Phospholipids separated from ox-LDL induce a decrease in TM mRNA levels in HUVECs. The crude lipid extracts (Lipid) from ox-LDL were separated as described in “Materials and methods” into the phospholipid (PL), cholesterol ester and triglyceride (CE/TG), and free cholesterol (Cho) fractions. (A) HUVECs were treated for 12 hours with each lipid fraction at a concentration equivalent to that found in 200 μg protein/mL ox-LDL. TM mRNA levels were determined by quantitative RT-PCR. The signal is expressed as the percentage of control values (CTL) after normalization to the β-actin mRNA signal. (B) Phospholipids n-PL and ox-PL were separated from crude lipid extracts of native LDL or ox-LDL, respectively, and dispersed in DMEM containing 20% FCS. HUVECs were incubated with or without increasing concentrations of the phospholipids for 12 hours and TM mRNA levels were determined. (C) The autoradiogram of panel B was analyzed by densitometry, and the data are expressed as the percentage of control values after normalization to the β-actin mRNA signal. Data show the mean ± SD from 4 independent experiments.