PROJECT SUMMARY/ABSTRACT Out-of-hospital cardiac arrest is a significant public health burden, affecting over 350,000 people annually in the United States. Survival remains less than 12% and long-term neurological deficit is common in survivors. Currently no drugs exist to reverse myocardial stunning or improve long-term survival with good neurological outcome, which highlights an urgent and unmet need in resuscitation. Pharmacological stimulation of cardiac glucose oxidation represents a potential key strategy for enhancing recovery and reversing a pathological increase in fatty acid oxidation which occurs after ischemia, although agents such as dichloroacetate are limited by toxicity. A novel cell-penetrating peptide, TAT-PHLPP9c, was developed which rapidly gains access to tissues and selectively inhibits PHLPP1, thereby enhancing activation of Akt. In a mouse model of cardiac arrest, intravenous administration of TAT-PHLPP9c during CPR improves recovery of cerebral blood flow and enhances activation of both Akt and pyruvate dehydrogenase in the heart and brain. In swine, administration of TAT- PHLPP9c during mechanical CPR significantly improves 24-hour survival. Agents such as TAT-PHLPP9c that quickly gain access to tissues to improve survival would represent a significant advancement in resuscitation. Targeting metabolic dysfunction with TAT-PHLPP9c may decrease the circuit flow rate needed for successful eCPR, which will allow for narrow cannulas to be used and may lead to wider availability of eCPR. Using high resolution magnetic resonance methods, this project will investigate the mechanisms underlying TAT-PHLPP9c cardioprotection and neuroprotection. The following hypotheses will be tested: 1) TAT-PHLPP9c directly targets the heart and enhances functional recovery from ischemia; 2) TAT-PHLPP9c decreases fatty acid oxidation in the post-ischemic heart; 3) TAT-PHLPP9c treatment during low flow eCPR improves cardiac arrest survival, neurological recovery, cerebral blood flow, and cerebral metabolism; 4) TAT-PHLPP9c reduces the circuit flow rate required for successful eCPR; and 5) TAT-PHLPP9c-mediated Akt activation in peripheral blood leukocytes reflects Akt activation in tissues from vital organs. These hypotheses will be tested using a Langendorff model of rat heart ischemia/reperfusion injury, a swine model of eCPR, and a mouse model of cardiac arrest. It is our ultimate goal to translate these findings to emergency resuscitative care in order to save lives and minimize long- term neurological disability after cardiac arrest. A comprehensive training plan will develop the principal investigator’s skills as a physician-scientist under the guidance of the sponsor (Terry L. Vanden Hoek, MD, University of Illinois at Chicago) and co-sponsor (Henry R. Halperin, MD, MA, Johns Hopkins University).