Constitutive NOS expression in cultured endothelial cells is elevated by fluid shear stress

1995 ◽  
Vol 269 (2) ◽  
pp. H550-H555 ◽  
Author(s):  
V. Ranjan ◽  
Z. Xiao ◽  
S. L. Diamond
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Umbilical Vein ◽  
Vessel Diameter ◽  
Mrna Levels ◽  
Laminar Shear Stress ◽  
Fluid Shear ◽  
Protein Levels ◽  
Flow Exposure

The role of chronic fluid shear stress on endothelial constitutive nitric oxide synthase (cNOS) levels may have an important role in vessel diameter control. We subjected primary human umbilical vein endothelial cells (HUVEC) or bovine aortic endothelial cells (BAEC, passages 2-14) to steady laminar shear stress. In both cell types, the intracellular level of cNOS was elevated within 3 h of flow exposure at 25 dyn/cm2 and remained elevated at 6 and 12 h of flow exposure, compared with stationary controls, as indicated by digital immunofluorescence microscopy. Shear stress exposure for 6 h caused a 2.2 +/- 0.3- and 2.8 +/- 0.3-fold elevation of cNOS protein levels in BAEC (n = 3, P < 0.01) and HUVEC (n = 3, P < 0.01), respectively, in the presence or absence of 1 microM dexamethasone. Dexamethasone suppresses induction of the inducible NOS gene, indicating that cNOS was elevated by fluid shear stress. Flow exposure at 4 dyn/cm2 caused no enhancement of cNOS levels in either cell type. The flow induction of the cNOS protein levels was not blocked by preincubation of BAEC with 100-400 microM of NG-nitro-L-arginine methyl ester, indicating that flow-induced NO (or guanosine 3',5'-cyclic monophosphate) was not involved in the elevation of cNOS levels. Protein kinase C inhibitor H-7 (10 microM) had no effect on induction of NOS protein in BAEC exposed to 25 dyn/cm2. The cNOS mRNA levels were found to be elevated by two- to threefold in BAEC after 6 or 12 h of flow exposure at either 4 or 25 dyn/cm2, and this induction of NOS mRNA occurred in the presence of dexamethasone. The elevation of cNOS levels by chronic flow exposure may provide a mechanism for chronic regulation of vessel diameter by endothelial response to prevailing blood flow.

Fluid shear stress induces the phosphorylation of small heat shock proteins in vascular endothelial cells

1996 ◽  
Vol 271 (3) ◽  
pp. C994-C1000 ◽  
Author(s):  
S. Li ◽  
R. S. Piotrowicz ◽  
E. G. Levin ◽  
Y. J. Shyy ◽  
S. Chien
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Heat Shock ◽  
Fluid Shear Stress ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Mrna Levels ◽  
Fluid Shear ◽  
Maximum Increase ◽  
Umbilical Vein Endothelial Cells

The small molecular mass heat shock protein of 27 kDa (HSP27) has been shown to influence actin filament dynamics and endothelial cell behavior in ways similar to those observed during laminar flow. We have employed human umbilical vein endothelial cells to determine whether fluid shear stress affects HSP27 expression or phosphorylation. After a shear stress of 16 dyn/cm2, HSP27 became more highly phosphorylated, with maximum increase in phosphorylation levels (3-fold) attained by 30 min and sustained for at least 20 h. HSP27 antigen levels did not change; however, HSP27 mRNA levels decreased by 20% after 16 h. In bovine aortic endothelial cells stably transfected with the wild-type human HSP27 gene, shear stress induced the phosphorylation of both the exogenous human HSP27 and the endogenous bovine HSP25. The product of a transfected mutant HSP27 gene in which the putative phosphorylation sites Ser-15, Ser-78, and Ser-82 had been replaced with Gly was not phosphorylated. Thus the modulation of HSP27 and its activity by shear stress is mediated through a posttranslational mechanism and differs from the shear stress induction of immediate early genes at the level of transcription.

Effects of Fluid Shear Stress on Endothelial Cell Invasion Into Three-Dimensional Matrices

2007 ◽  
Author(s):  
Hojin Kang ◽  
Kayla J. Bayless ◽  
Roland Kaunas
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Cell Invasion ◽  
Fluid Shear Stress ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Shear Stresses ◽  
Collagen Gels ◽  
Fluid Shear

We have previously developed a cell culture model to study the effects of angiogenic factors, such as sphingosine-1-phosphate (S1P), on the invasion of endothelial cells into the underlying extracellular matrix. In addition to biochemical stimuli, vascular endothelial cells are subjected to fluid shear stress due to blood flow. The present study is aimed at determining the effects of fluid shear stress on endothelial cell invasion into collagen gels. A device was constructed to apply well-defined fluid shear stresses to confluent human umbilical vein endothelial cells (HUVECs) seeded on collagen gels. Fluid shear stress induced significant increases in cell invasion with a maximal induction at ∼5 dyn/cm2. These results provide evidence that fluid shear stress is a significant stimulus for endothelial cell invasion and may play a role in regulating angiogenesis.

scholarly journals Vascular remodeling is governed by a VEGFR3-dependent fluid shear stress set point

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Nicolas Baeyens ◽  
Stefania Nicoli ◽  
Brian G Coon ◽  
Tyler D Ross ◽  
Koen Van den Dries ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Vascular Remodeling ◽  
Fluid Shear Stress ◽  
Umbilical Vein ◽  
Fluid Shear ◽  
Set Point ◽  
Vessel Remodeling ◽  
Umbilical Vein Endothelial Cells

Vascular remodeling under conditions of growth or exercise, or during recovery from arterial restriction or blockage is essential for health, but mechanisms are poorly understood. It has been proposed that endothelial cells have a preferred level of fluid shear stress, or ‘set point’, that determines remodeling. We show that human umbilical vein endothelial cells respond optimally within a range of fluid shear stress that approximate physiological shear. Lymphatic endothelial cells, which experience much lower flow in vivo, show similar effects but at lower value of shear stress. VEGFR3 levels, a component of a junctional mechanosensory complex, mediate these differences. Experiments in mice and zebrafish demonstrate that changing levels of VEGFR3/Flt4 modulates aortic lumen diameter consistent with flow-dependent remodeling. These data provide direct evidence for a fluid shear stress set point, identify a mechanism for varying the set point, and demonstrate its relevance to vessel remodeling in vivo.

scholarly journals Effects of fluid shear stress on the expression of Omi/HtrA2 in human umbilical vein endothelial cells

2012 ◽  
Vol 7 (1) ◽  
pp. 110-114 ◽  
Author(s):  
LIANG-LIANG SUN ◽  
LE ZHANG ◽  
XIANG-LAN MENG ◽  
FENG ZHANG ◽  
YUN ZHAO ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Umbilical Vein ◽  
Fluid Shear ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

scholarly journals Coxsackievirus and adenovirus receptor mediates the responses of endothelial cells to fluid shear stress

2019 ◽  
Vol 51 (11) ◽  
pp. 1-15 ◽  
Author(s):  
Jihwa Chung ◽  
Kyoung Hwa Kim ◽  
Shung Hyun An ◽  
Sunmi Lee ◽  
Byung-Kwan Lim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Vascular Endothelial Cells ◽  
Laminar Shear Stress ◽  
Fluid Shear ◽  
Viral Receptor ◽  
Disturbed Flow ◽  
Coxsackievirus And Adenovirus Receptor ◽  
Adenovirus Receptor

AbstractEndothelial mechanotransduction by fluid shear stress (FSS) modulates endothelial function and vascular pathophysiology through mechanosensors on the cell membrane. The coxsackievirus and adenovirus receptor (CAR) is not only a viral receptor but also a component of tight junctions and plays an important role in tissue homeostasis. Here, we demonstrate the expression, regulatory mechanism, and role of CAR in vascular endothelial cells (ECs) under FSS conditions. Disturbed flow increased, whereas unidirectional laminar shear stress (LSS) decreased, CAR expression in ECs through the Krüppel-like factor 2 (KLF2)/activator protein 1 (AP-1) axis. Deletion of CAR reduced the expression of proinflammatory genes and endothelial inflammation induced by disturbed flow via the suppression of NF-κB activation. Consistently, disturbed flow-induced atherosclerosis was reduced in EC-specific CAR KO mice. CAR was found to be involved in endothelial mechanotransduction through the regulation of platelet endothelial cell adhesion molecule 1 (PECAM-1) phosphorylation. Our results demonstrate that endothelial CAR is regulated by FSS and that this regulated CAR acts as an important modulator of endothelial mechanotransduction by FSS.

Flow-induced expression of endothelial Na-K-Cl cotransport: dependence on K+ and Cl− channels

2001 ◽  
Vol 280 (1) ◽  
pp. C216-C227 ◽  
Author(s):  
Jimmy Suvatne ◽  
Abdul I. Barakat ◽  
Martha E. O'Donnell
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Flow Chamber ◽  
Steady Shear ◽  
Laminar Shear Stress ◽  
Protein Levels ◽  
Steady Laminar Shear Stress ◽  
Umbilical Vein Endothelial Cells

Steady laminar shear stress has been shown previously to markedly increase Na-K-Cl cotransporter mRNA and protein in human umbilical vein endothelial cells and also to rapidly increase endothelial K+ and Cl− channel conductances. The present study was done to evaluate the effects of shear stress on Na-K-Cl cotransporter activity and protein expression in bovine aortic endothelial cells (BAEC) and to determine whether changes in cotransporter expression may be dependent on early changes in K+ and Cl− channel conductances. Confluent BAEC monolayers were exposed in a parallel-plate flow chamber to either steady shear stress (19 dyn/cm2) or purely oscillatory shear stress (0 ± 19 dyn/cm2) for 6–48 h. After shearing, BAEC monolayers were assessed for Na-K-Cl cotransporter activity or were subjected to Western blot analysis of cotransporter protein. Steady shear stress led to a 2- to 4-fold increase in BAEC cotransporter protein levels and a 1.5- to 1.8-fold increase in cotransporter activity, increases that were sustained over the longest time periods studied. Oscillatory flow, in contrast, had no effect on cotransporter protein levels. In the presence of flow-sensitive K+ and Cl− channel pharmacological blockers, the steady shear stress-induced increase in cotransporter protein was virtually abolished. These results suggest that shear stress modulates the expression of the BAEC Na-K-Cl cotransporter by mechanisms that are dependent on flow-activated ion channels.

scholarly journals Effects of Fluid Shear Stress on Expression of Smac/DIABLO in Human Umbilical Vein Endothelial Cells

2013 ◽  
Vol 74 ◽  
pp. 36-40 ◽  
Author(s):  
Feng Zhang ◽  
Le Zhang ◽  
Liang-liang Sun ◽  
Xiang-lan Meng ◽  
Yun Zhao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Umbilical Vein ◽  
Fluid Shear ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Sp1-mediated downregulation of P2X4 receptor gene transcription in endothelial cells exposed to shear stress

2001 ◽  
Vol 280 (5) ◽  
pp. H2214-H2221 ◽  
Author(s):  
Risa Korenaga ◽  
Kimiko Yamamoto ◽  
Norihiko Ohura ◽  
Takaaki Sokabe ◽  
Akira Kamiya ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Gene Transcription ◽  
Fluid Shear Stress ◽  
Adenine Nucleotides ◽  
Umbilical Vein ◽  
Receptor Gene ◽  
Mrna Levels ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Endothelial purinoceptors play an important role in vascular responses to extracellular adenine nucleotides and hemodynamic forces. Here we report that P2X4 purinoceptor expression in human umbilical vein endothelial cells is transcriptionally downregulated by fluid shear stress. When human umbilical vein endothelial cells were subjected to a laminar shear stress of 15 dyn/cm2, P2X4 mRNA levels began to decrease within 1 h and further decreased with time, reaching 60% at 24 h. Functional analysis of the 1.9-kb P2X4 5′-promoter indicated that a 131-bp segment (−112 to +19 bp relative to the transcription start site) containing a consensus binding site for the Sp1 transcription factor was critical for the shear stress responsiveness. Mutations of the Sp1 site decreased the basal level of transcription and abolished the response of the P2X4 promoter to shear stress. Electrophoretic mobility shift assays showed a marked decrease in binding of Sp1 to the Sp1 consensus element in shear-stressed cells, suggesting that Sp1 mediates the shear stress-induced downregulation of P2X4 gene transcription.

Fluid shear stress stimulates incorporation of hyaluronan into endothelial cell glycocalyx

2006 ◽  
Vol 290 (1) ◽  
pp. H458-H452 ◽  
Author(s):  
Mirella Gouverneur ◽  
Jos A. E. Spaan ◽  
Hans Pannekoek ◽  
Ruud D. Fontijn ◽  
Hans Vink
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Barrier Properties ◽  
Endothelial Glycocalyx ◽  
Stable Cell Line ◽  
Permeability Barrier ◽  
Fluid Shear

Vascular endothelial cells are shielded from direct exposure to flowing blood by the endothelial glycocalyx, a highly hydrated mesh of glycoproteins, sulfated proteoglycans, and associated glycosaminoglycans (GAGs). Recent data indicate that the incorporation of the unsulfated GAG hyaluronan into the endothelial glycocalyx is essential to maintain its permeability barrier properties, and we hypothesized that fluid shear stress is an important stimulus for endothelial hyaluronan synthesis. To evaluate the effect of shear stress on glycocalyx synthesis and the shedding of its GAGs into the supernatant, cultured human umbilical vein endothelial cells (i.e., the stable cell line EC-RF24) were exposed to 10 dyn/cm2 nonpulsatile shear stress for 24 h, and the incorporation of [3H]glucosamine and Na2[35S]O4 into GAGs was determined. Furthermore, the amount of hyaluronan in the glycocalyx and in the supernatant was determined by ELISA. Shear stress did not affect the incorporation of 35S but significantly increased the amount of glucosamine-containing GAGs incorporated in the endothelial glycocalyx [168 (SD 17)% of static levels, P < 0.01] and shedded into the supernatant [231 (SD 41)% of static levels, P < 0.01]. Correspondingly with this finding, shear stress increased the amount of hyaluronan in the glycocalyx [from 26 (SD 24) × 10−4 to 46 (SD 29) × 10−4 ng/cell, static vs. shear stress, P < 0.05] and in the supernatant [from 28 (SD 11) × 10−4 to 55 (SD 16) × 10−4 ng·cell−1·h−1, static vs. shear stress, P < 0.05]. The increase in the amount of hyaluronan incorporated in the glycocalyx was confirmed by a threefold higher level of hyaluronan binding protein within the glycocalyx of shear stress-stimulated endothelial cells. In conclusion, fluid shear stress stimulates incorporation of hyaluronan in the glycocalyx, which may contribute to its vasculoprotective effects against proinflammatory and pro-atherosclerotic stimuli.

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