Differential expressed genes in biopsies from discarded human kidneys after one hour of normothermic perfusion
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ABSTRACT: Nanostring nCounter Organ Transplant Panel data on 4 cortex biopsies from discarded human kidneys analysing the differential expressed genes after one hour of normothermic perfusion
Project description:Access to liver transplantation is limited by a significant organ shortage. The recent introduction of machine perfusion technology allows surgeons to monitor and assess ex situ liver function prior to transplantation. However, many donated organs are of inadequate quality for transplant, though opportunities exist to rehabilitate organ function with adjunct therapeutics during normothermic machine perfusion. In this preclinical study, we targeted the apoptosis pathway as a potential method of improving hepatocellular function. Treatment of discarded human livers during normothermic perfusion with an irreversible pan-caspase inhibitor, emricasan, resulted in significant mitigation of ischemia-reperfusion injury at both the transcriptional and protein level. This was evidenced by significantly decreased circulating levels of the pro-inflammatory cytokines, interleukin-6, interleukin-8, and interferon-gamma, compared to control livers. Untreated livers also demonstrated transcriptional changes notable for enrichment in pathways involved in innate immunity, leukocyte migration, and cytokine-mediated signaling. Targeting of unregulated apoptosis may represent a viable therapeutic intervention for rehabilitating liver hepatocellular function during machine perfusion.
Project description:Transportable normothermic kidney perfusion for 24 hours or longer could enable viability assessment of marginal grafts, increased organ use, and improved transplant logistics. Eleven clinically declined kidneys were perfused normothermically, with 6 being from donors after brain death (median cold ischemia time 33 ± 36.9 hours) and 5 being from donors after circulatory death (36.2 ± 38.3 hours). Three kidneys were perfused using Ringer's lactate to replace excreted urine volume, and 8 kidneys were perfused using urine recirculation to maintain perfusate volume without fluid replenishment. In all cases, normothermic perfusion either maintained or slightly improved the histopathologically assessed tubular condition, and there was effective urine production in kidneys from both donors after brain death and donors after circulatory death (2367 ± 1798 mL vs 744.4 ± 198.4 mL, respectively; P = .44). Biomarkers, neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 were successfully detected and quantified in the perfusate. All kidneys with urine recirculation were readily perfused for 24 hours (n = 8) and exhibited physiological perfusate sodium levels (140.7 ± 1.2 mmol/L), while kidneys without urine recirculation (n = 3) achieved a reduced normothermic perfusion time of 7.7 ± 1.5 hours and significantly higher perfusate sodium levels (159.6 ± 4.63 mmol/:, P < .01). Normothermic machine perfusion of human kidneys for 24 hours appears to be feasible, and urine recirculation was found to facilitate the maintenance of perfusate volume and homeostasis.
Project description:Background and Aims: Liver transplantation provides an effective cure for end-stage liver disease but is hampered by a severe organ shortage. Normothermic machine perfusion (NMP) of donor livers allows dynamic preservation in addition to viability assessment prior to transplantation. Little is known about the injury and repair mechanisms induced during NMP. Therefore, we examined gene and protein expression changes in a cohort of discarded human livers during NMP, stratified by liver viability. Approach and Results: 6 human livers from donation after circulatory death (DCD) underwent 12 hours of NMP, of which 3 met viability criteria. We applied bulk transcriptomics to evaluate differences in gene expression relating to injury, repair, and regenerative responses among livers based on viability. Viable livers demonstrated robust activation of innate immunity after 3 hours of NMP followed by enrichment of pro-repair and pro-survival mechanisms. Nonviable livers demonstrated delayed and persistent enrichment of innate immune responses. Viable livers demonstrated effective induction of autophagy, the cellular repair and homeostasis pathway, compared to nonviable livers. Enrichment of pro-survival signaling was also broader in these livers. Conclusions: NMP of discarded DCD human livers results in ischemia-reperfusion injury, but importantly activates autophagy as a means of cellular repair. More pronounced activation of autophagy was seen in livers that met viability criteria for transplantation. Therapeutic targeting of the autophagy mechanism may allow rehabilitation of nonviable livers for transplantation.
Project description:Human kidneys which were accepted for transplantation and subsequently not used were subjected to ex vivo normothermic machine perfusion. During perfusion it was found the tubular epithelia synthesized fibrinogen which led to red blood cell aggregation and pathologic plugging of renal microvasculature. Sequential ex vivo delivery of plasminogen and tissue plasminogen activator (tPA) during normothermic machine perfusion effectively lyses these fibrinogen-mediated plugs.
Project description:Normothermic machine perfusion (NMP) has been successfully implemented in clinical routine of liver transplantation over the past years. However, little is known about the mechanisms how NMP impacts on the transcriptome of a human donor liver. We herein examined gene expression profiles in transplanted and non-transplanted livers over NMP time. 50 livers subjected to NMP were included in this study. 30 were transplanted after a maximum of 20 hours (h) perfusion, while 15 were discarded due to poor performance. Biopsies were collected befor eNP (PRE), 1h, 6h, 12h, 20h of NMP and after reperfusion. Next-generation sequencing was applied in liver biopsies to assess differential gene expression over perfusion time. Perfusate samples were collected regularly to monitor liver function. Comparison in differential gene expression between PRE and 20h NMP showed 415 upregulated and 727 downregulated genes. Most significantly upregulated genes were associated with extra cellular matrix organization, cell growth/differentiation processes and cytokine signaling. A set of genes were identified which were significantly differentially expressed and important for classification of non-transplanted vs transplanted biopsies, especially at 12 and 20h of NMP. A 7-gene-signature showed good separation already at 6H NMP, thereby CD274 (PD-L1) expression was ponted out as most important.
Project description:Kidneys which had been taken for transplant but later declined were perfused for up to 4 hours using a normothermic perfusion (MNP) rig or left on ice (CS) and samples were taken for RNASeq at different time points. The effect of the addition of a heamoadsorber (HA) to the perfusion rig was also assessed.
Project description:Background The gap between demand and supply of kidneys for transplantation necessitates the use of kidneys from extended criteria donors. Transplantation of these donor kidneys is associated with inferior results, reflected by an increased risk of delayed graft function. Inferior results might be explained by the higher immunogenicity of extended criteria donor kidneys. Normothermic machine perfusion (NMP) could be used as a platform to assess the quality and function of donor kidneys. In addition, it could be useful to evaluate and possibly alter the immunological response of donor kidneys. In this study, we first evaluated whether complement was activated during NMP of porcine and human discarded kidneys. Second, we examined the relationship between complement activation and pro-inflammatory cytokines during NMP. Third, we assessed the effect of complement activation on renal function and injury during NMP of porcine kidneys. Lastly, we examined local complement C3d deposition in human renal biopsies after NMP. Methods NMP with a blood-based perfusion was performed with both porcine and discarded human kidneys for 4 and 6 h, respectively. Perfusate samples were taken every hour to assess complement activation, pro-inflammatory cytokines and renal function. Biopsies were taken to assess histological injury and complement deposition. Results Complement activation products C3a, C3d, and soluble C5b-9 (sC5b-9) were found in perfusate samples taken during NMP of both porcine and human kidneys. In addition, complement perfusate levels positively correlated with the cytokine perfusate levels of IL-6, IL-8, and TNF during NMP of porcine kidneys. Porcine kidneys with high sC5b-9 perfusate levels had significantly lower creatinine clearance after 4 h of NMP. In line with these findings, high complement perfusate levels were seen during NMP of human discarded kidneys. In addition, kidneys retrieved from brain-dead donors had significantly higher complement perfusate levels during NMP than kidneys retrieved from donors after circulatory death. Conclusion Normothermic kidney machine perfusion induces complement activation in porcine and human kidneys, which is associated with the release of pro-inflammatory cytokines and in porcine kidneys with lower creatinine clearance. Complement inhibition during NMP might be a promising strategy to reduce renal graft injury and improve graft function prior to transplantation.