Pharmacological Inhibition of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) in Aged Male and Female Mice Confers Neuroprotection after Ischemic Stroke

Presentation Number: WP339

Rachel Gunraj*¹, Changjun Yang¹, John A. Howell¹, Lei Liu¹, Eduardo Candelario-Jalil^1
1Neuroscience, University of Florida, Gainesville , Florida, United States

Disclosures:
Eduardo Candelario-Jalil: No relevant financial relationships to disclose at the current time or during the last 24 months. | John A Howell: No relevant financial relationships to disclose at the current time or during the last 24 months. | Changjun Yang: No relevant financial relationships to disclose at the current time or during the last 24 months. | Rachel Gunraj: No relevant financial relationships to disclose at the current time or during the last 24 months. | Lei Liu: No relevant financial relationships to disclose at the current time or during the last 24 months. |

Abstract Body
Background: Ischemic stroke triggers the metabolic reprogramming of cells in the infarct core and surrounding penumbra. These cells experience a shift towards glycolysis as their primary metabolic pathway, as it is faster than alternative pathways and can be performed anaerobically. This allows cells to survive longer in the hypoxic, low-glucose environment; however, long-term metabolic shift has been shown to inhibit the resolution of the inflammatory response and contribute to worsening outcomes in other cardio and neurovascular diseases. 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. Previous research in our lab supports a neuroprotective effect of PFKFB3 inhibition after stroke in young male mice. Here, we investigate whether PFKFB3 blockade impacts stroke outcomes in aged female and male mice. Hypothesis: Because glycolytic shift prolongs the inflammatory response and cell death, and PFKFB3 upregulates glycolysis after stroke, inhibition of PFKFB3 is neuroprotective in ischemic stroke. Methods: We induced permanent distal middle cerebral artery occlusion in aged female and male C57BL/6J mice (18-20mo), followed by treatment with a highly selective PFKFB3 inhibitor AZ67 (30mg/kg; Female N=10; Male N=7) or vehicle (Female N=9; Male N=7). Doses were administered intraperitoneally shortly after stroke onset with three repeated i.p. doses over the course of 48h. Open field, neurological deficit scoring, and adhesive removal tasks were administered at baseline, 24h, and 48h post stroke, after which mice were euthanized by perfusion, and brains were sliced and stained with TTC to quantify infarct size. Results: Our findings show a neuroprotective effect of PFKFB3 inhibition after stroke in both female and male aged mice. Mice receiving the PFKFB3 inhibitor showed significantly smaller infarcts and improved functional recovery after stroke. These results, in conjunction with our previous data in young males, further support the hypothesis that PFKFB3 inhibitors could be a viable option for the treatment of ischemic stroke.