Spatiotemporal transcriptomic analysis during cold ischemic injury to the murine kidney reveals compartment-specific changes.

Kidney transplantation is the gold standard treatment strategy for end-stage renal disease. Deceased donor kidneys usually undergo cold storage until kidney transplantation, leading to cold ischemia injury that may contribute to poor graft outcomes. However, the molecular characterization of potential mechanisms of cold ischemia injury remains incomplete. To bridge this knowledge gap, we leveraged spatial transcriptomics technology to perform full transcriptome characterization of cold ischemia injury (0-48 hours) using a murine model. We developed a computational workflow to identify spatiotemporal transcriptomic changes that accompany the injury pathophysiology in a compartment-specific manner. We identified potential metabolic reprogramming preferentially within the kidney inner medulla displaying strong oxidative phosphorylation signature in an ischemic environment. We found commonalities between the spatiotemporal transcriptomic presentation of cold ischemia and warm ischemia‒reperfusion injury, including an induction of an anti-viral like immune response throughout the renal tissue. Altogether, these systems-level biological insights enabled by our full transcriptome temporal characterization unveil a molecular basis for how cold ischemia injury may negatively affect kidney outcomes. Moreover, our spatial analyses highlight pathological developments deep within the renal tissue, suggesting potential opportunities for new insights beyond biopsy-focused superficial tissue examinations. We also developed an interactive online browser at https://jef.works/vitessce-cold-ischemia/ to facilitate exploration of our results by the broader scientific and clinical community.