Abstract 12709: Dynamics of Flow-Responsive Kinase Cε Modulates Glycolytic Metabolites to Promote Vascular Repair

Hemodynamic shear stress has recently been reported to modulate vascular development and repair via canonical Wnt--catenin signaling pathway. It is recognized that protein Kinase C isoform epsilon (PKCε) signaling in mitochondria confers cardioprotection via VEGF and eNOS activation in response to ischemia/reperfusion injury. Here, we hypothesized that shear stress-responsive PKCε signaling modulates glycolytic metabolites to promote vascular repair. By performing a metabolomic analysis, both oscillatory (OSS: ±1 dynes·cm -2 at 1 Hz) and pulsatile shear stress (PSS: 23 dynes·cm -2 at 1 Hz) significantly increased endothelial glycolytic metabolites; namely, xylitol and dihydroxyacetone ( n =6, p < 0.01 vs. control), but decreased gluconeogenic metabolites; namely, aspartic acid. Both OSS and PSS up-regulated PKCε mRNA and protein expression via VEGF receptor (n=3, p < 0.05); and constitutively active PKCε increased basal glycolysis and activity by the Seahorse assay ( n =4, p <0.01 vs. dominant negative PKCε control), implicating that shear stress-responsive PKCε modulates glycolysis. To recapitulate in transgenic Tg(flk1:GFP) zebrafish embryos, we performed micro-injection of GATA-1a morpholino oligonucleotide (MO) at 1-4 cell stage to inhibit hematopoeisis, thus decreasing viscosity and fluid shear stress. In response to tail amputation, GATA-1 MO impaired and delayed vascular repair compared with the control injection ( n =20, p <0.01 vs. control) ( Figure 1 ). Co-injection of PKCε mRNA with GATA-1a MO rescued tail repair ( n =5, p <0.05). Overall, shear stress-responsive VEGFR- PKCε signaling modulates glycolytic metabolites to influence vascular repair. Thus, hemodynamic shear stress imparts both developmental and metabolic effects to promote vascular regeneration. Figure 1. Tail repair in response to injection with GATA-1 MO or rescue by co-injection with PKCε mRNA, dpf: days post-fertilization; dpa: days post-amputation.