Effect of unfractionated heparin, enoxaparin and sulodexide on the relations between secretion and expression of OPG, RANKL and vWF in HUVEC.

Heparin modulates function of vascular endothelium. We studied the effects of unfractionated heparin (UFH) vs. enoxaparin vs. sulodexide on the levels and gene expression of osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kB Ligand (RANKL) and von Willebrand factor (vWF) in Human Umbilical Vein Endothelial Cells (HUVEC) culture. HUVEC were isolated from human umbilical vein by a standard method. The supernatant concentrations (ELISA) and gene expression (Real Time-PCR) of OPG, RANKL and vWF in HUVEC were determined after incubation with various concentrations of UFH, enoxaparin and sulodexide for up to 16 hours. In control HUVEC strong positive correlation between OPG and vWF levels was observed, whereas sRANKL negatively correlated with OPG and vWF levels. Only in control HUVEC a negative correlation between the supernatant level of vWF and its gene expression was found. Already the lowest concentration of UFH caused 2.5-fold increase in OPG gene expression while higher UFH concentrations substantially increased RANKL mRNA level. A negative correlation between the OPG and sRANKL concentration was noticed in supernatant HUVEC which were incubated with enoxaparine. In conclusion, the observed interrelationships between OPG, RANKL and vWF levels in unstimulated HUVEC support the presumption of the pathophysiological links between these proteins. Of the tested heparin formulas UFH seems to be the most potent in altering the OPG, RANKL and vWF axis.