Vascular smooth muscle cells (vSMC) from the coronary artery were purchased (Lonza, Cologne, Germany) and cultured in DMEM with 4.5 g/l glucose, 10% fetal bovine serum, 2 mM L-glutamine, 1 mM sodium-pyruvate, 100 U/ml penicillin, and 100 μg/ml streptavidin (Biochrom).
Fibroblasts (CCD-32Sk) were acquired from the American Type Culture Collection (ATCC, Manassas, VA, USA) and cultivated the same as vSMCs.
Immediately before reaching a confluent monolayer, cells were detached with trypsin (Biochrom). For the experiment, cells of the 2nd and 3rd passage were seeded onto 96-well plates at a cell density of 1×105 cells/cm2.