Abstract 614: Shear Stress-Induced Glycolytic Metabolites Promote Vascular Repair

Introduction: Hemodynamic shear stress is intimately linked with transcriptomic and epigenomic changes to maintain endothelial homeostasis. Metabolomics studies have led to emergent metabolic biomarkers and therapeutic targets. Whether shear stress modulates metabolomic pathway to promote vascular repair remains to be investigated. Hypothesis: We hypothesized that shear stress regulates VEGF receptor-PKCε-PFKFB3 signaling-mediated glycolytic metabolites to promote vascular repair. Method and Results: Both pulsatile (PSS: 23 ± 8 dyn·cm -2 at 1 Hz) and oscillatory shear stress (OSS: 0.1 ± 3 dyn·cm -2 at 1 Hz) up-regulated PKCε expressions and the activity (* P < 0.05, n =3), whereas silencing VEGFR2 with siRNA, or treating with VEGFR inhibitor, Cediranib, attenuated shear stress-mediated PKCε expression in human aortic endothelial cells(HAEC). Constitutively active (CA)-PKCε adenovirus infection enhanced tube formation assessed by Matrigel as well as significantly increased PFKFB3 expressions promoting glycolysis, whereas the dominant negative(DN) PKCε resulted in opposite effects. Co-localization of PKCε and PFKFB3 expression was demonstrated in the endothelium of aortic arch and thoracic aorta in a New Zealand White rabbit model. In the zebrafish tail amputation model, reduction of shear stress via GATA-1a morpholino oligonucleotide(MO) injection and inhibition of PKCε expression via PKCε MO impaired vascular repair between the dorsal aorta and the dorsal longitudinal anastomotic vessel at 3 days post amputation(dpa). PKCε mRNA rescued GATA-1a MO-mediated impairment of vascular repair (* P < 0.01, n =20, ** P < 0.05, n =5). Metabolomic analysis in HAEC applied to PSS and OSS revealed modulation of a number of metabolites including increased glycolytic metabolite dihydroxyacetone, which was blocked by PKCε siRNA. Treatment with dihydroxyacetone rescued PKCε-impaired vascular repair. Conclusion: In conclusion, shear stress-mediated VEGFR-PKCε-PFKFB3 signaling increased glycolytic metabolites to mediate vascular repair.