Early angiogenic response to shock waves in a three dimensional model of human microvascular endothelial cells culture (HMEC-1)

The exact nature of unfocused shock wave (uSW) action is not, as yet, fully understood, although a possible hypothesis may be that shock waves induce proliferation of endothelial cells and neoangiogenesis. To test this hypothesis, a three dimensional (3D) culture model on Matrigel was developed employing an human microvascular endothelial cell line (HMEC-1) which was stimulated with low energy uSW generated by a lithotripter machine. After 12 hours we observed a statistically significant increase in capillary connections subsequent to shock wave treatment with respect to the control group and a marked 3-hours down-regulation in genes involved in the apoptotic processes (BAX, BCL2LI, GADD45A, PRKCA), in cell cycle (CDKN2C, CEBPB, HK2, IRF1, PRKCA), oncogenes (JUN, WNT1), cell adhesion (ICAM-1), and proteolytic systems (CTSD, KLK2, MMP10). Our preliminary results indicate that endothelial cells in vitro quickly respond to SW, proliferating and forming vessel-like structures, depending on the energy level employed and the number of shocks released. The early decreased expression in the analysed genes could be interpreted as the “first reactive response” of the endothelial cells to the external stimuli and the prelude to the events characterizing the neo-angiogenic sequence.