scholarly journals A FIBRILLAR INTERCELLULAR MATERIAL BETWEEN REAGGREGATING EMBRYONIC CHICK CELLS

1969 ◽  
Vol 40 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Jane Overton
Keyword(s):  
Cell Aggregation ◽  
Surface Material ◽  
Embryonic Chick ◽  
Intact Tissue ◽  
Fibrillar Material ◽  
Dissociated Cells

Lanthanum staining of embryonic chick cell reaggregates reveals an intercellular material composed of fibrils. Fibrillar arrays may be composed of parallel fibrils with a 35 A center-to-center spacing. Fibrils may also be disoriented, long, and tortuous. Newly dissociated cells show little lanthanum staining surface material, but appreciable amounts are present after 6 hr of reaggregation. Examination of intact tissue does not give the same clear evidence of a fibrillar matrix surrounding the cells, but treatment with a number of agents permits observation of intercellular fibrils, and in some cases there is evidence of orientation. Thus fibrillar material must be taken into account in considering mechanisms of cell aggregation.

Effects of Cytochalasins on the Initial Aggregation in Vitro of Embryonic Chick Cells

1974 ◽  
Vol 14 (1) ◽  
pp. 187-196
Author(s):  
J. C. APPLETON ◽  
R. B. KEMP
Keyword(s):  
Cytochalasin B ◽  
Cell Aggregation ◽  
Cellular Injury ◽  
Cellular Motility ◽  
Carbon Dioxide Evolution ◽  
Site Of Action ◽  
Dissociated Cells ◽  
Cytochalasin A ◽  
Final Confirmation

The initial aggregation of trypsin-dissociated cells from the skeletal muscle tissue of 9-day-old chick embryos in the presence of cytochalasins A and B was studied in order to discover the effects of these agents on contact and adhesion. Cytochalasin B (3 µg/ml) had a negligible effect on the rate of aggregation of cells over an 8-h period, but cytochalasin A at concentrations between 3 and 20 µg/ml markedly inhibited aggregation. Both agents altered the shape and size of aggregates and caused cells at their periphery to appear more spherical. The oxygen uptake of the treated cells was not noticeably different from that of the controls, despite the severe inhibition of isotopic carbon dioxide evolution. The effect of cytochalasin B on cell aggregation was reversible and although the cytochalasin A effect could not be abolished on return to medium free of A, the unaltered oxygen consumption was taken as an indication that permanent cellular injury did not occur. The effect of the cytochalasins on aggregate structure was interpreted on the basis of arrested cellular motility, but the singular inhibition by cytochalasin A of the rate of aggregation must await final confirmation of its site of action.

Abolition by Myosin and Heavy Meromyosin of the Inhibitory Effect of Smooth-Muscle Actomyosin Antibodies on Cell Aggregation In Vitro

1973 ◽  
Vol 12 (2) ◽  
pp. 631-639
Author(s):  
R. B. KEMP ◽  
B. M. JONES ◽  
U. GRÖSCHEL-STEWART
Keyword(s):  
Smooth Muscle ◽  
Striated Muscle ◽  
Cell Aggregation ◽  
Inhibitory Effect ◽  
Regulatory Function ◽  
Rabbit Serum ◽  
Heavy Meromyosin ◽  
Γ Globulins ◽  
Dissociated Cells

The ability of anti-chicken smooth-muscle actomyosin γ-globulins (anti-GAM) to inhibit the aggregation of dissociated cells from the skeletal muscle and liver of chick embryos was abolished by pretreatment of the anti-GAM with either myosin or heavy meromyosin (HMM). When the same cells were treated with HMM at a concentration of 1 mg per 2 x 106 cells/ml Eagle's MEM they aggregated as readily as untreated cells. The negative electrophoretic mobility of the embryonic chick fibroblastic cells was significantly reduced by the globulin fraction of anti-GAM but not of HMM-treated anti-GAM or non-immunized rabbit serum. Anti-chicken striated muscle actomyosin γ-globulins slightly reduced negative mobility but HMM had no effect. The experiments show that the inhibitory effect on cell aggregation of anti-GAM preparations is produced by the anti-myosin antibodies. They also provide support for the theory that a surface-localized myosin-like protein has a regulatory function in cell adhesion.

The release of soluble H-2 alloantigens during disaggregation of mouse embryo tissue by a chelating agent

Development ◽  
1966 ◽  
Vol 16 (3) ◽  
pp. 519-530
Author(s):  
Michael Edidin
Keyword(s):  
Molecular Weight ◽  
Ethylenediaminetetraacetic Acid ◽  
Divalent Cations ◽  
Weight Bearing ◽  
Chelating Agent ◽  
Cell Aggregation ◽  
Sponge Cell ◽  
Antigenic Sites ◽  
Dissociated Cells ◽  
Embryo Tissue

Treatment with chelating agents binding divalent cations has been found to effect the dissociation of a variety of tissues of both embryo and adult animals (reviewed in Steinberg, 1958). In the course of dissociation it appears that materials are released from cell surfaces which play a part in their specific adhesion, and which may be shown experimentally to promote selectively the re-aggregation of dissociated cells (Humphreys, 1963; Moscona, 1963). The extracted materials appear to be glycoprotein complexes (Humphreys, 1965), made up of fairly small subunits, estimated to be of 13000–20000 molecular weight (Margoliash et al. 1965). Units of about the same size appear to be the antigenic sites involved in the blocking of sponge cell aggregation by rabbit anti-sponge serum, specific for a given sponge species (MacLennan, 1963). I shall here present evidence that materials of similar molecular weight bearing immunological specificities of the H-2 alloantigen system are released from the tissues of certain mouse embryos during the course of their dissociation by the chelating agent Versene (ethylenediaminetetraacetic acid).

The inhibition of cell aggregation by a pure serum protein

Development ◽  
1965 ◽  
Vol 13 (3) ◽  
pp. 309-326
Author(s):  
A. S. G. Curtis ◽  
M. F. Greaves
Keyword(s):  
Cell Adhesion ◽  
Serum Protein ◽  
Low Temperatures ◽  
Actinomycin D ◽  
Cell Aggregation ◽  
Embryonic Chick ◽  
Isolated Cells ◽  
Chemical Inhibition

The aggregation of isolated cells into coherent multicellular bodies is widely thought to be due mainly if not entirely to the adhesiveness of the cells for one another, according to Moscona (1961a, b), Curtis (1962) and Steinberg (1962a) amongst others. In consequence the aggregation of cells from dispersed (disaggregated) tissues has been widely used as a test for the degree of adhesiveness shown by the cells, and conditions affecting aggregation have been interpreted as affecting cell adhesion. Using this type of test Moscona (1961a, b) found that embryonic chick cells would not aggregate at temperatures below 14°C. It was also discovered that aggregation was inhibited at 37°C. by puromycin and actinomycin D (Moscona & Moscona, 1963), by glucosamine-HCl (Garber, 1963), and by chloramphenicol (Nakanishi et al., 1963). Moscona concluded from the failure of aggregation at low temperatures that the metabolic synthesis of an adhesive substance was being prevented under such conditions and this interpretation was reinforced by the evidence of chemical inhibition of aggregation.

Studies on the Mechanism Underlying the Inhibition by Puromycin of Cell Aggregation In Vitro

1970 ◽  
Vol 7 (2) ◽  
pp. 557-573
Author(s):  
M. J. DUNN ◽  
E. OWEN ◽  
R. B. KEMP
Keyword(s):  
Carbon Dioxide ◽  
Protein Synthesis ◽  
Cellular Metabolism ◽  
Cell Aggregation ◽  
Experimental Period ◽  
Inhibitory Effect ◽  
Dissociated Cells ◽  
Gyratory Shaker ◽  
Reduced Rate

Cells dissociated with 0.25% crude trypsin from the muscle tissue of 9-day-old chick embryos were employed to investigate the effect of puromycin on cellular metabolism. Parallel studies were also made, using the gyratory shaker, to confirm the effectiveness of puromycin in inhibiting cell aggregation and protein synthesis. Puromycin when introduced at a concentration of 10µg/ml into a suspension of cells in Eagle's MEM did not completely inhibit cell aggregation. Small aggregates were formed in the first 4 h of the experiment. Protein synthesis of the rotated cells, as measured by the incorporation of L-[α-14C]leucine into proteins, was arrested by 91.7% within 15 min of introducing puromycin into a cell suspension. The antibiotic retained its inhibitory effect on protein synthesis for the 24-h period of rotation. Puromycin inhibited the cellular oxygen uptake and carbon dioxide evolution of the rotated cells by 40% within 4 h of its introduction. However, treated cells were still respiring, though at a much reduced rate, at the end of the 24-h experimental period. The release of radioactive carbon dioxide by puromycin-treated cells was also inhibited by 40% at the 4-h stage but after 8 h no further 14CO2 was evolved. The presence of the antibiotic markedly inhibited the uptake of glucose by trypsin-dissociated cells. The level of glycogen and lactate in cells suspended in Eagle's MEM was reduced very considerably over a 24-h period. The presence of puromycin accelerated glycogen utilization over the first 6 h of rotation but at 24 h there was a difference of only 0.6% between the glycogen content of treated cells and controls. At 24 h 11.3% less lactate remained in the puromycin-treated cells than in the controls. The ATP/ADP ratio of trypsin-dissociated cells decreased from an initial value of 2.59 to 1.45 after rotation for 24 h. In the presence of puromycin the ATP/ADP ratio was 0.62 at 4 h and had further declined to 0.48 by 24 h. The effects of puromycin on the aggregation, protein synthesis and cellular metabolism of trypsin-dissociated cells are discussed in relation to cellular adhesive mechanisms.

The Effect of Neuraminidase (3:2:1:18) on the Aggregation of Cells Dissociated from Embryonic Chick Muscle Tissue

1970 ◽  
Vol 6 (3) ◽  
pp. 751-766
Author(s):  
R. B. KEMP
Keyword(s):  
Cell Surface ◽  
Muscle Tissue ◽  
Muscle Cells ◽  
Cell Aggregation ◽  
Inhibitory Effect ◽  
Sialic Acids ◽  
Embryonic Chick ◽  
Experimental Conditions ◽  
Cell Counts

Embryonic chick muscle cells were used to investigate the effect of removing cell-surface sialic acids on cell aggregation in vitro. Single cell suspensions were prepared by dissociating skeletal muscle tissue of 9-day-old chick embryos with either crystalline or crude trypsin. Cell aggregation was quantitatively estimated by turbidimetric and gyratory shaker methods. Cells dissociated with crude trypsin and suspended in Hanks's balanced salts solution (BSS) containing 25u./ml neuraminidase (NANase) only aggregated for 2h when rotated in an absorptiometer. The inhibitory effect of the enzyme was more pronounced with increasing concentration up to 25u./ml. Cells dissociated with crystalline trypsin and treated with 100u./ml NANase immediately exhibited a reduced aggregative competence when gyrated in Eagle's minimum essential medium (MEM) containing 25u./ml NANase, compared with the controls which were not exposed to NANase. The aggregation rate of muscle cells pretreated with 100u./ml NANase and suspended in Eagle's MEM was similar to that of the untreated controls. Cell counts showed that under all three experimental conditions cells were not added to aggregates after the 12-h stage. Aggregates formed in Eagle's MEM (the controls) joined together to form larger aggregates after 12 h, but those rotating in the presence of NANase did not display this property. Lissamine green viability tests showed that cells remained alive throughout the 24-h period in the presence of NANase. Determinations of oxygen uptake, protein synthesis and mitotic index confirmed that general cellular viability was not affected by NANase. Fluorescent-labelled NANase was not taken up by the cells. Treatment of crystalline trypsin-dissociated muscle cells with 100u./ml NANase for 30 min at 37°C significantly reduced their negative electrophoretic mobility. This diminution closely corresponded to the removal of cell-surface sialic acids, as measured by colorimetric tests. Interpretation of the results in the light of current theories of cell adhesion failed to give support to the concept of adhesion by physical forces. The mechanism by which cellular deformability could influence cellular adhesiveness is modified in the knowledge of the present results.

GROWTH OF ENTAMOEBA INVADENS IN ORGANOTYPIC CULTURES OF EMBRYONIC CHICK INTESTINE

1961 ◽  
Vol 7 (5) ◽  
pp. 685-695 ◽  
Author(s):  
E. Meerovitch
Keyword(s):  
Metabolic Activity ◽  
Embryonic Chick ◽  
Mucous Secretion ◽  
Organotypic Cultures ◽  
Fluid Medium ◽  
Intact Tissue ◽  
Entamoeba Invadens

Entamoeba invadens from axenic and monoxenic cultures was inoculated into expiants of embryonic chick intestine, which were then cultured in perfusion chambers at 30 °C. The growth and metabolic activity of the explants in cultures were evaluated in terms of fibroblastic outgrowth and extent of liquefaction of the plasma clots in which they were embedded. The effects of several media used to fill the perfusion chambers on the survival of the explants were studied. It was found that amoebae developed best in those explants which themselves showed most vitality; this was in turn related to the kind of fluid medium used in the culture. Amoebae in the explants fed on mucous secretion and on dead cells and penetrated into intact tissue without apparent histolytic activity. It is suggested that the living explants provided the amoebae with certain enzymes which the latter were unable to produce at the temperature of incubation. Approximately 40% of all cultures made became positive for amoebae. This is attributed to the fact that not all explants retained the amoebae injected into them, before they were placed in culture.

scholarly journals ARIA can be released from extracellular matrix through cleavage of a heparin-binding domain.

1995 ◽  
Vol 130 (1) ◽  
pp. 127-135 ◽  
Author(s):  
J A Loeb ◽  
G D Fischbach
Keyword(s):  
Spinal Cord ◽  
Extracellular Matrix ◽  
Acetylcholine Receptors ◽  
Limited Proteolysis ◽  
Heparin Binding ◽  
Embryonic Chick ◽  
Terminal Portion ◽  
Heparin Binding Domain ◽  
Dissociated Cells ◽  
Chick Spinal Cord

ARIA, or acetylcholine receptor-inducing activity, is a polypeptide that stimulates the synthesis of acetylcholine receptors in skeletal muscle. Here we demonstrate that the ability of ARIA to induce phosphorylation of its receptor in muscle is blocked by highly charged glycosaminoglycans. ARIA constructs lacking the NH2-terminal portion, containing an immunoglobulin-like domain, are fully active and are not inhibited by glycosaminoglycans. Limited proteolysis of ARIA with subtilisin blocks the glycosaminoglycan interaction by degrading this NH2-terminal portion, but preserves the active, EGF-like domain. We also show that ARIA can be released from freshly dissociated cells from embryonic chick spinal cord and cerebellum by either heparin, high salt or limited proteolysis with subtilisin, suggesting that ARIA is bound to the extracellular matrix through charged interactions. We present a model of how ARIA may be stored in extracellular matrix at developing synapses and how its release may be mediated by local proteolysis.

Reconstruction of Mammalian Heart Tissue from Isolated Embryonic Heart Cells

1977 ◽  
Vol 35 ◽  
pp. 580-581
Author(s):  
Asish C. Nag ◽  
Debra S. Buszke
Keyword(s):  
Basal Medium ◽  
Cell Aggregation ◽  
Heart Tissue ◽  
Cell Suspensions ◽  
Heart Cells ◽  
Mammalian Heart ◽  
Dissociated Cells ◽  
Gyratory Shaker ◽  
And Function

Although monolayer cultures are useful in various cell studies, they are not always adequate for examining the nature of cellular interrelationships and interactions in the formation, differentiation, and function of tissues. The procedures of aggregation in vitro of dissociated cells (Moscona & Moscona, 1966) enable one to study in detail the formation of cell contacts, the assembly of cells into multicellular systems, and cell cooperation in forming organized and differentiating tissues. We adapted the techniques of cell aggregation by rotation to studies on embryonic mammalian heart cells. Cell suspensions from the 18-day-old embryonic rat were prepared by dissociation with 0. 5% trypsin. The cells were dispersed in a culture medium which consisted of Eagle's basal medium with 10% fetal bovine serum, 1% glutamine solution, and 1% penicillin-streptomycin mixture. Cultured in 25ml Erlenmeyer flasks on a gyratory shaker at 70 rpm at 37°C were 3ml aliquots of the cell suspensions.

Artificial Design of Three-Dimensional Retina-Like Tissue from Dissociated Cells of the Mammalian Retina by Rotation-Mediated Cell Aggregation

2005 ◽  
Vol 11 (11-12) ◽  
pp. 1749-1756 ◽  
Author(s):  
Andrée Rothermel ◽  
Thomas Biedermann ◽  
Winnie Weigel ◽  
Randy Kurz ◽  
Markus Rüffer ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cell Aggregation ◽  
Mammalian Retina ◽  
Dissociated Cells
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