Umbilical Vein EC Culture and Transfection

Pooled human umbilical vein ECs cultured in proprietary media (PromoCell Growth Medium, ready-to-use) for 2 to 5 passages. For experiments, glass-bottomed imaging dishes were exposed to deep UV light for 6 minutes and coated with Poly-D-Lysine for a minimum of 20 minutes. Small interfering RNA was introduced into primary human umbilical vein ECs using the Neon transfection system (ThermoFisher). See Supplementary Table 5 for sources of siRNA. All siRNA were resuspended to a 20 μmol/L stock concentration and used at 0.5 μmol/L. Normal human lung fibroblasts and HEK-A were maintained in DMEM supplemented with 10% fetal bovine serum and antibiotics. Both normal human lung fibroblasts and HEKs were used up to 15 passages. All cells were maintained in a humidified incubator at 37 °C and 5% CO₂.