scholarly journals The Response of Corneal Endothelial Cells to Shear Stress in an In Vitro Flow Model

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Sujuan Duan ◽  
Yingjie Li ◽  
Yanyan Zhang ◽  
Xuan Zhu ◽  
Yan Mei ◽  
...  

Purpose. Corneal endothelial cells are usually exposed to shear stress caused by the aqueous humour, which is similar to the exposure of vascular endothelial cells to shear stress caused by blood flow. However, the effect of fluid shear stress on corneal endothelial cells is still poorly understood. The purpose of this study was to explore whether the shear stress that results from the aqueous humour influences corneal endothelial cells. Methods. An in vitro model was established to generate fluid flow on cells, and the effect of fluid flow on corneal endothelial cells after exposure to two levels of shear stress for different durations was investigated. The mRNA and protein expression of corneal endothelium-related markers in rabbit corneal endothelial cells was evaluated by real-time PCR and western blotting. Results. The expression of the corneal endothelium-related markers ZO-1, N-cadherin, and Na+-K+-ATPase in rabbit corneal endothelial cells (RCECs) was upregulated at both the mRNA and protein levels after exposure to shear stress. Conclusion. This study demonstrates that RCECs respond favourably to fluid shear stress, which may contribute to the maintenance of corneal endothelial cell function. Furthermore, this study also provides a theoretical foundation for further investigating the response of human corneal endothelial cells to the shear stress caused by the aqueous humour.

Author(s):  
Joanna Rossi ◽  
Léonie Rouleau ◽  
Jean-Claude Tardif ◽  
Richard L. Leask

Although originally designed as inhibitors of cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, are now known to also have non-lipid lowering benefits [1]. Statins have been reported to modulate gene expression in endothelial cells, however, the effect of statins on adhesion molecule expression is contradictory. Some studies report a decrease in adhesion molecule mRNA and/or protein after statin treatment [2], while others have shown that statins potentiate the effect of tumor necrosis factor alpha (TNFα) [3]. To the best of our knowledge, the effects of statins on gene expression in cultured endothelial cells has been done in static conditions only and no study has examined the effect of blood flow. This is particularly important since fluid shear stress is a strong regulator of endothelial cell function and phenotype [4]. The purpose of this study was to clarify the effects of statins on vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression in endothelial cells by evaluating their biological response under fluid flow.


2000 ◽  
Vol 20 (3) ◽  
pp. 617-623 ◽  
Author(s):  
Boris-Wolfgang Hochleitner ◽  
Elisabeth-Olga Hochleitner ◽  
Peter Obrist ◽  
Thomas Eberl ◽  
Albert Amberger ◽  
...  

1993 ◽  
Vol 265 (1) ◽  
pp. C289-C298 ◽  
Author(s):  
H. J. Schnittler ◽  
R. P. Franke ◽  
U. Akbay ◽  
C. Mrowietz ◽  
D. Drenckhahn

A rheological in vitro system has been developed to study and quantify cellular adhesion under precisely defined external shear forces. The system is similar to a cone-and-plate viscosimeter. A rotating transparent cone produces both steady and pulsatile flow profiles on cultured cells. Direct visualization of cells by phase-contrast or fluorescence optics and connection of the optical system to a computer-controlled x/y-linear stage allows automatic recording of any point of the cell cultures. With the use of up to 12 individual rheological units, this setup allows the quantitative analysis of cell substrate adhesion by determination of cell detachment kinetics. Two examples of application of this rheological system have been studied. First, we show that the extracellular matrix protein laminin strongly increases endothelial cell adhesion under fluid shear stress. In a second approach, we obtained further support for the concept that shear stress-induced formation of actin filament stress fibers is important for endothelial cells to resist the fluid shear stress; inhibition of stress fiber formation by doxorubicin resulted in significant detachment of endothelial cells exposed to medium levels of fluid shear stress (5 dyn/cm2). No detachment was seen under resting conditions.


2001 ◽  
Vol 90 (5) ◽  
pp. 1849-1854 ◽  
Author(s):  
E. A. Nauman ◽  
R. L. Satcher ◽  
T. M. Keaveny ◽  
B. P. Halloran ◽  
D. D. Bikle

Although there is no consensus as to the precise nature of the mechanostimulatory signals imparted to the bone cells during remodeling, it has been postulated that deformation-induced fluid flow plays a role in the mechanotransduction pathway. In vitro, osteoblasts respond to fluid shear stress with an increase in PGE2production; however, the long-term effects of fluid shear stress on cell proliferation and differentiation have not been examined. The goal of this study was to apply continuous pulsatile fluid shear stresses to osteoblasts and determine whether the initial production of PGE2 is associated with long-term biochemical changes. The acute response of bone cells to a pulsatile fluid shear stress (0.6 ± 0.5 Pa, 3.0 Hz) was characterized by a transient fourfold increase in PGE2 production. After 7 days of static culture (0 dyn/cm2) or low (0.06 ± 0.05 Pa, 0.3 Hz) or high (0.6 ± 0.5 Pa, 3.0 Hz) levels of pulsatile fluid shear stress, the bone cells responded with an 83% average increase in cell number, but no statistical difference ( P > 0.53) between the groups was observed. Alkaline phosphatase activity per cell decreased in the static cultures but not in the low- or high-flow groups. Mineralization was also unaffected by the different levels of applied shear stress. Our results indicate that short-term changes in PGE2 levels caused by pulsatile fluid flow are not associated with long-term changes in proliferation or mineralization of bone cells.


2021 ◽  
Vol 22 (11) ◽  
pp. 5635
Author(s):  
Katharina Urschel ◽  
Miyuki Tauchi ◽  
Stephan Achenbach ◽  
Barbara Dietel

In the 1900s, researchers established animal models experimentally to induce atherosclerosis by feeding them with a cholesterol-rich diet. It is now accepted that high circulating cholesterol is one of the main causes of atherosclerosis; however, plaque localization cannot be explained solely by hyperlipidemia. A tremendous amount of studies has demonstrated that hemodynamic forces modify endothelial athero-susceptibility phenotypes. Endothelial cells possess mechanosensors on the apical surface to detect a blood stream-induced force on the vessel wall, known as “wall shear stress (WSS)”, and induce cellular and molecular responses. Investigations to elucidate the mechanisms of this process are on-going: on the one hand, hemodynamics in complex vessel systems have been described in detail, owing to the recent progress in imaging and computational techniques. On the other hand, investigations using unique in vitro chamber systems with various flow applications have enhanced the understanding of WSS-induced changes in endothelial cell function and the involvement of the glycocalyx, the apical surface layer of endothelial cells, in this process. In the clinical setting, attempts have been made to measure WSS and/or glycocalyx degradation non-invasively, for the purpose of their diagnostic utilization. An increasing body of evidence shows that WSS, as well as serum glycocalyx components, can serve as a predicting factor for atherosclerosis development and, most importantly, for the rupture of plaques in patients with high risk of coronary heart disease.


1986 ◽  
Vol 83 (7) ◽  
pp. 2114-2117 ◽  
Author(s):  
P. F. Davies ◽  
A. Remuzzi ◽  
E. J. Gordon ◽  
C. F. Dewey ◽  
M. A. Gimbrone

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