Oxidized low density lipoprotein inhibited tissue factor pathway inhibitormRNA expression in human endothelial cells

Objective To understand the role of oxidized low density lipoprotein (OX-LD L) in the pathogenesis of thrombotic complications in atherogenesis. Methods Low density lipoprotein was isolated from normal heparinized blood by density gradient ultracentrifugation and oxidized by CuCl2. Total RNA wa s extracted from human umbilical vein endothelial cells (HUVECs) exposed to LDL or OX-LDL, using the guanidinium isothiocyanate method. The quantifica tion of tissue factor pathway inhibitor (TFPI) mRNA in HUVECs was carried o ut by reverse transcriptase-polymerase chain reaction (RT-PCR). Results HUVECs were able to express TFPI mRNA constitutively. The expressio n was not affected by LDL but was effectively inhibited by OX-LDL in a time - and dose-dependent manner. Conclusions The results suggest that oxidized LDL may play an important rol e in inducing coagulation in atherosclerotic lesions by the inhibition of e xpression of TFPI in vascular endothelial cells.