Evaluating the Effects of Subnormothermic Perfusion with AP39 in a Novel Blood-Free Model of Ex Vivo Kidney Preservation and Reperfusion

Abstract

The use of blood for normothermic and subnormothermic kidney preservation hinders the translation of these approaches and promising therapeutics. This study evaluates whether adding hydrogen sulfide donor AP39 to Hemopure, a blood substitute, during subnormothermic perfusion improves kidney outcomes. After 30 min of renal pedicle clamping, porcine kidneys were treated to 4 h of static cold storage (SCS-4 °C) or subnormothermic perfusion at 21 °C with Hemopure (H-21 °C), Hemopure + 200 nM AP39 (H200nM-21 °C) or Hemopure + 1 µM AP39 (H1µM-21 °C). Then, kidneys were reperfused with Hemopure at 37 °C for 4 h with metabolic support. Perfusate composition, tissue oxygenation, urinalysis and histopathology were analyzed. During preservation, the H200nM-21 °C group exhibited significantly higher urine output than the other groups and significantly higher tissue oxygenation than the H1µM-21 °C group at 1 h and 2h. During reperfusion, the H200nM-21 °C group exhibited significantly higher urine output and lower urine protein than the other groups. Additionally, the H200nM-21 °C group exhibited higher perfusate pO2 levels than the other groups and significantly lower apoptotic injury than the H-21 °C and the H1µM-21 °C groups. Thus, subnormothermic perfusion at 21 °C with Hemopure + 200 nM AP39 improves renal outcomes. Additionally, our novel blood-free model of ex vivo kidney preservation and reperfusion could be useful for studying other therapeutics.

Subnormothermic Oxygenated Machine Perfusion (24 h) in DCD Kidney Transplantation

“…Although potential benefits of SNMP on kidney graft preservation have been previously demonstrated in perfusion experiments of limited duration, 13,15,[22][23][24][25][26] this is the first study to validate this approach over such an extended interval and signals the possibility of furthermore establishing perfusion protocols for prolonged, multiday preservation. in the perfusate over time, reaching a peak of ~155 mM at 24 h (P < 0.001).…”

“…Indeed, the DCD model used in this study represents a high-risk clinical scenario frequently encountered in the current US allocation system, and our observations support the conclusion that ex vivo kidney perfusion, including SNMP, could be a viable method for rehabilitating extended criteria grafts. Although the potential benefits of SNMP on kidney graft preservation have been previously demonstrated in perfusion experiments of limited duration, 13,15,22-26 this is the first study to validate this approach over such an extended interval and signals the possibility of furthermore establishing perfusion protocols for prolonged, multiday preservation. That we report preliminary demonstration of successful cross-species perfusion of human kidneys further underscores the intrinsic simplicity, adaptability, and translational value of the SNMP platform.…”

Cellular and molecular mechanisms of cell damage and cell death in ischemia–reperfusion injury in organ transplantation

“…Additionally, mitochondrial transplantation resulted in less kidney damage while analysis of RNA sequencing showed increased mitochondrial bioenergetics and downregulated expression of pro-inflammatory genes [ 128 ]. Also, supplementation of organ preservation solution with mitochondria-targeted AP39 and sodium thiosulfate at 21ºC and 4ºC for 4 and 24 h respectively and reperfused for 4 h prevented apoptosis, protected against IRI and improved renal graft function in ex viv o porcine and rat models of kidney transplantation [ 129 , 130 ]. These experimental findings suggest that targeting the mitochondria by mitochondrial transplantation or by pharmacological approach could offer an innovative strategy against IRI in organ transplantation as well as in other aspects of mitochondrial medicine.…”

Updates in Kidney Transplantation From the 2022 Banff-Canadian Society of Transplantation Joint Meeting: Conference Report

“…69 In a subsequent in vivo pilot trial, patients undergoing DCD kidney transplantation with organs subject AP39-supplemented perfusion solution experienced decreased delayed graft function, higher urine output, and lower proteinuria as compared to standard solution. 70 Modified perfusion temperatures and AP39-supplemented perfusion solutions are inexpensive methods to potentially transform organ preservation.…”