Normothermic ex vivo kidney perfusion preserves ATP generation and graft function after warm ischemia, which is further enhanced with pharmacologic mitochondrial protection
Abstract
Background: Normothermic Ex-vivo kidney machine perfusion (NEVKP) is a novel preservation technique. We recently determined that NEVKP preserves the expression of proteins involved in mitochondrial biogenesis in kidneys. We hypothesize that ex vivo machine perfusion will replenish energy levels in mitochondria, thereby restoring mitochondrial function and reducing injury in kidney grafts. AP39, a mitochondria-targeted hydrogen sulfide donor, has been shown to stimulate mitochondrial electron transport and improve cellular bioenergetic function. Here, we investigated whether administering AP39 during NEVKP protects mitochondrial function and protects renal grafts from ischemia reperfusion injury.
Methods: Porcine kidneys were subjected to 60 minutes of warm ischemia (WI) followed by 5 hours of static cold storage (SCS) or NEVKP. The warm ischemia grafts were subsequently divided into three groups: SCS group, NEVKP group, and a group in which AP39 was additionally administered during NEVKP (NEVKP + AP39). After contralateral nephrectomy, grafts were auto-transplanted and animals were followed for 3 days. Renal function and ATP levels were assessed.
Results: All animals (n=5-6 in each group) survived the follow-up period. Grafts preserved with NEVKP had lower serum creatinine (SrCr) on postoperative day 3 compared to the SCS group. Treatment with NEVKP + AP39 further reduced SrCr when compared to the NEVKP group (SCS vs NEVKP vs NEVKP + AP39: 12.7±1.1 vs 7.6±2.8 vs 3.5±1.1 mg/dl, mean±SD). We measured ATP in biopsy-derived cell suspensions from grafts stored using SCS, NEVKP, and NEVKP + AP39. ATP levels were increased in the NEVKP group compared with SCS group at the time of pre-implantation and this level was further increased when AP39 was administered. (1.9±11.4 vs 73.6±9.3 vs 121.6±36.3 nM/10000cells).
Conclusions: For grafts subjected to warm ischemia, NEVKP has the potential to preserve ATP generation and graft function, which is further enhanced with mitochondria-targeted hydrogen sulfide donor, AP39.
source
