The Effect Of Fluid Shear Stress On The MRNA Of P-selectin In Human Umbilical Vein Endothelial Cell

At present, many research focus on the mechanism of atherosclerosis. As a barrier between blood and tissue, endothelial cell is sensitive to the hematological components and blood stream status. What's more endothelial cells play a key role in the formation of vascular dysfunction. They are involved in atherogenesis.It has been proved that the physiological function of endothelial cells can be influenced by fluid shear stress. P-selectin is one of the selectin family members, which can result in the adhesion between leucocytes and endothelial cells. It has been detected in atherosclerosis plaques. But it has not been studied how fluid shear stress affects the expression of P-selectin mRNA in endothelial cells.Objectives: To investigate whether fluid shear stress can influence the expression of P-selectin mRNA in endothelial cells. Methods: To study the effect of fluid shear stress on P-selectin mRNA in human umbilical vein endothelial cells (HUVECs) in vitro, we used a parallel-plate flow chamber system to imitate the human blood stream in pathophysiological conditions. Being put into the flow chamber, HUVECs were exposed to shear stress 0, 4, 12 and 28 dyne/cm2 and for 0, 10, 30, 60 and 120 min, respectively. Reversal transcription-polymerase chain reaction (RT-PCR) was used to evaluate the expression of P-selectin mRNA. Results: Treated with flow shear stress in different intensity, the expression of P-selectin mRNA was significantly different in HUVECs (F=69.281, P=0.000). When the treating intensity is 4 dyne/cm2, P-selectin mRNA expression is at the lowest level (=0.487), even lower than that in 0 dyne/cm2. At 28 dyne/cm2, the P-selectin mRNA expression is the highest (=0.806). P-selectin mRNA is upregulated while the intensity increaed from 4 to 28 dyne/cm2. This result suggests that fluid shear stress could upregulate the mRNA expression of P-selectin in this rang. The mRNA level of P-selectin was significantly increased in HUVECs in 10 min compared with in 0 min (P<0.01). But there were no differece among 10, 30, 60 and 120 min. Conclusion: In this study, we found that fluid shear stress could affect the expression of P-selectin mRNA in HUVECs. The expression of P-selectin mRNA was decreased when fluid shear stress is from 0 to 4 dyne/cm2, while increased when that is from 4 to 28 dyne/cm2. In addition, P-selectin mRNA expression has no relationship with the treating period.