ENDOTHELIAL NO-SYNTHASE GENE TRANSFER RESTORES REGENERATIVE CAPACITY OF ENDOTHELIAL PROGENITOR CELLS FROM PATIENTS WITH CORONARY ARTERY DISEASE

Background: Endothelial progenitor cells (EPCs) from patients with coronary arterydisease (CAD) or CAD risk factors exhibit greatly reduced regenerativecapacity, which likely contributes to the relatively modest nature of the benefit seen in recent clinical trials of autologous cell therapy postmyocardial infarction. We hypothesized that eNOS overexpression will improve the functional capacity of EPCs from these patients. Methods and Results: EPCs were isolated from the peripheral blood ofpatients with high Framingham risk scores (FRS > 15%) and were transducedusing lentiviral vectors containing either eNOS or GFP (sham). We observed that eNOS-transduction significantly improved migration toward chemotactic factors(VEGF and SDF-1) compared to sham-transduced cells. EPCs were co-cultured witha mature endothelial cell (EC) line on Matrigel to measure their pro-angiogenicfunction in vitro. eNOS-transduced EPCs induced longer angiogenic tubes withmore branch points compared to sham-transduced cells, and exhibited higherassociation with EC tubes. We did not observe a significant difference in the adhesion of EPCs to an EC layer pre-activated with TNF-?, suggesting that the association to angiogenictubes is likely through a different mechanism. In immunodeficient mice, eNOS-transduced EPCs resulted in significant improvement in ischemic hindlimbperfusion compared to sham-transduced cells. PCR arrays revealed changes in angiogenic and pro-survivalgene expression in response to eNOS overexpression, providing preliminaryinsight into the mechanisms underlying its beneficial actions. Conclusions: The present data show that reduced regenerative activity of EPCsisolated from CAD patients can be significantly improved by the overexpressionof eNOS. The combination of cell and gene therapy may improve the efficacy ofautologous cell therapies for cardiovascular disease