Shock wave treatment enhances endothelial proliferation via autocrine vascular endothelial growth factor

Extracorporeal cardiac shock wave (SW) therapy is an effective, safe, and non-invasive therapeutic strategy for severe coronary artery disease. Shock wave therapy might affect cardiac tissues because of its ability to promote angiogenesis. In this report, we investigated if the up-regulation of vascular endothelial growth factor (VEGF) by SW therapy is involved in cell proliferation in cultured endothelial cells. After human umbilical vein endothelial cells were treated with SW, the expression and secretion of VEGF as well as cell proliferation were analyzed. We also determined the mechanism underlying SW-induced the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) using western blotting. Our results demonstrated that SW treatment induced VEGF expression in endothelial cells in a hypoxia-inducible factor 1-independent manner. Up-regulation of VEGF expression led to an increase in its concentration in the cultured medium. The autocrine VEGF in the medium activated the ERK MAPK signaling, which in turn enhanced cell proliferation. Therefore, we concluded that VEGF mediates SW application-induced endothelial cell proliferation in a cell-autonomous manner.