Abstract 2036: Prognostic Impact Of Pfkfb3 Expression In Endothelial Cells Insights From Peripheral Arterial Disease Patients And The Effects Of Supervised Exercise

Background: Glycolysis constitutes 85% of ATP production in endothelial cells (ECs). Although upregulating PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3), the rate-controlling enzyme for EC glycolysis, has been considered a mean to induce angiogenesis, our group found this approach ineffective or even harmful in pre-clinical peripheral arterial disease (PAD) models. However, no EC specific PFKFB3 data in human PAD patients exists. Hypothesis: EC PFKFB3 upregulation is associated with poor prognosis in PAD patients. Goal: Assess PFKFB3 in ECs and correlate its’ expression with PAD clinical presentation and outcome. Methods: CD31 (EC marker) and PFKFB3 immunostaining was performed on age-matched gastrocnemius (GA) muscle sections from healthy adult control (HA), PAD patients with intermittent claudication (IC; patients experience pain during activity), and patients with chronic limb threatening ischemia (CLTI; the most severe presentation of PAD -patients experience pain at rest with increased risk of ulcers, gangrene, and amputation). A similar approach was used on GA muscle sections from PAD patients before and after 3 weeks of supervised exercise. qPCR was done on flow sorted live CD56-CD31+ EC population from HA and CLTI GA muscle biopsies, for CD31 and PFKFB3 expression. Results: The IC presentation did not increase the %PFKFB3 + ECs (17.08 ± 1.19 vs. 14.40 ± 2.32 SEM, n=6-7/group, p= 0.69) from HA. However, in CLTI tissues, the %PFKFB3 + ECs increased vs both HA (42.01 ± 4.32 SEM vs. 14.40 ± 2.327 SEM, n=7/group, p= 0.0025) and IC (42.01 ± 4.32 SEM vs. 17.08 ± 1.19 SEM, n=6-7/group, p= 0.01). Furthermore, qPCR analysis of PFKFB3 expression in flow sorted CD56-CD31+ EC fraction from CLTI vs. HA (1.855 ± 0.084 SEM vs. 1 ± 0.1768 SEM, n=4/group, P= 0.0052). Three weeks of supervised exercise in PAD patients, with tolerance for activity, decreased the %PFKFB3 + ECs compared vs. pre-exercise values (7.02 ± 1.74 SEM vs. 18.24 ± 2.15 SEM, n= 4 /group, p= 0.0077) respectively. Conclusion: In humans with PAD, higher EC expression of PFKFB3 + uniquely associated with CLTI, but not the IC presentation. Supervised exercise, the only non-surgical approved method to improve functional performance and angiogenesis in PAD patients, reduced EC PFKFB3 expression.