Expression of ephrinB2 in stretch-stimulated endothelial cells. Human umbilical vein endothelial cells (HUVECs) were exposed to cyclic stretch (15%, 0.5 Hz) for 3 and 18 hours, respectively. EphrinB2 protein abundance (A) as well as mRNA expression (B) analyses revealed that cyclic stretch up-regulates ephrinB2 in these cells (A, *P < .05 vs control, n = 5; B, *P < .05 vs control; n = 3). β-Actin as well as the housekeeping gene RPL32 were used as internal standards. (C) Exposure of HUVECs to cyclic stretch (15%, 0.5 Hz, 3 hours) resulted in an increased expression of ephrinB2 mRNA that was completely abrogated after pretreatment with an AP-1 decoy oligodeoxynucleotide (ODN; 10 μM, 4-hour preincubation; **P < .01; n = 3; n.s., not significant). Messenger RNA expression of the housekeeping gene GAPDH was used as an internal standard.