Vascular Endothelial Morphology as an Indicator of the Pattern of Blood Flow

1981 ◽  
Vol 103 (3) ◽  
pp. 172-176 ◽  
Author(s):  
R. M. Nerem ◽  
M. J. Levesque ◽  
J. F. Cornhill
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Endothelial Cell ◽  
Cell Morphology ◽  
Flow Direction ◽  
Rabbit Aorta ◽  
Shape Index ◽  
En Face ◽  
Length Width ◽  
Branch Vessel

A quantitative study of the en face size and shape of endothelial cells from aortic intercostal ostia has been carried out in rabbits. Photomicrographs were taken from vascular casts of the rabbit aorta and the endothelial cell outlines were analyzed quantitatively using a digitizer and digital computer. The morphology of the endothelial cells was described using 8 calculated parameters (area, perimeter, length, width, angle of orientation, width: length ratio, axis-intersection ratio and shape index). Marked changes in cell morphology were found in the regions proximal and distal to ostia as well as around flow dividers. Cells on the aorta are aligned with the flow direction, and the endothelial cells within the ostia have an angle of orientation of approximately 45 deg to the axis of the vessel. The results obtained to date suggest that endothelial cell morphology and orientation around a branch vessel may be a natural marker or indicator of the detailed features of blood flow.

Effects of Steady Spatial Wall Shear Stress Gradients on Endothelial Cell Morphology in Three-Dimensional Models

2007 ◽  
Author(s):  
Leonie Rouleau ◽  
Monica Farcas ◽  
Jean-Claude Tardif ◽  
Rosaire Mongrain ◽  
Richard Leask
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Wall Shear Stress ◽  
Cell Morphology ◽  
Flow Direction ◽  
Stress Gradient ◽  
Spatial Gradient ◽  
Stress Gradients ◽  
Wall Shear

Endothelial cell (EC) dysfunction has been linked to atherosclerosis through their response to hemodynamic forces. Flow in stenotic vessels creates complex spatial gradients in wall shear stress. In vitro studies examining the effect of shear stress on endothelial cells have used unrealistic and simplified models, which cannot reproduce physiological conditions. The objective of this study was to expose endothelial cells to the complex shear shear pattern created by an asymmetric stenosis. Endothelial cells were grown and exposed for different times to physiological steady flow in straight dynamic controls and in idealized asymmetric stenosis models. Cells subjected to 1D flow aligned with flow direction and had a spindle-like shape when compared to static controls. Endothelial cell morphology was noticeable different in the regions with a spatial gradient in wall shear stress, being more randomly oriented and of cobblestone shape. This occurred despite the presence of an increased magnitude in shear stress. No other study to date has described this morphology in the presence of a positive wall shear stress gradient or gradient of significant shear magnitude. This technique provides a more realistic model to study endothelial cell response to spatial and temporal shear stress gradients that are present in vivo and is an important advancement towards a better understanding of the mechanisms involved in coronary artery disease.

scholarly journals Morphology of endothelial cells from different regions of the cornea of dogs

2018 ◽  
Vol 48 (10) ◽  
Author(s):  
Paula Stieven Hünning ◽  
Maria Cristina Caldart de Andrade ◽  
André Carissimi ◽  
João Pigatto
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Morphology ◽  
Corneal Endothelium ◽  
Central Area ◽  
Alizarin Red ◽  
Central Cornea ◽  
Significant Difference ◽  
Peripheral Areas ◽  
Healthy Eyes

ABSTRACT: The aim of this study was to evaluate the morphology of endothelial cells from different areas of the cornea of dogs. Twenty healthy eyes from 10 dogs, females or males, of different ages were studied. Corneal endothelium morphology of superior, inferior, central, nasal and temporal areas was assessed by 0.2% alizarin red staining using an optic microscope. One hundred endothelial cells from each corneal area were analyzed. In all areas of the cornea studied were found endothelial cells with four sides, five sides, six sides and seven sides. There was no significant difference regarding endothelial cell morphology in all corneal regions evaluated. Thus, the morphology of the central cornea area represents the entire endothelial mosaic and may be applied to peripheral areas. Therefore, analysis of the central area is sufficient to estimate the shape of endothelial cells of peripheral areas of healthy dog corneas.

scholarly journals The nucleus of endothelial cell as a sensor of blood flow direction

Biology Open ◽  
2013 ◽  
Vol 2 (10) ◽  
pp. 1007-1012 ◽  
Author(s):  
E. Tkachenko ◽  
E. Gutierrez ◽  
S. K. Saikin ◽  
P. Fogelstrand ◽  
C. Kim ◽  
...  
Keyword(s):  
Blood Flow ◽  
Endothelial Cell ◽  
Flow Direction

scholarly journals EPAC2 acts as a negative regulator in Matrigel-driven tubulogenesis of human microvascular endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takayuki Ikeda ◽  
Yoshino Yoshitake ◽  
Yasuo Yoshitomi ◽  
Hidehito Saito-Takatsuji ◽  
Yasuhito Ishigaki ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Morphology ◽  
Molecular Mechanisms ◽  
Network Formation ◽  
Tissue Growth ◽  
Negative Regulator ◽  
Endothelial Cell Migration ◽  
Microvascular Endothelial Cells ◽  
Microvascular Endothelial

AbstractAngiogenesis is physiologically essential for embryogenesis and development and reinitiated in adult animals during tissue growth and repair. Forming new vessels from the walls of existing vessels occurs as a multistep process coordinated by sprouting, branching, and a new lumenized network formation. However, little is known regarding the molecular mechanisms that form new tubular structures, especially molecules regulating the proper network density of newly formed capillaries. This study conducted microarray analyses in human primary microvascular endothelial cells (HMVECs) plated on Matrigel. The RAPGEF4 gene that encodes exchange proteins directly activated by cAMP 2 (EPAC2) proteins was increased in Matrigel-driven tubulogenesis. Tube formation was suppressed by the overexpression of EPAC2 and enhanced by EPAC2 knockdown in endothelial cells. Endothelial cell morphology was changed to round cell morphology by EPAC2 overexpression, while EPAC2 knockdown showed an elongated cell shape with filopodia-like protrusions. Furthermore, increased EPAC2 inhibited endothelial cell migration, and ablation of EPAC2 inversely enhanced cell mobility. These results suggest that EPAC2 affects the morphology and migration of microvascular endothelial cells and is involved in the termination and proper network formation of vascular tubes.

3-D Stress Analysis in Cultured Endothelial Cells Exposed to Fluid Shear Stress

1999 ◽  
Author(s):  
T. Ohashi ◽  
H. Sugawara ◽  
Y. Ishii ◽  
M. Sato
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Fluid Shear Stress ◽  
Flow Direction ◽  
Stress Distributions ◽  
Fluid Shear ◽  
Surface Geometry ◽  
Cultured Endothelial Cells

Abstract Under fluid shear stress, applied both in vivo and in vitro, vascular endothelial cells show morphological changes. After applying shear stress, cultured endothelial cells showed elongation and orientation to the flow direction (Kataoka et al., 1998). Moreover, statistical image analysis showed that intercellular F-actin distributions were confirmed to change depending on the shear stress and the flow direction. Thus, the endothelial cell morphology relates closely with the cytoskeletal structures. Intercellular stress distributions in the cells may be also accompanied by the reorganization of cytoskeletal structures. The use of both atomic force microscopy measurements (AFM) of endothelial cell surface topography and computational fluid dynamics of shear stress distributions acting on the cell surface, it has revealed that the surface geometry defined the detailed distribution of shear stress (Davies et al., 1995).

scholarly journals The Metastatic Capacity of Melanoma Reveals Alternative Pathways of Cancer Dissemination

2021 ◽  
Vol 1 (3) ◽  
pp. 163-174
Author(s):  
Michela Corsini ◽  
Cosetta Ravelli ◽  
Elisabetta Grillo ◽  
Stefania Mitola
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Endothelial Cell ◽  
Cancer Cells ◽  
Cell Activity ◽  
Tumor Vascularization ◽  
Tumor Mass ◽  
Alternative Pathways ◽  
Metastatic Capacity ◽  
Cancer Dissemination

For many years the growth of solid tumors has been associated with their vascularization. The new vessels are needed to deliver oxygen and nutrients within the tumor mass. At the same time, these poorly stabilized vessels act as “Trojan horses” and open a way out for cancer cells. More recently, tumors have been identified whose growth appears to be independent of endothelial cell activity. Here we describe the ability of cancer cells to differentiate and reorganize themself in channels similar to blood vessels containing blood flow, overcoming the need for the angiogenic process of tumor vascularization. Together with the new vessels arising both from angiogenic and vasculogenic processes, these vessel-like structures can be exploited by tumor cells as a guide for migration and metastatic dissemination. In addition to classical intravascular dissemination, cancer cells can acquire pericytic features, interact with the endothelial basal lamina and migrate toward vessels or outside of the vessels. As expected, these alternative tumor behaviors assume greater importance if we consider that drugs with anti-angiogenic action directed against endothelial cells or their ligands are currently used in cancer therapy.

scholarly journals Increased endothelial expression of Toll-like receptor 2 at sites of disturbed blood flow exacerbates early atherogenic events

2008 ◽  
Vol 205 (2) ◽  
pp. 373-383 ◽  
Author(s):  
Adam E. Mullick ◽  
Katrin Soldau ◽  
William B. Kiosses ◽  
Thomas A. Bell ◽  
Peter S. Tobias ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Endothelial Cell ◽  
Lipid Accumulation ◽  
Laser Scanning ◽  
Cell Injury ◽  
Tlr2 Expression ◽  
Endothelial Cell Injury ◽  
Leukocyte Accumulation ◽  
Lesser Curvature

Toll-like receptors (TLRs) are pattern recognition receptors of innate immunity. TLRs initiate inflammatory pathways that may exacerbate chronic inflammatory diseases like atherosclerosis. En face laser scanning confocal microscopy (LSCM) of isolated aortic segments revealed the distribution of intimal TLR2 expression and the atheroprotective outcomes resulting from a TLR2 deficiency. TLR2 expression was restricted to endothelial cells in regions of disturbed blood flow, such as the lesser curvature region, in atherosclerosis-prone, low-density lipoprotein receptor–deficient (LDLr−/−) mice. Diet-induced hyperlipidemia in LDLr−/− mice increased this regional endothelial TLR2 expression. Bone marrow (BM) reconstitution of LDLr−/− and LDLr−/−TLR2−/− mice created chimeric mice with green fluorescent protein (GFP) expression in BM-derived cells (BMGFP+). Lesser curvature BMGFP+ leukocyte accumulation, lipid accumulation, foam cell generation and endothelial cell injury were all increased by hyperlipidemia, whereas hyperlipidemic double mutant BMGFP+LDLr−/−TLR2−/− mice had reduced BMGFP+ leukocyte accumulation, lipid accumulation, foam cells, and endothelial cell injury. This is the first report of in vivo site-specific expression of endothelial cell TLR2. Expression of this receptor on endothelial cells contributed to early atherosclerotic processes in lesion-prone areas of the mouse aorta.

Revealing anti-inflammatory mechanisms of soy isoflavones by flow: modulation of leukocyte-endothelial cell interactions

2005 ◽  
Vol 289 (2) ◽  
pp. H908-H915 ◽  
Author(s):  
Balu K. Chacko ◽  
Robert T. Chandler ◽  
Ameya Mundhekar ◽  
Nicholas Khoo ◽  
Heather M. Pruitt ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Principal Component ◽  
Vascular Endothelial ◽  
Physical Forces ◽  
Anti Inflammatory ◽  
Static Conditions

The antiatherogenic effects of soy isoflavone consumption have been demonstrated in a variety of studies. However, the mechanisms involved remain poorly defined. Adhesion of monocytes to vascular endothelial cells is a key step within the inflammatory cascade that leads to atherogenesis. Many factors, including the physical forces associated with blood flow, regulate this process. Using an in vitro flow assay, we report that genistein, a principal component of most isoflavone preparations, inhibits monocyte adhesion to cytokine (TNF-α)-stimulated human vascular endothelial cells at physiologically relevant concentrations (0–1 μM). This effect is absolutely dependent on flow and is not observed under static conditions. Furthermore, this inhibition was dependent on activation of endothelial peroxisomal proliferator-activated receptor-γ. No significant role for other reported properties of genistein, including antioxidant effects, inhibition of tyrosine kinases, or activation of estrogen receptors, was observed. Furthermore, the antiadhesive effects of genistein did not occur via modulation of the adhesion molecules E-selectin, ICAM-1, VCAM-1, or platelet-endothelial cell adhesion molecule-1. These data reveal a novel anti-inflammatory mechanism for isoflavones and identify the physical forces associated with blood flow and a critical mediator of this function.

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