Project Summary The proposed translational studies will determine the cereroprotective efficacy of GSK2256294, an FDA- approved soluble epoxide hydrolase (sEH) inhibitor. Inhibition of sEH increases the endogenous levels of its substrate epoxyeicosatrienoates (EETs), which are endogenous brain lipid mediators with multiple mechanisms of action that are beneficial in stroke, including vasodilation, cytoprotection, anti-inflammation and suppression of platelet aggregation. Ample evidence from our group and others demonstrate that sEH inhibition and gene deletion reduce infarct size and improve functional outcomes after experimental ischemia-reperfusion injury in brain. The benefits of sEH inactivation in experimental ischemic stroke have been demonstrated in young and old male and female mice with diabetes and hypertension. Importantly, gain of function mutations in the sEH gene, called EPHX2, are associated with increased risk of ischemic stroke and worse outcome in humans, whereas carriers of a loss-of-function mutation have reduced risk of stroke and improved outcome. We have recently completed a Phase Ib clinical trial using GSK2256294 in patients with aneurysmal subarachnoid hemorrhage (SAH). The trial demonstrated that GSK2256294, administered orally for 10 days, is safe and well tolerated in critically ill patients with SAH. Although not powered for efficacy, the trial also showed trends for improvement in relevant functional outcomes. The proposed studies will test the efficacy of GSK2256294 in the NINDS Stroke Preclinical Assessment Network (SPAN) using the transient MCAO occlusion (tMCAO) model in young adult and aged mice with type 2 diabetes. PI will participate on the SPAN Steering Committee, attend all SPAN meetings and work collaboratively with all awarded sites, the Coordinating Center (CC) and NINDS Program staff to achieve the goals of the SPAN program. GSK2256294 will be synthesized by a highly experienced contract research organization (BOC Sciences) and will be provided in a sufficient amount to be tested in parallel by the entire SPAN network. PI will work with the CC to validate activity, concentration and solubility of GSK2256294 and test its efficacy in the tMCAO model in a randomized and blinded fashion. The long-term goal is to support the use of GSK2256294 in a clinical trial for acute ischemic stroke (AIS) and advance its use in AIS patients. Because GSK2256294 is already approved by the FDA and has an established safety record in humans including in hemorrhagic stroke patients, it can be advanced rapidly for testing in clinical trials of AIS if efficacy is confirmed through rigorous testing by the SPAN network.