Neovasculogenic effect of 11,12-epoxyeicosatrienoic acid involves the Akt/eNOS signaling pathways in human endothelial progenitor cells

The 11,12-epoxy-eicosatrienoic acid (11,12-EET) is formed from arachidonic acid (AA) by cytochrome P450 2J2 (CYP 2J2) epoxygenase and function as an effector in blood vessels. Human endothelial progenitor cells (hEPCs), a preceding cell source for endothelial cells (ECs), involve in the vascular tissue repairing by postnatal neovasculogenesis. However, the effect of 11, 12-EET on hEPCs and neovasculogenesis is not well known. In the current study, we examined the function of 11, 12-EET in hEPCs-mediated neovasculogenesis by using tubular formation analysis, Western Blotting assay, immunofluorescence staining, flow cytometry analysis and zymogram analysis. The results suggest that 11, 12-EET significantly induces neovasculogenesis through the phosphorylation of phosphoinositide 3-kinase (PI3-K)/Akt, endothelial-nitric oxide synthase (e-NOS) and extracellular signal-regulated kinase 1/2 (ERK 1/2) signaling pathways. 11, 12-EET up-regulates the expression of cyclin D1, cyclin -dependent kinase 4 (CDK4) and nuclear factor kappa B (NF-kappa B) proteins. Moreover, 11, 12-EET augments the expression of VE-cadherin and CD31 proteins in hEPCs. 11, 12-EET also augmented Rac1/Rho A signaling cascades, cell migration and an up-regulation of matrix metalloproteinase (MMP) -2 and -9 proteins. These results demonstrate that 11, 12-EET exerts a significant function in the neovasculogenesis of hEPCs.