Gene expression is altered in perfused arterial segments exposed to cyclic flexure ex vivo

Certain regions of coronary and other arteries undergo cyclic flexure due to attachment to the heart or crossing of joints. Such motion gives rise to fluctuations in transmural stress and luminal shear stress. It is well known that cyclic variation of these biomechanical forces influences many aspects of vascular cell biology including gene expression. The purpose of this work was to investigate the hypothesis that cyclic flexure of arterial segments influences their gene expression. Bilateral porcine femoral arteries were obtained fresh from the abattoir. One vessel was mounted in an ex vivo perfusion system and subjected to an intraluminal pressure of 60 mmHg and flow of 50 ml/min to serve as a control. The other vessel was mounted in a second perfusion system with similar hemodynamic conditions, but also subjected to controlled cyclic bending consistent with that found in coronary arteries in vivo. Reverse transcriptase-polymerase chain reaction analysis demonstrated that E-selectin and matrix metalloproteinase-1 (MMP-1) were consistently and significantly downregulated in the specimens subjected to 4 h of cyclic bending as compared to the control (n = 8, p < 0.05). Our results show that cyclic flexure of arterial segments in vitro may influence their gene expression. Further investigation should follow this novel observation and focus on other known mediators to more carefully elucidate the consequence of cyclic flexure on arterial pathobiology.