Flow-pattern-specific regulation of KLF2 gene expression in human umbilical vein endothelial cells. (a) Pulsatile flow with a sinusoidal oscillatory shear stress of 1.2 ± 0.4 Pa. (b) Reciprocating shear stress with a very low mean shear stress of 0.05 Pa (to maintain nutrient delivery) and a sinusoidal oscillation of ±0.4 Pa. (c) KLF2 mRNA levels of confluent ECs subjected to pulsatile shear at 1.2 ± 0.4 Pa (PS) for 0, 1, 4, 12, and 24 h. Note the sustain elevation of KLF-2 over the 24 h of study. (d) KLF2 mRNA levels of confluent ECs subjected to reciprocating shear at 0.05 ± 0.4 Pa (RS) for 0, 1, 4, 12, and 24 h. Note the transient elevation of KLF-2 followed by a decline to a level below control at 24 h. Based on Wang et al.36