Date: Saturday, June 1, 2019
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Hall C & D
*Purpose: We have shown that 24h normothermic kidney perfusion (NKP) with urine recirculation (URC) is superior to non URC for maintaining homeostasis previously. However, the underline molecular mechanism was still unelusive. Here we investigate the protein alterations between NKP with and without URC, between DBD and DCD in discarded human kidneys using proteome profiling.
*Methods: 16 discarded human kidneys (n=8 DBD and n=8 DCD) were perfused for up to 24h with URC on an NKP device; 3 discarded human kidneys were perfused similarly without URC, replacing excreted urine with Ringer’s lactate. Biopsies were taken at T0,6,12 or 24h. Protein expression changes between with/without URC and donor types were measured by label free quantitative proteomics. Proteins with 2fold changes and student’s t-test p-value<0.05 were shortlisted and function annotated by gene ontology analysis. Molecular pathways were assigned by gene enrichment analysis (PANTHER).
*Results: Compared to NKP without URC, damage-associated molecular patterns (DAMPs), contributing to ischemia reperfusion injury (IRI) were significantly downregulated in biopsies after 6h NKP with URC. Protein changes involved succinate accumulation and ROS production; mitochondrial succinate dehydrogenase proteins were significantly downregulated in URC kidneys. The protein for the gene angiotensinogen, an essential component of the renin-angiotensin system (RAS) was >2fold downregulated in kidneys perfused with URC. The protein carbonic anhydrase (CA1), an enzyme to maintain pH, was >2fold upregulated in kidneys with URC. Key-enzymes involved in glucose metabolism, including mitochondrial malate dehydrogenase (MDH) and aspartate aminotransferase (GOT), were downregulated in DCD T0 biopsies as compared to DBD T0 biopsies. After 12h and 24h of NMP, enzymes involved in glucose metabolism were more upregulated in DCD tissue as compared to DBD. Interestingly, proteins involved in gluconeogenesis, phosphoenolpyruvate carboxykinase, were more upregulated after 24h NKP in DCD as compared to DBD tissue.
*Conclusions: Proteome data suggested that NKP with URC can minimize IRI and reduces ROS production while maintaining pH compared to NKP without URC in discarded human kidneys. DCD organs, suffering from more ischemic injury, appear to benefit more from NKP as indicated by a more active glucose metabolism.
To cite this abstract in AMA style:Weissenbacher A, Huang H, Thorne A, Faro LMLo, Hunter J, Ploeg R, Coussios CC, Friend PJ, Kessler B. Proteomics Reveals Molecular Window and Metabolism of Normothermically Perfused Human Kidneys [abstract]. Am J Transplant. 2019; 19 (suppl 3). https://atcmeetingabstracts.com/abstract/proteomics-reveals-molecular-window-and-metabolism-of-normothermically-perfused-human-kidneys/. Accessed January 16, 2021.
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