◽  
Author(s):  
Julia Hofmann ◽  
Giorgi Otarashvili ◽  
Andras Meszaros ◽  
Susanne Ebner ◽  
Annemarie Weissenbacher ◽  
...  

Mitochondria sense changes resulting from the ischemia and subsequent reperfusion of an organ and mitochondrial reactive oxygen species (ROS) production initiates a series of events, which over time result in the development of full-fledged ischemia-reperfusion injury (IRI), severely affecting graft function and survival after transplantation. ROS activate the innate immune system, regulate cell death, impair mitochondrial and cellular performance and hence organ function. Arresting the development of IRI before the onset of ROS production is currently not feasible and clinicians are faced with limiting the consequences. Ex vivo machine perfusion has opened the possibility to ameliorate or antagonize the development of IRI and may be particularly beneficial for extended criteria donor organs. The molecular events occurring during machine perfusion remain incompletely understood. Accumulation of succinate and depletion of adenosine triphosphate (ATP) have been considered key mechanisms in the initiation; however, a plethora of molecular events contribute to the final tissue damage. Here we discuss how understanding mitochondrial dysfunction linked to IRI may help to develop novel strategies for the prevention of ROS-initiated damage in the evolving era of machine perfusion.

2020 ◽  
Vol 9 (3) ◽  
pp. 846 ◽  
Author(s):  
Zoltan Czigany ◽  
Isabella Lurje ◽  
Moritz Schmelzle ◽  
Wenzel Schöning ◽  
Robert Öllinger ◽  
...  

Ischemia-reperfusion injury (IRI) constitutes a significant source of morbidity and mortality after orthotopic liver transplantation (OLT). The allograft is metabolically impaired during warm and cold ischemia and is further damaged by a paradox reperfusion injury after revascularization and reoxygenation. Short-term and long-term complications including post-reperfusion syndrome, delayed graft function, and immune activation have been associated with IRI. Due to the current critical organ shortage, extended criteria grafts are increasingly considered for transplantation, however, with an elevated risk to develop significant features of IRI. In recent years, ex vivo machine perfusion (MP) of the donor liver has witnessed significant advancements. Here, we describe the concept of hypothermic (oxygenated) machine perfusion (HMP/HOPE) approaches and highlight which allografts may benefit from this technology. This review also summarizes clinical applications and the main aspects of ongoing randomized controlled trials on hypothermic perfusion. The mechanistic aspects of IRI and hypothermic MP—which include tissue energy replenishment, optimization of mitochondrial function, and the reduction of oxidative and inflammatory damage following reperfusion—will be comprehensively discussed within the context of current preclinical and clinical evidence. Finally, we highlight novel trends and future perspectives in the field of hypothermic MP in the context of recent findings of basic and translational research.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ruta Zulpaite ◽  
Povilas Miknevicius ◽  
Bettina Leber ◽  
Kestutis Strupas ◽  
Philipp Stiegler ◽  
...  

Kidney transplantation remains the gold standard treatment for patients suffering from end-stage kidney disease. To meet the constantly growing organ demands grafts donated after circulatory death (DCD) or retrieved from extended criteria donors (ECD) are increasingly utilized. Not surprisingly, usage of those organs is challenging due to their susceptibility to ischemia-reperfusion injury, high immunogenicity, and demanding immune regulation after implantation. Lately, a lot of effort has been put into improvement of kidney preservation strategies. After demonstrating a definite advantage over static cold storage in reduction of delayed graft function rates in randomized-controlled clinical trials, hypothermic machine perfusion has already found its place in clinical practice of kidney transplantation. Nevertheless, an active investigation of perfusion variables, such as temperature (normothermic or subnormothermic), oxygen supply and perfusate composition, is already bringing evidence that ex-vivo machine perfusion has a potential not only to maintain kidney viability, but also serve as a platform for organ conditioning, targeted treatment and even improve its quality. Many different therapies, including pharmacological agents, gene therapy, mesenchymal stromal cells, or nanoparticles (NPs), have been successfully delivered directly to the kidney during ex-vivo machine perfusion in experimental models, making a big step toward achievement of two main goals in transplant surgery: minimization of graft ischemia-reperfusion injury and reduction of immunogenicity (or even reaching tolerance). In this comprehensive review current state of evidence regarding ex-vivo kidney machine perfusion and its capacity in kidney graft treatment is presented. Moreover, challenges in application of these novel techniques in clinical practice are discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daisuke Ishii ◽  
Naoto Matsuno ◽  
Mikako Gochi ◽  
Hiroyoshi Iwata ◽  
Tatsuya Shonaka ◽  
...  

AbstractThis study examined the efficacy of end-ischemic hypothermic oxygenated machine perfusion preservation (HOPE) using an originally developed machine perfusion system for split-liver transplantation. Porcine split-liver grafts were created via 75% liver resection after 10 min of warm ischemia. In Group 1, grafts were preserved by simple cold storage (CS) for 8 h (CS group; n = 4). In Group 2, grafts were preserved by simple CS for 6 h and end-ischemic HOPE for 2 h (HOPE group; n = 5). All grafts were evaluated using an isolated ex vivo reperfusion model with autologous blood for 2 h. Biochemical markers (aspartate aminotransferase and lactate dehydrogenase levels) were significantly better immediately after reperfusion in the HOPE group than in the CS group. Furthermore, the HOPE group had a better histological score. The levels of inflammatory cytokines (tumor necrosis factor-α, interferon-γ, interleukin-1β, and interleukin-10) were significantly lower after reperfusion in the HOPE group. Therefore, we concluded that end-ischemic HOPE for split-liver transplantation can aid in recovering the graft function and reducing ischemia–reperfusion injury. HOPE, using our originally developed machine perfusion system, is safe and can improve graft function while attenuating liver injury due to preservation.


2000 ◽  
Vol 279 (3) ◽  
pp. L528-L536 ◽  
Author(s):  
Scott D. Ross ◽  
Irving L. Kron ◽  
James J. Gangemi ◽  
Kimberly S. Shockey ◽  
Mark Stoler ◽  
...  

A central role for nuclear factor-κB (NF-κB) in the induction of lung inflammatory injury is emerging. We hypothesized that NF-κB is a critical early regulator of the inflammatory response in lung ischemia-reperfusion injury, and inhibition of NF-κB activation reduces this injury and improves pulmonary graft function. With use of a porcine transplantation model, left lungs were harvested and stored in cold Euro-Collins preservation solution for 6 h before transplantation. Activation of NF-κB occurred 30 min and 1 h after transplant and declined to near baseline levels after 4 h. Pyrrolidine dithiocarbamate (PDTC), a potent inhibitor of NF-κB, given to the lung graft during organ preservation (40 mmol/l) effectively inhibited NF-κB activation and significantly improved lung function. Compared with control lungs 4 h after transplant, PDTC-treated lungs displayed significantly higher oxygenation, lower Pco2, reduced mean pulmonary arterial pressure, and reduced edema and cellular infiltration. These results demonstrate that NF-κB is rapidly activated and is associated with poor pulmonary graft function in transplant reperfusion injury, and targeting of NF-κB may be a promising therapy to reduce this injury and improve lung function.


2008 ◽  
Vol 74 (8) ◽  
pp. 1009-1016 ◽  
Author(s):  
Atsunori Nakao ◽  
Gaetano Faleo ◽  
Hiroko Shimizu ◽  
Kiichi Nakahira ◽  
Junichi Kohmoto ◽  
...  

2020 ◽  
Author(s):  
Caitriona M. McEvoy ◽  
Sergi Clotet-Freixas ◽  
Tomas Tokar ◽  
Chiara Pastrello ◽  
Shelby Reid ◽  
...  

AbstractNormothermic ex-vivo kidney perfusion (NEVKP) results in significantly improved graft function in porcine auto-transplant models of DCD injury compared to static cold storage (SCS); however, the molecular mechanisms underlying these beneficial effects remain unclear. We performed an unbiased proteomics analysis of 28 kidney biopsies obtained at 3 time points from pig kidneys subjected to 30-minutes of warm ischemia, followed by 8 hours of NEVKP or SCS, and auto-transplantation. 70/6593 proteins quantified were differentially expressed between NEVKP and SCS groups (FDR<0.05). Proteins increased in NEVKP mediated key metabolic processes including fatty acid ß-oxidation, the TCA-cycle and oxidative phosphorylation. Comparison of our findings with external datasets of ischemia-reperfusion, and other models of kidney injury confirmed that 47 of our proteins represent a common signature of kidney injury reversed or attenuated by NEVKP. We validated key metabolic proteins (ETFB, CPT2) by immunoblotting. Transcription factor databases identified PPARGC1A, PPARA/G/D and RXRA/B as the upstream regulators of our dataset, and we confirmed their increased expression in NEVKP with RT-PCR. The proteome-level changes observed in NEVKP mediate critical metabolic pathways that may explain the improved graft function observed. These effects may be coordinated by PPAR-family transcription factors, and may represent novel therapeutic targets in ischemia-reperfusion injury.


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