Expression of PAI-1, t-PA and u-PA in cultured human umbilical vein endothelial cells derived from racial groups

To determine whether inherent fibrinolytic differences may exist in racial groups (black americans, BA vs. white americans, WA), 55 different individual racially-derived human umbilical vein endothelial cell (HUVEC) cultures (35 BA and 20 WA) were analyzed in terms of their fibrinolytic protein (t-PA, u-PA and PAI-1) antigen and mRNA levels. Values (mean ± SD) for measured fibrinolytic component levels include: cell-associated t-PA antigen (ELISA), 1.14 ± 0.82 ng/ml/8.6 × 10 5 cells/24 hr in BA and 0.70 ± 0.85 ng/ml in WA (p=0.0624); secreted t-PA antigen, 18.65 ± 17.06 ng/ml in BA and 10.37 ± 6.38 ng/ml in WA (p=0.0422); t-PA/cyclophilin mRNA ratios (Northern blot analysis), 1.90 ± 1.34 in BA and 1.32 ± 0.70 in WA (p=0.0776); cell-associated PAI-1 antigen, 71.10 ± 30.16 ng/ml/8.6 × 10 5 cells/24 hr in BA and 108.85 ± 56.89 ng/ml in WA (p=0.0022); secreted PAI-1 antigen, 1,582.13 ± 612.67 ng/ml in BA and 1,992.17 ± 711.50 ng/ml in WA (p=0.0285); 2.4 kb PAI-1/cyclophilin mRNA ratios, 0.59 ± 0.39 in BA and 0.79 ± 0.31 in WA (p=0.1085); 3.4 kb PAI-1/cyclophilin mRNA ratios, 0.70 ± 0.47 in BA and 0.77 ± 0.54 in WA (p=0.6322). These combined data suggest that cultured HUVECs from BA express significantly higher levels of t-PA, lower levels of PAI-1 and ∼1.72-fold lower molar ratio of PAI-1 t-PA antigen (183.99 ± 168.81 vs. 315.92 ± 164.99) (p < 0.05) than cultured HUVECs from WA, presumably reflecting an apparent inherent increased fibrinolytic potential in cultured HUVEC derived from BA.