Nucleophosmin Centered Diagnostics and Treatment of Ischemic Acute Kidney Injury

Project Summary/Abstract We discovered that NPM1, a required Bax chaperone, promotes regulated cell death and acute kidney injury (AKI) in the ischemic human kidney. The structure-function relationships (SAR) of NPM1 and its site of interaction with Bax are unknown, limiting the development of novel drugs to prevent NPM/Bax toxicity in kidney cells that are vulnerable to ischemic injury. Our integrative, cross disciplinary strategy combines cell biology with structural and medicinal chemistry to identify the features that render NPM toxic to kidney cells and localize the NPM domain responsible for binding Bax. Using protein structural analysis with x-ray crystallography, photo-labeling and cross-linking, we will optimize a novel Bax peptide for preventing and treating ischemic AKI in high risk cardiac surgery patients. In three aims, we will: (1) Characterize NPM structural features that cause regulated renal cell death; (2) Optimize drug design to inhibit NPM:Bax interaction, and (3) Select an effective therapeutic to prevent NPM:Bax toxicity in vitro and AKI in vivo. Prior validation of NPM’s causal role in ischemic injury in the human kidney and its conserved regulation during ischemic cell death across divergent species substantially increase the likelihood of translating our novel therapeutics to the clinic. Our scientific team has the combined expertise in regulated cell death, clinical and experimental AKI, peptide and assay design, x-ray crystallography, and mass spectrometry to advance our mechanistic understanding of ischemic cell death during AKI, identify targets and novel drugs for pre-clinical study, and potentially change the standard-of care for AKI patients.