Immunohistochemical study of dissociation and association of adherens junctions in splenic sinus endothelial cells

2021 ◽  
Vol 384 (1) ◽  
pp. 25-33
Author(s):  
Kiyoko Uehara ◽  
Akira Uehara
Keyword(s):  
Endothelial Cells ◽  
Immunohistochemical Study ◽  
Adherens Junctions ◽  
Sinus Endothelial Cells

scholarly journals Spatial and temporal relationships between cadherins and PECAM-1 in cell-cell junctions of human endothelial cells.

1994 ◽  
Vol 126 (1) ◽  
pp. 247-258 ◽  
Author(s):  
O Ayalon ◽  
H Sabanai ◽  
M G Lampugnani ◽  
E Dejana ◽  
B Geiger
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Vascular System ◽  
Adherens Junctions ◽  
Microscopic Analysis ◽  
Membrane Receptors ◽  
Temporal Organization ◽  
Cell Junctions ◽  
Short Treatment ◽  
Cell Cell

The integrity of the endothelial layer, which lines the entire cavity of the vascular system, depends on tight adhesion of the cells to the underlying basement membrane as well as to each other. It has been previously shown that such interactions occur via membrane receptors that determine the specificity, topology, and mechanical properties of the surface adhesion. Cell-cell junctions between endothelial cells, in culture and in situ, involve both Ca(2+)-dependent and -independent mechanisms that are mediated by distinct adhesion molecules. Ca(2+)-dependent cell-cell adhesion occurs mostly via members of the cadherin family, which locally anchor the microfilament system to the plasma membrane, in adherens junctions. Ca(2+)-independent adhesions were reported to mainly involve members of the Ig superfamily. In this study, we performed three-dimensional microscopic analysis of the relative subcellular distributions of these two endothelial intercellular adhesion systems. We show that cadherins are located at adjacent (usually more apical), yet clearly distinct domains of the lateral plasma membrane, compared to PECAM-1. Moreover, cadherins were first organized in adherens junctions within 2 h after seeding of endothelial cells, forming multiple lateral patches which developed into an extensive belt-like structure over a period of 24 h. PECAM-1 became associated with surface adhesions significantly later and became progressively associated with the cadherin-containing adhesions. Cadherins and PECAM-1 also differed in their detergent extractability, reflecting differences in their mode of association with the cytoskeleton. Moreover, the two adhesion systems could be differentially modulated since short treatment with the Ca2+ chelator EGTA, disrupted the cadherin junctions leaving PECAM-1 apparently intact. These results confirm that endothelial cells possess distinct intercellular contact mechanisms that differ in their spatial and temporal organization as well as in their functional properties.

scholarly journals Circulating extracellular vesicles from patients with acute chest syndrome disrupt adherens junctions between endothelial cells

2020 ◽  
Author(s):  
Gabrielle Lapping-Carr ◽  
Joanna Gemel ◽  
Yifan Mao ◽  
Gianna Sparks ◽  
Margaret Harrington ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Extracellular Vesicles ◽  
Adherens Junctions ◽  
Acute Chest Syndrome

scholarly journals Fine Structure of the Red Pulp of the Spleen in Hereditary Spherocytosis

Blood ◽  
1972 ◽  
Vol 39 (1) ◽  
pp. 81-98 ◽  
Author(s):  
ZELMA MOLNAR ◽  
HENRY RAPPAPORT
Keyword(s):  
Endothelial Cells ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Hereditary Spherocytosis ◽  
Probable Mechanism ◽  
Hemoglobin Content ◽  
Sinus Endothelial Cells ◽  
In Transit ◽  
Conventional Light Microscopy ◽  
Red Pulp

Abstract The spleens from two children and one adult with hereditary spherocytosis were studied in the electron microscope. Stagnation of the erythrocytes within the splenic cords is attributable to their lack of plasticity as evidenced by the absence of bilobed, tailed, or squeezed forms in transit through the walls of the sinuses. In contrast to the sections studied by conventional light microscopy, the splenic sinuses in hereditary spherocytosis were not "empty," but contained red blood cells, the majority of which had lost their hemoglobin content. Cordal macrophages were increased in all three cases and were abundant in the splenic cords of the adult patient, causing a further impediment to the rapid passage of erythrocytes. Macrophages, and, to a lesser degree, sinus endothelial cells contained the products of hemoglobin breakdown. The macrophages showed active erythrophagocytosis. Sinus endothelial cells rarely contained intact red blood cells, but showed pronounced pinocytotic activity, a probable mechanism of hemoglobin incorporation. Platelets within the endothelial cells of the sinuses were much more frequently seen in the three cases of hereditary spherocytosis than in control spleens. The presence of ferritin in platelets suggests that they too may play a role in clearing the end products of hemolysis from the spleen.

scholarly journals Structure of artificial and natural VE-cadherinbased adherens junctions

2008 ◽  
Vol 36 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Jean-Christophe Taveau ◽  
Mathilde Dubois ◽  
Olivier Le Bihan ◽  
Sylvain Trépout ◽  
Sébastien Almagro ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Actin Cytoskeleton ◽  
Self Assembly ◽  
Adherens Junctions ◽  
Actin Binding ◽  
Vascular Endothelial ◽  
Vascular Integrity ◽  
Trans Orientation ◽  
Annexin 2

In vascular endothelium, adherens junctions between endothelial cells are composed of VE-cadherin (vascular endothelial cadherin), an adhesive receptor that is crucial for the proper assembly of vascular structures and the maintenance of vascular integrity. As a classical cadherin, VE-cadherin links endothelial cells together by homophilic interactions mediated by its extracellular part and associates intracellularly with the actin cytoskeleton via catenins. Although, from structural crystallographic data, a dimeric structure arranged in a trans orientation has emerged as a potential mechanism of cell–cell adhesion, the cadherin organization within adherens junctions remains controversial. Concerning VE-cadherin, its extracellular part possesses the capacity to self-associate in solution as hexamers consisting of three antiparallel cadherin dimers. VE-cadherin-based adherens junctions were reconstituted in vitro by assembly of a VE-cadherin EC (extracellular repeat) 1–EC4 hexamer at the surfaces of liposomes. The artificial adherens junctions revealed by cryoelectron microscopy appear as a two-dimensional self-assembly of hexameric structures. This cadherin organization is reminiscent of that found in native desmosomal junctions. Further structural studies performed on native VE-cadherin junctions would provide a better understanding of the cadherin organization within adherens junctions. Homophilic interactions between cadherins are strengthened intracellularly by connection to the actin cytoskeleton. Recently, we have discovered that annexin 2, an actin-binding protein connects the VE-cadherin–catenin complex to the actin cytoskeleton. This novel link is labile and promotes the endothelial cell switch from a quiescent to an angiogenic state.

scholarly journals Flow mechanotransduction regulates traction forces, intercellular forces, and adherens junctions

2012 ◽  
Vol 302 (11) ◽  
pp. H2220-H2229 ◽  
Author(s):  
Lucas H. Ting ◽  
Jessica R. Jahn ◽  
Joon I. Jung ◽  
Benjamin R. Shuman ◽  
Shirin Feghhi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Laminar Flow ◽  
Adherens Junctions ◽  
Cell Junctions ◽  
Flow Conditions ◽  
Traction Forces ◽  
Disturbed Flow ◽  
Cytoskeletal Tension ◽  
Static Conditions ◽  
Cell Cell

Endothelial cells respond to fluid shear stress through mechanotransduction responses that affect their cytoskeleton and cell-cell contacts. Here, endothelial cells were grown as monolayers on arrays of microposts and exposed to laminar or disturbed flow to examine the relationship among traction forces, intercellular forces, and cell-cell junctions. Cells under laminar flow had traction forces that were higher than those under static conditions, whereas cells under disturbed flow had lower traction forces. The response in adhesion junction assembly matched closely with changes in traction forces since adherens junctions were larger in size for laminar flow and smaller for disturbed flow. Treating the cells with calyculin-A to increase myosin phosphorylation and traction forces caused an increase in adherens junction size, whereas Y-27362 cause a decrease in their size. Since tugging forces across cell-cell junctions can promote junctional assembly, we developed a novel approach to measure intercellular forces and found that these forces were higher for laminar flow than for static or disturbed flow. The size of adherens junctions and tight junctions matched closely with intercellular forces for these flow conditions. These results indicate that laminar flow can increase cytoskeletal tension while disturbed flow decreases cytoskeletal tension. Consequently, we found that changes in cytoskeletal tension in response to shear flow conditions can affect intercellular tension, which in turn regulates the assembly of cell-cell junctions.

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