Abstract: TH-OR125

A Proteomic Analysis of Kidneys Subjected to Normothermic Ex-Vivo Kidney Perfusion Demonstrates Metabolism and Energy Production Are Important Determinants of Kidney Function Following Warm Ischemia

Session Information

Category: Transplantation

  • 1701 Transplantation: Basic and Experimental

Authors

  • Reid, Shelby, Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
  • Urbanellis, Peter, University of Toronto, Toronto, Ontario, Canada
  • Hamar, Matyas, UHN/TGH/SickKids, Toronto, Ontario, Canada
  • Kaths, Moritz, University Hospital Essen, Essen, Germany
  • Robinson, Lisa, The Hospital for Sick Children, Toronto, Ontario, Canada
  • Selzner, Markus, Toronto General Hospital, Toronto, Ontario, Canada
  • Scholey, James W., University of Toronto, Toronto, Ontario, Canada
  • Konvalinka, Ana, University Health Network, University of Toronto, Toronto, Ontario, Canada
Background

Organ shortage remains a problem for kidney transplantation, leading to an increased use of marginal grafts. These grafts tolerate cold storage poorly, resulting in more severe ischemia-reperfusion injury (IRI) and a higher rate of delayed graft function (DGF). This has led to the development of alternative preservation techniques that aim to reduce IRI and the rate of DGF. Normothermic ex-vivo kidney perfusion (NEVKP) is a storage method that may result in improved kidney function and limit IRI compared to traditional static-cold-storage (SCS).

Methods

Porcine kidneys were explanted, subjected to 30-minutes of warm ischemia, and stored via NEVKP or SCS for 8 hours, followed by re-implantation. Creatinine and BUN were measured in serum samples daily, until post-operative day (POD) 10. Kidney biopsies were taken at time of explant, 30 minutes following anastomosis and on POD3. Biopsy tissue was subjected to proteomic analysis on Q-Exactive mass spectrometer. Cytoscape software was used for enrichment analysis of differentially expressed proteins.

Results

Serum creatinine and BUN measurements demonstrated lower values in NEVKP grafts compared with SCS kidneys with POD10 levels in the NEVKP group comparable to their baseline values. Proteomic analysis allowed for quantification of 6179 proteins in total. Eighty proteins were differentially expressed (p<0.05; paired t-test) between NEVKP and SCS biopsies at 30 minutes following anastomosis with top enriched pathways relating to regulation of metabolism in NEVKP and energy production in SCS (p<0.05; Cytoscape pathway analysis). Analysis of samples from POD3 revealed 112 differentially expressed proteins with top enriched pathways relating to metabolism and catabolism in both groups.

Conclusion

NEVKP leads to improved kidney function compared to traditional SCS. Metabolism, energy production and catabolism represent key biological processes differentiating NEVKP from SCS proteome. Better understanding and manipulation of metabolism in kidney grafts may lead to amelioration of IRI and prevention of DGF.