Protocol TOP-Study (tacrolimus organ perfusion): a prospective randomized multicenter trial to reduce ischemia reperfusion injury in transplantation of marginal liver grafts with an ex vivo tacrolimus perfusion

Background: Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the build-up of acidic metabolites results in decreased intracellular and extracellular pH that can reach as low as 6.0-6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly impacts cardiac function. Methods: We used genetic and pharmacological methods to investigate the role of acid sensing ion channel 1a (ASIC1a) in cardiac IRI at the cellular and whole organ level. Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as well as ex vivo and in vivo models of IRI were used to test the efficacy of ASIC1a inhibitors as pre- and post-conditioning therapeutic agents. Results: Analysis of human complex trait genetics indicate that variants in the ASIC1 genetic locus are significantly associated with cardiac and cerebrovascular ischemic injuries. Using hiPSC-CMs in vitro and murine ex vivo heart models, we demonstrate that genetic ablation of ASIC1a improves cardiomyocyte viability after acute IRI. Therapeutic blockade of ASIC1a using specific and potent pharmacological inhibitors recapitulates this cardioprotective effect. We used an in vivo model of myocardial infarction (MI) and two models of ex vivo donor heart procurement and storage as clinical models to show that ASIC1a inhibition improves post-IRI cardiac viability. Use of ASIC1a inhibitors as pre- or post-conditioning agents provided equivalent cardioprotection to benchmark drugs, including the sodium-hydrogen exchange inhibitor zoniporide. At the cellular and whole organ level, we show that acute exposure to ASIC1a inhibitors has no impact on cardiac ion channels regulating baseline electromechanical coupling and physiological performance. Conclusions: Collectively, our data provide compelling evidence for a novel pharmacological strategy involving ASIC1a blockade as a cardioprotective therapy to improve the viability of hearts subjected to IRI.

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Ex-vivo perfusion as a successful strategy for reduction of ischemia-reperfusion injury in prolonged muscle flap preservation – A gene expression study

Gene ◽

10.1016/j.gene.2019.03.021 ◽

2019 ◽

Vol 701 ◽

pp. 89-97 ◽

Cited By ~ 2

Author(s):

Anne Sophie Kruit ◽

Laura Smits ◽

Angéle Pouwels ◽

Marie-Claire J.M. Schreinemachers ◽

Stefan L.M. Hummelink ◽

...

Keyword(s):

Gene Expression ◽

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Muscle Flap ◽

Gene Expression Study ◽

Expression Study ◽

Ex Vivo Perfusion ◽

Successful Strategy

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

International Journal of Molecular Sciences ◽

10.3390/ijms21093132 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3132 ◽

Cited By ~ 3

Author(s):

Julia Hofmann ◽

Giorgi Otarashvili ◽

Andras Meszaros ◽

Susanne Ebner ◽

Annemarie Weissenbacher ◽

...

Keyword(s):

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Graft Function ◽

Ros Production ◽

Machine Perfusion ◽

Redox Stress ◽

Molecular Events ◽

Regulate Cell Death

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.

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Potentiating Tissue-Resident Type 2 Innate Lymphoid Cells by IL-33 to Prevent Renal Ischemia-Reperfusion Injury

Journal of the American Society of Nephrology ◽

10.1681/asn.2017070774 ◽

2018 ◽

Vol 29 (3) ◽

pp. 961-976 ◽

Cited By ~ 33

Author(s):

Qi Cao ◽

Yiping Wang ◽

Zhiguo Niu ◽

Chengshi Wang ◽

Ruifeng Wang ◽

...

Keyword(s):

Protective Effect ◽

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Protective Role ◽

Lymphoid Cells ◽

M2 Macrophages ◽

Humanized Mouse Model

The IL-33-type 2 innate lymphoid cell (ILC2) axis has an important role in tissue homeostasis, inflammation, and wound healing. However, the relative importance of this innate immune pathway for immunotherapy against inflammation and tissue damage remains unclear. Here, we show that treatment with recombinant mouse IL-33 prevented renal structural and functional injury and reduced mortality in mice subjected to ischemia-reperfusion injury (IRI). Compared with control-treated IRI mice, IL-33–treated IRI mice had increased levels of IL-4 and IL-13 in serum and kidney and more ILC2, regulatory T cells (Tregs), and anti-inflammatory (M2) macrophages. Depletion of ILC2, but not Tregs, substantially abolished the protective effect of IL-33 on renal IRI. Adoptive transfer of ex vivo–expanded ILC2 prevented renal injury in mice subjected to IRI. This protective effect associated with induction of M2 macrophages in kidney and required ILC2 production of amphiregulin. Treatment of mice with IL-33 or ILC2 after IRI was also renoprotective. Furthermore, in a humanized mouse model of renal IRI, treatment with human IL-33 or transfer of ex vivo–expanded human ILC2 ameliorated renal IRI. This study has uncovered a major protective role of the IL-33–ILC2 axis in renal IRI that could be potentiated as a therapeutic strategy.

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