NADPH oxidase activation played a critical role in the oxidative stress process in stable coronary artery disease

Objectives: The study was designed to investigate the oxidative stress levels of endothelial progenitor cells (EPCs) in stable coronary artery disease (CAD) and to explore the underlying mechanisms of NADPH oxidase activation and subsequent EPCs dysfunction.

Methods: EPCs were isolated from patients with stable CAD (n=50) and matched healthy volunteers (n=50). NADPH oxidase activation was detected by measuring the expression of each subunit using western blotting and qPCR analyses and the membrane translocation of p47^phox using immunofluorescence. The in vivo angiogenesis capacity was evaluated using immunofluorescence by transplanting EPCs into a rat hind limb ischemia model. The PKC inhibitor GÖ-6983 was used to determine the role of PKC in NADPH oxidase activation.

Results: Oxidative stress level was increased and the in vivo angiogenesis capacity was impaired in EPCs obtained from CAD subjects with the activation of NADPH oxidase. P47^phox membrane translocation increased in CAD group vs controls. These effects were resolved by NADPH oxidase inhibition. Up-regulation of PKCα/β2 was found in EPCs from CAD subjects, PKC inhibition GÖ-6983 could reduce the expression and activity of NADPH oxidation.

Conclusions: NADPH oxidase activation via p47^phox membrane translocation played a critical role in the initiation and progression of CAD, and the PKCα/β2 signaling pathway might be involved.