Scientists from Dr. Andrew McMahon’s stem cell lab at USC have uncovered the cellular responses that occur within damaged kidneys by using a unique “TRAP” mouse model. Their research builds upon TRAP (translating ribosome affinity purification), a method used to tag ribosomes, molecular structures that contain RNA and are responsible for protein synthesis. The scientists bred special TRAP mice, tagging four different kidney cell types—cells of the nephron and vascular endothelium, interstitial pericytes and fibroblasts, and macrophages and monocytes—to reveal early signals of acute kidney injury (AKI). Their exploration of AKI at a cellular level should allow earlier detection and a better understanding of the mechanisms behind kidney injury and repair, as well as the link between AKI and chronic kidney disease.