Dual Lactate Clearance in the Viability Assessment of Livers Donated After Circulatory Death With Ex Situ Normothermic Machine Perfusion.

Unlabelled: Perfusate lactate clearance (LC) is considered one of the useful indicators of liver viability assessment during normothermic machine perfusion (NMP); however, the applicable scope and potential mechanisms of LC remain poorly defined in the setting of liver donation after circulatory death.

Methods: The ex situ NMP of end-ischemic human livers was performed using the OrganOx Metra device. We further studied the extracellular signal-regulated kinases (phospho-extracellular signal-regulated kinase1/2 [pERK1/2]) pathway and several clinical parameters of these livers with successful LC (sLC, n = 5) compared with non-sLC (nLC, n = 5) in the perfusate (<2.

NRF2 assessment in discarded liver allografts: A role in allograft function and salvage.

Antioxidant defence mechanisms, such as the nuclear factor-erythroid 2-related-factor-2 (NRF2) axis, are integral to oxidative stress responses and ischemic injury. Hepatic antioxidant capacity is contingent on parenchymal quality, and there is a need to develop new insights into key molecular mechanisms in marginal liver allografts that might provide therapeutic targets. This study examines the clinical relevance of NRF2 in donor livers and its response to normothermic machine perfusion (NMP).

A Novel Multidrug Combination Mitigates Rat Liver Steatosis Through Activating AMPK Pathway During Normothermic Machine Perfusion.

Background: Hepatic steatosis is now the leading cause of liver discards in deceased donors. Previous studies [Yarmush formula (Y) defatting] have successfully reduced the fat content by treating rat steatotic livers on extracorporeal normothermic machine perfusion (NMP) with a multidrug combination including the GW compounds that were linked to an increased risk of carcinogenesis.

Methods: We developed a novel multidrug combination by replacing the GW compounds with 2 polyphenols, epigallocatechin-3-gallate (E) and resveratrol (R).

Antithrombin Perfluorocarbon Nanoparticles Improve Renal Allograft Function in a Murine Deceased Criteria Donor Model.

Background: Over 100 000 patients await renal transplantation and 4000 die per year. Compounding this mismatch between supply and demand is delayed graft function which contributes to short-term and long-term graft failures. Previously, we reported that thrombin-targeted perfluorocarbon nanoparticles (PFC-NP) protect kidneys from ischemic renal injury after transient arterial occlusion.

Enhanced immunosuppression improves early allograft function in a porcine kidney transplant model of donation after circulatory death.

It remains controversial whether renal allografts from donation after circulatory death (DCD) have a higher risk of acute rejection (AR). In the porcine large animal kidney transplant model, we investigated the AR and function of DCD renal allografts compared to the non-DCD renal allografts and the effects of increased immunosuppression. We found that the AR was significantly increased along with elevated MHC-I expression in the DCD transplants receiving low-dose immunosuppression; however, AR and renal function were significantly improved when given high-dose immunosuppressive therapy postoperatively.

Anti-CD47 monoclonal antibody therapy reduces ischemia-reperfusion injury of renal allografts in a porcine model of donation after cardiac death.

We investigated whether blockade of the CD47 signaling pathway could reduce ischemia-reperfusion injury (IRI) of renal allografts donated after cardiac death (DCD) in a porcine animal model of transplantation. Renal allografts were subjected to 30 minutes of warm ischemia, 3.5 hours of cold ischemia, and then perfused with a humanized anti-CD47 monoclonal antibody (CD47mAb) in the treatment group or HTK solution in the control group (n = 4/group).

CD47 blockade reduces ischemia/reperfusion injury in donation after cardiac death rat kidney transplantation.

Modulation of nitric oxide activity through blockade of CD47 signaling has been shown to reduce ischemia-reperfusion injury (IRI) in various models of tissue ischemia. Here, we evaluate the potential effect of an antibody-mediated CD47 blockade in a syngeneic and an allogeneic DCD rat kidney transplant model. The donor organ was subjected to 1 hour of warm ischemia time after circulatory cessation, then flushed with a CD47 monoclonal antibody (CD47mAb) in the treatment group, or an isotype-matched immunoglobulin in the control group.

Attenuation of Ischemia-Reperfusion Injury and Improvement of Survival in Recipients of Steatotic Rat Livers Using CD47 Monoclonal Antibody.

Background: Despite the efficacy of orthotopic liver transplantation in the treatment of end-stage liver diseases, its therapeutic utility is severely limited by the availability of donor organs. The ability to rehabilitate marginal organs, such as steatotic allografts, has the potential to address some of the supply limitations of available organs for transplantation. Steatotic livers are more susceptible to ischemia-reperfusion injury (IRI), which is exacerbated by the thrombospondin-1/CD47 pathway through inhibition of nitric oxide signaling.

Novel strategy to decrease reperfusion injuries and improve function of cold-preserved livers using normothermic ex vivo liver perfusion machine.

Normothermic extracorporeal liver perfusion (NELP) can decrease ischemia/reperfusion injury to the greatest degree when cold ischemia time is minimized. Warm perfusion of cold-stored livers results in hepatocellular damage, sinusoidal endothelial cell (SEC) dysfunction, and Kupffer cell activation. However, the logistics of organ procurement mandates a period of cold preservation before NELP.

Antibody mediated therapy targeting CD47 inhibits tumor progression of hepatocellular carcinoma.

Human hepatocellular carcinoma (HCC) has a high rate of tumor recurrence and metastasis, resulting in shortened survival times. The efficacy of current systemic therapies for HCC is limited. In this study, we used xenograft tumor models to investigate the use of antibodies that block CD47 and inhibit HCC tumor growth.

BH3-only proteins contribute to steatotic liver ischemia-reperfusion injury.

Background: Ischemia-reperfusion injury (IRI) to the liver continues to be a source of significant morbidity, especially in patients with hepatic steatosis. This is a growing problem given the increase in nonalcoholic fatty liver disease. B-cell lymphoma-2 homology3-only members of the B-cell lymphoma-2 protein family are known mediators of cellular apoptosis, although their role in hepatic IRI is still emerging.

CD47 blockade reduces ischemia/reperfusion injury and improves survival in a rat liver transplantation model.

Orthotopic liver transplantation (OLT) remains the standard treatment option for nonresponsive liver failure. Because ischemia/reperfusion injury (IRI) is an important impediment to the success of OLT, new therapeutic strategies are needed to reduce IRI. We investigated whether blocking the CD47/thrombospondin-1 inhibitory action on nitric oxide signaling with a monoclonal antibody specific to CD47 (CD47mAb400) would reduce IRI in liver grafts.

Protective role of bortezomib in steatotic liver ischemia/reperfusion injury through abrogation of MMP activation and YKL-40 expression.

Steatotic liver grafts tolerate ischemia-reperfusion (I/R) injury poorly, contributing to poor survival following transplantation. However the molecular mechanisms leading to I/R injury still remain to be defined. We have previously reported that the protective effect of bortezomib towards inhibiting cold induced I/R injury in obese rat liver transplant model is through NF-κB down modulation.

Novel in vitro model for studying hepatic ischemia-reperfusion injury using liver cubes.

Background: Although inflow occlusion techniques have given surgeons the ability to carry out increasingly complex liver resections, ischemia-reperfusion (IR) injury continues to be a source of morbidity. Efforts to ameliorate IR injury have been hindered in absence of adequate preclinical models. The goal of the present study was to develop a simple, efficient, and cost-effective means of studying hepatic IR injury.

Cold preservation of isolated sinusoidal endothelial cells in MMP 9 knockout mice: effect on morphology and platelet adhesion.

Cold preservation of rat sinusoidal endothelial cells causes actin disassembly, cell rounding, matrix metalloproteinase (MMP) secretion, and platelet adhesiveness. Studies in rats suggest that gelatinases MMP2 and MMP9 are the key mediators of the injury. We created a model of cold preservation injury in mouse sinusoidal endothelial cell (MSEC) to examine the effect of cold on MSEC, specifically on MSEC from genetically deleted mice (MMP9/KO) mice.

Saline-linked surface radiofrequency ablation: factors affecting steam popping and depth of injury in the pig liver.

Summary Background Data: Saline-linked surface radiofrequency (RF) ablation is a new technique for applying RF energy to surfaces. The surface is cooled, which prevents charring and results in deeper coagulation. However, subsurface heating may lead to steam formation and a form of tissue disruption called steam popping.

Leukocyte adhesion to cold-preserved rat endothelial cells: role of actin disassembly and ICAM-1.

Leukocyte adhesion on reperfusion is a critical component of cold preservation injury, and involves increased intercellular adhesion molecule 1 (ICAM-1) expression on sinusoidal endothelial cells (SEC). This study determined whether ICAM-1 expression occurs during cold preservation and whether actin disassembly is necessary for ICAM-1 expression and leukocyte adhesion. ICAM-1 expression was measured in isolated rat SEC during 8 hours of cold preservation by immunofluorescence techniques.