Identification of a cis -Element Regulating Transcriptional Activity in Response to Fluid Shear Stress in Bovine Aortic Endothelial Cells

The key mechanism responsible for maintaining cell volume homeostasis is activation of volume-regulated anion current (VRAC). The role of hemodynamic shear stress in the regulation of VRAC in bovine aortic endothelial cells was investigated. We showed that acute changes in shear stress have a biphasic effect on the development of VRAC. A shear stress step from a background flow (0.1 dyn/cm2) to 1 dyn/cm2 enhanced VRAC activation induced by an osmotic challenge. Flow alone, in the absence of osmotic stress, did not induce VRAC activation. Increasing the shear stress to 3 dyn/cm2, however, resulted in only a transient increase of VRAC activity followed by an inhibitory phase during which VRAC was gradually suppressed. When shear stress was increased further (5–10 dyn/cm2), the current was immediately strongly suppressed. Suppression of VRAC was observed both in cells challenged osmotically and in cells that developed spontaneous VRAC under isotonic conditions. Our findings suggest that shear stress is an important factor in regulating the ability of vascular endothelial cells to maintain volume homeostasis.

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The Morphological Responses of Cultured Bovine Aortic Endothelial Cells to Fluid-Imposed Shear Stress under Sparse and Colony Conditions.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.63.838 ◽

1997 ◽

Vol 63 (607) ◽

pp. 838-845 ◽

Cited By ~ 1

Author(s):

Noriyuki KATAOKA ◽

Shingo UJITA ◽

Keishu KIMURA ◽

Masaaki SATO

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Morphological Responses ◽

Aortic Endothelial

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Bovine Caveolin-2 Cloning and Effects of Shear Stress on Its Localization in Bovine Aortic Endothelial Cells

Endothelium ◽

10.1080/10623320490512282 ◽

2004 ◽

Vol 11 (3-4) ◽

pp. 189-198 ◽

Cited By ~ 1

Author(s):

Nolan L. Boyd ◽

Heonyong Park ◽

Wen-Ping Sun ◽

Sarah E. Coleman ◽

Ramakrishna S. Cherukuri ◽

...

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Aortic Endothelial

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Cultured bovine aortic endothelial cells show increased histamine metabolism when exposed to oscillatory shear stress

Atherosclerosis ◽

10.1016/0021-9150(87)90054-2 ◽

1987 ◽

Vol 64 (1) ◽

pp. 55-61 ◽

Cited By ~ 16

Author(s):

Sonia I. Skarlatos ◽

Theodore M. Hollis

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Oscillatory Shear ◽

Histamine Metabolism ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Oscillatory Shear Stress ◽

Aortic Endothelial

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Sustained JNK activation induces endothelial apoptosis: studies with colchicine and shear stress

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.277.4.h1593 ◽

1999 ◽

Vol 277 (4) ◽

pp. H1593-H1599 ◽

Cited By ~ 12

Author(s):

Ying-Li Hu ◽

Song Li ◽

John Y.-J. Shyy ◽

Shu Chien

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Colchicine Treatment ◽

Laminar Shear Stress ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Jnk Activation ◽

Laminar Shear ◽

Sustained Activation ◽

Aortic Endothelial

The disruption of microtubules by treating bovine aortic endothelial cells with 10−7–10−5M colchicine caused apoptosis, as evidenced by DNA laddering and TdT-mediated dUTP nick end labeling fluorescence staining. Colchicine treatment also induced a sustained activation of c-Jun NH2-terminal kinase (JNK) that lasted for ≥12 h. The blockade of JNK activity by using the negative interfering mutant JNK(K-R) markedly decreased the apoptosis induced by colchicine. Exposure of bovine aortic endothelial cells to laminar shear stress (12 dyn/cm2) caused a transient (<2 h) activation of JNK, and there was no induction of apoptosis. The sustained activation of JNK may play a significant role in the apoptosis induced by colchicine.

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Shear-induced tyrosine phosphorylation in endothelial cells requires Rac1-dependent production of ROS

AJP Cell Physiology ◽

10.1152/ajpcell.1999.276.4.c838 ◽

1999 ◽

Vol 276 (4) ◽

pp. C838-C847 ◽

Cited By ~ 110

Author(s):

Li-Hong Yeh ◽

Young J. Park ◽

Riple J. Hansalia ◽

Imraan S. Ahmed ◽

Shailesh S. Deshpande ◽

...

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Map Kinase ◽

Tyrosine Phosphorylation ◽

Protein Detection ◽

Pyrrolidine Dithiocarbamate ◽

Dependent Manner ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Aortic Endothelial

The shear-induced intracellular signal transduction pathway in vascular endothelial cells involves tyrosine phosphorylation and activation of mitogen-activated protein (MAP) kinase, which may be responsible for the sustained release of nitric oxide. MAP kinase is known to be activated by reactive oxygen species (ROS), such as H2O2, in several cell types. ROS production in ligand-stimulated nonphagocytic cells appears to require the participation of a Ras-related small GTP-binding protein, Rac1. We hypothesized that Rac1 might serve as a mediator for the effect of shear stress on MAP kinase activation. Exposure of bovine aortic endothelial cells to laminar shear stress of 20 dyn/cm2for 5–30 min stimulated total cellular and cytosolic tyrosine phosphorylation as well as tyrosine phosphorylation of MAP kinase. Treating endothelial cells with the antioxidants N-acetylcysteine and pyrrolidine dithiocarbamate inhibited in a dose-dependent manner the shear-stimulated increase in total cytosolic and, specifically, MAP kinase tyrosine phosphorylation. Hence, the onset of shear stress caused an enhanced generation of intracellular ROS, as evidenced by an oxidized protein detection kit, which were required for the shear-induced total cellular and MAP kinase tyrosine phosphorylation. Total cellular and MAP kinase tyrosine phosphorylation was completely blocked in sheared bovine aortic endothelial cells expressing a dominant negative Rac1 gene product (N17rac1). We concluded that the GTPase Rac1 mediates the shear-induced tyrosine phosphorylation of MAP kinase via regulation of the flow-dependent redox changes in endothelial cells in physiological and pathological circumstances.

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Fluid shear stress stimulates phosphorylation-dependent nuclear export of HDAC5 and mediates expression of KLF2 and eNOS

Blood ◽

10.1182/blood-2009-05-224824 ◽

2010 ◽

Vol 115 (14) ◽

pp. 2971-2979 ◽

Cited By ~ 111

Author(s):

Weiye Wang ◽

Chang Hoon Ha ◽

Bong Sook Jhun ◽

Chelsea Wong ◽

Mukesh K. Jain ◽

...

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Nuclear Export ◽

Transcriptional Activity ◽

Molecular Mechanisms ◽

Fluid Shear Stress ◽

Inhibitory Effect ◽

Fluid Shear ◽

Enos Expression ◽

Calcium Calmodulin Dependent

Abstract Fluid shear stress generated by steady laminar blood flow protects vessels from atherosclerosis. Krüppel-like factor 2 (KLF2) and endothelial nitric oxide synthase (eNOS) are fluid shear stress–responsive genes and key mediators in flow anti-inflammatory and antiatherosclerotic actions. However, the molecular mechanisms underlying flow induction of KLF2 and eNOS remain largely unknown. Here, we show a novel role of histone deacetylase 5 (HDAC5) in flow-mediated KLF2 and eNOS expression. We found for the first time that fluid shear stress stimulated HDAC5 phosphorylation and nuclear export in endothelial cells through a calcium/calmodulin-dependent pathway. Consequently, flow induced the dissociation of HDAC5 and myocyte enhancer factor-2 (MEF2) and enhanced MEF2 transcriptional activity, which leads to expression of KLF2 and eNOS. Adenoviral overexpression of a HDAC5 phosphorylation–defective mutant (Ser259/Ser498 were replaced by Ala259/Ala498, HDAC5-S/A), which shows resistance to flow-induced nuclear export, suppressed flow-mediated MEF2 transcriptional activity and expression of KLF2 and eNOS. Importantly, HDAC5-S/A attenuated the flow-inhibitory effect on monocyte adhesion to endothelial cells. Taken together, our results reveal that phosphorylation-dependent derepression of HDAC5 mediates flow-induced KLF2 and eNOS expression as well as flow anti-inflammation, and suggest that HDAC5 could be a potential therapeutic target for the prevention of atherosclerosis.

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Effect of Combined Cyclic Stretch and Fluid Shear Stress on Endothelial Cell Morphological Responses

Journal of Biomechanical Engineering ◽

10.1115/1.1894180 ◽

2005 ◽

Vol 127 (3) ◽

pp. 374-382 ◽

Cited By ~ 36

Author(s):

Tomas B. Owatverot ◽

Sara J. Oswald ◽

Yong Chen ◽

Jeremiah J. Wille ◽

Frank C-P Yin

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Time Course ◽

Fluid Shear Stress ◽

Cyclic Stretch ◽

Mechanical Stimuli ◽

Cell Orientation ◽

Fluid Shear ◽

Aortic Endothelial Cells

Endothelial cells in vivo are normally subjected to multiple mechanical stimuli such as stretch and fluid shear stress (FSS) but because each stimulus induces magnitude-dependent morphologic responses, the relative importance of each stimulus in producing the normal in vivo state is not clear. Using cultured human aortic endothelial cells, this study first determined equipotent levels of cyclic stretch, steady FSS, and oscillatory FSS with respect to the time course of cell orientation. We then tested whether these levels of stimuli were equipotent in combination with each other by imposing simultaneous cyclic stretch and steady FSS or cyclic stretch and oscillatory FSS so as to reinforce or counteract the cells’ orientation responses. Equipotent levels of the three stimuli were 2% cyclic stretch at 2%∕s, 80dynes∕cm2 steady FSS and 20±10dynes∕cm2 oscillatory FSS at 20dyne∕cm2-s. When applied in reinforcing fashion, cyclic stretch and oscillatory, but not steady, FSS were additive. Both pairs of stimuli canceled when applied in counteracting fashion. These results indicate that this level of cyclic stretch and oscillatory FSS sum algebraically so that they are indeed equipotent. In addition, oscillatory FSS is a stronger stimulus than steady FSS for inducing cell orientation. Moreover, arterial endothelial cells in vivo are likely receiving a stronger stretch than FSS stimulus.

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