scholarly journals Dynamic trafficking and turnover of Jam-C is essential for endothelial cell migration

2019 ◽  
Author(s):  
Katja B. Kostelnik ◽  
Amy Barker ◽  
Christopher Schultz ◽  
Vinothini Rajeeve ◽  
Ian J. White ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Migration ◽  
Intracellular Trafficking ◽  
Light And Electron Microscopy ◽  
Endothelial Cell Migration ◽  
Leukocyte Trafficking ◽  
Lysosomal Degradation ◽  
Blood Constituents ◽  
Junctional Proteins ◽  
Junctional Complexes

AbstractJunctional complexes between endothelial cells form a dynamic barrier that hinder passive diffusion of blood constituents into interstitial tissues. Re-modelling of junctions is an essential process during leukocyte trafficking, vascular permeability and angiogenesis. However, for many junctional proteins the mechanisms of junctional remodelling have yet to be determined. Here we used receptor mutagenesis, HRP and APEX-2 proximity labelling, alongside light and electron microscopy, to map the intracellular trafficking routes of junctional adhesion molecule-C (Jam-C). We found that Jam-C co-traffics with receptors associated with changes in permeability, such as VE-Cadherin, NRP-1 and 2, but not with junctional proteins associated with the transmigration of leukocytes. Dynamic Jam-C trafficking and degradation is necessary for junctional remodelling during cell migration and angiogenesis. By identifying new trafficking machinery we show that a key point of regulation is the ubiquitylation of Jam-C by the E3 ligase CBL, this controls the rate of recycling versus lysosomal degradation.

Cell migration from the chick olfactory placode: a light and electron microscopic study

Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 47-59
Author(s):  
A. S. Mendoza ◽  
W. Breipohl ◽  
F. Miragall
Keyword(s):  
Electron Microscopy ◽  
Cell Migration ◽  
Light And Electron Microscopy ◽  
Olfactory Mucosa ◽  
Electron Microscopic ◽  
Olfactory Placode ◽  
The Third ◽  
Epitheloid Cells ◽  
Migration Of Cells ◽  
Number Of Cells

The diflferentiation of the olfactory placode in the chick has been studied using light and electron microscopy. Special attention was paid to the appearance of neuronal cells within the placodal ectodermal thickening, the migration of cells out of this tissue and the appearance of the first fila olfactoria in the differentiating olfactory mucosa. Between the third and fifth day of incubation a large number of cells is observed leaving the base of the invaginating olfactory placode, often in contact with thin axon bundles. These cells are characterized by a well-developed Golgi apparatus, a considerable number of mitochondria and dense-core vesicles. The morphology of these migrating cells resembles that of cells observed near the basement membrane within the developing olfactory epithelium and is clearly different from the mesenchymal cells which are filled with polyribosomes. At the sixth day of incubation thick axon bundles can be observed within the epithelium and the underlying lamina propria. The possible fate of the migrated epitheloid cells is discussed.

scholarly journals CD112 Regulates Angiogenesis and T Cell Entry into the Spleen

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 169
Author(s):  
Erica Russo ◽  
Peter Runge ◽  
Neda Haghayegh Jahromi ◽  
Heidi Naboth ◽  
Angela Landtwing ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
T Cell ◽  
Cell Entry ◽  
Endothelial Cell Migration ◽  
Leukocyte Trafficking ◽  
Deficient Mice

Junctional adhesion proteins play important roles in controlling angiogenesis, vascular permeability and leukocyte trafficking. CD112 (nectin-2) belongs to the immunoglobulin superfamily and was shown to engage in homophilic and heterophilic interactions with a variety of binding partners expressed on endothelial cells and on leukocytes. Recent in vitro studies suggested that CD112 regulates human endothelial cell migration and proliferation as well as transendothelial migration of leukocytes. However, so far, the role of CD112 in endothelial cell biology and in leukocyte trafficking has not been elucidated in vivo. We found CD112 to be expressed by lymphatic and blood endothelial cells in different murine tissues. In CD112-deficient mice, the blood vessel coverage in the retina and spleen was significantly enhanced. In functional in vitro studies, a blockade of CD112 modulated endothelial cell migration and significantly enhanced endothelial tube formation. An antibody-based blockade of CD112 also significantly reduced T cell transmigration across endothelial monolayers in vitro. Moreover, T cell homing to the spleen was significantly reduced in CD112-deficient mice. Overall, our results identify CD112 as a regulator of angiogenic processes in vivo and demonstrate a novel role for CD112 in T cell entry into the spleen.

scholarly journals Structural characterization of a rat acinar cell tumor.

1982 ◽  
Vol 95 (3) ◽  
pp. 727-733 ◽  
Author(s):  
V Iwanij ◽  
B E Hull ◽  
J D Jamieson
Keyword(s):  
Electron Microscopy ◽  
Tumor Cells ◽  
Basal Lamina ◽  
Acinar Cell ◽  
Light And Electron Microscopy ◽  
Freeze Fracture ◽  
Cell Tumor ◽  
Zymogen Granule ◽  
Junctional Complexes ◽  
Freeze Fracture Electron Microscopy

A transplantable acinar cell tumor of the rat pancreas has been examined by light and electron microscopy. The tumor cells, though highly cytodifferentiated and characterized by the presence of abundant rough-surfaced endoplasmic reticulum, elements of the Golgi complex, and zymogen granules, undergo mitosis in a manner similar to that seen in the developing pancreas. Cells in the parenchyma of the tumor grow as disarrayed cords and sheets, are randomly oriented with respect to each other, and do not form acinar structures. However, when in contact with the adventitial surface of blood vessels, the tumor cells palisade and form a polarized layer of cells with their zymogen granule-rich poles oriented away from the vessel lumen. Only in this area of the tumor is a basal lamina present that underlies the basal plasmalemma of the reoriented epithelial cells. Freeze-fracture electron microscopy of tumor cells in the parenchyma shows extensive disruption of tight junctions whose sealing strands are randomly distributed over the entire plasmalemma. Gap junctions are infrequent and when present are often enclosed by tight-junctional strands. Intramembrane particles are randomly distributed over the cell surface. Both the absence of basal lamina and derangement of the junctional complexes may account in part for the altered morphogenesis of this tumor.

scholarly journals Building the actin cytoskeleton: filopodia contribute to the construction of contractile bundles in the lamella

2008 ◽  
Vol 180 (6) ◽  
pp. 1233-1244 ◽  
Author(s):  
Maria Nemethova ◽  
Sonja Auinger ◽  
J. Victor Small
Keyword(s):  
Electron Microscopy ◽  
Cell Migration ◽  
Actin Cytoskeleton ◽  
Myosin Ii ◽  
Light And Electron Microscopy ◽  
Proximal Part ◽  
Stress Fiber ◽  
B16 Melanoma ◽  
Cell Edge ◽  
Fiber Assembly

Filopodia are rodlike extensions generally attributed with a guidance role in cell migration. We now show in fish fibroblasts that filopodia play a major role in generating contractile bundles in the lamella region behind the migrating front. Filopodia that developed adhesion to the substrate via paxillin containing focal complexes contributed their proximal part to stress fiber assembly, and filopodia that folded laterally contributed to the construction of contractile bundles parallel to the cell edge. Correlated light and electron microscopy of cells labeled for actin and fascin confirmed integration of filopodia bundles into the lamella network. Inhibition of myosin II did not subdue the waving and folding motions of filopodia or their entry into the lamella, but filopodia were not then integrated into contractile arrays. Comparable results were obtained with B16 melanoma cells. These and other findings support the idea that filaments generated in filopodia and lamellipodia for protrusion are recycled for seeding actomyosin arrays for use in retraction.

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

1972 ◽  
Vol 30 ◽  
pp. 106-107
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Physiological Saline ◽  
Experimental Conditions ◽  
Vein Grafts ◽  
Arterial Blood ◽  
Saphenous Veins ◽  
Autogenous Vein ◽  
Control Of Parameters ◽  
Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

The Effect of Vitamin A on the Intermittent Nitrogen Dioxide Gas Exposure in Hamsters

1976 ◽  
Vol 34 ◽  
pp. 176-177
Author(s):  
J.C.S. Kim ◽  
M.G. Jourden ◽  
E.S. Carlisle
Keyword(s):  
Electron Microscopy ◽  
Vitamin A ◽  
Nitrogen Dioxide ◽  
Chronic Exposure ◽  
Light And Electron Microscopy ◽  
Specific Effect ◽  
Deficient Diet ◽  
Intermittent Exposure ◽  
Hypovitaminosis A ◽  
Gas Exposure

Chronic exposure to nitrogen dioxide in rodents has shown that injury reaches a maximum after 24 hours, and a reparative adaptive phase follows (1). Damage occurring in the terminal bronchioles and proximal portions of the alveolar ducts in rats has been extensively studied by both light and electron microscopy (1).The present study was undertaken to compare the response of lung tissue to intermittent exposure to 10 ppm of nitrogen dioxide gas for 4 hours per week, while the hamsters were on a vitamin A deficient diet. Ultrastructural observations made from lung tissues obtained from non-gas exposed, hypovitaminosis A animals and gas exposed animals fed a regular commercially prepared diet have been compared to elucidate the specific effect of vitamin A on nitrogen dioxide gas exposure. The interaction occurring between vitamin A and nitrogen dioxide gas has not previously been investigated.

Sign in / Sign up

Export Citation Format

Share Document