TM antigen and its mRNA levels in HUVECs treated with ox-PAPC, native PAPC, or the reduced form of ox-PAPC. (A-B) HUVECs were incubated with various concentrations of ox-PAPC or 100 μg/mL native PAPC for 12 hours. TM antigen (A) and its mRNA (B) levels in the cells were assayed by the method as described in “Materials and methods.” Data shown in panel A are the mean from 3 independent experiments. (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 shown represent the mean ± SD from 4 independent experiments. (D) HUVECs were treated with 50 μg/mL ox-PAPC for various times, and TM mRNA levels were quantitated by the RT-PCR method. (E) ox-PAPC was reduced by incubation with 500 μg sodium borohydride for 5 minutes, and the reduced form of ox-PAPC was extracted and dispersed in DMEM as described in “Materials and methods.” HUVECs were treated with 50 μg/mL ox-PAPC or 50 μg/mL reduced form of ox-PAPC for 12 hours, and TM mRNA levels were assayed. (F) The autoradiogram of panel E was analyzed by densitometry, and the data are expressed as the percentage of control values after normalization to the β-actin mRNA signal. Data shown are the mean ± SD from 4 independent experiments.