Titre
Nitric oxide synthase expression in endothelial cells exposed to mechanical forces
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Ziegler, T.
Auteure/Auteur
Silacci, P.
Auteure/Auteur
Harrison, V. J.
Auteure/Auteur
Hayoz, D.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
0194-911X
Statut éditorial
Publié
Date de publication
1998-08
Volume
32
Numéro
2
Première page
351
Dernière page/numéro d’article
5
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Aug
Research Support, Non-U.S. Gov't --- Old month value: Aug
Résumé
Nitric oxide (NO) has been demonstrated to play a central role in vascular biology and pathobiology. The expression of endothelial NO synthase (eNOS) is regulated in part by blood flow-induced mechanical factors. The purpose of this study was to evaluate how the expression of eNOS mRNA correlates with the activation of its promoter in both arterial and venous endothelial cells (ECs) exposed to mechanical forces, ie, shear stress and cyclic circumferential stretch. Bovine aortic ECs (BAECs) and EA hy.926, a cell line derived from human umbilical vein ECs, were grown on the inside of elastic tubes and subjected to combinations of pressure, pulsatile shear stress, and cyclic circumferential stretch for 24 hours. Two patterns of shear stress were used: unidirectional (mean of 6, ranging from 3 to 9 dyne/cm2) and oscillatory (mean of 0.3, ranging from -3 to +3 dyne/cm2). The expression of eNOS mRNA was quantified by Northern blot analysis. Activation of the promoter was assessed by luciferase activity after the cells were transiently transfected before the flow experiments with a plasmid construct containing the fully functional eNOS promoter coupled to a luciferase reporter gene. Expression of eNOS mRNA was increased and promoter activity was enhanced by unidirectional shear stress compared with static control. Oscillatory shear slightly upregulated eNOS mRNA in BAECs, whereas it downregulated eNOS mRNA in EA hy.926. In both BAECs and EA hy.926, there was a good correlation between the increase in eNOS mRNA expression and promoter activation by unidirectional shear stress. In contrast, in both BAECs and EA hy.926 cells exposed to shear stress, cyclic stretch did not change eNOS mRNA expression, but the activation of eNOS promoter was significantly lower. Moreover, when ECs were exposed to oscillatory shear stress, there was a dramatic activation of the eNOS promoter. These results demonstrate that unidirectional shear stress increases eNOS mRNA expression via a transcriptional mechanism. However, oscillatory shear stress and cyclic stretch appear to control eNOS expression through posttranscriptional regulatory events.
Sujets
PID Serval
serval:BIB_2FC113359649
PMID
Date de création
2008-01-17T15:38:48.576Z
Date de création dans IRIS
2025-05-20T16:55:01Z