Effects of lipoprotein(a) and low density lipoprotein on growth of mitogen-stimulated human umbilical vein endothelial cells.

We investigated the effects of lipoprotein(a) (Lp(a)) and low density lipoprotein (LDL) on proliferation of human umbilical vein endothelial cells (HUVECs). Both Lp(a) and LDL stimulated the growth of HUVECs synergistically with basic fibroblast growth factor and insulin in a dose-dependent manner. The potency of Lp(a) to promote the cell proliferation was 40% less than that of LDL. Addition of anti-transforming growth factor-beta 1 neutralizing antibody into the medium could not diminish the difference of HUVECs proliferation by Lp(a) and LDL. However, addition of anti-LDL receptor antibody suppressed HUVECs proliferation to the same level and sequestered the difference by the two lipoproteins. Moreover, cholesteryl ester content incubated with Lp(a) was 50% less than that with LDL. These results suggest that Lp(a) has less effect on HUVECs proliferation and cholesterol delivery to the cells than LDL. Therefore, Lp(a) may play a role as an atherogenic lipoprotein by delaying the repair of endothelium after injury.