Alteration of cell adhesion system in amphibian ectoderm cells during primary embryonic induction: changes in reaggregation pattern of induced neurectoderm cells and ultrastructural features of the reaggregate

1986 ◽  
Vol 195 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Akio S. Suzuki ◽  
Tetsuro Ueno ◽  
Tadao Matsusaka
Keyword(s):  
Cell Adhesion ◽  
Embryonic Induction ◽  
Adhesion System ◽  
Primary Embryonic Induction

Invasive behaviour of glioblastoma cell lines is associated with altered organisation of the cadherin-catenin adhesion system

2002 ◽  
Vol 115 (16) ◽  
pp. 3331-3340 ◽  
Author(s):  
Carla Perego ◽  
Cristina Vanoni ◽  
Silvia Massari ◽  
Andrea Raimondi ◽  
Sandra Pola ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Lines ◽  
Protein A ◽  
Cell Types ◽  
Glioblastoma Cell ◽  
Migration Assay ◽  
Adhesion System ◽  
Pdz Protein ◽  
Glioblastoma Cell Lines ◽  
Cell Cell

As little is known about the role of cadherin-mediated cell-cell adhesion in astrocytes and its alteration in migrating and invasive glioblastomas, we investigated its molecular composition and organisation in primary cultured astrocytes and the T98G and U373MG glioblastoma cell lines. Biochemical and morphological analysis indicated that all three cell types express all of the structural components of the adhesion system, including the LIN-7 PDZ protein,a novel component involved in the organisation of the junctional domain in epithelia and neurons. However, only the astrocytes and T98G cells generated and maintained mature adhesive junctional domains to which LIN-7 was recruited. Alterations in the junctional domain of U373MG cells were associated with higher motility in a poly-L-lysine migration assay. When the T98G cells were cultured on Matrigel matrix, they acquired invasive properties but, despite unchanged cadherin adhesion system protein levels, the invasive T98G cell-cell contacts failed to accumulate LIN-7 and failed to mature. These results identify the LIN-7 PDZ protein as a marker of cell adhesion maturity and cell invasion and indicate that instability and disorganisation of cadherin-mediated junctions rather than reduced expression of cadherin-catenin system components are required to promote migration and invasiveness in glioblastoma cell lines.

Changes in lectin-mediated agglutinability during primary embryonic induction in the amphibian embryo

Development ◽  
1980 ◽  
Vol 57 (1) ◽  
pp. 95-106
Author(s):  
Francisco D. Barbieri ◽  
Sara S. Sánchez ◽  
Enrique J. Del Pino
Keyword(s):  
Cell Surface ◽  
Concanavalin A ◽  
Cytochalasin B ◽  
The Other ◽  
Embryonic Induction ◽  
Potassium Oxalate ◽  
Amphibian Embryo ◽  
Structural Alterations ◽  
Significant Difference ◽  
Primary Embryonic Induction

The present study was undertaken to investigate structural alterations at the surfaceof presumptive neural cells after primary embryonic induction. For this purpose, plant lectinmediated agglutinability of dissociated cells from the epiblast of Bufo arenarum gastrulae was tested. Two fragments of epiblast were excised from the same mid-gastrula: one from the dorsal side of the egg, making contact with the invaginating chordamesoblast and assumed to be composed of determined cells and the other from the ventral region of the egg, facing the blastocoele cavity and assumed to be composed of undetermined cells. Cells of the pooled fragments were dissociated in calcium-free Holtfreter's solution with potassium oxalate and incubated in the presence of different concentrations of phytohemagglutinin and concanavalin A. Epiblast cells overlying the archenteron roof are less agglutinated with both lectins than undetermined cells. On the other hand, when egg fragments were removed from the dorsal and ventral regions of early gastrulae before the archenteron was formed, no significant difference in lectin-mediated agglutinability was observed, even after having been cultured in vitro in absence of inducing tissue. These results suggest that the target of the inducing signal generated in the mesoblast is likely to be located on the surface of epiblast cells. Additional experiments showed that cells pretreated with colchicine, cytochalasin B or colchicine and cytochalasin B simultaneously exhibit no significant variation in agglutinability, suggesting that the cytoskeleton was not be involved in the cell surface alteration here described. Treatment of whole embryos or sandwich explants with concanavalin A or phytohemagglutinin has no effect on neural tube formation, suggesting that the carbohydratecontaining binding sites for these lectins are not involved in primary embryonic induction. Changes in cell agglutinability described in this paper are to be interpreted thus as a secondary expression of structural alterations in the cell surface concomitant with neural determination.

Catenins in Xenopus embryogenesis and their relation to the cadherin-mediated cell-cell adhesion system

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 629-640 ◽  
Author(s):  
S. Schneider ◽  
K. Herrenknecht ◽  
S. Butz ◽  
R. Kemler ◽  
P. Hausen
Keyword(s):  
Cell Adhesion ◽  
Plasma Membranes ◽  
Early Embryo ◽  
Xenopus Embryo ◽  
Free Form ◽  
Beta Catenin ◽  
Metabolic Labelling ◽  
Adhesion System ◽  
E Cadherin ◽  
Cell Cell

In the course of an analysis of cell-cell adhesion in the Xenopus embryo, antibodies directed against alpha- and beta-catenin were applied to investigate their relation to the cadherins occurring early in this system. The results demonstrate that alpha- and beta-catenin are provided maternally and increase in amount throughout embryogenesis. Immunoprecipitations indicate that both of the catenins are complexed to U-cadherin in the early phase of embryogenesis and to E-cadherin, when it appears during gastrulation. An excess of alpha-catenin occurs in free form in the early embryo, whereas all of the beta-catenin seems to be complexed to cadherin. Synthesis of the two components throughout early embryogenesis and their binding to newly synthesized cadherins were demonstrated by metabolic labelling. The spatial distribution of alpha-catenin was analysed by immunohistology. During cleavage alpha-catenin is deposited evenly along the plasma membranes within the embryo, while the cell peripheries at the surface of the embryo remain devoid of alpha-catenin. At later stages, the pattern of alpha-catenin distribution becomes more complex. Quantitative differences in the intensity of staining along the plasma membranes in the different regions of the embryo can be distinguished. Particularly the appearance of E-cadherin in the gastrula ectoderm is accompanied by conspicuous depositions of alpha-catenin along the respective plasma membranes in this layer. All cells in the later embryo, apart from the neural crest cells, carry alpha-catenin on their plasma membranes indicating the universal character of cadherin-mediated cell-cell adhesion in the Xenopus embryo.

Neural cell adhesion molecules during embryonic induction and development of the kidney

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 749-761 ◽  
Author(s):  
G. Klein ◽  
M. Langegger ◽  
C. Goridis ◽  
P. Ekblom
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Kidney Development ◽  
Neural Cell ◽  
Cell Polarization ◽  
Embryonic Induction ◽  
Neural Cell Adhesion Molecules ◽  
Short Period ◽  
Neural Cell Adhesion

The neural cell adhesion molecules (N-CAM) are a family of related glycoproteins with Mr of 180, 140 and 120 × 10(3) (180K etc.). In the embryo, they are often highly sialylated and migrate as a diffuse band of 170–250K. N-CAM are found in non-neural tissues and we have now studied the expression of N-CAM in the developing mouse kidney. During kidney development, a unique conversion of a mesenchyme to an epithelium occurs and it is thought that this is mediated by an increase in cell adhesivity. By immunofluorescence, we show that N-CAM is present already at onset of kidney development on the cells of the uninduced nephrogenic mesenchyme. After induction, when the cells convert into an epithelium, they lose N-CAM gradually and instead begin to express uvomorulin, another primary CAM. By using an organ culture model, we could rather precisely show that N-CAM and uvomorulin are coexpressed for a short period, but, when epithelial cell polarization is evident, only uvomorulin is present on the epithelium, whereas N-CAM is confined to the surrounding mesenchyme. Immunoblotting for N-CAM revealed that the ‘embryonic’ form of N-CAM, the broad 170–250K band was not present in the embryonic kidney, which instead expressed the three distinct 180K, 140K and 120K bands typical of adult neurones. The 180K and 140K bands were gradually lost during development and were no longer detectable in adult kidneys. By using an N-CAM cDNA, we detected three different mRNAs of 7.4, 6.7 and 4.3 kb in the developing kidney, but this expression was restricted to the embryonic and early postnatal stages. No transcripts were detectable in adult kidneys. The studies do not support the hypothesis that N-CAM expression in the kidney is turned on by embryonic induction. Rather, we suggest that N-CAM are important adhesives for the predetermined, but not yet induced, nephrogenic mesenchyme.

scholarly journals Expression of cell-adhesion molecules in embryonic induction. I. Morphogenesis of nestling feathers.

1985 ◽  
Vol 101 (3) ◽  
pp. 1009-1026 ◽  
Author(s):  
C M Chuong ◽  
G M Edelman
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
General Pattern ◽  
Immunohistochemical Analysis ◽  
Dermal Papilla ◽  
Cross Reactivity ◽  
Basement Membranes ◽  
Embryonic Induction ◽  
Feather Follicle

The potential relationship of cell adhesion to embryonic induction during feather formation was examined by immunohistochemical analysis of the spatiotemporal distribution of three cell-adhesion molecules (CAMs), neural CAM (N-CAM), liver CAM (L-CAM), and neuron-glia CAM (Ng-CAM), and of substrate molecules (laminin and fibronectin) in embryonic chicken skin. The N-CAM found at sites of embryonic induction in the feather was found to be similar to brain N-CAM as judged by immuno-cross-reactivity, migratory position in PAGE, and the presence of embryonic to adult conversion. In contrast to the N-CAM found in the brain, however, only one polypeptide of Mr 140,000 was seen. N-CAM-positive dermal condensations were distributed periodically under L-CAM-positive feather placodes at those sites where basement membranes are known to be disrupted. After initiation of induction, L-CAM-positive placode cells became transiently N-CAM-positive. N-CAM was asymmetrically concentrated in the dorsal region of the feather bud, while fibronectin was concentrated in the ventral region. During feather follicle formation, N-CAM was expressed in the dermal papilla and was closely apposed to the L-CAM-positive papillar ectoderm, while the dermal papilla showed no evidence of laminin or fibronectin. The collar epithelium was both N-CAM- and L-CAM-positive. During the formation of the feather filament, N-CAM appeared periodically and asymmetrically on basilar cells located in the valleys between adjacent barb ridges. In contrast to the two primary CAMs, Ng-CAM was found only on nerves supplying the feather and the skin. These studies indicate that at each site of induction during feather morphogenesis, a general pattern is repeated in which an epithelial structure linked by L-CAM is confronted with periodically propagating condensations of cells linked by N-CAM.

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