Abstract: TH-PO093
Cold Storage-Mediated Global (Phospho)Proteome Changes Following Kidney Transplantation
Session Information
- AKI: Mechanisms - I
November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Author
- Parajuli, Nirmala, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
Group or Team Name
- Parajuli Research Team
Background
Extended cold storage (CS) of deceased donor kidney is associated with poor long-term outcome following transplantation. Previously, we showed impaired protein homeostasis and graft dysfunction following 18-hr CS combined with transplantation. However, the precise mechanisms responsible for this CS-mediated renal graft damage are largely unknown. We hypothesize that CS contributes to covalent post-translational modification of renal proteins leading to impaired protein homeostasis after transplantation.
Methods
Isolated donor rat kidneys were cold-stored for 0- or 18-hr followed by transplantation to recipient rats. Kidney transplant homogenates were digested and the resulting peptides were labeled using a tandem mass tag 10-plex isobaric label reagent set and enriched using phosphopeptide enrichment kits. Both enriched and un-enriched isobaric labeled peptides were employed for mass spectrometric analysis. Differential expression and enrichment analyses were performed on (phospho)proteomics data individually followed by integrative analysis.
Results
Quantitative proteomics data revealed that 18-hr CS plus transplantation (CS+transplant) resulted in the significant dysregulation of 378 or 256 renal proteins (Log2 FC =1, Adjusted p value = 0.05) when compared to sham or autotransplantation (ATx; transplant with 0-hr CS), respectively. Gene set enrichment analysis of renal proteomes showed activation of 12 pathways (e.g., complement and coagulation) and suppression of 15 pathways (e.g., glutathione) in the CS+transplant group when compared to sham or ATx groups. Differential abundance analysis with phosphoproteomics data showed that 232 or 143 proteins were differentially phosphorylated in the CS+transplant group when compared to the sham or ATx group, respectively. Integrated analysis of differentially regulated global proteomes (N=378 or N=256) and phosphoproteomes (N=232 or N=143) identified only 8 or 2 renal proteins that were differentially phosphorylated when comparing CS+transplant with the sham or ATx groups, respectively.
Conclusion
These data suggest, for the first time, that CS contributes to altered renal (phospho)proteomes, which may lead to disrupted protein homeostasis and graft dysfunction. New studies designed to target the affected renal phosphoproteomes during CS may have promising therapeutic implications for prolonging outcome after renal transplantation.
Funding
- NIDDK Support