Abstract WP310: Pharmacological Inhibition of 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 3 (PFKFB3) is Neuroprotective in an Acute Mouse Model of Ischemic Stroke

Abstract

Background: A major hallmark of stroke is the dysregulation of normal metabolic functions. In the ischemic environment, cells shift towards glycolysis, a metabolic pathway associated with a prolonged inflammatory response and delayed apoptotic cell death. One primary driver of glycolysis is 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). This enzyme is upregulated after injury and synthesizes fructose-2,6-biphosphate, an allosteric regulator of phosphofructokinase-1, which catalyzes the first rate-limiting step in glycolysis. Studies in other disease models support a neuroprotective effect of PFKFB3 inhibition. Hypothesis: Because aberrant glycolysis contributes to inflammation and cell death and PFKFB3 upregulates glycolysis after injury, inhibition of PFKFB3 is neuroprotective in stroke. Methods: We administered a 45-minute transient middle cerebral artery occlusion in male C57BL/6J mice, followed by treatment with a highly selective PFKFB3 inhibitor AZ67 (N=10) or vehicle (N=11). The vehicle or the inhibitor (30mg/kg) were administered starting at the onset of reperfusion via the jugular vein with three repeated retro-orbital doses over the course of 48h. Open field, vertical grid, weight test, and neural deficit scorings were conducted at 24 and 48h post-stroke, after which the mice were euthanized by perfusion with saline and stained with TTC to quantify infarct size. Results: Our findings show a neuroprotective effect of PFKFB3 inhibition in ischemic stroke with improved functional and behavioral recovery and smaller infarct sizes. These results support the hypothesis that PFKFB3 inhibitors may be used as a novel pharmacological treatment for reducing delayed cell death after ischemic stroke. Future studies are underway to investigate the molecular mechanisms and cell types involved in the protection conferred by PFKFB3 blockade in the context of ischemic stroke.